JP2001005159A - Heat developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat developing device capable of satisfactorily developing without the occurrence of irregularities in an outputted image. SOLUTION: The heat developing device 140 is provided with a pair of endless belts 164 and 166 which are wound round winding rollers 150 and 160, etc., and rotatably arranged opposite to each other in a press contact state, and which are prepared for holding and carrying a photosensitive material 16 and an image receiving material 72, and at least one of the endless belts has a thickness of 0.3 to 0.5 mm, the device 140 is also provided with heating means 180 and 182 which are arranged inside the loops of the endless belts 164 and 166 so as to heat the image receiving material and the image receiving material through the endless belts 166 and 164, and preheating means 184 and 186 which are adjacently arranged inside the loops of the endless belts 164 and 166 and on the upstream side of the heating means 180 and 182 in the material carrying direction so as to preheat the photosensitive material 16 and the image receiving material 72 up to a prescribed temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat developing apparatus which is applied to an image forming apparatus using a photosensitive material and an image receiving material and performs a heat developing process in a state where the photosensitive material and the image receiving material are superposed.

[0002]

2. Description of the Related Art In an image forming apparatus for performing image recording processing using two types of image recording materials, a photosensitive material and an image receiving material, the photosensitive material and the image receiving material are heated in a superposed state, and the photosensitive material and the image receiving material are heated. There is provided a thermal developing device for thermal development transfer.

In such a heat developing apparatus, a structure in which a photosensitive material and an image receiving material are nipped and conveyed by using a pair of endless belts, and the photosensitive material and the image receiving material are heated by a heating plate disposed in an endless belt loop. Is known. The heat developing device is useful in that good heat development efficiency can be achieved with a simple structure, and various improvements have been made for the purpose of improving the quality of an output image.

For example, for the purpose of reducing image unevenness of an output image, there has been proposed a heat developing apparatus in which a preheating plate is separately arranged near a heating plate in addition to a heating plate (FIG. 4). In the heat developing device 400 shown in FIG.
4 and the image receiving material 416 are located at the upstream end portions of the endless belts 402 and 404 (in a two-dot chain line state in FIG. 4), the endless belts 402 and 404 rotate, and the photosensitive material 414 and the image receiving material 416 become endless belt 402. are superimposed at the top side of the 404, it is conveyed in a state sandwiched endless belt 402 in the arrow Y ₃ direction in FIG. 4. The photosensitive material 414 and the image receiving material 416 are heated when passing between the preliminary heating plates 414 and 416, and then are conveyed to a position facing the heating plates 410 and 412. When the photosensitive material 414 and the image receiving material 416 are conveyed to a position facing the heating plates 410 and 412, the rotation of both endless belts 402 and 404 is stopped, and the photosensitive materials 4 and 412 are stopped by the heating plates 410 and 412.
14 and the image receiving material 416 are heated for a predetermined time. As a result, thermal development transfer is performed, and an image can be formed on the image receiving material 416. Further, when the thermal development transfer is completed, the endless belts 402 and 404 rotate again, whereby the photosensitive material 414 and the image receiving material 416 can be discharged from the thermal developing device 400.

As shown in FIG. 4, when a pre-heating plate is disposed near the heating plate for thermal development and more upstream, the photosensitive material 414 coated with an image forming solvent (for example, water) becomes a heat developing device. 400, the pre-heated plates 414, 416
After the heating, the heating plates 410 and 412 are conveyed to a position where they face each other.
The surface temperatures of the layers 10, 412 are not significantly reduced. As a result, the surface temperatures of the heating plates 410 and 412 can be maintained uniform, the surfaces of the photosensitive material 414 and the image receiving material 416 can be uniformly heated in a short time, and image unevenness (shading) in an output image can be achieved. ) Can be reduced.

[0006]

Although the thermal developing device has the structure shown in FIG. 4 and prevents transfer unevenness due to uneven heating temperature, image unevenness of an output image can be reduced. In the image, a slight inverted V-shape (meaning that it is an inverted V-shape with respect to the transport direction of the image receiving paper; the same applies hereinafter) may still occur. The present inventor analyzed the cause of this image unevenness,
It has been found that these image irregularities occur due to the non-uniform transport speed of the photosensitive material or the like by the endless belt.

