JPS6129859A - Paper conveying method for color copying machine - Google Patents

Abstract

PURPOSE:To improve the copying efficiency in monochromatic copying or black and white copying by providing a paper conveying path different from the stage of multi-color copying in the stage of monochromatic copying and constituting the same in such a manner that a transfer drum for multi-color copying is not substantially used. CONSTITUTION:The transfer drum 6 for multi-color copying is placed in a static state in the stage of monochromatic copying or black and white copying. The paper 5 taken out of a paper cassette 9 is guided via the 1st timing roll 14 and a change-over chute 16 to the conveying path 11 for a monochromatic copying mode. The paper 5 is further carried by the 2nd timing roller provided in the path 11 to a transfer region where the paper passes over a transfer corotron 18 and is transferred with an image. The paper 5 subjected to the image transfer is guided by a separating pawl 7 to a conveying belt 13 by which the paper is carried to a fixing device 12. The paper conveying path which is different from the stage of multi-color copying in the stage of monochromatic copying is provided and the transfer drum is not used and therefore the transfer speed is increased and the transfer efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of conveying paper in an electrostatic copying machine, and in particular, to a method for carrying paper in an electrostatic copying machine, and in particular to a method for carrying paper in an electrostatic copying machine, and in particular for producing black-and-white copies or The present invention relates to a paper conveyance method that can improve copying efficiency by speeding up transfer efficiency when performing monochrome copying compared to multicolor copying.

(Prior Art) Conventionally, color copying machines using electrostatic copying form color images by sequentially superimposing and transferring a plurality of color-separated toner images formed on a photosensitive drum onto transfer paper. ing.

Therefore, this color copying machine uses a rotating transfer drum equipped with paper holding means (hereinafter referred to as a gripper) that can repeatedly convey the paper onto which the first toner image has been transferred to the transfer area. The paper is wound around the surface of this transfer drum and conveyed. Therefore, since the outer diameter of this transfer drum is determined based on the maximum paper size that can be copied, black and white printing can be done using paper smaller than the maximum paper size, for example, less than half the maximum paper size. Alternatively, when attempting to perform monochrome copying, the gripper must constantly rotate once and return to a predetermined position in order to hold the next sheet of paper. Therefore, compared to conventional black-and-white copying machines, these machines have the drawback of increasing the number of copies processed and lowering copying efficiency. It also has the disadvantage that the image of the location held by the gripper is missing.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a paper conveyance method that eliminates the drawbacks of the above-mentioned prior art and improves the copying efficiency during black-and-white copying or monochrome copying by a color copying machine. It's all about providing.

(Means and operations for solving the problems) That is, the above-mentioned object of the present invention is to provide paper for a color copying machine that forms a copy image by superimposing and transferring a plurality of developed color charge latent images onto paper. A paper transport method for a color copying machine, characterized in that separate paper transport paths are provided for a monochrome copy mode and a multicolor copy mode, and the paper transport path is switched according to the copy mode. is achieved.

(Example) An example of implementing the present invention will be described below.

FIG. 1 is a schematic sectional view of a color copying machine embodying the present invention.

The color copying apparatus 30 includes a charging device 2 that uniformly charges the surface of a photosensitive drum 10 rotating in a clockwise direction, and a plurality of color photosensitive drums that expose the entire spectral image of a document onto the charged photosensitive drum 1 to form a color charge latent image. an exposure section 3 equipped with a separation filter, and a plurality of developing devices 4 (in this embodiment, there are three developing devices) each having a developer having a complementary color relationship with the color separation filter and developing the color charge latent image 1. (Y: Yellow; M: Magenta; C Nidian) is shown), which is rotatably provided in the counterclockwise direction to transfer the developed color image charge latent image onto the paper 5. Transfer drum 6, paper 5 from photosensitive drum 1 side during monochrome copying
separation claw 7 and cleaning device f' for separating the
8(r) are configured to be sequentially arranged in close proximity to each other.!, paper cassettes 9 provided for each paper size, and a transport path 10 for multicolor discard mode that transports the paper 5 from the paper cassette 9 to the transfer drum 6. A transport path 11 for monochrome copying mode and a transport belt 13 for transporting the paper 5 onto which the image has been transferred to the fixing device 12 are arranged at predetermined positions, respectively.

