JPH0443469B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is applicable to slit exposure using an imaging lens optical system, or modulation with a required image signal while a photosensitive film is traveling at a constant speed. Regarding an image recording device that records a duplicate image by performing scanning exposure in a direction (for example, perpendicular direction) to the film running direction using a recording light beam, it is particularly important to prevent unevenness in the film running speed. The present invention relates to a film feeding device.

[Prior Art] An image recording apparatus (hereinafter referred to as a flat scanner) that scans and exposes a traveling film in, for example, a direction intersecting the traveling direction of the film is well known.

Generally, in flat scanners, unevenness that occurs in the running state of the film appears as uneven scanning line pitch in the recorded image, reducing the quality of the reproduced image, so a highly accurate film feeder is used. and is driven in synchronization with the scanning period of the recording light beam.

For example, in addition to finishing the drive roller in the exposure section with high precision, a pulse motor is used as the drive source, and the pulse motor is controlled with a control pulse that is synchronized with the deflection scanning signal of the recording light beam to prevent pitch unevenness. Measures are being considered to prevent this.

[Problems to be Solved by the Invention] In the conventional means described above, the occurrence of pitch unevenness on the exposed film can be suppressed by devising the drive roller and the drive source, but the cause of the pitch unevenness is not necessarily due to exposure. It is not something that occurs only in the body, but there are other causes as well.

In particular, if the exposed film is sent out from the exposure section by the ejection means, if the film is subjected to excessive tension and is stretched, or conversely, if the film becomes sag more than necessary, resulting in a so-called jam condition.
This can cause pimples to occur.

[Means for Solving the Problems] In order to solve the above problems, the present invention is configured as follows.

In a film feeding device of an image recording apparatus, which exposes a duplicate image on the film in an exposure section while running the film supplied from a magazine at a constant speed, and discharges the exposed film into a storage section, the exposure section comprising: a drive roller that is arranged and rotates at a constant speed to run the film; and a drive roller that is arranged between the drive roller and the storage section and runs the film at a speed that is faster or slower than the feeding speed of the drive roller. a pair of feed rollers that are switched and driven; a detection means for detecting a tension or relaxation state of the film between the drive roller and the feed roller; and when the detection means detects the tension state of the film, the An image recording apparatus comprising: drive control means for switching the drive speed of the feed roller to a low speed, and switching the drive speed of the feed roller to a high speed when the detection means detects a relaxed state of the film. film feeding device.

[Function] With the above structure, the film between the drive roller and the feed roller is not in an excessively tensioned or relaxed state, and is always maintained at an appropriate tension when being transferred to the discharge side. Only the conveying force of the driving roller acts on the film in the section, so that accurate conveying conditions can be obtained, and occurrence of pitch unevenness can be reliably prevented.

[Example] The drawing is a schematic diagram showing the configuration of the device of the present invention.

A long roll film 3 wound around a shaft 2 is mounted inside a film magazine 1, and fed to an exposure section through a pair of light shielding rollers 4.

The exposure section is provided with a drive roller 5 perpendicular to the running direction of the film 3 and a pair of presser rollers 6, 6 that come into contact with and follow the drive roller 5. It is wound along and driven.

The drive roller 5 is configured according to the conventional device described above.
The film 3 is driven to rotate at a constant circumferential speed by an appropriate means such as a pulse motor, and the film 3 is brought into close contact with the circumferential surface of the driving roller 5 by presser rollers 6, 6, and conveyed at a constant speed.

On the other hand, a light beam 7 emitted from a recording scanning light source (not shown) is applied to a pair of presser rollers 6, 6.
The film 3 is exposed to light by traveling in the axial direction of the roller at a predetermined period. The light beam 7 is modulated by an image signal by appropriate modulation and deflection means, scans the film 3 in the width direction at a required period, and records a desired duplicate image by exposure. Note that as the means for modulating and deflecting the light beam 7, well-known means such as a well-known ultrasonic optical element may be applied, and since it is not relevant to the understanding of the present invention, a description thereof will be omitted.

The exposed film 3 changes direction along the outer periphery of the drive roller 5 and is fed into the storage case 11 by a pair of feed rollers 8, 8 driven by a motor 9. A cutter 10 for cutting the exposed portion of the film 3 is provided in front of the feed rollers 8, 8.