FIG. 5 shows a winding roller 512 and an endless belt 514 wound around the winding roller 512. The speed of the endless belt 514 driven by the driving roller (not shown) is determined by the speed Vm of the center line (shown by a broken line in the figure) of the endless belt 514, and in the region L that advances linearly, the speed of the endless belt 514 is changed. Centerline velocity Vm and surface velocity Vs
Are equal (Vm = Vs). On the other hand, in the curved region R, the radius from the rotation center to the belt center position and the radius from the belt surface differ by the thickness of the endless belt 54, and the center line speed Vm becomes smaller than the surface speed Vsr. (Vm <Vsr). Accordingly, a pushing force is applied to the photosensitive material and the like conveyed on the endless belt 514 in the carrying direction (indicated by an arrow in the drawing), and the accumulated force is applied to the photosensitive material and the like while being conveyed. Wrinkles are likely to occur. As a result, inverted V-shaped image unevenness occurs in the transport direction, and the image quality of the output image is impaired. This tendency becomes more remarkable as the curvature of the endless belt 514 with respect to the winding roller 512 increases.

An object of the present invention is to solve the above problems. That is, an object of the present invention is to provide a heat developing apparatus capable of forming a high-quality image without image unevenness.

[0009]

In order to solve the above-mentioned problems, a heat developing apparatus according to the present invention is wound around a plurality of winding rollers, and is rotatably opposed to each other in a state of being pressed against each other. A pair of endless belts having a thickness of at least one of 0.3 to 0.5 mm, and a photosensitive material and the image receiving material disposed via a loop of the endless belt. Heating means for heating the photosensitive material and the image receiving material via the endless belt, which is disposed in the loop of the endless belt and closer to the upstream side in the transport direction than the heating means. And a preheating applying means.

In the heat developing apparatus of the present invention, the photosensitive material and the image receiving material are superposed, sandwiched between a pair of endless belts having at least one of the thicknesses in the above-mentioned range, and conveyed in a predetermined direction. The preheating at a predetermined temperature is applied from the preheating applying unit via the endless belt, and the preheating unit is heated to a predetermined temperature by the heating unit via the endless belt, and the image is thermally developed and transferred from the photosensitive material to the image receiving material.

After the photosensitive material and the image receiving material are preheated in advance, heat of a predetermined temperature is immediately applied by a heating means provided in proximity to the preheating applying means. And uniform heating at a predetermined temperature becomes possible. In addition, since the thickness of the endless belt that conveys the photosensitive material and / or the image receiving material is thin, the speed substantially coincides between the case where the photosensitive material and / or the image receiving material travels linearly and the case where the photosensitive material and / or the image receiving material travels in a curved manner on the winding roller. The photosensitive material and the like can be transported to a heated position without causing wrinkles or the like. As a result, image unevenness occurring in the output image can be effectively prevented.

The heat developing device includes a pair of winding rollers arranged so as to form a nip portion through which a photosensitive material and an image receiving material pass first, and a first winding roller of the pair of winding rollers. , A first endless belt of a pair of endless belts is wound around at a curvature R ₁ , and a second endless belt is wound around a _second endless belt at a curvature R ₂ around a _second winding roller. It is preferable that the curvatures R ₁ and R ₂ and the thicknesses T ₁ and T _{2 of} the first endless belt and the second endless belt satisfy the following relational expressions. R ₁ <R ₂ T ₁ ≧ T ₂ The thickness of the endless belt on the photosensitive material side is preferably from 0.3 to 0.5 mm. Further, it is preferable that the second endless belt is an endless belt on the photosensitive material side.

[0013]

FIG. 3 is a schematic overall configuration diagram of an image recording apparatus 10 to which a heat developing apparatus according to a first embodiment of the present invention is applied.

As shown in FIG. 1, the image recording apparatus 1
Reference numeral 0 denotes a box-shaped machine base 12. A photosensitive material magazine 14 is disposed inside the machine base 12, and a photosensitive material 16 is provided.
Are stored in a rolled state. In the vicinity of the photosensitive material outlet of the photosensitive material magazine 14,
A nip roller 18 and a cutter 20 are arranged, and the photosensitive material 16 can be pulled out from the photosensitive material magazine 14 by a predetermined length and cut. Here, the cutter 20 is, for example, a rotary type cutter including a fixed blade and a movable blade. The photosensitive material 16 is moved by moving the movable blade up and down by a rotating cam or the like and engaging the movable blade with the fixed blade. Can be cut.

A plurality of transport rollers 24, 26, 28, 30, 32, and 34 are sequentially arranged inside the machine base 12. A guide plate (not shown) is provided between the transport rollers 24 to 34 to form a transport path for the photosensitive material 16.

An exposure section 22 is provided between the transport roller 24 and the transport roller 26. On the left side of the exposure section 22 (direction of arrow X ₂ side of FIG. 3), three kinds of laser diode, a lens unit, a polygon mirror, an exposure apparatus equipped with a mirror unit (all not shown) 38 is disposed And irradiates the light beam C toward the exposure unit 22 to irradiate the photosensitive material 16.
Can be exposed.

Above the exposure device 38 (arrow Y _{1 in} FIG. 3)
(In the direction side), a U-turn section 40 is provided, and while the photosensitive material 16 is curved in a U-shape, the transport rollers 28 and 30 are provided.
Thereby, it can be conveyed to the water application section 44 on the side of the U-turn section 40.

