JPH0419664A - pressure developing device - Google Patents

Abstract

PURPOSE:To eliminate fear that a work roller is stained by restoring an eccentric cam to an origin in a direction where a gap between a pair of work rollers is always opened from whatever state the eccentric cam is restored to the position of the origin. CONSTITUTION:This device is provided with a cam driving means 12 for normally and reversely rotating the eccentric cam 11 of a pressurizing force generation means, a cam position detecting means 13 for detecting the rotating position of the cam 11, and an origin restoration control means 14 for rotating and restoring the cam 11 to the position of the origin. The level of a detection signal is inverted at the position of the origin and a closing position of the rotation range of 180 deg. of the cam 11, and the means 13 confirms what range of the rotational angle the cam 11 exists in. By judging the position of the cam 11, it is known that the normal or reverse rotating direction where the cam 11 is rotated to the position of the origin without making the cam 11 at the closing position. Whatever position the cam 11 exists at, the eccentric cam is restored to the origin in the direction where the gap between a pair of work rollers 9 and 10 is always opened. Thus, the work rollers 9 and 10 are prevented from being stained at the time of controlling the pressurizing force.

Description

DETAILED DESCRIPTION OF THE INVENTION: Industrial Field of Application The present invention relates to a pressure developing device for copying machines, printers, etc. that uses photosensitive pressure sensitive paper (for example, microcapsule paper and color developer paper).

[Prior Art] A pressure developing device in a copying machine or the like that uses a long microcapsule paper is selectively exposed to light according to the image of the original, and a latent image formed on the microcapsule paper is pressure developed on a color developing paper to create an image. form.

This type of pressure developing device has a structure that includes a pair of work rollers that pressurize and develop microcapsule paper and developer paper, and an eccentric cam that variably controls the pressure applied by the pair of work rollers to the microcapsule paper and developer paper. Recently,
Proposed. The outline of the configuration of the device will be explained with reference to FIGS. 12 and 13.

The pressure developing device shown in the figure performs pressure development by pressing the microcapsule paper 3 and the color developing paper 4 linearly in the width direction using a large-diameter work roller 1 and a small-diameter work roller 2. FIG. 13 shows the time of development. A large-diameter work roller 1 is rotatably arranged at a fixed position, and a small-diameter work roller 2 is rotatably supported by a roller support 6 while being constantly pressed by a backup roller 5. Roller support 6
The small-diameter work roller 2 and the large-diameter work roller 1 swing toward and away from each other, and this swing is performed by rotating the eccentric cam 7 with the motor 8.

FIG. 12 shows the distance between the pair of work rollers 1.2, which is the maximum open origin distance between which the microcapsule paper 3 and the color developer paper 4 can pass without being pressurized. The cam origin position is shown when

At this time, the eccentric cam 7 is held at the origin position at a rotation angle of 0° where the contact point between the cam outer periphery and the roller support body 6 is at the minimum distance from the rotation center.

Figure 13 shows the minimum closing interval for developing with the maximum pressure when the pair of work rollers are spaced 1.29 times apart so that they can press the microcapsule paper 3 and color developer paper 4 with the desired pressure. The case of the cam closed position when set to L1 is shown. In this case, the eccentric cam 7 is moved 28 degrees from the origin position in FIG.
0' rotation to move the small-diameter work roller 2 through the roller support 6 in the direction of the large-diameter work roller l. By selecting the rotation angle of the eccentric cam 7 from the original position of 0° to 180°, the pressing force applied to the microcapsule paper 3 and the color developer paper 4 by the pair of work rollers 1 and 2 can be continuously selected. In other words, the appropriate pressure required for good development changes due to changes in the size of the developer paper 4 or environmental changes such as ambient temperature. - Pressure force is controlled by first returning to the original position and then rotating it by a desired angle.

The pressurizing force control described above is performed as follows. The eccentric cam 7 is equipped with an origin detection means (not shown) such as a photointerrupter that optically detects the origin position of the eccentric cam 7. is rotated in a predetermined direction, and the point in time when the eccentric cam 7 reaches the home position is detected by reversing the output signal level of the home position detection means. From this point on, the eccentric cam 7 is rotated in a predetermined direction by a desired angle based on a signal specifying an appropriate pressing force from the outside.

