JPH04120536A - Image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus using a long photosensitive recording medium.

[Prior Art] Conventionally, a long length of light-sensitive pressure-sensitive paper (photosensitive recording medium) wound into a roll is pulled out and an original image is exposed to the paper to form a latent image, and the exposed light-sensitive pressure-sensitive paper is then exposed to light. An image forming apparatus has been proposed that is configured to develop images by overlapping them with colored paper. For example, the technique disclosed in Japanese Unexamined Patent Publication No. 63-231345 is an example of such an image forming apparatus,
Figure 4 shows its schematic configuration.

The image forming apparatus shown in FIG. 4 is configured to expose a long photosensitive pressure sensitive paper M while moving it on an exposure table R. In this case, it is preferable in terms of image quality that the conveying speed of the photosensitive and pressure sensitive paper M is the same as the exposure speed, and for this purpose, the photosensitive and pressure sensitive paper M must be stably conveyed.

In order to stably transport the photosensitive and pressure sensitive paper M, the most important factor is the structure of the feed roller I that transports it. This is because if uneven feeding occurs in the feeding roller (2), the image quality will naturally deteriorate. For this reason, the present applicant
No. 172 proposes a technique in which a feed roller is driven by a drive means comprising a worm and a worm wheel. This proposed technique prevents uneven feeding by attaching a worm wheel to the shaft of the feed roller and engaging the worm with the worm wheel.

[Problems to be Solved by the Invention] However, in the above configuration, when the rotation of the worm is switched from normal rotation to reverse rotation, the direction of the thrust load applied to the hasp gear attached to the roller shaft is reversed.

For this reason, the direction of the thrust load acting on the feed roller is reversed depending on the rotation direction of the feed roller, and if the photosensitive and pressure sensitive paper is nipped by the feed roller in this state,
The photosensitive pressure sensitive paper moves in the axial direction together with the feed roller. As a result, wrinkles and meandering occur in the photosensitive and pressure sensitive paper, resulting in a problem of deterioration of image quality.

Also, in order to prevent the feed roller from moving (1. For example, is it possible to incorporate an adjustment mechanism into the device to adjust the axial play of the feed roller? In this case, such an adjustment mechanism A new problem arises in that not only is the cost of adjusting the structure relatively high, but additional management is required to adjust the looseness.

The present invention has been made in view of the above circumstances, and it is possible to transport a photosensitive recording medium stably, thereby preventing wrinkles and meandering of the photosensitive recording medium and improving image quality. The purpose is to provide a forming device.

[Means for Solving the Problems] The image forming apparatus of the present invention has a first
a driving means having a roller and a second roller, a worm and a worm wheel for driving the first roller;
rotating the first roller in the forward direction while maintaining the nip means for nipping the photosensitive recording medium in cooperation with the roller, and the nipping means when transporting the photosensitive recording medium in the forward direction; The apparatus includes a control means for canceling the nip state and rotating the second roller in the reverse direction without causing the first roller to rotate in the reverse direction when the photosensitive recording medium is conveyed in the reverse direction.

[Function] In the image forming apparatus having the above configuration, since the first roller is driven by a drive mechanism having a worm and a worm wheel, it is possible to prevent uneven feeding of the photosensitive recording medium. Since the forward feeding of the photosensitive recording medium is carried out by the first roller and the reverse feeding is carried out by the second roller, there is no need to switch the rotational direction of the first roller.

Therefore, movement of the first roller in the thrust direction can be prevented, and meandering and wrinkling of the photosensitive recording medium can be prevented.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view showing a copying machine (image forming apparatus) 1 according to an embodiment. The copying machine 1 includes a microcapsule paper 12 as a photosensitive recording medium and a color developing paper (hereinafter referred to as recording paper) 2.
8 is used. Note that microcapsules are coated on the surface of the support of the microcapsule paper 12 used in this example, and the microcapsules contain a dye precursor that reacts with a color developer described later. .

On the other hand, a color developer is applied to the surface of the recording paper 28.
It develops color by reacting with a dye precursor. More information on this can be found in U.S. Patent No. 439920.
It is described in the specification of No. 9, etc., and the explanation here will be omitted.

At the top of the copying machine 1, there is a document table glass 2 and a document table cover 3.
is arranged, and a desired original 4 is placed on the original platen glass 2.
is placed face down, and the document table cover 3 is closed in this state.

