JPS63503329A - Method and apparatus for improving multicolor electrographic images using corona cancellation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 15. The reverse charging means has an absolute value equal to or greater than (Vo - Vw) The invention according to claim 13, wherein the invention is adapted to provide a voltage of a certain value.

16. From a value that is approximately equal to (Vo - Vw), the reverse charging means (Vo - Vw) ). The invention described in item 13.

17. Claims including means for erasing and exposing the medium after toner processing and before the reverse charging step The invention described in item 13.

18, the medium includes a charge barrier layer, and the image generating device releases the medium after the reverse Exposure to radiation helps recombine trapped and mobile charges in the medium. The invention according to claim 13, comprising means for:

19. The medium may or may not include a charge blocking layer, and the image generating device may Subsequently, exposing the medium to radiation only if the medium includes a charge blocking layer Claims having means for assisting in the recombination of trapped and mobile charges in the The invention described in item 13.

20. Claim No. 20, wherein the radiation exposure means is adapted to expose both sides of the medium. The invention described in 18.

21. Claim 13, wherein the toner means is provided with means for supplying liquid toner. The invention described.

22, exhibiting low optical density and generally containing a non-conductive overcoat and charge carriers. Generates a multicolor electrograph on a p-type electrograph medium with The image generating device is designed to move along a predetermined path.

a substantially transparent carrier platen, the media and a first image-bearing transparency in the @1 position; means for mounting the carrier platen in alignment on the carrier platen; and means for translating the medium and the medium together on the predetermined path; and means for translating the medium and the medium together on the predetermined path; means for charging the body to a 111th pressure vO, and charging the medium to the transparent image in the @3 position; and then exposing the medium to a vJ1 light source to discharge the exposed portion of the medium to a second tolerance pressure Vw. means for engaging the overcoat of the media in a fourth position; means for providing a toner treatment agent and selectively toner treatment of an image-bearing charged area of the medium; means for generating a first color visual image, and whether the absolute value is equal to (Vo-VW); Or the voltage is larger than this and the polarity is opposite to (Vo - Vw), and the toner has been processed. means for oppositely charging the medium and exposing and trapping the medium to radiation from a second source; By recombining the trapped electrons with mobile holes, the trapped electrons can be neutralized. and means for returning the platen, transparency and neutralized media to the first location. the first transparency by a second image-bearing transparency registered therewith. alternative means and repeating the charging and exposing steps to expose the medium to the first source; 2 images are generated and the t*@2 image is toned by a second toner processing element to form the first toner image. means for generating a second color visual image aligned with the color visual image; Raw equipment.

Specification Method and apparatus for improving multicolor electrographic images using corona cancellation The present invention provides an improved method for electrographic development, more specifically for multi-stage development. Regarding the method. The following disclosure is made regarding preferred embodiments using liquid development. However, the present invention is equally applicable to systems using dry developers.

Electrostatic charges, such as in electrophotography and other processes that create and develop electrostatic charge patterns. In order to liquid-develop the latent image of A liquid developer having colloidal toner particles suspended therein is contacted. liquid developer usually also contain stabilizers or charge control agents. Liquid developers can be used in one or multiple stages. It can be used in the development process. The end of this developing process is one light guide. Develop two or more color separation images one after the other, and do not annotate previously developed images. involves repeatedly forming and developing an image on a reusable photoconductor; , transferred after each development.

A multi-stage development process using a liquid developer is used in photography to produce high-quality multicolor images electronically. This is particularly important when playing back photos. In these processes, electrostatic latent images are deposited one after another on a rechargeable medium such as an electrographic medium, i.e. a photoconductor. liquid development or toner treatment of each latent image before the next latent image is formed. The truth is done. This type of process involves four color separation transparent bodies arranged in a row. While sequentially exposing the electrographic media to light through the - Some require the treatment process four times.

Conventionally, for the formation of such high quality multistage or multicolor images, low optical density P The use of type photoconductors was considered impractical. This is mainly due to the mobile charge The photoconductor is movable during the thickening of the photoconductor compared to other types of photoconductors that occur This was to generate "holes" and trapped electrons. This is a track The elimination method used for these photoconductors because the pushed electrons cannot move. is the electric charge trapped throughout the thickness or interior of the photoconductor or in the vicinity of the positive surface value. There is some attribution from 511-fruit that children cannot be removed. This problem is caused by light Transfer the applied toner to the final receiver after multistage or multicolor development of the conductor Toner loading that can be used to transfer - requires the use of a transfer aid overcoat exaggerated in the imaging system.

This is especially true if the overcoat is non-conductive.

Generation of halftone images required in the field of graphic imaging or imaging It has been found that a non-conductive overcoat is required. conductive surface Halftone dots undergo image broadening and effectively disappear under unfavorable temperature conditions Therefore, a conductive overcoat is not sufficient to generate a halftone image. It was discovered that something was wrong. Continuous toner images also use a conductive overcoat It was also found that under certain conditions, it deteriorates significantly.

