JPS63285550A - Image forming device - Google Patents

Abstract

PURPOSE:To improve picture quality by providing a heater outside a tank at a coating part which applies a solvent for image formation to a heat- developed photosensitive material, powering on the heater so that its heat generation density is varied locally, and holding the solvent at uniform temperature. CONSTITUTION:The heat-developed photosensitive material 16 after exposure is conveyed to the solvent coating part 34 by rollers 44 and 46. The solvent coating part 34 packs the solvent 70 in the tank 72 and dips a coating roller 52. The heater 77 is provided outside the tank 72 and the heater 77 is so constituted that the heat generation density is larger at both side parts than at the center part, thereby uniformizing the solvent temperature distribution. Then the coating roller 52 is rotated as shown by an arrow C to carry away the solvent, and a bead 70A is formed between the solvent and photosensitive material 16 to apply the solvent to the photosensitive material 16. Then the photosensitive material 16 is carried out by rollers 48 and 50 and sent to a heat- development transfer part to perform transfer to an image receiving material. Thus, the heat generation density of the heater is varied locally to uniformize the solvent temperature distribution, so the obtained picture quantity is improved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus used to obtain an image by thermal development.

Prior art and its problems As an image forming apparatus for obtaining a color image using a heat-developable photosensitive element, for example, as disclosed in Japanese Patent Laid-Open No. 59-75247, a heat developing section is used after exposing the heat-developable photosensitive element. It is known that an image receiving element is brought into close contact with the photosensitive element after thermal development, and an image is transferred to the image receiving element through a transfer process.

In this case, the photosensitive element or image-receiving element is usually provided with a transfer aid (image-forming solvent) such as water in advance in order to improve transfer efficiency before being sent to the transfer section. .

This application of water is accomplished by providing a tank for containing water, and installing an application roller in the tank for applying water to the photosensitive element or image receiving element, the roller axis of which is perpendicular to the direction of conveyance of the photosensitive element or image receiving element. This is done using a water applicator that is arranged and configured as follows. In the image forming apparatus described above, no particular consideration is given to controlling the temperature of the water in the tank, but in order to uniformly apply water, it is preferable to maintain the water at a constant temperature during application. For this reason, the tank may be provided with a heating means such as a heater to control the temperature of the water contained in the tank.

As a device that performs coating while controlling the temperature of the coating liquid to be constant in this way, there is a patent application filed by the present applicant in 1983.
There is a sheet liquid coating device described in Japanese Patent No. 1-242261.

However, in this device, no particular consideration is given to the heat generation density distribution of the heater, and when the coating liquid adheres to the roller from inside the tank and is applied to the photosensitive element or image receiving element, the water temperature changes at both ends of the roller in the axial direction. Therefore, it is difficult to make the temperature distribution of the coating liquid uniform in the roller axis direction, and it is difficult to uniformly apply the coating liquid in the roller axis direction to obtain a homogeneous image. It was difficult.

■Object of the Invention An object of the present invention is to provide an image forming apparatus that can uniformize the temperature distribution of a coating solvent such as water in the roller axis direction in a solvent coating section, thereby improving image quality. There is a particular thing.

■Disclosure of invention Such objects are achieved by the invention described below.

That is, the present invention includes a tank containing an image-forming solvent, and an application roller disposed in the tank for applying the image-forming solvent to a heat-developable photosensitive element or an image-receiving element. In an image forming apparatus that obtains an image by transferring an image recorded on a heat-developable photosensitive element to an image receiving element in the presence of a solvent, a heater is used to heat the image forming solvent and keep the temperature constant. The image forming apparatus is characterized in that the tank is provided in the axial direction of the application roller, and the heat generation density at both outer sides of the heater in the axial direction of the roller is greater than that at the center.

■Specific structure of the invention The specific structure of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of an image forming apparatus 10 of the present invention.

