JPH01106011A - Light beam scanning device - Google Patents

Abstract

PURPOSE:To easily execute the adjustment of the magnification of image information and the setting of a read area or a write area by guiding a light beam for synchronizing to a reference grid plate constituted by carrying many segments whose transmissivity or reflectance can be individually controlled. CONSTITUTION:A pulse signal is obtained from the light beam for synchronizing L2 made incident on a transmission part 58a from the light beam L2 which scans the reference grid plate 34 and supplied to a comparator 42 through a condensing bar 24 and light detecting sensors 26a and 26b. Therefore a frequency synthesizer 46 generates a specified synchronizing signal phi as a reference based on the pulse signal and supplies it to a signal processing part 32. Now, the scanning position of the light beam for synchronizing L2 and the scanning position of the light beam for scanning L1 on an accumulating type fluorescent material sheet S correspond in the ratio one to one and an image processing part 40 constituting the signal processing part 32 can read the image information on the accumulating type fluorescent material sheet S corresponding to a range between the transmission parts 58a. Thus, the read range or the magnification, etc., of the image information can be easily set or altered with a simple constitution.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a light beam scanning device, and more specifically, a layer having a structure in which a large number of segments whose transmittance or reflectance of a light beam can be individually controlled is arranged. The present invention relates to a light beam scanning device that includes a reference grating plate, generates a synchronizing signal by guiding a synchronizing light beam to the reference grating plate, and reads or records an image or the like based on the synchronizing signal.

[Background of the Invention] For example, a recording medium on which image information is recorded is scanned with a light beam and the image information is read photoelectrically to obtain an image signal,
There is an image scanning reading/reproducing system that scans a record carrier such as a photographic light-sensitive material using a light beam modulated based on this image signal to form a visible image.

In this case, in order to accurately reproduce the image information, the system generates a synchronization signal every time the light beam changes by a predetermined amount in the main scanning direction when reading the image information, and based on the control of this synchronization signal, the image information is is read photoelectrically. Also, when recording the image information, a synchronization signal is generated, and a light beam is modulated based on the control of this synchronization signal and irradiated onto the record carrier.

FIG. 1 shows a light beam scanning device equipped with a mechanism for generating such a synchronization signal.

This light beam scanning device includes a laser optical system 2 that irradiates a light beam L onto a stimulable phosphor sheet S on which image information is recorded, which is conveyed in the sub-scanning direction (six directions of arrows), and a It basically consists of an image reading section 4 that photoelectrically converts the image information obtained, and a synchronization signal generation section 6 that generates a synchronization signal from the light beam L. Here, a stimulable phosphor refers to a stimulable phosphor that, when irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), accumulates a portion of this radiation energy and later emits excitation light such as visible light. The stimulable phosphor sheet S refers to a phosphor that emits stimulated light according to the stored energy when irradiated with the stimulable phosphor.

In this light beam scanning device, a light beam L output from a laser oscillation tube 8 is deflected in the direction of arrow B by a galvanometer mirror IO, and a scanning lens such as an rθ lens 1
2, a scanning light beam L1 and a synchronization light beam L2 whose emission directions differ by approximately 90' are separated by a half mirror 14.
It is divided into The scanning light beam L scans the stimulable phosphor sheet S in the main scanning direction (arrow C direction) by the swinging motion of the galvanometer mirror 10.

On the other hand, the stimulable phosphor sheet S is transported in the sub-scanning direction (direction of arrow A) by a transport mechanism (not shown). Therefore,
The scanning light beam L scans the entire area of the stimulable phosphor sheet S two-dimensionally.

In this case, the stimulable phosphor sheet S illuminated by the scanning light beam L emits stimulated luminescent light in accordance with the image information stored therein. This stimulated luminescence light enters the photomultiplier 18 via a transparent light guide 16 disposed near the stimulable phosphor sheet S. The stimulated luminescence light incident on the photomultiplier 18 is converted into an electrical signal and displayed on a display means such as a CRT, or recorded on a recording medium such as a magnetic tape.

On the other hand, the synchronization light beam L2 transmitted through the half mirror 14
is incident on the reference grating plate 22, and is incident on the light detection sensors 26a and 26b disposed at both ends of the cylindrical condensing bar 24 disposed on the back surface of the reference grating plate 22. In this case, the reference grating plate 22 has a synchronization light beam L.
A large number of bright and dark patterns 28 are formed at predetermined intervals along the two scanning directions. Therefore, the synchronizing light beam L2 corresponding to the scanning position of the scanning light beam L is incident on the photodetection sensors 26a and 26b as a light pulse signal.