Thus, an overcoat of non-conducting bales along with a P-type photoconductor for multi-stage imaging Exacerbating the problem of trapped charges inside the photoconductor thickness . The generation of trapped charges in the photoconductor under these conditions is is lost as residual charge generated with the charged-exposure cycle.

The net effect of this is a constantly increasing toe voltage in the photoconductor ( Torise). That is, the film voltage achieved as a result of large exposure is - Increases with exposure cycles. This is illustrated in Figure 1, where A large exposure vs. voltage effect is shown for four successive charge-exposure cycles. There is. As can be seen, in the first charge-exposure cycle, with high exposure Although the voltage achieved is the lowest value.

In each successive charge-exposure cycle, the same exposure amount.

This results in a constantly increasing final voltage. Therefore, the photoconductor film To maintain a usable working voltage, the initial charging voltage must be changed for each cycle. We must continue to grow.

A cumulative increase in film toe voltage of or above may occur. , thereby requiring an increase in the initial charging voltage by an equal amount. Therefore, it is charged Not only will it be difficult to control the equipment, but the capacity of the equipment and film will be quickly exceeded. To do.

The desired differential voltage is not provided by this method. Furthermore, torrise is inevitable control of the entire process to obtain satisfactory film behavior is difficult. It becomes very difficult, if not possible. Charging for the first time in a long time - Topping occurs with the exposure cycle. - Can be used in systems utilizing photoconductors with the above-mentioned development where the voltage increases. If no means are used to maintain the working voltage range, the resulting image will vary depending on humidity changes in one work area. It is easy to exhibit undesirable image changes as the image changes. Under such operating conditions, the image area Transverse changes can also occur. More importantly, the aforementioned toe voltage It can be seen that as the image density increases, the image density becomes unattainable due to the step or color that has been removed for a long time. It's being served. All these factors contribute to obtaining a picture of the quality of graphic arts. Works against you.

The general electrographic method according to the invention uniformly charges the photoconductive element. , exposing the photoconductive element to a pattern of actinic radiation to form an electrostatic latent image, e.g. The latent image is developed using a liquid developer containing a carrier liquid, toner, and a charge control agent, and then washed. The steps include rinsing the developed side of the photoconductive element with a cleaning solution and drying the image. So After the surface of the photoconductive element is recharged and exposed to a pattern of actinic radiation, a liquid developer forming a second electrostatic latent image that is exposed at .

The method of the present invention involves forming a charge pattern on a previously developed surface and developing it with a developer. It is useful in any electrostatic imaging method that images images.

However, one method of the present invention is a recently developed method for creating color proofs of phosphorus graphs. It is particularly useful in combination with emitted electrography methods. This new A new method is described in pending U.S. patent application Ser. 85 September 6). According to this method, a uniformly charged thin dielectric The photoconductor with the electrical overcoat is exposed through a series of aligned color separation transparencies. receive an offer. After each exposure, the dielectric layer is developed with a liquid developer and one surface is redone. is uniformly charged and exposed. This series of operations usually involves four color transparent images. is repeated for each and all developed images are superimposed.

Forms a multicolored image on the overcoat.

Summary of the invention Therefore, the present invention provides a solution for torization caused by the charging-exposure cycle of the photoconductor after a long period of time. Multicolor electrographic techniques that improve the final image by reducing or eliminating A method and apparatus for forming an image are provided. The improvement according to the invention is simple and requires only a few costs. Although this can be achieved relatively easily with a strike, it has a large negative effect on the results. It doesn't bring.

According to one aspect of the invention, the medium is charged and exposed to a first tortoise pressure vO; The discharged part is discharged to @22 tortoise pressure V, and then treated with toner to form the first town visual image. A method and apparatus for generating multi-stage electrographic images are proposed. Served.

(V o-Vw) to reversely charge the medium with a voltage of opposite polarity to the trapped charge. By recombining the mobile charge of the trapped charge with the trapped charge, the trapped particle is Neutralize.

Successive charging-exposure cycles of the media virtually eliminate tow voltage build-up .

According to another aspect of the invention, the absolute reversely charge the medium with a voltage having a value and a polarity opposite to (Vo − Vw); Ru.

According to yet another aspect of the invention, if the medium includes a charge or charge barrier layer, the Neutralization of wrapped charges is the process by which trapped charges and mobile charges are placed in a medium. exposing the medium to chemical radiation to facilitate recombination of the components.

According to yet another aspect of the invention, the medium may include or contain a charge blocking layer. If the medium does not contain a charge barrier layer, the trapping in the medium after reverse charging will only occur if the medium contains a charge barrier layer. means for exposing the medium to radiation to assist in recombining the mobile charge with the mobile charge. included.