In this image forming apparatus 10, a magazine 14 is mounted on a machine stand 12 and accommodates a heat-developable photosensitive material (thermally developable photosensitive element) 16. The photosensitive material 16 in the magazine 14 is pulled out from its outer periphery, cut into a predetermined length by a cutter 18, and then wound around the outer periphery of the exposure drum 20 (in the direction of arrow A in FIG. 1). An exposure head 2 is mounted on the outer periphery of the exposure drum 20.
After exposure, the exposure drum 20 is reversed and the photosensitive material 16 is peeled off by a scraper 24, and the water-applied portion 3
4 and then sent to a thermal development/transfer section 28.

On the other hand, the image receiving material (image receiving element) 3 accommodated in the tray 30
The photosensitive material 2 is sent to the thermal development/transfer section 28 and overlapped with the photosensitive material 16, and then heated by the heaters in the thermal development/transfer sections 2 and 8. As a result, the photosensitive material 16 is developed, and the developed image is transferred to the image receiving material 32.

After the transfer is completed, the photosensitive material 16 is stored in a waste tray 38 via a peeling section 36, and the image receiving material 32 is sent out via a drying section 40 to a take-out tray 42.

In the illustrated example, the image-receiving material 32 is in the form of a cut sheet, but it may be in the form of a roll. In this case, a cutter may be provided at a predetermined position to cut the image-receiving material 32.

FIG. 2 shows the water applicator 34 in the present invention.

As shown in FIG. 2, a pair of conveyance rollers 44, 46 that sandwich the conveyed photosensitive material 16 are arranged in the water application section 34, and a pair of conveyance rollers 44, 46 are arranged downstream of these conveyance rollers 44, 46. Rollers 48 and 50 are arranged to nip and convey the photosensitive material 16.

These rollers are configured to send out the photosensitive material 16 in the direction of arrow B to the thermal development/transfer section 28 by receiving the driving force of a motor (not shown). Furthermore, guide plates 51A and SIB are provided between these conveyance rollers, corresponding to both ends of the photosensitive material 16 being conveyed, to guide the photosensitive material 16 from between the conveyance rollers 44 and 46 to between the conveyance rollers 48 and 50. It is designed to guide you.

The photosensitive material 1 is placed between the conveyance roller 46 and the conveyance roller 50.
A coating roller 52 serving as a coating member is provided opposite the center portion of the back surface (emulsion side) of 6. This application roller 5
2 has its rotating shaft 54 pivotally supported by the machine stand 12. A motor (both not shown) is connected to the rotation shaft 54 via a shaft coupling, and the application roller 52 is rotated in the direction of arrow C by the driving force of this motor.

A portion of the coating roller 52 is immersed in a main tank 72 filled with water 70, which is an image forming solvent, so that when the coating roller 52 rotates, the water 70 is brought out on its circumferential surface.

The water 70 taken out by the application roller 52 is applied to the photosensitive material 16.
A bead 7OA is formed between the
In this state, the photosensitive material 16 is
The coating water is supplied to the back side of the plate.

In this case, the conveyance speed of the photosensitive material 16 is 5 to 25 mm/
It is said to be about s.

In the main tank 72 filled with water 70, a heater 77 is installed along the outer wall surface of the main tank 72 in the direction of the tank axis (roller axis).
is installed.

A plan view of this heater 77 viewed from above (in the direction of arrow a) is shown in FIG.

In the example shown in FIG. 3, the heater 77 is a sheet-like sheet with a rectangular plane, and by changing the winding density of the heating wire 771, the heat generation density at both outer sides becomes larger than the heat generation density at the center. It is configured so that Use of the sheet-shaped heater 77 facilitates assembly and control of heat generation density.

In this case, the heat generation density at the outer side of the heater is about 5.0 to 50% of the heat generation density at the center of the heater, preferably 10 to 15%.
It may be increased by about %.

More specifically, the length of the heater 77 in the axial direction of the roller, especially when the heater 77 is in sheet form, is 80 rn m /
The average heat generation density at the position of It is 120 mm at the center.
/ 10-20 of the heat generation density over the length of the IL
% is preferable.

