JPH02301756A - Pressurizing method for pressure developing roller - Google Patents

Abstract

PURPOSE:To easily execute the work of a jamming release, etc., by pressurizing the roller with pressure by which a media sheet does not become pressure-sensitive at other time than a pressure development processing at the time of forming an image, pressurizing the roller with pressure by which the medium sheet becomes pressure-sensitive at the time of pressure development processing, and also, releasing the pressure at other time than forming an image. CONSTITUTION:At other time than a pressure development processing at the time of forming an image, the roller is pressurized with pressure by which a media sheet 4 does not become pressure-sensitive, and at the time of pressure development processing, the roller is pressurized with pressure by which the medium sheet 4 becomes pressure-sensitive, and also, at other time than forming an image, the pressure is released. That is, when the pressure with the extent that the medium sheet 4 does not become pressure-sensitive is applied to pressure developing rollers 91, 92, it does not occur that dyestuff flows out of the medium sheet 4, and also, even if the force for drawing the medium sheet 4 is applied to a paper winding shaft through the pressure developing rollers 91, 92, its force is absorbed by the pressure developing rollers 91, 92 and it does not occur that the media sheet 4 is brought back. Also, when the roller is pressurized by high pressure, dyestuff flows out and an image is formed on the sheet. In such a manner, contamination on the surface of the roller, and creases on the surface of the sheet are prevented, and the workability of user when the meandering motion of the sheet and the jamming are generated can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION ta+ Industrial Application Field This invention relates to an improvement in a method of applying pressure to a pressure developing roller for developing a photosensitive pressure-sensitive sheet.

(bl Prior Art) In recent years, the development of image forming apparatuses that form images using media sheets (photosensitive pressure sensitive sheets) coated with photosensitive and pressure sensitive microcapsules has been progressing. 10-20 μm encapsulated with color-forming dye
It is of the diameter. Microcapsules harden when exposed to light and are not destroyed by pressure; however, if exposed to light, they are destroyed by pressure and the dye flows out. This dye forms an image.

By the way, when forming an image using a media sheet, it is desirable to set the media sheet feeding speed during exposure and the feeding speed during pressure development separately.

This is because it takes time to destroy the microcapsules. On the other hand, media sheets can be stored in rolls due to exposure to external light.
It is also convenient for protection from external pressure, and is usually wound around a supply shaft and housed in a cartridge. Conventionally, as mentioned above, the exposure speed and pressure development speed were set separately, so during exposure, the media sheet was exposed while being pulled out from the cartridge cartridge, and the exposed area was fed into the buffer section, and the exposure process was completed. After that, the exposed portion was sent to a pressure development roller and subjected to pressure development processing.

(C) Problem to be Solved by the Invention When a media sheet is stored in a roll, a non-image where exposure is not performed between the trailing edge of the previous image and the leading edge of the current image in the feeding direction of the media sheet. A formation area is created. Since the microcapsules in this non-image forming area are not cured, there is a problem in that when pressure is applied, the dye flows out and contaminates the pressure developing roller. Also,
If the media sheet is constantly pressurized, wrinkles may occur on the surface of the sheet, or if the sheet is meandering or jammed, release the pressure one by one and perform work such as correcting meandering or clearing the jam. There is a problem in that the operation becomes complicated.

The purpose of this invention is to prevent contamination of the roller surface and wrinkling of the sheet surface by controlling the pressure of the pressure developing roller, and to improve the workability of the user when meandering or jamming of the sheet occurs. An object of the present invention is to provide a method for applying pressure to a pressure developing roller.

(Means for Solving Problem d1) In this invention, a photosensitive pressure-sensitive sheet wound around a supply shaft is pulled out, exposed to light in an exposure section, then stocked in a buffer section, and after the exposure is completed, it is supplied from the buffer section to a pressure developing roller. A method of pressurizing a pressure developing roller in an image forming method in which a media sheet is subjected to pressure development and then wound onto a take-up shaft; It is characterized in that during pressure development processing, pressure is applied with the pressure that the media sheet is sensitive to, and the pressure is released at times other than during image formation.

If pressure is applied to the pressure development roller to the extent that the media sheet is not sensitive to pressure, the dye will not flow out from the media sheet, and the force that pulls the media sheet to the take-up shaft via the pressure development roller will be applied. (j) is absorbed by the pressure developing roller and the media sheet is not pulled back. Also, if high pressure is applied, the dye will flow out and an image will be formed on the sheet.

