JPH0748783B2 - Sheet body transport mechanism and control method thereof - Google Patents

Description

The present invention relates to a sheet conveying mechanism and a control method thereof,
More specifically, when recording or reading image information by scanning a light beam in the main scanning direction with respect to a sheet body that is sandwiched between a pair of rollers and conveyed in the sub scanning direction, the rollers forming the roller pair are BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet body transport mechanism for holding the sheet body without impact and smoothly transporting it in the sub-scanning direction by gradually displacing one of the rollers toward the other roller and a control method thereof.

Recently, a radiation image recording / reproducing system that obtains a radiation image of a subject using a stimulable phosphor (stimulable phosphor) has attracted attention. Here, the stimulable phosphor means radiation (X-ray, α
Radiation, β rays, γ rays, electron rays, ultraviolet rays, etc.) accumulates a part of this radiation energy, and when excitation light such as visible light is subsequently irradiated, it stimulates luminescence in accordance with the accumulated energy. A light body.

The above-mentioned radiation image recording / reproducing system uses this stimulable phosphor, and is a sheet having a layer of the stimulable phosphor for temporarily storing the radiation image information of a subject such as a human body (hereinafter referred to as "accumulative phosphor sheet"). Or simply referred to as a "sheet"), the accumulative phosphor sheet is scanned with excitation light such as laser light to generate stimulated emission light, and the stimulated emission light is photoelectrically read to generate electricity. A signal is obtained and the radiation image of the subject is recorded on the basis of this electrical signal.
The image is output to a display device such as T as a visible image.

Therefore, in such a radiation image recording / reproducing system, when the radiation image is read from the accumulative phosphor sheet in which the radiation image is accumulated and recorded, specifically, the following method is used.

That is, the accumulative phosphor sheet is two-dimensionally scanned with a light beam such as a laser beam, and stimulated emission light emitted from the sheet is detected in time series by a photodetector such as a photomultiplier. Get image information. In this case, in the two-dimensional scanning of the light beam, usually, the accumulative phosphor sheet is conveyed by a belt conveyor in the sub-scanning direction and the light beam is deflected in the main scanning direction orthogonal to the conveying direction of the sheet. Has been achieved by.

On the other hand, when reproducing the image information obtained as described above as a visible image, for example, a photographic light-sensitive material which is a recording material is modulated based on the image information obtained from a stimulable phosphor sheet. Laser light is irradiated to record a predetermined image on the photographic light-sensitive material. Then, this photographic light-sensitive material on which an image has been newly recorded is subjected to development processing, then stored in a predetermined place, and used for medical diagnosis or the like as necessary.

By the way, when reading a radiation image from a stimulable phosphor sheet, the stimulable phosphor sheet conveyed by a belt conveyor must be firmly positioned and fixed on the belt conveyor. This is because if the stimulable phosphor sheet is displaced in the direction different from the sub-scanning direction on the belt conveyor during scanning, the irradiation position of the light beam on this stimulable phosphor sheet will deviate from the desired position. . That is, when the excitation light is scanned on the accumulative phosphor sheet displaced with respect to the belt conveyor, the resulting image information is inaccurate due to misalignment, and based on this image information, for example, However, there is a possibility that a misdiagnosis or the like may occur when performing a medical diagnosis.

Therefore, conventionally, for example, a suction box is used so that the accumulative phosphor sheet during scanning is not displaced with respect to the belt conveyor. That is, the suction box is disposed in the space of the endless belt conveyor, and the belt conveyor has a plurality of suction holes. Then, when the accumulative phosphor sheet is conveyed to the belt conveyor, the vacuum generator connected to the suction box starts suction,
Since the stimulable phosphor sheet is sucked on the belt conveyor, it is positioned and fixed on the belt, and the sheet is 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 becomes complicated and large, and at the same time, a vacuum generator for sucking a sheet through the suction box and this apparatus are provided. A control system for drive control is required.

In addition, such a fixing and conveying means of the stimulable phosphor sheet becomes considerably expensive, and the cost of the whole radiation image recording / reproducing system is considerably increased.

Furthermore, in order to favorably adsorb the stimulable phosphor sheet to the belt conveyor, a conveyor path for conveying the stimulable phosphor sheet in parallel to the belt conveyor must be provided, and such a configuration is provided. Therefore, the radiation image recording / reproducing system itself becomes large. For this reason, it is pointed out that it is difficult to effectively utilize a small room, especially when the system is arranged in a hospital or the like.