As a result, a synchronization signal is generated from the optical pulse signal,
Accurate reading of image information from the stimulable phosphor sheet S is performed based on this synchronization signal.

Incidentally, it is desired that the image scanning reading and reproducing system has a function of enlarging or reducing an image to a desired size and reproducing it.

Furthermore, when reading image information from the stimulable phosphor sheet S, it is also desirable to have a configuration in which by specifying the reading area of the sheet +-S, only the image information within the reading area is captured and processed.

However, in the above-described light beam scanning device, the light pulse signal obtained from the reference grating plate 22 depends on the scanning speed of the synchronizing light beam L2 by the galvanometer mirror 10 and the interval between the bright and dark patterns 28 formed on the reference grating plate 22. Fixed to a certain frequency. Therefore, when enlarging or reducing an image based on a synchronization signal generated from the optical pulse signal, it is necessary to multiply or divide the frequency of the synchronization signal and process the image based on that signal. In this case, it has been pointed out that there is a problem that the processing circuit for the synchronization signal becomes complicated and it is extremely difficult to accurately multiply or divide the frequency of the synchronization signal. In addition, by capturing and processing only the image information that corresponds to the synchronization signal in a predetermined range, it is possible to obtain image information in the desired reading area. This results in the inconvenience that a special circuit configuration is required.

[Object of the Invention] The present invention has been made in order to overcome the above-mentioned disadvantages. By guiding the light beam, a synchronization signal of a desired frequency and/or desired range can be obtained, and based on this synchronization signal, it is possible to easily adjust the magnification of image information and set the reading area or writing area. The purpose of this invention is to provide a light beam scanning device that can perform the following tasks.

[Means for Achieving the Object] In order to achieve the above object, the present invention scans a scanned object with a scanning light beam and generates a synchronization signal by guiding the synchronization light beam to a reference grating plate. In a light beam scanning device that reads or records images based on the synchronization signal, a large number of segments whose transmittance or reflectance can be individually controlled are arranged along the scanning direction of the synchronization light beam. The present invention is characterized in that a reference grating plate is constructed by doing this, and a desired synchronization signal is generated by controlling each of the segments.

[Embodiments] Next, preferred embodiments of the light beam scanning device according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 2, reference numeral 30 indicates the main body of the light beam scanning device according to this embodiment. In this case, the same reference numerals are given to the same components as in the prior art shown in FIG.
The configuration will be schematically explained.

Therefore, the main body 30 includes a laser oscillation tube 8 that emits the light beam L, a galvanometer mirror 10 that deflects the light beam L, and a galvanometer mirror 10 that directs the light beam L deflected by the galvanometer mirror 10 onto the stimulable phosphor sheet S. The scanning lens 12 is an fθ lens that scans at high speed. In this case, the light beam L that has passed through the scanning lens 12 is divided by the half mirror 14 into a scanning light beam L1 and a synchronization light beam L2. Stimulated luminescent light obtained from the stimulable phosphor sheet S by the scanning light beam LI enters the photomultiplier 18 via the light guide 16 and is converted into an electrical signal.

Note that this electrical signal is sent to the signal processing section 32 and subjected to predetermined signal processing.

On the other hand, the synchronization light beam L2 enters the reference grating plate 34,
A condensing bar 24 disposed on the back side of the reference grid plate 34
The light enters the light detection sensors 26a and 26b via the light source.

In this case, the reference grid plate 34 has a large number of liquid crystal segments 35 whose light transmittance can be individually controlled according to the applied voltage, arranged at equal intervals in the scanning direction of the synchronizing light beam L2. The light transmittance is controlled by the synchronization signal generator 33. Note that the light detection sensors 26a and 2
6b sends the synchronizing light beam L2 transmitted through the reference grating plate 34 to the synchronizing signal generating section 33 as a pulse signal.

The signal processing section 32 and the synchronization signal generating section 33 are configured as shown in FIG. That is, the signal processing section 32 includes a sample and hold circuit 36, an A/D converter 38, and an image processing section 40. In this case, the sample hold circuit 36
samples the image signal charged and converted by the photomultiplier 18 and supplies it to the A/D converter 38. The A/D converter 38 converts the sampled image signal into a digital signal and supplies it to the image processing section 40.

In this case, the image processing section 40 performs arithmetic processing such as gradation processing and frequency processing on the image signal and outputs a desired image signal.

