JPH04153061A - Sensitized paper holding mechanism of electrophotographic device - Google Patents

Abstract

PURPOSE:To hold sensitized paper positively on picture formation operation, and to execute efficient picture formation operation having high accuracy by providing a first suction port being formed to the supporter of sensitized paper and sucking a front end section in the carrying direction to the supporter, a second suction port for sucking a rear end section to the supporter and a negative-pressure generating means for maintaining the first and second suction ports at negative pressure. CONSTITUTION:When the front end section 3a of sensitized paper 3 is arranged in response to a first suction port 24 formed to the outer circumference of an exposure drum 22, a negative-pressure generating means 28 is driven, and the first suction port 24 is brought to a negative pressure state through ducts 38, 34 and a casing 30. Consequently, the front end section 3a of sensitized paper 3 is sucked to the first suction port 24, and held to the exposure drum 22. When the rear end section 3b of sensitized paper 3 is disposed in response to the second suction port 26 of the exposure drum 22, the second suction port 26 is brought to the negative pressure state through ducts 38, 36 and a casing 32 under the action of the negative pressure generating means 2, and the rear end section 3b is sucked and sustained to the exposure drum 22.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an electrophotographic apparatus, and more specifically, a layer of a photosensitive paper holding layer for holding the photosensitive paper when an image is formed on the photosensitive paper. Regarding the mechanism.

[Prior Art] Electrophotographic devices that record visible images on recording paper (photosensitive paper) using photoelectric phenomena and electrostatic phenomena are widely used. This type of electrophotographic apparatus is generally constructed as shown in FIG.

In FIG. 3, reference numeral 1 indicates an exposure drum (support) that is rotatable around a support shaft 2. On the outer periphery of this exposure drum 1, a suction device is provided to attract and hold the leading edge of the photosensitive paper 3. Hole 4
is formed.

This suction hole 4 communicates with a conduit 6 via a casing 5, and this conduit 6 is taken out from the exposure drum l and connected to a negative pressure generating means 7.

Surrounding the exposure drum 1 are a charger 8 that applies an electrostatic charge to the photosensitive paper 3, an exposure device 9 that forms an electrostatic latent image on the photosensitive paper 3 based on predetermined image information, and a charger 8 that applies an electrostatic charge to the photosensitive paper 3. A developing device 10 for visualizing a latent image and a photosensitive paper 3 after development
A static eliminator 11 for removing electric charge remaining on the surface is sequentially provided.

In the conventional electrophotographic apparatus configured as described above, when the photosensitive paper 3 is supplied to the exposure drum 1 from a paper feeder (not shown), the conduit 6 and the casing 5 are moved under the action of the negative pressure generating means 70.
The suction hole 4 is maintained in a negative pressure state through the photosensitive paper 3.
The tip of the tube is sucked into the suction hole 4. Therefore, the photosensitive paper 3 is held on the outer periphery of the exposure drum 1, and is rotated in the direction of the arrow by a drive means (not shown), and the photosensitive paper 3 is first sent to the charger 8. electrostatic charge is applied uniformly to its surface.

Next, after a predetermined electrostatic latent image is formed by the exposure device 9, the photosensitive paper 3 is conveyed to the developing device 10, and the electrostatic latent image formed on the surface of the photosensitive paper 3 is visualized. After the development is completed, any charge remaining on the surface of the photosensitive paper 3 is removed via the static eliminator 11.

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, only the leading end portion of the photosensitive paper 3 is suctioned and held by the suction hole 4 formed on the outer periphery of the exposure drum 1. 3, or it is often not held securely on the exposure drum 1. For this reason, the photosensitive paper 3 may peel off from the exposure drum 1 during image forming work, or
There is a problem in that the image forming work is not improved in efficiency and precision because it separates from the exposure drum 1.

The present invention has been made to solve this type of problem, and it is possible to securely hold photosensitive paper during image forming operations, thereby making it possible to perform efficient and highly accurate image forming operations. It is an object of the present invention to provide a photosensitive paper holding mechanism for an electrophotographic device.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the photosensitive paper holding mechanism of the electrophotographic apparatus according to the present invention forms an electrostatic latent image on the photosensitive paper, and further forms an electrostatic latent image on the electrostatic latent image. a support for supporting the photosensitive paper when performing a development process to obtain a visible image; and a first reservoir provided on the support for adsorbing the leading end portion of the photosensitive paper in the conveying direction to the support. a suction hole; a second suction hole provided in the support for adsorbing the rear end portion of the photosensitive paper in the conveying direction to the support; and a second suction hole for maintaining the first and second suction holes at negative pressure. Negative pressure generating means.

