JP2913811B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus that forms an image by exposing a photosensitive recording medium, superimposing the photosensitive recording medium on an image receiving sheet, and performing pressure development.

2. Description of the Related Art Conventionally, in this type of apparatus, a pair of rollers for transporting a photosensitive recording medium is provided between a pressure developing device and a take-up core that winds a photosensitive recording medium after pressure development. Thus, a friction clutch was interposed between the winding core and the drive source. In this apparatus, the speed of the winding core is set to be higher than the transport speed of the roller pair, and the speed difference is eliminated by the friction clutch.

[Problems to be Solved by the Invention] However, the speed difference between the roller pair and the winding core after the pressure development is eliminated by the friction clutch, but during the pressure development, the conveying speed of the photosensitive recording medium is reduced by the pressure developing device. When the speed of the roller pair is high, the photosensitive recording medium is pulled and the roller pair slips due to the speed difference generated between the pressure developing roller and the roller pair that conveys the photosensitive recording medium. When a considerable load is applied to the roller pair and the speed of the pressure developing roller is high, the photosensitive recording medium may sag between the pressure developing roller and the roller pair, which may adversely affect the separation of the image receiving sheet. was there.

The present invention has been made in order to solve the above-described problems, and by opening and closing the nip of the roller pair behind the pressure developing device, by opening the nip of the roller pair during pressure development. The pressure developing roller completely controls the reaction of the photosensitive recording medium, thereby preventing a load on the roller pair due to the tension of the photosensitive recording medium and slipping of the roller pair. It is an object of the present invention to provide an image forming apparatus capable of preventing an adverse effect on separation of an image receiving sheet due to slack between a roller and a pair of rollers.

[Means for Solving the Problems] To achieve this object, an image forming apparatus according to the present invention comprises:
A pair of rollers capable of opening a nip for transporting the photosensitive recording medium between the winding means for winding the photosensitive recording medium after pressure development, the pressure developing device and the winding means, and a pressure roller of the pressure developing apparatus. Detecting means for detecting the opening and closing of the nip, and nip the roller pair when the pressure developing device is not pressing the photosensitive recording medium, and open the nip when the pressure developing device is pressing the photosensitive recording medium. Control means for performing the control.

[Operation] In the image forming apparatus of the present invention having the above-described configuration, the opening and closing of the nip of the pressure roller of the pressure developing device is detected by the detecting unit, and the control unit detects the nip of the pressure developing roller. When the pressure developing roller is not nipped, the roller pair is nipped. In either case, the winding and winding means via the friction clutch can eliminate the tension and slack of the photosensitive recording medium due to the speed difference between the pressure developing device and the roller pair.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view in which a monochrome laser printer 1 and a color image recording device 20 are combined and arranged.

First, the monochrome laser printer 1 is mounted on the upper part of the color image recording device 20. In the laser printer 1, an electrostatic latent image is drawn by irradiating a laser beam from the polygon scanner 2 on the charged photoconductor 3. The photoreceptor 3 on which the electrostatic latent image is formed is developed by a developing device 4, a toner image is transferred onto plain paper or an OHP sheet supplied from a paper feed cassette 5, and fixed by a fixing device 6. Normally, the monochrome laser printer 1 records data transmitted from a host computer.

The output from the laser printer 1 is supplied to a paper path switching unit 10.
If you need a black-and-white image in
11 or Automatic Document Feeder (ADF) Tray 12
To the ADF tray 12
After that, the image is taken into the color image recording device 20. The paper sent to the ADF tray 12 is taken into the color image recording device 20 one by one by the ADF paper feed roller 13, and three sheets of monochrome printed paper output from the laser printer 1 form one set. It is used as a mask master 15 (15R, 15G, 15B) of the color image recording device 20.

 Next, the configuration of the color image recording device 20 will be described.

A positioning device 31 is located at the lower part of the main body of the color image recording device 20, and the space between the ADF tray 12 and the positioning device 31 is connected by a mask original transport path 21. Roller pair 2 whose rotation direction can be controlled on both left and right sides of the positioning device 31
2,23,24,25,26,27, gates 28,29 and mask master storage 10
2 are located. In the middle of the mask master transport path 21,
A recurler roller pair 101 for removing the curl of the mask master 15 discharged from the laser printer 1 is arranged. Outside the pair of rollers 26 and 27, there is a used mask master 15
There is a mask original discharge tray 30 for discharging the original.