On the other hand, in an image recording apparatus, a photographic light-sensitive material is provided with a large-diameter drum which deflects and irradiates modulated laser light to perform main scanning, and which engages the photographic light-sensitive material with a rotary drive source. It is sandwiched by a pair of rollers and conveyed in a direction substantially orthogonal to the main scanning direction to perform sub scanning.

However, in this case, there is a possibility that a rotational drive source that rotationally drives the drum when the photographic light-sensitive material is conveyed, such as a motor, may cause load fluctuations and that suitable sub-scanning cannot be performed on the photographic light-sensitive material. Therefore, conventionally, a support base is provided in front of and behind the drum in the sub-scanning direction so as to minimize the load fluctuation on the motor during the sub-scanning. Therefore, a support base having a length equal to or longer than the length of the conveyed photographic photosensitive material in the sub-scanning direction must be disposed at the front and rear of the drum, and the image recording apparatus itself becomes considerably large. It exposes the drawbacks that cause it. Also,
The drum has a width larger than the width of the photographic light-sensitive material in order to stably convey the photographic light-sensitive material, and since a motor for rotating the drum is provided in the width direction of the drum, The image recording device has no choice but to extend greatly in the main scanning direction.

Furthermore, in order to perform highly accurate scanning on the photographic light-sensitive material,
It is necessary to strictly control the motor so as to convey the photographic light-sensitive material at a constant speed in a precise direction with high precision, and the controllable and high-precision motor is expensive as described above. There is also the problem that the cost will rise significantly. Further, in order to stably convey the photographic light-sensitive material, it is indispensable to dispose a pair of rollers that are in sliding contact with the drum, but by providing these roller pairs, the sub-scanning of the photographic light-sensitive material is performed. Scanning cannot be performed at both ends in the direction, and for example, there arises a disadvantage that it is not possible to meet a request for forming a black frame around the image, that is, a so-called black edge.

In view of the above-mentioned drawbacks of the conventional image reading apparatus and image recording apparatus, the applicant of the present application irradiates a sheet-shaped object to be scanned with a light beam deflected in a one-dimensional direction to perform main scanning, and In a light beam scanning device that moves the object to be scanned in a direction substantially orthogonal to the main scanning direction to perform sub-scanning and two-dimensionally scans the object to be scanned, a pair of nipping and conveying the object to be scanned. Two sets of rollers are arranged at an interval shorter than the length of the object to be scanned in the transport direction, the two pairs of rollers are synchronously rotated to perform sub-scanning, and the rollers are deflected between the pair of rollers. We applied for a light beam scanning device characterized in that it is configured to irradiate a selected light beam to perform main scanning (Japanese Patent Application No. 60-234182).

The present invention is based on the above-mentioned invention “light beam scanning device”.
When a sheet body such as a stimulable phosphor sheet or a photographic photosensitive material is sandwiched and conveyed by a pair of rollers for scanning, at least one of the pair of rollers is set to the other. By directing and gradually displacing,
No impact or the like is caused when the sheet body enters between the rollers, and therefore, the sheet body can be smoothly transported at a constant speed to suitably read or record a radiation image. Also, after the roller comes into contact with the sheet body, the roller is pressed against the sheet body as quickly as possible, so that the sheet body is not impacted and is brought into a desired pressure contact state in an extremely short time. An object of the present invention is to provide a sheet body transport mechanism that is sandwiched and enables a desired transport operation, and a control method thereof.

To achieve the above object, the present invention provides a sheet-shaped object to be scanned at a distance shorter than the length in the carrying direction when performing main scanning by deflecting and irradiating a light beam. In the sheet body transporting mechanism which carries out the sub-scanning transportation by sandwiching it by the two pairs of paired rollers, among the two pairs of rollers,
It is characterized by comprising an actuator for displacing at least one roller toward the other roller and a control means for controlling the actuator so that the one roller is displaced at a predetermined speed.