[Function] In the photosensitive paper holding mechanism of the electrophotographic apparatus according to the present invention having the above-mentioned configuration, when the photosensitive paper is conveyed onto the support, the photosensitive paper is attached to the support under the driving action of the negative pressure generating means. The leading end portion of the photosensitive paper in the conveyance direction is sucked through the first suction hole, and the rear end portion of the photosensitive paper in the conveyance direction is sucked through the second suction hole. Therefore, the photosensitive paper can be reliably held on the support, and peeling or separation of the photosensitive paper can be effectively prevented during image forming operations.

[Example] An example of the photosensitive paper holding mechanism of an electrophotographic apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a photosensitive paper holding mechanism according to a first embodiment of the present invention, and FIG. 2 is a perspective explanatory view of the photosensitive paper holding mechanism according to a second embodiment.

Note that the same reference numerals as in the photosensitive paper holding mechanism of the electrophotographic apparatus according to the prior art shown in FIG. 3 indicate the same components, and detailed explanation thereof will be omitted.

In FIG. 1, reference numeral 20 indicates a photosensitive paper holding mechanism according to this embodiment. The photosensitive paper holding mechanism 20 supports and rotates the photosensitive paper 3 when forming an electrostatic latent image on the photosensitive paper 3 and further developing the electrostatic latent image to obtain a visible image. an exposure drum 22 (support body), and a first suction hole 2 provided in the exposure drum 22 for attracting the leading end portion 3a of the photosensitive paper 3 in the conveyance direction to the exposure drum 22.
4, a second suction hole 26 provided in the exposure drum 22 and for attracting the rear end portion 3b of the photosensitive paper 3 in the conveyance direction to the exposure drum 22; the first and second suction holes 24;
26 at a negative pressure.

The first and second suction holes 24 and 26 are arranged in multiple stages in the axial direction of the exposure drum 22, communicate with the pipe lines 34 and 36 via the casing 30 and 32, and further generate negative pressure via the pipe line 38. It is connected to means 28 . Here, opening/closing valves (selection means) 40 and 42 for selectively applying negative pressure to the first suction hole 24 and the second suction hole 26 can be disposed in the conduits 34 and 36.

The operation of the photosensitive paper holding mechanism 20 configured as described above will be explained.

First, the photosensitive paper 3 is supplied to the exposure drum 22 via a paper feeding device (not shown), and the leading end portion 3a of the photosensitive paper 3 is
When arranged corresponding to the first suction hole 24 provided on the outer periphery of the exposure drum 22, the negative pressure generating means 28 is driven and the first suction hole is 24 becomes a negative pressure state. For this reason, photosensitive paper 3
The tip portion 3a of the photosensitive member is sucked into the first suction hole 24 and held on the exposure drum 22.

Further, when the rear end portion 3b of the photosensitive paper 3 is disposed corresponding to the second suction hole 26 of the exposure drum 22, it is moved through the conduit 38.degree. 36 and the casing 32 under the action of the negative pressure generating means 28. This second suction hole 26 is in a negative pressure state, and the rear end portion 3b is attracted and held by the exposure drum 22.

At this time, while the photosensitive paper 3 is being held on the exposure drum 22, the tip portion 3a is placed in the first suction hole 24, while the second suction hole 26 is open (see FIG. 1). (See double-dashed line). Here, when the negative pressure generating means 28 is driven, the first and second suction holes 24 and 26 are brought into a negative pressure state at the same time. , external air is sucked through the second suction hole 26.

Therefore, the on-off valves 40 and 42 may be controlled as described below. That is, first, the on-off valve 40 is opened, and the on-off valve 42 is closed, so that only the first suction hole 24 is brought into a negative pressure state under the action of the negative pressure generating means 28, and the air flows through the first suction hole 24. Then, the leading end portion 3a of the photosensitive paper 3 is attracted.

