JPS6129860A - Transfer device for color electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To increase transfer speed and to improve copying efficiency by the constitution in which color transfer is executed by using a transfer drum and that monochromatic copying or black and white copying is executed in the same manner as for an ordinary black and white copying machine without using the transfer device. CONSTITUTION:In monochromatic copying or black and white copying, the transfer drum 1 moves toward an arrow A and is put in a stationary state; at the same time, a corona discharger 2b and an auxiliary paper transport 7 are moved toward an arrow B to the position in proximity to the surface of a photosensitive drum 4, by which said copying is executed. The main paper transport 3 changes the introducing part thereof toward an arrow C so as to move near to the ejection side of the transport 7. The transfer paper 15 delivered by a timing roller 11 is thereby copied by the copying process similar to the copying process of the black and white copying machine. The copying speed is thus increased and the copying efficiency is improved.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a transfer device for a color electronic copying machine, and when the color copying machine performs black-and-white copying or monochrome copying, the copying efficiency is improved by increasing the transfer speed. Regarding the transfer device that can be used.

(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, the transfer device used in a color copying machine has a transfer paper holding means (hereinafter referred to as Grino ξ) that can repeatedly convey the transfer paper on which the first toner image has been transferred to the transfer area. By means of a rotating transfer drum equipped with
Transfer paper is wound around the surface of this transfer drum and conveyed. For this reason, the outer diameter of this transfer drum is determined based on the maximum paper size that can be copied, so it is possible to make black and white copies using paper that is smaller than the maximum paper size, for example, less than half the maximum paper size. When attempting to make a monochrome copy, the gripper must constantly rotate and return to a predetermined position in order to hold the next transfer sheet. Therefore, compared to conventional black-and-white copying machines, the number of copies processed is increased and the copying efficiency is poor.

It also has a drawback whenever 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 transfer device that eliminates the drawbacks of the above-mentioned prior art and improves the copying efficiency during black and white copying or overlapping color copying by a color copying machine. v It is to provide.

(Means and effects for solving the problems) That is, an object of the present invention is to transfer a color electronic copying machine that repeatedly transfers a color charge latent image formed on a photosensitive drum onto a transfer paper after development. In the device, photosensitive 1? a transfer ram or an endless transfer belt movably provided at a position away from the ram; and a transfer ram or an endless transfer belt movably provided outside the transfer drum or endless transfer belt and close to the photosensitive drum. The transfer drum or the endless transfer belt is moved to a position away from the photosensitive drum during monochrome copying or black-and-white copying, and the corona discharge device is rotated around the photosensitive drum. This is achieved by a transfer device of a color electronic copying machine, which is moved to a position close to the photosensitive P ram and transfers an image using this corona discharge device.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

1 and 2 are schematic diagrams of a color copying machine to which the present invention is applied.

The general structure of the transfer device 20 according to the present invention includes a movably provided hollow cylindrical transfer drum 1, first and second corona discharge devices 2a and 2b, and an inclination that changes as the transfer drum 1 moves. It consists of the main benoguchi transformer boat 3, which changes the main body.

The transfer 1 ram 1 has a first position (FIG. 1) close to the photosensitive F ram 4 and a second position away from the photosensitive drum 4 (see FIG.
(FIG. 2) is movably provided, and a transfer area is formed between the photosensitive drum 4 and the photosensitive drum 4 at the first position.

Furthermore, when the transfer drum 1 is disposed at the first position (a), the transfer drum 1 is configured to rotate in the opposite direction to the photosensitive drum 4 (counterclockwise rotation in this figure), and is equipped with a gripper that repeatedly conveys the transfer paper 15 to the transfer area. (not shown) is provided on its surface.

Note that the green plate ξ is provided on the outer circumferential surface of the transfer drum 1 along the axial direction, and is adapted to clamp the transfer paper 15 at the leading end in the conveyance direction. The transfer drum 1 also includes a grip cam 12 that releases the gripper to hold the transfer paper 15 and a release cam 1 that releases the gripper to separate the transfer paper 15 from the rolling ram 1.
3 is placed at a predetermined location close to its inner peripheral surface.

Also, the above transcription 1? In this first position, the ram 1 integrally accommodates therein a first corona discharge device f2a/r that discharges corona toward the photosensitive drum 4.

Next, the second corona discharge device 2b is located at a position away from the transfer area when the transfer drum 1 is installed in the first position, and the transfer drum 1 is located at a second position. 2, the photosensitive drum 4 moves between the transfer drum 1 and the photosensitive drum 4, as shown in FIG.
It has a configuration that forms a transfer area between the two. Also,
The second corona discharge device 2b is provided with an auxiliary pan-transport 7 integrally provided, and when the second corona discharge device 2b is transferred to the surface of the photosensitive drum 4, the auxiliary The transport 7 is arranged so as to be located on the exit side of the transfer area. In addition, the first and second corona release! The devices 2a and 2b are each composed of a transfer corotron 5 and a peeling corotron 6.

Further, the transfer paper 15 is transferred to the auxiliary paper transport 7.
A separating claw 8 for guiding the photosensitive drum 4 is provided on the exit side of the transfer area and near the circumferential surface of the photosensitive drum 4.

