JP2002040617A - Image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-forming device which can satisfactorily rewind a photosensitive material. SOLUTION: The image-forming device 10 exposes the rolled photosensitive material 18 by a scanning unit 26 and superposes the photosensitive material on image-receiving paper 42 on a heat drum 36, thereby images are formed on the image receiving paper 42. In this image-forming device 10, unexposed portions, in continuation with the exposed portions of the photosensitive material 18, reach at the heat drum 36. Since image formation is possible in the unexposed portions, the photosensitive material is rewound to the exposed position. At this time, the heat drum 36 is driven and rotated backward (in the rewinding direction), by which the rewinding resistance is lowered, and the rewinding of the photosensitive material 18 is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus in which a photosensitive material is efficiently used.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus has been used in which a predetermined image is formed on an image receiving material by exposing the image to the photosensitive material and transferring the image from the photosensitive material to the image receiving material.

In such an image forming apparatus, a roll-shaped photosensitive material is used, and an image is formed on the image receiving material by superposing the continuously exposed photosensitive material on an image receiving material on a heat drum.

In this case, since the roll-shaped photosensitive material is continuous, the unexposed portion follows the exposed portion and reaches the transfer position beyond the exposed position. Therefore, after the transfer of the exposed portion of the photosensitive material is completed, the unexposed portion of the photosensitive material is rewound to the exposure position and exposed to thereby use the photosensitive material efficiently.

[0005]

However, the exposed portion of the photosensitive material which has been coated with water and heated on the heat drum has viscosity, and has a large adhesive force with the outer peripheral surface of the heat drum. Therefore, if the heat drum is stopped during the rewinding of the photosensitive material, there is a disadvantage that the exposed portion of the photosensitive material having an adhesive force slides on the heat drum to increase the rewinding resistance.

The present invention has been made in view of the above circumstances, and has as its object to provide an image forming apparatus capable of satisfactorily rewinding a photosensitive material.

[0007]

According to the first aspect of the present invention,
In an image forming apparatus for exposing a photosensitive material at an exposure position to form an image and transferring an image formed on the photosensitive material to an image receiving material at a transfer unit, the photosensitive material is wound around the image receiving material at the transfer unit. A heat drum to be hung, and a driving unit for driving the heat drum to rotate in the conveying direction, wherein when the unexposed portion of the photosensitive material is rewound to the upstream side in the conveying direction from the exposure position after the transfer, the driving unit Drives the heat drum to rotate in the direction opposite to the transport direction.

The operation of the first aspect of the present invention will be described.

When rewinding the unexposed portion of the photosensitive material that has reached the transfer portion at the end of the transfer, the exposed portion of the transferred photosensitive material passes over the heat drum. At this time, if the heat drum is stopped, the transferred photosensitive material having adhesiveness slides on the heat drum, and the rewind resistance increases. Therefore, in the present invention, when the photosensitive material is rewound, the heat drum is rotationally driven by the driving means in the direction opposite to the transport direction, so that the sliding amount of the photosensitive material on the heat drum is suppressed and the rewind resistance is reduced.

According to a second aspect of the present invention, there is provided an image forming apparatus, wherein an image is formed by exposing a photosensitive material at an exposure position, and an image formed on the photosensitive material is transferred to an image receiving material at a transfer unit. A heat drum in which the photosensitive material is wound around in superposition with the image receiving material, and a driving unit for driving the heat drum to rotate in the transport direction,
When the unexposed portion of the photosensitive material is rewound to the upstream side in the transport direction from the exposure position after the end of the transfer, the transmission of the driving force between the driving unit and the heat drum is cut off, and the rewound of the photosensitive material is rewound. Accordingly, the heat drum is driven in a direction opposite to the conveying direction.

The operation of the second aspect of the present invention will be described.

When rewinding the unexposed portion of the photosensitive material that has reached the transfer portion at the end of the transfer, the exposed portion of the transferred photosensitive material passes over the heat drum. At this time, when the heat drum is stopped, the transferred photosensitive material having adhesiveness slides on the heat drum, and the resistance of rewinding increases. According to the present invention, when the photosensitive material is rewound, the drive means and the transmission system of the driving force of the heat drum are cut off, so that the heat drum follows the direction opposite to the transport direction together with the photosensitive material as the photosensitive material is rewound. Therefore, the sliding amount of the photosensitive material on the heat drum is suppressed, and the rewind resistance to the photosensitive material is reduced.

