US3100426A - Electrophotographic printers - Google Patents

Description

1953 E. K. KAPRELIAN 3, ,4

ELECTROPHOTOGRAPHIC PRINTERS Filed April 26, 1960 4 Sheets-Sheet 1 VOLTAGE SOURCE /48 F/GJO NONE I RED BLUE GREEN WH/TE Aug. 13, 1963 Filed April 2 6. 1960 NONE RED GREENBL JEW/H/TE WHITE LIGHT WH/ E R D E. K. KAPRELIAN ELECTROFHOTOGRAPHIC PRINTERS 4 Sheets-Sheet 2 INVENTOR.

,1963 E. K. KAPRELIAN I 3,100,426

ELECTROPHOTQGRAPHIC PRINTERS 4 Filed April 26, 1960 4 Sheets-Sheet 3 I I l l l l I l I l g I I l I l l l l l I Fie. l6

VOLT 6E IN VEN TOR.

Aug. 13, 1963 E. K. KAPRELIAN ELECTROPHOTOGRAPHIC PRINTERS 4 She ets-Sheet 4 Filed April 26, 1960 VOLTAGE SOURCE Fie.\3

9K INVENT'OR.

, 3,100,426 ELECTROPHOTOG'RAPHIC PRINTERS 1 Edward K. KapreliamRed Bank NJ.

(Rte. 3, Box 14, Joppa, Md.) Filed Apr. 26, 1960,Ser. No. 24,804 8 Claims. (Cl. 95-1.7)

This application is a continuation-in-part of application Ser. No. 669,866, filed July 3, 1957, and now Patent 2,940,847. r i

This invention relates to improved methods and means for electrostatic color photography or color printing.

' In ordinary electrostatic photography orprinting there is formed on an insulating surface an intermediate electrostatic image, corresponding in potentials to the lightvalues of the original object, and this electrostatic image is rendered visible by dusting with a' suitable powder which adheres selectively to the surface in a pattern corresponding to the electrostatic image. A description of this process may be found in US. Patent 2,297,691, issued Oct. 6, 1942, to C. F. Carlson.

It is also possible to practice electrostatic photography 1 byilluminating a layer of normally insulating photoconductive powder which is located in an electrical field. In this case powder lying in anilluminated area becomes charged and is attracted away to a region of opposite polarity. -A'description of this process may be found in U.S..Patent 2,758,939, issued Aug. 14, 1956, to M. L.

Sugarman.

Inthe electrophotographic processes of these and other patents of the prior art the action is essentially that of an ordinary monochromatic or black-and-white system. The basic image is one rendered in monochrome; and it is possible, by utilizing color separation techniques, to produce color prints or photographs by superimposing in proper registry separation images employing properly chosen dyes or pigments.

In contrast with previously known systems the present invention produces the color image directly'in a single step without the use of separation images. In the practice of this invention the color image is produced by the selective migration of charged color particles in an electrical field according to the color ;or wavelength .of the light. r

One of the objects of this-invention is to employ the principles of electrostatic electrophotography in the production of color prints.

Another object is to provide a relatively simple, direct and low cost arrangement for the production of color photographs, prints, posters and signs. t

Still another object is the'provision'of-a method and means for the continuous production of color prints.

These and other objects will become apparent from the specification and drawings in which FIG. 1 shows in cross section one form of photoconductive color particle.

FIG. 2 shows in cross section another orm of photo conductive color particle.

FIG. 3 shows in cross section still another form 0 photoconductive color particle. 1

FIG. 4 shows in cross section still another form of photoconductive color particle.

FIG. 5 shows in cross section one form of a non-photoconductive color particle.

FIG. 6 shows in cross section another form of nonphotoconductive particle.

FIG. 7 shows diagrammatically the arrangement of photoconductive color particles prior toexposure in one method of the invention. I

FIG. 8 shows diagrammatically the arrangement of the color particles of FIG. 7 after exposure.

FIG. 9 shows diagrammatically the arrangement of elements for FIG. 12:

electrophotographic prints.

given color. i

'anthracene, and sulfur. powder may be used, and it is preferred that the particle 'si zes fall in the range of 2 to 30'microns. The dyed layer 'may'consist of any suitable dye in gelatin, wax, vinyl or silicone resin, cellulose ester or similar material in a :7 thickness offrom' 4 to 25 microns. The powdered photo- Patented Aug. 13, 1963 photoconductive color particles prior to exposure in another method of the invention. I

FIG. 10 shows diagrammatically the arrange ent of the color particle of FIG. 9 after exposure.

