JPH035753B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses electrophotography to create a first original and a second original.
The present invention relates to an image composition method for copying original images onto the same recording medium, and particularly to an image composition method using an electronic printing method.

2. Description of the Related Art Conventionally, as one of image composition methods using electrophotography, the so-called form overlay method is well known, in which normal electrophotographic copying is performed with double originals stacked on a document table. With this method, latent images corresponding to two types of originals are simultaneously formed on the photoreceptor, so there is no problem in terms of uniformity of composite image density, but one of the originals is limited to a transparent original.
This method has drawbacks such as the possibility of misalignment of the originals, which tends to cause image misalignment of the composite image, and the hassle of having to superimpose the originals for each copying operation.

Another method is to sequentially form latent images corresponding to two types of originals on a photoreceptor and overlap them. For example, a method using a photoreceptor with two laminated photosensitive layers with different photosensitive regions and performing image exposure after the charging process with different wavelength ranges for each document, or JP-A-55
As shown in Japanese Patent Application No. 87175, there is a method in which a photoreceptor having a transparent insulating layer provided thereon is sequentially subjected to charging and simultaneous first image exposure, charging and simultaneous second image exposure, and whole surface exposure. These methods do not limit the number of originals or complicate overlapping of originals; however, because a special photoreceptor or process is used, the device configuration inevitably becomes complicated. In addition to the poor uniformity of the image quality of the composite image, when it is desired to superimpose a number of second document images with different contents on a constant first document image such as a line or frame, the latent image of both documents may be There is the complexity of having to repeat the forming process every day.

The object of the present invention is to provide an image synthesis method that eliminates the drawbacks of conventional methods, and that makes it possible to obtain a composite image with simple operations, no positional deviation, and excellent uniformity of image quality. The purpose is to provide law.

A further object of the present invention is to provide an image synthesis method for forming a composite image by repeatedly using the same format original and replacing only the other original.

The present invention achieves the above objects as follows.

That is, first, the electrophotographic photoreceptor is charged, and then the image of the first original is exposed. Next, the latent image of the first document is developed with toner to form a toner image, which is fixed to obtain a fixed toner image of the first document on the photoreceptor. Next, after recharging the photoconductor having this fixed toner image, image exposure of the second original is performed, and the charge image on the toner image for the first original is converted into a composite electrostatic latent image consisting of an electrostatic image for the second original. is formed on a photoreceptor, this electrostatic latent image is developed to obtain a composite toner image, and then this composite toner image is transferred and fixed to obtain a composite image. By cleaning the residual toner on the photoreceptor after transfer and performing the above process on a different second original (that is, the process after image exposure of the second original), the second original, which is different from the first original, is removed.
A composite image with the original can be obtained in the same manner.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a diagram showing an example of an apparatus used in the present invention, in which 1 is a rotating drum, 2 is a projection lens,
3 is a document table, 4 is a charger, 5 is a developing device, 6 is a transfer corotron, 7 is a flash fixing device, 8 is a cleaning device, 9 is a hot roll fixing device, 10 is a photoconductive sheet, 11 is a transfer paper, 12 is the paper output tray, 1
3 is a uniform exposure lamp, 14 is an original illumination lamp, 1
5 is a cleaner lamp, 16 is a photoconductive sheet inlet, and 17 is a photoconductive sheet discharge tray.

Next, the operation of this device will be explained.

The first document is in format, and the second document is in numerical format.
A case of a manuscript with variable content such as characters will be explained.

First, after the photoconductive sheet 10 is wrapped around and supported by the rotating drum 1, it is charged by the charger 4, and further illuminated by the document illumination lamp 14, the first document on the document table 3 is exposed to light through the projection lens 2. Conductive sheet 10
is projected onto the surface, forming an electrostatic latent image. Next, the latent image corresponding to this first document is visualized by the developing device 5, and then transferred to the photoconductive sheet 1 by the flash fixing device 7.
0 to obtain a fixed toner image.
Next, a second original is placed in place of the first original on the original platen 3, and the photoconductive sheet 10, which carries the above-mentioned fixed toner image and is wound around the rotating drum 1, is again charged with a charger. 4, and a second original image is projected by the original illumination lamp 14 and the projection lens 2, and a composite electrostatic latent image consisting of the charge image on the toner image for the first original and the electrostatic image for the second original is photoconductive. Obtained on sheet 10. Next, this composite latent image is visualized in the developing device 5, and then the transfer paper 11 is sent to the transfer section in synchronization with the rotation of the rotary drum 1.
The image on the photoconductive sheet 10 is transferred to the transfer paper 11 by the transfer corotron 6, and then becomes a fixed image by the heat roll fixing device 9, and is guided to the paper discharge tray 12 to become a copy.

On the other hand, the residual toner on the photoconductive sheet 10 after the transfer is cleaned by the cleaning device 8, and one composite image copying is completed. The fixed toner image corresponding to the first document remains on the photoconductive sheet 10, and after that, several different second toner images remain.
When compositing with the original image, simply replace the second original on the original table one by one and perform the above-mentioned recharging and second original.
The steps of exposing the original image, developing, transferring/fixing, and cleaning may be performed.

Known charging devices and image exposure devices can be used in the present invention.