A light source section 5 including a reflecting mirror 8, a halogen lamp 5a, and a reflector 5b is arranged below the document table glass 2 at the top of the copying machine 1. The light source section 5 is slidably supported on a shaft 13 installed parallel to the document table glass 2, and is capable of reciprocating along the shaft 13. The light source section 5 is configured to emit light in a line toward the document glass 2, and the irradiated light passes through the transparent document glass 2 and passes through the document 4 placed on it. is reflected downward.

A mirror portion 9 equipped with reflective mirrors 9a and 9b that is movable separately from the light source section 5 is arranged below the document table glass 2, and the light reflected from the document 4 is directed to the reflective mirror 8. ．．
The light beams 9a and 9b are reflected in this order and guided in parallel to the moving direction of the light source section 5.

Further, below the document platen glass 2, a projection lens 7 whose position is usually fixed and a filter 6 for adjusting the color tone of the copied image are arranged. The light reflected by the reflection mirror 9b enters the projection lens 7, and the light projected by the projection lens 7 is reflected by the reflection mirrors 10a, 10b, and 10c arranged ahead of the projection lens 7.

Microcapsule paper 12 is placed on the right side of the reflective mirror 10b.
An exposure table 11 is arranged for exposing. A reflecting mirror 10c arranged between the reflecting mirror 10b and the exposure table 11 switches the optical path of the light. With this configuration, image information on the document 4 is formed on the microcapsule paper 12 arranged along the exposure table 11.

In addition, although the positions of the reflecting mirrors 10a and 10b are normally fixed, in order to enlarge or reduce the size of the latent image formed on the microcapsule paper 12, the set projection magnification (m) In order to change the optical path length in accordance with the above, the light beams are configured to be movable together in the axial direction of the shaft 13.

On the other hand, a cartridge 15 is detachably installed in the center of the copying machine 1. Inside the cartridge 15,
A long length of microcapsule paper 12 is held in a wound state around a cartridge shaft 14. Then, with this cartridge 15 set at a predetermined position in the copying machine 1, the leading end of the microcapsule paper 12 is pulled out toward the exposure table 11.

A feed roller (first roller) 20, which will be described in detail later, is arranged below the exposure table 11, and a dancer roller 21 for adjusting the tension of the microcapsule paper 12 is arranged below the feed roller 2G. has been done. dancer
On the right side of the roller 21, there is a large diameter roller 22a and a backup roller 22 that is pressed against the large diameter roller 22a.
A pressure developing device (developing means) 22 is provided. A separation roller 23 is arranged on the right side of the pressure developing device 22 for separating the microcapsule paper 12 and the recording paper 28 which are in close contact with each other. Further, a winding shaft 24 for winding up the used microcapsule paper 12 is arranged between the separation roller 23 and the cartridge 15. With this, cartridge 1
The microcapsule paper 12 that comes out from the top of the paper 5 is guided by rollers 17a and 17b placed ahead of it and placed on the exposure table 11.
After passing above, it is sent out by the feed roller 2o, passes through the dancer roller 21 and the pressure developing device 22, is further guided to the separation roller (second roller) 23° 23A, and is then wound around the winding shaft 24. It is about to be taken. Note that the unexposed microcapsule paper 12 after leaving the cartridge 15 is maintained in an unexposed state by a light shielding cover (not shown).

A paper feed cassette 29 containing recording paper 28 is arranged below the pressure developing device 122 . Paper cassette 29
A suction cup-type paper feed mechanism 30 that sucks paper using negative pressure suction is arranged above the paper feed mechanism 30, and the recording paper 28 is taken out one by one by the paper feed mechanism 30. A feed guide 31d and a feed roller 31a are provided between the paper feeding mechanism 30 and the pressure developing device 22.

31b and 31c are arranged, and the recording paper 28 is conveyed by the feed rollers 31a, 31b, 31c, and the feed guide 31 (i) and carried into the pressure developing device 22.

Further, on the right side of the pressure developing device 22, a separation chute 27 is provided.
is arranged, and a heat fixing device 32 is arranged on the right side of the separation chute 27. On the right side of the thermal fixing device 32, a paper discharge tray 33 is arranged to store the recording paper 28 on which an image is formed.

Next, the configuration of the feed roller 20 and its drive mechanism, which is a feature of the present invention, will be explained in detail with reference to FIGS. 2(A) and 2(B).

Reference numerals 210a and 210b in FIG. 2(A) are frames inside the copying machine 5, and 209 is a motor for rotating the feed roller 20. In FIG. The frames 210a and 210b include
Both ends of the feed roller 20 are rotatably supported.

The feed roller 20 is configured by uniformly wrapping rubber 202 (for example, SBR rubber, hardness Hs 90 degrees) around the outer periphery of the feed roller M2O1. In addition, the feed roller shaft 2
Hasbagya (worm wheel) 20 is attached to one end of 01.
7 is installed. On the other hand, a worm gear 208 is attached to the output shaft of the motor 209, and the worm gear 208 meshes with the helical gear 207.

Further, on the outer peripheral side of the feed roller 20, a nip roller nub means 20A is arranged so as to be able to approach and separate from the feed roller 20. Torsion springs 211 are attached to both ends of this nip roller 2OA. As a result, the nip roller 2OA is brought into contact with the feed roller 20 with a force F, and the microcapsule paper 12 can be nipped and sent out by the frictional force between the feed roller 20 and the nip roller 2OA.

Here, a rubber 204 is evenly wrapped around the outer circumference of the roller shaft 203 of the nip roller 2OA, and the rubber 204
By setting the hardness of 04 to below s80 degrees,
Damage to the microcapsules on the surface of the microcapsule paper 12 is suppressed. In addition, the symbols 205 and 20 in the figure
6 is a bearing.

Next, a release mechanism for releasing the nip state between the nip roller 2OA and the feed roller 20 will be described with reference to FIG.

A frame 210a inside the copying machine 1 shown in Figure 2.

210b (not shown in FIG. 3) rotatably supports a shaft 215 parallel to the nip roller 2OA.

At both ends of this shaft 215, arms 219a,
219b is attached, each arm 219a, 219b
One end of the link plate 220 is rotatably connected to the end of a link plate 220 rotatably attached to both ends of the nip roller 2OA. Further, a gear 216 is rotatably supported on the frame 210b, and one side of the gear 216 has a
A cam 216a is fixed in sliding contact with the other end of the arm 219b. This gear 216 meshes with a gear 217 attached to the output shaft of a motor 218.
The cam 216a is rotated by the rotation of the output shaft No.8.

When the nip is to be released, the motor 218 is driven and the rotation of its output shaft is transmitted to the cup 2l6a via the gears 217 and 216. Then, the cam 216a pushes one end of the arm 219b in the M direction, and the arm 219
The other ends of a and 219b pull the link plate 220 in the M2 direction.

As a result, the nip roller 2OA is rotated by the torsion spring 211.
It moves in the M2 direction against the urging force of , and is separated from the feed roller 20.

Next, the overall operation of the copying machine 1 having the above configuration will be explained.

When a copy start key (not shown) provided in the copying machine 1 is operated, the microcapsule paper 12 is conveyed. Then, the halogen lamp 5a is turned on, and the reflection mirror 8 and the halogen lamp 5a
If the transport speed of 2 is ■ and the projection magnification is m, then the moving speed (
The reflecting mirrors 9a and 9b move at a moving speed (1/2 m)V.

The conveyance speed of the microcapsule paper 12 is mirror 8°9a,
Since the moving speed of the original document 4 is synchronized with the moving speed of the document 9b, latent images of predetermined lines of the original document 4 are sequentially formed on the microcapsule paper 12 as it passes through the exposure table 11.

Note that the predetermined speed ratio is predetermined based on the set value of the magnification.

The microcapsule paper 12 on which the latent image has been formed is sent out by the feed roller 20 and the nip roller 2OA, and is carried into the pressure developing device 22. In synchronization with this loading, the uppermost recording paper 28 of the paper feed cassette 29 is taken out by the paper feed mechanism 30. Then, the recording paper 28 is transferred to the feed roller 3
1a, 31b.

Continuously conveyed by the roller 31C, the pressure developing device 22
sent to. Next, the recording paper 28 is transferred to the pressure developing device 22.
Before reaching the microcapsule paper 12, the microcapsule paper 12 is brought into close contact with the microcapsule paper 12, and in this state, it is supplied to the pressure developing device 22. At this time, the microcapsule surface of the microcapsule paper 12 on which the latent image has been formed comes into contact with the developer-coated surface of the recording paper 28 on the inside, and is sandwiched between the large-diameter roller 22a and the backup roller 22b. This applies pressure. This pressure destroys the unexposed microcapsules and forms an image on the recording paper 28.

