JPH0812414B2 - Image forming apparatus including buffer roller - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image forming apparatus using a rolled light receiving sheet, and more particularly to an image forming apparatus including a buffer roller for pulling out the light receiving sheet.

(B) Conventional Technology FIG. 8 is a schematic configuration diagram of a main part of a general image forming apparatus including a buffer roller.

In this image forming apparatus, a light receiving sheet coated with a microcapsule containing a photocurable material and an image forming agent, and an image receiving sheet coated with a developing material that develops the color of the image forming agent are used.

The light receiving sheet 51 wound around the supply shaft 53 includes a tractor roller 61, an exposure plate 62, an exposure plate roller 63, a buffer roller 64,
It is wound around the winding shaft 54 via the pressure rollers 65 and 66. The light receiving sheet is pulled out by moving the buffer roller 64 in the direction of the arrow A, and is exposed at the exposure point P1 during that time to form a latent image. When the exposure process is completed, the winding shaft 54 winds up the light receiving sheet, the buffer roller 64 moves in the direction B, the image receiving sheet 41 is superposed on the latent image on the surface, and the pressure developing points are applied by the pressure rollers 65 and 66. It is pressure developed at P2. After pressure development, the trailing edge of the latent image is exposed to the exposure point P1 for effective utilization of the light-receiving sheet.
Rewind to the vicinity.

At the time of image formation, the home position of the buffer roller 64 is set to H1 in the figure. This is because if the home position is set closer to the pressure roller than this, the drawing length of the light receiving sheet at the start of movement cannot be accurately controlled.

At the time of rewinding, the buffer roller 64 is also positioned at the home position H1.

(C) Problems to be Solved by the Invention However, when the buffer roller is at the position H1 when rewinding the light receiving sheet after pressure development, the rewinding path of the light receiving sheet is complicated as shown in FIG. The curved line comes into contact with the buffer roller 64 and the exposure plate roller 63. Therefore, an extra load is applied to the rewinding, and the exposure plate roller 63 comes into contact with the coating surface of the light receiving sheet, so that the light receiving sheet is easily scratched and the image quality is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus including a buffer roller that reduces the rewinding load and does not damage the coating surface of the light receiving sheet when the light receiving sheet is rewound.

(D) Means for Solving the Problem The present invention, when forming an image, pulls out a light-receiving sheet wound around a supply shaft by moving a buffer roller, and then winds the light-receiving sheet around a winding shaft and rewinds it. Sometimes, in the image forming apparatus for rewinding from the take-up shaft to the supply shaft through the buffer roller, the guide roller is arranged at a position where the light receiving sheet hangs parallel to the buffer roller in the moving direction during image formation. In addition, the light receiving sheet has a first home position that serves as a reference point when the buffer roller moves during image formation and a second home position that serves as a fixed point of the buffer roller during rewinding. The position at which the buffer roller is hung parallel to the moving direction of the buffer roller, and whether the light receiving sheet is wound around the guide roller. And a home position setting means for moving the buffer roller based on the first home position during image formation and fixing the buffer roller to the second home position during rewinding. Is characterized by.

(E) Operation FIG. 1 is a block diagram of the present invention. At the time of image formation, the light receiving sheet 103 wound around the supply shaft is attached to the buffer roller 104.
Is pulled out by moving from the first home position H1. In the figure, the rollers located on both sides of the buffer roller 104 are guide rollers, and by the action of the guide rollers, when the buffer roller 104 moves during image formation, the light receiving sheet becomes parallel to the moving direction of the buffer roller 104. Moving. Therefore, by moving the buffer roller 104 at a constant speed, the light receiving sheet on the supply shaft 102 side moves at a constant speed that is twice the moving speed of the buffer roller 104. If the exposure is started from the time when the buffer roller 104 is in the second home position H2, the moving speed between the buffer roller and the light receiving sheet is 1: 2 until the buffer roller 104 exceeds H2 to H1. However, since the light receiving sheet does not move at a constant speed, the image at the front end portion is distorted. Therefore, at the time of image formation, the first home position H1 must be set as the home position of the buffer roller 104.