The surface of the microcapsule paper 3 is coated with microcapsules containing a dye precursor that reacts with a color developer described below, while the surface of the color developer paper 4 is coated with a dye precursor that reacts with the dye precursor described below. A color developer that develops color to form an image is applied. When the microcapsule-coated surface of the microcapsule paper 3 and the developer-coated surface of the color developer paper 4 are brought into contact and pressure is applied, only the unexposed microcapsules of the microcapsule paper 3 are destroyed by the pressure, and the contained microcapsules are destroyed. The dye precursor and the like are exposed and react with the color developer of the color developer paper 4 to form an image. Details of such image formation can be found in USP,
No. 4399209, etc., and a detailed explanation thereof will be omitted here.

[The problem that the invention seeks to solve.]

By the way, in the pressure developing device described above, when controlling the pressurizing force, the eccentric cam 7 is rotated in a predetermined direction until the origin detecting means attached thereto detects the origin position of the eccentric cam 7. , once the distance between the pair of work rollers 1.2 reaches the minimum closed distance L1, the distance between the pair of work rollers 1.2 becomes the minimum closed distance L1, and then the open origin distance. It may become. That is, for example, when the eccentric cam 7 located at the solid line position in FIG. 14 is rotated in the direction of the arrow in FIG. When the pair of work rollers 1.2 reach the position shown by the two-dot chain line, the pair of work rollers 1.2 are at the closed distance L1. Therefore, when the eccentric cam 7 returns to its origin and the pair of work rollers l and 2 are at the closed interval, the microcapsule paper 3 between the pair of work rollers 1 and 2 is temporarily pressurized. During this pressurization, the microcapsules of the microcapsule paper 3 are cleaned by the small diameter work roller 2, and the small diameter work roller 2 is contaminated.
There is a problem that this dirt stains the color developing paper 4 during development.

The present invention has been made as a first step to solve such problems, and no matter what state the eccentric cam is in when returning to the home position, the return to the home position is performed in a direction in which the distance between the pair of work rollers is always widened. The object of the present invention is to provide a pressure developing device in which there is no need to worry about the work roller becoming dirty.

5 Means for Solving the Problem] In order to achieve the above object, the pressure developing device of the present invention has a
) By rotating, the distance between the pair of work rollers can be varied between the maximum open origin distance that does not apply pressure to the photosensitive and pressure-sensitive paper, and the minimum closed distance that presses the photosensitive and pressure-sensitive paper with the maximum pressure within a predetermined range of pressure. b) a cam drive means for rotating the eccentric cam in forward and reverse directions;
) The rotational position of the eccentric cam is detected at a fixed position, and the detected signal level determines the origin position of the eccentric cam that brings the pair of work rollers to an open origin interval and the eccentric cam that brings the pair of work rollers to a closed interval. d) A detection signal level of the cam position detection means is determined based on a return-to-origin command signal from the outside, and based on the determination, the eccentric cam is activated via the cam drive means. and a return-to-origin control means for rotating the valve in the forward or reverse direction to avoid the closed position and return to the original position.

[Function] According to the pressure phenomenon device of the present invention having the above configuration, the cam position detection means of the eccentric cam detects the origin position and the closed position, which are both 0° and 180° positions of the 180° rotation range of the eccentric cam. Therefore, depending on whether the detection signal level of the cam position detection means is high level or low level, the eccentric cam moves from the origin position of 0° to the closed position of 18°.
It is confirmed whether the rotation angle is within the rotation angle range of 0° or within the rotation angle range of 180° to 360°. By determining the position of the eccentric cam, the rotation direction, either forward or reverse, that rotates the eccentric cam to the home position without bringing it to the closed position can be determined, so that no matter which position the eccentric cam is in, It becomes possible to return the eccentric cam to its origin in a direction that always opens the gap between the pair of work rollers. Therefore, the work roller is not contaminated at all during the pressurizing force control.

[Example code] The present invention will be described in detail with reference to FIGS. 1 to 11.

FIG. 1 is a front view of the pressure developing device during non-development, FIG. 2 is a sectional view taken along line A--A, and FIG. 4 is a sectional view during development.

The pressure developing device shown in the figure is driven by a cam drive that rotates an eccentric cam 11, which is a pressurizing force generating means, in a forward and reverse direction and variably controls the interval between a pair of work rollers 9 and 10 that apply pressure while sandwiching a microcapsule paper 3 and a color developer paper 4. means 12, cam position detection means 13 for detecting the rotational position of the eccentric cam 11, and eccentric cam 11.
Origin return control means 1 for rotationally returning to the origin position
4.

