JPH03189648A - Controller for conveying photosensitive sheet - Google Patents

Abstract

PURPOSE:To prevent a photosensitive sheet from being excessively drawn out or broken by the tensile force of a take-up shaft by releasing the pressure of a pressure roller in a state where a buffer roller is moved to loosen the photosenstive sheet. CONSTITUTION:At the time of processing for exposure, the buffer roller 3 is moved in a direction shown by an arrow A, the photosensitive sheet 2 is drawn out from a supply shaft 1a, and the exposed sheet 2 is stocked in a buffer part 3a. Next, the take-up shaft 1b is rotated and the roller 3 is moved in a direction shown by an arrow B to take up the sheet 2 and supply an image receiving sheet 8, then the pressure rollers 6a and 6b are pressurized to perform development. Since the rotating speed of the shaft 1b is higher than the speed of the rollers 6a and 6b, the sheet 2 is somewhat tense. After performing the pressure development, the roller 3 is moved in the direction B further and the pressure by the rollers 6a and 6b is released while loosing the sheet 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Al Industrial Field of Application) This invention conveys and processes a photosensitive sheet stretched between a supply shaft and a take-up shaft using a buffer roller disposed between the two shafts. The present invention relates to an image forming apparatus that applies pressure using a pressure roller that can press/release pressure.

(bl) Conventional technology In an image forming apparatus that forms an image using a photosensitive sheet having pressure sensitivity, a photosensitive sheet wound around a supply shaft is passed through an exposure section and a pressure development section.
Images are formed using pressure-sensitive processing. The pressure development section generally includes a pressure roller, and during pressure development processing, the roller is pressurized to apply pressure to the photosensitive sheet. After the pressure development process is completed, the pressure is released so that the photosensitive sheet is not pressurized. Further, a driving force in the direction of winding up the photosensitive sheet is applied to the winding shaft, and the photosensitive sheet is wound onto the winding shaft after passing through the pressure developing section.

(C) Problem to be Solved by the Invention However, the rotational speed of the take-up shaft is set to be slightly faster than the rotational speed of the pressure roller in order to give tension to the photosensitive sheet. When the photosensitive sheet is released, the photosensitive sheet is suddenly pulled, resulting in unnecessary pulling out of the photosensitive sheet, loosening of the pulled out photosensitive sheet, and tearing of the photosensitive sheet.

In view of the above problems, the purpose of this invention is to develop a supply axis.

An object of the present invention is to provide a photosensitive sheet conveyance control device that can prevent excessive pulling out of the photosensitive sheet and damage to the photosensitive sheet when pressure is released by adjusting the length of the photosensitive sheet between winding shafts.

(d) Means for Solving the Problems This invention consists of stretching a photosensitive sheet between a supply shaft and a winding shaft,
In the image forming apparatus, the image forming apparatus is provided with a pressure roller that changes the length between the two wheels by moving a heel roller provided between the two wheels, and that is capable of pressurizing/releasing the pressure between the two shafts. The present invention is characterized by providing means for moving the buffer roller in a direction in which the length between both shafts becomes shorter when the pressure on the roller is released.

(e) Working Pressure During the development process, the rotational speed of the winding shaft is slightly higher than that of the pressure roller, so the photosensitive sheet is slightly stretched between the pressure roller and the winding shaft.

If the pressure on the pressure roller is released in this state, the pressure roller
The photosensitive sheet between the supply shafts is suddenly pulled toward the take-up shaft. However, in this invention, as the pressure is released, the buffer roller moves and the length between the supply shaft and take-up shaft becomes shorter, and the photosensitive sheet between the two wheels becomes slack, canceling out the pulling force. Therefore, even if the pressure is released and the photosensitive sheet is pulled toward the take-up shaft, the photosensitive sheet will not be pulled out excessively.
Moreover, the photosensitive sheet will not be torn.

Embodiment FIG. 4 is a schematic front view of a copying machine equipped with a photosensitive sheet conveyance control device according to an embodiment of the present invention.

Media cartridge 1 is located approximately in the center of the copier body.
is removably provided. media cartridge 1
is equipped with a supply shaft 1a and a take-up shaft 1b, and an unused photosensitive sheet 2 is wound around the supply shaft 1a. The photosensitive sheet 2 is pulled out from the supply shaft 1a and placed in an exposure section P1 on the copying machine main body side.
The film is wound onto the winding shaft 1b via the buffer roller (BR) 3 and the pressure developing section P. Reflected light from the original on the original platen 5 is guided to the exposure section P1 by an optical system 4 at the top of the copying machine main body, and the photosensitive sheet 2 is image-formingly exposed to form a latent image. Further, the pressure developing section P2 includes upper and lower pressure rollers 5a and 5b.
The photosensitive sheet 2 on which the latent image is formed is pressed to visualize the latent image. An image receiving sheet 8 is fed to the pressure rollers 5a and 5b from a paper cassette 7 on the right side of the copying machine body, and an image is transferred onto this image receiving sheet. The buffer roller 3 is movable in the directions of arrows A and B in the figure. When the buffer roller 3 moves in the direction of arrow A, the path of the photosensitive sheet between the supply shaft 1a and the take-up shaft lb becomes longer, and when it moves in the direction of arrow B, it becomes shorter. A sensor S1 is arranged at the home position of the bar nofa roller 3, and a sensor S2 is arranged at a position slightly inside the home position.

