CA1047846A - Toner applicator for electrographic recording system - Google Patents
Toner applicator for electrographic recording systemInfo
- Publication number
- CA1047846A CA1047846A CA222,196A CA222196A CA1047846A CA 1047846 A CA1047846 A CA 1047846A CA 222196 A CA222196 A CA 222196A CA 1047846 A CA1047846 A CA 1047846A
- Authority
- CA
- Canada
- Prior art keywords
- toner
- recording
- recording medium
- electrode
- recited
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
- G03G15/0914—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush with a one-component toner
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
- G03G15/34—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the powder image is formed directly on the recording material, e.g. by using a liquid toner
- G03G15/344—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the powder image is formed directly on the recording material, e.g. by using a liquid toner by selectively transferring the powder to the recording medium, e.g. by using a LED array
- G03G15/348—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the powder image is formed directly on the recording material, e.g. by using a liquid toner by selectively transferring the powder to the recording medium, e.g. by using a LED array using a stylus or a multi-styli array
Abstract
ABSTRACT
A toner applicator for delivering an optimum amount of toner powder to a recording electrode of an electrographic recording system whereby a portion of said toner may be electrographically deposited on a recording medium in the form of toner images. The toner is fed from a toner reservoir onto the recording medium in a relatively uniform layer by a toner supply means that is adjustable to vary the thickness of the toner layer deposited on the recording medium. The toner layer is then transported in the recording medium to the recording electrode, and a magnetic field is induced in the recording electrode to draw the toner layer into a position bridging between the recording electrode and the recording medium for being redeposited on the recording medium in the form of toner images.
A toner applicator for delivering an optimum amount of toner powder to a recording electrode of an electrographic recording system whereby a portion of said toner may be electrographically deposited on a recording medium in the form of toner images. The toner is fed from a toner reservoir onto the recording medium in a relatively uniform layer by a toner supply means that is adjustable to vary the thickness of the toner layer deposited on the recording medium. The toner layer is then transported in the recording medium to the recording electrode, and a magnetic field is induced in the recording electrode to draw the toner layer into a position bridging between the recording electrode and the recording medium for being redeposited on the recording medium in the form of toner images.
Description
911,434 TONER APPLICATION FOR ELECTROGRAPHIC
RECORDING SYSTEM
The present invention relates in general to the electrographic recording of toner images on a recording medium and more specifically to a means and a method for supplying an optimum amount of toner powder to a recording electrode.
Electrographic recording systems for printing toner images on a recordlng medlum have in common the use of toner applicators for transporting toner to a recording region. Various types of toner transport systems have been 10 devised as illustrated by Fotland et al, U.S. Patent No. -3,121,375 and Nau et al, No. 2,932,548, which both teach the application of toner into the recording region through -what serves as a recording electrode of the systems shown.
Such toner applicators may serve satisfactorily in systems ~ -employing a relatively small number of recording electrodes;
however, in systems having 200-400 recording electrodes per inch the application of toner through each such electrode is undesirable.
A second common method for delivering toner into ~
20 the recording region is the use of a separate developing --element to which toner is first applied. The developing element may be in the form of a porous endless belt on which the toner rides into the recording region as diS-closed by Capps, U.S. Patent No. 3,355,743, or in the form of a cylinder that enclos~es a magnet rotor, the rotation ' ' - .
- , , 1~7846 of which brings the toner into the recording region as taught in Anderson, U.S. Patent No. 3,455,276. In Anderson, a doctor blade is employed to meter a uniform layer of toner onto the transport cylinder.
A primary deficiency with the above types of prior art toner applicators is that they do not provide suffi-ciently accurate metering of toner into the recording region when large numbers of narrowly spaced apart elec- ~ -trodes are employed in a printing array. It is difficult to precisely meter thin, uniform amounts of toner powder into the recording region without experiencing occasional plugging of metering orifices or doctor blade gaps because of toner powder agglomeration. If too much toner is trans-ported into the recording region the toner images formed will tend to bloom out and will not have sharply defined edges. Also, when uslng plastically deformable toners ;
such as thermoplastic resin, an excessive amount of toner ~-in the recording region may increase pressure applied on the toner by the recording electrode and the recording medium to the point that there is a gradual toner build up on the recording electrode due to pressure fusing. If inadequate toner is transported onto the recording region, the formed toner images suffer a loss of density and become light or dlsappear altogether.
The present invention resides in a toner applica-tor for an electrographic recording system that includes a pair of opposed electrodes spaced apart to define a record-ing reglon therebetween, and a recording medium that is
RECORDING SYSTEM
The present invention relates in general to the electrographic recording of toner images on a recording medium and more specifically to a means and a method for supplying an optimum amount of toner powder to a recording electrode.
Electrographic recording systems for printing toner images on a recordlng medlum have in common the use of toner applicators for transporting toner to a recording region. Various types of toner transport systems have been 10 devised as illustrated by Fotland et al, U.S. Patent No. -3,121,375 and Nau et al, No. 2,932,548, which both teach the application of toner into the recording region through -what serves as a recording electrode of the systems shown.