A pair of work rollers 9.10 and an eccentric cam 11 are connected to, for example, a pair of left and right plate-shaped fixed members 15.15 and a swinging member 16.
．． 16 and is supported. Specifically, one of the work rollers 9 is a horizontal large-diameter roller, and both ends thereof are rotatably supported between a pair of left and right plate-shaped fixing members 15 and 15. The other work roller 10 is a horizontal small diameter roller,
Both end portions are rotatably supported between a pair of left and right plate-shaped swinging members 16, 16.

The fixed member 15.15 is fixed at a fixed position in the copying machine, and the upper part of a pair of swinging members 16.16 is rotatable in the vertical direction by a pivot shaft 17 at approximately the middle position of each inner surface of the fixed member 15.15. Concatenated. Below the small-diameter work roller 10, both ends of a backup roller 18 that is in constant contact with the small-diameter work roller 10 are rotatably supported between a pair of swinging members 16 and 16. The eccentric cam 11 is located between the lower portions of the pair of fixed members 15.15.
Both ends are rotatably supported.

On the other hand, at the lower part of the pair of swinging members 16.16, pressurizing force adjustment means 19 that constantly contacts the eccentric cam 11 are installed respectively, and the swinging members 16.16 are arranged around the pivot shaft 17, with a small diameter. The work roller 10 rotates back and forth in directions approaching and away from the large-diameter work roller 9.

Note that the pair of pressurizing force adjusting means 19 and 19 have the same structure,
To explain one of them with reference to FIG. 2, this is the pressure spring 20.
, a pair of blocks 21.21 and a fixed plate 22.2
2 and nuts 23a, 23b, and a single pressure bolt 24
and a cap 25. Pair of blocks 21.2
1 sandwiching the pressure spring 20, the pressure bolt 24 and the nut 23
It is held compressed to an appropriate length by a. The cap 25 attached to the tip of the pressure bolt 24 is tapped (not shown), and the stroke length of the tip surface of the cap 25 is the same as that between the cap 25 and the nut 23.
It is adjusted to an appropriate size and fixed by b. The pressure adjustment means 19 inserts the block 21.21 and one end of the pressure spring 20 into the window hole 26 at the bottom of the swinging member 16.
6, it can be attached by tightening the fixing plates 22 and 22 with bolts.

The cap 25 is always in contact with the eccentric cam 11, and when the eccentric cam 11 rotates, the swinging member 16.16 swings and rotates via the pressurizing force adjusting means 19.

For example, as shown in FIG. 3, around the eccentric cam 11,
A pair of bearings 27.27 are coaxially mounted on both ends, and a bearing 28.28 is press-fitted inside the bearings 27.27 with an eccentric amount.

The eccentric cam 11 is connected to both ends of the eccentric cam 11 via the bearings 27 and 27, with the bearing 28 in contact with the cap 25 of the corresponding pressurizing force adjusting means 19.
15 so as to be rotatable.

The cam driving means 12 for rotating the eccentric cam 11 in forward and reverse directions is, for example, a nip motor fixed to a fixed member 15, and the rotational force of the nip motor 12 is transmitted to the eccentric cam 11 via a timing heald 30 and a pulley 31.

When the eccentric cam 11 is rotated by the nip motor 12, the hair rings 28.28 move up and down to move the rocking member 16.16 back and forth.

The cam position detection means I3 detects the rotational position of the eccentric cam II at a fixed position, and detects when the detection signal level is between a high level and a low level when the eccentric cam 11 reaches the home position and the closed position, which will be described later. Invert. For example, as shown in FIGS. 5 to 8, the cam position detection means 13 includes a slit plate 32 coaxially fixed to the eccentric cam 11, and a photo interrupter placed at a fixed position near the periphery of the slit plate 32. It is composed of an optical sensor 33 such as. The slit plate 32 has a semicircular slit 34 in a range of approximately 180° around the periphery.
An optical sensor 33 is placed at a position to detect this slit 34.

The home return control means 14 determines whether the detection signal level from the optical sensor 33 is high level or low level, determines whether to rotate the nip motor 12 forward or backward, and returns the eccentric cam 11 to the home position. . The details of the operations of the origin return control means 14 and the cam position detection means 13 will be described after the following description of the developing operation.

The working mode of pressure development in the above embodiment will be explained.