Further, according to the present invention, a sheet-shaped object to be scanned is deflected and irradiated to perform main scanning, and at the same time, the object to be scanned is arranged in two pairs of rollers arranged at intervals shorter than the length in the carrying direction. When sandwiched by and conveyed in the sub-scanning direction, at least one roller forming the roller pair is gradually displaced toward the other roller, and after the one roller comes into contact with the scanned object, The object to be scanned is nipped and conveyed by increasing the drive signal supplied to the displacement means of the one roller to rapidly increase the pressing force of the one roller against the object to be scanned.

Preferred embodiments of the sheet conveying mechanism and the control method thereof according to the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates an image reading apparatus incorporating a sheet conveying mechanism according to the present invention. A supply magazine 14 is loaded in the chamber 12 in the image reading apparatus 10, and the storage magazines A in which the radiation images have been stored and recorded are stacked and housed in the supply magazine 14. A single-wafer mechanism including a suction plate 16 is provided in the chamber 12 in the vicinity of the supply magazine 14. Below the suction plate 16, an endless first conveyor belt for conveying the stimulable phosphor sheet A is provided. 18 are provided. The first conveyor belt 18 extends downward in the vertical direction and is bent so as to be oriented in the horizontal direction at the internal corner of the image reading device 10. The first conveyor belt 18 is slightly separated from the end portion of the sheet according to the present invention. A body transport mechanism 20 is provided.

The sheet conveying mechanism 20 includes a first roller pair 22 and a second roller pair 24, and holds the accumulative phosphor sheet A conveyed between the roller pairs 22 and 24. Guide members 26a and 26b are provided. The first roller pair 22 includes a roller 30 that is driven to rotate and a roller 32 that rotates in sliding contact with the roller 30.
On the other hand, the second roller pair 24 is composed of a roller 34 which is rotationally driven and a roller 36 which is disposed above the roller 34. A detection sensor 37 for detecting the passage of the accumulative phosphor sheet A is disposed in the vicinity of the second roller pair 24.

In this case, the second roller pair 24 is constructed as shown in FIG. That is, one end of the roller 34 is an image reading device.
A support plate 38 that is erected inside the shaft 10 is rotatably supported by a shaft. A shaft 40 of the roller 34 is a rotary drive source, for example, a motor.
It engages with the rotary drive shaft of 42. The shaft 44 protruding from one end of the roller 36 is fitted into a long hole 46 formed in the support plate 38. A coil spring 48 is attached to the shaft 44 of the roller 36, and urges the roller 36 in a direction to separate the roller 36 from the roller 34. The other ends of the rollers 34 and 36 are pivotally supported by a support plate (not shown) as described above.

On the other hand, the shaft 44 of the roller 36 is in contact with the other end of the arm member 54 whose one end is pivotally supported by the rotary drive shaft 52 of the rotary solenoid 50 which is an electromagnetic actuator. In this case, the rotary solenoid 50 is fixed to the support plate 38, and the arm member 54 is rotated against the tensile force of the coil spring 48 under the action of a control circuit described later, and the roller 36 is rotated by the roller 34. It is intended to be displaced toward.

Here, a pulley 56 is engaged with the shaft 40 of the roller 34, and a pulley 57 is also engaged with the shaft 31 of the roller 30 constituting the first roller pair 22. The pulleys 56 and 57 are connected by the belt 61. Therefore, the roller 30
Motors 42 and 34 rotate synchronously. The first
Like the roller 36 of the second roller pair 24, the roller 32 forming the roller pair 22 is preferably configured to be displaced toward the roller 30 by a rotary actuator (not shown).

Therefore, the control circuit of the rotary solenoid 50 is configured as follows. That is, in FIG. 3, the control circuit drives the polarity changeover switch SW based on the sheet detection signal supplied from the detection sensor 37 close to the second roller pair 24 and the polarity changeover switch SW. Positive terminal 59
a or an integrator 60 that integrates the voltage applied from the negative terminal 59b based on a predetermined time constant, and a driver 62 that converts the voltage output from the integrator 60 into a current and drives the rotary solenoid 50. Including. In addition, rotary solenoid
The current driving 50 is converted into a voltage by converter 64 and supplied to comparator 66. In this case, the reference voltage V ₀ is applied to the comparator 66, and the comparator 66 uses the reference voltage V _0.
The time constant of the integrator 60 is controlled by comparing V ₀ with the voltage supplied from the converter 64.

