JPS63262958A - Condenser bar for generating synchronizing signal - Google Patents

Abstract

PURPOSE:To prevent condensing efficiency from being lowered, by forming a light diffusion band provided at a side opposite to the incident side of a beam and which diffuses a light beam so as to be spread widely and partially in the longitudinal direction of the side plane of a condenser bar. CONSTITUTION:The light diffusion band 2 provided at the side opposite to the incident side of the beam L0 and which diffuses the light beam L0 is formed partially and widely in the longitudinal direction of the side plane of the condenser bar 3 made of a transparent material which propagates the light beam L0 made incident from the side plane via a grid 14 in a direction of an end face along the longitudinal direction. At this time, it is preferable to form the wide part 2a of the light diffusion band 2 at a part responding to the scan starting position of a scanning light beam L2 in a light beam scanner. In such a way, it is possible to suppress the lowering of the condensing efficiency.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to a condensing bar for synchronizing signal generation, and more specifically,
The present invention relates to a focusing bar for generating a synchronizing signal in a light beam scanning device that scans a light beam for reading or recording image information.

<Prior art and its problems> In recent years, light beam scanning devices have been developed that read and/or record images using light beams. In a light beam scanning device that reads and/or records such images, a light beam emitted from a light source is generally reflected and deflected by an optical deflector and sent at a constant speed in a direction perpendicular to the direction of deflection. The object to be scanned (sub-scanned) is main-scanned.

In this case, keeping the scanning speed of the light beam constant is an important requirement to obtain good image quality. However, it is difficult to keep this strictly constant, so the position of the polarized light beam is usually detected according to the movement of the galvanometer, and a synchronization signal is generated based on this detection signal to convert the image signal. Recording or reading techniques are used.

As a synchronization signal generator for obtaining such a position detection signal of scanning light, conventionally, a grid consisting of bright areas and dark areas arranged alternately on the optical path of a synchronization light beam as shown in FIG. 8 has been used. 14, and a light diffusion band 2 formed in the longitudinal direction of the side opposite to the grid, which is a long cylindrical light collecting bar 3 made of acrylic resin provided behind the grid.
A type having a light-receiving element 4 provided on the end face of the condensing bar 3 is used. In such a synchronization signal generator, a light beam Lo emitted from a laser light source 5 passes through a beam expander 6 to have a desired beam diameter, and then is deflected by an optical deflector 8 and then passed through a scanning lens 9. , and is split into a scanning light beam L2 for scanning the object 10 to be scanned by a half mirror 10 and a synchronization light beam L for obtaining a synchronization signal. The synchronizing light beam L1 enters the condensing bar 3 through the grid 14 shown in 11j1, is diffused by the light diffusion zone 2, and further passes through the condensing bar 3.
While repeating reflection and scattering inside, the light reaches one end of the light collecting bar and enters the light receiving element 4.

The light incident on the light-receiving element 4 has a periodic change in the amount of light according to the scanning of the grid, but the light-receiving element 4 converts the change in the amount of light into an electrical signal, thereby obtaining a synchronization signal. I'm trying to be able to do that.

However, the light diffusion band 2 formed on the surface of the condensing bar used in such a synchronization signal generating device has conventionally had the following problems.

The width of the light diffusion zone 2 is preferably as narrow as possible in order to increase the light collection efficiency. If the width of the light diffusion zone 2 is wide, the light that enters the light concentration bar 3 and is diffused by the light diffusion zone 2 will be diffused again before reaching the light receiving element 4 while repeating reflection inside the light concentration bar. This is because the amount of light that is diffused and absorbed by the band and finally reaches the light receiving element 4 decreases, resulting in a low light collection efficiency.

However, if the width of the light diffusion zone 2 is narrowed, if the optical path of the light incident on the light concentration bar 3 is shifted, the light incident on the light concentration bar 3 will deviate from the light diffusion zone 2. The light passes through the condensing bar 3 without being diffused, making it impossible to obtain a synchronizing signal.

Therefore, if the optical axis of the incident light is expected to shift, the width of the light diffusion band 2 must be widened to correspond to the width of the shift, which causes a problem in that the light collection efficiency decreases. There was a point.

