WO1996008591A1 - Method for producing thin, uniform powder phosphor for display screens - Google Patents
Method for producing thin, uniform powder phosphor for display screens Download PDFInfo
- Publication number
- WO1996008591A1 WO1996008591A1 PCT/US1995/010491 US9510491W WO9608591A1 WO 1996008591 A1 WO1996008591 A1 WO 1996008591A1 US 9510491 W US9510491 W US 9510491W WO 9608591 A1 WO9608591 A1 WO 9608591A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- phosphor
- recited
- substrate
- deposited
- planarizing
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D13/00—Electrophoretic coating characterised by the process
- C25D13/02—Electrophoretic coating characterised by the process with inorganic material
Definitions
- the present invention relates generally to a method for producing a phosphor layer for a display screen, and more particularly to a method for making a phosphor layer including planarizing by mechanical pressing.
- a field emission flat panel display actively produces light from an area through the bombardment of a phosphor layer with electrons emitted from a low work function material as a result of the application of an electrical field.
- Such field emission devices depend upon a uniform layer of phosphor in order to achieve uniform brightness over large areas of a display.
- the electric field which causes the electrons to emit from a low work function (work function is the minimum energy required to liberate an electron from a solid, typically measured in electronvolts at absolute zero temperature) material towards the phosphor layer, is passed between a pair of electrodes. Often, one or more additional electrodes may be utilized to assist in controlling and directing the emission of electrons towards the phosphor layer.
- work function is the minimum energy required to liberate an electron from a solid, typically measured in electronvolts at absolute zero temperature
- diode structure field emission devices are desirable, but are more difficult to implement than triode, tetrode, s_ Sfifl- devices since the required gap (on the order of microns) between the low work function material and the phosphor layer must be precisely maintained to achieve a uniform bombardment of electrons upon the phosphor layer, resulting in the desired uniform brightness throughout the display.
- An added difficulty arises from the fact that a diode structure field emission device requires a much smaller gap than triode, tetrode, pentode, cl SCO- devices.
- achieving a flat and uniformly distributed phosphor layer is increasingly important with diode structure devices, since even small variations throughout the layer will affect the gap distance.
- One present technology for phosphor deposition is a screen printing technique, which typically produces a 10-25 ⁇ m thick phosphor film.
- Another technique, electrophoretic deposition typically produces a 3-6 ⁇ m thick phosphor film often resulting in a 200% variation in thickness throughout the layer. The films produced by these techniques are not uniform.
- the present invention deposits a phosphor on a support and then planarizes this deposited phosphor with a mechanical press.
- the present invention includes the steps of depositing a 3-30 ⁇ m thick powder phosphor film by an electrophoretic process on a glass substrate with an indium doped tin oxide (ITO) coating (the resulting structure often referred to hereinafter as the "sample”), stacking an optical flat on the phosphor coated side of the sample produced by the deposition of the phosphor film and the ITO on the glass substrate, and loading the sample onto a mechanical press, and applying pressure at 1,000 pounds per square inch (psi) or higher to force the optical flat and the substrate towards each other, thus planarizing the phosphor layer.
- ITO indium doped tin oxide
- the sample may be cured in an oven in an inert atmosphere up to 450° celsius.
- a second planarization and cure may be performed on the sample.
- FIGURE 1 illustrates a deposited powder phosphor film on a glass substrate prior to planarization by the present invention
- FIGURE 2 illustrates planarization of the powder phosphor film by mechanical pressing
- FIGURE 3 illustrates the powder phosphor film layer subsequent to planarization in accordance with the present invention
- FIGURE 4 illustrates a flow diagram of the process of a preferred embodiment of the present invention
- FIGURE 5 illustrates a portion of a flat panel display device implementing a phosphor deposited in a manner set forth herein;
- FIGURE 6 illustrates a data processing system with a display device made in a manner set forth herein;
- FIGURE 7 illustrates a mechanical press used in accordance with a preferred embodiment of the present invention.
- FIGURES 1-3 there are shown successive views of the application of powder phosphor to a glass substrate according to a particularly preferred embodiment of the present invention.
- a large area substrate 12 is provided.
- Substrate 12 is preferably glass and/or quartz, although other suitable materials may be used, the requirement being they provide a base upon which a thin film of ITO coating 11 (if desired) and phosphor powder 10 can be deposited.
- Sample 13 (comprising substrate 12, ITO 11 and phosphor 10) may then be used within a field emission device as discussed within the cross-referenced patent and patent applications.
- sample 13 may be utilized as an anode plate for a diode structure field emission flat panel display.
- the field emission device utilizing sample 13 is of a triode, tetrode, pentode, or some other multielectrode device with more than two electrodes, then ITO layer 11 may not be necessary and phosphor 10 may be directly applied to substrate 12, since addressing of sample 13 may not be necessary with such devices.
- FIGURE 4 there is illustrated a flow diagram of a process of a preferred embodiment of the present invention.
- the process begins at step 40, and proceeds to step 41 wherein approximately a 3-30 ⁇ m thick powder phosphor film 10 is deposited by a well-known electrophoretic process onto ITO 1 1 and substrate 12. Electrophoresis is the movement of colloidal particles in a liquid under the influence of an electric field. Note, other well-known techniques for depositing phosphor may be utilized.
- a typical phosphor solution utilized for display screens is prepared. Whether prepared or acquired as a stock solution, it is desired that phosphor particles be of 1 -2 ⁇ m in size.
- Such a typical phosphor solution may be prepared by combining in a clean storage container: (1 ) 1 gram phosphor (sieved through approximately a 250 mesh screen); (2) 100 milliliters isopropanol ("IPA"; cleanroom grade); (3) 0.0025 grams A1(N0 3 ) 3 • 9H,0; (4) 0.0025 grams of La(NOj) 3 ⁇ 6H 2 0; and (5) 2 milliliters HjO. Items (3)-(5) may be combined into a stock solution, which will save a significant amount of weighing time. This stock electrolyte solution can be stored indefinitely.
- the solution is mixed thoroughly and ultrasonically treated at a fairly intense level (>50 watts) for two minutes in order to break up particle agglomerates.
- Ultrasonic treatment is done by directly immersing a clean ultrasound horn into the solution.
- the solution may be subjected to intense ultrasound (75 watts) for five additionaJ minutes. Additional ultrasonic treatment may be used if desired.
- additional ultrasound should not be necessary.
- the conductivity of the deposition solution is an important measure of the quality of the solution, and, as such, it should be monitored at regular intervals. Before measuring the conductivity of the .solution, the conductivity meter utilized should be standardized.
- the conductivity standard solution is prepared with 0.05 grams of KCI (potassium chloride) in one liter of DI (dionized) water. The solution is then mixed well.
- the KCI solution is used as the calibrated standard and the supplied standards are only used to prepare more KCI solution. Then the conductivity meter probe is emersed in the solution until the electrodes are fully in the solution. Care must be taken to remove air bubbles out of the probe. The reading on the conductivity meter should be allowed to stabilize for several seconds. And, then the calibration knob on the conductivity meter should be manipulated in order to calibrate the meter so -as to standardize the conductivity meter.
- the conductivity of the solution is measured.
- Small amounts of water may be added to the solution to increase the conductivity, which is preferably between 5 .and 9 ⁇ S/cm; more IPA may be added to decrease the conductivity. It is important that all sources of water are kept separate from the prepared solution.
- the solution life time may be up to one month, as long as the conductivity remains relatively between 5 and 9 ⁇ S/cm and the depositions appear good.
- the phosphor should be allowed to .settle out of the solution, the IPA is decanted off and the phosphor is dried out by either air drying or gentle heating.
- the phosphor is then washed several times with DI H : 0 to remove electrolytes and then it is dried again. The phosphor may then be reused.
- Substrate 12 after applying ITO 1 1 in a well-known m-anner (if desired), is then washed and a mask (e.g., aluminum) placed thereon. Washing may be performed by uitrasonically treating the sample in a 5% micro solution, rinsing thoroughly in H-,0 and other various solutions such as DI H 2 0, acetone and methanol, and then blow drying with nitrogen. The sample may then be stored in a clean place, such as on wafer carriers.
- the display area When placing the mask onto the sample, the display area should be fully exposed.
- the mask should be pressed as flat as possible against the sample and as close to the display area as possible.
- the deposition apparatus utilized should be prepared by first standardizing the conductivity meter, as discussed above. Then, the deposition bath container should be cleaned and a Teflon stir bar should be placed therein. The deposition solution is then again mixed and poured into the deposition container. The solution conductivity is then checked so that it is preferably between 5 and 9 ⁇ S/cm. Thereafter, the conductivity probe is rinsed off with clean IPA and air dried and the deposition temperature is noted. The whole container is then placed on a magnetic stirrer for gentle stirring.