The circuit for controlling the second roller pair 24 is basically configured as described above, but in this case, the first roller pair 22
It goes without saying that the control circuit may be configured similarly to the second roller pair 24.

Then, the second conveyor belt 67 is brought close to the second roller pair 24.
Are provided (see FIG. 1). The second conveyor belt 67 once extends in the horizontal direction, then extends largely in the vertical direction in the figure, bends in the horizontal direction at the terminal end thereof, and has the tip end thereof directed slightly downward. A receive magazine 68 for accommodating the stimulable phosphor sheet A is arranged close to the tip of the second conveyor belt 67.

On the other hand, the reading unit 70 is arranged above the sheet conveying mechanism 20 of this embodiment. The reading unit 70 includes a laser light source 72, and a laser light 74 is provided on the laser light deriving side of the laser light source 72.
A mirror 76 and a galvanometer mirror 78 for scanning the sheet A on the sheet A are provided. In addition, laser light
A light guide 80 is disposed along the main scanning line at the scanning position on the sheet A of 74, and a photomultiplier 82 is mounted on the light guide 80.

Furthermore, in the chamber 12, for example, an erasing unit 84 is arranged at an intermediate portion of the conveyor belt 67. A plurality of erasing light sources (not shown) are provided inside the erasing section 84.

The image reading apparatus incorporating the sheet conveying mechanism according to the present embodiment is basically constructed as described above. Next, its operation and effect will be described.

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 a subject such as a human body are accumulated and recorded are stacked and accommodated.

Therefore, the stimulable phosphor sheet A is taken out one by one from the supply magazine 14 under the action of the sheet-fed mechanism including the suction plate 16, and is passed through the first conveyor belt 18 provided below the suction plate 16. And is conveyed to the sheet conveying mechanism 20 side.

Then, the accumulative phosphor sheet A is transferred to the first roller pair 22, that is, the roller 30 and the roller 32 that rotate under the action of the motor 42.
It is sandwiched between and and transferred in the direction of arrow B. At that time, the laser light emitted from the laser light source 72 by driving the reading unit 70
74 is reflected by the mirror 76 to reach the galvanometer mirror 78, and the laser beam 74 is scanned on the sheet A in the main scanning direction under the swinging action of the galvanometer mirror 78. As a result, the stimulated emission light emitted from the sheet A is made incident on the light guide 80, and this is applied to the photomultiplier.
It is converted into an electric signal by 82 and sent to, for example, an image recording device or the like. In this way, the stimulable phosphor sheet A is two-dimensionally scanned by the laser light 74, and the front end portion thereof is nipped by the second roller pair 24, that is, the rollers 34 and 36.

Therefore, based on FIG. 2 and FIG.
The operation of will be described. In this case, the rotary solenoid 50 is in the non-energized state before the stimulable phosphor sheet A reaches the second roller pair 24. Therefore, the roller
36 is displaced along a long hole 46 formed in the support plate 38 by the tensile force of the coil spring 48, and a predetermined space is defined between the roller 34 and the roller 36.

The stimulable phosphor sheet A is moved to the arrow B by the first roller pair 22.
When the front end portion of the sheet A is conveyed in the direction, and reaches the detection sensor 37 arranged in the vicinity of the second roller pair 24, the detection sensor 37 detects the passage of the sheet A and outputs the detection signal to the switch 58. To do. In this case, the changer 58 connects the polarity changeover switch SW to the positive terminal 59a of the power supply. Then integrator 6
For 0, the voltage applied from the power source through the polarity switch SW is integrated, and the current corresponding to the voltage is applied to the driver 62.
Is supplied to the rotary solenoid 50. In this case, the current supplied to the rotary solenoid 50 increases with time as shown in FIG.

Therefore, when the rotary solenoid 50 is supplied with a current of a constant increasing rate, the rotary drive shaft of the rotary solenoid 50 is rotated.
52 rotates at a predetermined speed against the tensile force of the coil spring 48, and the arm member 54 gradually presses the shaft 44 of the roller 36 in the arrow C direction. As a result, the shaft 44 descends along the elongated hole 46 formed in the support plate 38, and the roller 36 is displaced toward the roller 34 at a constant speed. In this case, the roller 34
The front end of the stimulable phosphor sheet A is placed on the top,
Sheet A is gently nipped by these rollers 34 and 36, and then the sheet A is gradually stressed.