In fact, in the synchronization signal generating device for the radiation image information reading device described in Japanese Patent Application Laid-Open No. 58-67244, etc., the optical path of the light incident on the condensing bar 3 is shifted according to functional needs. This reduction in light collection efficiency poses a problem.

That is, in the radiation image information reading device,
In the operation of carefully scanning a light beam across a stimulable phosphor sheet and accurately reading the radiographic image information recorded therein (hereinafter referred to as "reading"), the incident light on the condensing bar is precisely focused on its diffusion band. However, in order to grasp the outline of the image recorded on the stimulable phosphor sheet in advance, the stimulable phosphor sheet is peeled off and roughly scanned with the optical energy of the beam (hereinafter referred to as " In this method, the beam diameter of the light beam that scans the volumetric phosphor sheet is increased and the angle of incidence on the stimulable phosphor sheet is shifted, so that the incident light on the condensing bar is also shifted accordingly. It will be done. Therefore, the light diffusion band of the condensing bar of this device must have a wide width that can accommodate the incident light for both main reading and pre-reading, which poses a problem of a decrease in light condensing efficiency.

<Object of the Invention> The present invention aims to solve the problems associated with the prior art, and even when the optical path of the light incident on the condenser bar is shifted as necessary, The aim is to narrow the width of the diffusion band as much as possible to obtain the required synchronization signal, thereby suppressing a decrease in light collection efficiency.

<Detailed Description of the Invention> According to the present invention, a condenser bar made of a transparent material that propagates a light beam incident from the side through a grid along the longitudinal direction toward the end face thereof is provided with a condenser bar on the incident side of the beam. There is provided a condensing bar for synchronizing signal generation, characterized in that a light diffusion band provided on the opposite side of the condensing bar for diffusing the light beam is formed partially wide in the longitudinal direction of the side surface of the condensing bar. Ru.

In the above invention, it is preferable that the wide portion of the light diffusion band is formed at a portion corresponding to a scanning start position of the scanning light beam in the light beam scanning device.

<JL physical structure of the invention> The present inventor has conducted extensive research into narrowing the width of the diffusion band as long as the synchronization signal required according to the purpose of use of the synchronization signal generator can be obtained, and as a result, the above-mentioned In a radiation image information reading device, in order to strictly read image information from a stimulable phosphor sheet in main reading, it is necessary to obtain a synchronization signal over the entire area of light beam scanning, but in pre-reading, it is necessary to obtain a synchronization signal over the entire scanning area of the light beam. It is only necessary to understand the outline of the image being scanned and scan it coarsely enough to determine the reading conditions for the actual reading. It is not necessarily necessary to obtain a synchronization signal over the entire area of the light beam scan, but only to synchronize the start point of the scan. They have found that it is sufficient to have the same amount of energy as possible, and have completed the present invention.

Next, the synchronization signal generation condensing bar of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIGS. 1 and 2 are perspective views showing embodiments of a synchronization signal generation condensing bar according to the present invention.

A condensing bar 1 for generating a synchronization signal according to the present invention includes a condensing bar 3 in the form of a long column made of a transparent material that propagates light incident from a side surface in the direction of its end face along the longitudinal direction, and a condensing bar 3 in the shape of a long column made of a transparent material. In the longitudinal direction of the side surface, there is a light diffusion band 2 that is partially wide and that diffuses light.

Note that the condensing bar 3 is not limited to an elongated cylindrical shape, but may be an elongated prismatic shape.

The material of the condensing bar is not particularly limited as long as it is transparent and can transmit light, and acrylic resin, glass, etc. can be used.

The synchronization light beam that enters such a condensing bar after passing through the grid is diffused by the light diffusion zone 2, and the diffused light propagates through the condensing bar 3 and enters the light receiving element, and synchronization is performed. A signal will be obtained.

In the present invention, the light diffusion band 2 has a partially wide portion 2a formed in the longitudinal direction of the side surface of the condensing bar 3.

Here, the width of the narrow part that occupies most of the light diffusion band 2 that diffuses the light beam is the part where the optical path of the incident light to the condensing bar 3 reflects the light, as in the case of this reading. This is the width required when the beam is adjusted to approximately converge.