According to yet another aspect of the invention, regardless of whether the toner regeneration is positive or negative, In both P-type and n-type photoconductors, with or without a charge barrier. Means are provided to prevent torrise.

According to yet another aspect of the invention, a generally non-conductive overcoat and a charge blocking layer are provided. A multicolor electrograph on a low optical density p-type electrograph medium with An image generating device is provided that generates an image. This image generator is a substantially transparent a carrier platen, the carrier platen in the first position; mounting the media and the first image-bearing transparency in alignment with the carrier platen of the is adapted to move along a predetermined path with the means. in the second position The platen and the transparent image are placed on a predetermined path through means for charging the medium to one voltage Vo. Means are provided for translating the medium. Through transparency, the medium becomes the first light source The exposing means is arranged at a third position for discharging the exposed portion of the medium to a second tortoise pressure Vw. It is set in. Selectively treating image-bearing charged areas of the media with toner to form a first color A first toner processing element is positioned over the media in a fourth position to generate a visible image. - arranged to engage the coat. The absolute value is equal to (Vo - Vw) The toner is processed by a voltage of 100 liters or larger and the polarity is opposite to (VO-Vw). Means is provided to reversely charge the processed media. The trapped electrons are Exposing the medium to radiation from a light source recombines the trapped electrons with mobile holes. It is neutralized by combining. The image generator is neutralized with the platen and transparencies. The first transparency is aligned with the media by returning the media to the first position. By substituting a second image-bearing transparency and repeating the charging and exposing steps.

exposing the media to a first source, generating a second image (11), and subjecting the second image to a second toner treatment; toning the element to produce a second color visual image that is consistent with the first color visual image; It has the means to do so.

Various means for carrying out the invention and other features and advantages are illustrated in the accompanying drawings. By way of the following detailed description of exemplary preferred embodiments of the invention, reference is made. It will become even clearer.

Brief description of the drawing Figure 1 shows a torrent caused by the charging-exposure cycle, which is solved by the present invention. Figure 2 is a diagram showing the development of an electrograph system equipped with a torize prevention means. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention includes various electrographic elements, methods, and apparatus. Before Multicolor using p-type electrographic media of the type disclosed in the pending application of The present invention is directed to electrophotographic image forming apparatuses.

A multicolor electrographic imaging device is schematically illustrated in Figure 2 and described below. The process shown by the dashed line 14 passes through the various processing stations of the processing equipment. movable along a physical path.

It consists of a carrier or platen 12. Processing path 14 is based on the technology defined by guide rails or other structures on the equipment, and in a manner well known in the art. After moving from the first position shown in the diagram to the rightmost position, the marquee 12 is moved toward the starting position. Move to the left. The platen 12 is preferably transparent and is described in more detail below. used to generate an image in the electrographic medium 16, as described in with an image-supporting transparency 18 in between.

Support means, not shown, are provided for supporting the electrographic medium 16 on its lower surface. We are prepared.

As shown in the aforementioned pending application, electrographic media are based on photoconductive The top layer includes a photoconductive layer, and the photoconductive layer responds to the actinic radiation emitted from the photoconductive layer. I can do it. The dielectric support is removably adhered to the substrate and serves as a light guide. an electrostatic layer or overcoat thereof, which covers the outer surface of the element and retains an electrostatic charge. Form. To use this element, the surface of the dielectric support is electrically charged and exposed to light. The conductive layer forms a developable electrostatic image by imagewise exposure to actinic radiation. Formed on a dielectric surface. The static image is then developed with toner to form a first color image. . imagewise to the actinic radiation transmitted through the transparent support and the image-bearing transparency 18; Repeat the above operation one or more times, exposing the photoconductive layer, over each preceding image. Forming a composite color image on said element by developing with different colored toners can be achieved. The composite tone image is then combined with a dielectric support to increase the acceptance cost. Colors that faithfully simulate the color prints that are transferred and expected from a color printing press Form a color copy like a proof.

Thus, electrographic media 16 is mounted on platen 12 along with transparency 18. Can be attached. This was held in between.

It may be a color separation representing the colors to be printed. electrographic medium 16 and the transparent original 18 are closely spaced to ensure satisfactory exposure, processing and matching. so that it remains in the same state.

Platen 12 is clamped by any suitable means known in the art, such as by vacuum clamping. can be held. The electrographic media has a satisfactory @electronic process. must be properly grounded to the image generating device so that many earths The means are well known in the art and will not be described in detail here. Platen 12 is on the right (in Figure 2) with the transparency 18 and electrographic medium 16 above it. The dielectric support of the electrographic medium 16 is moved in translation by the charging device 20. A charge is applied to the entire surface of the dielectric support, creating a uniform potential vO on the surface of the dielectric support. .