Water (or an aqueous solution) is applied to the water application section 44.
Hereinafter, the same applies. ) Is provided in a dish-shaped coating tank 46 for holding about 100 to 500 cc. A supply roller 48 is provided at an end of the coating tank 46 on the upstream side in the transport direction of the photosensitive material 16, and a pair of squeeze rollers 50 and 52 are provided on an end on the downstream side in the transport direction. Supply roller 4
A shaft 54 rotatably supporting the guide plate 8 supports the guide plate 56 at a position above the coating tank 46 so as to be separated from and facing the coating tank 46, and the passage of the photosensitive material 16 is determined by the distance between the coating tank 46 and the guide plate 56. Is configured. A plurality of supply paths 58 for supplying water from a bottle (not shown) storing 1 to 2 liters of water to the application tank 46 are provided at the center of the guide plate 56. A heater 6 for keeping the temperature of the water in the tank 46 constant
0 and a temperature controller (not shown) are attached.

The coating tank 46 has a squeeze roller 5
A drain port 62 communicating with the storage section 2 is formed, and an overflow tank 64 is provided at the end, and water that is supplied from a bottle (not shown) through a water supply channel 58 and overflows in the application tank 46 is It is a circulation system that returns to the bottle.

On the other hand, on the left side of the filter 54, a receiving material magazine 70 is arranged, and the image receiving material 72 is stored in a rolled state. In addition, a nip roller 74 is disposed near the image receiving material take-out opening of the material receiving magazine 70, and can pull out the image receiving material 72 from the material receiving magazine 70 and release the nip. Here, the nip roller 74 has a length greater than the length of the photosensitive material 16 pulled out of the photosensitive material magazine 14 than the length of the photosensitive material 16.
Is set to draw out short.

A cutter 7 is provided beside the nip roller 74.
6 are arranged. The cutter 76 is a rotary type cutter like the cutter 20, and can cut the image receiving material 72 drawn from the receiving material magazine 70.

At the side of the cutter 76, there are transport rollers 80,
82, 84, 86 and a guide plate (not shown) are arranged to form a conveyance path for the image receiving material 72.

On the other hand, on the lower right side of the sub tank 58,
A heat development transfer unit 140 as a heat development device is provided.

FIG. 1 is an enlarged perspective view of the thermal development transfer unit 140, and FIG.
The front view which expanded 40 is shown.

As shown in these figures, the heat development transfer section 140 is provided with an endless belt 164 as a first endless belt.
And an endless belt 166 as a second endless belt. At least the endless belt 1 on the photosensitive material 16 side
The thickness T ₂ of 66 is 0.3 to 0.5 mm, preferably, the thickness of the first endless belt 164 also 0.3~0.5m
m.

The endless belt 164 is wound around a driving roller 142 and winding rollers 146, 148, 150, 152, and the endless belt 166 is wound around a driven roller 144 and winding rollers 154, 156, 158, 160, 162. Has been turned. Here, springs 176, 178 are attached to the winding rollers 150, 152, and the endless belt 1 is always driven by the urging force of these springs 176, 178.
66 side (i.e., direction of arrow X ₂ side of FIG. 1 to FIG. 3) is biased to. For this reason, the endless belts 164, 166
Are between the winding rollers 150, 152 and the winding rollers 160,
162 are in pressure contact with each other.

The winding roller 150 and the winding roller 160
The image receiving material 72 and the photosensitive material 16 are arranged so as to overlap each other to form a nip portion that passes first. Entraining rollers 158, and entraining roller 148, the curvature R ₂ with respect to the wrapping roller 160 of the endless belt 166 in the nip, each arranged so as to be larger than the curvature R ₁ for wrapping roller 150 of the endless belt 164 (R ₁ <R ₂ ), so that the photosensitive material 16 and the image receiving material 72 are inserted into the nip while maintaining an effective angle.

The driving roller 142 around which the endless belt 164 is wound is connected to a motor 168, and rotates by receiving the driving force of the motor 168 to rotate the endless belt 16
Rotate 4. Further, the motor 1 of the driving roller 142
A gear 170 is mounted on the side opposite to 68. On the other hand, a gear 172 having the same number of teeth as the gear 170 is attached to the driven roller 144 around which the endless belt 166 is looped. The gear 172 meshes with the gear 170, and the driving force received by the driving roller 142
0, and further transmits this driving force to the driven roller 144. As a result, the driven roller 144 rotates and the endless belt 166 rotates.

The gear 172 is attached to the driven roller 144 via a sprag type one-way clutch 174, for example. This one-way clutch 174
Is the transport direction of the image receiving material 72 (that is, FIGS. 1 to 3).
The rotation of the arrow Y ₂ gear 172 corresponding to the direction) but transmit to the driven roller 144, is idle when the gear 172 is reversed relative to the driven roller 144.