After the image formation, development processing is performed to rotate the winding shaft 105 to wind the light receiving sheet 103. When rewinding, the supply shaft 102 rewinds the light receiving sheet 103 wound around the winding shaft 105. At this time, the buffer roller 104 is moved to the second home position H2 by the home position setting means 101, and becomes a position where the light receiving sheet 103 is allowed to pass through in a substantially straight line. Therefore, when the buffer roller is located at the first home position H1, the coating surface of the light receiving sheet 103 is in contact with the roller or the like which is close to the buffer roller.
By moving to the home position, the light receiving sheet 103 does not wind around the guide roller, and the path is simplified. Therefore, the rewinding load is reduced, the surface of the light receiving sheet is prevented from being scratched, and the deterioration of the image quality can be prevented.

(F) Embodiment An image forming apparatus equipped with a buffer roller according to an embodiment of the present invention uses the apparatus shown in FIG.

A document table 2 is provided on the upper surface of the image forming apparatus main body 1,
An optical device 3 including a light source, a mirror, a lens and the like is disposed below the optical device 3. Media sheet (light receiving sheet)
The media cartridge 5 accommodating the 51 is mounted in the bucket 55 slightly left of the center of the main body, and the media sheet
51 is conveyed through a tractor roller 61, an exposure plate 62, an exposure plate roller 63, a buffer roller 64, pressure rollers 65 and 66, and is wound around a winding shaft 54 of the media cartridge 5. A paper feed unit 4 is arranged on the lower right side of the main body 1 and sends the image receiving sheet 41 to the pressure developing unit. A paper discharge unit 8 is arranged on the left side of the pressure developing unit 6. The exposure plate roller 63 and the pressure roller 65 correspond to the guide roller according to the present invention.

 The image forming operation will be described.

First, the optical device 3 scans a document placed on the document table 2. At this time, the buffer roller 64 is used for the first image formation.
Is moved from the home position H1 in the direction of arrow A to pull out the media sheet 51, and the reflected light of the document is irradiated onto the media sheet on the exposure plate 62 for exposure. At that time, the exposure plate roller 63 acting as a guide roller according to the present invention.
By the action of the pressure roller 65, the light receiving sheet moves in parallel to the moving direction of the buffer roller 64. Therefore, by moving the buffer roller 64 at a constant speed,
At the exposure point P1, the light receiving sheet is a buffer roller.
It moves at a constant speed twice the moving speed of 64. Thus, a selectively cured image is formed on the media sheet.

When the exposure is completed, the buffer roller 64 is moved in the direction of arrow B and the area where the selectively cured image is formed is conveyed to the pressure developing section 6. Buffalo 64 is in second home position
It stops when it returns to H2. The image receiving sheet 41 is fed from the sheet feeding section 4 and sent to the pressure developing section 6 in time with the selectively cured image on the media sheet.

The media sheet 51 and the image receiving sheet 41 are pressed by the pressure rollers 65 and 66 in a state of being superposed. Then, the uncured microcapsules on the media sheet are broken, the image forming agent flows out, and reacts with the developing material on the image receiving sheet to develop color.

After the pressure-developed media sheet is wound around the take-up shaft 54, when the trailing edge of the latent image on the media sheet passes the pressure point P2, the media sheet is rewound from that and the trailing edge of the latent image is exposed. It should be located near P1. At this time, the buffer roller 64 is moved to the second home position H2, and the rewinding path of the media sheet is formed as shown in the figure. Therefore, the surface of the media sheet does not come into contact with the exposure plate roller 63, reducing the rewinding load and preventing the surface of the media sheet from being scratched. On the other hand, the image receiving sheet 41 is heat-treated by the glossing device 7 and is discharged to the paper discharge unit 8.

