US3609028A

US3609028A - Imaging apparatus

Info

Publication number: US3609028A
Application number: US876640A
Authority: US
Inventors: Raymond K Egnaczak; Gino F Squassoni
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1969-11-14
Filing date: 1969-11-14
Publication date: 1971-09-28
Anticipated expiration: 1988-09-28
Also published as: DE2055343A1; PL82852B1; GB1335988A; NL7016546A; CH518580A; BE758806A; AT319749B; CA935012A; ES385452A1; FR2069729A5; SE361753B; SU465806A3

Abstract

A machine for automatically producing images from photoelectrophoretic suspensions using a cylindrical transparent conductive electrode which is inked and contacted by an imaging electrode in the presence of an electric field and electromagnetic radiation in image configuration. The cylinder electrode is cleaned and an image transferred from its surface to a transfer material. The electromagnetic radiation is imaged at the intersection of the transparent cylindrical electrode and the imaging electrode. The projection passes from the end of the transparent cylindrical electrode to an internal mirror for reflection to the intersection.

Description

United States Patent [72] Inventors Raymond K. Egnaczak 3,452,181 6/1969 Stryzewaki 355/3 Willlamson; S I M Gino F.Squassoni Pittsiord both of Mr. [21] A 1 No 876 640 ASSISM'II Examiner-D. J. Clement [22] m" 14 1969 Attorneys-James J. Ralabate, David C, Petre. and Barry a 45 Patented Sept. 28, 1971 Jay Kesselma" [73] Assignee XeroxCorporation Rochester, N.Y.

[54] IMAGING APPARATUS 15 Claims, 6 Drawing Figs.

52 us. Cl 35513, 355/8, 355/27, 355/28, 355/32, 355/47 [5 1] Int. Cl...; .J 603g 15/00 [50] Field of Search 355/3,8, 47, 4, 48, 49, 50, 17; 96/1 [56] References Cited UNITED STATES PATENTS 3,485,738 12/1969 Carreira 204/81 PATENTEU was m SHEET 1 [IF 4 IN VENTORS RAYMOND K.EGNACZAK GINO F. SQUASSONI ATTORNEY PATENTED SEP28l97| 3,609,028

sum

2 or 4 This invention relates to imaging machines and more particularly to machines employing photoelectrophoretic imaging techniques.

Since the new invention of photoelectrophoresis was disclosed for fornring black and white or full color images, various machine embodiments have been envisioned to accommodate this i 8i 8 technique in an automated machine environment. The basic inventions are described in U.S. Pat. Nos. 3,384,488; 3,384,565; 3,384,566, and 3,383,993. They disclose how to produce a visual image at one or both of two electrodes between which photoelectrophoretic particle suspensions are placed. The particles are photosensitive and appear to undergo a net change in charge polarity or a polarity alteration by interaction with one of the electrodes upon expo sure to activating electromagnetic radiation. Mixtures of two or more differently colored particles can secure various colors of images. Theparticles will migrate from one of the electrodes under the influence of an electric field when struck with energy of a wavelength within the spectral response of the colored particles.

A continuous imaging machine was disclosed in U.S. Pat. No. 3,427,242 which depicts apparatus for forming continuous images from photoelectrophoretic suspensions by projection of an original utilizing system requiring the image light rays to pass twice through the surface of a transparent cylindrical electrode. A problem may arise if the transparent cylindrical electrode is not completely cleaned of residual suspension materials when new images are being formed since that would interfere with the optical system. This problem may be severe in the nonirnage area where defects or residual materials can cause imaging degradation and light losses at the imaging zone between the transparent and imaging electrodes.

Therefore, it is an object of this invention to improve apparatus for automatically producing images. Another object of this invention is to employ the photoelectrophoretic technique in an improved automated continuous image-forming machine. Another object of this invention is to improve image-maintaining members for automatically forming and carrying an image for transfer to a transfer material. Yet another object of this invention is to project an object to be imaged internal to a transparent cylindrical member.