[0013] The invention according to claim 3 is the invention according to claim 1 or 2.
In the invention described in the above, there is provided a separating means for separating the photosensitive material from the heat drum so that an unexposed portion continuous to the exposed portion of the photosensitive material does not contact the heat drum, and rewinding the photosensitive material via the separating means. It is characterized by.

The operation of the third aspect of the present invention will be described.

The unexposed photosensitive material reaches the heat drum continuously after the exposed photosensitive material. At this time, since the unexposed photosensitive material is configured to be separated from the heat drum by the separating means, it is possible to prevent the unexposed photosensitive material from contacting the heat drum and becoming unusable for image formation.

Further, since the photosensitive material is rewound via the separating means, the distance of contact of the photosensitive material with the heat drum is reduced as compared with the time of the transfer, so that the rewound resistance of the photosensitive material is reduced.

According to a fourth aspect of the present invention, in the third aspect of the invention, the separating means is a rotatable shaft disposed at a position separated from the outer peripheral surface of the heat drum, and the photosensitive material is provided on the shaft. Is wound and unwound.

The operation of the fourth aspect of the present invention will be described.

Since the separating means is a rotatable shaft around which the photosensitive material is wound, the rewind resistance when the exposed photosensitive material is unwound is reduced.

According to a fifth aspect of the present invention, in the third aspect of the present invention, the separating means is a shaft disposed at a position separated from an outer peripheral surface of the heat drum, and is rotatable with respect to the shaft. With a hollow roller,
The photosensitive material is wound around the roller and rewound.

The operation of the invention according to claim 5 will be described.

Since the photosensitive material is wound around a roller rotatable with respect to the shaft and unwound, the rewind resistance of the photosensitive material is reduced.

According to a sixth aspect of the present invention, in the third aspect of the invention, the separating means is disposed at a position separated from the outer peripheral surface of the heat drum, and the outer peripheral surface is subjected to a surface treatment for reducing friction. A shaft, wherein the photosensitive material is wound around the shaft and rewound.

The operation of the invention according to claim 6 will be described.

Since the outer peripheral surface of the shaft is subjected to a surface treatment for reducing friction, the rewind resistance when the photosensitive material wound around the shaft is unwound is reduced.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to one embodiment of the present invention will be described. (Schematic description of image forming apparatus)
First, the outline of the image forming apparatus 10 will be described.

As shown in FIG. 1, a photosensitive material 18 wound around a supply reel 16 is set in a photosensitive material magazine 14 disposed below the housing 12 of the image forming apparatus 10. The supply reel 16 is rotated by driving means (not shown) to unwind the photosensitive material 18.

The front end of the photosensitive material 18 is nipped by a nip roller 20 provided at a mounting opening of the photosensitive material magazine 14. The nip roller 20 pulls out the photosensitive material 18 under predetermined conditions and sends it out to the guide plate 22.

The photosensitive material 18 having passed through the guide plate 22 is
An image is exposed around the exposure drum 24 by the scanning head 26. In this way, the photosensitive material 18 is wound around the exposure drum 24 and exposed to light, whereby the photosensitive material 1 is exposed.
No wrinkles or the like occur in the width direction of No. 8 and the flatness of the exposed surface can be ensured.

The photosensitive material 18 on which the image has been exposed is sandwiched between a support 28 and a pressure bonding plate 30, and water is applied by a water-absorbing coating member 34 (such as a sponge) provided on a water coating bottle 32.

The photosensitive material 18 to which water has been applied is wrapped around a heat drum 36 containing a halogen lamp by tension rollers 38 and 40 at a constant pressure. The wound photosensitive material 18 is superposed from above on an image receiving material 42 described later while being heated, and transfers an image.

The photosensitive material 18 on which the image has been transferred is taken up on a waste reel 44. In this way, by transferring the photosensitive material 18 from the supply reel 16 to the waste reel 44 without cutting, the photosensitive material 18 itself functions as a timing belt that applies a certain pressure to the image receiving material 42.

On the other hand, an image receiving material 42 wound around a supply reel 48 is set in a receiving material magazine 46 disposed above the housing 12. This image receiving material 42
Is pulled out by a nip roller 49 and cut by a cutter 50 to a predetermined length, and then is conveyed by a transport roller 52 and a guide plate 5.
3 and is wound around a heat drum 36 while being superposed on the photosensitive material 18.