The positioning device 31 includes a sensor (not shown), a pair of rollers 32 and 33 disposed near both right and left ends, and a glass plate 34 disposed therebetween.

An exposure device 41 is disposed below the positioning device 31, and the exposure device 41 is movable in the left-right direction along the positioning device 31. The exposure device 41 includes a linear white light source (hereinafter, referred to as a lamp) 42, a reflector 43 for reflecting light from the lamp 42, and a filter unit 44 including a red filter 44R, a green filter 44G, and a blue filter 44B. ing.

The photosensitive recording medium 50 is mainly composed of, for example, a photocurable resin using a photopolymerization initiator known in Japanese Patent Application Laid-Open No. Sho 62-143044, and is sensitive to light of each wavelength of red, green, and blue. A microcapsule containing a photocurable resin that cures by curing and cyan, magenta, and yellow dye precursors is applied on a sheet serving as a base material. The photosensitive recording medium 50 is housed in the cartridge 51 so as not to be exposed to light. The photosensitive recording medium 50 passes between the glass plate 34 and the exposure table 52 from inside the cartridge 51, and is routed to the winding roller 54 via the buffer 55, the separation roller 64, the pressure developing device 70, and the driving roller 57. . The exposure table 52 is configured so that the mask master 15 and the photosensitive recording medium 50 that are processed by the cam 53 and conveyed onto the glass plate 34 are brought into close contact with each other. The fixing roller 56 is arranged to be pressed against the left end of the exposure table 52 when the exposure table 52 is lowered to a predetermined position, and to fix the photosensitive recording medium 50 to the exposure table 52 during exposure of the mask master 15. Have been. Further, the drive roller 57 has two drive rollers 57a, as shown in FIG.
The driving roller 57a is held by a holding member 131 that is rotatable around a fixed shaft 132 as a rotation center. The holding member 131 is always driven by the driving member 57 by the spring member 133.
a is urged so as to press against the drive roller 57b. Further, the holding member 131 is opposed to the force of the spring
Is operated so that the nip of the roller pair 57 can be released. The take-up roller 54
A well-known friction clutch is interposed between the drive roller 128 and the take-up core drive device 128 to absorb a mismatch in the transport speed of the drive roller 57 and the pressure roller 71. The pressure developing device 70 is configured so that the nip roller 135 nips with the pressure roller 71 by rotating the eccentric cam 136.
It can be detected at 131.

The developer sheet 60 as an image receiving sheet is disclosed in, for example,
The developer disclosed in Japanese Patent Application Laid-Open No. 58-88739 is formed by applying a color developer on a base paper, and is set in a cassette 61 so that the color developer application surface faces downward. Above the cassette 61, a suction cup 62 for feeding the developer sheets 60 one by one is arranged.

The pressure developing device 70 includes a photosensitive recording medium 50 on which a latent image is formed by exposure, and a pair of pressure rollers 71 for superposing and developing the developer sheet 60.

The heat fixing device 80 has a casing 83 containing an upper heater 81 and an impeller 82, rubber rollers 84, 85, 86 for conveying the developer sheet 60 below, and a roller 87 and a roller 88. The endless belt 89 is provided, and a sheet ejection tray 63 is attached outside the heat fixing device 80.

 FIG. 3 shows a control device of the present image forming apparatus.

The control device is mainly composed of CPU 122, RAM 123, ROM 124 and bus 125.
Microcomputer 126.

The microcomputer 126 is further connected to a winding core drive device 128 and a solenoid 134 via a winding core control circuit 127 and a solenoid control circuit 129, respectively. A sensor 131 for detecting the nip state of the pressure developing device 70
Are also connected to the bus 125. The winding core 138 is for winding the photosensitive recording medium 50 after the pressure phenomenon,
The solenoid 134 is for opening the nip of the driving roller 57.

The operation of the above-described configuration for obtaining a plurality of color images from a set of mask originals will now be described.

