JPH04131847A - Heat developing device with cooling mechanism - Google Patents

Abstract

PURPOSE:To contrive the improvement of the reliability, the high functionality and the reduction in cost by blasting air with a blasting means through an opening to the inside of a heat-developing device when a shutter is opened and an opening is formed at a part of an enclosure. CONSTITUTION:Shutters 7a, 7b provided on an air blasting port 4 and an exhausting port 9 are covered with a heat insulating material and closed for heat insulation at the time of a development. When the development is finished and the cooling is carried out, the cooling fan 5 rotates to blast air through the air blasting port 4 to the inside of the developing device and a warm wind runs away from the exhausting port 9 to the outside. When the cooling is completed, the shutters 7a, 7b are again closed to prevent the infiltration of dust into the heat developing device. Hence the substantial life of a belt is prolonged and the rapid repairing work is carried out when the abnormality is generated at the inside of the developing device and the device cost is suppressed, as well because the constitution is simple.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to thermal development machines, and more particularly, to thermal development to release a diffusible dye and thermally transfer the dye to an image-receiving element. This invention relates to a diffusion transfer type thermal developing machine that separates the images to obtain color images.

(Background of the Invention) In the developing section of a diffusion type thermal development device, a color image is obtained by separating a silver image and a dye by releasing a diffusible dye by heat development and thermally transferring the second dye to an image receiving element. A plurality of pressure rollers and heating rollers are arranged in pairs inside a casing covered with a heat insulating material, and an endless belt is stretched over the pressure rollers and heating rollers.

The last roller of these rollers is a drive roller, and the pair of upper and lower endless belts rotates when this drive roller is driven by a motor. The heating roller has a built-in heater, and a temperature sensor is installed on the belt downstream of the heater. By monitoring the belt temperature, the heater is turned on and off to control the belt temperature to the developing temperature. Here, the development temperature refers to the average temperature measured at the same point on the endless belt. The image-exposed photothermographic sheet is overlapped with an image-receiving sheet and then fed between a pair of upper and lower endless belts.

Each ingredient is currently 1g! The sheets are sandwiched between a pair of endless belts that are heated to a temperature of about 150°C, and are conveyed while being overlapped for a predetermined period of time. The resulting image is then transferred to an image-receiving sheet.

After the development process, the power is turned off. However, if the rotation of the pair of endless belts is stopped immediately after the power is turned off, the part of the belt sandwiched between the pressure roller and the heating roller will be locally heated and pressurized, causing damage to the belt or extreme To avoid this, measure the amount of time it takes for the roller temperature to drop below a specified value, and continue rotating the belt until that time is reached to avoid damage to the equipment. I have to.

(Problem to be Solved by the Invention) When the inventor of the present application conducted a study on the above-mentioned heat developing machine, the following problems became clear.

In other words, it is necessary to rotate the belt until the temperature of the roller reaches a predetermined value, but since the roller and belt pair are insulated, the temperature does not drop easily, and the rotation of the belt takes a long time (for example, several times). This wasteful rotation actually shortens the belt's lifespan.

Also, if some abnormality occurs, the operation of the heat developing machine may be stopped urgently, and even in this case, the temperature of the roller and belt will not drop to a low level, so there is a risk of damage to the belt or shortening of its life. There is.

Furthermore, if there is an abnormality inside the heat developing machine, repair work cannot be carried out until the internal temperature drops, and there is a problem in that it is impossible to take prompt measures against the failure.

Furthermore, in order to control the rotation of the belt for a given period of time as described above, it is necessary to use an expensive control device such as a programmable controller with a built-in timer, which contributes to the high cost of the device. .

The present invention has been made in view of the above-mentioned considerations, and its purpose is to solve the above-mentioned problems and achieve improved reliability, higher functionality, and lower cost of the device.

(Means for Solving the Problems) A typical overview of the present invention is as follows.

That is, a shutter for opening and closing a part of the housing,
A fan is provided for blowing air through an opening formed by opening the shutter.

(Function) When the device is to be stopped, the shutter is opened to open a portion of the housing, and air is blown through this opening to efficiently cool the belt and the like. This opening is provided at a location where it is often exposed to the wind or the belt, for example, at the top of the housing. Moreover, it is desirable to provide an exhaust port on the side surface of the housing, in addition to this ventilation opening, to effectively flow wind and enhance the cooling effect.

