JP2733840B2 - Thermal development image forming method - Google Patents

Description

The present invention relates to a method for forming a heat-developable image with a reduced processing time.

[Background of the Invention]

A diffusion transfer type thermal development method has been proposed in which a diffusible dye is released by heat development and the dye is transferred to an image receiving element to separate a silver image and a dye to obtain a color image. Further, many techniques have been disclosed for the photosensitive element, the image receiving element, the heat development method and the apparatus in the heat development.

As an apparatus utilizing such a heat development method, for example, a dry color hard copy apparatus disclosed in Japanese Patent Application Laid-Open No. 62-201433 has been proposed. The outline of this device is that a photosensitive sheet is image-exposed to form a latent image thereon, which is superimposed on an image receiving sheet, and then sandwiched between a rotating drum and an endless belt pressed against the rotating drum. After heating and pressurizing to release the diffusible dye in the image portion from the photosensitive sheet and transferring it to the image receiving sheet, the two sheets are peeled off to obtain an image receiving sheet on which a color image is formed. .

In this case, if the conveying speed of the two sheets before entering the rotating drum, which is the heat developing unit, is different from the conveying speed of the rotating drum, the sheets are loosened or tensioned, and the developing time becomes undefined. For this reason, in the related art, the transport speed in each section in the apparatus has been made to match the rotational linear velocity of the rotating drum.

[Problems to be solved by the invention]

However, the heat developing unit is compact and the conveying speed inside the heat developing unit is relatively slow in order to realize necessary and sufficient heat development, and the conveying speed until both sheets are carried into the heat developing unit is also adjusted to this speed. There is a problem that the processing time per unit becomes long. Further, since the photosensitive material on which the latent image has been formed and the image receiving material are superimposed and heated and pressed in a heat developing section to transfer the latent image to the image receiving material, the two sheets come into close contact with each other and the two sheets are peeled off. There was also a problem that it became difficult.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method for forming a heat-developable image in which the processing time per sheet is reduced and a method for forming a heat-developable image in which both sheets are easily peeled off.

[Means for solving the problem]

For this purpose, the present invention is to superimpose a photosensitive material on which a latent image has been formed by image exposure and an image receiving material, and heat and press in a heat developing unit to develop the latent image and transfer the latent image to the image receiving material. In the heat development image forming method described above, the image receiving material and the photosensitive material exposed to light are conveyed at a first speed, and the image receiving material is temporarily stopped when it reaches a first position, and the photosensitive material is moved to the first position. The position is based on the fact that the distance to the heat developing section reaches a second position, and the image receiving material is re-conveyed and the image receiving material and the photosensitive material are moved at a second speed lower than the first speed. The speed was changed to 2, and the heat was sent to the heat developing section.

〔Example〕

Hereinafter, a method for forming a thermally developed image according to an embodiment of the present invention will be described. FIG. 4 is an overall schematic diagram of a thermal development image forming apparatus for performing the thermal development image forming method. In FIG. 1, reference numeral A denotes a photothermographic material supply unit which stores a plurality of photosensitive sheets N as a photothermographic material and supplies them one by one from a supply port 10. Near the outside of the supply port 10, a pair of first transport rollers 11, a photosensor PS1 for sensing the transported photosensitive sheet N, a first guide 12 for guiding the photosensitive sheet N in a predetermined direction, and the like. Are arranged.

Reference numeral B denotes an exposure unit disposed above the photothermographic material supply unit A, which is to expose a photosensitive sheet N passing through the first guide 12 to form a latent image.

Reference numeral 20 denotes a second transport roller, and reference numeral 21 denotes a second guide, which are devices for transporting the photosensitive sheet N after image exposure to a predetermined position.

C is an image receiving material supply unit for accommodating a plurality of image receiving sheets P and automatically supplying the image receiving sheets P one by one from a supply port 30. In the vicinity of the outside of the supply port 30, a pair of third transport rollers 31, a third guide 32 for guiding the image receiving sheet P in a predetermined direction, a photosensor PS2 for sensing the image receiving sheet P on the guide 32, and the like are provided. It is arranged.

