JP2530024Y2 - Photosensitive material transport device for copy camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photosensitive material transport device of a copying camera for exposing a document image on a photosensitive material such as a master paper to create a printing plate or the like.

[Conventional technology]

As a photosensitive material transporting device for appropriately feeding a photosensitive material wound in a roller shape in a copying camera to an exposure unit, for example, a photosensitive material conveying device disclosed in Japanese Patent Application Laid-Open No. 59-48343 by the present applicant is known. I have. In this apparatus, a one-way clutch (also referred to as a one-way clutch) that transmits rotational power only in the direction in which the photosensitive material is transferred is provided on the shaft of the transfer roller, thereby simplifying the structure of the transfer apparatus.

[Problems to be solved by the invention]

By the way, there is a case where it is desired to replace the light-sensitive material with another kind of light-sensitive material. At this time, it is necessary to rewind the light-sensitive material in a direction opposite to a normal transport direction. However, in a device in which a one-way clutch is provided on the shaft of the transport roller, there is a problem that it is difficult to rewind the photosensitive material. For example, even if the driving motor for rotating the one-way clutch in the transfer direction is reversed, the photosensitive material cannot be rewound because the one-way clutch idles. Also, if you try to rewind the photosensitive material by reversing the other transport rollers that do not have a one-way clutch, the one-way clutch locks and prevents the photosensitive material from rewinding. There was a problem that it could not be returned.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problem in the prior art, and is to provide a light-sensitive material transporting device using a one-way clutch, which can easily rewind the photosensitive material. The purpose is to do.

[Means for solving the problem]

In order to solve the above-mentioned problem, according to the invention of claim 1, in a photosensitive material transport device provided in a copying camera, a motor capable of rotating forward and reverse and a sheet-like photosensitive material are sequentially disposed in a predetermined transfer direction. A first and second pair of rollers for transferring the sheet-like photosensitive material; and a power transmission mechanism for transmitting the driving force of the motor to the first and second pair of rollers, respectively.
The first roller pair rotates forward / reverse upon receiving the driving force of the motor, and the power transmission mechanism is axially mounted on one of the second roller pairs and moves in the transfer direction. A one-way clutch for transmitting only the driving force of the motor;
The transfer speed of the first roller pair is set higher than the transfer speed of the first roller pair.

Further, in the invention of claim 2, the copying camera is provided with a cutting device for cutting the sheet-shaped photosensitive material, and the first and second copying devices are provided upstream of the cutting device in the transport direction. A roller pair is arranged.

[Action]

Since the transfer speed of the second roller pair provided with the one-way clutch is higher than the transfer speed of the first roller pair,
When the motor is rotated so as to rewind the photosensitive material in the direction opposite to the transport direction, the one-way clutch of the second roller pair is kept idle and does not enter the locked state.

〔Example〕

A. Schematic Configuration of Apparatus FIG. 1 is a side sectional view showing a main part of a slit exposure type copying camera to which an embodiment of the present invention is applied.

This copying camera includes an outer case 1, an original holder 2 provided on the outer case 1 so as to be able to run horizontally, a photosensitive material transport device 3 for transporting a sheet-like photosensitive material PM to an exposure position, A projection optical system 4 for irradiating light on the original held by the document and projecting light reflected by the original onto the photosensitive material PM, and a developing device 5 for developing and stabilizing the exposed photosensitive material PM And

The document holder 2 is a document table made of a transparent glass plate.
The document includes a document cover 21 and a document cover 22. The document is pressed and held between the document table 21 and the document cover 22. The document holder 2 is driven in a horizontal direction (left and right directions in the figure) by a motor 23 provided in the outer case 1.

The light-sensitive material transport device 3 includes first and second light-sensitive material rolls 31 and 32, and a sheet-shaped light-sensitive material PM is sent out from one of them as needed. In the example of FIG. 1, the photosensitive material PM is sequentially conveyed from the first photosensitive material roll 31, by three roller pairs 33 to 35. The exposure position is set between the two roller pairs 34 and 35. On the back side of the photosensitive material PM at the exposure position, a cutting device 36 for appropriately cutting the photosensitive material PM is provided. When the photosensitive material of the second photosensitive material roll 32 is used, the photosensitive material PM is sequentially conveyed by three roller pairs 37, 34, 35. The configuration and operation of the photosensitive material transport device 3 will be described later in detail.