Such toner applicators may serve satisfactorily in systems ~ -employing a relatively small number of recording electrodes;
however, in systems having 200-400 recording electrodes per inch the application of toner through each such electrode is undesirable.
A second common method for delivering toner into ~
20 the recording region is the use of a separate developing --element to which toner is first applied. The developing element may be in the form of a porous endless belt on which the toner rides into the recording region as diS-closed by Capps, U.S. Patent No. 3,355,743, or in the form of a cylinder that enclos~es a magnet rotor, the rotation ' ' - .
- , , 1~7846 of which brings the toner into the recording region as taught in Anderson, U.S. Patent No. 3,455,276. In Anderson, a doctor blade is employed to meter a uniform layer of toner onto the transport cylinder.
A primary deficiency with the above types of prior art toner applicators is that they do not provide suffi-ciently accurate metering of toner into the recording region when large numbers of narrowly spaced apart elec- ~ -trodes are employed in a printing array. It is difficult to precisely meter thin, uniform amounts of toner powder into the recording region without experiencing occasional plugging of metering orifices or doctor blade gaps because of toner powder agglomeration. If too much toner is trans-ported into the recording region the toner images formed will tend to bloom out and will not have sharply defined edges. Also, when uslng plastically deformable toners ;
such as thermoplastic resin, an excessive amount of toner ~-in the recording region may increase pressure applied on the toner by the recording electrode and the recording medium to the point that there is a gradual toner build up on the recording electrode due to pressure fusing. If inadequate toner is transported onto the recording region, the formed toner images suffer a loss of density and become light or dlsappear altogether.
The present invention resides in a toner applica-tor for an electrographic recording system that includes a pair of opposed electrodes spaced apart to define a record-ing reglon therebetween, and a recording medium that is
- 2 -:' ' , '',, ~ '- ' ~;' 1~47846 guided through the recording region. The applicator of the present invention is formed of a toner supply means that deposits toner powder on one side of the recording medium, and a force means for drawing the toner from the recording medium into the recording region in a condition for being redeposited on the medium.
In a preferred embodiment, the toner supply means is formed of a developer roll having an inner magnet assembly and an outer rotating shell. A toner reservolr containing magnetically attractable toner powder is positioned alongside the developer roll, and toner powder is magnetically attracted therefrom onto the surface of the developer roll outer shell in a unlform layer. The toner on the developer roll is transported to and deposited 15 on a portion of the recording medium in a layer of precise ~ ~-thickness through magnetic or electrographic means. Such portion of the recording medium is subsequently guided through the recording region wherein a force means formed of another developer roll attracts the toner powder from the recording medium and arranges the toner to bridge be-tween one of the opposed electrodes and the recording medlum.
The toner supply means is ad~ustable to vary the density of the toner layer deposited on the recording medium so that a precisely optimum amount of toner powder for producing high quality toner images is furnished to the recording region. However, the precise amount of toner deposlted on the recording medium is independent of ,, ~ ~ . .
16;~47846 :
metering gaps or orifices. Thus, the present invention ~ -provides a reliable and accurate means for transporting an optimum amount o~ toner powder to a recording electrode of an electrographic recording system in order that high quality, high resolution toner images may be formed.
A preferred embodiment of the invention is described below in connection with the accompanying drawings, wherein:
Fig. 1 is a diagrammatic end view of an elec-trographic recordlng system incorporating the tonerapplicator of the present invention; and Fig. 2 is an enlarged fragmentary view of portions of the recording system of Fig. 1.
Referring now to the drawings and with specific reference ~irst to Fig. 1, a recording system 1 employ-ing a preferred embodiment of the toner applicator of the present invention is shown. The recording system 1 includes a cyllndrical developer roll 3 and a rotatable recording member 4O
The developer roll 3 preferably has an inner magnet assembly 5 and an outer cylindrical shell 6 that is electrically nonconductive and nonmagnetic. The magnet as~embly 5 includes a cylindrical, magnet support core 7 :
, . . .
1~47846 and a plurality of permanent magnet sectors 8 arranged about the cylindrical periphery of the core 7 to define a surface having alternate North and South magnetic poles.
The developer roll 3 is mounted on an axle 9 and is con-structed such that the magnet assembly 5 rotates in acounterclockwise direction, whereas the outer shell 6 is spaced from the magnet assembly 5 and is preferably fixed in position.
Arranged on a line that extends parallel with the support core 7 are a plurality of individual, spaced apart recording electrodes 10 (only one of which is shown) that protrude from the periphery of the shell 6, but may also be disposed in the shell 6 so that the outer ends of the electrodes 10 are flush with the periphery of the shell 6.