D is a heat development transfer unit for developing the latent image on the photosensitive sheet N exposed to the image and transferring the image to the image receiving sheet P; 400, a rotary drum device rotatably disposed at the center thereof; Reference numeral denotes an endless belt which presses and wraps around a half of the outer peripheral surface of the rotary drum device 400 and rotates at the same speed as the rotary drum device 400 rotates.

The rotating drum 400A, which is the base of the rotating drum device 400,
A heat-resistant and smooth surface is used, and it is formed of a cylindrical aluminum having an outer surface coated with Teflon, another metal such as iron or stainless steel, or a heat-resistant plastic. In the case of aluminum, the thickness is set to 5 mm or more to have a heat capacity. Both sides of the rotary drum 400A are formed in a heat insulating structure by sticking silicone rubber. As a heat insulating material, asbestos, bake or other materials are effective if they have a large heat capacity. Further, a heater is attached to the inside so that heating can be performed at room temperature to about 200 ° C., and servo control of the internal temperature is possible.

The belt 401 is placed at an appropriate position on the rotation line of the belt 401.
A heating device 402 for heating the heater is provided.

403 is a group of rollers for rotatably holding the endless belt 401, an inlet roller 403A provided at the position of the inlet 400a of the rotary drum 400A, an outlet roller 403B provided at the position of the delivery unit 400b of the rotary drum 400A, and a drum. It comprises a holding roller 403C and a tension adjusting roller 403D provided at a position distant from 400A.

A drive motor 404 is attached to the exit roller 403B,
The outlet roller 403B serves as a drive source to rotate or rotate the belt 401, the group of rollers 403, and the rotating drum 400A.

The outlet roller 403B and the entire drive motor 404 are pressed against the rotating drum 400A by the pressing mechanism 405, and the outlet roller 403B is pressed against the rotating drum 400A via the belt 401.

In order to prevent the belt 401 from meandering due to thermal expansion or the like, it is effective to use a type roller as the tension adjusting roller 403D and the holding roller 404C.

Reference numeral 406 denotes a laminating roller mounted on the outer periphery of the rotating drum 400A.
It is for crimping to. The laminating roller 406
Also, it is formed of silicone rubber, neoprene rubber, or the like in order to increase the coefficient of friction with the belt 401 and to provide appropriate elasticity.

Reference numeral 407 denotes a cleaning roller disposed above the entrance roller 403A, and 408 denotes a neutralization brush disposed at an appropriate position on a rotation line of the belt 401 to prevent the belt 401 from being charged. This is for cleaning fine sheet pieces and dust remaining on the belt 401.

409 is the third guide 32 and the entrance 400a of the rotary drum 400A
This is a fourth guide disposed between the rotary drum 400A and the fourth guide for feeding the image receiving sheet P to the entrance 400a of the rotary drum 400A. At a predetermined position of the fourth guide 409, a photo sensor PS3 for sensing the image receiving sheet P being conveyed is arranged.

Reference numeral 410 denotes a fifth transport roller disposed on the exit side of the second guide 21. Reference numeral 411 denotes a fifth guide disposed between the transport roller 410 and the entrance 400a of the rotary drum 400A. Is a device for feeding the photosensitive sheet N to the entrance 400a of the rotary drum 400A. Therefore, the tip ends of the fourth guide 409 and the fifth guide 411 meet each other at a predetermined angle with respect to the entrance 400a.

On the other hand, the scraper 41 is attached to the delivery section 400b of the rotating drum 400A.
Two are arranged. The scraper 412 has the sharp portion oriented to the delivery portion 400b and comes into contact with the rotating drum 400A, and the sheets P and N which are superimposed and conveyed are rotated by the rotating drum 400A.
It is for peeling off from.

