JPS61138263A - Image forming device - Google Patents

Abstract

PURPOSE:To permit the simple copying of a synthetic image by holding preliminarily paper to a transfer drum in a transfer part by means of a grip provided to the drum, releasing the grip and feeding the paper to a fixing part upon ending of the transfer of the desired multi-color image. CONSTITUTION:The paper P fed by a feed guide 8a and feed rollers 9 is held by a gripper 10 incorporated to the transfer drum 6 and is wound around the drum 6 by the corona of an electrostatic charger 17, by which the paper is conveyed in an arrow A direction. The yellow image developed 4 on a photosensitive drum 1 is transferred by an electrostatic charger 7 for transfer to the paper P. The drum 6 rotates in synchronization with the drum 1 and the image of the next color is transferred onto the paper P. The gripper 10 holds the paper P until the copying of the desired multiple color copying ends in the above-mentioned manner. The gripper 10 is released after the end of transfer of another image and the paper P is stripped 13 and is fixed 15 in the stage of synthesizing another image. The formation of the synthetic image and multi- color images is thus made easy.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a grid in which the leading end of a recording sheet is provided on a rotating body;
While rotating the rotating body, the image formed on the image carrier is transferred onto a recording sheet supported on the rotating body, and the image is recorded on the recording sheet. It relates to an image forming apparatus, for example, by applying electrophotography, an electrostatic latent image formed on a photoreceptor is developed with colored toner, and a transfer drum rotates the image formed on the photoreceptor in this way. The present invention relates to a multicolor image forming apparatus that records a multicolor composite image on the recording sheet by transferring each color onto a recording sheet supported by a grid on the recording sheet.

[Background of the invention]

The above-mentioned type of image forming apparatus will be described below using a color electrophotographic copying machine as an example.

FIG. 3 shows a sectional view of a color electrophotographic copying machine to which the present invention can be applied. In the figure, A is a document, B is an optical system that scans the document, C is an image forming section where an image of the document is formed via the document scanning optical system, and D is a device that transfers nine strokes formed in the image forming section. The figure shows the transfer area to be transferred.

The image forming section CK includes a photoreceptor 1 on a rotating drum and a charger 2.
, 3. Developing device 4. A cleaner 5 is provided. The developing device 4 includes a yellow developing device 4Y, a magenta developing device 4M, a cyan developing device 4C, and a plastic developing device 4BK. Also,
The transfer section DK is provided with a transfer drum 6 and a transfer charger 7.

The photoreceptor 1 on the rotating drum is neutralized by a charger 2,
Thereafter, it is charged by the charger 3. Next, K11i exposure E is carried out, but in the illustrated example, it is carried out in the order of yellow, magenta, cyan, black, and black, so a color separation optical system (not shown) equipped with a complementary color filter for each color is used. , it performs electroimage exposure using blue light. Further, when exposing with a scanner such as a radar scanner, a yellow image signal is output and exposed.

Next, the yellow developer 4 is set in advance at the development position.
Development is performed by YK.

The transfer driver 56 is covered with a film or a mesh-like screen made of a dielectric material (not shown). The recording sheet that has been fed through the paper feed guide 8&, paper feed roller 9, and ID 8b is held by the grip 10 built into the transfer drum 6, and is charged by the corona of the charger 17 to a dielectric film or mesh screen. is maintained. At this time, the electrostatic adsorption effect is increased by pressing the paper against the paper using the pressing rollers 18 that can be moved into and out of contact with each other. The transfer drum 6 rotates in synchronization with the photosensitive dryer i1, and the yellow developer is transferred onto the recording sheet by the transfer charger 7 at the transfer section. The transfer drum 6 continues to rotate in preparation for transferring the next color (magenta in this figure).

On the other hand, after being cleaned by a cleaning member 5, the photosensitive drum 1 is charged by a charger 3 and subjected to color separation exposure using green light, which is the complementary color of the magenta toner. During this time, the yellow developing device 4Y is separated and the yellow developing device 4M is at the developing position. This kind of process will be carried out for cyan, black, and li from now on.

When the transfer is completed, the static electricity is removed by a circular charger installed inside and outside the transfer driver 56, for example, by an AC charger.
is released and the recording sheet is separated from the transfer drum 6 by the separation claw 13 and sent to the fixing device 15 by the conveyor belt 14, a copy image is formed, and the copy sequence ends. - In the sequence of recording a composite image on a recording sheet by multiple transfer as explained above, one recording sheet)
K In order to combine the same image or multiple images, it is necessary to create a combined image in some form in advance, and then expose the photoreceptor with the combined image.

For this purpose, a processing circuit and memory for synthesizing images are required in a system that performs exposure using a scanner such as a radar scanner.

Furthermore, in a system such as that shown in FIG. 3, in which a manuscript is directly exposed using an appropriate document scanning optical system, the document itself must have already been synthesized. Further, a method in which a recording sheet that has been ejected once is fed again is not suitable for process control.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of the image forming apparatus as described above, and to eliminate the need to separate the recording sheet from the transfer drum as necessary even after the transfer of all colors for one image is completed. An object of the present invention is to provide an image forming apparatus characterized in that a plurality of images can be synthesized by successively transferring the next image.

