JPS6249768A - Optical beam reader - Google Patents

Abstract

PURPOSE:To make the whole body of an optical beam reader smaller in size, especially in the direction of auxiliary scanning, by fixing a sheet and performing auxiliary scanning by moving an optical beam and photodetecting means on the sheet. CONSTITUTION:A sheet 8 is held on a sheet holding means 9 and exciting light 2 deflected by a rotating polygon mirror 3 is main-scanned in the direction shown by the arrow B on the sheet 8. A mirror 7 for auxiliary scanning rotates in the direction shown by the arrow C at a low speed around its rotating axis which is almost equal to the line of intersection of a plane including the optical path of the exciting light passing through an image forming lens 4 or a plane parallel to the plane and another plane vertical to the optical axis of the lens 4. Since the auxiliary scanning is performed by fixing the sheet 8 and moving the exciting light by rotating the mirror 7 for auxiliary scanning in such a manner, the size of this device in the auxiliary scanning direction can be reduced to about a half when compared with other types of devices which move the sheet side.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a light beam reading device for reading image information such as TIl ray image information, and more particularly, to a light beam reading device for reading image information such as TIl ray image information. The present invention relates to a light beam reading device capable of reading light beams.

(Technical Background and Prior Art of the Invention) Conventionally, image information is obtained by two-dimensionally scanning a light beam such as a laser beam over a sheet on which image information is recorded, and then irradiating the sheet with the beam light. Image information reading devices that read image information recorded on a sheet by detecting light containing image information (e.g., reflected light, transmitted light, emitted light) using a light detection means equipped with a photomultiplier tube, etc. are widely used. It is put into practical use.

Such image information reading devices include plate-making scanners, computer and facsimile input devices, etc.
A radiation image information recording and reproducing system using a stimulable phosphor sheet already proposed by the applicant
No. 12429, No. 56-11395.

There is a radiation image information reading device used in Japanese Patent No. 56-11397, etc.).

In other words, when certain types of phosphors are irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), this tiI
It is known that a part of the i-ray energy is accumulated in a phosphor, and when this phosphor is irradiated with excitation light such as visible light, the phosphor exhibits stimulated luminescence depending on the accumulated energy. A phosphor exhibiting such properties is called a stimulable phosphor (stimulable phosphor). The radiation image information reading device uses this stimulable phosphor to temporarily record radiation image information of a subject such as a human body on a stimulable phosphor sheet, and then excite this stimulable phosphor sheet with laser light or the like. It scans with light to generate stimulated luminescence light, and photoelectrically reads the obtained stimulated luminescence light to obtain 1q of image signals.

By the way, two-dimensional scanning of the light beam in these light beam reading devices involves deflecting the light beam with an optical deflector to cause it to main scan the sheet, and also moving the light beam and the sheet relative to the main scanning direction. This is performed by moving in a substantially orthogonal sub-scanning direction. However, in the conventional apparatus, various problems have arisen, such as that the apparatus becomes large due to the means for performing the sub-scanning, and that the optical system becomes expensive due to the large size of the apparatus. Hereinafter, the problems of the conventional optical beam reading device will be explained in terms of σ) with reference to the drawings from FIG. 9 onwards.

The light beam reading device shown in FIG. 9 is a radiation image information reading device, and excitation light 102 of a constant intensity emitted from an excitation light source 101 is incident on a galvanometer mirror 103 which is an optical deflector. As it rotates in the six directions of arrows, it is reflected and deflected. Excitation light 10 deflected by anti-tA by galvanometer mirror 103
After passing through an fθ lens 104, which is an imaging lens, provided on the optical path, the stimulable phosphor C+-105 is main-scanned in the direction of arrow B. stimulable phosphor sheet 1
05 is adsorbed onto the endless belt device 106,
Since the stimulable phosphor sheet 105 is transported in the direction indicated by the arrow substantially perpendicular to the main scanning direction, the entire surface of the stimulable phosphor sheet 105 is covered by the deflection of the light beam by the galvanometer mirror 103 and the transport of the stimulable phosphor sheet by the endless belt device. Two-dimensional scanning is performed using excitation light 102.