In addition, when the media cartridge 5 is mounted and the media sheet is loaded, in order to simplify the path of the light receiving sheet, the buffer roller is used in the same manner as at the time of rewinding.
64 moves to the second home position H2.

FIG. 5 is an external perspective view of the vicinity of the buffer roller of the image forming apparatus, and FIG. 6 is a schematic view of the buffer roller and its drive unit.

The buffer roller 64 is pivotally supported by the guide 11. A bearing portion 12 is biased at one end of the guide 11, a support rod 13 fixed to the main body of the image forming apparatus is fitted into the bearing portion 12, and the bearing portion 12 slides along the support rod 13. The longitudinal direction of the support rod 13 is the direction of arrows A and B in FIG. A roller 14 (not shown in FIG. 6) is pivotally supported at the other end of the guide 11 and rotates on a rail 16. Wire 17 is pulley 17a
As shown in FIG. 6, it is wound around the winding roller 18a arranged on the side surface of the pressure roller and then returned to the guide 11 via the pulley 17b. Power is transmitted to the winding roller 18a coaxially from the buffer roller driving unit 18c via the drive gear 18b, and the buffer roller 64 moves on the rail 16. Details of the winding roller 18a are as shown in FIG.

With the above configuration, the buffer roller 64 starts from the first home position H1 in the image forming process, moves to the position 64 'in the direction of arrow A, and then returns to the direction of arrow B to go through the first home position. Move to the second home position H2 and rewind the media sheet.

To move the buffer roller 64 to the first home position H1 or the second home position H2, use the guide
A detection plate 11a is formed on 11, and transmission type optical sensors S1 and S2 are provided at positions H1 and H2 along the rail 16 for detection.

FIG. 4 is a graph showing the position of the buffer roller 64 of the image forming apparatus.

The vertical axis represents the position of the buffer roller, and the horizontal axis represents the progress of the loading and image forming processes. First, when the media cartridge is installed, the buffer roller that was near the first home position H1 moves to the second home position H2.
Move to and autoloading will start. When the auto loading is completed, the buffer roller moves to the first home position H1 and waits until the print switch is pressed. At the same time when the print switch is pressed and exposure is started, the buffer roller moves in the direction of arrow A to the position 64 ', and then returns in the direction of arrow B, at which time the leading edge of the latent image on the media sheet and the image receiving sheet are aligned. When the tips are aligned, the pressure roller is pressed. At this time, since the media sheet is stopped, the buffer roller also stops moving. When the pressurization ends, pressure development starts, the buffer roller continues to move in the direction of arrow B, the pressure development ends near the first home position H1, and the buffer roller subsequently moves to the second home position H2. . With the buffer roller located at H2, rewind the trailing edge of the latent image on the media sheet to near the exposure point P1.
After the rewinding is completed, the buffer roller returns to the home position SHP at the time of image formation and stands by until the next image forming process.

FIG. 3 is a block diagram of a part of a control unit of the image forming apparatus.

ROM21, RAM22 are connected to the CPU20, the drive unit 24 of the main motor 25, the drive unit 18c of the buffer motor 27 of the buffer roller, the control circuit 28, the cover switch S3, via the I / O23.
A sensor group 31 including sensors such as a first home position H1 sensor S1 and a second home position H2 sensor S2 is connected. A clutch 29 for connecting the rotation of the motor to the buffer roller 64, a clutch 30 for connecting the rotation of the main motor, and a clutch 32 for connecting the rotation to the supply shaft 53 are connected to the control circuit.