- the electrodes are prepared by cleaning a stainless steel (or other inert metal, e.g., Ni, Pt, etc.) counter-electrode and mounting it and then cleaning the cathode (sample) connector. Stirring is stopped, which allows larger agglomerates to settle out of the solution before deposition begins. Stirring should be ceased at least 30 seconds before a deposition is commenced.
- a stainless steel or other inert metal, e.g., Ni, Pt, etc.
- the mask and sample 13 are then mounted into a typical apparatus utilized for electrophoresis to deposit phosphor 10.
- a connector should be placed in contact with the electrical contacts on the display side of sample 13.
- the display side of sample 13 should be mounted facing the counter-electrode.
- Sample 13 is then lowered into the deposition bath along with the counter-electrode.
- Sample 13 should be lowered to the point of fully covering the display area. Electrodes need to be parallel and 25 ⁇ 5 millimeters apart. A potential is then applied between the electrodes to provide a current density in the preferred range of 0.1-10 mA/cmM
- sample 13 is removed. The mask is then removed and sample 13 is washed with IPA and allowed to air dry. The washing with IPA should be done by gently spraying sample 13 near the top on the copper pads and allowing the IPA to wash down over the deposition.
- a loose phosphor "wash line" should appear on the deposit, it may be removed by directing a very gentle stream of IPA at the line. If the stream is too hard, it may remove phosphor 10 on the ITO 11. Air drying should be done in a vertical position to avoid unwanted particulates, and should be done in a clean room, if possible. Additionally, excess phosphor 10 may be removed with a lint-free wipe. Only the display area should have phosphor 10 on it. Thus, the back side of sample 13 should be cleaned. The clean sample 13 is then air baked at 110 ⁇ C for 1 hour to remove additional water. Refe ⁇ ing next to FIGURES 2 .and 4, sample 13 with the deposited phosphor 10 is then mounted between two optical flats 20, 21. Optionally, some other type of member may take the place of optical flat 21 in order to supply a force to the underside of substrate 12. Optical flats 20, 21 may be prepared by cleaning with methanol and then air dried and/or blown with dry nitrogen.
- the pressing parts should be stacked in the following arrangement (from bottom to top): bottom metal standoff, lint-free wipe, optical flat 21, sample 13 (face-up), optical flat 20 (directly aligned over optical flat 21), lint-free wipe, top metal standoff, ballbearing.
- the stacked portions shown in FIGURE 2 are then loaded into mechanical press 22, and a high pressure force is then applied by press 22 to compress optical flats 20, 21 towards each other (step 42).
- Press 22 may be a Carver Model-C 12 Ton Laboratory Press (shown in FIGURE 7). However, any uniaxial press that can supply the required force may be used. These presses are available from most lab supply retailers (Cole-Parmer, Baxter, SpectraTech, Harrick, etc.).
- press 22 is simply a modified hydraulic jack.
- the applied force may be between 500 and 5,000 psi (pounds per square inch), though other force magnitudes may be used as desired.
- sample 13 and optical flats 20, 21 are removed from mechanical press 22.
- Optical flat 20 is preferably removed vertically from phosphor 10. This is preferably done by holding the back of flat 20 as a lever point and lifting the front up .and away. A horizontal motion should be avoided in removing optical flat 20 since it may wipe off some of phosphor 10. If there is phosphor "lift-off' onto optical flat 20, sample 13 may be recleaned .and redeposited with phosphor 10 and the planarization (step 42) repeated.
- optical flats 20, 21 may be cleaned for the optional next planarization described below.
- sample 13 may again be washed with IPA, -as described above, and dried.
- Sample 13 is then dipped (step 43) into a silicate solution (e.g. a 0.525% potassium silicate solution).
- a silicate solution e.g. a 0.525% potassium silicate solution.
- the application of silicate solution performs a silicate binding operation on phosphor 10 so that phosphor 10 adheres more to the substrate.
- a typical binder solution is prepared with 15 milliliters of Kasil 2135 (a 35% electronic grade potassium silicate solution) and 985 milliliters of H 2 0.
- the solution lifetime may be indefinite. However, if an excess of phosphor particulates or other foreign material are noticed or the solution has evaporated to any appreciable extent, it should be replaced with a fresh solution before utilizing.
- silicate solution is then poured into a clean 250 milliliter beaker, and sample 13 is then dipped into the silicate solution in a slow, smooth motion. Sample 13 is then removed and any excess silicate is removed by wiping with a lint-free cloth on both sides. Excess silicate solution may be removed by gently tapping sample 13 to cause the excess silicate solution to move off the deposited phosphor 10 where it can be absorbed by a wipe. Sample 13 should be kept in a horizontal position as much as possible. S-ample 13 is then allowed to air dry. If desired, removed phosphor may be recovered.
- a surfactant such as methanol, ethanol, IPA, or any of a number of commercially available surfactants can be added to the silicate solution to enhance the wetting and penetrating abilities of the silicate.
- a surfactant such as methanol, ethanol, IPA, or any of a number of commercially available surfactants can be added to the silicate solution to enhance the wetting and penetrating abilities of the silicate.
- 0.001% to 5% by volume of the surfactant can be added to the silicate solution.
- 3% methanol is added to the silicate solution.
- sample 13 is placed into a curing (baking) container which is then placed into an oven with .an inert atmosphere flowing at -ca. 5 standard liters per minute (slm), preferably comprised of N, (nitrogen).
- slm standard liters per minute
- a ramped bake is then initiated within the baking container up to 450 °C (step 44).
- this ramped bake may follow the following standard temperature program: (1) dwell at 250 °C for 5 minutes, (2) ramp to 300 °C at 5 °C/minute, (3) dwell at 300 °C for 5 minutes, (4) ramp to 350 °C at 5 °C/minute, (5) dwell at
- sample 13 is removed from the oven and allowed to cool.
- the thickness variation, or uniformity, of the deposited phosphor powder 10 is dropped to 5% or less of the total maximum thickness of phosphor 10 with the overall thickness being reduced to approximately 5 ⁇ m.
- the planarized sample 13 is illustrated in FIGURE 3, which may be compared to FIGURE 1.
- a second planarization and cure process may be implemented, wherein optical flats 20, 21 are again applied to sample 13 and then mounted within mechanical press 22 (return to step 42).
- Optical flat 20 may be rotated 180 degrees to compensate for any unevenness in flat 20 during the second planarization.
- Step 43 of dipping sample 13 into a silicate solution may also be repeated along with the ramped bake process (step 44) described above. The process ends at step 45.
- This second planarization process further lowers the thickness variation to approximately 2-3% of the maximum thickness of phosphor 10 within the deposited phosphor layer 10.
- a test of the adherence of phosphor layer 10 upon sample 13 may be performed. Beginning at 40 psi, a focused stream of dry N 2 is directed at sample 13. In a sweeping motion, the stream of dry N 2 is increased to a flow of 80 psi. The phosphor layer 10 should remain adherent under this pressure. Other tests may be performed upon sample 13. For example, a test for surface uniformity and thickness may be performed with a profilometer. A test of emission may be performed with an electron gun or similar device. A test for uniformity of phosphor 10 may be performed with an ultraviolet lamp. And a test of adherence may also be performed with a ball tester. The above baking times aie given generally for a single sample of phosphor 10 upon sample 13. Obviously, many samples may be dried and baked at the same time, with adjustments in the baking process.
- the following two changes may be made: (1) use 75% IPA and 25% methyl carbitol as the deposition solution solvents and (2) lower the deposition temperature to ca. 5 °C.
- FIGURE 5 there is illustrated a portion of a flat panel display device 50, which makes use of an anode plate (i.e., sample 13) manufactured by the present invention.
- Cathode assembly 52 comprises substrate 57, typically glass, conductive layer 55, resistive layer 53, and low work function emitting material 54.
- Conductive layer 55, resistive layer 53 and material 54 comprise cathode strip 56, which may be addressable by driver circuitry (not shown).
- Sample 13 comprises, as described above, substrate 12, conductive layer 1 1, and phosphor 10, deposited in the manner described above.
- Device 50 illustrates a diode structure field emission device providing the capability of being matrix addressable through conductive layers 1 1 and 55. As a result, the portion of device 50 shown may be a pixel location within a flat panel display, which is addressable by driver circuitry driving the display.
- the present invention is utilized so that space 59 between material 54 and phosphor 10 is uniform. Spacers 51 and 58 assist in the mounting of assemblies 13 and 52 together.
- FIGURE 6 there is illustrated data processing system 600 employing display device 610 produced in accordance with the present invention.