The part of the stimulable phosphor sheet that is irradiated with the excitation light 102 as it is scanned by the excitation light 102 emits stimulated light according to the image information stored there, and this emitted light is transmitted to the stimulable phosphor sheet. IA @ parallel to the main scanning line in the vicinity
The light enters the light condenser 107 from the incident end surface 107a of the transparent light condenser 107 on which the surface 107a is formed.

The light collector 107 has a flat front end 107b located near the stimulable phosphor sheet 105, and gradually becomes cylindrical toward the rear end. Since it has a cylindrical shape and is connected to the photomultiplier 8 tube (photomultiplier) 108 provided on the exit end surface, the entrance end surface 107a
The stimulated luminescent light entering from the rear end portion 107C is collected and transmitted to the photomultiplier 108 via a filter (not shown) that selectively transmits the stimulated luminescent light. In the photomultiplier 108, the stimulated luminescent light is converted into an electrical signal, and the obtained electrical signal is sent to the image information reading circuit 109 for processing, and then outputted as a visible image to, for example, a CRTllo. The information may be recorded on the magnetic tape 111 or directly on a photographic material or the like as a hard copy.

However, in the above-mentioned apparatus, since the sub-scanning is performed by moving the stimulable phosphor sheet, as shown in Figure 1, the endless belt apparatus has a stimulable phosphor sheet after each scanning position by the excitation light. It needs to have a size that allows one sheet to be placed thereon. For this reason, the endless belt device has a length of at least two stimulable phosphor sheets in the sub-scanning direction, resulting in a problem that the entire device becomes large.

In addition, in reading radiation image information using the radiation image information reading device, the image signal for outputting the visible image described above is preliminarily attached to the stimulable phosphor sheet 105 prior to one reading (actual reading). There is a method in which pre-reading is performed to read the outline of radiographic image information stored and recorded, reading conditions etc. for performing the above-mentioned main reading are determined based on the image information obtained by this pre-reading, and the above-mentioned main reading is performed according to the reading conditions. Are known.

As a method for performing such pre-reading, for example, the stimulable phosphor sheet 105 is scanned using excitation light with an energy lower than that of the excitation light used for the above-mentioned main reading, and the stimulated luminescence light emitted by this scanning is Similarly, a method of reading by optical 'tBm collecting means (for example, Japanese Patent Application Laid-open No. 5
8-67240), etc.

In order to perform such pre-reading and main reading continuously,
First, the stimulable phosphor sheet 105 is conveyed in the direction of the arrow to perform pre-reading, and then the Endless Bell i-device 106
The IFW4 phosphor sheet, which has been pre-readed, is reversed in the D' direction and returned to the reading start position, and the stimulable phosphor sheet is again conveyed in the direction of the arrow for main reading. The stimulable phosphor sheet, which has been pre-read while being transported, is returned in the direction of arrow D' for main reading, and after the main reading is completed, the stimulable phosphor sheet is transported again in the direction of the arrow and taken out of the reading device. method is taken. However, in any case, with the above method, time is required for the stimulable phosphor sheet to be conveyed just to change its position, so it takes a lot of time to read the stimulable phosphor sheet in combination with one pre-reading, and it is not efficient. There is an inconvenience that reading cannot be performed. Further, as shown in FIG. 10, an excitation light source 1.01B for pre-reading and an excitation light source 101B for main reading are provided in the reading device, respectively. Endless Belt 109A, 109B, 109
A radiation image information reading device is also proposed in which the stimulable phosphor sheet is conveyed in the direction of arrow E by a conveying means consisting of C, 109D, and 1'09E, and one pre-read reading is performed sequentially without reversing the stimulable phosphor sheet. However, in such a device, in order to perform pre-reading and main reading on the stimulable phosphor sheet, a conveying means having a length of at least three sheets in the sub-scanning direction is required, so the device There is a problem in that the entire structure becomes even larger.

