JPH05273723A - Heat developing device - Google Patents

Abstract

PURPOSE:To uniformly heat a photosensitive member and to obtain a high- quality image by providing a guiding means constituted so that the photosensitive member is contacted and guided at a specified winding angle just before starting heating. CONSTITUTION:After the continuous sheet-like photosensitive member 8 fed from a cartridge in which the unexposed photosensitive member 8 is housed is exposed on an exposing table and a latent image is formed, it passes through a carrying roller and is heated and developed by a heat developing device provided with a guiding roller 44 being the guiding means. The guiding means 44 constituted so that the member 8 may be brought into contact and guided at the specified winding angle just before the member 8 starts to be heated is provided. Therefore, the high-quality image without the unevenness of density caused by the waviness of the member 8 just before a heating part which occurs because of the change of heat in the heating part is obtained with the simple constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat developing apparatus of an image forming apparatus for forming an image on a copying machine or a printer using a heat developing material.

[0002]

2. Description of the Related Art A wide variety of image forming methods and apparatuses are known, and a conventional example of an image forming apparatus using a heat developing material is, for example, a photosensitive transfer type heat developing material. No. 62-147461 can be mentioned. According to this publication, the exposure unit, the thermal development unit,
A main mechanism portion such as a pressure transfer portion is formed inside one constituent body, and image formation is performed by the following procedure.

First, a roll-shaped photosensitive transfer type heat-developable material is cut into a predetermined length and then imagewise exposed to form a latent image. Next, thermal development is performed with a heating roller. After that, the photosensitive member and the image receiving paper are superposed and pressure-transferred by the roller, and the photosensitive member is transferred to the photosensitive material discarding section by the separating device.
The image receiving paper is discharged to the tray via the fixing device.

During the thermal development, the photosensitive member was in contact with the heating roller without being wound around the guide member.

[0005]

However, the above-mentioned conventional technique has a problem that density unevenness often occurs on an output image.

The present inventor has discovered that the cause of the above-mentioned density unevenness is due to the instability of the contact start position of the photosensitive member to the heating portion of the heat developing device. That is, the photosensitive member often uses a resin film such as polyethylene terephthalate or paper as a base material, and is thermally sized by being heated. As a result, the width of the photosensitive member is different between the portion in contact with the heating portion of the heat developing device and the portion not heated before the heating portion. Then, the width of the photosensitive member abruptly changes at the contact start position to the heating unit of the thermal developing device which is the boundary, and as a result, the photosensitive member in front of the heating unit floating in the air undulates. When the corrugated photosensitive member comes into contact with a heating part such as a cylindrical shape, the contact start position is different between the crests and troughs of the wave, which causes a difference in heating time and unevenness in heat development. Caused uneven density. Further, in a remarkable case, the corrugation of the photosensitive member may enter into the heating portion and float at all from the heating portion, resulting in a portion which is not subjected to thermal development, resulting in remarkable deterioration of image quality.

The present invention has been made in view of the above circumstances and solves the above problems. An object of the present invention is to perform thermal development of an image forming apparatus capable of obtaining a high quality image by uniformly heating a photosensitive member. To provide a device.

[0008]

The heat developing apparatus of the present invention comprises:
It is characterized in that the photosensitive member has a guide means configured to be contact-guided with a predetermined wrapping angle immediately before the start of heating.

[0009]

EXAMPLES The heat developing apparatus of the present invention and the image forming apparatus using the same will be described in detail below with reference to Examples.

FIG. 1 is a front sectional view of a copying machine using a heat developing apparatus according to an embodiment of the present invention. First, the operation of the copying machine will be described.

A document 2 is placed on a document table 1 movably provided in the direction of arrow A in the figure, and light rays emitted from a red lamp 3, a green lamp 4 and a blue lamp 5 which are light sources are emitted from the document 2. And the reflected light from the original 2 is imaged on the photosensitive member 8 that moves on the exposure table 7 through the lens 6 to form a so-called scan exposure system.

A continuous sheet-shaped photosensitive member 8 delivered from a cartridge 20 containing an unexposed photosensitive member 8.
After being exposed on the exposure table 7 to form a latent image, it passes through the conveying roller 9 and then the guide roller 4 which is the guide means of the present invention.
4 is heat-developed by a heat-developing device 40. On the other hand, the cut sheet-shaped transfer member 1 housed in the paper feed tray 10.
The sheet 1 is sent out by the sheet feeding device 12, superposed on the photosensitive member 8 in synchronism with the image area formed on the photosensitive member 8, and transferred under pressure by a roller pressure type pressure transfer device 60. The pressure unit of the pressure transfer device 60 is composed of three rollers, an upper roller 61, a middle roller 62, and a lower roller 63, and pressure transfer is performed between the upper roller 61 and the middle roller 62.

After this, the transfer member 11 is separated from the photosensitive member 8 by the separating roller 64 and is discharged to the paper discharge tray 14 through the conveying roller 13. The photosensitive member 8 is pinched to promote the conveyance and separation of the photosensitive member 8. It is wound around the winding shaft 21 via the roller 65.