The diameter D ₁ of the driving roller 142, the diameter D ₂ of the driven roller 144, the thickness T ₁ of the endless belt 164, and each size relationship of the thickness T ₂ of the endless belt 166, D ₁ and T
₁ is greater than the sum of D ₂ and T ₂ (ie, D ₁ + T ₁ >
D ₂ + T ₂ ), and is set so that the rotation speed V ₂ of the surface of the endless belt 166 is lower than the rotation speed V ₁ of the surface of the endless belt 164 (that is, V ₂ <V ₁ ). ing.

Further, the thermal development transfer section 140 includes heating plates 180 and 182 as heating plates of a heating means having a flat plate shape. The heating plate 180 is disposed close to a contact portion of the endless belt 164 inside the loop with the endless belt 166. Furthermore, the heating plate 180 has a plurality of springs 188 are mounted, always endless belt 166 side (i.e., direction of arrow X ₂ side of FIG. 1 to FIG. 3) is biased to. On the other hand, the heating plate 182 is disposed close to a contact portion of the endless belt 166 inside the loop with the endless belt 164. A linear heater (not shown) is accommodated inside these heating plates 180 and 182, and the surface of each of heating plates 180 and 182 is appropriately heated by a heater in a predetermined range to obtain a desired temperature distribution. The photosensitive material 16 and the image receiving material 72 conveyed between the heating plate 180 and the heating plate 182 can be heated to a predetermined temperature via the endless belts 164 and 166.

Further, between the heating plate 180 and the winding roller 150 in the loop of the endless belt 164, the heating plate 18
0, a preheating plate 184 as a heating plate of the preheating applying means.
Is arranged. This is the preheating plate 184 and the spring 190 is attached, is always endless belt 166 side (i.e., direction of arrow X ₂ side of FIG. 1 to FIG. 3) is biased to. On the other hand, between the heating plate 182 and the winding roller 160 in the loop of the endless belt 166, a preheating plate 186 as a heating plate of preheating applying means is disposed close to the heating plate 182. These preheating plates 184 and 186 are formed in a flat plate shape having a length corresponding to the conveying direction of the photosensitive material 16 and the image receiving material 72 shorter than the heating plates 180 and 182. Also, inside these preheating plates 184 and 186,
Similar to the heating plates 180 and 182, linear heaters (not shown) are arranged, and the surfaces of the preheating plates 184 and 186 are appropriately heated by a predetermined range by these heaters so that the preheating plates 184 and 186 are heated. Can have a desired temperature distribution. Here, these preheating plates 184, 1
86 is set higher than the surface temperatures of the heating plates 180 and 182, preferably,
The surface temperature is set higher by 5 ° C. to 30 ° C. than the surface temperature of 182.

That is, before the photosensitive material 16 and the image receiving material 72 reach a predetermined position between the heating plates 180 and 182,
Preheating plates 184, 18 via endless belts 164, 166
6 allows heating to a predetermined temperature.

A peeling claw 90 is disposed below the thermal development transfer section 140. The peeling claw 90 is conveyed by endless belts 164 and 166, and the photosensitive material 16 and the image receiving material 72, whose tips project below the thermal development transfer unit 140.
Of these, the photosensitive material 16 can be separated from the image receiving material 72 by engaging only with the front end of the photosensitive material 16.

On the left side of the peeling claw 90, a photosensitive material discharge roller 92 is arranged. The photosensitive material discharge roller 92 conveys the photosensitive material 16 peeled by the peeling claw 90 to the waste photosensitive material accommodating portion 94.

The waste sensible material container 94 includes a drum 96 and a plurality of rollers 100. These drums 96
An endless belt 98 is wound around the plurality of rollers 100. When the roller 100 rotates, the endless belt 98 rotates, and the drum 96 rotates accordingly. Thus, the photosensitive material 1 guided by the photosensitive material discharge roller 92
6 can be wound around the drum 96 and collected.

The machine 1 is located below the thermal development transfer section 140.
In the vicinity of the bottom wall of No. 2, receiving material discharge rollers 102, 104,
106, 108 and 110 are arranged, and the photosensitive material 1
The image receiving material 72 from which 6 has been peeled can be transported in a predetermined direction. Further, a tray 112 is disposed near the final receiving material discharge roller 110, and the image receiving material 72 conveyed by the receiving material discharging rollers 102 to 110 can be accumulated.

