JPH01233457A - Heat developing device - Google Patents

Abstract

PURPOSE:To obtain always stable images without being affected by environment, resting time, etc., by providing a means of spraying an image forming solvent in the form of a mist from the outside to a photosensitive material prior to heat development of said material in a heat developing part. CONSTITUTION:This device is constituted of the means 10 for spraying and applying the image forming solvent in the form of the mist from the outside to the photosensitive material A, a preheating part 11 which preheats the photosensitive material A prior to the heat development after application of the image forming solvent to said material and the heat developing part 17 which executes the heat development of the photosensitive material A after the preheating. The photosensitive material is thereby subjected to the preheating or to the water coating prior to the heat development if the preheating is not executed and, therefore, the moisture in the photosensitive material is adjusted to the adequate ratio without being affected by the environment, resting time, etc. The always stable images are thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermal development device in an image forming apparatus that visualizes an imagewise exposed image by pressure.

<Prior art and its problems> Image recording (formation) in which a visible image is obtained by applying pressure, using a recording material (photosensitive material) whose support is coated with a substance on which an image formed by imagewise exposure is fixed by pressure. ) method is known.

Examples of recording materials used in such image recording methods include photosensitive materials that utilize microcapsules containing a photosensitive composition, and specifically, a photosensitive material containing a vinyl compound and a photopolymerization initiator precursor. A photosensitive material using a synthetic polymer resin wall capsule has been disclosed (Japanese Unexamined Patent Publication No. 179836/1983).

In this photosensitive material, microcapsules are imagewise cured by exposure to light, then pressure is applied to rupture the uncured microcapsules, and a color image is formed from the released colorant precursor. It has the characteristic of being able to obtain high quality images through extensive processing.

However, this photosensitive material has lower photosensitivity than photosensitive materials using silver halide such as photographic emulsifiers.

Therefore, a new photosensitive material has been disclosed which improves these points and has high photosensitivity and makes it possible to obtain high quality images through simple dry processing (Japanese Patent Laid-Open No. 61-27).
5742), this photosensitive material has at least a photosensitive silver halide, a reducing agent, a polymerizable compound, and a color image-forming substance coated on a support, and among these, at least the polymerizable compound and a color image-forming substance are coated on a support. The substances are encapsulated in the same microcapsule.

An image recording method for recording images using this photosensitive material is disclosed in Japanese Patent Application Laid-Open No. 61-278849. This image recording method first performs imagewise exposure to form a latent image, then develops it using a heating device, and polymerizes the polymerizable compound in the area where the latent image exists to form a high-molecular compound. Harden the capsule. Then, the image-receiving material having an image-receiving layer to which the color image-forming substance can be transferred is stacked and pressurized to rupture at least a portion of the microcapsules in the area where the latent image does not exist, and the color image-forming substance is transferred to the image-receiving material. to obtain an image on an image-receiving material.

Then, using the above-mentioned photosensitive material, this photosensitive material is subjected to imagewise exposure, heat development is performed, and then it is superimposed on an image-receiving material, and this is pressed, and an image is obtained on the image-receiving material by transfer, which is automatically performed. An example of a recording device is shown in Japanese Patent Application No. 1983-51896 filed by the present applicant.

As shown in FIG. 11, the heat developing device in this case includes a heating drum 44 heated to about 150 to 160°C.
and an endless belt 46 that is passed around belt support rollers 40, 41, 42, 43 so as to be indirectly connected to this heating drum 44. One example is one in which the endless belt 46 is wrapped around the outer periphery and the photosensitive material is conveyed while being held between the endless belt 46 and the heating drum 44.

However, when such a thermal development apparatus is used to heat the photosensitive material, the following disadvantages occur due to the small amount of water contained in the photosensitive material. In other words, the water contained in the photosensitive material evaporates and is trapped in areas where the contact pressure between the endless belt and the photosensitive material or the heating drum and the photosensitive material is low, resulting in non-uniform water vapor distribution. This causes wrinkles in the photosensitive material.

Further, since water in a photosensitive material has the function of promoting development, uneven distribution of water (or water vapor) on the surface of the photosensitive material results in uneven development of the photosensitive material, causing image unevenness.