These and other objects of this invention are accomplished by use of a transparent cylindrical, image-carrying, electrode member that rotates through a path interfacing with a series of components utilized for automated image formation on a support material. Photosensitive material is supplied between an imaging electrode and the transparent image-carrying cylindrical member in an electric field at an imaging position where light rays are projected from an object. The object light rays are projected from an open end of the transparent cylindrical member to a mirror internal to the cylindrical member for reflecting the light rays to the image plane between the two electrodes. The light rays are projected from the object as a flowing image moving in synchronism with the surface of the transparent member where it interfaces with the imaging electrode. The transparent, image-carrying, cylindrical member interfaces with a transfer mechanism after a transferable image is formed at the imaging position. The member is then cleaned by suitable cleaning apparatus after which it may again coact with the imaging electrode forming further images in the same manner as described above.

The invention herein is described and illustrated in a specific embodiment having specific components listed for carrying out the functions of the apparatus. Nevertheless, the invention need not be thought of as being confined to such a specific showing and should be construed broadly within the scope of the claims. Any and all equivalent structures known to those skilled in the art can be substituted for specific apparatus disclosed as long as the substituted apparatus achieves a similar function. It may be that other processes or apparatus will he invented having similar needs to those fulfilled by the herein to describe an invention for use in apparatus other than the embodiment shown.

These and other objects and advantages will become apparent to those skilled in the art after reading the following description taken in conjunction with the accompanying drawings wherein:

FIG. I schematically illustrates an embodiment of a machine for forming photoelectrophoretic images in accordance with this invention;

FIGS. 2-4 are portions of alternative schematic embodiments for the apparatus of FIG. 1;

FIG. 5 is a side sectional representation of the projection and drive mechanism; and

FIG. 6 is a timing diagram of the machine embodiment of FIG. 1.

A detailed description of the operation and theories relating to the actual imaging system automated by this invention and discussing the interaction of the photoelectrophoretic particles in the suspension used for image formation is found in the above cited patents. The imaging system therein described and which can be employed in the apparatus described herein operates by producing electromagnetic radiation in image configuration to which the individual photoelectrophoretic particles within the suspension are sensitive. The activating radiation and an electric field across the imaging suspension combine between two electrodes in the imaging area. An electrode referred to as the transparent injecting electrode" is maintained electrically positive relative to "imaging electrodes interfacing with it at the imaging area across the photosensitive suspension. Therefore, particles within the 4 suspension that are negatively charged will be attracted to the relatively positive, transparent injecting electrode.

The injecting electrode" is so named because it is thought to inject electrical charges into activated photosensitive particles during imaging. The term photosensitive" for the purposes of this invention refers to the property of a particle which, once attracted to the injecting electrode, will alter its polarity and migrate away from the electrode under the influence of an applied electric field when exposed to activating electromagnetic radiation. The term suspension" may be defined as a system having solid particles dispersed in a solid, liquid or gas. Nevertheless, the suspension used in the embodiment of this invention described herein is of the general type having a solid suspended in a liquid carrier. The tenn imaging electrode" is used to describe that electrode which interfaces with the injecting electrode through the suspension and which once contacted by activated photosensitive particles will not inject sufficient charge into them to cause them to migrate from the imaging electrode surface. The imaging zone or imaging area is that zone between two electrodes where photoelectrophoretic imaging occurs.