FIG. 11' shows diagrammatically the arrangement of non-photoconductive color particles prior to exposure in still another method of the invention.

" FIG. 12 shows diagrammatically the arrangementof'the color particles of FIG. 11 after exposure.

FIG. 13 shows diagrammatically the relationship of printing from the 'color image resulting in FIG. 14 shows diagrammatically the final arrangement of the color particles in FIG. 13 after exposure.

FIG. 15 shows diagrammatically, one device for producing electrophotographic prints, sectioned along line 15-15 of FIG. 16.

FIG. 16 is a viewer the device of FIG. 15 taken along line 16 16 of FIG. 15; a

FIG." 17 shows another device for the production of FIG. 18 shows in front elevational view another printing device for producing electrophotographic prints one continuous basis. FIG. 19 shows in side elevation the device of FIG. 18.

the method of photography described herein. In the use of any of these particles the essential action is that in a layer of mixed color particles, those particles of a given color will migrate or, if desirable, react oppositely by remaining unmoved when subjected to light of the The color particle 10 of FIGS. 1 and 2 comprises one or more bits 12 of asuitable photoconductor surrounded by a layer or coating 14 of dyed gelatin or similarmaterial. Typical photoconductive materials include selenium, zinc oxide, cadmium sulfide, cad-mium telluride, Actually any photoconductive conductor may bernixed with the dyed layer material together with a splvent and then dried while being agitated,

as by a'warmairblast. Spraying of the photoconductorsolvent-dye-layer mixture into aheated chamber will also 7 yield 'suitable'particles. ""Inforde'r'to increase the photo. graphi'cspe'ed of these particles it may be necessary'to add to the dyel'ayer a small amount of a suitable salt to reduce .the electricalresistance of the layer and thereby permit more rapid charging of the particle.

FIG. 3 shows a particle 16 comprising'a central core .18 which may consist of a clear, transparent glass or plastic bead carrying a transparent photoconductive layer 20 :and an outer, dyed, transparent layer 22. The multiple layers may be formed in the manner described in connection with particle 10, or the photoconductor layer may be evaporated onto the glass bead. Ahead diameter of 3 to 30 microns, a photoconductive layer of 5 to 60 microns thickness and a dyed layer of 4 to 25 microns thickness will yield satisfactory particles in the 21 to 250 micron diameter range.

FIG. 4 shows aparticle 24 comprising an inner capsule 26 containing a liquid dye 28, a photoconductor layer 20 and a dye layer or coating 22. The dye filled capsule 26 preferably in the diameter range of 3 to 20 microns, may be produced in the manner described in US. Patents 2,730,456, 2,730,457 and 2,714,074 issued to B. Green.

.The photoconductor layer may be added by evaporation the image.

. migrated or non-migrated and the [ye layer applied as described in connection with Pros. 1 and 2.

FIG. 5 shows a. particle 30 comprising a colored glass or plastic bead 32 covered with a thin layer 34 of aconducting material. In the case of glass beadsalayer of fused transparent tin' oxide is suitable. In the case of plastic heads a thin transparentlayer of evaporated metal is preferred, although treatment with socalled anti-static solutions is also suitable. Asshofwn inFIG. 6, it is also possible to produce beads'36 which comprise a solid, substantially spherical body 38 of tin oxide or other transparent electrically conducting materials which are suitably colored in the mass, 7 As in the case of other parti-' cles a diameter of between 3 and 40* microns is preferred for particles of this class, although for some applications,largerparticles are suitable; v I

In the practice of color electroph'otography as set forth inthe present invention the following series of steps or their equivalent must be performed in the approximate order shown: p I (1) Establishment of an electrostatic field. (2) Production of a light image. p (3) Charging or discharging of colored particles, which are in the electrostatic field and on which the light image is received, in accordance with the color and pattern of (4) Migration ofeit-her the charged orthe discharged plate 40 carries a transparent electrically conducting layer 42 of thin evaporated metal. NESA glass, made by the Pittsburgh Plate Glass Co., which carries a transparent conducting layer of tin oxide or the like may also be used.

