JPS63269669A - Method for controlling sheet body carrying system - Google Patents

Abstract

PURPOSE:To improve a picture processing speed, by setting the speed of setting nip rollers to their sheet body holding positions, speed of separating nip rollers from their sheet body holding positions, and sheet body carrying speed of nip rollers to prescribed speeds in accordance with reading and/or picture processing conditions. CONSTITUTION:Upon detecting that a sheet body S held and carried by a 1st roller pair 44a and 44b approaches a 2nd roller pair 46a and 46b, the speed of setting the rollers 46a and 46b constituting the 2nd roller pair to their sheet body S holding positions is controlled corresponding to the carrying speed of the sheet body S. Moreover, upon detecting that the tail end of the sheet body S approaches the 1st roller pair 44a and 44b, the speed for separating the rollers 44a and 44b constituting the 1st roller pair from their sheet body S holding positions is controlled corresponding to the carrying speed of the sheet body S. Therefore, reading or writing of a picture can be carried out as quickly as possible and surely and the overall throughput of a picture reader can be remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling a sheet conveyance system in a light beam scanning device, and more specifically, to a method for controlling a sheet conveyance system in a light beam scanning device, and more specifically, for controlling a stimulable phosphor sheet carrying radiation image information or an image. When reading or writing image information while nipping and conveying a sheet such as a film to be recorded using nip rollers, the rollers that make up the nip roller move toward each other in order to nip the sheet, and the sheet The speed at which the sheets are nipped (hereinafter referred to as the nipping speed), the speed at which the sheets are moved away from each other to release the nipping from the sheet body (hereinafter referred to as the separation speed), and the rotational speed of the nip rollers. Control of a sheet conveyance system that makes it possible to improve the throughput of the light beam scanning device as much as possible by setting the sheet conveyance speed to a predetermined speed based on image reading conditions or image writing conditions. Regarding the method.

[Background of the Invention] Recently, a radiation image recording and reproducing system that obtains a radiation image of a subject using a stimulable phosphor (stimulable phosphor) has been attracting attention. Here, stimulable phosphor refers to radiation (X-rays, α
rays, β rays, γ rays, electron beams, ultraviolet rays, etc.), a part of this radiation energy is accumulated, and later by irradiation with excitation light such as visible light, stimulated luminescence occurs according to the accumulated energy. A phosphor that produces light.

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 radiographic image recording and reproducing system, an image reading device that reads a radiographic image from a stimulable phosphor sheet on which the radiographic image is stored and recorded is specifically configured as follows.

That is, a stimulable phosphor sheet on which a radiation image has been accumulated and recorded is loaded into the image reading device in a state where it is stored in a cassette or a supply magazine, and the stimulable phosphor sheet is loaded into the image reading device through a sheet mechanism including a suction cup or the like. The body sheets are taken out one by one from the cassette or supply magazine.

Next, the sheet of stimulable phosphor sheet is conveyed to the reading section via a conveyance mechanism such as a belt. The reading section performs sub-scanning by mechanically transporting the stimulable phosphor sheet in one direction, and also uses a light beam such as a laser beam that is deflected in a direction substantially perpendicular to the transport direction of the stimulable phosphor sheet. is irradiated to perform main scanning, and the resulting stimulated luminescence light is detected in time series with a photodetector such as a photomultiplier to obtain image information. After the image reading is completed, the stimulable phosphor sheet is transported to the erasing section.
After erasing the radiation image remaining on the stimulable phosphor sheet by irradiating it with erasing light from a sodium lamp or the like, it is accumulated in a receive magazine or the like.

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 by exposure. It is composed of 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.

Therefore, when reading or recording image information in the image reading device or image recording device as described above, for example, a pair of rollers arranged at an interval shorter than the length of the sheet in the sub-scanning direction is used to scan the sheet. The present applicant has already proposed a system in which the light beam is deflected in the main scanning direction while the light beam is deflected in the main scanning direction while the light beam is conveyed in the sub-scanning direction at a predetermined speed by driving one pair of rollers. No. 232479).