The electrographic medium 16 thus charged is transferred to the transparent platen 12. transparent Exposure to cast light through the transparent conductive basis of the original image 18 and the electrographic medium 16 By passing below the lighting device 22, it is exposed according to the image. photoconductive layer is imagewise exposed in this way, the mobile charge carrier (in this case the charged holes) are formed in the photoconductive layer and the photoconductive moving away from the layer (or towards the photoconductive layer, giving a negative image) . Therefore, the surface potential in the fully exposed area decreases to the potential Vw, and the unexposed area The surface potential of the area remains at approximately the same potential Vo. Therefore, transparent image 18 An electrostatic differential pattern is formed on the dielectric support corresponding to the above pattern.

The platen 12 continues to move from side to side in FIG. Since it passes over the washing head 24, the head of the stream positioned there is in the processing direction, that is, to the right. When activated, the lower surface of the electrographic medium 16 that moves into contact with the 1 For example, when the platen 12 is moved to the left by one position in FIG. , when the fluid head is not activated, the fluid head is in contact with the electrographic medium 16. do not have. Prewash head 24 primes media 16 with a dispersive dielectric liquid prior to the liquid toner processing step. on the pre-humidifying side.

The platen 12 then passes through the ascending first liquid toner processing stage 26. pass Since this stage screen has moved up to the operating position, the bottom surface of the medium 16 is and a toner image is applied thereto in a known manner. In this system, liquid toner is deposited on exposed and still charged areas of the media 16. An image is formed which is a replica of the image carried by transparency 18. (The technology As is well known, the charge and toner applied to the medium 16 is such that it produces a negative image. Negative images can also be produced by similar electrographic methods with appropriate adjustments. ). The platen 12 passes through an appropriate washing head and dryer (not shown in Figure 1). Move to the right at . The last station 28 on the far right of the imager is the toner - Expose media 16 after processing to expose media 16 that was not exposed by the original image exposure. By exposing portions of the photoconductive layer, the entire media 16 has a substantially uniform exposure profile. This is an erasing lamp to keep track of the history.

The platen 12 is then inverted and transported back to the left to the first position shown in FIG. Ru. Upon reaching the charging device 20, the platen 12 is equipped with a corona eraser according to the present invention. activated by position.

However, the charge imparted by the corona erase mode of charging device 20 is The polarity is opposite to the initially given charge (V.

-VW). Small to 50% of the initial charge difference a medium or large potential provides satisfactory neutralization of the trapped charges in the photoconductive medium; It is found that the preferred value is equal to or greater than the absolute value of (Vo - Vw). Served.

In the case of photoconductive media that do not use a charge blocking layer, it is possible to In order to neutralize the applied charges, only reverse charging is adequate. However, the charge barrier layer In the case of photoconductive media used, re-erase lamps 30.32 on both sides of platen 12 exposure of the media to further processing. The re-erasing lamp is not connected to the photoconductor 16. In photoconductors that provide image blanket exposure and use charge barriers, a single conductive layer Releases mobile charges from the photoconductor to remove trapped charges within the thickness or interior of the photoconductor. neutralize the load.

The platen 12, the transparency 18, and the media 16 then reach the first position and the first transparency The image or color separation 18 is removed and replaced with a second transparency or color separation, and the second color image in preparation for the next pass through the image generator to generate a be given The medium 16 and the next original sheet 18 are collated again on the platen 12 ( Once the platen 12 is aligned, the platen 12 moves rightward again to the charging device 20 where the medium 1 6 is charged again. The platen then moves to the misting position 22, where the light is again exposed to the platen. The light is projected through the Latin 12 and the second color separation 18, at which time it comes into contact with the medium 16. The photoconductive layer is selectively charged according to the desired transparency and color separation. Platen 12 Next, the media 16 is moved to a pre-washing station 24 and subjected to a first and second toner processing station. -Move to section 34. This station 34 applies the second color toner to the medium 16. operating position for tonerizing to produce a second visible color image on the 11th quadrant. It is in. The platen 12 then passes through the washing head and drying station and is again After passing through the erase and erase exposure station 28, it is returned to the first position at the left end of the image generator. be done.

If it is desired to obtain a fourth color image or a third color image plus a black image, each Working with two separate toner processing stations 36.38 to one for extra colors The two extra color segments move the platen 12 and media 16 into dynamic contact. Each step of charging and toner processing is repeated for the original image.

As will be appreciated, as is well known in the art, the order of toner processing is not necessarily Not represented by the physical order of toner processing stations within the generator; The order given is merely an example. Also, the corona erasure cycle is This exposure is followed by a toning cycle after corona erasure. It will be done. Thus corona erasure occurs after the last charge-exposure-toner treatment cycle. Not required, but required after initial charge and exposure only calibration cycle .

