US3639049A - Copy system - Google Patents

Abstract

A rapid copy-making system for producing copies for example on photographically slow material such as a diazo, vesicular ''''Kalvar'''' or contact speed silver halide by producing an intermediate image from photoelectrophoretic material and more or less immediately using this intermediate image to contact print the slow photographic material. A separate light source of high intensity exposes the recently created photoelectrophoretic intermediate image for imaging the photographically slow material.

Description

Unite States Patent Rhodes et al. Feb, 1, 1972 [54] COPY SYSTEM [72] inventors: Warren L. Rhodes, Rochester, N.Y.; Vergffiyjgr g ii 2 :32: I L.M tOklh C't,Okl. arqual: a a oma ly a Attorney-James J. Ralabate, David C. Petre and Barry Jay [73] Assignee: Xerox Corporation, Stamford, Conn. Kesselman 22 Pl d: A 28 1970 1 57 ABSTRACT [2}] Appl. No.: 67,812

A rapid copy-making system for producing copies for example a on photographically slow material such as a diazo, vesicular [52] U.S. Cl .355/3, 96/l.n, 355/12 Kalvar" or Contact Speed Silver haiide by producing an inter- [51] 'f Cl 15,00,602 15/14 mediate image from photoelectrophoretic material and more [58] Field 0 Search 4, l l, 12, 17, or less immediately using hi intermediate image to Contact 96/1 print the slow photographic material. A separate light source of high intensity exposes the recently created photoelec- [56] References cued trophoretic intermediate image for imaging the photographi- UNITED STATES PATENTS Cally Slow 3,427,242 2/ 1969 Mihajlov ..96/1 .3 X 5 Claims, 2 Drawing Figures /3\ VACUUM SOURCE PATENTEU rm H97? 3,639,049

VACUUM INVTORS WARREN L. RHODES VERNON L. MARQUART A TTOR/VEV COPY SYSTEM This system relates to imaging systems and more particularly to systems employing photoelectrophoretic image intermediates.

The invention herein evolves around the new photoelectrophoretic imaging systems disclosed in US. Pat. Nos. 3,383,993; 3,384,448; 3,384,565 and 3,384,566. They disclose how to produce a visual image at one or both of two electrodes between which photoelectrophoretic particles suspensions are placed. The particles are photosensitive and appear to undergo a net change in charge polarity or a polarity alternation by interaction with one of the electrodes upon exposure to activating electromagnetic radiation. Mixtures of tow or more differently colored particles can secure various colors of images. The particles will migrate fromone of the electrodes under the influence of an electric field when struck with energy of a wavelength within the spectral response curve of the colored particles. The colors may be used independently or in subtractive color synthesis using particles of yellow, magenta and cyan colored particles. In a monochromatic system, i.e., a system employing particles of substantially one color, the particles will migrate if energy of any wavelength within the panchromatic spectrum of the particle response strikes the particle.

Certain terms of art have been used in conjunction with the photoelectrophoretic imaging system. A definition of these terms is helpful. The injecting electrode" is so named because it is designed to optimize charge exchange with activated photosensitive particles during imaging. The term photosensitive" when used in reference to particles refers to particles which, once attracted to the injecting electrode, will alter their polarity and migrate away from the electrode under the influence of an applied electric field when exposed to activating electromagnetic radiation within their spectral response curve. The term suspension" may be defined as a system having solid particles dispersed in a solid, liquid or gas.

Nevertheless, the suspension preferred for use in the disclosurc herein is of the general type having a solid suspended in a liquid carrier. The term imaging electrode" is used to described that electrode which interacts with the injecting electrode through the suspension and which once contacted by activated photosensitive particles will minimize charge exchange with the particles. The imaging electrode is covered with a dielectric surface composed of a material having a volume resistivity preferably in the order of or greater ohm-cm. and a conductive core member.

For photoelectrophoretic imaging to occur it is though that these steps, not necessarily listed in the sequence that they occur, take place: (I) migration of the particles toward the injecting electrode due to the influence of an electric field; (2)

the generation of charge carriers within the particles when struck with activating radiation within their spectral response curve; (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; (6) electrophoretic -migration toward the imaging electrode; and (7) particle deposition on the imaging electrode. This leaves an image on the injecting electrode that is optically positive inlight and in color.

Mechanisms associated with the photoelectrophoretic imaging system normally have a transparent electrode, preferably being the injecting electrode, through which the photosensitive pigment particles are exposed to electromagnetic radiation. These particles absorb the radiation, undergoing the phenomena of charge exchange, and migrate under the influence of the applied field between the injecting and imaging electrodes.

