JPH0741552U - Heating device - Google Patents

Abstract

(57) [Summary] [Purpose] A flat surface suitable for developing heat-developable diazo thermal paper, because the heat capacity of the backup roll is small and the warm-up time is short, and the nip property for pressing the sheet to be processed into contact with the flat heater is high. Provided is a heater type heating device. [Structure] A sheet to be processed supplied between a flat heater 4 and a backup roll 3 rotating in pressure contact with the flat heater 4 is driven by a frictional force of the backup roll 3,
In a heating device in which heat treatment is performed while sliding on a flat heater 4, the backup roll 3 has a structure in which an intermediate layer 33 made of foam sponge is interposed between a solid layer 32 of a skin made of silicon rubber and a core pipe 31. To

Description

[Detailed description of the device]

The present invention relates to an apparatus for performing heat treatment such as heat development and heat fixing on a sheet to be treated such as paper and film, and further, heating of a flat heater type suitable for development of heat development type diazo thermal paper. It relates to the device.

[0002]

[Prior art]

 Conventionally, in order to perform heat treatment such as heat development and heat fixing on the sheet to be treated, a heating device of a heat roll type has been mainly adopted. The heating device of the heat roll type has a pair of rolls, a heat roll for heating the sheet to be treated and a backup roll for pressing the sheet to be treated against the heat roll. Then, the sheet to be treated is supplied between both rotating rolls and is heat-treated while moving in a pressure-bonded state to the heat roll. This backup roll is made of a material with a high elasticity, such as silicon rubber, so that the sheet to be processed can be pressed securely, and it is also called a soft roll.On the other hand, the heat roll does not conduct heat. In order to improve the quality, many aluminum pipes are coated with Teflon on the surface, which is also called a hard roll. Inside, a tubular heater lamp such as a halogen bulb is arranged along the axial direction.

When the required heating time is relatively short, such as heat fixing of a PPC or a laser printer, a predetermined heating time can be secured only by heating between a pair of rolls. When a heat treatment that requires a relatively long heating time is performed as in the case of developing a heat-developable diazo thermal paper, it is necessary to slow down the rotation speed of the roll, which causes a problem that the development time becomes long. In order to solve this problem, multiple backup rolls are placed around the heat roll, and a guide member is provided between the backup rolls, which is slightly separated from the peripheral surface of the heat roll. The heating time is extended by pressing it so that it wraps around.

In such a hot roll method, since it is processed at a relatively low temperature of about 120 to 130 ° C. and the heating time is long, it is possible to obtain a uniform and good copied image. However, since it heats a heat roll with a large heat capacity, it has a problem of long warm-up time and large power consumption. In order to meet the recent demand for high-speed processing, it is necessary to increase the size of heat rolls, backup rolls, etc., resulting in higher weight and higher power consumption.

Therefore, recently, a heating device using a flat heater has been attracting attention. The flat heater type heating device consists of, for example, a flat heater in which a heating resistor is screen-printed on an alumina substrate and a backup roll that rotates in pressure contact with this flat heater. The processed sheet is driven by the frictional force of the backup roll and is heat-treated while sliding on the flat heater.

Since the planar heater type heating device can reduce the heat capacity of the entire heating portion, the warm-up time can be shortened, and the structure can be simplified and the size and weight can be reduced. Further, since the sheet to be treated can be intensively and efficiently heated, it has advantages that it can be processed at high speed and consumes less power.

[0007]

[Problems to be solved by the device]

 However, when performing a heat treatment that requires a relatively long heating time, such as in the case of developing a heat-developable diazo thermal paper, a good quality copy image can be obtained only by heating for a short time with a flat heater. Instead, it was found that it is necessary to heat the sheet to be processed from the back side by the heat of the backup roll preheated by the flat heater. Here, the backup roll is a long roll having an outer diameter of 40 mmφ and a length of about 700 mm, but it is required to have a large friction force for driving the sheet to be treated and heat resistance capable of withstanding the heat of the flat heater. Further, since the sheet to be processed is pressed against the flat heater, a large rigidity is required.

For this reason, if a back-up roll for developing the heat-developable diazo thermal paper is used, for example, a metal core pipe whose outer circumference is covered with silicon rubber having a thickness of about 6 mm is used, the above-mentioned requirement is met. Can be satisfied. However, the back-up roll having such a structure has a large heat capacity, and therefore has a problem that the warm-up time is long. If the silicone rubber is thinned to have a smaller diameter, the heat capacity will be reduced, but the rigidity will be reduced and the nip property for pressing the sheet to be treated against the flat heater will be reduced, so there is a limit to the reduction of the diameter of the backup roll.