413 is a curl straightening guide arranged on the side of the sending section 400b of the rotating drum 400A.
It is provided in the vicinity of the sending section 400b of 400A. A sixth conveyance roller 414 is provided in the middle of the curl correction guide 413. The roller 414 has a one-way clutch, and can follow the sheets P and N even if they are pulled at a high speed in the feed direction.

Reference numeral 415 denotes a light-shielding roller unit disposed at the outlet of the curl correction guide 413. The left and right wall surfaces in the drawing have slits through which the overlapped sheets P and N pass, and the inside has a slit that partitions the inside left and right. A plate 415a is attached. The slit plate 415a also has a slit formed in the center thereof for passing the sheets P and N. Further, a pair of sliding rollers 415b, 415c and the like are provided in both rooms of the slit plate 415a in the light shielding roller unit 415, respectively.

Since the arrangement direction lines a and b of the mounting of each pair of the sliding rollers 415b and 415c are not parallel to each other and are set at a certain angle, it is possible to prevent light from directly passing through. A sixth guide 416 is provided on the exit side of the light blocking roller unit 415.

E is a sheet peeling portion disposed on the exit side of the sixth guide 416, 50 is a pair of meandering correction rollers disposed on the exit portion of the guide 416, and 51 is a sheet discharge side of the correction roller 50. It is a pair of swing rollers arranged.

The upper swing roller 51a is configured so as to receive a predetermined signal and incline toward the feed side by an angle α around the rotation axis of the lower swing roller 51b. This swing drive is performed by a pulse motor.

Numeral 53 denotes a separator disposed on the sheet discharge side of the oscillating roller 51, the leading end of which is arranged to oppose the overlapped sheets P and N sent out from the oscillating roller 51. 54, 55
Are the seventh diagonally provided on the obliquely upper and lower portions behind the separator 53.
And an eighth transport roller for feeding the separated image receiving sheet P and photosensitive sheet N to the outside of the sheet peeling section E, respectively. 514 and 515 are guide plates for guiding the sheets separated by the separator 53 and the transport rollers 54 and 55, respectively.
In the apparatus of this embodiment, the peel angle of the two sheets can be adjusted by changing the mounting angle or shape of the guide plate.

The separator 53, the transport rollers 54, 55, and the like are incorporated in an integral frame body 56, and the whole is configured to be able to move in a predetermined range in the arrow X direction. Therefore, when a sheet jam occurs in the side of the separator 53, the jammed sheet can be easily removed by moving the frame 56 in the direction of arrow X to open the space between the tip of the separator 53 and the swing roller 51. Can be.

By the way, the present invention aims to carry the two sheets P and N to the entrance 400a of the rotary drum 400A at a high speed,
In the first embodiment, as shown in FIG. 1, the transport roller 31 and the transport roller 410 are driven by a drive motor 417 capable of high-speed rotation and low-speed rotation. The transport roller 31 is provided with a clutch / brake 418,
The rotation can be stopped or maintained or a free state can be maintained even during the continuous driving of the 17.

The drive motor 417 and the drive motor 404 that drives the rotary drum A and the like are the same type of AC servomotor (frequency control or P
Although it is desirable to use WM control), the present invention is not limited to this. Use of the same type has the following advantages. That is, there are various types of sheets, and it is necessary to change the developing time in the rotary drum A depending on the type. Therefore, when the rotation speed of the rotary drum 400A is changed, it is easy to control the rotation speed of the drive motor 417 to correspond to the rotation speed of the rotary drum 400A.

Now, when a start button (not shown) for starting copying is pressed, the photosensitive sheet N is fed out from the supply port of the photothermographic exposure supply device A, and is conveyed along the first guide 12.

At the same time, the clutch / brake 418 is turned on.
When the brake is turned off, the motor 417 rotates at a high speed to drive the third transport roller 31, and the image receiving sheet P is fed out from the supply port 30 of the image receiving material supply device C. Feeding of the fed image receiving sheet P is confirmed by crossing PS2,
It is conveyed at high speed along the fourth guide 409, and when it is sensed by the PS3, the clutch / brake 418 is turned off, the clutch / brake is stopped. At this time, the image receiving sheet P is stopped at an accurate position because the inertial motion is immediately and reliably suppressed.