In this invention, since the pressure on the pressure developing roller is released except during image formation, unnecessary microcapsules are not destroyed, and there is no need to release the pressure when clearing a jam or correcting meandering. do not have. During exposure, etc., pressure is applied with an appropriate force that does not destroy the microcapsules, so the media sheet is prevented from being pulled back from the take-up shaft and the sheet does not become misaligned. During pressure development, sufficient pressure is applied to perform the development process.

Child) Example An outline of the image forming apparatus main body will be explained.

FIG. 6 is a diagram showing the configuration of an image forming apparatus equipped with a pressure developing roller.

<Exposure Device> A document table 1 made of transparent hard glass is provided on the top surface of the main body of the image forming apparatus. A document A to be copied is placed on the document table 1 with the document surface facing downward. An optical system is provided below the document table 1. Optical system 2 is light source 2a
, 2b, mirrors 2C to 2f, lenses 2g, filters 2h
have. The document A on the document table 1 is illuminated by light sources 2a, 2.
b, and the reflected light is guided to an exposure point, which will be described later, via mirrors 20 to 2f, a lens 2g, and a filter 2h. Note that the filter 2h has a plurality of filters having different transmission wavelengths, and performs color correction of the light reflected from the document by adjusting the insertion amount of each filter into the optical path. The amount of filter insertion is determined depending on the sensitivity characteristics of the media sheet, the image color desired by the user, and the like.

A slide projector 3 is detachably provided on the right side of the image forming apparatus main body. slide projector 3
has a light source 3a, a slide holding portion 3b, and a lens 3C. A slide film to be printed is inserted into the slide holding section 3b. On the other hand, the mirror 2f of the optical system for reflecting light from the original is rotatable, and can be rotated approximately 90 degrees by rotating a handle (not shown) provided on the front side of the image forming apparatus main body. Ru. When the mirror 2f is rotated (the state indicated by the two-dot chain line in the figure), the transmitted light of the slide film inserted into the slide holder 3b is guided to the exposure point via the lens 3C. Note that this lens 3C is also equipped with a filter for color correction.

<Media Cartridge> A media sheet mounting section is provided on the left side of the main body of the image forming apparatus. The media sheet 4 is a sheet made of a light-reflecting material such as aluminum, on which microcapsules having a particle size of about 10 to 20 μm and containing a photocurable material 3 such as a color-forming dye are coated. The microcapsules are cured by exposure to light and destroyed by pressure, allowing the color-forming dye to flow out. This media sheet becomes a photosensitive pressure sensitive sheet in pair with a receiver sheet to be described later. Note that the receiver sheet is a sheet of paper coated with a thermoplastic resin and a developing material (that causes the color-forming dye to develop color).

The media seals 1 to 4 are wound around a supply shaft 51 and housed in a storage chamber R of a media cartridge 5 made of a light-shielding material to be protected from external light and external pressure. The supply shaft 51 is always urged in the direction opposite to the drawing direction, and can be locked by a ratchet mechanism including a solenoid. The media cartridge 5 also includes a take-up shaft 52, and the used media sheet is wound onto the take-up shaft 52. The winding shaft 52 is always biased in the winding direction to prevent the media sheet 4 from becoming slack. The used media sheet 4 is replaced with the entire cartridge 5.

The media cartridge 5 is replaced by taking it in and out of the bucket 6. The packet 6 is provided so that it can be pulled out along the slider 61, 61 toward the front side of the image forming apparatus main body, and the media cartridge 5 can be inserted from above.

A tractor roller 62 is provided at the upper right end of the bucket 6. A pin 62 is provided around the end of the tractor roller 62.
A is provided. On the other hand, in the new media cartridge 5, the leading end of the media sheet 4 is slightly pulled out from the opening 53 of the storage chamber R. This is pulled out by hand and hooked onto the tractor roller 62. A leader sheet that is strong and slightly wider than the media sheet l~ is attached to the tip of the media sheet, and holes formed at both ends of the leader sheet are attached to the pins 6 of the tractor roller 62.
Can be multiplied by 2a. Place the leader sheet on the tractor roller 62.
When the packet 6 is pushed into the main body of the image forming apparatus, the packet sensor S1 is turned on, and when the front cover of the main body of the image forming apparatus is closed, the cover switch S2 is turned on. By turning on both of these, automatic loading of the media sheet (automatic setting of the media sheet) is performed.

<Exposure Section and Pressure Development Section> An exposure table 7, a buffer roller 8, and a pressure development device 9 are provided on the right side of the media sheet mounting section. At the time of initial setting, the media sheet that was hung on the tractor roller 62 is automatically wound onto the take-up shaft 52 via the exposure table 7, buffer roller 8, and pressure developing device 9. The aforementioned original reflected light or slide transmitted light is guided to the exposure point P1 and exposes the media sheet 4. Then, the media sheet 4 has a latent image (an image of partially hardened microcapsules) corresponding to the original or the slide image. ) is formed. Note that 71 is a heater that is turned on during exposure, and the media sheet 4 is provided to keep the photosensitivity constant since it changes depending on the temperature.