By the way, when the sheet is conveyed in the sub-scanning direction by the pair of rollers mentioned above, the applicant has developed a pair of rollers so that reading or recording can be performed from the front edge of the sheet, and reading or recording can be performed up to the rear edge of the sheet. Japanese Patent Application No. 193533/1982 proposes that one roller can be brought close to and separated from the other roller to control sheet nipping (Japanese Patent Application No. 61-193533, etc.).

However, in such a sub-scanning conveyance mechanism, the speed at which the nip rollers nip the sheet body and the speed at which the nip rollers separate from the sheet body are relatively low, for example, during sub-scanning conveyance during book reading for image reproduction. (This means that when a sheet is held at high speed during reading or writing, or when the sheet is released at high speed due to the separation of rollers, a load is placed on the sheet conveyance system.) (The reason is to avoid the possibility that a precise image cannot be reproduced due to speed fluctuations occurring in the sub-scanning conveyance direction of the sheet body as a result)
In addition, when it is sufficient to carry out sub-scanning at high speed, such as during pre-reading to grasp the outline of a recorded image prior to main reading, the timing of nipping or separating the sheet by the nip rollers does not match and the sub-scanning is carried out appropriately. becomes impossible.

Therefore, it is conceivable to set the sub-scanning conveyance speed at the time of pre-reading to a relatively low speed, but this has the disadvantage that the throughput of the image reading device cannot be improved. The details of the above-mentioned pre-reading and main reading have already been disclosed in Japanese Patent Application Laid-open No. 56-165111.

[Object of the Invention] The present invention has been made to overcome the above-mentioned disadvantages, and is a method of nipping a sheet body such as a stimulable phosphor sheet carrying radiation image information or a film for recording an image using nip rollers. When reading or writing an image by conveying the sheet, the nipping speed at which the nip rollers nip the sheet, the separation speed at which they separate from the sheet, and the conveyance speed at which the sheet is conveyed are set to a predetermined nipping speed, It automatically sets a predetermined separation speed and a predetermined conveyance speed, making it possible to read or write images accurately in the shortest possible time, thereby significantly improving the overall throughput of the image reading device. It is an object of the present invention to provide a control method for a sheet conveyance system that enables this.

[Means for Achieving the Object] In order to achieve the above object, the present invention comprises at least one pair of first rollers and a second pair of rollers arranged with a predetermined distance apart from each other. A method for controlling a sheet conveyance system that substantially conveys a sheet held between a pair of rollers in a predetermined direction by driving one of the pair of rollers, the sheet being held and conveyed by a first pair of rollers. detecting that the rollers approach the second pair of rollers, and controlling the approaching speed at which the rollers forming the second roller pair reach the nipping position of the sheet body in accordance with the conveying speed of the sheet body; and/or Detecting that the rear end of the sheet body approaches the first pair of rollers, and controlling the speed at which the rollers forming the first pair of rollers separate from the sandwiching position of the sheet body in accordance with the conveying speed of the sheet body. It is characterized by

[Embodiments] Next, preferred embodiments of the method for controlling a sheet conveyance system according to the present invention in relation to an apparatus for carrying out the method will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates an image reading device incorporating a device for carrying out the method for controlling a conveyance system according to this embodiment. A supply magazine 14 is detachably attached to the chamber 12 in the image reading device 10, and stimulable phosphor sheets S on which radiation images have been stored and recorded are stored in a stacked manner. There is. A single wafer mechanism including a suction cup 16 is provided in the chamber 12 adjacent to the supply magazine 14, and below the suction cup 16 there is an endless conveyor belt 8 for conveying the stimulable phosphor sheet +-S. will be provided.

The conveyor belt 18 extends vertically downward and is bent at an internal corner of the image reading device 10 so as to be oriented in the horizontal direction. A plurality of rollers 20a to 20 arranged in the direction
d is provided. Furthermore, a large-diameter roller 22 is disposed at the lower bent portion of the conveyor belt 18 .