(Example) Next, an example of the present invention will be described with reference to the drawings.

Color development photosensitive sheets characterized in that development is carried out by heat treatment include those containing a binder, an organic silver salt, a photosensitive silver halide, a developer 1 dye-providing substance, etc. in the photosensitive layer or its adjacent layer. It is.

Examples of organic silver salts include galloic acid silver salt, oxalic acid silver salt,
Silver hehenate, silver stearate, silver palmitate,
Imidazole silver salt, benzotriazole silver salt, 4-sulfohenecitriazole silver salt, thione silver salt, saccharic acid silver salt, 5-nitrotriazole silver salt, 4-hydroquine benzotriazole silver salt, thione silver salt, 5-chlorsalicyl There are aldoxime silver salts, etc.

Examples of the photosensitive silver halide include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver iodobromide, and silver chlorobromoiodide. The preferred grain size of the photosensitive silver halide is from about 15 microns to about 0,001 microns, more preferably from about 0.5 microns to about 0,000 microns in diameter.
．． 05 microns.

Examples of the developer include phenols, sulfamide phenols, polyhydroxyhenzenes, naphthols, hydroxybinaphthyls, methylene bisnaphthols, methylene bisphenols, ascorbic acids, 3-pyrazolidones, pyrazolines, pyrazolones, and amino acids. Phenols, p-phenylene diamines, sulfamide anilines, sulfamic acids, and hydrazones can be used alone or in combination with the above-mentioned developers.

These developers may be used in the form of precursors.

As the dye-providing substance, there may be mentioned a compound which releases a H-color or diffusible dye upon thermal development. Regarding such compounds, JP-A-59-1
It is described in Publication No. 24332.

This compound is a thermally non-diffusible dye-providing substance that can release a sublimable dye or a sublimable dye precursor upon thermal development, and the sublimation temperature of the sublimable dye is said to be 80°C to 250°C.

As the binder for the photosensitive layer, either hydrophilic or hydrophobic polymers can be used.
Or you can use them in combination.

The image receiving layer of the image receiving sheet includes a saturated polyester layer, and examples of the saturated polyester include polyethylene terephthalate (PET, melting point, a260°C), polybutylene terephthalate (PBT, melting point 224°C), poly 1,4-cyclohexane. /methylene terephthalate (
PCHT (melting point: 290°C), etc. Since the heat-developable photosensitive material used in the present invention is heated to 80 to 200[deg.] C. during development, the melting point of the saturated polyester used in the image-receiving layer must be higher than the above-mentioned development temperature. Note that the above-mentioned saturated polyester is to be distinguished from unsaturated polyester, which contains a double bond in its molecular structure that can be crosslinked with a vinyl compound to form a three-dimensional network structure.

The support used for the above-mentioned image-receiving layer and photosensitive layer may be any support as long as it can withstand the temperature during heat development treatment, such as paper, polyamide film, acetyl cellulose film, cellulose ester film, polyvinyl Resin materials such as acetal film, polystyrene film, polycarbonate film, and polyethylene terephthalate film can be used.

(2) How to obtain a color image using a diffusion transfer type photosensitive material In order to obtain a color image using a diffusion transfer type photosensitive material, a photosensitive layer coated with a photosensitive silver salt hole is applied to the surface of the support. An image-receiving sheet is required, in which a photosensitive sheet is coated on a support, and a layer (referred to as an image-receiving layer) that receives the dye produced by developing the photosensitive sheet is coated on a support.

First, the photosensitive sheet is exposed in one image, and then the imagewise exposed photosensitive sheet and the image-receiving sheet are superimposed so that the photosensitive layer and the image-receiving layer are in contact with each other. While these two sheets are still overlapped, heat them at high temperature (120℃ to 160℃) for 30 minutes.
Add for ~120 seconds. The high temperature causes the photosensitive sheet to become visible (imagewise diffusive dyes are formed). Further, the generated diffusible dye is transferred to the image-receiving layer. In order to improve the adhesion between the photosensitive layer and the image-receiving layer and improve the transfer rate of the diffusible dye from the photosensitive layer to the image-receiving layer, pressure may be applied in addition to high temperature. The purpose of this pressure is to maintain close contact between the light layer and the image-receiving layer, and as long as the photosensitive layer or the image-receiving layer itself has adhesion, it does not need to be continuous and may be applied intermittently.