In order to deal with this problem, a method has been proposed in which the photosensitive material is preheated by a preheating means to evaporate water before heat development (Japanese Patent Application No. 61-298632).

An example of a thermal developing device having such a preheating section is the one shown in FIG. 12.

This □ is obtained by adding a preheating section 11 roughly having a roller 111 to the heat developing device having the structure shown in FIG.

By the time the photosensitive material A is sandwiched between the heating drum 44 and the endless belt 46 by the roller 40 and heat development is started, the photosensitive material A has been transferred to the heating drum 44 in the preheating section 47.
The contact surface with the photosensitive material A is heated, and the moisture contained in the photosensitive material A is evaporated.

When a thermal developing device having such a preheating section is used, the water content of the photosensitive material can be kept below a certain value.

However, the moisture content of photosensitive materials varies depending on the environment, the time they are left in the room, etc., so it is not possible to keep the moisture content of photosensitive materials constant just by keeping the temperature of the preheating part of the car constant.
A stable image has not been obtained.

Therefore, it is conceivable to control the temperature of the preheating section according to the environment. For example, it has been proposed to detect the moisture content of the photosensitive material after preheating and control the temperature of the preheating section based on this detection signal (Japanese Patent Application No. 62-223367).

However, in such a method, it is difficult to precisely control the temperature, etc., and it is not always possible to maintain a constant water content suitable for heat development, and it is difficult to obtain a stable image.

<Object of the Invention> An object of the present invention is to provide a thermal developing device that can always obtain stable images regardless of the environment, standing time, etc.

<Detailed Description of the Invention> Such an object is achieved by the invention described in claim (1) or (2).

That is, the invention described in claim (1) is a thermal development device having a heat development section of an image forming device that visualizes an image obtained by heat development of an imagewise exposed photosensitive material by pressure. 2. A thermal development apparatus characterized in that, before the photosensitive material is heat-developed in the heat-developing section, an image-forming solvent is applied to the photosensitive material by spraying it from the outside.

In addition, the invention described in claim (2) provides a heat development system that includes a preheating section and a heat development section of an image forming apparatus that visualizes an image obtained by heat development of an imagewise exposed photosensitive material under pressure. A thermal developing apparatus characterized by having means for applying an image forming solvent to the photosensitive material by spraying it in the form of a mist from the outside before preheating the photosensitive material in the preheating section. be.

<Specific structure of the invention> Hereinafter, a specific configuration of the present invention will be explained in detail.

FIG. 1 is a sectional view showing one embodiment of an image forming apparatus equipped with a thermal developing device 1 of the present invention.

As shown in FIG. 1, a housing 12 constituting the image forming apparatus includes a photosensitive material supply section 13 that stores a photosensitive material A, an image reading section 15 that reads image information carried on a document S, and a photosensitive material Thermal development device 1 of the present invention performs heat development on photosensitive material A, a superimposing section 19 that superimposes image receiving paper C on photosensitive material A, pressure transfer section 21 that presses photosensitive material A and image receiving paper C, A peeling unit 23 that peels off the image receiving paper C from the photosensitive material A and the image receiving paper C are heated to fix the image,
A post-heating device 25 for improving image density is installed in each case.

A transparent supporting glass plate 14 on which the original document S is placed is arranged on the upper surface of the housing 12, and the supporting glass plate 14 is moved over an opening 16 defined in the upper surface of the image reading section 15 by a transport means (not shown). It is possible to move back and forth in the direction of the arrow. The image reading unit 15 includes a light source 18 that illuminates the original S through the opening 16 and a condensing optical system 20.
These are surrounded by a partition wall 22.

Although the illustrated example is of a document stand type, it may be a light source type.

The photosensitive material supply section 13 is provided in the upper part of the housing 12 and is held in a light-tight manner by a partition wall 26 . A magazine 30 in which the photosensitive material A is wound is loaded into the photosensitive material supply section 13 via a cover member 28 that can be opened and closed and is attached to the upper surface of the housing 12.

A cutter 34 for cutting the photosensitive material A into predetermined lengths is disposed between the photosensitive material supply section 13 and the image reading section 15.

In the illustrated example, the photosensitive material A (it is in the form of a t-roll, but it may also be in the form of a cut sheet.
The configuration etc. may be selected as appropriate.

