JPH0272353A - Image forming device with pressure roller - Google Patents

Abstract

PURPOSE:To improve operability in jamming removal by releasing the press- contacting force of a pressure roller automatically when jamming sensors provide din front of and behind the pressure roller detect a jamming. CONSTITUTION:The jamming sensors MS2 and MS3 are provided in front of and behind the pressure roller 2. Then, when an image receiving sheet jams at the part of the pressure roller 2, the image receiving sheet in the jamming state is detected by at least one of the jamming sensors MS2 and MS3 provided in front of and behind the pressure roller 2. Here, a pressure releasing means 24c is operated to release the press-contacting force of the pressure roller 2. Consequently, when a jamming occurs at the part of the pressure roller 2, a user can remove the image receiving sheet in the jamming state without releasing pressure manually.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field This invention is capable of receiving an image by overlapping a media sheet coated with photosensitive and pressure-sensitive microcapsules with an image receiving sheet and applying high pressure with a pressure roller. The present invention relates to an improvement in an image forming apparatus having a pressure roller that forms an image on a sheet.

(b) Conventional technology An image is formed using a media sheet coated with a photosensitive pressure-sensitive microcapsule containing a photocurable material and a colorless dye, and an image receiving sheet coated with a developing material that develops color from the colorless dye. There is a way to do it (Japanese Patent Application Laid-Open No. 58-8.873
No. 9, etc.). When the media sheet is exposed to imaging light such as reflected light from the original, the microcapsules are partially cured, and a selectively cured image is formed as a whole. When an image-receiving sheet is placed over the selectively cured image and pressure is applied, the uncured microcapsules are destroyed and the encapsulated colorless dye flows out, and the color is developed by the developing material on the image-receiving sheet, forming an image on the image-receiving sheet. The microcapsules that are formed have a small particle size of about 5 μm, and in order to destroy the uncured microcapsules, a particle size of, for example, 90 kg/cm is required.
Requires moderately high pressure. For this reason, pressure rollers that can easily apply high pressure have been used in devices for pressurizing media sheets and image-receiving sheets.

(C) Problem to be Solved by the Invention By the way, when forming an image on paper (image receiving sheet) in an image forming apparatus, it is assumed that paper jams will occur more than a little, so a mechanism to deal with the occurrence of paper jams should be provided. There is a need. Conventionally, image forming apparatuses equipped with a pressure roller as described above are provided with a mechanism that allows a user to manually release the pressure when a jam occurs in the pressure roller section, and the jam location is the pressure roller section. In such cases, the user releases the pressure and then removes the jammed paper (image receiving sheet).

However, as mentioned above, the pressure roller has a weight of 90 kg/
A high pressure of about cT11 is required, which is r29 for passing a horizontally long A4 size image receiving sheet.
．． This means that a high pressure of more than 7 x 90 = 2673 kg J is applied to the pressure roller. Therefore, when a jam occurs, it is extremely difficult for the user to manually release the high pressure, resulting in a problem of increasing the burden on the user.

An object of the present invention is to automatically release the pressure on the pressure roller when there is a possibility that the jamming position of the image receiving sheet is at the pressure roller position, thereby reducing the burden on the user. An object of the present invention is to provide an image forming apparatus having the following features.

Means for Solving the Problems This invention provides an image forming method in which a media sheet coated with photosensitive and pressure-sensitive microcapsules and an image receiving sheet are overlapped and an image is formed on the image receiving sheet by applying pressure with a pressure roller. In the apparatus, a pressure release means for releasing the pressing force of the pressure roller is provided, and a jam sensor for detecting a jam is provided at each side of the pressure roller in the conveyance path of the image receiving sheet, and at least one of the jam sensors detects a jam. The present invention is characterized in that means is provided for activating the pressure release means when the pressure release means is activated.

te+ effect According to the image forming apparatus having the pressure roller of the present invention,
Jam sensors are provided before and after the pressure roller, and when a jam occurs in the image receiving sheet at the pressure roller portion, the jammed image receiving sheet is detected by at least one of the jam sensors provided before and after the pressure roller. .

Since the pressure release means is activated when at least one of the jam sensors detects the image receiving sheet, the pressing force of the pressure roller is released when a jam occurs in the pressure roller section. Therefore, when a jam occurs in the pressure roller section, the user can remove the jammed image receiving sheet without manually releasing the pressure.

(f) Embodiment FIG. 3 is a schematic front view of a copying machine which is an embodiment of the present invention.

A document table 11 on which a document to be copied is placed is provided on the upper surface of the main body of the copying machine, and an optical system 12 including a light source, mirrors, lenses, etc. is provided below the document table 11. The document on the document table 11 is scanned by the light source of the optical system 12 moving along the document table 11, and the reflected light is guided to an exposure section to be described later.