Torise, i.e. the increase in final voltage that can be obtained on extended exposure. The main reason is that after multiple charge-exposure cycles, the trapped charge is transferred to the thickness of the photoconductor. or occurring within it or in the vicinity of a surface having an opposite potential to that of the charge. cause P! In p-type photoconductors, the trapped charges are electrons. In an n-type photoconductor, the trapped charges are holes. these Problems related to the generation of trapped charges can be solved if a charge barrier layer is also incorporated. has been found to increase. Traditionally, these trapped charges are The entire thickness of the photoconductor cannot be removed by conventional charging or erasing means. It was thought that there was no such thing. However, depending on the method of the present invention, the thickness or generates mobile charges inside it, and the trapped charges It was discovered that scales were recombined with light very close to the surface or interface of the photoconductive layer. The newly trapped charges generated are substantially harmless. these tigers The trapped charge is generated by the recombination of two molecules, the trapped charge and the mobile charge. It is believed that it is neutralized by

In photoconductive systems where a charge barrier layer is not used, applying reverse voltage charging can Dynamic charges are spontaneously injected from the conductive layer into the photoconductor, effectively displacing the trapped charges. was found to be removed. In photoconductive systems using charge barrier layers, the movable The charge is due to the reverse charging of the photoconductor followed by re-erasure lamp exposure light is generated.

The present invention therefore substantially rejuvenates the media to a state very similar to its virgin state. The unitary conductor is rebuilt to substantially eliminate the increase in toe voltage associated with conventional approaches. Provides a method and apparatus for producing the same. This method and device are simple and easy to use. is economically realized and produces high quality images suitable for graphic art quality reproduction. let

Further, the inside of the line is exposed through a negative image, and the positive image is formed by a toned image. Re-erase lamp to expose both sides of the media as in negative/positive mode. It is clear that it is necessary to arrange the . In other cases, one of the media The invention can be satisfactorily used by exposing only the surface to the re-erasing lamp. Wear.

Electrography, which performs exposure via a transparency, a transparent platen, and a photoconductor Although the invention has been described above in terms of elements, it will be clear that all of these elements systems in which other means are utilized to expose the medium without the need to make it transparent The present invention can also be applied to.

Having thus described the invention with respect to specific embodiments and variations thereof, it will be apparent that There may be other claims within the spirit and scope of the invention as defined by the following claims. You can also try making changes.

Submission of translation of written amendment (Article 184-8 of the Patent Act) September 7, 1988 Yoshi, Commissioner of the Patent Office 1) Takeshi Moon 1. Display of patent application PCT/US87100383 2. Name of the invention Method and apparatus for improving multicolor electrographic images using corona cancellation 3. Patent applicant Address: State Street, Rochinister, New York 14650, United States Treat 343 Name (707) Eastman Kodak Company 4, Agent Address: Shin-Otemachi Building 206, 2-2-1 Otemachi, Chiyoda-ku, Tokyo December 11, 1986 6. List of attached documents 1 translation of the written amendment /te]X (English Civilization Book, page 7) According to yet another aspect of the invention, a generally non-conductive overcoat and a charge blocking layer are provided. A multicolor electrograph on a low optical density p-type electrograph medium with An image generating device is provided that generates an image. This image generator is a substantially transparent a carrier platen, the carrier platen in the first position; mounting the media and the first image-bearing transparency in alignment with the carrier platen of the is adapted to move along a predetermined path with the means. in the second position The platen and the transparent image are placed on a predetermined path through a means for charging the medium to a voltage v0 of 1. Means are provided for translating the medium. Through transparency, the medium becomes the first light source Means for exposing the exposed portion of the medium to a second voltage V. 3rd position to discharge It is set in. Selectively treating image-bearing charged areas of the media with toner to form a first color A first toner processing element is positioned over the media in a fourth position to generate a visible image. - arranged to engage the coat. Absolute value is equal to (Vo-Vw) Toner processing is performed using a voltage that is larger than this or has a polarity opposite to (V, -V, ). Means is provided for reversely charging the spent media. The trapped electron is the second light Expose the medium to radiation from a source to recombine trapped electrons with mobile holes It is neutralized by causing The image generator was neutralized with the platen and the transparency By returning the medium to the first position, the first transparent image is replaced with the medium and charged. and repeating the exposure steps to expose the medium to a first light source and produce a second image. and toning the second image with a second toner processing element to form a first color visible image. Means are provided for generating a matching second color visible image.

The scope of the claims ■, elect with a relatively non-conductive overcoat on which the image is formed. An image generation method for producing a multi-stage electrophotographic image on a photographic medium, the method comprising: placing rough media on the carrier in a first position and moving the media on a predetermined path; to charge the medium to a first voltage v0 in a second position, and then in a third position. exposing the medium to a first light-bearing image and applying the exposed portion of the medium to a second voltage v,1. a first toner treatment element configured to discharge and engage the media in a fourth position; selectively toning portions of the image-bearing medium to generate a first visible image; Returning the media to the first location and repeating the charging-exposure process to convert the media into a second photo-bearing image. exposing and toning the second image with a second toner element to produce a second visible image; In the generation method consisting of each step of The medium is reversely charged, and a mobile charge of opposite polarity to that of the trapped charge is connected to the trapped charge. neutralizing the trapped charges in the medium by recombination with the trapped particles; After the first toner treatment and before the second charging, the reverse charging and neutralization of the medium charge are performed. A method for generating an image comprising steps of substantially neutralizing the trapped charge in the medium. .