It is an object of this invention to reduce the steps required for producing copies of objects on slow photographic materials. Another object of the invention is to increase the speed for making copies on photographic materials. Yet another object of this invention is to improve imaging with selected photographic intermediates. A further object of this invention is to reduce the cost and time for forming microsize images.

These and other objects of this invention will become apparent to those skilled in the art after reading the description in conjunction with the accompanying drawings wherein:

FIG. 1 schematically represents an embodiment of this invention in an automatic machine for producing copies of an original through an intermediate, and

FIG. 2 is an alternative schematic representation of this invention.

The invention herein is described and illustrated in specific embodiments having specific components listed for carrying out the functions of the apparatus. Nevertheless, the invention need not be though of being confined to such a specific showing andshould 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 apparatus described and claimed herein and it is the intention herein to describe an invention for use in apparatus other than the embodiment or application shown.

FIG. 1 illustrates apparatus for using a photoelectrophoretic imaging suspension in an image configuration as the intermediate or original for contact or close-spaced copying with a duplicating film. The duplicating film may be typically a diazo or vesicular Kalvar or a contact speed silver halide material. One benefit of the system is that if special high intensity illumination is required for the reproduction material such as a high intensity UV source, that need not effect the image formation on the intermediate master used for the contact or close copying, or need it effect originals that may otherwise be harmed by the high intensity illumination. In the illustration of FIG 1 the light source It) illuminates an original 11 shown in the form of a moving film strip which is projected through a lens 12 and off a mirror 13 to the imaging position between an injecting electrode 14 and an imaging electrode 15. The injecting electrode is composed of a transparent glass member coated with a transparent electrically conductive material such as, for example, tin oxide. The imaging electrode has a surface composed of a dielectric material sleeve and an electrically conductive substrate which is connected to a potential source. The injecting electrode is electrically connected to ground to provide a field between the injecting and imaging electrodes. An imaging suspension dispenser 16 meters the imaging suspension 17 to flow past the imaging position between the two electrodes. Imaging suspension removed by the imaging electrode 15 is evacuated through the vacuum system schematically represented by the numeral 18. The suspension remaining on the injecting electrode 14 is in an image configuration and may be partially fixed so that it will not readily be removed by contact with the copy material. The fixing takes place by unit such as the drying unit 19. The dry photoelectrophoretic imaging suspension will cling fairly well to its support cylinder, the injecting electrode 14 without rubbing off ontothe duplicating film 20. A high intensity light source 21 with a slotted reflector 22 illuminates the copying imaging position between the injecting electrode 14 and the copy film support drum 23 holding the duplicating film 20 on its surface. The surface of the electrodes 14 and 15 are moved in rolling contact or near contact at substantially the same speeds to avoid smearing the'image as it is formed. Actually, both electrodes may be rotated by external means such as a motor and gearing system. Alternatively, one may drive the other by friction.

The copy drum 23 rotates with a surface velocity substantially equal to the surface velocity of the injecting electrode '14. lt carries with it the copy film20 supplied from a supply spool- 24 and wound around a takeup reel 25. ldler rollers 26 and 27 maintain the film 20 tight against the surface of the support 23. The copy film 20 is sensitive to light in the spectrum emitted by'the high intensity illumination source 21. By

beaming the illumination through the image formed of the imaging suspension 17 maintained in contact or close proximity to the copy film 20, the copy film is modified by the light passing through the image formed of the suspension 17. After the required number of copies are made from the image formed on the injecting electrode 14, the injecting electrode 14 is cleaned by a vacuum system 28 which scrapes and cleans the loosely adhered dried image-pattern suspension 17 from the surface of the injecting electrode 14. To permit multiple copies to be made from a single-imaged intermediate, a program device 30 modifies the imaging cycle of the photoelectrophoretic imaging system by stopping the flow of suspension from the dispenser 16 such as, for example, by closing the valve 31, removing the imaging electrode from contact at the imaging position with the injecting electrode 14 and also turning off the illumination source 10. The cleaning mechanism 28 is also disengaged so that the image formed on the injecting electrode-support cylinder 14 may pass any selected number of times by the copying station to be imaged onto the duplicating film 20. When the desired number of copies are made on the copy film 20, the programmer 30 engages the cleaning mechanism 28 and reinstitutes the imaging cycle for the photoelectrophoretic imaging system.