A support plate 12 is rotatably disposed on the lower surface between the drive roller 5 and the feed rollers 8, 8 by a shaft 13 at the positions indicated by the solid line and the chain line in the figure. This support plate 12 supports the film 3 when it is cut by the cutter 10, and also transports the leading end of the cut film to the feed roller 8.
8, and when cutting the film and inserting the leading end thereof, it rises to the position shown by the chain line to support the film, and in other cases it falls to the position shown by the solid line.

A guide plate 14 is disposed at a position facing the support plate 12 across the path of the film 3. This serves as a guide when inserting the leading end of the film, and an opening is provided in the middle thereof.

An L-shaped sensor 15 is attached to the shaft 16 in this opening.
Accordingly, the film 3 is rotatably provided in the positions shown by the solid line and the chain line shown in the figure. takes the position of the dashed line.

By moving the sensor 15 in the above position, the contacts of the micro switch 17 are switched, and ON-OFF or switching between the A circuit and the B circuit is performed. This signal is input to the control circuit 18, and the speed of the motor 9 is switched between high and low speeds.

In other words, the film 3 is tense and the sensor 1
When 5 assumes the solid line position, the motor 9 is switched to low speed and, conversely, the film 3 is relaxed and
When the sensor 15 takes the position indicated by the chain line, switching is performed at high speed. Naturally, the rotational speeds of the feed rollers 8, 8 driven by the motor 9 can also be switched in the same manner.

Therefore, when the film between the drive roller 5 and the feed rollers 8, 8 is tensed, the film feed speed by the feed rollers 8, 8 is reduced to reduce the tension of the film, and the film is relaxed. When this occurs, the feed speed becomes high and the film becomes taut.

As mentioned above, this device detects changes in the position of the film and controls the speed of the feed rollers 8, 8 in feedback manner, and the shape of the sensor 15, the position relative to the micro switch 17, and the speed of the feed rollers 8, 8 are By appropriately selecting the high and low speeds, etc., the film 3 can be conveyed while being maintained at a substantially constant tension at all times.

Therefore, no external force other than the conveyance driving force from the drive roller and presser rollers 6, 6 acts on the film 3 in the exposed portion of the circumferential surface of the drive roller 5, and an extremely stable running state is obtained. Scanning unevenness can be completely prevented.

Note that the sensor 15 is not limited to a contact type as shown in the figure, but may also be a non-contact type that detects the position of an object by emitting ultrasonic waves and measuring the reflected waves. .

Further, the speed switching of the feed roller is not necessarily limited to two-stage switching of high speed and low speed, but may also apply switching in more stages or continuously variable speed.

Furthermore, although the above description has been made based on the case where the present invention is applied to a flat scanner, the present invention apparatus is also applicable to slit scanning via an imaging optical system commonly used in, for example, electrophotographic copying machines. It can also be used for film feeding in exposure means.

[Effects of the Invention] According to the present invention, the detection means detects the tension or relaxation state of the film between the drive roller and the feed roller, and when the film is in the tension state, the drive control means drives the feed roller at a low speed. When the film is in a relaxed state, the drive control means drives the feed roller at high speed.

Therefore, the film between the drive roller and the feed roller does not become excessively tense or relaxed, so that only the transport force of the drive roller acts on the film in the exposure section.
It is possible to prevent unevenness in the film.

[Brief explanation of drawings]

The drawing is a schematic diagram showing the configuration of an apparatus according to an embodiment of the present invention. 1...Film magazine, 2...Film shaft,
3... Film, 4... Light shielding roller, 5... Drive roller, 6... Presser roller, 7... Recording light beam, 8... Feed roller, 9... Motor, 10... Cutter, 11... Exposed film storage case, 12... support plate, 14... guide, 15... sensor, 17... micro switch, 18... control circuit.

Claims (1)

[Scope of Claims] 1. Film feeding in an image recording device in which a duplicate image is exposed on the film in an exposure section while the film fed from a magazine is run at a constant speed, and the exposed film is discharged into a storage section. In the apparatus, a drive roller is arranged in the exposure section and rotates at a constant speed to run the film, and a drive roller is arranged between the drive roller and the storage section and moves the film at a speed higher than that of the drive roller. or a pair of feed rollers that are driven at a speed that causes the film to run at a low speed; a detection means that detects the tension or relaxation state of the film between the drive roller and the feed roller; and a detection means that detects the tension state of the film. drive control means for switching the drive speed of the feed roller to a low speed when detecting the loosened state of the film; and for switching the drive speed of the feed roller to a high speed when the detection means detects a relaxed state of the film. A film feeding device in an image recording device characterized by: