JPH01236152A - Conveying roller for image former - Google Patents

Abstract

PURPOSE:To make frictional force being produced in a gap with a photoconductive sheet larger without exerting any influence on conveying accuracy as well as to reduce any feed irregularity at the time of conveyance by forming a roller on one side in conveying rollers for the photoconductive sheet after being exposed to a laser beams, with an elastic body, and machining the surface of a driving roller on the other made of metal into roughness. CONSTITUTION:A roller 9 on one side in a pair of conveying rollers 9, 10 in a laser roller part (c) is formed with an elastic body, and a metal surface of a driving conveying roller 10 on the other is formed into roughness. With this formation, frictional force being produced in a gap with a photoconductive sheet S can be made larger without exerting any influence on conveying accuracy, and a slip between the sheet S and the rollers 9, 10 is checked, whereby any feed irregularity at the time of conveyance is reduced and thus the photoconductive sheet S is stably conveyable. Consequently, any nonconformity at the time of laser beam exposure being produced by a slipping phenomenon is eliminated, so that any drop in image quality is preventable.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention charges the surface of a photoconductive sheet supplied from a supply mechanism in a charging mechanism section, and imagewise exposes the photoconductive sheet to a laser beam. The present invention relates to a conveyance roller of an image forming apparatus that forms an image on a photoconductive sheet by developing, drying, and fixing an electrolytic latent image.

(Conventional technique*) Some conventionally used conveyor rollers have a rubber roller on one side and a metal roller on the other.
The surface of the metal roller is polished and smooth.

(Problems to be Solved by the Invention) In a laser light exposure mechanism, it can be said that the quality of the image formed is determined by the precision with which the laser light is conveyed at each exposure section. In a method in which a sheet is conveyed linearly at a constant speed and an image is formed by exposing the sensitive material to laser light, the dimensional accuracy of the conveyance roller is an important factor for smooth conveyance. Therefore, when the optical core is held between a pair of rollers, metal rollers must be used to prevent the roller diameter from changing due to the applied pressure. However, if the surface of the metal roller is smooth as in the conventional example, the coefficient of friction is small, and therefore, a sliding phenomenon occurs in the photoconductive sheet being conveyed due to disturbance. This slipping phenomenon causes unevenness in the conveyance speed of the photoconductive sheet, leading to problems such as not being able to perform accurate exposure with laser light, resulting in a deterioration in image quality.

(Means for Solving the Problems) The present invention aims to solve the above-mentioned problems, and as a means thereof, provides the configuration described below.

That is, various paper-based, plastic-based, and metal-based photoconductive sheets or plates (hereinafter simply referred to as photoconductive sheets) are conveyed linearly by rollers, and the photoconductive sheets are exposed to laser light. In the device, one of the pair of transport rollers is made of an elastic body, and the other driving roller is made of metal, and the surface of the metal roller is roughened to increase the coefficient of friction. That is.

(Function) According to the present invention, by roughening the metal surface of the driving conveyance roller, the frictional force generated between the driving conveyance roller and the photoconductive sheet can be increased without affecting the conveyance accuracy. It suppresses slippage between the sheet and the rollers, reduces uneven feeding during conveyance, and enables stable conveyance of the photoconductive sheet. Therefore, it is possible to eliminate defects during laser light exposure that occur due to the slip phenomenon, and to prevent deterioration in image quality.

(Example) FIG. 1 is a schematic diagram of the configuration of a laser engraving device incorporating a conveyance roller according to the present invention.

Reference numeral 1 designates a plate feeding cassette of a photoconductive sheet S supply mechanism A, which can store up to 50 photoconductive sheets S. Plate supply cassette) When a sheet is taken out from A, it is designed to be covered with a lid to prevent it from being exposed to light. When using,
Open the lid, insert it along the guide at the main body entrance, and move it until it locks. Reference numeral 2 denotes a pickup roller, which consists of three coaxial rollers. When feeding the sheet S,
The plate feeding solenoid 3 is operated under the control (the same applies hereinafter) of a built-in computer (not shown), and the pickup roller 2 is lowered and pressed against the sheet S stored in the plate feeding cassette l. When the pickup roller 2 comes into close contact with the sheet S, and at the same time the controller confirms that there is a remainder of the sheet S by a detector (not shown), the drive motor 12 starts rotating, and the rotational force is adjusted to the timing. belt 1
1, the sheet S is transmitted to a pickup roller 2 by a third gear, and the sheet S is supplied to a plate feeding section F of a feeding mechanism A.

The plate feeding section F consists of an upper and lower pair of plate feeding rollers 4 and 5, and a sheet edge detector (not shown). Both the upper and lower plate feeding rollers 4 and 5 are rubber rollers, and are driven by a drive motor (
(not shown). When the sheet S is held between the plate feeding rollers 4 and 5, the P2 quadrup roller 2 is raised by the stoppage of the solenoid 3, and the conveying operation is carried out by the plate feeding rollers 4 and 5.
Move on to 5. The sheet tip detector detects the traveling sheet S.
When the leading edge of the sheet S is detected, a timer-based delay circuit is activated, and as the sheet S enters the charging mechanism B as it travels, the
The surface is charged with static charge by the charger 6 and the ○ charger 7.

