JPS6392954A - Photosensitive transfer type image forming device - Google Patents

Abstract

PURPOSE:To prevent contamination of the surfaces of pressurizing rollers by microcapsules by pressing a transfer member right after the passage of the front end of the transfer member superposed on a photosensitive member between the rollers and relieving the pressure just before the passage of the terminal end of the transfer member between the rollers. CONSTITUTION:The photosensitive member 4 is delivered from a roller 8 and is superposed thereon with the transfer member 5 after the photosensitive member is selectively exposed by a writing head 1. The members are then fed into the spacing between a pair of the rollers 3 and are subjected to pressing and development. For example, a difference in the reflectivity between the members 4 and 5 is detected and the gap of the rollers 3 is narrowed when the front end of the member 5 on the member 4 arrives at a detector 71. The gap of the rollers 3 is restored to the initial state by detecting the terminal end of the member 5 similarly with a detector 61. The member 5 is thereafter housed in a tray 10 and the member 4 is taken up on the roller 11. The breakage of the microcapsules which do not contribute to the image formation and the consequent contamination of the surfaces of the rollers 3 are thereby prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image forming apparatus using light, and more specifically, to an image forming apparatus using light.
In a photosensitive transfer type image forming apparatus that controls the transferability of a transfer material by exposing the photosensitive material to light, and forms an image by transferring and fixing the transfer material to the transfer member by pressure development, a continuous sheet-like photosensitive member is used. and a discontinuous transfer member.

[Prior Art] In a conventional photosensitive transfer type image forming apparatus, in a pressure developing process in which a continuous sheet-like photosensitive member and a discontinuous transfer member are overlapped and pressure developed, a pressure roller of a pressure developing device is used. The applied pressure remains at a constant value after the initial value is set, and there is no example in which the distance between the pressure rollers is adjusted depending on the conveyance position of the photosensitive member and the transfer member.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, pressure is applied even to parts of the continuous photosensitive member where there is no transfer member, which leads to the destruction of microcapsules that do not contribute to image formation, and the pressure roller There is a problem in that the microcapsules are contaminated by the photosensitive material and transfer material seeping out.

Furthermore, since pressure is always applied to the photosensitive member, compared to the case where pressure is applied only during transfer and fixing.

Another problem is that the incidence of troubles in the conveyance system such as wrinkles, skew, and jams is high.

Furthermore, since pressure is applied over the entire surface of the transfer member from the leading end to the rear end, the entire surface of the transfer member comes into close contact with the photosensitive member, making it difficult to separate the transfer member from the photosensitive member after pressure development. There is another problem.

In addition, since pressure is applied over the entire surface from the leading end to the rear end of the transfer member, rapid torque fluctuations occur when the pressure roller bites the transfer member and when it discharges the transfer member, causing the pressure roller, pressure roller drive motor, and pressure roller There are many problems in that the damage to the bearings and the like is great, and furthermore, smooth conveyance is obstructed by the above-mentioned rapid torque fluctuations, which may cause troubles in the conveyance system such as wrinkles, skew, and jams.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and its purpose is to contribute to image formation between the pressure rollers of a pressure developing device from immediately after passing the tip of the transfer member to immediately after passing the tip of the transfer member. By applying a predetermined pressure in only one area and creating a gap between the pressure rollers in other areas that is wider than the thickness of the two members (transfer member and photosensitive member), the pressure roller is not contaminated with microcapsules that do not contribute to image formation. This makes it easy to separate the transfer member from the photosensitive member, which is a set of two after the transfer, and also prevents sudden fluctuations in the torque of the pressure roller, resulting in excellent durability and transport stability. It is an object of the present invention to provide a photosensitive transfer type image forming apparatus which is excellent in the following.

[Means for Solving the Problems] The photosensitive transfer type image forming apparatus according to the present invention includes a support, a microcapsule coated on the support, a photosensitive material and a transfer material sealed within the microcapsule. A detector installed near a pair of pressure rollers in a photosensitive transfer type image forming apparatus that transfers and fixes a continuous photosensitive member composed of a continuous photosensitive member made of detecting the position of the transfer member, applying pressure immediately after the leading end of the transfer member passes through a plane containing the two axes of the pair of pressure rollers, and immediately before the end of the transfer member passes through the plane; It is characterized by unloading.