I particles" of step 3, corresponding to the image, to'a new v An upper electrode plate 44 spaced from plate 40 by any suitable distance from 1 or'2 millimeters to several centimeters, carries at its lower surface a particle receiving layer 46 to be described below. A suitable source 48 of DC. voltage, connected to layer 42 andelectrode, 44 is provided with suitable switching means 50. A negative potential of from 300 volts to 5000 volts is applied to electrode 44 depending upon its spacing from plate 40 and the characteristics of the particlesemployed.

In this arrangement primary color particle's 10 and 16 of the type shownin FIGS. 1, 2 and 3, colored red,

green and blue, are employed; A substantially uniform layer of these particles is placed on conducting glass 42.

For purposes, of illustration a single layer is shownin FIG. 7; the layer may be 3 or more particles deep and areas of .the original subject.

4 ticles may be immobilized bymeans adhesive overlay. W

If desired, surface 46 may, constitute an adhesive layer supported on a suitable base sheet in which case it becomes the image support. The image which remains on surface 42 is a negative'image, also of the additive type and may be also transferred to a black base. This I of a transparent may be the desired image if color reversal is a requirement of the process.

As shown in the arrangement of FIGS. 9 and 10 this method can also be adapted to subtractive color photography. Here the arrangement of electrodes is similar to that ofFIGS. 7 and 8 and the pants have been numbered correspondingly. In this modification, transparent primary colored particles 52 of the type'shown in FIG.

4 are employed, containing cyan, magentaand'yellow dye at centers 28 and colored red, green and blue respectively at layers 32. Initially particles 52 are randomly distributed on surface 42 in a layer 3 to 4 particles deep,

although in FIG. 9 they are shown in a single layer with regular distribution for the purpose of explanation. when subjected to a light image some of the particles Wlll be moved upwardly depending upon the color 'of light.

Where red strikes a red jacketed particle 24 containing cyan dye resting on surface. 42 the resistance of the photoconductive layer is reduced, the particle becomes charged and migrates to surface 46. The. photoconductive layer of a blue jacketed yellow containing particle struck by red light will remain unchanged in electrical resistance and will not acquire a charge from surface 42 and will not migrate. Neither will a green jacketed magenta con taining particle mignate when struck by redlight. Blue light will cause blue jacketed yellow containing particles to migrate while leaving the red and green jacketed particles unmoved,and green light will cause green acketed magenta containing particles to migrate while leaving the cyan and yellow jacketed particles unmoved. Exposure 7 to white light causes panticles of'all' three jacket colors to migrateto surface 46. Following exposure the red acketed cyan containing panticl'es, blue jacketed yellow ccntaining particles and green jacketed magenta containing particles willdelineate on surface 46 red, blue and green These particles are transferred, preferably by electrostatic means, to a transparent base or to a whiteie'flective base coated with a suitable transparent absorbent layer, such as gelatin. A similar sheet is laid over the. particle carrying surface, absorbing surface'in contact with the particles, and the resulting sandwich subjected topressure as, for example, by passing between a pair of rollers. The pressure causes the particles to burst, and the dye previously contained within them is absorbed by the absorlbent surf-ace of the base material. The two base layersare stripped apart and the particles of debris removed by means of brushing or washing. The resulting image will be a color'reversal'of the original.

can'b e applied by simply cascadingonto surface 42, or

by spraying, or by applying with a roller.

i-After exposure to light of various colors the particles 'inigrate to the position shown in FIG. 8. Where red, green and blue light reach surface 42, the red, green and blue particles, respectively, migrate to surface Where S White light reaches surface 42 particles of all three colors migrate, while at the non-illuminated; areas there is no migrationof particles. The imagewhich results on surface 46 is a positive image of the additive type, which for proper viewing as' a print must be transferred to a black base, for example a sheet of black surfaced paper or plastic material. The image maybe transferred to such a base by the usual'electrostatic means or through actionof a suitable adhesive layer. Fixing of the image may be accomplished by heating the surface to cause -fusion and bonding of the-particle surface or the par- If the transfer is made from surface 42 after exposure the resulting color. image will be a positive color photograph. 7