A pressure roller 2 is provided approximately at the center of the main body of the copying machine. The pressure roller 2 consists of an upper roller 2a and a lower roller 2b, which are supported by holders 21a and 2gb, respectively. The holder 21b of the lower roller 2b is supported by the fulcrum 22.
It is rotatably supported by the holder 21a.

The holder 21b is biased upward by a compression spring 23 closer to the lower roller 2b than the fulcrum 22, thereby pressing the lower roller 2b against the upper roller 2a. Further, a jack 24 is provided on the opposite side of the compression spring 23 with the fulcrum 22 in between. The jack 24 has a worm screw shaft 24a, a pressure release rift 24b, and a pressure release motor 24C. Pressure release motor 24
C is, for example, a C motor capable of forward and reverse rotation. As the pressure fighting motor 24c rotates forward, the pressure releasing lift 24b pushes up the end of the holder 21b against the force of the compression spring 23, thereby pushing up the upper and lower rollers 2a.
, 2b pressure release is performed. In addition, the pressure release motor 24C rotates in the opposite direction, so that the pressure release lift 24
b is lowered, and the lower roller 2b is pressed against the upper roller 2a by the pressing force of the compression spring 23. Upper and lower rollers 2a
With the pressure of 2b released, the user can remove the image receiving sheet jammed between the pressure rollers.

A media cartridge 13 for storing media sheets is provided on the left side of the pressure roller 2. The media sheet is pulled out from the media cartridge 13, transferred to the transport rollers 14a, 14b, the exposure section P1, and the transport roller 14.
After passing through G, the upper and lower rollers 2a and 'l of the pressure roller 2
b (pressure developing section P2) and is wound up on the winding shaft 15.

Also, paper cassettes 15a and 1 are provided on the right side of the copying machine main body.
6b and a tray 16c for manual feeding.

Image receiving sheets are stored in the paper cassettes 16a and 16b, and the image receiving sheets can also be fed from the tray 16c. Paper cassettes 16a, 16b and tray 16c
are provided with paper feed rollers 17a to 17C, respectively. During image formation, an image-receiving sheet is fed from one of the paper cassettes 16a, 16b, and tray 16c by rotating one of the paper feed rollers 17a to 17c.

The downstream side of the paper force cellars l-16a, 16b and the tray 16c with respect to the paper conveyance direction (hereinafter, upstream side and downstream side with respect to the paper conveyance direction are simply referred to as upstream).

It is called downstream. ) is provided with a registration roller 18. The registration rollers 18 are rollers for feeding the image receiving sheet at a predetermined timing.

The media sheet is exposed to light reflected from the original by the optical system 12 in the exposure section P1, and the microcapsules hit by the light are hardened to form a selectively hardened image on the surface.

On the other hand, in parallel with this, an image receiving sheet is fed from a paper cassette or a manual feed tray, and is held by the registration rollers 18. This image-receiving sheet is fed by rotation of the registration rollers 18 at the timing when the image-receiving sheet is superimposed on the selectively cured image. And both sheets are pressed by pressure roller 2
Pressurized by As a result, the uncured microcapsules are destroyed, the colorless dye flows out, and a colored image is formed on the image receiving sheet.

The image receiving sheet on which the colored image has been formed is transferred to the suction belt 31
The sheet is conveyed to the glossing device 32, and after the color image is improved in quality, it is discharged onto the paper discharge tray 34 by the paper discharge roller 33. The glossing device is a device that heats and presses the image-receiving sheet on which a colored image has been formed, and the heating accelerates the coloring reaction of the colorless dye to form a good-colored image. In addition, if a thermoplastic resin is coated on the image-receiving sheet, the thermoplastic resin is softened by heating and covers the surface of the colored image, and the thermoplastic resin is smoothed by pressure, and the colored image is Gives a high gloss.

In the copying machine configured as described above, a jam sensor for detecting a jam in the image receiving sheet is provided on the conveyance path of the image receiving sheet. In this embodiment, jam sensors MSI, MS2. MS3. MS4 is provided. The jam sensors MSI to MS4 are micro-sinches, and are turned on while the image receiving sheet is passing. Note that an optical sensor or the like may be used as the jam sensor.

FIG. 2 is a block diagram of the main parts of the copying machine.

The copying machine is controlled by CPU41. The detection states of the jam sensors MSI to MS4 and the detection state of the door switch 42 are input to the CPU 41.

Further, the CPU 41 is connected to a copy processing section 43 such as an optical system, a media sheet conveyance system, an image receiving sheet conveyance system, a pressure release motor 24c, a display section 44, and the like.