2. Claims in which the oppositely charged charge has an absolute value in the range of ±50% of (Vo-Vw) The method described in box 1.

3. The reverse charging voltage has an absolute value equal to or larger than (V, -V,). The method according to claim 1.

4. The reverse charging voltage is in the range of (Vo-Vw) to (Vo-Vw) 0) approximately 150% 2. The method of claim 1, having an absolute value of .

5. A claim including a step of erasing and exposing the medium after the toner treatment step and before the reverse charging step. The method described in Scope 1.

6. the medium includes a charge blocking layer, and the neutralization step exposes the opposite charge transfer medium to radiation; a step of assisting the recombination of trapped charges and mobile charges in the medium by A method according to claim 1 comprising:

7. The method wherein the medium has or has a charge blocking layer, wherein the medium has a charge blocking layer. Expose the medium to radiation only if it contains trapped charges and mobile 2. The method of claim 1, including the step of assisting recombination with charge.

8. The medium is an n-type electrographic photoconductor, and the trapped charges are electrons. The method according to claim 1.

9. The electrographic medium is an n-type photoconductor, and the trapped charges are converted into holes. The method according to claim 1.

10, the negative image source is used to expose the media and the toner processing requirements The element then selectively tonerizes the more exposed portions of the media. and the radiation exposure step of the neutralization step exposes both sides of the medium. The method described in Section 6.

11. The method of claim 1, wherein said toner treatment element comprises liquid toner.

12. In the first position, on the substantially transparent carrier platen, place the p-electrode positioning the logographic medium and the first image-bearing transparency in registration with each other; The medium exhibits a low optical density and generally contains a non-conductive overcoat and a charge carrier. and further arranging the platen, the transparent image, and the medium together on a predetermined path. The medium is charged to the first voltage v0 at the second position, and the medium is charged to the first voltage v0 at the third position. and exposing the media through the transparency to a first light source to expose the exposed portion of the media to a second light source. 1!Discharge to 1 pressure V@ and engage the overcoat of the medium in the fourth position a first toner treatment element configured to selectively toner image-bearing charged areas of the media; color processing to generate a first color visible image, the absolute value of which is equal to (Vo-Vil) or a voltage greater than this and opposite in polarity to (Vo-Vf=) is used to reversely charge the medium. The medium is then exposed to radiation from a second light source to transform the trapped electrons into mobile holes. Neutralizes the trapped electrons in the medium by recombining with the plate returning the transparent image and the media to the first location and aligning the first transparency therewith. replacing the medium with a second image-bearing transparency and repeating the charging and exposing steps to exposure to a first light source to generate a second image, and toning the second image by a second toner processing element; each color to produce a second color visible image aligned with the first color visible image. A method of generating multicolor electrographic images consisting of steps.

13. Electronics with a relatively non-conductive overcoat on which an image is formed. producing a multi-stage photographic image on the trographic medium and on the carrier in a first position; means for providing an electrographic medium to a computer; and means for translating the medium together on a predetermined path. means for moving the medium; and means for charging the medium to a first voltage v0 in a second position; , exposing the medium to a first light-bearing image in a third position to expose the exposed portion of the medium. Second voltage V. means for engaging the medium at a fourth position to discharge the image bearing medium; a first toner that selectively tonerizes a body part to generate a first visible image; a means for dispensing a processing element; means for repeating the charging step with the same polarity as the first voltage VO by the charging means; means for exposing the medium to a second light-bearing image in a third position; and a second toner processing element. and means for processing the second image toner to produce a second visible image. In the electrographic image generation device, exposing the medium to light by the exposure means; asynchronously charges the medium in the opposite direction with a voltage of opposite polarity to (Vo-Vs=). By separating the trapped charge with a mobile charge of opposite polarity, By being recombined, the trapped charges in the medium are neutralized and the reverse band The charging means and the charge neutralization occur after the first toner treatment and before the second charging, and the charging means and the charge neutralization occur in the medium. An image generating device characterized in that said trapped charge is substantially neutralized.

14. The reverse charging means provides a voltage with an absolute value within a range of approximately ±50% of (vo-vw). 14. An image generating device according to claim 13, which is adapted to provide:

15. The reverse charging means has an absolute value equal to or larger than (Vo-Vw). 14. An image generating device as claimed in claim 13, adapted to apply a voltage.

16. The reverse charging means (Vo-Vl, l) is approximately equal to (Vo-VJ ( Claim 1 adapted to provide a voltage with an absolute value in the range of up to about 150% D. The image generating device according to item 3.