After developing and transferring for a predetermined period of time, the photosensitive sheet and image receiving sheet are peeled off. The separation of the photosensitive layer and the image-receiving layer corresponds to fixing in general silver salt sensitive materials. Further, the final product is an image-receiving sheet onto which the diffusible dye is transferred.

(3) Structure and operation of the thermal development section 1 (Fig. 1) The thermal development section 19, which performs development and transfer, is installed inside a housing 8 covered with a heat insulating member 10, as shown in Fig. 1. a pair of endless belts 15, a heating roller 12 which is a heat source provided inside these endless belts 15, and this heating roller 12.
It is equipped with a pressure roller 3 which is opposed to each other with a belt interposed therebetween. The endless belt pair is rotated by driving the final drive roller 13 with a motor (represented by M (reference number 22) in FIG. 2). stacked photosensitive sheets 1
The image receiving sheet 2 is conveyed while being sandwiched between a pair of endless belts, and is subjected to development and transfer.

The material for the endless belt 15 is preferably silicone rubber with a core made of carbon fiber, or fluororubber with a core type. When a silicone rubber belt is used, it is preferable to polish the surface of the silicone rubber belt to make it flat so that unevenness does not affect the obtained image. Also, to prevent static electricity, it is recommended that the rubber belt be made of a conductive material. In addition, when using a silicone rubber belt with a carbon fiber core, the axial shift when the belt is rotated changes depending on the weave of the core. It is recommended to use a silicone rubber belt. In addition, since belts, such as those with a diameter of 100 mm, always come to one side in the axial direction, it is necessary to prevent the belt from shifting by providing a guide to hold the edge of the belt or by providing a liner on the belt. is necessary.

The heating roller 12 has a pipe shape, and a heat source 11 such as a halogen lamp or a nichrome wire is provided inside the heating roller 12. Since halogen lamps and nichrome wires emit light as well as heat, it is necessary to provide caps at both ends of the heating roller to prevent light leakage, so that the heating roller is not exposed to the light from the phosphorescent sheet or heat source. The material of this cap needs to be difficult to transmit light and have sufficient heat resistance. Also, depending on the wiring of the heat source, it may be necessary to have insulation properties. Specifically, silicone rubber, fluororubber, phenol resin, polycarbonate, etc. are desirable.

The heating roller 12 is supported by the inner frame via a hair link, or a heat insulating member (not shown) is installed between the heating roller and the hair ring for heat insulation. Without this heat insulating member, the heat of the heating roller 12 would escape through the bearings, causing problems such as uneven heat distribution in the axial direction of the heating roller and increased power consumption. . It is effective to install this heat insulating part on the pressure roller 3 as well.

Furthermore, heaters may be installed in both the upper and lower stages of the heating roller 12, or they may be thinned out appropriately. The material of the roller is aluminum such as A5056, 5U.
Iron-based metals such as S304 and STKM are suitable. When using iron-based materials, anti-rust treatment such as parkerized zinc is required.

The heating roller 12 may be heated from the outside using a surface heater or the like. Since it is preferable that the heating roller 12 has a uniform temperature distribution in the axial direction of the roller, it is preferable that the distribution density of the nichrome wire inside the Haloken lamp is dense at both ends. In addition, the heating roller 12
It is a good idea to have a temperature fuse in contact with the heater, so that if the temperature of the heating roller becomes abnormally high, the heater can be turned off. This upper limit value is set to a temperature at which the infinite hell N,5 melts or a temperature at which the life span is extremely reduced.

A temperature sensor 1B for monitoring the temperature of the belt is installed on the belt downstream of each heating roller 2. The detection output of this temperature sensor 16 is manually input to the temperature control section 14, and the temperature control section 14 turns on/off the heater 11 based on the input temperature signal (temperature on the belt), and changes the temperature of the belt to the developing temperature. It works to keep it.

As the temperature sensor 16, a thermoelectric lamp, a platinum side temperature resistance element,
The most suitable one is used depending on the situation, such as a thermistor or an IC temperature sensor.

The casing 8 of the heat developing machine must also have a function of preventing light from entering the heat developing machine and preventing heat generated by the heat developing machine from being released to the outside, that is, a heat insulating function. In order to improve the heat insulating function, the casing may have a structure in which heat insulating material 10 made of non-woven fabric is attached to the inside and outside of the metal plate.