The projection optical system 4 includes a light source 41 for irradiating the document held in the document holder 2 with light, mirrors 42 to 44 for reflecting light LB reflected from the document, and an image of the document on the photosensitive material PM. A projection lens 45 for forming an image and a slit 46 for limiting the width of the light LB projected on the photosensitive material PM are provided. In addition, an LED 4 for uniformly exposing the peripheral portion of the photosensitive material PM that cannot be exposed by the reflected light LB from the original for printing as a non-image forming unnecessary portion.
7 is provided below the roller pair 35.

In this copying camera, the projection optical system 4 can be adjusted to change the projection magnification. The mirrors 43 and 44 are fixed to the same support plate 44a, and the support plate 44a is driven by a motor (not shown) and slides on the slide table 48. Further, the support 45a of the projection lens 45 is also driven by a motor (not shown) and slides on the slide 48. In this way, by moving the mirrors 43 and 44 and the projection lens 45 in parallel, the projection magnification can be changed.

When performing copying, first, the original is set in the original holder 2, and while the original is illuminated with the light source 41, the original holder 2 and the photosensitive material are
Link with PM. That is, the document holder 2 is moved to the left in the figure, and the photosensitive material PM is sent out downward by the roller pairs 33 to 35. The reflected light LB from the document is sequentially reflected by the mirrors 42 to 44, passes through the projection lens 45 and the slit 46, and is then focused on the photosensitive material PM. Since the photosensitive material PM is conveyed simultaneously with the movement of the document holder 2, slit images of the document are sequentially projected on the photosensitive material PM. When the exposure is completed, the photosensitive material PM is cut by the cutting device 36 and sent to the developing device 5.

The exposed photosensitive material PM sent to the development processing device 5 is sequentially sent by a plurality of rollers, and undergoes development, fixing, and drying processes along a path indicated by a two-dot chain line in the figure. That is, the photosensitive material PM first passes through the developing tank 51 containing the developing solution, and then passes through the fixing tank 52 containing the fixing solution. Then, after passing through a drying section having a drying heater 53 and a fan 54,
It is carried out onto a tray 6 provided outside the outer box 1. Thus, the developed, fixed and dried photosensitive material PM becomes a printing plate for offset printing.

B. Structure and Operation of Sensitive Material Transporting Apparatus FIG. 2 is a schematic side view showing the photosensitive material transporting apparatus 3 in an enlarged manner. FIG. 3 is a perspective view of the main part. However,
These figures show a side opposite to that of FIG. 1 (that is, a view of the apparatus from the back side of the paper of FIG. 1).

Each drive roller 33a, 34a, 37 of the roller pair 33, 34, 37
Sprockets 33b, 34b, and 37b are axially mounted on a, respectively. These sprockets 33b, 34b, 37b are connected by a chain 39 to a sprocket 38a mounted on a motor 38 capable of rotating forward and backward. Note that the roller pair 33 (or 37) corresponds to the first roller pair in the configuration of the present invention, and the roller pair 34 corresponds to the second roller pair. Then, as described later in detail, the transfer speed of the roller pair 34 is configured to be higher than the transfer speed of the roller pairs 33 and 37.

FIG. 4 is a front view showing the drive roller 34a and the sprocket 34b. A one-way clutch 34c is incorporated inside the sprocket 34b. That is, the outer race of the one-way clutch 34c is fixed to the sprocket 34b, and the inner race is fixed to the shaft 34d of the drive roller 34a. When the sprocket 34b is driven around the time, the one-way clutch 34c locks the sprocket 34b and the drive roller 34a, and sends out the photosensitive material PM to the lower right direction in the figure. Conversely, when the drive roller 34a rotates clockwise relative to the sprocket 34b, the one-way clutch 34c enters an idle state. That is, clockwise angular velocity omega _r of the drive roller 34a is as large as the one-way clutch 34c than clockwise angular velocity omega _s of the sprocket 34b is idle.

