JPS62254568A - Light beam scanning device - Google Patents

Abstract

PURPOSE:To form a black edge with simple structure by bringing a transparent nip into press-contact with a carrier member and scanning a writing light beam via a transparent nip roller to carry accurately a body to be scanned at a prescribed speed and scanning the entire face of the body to be scanned. CONSTITUTION:The transparent nip roller 50 made of a transparent material is arranged on a reflection light axis 18 of a dichroic mirror 16. The lowermost circumferential face of the roller 50 is aligned to be a focus of projected luminous fluxes by the roller 50 and a Ftheta lens 14. The carrier roller 52 is arranged in press-contact with the lowermost circumference of the roller 50 and the transparent nip roller 50 and the carrier roller 52 form paired exposure carrier rollers 54. Then the roller 52 and the transparent nip roller 50 clip a film to perform subscanning conveyance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light beam scanning device, and more particularly, the present invention relates to a light beam scanning device that scans a scanned object two-dimensionally with a light beam. The present invention relates to a light beam scanning device that records an image on the photographic material by irradiating it with light.

[Prior art]

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, the storage fluorophore refers to radiation (X-rays, α
When irradiated with rays, β rays, γ rays, electron beams, ultraviolet rays, etc., a part of this radiation energy is accumulated, and later when excitation light such as visible light is irradiated, stimulated luminescence light corresponding to the accumulated energy is generated. A fluorescent material that emits 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 made of a stimulable phosphor (hereinafter referred to as a ``stimulable phosphor sheet''). (or simply referred to as a "sheet"), this stimulable phosphor sheet is scanned with excitation light such as a laser beam to generate stimulated luminescent light, and this stimulated luminescent light is read photoelectrically. An electrical signal is obtained, and based on this electrical signal, a radiation image of the subject is output as a visible image to a recording material such as a photographic light-sensitive material or 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 specifically reads the radiographic image by the following method. reading.

That is, a stimulable phosphor sheet is scanned two-dimensionally with a light beam such as a laser beam, and the stimulated luminescence light generated at this time is photoelectrically detected in time series using a photodetector such as a photomultiplier. image information as an electrical signal. In the two-dimensional scanning of the light beam, the light beam is normally deflected one-dimensionally and irradiated onto the stimulable phosphor sheet to perform main scanning, and the sheet is scanned 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 performing sub-scanning.

Next, when the image information obtained as described above is to be reproduced on a photographic material, the image information 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, so as to record a predetermined image on the photographic light-sensitive material. It is configured. After the photographic light-sensitive material on which the image has been recorded is subjected to development processing, it is used for medical diagnosis and the like.

By the way, in a conventional image recording apparatus, a photosensitive material is sandwiched and conveyed by a large-diameter drum that engages with a rotational drive source and a pair of nip rollers that are in pressure contact with this drum, and sub-scanning is performed. There is known a method in which a laser beam modulated onto the photographic light-sensitive material is one-dimensionally deflected in a direction substantially perpendicular to the sub-scanning method and irradiated onto the photographic light-sensitive material to perform main scanning.

However, in this configuration, in order to convey the photosensitive material 7 at a constant speed and in an accurate direction with high precision, it is necessary that the photosensitive material is nipped by both of the pair of nip rolls. Therefore, the photographic light-sensitive material is exposed from the time when the nip by both nip rollers starts until the nip by the upstream nip roller is released, and as a result, the leading and trailing ends of the photographic light-sensitive material in the sub-scanning direction are exposed. There will be some areas that are not exposed to light.

This unexposed area of the photosensitive material becomes transparent after development, making it impossible to form black edges (black edges outside the image area of the photosensitive material). When observing using a light transmission method, there is a problem in that the transparent portions at the leading and trailing ends become bright, which hinders clear reading of the central image portion to be observed.

In another conventional image recording method, a photographic material is conveyed on an endless belt conveyor, and a suction box is arranged to prevent the photographic material from being displaced with respect to the belt conveyor. 2. That is, the suction box is disposed in a space of an endless belt conveyor, and the belt conveyor is provided with a plurality of suction holes. When the photosensitive material is conveyed to the belt conveyor, a vacuum generator connected to the suction box starts suction, and the photographic photosensitive material is positioned and fixed on the belt in order to be sucked on the belt conveyor. and is transferred as the belt conveyor is displaced in the sub-scanning direction.