8 is a laser scanning unit. Although not shown, a laser optical system consisting of a semiconductor laser, a collimator lens, a polygon mirror, an fθ lens group, and a folding mirror is housed inside.

A laser vision modulated by image data is exposed to a laser exposure location downstream of the charging mechanism. When the leading edge of the sheet S passes through the charging mechanism B, the entire surface of the leading edge is exposed by the laser beam. While the entire surface is being exposed, the leading edge of the sheet S advances and is held and conveyed by the upper roller 9 and lower roller 10 of the rotating laser roller section C. The upper roller 9 is a rubber roller, and the lower roller 10 is a metal roller whose surface is roughly processed. The driving force transmission timing belt 11 is wrapped around the pulley of the lower roller 10 of the laser roller section C, and the lower roller 10 of the laser roller section C has a conveyance driving force. Upper and lower rollers 9 and 10 of the laser roller section
When the sheet S is held between the laser scanning unit 8
A laser beam modulated with image data is exposed to the sheet S to form an electrostatic latent image of the image.

The laser exposure position is the midpoint between the band 1i$6.7 and the laser roller portion C. The conveyance of the sheet S depends on the rotation of the upper and lower rollers 9 and 10 of the laser roller section C, and the peripheral speed of the lower roller 10 of the laser roller section C governs the conveyance speed. The sheet S conveyed by the upper and lower rollers 9 and 10 of the laser roller section C is guided to the developing mechanism 13. Developing mechanism 13
A developing solution tank T is formed below. The developer in the tank is sent in the direction F by a pump (not shown), and then supplied in the transport direction of the sheet (S) along a pair of guide electrodes P provided in the developing mechanism 13, and is then supplied to the static IIi Toner is poured from above onto the sheet S on which the latent image has been formed, and toner development is performed. The sheet S to which the toner has adhered is visualized by the toner. When the zero image data has been read in, the laser again exposes the entire surface. When the trailing edge of the sheet S passes the laser roller section C, the laser stops and the developing mechanism The drive of the roller group upstream from 13 stops. The developed sheet S passes through the developing mechanism 3, and upper and lower rerollers 14 and 15 squeeze out the developing solution on the surface of the sheet S, and the sheet is led to a drying and fixing mechanism 16, where hot air drying and heat fixing are performed. Reference numerals 17 and 18 are the upper and lower rollers of the discharge roller, respectively, and the sheet S that has completed all the plate-making processes is transported to the upper and non-discharge rollers 17°1.
8 and transported, and stored in the discharge tray 22.

The upper and lower aperture rollers 14, 15 and the lower discharge rollers 17, 18 are driven by a motor 21 via timing belts 19, 20. After the sheet S is discharged, the motor 21 is also stopped, and all operations of the plate making apparatus are completed.

(Effects) According to the present invention, one of the rollers for conveying the photoconductive sheet after exposure to laser light is made of an elastic body, and the other is made of metal, and the metal surface is rough processed. Because of this, the frictional force generated between the photoconductive sheet and the photoconductive sheet can be increased without affecting the conveyance accuracy, which suppresses slippage between the sheet and the roller, reduces unevenness during conveyance, and stabilizes the conveyance. It becomes possible to transport the photoconductive sheet.

Therefore, problems caused by the sliding phenomenon during laser light exposure can be eliminated and image quality can be reduced by Uj+L-.

[Brief explanation of the drawing]

FIG. 1 is an A diagram of the configuration of a laser plate making apparatus incorporating the conveyance roller of the present invention. A... Supply mechanism, B... Charging mechanism, C... Laser roller section, Text... Laser light, S... Photoconductive sheet, F... Plate feeding unit, 1... Plate feeding cassette, 2...Pickup roller, 4...Plate feeding upper roller, 5...Plate feeding lower roller, 6...■ band'I cracker, 7...○ band tt
t i, 8...Laser scan unit, 9...Laser roller part upper roller, 10...Laser roller lower roller, 11...Timing belt, 12...Drive motor, 13...Developing mechanism , 14... Drawing upper roller,
15... Squeezing lower roller, 16... Drying fixing mechanism, 1
7... Upper discharge roller, 18... Lower discharge roller, 22
...Discharge tray Applicant Copal Electronics Co., Ltd. Agent Patent attorney Sakae Kobayashi

Claims (1)

[Claims] 1. A supply mechanism for supplying a photoconductive sheet, the photoconductive sheet supplied from the supply mechanism is conveyed to a charging mechanism between a pair of opposing rollers of the plate feeding section, and the photoconductive sheet that has been conveyed is A charging mechanism that charges an electrostatic charge, an exposure section that exposes a photoconductive sheet sent out from this charging mechanism to an image with a laser beam, a developing mechanism that develops an electrostatic latent image formed by this laser beam exposure section with toner, and a developing device. In an image forming apparatus including at least a drying and fixing mechanism for drying and fixing the photoconductive sheet, one of the rollers for conveying the photoconductive sheet after exposure to laser light is formed of an elastic material,
A conveying roller for an image forming apparatus, characterized in that the surface of the other driving roller made of metal is roughened.