The particles within the suspension are generally insulating when not struck by activating .radiation within their spectral response curve. The negative particles come into contact with or are closely adjacent to the injecting electrode and remain in that position under the influence of the applied electric field until they are exposed to activating electromagnetic radiation. The particles near the surface of the injecting electrode make up the potential imaging particles for the final image to be reproduced thereon. When activating radiation strikes the particles, it makes them conductive "creating" an electrical junction of charge carriers which may be considered mobile in nature. The negative charge carriers of the electrical junction orient themselves toward the positive injecting electrode while the positive charge carriers move toward the imaging electrode. The negative charge carriers near the particle-electrode interface at the injecting electrode can move across the short distance between the particle and the surface of the electrode leaving the particle with a net positive charge. These polarity altered, net positively charged particles are now repelled away from the positive surface of the injecting electrode and are attracted to the negative surface of the imaging electrode. Ac-

apparatus described and claimed herein and it is the intention cordingly, the particles struck by activating radiation of a wavelength with which they are sensitive, i.e., a wavelength which will cause the formation of an electrical junction within the particles, move away from the injecting electrode to the imaging electrode leaving behind only particles which are not exposed to sufficient electromagnetic radiation in their responsive range to undergo this change.

Consequently, if all the particles in the system are sensitive to one wavelength of light or another and the system is exposed to an image with that wavelength of light, a positive image will be formed on the surface of the injecting electrode by the subtraction of bound particles from its surface leaving behind particles in the unexposed areas only. The polarities on the system can be reversed and imaging will occur. The system may beoperated with dispersions of particles which initially take on a net positive charge or a net negative charge.

The imaging suspension may contain one, two, three or more different particles of various colors having various ranges of spectral response. In a monochromatic system the particles included in the suspension may be of any color and produce any color and the particle spectral response is relatively immaterial as long as there is a response in some region of the spectrum which can be matched by a convenient radial tion exposure source. In polychromatic systems the particles may be selected so that particles of different colors respond to necessarily listed in the sequence that they occur) take place:

(i) migration of the particles toward the injecting electrode due to the influence of the field, (2) the generation of charge carriers within the particles when struck with activating radiation, (3) particle deposition on or near the injecting electrode surface, (4) phenomena associated with the forming of an electrical junction between the particles and the injecting electrode, (5) particle charge exchange with the injecting electrode, (6) electrophoretic migration toward the imaging electrode, and (7) particle deposition on the imaging electrode. This leaves a positive image on the injecting electrode.

After the image is formed on the injecting electrode, the electrode may be brought into interface with a transfer member which has a charge polarity opposite to that of the imaging electrode. The injecting electrode is now maintained negative relative to the transfer member. The particles having a net negative charge will be attracted to the relatively positive transfer member. If a support material is interposed between the transfer member and the particle image, the particles will be attracted to the support material. Therefore, a photo graphically positive image can be fonned on any support material.

FIG. 1 illustrates schematically a machine embodiment of this invention for automatically forming photoelectrophoretic images. Although the machine is not restricted to the input original which is to be reimaged and copied it is preferred that a transparency input be used.

A timing diagram (FIG. 6) will describe the coordinated actions of the various components used in the illustrations of this invention but for the time being the photoelectrophoretic imaging process may be described in relation to H6. 1 by viewing the various stations positioned around the injecting electrode 1. At the first station, Station A, the surface of the injecting electrode 1 is cleaned of any residual materials or waste products from the previous image formations. A preclean foam roller 2 rotates in contact with the surface 3 of the injecting electrode cylinder. it in turn is cleaned by a protruding bar 5 pinching the foam material of the roller 2. This action squeezes out liquids and solid materials suspended therein to be evacuated from the immediate vicinity of the foam roller and protruding bar via a vacuum duct 7. A baffle arm 9 aids in collecting the materials squeezed out of the foam roller 2 for removal from the system.

A wiper blade 10 contacts the surface 3 of the injecting electrode 1 to trap any liquids left on the surface 3 after in teraction with the foam cleaner roll 2. The vacuum squeegee lected materials through the vacuum duct 12. To ensure full cleaning a cleaning brush 14 contacts and dries the surface 3 of the injecting electrode. Through suitable duct work 16 this mechanism is also attached to a pressure reducing means 18 as are the other vacuum ducts 7 and 12 of the cleaning system. Each of the three subsystems are cyclically removable from the path of rotation of the injecting electrode cylinder 1. Therefore, a solenoid 8 moves the housing in which the cleaning roller 2 is positioned and the solenoid l3 removes the vacuum squeegee 11 while the solenoid 15 moves the cleaner 14. The solenoids are activated during the machine cycle in the manner described in FIG. 6. A vacuum" as used herein refers to a negative pressure below atmospheric pressure but not necessarily a void. Likewise negative pressure" refers to a partially evacuated state of less than atmospheric pressure.