The buffer roller 8 is movable in the directions of arrows B and C in the figure. Movement in the direction of arrow B feeds the media sheet into the buffer portion (upper right portion of the buffer roller 8), and movement in the direction of arrow C feeds the media sheet from the buffer portion to the pressure developing device 9. Movement in the direction of arrow B is performed by a motor (not shown), and movement in the direction of arrow C when the media sheet 4 is pulled by a pressure developing roller. A home position sensor S3 is provided at the Baum position of the buffalo roller 8.

FIG. 4 is a front view of the pressure developing device, and FIG. 5 is an external view of the device.

The pressure developing device 9 has pressure developing rollers 91 and 92. Pressure development point P is between pressure development rollers 91 and 92
It is 2. Above the upper pressure developing roller 91, hack up rollers 91a and 91b are provided which apply a uniform downward biasing force to the pressure developing roller 91 in the axial direction. These are pivotally supported by an upper holder 93. The pressure developing roller 91 is point-supported so as to be movable in the vertical direction.
Backup roller 912.91b is rotatably supported by a bearing. The lower pressure developing roller 92 is rotatably supported by a lower holder 94.

The upper and lower holders 93 and 94 are rotatable about the support portion 95 as a fulcrum. A spring 96 is attached to the opposite end of the support portion 95.
A pressure mechanism is provided, and the upper and lower holders 93 and 94 are pressed against each other. As a result, the pressure developing rollers 91 and 92 are brought into a pressurized state. A cam 97 is provided near this pressure mechanism. The cam 97 is connected to a main motor (not shown) and can rotate only in one direction. The pressure between the pressure developing rollers 91 and 92 is adjusted based on the rotational state of the cam. That is, the pressurization state is increased in several stages from a strongly pressurized state to a pressure release state.

<Paper Feed Unit and Paper Discharge Unit> A paper cassette 10 is provided on the right side of the main body of the image forming apparatus. Paper cassette 10 has receivers 1 and 1.
1 is stored and sent out by the paper feeding device 12. Note that the receiver sheet 11 sent out by the paper feeding device 12 is temporarily stopped by a timing roller 13, and is fed at the timing when it is superimposed on the slot on the media sheet. A sensor S4 for detecting a receiver sheet is provided at the timing roller position.

When the media sheet 4 and the receiver sheet 11 are stacked and pressurized, the uncured microcapsules are destroyed and the coloring dye flows out. This dye is developed by the developing material and forms an image on the receiver 1. Thereafter, both sheets are separated, the media sheet 4 is wound onto the take-up shaft 52, and the receiver sheet is sent to the glossing device 20. The glossing device 20 heats and presses the receiver sheet 11 to soften the resin on the sheet to cover the image surface and smooth it. This gives the image a high gloss. This heating also accelerates the color-forming reaction of the color-forming dye. The image created in this manner is discharged to a paper discharge tray 21 on the left side of the main body of the image forming apparatus.

Next, pressure control of the pressure developing roller according to the present invention will be explained.

FIG. 1 is a flowchart showing the main steps of image forming processing, and FIG. 2 is a time chart 1 thereof.

3(A) to 3(C) are diagrams showing the state of the pressure developing device during image formation, and FIG. 3(A) shows the pressure released state, and FIG.
B) shows a semi-pressurized state, and (C) of the same figure shows a pressurized state. Here, the pressure release state is a state in which the media sheet can freely move between the rollers, and the semi-pressure state is a state in which pressure is applied that does not destroy the microcapsules of the media sheet. In these states, the media sheet 4 is held between the pressure developing rollers 91 and 92, and the pressure developing roller 91.
The sheet is conveyed only when 92 rotates. Also,
Under pressure, unhardened microcapsules on the surface of the media sheet are destroyed. 1 cm in the pressurized state, depending on the type of media sheet and the image density desired by the user.
A pressure of around 90 kg is applied per unit.

