JPH05313333A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device capable of stably feeding a photosensitive member without damaging it, always obtaining a clear outputted image, and also having high reliability as to a photosensitive transferring type image forming device having a heat developing mechanism. CONSTITUTION:It is assumed that nipping pressure given to the photosensitive member 8 by feeding rollers 9 and 10 which are the main constituting elements of a feeding device is <=4kgf/cm<2>. And a cleaning mechanism can be provided on the rollers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a copying machine, a printer or the like using a photosensitive transfer type 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 photosensitive transfer type heat developing material is, for example, Japanese Patent Laid-Open No. 62-
No. 147461 can be mentioned. According to this publication, main mechanical parts such as an exposure part, a heat developing part, and a pressure transfer part are formed inside one constituent body in the apparatus, and image formation is performed in 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.

[0004]

However, the above-mentioned prior art has the following problems.

First, both sides of the photosensitive member are nipped and conveyed by rollers at the time of image exposure. However, if excessive nip pressure is applied, the microcapsules may be damaged and the image quality of the output image may be impaired. is there.

Secondly, the photosensitive material or coloring material oozing out from the microcapsules damaged at the time of the nip adheres to the conveying roller, and the adhered material adheres to the next photosensitive member again and the output image is damaged. However, this may cause a decrease in conveyance accuracy of the photosensitive member or a conveyance failure.

The present invention solves the above problems in view of such a situation. The purpose of the present invention is to always obtain a clear output image by devising a conveying device.
Moreover, it is to provide a highly reliable image forming apparatus.

[0008]

An image forming apparatus of the present invention comprises an exposure device for exposing a photosensitive member having microcapsules, in which at least a photosensitive substance and a coloring material are encapsulated, on a support, and the photosensitive member. A heat developing device for heating, and a pressure transfer device for superposing and pressing the photosensitive member and the transfer member,
An image forming apparatus having a transport device for transporting the photosensitive member, wherein the nip pressure applied to the photosensitive member by the transport device is 4 Kgf or less per square cm, and the transport device is a transport unit. It is characterized by having a cleaning mechanism.

[0009]

According to the image forming apparatus of the present invention, by devising and optimizing the mechanism section, the photosensitive member can be conveyed without damaging it, the reliability of the conveying system can be improved, and the above-mentioned object can be achieved. Is.

[0010]

EXAMPLES The present invention will be described in detail below with reference to examples.

FIG. 1 is a front sectional view of a copying machine showing the entire structure of the embodiment.

In FIG. 1, when the copying operation is started, the original table 2 holding the original 1 and the original cover 3 move to the left of arrow A to reach the exposure start position, and then scan to the right of arrow A. start. At the same time, the transport rollers 9 and 10 rotate to nip transport the unused photosensitive member 8 and feed the roll 2.
The sheet is pulled out from 0 and conveyed in synchronization with the scanning of the original. Here, the light source 4 is turned on, and the light collected by the reflector 5 is emitted from the original 1
And a latent image of the original 1 is formed on the photosensitive member on the exposure table 7 through the lens 6.

Almost at the same time as the conveyance of the conveyance rollers 9 and 10 is started, the upper transfer roller 12 is rotated and the pinch roller 18 is pressed against the upper transfer roller 12 in the direction of the arrow B to form a photosensitive member 8 on which a latent image is formed. Heat developing roller 1
It is conveyed in the direction of 1 and developed by contact heating with the heat developing roller 11.

After the development, when the leading edge of the image recorded on the photosensitive member reaches the vicinity of the upper transfer roller 12, the paper feed tray 1
5, the transfer member 14 is fed by the paper feed roller 16 and overlaps the image area on the photosensitive member.
3 moves in the direction of arrow C to press them against the upper transfer roller 16, and the image on the photosensitive member 8 is transferred to the transfer member 14.
Is transcribed to. After the transfer, the photosensitive member 8 is separated by the separation roller 17
Is peeled off from the transfer member 14 by the pinch roller 1
It is collected by the take-up roll 21 after going through 8.

When the exposure scanning of the original 1 is completed, the light source 4 is turned off, and the original table 2 holding the original 1 and the original cover 3 return to the center of the apparatus.

When the pressure transfer is completed to the rear end of the image, the lower transfer roller 13 descends. After that, the conveyance rollers 9 and 10 stop the conveyance, the pinch roller 18 also separates from the upper transfer roller 12, the conveyance of the photosensitive member 8 stops, and the transfer member 14 after the pressure transfer is discharged by the paper discharge roller 19. The sheet is discharged to the tray 22 and a series of operations is completed.

Next, the construction of the transport rollers 9 and 10 will be described in more detail with reference to FIG.

FIG. 2 is a perspective view showing a part of the photosensitive member conveying mechanism shown in FIG.