In the case of continuous transfer, the tension roller 38 is at the transfer position shown in FIG. 2, and the photosensitive material 18 on which an image has been formed is pressed against the image receiving material 42 between the tension rollers 38 and 40 on the heat drum 36. Is transferred continuously.

When only one sheet is transferred, or when the last image receiving material 42 that is continuously transferred is transferred, the tension roller 38 moves along the guide groove 90 together with the rear end of the image receiving material 42. Then, the separation rollers 84, 86, 88 of the movable arm 82 separate the unexposed photosensitive material 18 from the heat drum 36 (see FIG. 3). This prevents the unexposed photosensitive material 18 from contacting the heat drum 36 to prevent the image from being unable to be formed. The unexposed photosensitive material 18 is rewound to the photosensitive material magazine 14 after the transfer is completed.

On the other hand, the image receiving material 42 to which the image has been transferred from the photosensitive material 18 is peeled off from the heat drum 36 by a peeling claw (not shown), guided by the transport roller 54 and the guide plate 56, and reaches the tray 58. (Description of Main Part) As shown in FIG.
Gear mechanism 1 in which driving force of motor 100 is composed of a plurality of gears
02 and the gear 104 on the side surface of the heat drum 36, and is rotatable in both the transport direction (counterclockwise in the figure) and the rewind direction (clockwise in the figure).

As shown in FIG. 5, the separation rollers 84, 86 and 88 are rotatably supported by a pair of movable arms 82 via bearings 106. Therefore, the photosensitive material 18 wound around the separation rollers 84, 86, 88 is conveyed, thereby causing the separation rollers 84, 86, 88 to be separated.
Rotate. (Operation) The operation of the image forming apparatus 10 thus configured will be described.

When an image is to be formed, the unexposed photosensitive material 18 is exposed on the exposure drum 24 by the scanning unit 26, and after the water of the water application bottle 32 is applied through the application member 34, An image is formed on the image receiving paper 42 by being superimposed on the image receiving paper 42 formed in a sheet shape on 36.

Since the photosensitive material 18 is in the form of a roll, the unexposed portion reaches the position of the heat drum 36 following the exposed portion. At this time, the movable arm 82 rotates along the guide groove 90 together with the unexposed portion that is continuous with the exposed portion of the photosensitive material 18 to be transferred to the last image receiving material 42, and the heat drum 82 36 (see FIG. 3).

When the transfer to the image receiving paper 42 is completed, the conveyance of the photosensitive material 18 is moved, and the unexposed portion of the photosensitive material 18 is rewound upstream from the exposure position (exposure drum 24). At this time, the drive motor 100 is driven to rotate in the rewinding direction (clockwise in the figure).

The exposed portion of the photosensitive material 18 is moved between a tension roller 40 and a tension roller 38 by a heat drum 36.
, And passes over the separation rollers 84, 86, 88 to be rewound. As a result, the leading end of the unexposed portion of the photosensitive material is located at least upstream in the transport direction from the exposure position.

After the rewinding is completed, the arm 82 and the tension roller 38 rotate counterclockwise along the guide groove 90, and return to the state shown in FIG.

As described above, when rewinding, the heat drum 36
Is rotated in the rewinding direction, so that even if the exposed portion of the photosensitive material 18 which has adhesiveness due to being applied with water and heated adheres to the heat drum 36,
6 is suppressed, and it is easy to separate from the heat drum 36. In particular, it is preferable that the rotation speed of the heat drum 36 be substantially the same as the rewind speed of the photosensitive material 18 because the sliding amount on the heat drum 36 is most suppressed and the rewind resistance is further reduced.

Further, the movable arm 82 is moved back when rewinding as shown in FIG.
, The length of the exposed portion of the photosensitive material 18 in contact with the heat drum 36 is reduced as compared with that at the time of transfer, and the rewind resistance is reduced.

Further, since the separation rollers 84, 86 and 88 are rotatable, the photosensitive material 18 is separated from the separation roller 8
4, 86, 88, the resistance at the time of winding and rewinding is reduced.

As described above, by reducing the rewind resistance of the photosensitive material 18, the unexposed portion of the photosensitive material 18 that has reached the heat drum 36 can be satisfactorily rewound to the exposure position.