Furthermore, in each of the above devices, it is necessary to read the stimulable phosphor sheet with high precision while conveying the sheet, so the stimulable phosphor sheet is transported at a constant speed and accurately by a conveying means such as an endless belt device. It is necessary to convey the material with high precision in the direction.

Therefore, the motor etc. that drive the conveying means must be strictly controlled so that stable driving of the conveying means can be maintained even if load fluctuations occur due to movement of the stimulable phosphor sheet. Since a highly accurate motor that can be controlled in this manner is expensive, there is also the problem that the cost of the entire device increases significantly.

As described above, a light beam reading device that performs sub-scanning by conveying a sheet has various problems. In view of these problems, a device has been proposed that performs sub-scanning without moving the sheet.Hereinafter, a light beam scanning device in which the sheet is fixed will be described with reference to FIG.

The apparatus shown in FIG.
The surface to be scanned 207 rotates at a low speed in the direction of arrow C and is fixed at a predetermined position along with a rotating polygon mirror 203 which is an optical deflector that performs main scanning in the direction of arrow B on the surface to be scanned 207. An 11-scanning galvanometer mirror 205 is provided to reflect and deflect the light beam so that the main scanning line moves in the direction indicated by the arrow. That is, the sub-scanning galvanometer mirror 205 rotates once at a low speed in the direction of arrow C, which is a direction substantially perpendicular to the main scanning direction of the light beam, and the light beam 202
The entire surface to be scanned 207 is scanned in two-dimensional directions by the sub-scanning galvanometer mirror 205.

When the sub-scanning galvanometer mirror 205 finishes scanning one surface to be scanned, it returns to its original position and prepares for scanning the next surface to be scanned.

Furthermore, an fθ lens 206 which is an imaging lens is provided between the sub-scanning galvanometer mirror 205 and the scanned surface 207, and this fθ lens is rotated at a constant angular velocity by the rotating polygon mirror 203 and the sub-scanning galvanometer mirror 205. A light beam deflected by anti-tJ1 is caused to scan linearly at a constant speed on a flat surface to be scanned.

By the way, in the above-mentioned apparatus, in order to make the light beam directed by the rotating polygon mirror 203 and taking a spread optical path enter the reflecting surface of the relatively small sub-scanning galvanometer mirror, the optical path of the sunlight beam is focused. A relay lens 204 is provided which adjusts the optical path of the light beam so that it reproduces the deflection by the rotating polygon mirror and spreads again after passing through this convergence position. The sub-scanning galvanometer mirror is arranged at a position where the optical path of the light beam is focused by the relay lens 204, and the light beam is focused by the relay lens 204.
4, all of the beams are made incident on the sub-scanning galvanometer mirror and deflected. After being reflected and deflected by the sub-scanning galvanometer mirror, the light beam passes through the rotating polygon mirror 20.
Since the optical path is widened again at an angle corresponding to the deflection of 3, a main scanning line of the required length can be obtained on the scanned surface 207. When the illustrated device is used as a light beam reading device and the surface to be scanned is a sheet carrying image information, a light detection means is provided close to the surface to be scanned, and the light detection means is positioned at the main scanning line. The image information is read by moving the camera in accordance with the image.

However, since the apparatus shown in FIG. 11 is provided with the relay lens 204 in addition to the imaging lens 206 as described above, the optical system is not correct. This results in a complicated structure, and it is not possible to achieve sufficient miniaturization of the device.

There is also the problem that the provision of the relay lens increases the number of optical elements, increasing manufacturing costs. Further, in the above device, the fθ lens 206 is connected to the rotating polygon mirror 203 and the sub-scanning galvanometer mirror 20.
Since the light beam two-dimensionally deflected by 5 enters from almost the entire surface of the incident surface, it is necessary to improve the lens characteristics two-dimensionally, making the lens expensive and further increasing the manufacturing cost of the device. There is the inconvenience of raising the temperature.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and it performs sub-scanning without moving the sheet on which image information is recorded, and eliminates the need for an increase in the size of the device due to the movement of the sheet. In addition to solving the various problems of 8! images without using a complicated optical system with expensive optical elements! It is an object of the present invention to provide a light beam reading device that can further downsize the entire device and reduce manufacturing costs by recording information.