Each electrode 10 is magnetically permeable and passes a large amount of magnetic flux emanating from the magnet sectors 8 of the developer roll 3 so that the developer roll 3 serves as a force means for providin~ a relatively high magnetic flux density at the outer ends of the electrodes 10. Each electrode 10 is used to print a dot that has a definition defined by its shape, density and distribution of density and the electrodes 10 are normally utilized to serve as a printing matrixO The number of electrodes 10 employed is dependent upon the printing application for which the matrix is to be used.
In the case of a standard computer output line width of one hundred thirtv-six ? 5 x 7 dot matrix characters, ... , . .. ~ . .. - . . ~ .
1~47846 nearly 1000 electrodes are employed. A voltage source 11 supplies record voltage potential pulses to the electrodes 10 in a manner and for a purpose as will be described here-inafter.
The recording member 4 is mounted on an axle 12 that is parallel to the developer roll 3 and is rotatably driven counterclockwise to rotate in the same direction as the developer roll magnet assembly 5. The member 4 is positioned in a spaced relationship with the electrodes 10 to define a narrow recording region 15 therebetween. Form-ing the member 4 are an electrically conductive cylindrical electrode 13 and an endless recording medlum 14 that over-lles the cylindrical surface of the electrode 13. Prefer-ably, the electrode 13 is electrically grounded, and the medlum 14 is formed from an anodized aluminum.
In additlon to the above components, the record-ing system 1 includes a second developer roll 16 that is rotatably disposed on an axle 17 and serves as a toner supply means for the recording member 4. The roll 16 is disposed in a spaced relationship with the recording member 4, similar to that existing between the electrodes 10 and the member 4. The constructions of the roll 16 and the roll 3 are slmilar in that the roll 16 has an electrically conductive outer shell 18 and an lnner magnet assembly 19 with a plurality of permanent magnet sectors 20 disposed on a magnet support core 21. However, the roll 16 differs from the roll 3 in that the outer shell 18 rotates while the magnet assembly 19 is fixed. As the outer shell 18 rotates in a clockwise direction, a uniform layer of toner powder 22 contained in a powder reservoir 23 ad~acent the developer roll 16 is laid down on the shell 18.
The toner 22 is magnetically attractable and elec-tronically conductive. The reservoir 23 includes an ad~ust-able doctor blade 24 for metering the toner 22 in a uniform .
layer onto the outer shell 18 of the developer roll 16. Due to the magnetic fields of the magnet sectors 20, the toner 22 on the shell 18 becomes arranged in the form of toner particle chains 26. Referring now to Fig. 2, the rotation of the outer shell 18 transports the toner chains 26 into a nip 27 defined by the spacing between the recording member 4 and the developer roll 16. As the toner chains 26 move through the nip 27, end portions of certain of the toner 15 chains 26 physically contact the recording medium 14. When -~.
a sufficient voltage potential exists between the outer shell 18 and the cylindrical electrode 13, the portions of the toner chains 26 contacting the medium 14 are deposited therecn in a uniform layer 29. A voltage potential adequate to produce such deposltion is provided by a variably ad~ust-able voltage source 30. Thus, the source 30 may be reg-ulated to increase or decrease the potential difference ~:
between the shell 18 and the electrode 13 to, in turn, respectively increase or decrease the density of toner in the layer 29 deposited on the medium 14. In this way, the density of toner in the layer 29 on the recording medium 14 :
may be precisely ad~usted to provide an optimum amount of toner to the recording electrodes 10 so that the electrodes 10 will provide a print of data having a high quality ~ .
,'.... , - . . ,' . .' ' '- :......... ' " '' ' . - ' ' -'' ' ~- i ' ' . ' ' -definition.
It should be appreciated that there are a wide variety of means for distributing the toner 22 in a precise, uniform layer on the recording medium 14 and the use of the roll 16 is only one means for accompllshing this purpose.
The essence of the present invention does not key on the use of such apparatus, but rather resides in part in the application of a precise, uniform toner layer 29 on the medlum 14. Another means for achieving such results would be the use of a magnetically ad~ustable magnetized sheet material under the recording medium 14 to magnetically attract appropriate portions of the toner powder chains 26 to the recording medium 14.
Once deposlted on the recording medium 14, the toner layer 29 is loosely held thereon and is transported on the medium 14 to the recording region 15. Thereupon, the toner layer 29 comes under the influence of the magnetic field from the developer roll 3 that exists at the outer ends of the electrodes 10 and is drawn thereby from the surface of the medium 14 into the recording region 15 to form toner chains 31. As best illustrated in Fig. 2, the toner chains 31 bridge between the electrodes 10 and the recording medium 14.
The voltage source 11 serves to provide voltage record pulses to the electrodes 10 to produce a potential difrerence between the electrodes 10 and the grounded electrode 13. Such potential difference results in toner deposition on the recording medium 14 as previously discussed with reference to the developer roll 16. However, the electrodes 10 are selectively pulsed by the source 11 to form toner images on the medium 14 rather than a uniform layer of toner powder as provided by the roll 16. The portion of the toner 22 that is deposited on the medium 14 in the form of toner images initially has a relatively high charge and is held on the medium 14 by the potential dif-ference between the charged toner 22 and the grounded elec-trode 13. However, the charge on the deposited toner 22 rapidly dissipates so that when the deposited toner 22 approaches the nip 27, it is attracted from the medium 14 by the magnets of the developer roll 16.