17. Claims including means for erasing and exposing the medium after toner processing and before the reverse charging step 14. The image generating device according to item 13.

18, the medium includes a charge blocking layer, and the image generating device discharges the medium after the reverse charging means. Exposure to radiation helps recombine trapped and mobile charges in the medium. 14. An image generating apparatus as claimed in claim 13, comprising means for generating an image.

19. The medium may or may not include a charge blocking layer, and the image generating device may Subsequently, exposing the medium to radiation only if the medium includes a charge blocking layer Claims having means for assisting in the recombination of trapped and mobile charges in the 14. The image generating device according to item 13.

20. Claim No. 20, wherein the radiation exposure means is adapted to expose both sides of the medium. The image generating device according to item 18.

216 Claim 13, wherein said toner means is provided with means for supplying liquid toner. image generator.

22, exhibiting low optical density and generally containing a non-conductive overcoat and charge carriers. A multicolor electrographic image is generated on a p-type electrographic medium having a an image generating device for moving on a predetermined path; a qualitatively transparent carrier platen, the media and a first image-bearing transparency in a first position; means for mounting the carrier platen in alignment on the carrier platen; and the platen and the transparency. means for co-translating the medium on the predetermined path; and means for co-translating the medium on the predetermined path; means for charging the medium to a first voltage v0; and a means for charging the medium through the transparency in a third position. exposing the media to a first light source and applying a second voltage V to the exposed portion of the medium. means for discharging and a first toner adapted to engage an overcoat of the media in a fourth position. means for providing a processing element and selectively toning an image-bearing charged area of the media; means for generating a one-color visible image, the absolute value of which is equal to (V, -V,,l) or is a voltage greater than this and opposite in polarity to (ν.-Vs=), and the toner-treated media means for reversely charging the medium, and exposing the medium to radiation from a second light source to trap the medium. Neutralize the trapped electrons by recombining them with mobile holes. and means for returning the platen, transparency and neutralized media to the first location. Thus, the first transparency is replaced by a second image-bearing transparency registered thereto. and repeating the charging and exposing steps to expose the medium to the first light source and form a second image. and tonerize the second image by a second toner processing element to produce a toner of the first color. and means for generating a second color visible image aligned with the visible image. .

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Claims (22)