Therefore, a scanning mechanism 24 is installed in the center of the lower part of the image reading section N10.
will be provided. In this case, the scanning mechanism 24 is located below the image reading section 26 and the reading section 26, and the conveyor belt 18 is located below the image reading section 26.
The transport section 28 is provided at a slight distance from the terminal end of the transport section 28.

The reading unit 26 includes a laser light source 30, and on the laser light output side of the laser light source 30, a mirror 34 for scanning and scanning the laser light 32 onto the sheet S, a galvanometer mirror 36, and a condensing reflective mirror 38 are provided. is provided. Furthermore, a light guide 40 is disposed along the main scanning line at the scanning position of the laser beam 32 on the sheet S, and a photomultiplier 42 is mounted above the light guide 40.

On the other hand, the conveyance section 28 includes a first nip roller pair 44a,
44b and a second nip roller pair 46a, 46b, the second nip roller pair 44a, 44b and 46a,
Guide members 48a and 48b for holding the stimulable phosphor sheet S being conveyed are arranged between the guide members 46b. In addition, nip roller pairs 44a, 44b and 46a, 46
Among the nip rollers constituting b, rollers 44a and 4
An endless conveyor belt 47 for placing and conveying the stimulable phosphor sheet S is disposed between the sheets 6a.

Further, stimulable phosphor sheets S are provided at both ends of the conveying section 28.
A light sensor 41.43 that determines the presence or absence of the light source 41.43 is disposed adjacent to the light source 41a, 4
3a and light receiving elements 41b and 43b.

A relatively large diameter roller 52 is located close to the second nip roller pair 46a, 46b of the scanning mechanism 24 configured as described above.
and an endless conveyance heald 54, and the conveyance belt 54 is constructed over a first support roller 56a and a second support roller 56b provided above the roller 52 and in sliding contact with the roller 57. . Furthermore, the conveyor belt 54
A tension roller 58 is in sliding contact with the inner circumferential surface of the tension roller 58, and one end of the tension roller 58 is pulled vertically downward by a coil spring 68 that engages with the side plate 60. Therefore, the tension roller 58 is always pulled vertically downward by the tensile force of the coil spring 68 to maintain the conveyor belt 54 in a predetermined tension state.

An endless conveyor belt 72 is provided above the second support roller 56b. The conveyor belt 72 extends vertically upward, is bent horizontally at its terminal end, and has its tip directed slightly downward. A plurality of rollers 74a to 74e are disposed in sliding contact with the vertically extending portion of the conveyor belt 72.
A large diameter roller 76, a roller 78a,
78b is provided to convey the stimulable phosphor sheet S vertically downward. A receive magazine 80 for storing the stimulable phosphor sheet S is provided adjacent to the roller 78b.

Furthermore, an erasing section 82 is disposed within the chamber 12, for example, between rollers 74b and 74c provided on the conveyor belt 72. Note that a plurality of erasing light sources (not shown) are provided inside the erasing section 82.

This apparatus further includes a main body control section 84 that controls and processes the conveyance, reading, development, etc. of the stimulable phosphor sheet +-S, and a first nip roller pair 4 that is connected to the main body control section 84.
4a, 44b and second nip roller pair 46a, 46b
A nip roller control section 86 is provided to control the nipping speed, separation speed, and conveyance speed of the rollers. As shown in FIG. 2, the nip roller control section 86 includes a main body control section 84.
Input information such as the dimensions of the stimulable phosphor sheet (S), actual reading processing or pre-reading processing, and drive start signals of the nipping speed, separation speed, and conveyance speed of the nip rollers are introduced. The input information and drive start signal are introduced into the interface section 88 in the nip roller control section 86, and the input information is introduced into the speed switching section 92 via the decoder section 90. Furthermore, the speed switching signal from the speed switching section 92 is introduced into the first input terminal of the drive signal generating section 94 . On the other hand, the drive start signal is introduced to the second input terminal of the drive signal generator 94 via the interface section 88 . The output signal of the drive signal generator 94 is connected via a power amplifier 96 to a solenoid 98 that controls the nipping speed and rotational speed of the nip roller pairs 44a, 44b and 46a, 46b. The configuration is such that the signal is fed back to the third input terminal of the drive signal generator 94 via the signal generator.