In this conventional technique, it is possible to scan the entire surface of the photographic material so as to form a so-called black edge.
As mentioned above, since the suction box is used, the machine becomes large and has a plurality of machines, and also requires a vacuum generator to suck the sheet through the suction box and a control system to drive and control this device. do.

Therefore, such a means for fixedly conveying the photographic material becomes quite expensive, and the cost of the entire radiation image recording system also rises considerably.

Furthermore, in order to suitably adsorb the photosensitive material onto the belt conveyor, it is necessary to provide a withdrawal path for conveying the stimulable photoreceptor sheet parallel to the photoconveyor, and the radiation image recording and reproducing system itself is It becomes large. 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.

[Purpose of the invention]

The present invention has been devised in view of the above-mentioned problems of conventional light beam scanning devices. An object of the present invention is to provide a light beam scanning device that can scan the entire surface of a photosensitive material, and in particular, when recording an image, can also scan the front and rear ends of a photosensitive material in the sub-scanning direction, thereby forming a so-called black edge. .

[Structure of the invention]

The structural features of the light beam scanning device according to the present invention that achieves the above object are as follows: Main scanning is performed by irradiating a sheet-shaped object to be scanned with a light beam deflected in a one-dimensional direction; In a light beam scanning device that performs sub-scanning by transporting the object to be scanned in a direction substantially perpendicular to the main scanning direction, and scans the object to be scanned two-dimensionally, a sub-scanning conveying member that transports the object to be scanned; A transparent nip roller is brought into pressure contact with the object to be scanned, the object to be scanned is held between the sub-scanning conveyance member and the transparent nip roller, and a light beam is irradiated onto the object to be scanned through the transparent roller together with the sub-scanning conveyance member.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

As shown in the figure, the writing light beam scanning device 1 includes a synchronizing signal light source 4 and a writing infrared light source 6 disposed within the rotation plane of a continuously rotating rotating polygon mirror 2. A collimator lens 8 and a guichroic mirror 10 that transmits infrared light and reflects visible light are arranged in front of the synchronization signal light source 4. A light modulator 12 is provided between the writing infrared light source 6 and the guichroic mirror 10 to modulate the amount of transmitted light based on an image signal.

In front of the rotating mirror 2, that is, on the reflection optical axis 13, an Fθ lens 14 serving as a scanning lens and a guichroic mirror 16 that transmits visible light and reflects infrared light are arranged. A transparent nip roller 50 made of a transparent material is arranged on the reflective optical axis 18 of the guichroic mirror 16. The transparent nip roller 50 is positioned such that its lowermost circumferential surface is the focal position of the light beam projected by the Fθ lens 14 and the transparent nip roller 50.

A conveying roller 52 is arranged so as to be in pressure contact with the lowermost peripheral surface of the transparent nip roller 50, and the transparent nip roller 50 and the conveying roller 52 form an exposure conveying roller pair 54.

A first pair of guide plates 56 and a second pair of guides 58 are provided on both sides of the pair of exposure conveyance rollers 54, and a first pair of feed rollers 60 and a pair of second feed rollers 62 are arranged on the outside thereof, respectively. Further upstream of the first feed roller pair 60, a film front end detector 64 is arranged.

On the other hand, a grid 22 in which portions that transmit light and portions that do not transmit light are formed alternately in the scanning direction is arranged near the rear of the guichroic mirror 16, and further behind the grid 22 is a long circle made of acrylic resin. A light detection means 28 is arranged, which is a columnar light guide 26 and a photomultiplier tube 24 arranged at the end thereof. The position of the grid 22 is closer to the gicroic mirror 16 than the focal position of the projected light flux from the Fθ lens 140, and the projected light flux is
is incident on the object in an out-of-focus state. Note that since the synchronizing signal light beam scanning the grid 22 deviates from the Fθ characteristic of the Fθ lens, the pitch of the grid is formed at irregular pitches.

The fundamental pulse output from the photomultiplier tube 24 is input to a multiplier circuit 32 via a high frequency amplifier 30. The multiplier circuit 32 is constituted by a slicer and PLL circuit 34 and a clock generator 36, and multiplies the input basic pulse to form a synchronization signal and outputs it to the control circuit 38. The control circuit 38 captures the image signal at a timing based on the periodic signal, outputs a signal for controlling the modulation circuit, and controls the optical modulator 12 by the modulator drive signal output from the modulation circuit 40.
is activated, and the modulation of the light beam emitted from the writing infrared light source 6 and reaching the film 20 is controlled based on a predetermined image signal.

