JPH0273253A - Pressure developing device - Google Patents

Abstract

PURPOSE:To surely form an image in the tip part of developing paper, and also, to prevent a paper jamming of the developing paper by adjusting the timing of feeding-in of the developing paper between pressure developing rollers and the generation of a pressure load between the rollers. CONSTITUTION:Microcapsule paper on which a latent image is formed and developing paper are superposed and fed in between pressure rollers 21, 31 being in a half open state of a pressure developing device 20. When both sheets rushes in between the rollers, since the clearance of the rollers is made a little narrower than thickness of both sheets, driving torque increases and the speed of revolution of a roller driving motor 42 drops. Its speed of revolution is detected by an encoder 43, and when a CPU 44 detects a fact that both sheets rushes in between the rollers, the clearance between the rollers 21, 31 is set to a closed state by driving a roller opening/closing motor 41. In this state, the latent image is transferred onto the developing paper and an image is formed, and after the pressure development is ended, the clearance between the rollers is set to a half opened state.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for producing a visible image on the surface of the color developer paper by overlaying a color developer paper on a photosensitive pressure sensitive recording medium on which a photolayer image is formed and applying pressure. The present invention relates to a pressure developing device.

[Prior Art] Conventionally, for example, a continuous band-shaped photosensitive pressure sensitive recording medium is passed through an exposure device and a pressure developing device, and the surface of the photosensitive pressure sensitive recording medium is exposed to light in the exposure device to form a latent image, and then a latent image is formed. There is already known a method in which a visible image is formed on the color developing paper by stacking it on colored paper and developing it under pressure using the pressure developing device.

In such an image forming apparatus, the pressure developing device has a pair of pressure developing rollers that are arranged so as to be able to approach and separate from each other, and a sensor detects that the developer paper is fed between the two rollers, and a sensor detects that the developing paper is fed between the two rollers. The gap between the two rollers is closed and pressure development is performed, but in reality it is difficult to install a sensor to detect the moment when the developing paper reaches the gap between the two rollers. A sensor is installed in front of both rollers on the entrance side, and the sensor detects the time when the leading edge of the color developer paper passes a certain point, and a preset time elapses from the time of detection until it reaches between the two rollers. The space between the two rollers is closed by the rollers, and is opened after the developer paper passes through the rollers.

[Problems to be Solved by the Invention] However, the color developing paper feeding speed may be too fast or too slow due to torque fluctuations in its drive system. Therefore, the time from when the leading edge of the color developing paper is detected by the sensor until the leading edge reaches between the two rollers varies. In this case, for example, if there is a delay in feeding the developer paper, the developer paper will try to enter between the two rollers with both rollers closed, but since the pressure applied to both rollers of the pressure developing device is large, The leading edge of the developing paper may not fit between the rollers, resulting in a paper jam. If the color developer paper is fed in too quickly, the pressure applied by both rollers will be applied from the middle of the leading end of the color developer paper, and no image will be formed near the edge of the color developer paper. This is inconvenient when it is desired to form an image on the entire screen.

The present invention was made to solve the above-mentioned problems, and by adjusting the timing of feeding the color developer paper between the pressure developing rollers and the generation of pressure load between the two rollers, it is possible to improve the front surface of the color developer paper. The purpose is to form a clear image and at the same time prevent paper jams from occurring on color developer paper.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a pair of pressure developing rollers, which are arranged so as to be able to approach and separate from each other, and at least one of which is a drive roller, and a gap between the two rollers is stepped. and a pressure roller opening/closing means that can be opened and closed, and the latent image on the photosensitive and pressure sensitive recording medium is developed by passing the photosensitive recording medium and color developing paper over both rollers under pressure. In a pressure developing device for visualizing an image on a paper surface, the gap between the two rollers is larger than the thickness of the light-sensitive pressure-sensitive recording medium at the time when the light-sensitive pressure-sensitive recording medium and the color developing paper enter between the pressure-sensitive developing rollers. means for detecting rotational load fluctuations of the driving roller caused by the thickness being smaller than the total thickness of the photosensitive pressure-sensitive recording medium and the color developing paper; and roller gap control means for closing the gap between the two rollers based on the detected signal. We are prepared.

[Function] According to the pressure developing device of the invention having the above configuration, since the gap between the two rollers is smaller than the total thickness of the light-sensitive pressure-sensitive recording medium and the color developer paper when no pressure is applied, the leading edge of the color developer paper When the edge reaches between the rollers, the developer paper applies a brake to both rollers, causing a sudden increase in the pressure roller drive torque and a decrease in the rotational speed of the drive roller.

When this decrease in rotation speed is detected, the pressure roller is closed by the pressure roller opening/closing device. At the same time, the drive roller is kept at a constant speed by servo control, which allows
Pressure can be applied from the leading edge of the color developer paper, and a good image can be obtained on the front surface of the color developer paper.

As is clear from the above detailed description, according to the present invention, when the leading edge of the developer paper is bitten by the pressure roller, the pressure roller is instantly brought into a closed state, and the photosensitive pressure-sensitive recording medium and the developer paper Since the image is pressure developed, an image can be reliably formed from the leading edge of the color developing paper. Furthermore, there is an effect of preventing the occurrence of paper jams when the developer paper is delayed in entering the pressure roller.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a photosensitive pressure-sensitive copying machine. The photosensitive paper used here and JP-A-58-88739
This method has been proposed in a number of publications, etc., and will not be discussed in detail here.