On the other hand, the synchronization signal generation section 33
It has a comparator 42 that converts the pulse signal supplied from b into an on/off signal, and the output signal from this comparator 42 is supplied to a frequency synthesizer 46 via a starting point adjustment section 44. In this case, the starting point adjustment section 44 adjusts the scanning start position of the scanning light beam L1. Further, the frequency synthesizer 46 generates the synchronization signal φ by multiplying the on/off signal supplied via the starting point adjustment section 44. This synchronizing signal φ is supplied as a timing clock to the sample hold circuit 36, A/D converter 38, and image processing section 40 that constitute the signal processing section 32.

The synchronization signal generating section 33 further includes a control section 48, and this control section 48 includes a ROM 52 in which a predetermined pattern of the reference grating plate 34, which will be described later, is recorded.

The pattern data stored in the ROM 52 is sent to the CPU 5.
According to this pattern data, the liquid crystal segments 35 of the reference grid plate 34 are driven and controlled via the pattern switching unit 56. In this case, the pattern switching section 5
Reference numeral 6 is for driving and controlling each liquid crystal segment 35 so that it selectively becomes a transmissive part 58a and a non-transmissive part 58b, as shown in FIGS. 4A to 4C. The combination pattern of the liquid crystal segments 35 is set based on pattern data stored in the ROM 52.

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

In FIG. 2, a stimulable phosphor sheet S that has accumulated predetermined image information by being exposed to X-rays or the like is transported in the sub-scanning direction (direction of arrow A) by a transport mechanism (not shown). On the other hand, the surface of the stimulable phosphor C+-S is irradiated with a scanning light beam L output from the laser oscillation tube 8 in the main scanning direction (direction of arrow C).

That is, the light beam L output from the laser oscillation tube 8 is deflected and scanned in the direction of arrow B by the galvanometer mirror 10, and enters the half mirror 14 via the scanning lens 12 consisting of an fθ lens.Then, the light beam L is Scanning light beam L1 reflected by half mirror 14
The stimulable phosphor sheet S is irradiated with the stimulable phosphor sheet S. In this case, the image information of the subject stored and recorded on the stimulable phosphor sheet S is extracted as stimulated luminescence light by the scanning light beam L, and this stimulated luminescence light is transmitted through the light guide 16 to the photomultiplier. 18 and converted into an electrical signal.

On the other hand, the light beam L transmitted through the half mirror 14 enters the reference grating plate 34 as a synchronization light beam L2. In this case, the synchronizing light beam L2 transmitted through the transmission part 58a of the liquid crystal segment 35 constituting the reference grating plate 34 set in the states shown in FIGS. Thereafter, the light is reflected by its inner surface and guided to photodetection sensors 26a and 26b.

The optical pulse signals guided to the optical detection sensors 26a and 26b are converted into electrical signals, and then compared with a reference voltage Vrsf by a comparator 42 constituting the synchronization signal generator 33, and converted into an on/off signal. Ru. Next, this on/off signal is guided to the frequency synthesizer 46 after the scan start timing is adjusted by the start point adjustment section 44 . Therefore, the frequency synthesizer 46 multiplies the on/off signal to a predetermined frequency and outputs it as a synchronizing signal φ to the sample hold circuit 36 and A/D converter 38 that constitute the signal processing section 32.
and is supplied to the image processing section 40.

On the other hand, the image signal obtained from the stimulable phosphor sheet S by the scanning light beam L+ is photoelectrically converted by the photomultiplier 18 and guided to the sample hold circuit 36. The sample hold circuit 36 outputs this image signal to the A/D converter 38 based on the synchronization signal φ, and the A/D converter 38 supplies the signal to the image processing section 40 as a digital signal. In this case, the image processing section 40 performs arithmetic processing such as gradation processing and frequency processing on the digital signal and outputs a desired image signal.

Here, the image signal is processed in the signal processing section 32 based on the synchronization signal φ converted into a desired range or desired interval by the pattern switching section 56. That is, the pattern switching section 56 sets the desired liquid crystal segment 35 to the transparent state B (transmissive section 58a) or the non-transmissive state (non-transmissive section 58b) based on the pattern data stored in advance in the ROM 52 of the control section 48. .

Therefore, for example, as shown in FIG. 4a, the reference grid plate 3
The liquid crystal segments 35 constituting 4 are driven so that two transparent parts 58a and two non-transparent parts 58b are alternately arranged, and this state is taken as a reference state. in this case,
In the synchronization light beam L2 scanning the reference grating plate 34,
A pulse signal is obtained from the synchronization light beam L2 incident on the transmission part 58a, and the pulse signal is transmitted to the condensing bar 24 and the light detection sensor 26a.
, 26b to the comparator 42. Therefore, the frequency synthesizer 46 generates a predetermined reference synchronization signal φ based on the pulse signal and supplies it to the signal processing section 32. Here, the scanning position of the synchronizing light beam L2 on the reference grating plate 34 and the scanning position of the scanning light beam L1 on the stimulable phosphor sheet S have a one-to-one correspondence. As a result, the image processing unit 4 that constitutes the signal processing unit 32
0 can read the image information on the stimulable phosphor sheet S corresponding to the range between the transparent parts 58a on both end sides of the reference grid plate 34.