Here, when the roller 36 is displaced toward the roller 34 based on the current characteristics shown in FIG. 4, the stimulable phosphor sheet A is nipped by the second roller pair 24 with a predetermined stress. Since it takes some time, for example, when the sheet A is scanned at a high speed, there is a problem. Therefore,
The converter 64 converts the current supplied to the rotary solenoid 50.
If the configuration is such that the voltage is converted into a voltage and the time constant of the integrator 60 is changed based on this voltage, a current having the characteristics shown in FIG. 5 can be supplied to the rotary solenoid 50, and a quick clamping operation can be performed. Is possible.

That is, the voltage from the converter 64 is compared with the reference voltage V ₀ in the comparator 66, and when the voltage reaches the reference voltage V ₀ , a signal for switching the time constant is output to the integrator 60. In this case, the reference voltage V ₀ is the rotary solenoid 50
It is set in advance from the relationship between the drive current and the amount of displacement of the roller 36. Therefore, when the roller 36 comes into contact with the sheet A and is displaced by a predetermined amount (displacement point a of the current increase rate), the time constant of the integrator 60 is switched to a larger value than before by the signal, and the increase rate is increased. Electric current is supplied to the rotary solenoid 50. Therefore, the rotary solenoid
In 50, the roller 36 comes into contact with the stimulable phosphor sheet A and is displaced by a predetermined amount, and then the arm member 54 is displaced at a high speed so that the roller
The roller 36 is quickly pressed against the roller 34. Then, the rollers 34 and 36 teach the sheet A with a predetermined stress. As a result, the stimulable phosphor sheet A is the second roller pair.
Since the sheet 24 is nipped in a short time and brought into a transportable state, it becomes possible to carry out the sheet A with extremely efficient sub-scanning transport, that is, high-speed scanning. Further, the stimulable phosphor sheet A is nipped by the rollers 34 and 36 without any particular impact and is transported in the direction of the arrow B extremely smoothly and continuously. The image reading operation of the body sheet A is performed extremely well.

The rear end portion of the accumulative phosphor sheet A has the first roller pair 22.
If the nip action of the sheet A by the first roller pair 22 is released when the sheet passes through the sheet, a better image reading operation can be performed without causing an impact when the sheet is separated from the first roller pair 22. Become.

Next, the stimulable phosphor sheet A reaches the erasing section 84 via the second conveyor belt 67. In the erasing unit 84, a plurality of erasing light sources (not shown) are turned on, and the irradiation light thereof completely erases the radiation image remaining on the stimulable phosphor sheet A. The storage phosphor sheet A from which the radiation image has been erased is the second
After being conveyed to the upper part of the image reading device 10 by the conveyor belt 67, it is stored in the receive magazine 68.

Here, in FIG. 5, instead of setting the displacement point a at which the rate of increase of current changes by the reference voltage V ₀ input to the comparator 66, the contact state between the roller 36 and the accumulative phosphor sheet A is changed. May be detected by a contact sensor or the like, and the detection signal may be input to the integrator 60 to switch the time constant.

Further, the control circuit shown in FIG.
It can also be configured to drive control 50. That is, the detection sensor 37 detects the front end of the stimulable phosphor sheet A and outputs a detection signal to the clock signal generator 110.
The clock signal generator 110 supplies the clock signal to the frequency divider 112 when the detection signal is received, and the frequency divider 112 converts the clock signal into a pulse signal having a predetermined cycle and supplies the pulse signal to the counter 114. The output signal of the counter 114 is converted into an analog signal by the D / A converter 116 and the driver 1
Supplied to 17. Then, the driver 117 drives the rotary solenoid 50. So the rotary solenoid
Reference numeral 50 causes the arm member 54 to rotate based on the current that changes stepwise, and causes the roller 36 to gradually approach the roller 34.

On the other hand, the roller 36 has a contact sensor 118, which outputs a contact detection signal to the frequency divider 112 when the roller 36 contacts the accumulative phosphor sheet A. In this case, the contact detection signal switches the frequency division ratio of the frequency divider 112 to reduce the period of the pulse signal output from the frequency divider 112. As a result, the input clock frequency of the counter 114 increases and the increase rate of the output voltage of the D / A converter 116 increases. That is, the output current of the driver 117 also increases rapidly. Therefore, the rotary solenoid 50 is
The arm member 54 is rotated based on a current that changes faster than before the roller 36 contacts the stimulable phosphor sheet A,
The roller 36 is quickly pressed against the roller 34. As a result, the sheet A is nipped by the rollers 34 and 36 promptly, and is smoothly moved without any impact.