The most suitable material for the non-woven fabric is a non-woven fabric made from aramid fibers, as it must have a low thermal conductivity and be non-flammable or non-flammable.

More preferably, a heat-reflecting material such as aluminum foil is provided on the surface of the inner heat insulating material to prevent heat from reaching the non-woven fabric that is the insulating material.

When finishing development, if the developing section stops too soon, the belt will be locally heated and pressurized, causing damage or shortening its lifespan, so the heater 11 is turned off and the belt temperature drops below a predetermined temperature. The belt rotates until the end of the rotation, and then it is stopped.

(4) Cooling mechanism of the heat developing machine (Fig. 1) In order to quickly lower the temperature inside the heat developing machine and prevent unnecessary rotation of the belt for a long time, the embodiment shown in Fig. 1 uses an air blower. the opening 4, the cooling fan 5, the exhaust port 9, the shutter 7a for opening and closing the ventilation port 4 and the exhaust port 9,
7b is provided.

The air outlet 4 is provided at a location suitable for cooling the belt 15 inside the housing 8, that is, at a location where the belt is often exposed to wind, for example, at the top of the housing. Further, the exhaust port 9 is installed in a place where wind can easily escape, for example, at the top of the housing or on the side of the housing.

It should be noted that if sufficient exhaust air can be obtained from the sheet entry portion and the sheet ejection portion, the exhaust port 9 may not be installed.

Shutter 7a provided above the air outlet 4 and exhaust port 9
, 7b are covered with a heat insulating material and are closed for heat insulation during development. When the development is completed and cooling is performed, the shutter is opened and the cooling fan 5 rotates to blow air into the inside of the developing machine from the air outlet 4. In addition, hot air escapes to the outside from the exhaust port 9. When cooling is completed, the shutters 7a and 7b are closed again to prevent dirt from entering the thermal developing machine.

Such operation of the shutters 7a, 7b is realized, for example, by a control circuit as shown in FIG.

This circuit includes a power supply 27, a motor 22 that drives the drive roller 13, power switches 21a and 21b, and a first
It also has a second temperature switch 24, 23, a shack-driving solenoid 25, and a cooling fan driving means (motor) 26.

A power source 27 is a charging source for the entire thermal development image forming apparatus.

The power switch 21a is provided for switching the power in the thermal development machine (the power switch 21a is not limited thereto, and may be used as a power switch for the entire thermal development image forming apparatus). Further, the power switch 21b is turned on/off in conjunction with the power switch 21a.

The temperature switches 24 and 23 are temperature-sensitive switches that turn on and off depending on the temperature. This temperature switch 24.23
turns on when the temperature at the detected location exceeds the set temperature T5, and turns off when the temperature falls below Ts. Set temperature T
, is set at a temperature that is above room temperature and below high temperatures that would cause damage to the belt or extremely shortened service life, and that it would not be dangerous for workers to touch it when repairing a malfunction. . Specifically, the temperature is set in a range of about 35°C to about 100°C.

Further, the temperature switches 23, 24 are installed on any roller, on the \rut, on the roller support housing, or the like.

In the state before turning on the power switches 21a and 21b,
The first and second temperature switches 24 and 23 are all off, and the drive roller 13 is not rotating. Next, when the power switch 21a (21b) is turned on, the motor 22 of the drive roller 13 rotates, the endless belt pair 15 rotates, the internal circuit of the temperature control section 14 is turned on, and warm-up is started. Thereafter, development processing is started. During warm-up, whether the first temperature switch 24 and the second temperature switch 23 are turned on near the set temperature, or whether the second temperature switch 23 is turned on has no bearing on the operation;
Even if the temperature switch 24 is turned on, the solenoid 25 and fan drive means 26 remain off because the power switch 21 is on the A side (on).

When the developing process is completed and the power switch is turned off to the terminal A side, the heater 11 is also turned off. At this time, since the temperature inside the heat developing machine is high, the second temperature switch 23 remains on, and the drive roller motor 22 continues to rotate. As a result, the endless belt 15 continues to rotate.

In addition, the first temperature switch 24 is also turned on due to the high temperature, and by switching the power switch 21 to the terminal A side, a closed loop including the solenoid 25 and the fan 5 is formed, and the solenoid 25 is turned off, and the shutter is turned off. 7 is opened, the cooling fan driving means 26 is operated, the fan 5 is rotated, and the belt 15 is cooled by blowing air.