FIGS. 11 to 14 illustrate still another way in which the invention may be employed to produce subtractive color images. Here the particles 34 are non photoconductive and possess the characteristics described. in connection with FIGS. Sand '6. A layer of particles 34, 3 m4 deep,

is deposited on a photoconductive layerfitl of selenium-or -other suitable material supported on an electrically conducting base 62 of brass, aluminum or the like which'is connected to one-terminal of a voltage source such as described in connection with FIG. 7. Spaced from and 7 parallel to the surface 60 is a sheet of glass 64 carrying at its under side a layer 66 of transparent electrically conducting material which is connected to the second terminal of the high voltage source. The layer of particles is exposed by light passing downwardly through sheet 64- and conductive layer 66 onto particles 34. For

a given color or spectral band'of exposing light one or more of head colors, which are cyan, magenta or yellow, will transmit the light to the selenium layer below. The selenium layer thereupon becomes conducting, the transmitting bead becomesv charged and migrates upwardly to layer 66.

As shown in FIG. 12, red, green and blue light exposure results in migration of magenta and yellow, cyan and yellow, and cyan and magenta particles, respectively, to :form subtractive color layers. In order to assure that the particles apply themselves in substantially layer form it is preferred that the sizes and conductivities of theparticles be controlled. By making the cyan particles somewhat smaller and utilizing a relatively lower conductivity surface 38 over the core, these particles will migrate first to form a cyanlayer. By increasing the size of the magenta particles and increasing the electrical resistivity of their surface the magenta particles will migrate next to form the second layer. Preferably the yellow particles are the largest'and-possess the highest resistivity, thereby being deposited last. While the diagrammatic representation in the drawing has been that of a single layer for thesake of simplicity, it should be borne in mind that multiple layers of the type described represent the actual structure. Where white light reaches the particle layer all particles migrate to surface 66. Where no light strikes the particle layer no particles migrate. 1

The intermediate image appearing on surface 66 is next used for printing asshown in FIGS. 13 and 14. The image on surface '66 is projected onto a selenium plate 7072, similar to plate 60-62, through a'transparent conducting plate 7476 similar to plate 6466 onto color particles 34. During exposure these particles migrate to, surface 76 to form a subtractive color imagecorresponding to the original subject of FIG. 11.

FIGS. 15 and 16 show one means for employing color particles for the production of color photographs. A transparent plate 64 carrying a transparent conductive layer 66, such as shown in FIGS. 7 to is spaced away from and parallel to a grid 80.- Layer'66 and grid 80 are maintained at a suitable potential difference by a connection to a source 48of high voltage through a reversing switch-50. Spaced away frorn the opposite surface of grid 80 and parallel thereto is a particle distribution head indicated generally at 82, consisting of spaced apart plates 84 which form a series of alternate duct areas 86 and 88. Duct areas 86 are connected to a supply chamber 90 while ducts -88 are'cori'nected to a pair of return chambers 92. An airblast shown by arrow 94 carries mixed color particles, such as those showninFIGS. 1,2 and 3, into duct areas 86, through screen 80" and against layer 66 in a direction generally perpendicular to the latter. The appropriately colored particles are charged by their passage through the grid and adhere to layer 66, forming the color image in the manner described. Particles which remain inactive," because of their non-response to light of a wavelength to which their resistance remains unchanged, are drawn into duct areas 88, through chamber 92, and returned as indicated by arrow 96 to a receiving chamber, not shown. The color particles on layer 66 are transferred to a black paper or plastic base and are there fixed by heat or other well known means. 1

FIG. 17 shows diagrammatically a continuous color print machine employing color particles.

. trode 114; the image at 116 moves synchronously with belt 100 and web 106.

An endless, belt 100 of electrically conducting flexible material car- Layer 102 receives a charge of color particles such as that shown in FIGJS from a hopper-like distributor 118 which cascades the particles onto the belt, the angle of repose of the latter being such that only a suflicient depth of particles is retained, the remainder being carried away for reuse through'duct 120. Layer 102 is cleaned of unused particles by means of a rotary brush 122, and the unused particles are retained in chamber 124 for reclassification and reuse. Reclassification of the particles into threeportions, each containing a single color is accomplished in a fashion analogousto the color process itself, i.e. by successive exposure of the particles, while on a photoconductive surface, to light of a given color.

The continuous printer shown in FIGS. 18 and 19 employs a rotary transparent drum of glass or suitable plastic and carrying on its outer surface a transparent conductive coating 13-2. The drum is supported through a plate 134 and bearing members 136 and 138 by a solid shaft 140. The outer end of shaft 140 is rigidly attached to a base member 142 which supports the entire printer.