On the other hand, the sheet conveying mechanism according to the present invention can be configured as follows. That is, in FIG. 7, one end of the arm member 86 is pivotally supported on the rotary drive shaft 52 of the rotary solenoid 50. Further, a pin 88 is planted at the other end of the arm member 86, and one end of the link member 90 is brought into contact with the pin 88. The other end of the link member 90 is attached to the support plate 38 by a shaft.
A leaf spring 94 is rotatably attached via a shaft 92, and one end of a leaf spring 94 is fixed to the other end. On the other hand, the other end of the leaf spring 94 is brought into contact with the shaft 44 of the roller 36, and the strain gauge 96 is bonded to the intermediate portion of the leaf spring 94. The configurations of the roller 34 and the first roller pair 22 are the same as those described above, and the description thereof is omitted.

Here, the control circuit of the rotary solenoid 50 is configured as follows. That is, in FIG. 8, the control circuit includes a pressure sensor 102 including a strain gauge 96 and an amplifier 100, an integrator 106 including an amplifier 104, a resistor R for setting a time constant, and a capacitor C. It is composed of a driver 108 that converts a voltage into a current and drives the rotary solenoid 50.

Therefore, when the detection sensor 37 arranged near the second roller pair 24 detects the front end of the stimulable phosphor sheet A, the detection sensor 37 outputs a sheet detection signal to the switch 58. The switch 58 is based on this detection signal
SW is connected to the positive terminal 59a of the power supply to supply a predetermined voltage signal to the integrator 106. The integrator 106 integrates the voltage based on the time constant set by the resistor R and the capacitor C. The output signal from the integrator 106 is converted into a current by the driver 108 and supplied to the rotary solenoid 50. The rotary solenoid 50 rotates the rotary drive shaft 52 by the electric current, and the arm member 86 and the arm member 86 are rotated.
The link member 90 is rotated about the shaft 92 via the pin 88 implanted in the. In this case, one end portion of a leaf spring 94 is connected to the link member 90, and the shaft 44 of the roller 36 that abuts the other end portion of the leaf spring 94 is pressed by the drive action of the rotary solenoid 50, The roller 36 is gradually displaced toward the roller 34.

Here, a strain gauge 96 is bonded to the center of the leaf spring 94, and the strain gauge 96 detects the amount of strain generated in the leaf spring 94. This distortion amount is converted into a voltage by the amplifier 100 that constitutes the pressure sensor 102, and is integrated as a voltage.
Supplied to 106. Therefore, the integrator 106 is supplied with a constant voltage from the power source supplied via the polarity changeover switch SW and a voltage output from the pressure sensor 102 and gradually increasing according to the displacement amount of the roller 36, and the driver 108 is supplied with the voltage. The current thus converted and supplied to the rotary solenoid 50 has a characteristic of gradually increasing with time as shown in FIG. Therefore, the roller 36 is gradually displaced toward the roller 34 with a relatively small pressing force at first, and then the pressing force is accelerated to increase the accumulative phosphor sheet A by a predetermined stress in a short time. It leads to sandwiching. As a result, the second roller pair 24
Indicates that the accumulative phosphor sheet A is quickly pinched in a desired state without giving any impact to the accumulative phosphor sheet A, and the arrow B
Transfer smoothly in the direction.

When the roller 36 is separated from the roller 34, the switching device 58
By the switching operation of the polarity changeover switch SW due to, a current signal having a characteristic symmetrical with the current characteristic shown in FIG. 9 is supplied to the rotary solenoid 50, and the roller 36 is separated from the roller 34 by the operation opposite to the above case. It

By the way, the radiation image recording / reproducing system employs the image recording apparatus as described above, and while the photographic photosensitive material is nipped and conveyed by the drum and the roller, the modulated laser light is applied to the photographic photosensitive material to convey the photographic photosensitive material. A predetermined image is recorded on the basis of the radiation image information. Therefore, when the sheet conveying mechanism according to the present invention is used in the image recording apparatus, the photographic light-sensitive material can be accurately and smoothly conveyed without causing an impact, and as a result, the photographic light-sensitive material is recorded. The resulting image is even better.