[Embodiment] FIG. 1 is a basic configuration diagram of an embodiment of a photosensitive transfer type image forming apparatus using the present invention. A continuous photosensitive member 4, in which microcapsules encapsulating a photosensitive material and a transferable material are coated on a support and wound around a photosensitive member delivery roller 8, is selectively exposed to light by an optical writing head 1, and the transfer material is transferability is controlled. Next, the transfer member 5 is superimposed on the exposed photosensitive member 4-H, and is fed between the pressure rollers 3 of the pressure developer 2, and the tip of the transfer member 5 is detected by the detectors a6 and b7. Then, pressure is applied between the pressure rollers 3, and the transferred material on the exposed photosensitive member 4, whose transfer properties are controlled, is pressure-developed only in the image forming area on the transfer member 5. , image formation is performed.

After pressure fixing, the photosensitive member 4 and the transfer member 5 are assembled into a set of two.
is separated into two sheets by a separating mechanism 9, the transfer member 5 is stored in an output image tray 10, and the photosensitive member 4 is wound up on a used photosensitive member winding roller 11, respectively.

FIG. 2 shows the configuration of an embodiment of a pressure developing device 2 for pressure-developing the photosensitive member 4 onto the transfer member 5, which is a feature of the present invention. The leading ends of the transfer members 5 that have been conveyed in a stacked manner are placed between the pressure rollers 3 having a gap wider than the thickness of the two members, the photosensitive member 4 and the transfer member 5 (hereinafter abbreviated as member P). When it reaches the detector b7 arranged on the exit side, a predetermined electric power is applied to the piezoelectric actuator 17, and the dimension t of the piezoelectric actuator 17 increases, and the upper frame 13 and the lower frame to which the piezoelectric actuator 17 is fixed are separated. 14 rotates around the fulcrum 15, and the pressure roller 3
The gap between them is narrowed and a predetermined pressure is applied to the member P to transfer and develop the image.Next, when the rear end of the transfer member 5 reaches the detector a6 arranged on the entrance side of the pressure roller, the piezoelectric actuator Since the applied voltage 17 is released and the dimension t of the piezoelectric actuator 17 returns to its initial value, the gap between the pressure rollers 3 returns to its initial state due to the force of the pressure spring 16. Note that the initial setting of the gap between the pressure rollers 3 is performed using the adjusting screw 18.

Here, a method for detecting the position of the transfer member 5 using the detector a6 and the detector b7 will be described.

FIG. 3 shows a method for detecting the difference in the amount of reflected light between the transfer member and the photosensitive member. Detector a61 and detector b71 are each a photodetector in which a light-emitting element such as a light-emitting diode and a light-receiving element such as a phototransistor are integrated. The objective is to detect the difference in reflectance between the surface of the photosensitive member 40 (arrow G surface) and the surface of the transfer member 5 (arrow H surface) using a fogger. When the tip of the transfer member 5 hits the detector 71, since the ratio of transfer member 50 to 4·I is larger, the amount of light incident on the light-receiving element increases, and the current flowing through the light-receiving element increases. A control circuit (not shown) determines this change and energizes the piezoelectric actuator 17 to narrow the gap between the pressure rollers.

The end of the transfer member 5 is detected by the detector a6, and the operating principle is the same as that described above, so a description thereof will be omitted.

Furthermore, Fig. 4 shows a method for detecting changes in the amount of transmitted light.
Detector a6 and detector b7 are light emitting parts 62 and 72, respectively.
and light receiving sections 63 and 73. Each light emitting section is composed of a light emitting element such as a light emitting diode, and the light receiving section is composed of a light receiving element such as a phototransistor. The light receiving portions 63.73 are arranged to receive the light from the light emitting portions 62, 72, and the amount of light received decreases when the transfer member 5 falls on the detector. A control circuit (not shown) determines this change and controls energization to the piezoelectric actuator 17.

In the above embodiment, by controlling the voltage applied to the piezoelectric actuator 17, it is also possible to set the distance between the pair of pressure rollers 3 to an arbitrary value.

FIG. 5 is a block diagram of a second embodiment of the pressure developing device 2 of the present invention, in which the pressure is applied by rotating the rotating shaft 19 with a dimension of the long axis and a dimension of the short axis. This is done by changing the dimension t by the maximum value a-b using the cam 20. The method of detecting the position of the transfer member 5 with the detector 6.7 and controlling the output of the control circuit is the same as in the first embodiment.

The circular cam 20 is fixed at its center to a rotating shaft 19, and the rotating shaft is connected to a motor via a gear train (not shown). The rotation of the motor is set to be decelerated by the gear train.The motor is rotated by an output from a control circuit (not shown), the circular cam 20 is rotated, the dimension t is changed, and the distance between the pressure rollers is adjusted. Also in this embodiment, the distance between the pressure rollers can be set to an arbitrary value by controlling the amount of rotation of the motor.