- Display device 610 is coupled to microprocessor ("CPU") 601, keyboard 604, input devices 605, mass storage 606, input/output ports 611, and main memory 602 through bus 607. All of the aforementioned portions of system 600 may consist of well-known and commercially available devices performing their respective functions within a typical data processing system.
- Display device 610 may be a cathode ray tube, a liquid crystal display, a field emission display such as illustrated in FIGURE 5, or any other type of display that utilizes a phosphor layer for emission of photons to produce images on a display.
- Sample 13 may also be utilized within device 50, which may be utilized as a backlight source for a liquid crystal display for display device 610.
Abstract
A system and method for producing thin, uniform powder phosphors for field emission display screens wherein a planarization of the phosphor powder layer (10) is accomplished by placing the deposited phosphor layer (10) in an anode plate between two optical flats (20, 21), which are then mounted within a mechanical press (22).
Description
METHOD FOR PRODUCING THIN. UNIFORM POWDER PHOSPHOR FOR DISPLAY SCREENS
CROSS REFERENCES
U. S. Patent No. 5,199,918, U. S. Patent No. 5,312,514, co-pending patent application entitled "FLAT PANEL DISPLAY BASED ON DIAMOND THIN FILMS," Serial No. (M0050-P01C1), co-pending patent application entitled
"DIODE STRUCTURE FLAT PANEL DISPLAY," Serial No. 07/995,846, co-pending patent application entitled "TRIODE STRUCTURE FLAT PANEL DISPLAY EMPLOYING FLAT FIELD EMISSION CATHODE," Serial No. 07/993,863, collectively assigned to a common assignee are hereby incorporated by reference herein.
TECHNICAL BACKGROUND OF THE ΓNVENTTON
The present invention relates generally to a method for producing a phosphor layer for a display screen, and more particularly to a method for making a phosphor layer including planarizing by mechanical pressing.
R A PK GROUND OF THE INVENTION
The flat panel display market is growing quite rapidly. In this market, field emission (cold emission) displays comprise one of the most promising technologies for the future. Such displays are subjects of the patents and patent applications cross-referenced herein.
A field emission flat panel display actively produces light from an area through the bombardment of a phosphor layer with electrons emitted from a low work function material as a result of the application of an electrical field. Such field emission devices depend upon a uniform layer of phosphor in order to achieve uniform brightness over large areas of a display.
The electric field, which causes the electrons to emit from a low work function (work function is the minimum energy required to liberate an electron from a solid, typically measured in electronvolts at absolute zero temperature) material towards the phosphor layer, is passed between a pair of electrodes. Often, one or more additional electrodes may be utilized to assist in controlling and directing the emission of electrons towards the phosphor layer. Please refer to Serial Nos. 07/995,846 and 07/993,863 cross-referenced above for further discussions of diode, triode, tetrode, pentode, cl S£Q- field emission devices. Because of lower manufacturing costs and ease of manufacturing, diode structure (only two electrodes) field emission devices are desirable, but are more difficult to implement than triode, tetrode, s_ Sfifl- devices since the required gap (on the order of microns) between the low work function material and the phosphor layer must be precisely maintained to achieve a uniform bombardment of electrons upon the phosphor layer, resulting in the desired uniform brightness throughout the
display. An added difficulty arises from the fact that a diode structure field emission device requires a much smaller gap than triode, tetrode, pentode, cl SCO- devices. Thus, achieving a flat and uniformly distributed phosphor layer is increasingly important with diode structure devices, since even small variations throughout the layer will affect the gap distance.
One present technology for phosphor deposition is a screen printing technique, which typically produces a 10-25 μm thick phosphor film. Another technique, electrophoretic deposition, typically produces a 3-6 μm thick phosphor film often resulting in a 200% variation in thickness throughout the layer. The films produced by these techniques are not uniform.
Thus, it is quite apparent that in order to improve the performance of flat panel displays, such as triode, tetrode, pentode, ej SCQ. field emission displays, and to make more feasible a diode field emission display, a uniform gap between the emission material and the phosphor layer is critical for achieving uniform brightness over large areas. To assist in achieving this goal, it is important that a flat and uniformly distributed phosphor layer be coated so that a uniform emission of photons results upon activation by electrons within the field emission device. Thus, there is a need in the art for a method of producing a powder phosphor film in a thin, uniform layer.
SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to produce a thin, uniform powder phosphor film for a display screen. In the attainment of this object, the present invention deposits a phosphor on a support and then planarizes this deposited phosphor with a mechanical press.
In a preferred embodiment, the present invention includes the steps of depositing a 3-30 μm thick powder phosphor film by an electrophoretic process on a glass substrate with an indium doped tin oxide (ITO) coating (the resulting structure often referred to hereinafter as the "sample"), stacking an optical flat on the phosphor coated side of the sample produced by the deposition of the phosphor film and the ITO on the glass substrate, and loading the sample onto a mechanical press, and applying pressure at 1,000 pounds per square inch (psi) or higher to force the optical flat and the substrate towards each other, thus planarizing the phosphor layer.
Thereafter, the sample may be cured in an oven in an inert atmosphere up to 450° celsius.
Optionally, a second planarization and cure may be performed on the sample. The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWING
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIGURE 1 illustrates a deposited powder phosphor film on a glass substrate prior to planarization by the present invention;
FIGURE 2 illustrates planarization of the powder phosphor film by mechanical pressing; FIGURE 3 illustrates the powder phosphor film layer subsequent to planarization in accordance with the present invention;
FIGURE 4 illustrates a flow diagram of the process of a preferred embodiment of the present invention;
FIGURE 5 illustrates a portion of a flat panel display device implementing a phosphor deposited in a manner set forth herein;
FIGURE 6 illustrates a data processing system with a display device made in a manner set forth herein; and
FIGURE 7 illustrates a mechanical press used in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Referring now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views, and more particularly to FIGURES 1-3, there are shown successive views of the application of powder phosphor to a glass substrate according to a particularly preferred embodiment of the present invention. With reference now to FIGURE 1, a large area substrate 12 is provided.
Substrate 12 is preferably glass and/or quartz, although other suitable materials may be used, the requirement being they provide a base upon which a thin film of ITO coating 11 (if desired) and phosphor powder 10 can be deposited.
Sample 13 (comprising substrate 12, ITO 11 and phosphor 10) may then be used within a field emission device as discussed within the cross-referenced patent and patent applications. For example, sample 13 may be utilized as an anode plate for a diode structure field emission flat panel display. Note, if the field emission device utilizing sample 13 is of a triode, tetrode, pentode, or some other multielectrode device with more than two electrodes, then ITO layer 11 may not be necessary and phosphor 10 may be directly applied to substrate 12, since addressing of sample 13 may not be necessary with such devices.
Referring to FIGURE 4, there is illustrated a flow diagram of a process of a preferred embodiment of the present invention. The process begins at step 40, and proceeds to step 41 wherein approximately a 3-30 μm thick powder phosphor film 10 is deposited by a well-known electrophoretic process onto ITO 1 1 and
substrate 12. Electrophoresis is the movement of colloidal particles in a liquid under the influence of an electric field. Note, other well-known techniques for depositing phosphor may be utilized.
As an example, a typical phosphor solution utilized for display screens is prepared. Whether prepared or acquired as a stock solution, it is desired that phosphor particles be of 1 -2 μm in size. Such a typical phosphor solution may be prepared by combining in a clean storage container: (1 ) 1 gram phosphor (sieved through approximately a 250 mesh screen); (2) 100 milliliters isopropanol ("IPA"; cleanroom grade); (3) 0.0025 grams A1(N03)3 • 9H,0; (4) 0.0025 grams of La(NOj)3 ■ 6H20; and (5) 2 milliliters HjO. Items (3)-(5) may be combined into a stock solution, which will save a significant amount of weighing time. This stock electrolyte solution can be stored indefinitely.
The solution is mixed thoroughly and ultrasonically treated at a fairly intense level (>50 watts) for two minutes in order to break up particle agglomerates. Ultrasonic treatment is done by directly immersing a clean ultrasound horn into the solution. For greater breaking of agglomerates, the solution may be subjected to intense ultrasound (75 watts) for five additionaJ minutes. Additional ultrasonic treatment may be used if desired. As long as the phosphor does not dry out, additional ultrasound should not be necessary. The conductivity of the deposition solution is an important measure of the quality of the solution, and, as such, it should be monitored at regular intervals. Before measuring the conductivity of the .solution, the conductivity meter utilized should be standardized. First, the meter should be allowed to warm up several minutes before taking a reading. Also, it should be ensured that the temperature of the standard solution and the deposition solution are the same. The
conductivity standard solution is prepared with 0.05 grams of KCI (potassium chloride) in one liter of DI (dionized) water. The solution is then mixed well. The conductivity of the standard solution should be around 100 μS/cm (S=Seimen or ohm"1). Specifically, one gram per liter of KCI in water (1,000 parts per million) will give a specific conductivity of 1880 μS/cm at 25 °C. The conductivity scales fairly linearly with concentrations below 2000 μS/cm. The KCI solution is used as the calibrated standard and the supplied standards are only used to prepare more KCI solution. Then the conductivity meter probe is emersed in the solution until the electrodes are fully in the solution. Care must be taken to remove air bubbles out of the probe. The reading on the conductivity meter should be allowed to stabilize for several seconds. And, then the calibration knob on the conductivity meter should be manipulated in order to calibrate the meter so -as to standardize the conductivity meter.