In the normal state, the pressure developing rollers 91, 91 are as shown in Fig. 3(A).
As shown in the figure, the pressure is released. When the print switch is operated, the main motor rotates, and the pressure developing rollers 9'l and 92 are brought into a semi-pressurized state as shown in FIG. 3(B) (nl→n2→n3). At the same time, the supply shaft 51 is unlocked and the media sheet 4 can be pulled out. Then, as the buffer roller 8 moves in the direction of arrow B, the optical system (for document scanning or slide exposure) is activated, and the media sheet 4 is exposed on the exposure table 7 to form a latent image (n4→n5). At this time, the pressure nozzle J developing rollers 91 and 92 are in a semi-processed state, so the media sheet is not pulled back from the take-up shaft 52, and the speed at which the media sheet is pulled out from the supply shaft 51 is kept constant. It will be done. When the exposure process is completed, the supply shaft 51 is locked to prevent the media sheet from being pulled out during pressure development etc. (n6→n7→n8)
.

By the way, the leading edge of the latent image on media sheet J2 at the end of exposure is a dot. This is located at the exposure point P1 at the start of exposure, and during pressure development, the receiver sheet is stacked and pressurized after the point. Therefore, as the next operation, the leading edge of the latent image is transported to the pressure development point 1-P2. When the pressure developing rollers 91 and 92 are rotated, the media sheet 4 is pulled, the roller roller 8 moves in the direction of arrow C, and the media sheets 1 to 4 are wound around the winding shaft 52. Then, when time T has elapsed, the timing roller 13 is rotated to feed the receiver sheet 11. Then, after time T2, the leading edge of the latent image and the leading edge of receiver I/11 overlap at the pressure developing point 1-P2, and in this state, the pressure developing roller stops rotating (
n9 to n14). Then, the pressure developing rollers 91 and 92 are pressed with a pressure suitable for the developing process, as shown in FIG. 3(C) (n15). If the pressing operation of the pressure developing roller is performed while both sheets are stopped in this manner, the leading end will not go too far during the pressing operation, and development can be reliably performed from the leading end. Further, sudden torque fluctuations due to thickness changes do not occur.

After pressurization, the pressure development rollers 91 and 92 rotate to perform pressure development processing (n16 to n22). During pressure development processing,
When the roller roller 8 returns to the home position, the supply shaft 51 is unlocked, and while the media sheet is being pulled out, the portion up to the exposure point P1 is sent to the pressure development point P2 (n17→n18 to n22).

When the rear end of the receiver sheet 11 is detected at the position of the timing roller 13, the pressure developing roller stops rotating 13 hours later, the pressure on the pressure developing rollers 91 and 92 is released, the supply shaft 51 is locked, and the pressure is released. Finish the development process (
n19-n22). In addition, T3 time is receiver sheet 11
This is the time required for the rear end of the timing roller 13 to move from the pressure development point 1-P2. and,
When the receiver sheet 11 is ejected to the paper ejection tray 21, the main motor stops and the image forming process ends (n23→n
24).

On the other hand, if an error such as a receiver sheet jam occurs during the image forming process, the rotation of the pressure developing rollers 91 and 92 is stopped and the pressure is released (n31→n32→n33).
). Therefore, work such as clearing a jam can be easily performed.

(g+ Effects of the Invention As described above, according to the present invention, the pressure of the pressure developing device is released in the normal state, so work such as clearing a jam can be easily performed. Also, during exposure, winding, etc. When an image forming process other than pressure development is performed, the media sheet is pressurized with a pressure that is not sensitive to pressure, so it is possible to prevent the media sheet from shifting its position and to prevent contamination of the apparatus. Since the media sheet can be prevented from shifting during image formation by controlling the pressure of the pressure developing device, there is an advantage that there is no need to provide a special media sheet locking mechanism.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing the main part of the image forming processing procedure, Fig. 2 is a time chart thereof, and Fig. 3 is a diagram showing the pressure state of the pressure developing roller ((A) in the same figure shows the pressure release). The figure (B) shows the semi-processed state, and the figure (C) shows the pressurized state. Figures 4 and 5 are a front view and external view of the pressure developing device, and Figure 6 is the image forming state. 4-media sheet, 8-bumper roller, 51-supply shaft, 52-winding shaft, 91, 92-pressure developing roller, which is a configuration diagram of the entire apparatus.

Claims (1)

[Claims] (1) The photosensitive pressure-sensitive sheet wound around the supply shaft is pulled out and exposed in the exposure section, then stocked in the buffer section, and after the exposure is completed, it is supplied from the buffer section to the pressure developing roller to perform pressure development, and then the take-up shaft A method of pressurizing a pressure developing roller in an image forming method in which the media sheet is not sensitive to pressure at times other than pressure development processing during image formation, and the media sheet is pressure sensitive during the pressure development processing. A method for applying pressure to a pressure developing roller, which is characterized by applying pressure and releasing the pressure at times other than when forming an image.