Drum 130 is rotated by means of pulley 144, belt 146 and pulley 148 driven by motor 150. The inner end of shaft 1'40 fixedly supports an exposure station base plate 152 on which is mounted a light housing 154 provided with a light source 156 and condensers 158. A film gate 160, preferably curved, and a projection lens 162 lie on a common axis with the light source and condensers. The transparency to be printed is shown in the form of a web 164 fed from a supply reel 166 to a takeup reel 168, the rate of feed being controlled by a sprocket 170. Sprocket 1170 is driven synchronously with drum 130 by bearing member 138 through gears 172 and 174 sorthat the moving image of the web 164 is stationary with respect to the outer surface 132 of the. drum. A tray 176,. preferablyof electrically nonconduct-ive material, contains a mixture 178 of color developer particles of the type shown in FIG. 4 suspended in a liquid dielectric such as light mineral oil or carbon tetrachloride. One terminal of high voltage source 48 connects through switch 50 to conductive coating :132 and the second terminal connects to 'a fine mesh electrode 180' submerged in mixture 178 and spaced uniformly from layer 132. The spacing can be in the range of from 0.1 mm..to*10 mm. depending upon particle size and concentration as well as the potential being employed. 'An air squeegee 182 directs air against the surface of the drum to .rernove unwanted particles and to wholly or partially dry the drum surface.

. A web or transparent plastic base material 184 is held in contact with the drum by means of roller 186 and passes under 'a suitable fixing station 188 before being taken up on reel 190. A brush 192 removes'fromthe drum surface the debris of ruptured developer particles prior to exposure. Ultrasonic generator 194 in the sump of the developer tray 176 below electrode 180 causes the impingement of developer particles against the drum in a direction substantially normal to the drum surface.

In operation, the original on film 164 is imaged through the drum and onto the layer of particles between surface 132 and the grid 180, the image moving at the same speed as the periphery of the drum. Particles of the correct color are energized in accordance with the showing in FIGS. 9 and 10 and adhere to coating 132. Accidentally entrained particles are removed by the air jet 182, the developer particles are ruptured by roller 186, and the color image is transferred to base 184 and fixed by heat or similar means, as necessary, at station 188. The cleaning action'of brush 192 insures that surface 132 is free of contaminating particles prior to exposure. From time to time the proper relationship of relative concentration of the color particles in the mixture 178 must be restored by addition of the needed color or colors.

It is apparent that other arrangements of printer devices could be constructed for utilizing the color developer particles and the method described herein 'by those skilled in the art. The printers are not limited to the production printing of signs, labels, posters and reflective traffic signs. 5

I claim: 1. A device for producing color and coextensive with said first electrode, said secondelectrode being provided with perforations over its entire extent and being electrically insulatedfron said'fir-stelecelectrophotographs comprising a first non-photoconductive electrode trans- 1 parent to the colors of the visible spectrum, a second non-v photoconductive electrode parallel to, spaced apart from of color photographs but lend themselves well to the v trode, said two electrodes forming thercbetweena'deyelopment chamber, a developer housing terminating, at the face of said second electrode opposite frornthat adjacent said first electrode, means for projecting through said first electrode and into the space between said firstlele ctrode and said second electrode a coiored'light-i'mage, means for establishing a potential difference between said first and second electrode, motion imparting means within said jdevela oper housing for passing fluid suspended photoconductive developer particles through said second electrode into said thereon .-a pattern corresponding to thel projected image, a

web of black colored image receiving material and means 1 for transferring said pattern'of particles tosaid receiving material. i v a 2. A device for the continuous' production 'ofjcolor electrophotographs comprising a cylindrical non-light sensitive electrode transparent to the colors ofthe visible spectrum, a stationary perforated arcuate' electrode parallelto and spaced from said transparent electrode,

a developing chamber comprising the space betweensaid I electrodes, means withinsaid cylindrical electrode for projecting a moving image in colors throughs'aid trans parent electrode and into said developing chamber, means for rotating said cylinder,- a developer supply chamber containing photoconductive color developer-particles suspended in a liquid dielectric, said supply chamber surrounding said developing chamber and filIin'g said developing chamber with developer particles through the'perfo rations in said arcuate electrode, means for synchronizing the movement of said vprojectedimage and themo'vernent 1 of said transparent electrode to maintain 'said projected 7 image stationary with respect' to saidtnan-sparent'electrode I and means for establishing 'an' electricalpotential between said two eectrodes whereby developer particles illumii-- nated by said moving image are selectively attracted onto said transparent electrodeto form thereon a pattern corresponding to the projected color image;

