JPS63139847A - Sheet body conveying mechanism - Google Patents

Abstract

PURPOSE:To avoid the deformation, etc. of rollers and convey a scanned object to a sub-scanning direction with high accuracy by interlocking two pairs of conveying rollers via a power transmitting roller and separating said power transmitting roller off of said pairs of rollers at the time of nonconveyance. CONSTITUTION:When a picture image reading operation for an accumulating fluorescent material sheet A is not carried out, i.e., with a first and a second pair of rollers 20, 20 at a stop, a power transmitting roller 38 is separated off of pairs of rollers 20, 24 via a displacing means. Accordingly, the power transmitting rollers 38 is not brought into contact with rollers 30, 34 which are formed with a relatively soft material, without causing deformation while enabling the sub-scanning conveyance of the sheet body A at a uniform speed. And, further, since the power transmitting roller 38 is gradually brought into sliding contact with the rollers 30, 34 under the action of the displacing means, any breakage, deformation, or damage to other parts which are liable to occur at the time of suddenly bringing the power transmitting roller 38 into contact with the rollers 30, 34 can be avoided as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet conveyance mechanism, and more specifically, for example, when scanning and reading a scanned object such as a stimulable phosphor sheet on which a radiation image is accumulated by irradiating excitation light onto the object to be scanned. In order to convey the object to be scanned, two pairs of rollers arranged at a predetermined distance are interlocked via a transmission roller, and when the object is not conveyed, the transmission roller is separated from each pair of rollers. The present invention relates to a sheet conveying mechanism configured to accurately convey a scanned object in the sub-scanning direction by separating the roller pair or the transmission roller from deformation or the like.

Recently, a radiation image recording and reproducing system that obtains a radiation image of a subject using a stimulable phosphor has been attracting attention. Here, stimulable phosphor refers to radiation (X-rays, α
When irradiated with rays, β rays, T rays, electron beams, ultraviolet rays, etc., a part of this radiation energy is accumulated, and when excitation light such as visible light is irradiated later, fluorescence that emits stimulated light according to the accumulated energy. Refers to the body.

The radiation image recording and reproducing system described above utilizes this stimulable phosphor, and the radiation image information of a subject such as a human body is stored on a sheet having a layer of stimulable phosphor (hereinafter referred to as a ``stimulable phosphor sheet''). This stimulable phosphor sheet is scanned with excitation light such as a laser beam to generate stimulated luminescent light, and the stimulated luminescent light is read photoelectrically to obtain an electrical signal. Based on this electrical signal, the radiation image of the subject is output as a visible image to a recording material such as a photographic light-sensitive material or to a display device such as a CRT.

Therefore, in such a radiation image recording and reproducing system, when reading a radiation image from a stimulable phosphor sheet on which a radiation image has been stored and recorded, specifically, the radiation image is read by the following method.

In other words, a stimulable phosphor sheet is scanned two-dimensionally with a light beam such as a laser beam, and the stimulated luminescence light emitted by this is detected in time series with a photodetector such as a photomultiplier to obtain image information. get. In the two-dimensional scanning of the light beam, the light beam is normally deflected and irradiated onto the stimulable phosphor sheet in a -dimensional manner to perform main scanning, and the sheet is moved in a direction substantially orthogonal to the main scanning direction. This is achieved by mechanically conveying the image using a belt conveyor or the like, and thereby performing sub-scanning.

Next, the image information obtained as described above is sent to an image recording device. The image recording device irradiates a photographic light-sensitive material, which is a recording material, with a laser beam modulated based on the image information obtained from a stimulable phosphor sheet, and records a predetermined image on the photographic light-sensitive material. It is configured.

After the photographic light-sensitive material on which the new image has been recorded is subjected to development processing, it is stored at a predetermined location and used for medical diagnosis, etc., as necessary.

In this case, in the image reading device, the stimulable phosphor sheet conveyed by a belt conveyor must be firmly positioned and fixed on the belt conveyor. That is, if the stimulable phosphor sheet moves on the belt conveyor during scanning, the irradiation position of the light beam on the stimulable phosphor sheet shifts from the desired position, and as a result, as described above, the belt conveyor This is because if the excitation light continues to scan the stimulable phosphor sheet that has been displaced, the image information obtained will be inaccurate due to positional deviation.

In other words, it is no longer possible to obtain accurate radiation image information from the stimulable phosphor sheet that has caused the positional shift, and therefore,
If the subject is a patient, this poses disadvantages such as the possibility of making a medical diagnosis error.