All of the toner 22 that ls delivered to the recordlng region 15 may not be redeposited upon the medium 14 in the form of recorded toner images. Instead a portion of the toner 22 may be held on the outer shell 6 of the developer roll 3 and transported in a clockwise direction around the periphery of the shell 6 by the rotation of the magnet assembly 5. The nonrecorded toner 22 remains on the developer roll 3 until it reaches the chute 32. One end of the chute 32 is in contact with the periphery of the developer roll 3 to remove the particles of toner powder 22 coming from the recording region 15 and gravity feed them onto the periphery of the second developer roll 16. The nonrecorded toner 22 is thereupon transported by the roll 16 back to the toner reservoir 23. Accordingly, the chute 32 and the developer roll 16 serve as a toner transport means for carrying the nonrecorded toner 22 from the developer roll 3 to the reservoir 23.
1~47846 Thus, the present invention provides a toner applicator that furnishes a precisely optimum amount of toner to the recording region 15 in a manner that is not dependent for its preciseness upon the use of metering orifices or gaps that are susceptible to being plugged wlth toner powder. The employment of the developer roll 16 as a toner supply means provides a precise amount of toner 22 to the recording medium 14 in order that an optimum amount of toner is transported to the recording region 15 for producing dense, well defined images, and the roll 16 also serves as a means for later erasing the toner images.
In a preferred embodiment, the toner supply means is formed of a developer roll having an inner magnet assembly and an outer rotating shell. A toner reservolr containing magnetically attractable toner powder is positioned alongside the developer roll, and toner powder is magnetically attracted therefrom onto the surface of the developer roll outer shell in a unlform layer. The toner on the developer roll is transported to and deposited 15 on a portion of the recording medium in a layer of precise ~ ~-thickness through magnetic or electrographic means. Such portion of the recording medium is subsequently guided through the recording region wherein a force means formed of another developer roll attracts the toner powder from the recording medium and arranges the toner to bridge be-tween one of the opposed electrodes and the recording medlum.
The toner supply means is ad~ustable to vary the density of the toner layer deposited on the recording medium so that a precisely optimum amount of toner powder for producing high quality toner images is furnished to the recording region. However, the precise amount of toner deposlted on the recording medium is independent of ,, ~ ~ . .
16;~47846 :
metering gaps or orifices. Thus, the present invention ~ -provides a reliable and accurate means for transporting an optimum amount o~ toner powder to a recording electrode of an electrographic recording system in order that high quality, high resolution toner images may be formed.
A preferred embodiment of the invention is described below in connection with the accompanying drawings, wherein:
Fig. 1 is a diagrammatic end view of an elec-trographic recordlng system incorporating the tonerapplicator of the present invention; and Fig. 2 is an enlarged fragmentary view of portions of the recording system of Fig. 1.
Referring now to the drawings and with specific reference ~irst to Fig. 1, a recording system 1 employ-ing a preferred embodiment of the toner applicator of the present invention is shown. The recording system 1 includes a cyllndrical developer roll 3 and a rotatable recording member 4O
The developer roll 3 preferably has an inner magnet assembly 5 and an outer cylindrical shell 6 that is electrically nonconductive and nonmagnetic. The magnet as~embly 5 includes a cylindrical, magnet support core 7 :
, . . .
1~47846 and a plurality of permanent magnet sectors 8 arranged about the cylindrical periphery of the core 7 to define a surface having alternate North and South magnetic poles.
The developer roll 3 is mounted on an axle 9 and is con-structed such that the magnet assembly 5 rotates in acounterclockwise direction, whereas the outer shell 6 is spaced from the magnet assembly 5 and is preferably fixed in position.
Arranged on a line that extends parallel with the support core 7 are a plurality of individual, spaced apart recording electrodes 10 (only one of which is shown) that protrude from the periphery of the shell 6, but may also be disposed in the shell 6 so that the outer ends of the electrodes 10 are flush with the periphery of the shell 6.
Each electrode 10 is magnetically permeable and passes a large amount of magnetic flux emanating from the magnet sectors 8 of the developer roll 3 so that the developer roll 3 serves as a force means for providin~ a relatively high magnetic flux density at the outer ends of the electrodes 10. Each electrode 10 is used to print a dot that has a definition defined by its shape, density and distribution of density and the electrodes 10 are normally utilized to serve as a printing matrixO The number of electrodes 10 employed is dependent upon the printing application for which the matrix is to be used.
In the case of a standard computer output line width of one hundred thirtv-six ? 5 x 7 dot matrix characters, ... , . .. ~ . .. - . . ~ .