Next, the operation of the thermal development transfer section 140 as the thermal development apparatus according to the present embodiment will be described through the processing steps of the image recording apparatus 10. In the image recording apparatus 10 having the above configuration, the nip roller 18 operates to operate the photosensitive material 16.
Is pulled out of the light-sensitive material magazine 14, the cutter 20 is operated to cut the photosensitive material 16 into a predetermined length, and
Conveyed to 2. Next, when the photosensitive material 16 passes through the exposure unit 22, the exposure device 38 operates to scan and expose the photosensitive material 16 located at the exposure unit 22 with the light beam C. As a result, a latent image (image) is formed on the photosensitive material 16.

When the exposure of the light beam C is completed, the photosensitive material 16
Is sent to the water application section 44, and the application tank 46 and the guide plate 5
6, water is applied to the photosensitive material 16. Further, the photosensitive material 16 to which the water is applied is transported to the thermal development transfer unit 140 by the transport roller 34.

On the other hand, the nip roller 74 operates in synchronization with the transport of the photosensitive material 16 and the scanning exposure, and the image receiving material 72 is pulled out of the material receiving magazine 70 and cut into a predetermined length by the cutter 76. The cut image receiving material 72 is conveyed by conveying rollers 80 to 8 while being guided by a guide plate.
6 transported. When the leading end of the image receiving material 72 is nipped by the transport roller 86, the image receiving material 72 enters a standby state immediately before the thermal development transfer unit 140.

Further, when the photosensitive material 16 is transported to the thermal development transfer section 140 by the transport roller 34, the image receiving material 7
2 is resumed, and the image receiving material 72 is sent to the nip portions of the winding rollers 150 and 160 between the endless belts 164 and 166 with the photosensitive material 16 superposed thereon. Since the curvature R ₂ of the endless belt 166 with respect to the winding roller 160 in the nip portion is larger than the curvature R ₁ of the endless belt 164 with respect to the winding roller 150, the image receiving material 72 conveyed via the conveyance roller 86. And the photosensitive material 16 conveyed from the water application section 44 via the conveyance roller 34 are bonded together in the nip while maintaining an effective angle. As a result, when bonding
It is possible to prevent air or the like from entering between the photosensitive material 16 and the image receiving material 72, and it is possible to further prevent image unevenness of an output image.

In this state, the motor 1 of the heat development transfer section 140
When 68 operates, the drive roller 142 rotates and the endless belt 164 rotates. Further, the driving force of the motor 168 is rotated by the driven rollers 144 via the gears 170 and 172 and the one-way clutch 174, and the endless belt 166 is rotated.
Is rotated.

Here, the driving roller 142 and the driven roller 1
44 each of a diameter dimension D _1, D ₂ and the endless belt 164,
From the dimensional relationship between the belt thicknesses T ₁ and T ₂ of the endless belt 166, the set rotation speed V ₂ of the endless belt 166 is changed to the endless belt 164.
Becomes slower than the rotation speed V _{1 of} . Therefore, the motor 16
When both the endless belts 164 and 166 rotate by driving the endless belt 8, a speed difference is generated between the endless belts 164 and 166, thereby causing friction between the endless belts 164 and 166. This frictional force, the endless belt 166 is the same rotational speed as the endless belt 164 follows the endless belt 164, i.e., attempts to rotate at a speed higher than the rotational speed V _2.

In this case, the endless belt 166 rotates the driven roller 144, and the driven roller 144 rotates at a speed higher than the initial rotation speed (that is, the rotation speed for rotating the endless belt 166 at the speed of V ₂ ). try to. Here, since the one-way clutch 174 is interposed between the gear 172 and the driven roller 144, when the driven roller 144 exceeds the initial rotation speed, the one-way clutch 174 idles, and the driven roller 144 exerts the influence of the gear 172. The endless belt 166 is smoothly rotated without receiving the rotation (ie, without being affected by the drive roller 142). Accordingly, the substantial rotation speed of the endless belt 166 matches the rotation speed V ₁ of the endless belt 164, so that the photosensitive material 16 and the image receiving material 72 can be favorably conveyed in a superimposed state, and there is no transfer deviation or the like at all times. High quality images can be obtained.

The frictional force generated between the endless belt 164 and the endless belt 166 only needs to compensate for the difference between the rotation speed V ₁ of the endless belt 164 and the set rotation speed V ₂ of the endless belt 166. Therefore, the rotation speed of the endless belt 164 and the substantial rotation speed of the endless belt 166 are matched with an extremely small frictional force.
Even if the frictional resistance between the endless belts 66 decreases due to abrasion or the like, the rotational speeds of both endless belts 164 and 166 can be matched.