Therefore, conventionally, a suction box, for example, has been used to prevent the stimulable phosphor sheet from being displaced with respect to the belt conveyor during scanning. That is, a suction box is placed in the space of an endless belt conveyor in which multiple suction holes are bored, and a stimulable phosphor sheet is placed under the suction action of a vacuum generator connected to the suction box. It is configured to be fixed by suction on the belt conveyor and transferred as the belt conveyor is displaced in the sub-scanning direction.

However, in this type of conventional technology, since the suction box is used as described above, the mechanism is complicated and large, and the vacuum generator that sucks the sheet through the suction box and this device are required. A control system is required to drive and control the

Moreover, such fixed conveyance means for the stimulable phosphor sheet becomes quite expensive, and the cost of the entire radiation image recording and reproducing system also rises considerably.

Furthermore, in order to suitably adsorb the stimulable phosphor sheet onto the belt conveyor, a conveyance path must be provided for conveying the stimulable phosphor sheet in parallel to the belt conveyor. For example, the radiation image recording and reproducing system itself becomes larger. For this reason, particularly when the system is placed in a hospital or the like, it is pointed out that there is a drawback that it is difficult to effectively utilize a narrow room.

Therefore, in view of the above-mentioned drawbacks, the applicant of the present application has arranged two sets of rollers for sandwiching and conveying a sheet-like object to be scanned at an interval shorter than the length of the object to be scanned in the conveying direction. We have developed a light beam scanning device that performs main scanning by irradiating a deflected light beam between a pair of rollers, and have already filed patent applications (Japanese Patent Application Nos. 60-232479 and 60-232479).
0-234182).

In this case, in order to achieve a good scanning operation in the above-mentioned light beam scanning device, it is necessary to accurately convey the object to be scanned in a direction perpendicular to the main scanning direction (sub-scanning direction). For example, a rotation drive source is connected to a first roller constituting one roller pair, and a rotation drive source is connected to a first roller constituting the other roller pair. A transmission roller is brought into sliding contact with the first roller.Then, by rotating the first roller under the driving action of the rotational drive source and rotationally driving each pair of rollers integrally via the transmission roller, these rollers are rotated. A conveying means configured to smoothly convey the object to be scanned held between a pair of rollers in the sub-scanning direction has been considered, and the present applicant has filed a patent application regarding the specific configuration thereof (Japanese Patent Application No. 61-019497). reference).

By the way, in order to accurately convey the object to be scanned by the pair of rollers, a relatively large frictional force is required in the pair of rollers.
For this reason, each roller constituting the roller pair is made of a considerably soft material. Therefore, in the above-mentioned conveyance means, when the object to be scanned is not conveyed, the transmission roller is pressed against each roller with a predetermined pressing force while the rotational drive source is stopped, and the transmission roller is made of a soft material. There is a risk of deformation of the roller. The object to be scanned is conveyed while being held between the pair of rollers that have been deformed in this way, and the conveyance speed changes in the sub-scanning direction due to the deformation of the pair of rollers.
It has been pointed out that there is a concern that the image scanning reading or scanning recording operation of the object to be scanned may be inaccurate.

The present invention has been made in view of the above, and includes two pairs of rollers that sandwich and convey a sheet such as a stimulable phosphor sheet or a photographic light-sensitive material, which are synchronously driven to rotate via a transmission roller. When the rotational drive source is stopped, the transmission rollers are displaced in the direction away from the respective roller pairs under the action of the actuator, so that the respective roller pairs and the transmission rollers are mutually separated when the sheet is not conveyed. This prevents deformation of the respective rollers constituting the roller pair or the transmission roller, and therefore allows the sheet to be accurately and smoothly conveyed in the sub-scanning direction for image reading or scanning. It is an object of the present invention to provide a sheet conveyance mechanism that enables suitable recording of visual images.

In order to achieve the above object, the present invention provides a method for scanning a sheet-shaped object to be scanned at an interval shorter than the length of the object in the conveyance direction when performing main scanning by deflecting and irradiating a light beam onto a sheet-like object to be scanned. In a sheet conveyance mechanism in which the sheet is held between two pairs of rollers and conveyed in the sub-scanning direction, a first roller constituting one pair of rollers and a second roller constituting the other pair of rollers. A transmission roller is disposed in sliding contact with and rotates the first roller and the second roller in synchronization, and a displacement means is provided for displacing the transmission roller away from the first roller and the second roller. It is characterized by

Next, preferred embodiments of the sheet conveyance mechanism according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates an image reading device incorporating a sheet conveyance mechanism according to the present invention. A supply magazine 14 is loaded in a chamber 12 in the image reading device 10, and stimulable phosphor sheets A) in which radiation images have been stored and recorded are stored in a stacked manner.