In the embodiment described above, two sets of detectors are used. First, the transfer member 5 is Immediately after the tip of the transfer member 5 passes through a plane containing the two axes of the pressure roller, pressure is applied using the structure of the above embodiment, and then the end of the transfer member is detected by the same detector. By unloading at the same time, the same effect as in the above embodiment can be obtained. The timing of the above pressurization is determined by the distance 1i from the detector to the pressure point of the pressure roller.
It can be determined based on the time obtained by dividing 1H by the conveying speed υ of the transfer member.

FIG. 6 shows the relationship between the conveyance time t and the torque T of the pressure roller in the pressure developing device 2 of the present invention and the conventional pressure developing device. The values according to the present invention are represented by solid lines, and the values of the conventional example are represented by dotted lines.
The transfer member 5 at each time point of the conveyance time t on the horizontal axis in the figure below.
The positional relationship is as follows.

Point A...The tip starts getting caught between the pressure rollers 3 Point B...The tip ends getting caught Point 0...The tip is detected jQ? , reached b7, point D...
・Point E when the rear end reaches the detector a6...Point F where the rear end starts to be discharged from between the pressure rollers 3...The rear end is completely discharged In the example of the present invention, pressure is applied only to the image forming section. Since there is a gap between the pressure rollers 3 in the other parts,
The torque TI up to point A is lower than T2 in the conventional example in which pressure is always applied, and the transfer member 5 is When the tip reaches point C after passing between the pressure rollers 3, pressure is applied, so the sudden torque fluctuation that occurs when biting between points A and B, which occurs in the conventional example, does not occur, and the pressure is increased from point 0. When the rear end is released at point D, where the torque gradually rises to T3 during fixing, the pressure is released, a gap is again formed between the pressure rollers 3, and the torque returns to the initial torque TI. At this time as well, the sudden torque fluctuation that occurs during ejection as between points E and F in the conventional example does not occur.

[Effects of the Invention] As described above, according to the present invention, the transfer member is pressurized by the pressure roller after passing through the pressure roller, and the end of the transfer member passes through the detector installed in front of the pressure roller. In order to release the pressure from the pressure roller,
This has the effect of preventing microcapsules that do not contribute to image formation from being destroyed by pressure and contaminating the surface of the pressure roller.

Furthermore, since no pressure is applied to the parts other than between the image formation diagrams at the front end and rear end of the member P, it becomes a trigger for separation when the member P is later separated into two pieces, making it easier to separate.
Furthermore, it has another effect of being able to prevent drastic torque fluctuations of the pressure roller during biting and ejection, reducing damage to the pressure developing device, and improving durability.

Furthermore, as mentioned above, sudden torque fluctuations of the pressure roller are prevented, so smooth conveyance can be performed, and wrinkles on the member P can be prevented.
Another effect is that a stable conveyance system with less occurrence of troubles such as skew and jamming can be realized.

Furthermore, since the distance between the pressure rollers can be set to an arbitrary value, it is possible to control the pressing force during pressure development to an arbitrary value.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic configuration of an embodiment of a photosensitive transfer type image forming bag using the present invention. FIG. 2 is a side view showing one embodiment of the pressure developing device of the present invention. FIG. 3 is a side view showing the detection mechanism of the present invention. FIG. 4 is a side view showing another detection mechanism of the present invention. FIG. 5 is a side view showing another embodiment of the pressure developing device of the present invention. FIG. 6 is a diagram showing the relationship between conveyance time and torque in pressure fixing devices of the present invention and a conventional example. 2...Pressure developer 3...Pressure roller 4...Photosensitive member 5...Transfer member 6...Detector a 7...Detector b 9...Minute 1! lit tower 15...fulcrum 16...pressure spring 17...piezoelectric actuator 18...adjusting screw 19...rotary shaft 20...cam and above Applicant Seiko Epson Corporation Agent Patent Attorney Tsutomu Mogami 1 other personFigure 1Figure 2Figure 3Figure 4

Claims (1)

[Claims] a support, microcapsules coated on the support;
A photosensitive transfer type image forming apparatus that transfers and fixes a continuous photosensitive member made of a photosensitive material and a transfer material encapsulated in the microcapsules to the transfer member by overlapping the photosensitive member and the transfer member and applying pressure after exposing the photosensitive member to light. , the position of the transfer member is detected by a detector installed near the pair of pressure rollers, and pressure is applied immediately after the tip of the transfer member passes through a plane containing the two axes of the pair of pressure rollers. . A photosensitive transfer type image forming apparatus, wherein the load is unloaded immediately before the end of the transfer member passes through the plane.