As a result of this cooling, if the temperature inside the heat developing machine or the temperature detected by the lower temperature switch falls below the set temperature TS,
Both the first and second temperature switches 2423 are turned off. Then, the drive roller motor 22 stops, and the belt 15 stops rotating.

Further, the solenoid 25 is turned off, the shutter 7 is automatically closed, and the cooling fan 5 is also stopped.

The control circuit may have a configuration as shown in FIG. Figure 3 is the second
This shows a modification of the circuit shown in the figure, and the difference from the circuit shown in Fig. 2 is that the first and second microswitches 30 and 31 are installed in the positions shown in Fig. 4, and the opening and closing of the Nyattani is The second method is to use a motor. The operation will be explained below.

When the power is off, the shutter 7 is open and the first
The microswitch 30 is pressed and turned off. The first and second microswitches 30 and 31 are always on and are disconnected when pressed.

When the power is turned off, the drive roller motor 22 is stopped, the temperature switches 23, 24 are turned off, and the fan drive means 26 is also stopped. Although the first microswitch 30 is on, the power switch 21a is also off, so the shutter 7 does not operate.

Next, when the power is turned on, the drive roller motor 2
2 begins to rotate and the belt rotates. During warm-up, the first and second temperature switches 2423 are turned on.

When the developing process is completed and the power switches 21a and 21b are turned off, the shutter rotates in the CW force direction, presses the first microswitch 30, and stops. This causes the cooling fan 5 to rotate. When the temperature detected by the temperature switches 24 and 23 becomes lower than the set temperature, these switches are turned off, the drive roller motor 22 stops, the belt stops rotating, and the cooling fan 5 also stops.

In the above embodiments, the power switch was turned off manually, the photosensitive sheet or image receiving sheet jammed in the heat developing section, the belt meandered and stopped rotating, or the temperature control section 14 malfunctioned. When an abnormality such as a failure occurs, it is preferable to provide an abnormality detection section 28 as shown in FIG. 5 to automatically turn off the power switch.

(5) Specific structure of the shutter FIG. 6 is a view of the shutter 7 seen from above the air outlet 4.

The shutter 7 slides in a sliding direction (indicated by an arrow in the figure) to open and close by turning the solenoid 25 on and off. The shutter 7 is a shutter position return means 35a
, 35b are used to return the shutter to its original position when the solenoid 25 is turned off.

The shutter shown in FIG. 7 is an example of a shutter used when the amount of tension of the solenoids 25a and 25b cannot be increased to a large extent. The operation is the same as that shown in FIG. 6, but the arm 36a,
36b has the advantage of reducing the amount of operation of the solenoids 25a and 25b. Arms 38a, 36
b has regulation holes 38a and 38b, and slides laterally within this range.

The shutters in FIGS. 6 and 7 were opened and closed by parallel movement, whereas the shutters in FIGS. 8 and 9 were opened and closed by rotational movement.

That is, in the case of FIG. 8, the rotary solenoid 40 rotates about the fulcrum 41 to open and close. In the case of FIG. 9, it rotates left and right about fulcrums 44a and 44b by the action of rotary solenoids 43a and 43b.

FIGS. 1O and 11 are sectional views of other examples of the shutter. The shutter in Fig. 10 is one that opens on one side.
The shutter in Figure 1 is a double-opening type.

12 and 13 are cross-sectional views showing still another embodiment of the shutter, with FIG. 12 showing the shutter in a closed state and FIG. 13 showing it in an open state.

In this embodiment, a plurality of small shutters are connected by a connecting arm 63, and are opened and closed simultaneously by driving a solenoid 60. This allows the shutter to be made smaller.

14 and 15 are sectional views showing still another embodiment of the shutter, with FIG. 14 showing the shutter in a closed state and FIG. 15 showing the shutter in an open state.

The configuration of this embodiment is similar to that of FIGS. 12 and 13, but is unique in that a rack 70 and a gear 73 are used to open and close the shutter.

(Effects of the Invention) As explained above, the present invention allows a part of the heat developing machine to be opened and closed by a shutter, and allows the development of the image processing machine. J! By opening the shutter and blowing air after the end of the process, the following effects can be obtained by strongly cooling the belt and the like.