Here, the thickness T of the endless belt 166
₂ , preferably the thickness T ₁ of the endless belt 164 is also 0.3 to
Since it is 0.5 mm, the endless belt 166 and / or the endless belt 166 when the photosensitive material 16 and the image receiving material 72 are conveyed around the winding rollers 150 and 160 in a superimposed state immediately after the photosensitive material 16 and the image receiving material 72 are inserted into the heat development transfer unit 140. Or 164, and then the heating plate 1 from the position facing the preheating plates 184, 186.
The difference between the speed of the endless belt 166 and / or the speed of the endless belt 164 when the sheet is conveyed to the position facing the sheets 80 and 182 is slight, and the heating plates 180 and 182 are Up to the opposing predetermined position,
It can be transported without wrinkles or the like.

The wrinkling of the photosensitive material 16 and the image receiving material 72 is caused by the fact that the endless belts 164 and 166 wound around the winding rollers 150 and 160 have the thicknesses T ₁ and T _{2, and} are conveyed linearly. This is due to the fact that the speed at which the sheet is conveyed is different from the speed at which the sheet is conveyed in a curved shape. In the thermal development transfer section 140, the endless belt 1
The curvature of 66 indicates that the endless belt 1
Is greater than 64 the curvature of the endless belt 1 thickness T ₂ is an image-receiving material 72 side of the photosensitive material 16 side of the endless belt 166
62 as compared to the thickness T ₁ of the greatly contributes the generation of wrinkles. In the heat development transfer section 140, since the thickness T ₂ of the endless belt 166 is 0.3 to 0.5 mm, the photosensitive material 1
6 and the image receiving material 72 can be satisfactorily conveyed in a superposed state, and a high-quality image free of wrinkles can be obtained. It is preferable that the thickness T ₁ of the endless belt 164 is also 0.3 to 0.5 mm.

As shown in FIG. 5, it is preferable that the endless belt is thinner, since the unevenness of the output image can be reduced.
If it is too thin, durability tends to deteriorate. When the thickness of the endless belt is 0.3 to 0.5 mm, image unevenness of an output image can be remarkably reduced, and the durability of the endless belt is also improved. As a material of the endless belt, Nomex aramid paper (manufactured by DuPont) is preferably used.

Thus, the endless belts 164, 166
First, the photosensitive material 16 and the image receiving material 72 transported between the preheating plates 184 and 186 pass through. Here, the preheating plate 1
84 and 186 are previously heated to a predetermined temperature for each predetermined range, so that the photosensitive material 16 and the image receiving material 72 are preheated at a predetermined temperature from the preheating plates 184 and 186 via endless belts 164 and 166. Granted.

The preheated photosensitive material 16 and image receiving material 72 are conveyed by endless belts 164 and 166, and are conveyed until they are located between the heating plate 180 and the heating plate 182. When the photosensitive material 16 and the image receiving material 72 are located between the heating plate 180 and the heating plate 182, the motor 168 temporarily stops and the endless belts 164 and 166 stop. In this state,
The heat from the heating plates 180 and 182 is transferred to the endless belts 164 and 164.
66 to the photosensitive material 16 and the image receiving material 72 via
The image is thermally developed and transferred from the photosensitive material 16 to the image receiving material 72.

Here, the preheating plates 184 and 186 are
80, 182, the photosensitive material 16
The image receiving material 72 is heated mainly by the heating plates 180 and 182 immediately after passing between the preheating plates 184 and 186 and being preheated. For this reason, the heating plate 18
0, 182 can greatly reduce the heating time.

Since the photosensitive material 16 and the image receiving material 72 are preheated, the heating plates 180 and 182 are not cooled by the photosensitive material 16 and the image receiving material 72, and the heating plates 180 and 182 are 16 and the image receiving material 72 can be heated very uniformly, and an extremely high quality image without output can be formed.

Further, the preheating plates 184 and 186 and the heating plate 1
Since 80 and 182 are separate, the preheating plate 184,
The heat of 186 and the heat of the heating plates 180 and 182 do not interfere with each other and affect the temperature.
And the heating plates 180 and 182 can reliably apply heat of a predetermined temperature to the photosensitive material 16 and the image receiving material 72.

In this manner, the thermal development transfer is completed, and the photosensitive material 16 and the image receiving material 72 discharged from the thermal development transfer unit 140 are separated from the photosensitive material 16 conveyed ahead of the image receiving material 72 by a predetermined length. The peeling claw 90 is engaged with the leading end, and peels the leading end of the photosensitive material 16 from the image receiving material 72. The photosensitive material 16 is further conveyed by the photosensitive material discharge roller 92 and is accumulated in the waste photosensitive material storage portion 94.

On the other hand, the image receiving material 72 separated from the photosensitive material 16 is conveyed by receiving material discharge rollers 102 to 110 and discharged to a tray 112.

As described above, the pair of endless belts 164, 1
The image receiving material 72 on which a predetermined image is formed (recorded) by the thermal development transfer process sandwiched between the pair of endless belts 16.
After being discharged from 4, 166, they are nipped and conveyed by a plurality of receiving material discharge rollers 102 to 110 and taken out of the apparatus.