1~47846 nearly 1000 electrodes are employed. A voltage source 11 supplies record voltage potential pulses to the electrodes 10 in a manner and for a purpose as will be described here-inafter.
The recording member 4 is mounted on an axle 12 that is parallel to the developer roll 3 and is rotatably driven counterclockwise to rotate in the same direction as the developer roll magnet assembly 5. The member 4 is positioned in a spaced relationship with the electrodes 10 to define a narrow recording region 15 therebetween. Form-ing the member 4 are an electrically conductive cylindrical electrode 13 and an endless recording medlum 14 that over-lles the cylindrical surface of the electrode 13. Prefer-ably, the electrode 13 is electrically grounded, and the medlum 14 is formed from an anodized aluminum.
In additlon to the above components, the record-ing system 1 includes a second developer roll 16 that is rotatably disposed on an axle 17 and serves as a toner supply means for the recording member 4. The roll 16 is disposed in a spaced relationship with the recording member 4, similar to that existing between the electrodes 10 and the member 4. The constructions of the roll 16 and the roll 3 are slmilar in that the roll 16 has an electrically conductive outer shell 18 and an lnner magnet assembly 19 with a plurality of permanent magnet sectors 20 disposed on a magnet support core 21. However, the roll 16 differs from the roll 3 in that the outer shell 18 rotates while the magnet assembly 19 is fixed. As the outer shell 18 rotates in a clockwise direction, a uniform layer of toner powder 22 contained in a powder reservoir 23 ad~acent the developer roll 16 is laid down on the shell 18.
The toner 22 is magnetically attractable and elec-tronically conductive. The reservoir 23 includes an ad~ust-able doctor blade 24 for metering the toner 22 in a uniform .
layer onto the outer shell 18 of the developer roll 16. Due to the magnetic fields of the magnet sectors 20, the toner 22 on the shell 18 becomes arranged in the form of toner particle chains 26. Referring now to Fig. 2, the rotation of the outer shell 18 transports the toner chains 26 into a nip 27 defined by the spacing between the recording member 4 and the developer roll 16. As the toner chains 26 move through the nip 27, end portions of certain of the toner 15 chains 26 physically contact the recording medium 14. When -~.
a sufficient voltage potential exists between the outer shell 18 and the cylindrical electrode 13, the portions of the toner chains 26 contacting the medium 14 are deposited therecn in a uniform layer 29. A voltage potential adequate to produce such deposltion is provided by a variably ad~ust-able voltage source 30. Thus, the source 30 may be reg-ulated to increase or decrease the potential difference ~:
between the shell 18 and the electrode 13 to, in turn, respectively increase or decrease the density of toner in the layer 29 deposited on the medium 14. In this way, the density of toner in the layer 29 on the recording medium 14 :
may be precisely ad~usted to provide an optimum amount of toner to the recording electrodes 10 so that the electrodes 10 will provide a print of data having a high quality ~ .
,'.... , - . . ,' . .' ' '- :......... ' " '' ' . - ' ' -'' ' ~- i ' ' . ' ' -definition.
It should be appreciated that there are a wide variety of means for distributing the toner 22 in a precise, uniform layer on the recording medium 14 and the use of the roll 16 is only one means for accompllshing this purpose.
The essence of the present invention does not key on the use of such apparatus, but rather resides in part in the application of a precise, uniform toner layer 29 on the medlum 14. Another means for achieving such results would be the use of a magnetically ad~ustable magnetized sheet material under the recording medium 14 to magnetically attract appropriate portions of the toner powder chains 26 to the recording medium 14.
Once deposlted on the recording medium 14, the toner layer 29 is loosely held thereon and is transported on the medium 14 to the recording region 15. Thereupon, the toner layer 29 comes under the influence of the magnetic field from the developer roll 3 that exists at the outer ends of the electrodes 10 and is drawn thereby from the surface of the medium 14 into the recording region 15 to form toner chains 31. As best illustrated in Fig. 2, the toner chains 31 bridge between the electrodes 10 and the recording medium 14.
The voltage source 11 serves to provide voltage record pulses to the electrodes 10 to produce a potential difrerence between the electrodes 10 and the grounded electrode 13. Such potential difference results in toner deposition on the recording medium 14 as previously discussed with reference to the developer roll 16. However, the electrodes 10 are selectively pulsed by the source 11 to form toner images on the medium 14 rather than a uniform layer of toner powder as provided by the roll 16. The portion of the toner 22 that is deposited on the medium 14 in the form of toner images initially has a relatively high charge and is held on the medium 14 by the potential dif-ference between the charged toner 22 and the grounded elec-trode 13. However, the charge on the deposited toner 22 rapidly dissipates so that when the deposited toner 22 approaches the nip 27, it is attracted from the medium 14 by the magnets of the developer roll 16.