Thereafter, the conductivity of the solution is measured. Small amounts of water may be added to the solution to increase the conductivity, which is preferably between 5 .and 9 μS/cm; more IPA may be added to decrease the conductivity. It is important that all sources of water are kept separate from the prepared solution. Generally, the solution life time may be up to one month, as long as the conductivity remains relatively between 5 and 9 μS/cm and the depositions appear good. At the end of the solution life time, the phosphor should be allowed to .settle out of the solution, the IPA is decanted off and the phosphor is dried out by either air drying or gentle heating. The phosphor is then washed several times with DI H:0 to remove electrolytes and then it is dried again. The phosphor may then be reused.
Substrate 12, after applying ITO 1 1 in a well-known m-anner (if desired), is then washed and a mask (e.g., aluminum) placed thereon. Washing may be performed by uitrasonically treating the sample in a 5% micro solution, rinsing thoroughly in H-,0 and other various solutions such as DI H20, acetone and methanol, and then blow drying with nitrogen. The sample may then be stored in a clean place, such as on wafer carriers.
When placing the mask onto the sample, the display area should be fully exposed. The mask should be pressed as flat as possible against the sample and as close to the display area as possible. Thereafter, the deposition apparatus utilized should be prepared by first standardizing the conductivity meter, as discussed above. Then, the deposition bath container should be cleaned and a Teflon stir bar should be placed therein. The deposition solution is then again mixed and poured into the deposition container. The solution conductivity is then checked so that it is preferably between 5 and 9 μS/cm. Thereafter, the conductivity probe is rinsed off with clean IPA and air dried and the deposition temperature is noted. The whole container is then placed on a magnetic stirrer for gentle stirring. Next, the electrodes are prepared by cleaning a stainless steel (or other inert metal, e.g., Ni, Pt, etc.) counter-electrode and mounting it and then cleaning the cathode (sample) connector. Stirring is stopped, which allows larger agglomerates to settle out of the solution before deposition begins. Stirring should be ceased at least 30 seconds before a deposition is commenced.
The mask and sample 13 are then mounted into a typical apparatus utilized for electrophoresis to deposit phosphor 10. A connector should be placed in contact with the electrical contacts on the display side of sample 13. The display
side of sample 13 should be mounted facing the counter-electrode. Sample 13 is then lowered into the deposition bath along with the counter-electrode. Sample 13 should be lowered to the point of fully covering the display area. Electrodes need to be parallel and 25± 5 millimeters apart. A potential is then applied between the electrodes to provide a current density in the preferred range of 0.1-10 mA/cmM
Phosphor 10 is then deposited and may be varied due to the desired thickness and density of the phosphor deposit. For a typical deposition using V=200V and a current density of 1 mA cm2, a 5 second deposition will result in approximately 50% theoretical density and a 3 micrometer thick deposit. A 30 second deposition under the same conditions will result in 99% theoretical density and an 8-9 micrometer deposit after all subsequent procedures have been performed. After the desired deposition of phosphor 10 is achieved on substrate 12 and ITO 11, sample 13 is removed. The mask is then removed and sample 13 is washed with IPA and allowed to air dry. The washing with IPA should be done by gently spraying sample 13 near the top on the copper pads and allowing the IPA to wash down over the deposition. If a loose phosphor "wash line" should appear on the deposit, it may be removed by directing a very gentle stream of IPA at the line. If the stream is too hard, it may remove phosphor 10 on the ITO 11. Air drying should be done in a vertical position to avoid unwanted particulates, and should be done in a clean room, if possible. Additionally, excess phosphor 10 may be removed with a lint-free wipe. Only the display area should have phosphor 10 on it. Thus, the back side of sample 13 should be cleaned. The clean sample 13 is then air baked at 110 βC for 1 hour to remove additional water.
Refeπing next to FIGURES 2 .and 4, sample 13 with the deposited phosphor 10 is then mounted between two optical flats 20, 21. Optionally, some other type of member may take the place of optical flat 21 in order to supply a force to the underside of substrate 12. Optical flats 20, 21 may be prepared by cleaning with methanol and then air dried and/or blown with dry nitrogen.
The pressing parts should be stacked in the following arrangement (from bottom to top): bottom metal standoff, lint-free wipe, optical flat 21, sample 13 (face-up), optical flat 20 (directly aligned over optical flat 21), lint-free wipe, top metal standoff, ballbearing. The stacked portions shown in FIGURE 2 are then loaded into mechanical press 22, and a high pressure force is then applied by press 22 to compress optical flats 20, 21 towards each other (step 42). Press 22 may be a Carver Model-C 12 Ton Laboratory Press (shown in FIGURE 7). However, any uniaxial press that can supply the required force may be used. These presses are available from most lab supply retailers (Cole-Parmer, Baxter, SpectraTech, Harrick, etc.). Optical flats 20,
21 may each be a disk (usually quartz or Zerodur but can be of other materials) that has been polished so that its surface roughness is less than approximately 150nm. Such optical flats are available from numerous commercial optics suppliers including Edmund Scientific, Oriel, etc. Essentially, press 22 is simply a modified hydraulic jack.
In a preferred embodiment, the applied force may be between 500 and 5,000 psi (pounds per square inch), though other force magnitudes may be used as desired. Thereafter, sample 13 and optical flats 20, 21 are removed from mechanical press 22. Optical flat 20 is preferably removed vertically from phosphor 10. This is preferably done by holding the back of flat 20 as a lever
point and lifting the front up .and away. A horizontal motion should be avoided in removing optical flat 20 since it may wipe off some of phosphor 10. If there is phosphor "lift-off' onto optical flat 20, sample 13 may be recleaned .and redeposited with phosphor 10 and the planarization (step 42) repeated. Next, optical flats 20, 21 may be cleaned for the optional next planarization described below.
Thereafter, sample 13 may again be washed with IPA, -as described above, and dried. Sample 13 is then dipped (step 43) into a silicate solution (e.g. a 0.525% potassium silicate solution). The application of silicate solution performs a silicate binding operation on phosphor 10 so that phosphor 10 adheres more to the substrate. A typical binder solution is prepared with 15 milliliters of Kasil 2135 (a 35% electronic grade potassium silicate solution) and 985 milliliters of H20. The solution lifetime may be indefinite. However, if an excess of phosphor particulates or other foreign material are noticed or the solution has evaporated to any appreciable extent, it should be replaced with a fresh solution before utilizing. The silicate solution is then poured into a clean 250 milliliter beaker, and sample 13 is then dipped into the silicate solution in a slow, smooth motion. Sample 13 is then removed and any excess silicate is removed by wiping with a lint-free cloth on both sides. Excess silicate solution may be removed by gently tapping sample 13 to cause the excess silicate solution to move off the deposited phosphor 10 where it can be absorbed by a wipe. Sample 13 should be kept in a horizontal position as much as possible. S-ample 13 is then allowed to air dry. If desired, removed phosphor may be recovered. A surfactant such as methanol, ethanol, IPA, or any of a number of commercially available surfactants can be added to the silicate solution to enhance the wetting and penetrating abilities of the silicate. Depending
on the surfactant used, 0.001% to 5% by volume of the surfactant can be added to the silicate solution. In a preferred embodiment, 3% methanol is added to the silicate solution.
Next, sample 13 is placed into a curing (baking) container which is then placed into an oven with .an inert atmosphere flowing at -ca. 5 standard liters per minute (slm), preferably comprised of N, (nitrogen). A ramped bake is then initiated within the baking container up to 450 °C (step 44). In a preferred embodiment, this ramped bake may follow the following standard temperature program: (1) dwell at 250 °C for 5 minutes, (2) ramp to 300 °C at 5 °C/minute, (3) dwell at 300 °C for 5 minutes, (4) ramp to 350 °C at 5 °C/minute, (5) dwell at
350 °C for 5 minutes, (6) ramp to 400 °C at 5 βC minute, (7) dwell at 400 °C for 5 minutes, (8) ramp to 450 °C at 2 °C/minute, (9) dwell at 450 °C for 5 minutes, and (10) return to 250 °C.