(Structure of the Invention) The light beam reading device of the present invention includes: a main scanning optical deflector that is provided on the optical path of the light beam emitted from the beam light source and deflects the light beam; an imaging lens provided on the optical path of the light beam deflected by the imaging lens; an imaging lens provided on the optical path of the light beam that passed through the imaging lens, the light beam was reflected by a reflective surface, and the light beam passed through the imaging lens; A sub-scanning mirror that rotates approximately around a rotation axis about a plane including an optical path of a light beam, a plane parallel to the plane, and a plane perpendicular to the optical axis of the imaging lens, and rotation of the sub-scanning mirror. a sheet holding means for holding the sheet in an arcuate shape rightward of a central axis that substantially coincides with a moving axis; and a light detecting means that rotates about a drive shaft that substantially coincides with a rotational axis of the sub-scanning mirror. It is characterized by the fact that it is equipped with

In other words, in the light beam reading device of the present invention, since the sheet is fixed by the sheet holding means, it is not necessary to make the device large in the sub-scanning direction, as in the case where the sheet is conveyed for sub-scanning. This eliminates the problem, and the entire device can be made more compact. Also, when the device is a radiation image information reading device and performs pre-reading and main reading on a stimulable phosphor sheet, the excitation light is scanned back and forth,
Pre-reading and main reading can be performed efficiently. In addition, the light beam reflected by the main scanning optical deflector passes through the imaging lens and is directly reflected by the sub-scanning mirror for sub-scanning, so there is no need to provide a relay lens, etc., and the optical system is simple. It will be cheap. Note that since the light beam whose optical path has been expanded by being deflected by the main scanning optical deflector is incident on the sub-scanning mirror, there are
Preferably, it is a long mirror extending in the main scanning direction. Furthermore, in the apparatus of the present invention, since the sheet has an arcuate shape as described above, there is no need to provide an imaging lens such as an f-theta lens in the optical path of the light beam reflected by the sub-scanning mirror. The lens may be provided between the main scanning optical deflector and the sub scanning mirror.

(Embodiment) Hereinafter, embodiment 11B of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an outline of a radiation image information reading device according to an embodiment of the present invention.

Excitation light 2 emitted from an excitation light source 1 is incident on a rotating polygon mirror 3, which is a main scanning optical deflector, and is deflected, which rotates in six directions of arrows. As the excitation light source 1, in addition to a He-Ne laser, an Ar laser, etc., an excitation light source formed by a combination of a light emitting diode and a beam shaping optical system is used. In addition to the above-mentioned rotating polygon mirror, the main scanning optical deflector includes a galvanometer mirror and an acousto-optic deflector (AOD).
Other types of optical deflectors may also be used.

The excitation light deflected by the rotating polygon mirror 3 passes through an imaging lens 4 such as a θ lens provided on the optical path.
The light is incident on the reflective surface 7a of a long sub-scanning reflective mirror 7 extending in the main scanning direction, which is driven by the motor 6 and rotated at a low speed in the direction of arrow C, and is reflected. Below this sub-scanning mirror 7, on the optical path of the excitation light reflected by the sub-scanning mirror, a stimulable phosphor sheet (hereinafter simply referred to as a sheet) 8 has an arcuate holding surface 9a. The sheet is held in an arcuate shape by sheet holding means 9. This sheet holding means 9 is formed by, for example, bending a plate-like object or integrally molding it using synthetic resin or the like. Further, the central axis of the circular arc surface formed by the sheet 8 substantially coincides with the rotation axis of the sub-scanning mirror 7.