When a multicolor copy image is produced using this color copying machine, the uniformly charged photosensitive drum 1 is one of the color separation filters. The document is exposed to light to form a color charge latent image. In the violet, the color charge latent image is developed by a developing device 4 containing toner of a color complementary to the color of the color separation filter, and is transferred to a transfer area facing the transfer drum 6. On the other hand, the second
As shown in the figure, which is an enlarged view of the main parts of this embodiment, the paper 5Fi taken out from the paper cassette 9 is transported by the first timing roll 14, and the switching chute 16 (solid line) provided in the transport path is set to the multicolor copying mode. guided to the transport path 10. The paper 5 that has passed through the multicolor copying mode conveyance path 10 is held by a gripper 17 provided on a rotating transfer drum B and is carried to a transfer area, where it passes over a transfer roller 18 that performs corona discharge toward one surface of the photosensitive drum. The image is transferred by passing through it. At this time, the gripper 17
(by the grip cam 19 disposed close to the inner peripheral surface of the transfer drum 6) at a position immediately before holding the paper 5, and is placed in a state where it can hold the paper 5.

The paper 5 on which the image has been transferred is wound around the transfer drum 6 and rotates once, and when the surface of the photosensitive drum 1 is cleaned by the cleaning device 8, the first image forming cycle is completed. When such an image forming process is repeated for each of the other color separation filters and a multicolor copy image is formed by overlaying each color image on the paper 5, the paper 5 held on the transfer drum 6 is It is carried to a release cam 20 which releases the gripper 17. The IJ IJ-scum 20 is disposed on the inner peripheral surface of the transfer drum 6 and near the exit side of the transfer area, and the gripper 17 [ As a result, the paper 5 is released from the transfer drum 6. The paper 5 released from the transfer drum 6 is carried by the conveyor belt 13 to the fixing device 12, where the unfixed image is fixed and the copying process is completed.

Next, during monochromatic or black-and-white copying, the transfer drum is used in a stationary state.

The paper 5 taken out from the paper cassette 9 is guided to the monochrome copying mode transport path 11 via the first timing roll 14 and the switching chute 16 (break #'). The discharge section of the single-color copy mode conveyance path 11 is located closer to the transfer area than the discharge section of the multicolor copy mode conveyance path 10, and is provided near a substantially tangential line between the transfer drum 6 and the photosensitive drum 1. The paper 5 conveyed by the switching chute 16 to the conveyance path 11 for monochrome copying mode is further conveyed to the transfer area by the second timing roll 15 provided in the conveyance path 11 for monochrome copying mode, and is transferred to the transfer area by the transfer corotron 18. The image is transferred by passing through the top. The paper 5 on which the image has been transferred is further moved by the second timing roll 15, guided by the separation claw 7 to the conveyor belt 13, and conveyed to the fixing device 12. During this monochrome copying, the paper 5 is transported to the transfer area only by the second timing roll 15 and the transport belt 13, so the discharge section of the transport path 11 for the monochrome copy mode is used for the transport for the multicolor copy mode. It is provided closer to the transfer area than the outlet of the path 10. Furthermore, during monochrome copying, the gripper 17 is placed and stopped at a position that does not interfere with monochrome copying.

As explained above, in the present invention, in order to improve the copying efficiency during monochrome copying, the transfer drum is not substantially used, and the paper is conveyed through a short conveyance path even during multicolor copying. It is.

(Effects of the Invention) As described above, according to the paper conveyance method of the present invention, by providing a paper conveyance method different from that for multicolor copying during monochrome copying and substantially eliminating the use of the transfer drum, the rotation of the transfer drum is reduced. You can increase the number of copies by speeding up the transfer speed without being affected.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a color copying machine implementing the present invention;
FIG. 2 is an enlarged view of the main part of FIG. 1. Reference numerals in the figure 1... Photosensitive drum, 2... Charging device, 3... Exposure section, 4... Developing device, 5... Paper, 6... Transfer drum, 7-... Separation claw , 8...-Cleaning device, 9.
... Paper sumo wrestler, 10... Conveyance path for multicolor copying mode, 11... - Conveyance path for single color copying mode, 12... Fixing device, 13... Conveyance belt, 14... First timing Roll, 15...Second timing roll, 16...
Switching chute, 17...Grip, 18...Transfer corotron, 19...Grip cam, 20...Release cam, 60...Color copying device neck Aq

Claims (1)

[Claims] In the paper transport method of a color copying machine that forms a copy image by superimposing and transferring a plurality of developed color image charge latent images onto paper, separate paper transport is used for monochrome copying mode and multicolor copying mode. 1. A method for transporting paper in a color copying machine, comprising: providing a paper transport path, and switching the paper transport path according to a copying mode.