JPH03131165A - Light beam scanner - Google Patents

Abstract

PURPOSE:To carry a scanned body smoothly in the subscanning direction with high accuracy by adopting the constitution such that a friction force between a carrier belt and a scanned body is larger than the friction force between a pressing member and the scanned body. CONSTITUTION:When a storage fluorescent sheet A is carried to a light beam scanner 10, a rotary drive source 16 forming a subscanning carrier mechanism 12 is driven, the storage fluorescent sheet A is carried and a fluorescent face side is pressed on a carrier belt 22 by a pressing member 30 via an elastic force of a spring member 32. Thus, production of position deviation of the storage fluorescent sheet A with respect to the carrier belt 22 is blocked to carry the storage fluorescent sheet A accurately. In this case, the friction force between the pressing member 30 and the storage fluorescent sheet A is selected smaller than the friction force between the rear side of the storage fluorescent sheet A and the carrier belt 22.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention mainly scans an object to be scanned, such as a stimulable phosphor sheet on which a radiation image has been accumulated and recorded, with a one-dimensionally deflected light beam, and The present invention relates to a light beam scanning device that two-dimensionally scans a scanned object by sub-scanning the scanned object in a direction substantially orthogonal to the main scanning direction.

[Prior Art] A radiation image recording and reproducing system is known that uses a stimulable phosphor to obtain a radiation image of a subject as a visible image.

In the radiation image recording and reproducing system, a light beam scanning device is employed to photoelectrically read a radiation image from a stimulable phosphor sheet on which the radiation image is stored and recorded. The light beam scanning device performs main scanning by one-dimensionally irradiating a light beam onto a stimulable phosphor sheet as a scanned object, and also scans the stimulable phosphor sheet in a direction substantially perpendicular to the main scanning direction. The light beam is transported in the sub-scanning direction, thereby performing two-dimensional scanning with the light beam.

In this case, the stimulable phosphor sheet must be conveyed accurately in the sub-scanning direction so that the stimulable phosphor sheet during scanning does not cause unnecessary positional deviation and the image information read from now on becomes inaccurate. It won't happen. For this reason, conventionally, devices have been used in which a suction box is placed in the space of an endless belt conveyor, and the object to be scanned, such as a stimulable phosphor sheet, is sucked and positioned on the belt conveyor. (Refer to Japanese Patent Publication No. 59-33451).

Furthermore, two pairs of rollers are arranged at intervals shorter than the length of the object to be scanned in the sub-scanning direction to sandwich and convey the object to be scanned, such as a stimulable phosphor sheet, in the sub-scanning direction. A device has been proposed that is configured to synchronously rotate and convey the object to be scanned in the sub-scanning direction (Japanese Patent Laid-Open No. 62-9406).
(See Publication No. 8).

[Problems to be Solved by the Invention] However, the suction box requires a vacuum generator for suctioning the object to be scanned, a suction switching means, etc. (Refer to Japanese Patent Laid-Open No. 61-94952), the manufacturing cost increases and the device becomes complicated and large.

On the other hand, in a pair of rollers, when a scanned object is inserted between or ejected from a pair of rollers, load fluctuations occur, and there is a possibility that a smooth and highly accurate image reading operation cannot be achieved. Therefore, an actuator is required to displace one roller of each pair of rollers toward or away from the other roller so as to prevent the above-mentioned load fluctuation (see Japanese Patent Laid-Open No. 63-67859). The drawback is that the manufacturing cost of the entire device increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light beam scanning device that can transport an object to be scanned in the sub-scanning direction smoothly and with high precision, and has a simple configuration and can be manufactured at low cost.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a method for irradiating a sheet-shaped object to be scanned with a light beam in the main scanning direction. A conveyor belt that is conveyed in a substantially orthogonal sub-scanning direction; and a pressing member that brings the object to be scanned into close contact with the conveyor belt, and a frictional force between the conveyor belt and the object to be scanned is applied to the pressing member and the object to be scanned. It is characterized by being constructed so that the frictional force is greater than the frictional force with the body.

[Function] In the light beam scanning device according to the present invention, when a sheet-shaped object to be scanned is fed onto a conveyor belt, a pressing member disposed close to the conveyor belt pushes the object to be scanned. It is pressed tightly onto this conveyor belt. At this time, since the frictional force between the conveyor belt and the object to be scanned is greater than the frictional force between the pressing member and the object to be scanned, the object to be scanned is conveyed in the sub-scanning direction under the driving action of the conveyor belt, and the object to be scanned is transported in the main scanning direction. Two-dimensional scanning is performed on the object to be scanned through the light beam irradiated in the scanning direction.

[Example] An example will be given regarding the light beam scanning device according to the present invention,
A detailed description will be given below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a light beam scanning device according to this embodiment, and the light beam scanning device 10 includes a sub-scanning transport mechanism 12 and a scanning reading mechanism 14.