Then, sample 13 is removed from the oven and allowed to cool. After this first planarization, the thickness variation, or uniformity, of the deposited phosphor powder 10 is dropped to 5% or less of the total maximum thickness of phosphor 10 with the overall thickness being reduced to approximately 5 μm. The planarized sample 13 is illustrated in FIGURE 3, which may be compared to FIGURE 1. Optionally, a second planarization and cure process may be implemented, wherein optical flats 20, 21 are again applied to sample 13 and then mounted within mechanical press 22 (return to step 42). Optical flat 20 may be rotated 180 degrees to compensate for any unevenness in flat 20 during the second planarization. Step 43 of dipping sample 13 into a silicate solution may also be
repeated along with the ramped bake process (step 44) described above. The process ends at step 45.
This second planarization process further lowers the thickness variation to approximately 2-3% of the maximum thickness of phosphor 10 within the deposited phosphor layer 10.
Thereafter, a test of the adherence of phosphor layer 10 upon sample 13 may be performed. Beginning at 40 psi, a focused stream of dry N2 is directed at sample 13. In a sweeping motion, the stream of dry N2 is increased to a flow of 80 psi. The phosphor layer 10 should remain adherent under this pressure. Other tests may be performed upon sample 13. For example, a test for surface uniformity and thickness may be performed with a profilometer. A test of emission may be performed with an electron gun or similar device. A test for uniformity of phosphor 10 may be performed with an ultraviolet lamp. And a test of adherence may also be performed with a ball tester. The above baking times aie given generally for a single sample of phosphor 10 upon sample 13. Obviously, many samples may be dried and baked at the same time, with adjustments in the baking process.
Further, if it is desired to keep the vapor pressure of the deposition solution down, the following two changes may be made: (1) use 75% IPA and 25% methyl carbitol as the deposition solution solvents and (2) lower the deposition temperature to ca. 5 °C.
The technique of the present invention may be applied to a curved substrate and phosphor combination by use of an appropriately shaped planarization device. Moreover, a pattern stamp could be formed within optical flat 20 to form some type of pattern in phosphor 10.
Referring now to FIGURE 5, there is illustrated a portion of a flat panel display device 50, which makes use of an anode plate (i.e., sample 13) manufactured by the present invention. Cathode assembly 52 comprises substrate 57, typically glass, conductive layer 55, resistive layer 53, and low work function emitting material 54. Conductive layer 55, resistive layer 53 and material 54 comprise cathode strip 56, which may be addressable by driver circuitry (not shown).
Sample 13 comprises, as described above, substrate 12, conductive layer 1 1, and phosphor 10, deposited in the manner described above. Device 50 illustrates a diode structure field emission device providing the capability of being matrix addressable through conductive layers 1 1 and 55. As a result, the portion of device 50 shown may be a pixel location within a flat panel display, which is addressable by driver circuitry driving the display.
As discussed above, the present invention is utilized so that space 59 between material 54 and phosphor 10 is uniform. Spacers 51 and 58 assist in the mounting of assemblies 13 and 52 together.
For further discussion of the device illustrated in FIGURE 5, refer to Serial No. 07/995,847, cross-referenced herein.
Referring next to FIGURE 6, there is illustrated data processing system 600 employing display device 610 produced in accordance with the present invention.
Display device 610 is coupled to microprocessor ("CPU") 601, keyboard 604, input devices 605, mass storage 606, input/output ports 611, and main memory 602 through bus 607. All of the aforementioned portions of system 600 may consist of well-known and commercially available devices performing their respective functions within a typical data processing system. Display device 610 may be a
cathode ray tube, a liquid crystal display, a field emission display such as illustrated in FIGURE 5, or any other type of display that utilizes a phosphor layer for emission of photons to produce images on a display.
Sample 13 may also be utilized within device 50, which may be utilized as a backlight source for a liquid crystal display for display device 610.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims
1. A process comprising the steps of: depositing a phosphor on a support; and planarizing said deposited phosphor with a mechanical press.
2. The process as recited in claim 1 wherein said depositing step employs an electrophoretic process.
3. The process as recited in claim 1 wherein said support is comprised of a glass substrate.
4. The process as recited in claim 1 wherein said planarizing step further comprises the steps of: placing an optical flat on said deposited phosphor; and pressing said optical flat towards said support with said mechanical press.
5. The process as recited in claim 1, further comprising the step of: curing said planarized deposited phosphor.
6. The process as recited in claim 5 wherein said curing step comprises a ramped baking of said phosphor.
7 The process as recited in claim 1, further compπsmg the step of immersing said planaπzed deposited phosphor in a silicate solution
8 The process as recited in claim 5, further compπsmg the step of repeating said planarizing step after said cunng step
9 The process as recited in claim 4 wherein said pressing step employs a force up to 2000 psi
10 The process as recited in claim 1 wherein said phosphor is a phosphor powder comprised of ZnO.
11 The process as recited in claim 1, further comprising the step of masking said support prior to said depositing step
12. A method of providing a phosphor on a substrate, comprising the following steps in the sequence set forth: depositing said phosphor on said substrate; placing an optical flat on said deposited phosphor; planarizing said deposited phosphor by pressing said optical flat towards said substrate with a mechanical press; and curing said planarized deposited phosphor.
13. The method as recited in claim 12 wherein said depositing step employs an electrophoretic process.
14. The method as recited in claim 12 wherein said substrate is comprised of a glass substrate and an ITO layer.
15. The method as recited in claim 12 wherein said curing step comprises a ramped baking of said phosphor.
16. The method as recited in claim 12, further comprising the step of: immersing said planarized deposited phosphor in a silicate solution prior to said curing step.
17. The method as recited in claim 12, further comprising the step of: repeating said planarizing and curing steps.
18. A method of providing a phosphor layer on a substrate, wherein said phosphor layer has less than a 3% variation in its thickness, said method comprising the steps of: depositing said phosphor layer on said substrate; and planarizing said deposited phosphor.
19. The method as recited in claim 18 wherein said planarizing step is performed with a mechanical press.
20. The method as recited in claim 19 wherein said planarizing step further comprises the steps of: placing an optical flat on said deposited phosphor layer; and pressing said optical flat towards said substrate with said mechanical press.
21. The method as recited in claim 19, further comprising the step of: curing said planarized deposited phosphor layer.
22. The method as recited in claim 21, further comprising the step of: repeating said planarizing step after said curing step.
23. An apparatus comprising: a substrate; and a phosphor layer deposited on said substrate, wherein said phosphor layer has less than a 3% variation in its thickness.
24. The apparatus as recited in claim 23 wherein said substrate and said phosphor layer form a portion of a display device.
25. The apparatus as recited in claim 24 wherein said display device is included within a data processing system.
26. A method of making a display device, said method comprising the steps of: providing an electron emitting device; depositing a phosphor on a substrate; planarizing said deposited phosphor with a mechanical press; and mounting said substrate a specified distance from said electron emitting device.