First, the mask original 15R for red is created by the monochrome laser printer 1. This mask master 15R is a mask master in which toner, which is a light-shielded image, is placed on the other portions of the microcapsules applied to the photosensitive recording medium 50 in order to cure the microcapsules having a cyan dye precursor in the microcapsules applied to the photosensitive recording medium 50. is there. At this time, the mask original 15R output from the monochrome laser printer 1 is fed into the color image recording device 20 by the ADF paper feed roller 13 sent to the ADF tray 12. The mask master 15R fed into the color image recording device 20 passes through the mask master transport path 21 and is sent to the alignment device 31 by the pair of rollers 24 and 22. On the way, the curl of the mask master 15R is corrected by the recurler roller 101. At this time, the gate 28 is at the position indicated by the solid line.

Next, the alignment device 31 transports the mask master 15R to an appropriate exposure position by the roller pair 32, and then reads the alignment mark printed on the mask master 15R with a sensor while driving the mask master 15R by a drive source (not shown). Is moved to a predetermined position.

Immediately before the alignment is performed, the exposure table 52 is lowered by the cam 53 to a predetermined position, and a fixed roller 56 is pressed against the left end of the exposure table 52 to fix the photosensitive recording medium 50 to the exposure table 52.
After the completion of the alignment, the exposure table 52 is further lowered by the cam 53, comes into contact with the glass plate 34 of the alignment device 31, and brings the mask original 15R and the photosensitive recording medium 50 into close contact.

When the exposure table 52 comes into close contact with the positioning device 31, the lamp 42 is turned on, and the red light is exposed to the photosensitive recording medium 50 via the mask master 15R via the red filter 44R.
The exposure device 41 performs scanning exposure in the direction of arrow A. When the exposure is completed, the lamp 42 is turned off, and the exposure device 41 moves back in the direction of arrow B. At this time, the filter unit of the exposure device 41
44 is moved by a driving source (not shown), and a green filter 44G is located above the lamp 42.

While the exposure device 41 moves backward, the exposure table 52 is raised by the rotation of the cam 53, and the photosensitive recording medium 50 is moved to the position adjustment device 31.
And the mask master 15R. At this time, the photosensitive recording medium 50 contains the photosensitive recording medium in the cartridge 51.
The back tension is applied at the center of rotation of the roll 50, and when the exposure table 52 is lowered, a length corresponding to the descending amount of the exposure table 52 is pulled out from the storage cartridge 51, and when the exposure is completed and the exposure table is When 52 rises,
The photosensitive recording medium 50 is rewound in a direction to remove the slack.

Even after the exposure of the red mask master 15R is completed, the exposure table 52 rises only to a predetermined position, and the photosensitive recording medium 50
Keeps being fixed to the exposure table 52 by the fixing roller 56 pressed against the left end of the exposure table 52.

Next, the green mask master 15R created by the monochrome laser printer 1 passes through the ADF tray 12, the ADF paper feed roller 13, the recurler roller 101 and the mask master conveyance path 21 to reach just before the roller pair 24. 22,24,25,2
7, The roller pair 32, 33 of the alignment device 31 is rotated in the direction of transporting the mask master 15R rightward, and the mask master 15R is rotated.
Is sent from the positioning device 31 and the mask master 15
G is transported to the exposure position and stopped. At this time, gate 28,
Reference numeral 29 denotes a position indicated by a solid line, and the exposed mask master 15R is held by stopping the rotation of the roller pair 27 with the rear end of the gate 29 passing between the roller pair 27 and the gate 29 passing therethrough.

The mask master 15G guided to the alignment device 31 is positioned with respect to the photosensitive recording medium 50, as in the case of the mask master 15R. It is made to adhere. Thereafter, the lamp 42 is turned on, and exposure with green light is performed via the green filter 44G. After the exposure, the exposure table 52 is raised to a predetermined position. The exposure device 41 is moved back to the origin position, and moves the filter unit 44 so that the blue filter 44B is positioned above the lamp 42.