The width of the light diffusion band 2 and the length of the wide portion 2a thereof are determined as appropriate depending on the diameter or length of the condensing bar 3. For example, the focusing bar 3 has a diameter of 15 mm and a length of 40 mm.
If it is 0 mm, the wide part 2a of the light diffusion zone 2 has a width of 3
It is preferable that the width of the narrow portion that occupies most of the diffusion zone 2 is 1 to 1.5 mm.

Here, regarding the position of the wide portion 2a, it is preferable to form it at a portion corresponding to the scanning start position of the scanning light, and generally it is preferable to form it at the end of the condensing bar as shown in FIG. However, as shown in FIG. 2, it may also be formed in the intermediate portion if necessary. In other words, when the object to be scanned has various sizes, or when image information is recorded on a part of the object to be scanned, the scanning light is adjusted depending on the size of the object to be scanned and the position where the image information is recorded. If it is desired to control the starting point, it is preferable to form the wide portion 2a of the light diffusion band at a position corresponding to the scanning start position in the middle of the condensing bar 3.

Such a light diffusion band 2 may be formed by printing, coating, etc. on the surface of the light-scattering bar using light-scattering paint in the same way as conventional light-scattering bars, or may be formed by printing or coating the surface of the light-scattering bar. A light-diffusing band may be formed to be embedded in the condensing bar by injecting a light-scattering paint into a groove formed in the bar.

The condensing bar for synchronizing signal generation of the present invention can be applied to various photodetecting devices in the same way as a condensing bar having a normal light diffusion band.

Next, an embodiment in which the condensing bar for synchronizing signal generation of the present invention is applied to a radiation image information reading device will be described with reference to the accompanying drawings.

FIG. 7 is a perspective view conceptually showing an embodiment in which the synchronization signal generation condensing bar 1 of the present invention is applied to a radiation image information reading device.

This radiation image information reading device basically uses a light beam L. Laser light that generates #! 5. A beam expander 6 that makes the light beam a desired diameter; a pre-reading optical system 7 that is inserted into the optical path during pre-reading and is withdrawn from the optical path during main reading; and a light beam expander 6; a rotating polygon mirror 8, a scanning lens 9, a half mirror 10 provided on the optical path extending in the scanning direction,
A sub-scanning conveying means (not shown) for sub-scanning the stimulable phosphor sheet 11 in the B force direction, a photomultiplier 12 as a photoelectric conversion stage, and a sub-scanning conveying means (not shown) that sub-scans the stimulable phosphor sheet 11 in the direction of the B force, a photomultiplier 12 as a photoelectric conversion stage, and a sub-scanning conveyance means (not shown) that sub-scans the stimulable phosphor sheet 11 in the direction of the B force; A light guide 13 having an incident end face and formed so as to match the shape of the light receiving part of the photomultiplier 12 toward the output end face side, and arranged at a focusing position of the synchronizing light beam L1, light beams are arranged at predetermined intervals. The grid 14 is provided with a portion that transmits and a portion that does not transmit.
, a synchronization signal generating collection according to the present invention, which is arranged at a position to receive the light beam transmitted through the grid 14, and is formed so that the light diffusion band 2 is located on the opposite side to the side on which the light beam is incident. It has a light bar 1 and a light receiving element 4 such as a photodiode provided on the end face of the light bar 1.

Further, it is preferable that a mirror is provided at the end of the synchronizing signal generating condensing bar 1 opposite to the end where the light receiving element 4 is provided.

Further, the light receiving elements 4 may be provided at both ends.

In such a radiation image information reading device, during actual reading, the pre-reading optical system 7 is retracted out of the optical path, and the scanning light beam is precisely focused on the object to be scanned, as shown by the solid line. On the other hand, during pre-reading, by inserting the pre-reading optical system 7 into the optical path, the beam diameter of the scanning light beam increases as shown by the - single chain line, and the optical path also shifts.゛〈Specific Effects of the Invention〉 Hereinafter, the effects of the above radiation image information reading device to which the synchronization signal generation condensing bar of the present invention is applied will be explained based on the drawings.