Reference numeral 15 is a manual paper feed port, and 16 is a gas filter for removing gas generated in the machine.

Next, an embodiment of the heat developing apparatus of the present invention will be described in detail.

FIG. 2 is a thermal developing device 4 of the image forming apparatus of FIG.
It is the perspective view which showed 0. The photosensitive member 8 is wound around the guide roller 44 by a predetermined amount so that the side coated with microcapsules is in contact, and the heating cylinder 4 having a heating peripheral surface so that the side not coated with microcapsules is in contact.
Each of them is wound by a predetermined amount, and while being conveyed while being given a tension, it is contact-heated immediately after passing through the guide roller 44. Both ends of the heating cylinder 41 are rotatably supported by bearings 42 attached to a frame (not shown). Further, the heating cylinder 41 has a halogen lamp heater 43 inside the cylinder, and has a heating peripheral surface of about 12
The heating amount is appropriately controlled so as to be constant at a predetermined temperature between 0 ° C and 160 ° C. The guide roller 44 is rotatably attached to a frame (not shown).

FIG. 3 is a sectional view showing the positional relationship between the guide roller 44 and the heating cylinder 41. As shown in FIG. 3, the guide roller 44 and the heating cylinder 41 are separated from each other, and as shown in FIG. 3, the photosensitive member 8 floats in the air for a predetermined distance d immediately before heating. It has been confirmed that when the distance d is 50 mm or less, it is effective in reducing the occurrence of density unevenness due to waviness, and when it is 10 mm or less, it is significantly effective. Also,
The wrapping angle α of the photosensitive member 8 around the guide roller 44 may be approximately 5 degrees or more.

Next, a second embodiment of the heat developing apparatus of the present invention will be described.

FIG. 4 is a sectional view showing the positional relationship between the guide roller 44 and the heating cylinder 41 of the heat developing apparatus of this embodiment. As shown in FIG. 4, in this embodiment, the guide roller 44 is in pressure contact with the heating cylinder 41 via the photosensitive member 8. The guide roller 44 is a spring 4 fixed to a frame (not shown).
6 is rotatably supported by a bearing 45 which is biased in the direction indicated by arrow F in the figure. The other structure is similar to that of the first embodiment described above.

In this embodiment, since the photosensitive member 8 is not floating in the air immediately before the heating portion, uneven density due to waviness does not occur, and the effect is greater than that in the first embodiment described above. It is extremely effective when the surface of the member 8 to which the microcapsules are applied does not come into contact with the image when the heating of the member 8 is started.

Further, in all of the above-described embodiments, the heating cylinder is configured to rotate along with the static friction force generated by the conveying force of the photosensitive member 8, but the heating cylinder is stationary and the photosensitive member slides on the heating surface. However, it has been confirmed that the same effect can be obtained with a configuration in which heating is performed. In that case, it is not always necessary to have a completely cylindrical shape, and a heat developing apparatus having a heating surface using a part of an arc may be used.

Further, the present invention can be widely applied to all photothermographic materials and is not limited to the photoconductive transfer type photothermographic material described in this embodiment.

In the present embodiment, the copying machine has been described as an example, but the present invention is not limited to this, and it is needless to say that the present invention can be applied to all image forming apparatuses such as printers, facsimiles, and electronic cameras. Absent.

[0024]

As described above, according to the present invention, in the heat developing apparatus of the image forming apparatus using the photosensitive transfer type heat developing material, the photosensitive member has a predetermined wrapping angle immediately before the start of heating. Since there is a guide means configured so as to be contact-guided by a touch panel, it is possible to obtain a high-quality image with no density unevenness caused by the corrugation of the photosensitive member immediately before the heating section due to thermal sizing in the heating section with a simple configuration. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an image forming apparatus using the present invention.

FIG. 2 is a perspective view showing a first embodiment of the heat developing apparatus of the invention.

FIG. 3 is a sectional view showing a first embodiment of the heat developing apparatus of the invention.

FIG. 4 is a sectional view showing a second embodiment of the heat developing apparatus of the invention.

[Explanation of symbols]

 1 Original Plate 2 Original 3 Red Lamp 4 Green Lamp 5 Blue Lamp 6 Lens 7 Exposure Plate 8 Photosensitive Member 9, 13 Conveying Roller 10 Paper Tray 11 Transfer Member 12 Paper Feeding Device 14 Paper Ejection Tray 15 Manual Paper Feeding Port 16 Gas Filter 20 Cartridge 21 Winding Shaft 40 Thermal Development Device 41 Heating Cylinder 42 Bearing 43 Halogen Lamp Heater 44 Guide Roller 60 Pressure Transfer Device 61 Upper Roller 62 Middle Roller 63 Lower Roller 64 Separation Roller 65 Pinch Roller

Claims (1)

[Claims] 1. A heat developing device for heating a heat-developable photosensitive member, comprising guide means configured so that the photosensitive member is contact-guided with a predetermined wrapping angle immediately before the start of heating. And thermal development equipment.