27. The method as recited in claim 26 wherein said display device is a flat panel display.
28. The method as recited in claim 26 wherein said display device is a field emission display device.
29. The method as recited in claim 26 wherein said planarizing step further comprises the steps of: placing an optical flat on said deposited phosphor; and pressing said optical flat towards said substrate with said mechanical press.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/304,918 | 1994-09-13 | ||
US08/304,918 US5531880A (en) | 1994-09-13 | 1994-09-13 | Method for producing thin, uniform powder phosphor for display screens |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1996008591A1 true WO1996008591A1 (en) | 1996-03-21 |
Family
ID=23178536
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1995/010491 WO1996008591A1 (en) | 1994-09-13 | 1995-08-17 | Method for producing thin, uniform powder phosphor for display screens |
Country Status (2)
Country | Link |
---|---|
US (2) | US5531880A (en) |
WO (1) | WO1996008591A1 (en) |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5763997A (en) | 1992-03-16 | 1998-06-09 | Si Diamond Technology, Inc. | Field emission display device |
US5744907A (en) * | 1996-01-19 | 1998-04-28 | Micron Display Technology, Inc. | Binders for field emission displays |
US6117294A (en) * | 1996-01-19 | 2000-09-12 | Micron Technology, Inc. | Black matrix material and methods related thereto |
US5688438A (en) * | 1996-02-06 | 1997-11-18 | Micron Display Technology, Inc. | Preparation of high purity silicate-containing phosphors |
US5593562A (en) * | 1996-02-20 | 1997-01-14 | Texas Instruments Incorporated | Method for improving flat panel display anode plate phosphor efficiency |
US5830527A (en) * | 1996-05-29 | 1998-11-03 | Texas Instruments Incorporated | Flat panel display anode structure and method of making |
US5926239A (en) * | 1996-08-16 | 1999-07-20 | Si Diamond Technology, Inc. | Backlights for color liquid crystal displays |
WO1998007066A1 (en) * | 1996-08-16 | 1998-02-19 | Si Diamond Technology, Inc. | Backlights for color liquid crystal displays |
US6171464B1 (en) | 1997-08-20 | 2001-01-09 | Micron Technology, Inc. | Suspensions and methods for deposition of luminescent materials and articles produced thereby |
US6203681B1 (en) | 1999-05-07 | 2001-03-20 | Micron Technology, Inc. | Methods of fabricating display screens using electrophoretic deposition |
US6312303B1 (en) * | 1999-07-19 | 2001-11-06 | Si Diamond Technology, Inc. | Alignment of carbon nanotubes |
US6743279B2 (en) * | 2002-05-17 | 2004-06-01 | Airborne Contaminant Systems, Llc | Air purification device for air handling units |
US20040056209A1 (en) * | 2002-09-24 | 2004-03-25 | Konica Corporation | Radiation image converting panel and production method of the same |
US20080012461A1 (en) * | 2004-11-09 | 2008-01-17 | Nano-Proprietary, Inc. | Carbon nanotube cold cathode |
CN100423165C (en) * | 2006-08-08 | 2008-10-01 | 甘肃省分析测试中心 | Method for mfg. piezo-optical x-ray screen |
TW200903851A (en) * | 2007-07-10 | 2009-01-16 | Univ Nat Central | Phosphor package of light emitting diodes |
US10846433B2 (en) | 2016-06-10 | 2020-11-24 | OneTrust, LLC | Data processing consent management systems and related methods |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1984001172A1 (en) * | 1982-09-16 | 1984-03-29 | Benzon As Alfred | Stabilized plasmids |
EP0115613A2 (en) * | 1982-12-24 | 1984-08-15 | BOEHRINGER INGELHEIM INTERNATIONAL GmbH | DNA sequences, their preparation, plasmids containing these sequences and their use in the synthesis of eukaryotic gene products in prokaryotes |
EP0360006A2 (en) * | 1988-08-19 | 1990-03-28 | Takeda Chemical Industries, Ltd. | Acid-resistant fibroblast growth factor composition for treating ulcerating diseases of the gastrointestinal tract |
FR2642086A1 (en) * | 1989-01-26 | 1990-07-27 | Sanofi Sa | Recombinant gene encoding a basic fibroblast growth factor and the said factor |
EP0406738A2 (en) * | 1989-07-03 | 1991-01-09 | Takeda Chemical Industries, Ltd. | Production of acidic FGF protein |
WO1991016439A1 (en) * | 1990-04-24 | 1991-10-31 | Rhone-Poulenc Biochimie | New cloning and/or expression vectors, process for their preparation and use thereof |
Family Cites Families (115)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1954691A (en) * | 1930-09-27 | 1934-04-10 | Philips Nv | Process of making alpha layer containing alpha fluorescent material |
US2851408A (en) * | 1954-10-01 | 1958-09-09 | Westinghouse Electric Corp | Method of electrophoretic deposition of luminescent materials and product resulting therefrom |
US2959483A (en) * | 1955-09-06 | 1960-11-08 | Zenith Radio Corp | Color image reproducer and method of manufacture |
US2867541A (en) * | 1957-02-25 | 1959-01-06 | Gen Electric | Method of preparing transparent luminescent screens |
US3070441A (en) * | 1958-02-27 | 1962-12-25 | Rca Corp | Art of manufacturing cathode-ray tubes of the focus-mask variety |
US3108904A (en) * | 1960-08-30 | 1963-10-29 | Gen Electric | Method of preparing luminescent materials and luminescent screens prepared thereby |
US3360450A (en) * | 1962-11-19 | 1967-12-26 | American Optical Corp | Method of making cathode ray tube face plates utilizing electrophoretic deposition |
US3314871A (en) * | 1962-12-20 | 1967-04-18 | Columbia Broadcasting Syst Inc | Method of cataphoretic deposition of luminescent materials |
US3525679A (en) * | 1964-05-05 | 1970-08-25 | Westinghouse Electric Corp | Method of electrodepositing luminescent material on insulating substrate |
US3481733A (en) * | 1966-04-18 | 1969-12-02 | Sylvania Electric Prod | Method of forming a cathodo-luminescent screen |
US3554889A (en) * | 1968-11-22 | 1971-01-12 | Ibm | Color cathode ray tube screens |
US3675063A (en) * | 1970-01-02 | 1972-07-04 | Stanford Research Inst | High current continuous dynode electron multiplier |
US3789471A (en) * | 1970-02-06 | 1974-02-05 | Stanford Research Inst | Field emission cathode structures, devices utilizing such structures, and methods of producing such structures |
US3755704A (en) * | 1970-02-06 | 1973-08-28 | Stanford Research Inst | Field emission cathode structures and devices utilizing such structures |
US3665241A (en) * | 1970-07-13 | 1972-05-23 | Stanford Research Inst | Field ionizer and field emission cathode structures and methods of production |
US3812559A (en) * | 1970-07-13 | 1974-05-28 | Stanford Research Inst | Methods of producing field ionizer and field emission cathode structures |
NL7018154A (en) * | 1970-12-12 | 1972-06-14 | ||
US3764514A (en) * | 1972-11-30 | 1973-10-09 | Gte Sylvania Inc | Apparatus for coating a pattern mask for use in forming a color crt screen structure |
US3904502A (en) * | 1973-03-05 | 1975-09-09 | Westinghouse Electric Corp | Method of fabricating a color display screen employing a plurality of layers of phosphors |
US3898146A (en) * | 1973-05-07 | 1975-08-05 | Gte Sylvania Inc | Process for fabricating a cathode ray tube screen structure |
CA1083266A (en) * | 1975-06-27 | 1980-08-05 | Hitachi, Ltd. | Field emission cathode and method for preparation thereof |
US4084942A (en) * | 1975-08-27 | 1978-04-18 | Villalobos Humberto Fernandez | Ultrasharp diamond edges and points and method of making |
US4168213A (en) * | 1976-04-29 | 1979-09-18 | U.S. Philips Corporation | Field emission device and method of forming same |
US4178531A (en) * | 1977-06-15 | 1979-12-11 | Rca Corporation | CRT with field-emission cathode |
US4141405A (en) * | 1977-07-27 | 1979-02-27 | Sri International | Method of fabricating a funnel-shaped miniature electrode for use as a field ionization source |
JPS54110780A (en) * | 1978-02-20 | 1979-08-30 | Hitachi Ltd | Forming method for fluorescent screen of color television picture tube |
US4307507A (en) * | 1980-09-10 | 1981-12-29 | The United States Of America As Represented By The Secretary Of The Navy | Method of manufacturing a field-emission cathode structure |
US4507562A (en) * | 1980-10-17 | 1985-03-26 | Jean Gasiot | Methods for rapidly stimulating luminescent phosphors and recovering information therefrom |
US4528474A (en) * | 1982-03-05 | 1985-07-09 | Kim Jason J | Method and apparatus for producing an electron beam from a thermionic cathode |