As described above, the present image recording apparatus 1
0, even when the photosensitive material 16 and the image receiving material 72 are conveyed on the winding rollers 150 and 160 in a curved shape in the thermal development transfer section 140, the heat is applied between the preheating plates 184 and 186 to the heating plates 180 and 182. Even when being transported in a straight line,
Since they are conveyed at almost the same speed, the heating plates 180, 18
2, the photosensitive material 16 and the image receiving material 72 do not have wrinkles or the like, and can form a good image without image unevenness. Further, since the heating is immediately performed by the heating plates 180 and 182 immediately after the preheating is applied by the preheating plates 184 and 186, the heating time of the heating plates 180 and 182, that is, the heat development transfer time can be significantly reduced. An image can be formed in a short time.

Since the photosensitive material 16 and the image receiving material 72 are preheated and heated to a predetermined temperature before they are heated by the heating plates 180 and 182, the photosensitive material 16 and the image receiving material 72 enter. Heating plate 18
0, 182 can be prevented, and an extremely uniform image without output image unevenness can be formed.

Further, the preheating plates 184 and 186 and the heating plate 1
Since the 80 and 182 are separated, the preheating plates 184 and 186
And the heat of the heating plates 180 and 182 do not interfere with each other and affect the temperature, and the preheating plates 184 and 186 and the heating plates 180 and 182 reliably receive heat of a predetermined temperature set in advance. It can be applied to the material 72.

Further, the driving force obtained by the driving roller 142 is transmitted to the driven roller 144 via the one-way clutch 174, and the rotation setting V of the endless belt 166 is set.
₂ is made lower than the rotation speed V ₁ of the endless belt 164, and this speed difference is compensated for by friction between the endless belt 164 and the endless belt 166, so that the rotation speed of the endless belt 164 and the rotation speed of the endless belt 166 are made equal. Because it was configured
Even if the endless belts 164 and 166, the driving roller 142, the driven roller 144, and the like have a dimensional error, the endless belt 164 and the endless belt 166 can be reliably driven at the same rotation speed.
For this reason, a shift between the photosensitive material 16 and the image receiving material 72 can be prevented, and a high-quality image without transfer deviation can be formed.

Further, both endless belts 164, 166
Both rotate at a constant speed (in other words, photosensitive material 1
6 and the image receiving material 72 are transported at a constant speed),
Temperature control of the preheating plates 184 and 186 and the heating plates 180 and 182 becomes easy, and a high-quality image can be obtained.

The heat development transfer section 1 of the image recording apparatus 10
At 40, the rotational speed V ₂ of the endless belt 166 on the setting is determined by the dimensional relationship between the diameters D ₁ and D _{2 of} the driving roller 142 and the driven roller 144, and the thicknesses T ₁ and T ₂ of the endless belts 164 and 166. To the rotation speed V ₁ of the endless belt 164.
Although a configuration in which slower than, for example, the rotation speed V ₁ of the endless belt 164 the rotation speed V ₂ of the endless belt 166 on set by setting the number of teeth of the gear 170 smaller than the number of teeth of the gear 172 May also be delayed. Also,
By using a material having a small surface friction coefficient for the endless belts 164 and 166, the set endless belt 16
The rotational speed V ₂ of 6 may be slower than the rotation speed V ₁ of the endless belt 164. Further, it may be formed by combining suitably a configuration for slower than the rotational speed V ₁ of the endless belt 164 the rotation speed V ₂ of the endless belt 166 on or more such setting.

In the thermal development transfer section 140 of the image recording apparatus 10, the driving rollers 1 are driven by using gears 170 and 172.
Although the rotation has been transmitted from the driven roller 42 to the driven roller 144, the configuration for transmitting the rotation to the driven roller 144 is not limited to this. Instead of the gears 170 and 172, another movement transmitting mechanism such as a belt transmission may be used. You may apply it.

The thermal development transfer section 140 of the image recording apparatus 10
Although the preheating plates 184 and 186 are used as means for applying preheating to the photosensitive material 16 and the image receiving material 72, a preheating roller including an internal heater is used instead of the preheating plates 184 and 186 and the winding rollers 150 and 160. Rolling roller 15
It may be arranged at positions 0 and 160. Further, a configuration in which the preheating roller and the preheating plates 184 and 186 are used in combination may be employed. Further, two pairs of heating plates that sandwich the endless belts 164 and 166 may be arranged upstream of the heating plates 184 and 186 to apply preheating to the endless belts 164 and 166.