On the other hand, a part of the output signal from the power amplifying section 96 is introduced into the error detecting section 102 as a monitor signal, and then introduced into the main body controlling section 84 via the interface section 88.

The apparatus for carrying out the method of controlling a sheet conveyance system according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, the supply magazine 14 is installed in the chamber 12 of the image reading device 10 . In this case, the supply magazine 1
A plurality of stimulable phosphor sheets S on which radiographic images of a subject such as a human body are stored and recorded are stacked and housed in the storage unit 4 . Here, the main body control unit 84 outputs information such as the dimensions of the stimulable phosphor sheet S, the pre-reading process, the actual reading process, and the like. In this case, the dimensions of the stimulable phosphor sheet S are determined by reading a barcode attached to the edge of the stimulable phosphor sheet S as identification information using a barcode league disposed upstream of the image reading section 26. Detected based on this information. Here, the pre-reading process refers to the work of reading radiation image information (actual reading process) for scanning the stimulable phosphor sheet S with excitation light and reproducing a visible image for observation and interpretation.
Prior to this, in order to optimally set the reading conditions and/or image processing conditions in the main reading process, the stimulable phosphor sheet S is irradiated with excitation light of lower energy than in the main reading process to obtain radiation image information. In the process of reading the outline, the output information output from the main body control unit 84 is sent to the main reading process via the interface unit 88 and the decoder unit 90.
It is introduced into a speed switching section 92 for switching the conveyance speed or nipping speed of the stimulable phosphor sheet S related to the pre-reading process or the like.

Therefore, the stimulable phosphor sheets S 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 a conveyor belt 18 provided below the suction cup 16 and a plurality of rollers. It is conveyed at high speed to the scanning mechanism 24 side via 20a to 20d and the roller 22. Then, when the stimulable phosphor sheet S enters the optical sensor 41 and the light from the light source 41a is blocked by the stimulable phosphor sheet S (see FIG. 3a), the output signal of the light receiving element 41b is is introduced into the main body control section 84.

Next, a drive start signal is input from the main body control section 84 to the nip roller control section 86 into the second input terminal of the drive signal generation section 94 . In this case, since a pre-reading process is introduced in the drive signal generating section 94, the nip rollers 44a and 46a are driven to rotate at high speed by a motor (not shown) via the power amplifying section 96 and the solenoid 98, and the accumulative fluorescence is detected in the reading section 26. (see Figure 3). Therefore, in the pre-reading step, it is possible to read the image information carried on the stimulable phosphor sheet S at high speed. In addition, in the pre-reading step,
In order to roughly read the image, it is sufficient to perform rough scanning, and the diameter of the laser beam 32 from the laser light source 30 is increased.

This pre-read information is taken into the main body control section 84 via the light guide 40 and photo multiplier 42, and optimal image processing conditions are set for exposure during actual reading or image writing. In addition, the pre-reading process is in progress, and the third
When the stimulable phosphor sheet S is conveyed to the point shown in FIG. The pre-reading process is continued by conveying the stimulable phosphor sheet S in the direction (see Fig. 3 d).
.

Next, when the stimulable phosphor sheet S enters the optical sensor 43, the output signal of the optical sensor 43 causes the main body controller 8 to
4. Nip roller control section 86 and drive signal generation section 94
is activated, and the first nip roller pair 44a, 44b is connected to the stimulable phosphor sheet 1 via the power amplifying section 96 and the solenoid 98.
-3 (see Figure 3e). In addition, in that case,
The speed at which the second nip roller pair 46a, 46b grips the stimulable phosphor sheet S, the first nip roller pair 44
The speed at which the stimulable phosphor sheets a and 44b are separated from the stimulable phosphor sheet S and the rotational speed of the nip rollers 44a and 46b can be set at high speeds. This is due to the slight positional deviation of the stimulable phosphor sheet (S) caused by the high-speed operation of the nip roller pairs 44a, 44b and 46a, 46b for nipping, separating, and conveying in the pre-reading process. This is because the signal is used only as data for determining image processing conditions, etc., and is not used as a signal for actually forming a reproduced image, so it does not pose a problem. When the pre-reading step is completed (see FIG. 3 f), the nip roller pairs 44a, 44b and 46a, 46 are then
As shown in FIG. 3g, the light beam b is rotated in the opposite direction and transported to the front of the light guide 40 again (see the third diagram). In this case, the first pair of nip rollers 44a, 44b are spaced apart from each other in advance at a distance slightly shorter than the thickness of the stimulable phosphor sheet S.