JPS6010120B2 (en) * | 1982-09-14 | 1985-03-15 | ソニー株式会社 | Non-aqueous electrodeposition method of powder |
US4513308A (en) * | 1982-09-23 | 1985-04-23 | The United States Of America As Represented By The Secretary Of The Navy | p-n Junction controlled field emitter array cathode |
DE3319526C2 (en) * | 1983-05-28 | 1994-10-20 | Max Planck Gesellschaft | Arrangement with a physical sensor |
FR2547828B1 (en) * | 1983-06-23 | 1985-11-22 | Centre Nat Rech Scient | LUMINESCENT MATERIAL COMPRISING A SOLID MATRIX WITHIN A FLUORESCENT COMPOUND, ITS PREPARATION METHOD AND ITS USE IN A CELL |
JPS6038490A (en) * | 1983-08-11 | 1985-02-28 | Toshiba Corp | White light-emitting phosphor mixture and cathode-ray tube using the same |
JPS6074231A (en) * | 1983-09-30 | 1985-04-26 | Hitachi Ltd | Method of manufacturing cathode ray tube |
US4816717A (en) * | 1984-02-06 | 1989-03-28 | Rogers Corporation | Electroluminescent lamp having a polymer phosphor layer formed in substantially a non-crossed linked state |
JPS60207229A (en) * | 1984-03-30 | 1985-10-18 | Toshiba Corp | Formation of phosphor screen of cathode-ray tube |
JPS6110827A (en) * | 1984-06-27 | 1986-01-18 | Matsushita Electronics Corp | Forming method of crt phosphor film |
US4633131A (en) * | 1984-12-12 | 1986-12-30 | North American Philips Corporation | Halo-reducing faceplate arrangement |
JPS61237341A (en) * | 1985-04-12 | 1986-10-22 | Matsushita Electric Ind Co Ltd | Phosphor display panel and its manufacture |
US5124558A (en) * | 1985-10-10 | 1992-06-23 | Quantex Corporation | Imaging system for mamography employing electron trapping materials |
US5166456A (en) * | 1985-12-16 | 1992-11-24 | Kasei Optonix, Ltd. | Luminescent phosphor composition |
US4684540A (en) * | 1986-01-31 | 1987-08-04 | Gte Products Corporation | Coated pigmented phosphors and process for producing same |
US4857799A (en) * | 1986-07-30 | 1989-08-15 | Sri International | Matrix-addressed flat panel display |
US5015912A (en) * | 1986-07-30 | 1991-05-14 | Sri International | Matrix-addressed flat panel display |
US4900584A (en) * | 1987-01-12 | 1990-02-13 | Planar Systems, Inc. | Rapid thermal annealing of TFEL panels |
US4851254A (en) * | 1987-01-13 | 1989-07-25 | Nippon Soken, Inc. | Method and device for forming diamond film |
US4822466A (en) * | 1987-06-25 | 1989-04-18 | University Of Houston - University Park | Chemically bonded diamond films and method for producing same |
FR2623013A1 (en) * | 1987-11-06 | 1989-05-12 | Commissariat Energie Atomique | ELECTRO SOURCE WITH EMISSIVE MICROPOINT CATHODES AND FIELD EMISSION-INDUCED CATHODOLUMINESCENCE VISUALIZATION DEVICE USING THE SOURCE |
US5153901A (en) * | 1988-01-06 | 1992-10-06 | Jupiter Toy Company | Production and manipulation of charged particles |
US5054046A (en) * | 1988-01-06 | 1991-10-01 | Jupiter Toy Company | Method of and apparatus for production and manipulation of high density charge |
US5123039A (en) * | 1988-01-06 | 1992-06-16 | Jupiter Toy Company | Energy conversion using high charge density |
DE3817897A1 (en) * | 1988-01-06 | 1989-07-20 | Jupiter Toy Co | THE GENERATION AND HANDLING OF CHARGED FORMS OF HIGH CHARGE DENSITY |
US5148461A (en) * | 1988-01-06 | 1992-09-15 | Jupiter Toy Co. | Circuits responsive to and controlling charged particles |
US4874981A (en) * | 1988-05-10 | 1989-10-17 | Sri International | Automatically focusing field emission electrode |
US5285129A (en) * | 1988-05-31 | 1994-02-08 | Canon Kabushiki Kaisha | Segmented electron emission device |
US4926056A (en) * | 1988-06-10 | 1990-05-15 | Sri International | Microelectronic field ionizer and method of fabricating the same |
US4956202A (en) * | 1988-12-22 | 1990-09-11 | Gte Products Corporation | Firing and milling method for producing a manganese activated zinc silicate phosphor |
US4892757A (en) * | 1988-12-22 | 1990-01-09 | Gte Products Corporation | Method for a producing manganese activated zinc silicate phosphor |
ATE156648T1 (en) * | 1988-12-27 | 1997-08-15 | Canon Kk | LIGHT EMITTING DEVICE BY ELECTRICAL FIELD |
JP2548352B2 (en) * | 1989-01-17 | 1996-10-30 | 松下電器産業株式会社 | Light emitting device and method of manufacturing the same |
US4994205A (en) * | 1989-02-03 | 1991-02-19 | Eastman Kodak Company | Composition containing a hafnia phosphor of enhanced luminescence |
US5142390A (en) * | 1989-02-23 | 1992-08-25 | Ricoh Company, Ltd. | MIM element with a doped hard carbon film |
US5101288A (en) * | 1989-04-06 | 1992-03-31 | Ricoh Company, Ltd. | LCD having obliquely split or interdigitated pixels connected to MIM elements having a diamond-like insulator |
US5153753A (en) * | 1989-04-12 | 1992-10-06 | Ricoh Company, Ltd. | Active matrix-type liquid crystal display containing a horizontal MIM device with inter-digital conductors |
JP2799875B2 (en) * | 1989-05-20 | 1998-09-21 | 株式会社リコー | Liquid crystal display |
US4990766A (en) * | 1989-05-22 | 1991-02-05 | Murasa International | Solid state electron amplifier |
JP2757207B2 (en) * | 1989-05-24 | 1998-05-25 | 株式会社リコー | Liquid crystal display |
US4990416A (en) * | 1989-06-19 | 1991-02-05 | Coloray Display Corporation | Deposition of cathodoluminescent materials by reversal toning |
KR910008017B1 (en) * | 1989-08-30 | 1991-10-05 | 삼성전관 주식회사 | Manufacturing method for flourescent screen for color crt |
EP0420188A1 (en) * | 1989-09-27 | 1991-04-03 | Sumitomo Electric Industries, Ltd. | Semiconductor heterojunction structure |
US5214416A (en) * | 1989-12-01 | 1993-05-25 | Ricoh Company, Ltd. | Active matrix board |
US5229682A (en) * | 1989-12-18 | 1993-07-20 | Seiko Epson Corporation | Field electron emission device |
US5228878A (en) * | 1989-12-18 | 1993-07-20 | Seiko Epson Corporation | Field electron emission device production method |
EP0434001B1 (en) * | 1989-12-19 | 1996-04-03 | Matsushita Electric Industrial Co., Ltd. | Electron emission device and method of manufacturing the same |
US5064396A (en) * | 1990-01-29 | 1991-11-12 | Coloray Display Corporation | Method of manufacturing an electric field producing structure including a field emission cathode |
US5235244A (en) * | 1990-01-29 | 1993-08-10 | Innovative Display Development Partners | Automatically collimating electron beam producing arrangement |
US5142184B1 (en) * | 1990-02-09 | 1995-11-21 | Motorola Inc | Cold cathode field emission device with integral emitter ballasting |
US5156770A (en) * | 1990-06-26 | 1992-10-20 | Thomson Consumer Electronics, Inc. | Conductive contact patch for a CRT faceplate panel |
US5202571A (en) * | 1990-07-06 | 1993-04-13 | Canon Kabushiki Kaisha | Electron emitting device with diamond |
US5204581A (en) * | 1990-07-12 | 1993-04-20 | Bell Communications Research, Inc. | Device including a tapered microminiature silicon structure |
US5075591A (en) * | 1990-07-13 | 1991-12-24 | Coloray Display Corporation | Matrix addressing arrangement for a flat panel display with field emission cathodes |
US5141459A (en) * | 1990-07-18 | 1992-08-25 | International Business Machines Corporation | Structures and processes for fabricating field emission cathodes |
US5203731A (en) * | 1990-07-18 | 1993-04-20 | International Business Machines Corporation | Process and structure of an integrated vacuum microelectronic device |
US5089292A (en) * | 1990-07-20 | 1992-02-18 | Coloray Display Corporation | Field emission cathode array coated with electron work function reducing material, and method |
US5183529A (en) * | 1990-10-29 | 1993-02-02 | Ford Motor Company | Fabrication of polycrystalline free-standing diamond films |
US5132585A (en) * | 1990-12-21 | 1992-07-21 | Motorola, Inc. | Projection display faceplate employing an optically transmissive diamond coating of high thermal conductivity |
US5212426A (en) * | 1991-01-24 | 1993-05-18 | Motorola, Inc. | Integrally controlled field emission flat display device |
GB9101723D0 (en) * | 1991-01-25 | 1991-03-06 | Marconi Gec Ltd | Field emission devices |
JP2626276B2 (en) * | 1991-02-06 | 1997-07-02 | 双葉電子工業株式会社 | Electron-emitting device |
US5312514A (en) * | 1991-11-07 | 1994-05-17 | Microelectronics And Computer Technology Corporation | Method of making a field emitter device using randomly located nuclei as an etch mask |
US5281891A (en) * | 1991-02-22 | 1994-01-25 | Matsushita Electric Industrial Co., Ltd. | Electron emission element |