3. A device'for the continuous production of color electrophotographs as claimed in 'claim 2, said developer development chamber, whereby selectedi developer "-parfia cles migrate onto the surfaceof said first-electrodeto form supply chamber including means for producing an oscil-.

latory motion of developer particles in afidirection sub: A

stantially perpendicular to said electrodes,

. 4. A device for the continuous production of color electrophotographs as claimed in claim 2. including a transfer station for transferring said developer image to an image receiving surface, r

5. A device for the continuous production of color electnophotographs as claimed in claim 4, including airsqueegee means for removing unwanted developer particles from said transparent electrode prior to transferring said d lop i 6. A device for producing color electrophotographs comprising a fixed electrode transparent to the colors oi the visible spectrum, a photoconductive surface movable parallel to and spaced apart from saidelectrode to form 1' therebet-ween a developing chamber, a layer of transparent image-receiving material carried by said electrode and having one surface forming one side of the developing chamber, a voltage source for maintaining an electrical potential between said electrode and said photoconductive surface, meansfor depositing onsaid photoconductive surface a multiple layer of developer particles 5513C: tively responsive to light of different colors and means for projecting a light image in color through said transparent electrode and ir'nagereceiving material and through said developer particles onto said photoconductive survtace', whereby said developer particlesmigrate to said image-receiving material to form thereon a pattern correspending to said light image. 7 device for producing color electrophotographs as clalmed in claim 6, said photoconductive material being the formof an endless belt.

2 8. A device for producing color electrophotographs as claimed in claim '6, said image receiving material, said photoconductive material and said light image moving (synchronously to maintain integrity of the pattern produced by the developer.

References Cited in the file of this patent UNITED STATES PATENTS SsP 15, 1,952

Claims (1)

1. A DEVICE FOR PRODUCING COLOR ELECTROPHOTOGRAPHS COMPRISING A FIRST NON-PHOTOCONDUCTIVE ELECTRODE TRANSPARENT TO THE COLORS OF THE VISIBLE SPECTRUM, A SECOND NONPHOTOCONDUCTIVE ELECTRODE PARALLEL TO, SPACED APART FROM AND COEXTENSIVE WITH SAID FIRST ELECTRODE, SAID SECOND ELECTRODE BEING PROVIDED WITH PERFORATIONS OVER ITS ENTIRE EXTENT AND BEING ELECTRICALLY INSULATED FROM SAID FIRST ELECTRODE, SAID TWO ELECTRODES FORMING THEREBETWEEN A DEVELOPMENT CHAMBER, A DEVELOPER HOUSING TERMINATING AT THE FACE OF SAID SECOND ELECTRODE OPPOSITE FROM THAT ADJACENT SAID FIRST ELECTRODE, MEANS FOR PROJECTING THROUGH SAID FIRST ELECTRODE AND INTO THE SPACE BETWEEN SAID FIRST ELECTRODE AND SAID SECOND ELECTRODE A COLORED LIGHT-IMAGE, MEANS FOR ESTABLISHING A POTENTIAL DIFFERENCE BETWEEN SAID FIRST AND SECOND ELECTRODE, MOTION IMPARTING MEANS WITHIN SAID DEVELOPER HOUSING FOR PASSING FLUID SUSPENDED PHOTOCONDUCTIVE DEVELOPER PARTICLES THROUGH SAID SECOND ELECTRODE INTO SAID DEVELOPMENT CHAMBER, WHEREBY SELECTED DEVELOPER PARTICLES MIGRATE ONTO THE SURFACE OF SAID FIRST ELECTRODE TO FORM THEREON A PATTERN CORRESPONDING TO THE PROJECTED IMAGE, A WEB OF BLACK COLORED IMAGE RECEIVING MATERIAL AND MEANS FOR TRANSFERRING SAID PATTERN OF PARTICLES TO SAID RECEIVING MATERIAL.

Images