[Claims] 1. An electrographic medium is placed on the carrier platen in a first position and the electrographic medium is placed on the carrier platen in a first position. Translate the latin and the medium together on a predetermined path, and charging the medium to one voltage Vo and exposing the medium to a first light-bearing image at a third position; to discharge the exposed portion of the medium to a second voltage Vw; providing a first toner treatment element adapted to engage a portion of the image bearing medium selectively; toner to produce a first visible image, and the platen and the media in the first position. The medium is returned and the charging-exposure process is repeated to expose the medium to a second light-bearing image and apply a second toner. toning the second image by an element to generate a second visible image; In a method for generating multistage electrophotographic images, the medium is The body is reversely charged, and a mobile charge of opposite polarity to that of the trapped charge and the trapped charge are charged. By recombining with the trapped particles, the trapped particles are neutralized and the first toner is recombined with the trapped particles. - After the treatment and before the second charging, the reverse charging and the charge neutralization are performed to remove the torpedo in the medium. An image generation method comprising steps of substantially neutralizing the absorbed charges. 2. Claims in which the oppositely charged charge has an absolute value in the range of ±50% of (Vo-Vw) The method described in box 1. 3. The reverse charging voltage has an absolute value equal to or larger than (Vo-Vw). The method according to claim 1. 4. The reverse charging voltage is an absolute voltage in the range of about 150% of (Vo-Vw) to (Vo-Vw). 2. The method of claim 1, wherein the method has a pairwise value. 5. The claim includes a step of erasing and exposing the medium after the toner treatment step and before the reverse charging step. The method described in Scope 1. 6. the medium includes a charge blocking layer, and the neutralization step involves exposing the medium to radiation to Claims including the step of assisting in the recombination of trapped charges and mobile charges in the medium. The method described in Scope 1. 7. The medium has or does not have a charge blocking layer, and the method includes charging the medium after the reverse charging. Exposing the medium to radiation and trapping the medium only if the medium includes a heavy barrier layer 2. The method of claim 1, further comprising the step of assisting recombination of the mobile charge and the mobile charge. . 8. The medium is an n-type electrographic photoconductor, and the trapped charge is an electron The method according to claim 1. 9. The electrographic medium is an n-type photoconductor, and the trapped charges are converted into holes. The method according to claim 1. 10. The platen also carries a negative image source, and the negative image source exposes the media. the toner treatment element is used to is selectively treated with toner, and the radiation ejection process in the neutralization process is 7. The method of claim 6, wherein both sides of the medium are exposed. 11. 2. The method of claim 1, wherein said toner treatment element comprises liquid toner. 12. In a first position, a p-electronic conductor is placed on a substantially transparent carrier platen. positioning the logographic medium and the first image-bearing transparency in registration with each other; The medium exhibits a low optical density and generally contains a non-conductive overcoat and a charge carrier. and further arranging the platen, the transparent image, and the medium together on a predetermined path. The medium is charged to the first voltage Vo at the second position, and the medium is charged to the first voltage Vo at the third position. and exposing the media through the transparency to a first light source to expose the exposed portion of the media to a second light source. discharge to a voltage Vw to engage the overcoat of the media in a fourth position. a first toner treatment element configured to selectively target image-bearing charged areas of the media with toner; processing to generate a first color visible image, the absolute value of which is equal to (Vo-Vw) or The medium is reversely charged with a voltage greater than this and the polarity is opposite to (Vo-Vw), and the second Expose the medium to radiation from a light source to recombine the trapped electrons with mobile holes Neutralizes the trapped electrons by causing the blasten, transparency and media to a second image-bearing transparency returning the body to the first position and aligning the first transparency therewith; repeating the charging and exposing steps to expose the medium to the first light source; generating a second image and toning the second image with a second toner processing element; Multicolor consisting of steps that produce a second color visible image that is matched to a one color visible image. How electrographic images are generated. 13. dispensing an electrographic medium onto a carrier platen in a first position; means for translating the platen and the media together on a predetermined path; means for charging the medium to a first voltage Vo in two positions; and means for charging the medium to a first voltage Vo in a third position; exposing the medium to the first light-bearing image and discharging the exposed portion of the medium to a second voltage Vw; means for engaging the medium in a fourth position to selectively torto a portion of the image bearing medium; a hand for providing a first toner treatment element adapted to be toner treated to produce a first visible image; step, return the platen and the media to the first position and repeat the charging and exposing process. exposing the media to a second light-bearing image and toning the second image with a second toning element; and means for generating a second visible image. the medium is reversely charged by a voltage of opposite polarity to (Vo-Vw) at By connecting the trapped charge to a mobile charge of opposite polarity, By recombining, the trapped charges are neutralized and the reverse charging means and and the charge neutralization occurs after the first toner treatment and before the second charging to reduce the charge neutralization in the media. An image generating device characterized in that the absorbed charges are substantially neutralized. 14. The reverse charging means provides a voltage with an absolute value within a range of approximately ±50% of (Vo-Vw). The invention according to claim 13, wherein the invention is made to provide the following: 15. The reverse charging means has an absolute value equal to or larger than (Vo-Vw). The invention according to claim 13, wherein the invention is adapted to supply a voltage. 16. The reverse charging means ranges from a value approximately equal to (Vo-Vw) to approximately 1 of (Vo-Vw). Claim 13 adapted to provide a voltage with an absolute value in the range of up to 50%. The invention described. 17. Claims including means for erasing and exposing the medium after toner treatment and before the reverse charging step. The invention described in item 13. 18. the medium includes a charge blocking layer and the image generating device discharges the medium after the reverse charging means. Exposure to radiation helps recombine trapped and mobile charges in the medium. The invention according to claim 13, comprising means for: 19. The medium may or may not include a charge blocking layer, and the image generating device may Subsequently, exposing the medium to radiation only if the medium includes a charge blocking layer Claims having means for assisting in the recombination of trapped and mobile charges in the The invention described in item 13. 20. Claim 1, wherein the radiation exposure means is adapted to expose both sides of the medium. The invention described in item 18. 21. Claim 13, wherein said toner means is provided with means for supplying liquid toner. The invention described. 22. exhibits low optical density and generally has a non-conductive overcoat and charge carriers. A multicolor electrographic image is generated on a p-type electrographic medium having a an image generating device for moving on a predetermined path; a qualitatively transparent carrier platen, the media and a first image-bearing transparency in a first position; means for mounting the carrier platen in alignment on the carrier platen; and the platen and the transparency. means for co-translating the medium on the predetermined path; and means for co-translating the medium on the predetermined path; means for charging the medium to a first voltage Vo; and a means for charging the medium through the transparency in a third position. means for exposing the medium to a first light source and discharging the exposed portion of the medium to a second voltage Vw; and a first toner adapted to engage an overcoat of the media in a fourth position. means for providing a processing element and selectively toning an image-bearing charged area of the media; means for generating a one-color visible image, the absolute value of which is equal to (Vo - Vw) or Toner-treated media is reversely charged with a voltage that is greater than that and has a polarity opposite to (Vo-Vw). means for exposing the medium to radiation from a second light source to generate trapped electrons; means for neutralizing the trapped electrons by recombining them with mobile holes; and by returning the blanken, transparency and neutralized media to the first location. , substituting the first transparency by a second image-bearing transparency registered thereto; repeating the charging and exposing steps to expose the medium to the first light source and generate a second image; and tonerize the second image with a second toner processing element to form the first color visible image. and means for generating a second color visible image aligned with the image.