JP2952792B2 - Thermal developing apparatus and image forming apparatus having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive member having a film surface coated with a microcapsule in which at least a photosensitive substance and a coloring material are enclosed (for example, Japanese Patent Application Laid-Open No. 61-275).
742), a transfer member, optical writing means for exposing the photosensitive member, heat developing means for heating and developing the photosensitive member, and a pressure transfer device for pressurizing and transferring the photosensitive member and the transfer member. The present invention relates to an image forming apparatus having such a configuration, and particularly to a thermal developing unit.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, heat development is performed while rotating a cylinder along a heated cylindrical curved surface with a photosensitive member, or while fixing the cylinder and sliding the photosensitive member. The back surface of the photosensitive member was contacted and heated.

[0003]

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

A photosensitive member is often made of a resin film such as polyethylene terephthalate as a base material, and greatly expands when heated. As a result, as shown in FIG. 6, wrinkles are gradually generated from the contact portions, and the wrinkled and floating portions are insufficiently heated, so that the development becomes nonuniform, and image density unevenness and paper wrinkles due to pressure transfer. cause.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has been made to solve the above-mentioned problems. It is an object of the present invention to provide an image forming apparatus capable of obtaining a high quality image by uniformly heating and developing a photosensitive member. Is to do.

[0006]

Means for Solving the Problems The heat developing apparatus of the present invention comprises:
The photosensitive member is heated while being conveyed, and a linear protrusion is formed on a part of a contact surface of a heating unit that heats the photosensitive member. Accordingly, the position in contact with the photosensitive member is formed so as to continuously change in a predetermined direction with respect to a direction orthogonal to the conveying direction of the photosensitive member, and is generated by heating the photosensitive member. It is characterized in that wrinkles are absorbed by following the protrusions, and the heated portion of the photosensitive member by the protrusions continuously changes in a predetermined direction. in this case,
It is desirable that the projection is formed continuously in a direction in which the photosensitive member is pushed outward from the center with respect to the transport direction of the photosensitive member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming apparatus of the present invention will be described in detail below with reference to embodiments.

FIG. 1 is a front sectional view of a copying machine showing 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 emitted from a red lamp 3, a green lamp 4, and a blue lamp 5 as light sources , And the reflected light from the original 2 forms an image on a photosensitive member 8 that moves on an exposure table 7 through a lens 6 to form a so-called scan exposure system.

A continuous sheet-like photosensitive member 8 sent out from a cartridge 20 containing an unexposed photosensitive member 8
Is exposed on an exposure table 7 to form a latent image, and is heated and developed by a heat developing device 40 via a transport roller 9. on the other hand,
The transfer member 11 in the form of a cut sheet stored in the paper feed tray 10 is sent out by the paper feed device 12 and is superimposed on the photosensitive member 8 in synchronization with an image area formed on the photosensitive member 8 so that a roller pressing system is used. Pressure transfer is performed by the pressure transfer device 60.

After this, the transfer member 11 is separated from the photosensitive member 8 by a separation roller 64 and is discharged to a paper discharge tray 14 through a transfer roller 13. The photosensitive member 8 is pinched to transfer the photosensitive member 8 and to promote separation thereof. It is wound on the winding shaft 21 via the roller 65. 15 is a manual feed slot,
Reference numeral 16 denotes a gas filter for removing gas generated in the machine.

Next, a description will be given of a heat developing apparatus which is a feature of the present invention.

FIG. 2 is a perspective view of the thermal developing device 40 shown in FIG. The thermal developing device 40 includes an aluminum pipe 41, a wire 42 wound spirally around the aluminum pipe 41, and a halogen lamp 43 provided for heating.
The aluminum pipe 41 is fixed, and the photosensitive member 8 is fixed.
Slides on it. In this embodiment, the diameter of the aluminum pipe is 30 mm, the heating temperature is 150 degrees Celsius, and the wire 4
As 2, stainless steel wire having a diameter of 0.3 mm was used. The wire 42 is a feature of the present invention, and even if the photosensitive member 8 thermally expands in a direction perpendicular to the traveling direction, that is, in the longitudinal direction of the aluminum pipe 41, the portion riding on the wire 42 absorbs and suppresses wrinkles. be able to. Also, wire 42
Is wound in a spiral shape, the portions riding on the wire 42 are switched, and all portions are uniformly heated and developed. The wire 4 depends on the nature of the substrate of the photosensitive member 8 and the heating temperature.
Optimum conditions can be obtained by changing the thickness and the number of turns of No. 2.