The photoconductive sheet 10 has ZnO,
Those coated with a photosensitive layer in which photosensitive particles such as CDS are dispersed in resin, or those coated with an organic photosensitive material such as polyvinylcarbazole-trinitrofluorenone (PVK-TNF) can be used, and the shape is also sheet-like. It can be used in any form such as , belt shape, scroll shape, etc. When formed into a sheet, the photoconductive sheet carrying the fixed toner image can be once discharged from the apparatus and stored for reuse. Further, when the photoconductive sheet is formed into a scroll shape, the complexity associated with feeding and discharging the photoconductive sheet is eliminated, and the apparatus can be simplified.

The developing method may be any conventionally known method such as a magnetic brush method or a cascade method, and either a two-component developer or a one-component developer can be used.

As a method for fixing the toner image corresponding to the first original image on the photoconductive sheet 10, a pressure fixing method or a heat fixing method is used. Since the photoconductive sheet 10 carrying the fixed toner image is subsequently recharged, any fixing method that does not cause a change in the chargeability of the photoconductive sheet 10 may be used. Examples of thermal fixing methods include hot roll fixing and flash fixing, but these methods are preferred because they simplify the equipment and cause less deterioration in image quality during toner fixation.
Preference is given to using flash fixing methods. A schematic cross-sectional view of a specific flash fixing device suitable for use in the present invention is shown in FIG. In the figure, 18 is a flash lamp, and 19 is a reflector. The position of the flash lamp 18 and the shape and position of the reflector 19 are determined by the photoconductive sheet 10 wound and supported on the rotating drum 1.
In order to efficiently and uniformly fix the upper toner image, the reflector 19 is composed of two ellipsoidal parts each sharing one focal point, and the flash lamp 18 is disposed in the shared focal part. The recording surface is arranged in the vicinity of the focal point of the other of the two ellipsoidal parts.

As the device for recharging and the device for exposing the image of the second document, the same device used for forming the fixed toner image corresponding to the first document image may be used again, or a separate device may be provided.

State diagrams on the photoconductive sheet during the formation and visualization of electrostatic latent images corresponding to the first and second originals are shown in FIGS. 3a-i.

In the figure, a is a charging process, b is a first original image exposure process, c is a developing process, d is a fixing process, e is a recharging process, f is a second original image exposure process, g is a reproduction process,
h indicates a transfer process, and i indicates a toner fixing process on the transfer paper. Further, 20 indicates toner particles, 21 indicates a fixed toner image, and 22 indicates a toner image on the transfer paper.

A photoconductive sheet 10 carrying a fixed toner image corresponding to a first document formed by steps a to d.
By performing recharging in the step e and exposing the second original image in the step f, the charges in the bright areas of the photosensitive layer portion of the photoconductive sheet 10 flow out through the conductive support, and the charges in the dark areas are discharged through the conductive support. The charge at is retained. On the other hand, the toner image part fixed on the photoconductive sheet 10 plays the role of an optical shielding mask for the photoconductive layer part immediately below it, so that it hardly affects the bright and dark parts caused by the second original image exposure. The charge is retained. In this state, the reproduction step g, the transfer step h, and the toner fixing step i on the transfer sheet are sequentially performed to obtain a copy of the composite image.

FIG. 4 shows that by combining a first document a representing a format and a second document b representing variable contents such as symbols and characters using the method of the present invention, a copy of a composite image as shown in c is obtained. This shows that.

As a method for cleaning the toner remaining on the photoconductive sheet 10 in the present invention, conventionally known fur brush methods, magnetic brush methods, etc. can be used.

Further, as a method for removing residual charges on the photoconductive sheet 10, conventional methods such as AC corona discharge and uniform exposure can be used.

As explained above, according to the method of the present invention, it is possible to obtain a composite image of uniform image quality without positional deviation with simple operations.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example of an apparatus used to carry out the method of the present invention, FIG. 2 is a schematic sectional view of an example of a flash fixing device used in the method of the present invention, and FIGS. FIGS. 4a to 4c, which are explanatory diagrams sequentially showing the steps of the method of the present invention, represent examples of a first original image, a second original image, and a composite image, respectively. Symbols in the figure: 1... Rotating drum, 2... Projection lens,
3... Original table, 4... Charger, 5... Developing device, 6... Transfer corotron, 7... Flash fixing device, 8... Cleaning device, 9... Heat roll fixing device, 10... Photoconductive sheet, 11... Transfer paper, 12 ...Output tray, 1
3...Uniform exposure lamp, 14...Original illumination lamp, 1
5...Cleaner lamp, 16...Sheet inlet, 1
7...Sheet discharge tray, 18...Flash lamp, 19...Reflector, 20...Toner particles, 21...Fixed toner image, 22...Fixed toner image on transfer paper.

Claims (1)

[Claims] 1 After charging the electrophotographic photoreceptor, perform image exposure of the first original to obtain a latent image, and develop this latent image to form the first original.
After forming and fixing a toner image of the original document to form a fixed toner image of the first original document on the photoconductor and then recharging the photoconductor having the fixed toner image, image exposure of the second document is performed. A composite electrostatic latent image is formed from the charge image on the toner image for the first original and the electrostatic image for the second original, this composite electrostatic latent image is developed to obtain a toner image, and this toner image is transferred to a transfer material. An image composition method characterized by obtaining a composite image by transferring and fixing the image.