(1) After the power is turned off, the temperature inside the developing machine drops quickly, shortening the rotation time of the belt. This increases the practical life of the belt. Furthermore, repair work can be carried out quickly when an abnormality occurs inside the developing machine.

(2) Operation control can be realized by a control circuit with a simple configuration using a temperature-sensitive switch, and since a programmable controller with a built-in timer is not required, the configuration can be done in-house, and the cost of the device can be reduced.

(3) As a result, the performance of the thermal development image forming apparatus is improved, and an easy-to-use apparatus can be provided.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of an embodiment of the heat developing machine of the present invention, Fig. 2 is a diagram showing an example of a control circuit used in the embodiment of Fig. 1, and Fig. 3 is a diagram showing an example of the control circuit used in the embodiment of Fig. 1. 4 is a diagram showing the arrangement of the first and second microswitches in the control circuit of FIG. 3, FIG. 5 is a diagram showing still another example of the control circuit, and FIG. 6 is a diagram showing another example of the control circuit. is a diagram showing the first example of the shutter used in the embodiment of FIG. 1, FIG. 7 is a diagram showing the 20th pj of the shutter, FIG. 8 is a diagram showing the third example of the shutter, and FIG. is a diagram showing a fourth example of the shutter, FIG. 10 is a diagram showing a fifth example of the shutter, FIG. 11 is a diagram showing a 6th σ example of the shutter,
2 and 13 are diagrams showing a seventh example of the shutter, with FIG. 12 showing the closed state, FIG. 13 showing the open state, and FIGS. 14 and 15 showing the seventh example of the shutter. FIG. 14 shows the closed state and FIG. 15 shows the opened state. 1... Photosensitive sheet 3... Pressure roller 5... Cooling fan 7 (7a, 7b)... Shutter 8... Housing lO... Heat insulating member 12... Heating roller 14 Temperature control section 16・Temperature sensor 2・Receiver 1・Address 4・Blower outlet Exhaust outlet Heater drive roller Endless belt

Claims (4)

[Claims] (1) A photosensitive sheet on which a latent image has been formed by image exposure is superimposed on an image-receiving sheet, and the sheet is conveyed while being sandwiched between a pair of endless belts installed in a heat developing machine to heat and press the sheet, and the latent image is developed and the image is received. A heat developing machine that transfers an image onto a sheet, the heat developing machine being provided with a shutter that opens and closes a part of a casing, and a blowing means, and when the shutter opens, an opening is formed in a part of the casing. In the heat developing machine with a cooling mechanism, the blowing means blows air into the heat developing machine from the opening. (2) The heat developing machine with a cooling mechanism according to claim 1, wherein the pair of endless belts continues to rotate until the temperature at a predetermined location within the heat developing machine falls below a predetermined temperature due to air blowing from the blowing means. (3) The housing of the heat developing machine is provided with another shutter in addition to the shutter, and the other shutter is
3. The heat developing machine with cooler grooves according to claim 2, wherein the shutter opens in conjunction with the other shutter, and the opening formed by opening the other shutter is used as an exhaust port. (4) a shutter that opens and closes a part of the housing of the heat developing machine;
An opening/closing means for opening and closing the shutter, an air blowing means, a driving means for driving the air blowing means, a motor for rotating a pair of endless belts, and a sense that turns on/off depending on the temperature of a predetermined location within the heat developing machine. It has a temperature switch, a temperature control unit that controls the developing temperature of the thermal developing machine, and a power switch that switches between operation and non-operation of the temperature control unit, and when the power switch is turned off and the temperature control unit is inoperable. When the heating in the heat developing machine stops, the opening/closing means and the driving means are turned on, the shutter is opened, and the air blowing means starts blowing air, and the motor continues to rotate, causing the pair of endless belts to rotate. During the period in which the detected temperature of the temperature-sensitive switch is higher than a predetermined set temperature, the temperature-sensitive switch is maintained in the on state, and the shutter is kept open, the air is blown by the air blowing means, and the endless belt pair is rotated. When the operation continues and the temperature detected by the temperature-sensitive switch becomes equal to or lower than the predetermined set temperature, the temperature-sensitive switch is turned off, the shutter is closed, and the air blowing by the air blowing means and the rotation of the endless belt pair are stopped. 3. The heat developing machine with a cooling mechanism according to claim 2.