During this time, the photosensitive sheet N passing through the first guide 12 is image-exposed by the FOT or the like of the exposure unit B to form a latent image. The latent image is a so-called mirror image opposite to the normal image. After that, the image-exposed photosensitive sheet N is transferred to the second conveying roller 20.
When the micro switch MS1 detects this, the signal is transmitted to the control unit, the clutch / brake 418 is turned on / off, and the third roller 31 in the stopped state is conveyed. Is driven to restart the conveyance of the image receiving sheet P. After a lapse of a certain time from that point, the motor 417 rotates at a low speed. As a result, the two sheets P and N are superimposed at the position of the draw-in section 400a with the conveyance speed being adjusted to the rotational linear speed of the rotary drum 400A.

At the beginning of the superposition, the front ends of the image receiving sheets P are superimposed slightly (for example, 3 to 10 mm) from the front ends of the photosensitive sheets N. To obtain such a timing, the microswitch MS1 is set at a predetermined position.

In this way, the two sheets P and N that have advanced to the draw-in section 400a of the rotary drum 400A are superimposed, but the two sheets N and P are not completely adhered near the draw-in section 400a and gradually come into close contact with the rotation. . Here, both sheets P and N are 150 ° C.
Because of the heating to a certain degree, the water content in the emulsion and base evaporates. When the vaporized water reaches the laminating roller 406 due to the progress of the sheets P and N, it is extruded and removed.

The sheets P and N that have passed through the laminating roller 406 are completely pressed by the rotating drum 400A and the endless belt 401, the latent image on the photosensitive sheet N is developed there, and the image is transferred to the image receiving sheet P without unevenness. . The image is inverted by this transfer and becomes a normal image.

When a certain time has elapsed after the end of the image receiving sheet P has passed through the PS3 or the end of the photosensitive sheet N has passed through the MS1, the motor 417 stops and the clutch / brake 4
18 turns off the clutch and brake (see Fig. 2).

In the above transfer, both sheets P and N are sent out from the rotating drum 400A.
Completed before reaching 400b.

Then, both sheets P and N are sent to the sending section 400b in a state of being in close contact with and sticking to the rotating drum 400A side, where they are separated from the rotating drum 400A by the scraper 412. Thereafter, both sheets P and N are curled by the curl straightening guide 41.
The curl is corrected during conveyance to 3, is passed through the light blocking roller unit 415, is sent out from the guide 416, abuts on the correction roller 50, and if the direction is shifted, the shift is corrected.

Then, both sheets P and N are conveyed to the swing roller 51,
The leading end is fed out from the roller 51. Since the leading ends of the fed-out sheets P and N protrude on the upper side of the image receiving sheet P, the leading end of the image receiving sheet P is placed on the upper side of the separator 53, and the swing roller 51 is shown by α in FIG.
The photosensitive sheet N is peeled off from the image receiving sheet P by being inclined downward by an angle.

Thereafter, the leading end of the separator 53 separates the sheets P and N as the sheets P and N progress. The separated image receiving sheet P is sent out to the outside by the seventh transport roller 54, and the photosensitive sheet N is discarded by the eighth transport roller 55 in the dust box.

In the present embodiment, the clutch / brake 418 is provided on the transport roller 31.
04, it is also possible to obtain the driving force of only the low-speed rotation of the conveying rollers 31 and 410 from the motor 404.

Next, as a second embodiment, there is provided one in which a material having low frictional resistance such as, for example, velvet is provided on the surfaces of the transport rollers 30, 410. In this example, both sheets P and N are conveyed at a high speed until they enter the drum 400A, and after entering the drum 400A, the respective transport rollers 31, 410 are in a state of slippage with respect to both sheets P and N. The forced pushing into the 400A is prevented, and the conveyance is performed according to the low rotational linear speed of the rotating drum 400A. Therefore, the conveying rollers 31 and 410 only need to continuously rotate at a high speed.