Next, the blue mask master 15B created by the monochrome laser printer 1 is similarly
0, and the roller pair 24, 22, 25, 26 and the roller pair 32, 33 of the positioning device 31 in a state of being transported immediately before the roller pair 24.
The mask master 15G is rotated in the direction of conveying the mask master 15G rightward, so that the mask master 15G is sent out from the alignment device 31, and the mask master 15B is transferred to the exposure position and stopped. At this time, the gate 28 is located at the position indicated by the solid line, the gate 29 is located at the position indicated by the broken line, and the mask master 15G at the time of exposure is
The roller pair 27 is stopped by the rotation of the roller pair 27 while the rear end of the gate 29 has passed through the gate 29.

The mask master 15B guided to the alignment device 31 is brought into close contact with the photosensitive recording medium 50 by the same operation. The photosensitive recording medium 50 is exposed to blue light through the mask master 15B.

By the above operation, a latent image of a desired color image is recorded on the photosensitive recording medium 50.

Next, raise the exposure table 52 to the initial position, and
56 and the left end of the exposure table 52
By moving 55 in the direction of arrow E, the unexposed portion of the photosensitive recording medium 50 is moved below the exposure table 52 by the cartridge 51.
Come out from within. The drive roller 57 conveys the photosensitive recording medium 50 and stops when the leading end of the latent image reaches the pressure roller 71 of the pressure developing device 70.

The developer sheet is synchronized with the movement of the photosensitive recording medium 50.
60 is sent out from the cassette 61 by the suction cup 62, and is stopped after the tip of the developer sheet 60 is conveyed to a position corresponding to the tip of the latent image on the photosensitive recording medium 50.

Next, the step of pressure-developing the latent image will be described with reference to the flowchart of FIG.

In the pressure developing device 70, an eccentric cam 135 of the pressure developing device 70 is rotated by a driving device (not shown), and the nip roller 131 is pressed against the pressure roller 71. At this time,
By lowering the exposure table 52 to a predetermined position, a fixed roller 56 is pressed against the left end of the exposure table 52, and the photosensitive recording medium 50 is fixed to the exposure table 52. The photosensitive recording medium 50 is sent while being pressed while being superposed on the developer sheet 60, and the uncured microcapsules on the photosensitive recording medium 50 are destroyed by the pressure, and the latent image on the photosensitive recording medium 50 is broken. A corresponding color image is developed on the developer sheet 60.

By rotating the pressure roller 71 of the pressure developing device 70 in the direction of the arrow, the buffer 55 is moved in the direction of the arrow F. In this case, the eccentric cam 135 rotates in step 1 of the flowchart of FIG.
When the nip roller 136 is brought into pressure contact with the nip roller 136, the pressure roller nip detection sensor 131 detects this. Next, in operating the solenoid 134 in S2, the holding member 131 rotates, and the nip of the drive roller 57 is released (S2).
2). As a result, the photosensitive recording medium 50 is conveyed under the control of the conveying force of the pressure roller 71 and the nip roller 135.

The developer sheet 60 is separated from the photosensitive recording medium by a separation roller 64.
At the same time as being separated from 50, it is guided in the direction of the heat fixing device 80. Immediately before the rear end of the developer sheet 60 has passed through the pressure roller 71 and the nip roller 135, the eccentric cam 135
Is rotated by a driving source (not shown), and the nip roller 135 is separated from the pressure roller 71, whereby the nip is opened. At this time, whether or not the nip is opened is detected again by the pressure roller nip detection sensor 131 (S1). Upon detecting that the nip has been opened, the power supply to the solenoid 134 is cut off at the same time, and the drive roller 57a held by the holding member 131 causes the spring member 133 to rotate around the fixed shaft 132.
And the drive roller 57 is nipped (S3). In this case, the photosensitive recording medium 50 is
It is controlled and transported.

In the heat fixing device 80, the developer sheet 60 includes a heater 81.
, And is heated by the air circulating in the casing 83 by the impeller 82, thereby promoting color development of a color image. At the same time, the binder polymer (fixing resin) for fixing the developer medium to the base paper of the developer sheet 60 is melted by heat, and the surface becomes smooth, and the surface of the developer sheet 60 has an appropriate gloss. Can be The developer sheet 60 on which the color development and the gloss processing have been completed is discharged to the paper discharge tray 63.