In the case of main reading, the light beam emitted from the laser light source 5 is used. After passing through the beam expander 6 and reaching a desired beam diameter, the beam enters a rotating polygon mirror 8 that rotates in the six directions of arrows and is reflected and deflected. Light beam L. In addition to this rotating polygon mirror, optical deflectors that deflect the light include galvano rotor mirrors, hologram scanners, and AOD (r
f-arm optical light deflector), etc. can be used.

The light beam L0 reflected and deflected by the rotating polygon 21B passes through a scanning lens 9 such as an fθ lens provided on the optical path, and then enters a half mirror 10 provided on the optical path extending in the main scanning direction.

Of the incident light beam L, this half mirror 10
The amount of light beam necessary for scanning is reflected as a scanning light beam L2, and the remaining light beam is transmitted as a position detection light beam of the scanning light beam, that is, a synchronization light beam L.

Scanning light beam L2 reflected by half mirror 10
is focused on the stimulable phosphor sheet 11 disposed on the optical path, and repeatedly main-scans the stimulable phosphor sheet 11 in the direction of arrow C, which is conveyed (sub-scanned) in the direction of arrow B. . Here, the scanned part of the stimulable phosphor sheet 11 emits stimulated light according to the image information stored there.
This emitted light enters the light receiving surface of the photomultiplier 12 via the light guide 13 and is photoelectrically converted to obtain an image signal.

On the other hand, the synchronizing light beam L transmitted through the half mirror 10 is connected to the stimulable phosphor sheet 11 and the half mirror 1.
A grid 14 arranged at a position conjugate to zero is scanned, and a light beam that passes through the lattice of the grid 14 is incident on the condensing bar 1 for generating a synchronizing signal according to the present invention.

The incident light beam L is reliably diffused in the light diffusion zone 2, as shown in FIG. As shown in Fig. 4, the longitudinal cross section of the condenser bar 3
The light enters a light receiving element 4 such as a photodiode provided at the end of the light collecting bar 3 while undergoing total internal reflection.

The grid 14 is formed in a lattice shape by chromium deposition or the like, with portions that transmit light and portions that do not transmit light at a pitch corresponding to the pixels. It changes periodically with the main scanning of the beam L2. Therefore, the light receiving element 4 detects periodic changes in the synchronizing light beam as shown in FIG. The signal is converted and a periodic signal is obtained.

On the other hand, in the case of pre-reading, it is necessary to scan the stimulable phosphor sheet 11 with a scanning light beam with a wider beam system and lower energy than in the case of main reading, so the beam expander 6 and the rotating polygon l! A pre-reading optical system 7 is added between the 8 and 8. As a result, the beam diameter of the scanning light that has passed through the beam expander 6 is increased, as shown by the dashed line in the seventh elbow, and the optical path of the scanning light is also shifted from that during main reading. Therefore, the optical path of the scanning light beam L' 2 that is reflected and deflected by the rotating polygon mirror 8 and reflected by the half mirror 1O, as well as the synchronization light beam L' that has passed through the half mirror 10, is shifted from the one at the time of main reading. Become. Such a synchronizing light beam L/.

When the light enters the light condensing bar 3 whose position has been adjusted for main reading, the width of the light diffusion band 2 increases in accordance with the deviation of the optical path. , a synchronizing signal is obtained as in the main reading, but on the other hand, in the narrow part of the light diffusion band 2, the incident light L on the condensing bar 3
', as shown in Fig. 3, passes through the condensing bar 3 without being diffused by the light diffusing zone 2, so the light is not detected by the light receiving element 4 provided at the end of the condensing bar. , synchronization signal cannot be obtained.

Therefore, during pre-reading, a signal is output from the light receiving element only when the wide portion 2a of the light diffusion band is scanned.

Therefore, a starting point signal as shown in FIG. 5 is obtained in which the signal is output only at the scanning starting position.

Conventionally, a synchronization signal was obtained over the entire scanning area during pre-reading as well as during main reading, but the inventor of the present invention grasped the recording pattern of the object to be scanned during pre-reading and determined the reading conditions etc. for main reading. It is only necessary to perform the reading scan as roughly as possible, and it is not necessarily necessary to obtain a detailed synchronization signal over the entire scanning area as required during main reading. This is because the wide portion of the light diffusion band is partially formed as described above, so that an output signal corresponding to that portion can be obtained.