When the sheet 8 is held on the sheet holding means 9 as described above, the excitation light 2 deflected by the rotating polygon mirror 3 is main-scanned on the sheet 8 in the direction of arrow B. The imaging lens 4 is a lens that scans at a constant velocity the excitation light deflected by the rotating polygon m3 at a constant angular velocity on the sheet 1-8 which is flat in the main scanning direction. The rotation axis of the sub-scanning mirror 7 is approximately a branch line between a plane including the optical path of the excitation light that has passed through the imaging lens 4 or a plane parallel to the plane and a plane perpendicular to the optical axis of the imaging lens 4. It rotates at a low speed in the direction of arrow C, and preferably, the reflection position of the excitation light 2 on the reflecting surface 7a and the rotation 8 axis coincide or almost coincide (for example, near the center of the thickness of the mirror 7). It has become a thing. A pulley 10A provided at the end of the sub-scanning mirror 7 is connected via a belt 10C to a pulley 1013 which is pivotally attached to the rotating shaft 6A of the motor 6, and when the motor 6 is driven, the pulley 10B rotates, and this rotational force is transmitted to the pulley 10A via the bells 1 to 10G, causing the sub-scanning mirror 7 to rotate.

In this way, the sub-scanning mirror 7 rotates back and forth by a predetermined angle sufficient for the excitation light to scan the entire surface of the sheet in the direction of the arrow C while reading image information on one sheet. By the rotation of the sub-scanning mirror, the main scanning line formed by the excitation light 2 on the sheet 8 gradually changes to the direction of the arrow EI.
The sub-scanning is performed by moving in the JD direction. Therefore, the entire surface of the sheet 8 is two-dimensionally scanned by the excitation light 2.

At the scanning position on the sheet 8 irradiated with the excitation light 2,
Stimulated luminescence occurs depending on the image information stored therein. In the apparatus of this embodiment, a long photomultiplier tube (photomultiplier) 5, which will be described later, is provided in the vicinity of the sheet 8 as a photodetection means for detecting stimulated luminescence light emitted from this scanning position. It is being

The photomultiplier 5 has a light-receiving surface 52 arranged along the main scanning line, and is particularly designed so that stimulated luminescence light emitted from any position in the main-scanning direction can efficiently enter the interior through the light-receiving surface 52. Preferably, the length of the light receiving surface 52 is longer than the reading scanning width on the sheet 8. The photomultiplier 5 converts the stimulated luminescent light into an electrical signal, and the obtained electrical signal is sent to an image information reading circuit (not shown) and processed, and then output as a visible image on a CRT or magnetically transmitted. be recorded on tape.

The photomultiplier 5 needs to move in the sub-scanning direction so as to always be close to the main scanning line, which moves in the sub-scanning direction as the sub-scanning mirror 7 rotates. Therefore, in this embodiment, the photomultiplier 5
A pulley 12A is attached to the end of the arm 11,
This pulley 12A is connected by a belt 12C to a boot 9128 attached to the rotating shaft 6A of the motor, and a photomultiplier is connected coaxially with the sub-scanning mirror 7.
5 can be rotated. Note that the photomultiplier 5 needs to rotate at twice the angular velocity of the sub-scanning mirror 7 that reflects the excitation light. The attached pulley 12A has a diameter approximately 1/2 times that of the pulley 1oΔ attached to the sub-scanning mirror 7. In addition, the real 7il! In the i embodiment, the motor 6 rotates both the sub-scanning mirror and the photo multiplier, but two motors are provided, and the sub-scanning mirror and the photo multiplier are rotated by completely independent means. They may also be rotated coaxially with each other.

As described above, when the sub-scanning mirror 7 and the photo multiplier 5 rotate by a predetermined angle at a predetermined speed and image information is read over the entire surface of the sheet, the sub-scanning mirror 7 and the photo The multiplier 5 is rotated in the opposite direction to the rotation direction, or further rotated in the rotation direction to complete one rotation, and returned to the initial position in preparation for reading the next sheet. In this embodiment, as shown in FIG. 1, a photodetector 13 is attached to the sheet holding means 9, and the excitation light is detected by the photodetector 13.
The reading scanning start position is determined. That is, the sub-scanning mirror 9 is rotated from the initial position in the direction of arrow C, and it is detected that the light beam 2 has reached the end of the sheet 8. At this point, the photomultiplier 5 is activated to read the image information. It is set to start reading.