The length of the heater 77 in the axial direction of the roller, that is, the length of the heat-generating portion 2 is larger than the length of the application roller 52 in the axial direction, and may be generally about 110 to 180% larger.

Note that 2 is usually about 100 to 400 mm.

Regarding the shape of the heater 77 in the present invention, when a sheet-like heater 77 is used, it is not limited to a rectangular plane as shown in FIG. The heat generation density can also be changed by changing it in the axial direction.

In addition, depending on the heater used, multiple heaters may be installed in parallel,
The heat generation density can be similarly changed by changing the arrangement of individual heaters.

By using such a heater 77, it is possible to make the temperature distribution in the tank in the axial direction of the roller uniform, and the variation in the temperature distribution of the water temperature in the tank and the water temperature at the application area (bead area) can be reduced by ±2. It can be kept within ℃.

The main tank 72 filled with water 70 has a supply vibrator 74 for supplying the water 70 and a discharge pipe 76 for discharging the water 70 in the main tank 72. A pump 81 is attached. Also,
A replenishment tank 82 is installed at one end of the supply vibrator 74, and water can be supplied from the replenishment tank into the main tank 72 as needed by driving the slave pump 81.

A solenoid valve 80 is attached to the middle part of the discharge pipe 76, and normally this solenoid valve 80 is closed and the main tank 72 is closed.
The amount of water inside is maintained constant. Here, 7i magnetic valve 8
0 is opened, the water 70 in the main tank 72 is guided to a waste liquid tank 84 installed at one end of the discharge pipe 76. Note that the discharge pipe 76 can also be connected to the replenishment tank 82 and used for circulation. This method will be described later.

These pump 81 and solenoid valve 80 are each operated by a microcomputer 86.

The microcomputer 86 has a counting circuit (not shown) disposed therein. A signal line 90 of a sensor 88 that sends a signal to the coefficient circuit every time the photosensitive material 16 is conveyed is connected to a part of the microcomputer 86.

Further, a power line 92 from a drive circuit for operating the pump 81 and the electromagnetic valve 80 is connected to another part of the microcomputer 86, and a counting circuit is interposed in the middle of the power line 92.

As a result, a minute current flows to the counting circuit every time a signal is transmitted from the sensor 88, and the internal switch of this circuit becomes conductive, allowing power to be supplied to the pump 81 and the solenoid valve 80. Accordingly, the pump 81 is operated and the solenoid valve 80 is opened.

The operation timing of the pump 81 and the solenoid valve 80 is such that the pump 81 is activated after the solenoid valve 80 is opened for a predetermined time and then closed again.

The main tank 72 contains water 7 that is filled into the main tank 72.
An overflow pipe 78 is attached to discharge the surplus amount. The opening 78A of this overflow pipe 78 is arranged at a predetermined height from the bottom surface 72A of the main tank 72, and when the water 70 supplied from the supply vibrator 74 reaches above this opening 78A, the water 70
is discharged to the outside of the main tank 72, and the amount of water in the main tank 72 (
water surface height) can be kept constant.

The opening 78B on the opposite side of the overflow pipe 78 is connected to a solenoid valve 80 in the discharge pipe 76 and a waste liquid tank 8.
It is piped between 4 and 4.

Note that the water surface in the main tank 72 is about 1/3 of the coating roller 52.
It is preferable that the level is the same as the height of the immersion.

Further, as shown in FIG. 2, the applicator roller 52 has a gap between the outer periphery of the applicator roller 52 and the right side wall 72B of the main tank 72 (second dimension). Left side wall 72. Gap dimension with C (Fig. 2 M
dimensions).

This minimizes the amount of water required in the tank. In addition, the surface M dimension is 1III11
It is necessary to have a thickness of at least 3 mm, and it is particularly preferable to set it to 3 mm.

By doing so, the amount of water can be reduced to about 35 m2.

The image forming apparatus 10 of the present invention is preferably configured so that the water 70 in the main tank 72 is supplied and replaced every time the water 70 is applied to one sheet of the photosensitive material 16.