As described above, according to the present invention, when a sheet body such as a stimulable phosphor sheet is sandwiched and conveyed by two pairs of rollers, at least one roller of the roller pair is operated by an actuator. The sheet body is pinched and conveyed while being gradually displaced toward the other side. Therefore, it is possible to read or record the image information over the entire surface of the sheet body. Moreover, the sheet body can smoothly enter between the rollers. For example, when the whole surface of the stimulable phosphor sheet is irradiated with excitation light to obtain radiation image information, or the entire surface of the photographic light-sensitive material is irradiated with laser light. When a visible image is obtained by irradiating light, a clear and highly accurate image information or a visible image can be obtained without any shock. Further, after the roller comes into contact with the sheet body, if the changing speed of the pressing force against the sheet body is increased, the pinching operation of the sheet body can be completed in a short time, and the sheet body conveying operation can be performed quickly. Can be started, which has the advantage that the cycle time of image reading or recording can be reduced all at once.

Although the sheet body transport mechanism and the control method therefor according to the present invention have been described above with reference to the preferred embodiments, the present invention is not limited to these embodiments, and various modifications are possible without departing from the scope of the present invention. Of course, it is possible to improve and change the design.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an image reading apparatus incorporating a sheet body conveying mechanism according to the present invention, FIG. 2 is a schematic perspective view of a sheet body conveying mechanism according to the present invention, and FIG. 3 is a sheet body conveying according to the present invention. FIG. 4 is a block diagram of a control circuit in the mechanism, FIG. 4 and FIG. 5 are driving current characteristic diagrams of actuators in the sheet conveying mechanism according to the present invention, and FIG. 6 is another control circuit in the sheet conveying mechanism according to the present invention. 7 is a schematic perspective view showing another embodiment of the sheet body transport mechanism according to the present invention, and FIG. 8 is a block diagram of a control circuit in the sheet body transport mechanism shown in FIG. FIG. 9 is a drive current characteristic diagram of an actuator in the sheet conveying mechanism shown in FIG. 7. 10 ... Image reading device, 20 ... Sheet transport mechanism 22, 24 ... Roller pair, 42 ... Motor 50 ... Rotary solenoid 54, 86 ... Arm member, 90 ... Link member 94 ... Leaf spring, 96 …… Strain gauge A …… Accumulative phosphor sheet

Claims (4)

[Claims] 1. When a sheet-shaped object to be scanned is deflected and irradiated with a light beam to perform main scanning, the object to be scanned is arranged in two pairs at intervals shorter than the length in the carrying direction. In a sheet body conveying mechanism that is sandwiched by rollers and conveys in a sub-scanning manner, an actuator that displaces at least one roller of the two pairs of rollers so as to be directed toward the other roller,
A sheet conveying mechanism, comprising: a control unit that controls the actuator so that the one roller is displaced at a predetermined speed. 2. The mechanism according to claim 1, wherein the actuator is a rotary solenoid whose rotational movement is forcibly controlled by an elastic body, and the arm member connected to the rotary drive shaft of the rotary solenoid is A sheet configured to direct one roller of a roller pair toward the other roller against a resilient force of the elastic body by a drive signal supplied to the rotary solenoid and increasing with time to displace the roller at a predetermined speed. Body transport mechanism. 3. The mechanism according to claim 2, wherein the arm member comprises a leaf spring to which a strain gauge for detecting the amount of bending is attached, and the rotary solenoid is provided with a driving signal that increases with time. A sheet conveying mechanism configured to add and supply signals according to the amount. 4. A pair of rollers in which a sheet-shaped object to be scanned is deflected and irradiated to perform main scanning, and the object to be scanned is arranged at intervals shorter than the length in the carrying direction. When sandwiched by and conveyed in the sub-scanning direction, at least one roller forming the roller pair is gradually displaced toward the other roller, and after the one roller comes into contact with the scanned object, A sheet body for sandwiching and carrying the object to be scanned by increasing the drive signal supplied to the displacement means of the one roller to rapidly increase the pressing force of the one roller against the object to be scanned. Control method of transport mechanism.