A single sheet mechanism including a suction cup 6 is provided in the chamber 12 adjacent to the supply magazine 14, and below the suction cup 16 is an endless first conveyor belt for conveying the stimulable phosphor sheet A. 18 are provided. The first)1) feeding belt 18 extends vertically downward to the image reading device 10.
It is bent so as to be oriented in the horizontal direction at an internal corner thereof, and a sheet conveying mechanism 20 according to the present invention is provided at a slight distance from the terminal end thereof.

The sheet conveyance mechanism 20 includes a first pair of rollers 22 and a second pair of rollers.
The roller pairs 22 and 24 are arranged at an interval shorter than the length of the stimulable phosphor sheet A to be transported in the transport direction.

The first roller pair 22 includes a roller 30 that is connected to a rotational drive source (not shown) and is rotationally driven, and a roller 32 that rotates in sliding contact with the roller 30, while the second roller pair 24 is a roller that is rotationally driven. 34 and a roller 36 disposed above this. In this case, a large-diameter transmission roller 38 comes into sliding contact with the rollers 34 and 30 and transmits the rotational force of the roller 30 to the roller 34. roller 30.3
It is configured so that it can be separated from 4.

That is, as shown in FIG. 2, a rotary solenoid 44, which is an electromagnetic actuator, is fixed to a support plate 42 provided upright within the image reading device 10, and an arm member 48 is attached to a rotational drive shaft 46 of the rotary solenoid 44. is pivoted at one end. A pin 5 is attached to the other end of the arm member 48.
0, and a first link 54 constituting a link member 52 exhibiting a bent shape abuts on this pin 50. In this case, a support shaft 56 is implanted at the bent portion of the link member 52, and the support shaft 56 is rotatably supported by the support plate 42.

Further, a shaft 38a of a transmission roller 38 is mounted on a second link 58 constituting the link member 52, and the shaft 38 is inserted into a long hole 60 formed in the support plate 42 and extending in the vertical direction. Fit together.

Therefore, the control circuit for the rotary solenoid 44 is configured as follows. That is, in FIG. 3, the control circuit includes, for example, a switching device 64 that drives a polarity changeover switch SW based on a sheet detection signal supplied from a detection sensor 62 disposed close to the first roller pair 22; an integrator 68 that integrates the voltage applied from the positive terminal 66a or the negative terminal 66b via the polarity changeover switch SW based on a predetermined time constant; and an integrator 68 that converts the voltage output from the integrator 68 into a current. A driver 70 that drives the rotary solenoid 44 is included.

Next, a second conveyor belt 72 is provided adjacent to the second roller pair 24 (see FIG. 1). The second conveyor belt 72 once extends in the horizontal direction, then extends largely vertically upward in the figure, and bends in the horizontal direction at its terminal end,
Furthermore, the leading end of the second conveyor belt 72 is directed slightly downward.
A receive magazine 74 that stores therein is arranged nearby.

On the other hand, a reading section 76 is arranged at the top of the sheet conveyance mechanism 20 of this embodiment. The reading section 76 is a laser light source 7
8, and a mirror 82 for scanning the laser beam 80 onto the sheet A on the laser beam output side of the laser light source 78.
and galvanometer mirror 84 and condensing reflection mirror 8
5 is provided.

Furthermore, a light guide 86 is disposed along the main scanning line at the scanning position of the laser beam 80 on the sheet A.
A photomultiplier 88 is attached to the upper part of 6.

Furthermore, an erasing section 90 is disposed within the chamber 12, for example, at an intermediate portion of the conveyor belt 72. Note that the erasing section 90
A plurality of erasing light sources (not shown) are disposed inside.

The image reading apparatus incorporating the sheet conveyance mechanism of this embodiment is basically constructed as described above, and its operation and effects will be explained next.

First, the supply magazine 14 is attached to the image reading device 10. In this case, in the supply magazine 14,
For example, a plurality of stimulable phosphor sheets (A) on which radiation images of subjects such as human bodies are stored are stacked and stored.