On the other hand, in FIG. 2, two sprockets 33b, 37b
Are the driving rollers 33 via the electromagnetic clutches 33c and 37c, respectively.
a, 37a.

First, the operation when sending out the photosensitive material PM in the forward direction will be described. Initially, the tip of the photosensitive material PM of the first photosensitive material roll 31 and the second
The ends of the photosensitive material PM of the photosensitive material roll are located at the respective photosensitive material standby positions SP ₁ and SP ₂ . When supplying the photosensitive material PM from the first photosensitive material roller 31, the photosensitive material PM is first sandwiched between the roller pair 33. Then, the chain 39 is rotated clockwise by rotating the motor 38 in the forward direction. At this time, roller pair 33
The electromagnetic clutch 33c is turned on (gripping state), while the electromagnetic clutch 37c is turned off (idling state).
The on / off control of these electromagnetic clutches is performed by clutch control means, but is not particularly shown because it is simple. When the photosensitive material PM arrives at the next roller pair 34 after being sent out from the roller pair 33, it is driven by this roller pair 34 and further sent out in the direction of the next roller pair 35 having a higher transfer speed than the roller pair 34. Then, when the leading end of the photosensitive material PM reaches the exposure position (the position where the reflected light LB is projected), a sensor (not shown) detects this and turns off the electromagnetic clutch 33c of the roller 33a to idle. As a result, the photosensitive material PM is transported by the roller pair 34. Roller pair
The motor 35 is driven by a motor (not shown) different from the motor 38, and sends out the photosensitive material PM at a higher transfer speed than the roller pair 34. When the photosensitive material PM is sent out by the roller pair 35,
The one-way clutch 34c of the roller pair 34 having a low transfer speed idles. As a result, the photosensitive material PM is fed at the feed speed of the roller pair 35. At this time, even if the one-way clutch 34c idles, the nip force (pinching force) of the roller pair 34 is not lost.
It is transported while being tensioned between 4,35. As a result,
The light sensitive material PM between the two roller pairs 34 and 35 is stretched without sagging due to the tension, and the reflected light LB from the original is placed on the light sensitive material PM.
Is projected.

Next, an operation when the photosensitive material PM is rewound to the first photosensitive material roller 31 will be described. Normally, rewinding is performed after the photosensitive material PM is cut by the cutting device 36, so that the tip of the photosensitive material PM is at the position where the cutting is performed by the cutting device 36. When rewinding the photosensitive material PM.
The chain 39 is rotated by rotating the motor 38 in the reverse direction.
Turn counterclockwise. At this time, as in the forward operation. The electromagnetic clutch 33c of the roller pair 33 is turned on (gripping state), while the electromagnetic clutch 37c is turned off (idling state). As a result, the driving roller 33a of the roller pair 33, 34 rotates counterclockwise, but the sprocket 34b
The one-way clutch 34c is not locked by the counterclockwise rotation of the drive roller 34a, so that the drive roller 34a becomes a kind of free state (within the above ω _r > ω _s ) and the roller pair
The photosensitive material PM is rewound toward the photosensitive material roll 31 by 33.

Further, the situation at this time will be described in detail in relation to each roller diameter, transfer speed and the like. FIG. 5 is a conceptual diagram showing the operation of the two roller pairs 33 and 34 in the embodiment. Two sprockets 33b in this embodiment, 34b, the number of teeth H ₃ of, H ₄ are equal to each other. Therefore, the sprockets 33b and 34b rotate counterclockwise at the same angular velocity ω _s (rad / sec). In the figure, a negative sign is given to the counterclockwise angular velocity n. Since the electromagnetic clutch 33c incorporated in the driving roller 33a is in a gripping state, the driving roller 33a is
Rotates counterclockwise at the same angular velocity ω _s and 3b. Assuming that the outer diameter of the drive roller 33a is D ₃ (m), the speed of the outer peripheral surface of the drive roller 33a, that is, the transfer speed v (m / sec) of the photosensitive material PM is given by the following equation.