The supply method will be explained in detail below.

Since the photosensitive material 16 is sequentially conveyed at predetermined intervals, the water 70 is repeatedly lifted up by the coating roller 52 and returned to the main tank 72. The number of times this is repeated is proportional to the number of sheets of photosensitive material 16 transported, and the sensor 88 sends a signal to the counting circuit of the microcomputer 86 each time the photosensitive material 16 is transported, and this causes a minute current to flow through the counting circuit. hit

In response to this current, the pump 81 is operated and the main tank 7
Water is supplied into the tank 2 from a replenishment tank 82. After coating 1ji, the solenoid valve 80 is opened and the water 7 in the -L tank 72 is released.
0 is collected into the waste liquid tank 84 via the discharge vibe 76.

Note that water is supplied into the main tank 72 from the replenishment tank 82 at the same time as the operation of pulling out the photosensitive material 16 from the magazine 14 begins, or before that, or when the remaining water is collected after the previous coating is completed. It is preferable to start immediately after the

By supplying water to the main tank 72 early in this manner, the temperature distribution of the water supplied into the tank can be made as uniform as possible. In particular, as mentioned above, when the heater 77 is also provided in the main tank 72 to control the water temperature in the main tank to be constant, water is supplied to the main tank 72 early to control the water temperature. needs to be kept constant. In this way, it is possible to further prevent uneven thermal development and transfer due to non-uniform temperature distribution of water.

As mentioned above, since the water in the main tank 72 is replaced every time the photosensitive material 16 is coated, the surface condition of the coating roller 52 is prevented from becoming gradually contaminated by gelatin peeled off from the photosensitive material 16. There is no uniformity, and it is possible to prevent the occurrence of step unevenness, etc.

Further, there is no need to periodically clean the application roller 52 and the main tank 72, and the amount of water 70 consumed is reduced.

Further, even if the conveyance gap between the photosensitive materials 16 is large, the surface of the application roller 52 will not dry out and no dirt will stick to it.

Here, it is preferable that the amount of replenishment and the amount of water drained are the same, but since the overflow vibe 78 is attached to the main tank 72, if the amount of replenishment water is slightly larger than the amount of water drained, this difference amount will be drained by the overflow vibe 78. Therefore, a constant amount of water can be maintained in the main tank 72.
In addition, in the above-mentioned fiR, a replenishment tank 82 is attached to the supply vibrator 74, and a waste liquid tank 84 is attached to the discharge vibrator 76, so that the water 70 is disposable, but as shown in FIG. A circulation tank 94 to which both ends of the discharge vibrator 76 are attached is provided to collect the water 7.
0 may be reused, and each circulation tank 94 may be replaced periodically depending on the number of sheets of photosensitive material 16 processed.

In this case, it is preferable to install a filter 96 or the like in the middle of the discharge vibrator 76 and filter the once used water 70 when returning it to the circulation tank 94.

Further, in the above-described embodiment, the case where the photosensitive material 16 is coated with water has been described, but the present invention is similarly applicable to the case where the image receiving material 32 is coated with water.

In the above embodiment, the heat development section that heat develops the exposed heat-developable photosensitive material is the same as the transfer section that heats the heat-developed photosensitive material and image-receiving material by overlapping them and transferring the image to the image-receiving material. In other words, those equipped with a heat development/transfer section that overlaps and heats the exposed heat-developable photosensitive material and image-receiving material to perform heat development and heat transfer at the same time. A developing section and a thermal transfer section may be provided separately to perform thermal development and thermal transfer separately.