FIG. 3 is a block diagram of the control section of the copying machine.

The entire copying machine is controlled by CPU II.

The detection states of the sensors Sl, S2, etc. are input to the CPU II. Depending on these input states, CPll drives the buffer motor 12, pressure clutch 13, supply shaft 1a, clutches 14 and 15 of the take-up shaft 1b, main motor 16, optical system 17, etc. The buffer motor 12 is rotatable in forward and reverse directions, thereby moving the buffer roller 3 in the directions of arrows A and B. The pressure clutch 13 is a clutch that rotates a cam that pressurizes and releases pressure from the pressure rollers 6a and 6b. When the clutches 14 and 15 are turned on, the supply shaft 1a and the take-up shaft 1b rotate in a direction in which the photosensitive sheet 2 is sent out from the supply shaft toward the take-up shaft. The main motor 16 is connected to the cam of the pressure roller, the supply shaft 1a, and the take-up shaft 1.
This is a motor that generates the driving force that is transmitted to b.

The image forming operation in the copying machine configured as described above will be explained with reference to FIGS. 1 and 2. FIG. 1 is a flowchart showing the main processing procedure during image forming processing, and FIGS. 2(A) to (E) show the buffer roller 3 during the same processing. It is a figure showing the operating state of pressure rollers 6a, 6b, etc.

When the print switch is operated, copy processing is started (nl). First, as shown in FIG. 2(A), the supply shaft 1a
is unlocked, the buffer roller 3 moves in the direction of arrow A, and the exposure process is started (n2-n3). The photosensitive sheet 2 in the exposure area is a bumper area 3a (see Figure 4).
It will be stocked in.

When the exposure process is completed, the supply shaft 1a is locked, the buffer roller 3 is stopped, and the drawing of the photosensitive sheet 2 is stopped (n4-n5). Then, pressure development processing is started. First, as the winding shaft 1b rotates, the buffer roller 3 moves in the direction of arrow B and winds up the photosensitive sheet in the buffer section 3a (n6). After L1 hours have elapsed after the buffer roller 3 starts moving in the B direction, the pressure rollers 5a and 5b are pressurized to start the pressure development process as shown in FIG. 2(B). On the photosensitive sheet pulled out to the buffer section 3a, the leading edge of the latent image is at P at the start of exposure.
1 position. Therefore, the photosensitive sheet is wound up without applying pressure until the leading edge of the latent image reaches the pressure developing section P2 (until 1 + time has elapsed), and when the leading edge of the latent image reaches the pressure developing section P2, the pressure is applied. Developing rollers 5a, 6b
Pressure is applied to start the pressure development process.

Incidentally, the image receiving sheet 8 is fed to the pressure developing section P2 at this timing.

After the pressure development process is started, when the sensor S1 is turned on, the movement of the supply buffer roller 3 is stopped, and at the same time, the supply shaft 1a is unlocked (n9→n10).

This is because at the end of the exposure process, the rear end of the latent image is at Pl, and the photosensitive sheet up to Pl is sent to the pressure developing section P2 (
Figure 2 (C)). If the photosensitive sheet up to the trailing edge of the latent image is sent to the pressure development section P2 (=end of pressure development processing; the length during this period is always constant, it can be controlled by time), as shown in Fig. 2 ( As shown in D), the rotation of the winding shaft 1b is stopped and the supply shaft 1a is locked (n 1).
-n 12). Then, the pressure is released.

During the pressure development process, as mentioned above, the rotation speed of the take-up shaft 1b is faster than the rotation speed of the pressure rollers 5a, 5b, so the photosensitive sheet 2 is stretched between the pressure rollers 5a, 5b and the take-up shaft 1b. It has become.

Therefore, as shown in Figure 2 (E), the Buffalo 3
By moving the supply shaft 1a in the B direction.

The pressure on the pressure rollers 6a and 6b is released while creating slack in the photosensitive sheet 2 between the take-up shafts lb (n13). As a result, the photosensitive sheet is slightly loosened between the supply shaft 1a and the pressure rollers 6a and 6b, and the pressure roller 6a6b and the take-up shaft lb
The tension between the photosensitive sheet and the photosensitive sheet are perfectly relaxed,
This prevents the photosensitive sheet from tearing. The movement of the buffer roller 3 in the B direction continues until the sensor S2 is turned on, and when the sensor S2 is turned on, the movement of the buffer roller 3.
Both pressure release clutches are turned off (n14→n15).

(g1 Effects of the invention As described above, according to this invention, the pressure on the pressure roller is released with a slack between the pressure roller and the supply shaft due to the buffalo groove, so the tensile force of the take-up shaft is used to release the pressure on the pressure roller. This also prevents the photosensitive sheet from being damaged or being pulled out excessively.

FIG. 4 is a schematic front view of the copying machine.

1a-supply shaft, 1b-take-up shaft, 2-photosensitive sheet, 3 buffer roller, 5a, 6bBE roller.

Claims (1)

[Claims] (1) A photosensitive sheet is stretched between a supply shaft and a take-up shaft, and the length between the two shafts is changed by moving a buffer roller provided between the two shafts, and the length between the two shafts is changed. An image forming apparatus equipped with a pressure roller capable of pressure/pressure release, characterized in that a means is provided for moving the buffer roller in a direction where the length between both axes becomes shorter when the pressure of the pressure roller is released. Photosensitive sheet conveyance control device.