Therefore, the stimulable phosphor sheets A are taken out one by one from the supply magazine 14 under the action of a sheet-feeding mechanism including a suction cup 16, and transported via a second conveyor belt 72 provided below the suction cup 16. The sheet is then transported to the sheet transport mechanism 20 side.

In this case, before the stimulable phosphor sheet A reaches the sheet conveyor 120, the rotary solenoid 44
is in a de-energized state. Therefore, the transmission roller 38
is displaced vertically downward along a long hole 60 formed in the support plate 42 due to its own weight, and a predetermined interval is defined between the transmission roller 38 and each roller 30, 34. Then, when the stimulable phosphor sheet A is conveyed to the sheet conveying mechanism 20 side and its front end reaches the detection sensor 62 disposed close to the first pair of rollers 22, the detection sensor 62 detects the sheet A. Detects the passage of the signal and outputs the detection signal to the switch 64. In this case, the switch 64 connects the polarity changeover switch SW to the positive terminal 66a of the power supply. Next, the integrator 68 integrates the voltage applied from the power source via the polarity changeover switch SW, and a current corresponding to the voltage is supplied from the driver 70 to the rotary solenoid 44. In this case, the current supplied to the rotary solenoid 44 increases with time, as shown in FIG.

When a current with a constant increasing rate is supplied to the rotary solenoid 44, the rotary drive shaft 46 of the rotary solenoid 44
moves at the arrow C at a predetermined speed against the weight of the transmission roller 38.
The link member 52 rotates in the direction indicated by the arrow through the pin 50 implanted in the arm member 48 about the support shaft 56 . As a result, the second link 58 swings upward in the vertical direction, and the shaft 38a placed on it swings around the support plate 4.
2, the transmission rollers 38 come into sliding contact with the respective rollers 30, 34. In this case, the roller 30 is rotationally driven under the action of a rotational drive source (not shown), and the roller 30 and the roller 34 are rotated synchronously via the transmission roller 38.

Therefore, the stimulable phosphor sheet A is conveyed in the direction of arrow B (sub-scanning direction) while being held between the first pair of rollers 22 and the second pair of rollers 24 which are rotationally driven in synchronization as described above. At this time, the reading section 76 is driven to cause the laser beam 80 emitted from the laser light source 78 to be reflected by the mirror 82 and reach the galvanometer mirror 84, and the laser beam 80 is directed to the sheet under the swinging motion of the galvanometer mirror 84. A is scanned in the main scanning direction. As a result, the stimulated luminescence light emitted from C) A is input directly or reflected by a reflecting mirror 85 into a light guide 86, and is converted into an electrical signal by a photomultiplier 88, for example, in an image recording device. etc. in this way,
The stimulable phosphor sheet A is two-dimensionally scanned by the laser beam 80.

Next, the stimulable phosphor sheet)A is transferred to the second conveyor belt 72.
The data reaches the erasing section 90 via. In the erasing section 90, a plurality of erasing light sources (not shown) are turned on, and the irradiated light completely erases the radiation image remaining on the stimulable phosphor sheet A. The stimulable phosphor sheet A from which the radiation image has been erased is transferred to the image reading device by the second conveyor belt 72. After being transported to the upper part of &10, it is stored in the receive magazine 74.

Here, the stimulable phosphor sheet A is transferred to the sheet transport mechanism 20.
After passing through the rotary solenoid 4, the rotary drive source (not shown) is stopped to make the roller 30 stand still, and the rotary solenoid 4
4 is in a non-energized state, and the transmission roller 38 descends due to its own weight, and this transmission roller 38 moves to each roller pair 2.
From 2.24 onwards, it will be separated.

As described above, in this embodiment, when the image reading operation of the stimulable phosphor sheet A is not performed, that is, when the first and second roller pairs 20 and 24 are stopped, the transmission roller is 38 is spaced apart from the roller pair 20.24. Therefore, the transmission roller 38 is pressed against each roller 30.34 formed of a relatively soft material, and the pressed portion of the roller 30.34 is deformed to move the stimulable phosphor sheet A at a uniform speed. This does not cause the inconvenience of not being able to perform sub-scanning conveyance.