All of the toner 22 that ls delivered to the recordlng region 15 may not be redeposited upon the medium 14 in the form of recorded toner images. Instead a portion of the toner 22 may be held on the outer shell 6 of the developer roll 3 and transported in a clockwise direction around the periphery of the shell 6 by the rotation of the magnet assembly 5. The nonrecorded toner 22 remains on the developer roll 3 until it reaches the chute 32. One end of the chute 32 is in contact with the periphery of the developer roll 3 to remove the particles of toner powder 22 coming from the recording region 15 and gravity feed them onto the periphery of the second developer roll 16. The nonrecorded toner 22 is thereupon transported by the roll 16 back to the toner reservoir 23. Accordingly, the chute 32 and the developer roll 16 serve as a toner transport means for carrying the nonrecorded toner 22 from the developer roll 3 to the reservoir 23.
1~47846 Thus, the present invention provides a toner applicator that furnishes a precisely optimum amount of toner to the recording region 15 in a manner that is not dependent for its preciseness upon the use of metering orifices or gaps that are susceptible to being plugged wlth toner powder. The employment of the developer roll 16 as a toner supply means provides a precise amount of toner 22 to the recording medium 14 in order that an optimum amount of toner is transported to the recording region 15 for producing dense, well defined images, and the roll 16 also serves as a means for later erasing the toner images.
Claims (11)
1. An electrographic recording system that records toner images on a recording medium and includes first and second opposed electrodes spaced apart to define a recording region therebetween, means for driving the recording medium through said recording region, and a toner applicator for transporting electrically conductive toner powder from a toner reservoir to said recording region into a condition for being selectively deposited on said recording medium in response to the selective application of voltage record pulses across said elec-trodes, which toner applicator is characterized by the features of:
A toner supply means for depositing a precise amount of said toner powder on a portion of one surface of said recording medium in a uniform layer of adjustable density, which toner powder is deposited prior to said portion entering said recording region; and a force means for attracting said toner powder from said portion of said recording medium as said portion enters the recording region, and for arranging said toner to bridge between said first of said electrodes and said recording medium.
A toner supply means for depositing a precise amount of said toner powder on a portion of one surface of said recording medium in a uniform layer of adjustable density, which toner powder is deposited prior to said portion entering said recording region; and a force means for attracting said toner powder from said portion of said recording medium as said portion enters the recording region, and for arranging said toner to bridge between said first of said electrodes and said recording medium.
2. A recording system as recited in claim 1 wherein the second of said electrodes is in the form of a cylinder and the recording medium overlies the cylindrical surface of said cylinder.
3. A recording system as recited in claim 1 wherein said first electrode is located at the periphery of the force means.
4. A recording system as recited in claim 1 wherein said toner powder is magnetically attractable and is magnetically attracted from said portion of said recording medium by said force means as said toner enters the recording region.
5. A recording system as recited in claim 4 wherein said force means comprises a first cylindrical magnetic developer roll that draws the portion of the toner powder that is not selectively deposited on said medium out of the recording region and onto the outer shell of said developer roll.
6. A recording system as recited in claim 5 wherein a toner transport means is associated with said first developer roll for returning the undeposited portion of the toner to the toner supply means.
7. A recording system as recited in claim 6 wherein a portion of said toner powder bridging between said first electrode and said recording medium is re-deposited on said recording medium in the form of toner images and said redeposited toner is later erased from said medium by said toner supply means.
8. A recording system as recited in claim 4 wherein said toner supply means comprises a second cylindrical magnetic developer roll that draws toner powder from said reservoir onto the outer shell of said second roll, which toner powder is transported thereon and deposited on said recording medium to provide said uniform layer.
9. A process for supplying toner powder to the recording region of an electrographic recording system that includes a first and second electrode means in a spaced opposed relationship to provide a recording region therebetween and a recording medium that is guided through said recording region with a surface of said recording medium spaced from said first electrode, which process is characterized by the following steps:
(1) depositing a uniform layer of toner powder on a portion of said surface of said recording medium prior to movement of the recording medium through said re-cording region;
(2) attracting the toner powder from said portion of said recording medium when said portion enters said recording region;
and (3) arranging the toner powder from said portion of said medium to bridge between said first electrode and the recording medium.
(1) depositing a uniform layer of toner powder on a portion of said surface of said recording medium prior to movement of the recording medium through said re-cording region;
(2) attracting the toner powder from said portion of said recording medium when said portion enters said recording region;
and (3) arranging the toner powder from said portion of said medium to bridge between said first electrode and the recording medium.
10. A process as recited in claim 9 wherein said toner powder is magnetically attractable.
11. A process as recited in claim 9 wherein a further step includes selectively applying voltage record pulses to at least one of said electrode means causing a portion of said toner bridging between said one of said electrode means and said recording medium to be redeposited on said recording medium.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/473,328 US3946402A (en) | 1974-05-28 | 1974-05-28 | Toner applicator for electrographic recording system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047846A true CA1047846A (en) | 1979-02-06 |
Family
ID=23879102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA222,196A Expired CA1047846A (en) | 1974-05-28 | 1975-03-17 | Toner applicator for electrographic recording system |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US3946402A (en) |
| JP (1) | JPS6030940B2 (en) |
| AU (1) | AU497033B2 (en) |
| CA (1) | CA1047846A (en) |
| DE (1) | DE2523811C2 (en) |
| FR (1) | FR2273310B1 (en) |
| GB (1) | GB1494798A (en) |
| IT (1) | IT1035857B (en) |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4214160A (en) * | 1976-03-04 | 1980-07-22 | Finnigan Corporation | Mass spectrometer system and method for control of ion energy for different masses |
| GB1573106A (en) * | 1976-03-19 | 1980-08-13 | Dynic Corp | Method and apparatus for manufacturing fusible interlinings |
| US4087826A (en) * | 1976-08-02 | 1978-05-02 | Epp Corp. | Pulsed electrical printer with dielectrically isolated electrode |
| US4446471A (en) * | 1978-12-20 | 1984-05-01 | Ricoh Company, Ltd. | Electrostatic recording method and apparatus therefor |
| US4402000A (en) * | 1979-03-22 | 1983-08-30 | Minnesota Mining And Manufacturing Company | Electrographic recording method and apparatus with control of toner quantity at recording region |
| CA1142996A (en) * | 1979-03-22 | 1983-03-15 | George W. Fabel | Electrographic recording method and apparatus |
| JPS5723964A (en) * | 1980-07-18 | 1982-02-08 | Canon Inc | Picture forming device |
| US4439781A (en) * | 1980-07-28 | 1984-03-27 | Ricoh Company, Ltd. | Image recording method and apparatus |
| US4418357A (en) * | 1981-05-28 | 1983-11-29 | Minnesota Mining And Manufacturing Company | Toner transport system for electrographic imaging |
| JPS5878783A (en) * | 1981-11-06 | 1983-05-12 | Fuji Xerox Co Ltd | Recording method of image |
| JPS58205169A (en) * | 1982-05-24 | 1983-11-30 | Canon Inc | Picture forming device |
| JPS58210561A (en) * | 1982-05-31 | 1983-12-07 | Shimadzu Corp | Quadrupole mass analyzer |
| US4464672A (en) * | 1982-06-15 | 1984-08-07 | Minnesota Mining And Manufacturing Company | Electrographic recording apparatus |
| US4454520A (en) * | 1982-06-24 | 1984-06-12 | Honeywell Inc. | Electrographic recorder with enhanced writing speed |
| US4532531A (en) * | 1983-05-16 | 1985-07-30 | Minnesota Mining And Manufacturing Company | Electrographic recording apparatus |
| JPS61264653A (en) * | 1985-05-17 | 1986-11-22 | Shimadzu Corp | Mass analyzing method |
| US4666780A (en) * | 1985-08-08 | 1987-05-19 | Minnesota Mining And Manufacturing Company | Dielectric coating for recording member |
| US4739348A (en) * | 1985-10-01 | 1988-04-19 | Canon Kabushiki Kaisha | Recording head assembly using magnetic toner and image forming apparatus using the same |
| US4646112A (en) * | 1986-03-07 | 1987-02-24 | Minnesota Mining And Manufacturing Company | Electrographic stylus recording apparatus |
| US4733255A (en) * | 1986-05-01 | 1988-03-22 | Minnesota Mining And Manufacturing Company | Dielectric coating for recording member |
| US4788564A (en) * | 1986-07-10 | 1988-11-29 | Canon Kabushiki Kaisha | Board recording apparatus with reduced smudge |
| US5064715A (en) * | 1986-11-12 | 1991-11-12 | Minnesota Mining And Manufacturing Company | Dielectric coating for recording member containing hydrophobic silica |
| EP0267787B1 (en) * | 1986-11-12 | 1995-01-25 | Minnesota Mining And Manufacturing Company | Dielectric coating for recording member |
| NL9200977A (en) * | 1992-06-04 | 1994-01-03 | Oce Nederland Bv | IMAGING DEVICE. |
| NL9201892A (en) * | 1992-10-30 | 1994-05-16 | Oce Nederland Bv | Method for manufacturing an image recording element. |
| NL9301300A (en) * | 1993-07-23 | 1995-02-16 | Oce Nederland Bv | Imaging device, as well as an image recording element for use therein. |
| NL9302135A (en) * | 1993-12-08 | 1995-07-03 | Oce Nederland Bv | Imaging device, as well as an image recording element for use therein. |
| NL9402196A (en) | 1994-12-23 | 1996-08-01 | Oce Nederland Bv | Method for recording images, as well as an imaging device for applying the method. |