The thermal development transfer section 140 has a curvature R ₂ of the endless belt 166 on the photosensitive material 16 side with respect to the winding roller 160.
Is the winding roller 1 of the endless belt 164 on the image receiving material 72 side.
Although the structure is larger than the curvature R ₁ (R ₁ <R ₂ ) with respect to 50, the present invention is not limited to this. Depending on the arrangement of other members such as the coating section 44, the magnitude relationship between R ₁ and R ₂ is reversed. (R ₁ ≧ R ₂ ). In that case, at least the endless belt 16
4 of the thickness T ₁ and 0.3 to 0.5 mm, setting the thickness T ₂ equal to or smaller than the endless belt (T ₁ ≦ T ₂₎
Is preferred.

[0066]

EXAMPLE An image was actually formed by using an image recording apparatus (experimental machine) having the same configuration as that of FIG. 3 equipped with the thermal developing device of the configuration of FIG. 0.5mm thick as endless belts 164 and 166
In the case of using a belt having a thickness of 0.5 mm as the endless belt 164, a case of using a belt having a thickness of 0.3 mm as the endless belt 166, and a belt having a thickness of 0.3 mm as the endless belts 164 and 166. An image was formed under three conditions when used, and inverted V-shaped unevenness generated in the image was observed. Image formation was performed 10 times continuously, the heat development temperature was set to 83 ° C., and the water temperature in the water coating tank 46 was set to 40 ° C. Commercially available photosensitive materials and image receiving papers were used.

Comparative Example An image was formed under the same conditions using the same image forming apparatus as in the above example, except that a 0.7 mm belt was used as the endless belts 164 and 166.

In the examples and comparative examples, the results of observing the image unevenness of the images obtained by the image formation 1 to 10 times are shown in Table 1 below. In Table 1, “◎” indicates that no inverted V-shaped image unevenness was observed in the obtained image. “〇” indicates that the inverted V-shaped image unevenness could not be recognized at first glance, but the image unevenness could be recognized when observed in detail. “X” indicates that the inverted V-shaped image unevenness was recognized in the obtained image.

[0069]

[Table 1]

From the results shown in Table 1, it was proved that the image unevenness was reduced by setting the thickness of at least one of the endless belts to 0.3 to 0.5 mm. Furthermore, as the thickness of the endless belt becomes thinner (0.3 m
m (with a belt of m), it was demonstrated that image unevenness can be further reduced.

The endless belt 166 has a thickness of 0.2 m.
When the belt of m was used, image formation was performed in the same manner as in the example. However, the endless belt 166 immediately deteriorated, such as generation of wrinkles on the endless belt 166.

[0072]

As described above, the heat developing apparatus according to the present invention has an extremely excellent effect that heat transfer from a photosensitive material to an image receiving material can be favorably performed without causing a problem of uneven output image. .

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a heat developing apparatus according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a heat developing device according to an embodiment of the present invention.

FIG. 3 is a front view schematically showing the configuration of an image recording apparatus to which the heat developing device according to the embodiment of the present invention is applied.

FIG. 4 is an overall configuration diagram of the heat developing device.

FIG. 5 is a diagram illustrating that a speed difference occurs due to the curvature of the winding roller and the endless belt.

[Explanation of symbols]

 140 Thermal development transfer section (thermal development device) 142 Drive roller 143 Follower roller 146 Roller 148 Roller 150 Roller 152 Roller 154 Roller 156 Roller 158 Roller 160 Roller 162 Roller Hanging roller 164 Endless belt (first endless belt) 166 Endless belt (second endless belt) 170 Gear 172 Gear 174 One-way clutch 180 Heating plate 182 Heating plate 184 Preheating plate 186 Preheating plate

Claims (4)

[Claims] 1. A photosensitive material and an image receiving material which are wound around a plurality of winding rollers and are rotatably opposed to each other while being pressed against each other.
A pair of endless belts having a length of 3 to 0.5 mm, heating means disposed in a loop of the endless belt, heating the photosensitive material and the image receiving material via the endless belt, and a loop of the endless belt. And a preheating means which is disposed closer to the upstream side in the transport direction than the heating means and which preheats the photosensitive material and the image receiving material to a predetermined temperature via the endless belt. 2. The photosensitive material-side endless belt has a thickness of 0.3.
The heat developing apparatus according to claim 1, wherein the thickness is from 0.5 to 0.5 mm. 3. A pair of winding rollers arranged so as to form a nip portion through which a photosensitive material and an image receiving material first pass, and a first winding roller of the pair of winding rollers has a pair of winding rollers. the first endless belt of the endless belt is wound around curvature R _1, the second wrapping roller, a second endless belt of the pair of endless belts is wound around with a curvature R _2, the curvature R ₁ , R _2, and the first endless belt and the thickness T ₁ of the each of the second endless belt, T ₂ a heat development apparatus according to claim 1 or claim 2 satisfies the following relationships. R ₁ <R ₂ T ₁ ≧ T ₂ 4. The heat developing apparatus according to claim 3, wherein the second endless belt is an endless belt on the photosensitive material side.