By the way, in this embodiment, a 1-scale photomultiplier is used as described above, but conventional photomultipliers are generally equipped with a multiplier that multiplies a minute photocurrent to an appropriate level. There are several types of photomultipliers depending on the structure of the electrodes in the multiplier, and the long photomultiplier in this embodiment can be created by extending these various types of photomultipliers in a direction perpendicular to their side surfaces. can. The photomultiplier 5 used in the present invention shown in FIGS. 2(A) and 2(B) has an electrode structure generally called a box shape.

This photomultiplier 5 is provided with a photocathode (photocathode) 53 that emits photoelectrons and faces a long light-receiving surface 52 in a main body 51 that is made of glass or the like and has a vacuum inside. Multiple (in this embodiment, 1)
3) quarter-cylindrical electrodes (3 pieces) having a secondary electron emission effect (
A multiplier section 67 in which dynodes) 54 to 6G are combined is provided.

A shield electrode 68 is provided opposite to the dynode 66 at the lowermost end of the multiplier 67, and further collects the electron flow multiplied in the multiplier within the shield electrode 68 and prevents it from being taken out as a signal at the anode 69. are arranged. Each of these electrodes is electrically connected on a one-to-one basis to each terminal of the terminal group 70, the number of which corresponds to the number of electrodes provided on the opposite side of the light-receiving surface 52. Note that the dynodes 53 to 65 and the shield electrode 68 are supported by a support member 71 formed of an insulator.
It is fixedly held within the main body 51 by.

FIG. 3 shows an electric circuit 80 for driving the photomultiplier 5 and extracting photoelectric output, and parts corresponding to each part of the photomultiplier 5 are given the same reference numerals. A negative high voltage is applied to the photocathode 53 via a negative high voltage application terminal 81 . Further, the negative high voltage applied to the negative high voltage application terminal 81 is divided by the leader resistor group 82 and applied to the dynodes 53 to 65, respectively. Further, the shield electrode 68 is grounded, the anode 69 is grounded via a resistor 83, and the amplifier 84
is input to one terminal of The other terminal of the amplifier 54 is grounded, and the photoelectrically converted image information is taken out as an electrical signal from an output terminal 85.

FIGS. 4A and 4B show another photomultiplier 5 used in the present invention, which has an electrode structure generally referred to as a Venetian blind type. In this photomultiplier 5, a main body 151 has a cylindrical shape, and a photocathode 153 is provided along the main body 151 facing a light-receiving surface 152.
A plurality of plates (13 in this embodiment) of dynodes 154 to 166 are stacked on top of each other below 3 with an insulating member 172 in between and fixed with pins 173 to form a multiplier 167. Each of the dynodes 154 to 1θG is formed by making a large number of U-shaped cuts in a single conductive plate and bending the plate into a blind shape. A shield electrode 168 is fixed with a bottle 173 below this multiplier 167 via an insulating member 172, and an anode 16 is fixed in the shield electrode 168.
9 is provided. These electrodes are electrically connected to a terminal group 170 provided at the side end of the main body 151, similar to the photomultiplier 5 shown in FIG. In addition,
The photoelectric output can be taken out using the same circuit as shown in FIG. In addition, the elongated photomultiplier used in the present invention may include a multiplication section made of other types of conventionally known electrodes or a multiplication section formed by combining a plurality of types of electrodes. It can be created by extending a photomultiplier. Moreover, a contact type photosensor array or the like may be used as the light detection means instead of the long photomultiplier. Furthermore, it is also possible to use a photodetector in which a photomultiplier is provided on the exit end face of a conventional light condenser as described above.

If a long photomultiplier is used as the light detection means in this way, sub-scanning can be performed by moving the excitation light, and even if the photomultiplier is moved along with this sub-scanning, the device will not be large. There is no risk of it happening. In addition, the conventionally used condenser is difficult to process. Although the manufacturing cost is high, the device of this embodiment does not require this light condenser, so it also has the effect of reducing the manufacturing cost of the device. In general, if a long photomultiplier is used, the scanning position where stimulated luminescence light is generated is close to the light receiving surface, and most of the stimulated luminescence light is directly incident on the light receiving surface, so the stimulated luminescence light can be focused. It is also possible to improve the light collection efficiency compared to the case where light is collected through the body.

In addition, at a position facing the light receiving surface via the main scanning line,
By providing a reflecting mirror, the efficiency of collecting stimulated luminescence light can be further increased.

By the way, in the above-mentioned radiation image information reading apparatus among the light beam reading apparatuses, it is particularly necessary to efficiently condense the stimulated luminescence light that is the light emitted from the stimulable phosphor sheet. Furthermore, when the excitation light is incident on the sheet, a part of it may be reflected on the sheet, and a part of the reflected light may reach the light receiving surface of the photomultiplier, and the photomultiplier is It is necessary to correctly detect only the emitted light and not to detect the reflected light of the excitation light. Therefore, it is necessary to provide a long photomultiplier in a radiation image information reading device with a very thin light condenser on its light receiving surface and a filter that selectively transmits only light in the wavelength range of stimulated luminescence light. is preferred. A specific example of a photomultiplier in which the light condenser and filter are provided on the light receiving surface is not shown in FIG.

FIG. 5(a) shows a photomultiplier whose light-receiving surface is flat, for example, a box-shaped photomultiplier 5 shown in FIG. 2, with a filter 14 provided on the light-receiving surface 52.
Furthermore, an example is shown in which a plate-shaped condenser 15 made of acrylic or the like is provided on the filter 14. The light condenser 15 used in the device of the present invention has a very thin thickness and a simple shape as shown in the figure, so the size of the device increases which would be expected if a conventional light condenser was used. , there is no risk of causing problems such as increased manufacturing costs. Further, the positions of the filter 14 and the condenser 15 may be interchanged as shown in FIG. 5(1). Furthermore, as shown in FIG. 5(C), only light in the wavelength range of stimulated luminescence light is selectively transmitted through the light condenser 15' provided on the light receiving surface 52,
By applying a color that absorbs light in the wavelength region of the excitation light, the condenser 15' has the function of a filter, and the multiplication factor of the cocurrent current is inconveniently changed. Since the photomultiplier in the present invention is long, it is considered that it is more susceptible to the influence of magnetic fields than a small photomultiplier due to its structure and overall device design.

Therefore, it is more preferable that the light-shielding case 16 is made of permalloy or the like and also has the function of a magnetic shielding case.

As described above, in the apparatus of the present invention, sub-scanning is performed by fixing the sheet and moving the excitation light by rotating the sub-scanning mirror 7, compared to the case where the sheet side is moved. , the size of the device in the sub-scanning direction can be reduced to about half. Further, as described above, when pre-reading is performed prior to main reading to obtain an image signal for outputting a visible image, the sub-scanning mirror 7 can be reciprocated to perform pre-reading and main reading in succession. Therefore, there is no time loss that occurs when conveying a sheet, and image information can be read efficiently by combining pre-reading and main reading. Note that the sub-scanning mirror 7 only needs to have a length sufficient to allow the excitation light deflected by the main-scanning optical deflector to enter (, the main-scanning optical deflector (
It does not necessarily have to be long if it can be placed sufficiently close to the imaging lens. Further, its shape may be any shape as long as it rotates about the above-mentioned rotation axis and allows the excitation light to enter without fail. Furthermore, the motor that drives the sub-scanning mirror 7 is easy to control as there is no load fluctuation during sub-scanning, compared to the conventional method that performs sub-scanning by moving the sheet, and it is easy to control with relatively low torque. A small and inexpensive motor can be used.