Next, when the rear end portion 3b reaches the position corresponding to the second suction hole 26, the on-off valve 42 is opened and the second suction hole 26 is opened.
6, the rear end portion 3b is also attracted. For this reason,
Sufficient suction force is obtained by the first suction hole 26, and the fear of misalignment of the photosensitive paper 3 or the exposure drum 22, for example, is eliminated.

In this case, in this embodiment, a first groove is provided on the outer periphery of the exposure drum 22 corresponding to the leading end portion 3a and the trailing end portion 3b of the photosensitive paper 3.
and second suction holes 24 and 26 are provided, and the negative pressure generating means 2
8, the front end portion 3a and rear end portion 3b are sucked into the first and second suction holes 24,26. Therefore, it is possible to effectively prevent the photosensitive paper 3 from peeling off or coming off the exposure drum 22, unlike the conventional structure in which only the leading end portion 3a of the photosensitive paper 3 is held by suction. As a result, the image forming operation on the photosensitive paper 3 can be carried out efficiently and with high precision.

Next, the photosensitive paper holding mechanism 50 according to the second embodiment is
This will be explained below with reference to the figures.

Note that the same reference numerals as in the photosensitive paper holding mechanism 20 shown in FIG. 1 indicate the same components, and detailed explanation thereof will be omitted.

This photosensitive paper holding mechanism 50 is particularly configured to accommodate two types of photosensitive paper having different lengths, and a first suction hole 24 is provided on the outer periphery of the exposure drum 52 to correspond to the length of each photosensitive paper. A second suction hole 54 and a third suction hole 56 are formed.

The second and third suction holes 54,56 are connected to the first suction hole 24.
Similarly, it is connected to the negative pressure generating means 28 via a conduit 38. Note that the first to third suction holes 24, 54, 56
It is also possible to selectively maintain the first to third suction holes 24, 54, 56 in a negative pressure state by disposing on-off valves (not shown) between the pipe 38 and the pipe 38, respectively.

In this way, in the second embodiment, when photosensitive papers of different sizes are used, it is possible to suction and hold the photosensitive papers in accurate correspondence with the leading edge and trailing edge of each photosensitive paper. . As a result, it is possible to more reliably prevent peeling of the photosensitive paper.

In addition, when using various types of photosensitive papers of different lengths, this can be easily accommodated by forming multiple rows of suction holes separated by a predetermined distance according to the lengths of these photosensitive papers. .

[Effects of the Invention] As detailed above, in the photosensitive paper holding mechanism of the electrophotographic apparatus according to the present invention, when the photosensitive paper is conveyed onto the support,
Under the driving action of the negative pressure generating means, the leading end portion in the conveying direction and the trailing end portion in the conveying direction of the photosensitive paper are sucked through the first suction hole and the second suction hole provided in the support. The photosensitive paper can be held securely on the support.

This makes it possible to effectively prevent the photosensitive paper from peeling off or coming off the support during the image forming process, allowing the image forming process to be carried out efficiently and with high precision. can.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a photosensitive paper holding mechanism according to a first embodiment of the present invention, FIG. 2 is a perspective explanatory view of a photosensitive paper holding mechanism according to a second embodiment, and FIG. 3 is a general 1 is a schematic configuration diagram of an electrophotographic apparatus. 3... Photosensitive paper 3a... Tip part 3b.
・Rear end portion 20 ・Photosensitive paper holding mechanism 22 ・
...Exposure drum 24°26...Suction hole 28...Negative pressure generating means 32...Casing 36°38...Pipe line 0°2...On-off valve 50...Photosensitive paper holding mechanism 52 ...Exposure drum 54゜56...Suction hole

Claims (2)

[Claims] (1) A support for supporting the photosensitive paper when forming an electrostatic latent image on the photosensitive paper and further developing the electrostatic latent image to obtain a visible image; a first suction hole provided in the support for adsorbing a leading end portion of the photosensitive paper in the transport direction to the support; and a first suction hole provided in the support for adsorbing the rear end portion of the photosensitive paper in the transport direction to the support. A photosensitive paper holding mechanism for an electrophotographic apparatus, comprising: two suction holes; and negative pressure generating means for maintaining the first and second suction holes at negative pressure. (2) The photosensitive paper holding mechanism for an electrophotographic apparatus according to claim 1, further comprising a selection means for selectively applying negative pressure to the first suction hole and the second suction hole. Retention mechanism.