The cleaned injecting electrode surface 3 rotates in synchronism with the projection of the original to be copied at the imaging area at Station B which interfaces with a first imaging electrode 20. The electrode 20 has a surface 21 thereon fonned of a blocking material which apparently functions to prevent sufi'rcient charge injection into the particles of the imaging suspension to cause them to migrate away from its surface even if the particles are struck by electromagnetic radiation of a wavelength to which they are sensitive. imaging suspension is applied to the surface 21 of the imaging electrode 20 via a suspension application means shown here to be an applicator roller 22. The suspension is carried around the surface 21, past a smoothing roller 25 for passing a uniformly thin layer of suspension into contact with the surface 3 of the injecting electrode.

While between the irrraging electrode 20 and the injecting electrode 1, the suspension and particles therein are subjected to electromagnetic radiation in image configuration presented by the image projection system to the area between the two electrodes. This image area encompasses the contact portion between the two electrodes and the suspension as well as surrounding areas where the suspension is in close proximity to the injecting electrode surface 3. In short, it includes any area or portion of an area in which photoelectrophoretic migration is likely to occur. The image light rays are projected to the image area via a projection system including a mirror 24 which is positioned within the injecting electrode cylinder 1. Simultaneously, an electric field is applied between the

electrodes

1 and 20. This field can be between 300 v. and 5,000 v. per mil, for example, but need only be within a range to cause particle migration when the particle is struck by activating radiation. An electrical source 23 supplies the electrical potential. The dotted arrow and film strip 26 are shown to indicate a strip of transparency film moved, during imaging, in the direction shown by the arrow at a velocity related to the velocity of the surface 3 of the injecting electrode such that a flowing image of the data on the film strip 26 is projected to the image area in a synchronized movement with the surface 3 of the injecting electrode moving therethrough.

After the object has been imaged at the image area, the injecting electrode cylinder 1 continues its rotation. Simultaneously, the imaging electrode 20 is removed from the interface position with the surface 3 of the injecting electrode 1. This is accomplished by rotating the eccentric 28 thereby lowering the carriage 30. When the imaging electrode 20 is lowered, a reversible motor 32 moves the tank carriage 33 shuttling the electrode 20 away from the image area and bringing the second imaging electrode 34 near the area where its surface 36 can interface with the injecting electrode 1 by the operation of the eccentric 28.

The function of the imaging electrode 34 is to remove background from the image formed at the image area during 7 interaction with the imaging electrode 20. Therefore, carrier liquid is applied to the surface 36 to carry away particles removed from the injecting electrode surface 3 which are not desirable for forming the final image to be transferred. A carrier applicator means such as the brush 42 applies fresh carrier 11, of which the wiper blade 10 is a part, removes the colto the surface 36 of the imaging electrode 34 prior to that portion of the surface entering the image area. A cleaning mechanism including two squeegee blades 43 and 44 maintained in a bracket 45 removes used carrier and residual particles from the surface 36 so that only cleaned portions of the surface are brought to the image area. During the second pass of the surface 3 of the injecting electrode into the image area for interaction with the imaging electrode 36, the original document is again scanned or moved to present a flowing image at the image area. This second scan presents a precisely aligned projected image with the flowing image previously presented at the image area and used to form the particle image maintained on the surface 3. An electrical field of the same sign as is presented between the electrodes 1 and is supplied between the

electrodes

1 and 34 by an electrical source 35.