Further, in the above embodiment, a photosensitive material and an image receiving material (dye fixing material) in which a photosensitive element and an image receiving element are respectively formed on separate supports are used as photographic materials, but the photosensitive element and the image receiving element are They may be formed on the same support. Furthermore, although the example is taken in which both are peeled off after thermal development and thermal transfer, it may be a type that does not require peeling. Such photographic materials (photographic elements) include, for example, U.S. Pat.
No. 500626, No. 4503137, JP-A-59-
154445, JP 59-165054, JP 59-180548, JP 59-218443,
JP 60-120356, JP 61-88256
No., Patent Application No. 1983-79709, Patent Application No. 1982-1695
No. 85, Japanese Patent Application No. 60-244873, etc., include heat-developable photosensitive materials and image-receiving materials (dye fixing materials),
Any of these can be used.

In the above embodiments, water is mentioned as the image forming solvent required for image formation, but other low boiling point organic solvents (alcohols, ketones, amides, etc.) or surfactants, Examples include those containing various additives such as a development accelerator and a development stopper.

(2) Specific Effects of the Invention The photosensitive material 16 housed in the cassette 14 is cut into a predetermined length, wound around the exposure drum 20, exposed by the exposure head 22, and then sent to the water coating section 34.

The application roller 52 rotates in the direction of arrow C in FIG.
The water 70 in the main tank 72 provided with the bead 70 adheres to the surface thereof and is taken out, forming a bead 70A between it and the back surface (emulsion surface) of the photosensitive material 16, and this is applied to the back surface of the photosensitive material 16. .

When the rear end of the photosensitive material 16 passes the application roller 16,
The bead 70A is returned to the main tank 72 by its own weight.

The photosensitive material 16 coated with water in the water coating section 34 is sent to the thermal development/transfer section 28 . The image receiving material 32 taken out from the tray 30 is sent to the thermal development/transfer section 28,
It is overlapped with the photosensitive material 16. Here, heat development is carried out in the presence of water, and at the same time the formed dye image is heat-transferred to the emulsion surface of the image-receiving material 32. In this transfer state, the photosensitive material 16 is already kept at a constant temperature with good temperature control and the necessary amount of water has been appropriately applied, so that an extremely good transfer operation can be performed.

After the transfer, the photosensitive material 16 and the image receiving material 32, which remain in close contact with each other, are sent from the thermal development/transfer section 28 to the peeling section 36.
The photosensitive material 16 is received in a collecting device 38 and the image receiving material 32
is sent to the take-out section 40 and taken out.

At this time, in the present invention, the heater 77 is connected to the main tank 7.
The heater 77 is provided along the roller axis in the main tank 72, and the heat generation density at the inner and outer parts of the heater 77 is larger than that at the center, so that the water temperature in the tank axis direction in the main tank 72 is lowered. The distribution can be made uniform.

This makes it possible to make the temperature and amount of the image forming solvent such as water uniform in the bead when it is applied to the film surface of the photosensitive element or the image receiving element. As a result, it is possible to improve the image quality obtained.

Furthermore, by configuring the water application section 34 so that the solvent in the main tank 72 is replaced every time the image forming solvent is applied to the photographic material by the application roller 16, the solvent generated by the application of the solvent by the application roller 16 can be removed. It can prevent stains.

(2) Specific Examples of the Invention Hereinafter, specific examples of the present invention will be shown, and the effects of the present invention will be explained in detail.

Example Water application section 34 (Fig. 2) consisting of a main tank 72 provided with a heater 77 as shown in Fig. 3 in the axial direction of the tank
The images were processed using the image forming apparatus io (FIG. 1) of the present invention having the following technology, and the photosensitive material and dye-fixing material (image-receiving material) described in Japanese Patent Application No. 73714/1982.

In addition, the volume of water put into the main tank 72 in the water application section 34 is 35 ml, the L dimension is 3 mm, and the M dimension is 5 mm.
myin, and the length of the tank in the roller axial direction was 320 mm. Further, the application roller 52 has a diameter of 30 m, and a length of 2
The length was 36 mm, and the material was 2 mm thick AjZ.

The heater 77 is l = 28411Im in FIG.
, It , = 80 aIll (outer part 771),
The one with It2=120 mm (center portion 772) was used.