When the image receiving sheet is fed by rotation of the paper feed roller (any one of 17a to 17G), a timer of the CPU starts. This timer measures the time required until the image-receiving sheet is ejected to the paper ejection tray 34, and is set according to the size of the image-receiving sheet being fed. Note that when paper is fed from the manual feed tray 16C, the timer time is set according to the maximum usable image receiving sheet size.

By the time this timer expires, the jam sensor MS
If 4 is never turned on, it is determined that the image receiving sheet is jammed somewhere within the main body of the copying machine. The door switch 42 is a switch that detects the opening/closing of the front door of the copying machine.When a jam occurs, the door switch 42 is activated.
However, it is determined that the jam removal work has been completed by turning off and then on.

FIG. 1 is a flowchart showing the processing procedure when a jam occurs in the copying machine.

As described above, if the jam sensor MS4 is not turned on even after a predetermined period of time has elapsed after the image-receiving sheet is fed, this flowchart starts. First, each copying processing section is stopped at nl to interrupt the copying process. Then, in steps n2 to n5, it is determined whether the jam sensors MSI to MS3 are on or off. Here, jam sensor MS2. If MS3 is low (either one is on), it is determined that a jam has occurred in the pressure roller 2, and the process proceeds to n6.

At step n6, the pressure release motor 24C is turned on to release the pressure on the pressure roller 2 using the pressure release lift 24b against the force of the compression spring 23. When the pressure release motor 24c is turned on, a counter that counts the rotation amount of the motor is started, and when this rotation amount (m) reaches a predetermined value ffi (mK), the pressure release motor 24c is turned off (n7→n8→n9). . Here, the predetermined it (m
K) is the rotation amount of the motor to form a certain amount of gap between the upper and lower rollers 2a and 2 parts of the pressure roller 2, and the amount of the gap is such that the image receiving sheet jammed between the upper and lower rollers 2a and 'lb can be removed by the user. is an interval that can be easily removed.

In this way, the jam sensor MS2. When MS3 is on, the pressure between the upper and lower rollers 2a of the pressure roller 2 is released, and in other cases, the process proceeds to nlo without releasing the pressure, and the occurrence of a jam is notified on the display on the copying machine main body. display (nlo) and wait for the jam to be cleared (nil, n
12). When a jam occurs, the user opens the door on the front of the copying machine and removes the jammed image receiving sheet (n
11) At this time, if the jammed image receiving sheet is between the pressure rollers 2, the pressure on the pressure rollers 2 has been released, so that the jammed paper can be easily removed. Note that the jam sensor MS2. Jam unrelated to pressure roller 2 even when MS3 is on, such as jam sensor MS
There is also a jam when the leading edge of the image receiving sheet is stuck in 2, but in this case there is a possibility of a jam occurring at the pressure or roller 2 (when at least one of the jam sensors MS2 and MS3 is on) ), the pressure on the pressure roller 2 is always released.

When the jam removal is completed and the front door of the copying machine is closed (n12), the pressure release motor 24c rotates in the opposite direction by the same amount as the predetermined amount (mK' times), and the pressure roller 2 is released by the compression spring 23. begins to be pressurized at high pressure (n13→n14→n15). and n16
At this point, the optical system and the like are moved to a state where image formation can be started, and the process returns to the main routine.

As described above, when a jam occurs in the pressure roller 2 portion, the jammed paper (image receiving sheet) can be easily removed. Note that the r pressure release means j of the present invention corresponds to the jack 24 maid; and the means 1 for operating the r pressure release means corresponds to n6. in the flowchart. n7. Corresponds to n8n9.

(Effects of the g1 invention) According to the invention, when the jam sensor installed before and after the pressure roller detects a jam, the pressing force of the pressure roller is automatically released, so the image receiving sheet is placed between the pressure rollers. If there is a possibility that something is stuck, the pressure will be automatically released.

Therefore, the user does not have to manually release the pressure on the pressure roller, and the operability during jam removal can be improved.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a processing procedure when a jam occurs in a copying machine according to an embodiment of the present invention, FIG. 2 is a block diagram of the copying machine, and FIG. 3 is a schematic front view of the copying machine. One-pressure corolla, a-upper roller, b-lower roller, 4-jacket\4C-pressure release motor.

Claims (1)

[Claims] (1) In an image forming apparatus that forms an image on the image receiving sheet by overlapping a media sheet coated with photosensitive and pressure sensitive microcapsules with an image receiving sheet and applying pressure with a pressure roller, the pressing force of the pressure roller A pressure release means for releasing the pressure roller is provided, and a jam sensor for detecting a jam is provided before and after the pressure roller in the conveyance path of the image receiving sheet, and when at least one of the jam sensors detects a jam, the pressure release means is set to release the pressure release means. An image forming apparatus having a pressure roller, characterized in that it is provided with means for actuating it.