Then, when the conveyance in the opposite direction is completed, the second pair of nip rollers 46a, 46b are separated from each other (see FIG. 3i).

Next, the main reading process is started. In this case, the output signal of the drive signal generator 94 is introduced to the solenoid 98 via the power amplifier 96, and the stimulable phosphor sheet S is conveyed at a low speed in order to precisely read the image information carried thereon. Ru. That is, the nip roller 44 that constitutes the conveyance section 28
a and 46a are driven to rotate at a low speed, and the stimulable phosphor sheet (S) placed on an endless conveyor heald 47 is conveyed at a low speed in the sub-scanning direction (direction of arrow B). At that time, the reading section 26 is driven again. In this case, the laser beam 32 emitted from the laser light source 30 is reflected by the mirror 34 to reach the galvanometer mirror 36, and the laser beam 32 is scanned on the sheet S while the galvanometer mirror 36 swings. As a result, the stimulated luminescent light emitted from the stimulable phosphor sheet S is incident directly or reflected by the reflecting mirror 38 into the light guide 4o, and is converted into an electrical signal by the photomultiplier 42 and sent to the main body controller 84. to be sent to.

Then, the main reading is performed through a series of steps shown in FIGS. 3j to 3m. In this case, the speed at which the rollers constituting the second nip roller pair 46a, 46b come close to each other and sandwich the stimulable phosphor S between the steps from FIG. 3j to FIG. 3k is controlled by speed control. The feedback effect of section 100 allows extremely high-speed control. That is, immediately after the pair of nip rollers 46a and 46b start operating, a large current is supplied to the solenoid 98 in a short time to move them close together at high speed, and just before nipping is expected, the current gradient is weakened to reduce the accumulation caused by sudden nipping. The phosphor sheet S is moved and clamped at a very low speed so as not to cause deformation of the phosphor sheet S, and after the clamping is completed, the current is steepened again until a predetermined clamping force is obtained to perform the clamping process. In this way, it is possible to eliminate misalignment of the stimulable phosphor sheet S and to shorten the time required for the entire nipping process as much as possible. Similarly, Figure 3k to Figure 3! The speed at which the rollers constituting the first nip roller pair 44a, 44b separate from each other during the process leading to is as follows:
The speed of the stimulable phosphor sheet S is controlled to be low from the conveyance and clamping position to the position just before it is separated, and the speed from immediately after the separation until it returns to the specified separation original position is controlled to be high. Therefore, when the nip rollers 44a and 46a are separated, the load fluctuations applied to the motors (not shown) that rotate the nip rollers 44a and 46a can be suppressed to an extremely small level. and stimulable phosphor C)S
When the nip roller pair 4 reaches the position shown in FIG.
6a and 46b release the nipping action and are transported to the next process by rollers 52) and transport belt 54.

In addition, during the main reading process or the pre-reading process, the error detection unit 102 in the two roller control unit 86 is replaced by the power amplification unit 96.
The monitor signal is compared with a predetermined signal change to see if there is a difference, and if a difference is detected, it notifies the main body control section 84 of an abnormal operation of the solenoid 98, and the nip roller Pairs 44a, 44b, 46a, 46b
This is to stop the conveyance process.