In addition, the transmission roller 38 is gradually displaced under the action of the displacement means 40 so as to come into sliding contact with the respective rollers 30, 34. Therefore, damage or deformation of the rollers 30.34, which is likely to occur when the transmission roller 38 is brought into sudden contact with the respective rollers 30.34, or damage to other parts is avoided as much as possible. becomes possible. - In this case, the transmission rollers 38 are the same as the respective rollers 30.
．． Although it is formed into a single columnar shape like 34, for example, a transmission roller 92 shown in FIG. 5 may be used. That is, the transmission roller 92 includes a shaft 94, and the shaft 94 has two rollers 95a and 96b having a predetermined width.
are engaged at selected positions so as to be in sliding contact with both end edges of the respective rollers 30, 34. Therefore, it is easily understood that the transmission roller 92 performs the same function as the transmission roller 38 described above.

Further, in the displacement means 40, it is also possible to configure the arm member 48 to directly hold the shaft 38a of the transmission roller 38 without providing the link member 52.

As described above, according to the present invention, a sheet such as a stimulable phosphor sheet is conveyed while being held between two pairs of rollers, and a transmission roller that can freely displace the two pairs of rollers is provided. They are rotated synchronously through the Therefore, if the transmission roller is separated from each pair of rollers when not being transported, the transmission roller will come into contact with the stopped roller, causing problems such as deformation of the roller or the transmission roller. Never. Therefore, the two roller pairs can be smoothly and reliably rotated to transport the sheet body with high precision.For example, when obtaining radiation image information by irradiating a stimulable phosphor sheet with excitation light, or When a visible image is obtained by irradiating a photographic light-sensitive material with a laser beam, uneven conveyance does not occur, and as a result, clear and highly accurate image information or a visible image can be obtained.

Furthermore, if the displacement speed of the transmission rollers is suitably controlled, an advantage can be obtained that the transmission rollers can be brought into smooth sliding contact without causing impact or the like to each pair of rollers.

Although the sheet conveyance mechanism according to the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and designs can be made without departing from the gist of the present invention. Of course, it is possible to change.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an image reading device incorporating a sheet conveyance mechanism according to the present invention, FIG. 2 is a schematic perspective view of a sheet conveyance mechanism according to the present invention, and FIG. 3 is a sheet conveyance according to the present invention. A block diagram of the control circuit in the mechanism, FIG. 4 is a drive current characteristic diagram of the actuator in the sheet conveyance mechanism according to the present invention, and FIG. 5 is a diagram showing one of the other transmission rollers constituting the sheet conveyance mechanism according to the present invention. It is an explanatory diagram with parts omitted. 10... Image reading device 20... Sheet body conveyance mechanism 22.24... Roller pair 30.34...
Roller 38...Transmission roller 40...Displacement means 44...Rotary solenoid 48...Arm member 52...Link member 5
4.58... Link 60... Long hole FIG,
1 η1 [1

Claims (4)

[Claims] (1) When performing main scanning by deflecting and irradiating a sheet-shaped object with a light beam, the object to be scanned is scanned by two pairs of rollers arranged at an interval shorter than the length of the object in the conveyance direction. In a sheet conveyance mechanism that carries out nipping and sub-scanning conveyance, the first roller and the second roller are in sliding contact with a first roller constituting one pair of rollers and a second roller constituting the other pair of rollers. 1. A sheet conveyance mechanism, comprising: a transmission roller that rotates two rollers in synchronization; and a displacement means that displaces the transmission roller away from the first roller and the second roller. (2) In the mechanism according to claim 1, the displacement means is substantially composed of a rotary solenoid, and the displacement means is configured to swingably displace the arm member connected to the rotational drive shaft of the rotary solenoid in a predetermined direction. A sheet conveyance mechanism configured to move a transmission roller that engages a member forward and backward relative to two pairs of rollers. (3) In the mechanism according to claim 2, a rotatable link member is disposed between the arm member connected to the rotational drive shaft of the rotary solenoid and the transmission roller, and the link member is An arm member is engaged with the first link piece, while a transmission roller is placed on the second link piece of the link member, and the arm member is rotated in one direction under the driving action of the rotary solenoid. The sheet conveying mechanism comprises: raising the transmission roller via the link member, and bringing the transmission roller into sliding contact with each roller so as to rotate two pairs of rollers synchronously. (4) In the mechanism according to any one of claims 1 to 3, a rotation drive source is connected to a first roller constituting one pair of rollers, and a rotary drive source is connected to a first roller constituting one pair of rollers. A transmission roller is in sliding contact with a second roller constituting a pair of rollers, and the first roller is rotated under the action of the rotational drive source to synchronize the second roller with the first roller via the transmission roller. A sheet conveyance mechanism that rotates.