The sub-scanning conveyance mechanism 12 includes a rotational drive source 16, and an auxiliary drive roller 18 is coaxially connected to the rotational drive shaft of the rotational drive source 16 via a speed reducer 17.

A stepped driven roller 20 is disposed at a predetermined distance from and parallel to the drive roller 18, and a plurality of endless conveyor belts 22 are arranged on the small diameter side of the outer peripheral surfaces of the drive roller 18 and the driven roller 20. It is strung up. in this case,
The conveyor belt 22 conveys the stimulable phosphor sheet A in the sub-scanning direction (direction of arrow B), and the stimulable phosphor sheet A is transferred to the conveyor belt 22 via the first and second pressing members 24 and 26. Closely held.

The first pressing member 24 is disposed on the upstream side in the sub-scanning direction with respect to the scanning position of the laser beam on the stimulable phosphor sheet A, which will be described later, and is located at the end where the stimulable phosphor sheet A enters. The portion 24a is curved so as to be spaced apart from the conveyor belt 22 (see FIG. 2). The first pressing member 24 is a plate body 28
and a pressing member 30 affixed to the lower surface side of the plate body 28, and the first pressing member 24 is urged toward the conveyor belt 22 side by a plurality of spring members 32 engaged with the plate body 28. There is.

The pressing material 30 is brought into sliding contact with the phosphor screen (front surface) side of the stimulable phosphor sheet A, and the frictional force between the back surface of the stimulable phosphor sheet A and the conveyor belt 22 The materials of the pressing material 30 and the conveying belt 22 are selected so that the frictional force between the phosphor screen of the fluorescent phosphor sheet A and the pressing material 30 is greater than the frictional force between the pressing material 30 and the fluorescent surface of the fluorescent phosphor sheet A. In practice, the conveyor belt 22 is made of a polyester sheet coated with a synthetic rubber material, while the pressing member 30 is made of a flocked material made of wool or rayon, or a foamed material such as foamed polyethylene. be done.

The second pressing member 26 disposed on the downstream side (in the sub-scanning direction (direction of arrow B)) presses the end 2 into which the stimulable phosphor sheet A is inserted.
6a is curved in the vertically upward direction in FIG.
Components similar to those of the first pressing member 24 described above are given the same reference numerals, and detailed explanation thereof will be omitted.

The scanning/reading mechanism 14 includes a laser light source 40, and a mirror 44 and a galvanometer mirror 46 for scanning the laser light 42 onto the stimulable phosphor sheet A are provided on the laser light output side of the laser light source 40. An incident end 48a of a light guide 48 is arranged opposite to the scanning line at the scanning position on the stimulable phosphor sheet A of the laser beam 42, and a photomultiplier 50 is attached to the upper part of the light guide 48. . Incidentally, the incident end 48 of the light guide 48 is located across the scanning line.
On the opposite side of H, a condensing reflecting mirror 52 is provided to efficiently guide stimulated luminescent light emitted from the stimulable phosphor sheet A to the incident end 48a.

The light beam scanning device according to this embodiment is basically constructed as described above, and its operation will be explained next.

For example, when a stimulable phosphor sheet A on which a radiation image of a subject such as a human body is stored and recorded is conveyed to the light beam scanning device 10, the rotational drive source 16 constituting the sub-scanning conveyance mechanism 12 is driven. drive roller 18 connected to
is rotated in the direction of the arrow. Therefore, the plurality of conveyor belts 22 stretched around the drive roller 18 and the driven roller 20 are displaced in the direction of the arrow, and the stimulable phosphor sheet whose one end is placed on the conveyor belt 22 is moved. )A is arrow B
The image is conveyed in the sub-scanning direction.

The end of the stimulable phosphor sheet A is first pressed against the first pressing member 2.
facing the end 24a of 4. At this time, since this end portion 24a is curved in a direction away from the conveyor belt 22, load fluctuations are caused between the first pressing member 24 and the conveyor belt 22 in the stimulable phosphor sheet A. It enters without any hesitation.

When the stimulable phosphor sheet A is further conveyed in the direction of arrow B, the phosphor screen side of the stimulable phosphor sheet A is pressed against the conveying belt 22 side by the pressing member 30 through the elastic force of the spring member 32. This allows the storage of stimulable phosphor (see)
It is possible to prevent the stimulable phosphor sheet A from causing misalignment with respect to the conveyor belt 22, and it is possible to accurately convey the stimulable phosphor sheet A in the direction of the arrow B.

In this case, in particular, the frictional force between the pressing material 30 and the phosphor screen of the stimulable phosphor sheet A is selected to be smaller than the frictional force between the back surface of the stimulable phosphor sheet A and the conveyor belt 22. The stimulable phosphor sheet A is reliably and accurately conveyed in the direction of arrow B. In addition, since the pressing material 30 is made of a flocked material made of wool or rayon, it is possible to remove dust etc. that adheres to the phosphor screen of the stimulable phosphor sheet (A), and the image reading operation described later can be performed accurately. be exposed.