After the microcapsule paper 12 and the recording paper 28 that have come out of the pressure developing device 22 are separated by a separation roller 23,
After the recording paper 28 is accelerated in color by the heat roller 32a of the heat fixing device 32 and an image is formed, the recording paper 28 is transferred to the paper ejection roller 3.
2b, the paper is delivered to the paper discharge tray 33. Further, the separated microcapsule paper 12 is passed through a separation roller 23 and wound onto a winding shaft 24 .

The above is an outline of the operation of the copying machine 1, and the operations of the feed roller 20 and the nip roller 2OA will be explained in detail as follows. In the following description, it is assumed that the teeth of the worm gear 208 and the helical gear 207 are formed in a right-handed screw direction.

The worm gear 208 is rotated by the rotation of the motor 209.
Rotation in direction C in Figure (A) results in forward rotation (copy operation), and rotation in direction d results in reverse rotation. Now, when the worm gear 208 rotates in the C direction, the helical gear 207 rotates in the b direction, and a thrust load acts in the C direction due to the helix angle of the teeth.

At this time, if the positions of the worm gear 208 and the feed roller 20 are fixed, the feed roller 20 will move in the C direction by the amount of play in the shaft. On the other hand, when the worm gear 208 rotates in the d direction, the helical gear 207 reverses in the C direction, and the feed roller 207 rotates in the C direction.
0 will move in the f direction.

However, in the copying machine 1 described above, the feed roller 20 is driven only during normal rotation. At this time, nip roller 2OA
are in a nip state due to the biasing force F of the torsion spring 211. During reverse rotation (winding up the unexposed microcapsule paper 12), the feed roller 20 is not driven, and the nip roller 2O is not driven.
The microcapsule paper is sent back by the separation roller 23.2'3A and the microcapsule paper is wound up from the winding shaft 24. Then, the microcapsule paper 1 is sent back by the separation rollers 23 and 23A.
2 is rewound toward the cartridge 15 by the pack tension applied to the cartridge shaft 14.

In this way, in the copying machine 1 having the above configuration, a thrust load in one direction is always applied to the feed roller 20, which is the center of feeding the microcapsule paper 12, during copying (normal rotation). The roller 20 does not move in the axial direction, and the microcapsule paper 12 can be prevented from meandering or wrinkling.

Note that the present invention is not limited to the above embodiments,
For example, various known mechanisms can be applied to the nip release mechanism of the nip roller 20A.

[Effects of the Invention] As explained above, according to the present invention, a driving means having a first roller and a second roller that convey a photosensitive recording medium, a worm and a worm wheel that drives the first roller, and a driving means that has a worm wheel that drives the first roller; When the photosensitive recording medium is conveyed in the forward direction, the first roller is rotated in the forward direction while maintaining the nip state between the nip means that nip the photosensitive recording medium in cooperation with the nip means and the nip means when the photosensitive recording medium is conveyed in the forward direction. When the roller is conveyed in the reverse direction, the nip state is canceled and the second roller is rotated in the reverse direction without causing the first roller to rotate in the reverse direction. A thrust load in one direction always acts on the feed roller 20 that conveys the medium. Therefore, the feed roller does not move in the axial direction during reverse rotation, and the photosensitive recording medium can of course be stably transported, and the meandering and wrinkles of the photosensitive recording medium can be prevented. This has the effect of being able to.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention,
FIG. 1 is a side sectional view of the image forming apparatus, FIG. 2(A) is a side sectional view showing details of the feed roller and its drive mechanism, and FIG. 2(B) is an arrow in the direction of FIG. 2(A). FIG. 3 is a perspective view showing a nip release mechanism using nip rollers, and FIG. 4 is a side sectional view showing an example of a conventional image forming apparatus. 20...Feeding roller (first roller), 22...Pressure developing device (developing means), 23...Separation roller (second roller), 2OA...nip roller (slip means), 20
7... Hasbagya (worm wheel), 208...
・Worm gear (worm). Applicant's representative Yasushi Ishikawa 19a Figure

Claims (1)

[Scope of Claims] An image forming apparatus comprising an exposure means for exposing a long photosensitive recording medium to form a latent image and a developing means for developing the latent image after exposure, the image forming apparatus comprising: transporting the photosensitive recording medium; a driving means having a worm and a worm wheel that drives the first roller; a nipping means that cooperates with the first roller to nip the photosensitive recording medium; When the medium is transported in the forward direction, the first roller is rotated in the forward direction while maintaining the nip state with the nipping means, and when the photosensitive recording medium is transported in the reverse direction, the nip state is released. An image forming apparatus comprising: a control means for rotating the second roller in the reverse direction without rotating the first roller in the reverse direction.