Furthermore, an exposure opening 36 defined on the bottom of the partition wall 22 surrounding the image reading section 15 faces downstream of the cutter 34 .

The thermal developing device 1 of the present invention is disposed downstream of the image reading section 15, and the photosensitive material A is carried into this thermal developing device 1 via the image reading section 15.

The thermal development apparatus 1 of the present invention includes a means 10 for applying an image forming solvent to a photosensitive material A by spraying it in the form of a mist from the outside, which will be described in detail later. It consists of a preheating section 11 that heats the photosensitive material A, and a thermal development section 17 that heats and develops the photosensitive material A after preheating.

In the illustrated example, the preheating section 11 is installed, and although it is more preferable to install the preheating section 11, it does not necessarily have to be installed.

Hereinafter, as will be described later, since the preferred image forming solvent is water, the means 10 for applying water as the image forming solvent or spraying the image forming solvent in the form of a mist from the outside will be referred to as the water application section 10.

As shown in FIG.
A vessel 101 having a rectangular cross section and a vessel 1 facing the
It has a water tank 104 for supplying water into the vessel 101, and a blower vibrator 107 provided on the side of the vessel 101 opposite to the photosensitive material A.

The length of the vessel 101 in the direction perpendicular to the plane of the second drawing is approximately the same as the length of the photosensitive material A in the width direction. A vibrator 102 is provided on the bottom of the vessel 101, and is configured to generate ultrasonic waves by a transmitting circuit (not shown).

A vibrator 103 protruding from the bottom of the water tank 104
is fitted into the vessel 101, and the vessel 101
Water 106 is supplied inside. water 106
The height of the water surface is always equal to the lower end position of the vibrator 103, so that the amount of water vapor generated by the vibrator 102 is always maintained at a constant level.

A fan 108 is disposed within the blower vibrator 107 and blows outside air into the vessel 101. An obstacle plate 105 is installed on the bottom of the vessel 101 on the downstream side of the vibrator 102, and when the fan 108 blows water vapor toward the photosensitive material A side, only the water vapor of fine particles is sent to the obstacle plate 105. It is designed to pass above. A blowout port 109 is provided on the side surface of the vessel 101 facing the photosensitive material A, and the water vapor is accelerated and narrowed to be blown out from the blowout port 109. The air outlet 109 is formed along the width direction of the photosensitive material A, and has approximately the same width as the photosensitive material A. The obstruction plate 105, the outlet 109, and the portion of the vessel 101 between them constitute a nozzle 100.

As the image forming solvent in the present invention, water is particularly preferred as described above, but other solvents include caustic soda, caustic potash,
Inorganic alkali metal salts and organic bases or their salts (
For example, a basic aqueous solution containing guanidine carbonate) can be used. These bases are usually used as image formation accelerators. Furthermore, a low boiling point solvent such as methanol, N,N-dimethylformamide, acetone, and shisoisobutyl ketone, or a mixed solution of these low boiling point solvents and a basic aqueous solution may be used.

When spraying this image-forming solvent in the form of a mist, it is preferable to include a surfactant therein to lower the interfacial tension of the solvent. The surfactant that can be used at this time may be any of anionic, cationic, and nonionic surfactants. As examples of compounds, those described in Surfactant Handbook (published by Kogaku Tosho) can be used.

The water application section 10 according to the present invention may have not only the embodiment shown in FIG. 2 but also the embodiment shown in FIG. 3.

In the water application section 10A shown in FIG. 3, instead of providing the obstacle plate 105 in the embodiment shown in FIG.
A small tube 110a extends from the upper end of the photosensitive material A and is bent toward the photosensitive material A, and a nozzle 112 is provided at the tip of the small tube 110a. Further, an air outlet 113 is provided on the side surface of the nozzle 112 facing the photosensitive material A.

Furthermore, an embodiment as shown in FIG. 4 may be used.

In the filter water application section 10B shown in FIG. 4, a heater 114 is used instead of the vibrator 102 in the embodiment shown in FIG.
The configuration is such that

Further, embodiments as shown in FIGS. 5 and 6 may be used.

In the filter water application section 10C shown in FIGS. 5 and 6, dew is blown out using negative pressure.