During the rotation of the injecting electrode 1 between its interaction with the

imaging electrodes

20 and 34, the transfer mechanism and the previously described cleaning mechanisms are maintained out of contact with the surface 3 and any particle suspension maintained thereon. After the second pass of v p the surface through the imaging area, the transfer mechanism 7 is interfaced with the surface 3 of the moving injecting electrode cylinder 1.

In order to attract the particles from the injecting electrode cylinder 1 at the transfer station, Station C, a potential from the electrical source 51 is applied to the transfer roller 50. The potential is opposite in sign from that applied to the imaging 1

electrodes

20 and 34 and approximately between 300 v. and

5,000 v. Between the transfer roller 50 and the surface 3 of the injecting electrode is an image support material web 53 such as web of paper. The web is fed from a supply spool 54 and over

idler rollers

56 and 58 past a prewetting tank 59 where a liquid 60 similar to the carrier liquid of the suspension is applied through an applicator roll 61 to the surface of the web 53 that is contacted by the surface 3 of the injecting electrode cylinder. A pressure roll 64 is positioned on the side of the web opposite from that being coated at the liquid coating tank roll 61.

The wetted support material web passes over the surface of the transfer roll 50 where the image formed on the surface 3 is transferred to the wetted surface of the web 53. The material is then fed through a fixer 66 via a transport belt 68 where the image is dried. A cutter mechanism 67 cuts the web into sheets. The cut sheets are then fed into a copy catch tray 68a for removal by the machine operator as he desires.

FIG. 2 shows a portion of the machine illustrated in FIG. 1. Only that portion of the machine environment which is modified from that shown in FIG. 1 is reillustrated in FIG. 2. The functioning of the machine is in all matters the same as in FIG. 1 except where specifically pointed to be different. In FIG. 2 the surface 3 of the injecting electrode 1 is inked directly by an extruder inker 70 which is moved into and out of operable interface with the surface 3 by a solenoid 72 connected through suitable linkage 73 to a bracket 74. This action pivots the extruder 70 about a pivot point 76 for the necessary movement. A smoothing rod 78 is attached by a bracket 79 to the extruder and functions to ensure that a smooth layer of imaging suspension is allied to the surface 3 for imaging at the interface with the surface 80 of the electrode 81.

The functioning of the extruder is described in detail in copending application Ser. No. 876,646 filed on Nov. 14, 1969 in the name of Raymond Egnaczak.

The injecting electrode cylinder 1 passes with the imaging suspension thereon to the interface with the electrode 81. An eccentric 28 raises the electrode carriage 82 for interface activities between the surface 80 and the surface 3 of the interacting electrodes in order to fon'n an image. Image light rays are projected via mirror 24 to the interface between the two electrodes for image formation.

The electrical field used for causing the migration of particles in image configuration is supplied by a corona discharge device such as the corotrons 84 operatively near the surface the image area. Immediately downstream from the image area of the machine is a corona discharge device corotron 86 used to discharge the surface and any suspension gathered thereon during the imaging cycle. A scrubbing brush 88 removes the particles from the surface 80 with the aid of a cleaning fluid 89 maintained in the sump portion of the tank 82.

Squeegee blades

90 and 91 can be moved into and out of contact via a pivotable bracket 92 to help wipe the surface 80 clean of fluids and particles. A sprayer nozzle 94 is adapted to spray fresh cleaning fluid onto the surface while a removable wiper blade 96 when applied prevents any fluids from passing its edge along the surface 80. During a portion of the two pass machine cycle when the transparent electrode rotates 720 or more, it is preferable to allow carrier fluids dispensed through the sprayer 94 to remain on the surface 80 of the electrode 81 to aid in the removal of particles in image configuration from the surface 3 of the injecting electrode 1. When this sequence of machine operation is desired, the wiper blade 96 can be removed from the surface 80 of the electrode 81 by activating the solenoid 98.