First, in the initial state where there is a sufficient gap between the pair of work rollers 9 and 10 for the microcapsule paper 3 and the color developer paper 4 to pass through without being pressurized, as shown in FIGS. As shown, the eccentric cam 11 is held at the origin position where the outer periphery of the bearing 28 located at the shortest distance from its center hits the cap 25. In other words, the swinging member 16
．． 16 rotates around the pivot shaft 17 under its own weight in the direction of the arrow in FIG. 2, and stops at the position where the cap 25 hits the bearing 28. The contact between the cap 25 and the bearing 28 is set to be maintained stably under any conditions due to the weight of the swinging member 16, 16 and its unit. At this time, the distance between the pair of work rollers 9 and IO is the maximum open origin distance. is maintained.

In the pressure developing state, as shown in FIG. 4, the eccentric cam 11 rotates and the bearing 28 pushes the cap 25 in the direction of the arrow in FIG. The microcapsule paper 3 and the color developer paper 4 are pressed by a pressure corresponding to the amount of movement, and pressure development is performed. At this time, the distance between the pair of work rollers 9 and 10 is
It is smaller than the maximum open origin spacing Lo by an amount corresponding to the rotation angle of the eccentric cam 11, and in FIG.
Cap 25 at the apex P of the outer periphery located at the maximum distance from the center of
is pressed by the maximum displacement amount, and the state in which the microcapsule paper 3 and the color developer paper 4 are pressed with the maximum pressing force by the pair of work rollers 9 and 10 is shown. A pair of work rollers 9 in this case of FIG.
The interval lO is the closing interval, which is the rotational position or the closed position of the eccentric cam 11.

Here, the relationship between the slit plate 32 of the cam position detection means 13 of the eccentric cam 11 at the origin position and the optical sensor 33 is such that, for example, as shown in FIG. It is set so that the detection signal level of the optical sensor 33 at this time is at a high level. From this origin position, move the eccentric cam 11 180° in the direction of the arrow in FIG.
When rotated close, the detection signal level of the optical sensor 33 remains at a high level, but when rotated 180 degrees, as shown in FIG. 6, the end of the slit 34 reaches the position of the optical sensor 33. The detection signal level of the optical sensor 33 is reversed from high level to low level, and the eccentric cam 11 is placed in the closed position. Furthermore, the eccentric cam 11 is
When the optical sensor 33 is rotated from 80° to nearly 360°, the optical sensor 33 faces the slit 34 and the detection signal level remains at a low level. The detection signal level of the optical sensor 33 is reversed from a low level to a high level, and the eccentric cam 11 returns to its original position. The above series of operational relationships are as shown in the waveforms of FIG. 9.

The return of the eccentric cam 11 to the home position is performed when the power is turned on or when the pressure applied during development of the microcapsule paper 3 and the color developer paper 4 is changed, and this return to the home position is controlled by the home return control means 14. The process is carried out as shown in the flowchart shown in FIG.

That is, when the eccentric cam 11 before returning to the origin is in the position shown in FIG. The signal level is high. Then, the origin return control means 14 determines that the detection signal of the optical sensor 33 is at a high level, and outputs a signal for rotating the nip motor 12 in the reverse direction, for example, so that the nip motor 12 rotates the eccentric cam 11 in the direction of the arrow in FIG. Rotate it in the opposite direction.

In this case, the reverse rotation is a direction in which the apex P of the bearing 28 of the eccentric cam 11 is always separated from the cap 25, and a direction in which the time of the pair of work rollers 9 and 10 is expanded to the open origin interval Lo. . When the eccentric cam 11 rotates in the opposite direction and reaches the end of the slit 34 of the slit plate 32 or the position of the optical sensor 33, and the detection signal level of the optical sensor 33 is reversed from high level to low level, this is controlled to return to the origin. The means 14 detects and the nip motor 12
The rotation of the eccentric cam 11 is stopped, and the return of the eccentric cam 11 to its original position is completed. Thereafter, the eccentric cam 11 rotates at a rotation angle corresponding to the necessary pressing force on the microcapsule paper 3 and the color developer paper 4, and pressure development is performed.

Further, when the positional relationship of the eccentric cam 11 before returning to the origin is such that the optical sensor 33 faces the slit 34 of the slit plate 32, as shown in FIG. 8, the origin return operation is as follows. It will be held on.

First, the origin return control means 14 detects that the detection signal level of the optical sensor 33 is a low level, outputs a signal to rotate the nip motor 12 in the forward direction, and the eccentric cam 11
rotates in the direction of the arrow in FIG. In this case as well, when the eccentric cam 11 rotates in the normal direction, the apex P of the bearing 28 is aligned with the cap 2.
5, the distance between a pair of work rollers 9.10 or the open origin distance. Expand to.