_{v = ω s D 3/2} ...... (1) the outer peripheral surface of the drive roller 34a of the roller pair 34 is tensile velocity v on the left side in the figure by the photosensitive material PM. Assuming that the outer diameter of the driving roller 34a is D ₄ (m), its counterclockwise angular velocity ω _r4
Is given by the following equation.

ω _r4 = 2v / D ₄ = ω _s D ₃ / D ₄ (2) As described above, the transfer speed of the roller pair 33 in the forward direction is set to be higher than the transfer speed of the roller pair 34. To achieve this, in this embodiment, the outer diameter D ₃ of the drive roller 33a, is set to be smaller than the outer diameter D ₄ of the drive roller 34a. Therefore, in the equation (2), the value of D ₃ / D ₄ is less than 1, and the magnitude relationship between the angular velocities ω _r4 and ω _s is expressed by the following inequality.

ω _r4 <ω _s (3) Equation (3) indicates that the counterclockwise angular velocity ω _r4 of the drive roller 34a during rewinding is equal to or less than the counterclockwise angular velocity ω _{s of} the sprocket 34b. I have. In other words, the drive roller 34a is moving clockwise relative to the sprocket 34b. Such a relative movement is a rotation in the opposite direction to the one-way clutch 34c as described above, so that the one-way clutch 34c
Spins. As a result, the photosensitive material PM is rewound at the speed v without being locked by the roller pair 34.

As described above, in this embodiment, the angular velocity ω _r4 of the drive roller 34a during the rotation in the reverse direction is set to be smaller than the angular velocity ω _{s of the} sprocket 34b. Can be rewound.

In the above embodiment, the number of teeth of the two sprockets 33b and 34b
Although N ₃ and N ₄ are equal, they may be different from each other. Angular velocities ω _s3 and ω _{s4 of} sprockets 33b and 34b
Is inversely proportional to the number of teeth N ₃ and N ₄ , respectively, and is expressed as follows.

ω _s3 = k / N ₃ (3) ω _s4 = K / N ₄ (4) where k is a constant.

The angular velocity of the driving roller 33a is the angular velocity ω _{s4 of the} sprocket 33b.
Is equal the velocity v ₃ of the outer periphery of the drive roller 33a is expressed as follows.

_{v 3 = ω s3 D 3/} 2 = kD 3 / 2N 3 ...... (5) photosensitive material PM at this speed v ₃ is rewound, further driving roller 34a by the photosensitive material PM is rotated counterclockwise. At this time, the angular velocity ω _r4 of the driving roller 34a is expressed by the following equation similar to the equation (2).

ω _r4 = 2v ₃ / D ₄ = kD ₃ / (D ₄ N ₃ ) ... (6) The photosensitive material PM without the one-way clutch 34c being locked
In order to rewind, the angular velocity ω _r4 of the drive roller 34a may be made smaller than the angular velocity ω _{s4 of the} sprocket 34b. That is, ω _r4 <ω _s4 (7) By substituting equations (4) and (6) into equation (7) and rearranging, the following equation is obtained.

D ₃ / N ₃ <D ₄ / N ₄ (8) Equation (8) is the outer diameter D ₃ of the driving roller 33a and the sprocket 3
The ratio between the number of teeth N ₃ and 3b is smaller than the ratio between the teeth number N ₄ of the outer diameter D ₄ and the sprocket 34b for driving rollers 34a, show that it is possible to rewind the photosensitive material PM.

In the above embodiment, the chain 39 and the sprocket 33a,
Although the roller pair 33, 34 was driven using 33b, the roller pair 33, 3 was driven using another power transmission mechanism such as a pulley and a belt.
4 may be driven. When a pulley and a belt are used, the number of teeth N ₃ and N ₄ of the sprocket in Expression (8) may be replaced with the diameter of each pulley.