On the other hand, as shown in FIG. 4, if the pattern of the reference grid plate 34 is changed from the state of FIG. 4a so that the transparent parts 58a on both end sides become non-transparent parts 58b, When the state is set as the reference state, partial reading of image information can be performed. That is, the synchronization signal φ is transmitted through the transparent section 58.
Since the image information is obtained only from a, the image information in a narrowed range on the stimulable phosphor sheet S corresponding to the range of these transparent parts 58a is read.

Also, the pattern of the reference grid plate 34 is changed to C or d in FIG.
If the setting is made as shown in FIG. 4A, image information can be read in an enlarged or reduced size using the state shown in FIG. 4A as a reference state. That is, when the pattern of the reference grid plate 34 is changed from the state shown in FIG. 4A to the state shown in FIG. The synchronization signal φ obtained from the grating plate 34
Since the distance between the stimulable phosphor sheets S increases, the amount of image information read from the stimulable phosphor sheet S decreases. Therefore, the image reproduced based on the image signal output from the image processing section 40 will be reduced in size compared to the case where the reference grid plate 34 is set to the pattern shown in FIG. 4a.

Similarly, if the reference grid plate 34 is changed from the pattern shown in FIG. 4a to the pattern shown in FIG. Since the interval between the synchronizing signals φ becomes narrower, the amount of image information read from the stimulable phosphor sheet S increases, and an enlarged image can be obtained.

In the embodiment described above, the state of the reference grid plate 34 is set based on the pattern data stored in the ROM 52, but this pattern data can be stored in a RAM or the like and can be rewritten as desired by the user. It is also possible to configure it so that In this case, the user can arbitrarily change the image reading range or magnification.

[Effects of the Invention] As described above, according to the present invention, the reference grating plate is configured by arranging a large number of segments along the scanning direction, the transmittance or reflectance of which can be individually controlled. A synchronization signal is generated by guiding a synchronization light beam to a reference grating plate, and image information is read or recorded based on this synchronization signal. In this case, the output range or interval of the synchronizing signal can be freely changed by appropriately setting the combination pattern of the segments that transmit or reflect the light beam. Therefore, it is possible to easily set or change the reading range or magnification of image information based on the synchronization signal with a simple configuration.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
For example, it is possible to arrange a mirror on the back side of the liquid crystal segment and generate a synchronization signal based on the light beam reflected by this mirror, and it is also possible to use an electrochromic device instead of the liquid crystal to create a reference grid plate. It goes without saying that various improvements and changes in design are possible without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a light beam scanning device according to the prior art, FIG. 2 is a schematic configuration diagram of a light beam scanning device according to the present invention, and FIG. 3 is a configuration block diagram of a light beam scanning device according to the present invention. , FIGS. 4a to 4d are explanatory diagrams of a reference grating plate in a light beam scanning device according to the present invention. 8... Laser oscillation tube 10... Galvanometer mirror 12... Scanning lens 18... Photo multiplier 24... Focusing bars 26a, 26b... Light detection sensor 30... Main body 32. ...Signal processing section 3
3... Synchronization signal generator 34... Reference grid plate 35
...Liquid crystal segment 40...Image processing section 46...
Frequency synthesizer 48...control unit 52...ROM56...
...Pattern switching section LI...Scanning light beam L2
...Synchronization light beam S...Stormable phosphor sheet

Claims (5)

[Claims] (1) Light beam scanning in which a scanning light beam scans the object to be scanned, and a synchronization signal is generated by guiding the synchronization light beam to a reference grating plate, and images, etc. are read or recorded based on the synchronization signal. In the device, a reference grating plate is constructed by arranging a large number of segments whose transmittance or reflectance can be individually controlled along the scanning direction of the synchronization light beam, and desired synchronization is achieved by controlling each segment. A light beam scanning device characterized in that it generates a signal. (2) A light beam scanning device according to claim 1, in which the segments are made of liquid crystal. (3) A light beam scanning device according to claim 1, in which the segments are constructed using electrochromic devices. (4) A light beam scanning device according to claim 1, wherein the pattern of the reference grating plate composed of segments is set in advance in a storage means. (5) A light beam scanning device according to claim 4, wherein the pattern of the reference grating plate set in the storage means can be arbitrarily specified.