FIG. 3 again illustrates the machine shown in FIG. 1 and is similar to that shown in FIG. 2 except that the electrical field is supplied by a potential source 99 similar to the source 23 of FIG. 1. Also similar to FIG. 1, the inking is done directly on the surface 100 of the imaging electrode here designated as 101. The ink is applied by an extruder 102 and smoothed by a smoothing rod 104 so that a smooth layer of imaging suspension is presented at the interface between the

surfaces

3 and 100 of the interacting electrodes. A solenoid 106 moves the ink suspension supplying and smoothing means into operable position with the surface 100 and only in that position is imaging suspension supplied through the extruder 102. Here, as in FIG. 2, the corotrons 86 are used to discharge the surface 100 of the imaging electrode 101. All other apparatus shown function in the manner described in the previous figures.

In FIGS. 2 and 3 it may be desirable to rotate the injecting electrode cylinder past the imaging electrode a second time without the application of ink. This obtains a function similar to that described in conjunction with electrode 34 of FIG. 1. This can be accomplished by merely disengaging the inking mechanism 70 of FIG. 2 or 102 of FIG. 1 and removing the wiper blade 96 so that fresh carrier material can be brought to the interface from the sprayer 94 via the surface of the imaging electrode.

Another configuration is shown in FIG. 4. Once again the function is that of the machine described in FIG. 1 and common reference numerals refer to common apparatus of the previous figures. The imaging electrode in FIG. 4 is composed of a conductive inner core 110 and a flexible continuous belt 1 12 formed of a blocking material similar to the surface 21 of FIG. 1. This blocking material may be any material functioning in a manner described in US. Pat. No. 3,383,993 referred to above being any suitable material having a resistivity about 10 ohm-cm. or greater. The necessary electrical field is sup plied by an electrical power source 114 connected to the conductive core 110 of the injecting electrode system. Imaging suspension is applied and smoothed by the extruder 102 and smoothing rod 104 in the manner described in FIG. 3.

After the flexible imaging electrode surface 112 passes the interface of the injecting electrode surface 3, it is transported past corona discharge devices such as the corotrons 116 where residual charge on the surface 112 or the suspension adhering thereto are neutralized. The belt continues to move into the tank 118 around a power roller 120, powered by motor 121, and an idler roller 122. In the tank 118 cleaning brushed 124 and 126 apply cleaning solution 128 to the surface 112 to remove residual materials therefrom. Intermittent squeegee wipers 129-133 wipe the fluids from the belt 112 removing all residual fluids and contaminants therefrom. The belt egresses from the tank 1 18 for further application of imaging suspension by the extruder 102 or for application of carrier liquid via the sprayer 94. If the latter occurs, the belt 80 of the electrode 81 upstream from the interface position of 75 functions in a manner similar to the surface 36 of the electrode 34 of FIG. 1. Therefore, it brings carrier solution to the interface with the surface 3 for removal of background particles therefrom. The mechanism can be cycled to image on one pass or on two passes as described in FIG. 1 by engaging or disengaging the image supply extruder or the fluid sprayer.

imaging suspension is pumped by pump P-! to the extruder 102 from an image suspension supply tank 136 when the imaging suspension is required. When no suspension is being supplied to the surface 112, the pump P-l is disengaged ending the ink supply to the belt surface 112. When the sprayer 94 is functioning to supply the belt surface 112 with carrier fluids, the pump P-2 draws the necessary fluids from the fluid supply sump 138. When the sprayer is not actively engaged in the imaging process the pump P-2 is deactivated so that no fluids are sprayed from the sprayer 94.

Particular benefits are derived from the use of an imaging electrode continuous belt that are not provided by the roller type electrodes shown in the previous figures. For example, there is more time for cleaning the surface and dissipating the residual charges maintained thereon during the process.

FIG. is a side sectional view of a portion of the apparatus shown schematically in FIG. 1. Like reference numerals represent like parts on each of the drawings. The injecting electrode 1 has a surface 3 of an electrically conductive transparent coating 3 over a transparent glass substrate 150. The injecting electrode structure can be NESA glass which is a tin oxide coated glass structure available from Pittsburgh Plate Glass Company. It could also be fonned by an electrically conductive transparent coating over a transparent substrate for the purposes of this invention.