Therefore, the present invention has a backup roll having a small heat capacity and a short warm-up time, and has a high nip property for pressing a sheet to be processed into contact with a flat heater, which is suitable for development of heat-developable diazo thermal paper. It is an object of the present invention to provide a heater type heating device.

[0010]

[Means for Solving the Problems]

 In order to achieve such an object, according to the present invention, a sheet to be processed supplied between a flat heater and a backup roll which is pressed against the flat heater and rotates is driven by the frictional force of the back up roll to slide on the flat heater. In a heating device that performs heat treatment while moving, a backup roll has a structure in which an intermediate layer made of foam sponge is interposed between a solid layer of a skin made of silicon rubber and a core pipe.

[0011]

[Action]

 That is, since the intermediate layer made of foam sponge having low thermal conductivity is interposed between the solid layer of the silicone rubber skin and the core pipe, the solid layer of the silicone rubber skin becomes thin and the heat capacity decreases. The warm-up time can be shortened significantly. Further, since the foamed sponge has a large flexibility, the flexibility as a backup roll also becomes large, and the sheet to be processed can be reliably pressed against the flat heater with a small pressing force, improving the nip property and the core. The pipe is not required to have a large rigidity and can be lightweight.

[0012]

【Example】

 The present invention will be described in detail below based on the embodiments shown in the drawings. Fig. 1 shows a heat-developing diazo copying machine. In Fig. 1, a casing 1 injection-molded with synthetic resin has an inverted W-shape in which the upper part has two peaks 11 and 12 arranged side by side. The exposure device A is housed in the front mountain 11, and the heat developing device B, which is the heating device of the present invention, is housed in the rear mountain 12. The front slope 11a of the front mountain 11 is provided with an exposure inlet 13 for supplying the diazo photosensitive paper coated with the diazo sensitive material and the original image to the exposure apparatus A in a superimposed manner, and an exposure outlet 14 for discharging after the exposure. In addition, a developing inlet 15 for separating the exposed diazo photosensitive paper from the original drawing and supplying it to the heat developing apparatus B is provided at the lower end of the front slope 12a of the rear mountain 12, and the diazo photosensitive paper which has completed the thermal development. The developing outlet 16 through which the paper is discharged is provided on the rear slope 12b of the rear mountain 12. A bottom plate 17 is attached to the lower surface of the casing 1 and accommodates drive motors (not shown) and electrical components constituting various control units, etc., inside the bottom plate 17.

A cylinder 21 made of transparent Pyrex glass is rotatably arranged in the exposure apparatus A, and a tube type that has a rating of 100 W and a wavelength of 420 nm is strongly emitted inside the cylinder 21. One fluorescent lamp 22 is arranged. An endless backup belt 25 is wound around the four idle rolls 23, one drive roll 24, and the cylinder 21, and the backup belt 25 holds the cylinder 21. When the drive roll 24 is driven and rotated by a motor (not shown), the cylinder 21 rotates in the direction of the arrow together with the backup belt 25.

Next, as a heating unit of the heat developing device B, a heating device including a flat heater 4 and a backup roll 3 which is pressed against the flat heater 4 and rotates is arranged. A carry-in guide 5 and a discharge guide 6 are arranged around the backup roll 3, and a discharge roll 71 and a discharge plate 72 are arranged on the downstream side of the discharge guide 6. Then, the backup roll 3 and the discharge roll 71 rotate in the direction of the arrow by a motor (not shown). Further, the temperature sensor 8 contacts the backup roll 3 so that the temperature of the backup roll 3 can be detected.

The structure of the flat heater 4 will be described with reference to FIG. 2. A heating resistor 42 having a width of 3 mm is screen-printed on the surface of an alumina substrate 41 having a width of 10 mm, and the surface is an overcoat layer 43. Is covered. The alumina substrate 41 is held by a heat resistant resin material 44 for preventing heat of the heat generating resistor 42 from escaping to other than the pressure contact portion, and the heat resistant resin material 44 has rigidity to withstand the pressure contact force of the backup roll 3 and the like. It is fixed to the support frame 45. Although the rated power of the heating resistor 42 is 1200 W, a thermistor (not shown) detects the temperature of the flat heater 4 and controls it to a predetermined temperature by phase control.