The motor 23 is a drive source for rotating the carrying roller 9, and a nip load F is applied to both ends of the carrying roller 10 by springs or the like (not shown) to nip the photosensitive member 8. The transport rollers 9 and 10 are preferably made of a material having rigidity such as a steel material or a material having the same material as a core material and covered with an elastic material such as silicon rubber, ethylene propylene rubber or nitrile rubber. In addition, it is suitable that the rubber as the elastic material has a hardness of about 20 to 70 degrees in a constant load type hardness test (Pseudo-Johns type) of JIS-K-6301.

When a load is applied to both ends of the transport roller 10, the roller is bent in the axial direction, and the nip pressure near both ends of the roller becomes higher than that in the center. In order to prevent this, at least one of the transport rollers 9 or 10 may have a crown shape in which the center of the roller is thicker than both ends.

With the apparatus of this example, the conveyance force obtained when the nip pressure of the photosensitive member is changed by changing the nip load F of FIG. 2 and the damage to the output image by nipping the photosensitive member The results of the degree tests are shown in Table 1. The transport rollers 9 and 10 of the test apparatus
Does not adopt the above-mentioned crown shape, and the nip pressure in Table 1 is the maximum value near the roller end.

[0022]

[Table 1]

In Table 1, the maximum nip pressure is 1 square c.
At around 6 kgf per m, a stable conveying force cannot be obtained,
The image quality has also dropped significantly. As a result of the analysis, the microcapsules with a large particle size were partially destroyed by the nip pressure, the photosensitive material and coloring material exuded from the microcapsules adhered to the transfer roller, and the transfer force became unstable, and It turned out that it appeared as unnecessary dirt. It was also found that similar injuries occur rapidly when the maximum nip pressure exceeds 4 kgf per square cm.

From the above results, it was concluded that the maximum nip pressure of the photosensitive member is preferably 4 Kgf or less per square cm.

Next, the cleaning mechanism of the carrying device will be described.

3 to 5 are views in which a cleaning mechanism is added to the transport roller portion of FIG.

In FIG. 3, the cleaner 24 is an elastic member such as wool felt or synthetic felt, and in FIG. 4, the cleaner 24 is a rubber or metal blade. By pressing these cleaners 24 against the transport roller 10, the surface of the roller is cleaned. The cleaner 24 may be constantly pressed against the transport roller 10, or may be normally waiting in the direction of the arrow D and may be pressed only when necessary. Further, it is more effective to provide the cleaning mechanism on both sides of the transport rollers 9 and 10, and the cleaning effect can be improved by impregnating the cleaner 24 of FIG. 3 with a solvent or the like.

Further, since the transport roller is contaminated mainly at the portion in contact with the end portion of the photosensitive member, the cleaning mechanism may be provided only at this portion as shown in FIG.

By providing these cleaning mechanisms, the apparatus maintenance cycle can be extended 5 to 20 times, and the time and effort required for the apparatus maintenance can be greatly reduced.

[0030]

As described above, according to the image forming apparatus of the present invention, by devising and optimizing the mechanical section,
The photosensitive member can be conveyed without being soiled or damaged, and a stable output image can always be provided to the user.

Further, by improving the reliability of the transfer system by means of the cleaning mechanism, it is possible to greatly save the time and effort for maintenance of the apparatus.

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing an operation of a part of the transport device of FIG.

FIG. 3 is a perspective view showing a first example of a transport section cleaning mechanism of the present invention.

FIG. 4 is a perspective view showing a second example of the transport section cleaning mechanism of the present invention.

FIG. 5 is a perspective view showing a third example of the transport unit cleaning mechanism of the present invention.

[Explanation of symbols]

 1 Original 2 Original Platen 3 Original Plate Cover 4 Light Source 5 Reflector 6 Lens 7 Exposure Stand 8 Photosensitive Member 9 Conveying Roller 10 Conveying Roller 11 Heat Developing Roller 12 Upper Transfer Roller 13 Lower Transfer Roller 14 Transferring Member 15 Paper Feed Tray 16 Paper Feeding Roller 17 Peeling Roller 18 Pinch Roller 19 Paper Ejection Roller 20 Supply Roll 21 Winding Roll 22 Paper Ejection Tray 23 Motor 24 Cleaner

Claims (2)

[Claims] 1. An exposure device for exposing a photosensitive member having a microcapsule in which at least a photosensitive material and a color material are encapsulated on a support, a heat developing device for heating the photosensitive member, the photosensitive member and a transfer. In an image forming apparatus having a pressure transfer device that stacks and presses members, and a conveying device that conveys the photosensitive member, a nip pressure applied to the photosensitive member by the conveying device is 4 Kgf or less per square cm. Image forming apparatus. 2. An exposure device for exposing a photosensitive member having a microcapsule, in which at least a photosensitive material and a color material are encapsulated, on a support, a heat developing device for heating the photosensitive member, and the transfer to the photosensitive member. An image forming apparatus having a pressure transfer device for stacking and pressing members and a transport device for transporting the photosensitive member, wherein the transport device has a cleaning mechanism for a transport portion.