The entire drum 1 is mounted on an end cap 151 which is formed on a hollow shaft 152. The shaft 152 rotates from the action of the motor M-l through the bearing 153 in the machine frame member 154. However, the mirror 24 remains stationary in its housing 155 because the shaft 156 formed as part of the housing is held fast. it is unaffected by the rotation of the hollow shaft 152 since it passes between bearings 157 and 158 providing for movement of the hollow shaft 152 without affecting the shaft 156.

The optical object is a film strip transparency 160 held within a projector 161 that moves the film strip 160 in synchronized movement with the rotation of the injecting electrode drum 1. The projection is enlarged and reflected off the mirror 24 to the inside surface of the injecting electrode 1. Since the injecting electrode drum is transparent, the light rays 162 and 163 pass through the drum to the outer surface interface with the imaging electrode 20. The imaging electrode has a surface 22 thereon formed of a plastic such as Tedlar, a polyvinylfluoride, made by E. l. du Pont de Nemours and Co. which has electrical qualities desirable for the imaging process having a resistivity of at least ohm-cm. The inner structure of the imaging electrode is an electrically conductive material 168 formed of a rubber or other resilient material having good electrical qualities. A potential is applied to the imaging electrode 20 through an electrical connection 169 making a field across the interface of between 300 v. and 5,000 v. A similar electrical connection 170 applies an electrical potential of opposite sign to that of the imaging electrode on the transfer roller 50 having the web of support material 53 passing thereover. The injecting electrode drum 1 is mounted within the frame 172 by a bearing 173 which cooperates in conjunction with the bearing 153 to maintain the drum in a circular path during its rotation through the movement of the shaft 52.

The timing diagram, FIG. 6, relates to the machine shown schematically in FIG. 1. The vacuum equipment referred to as 18 is turned on with the machine and remains on for the entire operation of the machine. Various motors used to operate the various moving parts discussed can assume to be turned on simultaneously with the required motion or activity of the part and turned off immediately thereafter. Other apparatus would remain activated for as long as the machine is in a ready position. The cleaning brushes of section A namely 2 and 14 are rotated when the machine is turned on and the solenoids 8 and 15. Shortly afier the activation of the cleaning mechanisms and the solenoids 8 and 15, the solenoid 13 moves the vacuum squeegee 11 so that the blade 10 contacts the surface 3 of the injecting electrode 1.

Next, the applicator roll 22 begins to apply imaging suspension to the surface 21 of the first imaging electrode 20. After ink has been applied to a portion of the surface of the imaging electrode the imaging electrode 20 is moved into interface relation with the surface 3 of the injecting electrode by turning the eccentric 28 via an air cylinder or solenoid or other device. Shortly thereafter, the high voltage is activated to cause a field between the first imaging electrode 20 and the injecting electrode 1. The illumination system is then turned on so that images can be projected to the image area. After imaging is complete, the reversible motor 32 moves the carriage 33 to its second position where the second imaging roller 34 is engaged at the image area with the injecting electrode 1. Shortly thereafter, the high voltage is turned on relative to the second imaging electrode to create the field at the interface between it and the injecting electrode 1. While the second imaging pass continues the transfer roll is clutched in and rotates in engagement with the injecting electrode 1 under suitable field conditions.

As the injecting electrode transfers the image it continues its rotation through a third cycle where its surface is cleaned of residual materials thereon.

While this invention has been described with reference to the structures disclosed herein and while certain theories have been expressed, it is not confined to the details set forth; and this application is intended to cover such modifications or changes as may come within the purposes of the improvements and scope of the following claims.