Sprocket teeth N ₃ and N ₄ and drive roller outer diameters D ₃ and D ₄
Is set as shown in Expression (8), when the photosensitive material PM is fed in the forward direction, the transport speed of the roller pair 34 is larger than that of the roller pair.
33 transfer speed. At this time, if the nip pressure (pinching force) between the two roller pairs 33 and 34 is strong, the photosensitive material PM may be stretched between them. Therefore, the nip pressure of the roller pair 33 is set relatively weak, and the photosensitive material PM is set.
Is fed at the transfer speed of the roller pair 34 while sliding between the roller pairs 33.

The feeding and rewinding of the photosensitive material by the second photosensitive material roller 32 is performed in the same manner as the above-described sending and rewinding of the photosensitive material by the first photosensitive material roller 33. The roller pair 33 for the first photosensitive material roll 32 and the roller pair 37 for the second photosensitive material roll 32 have structures equivalent to each other. That is, the ratio between the outer diameter of the drive roller and the number of teeth of the sprocket is configured to be equal between the two roller pairs 33 and 37. Therefore, the photosensitive material can be rewound to the second photosensitive material roller 32 in the same manner as described above.

In the above-described embodiment, the two photosensitive material rolls 31 and 32 are provided in the copying camera. However, one or more photosensitive material rollers may be used. In the case of one photosensitive material roller, roller pair 37
Is also unnecessary. However, when two or more photosensitive material rollers are provided as in the above-described embodiment, since two types of photosensitive materials can be copied while being switched in the camera as needed, there is an advantage that the working efficiency is improved.

[Effect of the invention]

As described above, according to the invention of claim 1, the transfer speed of the second roller pair including the one-way clutch is
Since the speed is higher than the transport speed of the first roller pair, when the motor is rotated to rewind the photosensitive material in the direction opposite to the transport direction, the photosensitive material is rewound by the first roller pair and Of the pair of rollers is kept idle. Therefore, there is an effect that the photosensitive material can be easily rewound in the reverse direction even if the one-way clutch is provided.

According to the invention of claim 2, in the transfer direction,
First upstream of the cutting device provided in the copying camera
Since the second roller pair is arranged, the photosensitive material cut by the cutting device can be easily rewound.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing a main part of an apparatus to which one embodiment of the present invention is applied, FIG. 2 is a schematic side view showing a photosensitive material transporting apparatus as one embodiment of the present invention, and FIG. FIG. 4 is a front view showing a roller pair incorporating a one-way clutch, and FIG. 5 is an explanatory diagram showing the operation of the roller pair in the embodiment. PM: photosensitive material, 33, 34: roller pair, 33a, 34a: drive roller, 33b, 34b: sprocket, 33c: electromagnetic clutch,
34c …… One-way clutch, 38 …… Motor, 39 …… Chain

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiji Miyasaka, one of 480 Takamiya-cho, Hikone-shi, Shiga Prefecture. (1) Dainichi Screen Manufacturing Co., Ltd. Hikone Area Office (56) References JP-A-59-48343 (JP, A)

Claims (2)

(57) [Scope of request for utility model registration] 1. A photosensitive material transporting device provided in a copying camera, comprising: a motor capable of rotating forward and reverse; and a motor sequentially rotatable in a predetermined transfer direction of the photosensitive material for transporting the photosensitive material. A first and a second roller pair; and a power transmission mechanism for transmitting a driving force of the motor to the first and the second roller pair, respectively, wherein the first roller pair has a driving force of the motor. The power transmission mechanism includes a one-way clutch that is axially mounted on any one of the second roller pair and that transmits only the driving force of the motor in the transfer direction. And a transfer speed of the second roller pair in the transfer direction is higher than a transfer speed of the first roller pair. 2. The copying camera according to claim 1, further comprising a cutting device for cutting the sheet-shaped photosensitive material, wherein the first and second roller pairs are provided upstream of the cutting device in the transport direction. Claim 1 which is arranged
A photosensitive material transport device for the copying camera according to the above.