The CPU 20 controls the entire image forming apparatus, and the ROM 21 has a control program written in advance. A working area is assigned to the RAM 22. When the rear end of the image receiving sheet passes the pressure point P2, a sensor (not shown) of the sensor group 31 detects and outputs a signal via I / O. The signal is C
The PU 20 takes in through I / O and outputs an ON signal to the buffer motor driving unit 18c of the buffer roller and the control circuit 28. As a result, the clutch 29 is turned on, the rotation of the buffer motor is transmitted to the buffer roller, and the buffer roller moves. Buffer roller moves and guide detection plate 11a
When the light transmissive sensor S2 detects
The signal is taken in via / O, and an OFF signal is output to the buffer motor drive unit 18c of the buffer roller and the control circuit 28, and the buffer roller stops and returns to the second home position H2. After that, the CPU 20 drives the main motor 25 to drive the drive shaft 24 and supply shaft 5.
The ON signal is output to the clutch 32 that connects the rotation to 3 through I / O to rewind the light receiving sheet.

FIG. 2 is a flowchart of the movement operation of the buffer roller in the image forming process of the image forming apparatus.

When the power is turned on and the initialization of each part is completed (n
1) Wait for the print switch to be pressed. When the print switch is pressed (n2), the supply shaft is locked so as not to rotate (n3), and the buffer roller moves in the direction of arrow A (see FIG. 8) to pull out the light receiving sheet and perform exposure (n4). ). Next, the buffer roller moves in the direction of arrow B (see FIG. 8) to align the latent image formed by exposure with the leading edge of the image receiving sheet (n5). When the tips match, the buffer roller is stopped and the pressure roller is pressed (n
6). Again, the buffer roller is in the direction of arrow B (see Fig. 8).
To move to the home position. When the buffer roller returns to the second home position H2 (n8), the supply shaft is unlocked (n9) and the light receiving sheet is rewound (n10). When rewinding is completed, the buffer roller is set to the first position.
(N11) to wait for the next image forming process.

With the above configuration, n8 to n10 correspond to home position setting means.

(G) Effect of the Invention As described above, according to the present invention, in the image forming apparatus including the buffer roller using the light receiving sheet, the buffer roller is provided with the second roller when the light receiving sheet is rewound after pressure development. Move to home position H1. For this reason,
The conveyance path of the sheet to the passage through the buffer roller is substantially linear and simplified so that the coating surface of the sheet does not come into contact with the roller or the like, the rewinding load is reduced, and the sheet is not damaged. Therefore, the image quality can be stabilized.

[Brief description of drawings]

FIG. 1 is a block diagram of the present invention. FIG. 2 is a flowchart of the movement operation of the buffer roller in the image forming process of the image forming apparatus including the buffer roller according to the embodiment of the present invention. FIG. 3 is a block diagram of a part of the control unit of the image forming apparatus. FIG. 4 is a graph showing the position of the buffer roller of the image forming apparatus. FIG. 5 is an external perspective view of the vicinity of the buffer roller of the image forming apparatus. FIG. 6 is a schematic view of the buffer roller and its drive unit. FIG. 7 is a diagram showing details of the winding roller of the buffer roller. FIG. 8 is a schematic configuration diagram of an image forming apparatus including a general buffer roller. 41 …… image receiving sheet, 51 …… light receiving sheet, 53 …… supply axis, 54 …… winding axis, 62 …… exposure plate, 63 …… exposure plate roller, 64 …… buffer roller, 65, 66 …… Pressure roller, H1
...... First home position, H2 ...... Second home position.

Claims (1)

[Claims] 1. At the time of image formation, a light-receiving sheet wound around a supply shaft is pulled out by moving a buffer roller, and then is wound around a winding shaft, and at the time of rewinding, the buffer roller is moved from the winding shaft. In an image forming apparatus for rewinding onto a supply shaft through a guide roller, a guide roller is arranged at a position where a light receiving sheet hangs parallel to a buffer roller in a moving direction of the buffer roller at the time of image formation, and the buffer roller at the time of image formation. The light receiving sheet has a first home position which is a reference point when the sheet moves and a second home position which is a fixing point of the buffer roller when the sheet is rewound. And a position where the light receiving sheet is not wound around the guide roller, respectively. An image including a buffer roller, characterized in that home position setting means is provided for moving the buffer roller with the first home position as a reference at the time of forming and for fixing the buffer roller to the second home position at the time of rewinding. Forming equipment.