That is, an inlet pipe 116 is provided on the back surface of the inner vessel 115 having parallel plates with a short gap, and water is supplied into the inner vessel 115 through a rubber pipe 117 attached to the inlet pipe 116. ing.

Inside the inner vessel 115, as shown in FIG. 6, a rectifying plate 118 is provided along the longitudinal direction of the inner vessel 115 (the width direction of the photosensitive material A). The current plate 118 divides the chamber of the inner vessel 115 into two.

A large number of small holes 119 are bored in the current plate 118, and the two halves of the chamber are communicated with each other. Further, between the inlet pipe 116 and the current plate 118, an obstacle plate 121 is installed in parallel with the current plate 1!8. Due to the current plate 118 and the obstruction plate 121, the flow rate passing through each small hole 119 of the current plate 118 is approximately constant.

A water outlet 122 is formed on the downstream end face of the inner vessel 115 to allow the water to flow out.

On the other hand, an outer vessel 123 is provided to cover the outer surface of the inner vessel 115. Artificial tubes 124 are protruded from the upper and lower surfaces of the acta vessel 123. A rubber tube 125, a single-shaped connecting fitting 126, and a rubber tube 127 are sequentially connected to the inlet tube 124 so that air is supplied between the actuator vessel 123 and the inner vessel 115. A current plate 128 similar to the above-described current plate 118 is provided between the outer vessel 123 and the inner vessel 115. The current plate 128 is parallel to the current plate 118. A plurality of small holes 129 having a larger diameter than the small holes 119 are bored in the current plate 128 so that the flow rate of air passing through each of the small holes 129 is approximately the same. An air outlet 130 is formed on the downstream side surface of the outer vessel 123.

When air is supplied between the inner vessel 115 and the outer vessel 123 via the rubber pipe 127, the water outlet 122
Negative pressure is created near the water outlet 122 and water is pulled out in the form of a mist from the water outlet 122 toward the air outlet 130, and this mist is sprayed onto the photosensitive material A.

Alternatively, a mode as shown in FIG. 7 may be used.

The water application section 10D has a structure shown in FIG. 2, in which the filtered water application section 10 is provided with a water vapor recovery section.

That is, a hood 131 is provided to cover the outer surface of the vessel 101. The air blower vibrator 107 side of the hood 131 has a water recovery pipe 132 that is bent downward and has a small diameter.
is provided. A recovery tank 133 for water recovery is provided below the water recovery pipe 132. Water recovery pipe 132
A water vapor exhaust pipe 134 is provided on the side wall of the water vapor exhaust pipe 134, and a fan 135 for releasing water vapor is provided inside the water vapor exhaust pipe 134.

Furthermore, an embodiment as shown in FIG. 8 may be used.

The filtrate application section 10E shown in FIG.
1.

In the shutter 160, a plunger 164 of a solenoid 163 is fixed to the upper center of a shutter plate 162 that covers the front surface of the air outlet 109. This solenoid 1
63 is connected to the vessel 10 via an L-shaped bracket 164.
It is fixed on the top surface of 1. Further, the widthwise end portion of the shutter plate 162 is configured to be guided by a guide 170 fixed to the front surface of the vessel 101.

A long hole 165 is bored in the mask 161, and a bolt 166 is passed through the hole 165, so that the mask 161 is screwed onto the front surface of the guide 170.

In addition, in the present invention, it is only necessary to spray water in the form of particulates only to the surface that requires application, and the methods are not limited to the ultrasonic method, heater heating method, and mist spray method described in the above embodiments.
A rotary atomization centrifugal spray method, an inkjet method, a bubble jet method, etc. may be used.

In the present invention, the amount of water applied may be 1 to 20 m/L, preferably 2 to 6 mj2 per inch of photosensitive material.

That is, the conveyance speed of photosensitive material A was set to 20 mm/s.
When e c, coating efficiency is about 10% and 24
Water may be sprayed at a speed of about 72 mu/min.

As shown in FIG. 1, a preheating section 11 and a heat developing section 17 surrounded by a heat-insulating partition wall 38 are disposed downstream of the water application section 10.