FR2675947A1 (en) * | 1991-04-23 | 1992-10-30 | France Telecom | PROCESS FOR LOCAL PASSIVATION OF A SUBSTRATE BY A HYDROGEN AMORPHOUS CARBON LAYER AND METHOD FOR MANUFACTURING THIN FILM TRANSISTORS ON THE PASSIVE SUBSTRATE. |
US5138237A (en) * | 1991-08-20 | 1992-08-11 | Motorola, Inc. | Field emission electron device employing a modulatable diamond semiconductor emitter |
US5141460A (en) * | 1991-08-20 | 1992-08-25 | Jaskie James E | Method of making a field emission electron source employing a diamond coating |
US5129850A (en) * | 1991-08-20 | 1992-07-14 | Motorola, Inc. | Method of making a molded field emission electron emitter employing a diamond coating |
US5199918A (en) * | 1991-11-07 | 1993-04-06 | Microelectronics And Computer Technology Corporation | Method of forming field emitter device with diamond emission tips |
US5124072A (en) * | 1991-12-02 | 1992-06-23 | General Electric Company | Alkaline earth hafnate phosphor with cerium luminescence |
US5199917A (en) * | 1991-12-09 | 1993-04-06 | Cornell Research Foundation, Inc. | Silicon tip field emission cathode arrays and fabrication thereof |
DE69214780T2 (en) * | 1991-12-11 | 1997-05-15 | Agfa Gevaert Nv | Method of making a radiographic screen |
US5204021A (en) * | 1992-01-03 | 1993-04-20 | General Electric Company | Lanthanide oxide fluoride phosphor having cerium luminescence |
US5180951A (en) * | 1992-02-05 | 1993-01-19 | Motorola, Inc. | Electron device electron source including a polycrystalline diamond |
US5252833A (en) * | 1992-02-05 | 1993-10-12 | Motorola, Inc. | Electron source for depletion mode electron emission apparatus |
US5213712A (en) * | 1992-02-10 | 1993-05-25 | General Electric Company | Lanthanum lutetium oxide phosphor with cerium luminescence |
US5229331A (en) * | 1992-02-14 | 1993-07-20 | Micron Technology, Inc. | Method to form self-aligned gate structures around cold cathode emitter tips using chemical mechanical polishing technology |
US5151061A (en) * | 1992-02-21 | 1992-09-29 | Micron Technology, Inc. | Method to form self-aligned tips for flat panel displays |
US5259799A (en) * | 1992-03-02 | 1993-11-09 | Micron Technology, Inc. | Method to form self-aligned gate structures and focus rings |
US5186670A (en) * | 1992-03-02 | 1993-02-16 | Micron Technology, Inc. | Method to form self-aligned gate structures and focus rings |
KR950004516B1 (en) * | 1992-04-29 | 1995-05-01 | 삼성전관주식회사 | Field emission display and manufacturing method |
US5256888A (en) * | 1992-05-04 | 1993-10-26 | Motorola, Inc. | Transistor device apparatus employing free-space electron emission from a diamond material surface |
US5329207A (en) * | 1992-05-13 | 1994-07-12 | Micron Technology, Inc. | Field emission structures produced on macro-grain polysilicon substrates |
US5283500A (en) * | 1992-05-28 | 1994-02-01 | At&T Bell Laboratories | Flat panel field emission display apparatus |
US5278475A (en) * | 1992-06-01 | 1994-01-11 | Motorola, Inc. | Cathodoluminescent display apparatus and method for realization using diamond crystallites |
US5242620A (en) * | 1992-07-02 | 1993-09-07 | General Electric Company | Gadolinium lutetium aluminate phosphor with cerium luminescence |
US5302423A (en) * | 1993-07-09 | 1994-04-12 | Minnesota Mining And Manufacturing Company | Method for fabricating pixelized phosphors |
-
1994
- 1994-09-13 US US08/304,918 patent/US5531880A/en not_active Expired - Fee Related
-
1995
- 1995-06-07 US US08/488,066 patent/US5697824A/en not_active Expired - Fee Related
- 1995-08-17 WO PCT/US1995/010491 patent/WO1996008591A1/en active Application Filing
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1984001172A1 (en) * | 1982-09-16 | 1984-03-29 | Benzon As Alfred | Stabilized plasmids |
EP0115613A2 (en) * | 1982-12-24 | 1984-08-15 | BOEHRINGER INGELHEIM INTERNATIONAL GmbH | DNA sequences, their preparation, plasmids containing these sequences and their use in the synthesis of eukaryotic gene products in prokaryotes |
EP0360006A2 (en) * | 1988-08-19 | 1990-03-28 | Takeda Chemical Industries, Ltd. | Acid-resistant fibroblast growth factor composition for treating ulcerating diseases of the gastrointestinal tract |
FR2642086A1 (en) * | 1989-01-26 | 1990-07-27 | Sanofi Sa | Recombinant gene encoding a basic fibroblast growth factor and the said factor |
EP0406738A2 (en) * | 1989-07-03 | 1991-01-09 | Takeda Chemical Industries, Ltd. | Production of acidic FGF protein |
WO1991016439A1 (en) * | 1990-04-24 | 1991-10-31 | Rhone-Poulenc Biochimie | New cloning and/or expression vectors, process for their preparation and use thereof |
Non-Patent Citations (4)
Title |
---|
GENE (AMST) 110 (1). 1992. 105-108. CODEN: GENED6 ISSN: 0378-1119, CROUZET J ET AL 'CONSTRUCTION OF A BROAD-HOST-RANGE NON-MOBILIZABLE STABLE VECTOR CARRYING RP4 PAR-REGION.' * |
J. BIOTECHNOLOGY, vol. 28, no. 2,3, ELSEVIER, AMSTERDAM,NL, pages 291-299, C. HAIGERMOSER ET AL. 'Stability od r-microbes: Stabilization of plasmid vectors by the patitioning function of broad-host-range plasmid RP4' * |
METHODS IN ENZYMOLOGY, vol. 185, ACADEMIC PRESS, INC., NEW YORK, US, pages 60-89, F.W. STUDIER ET AL. 'Use of T7 RNA polymerase to direct expression of cloned genes' cité dans la demande * |
PROC. NATL.ACAD SCI., vol. 82, no. 4, NATL. ACAD SCI.,WASHINGTON,DC,US;, pages 1074-1078, S. TABOR AND C.C. RICHARDSON 'A bacteriophage T7 RNA polymerase/promoter system for controlled exclusive expression od specific genes' * |
Also Published As
Publication number | Publication date |
---|---|
US5531880A (en) | 1996-07-02 |
US5697824A (en) | 1997-12-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5697824A (en) | Method for producing thin uniform powder phosphor for display screens | |
US6462467B1 (en) | Method for depositing a resistive material in a field emission cathode | |
US6902658B2 (en) | FED cathode structure using electrophoretic deposition and method of fabrication | |
KR100214393B1 (en) | Method of manufacturing electron-emitting device, method of manufacturing electron source and image-forming apparatus and manufacturing apparatus thereof | |
EP1596411B1 (en) | Image display apparatus and method for manufacturing the same | |
KR100508372B1 (en) | Electron emitting device, electron source and image display device and methods of manufacturing these devices | |
JP3634852B2 (en) | Electron emitting device, electron source, and manufacturing method of image display device | |
JPH08236010A (en) | Field emission device using hyperfine diamond particle-form emitter and its preparation | |
JP3634805B2 (en) | Manufacturing method of image forming apparatus | |
US6890230B2 (en) | Method for activating nanotubes as field emission sources | |
JP3323851B2 (en) | Electron emitting element, electron source using the same, and image forming apparatus using the same | |
JP3323852B2 (en) | Electron emitting element, electron source using the same, and image forming apparatus using the same | |
US20060292297A1 (en) | Patterning CNT emitters | |
EP0861498B1 (en) | Annealed carbon soot field emitters and field emitter cathodes made therefrom | |
JP3902964B2 (en) | Manufacturing method of electron source | |
Minì et al. | Copper patterning on dielectrics by laser writing in liquid solution | |
JP2000123712A (en) | Field emission cold cathode and its manufacture | |
CN113764137A (en) | Preparation method of nano silver wire conductive film, nano silver wire conductive film and application thereof | |
JP2021089841A (en) | Field electron-emitting element and light-emitting element, and manufacturing methods thereof | |
JPH02247940A (en) | Electron emission element and image formation apparatus using it | |
JP2003288837A (en) | Manufacturing method of electron emission element | |
US8414757B2 (en) | Process for improving the oxidation resistance of carbon nanotubes | |
JP3413192B2 (en) | Method of manufacturing electron-emitting device and image forming apparatus | |
JPH06203741A (en) | Electron emitting element, electron beam generator and image forming device | |
JPH0494032A (en) | Electron emission element and image forming device using electron emission element |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CA JP KR |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
122 | Ep: pct application non-entry in european phase | ||
NENP | Non-entry into the national phase |
Ref country code: CA |