[Summary of the invention]

The image forming apparatus according to the present invention grips the leading edge of a recording sheet with grips provided on a rotating body, and while rotating the rotating body, images formed on an image carrier are transferred onto the rotating body. In an image recording apparatus that records an image on a recording sheet supported by a recording sheet, the gripper is released after the first image is formed on the recording sheet, and the recording sheet is A normal mode in which the recording sheet is separated from the rotating body and discharged, and a second image is further transferred onto the first image without releasing the grits even after the first image is formed on the recording sheet. The present invention is characterized in that it is provided with means for selecting an overlapping mode for overlapping.

[Embodiments of the invention]

Examples of the present invention will be described below. The present invention can be carried out with respect to the color electrophotographic copying machine shown in FIG. However, it is generally applicable to image forming apparatuses in which a recording sheet is gripped by a rotating body with grips and nozzles, and images are sequentially recorded on the recording sheet to form an image. .

FIG. 1 shows the control section of the copying machine shown in FIG. 3.

A diagram is shown below.

The operation unit 201 includes a switch for inputting the number of composite images and its display, a color mode selection layer switch (for example, a switch for selecting whether to copy in full color or red monochrome) and its display, and a switch for inputting the number of composite images and its display. There is a switch for discharging commands to stop the process midway through, and other switches and display units necessary for the copying machine, and these are connected to the CPU via an I10 port 205.

Loads 01 to On (for example, photosensitive drum rotating motor, etc.) necessary for controlling the copying machine are output through the entire I10 port 205 to the output interface 2 according to instructions from the CPU 202.
06. In addition, the input means 11 to In required for control (for example, a sensor for jam detection, etc.) are connected via the input interface 206 and the I10 port 205.
Po 202K is input.

FIG. 2 is a flowchart of a copying sequence for obtaining a composite image according to the present invention. This figure shows an example when full color is selected.

Here, as will be described later, the conventional example described above is different from the conventional example described above, except that the recording sheet is not separated from the transfer drum immediately after the transfer of all colors for one image by the number of composite images KE is completed. Since the sequence is almost the same, we will omit the details below.

When the sequence starts, the number of images N to be combined, the color mode for the first image, and other key inputs necessary for controlling the copying machine are accepted (Flows 301, 302, 3).
03), determine whether copying is possible (for example, presence or absence of a recording sheet, etc.) (flow 304); if copying is possible, send the copy button and wait until the copy button is pressed (flow 305). It should be noted that the CPU stores in RAM K which keys have been selected such as the number of composite images N, and the following control is performed according to the contents.

When the copy button is pressed, the recording sheet starts feeding and grips the transfer drum (flows 306 and 307).
. Next, depending on the selected color mode, yellow, magenta, cyan, de2. Exposure, development, and transfer are performed for the necessary colors from among the images (flows 308 to 311). Here, since FIG. 2 is an example in the case of full color, all steps 308 to 311 are performed, but some steps may be omitted depending on the color mode. (For example, in the case of red single color, flows 310- and 311 are omitted.) Next, regarding the number N of composite images stored in the RAM, N
=N-1 (7er-312), and if N=0 (Flow 313), the recording sheet is directly separated from the transfer drum (Flow 317) and fixed (Flow 318) to form a copy image.

If N>0, this indicates that there are more images to be combined, so the remaining image @N is recorded in RAM K again and jumps to flow 314.

In flow 314, an ejection switch is accepted.

When the ejection switch is pressed, the image composition is stopped there, and the process proceeds to flow 317, where the images are separated, fixed, and ejected to obtain the image that has been synthesized up to that point.

If the discharge switch is not pressed in flow 314, input of the color mode for the next image is accepted (flow 315).
, flows 314, 315 . until the copy button is pressed.
Repeat 316.

When the copy button is pressed again, the process moves to flow 308, and then repeats steps 308 to 316 until N=O. When N=O, the recording sheet is separated from the transfer drum (flow 3i7), and the fixing process starts (flow 3i7). 318) and ejected (flow 319) to obtain a composite image.

〔Effect of the invention〕

As explained above, in the present invention, even after forming the first image on the recording sheet, the recording sheet is held on the rotating body without releasing the gripper, and the rotation of the rotating body is continued to produce the second image. By transferring the image onto a recording sheet, it is possible to obtain a composite image without using any special memory circuit, and it is also combined with functions such as changing the color mode for each image and enlarging/reducing functions. By doing so, it is possible to obtain a further variety of copied images.

Furthermore, it is also effective to use the above method in combination when a processing circuit such as a memory is used to synthesize images.

[Brief explanation of the drawing]

FIG. 1 is a professional diagram of a control section according to an embodiment of the present invention.
FIG. 2 is a diagram showing an example of a flowchart based on the present invention, and FIG. 3 is a sectional view of a color electrophotographic copying machine for implementing the present invention. A... Original B... Original scanning optical system C
...Image forming section D...Transfer section E...Exposure 1...Photosensitive drum 4...Developing device
6...Transfer drum 7...Transfer charger

Claims (2)

[Claims] (1) The leading edge of the recording sheet is gripped by a gripper provided on a rotating body, and while the rotating body is rotated, the image formed on the image carrier is transferred onto the recording sheet supported on the rotating body. In an image forming apparatus that transfers and records an image on the recording sheet, after a first image is formed on the recording sheet, the gripper is released to separate the recording sheet from the rotating body and discharge it. A normal mode in which the first image is formed on the recording sheet, and an overlapping mode in which the second image is further transferred and overlaid on the first image without releasing the gripper even after the first image is formed on the recording sheet. An image forming apparatus characterized by comprising means. (2) The image forming apparatus according to claim (1), wherein the first and second images are color images.