What is claimed is:

1. Apparatus for forming images including:

a hollow transparent member formed as a cylinder and adapted for rotating movement about a central axis,

an optical system including an illumination source and means for projecting light to the transparent member outer surface at an image zone, reflection means internal to said hollow transparent member such that the optical path passes internally through the transparent member to the outer surface thereof,

an electrode member positioned in the path of rotation of the transparent member for interfacing therewith at the image zone and adapted for synchronized movement with the surface of said transparent member. and

means to couple at least one of said members to an electrical source capable of forming an electric field between said members.

2. The apparatus of claim 1 including suspension application means to apply photoelectrophoretic suspension to one of said members along the path of movement thereof prior to the interfacing therebetween.

3. The apparatus of claim 1 wherein said transparent member has operatively associated therewith cleaning means located in the path of rotation of the transparent member and removably positionable to contact the outer surface thereof.

4. The apparatus of claim 3 including image transfer means capable of removing suspension from the transparent member and removably positionable to interface with the transparent member along the path of travel thereof downstream from said electrode member.

5. The apparatus of claim 4 further including feed means for presenting a support material between said transparent member and said image transfer means such that the image is transferred to the support material.

6. The apparatus of claim 5 wherein said support material includes a web wherein said web is cut after transfer of the image thereto.

7. The apparatus of claim 3 wherein said suspension application means includes an extruder.

- 8. The apparatus of claim 7 further including a smoothing means upstream from the extruder along the path of movement of the member.

9. The apparatus of claim 3 including means to remove said suspension application means from the member with which it interacts.

10. The apparatus of claim 1 wherein said optical system includes a lens means having an object plane and an image plane and wherein said transparent member outer surface passes through the image plane at the image zone.

11. The apparatus of claim 1 including electrode member cleaning means positioned in the path of travel of said electrode member.

12. The apparatus of claim 1 including means for applying electrical charge to the surface of said electrode member.

13. The apparatus of claim 1 wherein said electrode member comprises an endless belt.

14. The apparatus of claim 1 including means to spray fluids on the surface of the electrode member upstream from the interface of said member with said transparent member.

15. The apparatus of claim 1 wherein said optical projection system includes a movable object and image plane for presenting a flowing image of the object at the image plane moving at the same rate as said transparent member surface thereat.

Claims

2. The apparatus of claim 1 including suspension application means to apply photoelectrophoretic suspension to one of said members along the path of movement thereof prior to the interfacing therebetween.
3. The apparatus of claim 1 wherein said transparent member has operatively associated therewith cleaning means located in the path of rotation of the transparent member and removably positionable to contact the outer surface thereof.
4. The apparatus of claim 3 including image transfer means capable of removing suspension from the transparent member and removably positionable to interface with the transparent member along the path of travel thereof downstream from said electrode member.
5. The apparatus of claim 4 further including feed means for presenting a support material between said transparent member and said image transfer means such that the image is transferred to the support material.
6. The apparatus of claim 5 wherein said support material includes a web wherein said web is cut after transfer of the image thereto.
7. The apparatus of claim 3 wherein said suspension application means includes an extruder.
8. The apparatus of claim 7 further including a smoothing means upstream from the extruder along the path of movement of the member.
9. The apparatus of claim 3 including means to remove said suspension application means from the member with which it interacts.
10. The apparatus of claim 1 wherein said optical system includes a lens means having an object plane and an image plane and wherein said transparent member outer surface passes through the image plane at the image zone.
11. The apparatus of clAim 1 including electrode member cleaning means positioned in the path of travel of said electrode member.
12. The apparatus of claim 1 including means for applying electrical charge to the surface of said electrode member.
13. The apparatus of claim 1 wherein said electrode member comprises an endless belt.
14. The apparatus of claim 1 including means to spray fluids on the surface of the electrode member upstream from the interface of said member with said transparent member.
15. The apparatus of claim 1 wherein said optical projection system includes a movable object and image plane for presenting a flowing image of the object at the image plane moving at the same rate as said transparent member surface thereat.