Note that the wide portion of the light diffusion band can be formed at a desired position on the synchronization signal generation condensing bar, if necessary.

For example, when reading stimulable phosphor sheets of different sizes, use the wide part of the stimulable phosphor sheet to determine the scanning start position according to the size of the stimulable phosphor sheet. It is preferable to form a plurality of locations at positions depending on the size.

In addition, even if image information is recorded only on a part of the E hI phosphor sheet, a wide-width scanner is used to scan only the area where the image information is recorded, reducing the reading time. It is preferable to form a portion corresponding to the recording area in the longitudinal direction of the condensing bar. “□ In the above embodiment, the light beam L emitted from the laser light source 5 is deflected by the rotating polygon mirror 8, passes through the scanning lens 9, and then is converted into the scanning light beam L2 and the synchronization light beam L1 by the half mirror 10. However, it is also possible to divide the light beam L into the bait that is incident on the rotating polygon mirror 8 so that each light beam L is incident on a separate reflecting surface of the rotating polygon mirror 8.Furthermore, the scanning light beam It is also possible to provide separate light sources for the synchronizing light beams. In this case, if the scanning light beam and the synchronizing light beam have different wavelengths, they can be placed on the same optical path using a dichroic mirror or the like. It is also possible to combine and divide again.

In addition, in the above embodiment, the synchronization signal generation condensing bar of the present invention is applied to a light beam scanning device in a radiation image information reading device, but the present invention is not limited to this, and other light beams can be used. It is also widely applicable to scanning devices.

<Effects of the Invention> According to the present invention, in a photodetecting device used in a light beam scanning device or the like, even when the optical path of the incident light to the condensing bar is shifted as necessary, the required light can be As long as a detection signal can be obtained, the width of the portion that reflects light is formed to be narrow, so that a decrease in light collection efficiency can be suppressed to a minimum.

In addition, in the present invention, if the wide portion of the light diffuser is formed at each scan start position according to the size of the object to be scanned or the recording area in the light beam scanning device, it is possible to You can scan accordingly.

[Brief explanation of drawings]

FIGS. 1 and 2 are perspective views showing embodiments of a synchronization signal generation condensing bar according to the present invention. FIGS. 3 and 4 are explanatory views for explaining the functions of the synchronization signal generation condensing bar of the present invention. FIG. 5 is a waveform diagram representing a signal output from the light receiving element during main reading. FIG. 6 is a waveform diagram showing a signal output by a light receiving element during pre-reading. FIG. 7 is a perspective view conceptually showing an implementation in which the synchronization signal generation condensing bar of the present invention is applied to a radiation image information reading device. FIG. 8 is a schematic diagram showing an example of a conventional light beam scanning device. Explanation of symbols l...Concentrating bar for synchronizing signal generation, 2...Light diffusion band, 2a---Wide portion, 3...Concentrating bar, 4...Light receiving element, 5...Laser Light source, 6... Beam expander, 7... Pre-reading optical system, 8... Rotating polygon mirror, 9... Scanning lens, 10-... Half mirror-1 11.'' FF phosphor sheet , 12--Photo multiplier, 13--Light guide, 14--Grid, Lo--Light beam, L,--Synchronization light beam, L2--Scanning light beam Patent applicant Fuji Photo Film Co., Ltd. -FIG,
2 FIG, 4 FIG, 5 FIG, 8

Claims (2)

[Claims] (1) A light beam that enters from the side through the grid is propagated along the longitudinal direction toward its end surface.The light beam is diffused into a condensing bar made of a transparent material provided on the side opposite to the incident side of the beam. There is a light diffusion band along the longitudinal direction of the side surface of this condensing bar.
A condensing bar for synchronizing signal generation characterized by being partially wide. (2) A synchronization signal according to claim 1, wherein the wide portion of the light diffusion band is formed at a portion corresponding to a scanning start position of a scanning light beam in a light beam scanning device. Focusing bar for generation.