The preheating section 11 heats the photosensitive material A after coating with water on a heating drum 44.
The heating drum 44 has a roller 111 that presses the roller 111 to a point directly below the roller 40 where heat development is started, and the heating drum 44 has an arc of 60° to 180°. The temperature of the heating drum in the preheating section 11 may be about 120 to 140°C.

In the illustrated example, the preheating section 11 has the above-mentioned configuration, but it may have various other configurations. For example, a heating roller, a heating plate, or a hot air generator provided separately from the heating drum 44 may be used.

The heating and developing section 17 includes a hollow cylindrical heating drum 44 containing a heat source such as a halogen lamp, and belt support rollers 40, 41.
42.43 has an endless belt 46 which is passed over the heating drum 44.
The endless belt 46 is wound around the outer periphery of an arc of 0° to 300°, and the photosensitive material A is sandwiched and conveyed between the endless belt 46 and the heating drum 44.

The temperature of the heating drum 44 in this case may be approximately 130 to 160°C.

The photosensitive material A discharged from the heat developing section 17 is conveyed to the overlapping section 19. The overlapping section 19 has a Y-shaped guide plate 50, and this Y-shaped guide plate 50 has an input path 52a for guiding the photosensitive material A, an input path 5'2b for guiding the image-receiving paper C, which will be described below, and the aforementioned Y-shaped guide plate 50. It is composed of an unloading path 54 where the loading paths 52a and 52b merge.

On the other hand, a cassette 56 for storing image-receiving paper C is loaded into a lower corner portion of the housing 12.

In this case, a paper feed roller 58 is disposed at the top of the cassette 56, and the image receiving paper C is transferred to the paper feed roller 58.
is supplied to the carry-in path 52b of the Y-shaped guide plate 50. Note that a manual feed port 60 is defined in the upper part of the cassette 56 in the housing 12;
It is also possible to supply the image-receiving paper C to the carry-in path 52b from there.

In the illustrated example, the image-receiving paper C is in the form of a cut sheet, but it may also be in the form of a roll, in which case it may be configured to be cut as appropriate with a cutter or the like.

A pressure unit 66 including a pressure transfer section 21 and a peeling section 23 is disposed behind the overlapping section 19 .

The pressure transfer section 21 includes a pair of pressure nip rollers 74.80 and a backup roller 96.120 for making the pressure of the pressure nip rollers 74.80 uniform in the axial direction. The pressure nip rollers 74,80 are pressed together with a pressure of approximately 500 kg/cm2.

In the illustrated example, the development and transfer steps are performed separately, but they may be performed simultaneously.

The peeling section 23 includes a guide plate 142, a pair of rollers 32, and a peeling claw 146 that faces the pair of rollers 32 and has a pointed end. (2) is configured to be rotatably supported.

A waste tray 150 disposed below the photosensitive material supply section 13 is connected to one downstream side of the pressure transfer unit 66 . In this case, the photosensitive material A is carried into the waste tray 150.

Further, on the other downstream side of the pressure transfer unit 66, a post-heating device 25 is provided which heats the image receiving paper C onto which the image has been transferred to fix the image and improve the image density.

The post-heating device 25 is composed of a pair of rollers 251 and 252, one of which includes a heating source such as a halogen lamp.

The roller temperature in this case is usually 60 to 120°C. Further, a driving source (not shown) is installed on one of the rollers, so that the rollers 251 and 252 are configured to rotate synchronously.

A take-out tray 152 disposed at a lower corner of the housing 12 is connected downstream of the post-heating device 25, and the image-receiving paper C is led out to this take-out tray 152.

In the image forming apparatus shown in FIG. 1, a photographic material in which a photosensitive material A as a photosensitive element and an image receiving paper C as an image receiving element are provided on separate supports is used. The element and the image receiving element may be formed on the same support. Furthermore, after transcription,
Although we have taken as an example a type in which both are peeled off, a type that does not require peeling may also be used.

Among the recording materials that can generally be used in an image forming apparatus equipped with the thermal development device of the present invention, the following are examples of photosensitive materials.

For example, there is a type of photosensitive material disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 57-179836 in which a polymerizable compound is imagewise cured by imagewise exposure and then pressure is applied to obtain a visible image. This photosensitive material has a synthetic polymer resin wall capsule containing a vinyl compound, a photopolymerization initiator, and a colored precursor supported on a support.