In the above configuration, the light beam from the synchronizing signal light source 4 and the light beam emitted from the writing infrared light source 6 and passing through the optical modulator 12 are coaxially formed by the guichroic mirror 10 and rotated into the rotating polygon mirror 2. incident on . The light beam reflected and deflected by each mirror surface of the continuously rotating rotating polygon mirror 8 reaches the gicroic mirror 16 via the Fθ lens 14.

At the guichroic mirror 16, the writing infrared light beam is reflected and focused onto the film 20 via a transparent nip roller 50. On the other hand, the synchronizing signal light beam passes through the grid 22 and enters the elongated cylindrical member 26, and the incident light amount information is detected by the photomultiplier tube 24.
A synchronization signal is formed by the high frequency amplifier 30 and the multiplier circuit 32 and is input to the control circuit 38.

On the other hand, the film 20 is sent from a film stocker (not shown), and the front end of the film 20 is first detected by the film front end detector 64.

The film 20 is then transferred to a tenth roller pair 61, a first guide plate pair 56, an exposure transport roller pair 54, and a second guide plate pair 58.
and is sent in the six directions of arrows by the 20th pair 62.

Here, the control circuit 38 controls the control circuit 38 to black out the film at a timing based on a synchronization signal from the multiplier circuit 32 when the leading edge of the film is sandwiched between the pair of exposure transport rollers 54 after a predetermined period of time has elapsed after the leading edge of the film is detected by the detector 64. The optical modulator 12 is activated by the modulator drive signal outputted from the modulation circuit 40, and the optical modulator 12 is activated based on the predetermined image signal including the black edge signal. The modulation of the light beam emitted from the writing infrared light source 6 and reaching the film 20 is controlled;
When the film 20 passes through the pair of exposure transport rollers 54, the entire surface of the film is scanned, ie, exposed, to a predetermined image including black edges by the writing infrared light beam. Thereafter, the film is sent to a developing section (not shown), and after development, an image having so-called black edges is formed.

In the above embodiment, the film is held between the transport roller 52 and the transparent nip roller 50 for sub-scan transport, but instead of the transport rollers, the film is held between a transport belt and a transparent nip roller for sub-scan transport. You may do so as you would do.

Further, although the above embodiments have been described with respect to a light beam scanning recording device, it goes without saying that the light beam scanning device of the present invention can also be applied to a reading device. Instead, a reading means having a photodetector for detecting transmitted light, reflected light, emitted light, etc. from the object to be scanned may be provided facing the main scanning line.

〔Effect of the invention〕

As described above, in the present invention, the transparent nip is pressed against the conveying member and the writing light beam is scanned through the transparent nip roller, so that the object to be scanned can be accurately conveyed at a predetermined speed.
, and has the advantage that it is possible to scan the entire surface of the object to be scanned, and that a so-called black edge can be formed with a simple structure.

[Brief explanation of drawings]

The present invention is a perspective view of a light beam scanning device according to an embodiment of the present invention. 1...Light beam scanning device 2...Rotating mirror 4...Light source for synchronization signal 8...Collimator lens 10...GiCroic Mirror 12...
・Light modulator 16...Gicroic mirror 20...
・Film 22... Grid 28... Photodetector 32... Multiplier circuit 38... Control circuit 40... Modulation circuit 50... ...Transparent nip roller 52 ...Conveyance roller

Claims (5)

[Claims] (1) Main scanning is performed by irradiating a sheet-shaped object to be scanned with a light beam deflected in a one-dimensional direction, and sub-scanning is performed by transporting the object to be scanned in a direction approximately perpendicular to the main scanning direction. In the light beam scanning device that scans the object to be scanned two-dimensionally, a transparent nip roller is pressed against a sub-scanning conveyance member that conveys the object to be scanned, and the object to be scanned is held between the sub-scanning conveyance member and the transparent nip roller. A light beam scanning device characterized in that a light beam is irradiated onto an object to be scanned through the transparent roller while conveying the object in a sub-scanning direction. (2) The light beam scanning device according to claim (1), wherein the transparent nip roller is made of glass. (3) The light beam scanning device according to claim (1), wherein the transparent nip roller is made of acrylic resin. (4) The light beam scanning device according to claim (1), wherein the sub-scanning conveyance member is a conveyance belt. (5) The light beam scanning device according to claim (1), wherein the sub-scanning conveyance member is a conveyance drum.