FIG. 3 shows another embodiment of the present invention. 1 is basically the same as the embodiment shown in FIG. 1, but is characterized in that the wire 42 is wound in a direction in which the wire 42 is pushed outward from the center with respect to the traveling direction of the photosensitive member 8 in the direction of the arrow. As a result, even if the photosensitive member 8 starts to wrinkle, it is naturally pulled outward and disappears. Further, since the photosensitive member is symmetrical, skewing of the photosensitive member can be prevented.

FIG. 4 shows another embodiment of the present invention. Although the configuration is similar to that of the embodiment shown in FIG. 3, in this embodiment, the aluminum pipe 41 is rotated by the drive motor 44 via the gear 45. The rotation direction is the same as the conveying direction of the photosensitive member 8, but since the peripheral speed is higher than the conveying speed of the photosensitive member 8, it also works to push the photosensitive member 8 outward. Of course, the winding direction of the wire 42 may be reversed and the photosensitive member 8 may be rotated so as to face the conveying direction. According to the configuration of this embodiment, even if the winding angle of the photosensitive member 8 around the aluminum pipe 41 is small, the contact time of the wire 42 can be uniformly taken at all places on the photosensitive member 8, so that the unevenness of development by the wire 42 can be obtained. Can be avoided.

FIG. 5 shows an example in which a heat plate 46 is formed by integrating aluminum by casting or forging, instead of using a wire and a pipe as described above to obtain the same effect. Further, in this example, a sheet heating element 47 was used as a heat source instead of a halogen lamp. Integrating the structure makes it possible to improve the durability and reduce the manufacturing cost, and also increases the degree of freedom of the shape, thereby enabling more uniform development.

[0017]

As described above, according to the image forming apparatus of the present invention, an output having less density unevenness and paper wrinkles can be stably obtained by the thermal developing device capable of absorbing the thermal expansion of the photosensitive member. There is an effect that a high quality, low cost image forming apparatus with high performance can be obtained.

Further, since the allowable amount of the photosensitive member against thermal deformation is increased, there is an effect that the range of choice of the base material of the photosensitive member is increased, and the running cost is reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing one embodiment of the present invention.

FIG. 2 is a perspective view of a heat developing device which is a feature of the present invention.

FIG. 3 is a plan view showing a second embodiment of the heat developing device of the present invention.

FIG. 4 is a plan view showing a third embodiment of the heat developing device of the present invention.

FIG. 5 is a plan view showing a fourth embodiment of the heat developing device of the present invention.

FIG. 6 is a development view showing occurrence of wrinkles of a photosensitive member in a conventional heat developing device.

FIG. 7 is a perspective view showing a conventional heat developing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Document table 2 Document 3 Red lamp 4 Green lamp 5 Blue lamp 6 Lens 7 Exposure table 8 Photosensitive member 9, 13 Conveyance roller 10 Paper feed tray 11 Transfer member 12 Paper feeder 14 Paper discharge tray 15 Manual paper feed port 16 Gas filter DESCRIPTION OF SYMBOLS 20 Cartridge 21 Winding shaft 40 Thermal developing device 41 Aluminum pipe 42 Wire 43 Halogen lamp 44 Drive motor 45 Gear 46 Heat plate 47 Planar heating element 60 Pressure transfer device 64 Separation roller 65 Pinch roller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-102561 (JP, A) JP-A-2-212840 (JP, A) Fully open 64-13050 (JP, U) Fully open Showa 51- 70539 (JP, U) Japanese Utility Model Application Hei 2-58236 (JP, U) Japanese Utility Model Showa 43-29356 (JP, Y1) Japanese Utility Model Utility Model 44-16310 (JP, Y1) (58) Fields surveyed (Int. ⁶ , DB name) G03D 13/00

Claims (3)

(57) [Claims] 1. A thermal developing apparatus for performing thermal development by heating an exposed photosensitive member while transporting the exposed photosensitive member, wherein a linear projection is formed on a part of a contact surface of a heating unit for heating the photosensitive member. The projection is formed such that a position in contact with the photosensitive member changes continuously in a predetermined direction with respect to a direction orthogonal to a direction in which the photosensitive member is transported as the photosensitive member is transported. Wrinkles generated by heating the photosensitive member,
The heat developing device according to claim 1, wherein the heat is absorbed by the protrusions, and a heated portion of the photosensitive member by the protrusions continuously changes in a predetermined direction. 2. The thermal developing device according to claim 1, wherein the protrusion is formed continuously in a direction in which the photosensitive member is pushed outward from a center with respect to a conveying direction of the photosensitive member. apparatus. 3. An image forming apparatus comprising the heat developing device according to claim 1.