As shown in the figure, the photosensitive and pressure-sensitive copying machine 40 places an original face down on a movable original platen glass 2, closes the original platen cover, and then irradiates the document with light from a halogen lamp 3. Then, the light reflected on the document surface is filtered through filter 8 and lens 9.
Microcapsule paper 3, which is a photosensitive and pressure sensitive recording medium, passes through the
Irradiated on 7 sides. As a result, the microcapsule paper 37
An optical latent image corresponding to the original is formed thereon. The long microcapsule paper 37 is pulled out from the cartridge 13, passes through the exposure system 19 where the aforementioned latent image is formed via the feed roller 15 and the guide roller 17, and then is supplied to the pressure developing device 20. After passing through the pressure developing device 20, the sheet is guided to a peeling roller 23 and a meandering adjustment roller 24, and then wound onto a winding shaft 25. The microcapsule paper 37 pulled out from the cartridge 13 is kept in an unexposed state by the light shielding cover 16.

In addition, the cut paper type developer paper 38 is used in the developer paper cassette 3.
2, the sheets are taken out one by one from the half-moon roller 33, and after their leading ends are aligned by the developer paper roller 34 and the registration gate 35, they are conveyed to the paper inlet of the pressure developing device 20. Therefore, the microcapsule paper 37 and the color developing paper 38 are supplied to the pressure developing device 20 in a state in which they are in close contact with each other and are integrated. Thus, the pressure developing device 20, which is a feature of the present invention, has the structure shown in FIG. That is, the fixed roller 21
A rotating cam 39 is arranged in contact with the opposing roller 31, and the rotating cam is pressurized by a motor or the like. A roller opening/closing means 41 is connected. As the rotating cam rotates, the pressure rollers (small diameter roller 21 and backup roller 31) are opened and closed in three stages: fully opened, partially opened, and fully closed.

Fully open is a state where the roller gap is approximately 1mm open.
Replace the cartridge 13 and insert the microcapsule paper 37.
This state is used when passing paper or removing jammed color developing paper. In the semi-open state, the roller gap is slightly narrower than the thickness of the superimposed microcapsule paper 37 and color developer paper 38, and only the microcapsule paper 37 can pass through the pressure developing device. The pressure roller is driven by a pressure roller drive means 42 such as a motor, and the rotation speed of the motor 42 is detected by a load detection means 43 such as an encoder.

The operation of the pressure developing device configured as above will be explained below.

The pressure roller of this pressure developing device 20 is now in a semi-open state. In that state, the color developer paper 38 is replaced by the microcapsule paper 37.
It is sent in a state where it is superimposed on the latent image formed above. Then, when it enters the pressure roller, the fixed roller 21
Since the gap between the microcapsule paper 37 and the opposing roller is slightly narrower than the thickness of the microcapsule paper 37 and the color developing paper 38, the driving torque increases and the rotation speed of the pressure roller drive motor 42 decreases. The encoder 43 detects the rotational speed, and the CPU 44 detects that the developer paper 38 has entered the pressure roller.

When it is detected that the developer paper 38 has entered the pressure roller, the pressure roller is brought into a fully closed state by the pressure roller opening/closing motor 41. With the pressure roller fully closed, the pressure developing device 20 transfers the latent image on the microcapsule paper 37 onto the developer paper 38 to form an image. After the pressure development is completed, the pressure roller is brought into a semi-open state by the pressure roller opening/closing motor 41.

Thereafter, the developing paper 38 is thermally fixed by a thermal fixing device and then discharged from the copying machine 40 . On the other hand, pressure developing device 20
The microcapsule paper 37 that has passed through the winding shaft 2 is
5. In this embodiment, the pressure roller drive motor 42
Although the rotation speed of the pressure roller drive motor 42 is detected by the encoder 43, the load detection means 43 can also detect changes in the load of the pressure roller drive motor 42, such as by detecting changes in the current of the pressure roller drive motor 42. .

Although only the leading edge of the image has been described above, it is also possible to perform the above-mentioned operation in the opposite direction for the trailing edge of the image.

[Brief explanation of the drawing]

1 to 2 show embodiments embodying the present invention. FIG. 1 is a schematic sectional view of a copying machine to which this embodiment is applied, and FIG. 2 is a schematic cross-sectional view of a copying machine to which this embodiment is applied. FIG. 3, which is a block diagram of the pressure developing device, is a flowchart during the pressure roller opening operation of this embodiment. In the figure, 20 is a pressure developing device, 21 is a fixed roller, 31 is a backup roller, 37 is a microcapsule paper, and 38
3 are developer paper, 3 are opening/closing cams, 41 are creeping opening/closing motors, 42
43 is a load detection means, and 44 is a CPU.
It is. -Evening Pressure port patent applicant Katsuji Kawashima, President and CEO of Brother Industries, Ltd. Figure 2 Figure 3

Claims (1)

[Claims] 1. A pair of pressure developing rollers, which are arranged so as to be able to approach and separate from each other, and at least one of which is a drive roller, and a pressure roller opening/closing means that can open and close a gap between the two rollers in stages. , in a pressure developing device that visualizes the latent image on the photosensitive pressure-sensitive recording medium on the surface of the developer paper by overlapping the photosensitive recording medium and the developer paper between both rollers and passing them under pressure; When the photosensitive pressure-sensitive recording medium and the color developer paper enter between the pressure developing rollers, the gap between the two rollers is larger than the thickness of the photosensitive pressure-sensitive recording medium and the total thickness of the photosensitive pressure-sensitive recording medium and the color developer paper. A pressure developing device comprising means for detecting rotational load fluctuations of the drive roller caused by the smaller rotational load, and roller gap control means for closing the gap between both rollers based on the detected signal.