In this embodiment, the heat drum 36 is driven to rotate in the rewinding direction. However, only the driving force in the conveying direction is transmitted, and the driving force is transmitted in the direction opposite to the conveying direction (rewinding direction). By disposing a gear 108 (see FIG. 4) with a one-way clutch that does not transmit the heat, the heat drum 36 can be rotatable in the rewinding direction. With this configuration, when the photosensitive material 18 is rewound, the photosensitive material 18 having an adhesive property adheres to the heat drum 36, and
6 rotates (follows) in the rewinding direction. Therefore, the rewind resistance of the photosensitive material 18 can be suppressed.

In this embodiment, the separation roller 84,
Although 86 and 88 are rotatable with respect to the movable arm 82, the shaft 110 is fixed to the movable arm and the rotatable roller 112 is attached to the shaft 110 to reduce the rewind resistance. be able to.

Further, for the same purpose, the separation roller 84,
The surface of each of the surfaces 86 and 88 is treated to reduce sliding resistance (for example,
By performing Teflon (registered trademark) processing, the sliding friction of the photosensitive material 18 with respect to the separation rollers 84, 86, and 88 can be reduced. In this case, as shown in FIG. 5 and FIG. 6, instead of a rotatable member such as a roller or a roller, a shaft having a fixed shaft subjected to a surface treatment may be used.

[0050]

As described above, the image forming apparatus according to the present invention can reduce the rewinding resistance when the unexposed photosensitive material rewinds the photosensitive material to the exposure position, and can satisfactorily rewind the photosensitive material.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a transfer unit of the image forming apparatus according to one embodiment of the present disclosure.

FIG. 3 is a schematic configuration diagram of a transfer unit of the image forming apparatus according to the embodiment of the present disclosure.

FIG. 4 is a view showing a drive mechanism of a heat drum according to one embodiment of the present invention.

FIG. 5 is an explanatory diagram of a separation roller according to an embodiment of the present invention.

FIG. 6 is a rotation diagram of a separation roller according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 14 ... Sensitive material magazine (light shielding part) 18 ... Photosensitive material 20 ... Nip roller (conveying means) 26 ... Scanning head (exposure position) 36 ... Heat drum (transfer part) 38, 40 ... Tension roller (transfer part) 42: image receiving material 100: drive motor (drive means)

Claims (6)

[Claims] 1. An image forming apparatus for exposing a photosensitive material at an exposure position to form an image and transferring an image formed on the photosensitive material to an image receiving material at a transfer unit, wherein the photosensitive material is transferred to the image receiving material at the transfer unit And a driving means for rotating and driving the heat drum in the conveyance direction, wherein the unexposed portion of the photosensitive material is rewound to the upstream side in the conveyance direction from the exposure position after the transfer is completed. An image forming apparatus, wherein the driving unit rotationally drives the heat drum in a direction opposite to a conveying direction. 2. An image forming apparatus for exposing a photosensitive material at an exposure position to form an image and transferring an image formed on the photosensitive material to an image receiving material at a transfer unit, wherein the photosensitive material is transferred to the image receiving material at the transfer unit And a driving means for rotating and driving the heat drum in the conveyance direction, wherein the unexposed portion of the photosensitive material is rewound to the upstream side in the conveyance direction from the exposure position after the transfer is completed. An image forming apparatus, wherein the transmission of the driving force between the driving unit and the heat drum is cut off, and the heat drum is driven in a direction opposite to a conveying direction as the photosensitive material is rewound. 3. A rewinding device for separating a photosensitive material from a heat drum so as to prevent an unexposed portion of the photosensitive material from being exposed to an unexposed portion from contacting the heat drum, and rewinding the photosensitive material via the separating device. Claim 1 characterized by the following:
Or the image forming apparatus according to 2. 4. The apparatus according to claim 1, wherein the separation unit is a rotatable shaft disposed at a position separated from an outer peripheral surface of the heat drum, and the photosensitive material is wound around the shaft and rewound. Item 4. The image forming apparatus according to Item 3. 5. The separation means includes: a shaft disposed at a position separated from an outer peripheral surface of the heat drum; and a hollow roller rotatable with respect to the shaft. 4. The image forming apparatus according to claim 3, wherein the image is wound and rewound. 6. The separating means is a shaft disposed at a position separated from the outer peripheral surface of the heat drum and having a surface treatment for reducing friction on the outer peripheral surface, wherein the photosensitive material is wound around the shaft. The image forming apparatus according to claim 3, wherein the image forming apparatus is rewound.