The main paper transport 3 that transports the transfer paper 15 on which the image has been transferred to the fixing device 9 is disposed on the exit side of the transfer area, and the position of its introduction portion is variable in accordance with the movement of the transfer drum 1. It is being That is, when the transfer drum 1 is provided at the first position, the introduction section is located on the exit side of the transfer area and close to the outer peripheral surface of the transfer drum 1. Moreover, when the transfer drum 1 is provided at the second position, the introduction section is arranged close to the output side of the auxiliary paper transport 7. In addition, A
The unloading section of the ffF main vane transporter 3 is arranged close to the fixing device 9.

Note that the transfer paper 15 taken out from the paper cassette 10 is conveyed to the transfer area by the timing roll 11.

In this embodiment, the transfer drum 1 is formed by covering the circumferential surface with a mesh-like insulating material, but a sheet-like insulating material is also used or no insulating material is provided. It is also possible to have a configuration in which roasting is carried out only by the frames on both sides.

Next, a color copying machine equipped with the transfer device 20 according to the present invention will be explained based on the copying process.
This is done by placing the transfer drum 1 in a first position as shown in FIG. Further, the second corona discharge device f2b, the auxiliary paper transport 7, and the main paper transport 3 are each arranged at the predetermined positions described above.

A color-separated charge latent image formed on the photosensitive drum 4 through the color-separation filter is developed by a developing device 14 (Y: yellow) containing toner of a color complementary to that of the color-separation filter, and the developing device 14 faces the transfer drum 1. moved to the transfer area. On the other hand, the transfer paper 15 taken out from the paper cassette 10
is conveyed to the transfer drum 1-H by the timing row A/ 11a, held by the gripper of the rotating transfer drum 1 and carried to the transfer area, and then corona is applied from the back side by the transfer corotron 5a disposed inside the transfer drum 1. The toner image of the first color is transferred by being discharged. The transfer paper 15 to which the first color toner image has been transferred continues to rotate once while being held by the transfer drum 1, and the surface of the photosensitive drum 4 is cleaned, completing the first image forming cycle. This image forming process is repeated for each of the other color separation filters, and when the color images are superimposed and transferred onto the transfer paper 15 to form a color image, the transfer paper 15 is removed by the peeling corotron 6a and the release cam 13. The paper is separated from the transfer drum 1 and transported to a main paper transport 3 having an inlet at a suitable position. Mainly, the transfer paper 15 carried out by the saw transport 3 is conveyed to the fixing device 9, where the unfixed image is fixed, and the copying process is completed.

Next, as shown in FIG. 2, for monochrome copying or black-and-white copying, the transfer drum 1 is moved to the second position (in the direction indicated by arrow A in the figure) and kept in a stationary state without rotating. The second corona discharge device 2b and the auxiliary bay transport 7 are moved to a position close to the surface of the photosensitive drum 4 (in the direction indicated by arrow B in the figure).

In addition, the main paper transport 3 is in a state in which the introduction portion thereof is changed to be close to the discharge side of the auxiliary paper transport 7 (in the direction shown by arrow C in the figure) so that the transfer paper 15 can be suitably transported. It is set up in

That is, the transfer paper 15 sent out by the timing roll Ilb passes over the second transfer corotron 5b and the peeling corotron 6b, and the ridge where the image is transferred is separated by the separating claw 8 on the exit side of the transfer area. The paper is guided by the seventh paper transport 7 and the main paper transport 3 to the fixing device 9 to complete the copying process.

In the above embodiment, a case was described in which the transfer drum 1 was used as the transfer means, but in the present invention, instead of the transfer drum,
It can also be constructed by an endless transfer belt made of the same material as the surface material of this transfer drum.

(Effects of the Invention) As described above, according to the transfer apparatus of the present invention, color copying is performed using a transfer drum, and monochrome copying or black-and-white copying is performed in the same way as a normal black-and-white copying machine without using a transfer drum. By adopting such a configuration, the transfer speed can be increased and the copying efficiency can be improved. Also, when making monochrome copies or black and white copies,
Since the transfer paper is not conveyed by creases or grooves, image defects do not occur.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views of a color copying machine illustrating an embodiment of the present invention. Reference numerals in the figure 1... Transfer drum, 2-... Corona discharge device, 3-...
・Main Peichi no So Trance; I? -G, 4...G light 1' A, 5...Transfer corotron, 6...Peeling corotron, 7...Auxiliary base/saw transport, 8...Separation claw, 9.Fixing device , 10...Paper cassette, 11...
・Timing roll, 12...Grip cam, 13-
...Release cam, 14...Developer, 15...Transfer paper, 20...Transfer device (and 3 others)

Claims (1)

[Claims] A transfer drum that is movably provided at a position away from the photosensitive drum in a transfer device of a color electronic copying machine that repeatedly transfers a color charge latent image formed on the photosensitive drum onto transfer paper after development. Alternatively, it has an endless transfer belt, and a corona discharge device that is movably provided outside the transfer drum or the endless transfer belt and close to the photosensitive drum and performs corona discharge toward the photosensitive drum. During monochrome copying or black-and-white copying, the transfer drum or the endless transfer belt is moved to a position away from the photosensitive drum, and the corona discharge device is moved to a position close to the photosensitive drum. A transfer device for a color electronic copying machine, characterized in that image transfer is performed by a color electronic copying machine.