The heat generation density is io higher in the bilateral side 21 part than in the central part 2□ part.
% higher. Conveyance speed of photosensitive material is 12.0mm
/second, and the rotation speed of the coating roller was 200 rpm.

The photosensitive material 16 pulled out from the magazine 14 and cut into a predetermined length is wound around the exposure drum 20 and exposed for 1 second using G, RlIR light emitting diodes, and then sent to the water coating section 34 where it is coated with an emulsion by applying the present invention. Water was applied to the surface.

In addition, the temperature of the water in the M dimension position of the main tank 72 is set to 35°C.
The water temperature was measured at the center and ends of the main tank in the axial direction of the tank.

As a result, the temperature at the center of the roller 52 was 35.degree. C., and the temperature at the end of the roller 52 was 35.degree.

In addition, the water temperature in the main tank was measured in the same manner as above except that the main tank was equipped with a conventional heater with the same heat generation density in the inner and outer parts and the center part.

As a result, the temperature at the center of the roller is 35℃, and the edge of the roller is 35℃.
It showed a temperature of 2°C.

From the above results, it can be seen that in the present invention, the temperature of the water in the roller axis direction in the main tank can be kept within a range of ±2°C, whereas in the conventional case, there is a large variation in temperature.

In this way, water was applied to the photosensitive material 16 at a rate of 10 mf/m2. This photosensitive material 16 is transferred to a heat development/transfer section 28.
Here, the image-receiving material 32 sent out by a predetermined method is
and heated with a heater in the thermal development/transfer section 28. In this case, the temperature of the membrane that absorbed water was adjusted to 90 to 95° C. and heated for 25 seconds.

Thereafter, the image-receiving material 32 is transported to the peeling section 36, and the image-receiving material 32 is transferred to the photosensitive material! I tore it off from 6.

With the image forming apparatus of the present invention, a uniform, clear image without unevenness was obtained on the image-receiving material.

On the other hand, in the conventional image forming apparatus, line-shaped unevenness occurs in the image-receiving material at positions corresponding to both ends of the coating roller in the axial direction, with a period equal to one rotation of the coating roller.

Further, when the image forming apparatus of the present invention having a water application section 34 as shown in FIG. 4 was used, results similar to those obtained when using the above-described apparatus of the present invention were obtained.

Furthermore, results similar to those described above were obtained even when the image-forming solvent was other than quince.

From the above, the effects of the present invention are clear.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the image forming apparatus of the present invention. FIG. 2 and FIG. 4 are sectional views each showing a water application section constituting the image forming apparatus of the present invention. FIG. 3 is a plan view of the heater in the present invention. Explanation of symbols 〇-Image forming device, 16-Photosensitive material, 32-Image receiving material, 34-Water coating section, 52-Coating roller, 70-Water, ? OA-・Bead, 72-・Main tank 7 foot heater, 771-・Outside part, 772-Center part Applicant: Fuji Photo Film Co., Ltd. Representative Patent attorney: Minoru Watanabe
Patent attorney Akira Ishii - Authorized letter of procedure (spontaneous) July 15, 1986 Kunio Ogawa, Commissioner of the Patent Office Body 2, Title of invention Image forming device 6, Contents of amendment (1) Description No. “About 10-15%” on page 9, line 9
is corrected to ``about 10 to 20%.'' (2) "Make the size 10 to 20%" on the 15th line of the 9th page is corrected to "Increase the size by 10 to 20%." (3) "110-180" on page 9, lines 19-20
% larger” is corrected to “10 to 80% larger.”

Claims (1)

[Claims] (1) It has a tank that contains an image forming solvent, and an application roller that is placed in the tank and applies the image forming solvent to a heat-developable photosensitive element or an image receiving element, and the solvent is applied by the application roller. In an image forming apparatus that obtains an image by transferring an image recorded on a heat-developable photosensitive element to an image receiving element in the presence of The image forming apparatus is characterized in that the heater is provided in the axial direction of the application roller, and the heat generation density at both outer sides of the heater in the roller axial direction is greater than that at the center.