Another example is a type in which a visible image is obtained by applying pressure after preliminary thermal development or wet development of a latent image generated by imagewise exposure.

Examples of such materials include Japanese Patent Application Laid-open No. 6, published by the present applicant.
Publication number 1-278849 or patent application No. 1988-5388
Examples include the material shown in No. 1. Said Japanese Unexamined Patent Publication No. 1986-
The material disclosed in Japanese Patent No. 278849 is a material that is thermally developed and then transferred to an image-receiving material having an image-receiving layer to obtain an image on the image-receiving material. Silver, a reducing agent, a polymerizable compound, and a color image-forming substance are coated, and at least the polymerizable compound and the color image-forming substance are encapsulated in the same microcapsule.

Furthermore, the material disclosed in the above-mentioned Japanese Patent Application No. 61-53881 is for obtaining an image on a photosensitive material without using an image-receiving material. In other words, the image-receiving layer is provided on the photosensitive material itself, and contains silver halide, a reducing agent, a polymerizable compound, and two substances that cause a color-forming reaction when in contact. and the polymerizable compound is contained in microcapsules,
It has a photosensitive layer on the support, which is present outside the microcapsules in which the material that causes the coloring reaction is a polymerizable compound.

<Specific action of the invention> Hereinafter, specific effects of the present invention will be explained.

The imagewise exposed photosensitive material A is conveyed to a thermal development apparatus 1 of the present invention as shown in FIG.

First, in the thermal developing device 1, the photosensitive material A is conveyed to the water coating section 10 shown in FIG. 2 and is coated with water. Further, since the water coating section 10 applies water while the photosensitive material A is being conveyed, continuous processing is possible. Further, by keeping the transport speed of the photosensitive material A constant, water can be uniformly applied to the photosensitive material A.

Further, water can be applied only to the surface of the photosensitive material A.

The photosensitive material A coated with water is conveyed to the preheating section 11, and is pressed against the heating drum 44 by the roller 111 and heated.

The temperature in this case is 120-140°C.

The photosensitive material A that has been conveyed through the preheating section 11 is conveyed to the heat developing section 17 and is transferred to the heating drum 44 by the endless belt 46.
It is pressed and heat developed. The temperature in this case is 13
The temperature is 0 to 160°C.

In the present invention, since water is applied as described above, there is no need to supply extra heat in the preheating section 11 to the heat development section 17, and there is no need to generate more water vapor than necessary. Paper wrinkles do not sometimes occur on the photosensitive material A. Further, since an appropriate amount of water is contained in the photosensitive material A, uneven development does not occur.

In the embodiment of the water application section 10A shown in FIG. 3, water vapor with large particle diameters cannot pass through the small tube 110a due to its own weight, so only the water vapor with fine particles can be blown out from the nozzle 112 to the photosensitive material A. Since the small tube 110a extends toward the photosensitive material A, the main body of the water coating device 10A can be placed apart from the photosensitive material A.

In the embodiment of the filter water applying section 10B shown in FIG.
By changing the electric power supplied to 14, the amount of water vapor generated can be easily adjusted. Moreover, this water vapor can spray fine particles of water compared to the embodiments shown in FIG. 3 or FIG. 5.6, and uneven water droplets are less likely to occur.

In the embodiment of the water application section 1°C shown in Figs. 5 and 6, dew is blown out using negative pressure, and there is no need to use an ultrasonic transmitter or a heater, thus saving electricity. There is no need to supply it. Furthermore, by adjusting the flow rate of air supplied through the rubber tube 127, the amount of dewy water blown out from the current plate 128 can be easily adjusted.

In the water application section 10D shown in FIG. 7, most of the water vapor blown out from the outlet 109 is sprayed onto the photosensitive material A, but a portion passes through between the hood 131 and the vessel 101 and descends. A part of the water vapor becomes water droplets and is collected in the collection tank 133, and the water vapor is discharged to the outside from the water vapor discharge pipe 134. Therefore, water is completely applied only to the surface side of the photosensitive material A.

In the water application section 10E shown in FIG. 8, the spacing between the masks 166 and 161 is adjusted in advance according to the width of the photosensitive material A.