Next, the stimulable phosphor sheet S reaches the erasing section 82 via the conveyor belt 72 and rollers 74a and 74b. In the erasing section 82, a plurality of erasing light sources (not shown) are turned on, so that the irradiated light erases the radiation image remaining on the stimulable phosphor sheet S. The stimulable phosphor sheet (S) from which the radiation image has been erased is transported to the upper part of the image reading scanning area via the transport heald 72) rollers 74c to 74e, and is displaced in its traveling direction via the rollers 76 and rollers 78a and 78b. and is stored in the receive magazine 80. ' Note that in the above embodiment, the nipping speed and separating speed of the nip rollers are changed depending on the conveyance speed of the stimulable phosphor sheet S in the pre-reading process and the main reading process, but as described above, the stimulable phosphor sheet detected The conveying speed may be controlled according to the size of S, and the nipping speed and separating speed of the nip rollers may be changed.

[Effects of the Invention] As described above, according to the present invention, when reading or writing an image while nipping a sheet such as a stimulable phosphor sheet carrying radiation image information using nip rollers, the reading conditions and/or Alternatively, the speed at which the nip rollers are nipped, the speed at which the nip rollers are separated, and the speed at which the sheet is conveyed by the nip rollers are set to predetermined speeds based on image processing conditions.

Therefore, it is possible to maintain the accuracy of image reading and perform image processing in as short a time as possible, and therefore, it is possible to significantly improve the throughput of the apparatus.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
It goes without saying that various improvements and design changes can be made without departing from the gist of the present invention, such as the ability to further improve image processing speed by using the method of the present invention even when writing images. be.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration explanatory diagram of an apparatus for carrying out the method of the present invention, Fig. 2 is a block diagram of an electric circuit of a nip roller control unit incorporated in the apparatus for carrying out the method of the present invention, and Figs. 3 a to m. FIG. 2 is an explanatory diagram of the operation of a conveyance mechanism including a nip roller that is incorporated into an apparatus for carrying out the method of the present invention. 10... Image reading device 24... Scanning mechanism 2
6... Image reading section 28... Conveyance section 41.
...Light sensor 41a...Light source 41b...
- Light receiving element 43... Optical sensor 43a...
Light source 43b...light receiving elements 44a, 44
b, 46a, 46 b---Tuburora pair 47...
Conveyor belt 84...Body control section 86...Nip roller control section 92...Speed switching section 94...Drive signal generation section 96...Power amplification section 98...Solenoid 100...Speed control section 102...Error detection section S...Stormable phosphor sheet patent applicant Fuji Photo Film Co., Ltd. 4'lO4
40zI5 4'/4t)G 4
JGF IG, 3e ÷ 2 FIG, 3f

Claims (3)

[Claims] (1) A sheet consisting of at least one pair of first rollers and a second pair of rollers arranged with a predetermined distance apart, and which is sandwiched between the pair of rollers by driving one of the pair of rollers. A method for controlling a sheet conveying system for conveying a sheet substantially in a predetermined direction, the method detecting that a sheet conveyed while being nipped by a first pair of rollers approaches a second pair of rollers, and conveying the sheet body in a predetermined direction. Controlling the approach speed at which the rollers constituting the second roller pair reach the sandwiching position of the sheet body in accordance with the speed, and/or detecting that the rear end of the sheet body approaches the first roller pair. A method for controlling a sheet conveyance system, characterized in that the speed at which the rollers constituting the first roller pair move away from a nipping position of the sheet body is controlled in accordance with the conveyance speed of the sheet body. (2) In the method according to claim 1, the second
The approaching speed at which the rollers constituting the roller pair reach the position where the sheet body is held is high until the rollers reach a predetermined approach range, and then reduced to a low speed just before the rollers mutually nip the sheet body. A control method for a sheet conveyance system comprising controlling the sheet body conveyance system so that (3) In the method according to claim 1 or 2, the separation speed at which the rollers constituting the first roller pair separate from each other from the sheet body and return to the separated original position is:
A control method for a sheet conveyance system comprising controlling a sheet conveyance system such that the speed is low from a conveyance clamping position to a position immediately after separation, and the speed from immediately after separation to a return to the original position after separation is high speed.