During the above-described series of development and color gloss processing, the photosensitive recording medium 50 is held and fixed by the exposure table 52 and the fixing roller 56. The exposure process of the latent image of the color image can be performed.

When performing the exposure processing of the latent image of the second color image, first, the mask master 15B at the exposure position is sent to the left, and the mask master 15R held at the position of the roller pair 27
Roller pair 24,22,2 to feed
5, 27 and the roller pair 32, 33 of the alignment device 31 are the mask master 1
Rotated to transport 5R to the left. At this time, the gates 28 and 29 are located at positions indicated by solid lines. Mask original 15B
Is stopped by the roller pair 24 at a position where the trailing end of the gate 28 has passed by the roller pair 24, and the rotation of the roller pair 24 is stopped. The mask master 15R sent to the positioning device 31 is aligned and brought into close contact with the photosensitive recording medium 50. The photosensitive recording medium 50 is exposed to red light via the mask master 15R.

Next, the mask master 15R at the exposure position is sent to the left, and the mask master 15R held at the position of the roller pair 26 is moved.
Roller pair 22, 23, 2 to feed G into alignment device 31
Roller pairs 32 and 33 of 5,26 and positioning device 31 are the mask original 1
Rotated to carry 5G to the left. At this time, the gates 28 and 29 are located at the positions indicated by the broken lines. Mask original 15R
Is held between the pair of rollers 23, and the rotation of the pair of rollers 23 is stopped at a position where the rear end of the gate 28 has passed the gate 28. Mask master 15 sent to alignment device 31
G is aligned and brought into close contact with the photosensitive recording medium 50. The photosensitive recording medium 50 is exposed to green light through the mask master 15G.

Next, the mask master 15G at the exposure position is sent out to the right, and the mask master 15G held at the position of the roller pair 24 is moved.
A similar operation is performed to send B to the positioning device 31 to form a latent image of a color image on the photosensitive recording medium 50 and a color image on the developer sheet 60.

By repeating the same operation, one set of mask master
15, a predetermined number of color images can be output.

After the required number of color images from the same mask master 15 have been obtained, each mask master 15 is discharged to the paper discharge tray 30 from the roller pair 27 or the roller pair 26. If the next mask original 15 is output from the monochrome laser printer 1 during the exposure processing of a series of color images, it is temporarily stored in the ADF tray 12, and the exposure of the previous set is completed. Thereafter, the paper is fed into the color image recording apparatus 20 one by one by the ADF paper feed roller 13.

When a mask original output from another monochrome laser printer or a previously used mask original is used again, the mask original can be input by setting it on the ADF tray 12.

[Effects of the Invention] As is clear from the above, according to the present invention, the nip of the roller pair is opened during the pressure development by the pressure developing device, so that the conveying speed of the photosensitive recording medium is reduced. A considerable load on the roller caused by the speed difference between the pressure roller and the roller pair of the pressure developing device caused by being supported by the pressure developing device during development, and separation of the image receiving sheet due to slack of the photosensitive recording medium. Adverse effects can be prevented.

[Brief description of the drawings]

1 is a cross-sectional view of an image forming apparatus showing the configuration of the present invention, FIG. 2 is a diagram showing a control flowchart, FIG. 3 is a block diagram showing an electrical configuration, and FIG. 4 is a perspective view showing a driving roller. It is. In the figure, 50 is a photosensitive recording medium, 57 is a drive roller, 70 is a pressure developing device, 71 is a pressure roller, 131 is a sensor, and 135 is a nip roller.

Claims (1)

(57) [Claims] An image forming apparatus for exposing a photosensitive recording medium to pressure development in a state where the photosensitive recording medium is superimposed on an image receiving sheet, and recording an image, comprising: winding means for winding the photosensitive recording medium after pressure development; A pair of rollers capable of opening a nip for transporting a photosensitive recording medium between a developing device and the winding unit; a detecting unit configured to detect opening and closing of a nip of a pressure roller of the pressure developing device; Control means for controlling the nip when the pressure developing device is not pressurizing the photosensitive recording medium, and for opening the nip when the pressure developing device is pressing the photosensitive recording medium. Image forming device.