| DE102004046078A1 (en) * | 2004-09-23 | 2006-04-13 | Volkswagen Ag | Gas cooker especially for camping has actuating element to selectively open and close shut-off valve which can only be opened when securing device for gas container is in securing position |
| KR20080070342A (en) * | 2007-01-26 | 2008-07-30 | 삼성전자주식회사 | Image forming apparatus |
| CN102265225B (en) * | 2008-12-23 | 2014-06-04 | 奥西-技术有限公司 | Method for operating an image-forming device and an image forming device for application of the method |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2932548A (en) * | 1956-09-21 | 1960-04-12 | Addressograph Multigraph | Apparatus for reproduction of images |
| FR1259438A (en) * | 1959-05-07 | 1961-04-28 | Rank Xerox Ltd | A method of producing a powder image on an insulating transfer surface |
| US3257222A (en) * | 1962-07-02 | 1966-06-21 | Xerox Corp | Electrostatic recording method and apparatus using shaped electrodes |
| US3355743A (en) * | 1963-11-29 | 1967-11-28 | Minnesota Mining & Mfg | Electrographic recording apparatus having a porous carrier web for electroscopic print powder |
| DE1546758B2 (en) * | 1965-11-23 | 1971-12-02 | Philips Patentverwaltung Gmbh, 2000 Hamburg | METHOD AND DEVICE FOR ELECTROGRAPHIC PRINTING PHILIPS PAT |
| US3358594A (en) * | 1966-01-17 | 1967-12-19 | American Can Co | Electrostatic printing with a magnetic brush feed |
| US3455276A (en) * | 1967-05-23 | 1969-07-15 | Minnesota Mining & Mfg | Magnetically responsive powder applicator |
| US3683406A (en) * | 1969-12-30 | 1972-08-08 | Xerox Corp | Magnetic incremental cascade developement system |
| GB1362844A (en) * | 1970-07-29 | 1974-08-07 | Varian Associates | Method of making an electrostatic wire stylus recording head and lead wires therefor |
| US3816840A (en) * | 1973-04-20 | 1974-06-11 | Minnesota Mining & Mfg | Electrographic recording process and apparatus using conductive toner subject to a capacitive force |
-
1974
- 1974-05-28 US US05/473,328 patent/US3946402A/en not_active Expired - Lifetime
-
1975
- 1975-03-17 CA CA222,196A patent/CA1047846A/en not_active Expired
- 1975-05-14 GB GB20424/75A patent/GB1494798A/en not_active Expired
- 1975-05-27 JP JP50063402A patent/JPS6030940B2/en not_active Expired
- 1975-05-27 AU AU81546/75A patent/AU497033B2/en not_active Expired
- 1975-05-27 IT IT49807/75A patent/IT1035857B/en active
- 1975-05-27 FR FR7516441A patent/FR2273310B1/fr not_active Expired
- 1975-05-27 DE DE2523811A patent/DE2523811C2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2523811C2 (en) | 1985-12-05 |
| IT1035857B (en) | 1979-10-20 |
| AU8154675A (en) | 1976-12-02 |
| FR2273310B1 (en) | 1980-01-11 |
| JPS513239A (en) | 1976-01-12 |
| DE2523811A1 (en) | 1975-12-18 |
| FR2273310A1 (en) | 1975-12-26 |
| JPS6030940B2 (en) | 1985-07-19 |
| GB1494798A (en) | 1977-12-14 |
| AU497033B2 (en) | 1978-11-23 |
| US3946402A (en) | 1976-03-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1047846A (en) | Toner applicator for electrographic recording system | |
| US3914771A (en) | Electrographic recording process and apparatus employing synchronized recording pulses | |
| CA1051504A (en) | Electrographic recording stylus | |
| WO1995024675A1 (en) | Method for dynamically positioning a control electrode array in a direct electrostatic printing device | |
| JPS58152260A (en) | Method and apparatus for developing electrostatic latent image formed on record carrier | |
| US5327169A (en) | Masked magnetic brush direct writing for high speed and color printing | |
| US3941084A (en) | Automatic toner supplying device | |
| US4218691A (en) | Recording apparatus with improved counter electrode | |
| JPH0647298B2 (en) | Powder image recording method | |
| US4187330A (en) | Electrostatic developing method and apparatus using conductive magnetic toner | |
| CA1168695A (en) | Electrographic recording | |
| US4502061A (en) | Image forming apparatus | |
| US4122455A (en) | Magnetic imaging for photocopying | |
| JPS6024465B2 (en) | Toner density control method and device | |
| US3810193A (en) | Bitting card for data recording | |
| CA1102617A (en) | Printing head and brush configuration for a magnetic printer | |
| US4394671A (en) | Electrographic recording | |
| EP0066431B1 (en) | Toner transport system for electrographic imaging | |
| JPH0310313B2 (en) | ||
| JPH02106766A (en) | Electrostatic recording head, image recorder, developer supplying device, display device, and manufacture of electrostatic recording head | |
| CA1211494A (en) | Electrographic recording apparatus | |
| JPH02153365A (en) | Original plate copying method | |
| US3401393A (en) | Electrographic recorder employing a moving stylus | |
| JPS6125166A (en) | Method and device for elctrostatic recording | |
| JPH04285989A (en) | Method for developing magnetic latent image and magnetic recording device |