Next, the backup roll 3 is a long roll having an outer diameter of 40 mmφ and a length of 700 mm, and a foam sponge having a thickness of 8.5 mm is formed on the outer circumference of a stainless steel core pipe 31. The intermediate layer 33 made of silicon is disposed, and the intermediate layer 33 is covered with a solid layer 32 having a thickness of 2 mm and made of silicone rubber. That is, the backup roll 3 has a double structure of a solid layer 32 having a large frictional force and a high heat resistance, a thin and small heat capacity, and an intermediate layer 33 having a low thermal conductivity and a large flexibility. As a whole, the roll has a small heat capacity and high flexibility.

Then, the power switch (not shown) is turned on to energize the heating resistor 42 and rotate the backup roll 3, but the warm-up time elapses and the flat heater 4 heats the backup roll 3. When the roll 3 has risen to a predetermined temperature and can be duplicated, a copy OK message is displayed. Here, since the heat capacity of the solid layer 32 of the skin of the backup roll 3 is small, the warm-up time is greatly shortened compared to the conventional case. Incidentally, in this embodiment, the backup roll 3 was heated to 180 ° C. at which copying is possible in 150 seconds, but the outer diameter is the same 40 mmφ, and the outer periphery of the core pipe is covered with silicon rubber having a thickness of 6 mm. It took 290 seconds to raise the temperature to 180 ° C with the conventional backup roll.

After that, when the original image and the diazo photosensitive paper coated with the diazo photosensitive material are overlapped and inserted from the exposure inlet 13, the backup belt 25 presses the cylinder 21 to move it, and in the process, it passes through the cylinder 21. The light emitted from the fluorescent lamp 22 passes through the original image, exposes the photosensitive paper, and is discharged from the exposure outlet 14.

Next, when the diazo photosensitive paper which is the sheet to be processed is separated from the original drawing and supplied from the developing inlet 15, it is guided to the carry-in guide 5 and supplied between the backup roll 3 and the flat heater 4. Then, the diazo photosensitive paper is driven by the frictional force of the backup roll 3, slides in a state of being pressed against the flat heater 4, and is heated by the flat heater 4 and the preheated backup roll 3 to be thermally developed. . The diazo photosensitive paper that has been colored according to the original drawing is guided to the discharge guide 6, the rotating discharge roll 71 and the discharge plate 72, and is discharged from the developing outlet 16. Here, since the backup roll 3 has a large flexibility, the diazo photosensitive paper can be reliably pressed against the flat heater 4 with a small pressing force, and excellent nip property can be obtained.

[0020]

[Effect of device]

 As described above, in the flat heater type heating device of the present invention, the backup roll has a structure in which the solid layer of the skin made of silicone rubber and the intermediate layer made of foam sponge are interposed between the core pipe. As a result, the heat capacity of the backup roll is small, the warm-up time is short, and the nipping property of pressing the sheet to be processed into contact with the flat heater is high, making it a heating device suitable for developing heat-developable diazo thermal paper. be able to. (Note) Teflon is a registered trademark in the detailed description of the device.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of a heat development type diazo copying machine.

FIG. 2 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 1 Casing 21 Cylinder 22 Fluorescent Lamp 3 Backup Roll 31 Core Pipe 32 Solid Layer 33 Intermediate Layer 4 Flat Heater 5 Carrying Guide 6 Discharge Guide

Front page continuation (72) Inventor Shigeo Kijima 262 Kondo, Tatebayashi, Gunma Gunma Ushio Electric Co., Ltd. (72) Inventor Hiroyuki Kushida 262, Kondo, Tatebayashi Gunma Gunma Ushio Electric Co., Ltd. (72) Taro Hayashi, 262 Kondo, Tatebayashi, Gunma Prefecture Gunma Ushio Electric Co., Ltd. (72) Inventor, Hiroshi Shimizu 262, Kondo, Tatebayashi, Gunma Gunma Ushio Electric Co., Ltd. (72) Yasushi Yao Nishiazabu, Minato-ku, Tokyo 2 chome 26-30 Fuji Photograph Shin Film Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A sheet to be processed supplied between a flat heater and a backup roll rotating in pressure contact with the flat heater is driven by frictional force of the backup roll and is heat-treated while sliding on the flat heater. The heating device according to claim 1, wherein the backup roll has a solid layer of a skin made of silicone rubber and an intermediate layer made of foam sponge interposed between a core pipe.