When the stimulable phosphor sheet A reaches the scanning position, the scanning/reading mechanism 14 is driven and the laser beam 42 emitted from the laser light source 40 is reflected by the mirror 44 and then reaches the galvanometer mirror 46 . The laser beam 42 is scanned on the stimulable phosphor sheet A under the swinging action of the galvanometer mirror 46, whereby the stimulated luminescent light emitted from the stimulable phosphor sheet A is reflected directly and by the reflecting mirror 52. and enters the light guide 48. The laser light 42 incident on the light guide 48 is converted into an electrical signal by a photomultiplier 50, and is sent to, for example, an image recording device.

In this way, the laser beam 42 is placed on the stimulable phosphor sheet A.
The stimulable phosphor sheet A is scanned two-dimensionally by the second pressing member 26, and the stimulable phosphor sheet A
2 and is guided out from the light beam scanning device 10.

Here, the end portion 26a of the second pressing member 26 is
Because it is curved in the direction away from the second
When the stimulable phosphor sheet A enters the pressing member 26, load fluctuations etc. are not caused.

Next, a light beam scanning device 6 according to another embodiment of the present invention
0 is shown in FIG. Note that the same components as those of the light beam scanning device 10 according to the first embodiment are given the same reference numerals, and detailed explanation thereof will be omitted.

In this case, the plate body 28 constituting the first mounting member 24 is formed of an iron plate, and the spring member 62 engaged with the plate body 28 pulls the first pressing member 24 in the direction separating it from the conveyor belt 22. I'm letting you do it. An electromagnet 64 is disposed below the first pressing member 24 inside the conveyor belt 22, while an electromagnet 66 is disposed below the second pressing member 26, which includes a plate body 28, which is also formed of an iron plate. provided.

In such a configuration, when the stimulable phosphor sheet A is conveyed in the direction of arrow B via the conveyor belt 22, the electromagnet 64 is energized and the plate body 28, which is an iron plate, is moved against the spring member 6.
2 is displaced toward the conveyor belt 22 side against the tensile force of 2. Therefore, the stimulable phosphor sheet A is pressed closely to the conveyor belt 22 side via the pressing member 30 and is conveyed in the direction of arrow B. Furthermore, the electromagnet 66 is energized, and the stimulable phosphor sheet A is brought into close contact with the conveyor belt 22 and is accurately conveyed in the sub-scanning direction.

Note that in the light beam scanning device 10 according to the first embodiment, the first and second pressing members 24 and 26 are connected to each other via the spring member 32.
The stimulable phosphor sheet A is urged toward the conveyor belt 22 side, but the stimulable phosphor sheet A is brought into close contact with the conveyor belt 22 via the weight of each plate body 28, 28 without using the spring member 32. You can also do that.

In addition, although the above embodiment described an apparatus for reading a stimulable phosphor sheet, it is also possible to use an apparatus for reading image information from a recording sheet other than a stimulable phosphor sheet on which image information is recorded, or an apparatus for reading image information from a photographic material or the like. Of course, the present invention can also be applied to an apparatus that records an image by scanning with a light beam modulated based on information.

[Effects of the Invention] The light beam scanning device according to the present invention configured as described above has the following effects.

Since the object to be scanned on the conveyor belt is brought into close contact with the conveyor belt via the pressing member, the object to be scanned does not cause unnecessary positional deviation.

Furthermore, since the frictional force between the conveyor belt and the object to be scanned is greater than the frictional force between the pressing member and the object to be scanned, the object to be scanned is moved through the conveyor belt without being stopped by the pressing member. It can be conveyed with high precision in the sub-scanning direction. Furthermore, in order to bring the object to be scanned into close contact with the conveyor belt, it is only necessary to substantially provide a mounting member, which simplifies the configuration at once, and easily achieves miniaturization and cost reduction of the entire light beam scanning device. becomes possible.

4,

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a light beam scanning device according to the present invention, FIG. 2 is a side view of the light beam scanning device, and FIG. 3 is a light beam scanning device according to a second embodiment of the present invention. FIG. 10... Light beam scanning device 14... Scanning reading mechanism 24.26... Pressing member 30... Pressing material 12... Sub-scanning conveyance mechanism 22... Conveyance belt 28... Plate body

Claims (1)

[Claims] (1) A conveyor belt that transports the sheet-shaped object to be scanned in a sub-scanning direction substantially perpendicular to the main-scanning direction when the sheet-like object to be scanned is irradiated with a light beam in the main-scanning direction; a pressing member that brings the object to be scanned into close contact with each other, and is configured such that the frictional force between the conveyor belt and the object to be scanned is greater than the frictional force between the pressing member and the object to be scanned. Light beam scanning device.