FIG. 2 shows a modified apparatus for achieving the invention described herein. In this schematic apparatus a monochrome photoelectrophoretic composition such as, for example, phthalocyanine dispersed in a wax is applied by feed rolls 37 to a rotating injecting electrode cylinder 36 which is transparent and has a transparent electrically conductive coating on its outer surface. The photoelectrophoretic suspension is moved to a uniformly thin film by smoothing roll 39. The material can be softened with a spray of solvent from the solvent=spray mechanism 40. The rotating injecting electrode then passes into contact with an imaging electrode transfer cylinder where a light image strikes the suspension at the interface thereof. The light image may be a reduced image from a selected original maintained at the object plane of a lens 42 which projects light rays from the original to a mirror 44 and to an image plane coinciding with the interface of the two electrodes 36 and 41 at the imaging position on the transfer cylinder 41. The electrical potential supplied to the backing of backing 46 of the transfer cylinder 41 will determine whether the image transferred to the transfer cylinder is optically positive or negative.

In the reproduction section of the transfer cylinder located away from the interface of the transfer cylinder with the injecting electrode cylinder 36 a copy or duplicating film material 48 passes the exposure station 50. A sheet or web of the duplicating film is kept in rolling contact with the transfer cylinder 41. It is exposed at the exposure station 50 by a high intensity illumination source 52. A backing plate 54 maintains the duplicating film 48 in close contact at the exposure station 50.

A suitable film, or paper, supply 56 is maintained and fed by a roller system through the exposure station and then to a heating source 58 containing, for example, radiant heaters 59 for development for those types of film requiring infrared or heat development after exposure to such high intensity sources as ultraviolet ray emitters. The developed film or paper would then be fed into a copy-catch tray 60 for removal by an operator when convenient.

Although many current used would prefer a reduced-size 7 copy device for bringing originals to a microsize for easy storage and reproduction that is not a necessary limitation of this apparatus and in fact any size reproduction including magnifications of greater than I to l or magnifications equal to or less than I to l are possible without diverting from the scope of the invention.

In order to prepare the injecting electrode 36 for further imaging, the counter image 62 is removed from the surface of the cylinder 36 by cleanup rolls 63 using a solvent 64 to remove the imaging suspension formed as a counter image from the surface of the injecting electrode cylinder.

Various drives and mechanical and electrical connections are not shown in the schematic representation of the attached figures. However, it is understood that means known to those in the art can be used to implement the drawings shown to cause them to function in the manner described herein. Such means and all equivalents thereof including methods of color balancing and photographic filtering as well as machine design are not fully described herein since they are known to those skilled in the art and could readily be applied by such persons to the invention claimed in light of the disclosure herein.

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 photoelectrophoretic imaging comprising in combination a first electrode,

a second electrode adapted for movement in close proximity to said first electrode,

means to apply an imaging suspension between said first and second electrodes,

means to move said first and second electrodes at substantially the same surface speed,

means to project an image onto said suspension between said electrodes,

means to apply an electric field across said suspension at said electrodes whereby an image is produced on said second transparent electrode, means to illuminate the image at a copy position whereat the second electrode is adapted to maintain the image produced between said first and second electrodes,

support means interfacing with the second electrode at the copy position on the image-bearing surface of the second electrode,

means to pass a photosensitive copy medium on the support means in synchronous movement with the second electrode surface for activation by said means to illuminate for exposing the photosensitive copy medium to the image on the second electrode.

2. The apparatus of claim 1 wherein said means to illuminate radiates in the ultraviolet region of the spectrum.

3, The apparatus of claim 1 wherein the copy medium supportable on said support member is support to contact the image on said second electrode.

4. The apparatus of claim 1 including cleaning means to remove suspension from the second electrode after interfacing with said support means.

5. The apparatus of claim 4 including programming means to disengage said means to apply imaging suspension, said means to project an image, said means to apply an electric field and said cleaning means from interacting with said second electrode.

Claims (5)

1. Apparatus for photoelectrophoretic imaging comprising in combination a first electrode, a second electrode adapted for movement in close proximity to said first electrode, means to apply an imaging suspension between said first and second electrodes, means to move said first and second electrodes at substantially the same surface speed, means to project an image onto said suspension between said electrodes, means to apply an electric field across said suspension at said electrodes whereby an image is produced on said second transparent electrode, means to illuminate the image at a copy position whereat the second electrode is adapted to maintain the image produced between said first and second electrodes, support means interfacing with the second electrode at the copy position on the image-bearing surface of the second electrode, means to pass a photosensitive copy medium on the support means in synchronous movement with the second electrode surface for activation by said means to illuminate for exposing the photosensitive copy medium to the image on the second electrode.

2. The apparatus of claim 1 wherein said means to iLluminate radiates in the ultraviolet region of the spectrum.

3. The apparatus of claim 1 wherein the copy medium supportable on said support member is support to contact the image on said second electrode.

4. The apparatus of claim 1 including cleaning means to remove suspension from the second electrode after interfacing with said support means.

5. The apparatus of claim 4 including programming means to disengage said means to apply imaging suspension, said means to project an image, said means to apply an electric field and said cleaning means from interacting with said second electrode.

Images