Then, when the eccentric cam 11 rotates forward to near the origin position, the optical sensor 33 comes off the edge of the slit 34, and when the detection signal level is reversed to high level, the rotation of the nip motor 12 is stopped, and the rotation of the eccentric cam 11 is stopped. The return to the origin position is completed.

The above return operation of the eccentric cam 11 to the origin is performed by selecting the forward and reverse rotation directions as described above, regardless of the rotational angle position of the eccentric cam 11 before return.
．． The interval of 10 is the open origin interval.

It is carried out in the direction of expanding to. In other words, when returning to the origin, the distance between the pair of work rollers 9.10 only increases and does not decrease to the minimum closing distance. There is no need to worry about being pressurized when returning to the origin.

[Effects of the Invention] As is clear from the detailed description above, according to the pressure developing device of the present invention, no matter what position the eccentric cam is in before returning to the origin, it can be set to 0° with this or the origin position as 0°. °~1
Whether the range is 80° or 180° to 360° is determined by the detection signal level of the position detection means, and based on this determination, the direction of rotation of the eccentric cam when returning to the origin is set in either the forward or reverse direction. If the return to the origin is performed by selecting , there is no possibility that the distance between the pair of work rollers will be reduced during the return to the origin and pressurize the photosensitive and pressure sensitive paper. Therefore, if the light-sensitive and pressure-sensitive paper is microcapsule paper, there is a problem that the microcapsules coated on the surface are inadvertently crushed when returning to the origin when the power is turned on, and the work roller and the microcapsule paper become dirty. This has the effect of increasing the value of products such as copying machines. Furthermore, by inverting the detection signal level of the cam position detection means when the eccentric cam is at the 0° and 180° rotational positions, one cam position detection means can detect all 360° rotational positions of the eccentric cam. This is effective in simplifying the configuration.

[Brief explanation of drawings]

1 to 11 show a pressure developing device according to an embodiment of the present invention.
Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a front view of the eccentric cam in Fig. 1, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 1.
A cross-sectional view of a portion along line A during development, Figures 5 to 8 are cross-sectional views showing each operating state of the eccentric cam, and Figure 9 is a rotation angle and its position of the eccentric cam in the device shown in Figure 1. FIG. 10 is a waveform diagram showing the relationship between detection signal levels of the detection means, FIG. 10 is a block diagram of the electric circuit of the device shown in FIG. 1, and FIG. 11 is a flowchart explaining the operation of the origin return control means in the device shown in FIG. be. Figures 12 to 14 are for explaining the outline of the previous pressure developing device.
FIG. 12 is a side view during non-development, FIG. 13 is a side view during development, and FIG. 14 is a sectional view of the eccentric cam when returning to the origin. 3... Microcapsule paper, 4... Color developer paper, 9
．． 10...Work roller, II...Eccentric cam, I
2...Cam drive means, 13...Cam position detection means, 14...Home return control means. Figure 8 Figure 9 Figure 10 Return to origin %II meeting Takuka Kasumi Figure S Figure 6 Figure 7 Figure 13 74m Figure 11 Figure 12

Claims (1)

[Claims] In a pressure developing device that applies pressure to photosensitive and pressure-sensitive paper using a pair of work rollers arranged in parallel, the distance between the pair of work rollers is adjusted by rotation to the maximum distance that does not apply pressure to the photosensitive and pressure-sensitive paper. an eccentric cam for generating pressing force that is variably controlled between an open origin interval and a closing interval that presses the photosensitive and pressure-sensitive paper with the maximum pressing force in a predetermined range of pressing forces; a cam driving means for rotating the eccentric cam in forward and reverse directions; The rotational position of the eccentric cam is detected at a fixed position, and the detected signal level determines the origin position of the eccentric cam that brings the pair of work rollers to an open origin interval and the closed position of the eccentric cam that brings the pair of work rollers to a closed interval. and a cam position detection means that is reversed by the cam position detection means, and a detection signal level of the cam position detection means is determined based on a return-to-origin command signal from the outside, and based on the determination, the eccentric cam is rotated in the forward direction or rotated via the cam drive means. Rotate it in the opposite direction,
What is claimed is: 1. A pressure developing device comprising: an origin return control means for avoiding the closed position and returning to the origin position.