When the photosensitive material A passes through the front surface of the vessel 101, only when the photosensitive material A is located in front of the air outlet 109, the solenoid 163 is energized to attract the plunger 164, and the shutter plate 161 is lifted upward to move the air outlet 109. Open it and apply water to photosensitive material A. Therefore, an appropriate amount of water can be applied.

If the solenoid 163 is demagnetized, the shutter plate 161
falls freely, and the air outlet 109 is closed to prevent water from being applied.

The photosensitive material A heat-developed in the thermal development apparatus 1 of the present invention is carried into the overlapping section 19 and overlapped with the image receiving paper C. After that, it is carried into the pressure transfer section 21 and the image is transferred onto the image receiving paper C. After the transfer, the photosensitive material A and the image receiving paper C are carried into the peeling section 23! ! IIM work is performed. The peeled image-receiving paper C is carried into the post-heating device 25 and heated, thereby fixing the image and improving the image density. The image-receiving paper C on which the image has been formed in this way is placed in the take-out tray 1.
It will be carried out on 52nd. On the other hand, the peeled photosensitive material A is carried out to a waste tray 150.

<Effects of the Invention> According to the present invention, since water is applied before heating or heat development when preheating is not used, the amount of water in the photosensitive material can be maintained at an appropriate level regardless of the environment, standing time, etc. This allows you to always obtain stable images.

In order to confirm such an effect, the present inventor conducted various experiments. An example is shown below.

Experimental Example> The photosensitive material and image receiving paper described in JP-A-62-198850 were used as photosensitive material A and image receiving paper C, and the image forming apparatus shown in FIG. Under, 23℃, 60%RH condition, or 30℃, 80%
Images were each obtained under RH conditions. The preheating temperature and heat development temperature at this time were 120°C and 15°C, respectively.
The temperature was 0°C.

The characteristic curve at this time is shown in FIG.

Further, the same processing as above was performed using the image forming apparatus shown in FIG. 1 with the same structure except that the water application section 10 was not provided. However, in order to adjust the water content of the photosensitive material to suit the environmental conditions, the preheating temperature was set as follows.

15℃, 20%RH condition...100℃23℃
, 60% RH condition...120℃30℃, 80
%R) [Condition: 140° C. The characteristic curve at this time is shown in FIG.

In addition, in FIG. 10 and FIG. 11, D is image density,
E indicates the exposure amount.

The effects of the present invention are clear from the results shown in FIGS. 10 and 11.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of an image forming apparatus equipped with a thermal development device of the present invention. FIG. 2 is a sectional view showing an aspect of the water application section in the heat developing apparatus of the present invention. FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are sectional views showing other embodiments of the water application section in the heat developing apparatus of the present invention. FIG. 8 is a perspective view showing another embodiment of the water application section in the thermal development apparatus of the present invention. FIG. 9 is a graph showing characteristic curves of images obtained using the thermal development apparatus of the present invention. FIG. 10 is a graph showing a characteristic curve of an image obtained by applying a conventional thermal development apparatus. FIG. 11 and FIG. 12 are sectional views each showing an aspect of a conventional heat developing device. Explanation of symbols 1...Thermal development device, 10...Water coating section, 11
...Preheating section, 17...Heat developing section, 44...
・Heating drum, 6... Endless belt, A...
・Photosensitive material, C... Receiving paper FIG, 2 10, FIG, 3 10C FIG, 8 FIG, 9 FIG, 10 ogE FIG, 11 FIG, 12

Claims (2)

[Claims] (1) A thermal development device having a heat development section of an image forming apparatus that visualizes an image obtained by heat development of an imagewise exposed photosensitive material under pressure, wherein the photosensitive material is heated and developed in the heat development section. 1. A thermal development apparatus characterized by having means for applying an image forming solvent to the material by spraying it in a mist form from the outside before carrying out heat development. (2) A thermal development device having a preheating section and a heat development section of an image forming apparatus that visualizes an image obtained by heat developing an imagewise exposed photosensitive material under pressure, wherein the photosensitive material is subjected to the preheating. 1. A thermal development apparatus comprising a means for spraying an image forming solvent in the form of a mist onto the material from the outside before preheating the material.