FIG. 3 is a view showing a third embodiment. In this example,
Solenoid when both sheets P and N enter drum 400A
The pinching of the pair of transport rollers 31 'is released by the operation of 420,
Thereafter, both sheets P and N are conveyed in accordance with the rotation of the rotary drum 400A as in the second embodiment. Therefore, also in this example, the transport roller 419 does not need to be rotated at a low speed, but may be rotated at a high speed.

Further, as a fourth embodiment, there is the following method. That is, when the leading ends of both sheets P and N enter the rotary drum 400A, the power of the drive motor 417 of the conveying rollers 31 and 410 is turned off.
Then, the transport rollers 31, 410 are set in a free state (no driving force or braking force), and the transport rollers 31, 410 are rotated at a low speed as the two sheets P, N are pulled by the drum 400A.

In the above-described embodiment, the so-called drum-belt type heat developing section has been described. However, the heat developing section is not limited to this example and may be a type described in JP-A-61-153651. Of course, various types such as a belt-belt type or various types such as a sheet heater-pressing platen type as described in JP-A-61-184544 can be used. is there.

〔The invention's effect〕

As described above, according to the present invention, both sheets are conveyed at a higher speed than the linear speed of the rotary drum before entering the heat developing section, so that the processing time of the sheet can be reduced. Also, since the leading end of the superposition of both sheets is shifted and conveyed to the heat developing section, and the conveying speed of both sheets is set to match the rotation speed of the heat developing section at the heat developing section entrance, the heat developing section Insertion of both sheets becomes smoother and peeling of both sheets becomes easier.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a thermal development image forming apparatus used in the first embodiment of the present invention, FIG. 2 is a flowchart showing the operation thereof, and FIG. FIG. 4 is a schematic diagram of the entire thermal development image forming apparatus. A: photothermographic element supply section, B: exposure section, C: image receiving element supply section, D: thermal development transfer section, E: sheet peeling section, 10: supply port, 11: first ... A first guide, 20... A second guide roller, 21... A first guide, 30... A supply port, 31.
... conveying roller, 32 ... third guide, 400 ... rotary drum device, 400a ... draw-in unit, 400b ... sending unit, 400A ... rotary drum, 401 ... endless belt, 402 ... heating device, 403 …… Roller group, 403A …… Inlet roller, 403B ……
Outlet roller 403C Holding roller 403D Tension adjusting roller 404 Drive motor 407 Cleaning roller 408 Static elimination brush 409 Fourth guide 41
0: Fifth transport roller, 411: Fifth guide, 412:
… Scraper, 413… Curl straightening guide, 414 …… Sixth
415 …… Light-blocking roller unit, 415a ……
Slit plate, 415b, 415c: sliding roller, 416: sixth
Guide 417 Drive motor 418 Clutch brake 420 Solenoid E Sheet peeling section 50
… Straightening roller, 51… swing roller, 53… separator
54 ... 7th transport roller, 55 ... 8th transport roller, 56
…… Frame, PS1, PS2, PS3 …… Transmissive photo sensor, MS1, M
S2, MS3: micro switch, N: photosensitive sheet, P:
... Image receiving sheet.

Claims (1)

(57) [Claims] 1. A heat-sensitive material in which a photosensitive material on which a latent image has been formed by image exposure and an image receiving material are superimposed and heated and pressed in a heat developing section to develop the latent image and transfer the latent image to the image receiving material. In the developed image forming method, the image receiving material and the photosensitive material exposed to light are conveyed at a first speed, and the image receiving material is temporarily stopped when it reaches a first position, and the photosensitive material is moved to the first position. Re-conveys the image receiving material based on reaching a second position having a different distance from the heat developing unit, and moves the image receiving material and the photosensitive material to a second speed lower than the first speed. A method for forming a heat-developable image, wherein the heat-development image is sent to the heat-development unit at a speed.