In addition, in the apparatus of the present invention, as described above, a sub-scanning mirror is provided that allows all of the excitation light deflected by the main-scanning optical deflector to enter, so that the optical path of the excitation light can be adjusted and racing etc. There is no need to provide the optical system, which simplifies the optical system, making the device more compact and reducing its manufacturing cost. Furthermore, since the sheet has an arcuate shape, the imaging lens can be installed between the main scanning optical deflector and the sub-scanning mirror, so the imaging lens can be placed between the sub-scanning mirror and the sheet. It can be made smaller and easier to manufacture than when it is provided in the same place.

By the way, the sheet 8 may be carried in and out of the sheet holding means 9 manually, but it is also possible to provide a carry-in roller and a carry-out roller at both ends of the sheet holding means 9 in the sub-scanning direction, and further position the sheet. If this is provided, sheets can be carried in and out more efficiently. That is, as shown in FIG. 8, a pair of sheet carry-in rollers 17A and 17B are provided at one end of the sheet holding means, and
First, the sheet 8 is carried onto the sheet holding means 9. Next, as shown in FIGS. 1 and 8, a sheet delivery plate 20 is fixed to a rotating shaft 19 that is rotationally driven by a motor 18.
is rotated in the direction of arrow E1 to push the rear end of the sheet 8 and move the sheet until it reaches a predetermined position on the sheet holding means. In addition, as shown in both figures, if a detector 22 such as a reflective photointerrupter or a limit switch for determining the position of the leading edge of the sheet is provided on the sheet holding means 9, and the leading edge of the sheet is detected by these detectors. The seat position can be determined accurately and easily. Depending on the type of sheet, if the sheet does not conform well to the holding surface of the sheet holding means and it is difficult to maintain it in a cylindrical shape, a suction means may be provided within the sheet holding means to suction the sheet onto the holding surface. Bye.

When the sheet position is determined as described above and the reading of the image information by scanning the excitation light is completed at that position,
The sheet delivery plate 20 roughly rotates in the direction of arrow E2 in FIG. 8 to move the sheet, and the sheet is moved by sheet delivery rollers 21A and 21 provided at the other end of the sheet holding means.
The sheet is delivered to B, and transported out by this sheet transport roller.

In addition, as shown in FIG. 1, when the sheet is placed at a predetermined recording position, there is provided a width deflecting plate 24 that presses the recorder against a guide plate 23 that is set on the side end of the sheet holding means 9. If provided, the sheet can be reliably positioned in the main scanning direction.

The apparatus of the present invention has been described above using a tli radiation image information reading apparatus using a stimulable phosphor sheet as an example, but the apparatus of the present invention may be a light beam reading apparatus other than the above radiation image information reading apparatus. , the same effects as those described above can be achieved in devices other than the actual 1M mode.

(Effects of the Invention) As explained above, according to the light beam reading device of the present invention, the entire device can be scanned by fixing the sheet and moving the light beam and the light detection means on the sheet to perform sub-scanning. Particularly, the size can be reduced in the sub-scanning direction. Further, even when the apparatus of the present invention is a radiation image information reading apparatus and performs pre-reading prior to main reading, these readings can be performed efficiently. Furthermore, since the light detection means is made long and extends along the main scanning line, there is no fear that the device will become larger even if the light detection means is moved in the sub-scanning direction, unlike conventionally provided devices. By eliminating the large condensing body, manufacturing costs can be reduced and light condensing efficiency can be improved. Furthermore, by performing sub-scanning with a sub-scanning reflective mirror and making the sheet into an arcuate surface,
The optical system within the device can be simplified, making it possible to further downsize the entire device. Furthermore, since the number of optical elements used can be reduced and the need for expensive optical elements can be eliminated, the cost of the apparatus can be reduced, and the sub-scanning motor can also be made cheaper. As described above, the device of the present invention can achieve the various effects described above at the same time, and its practical value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an outline of a radiation image information reading device according to an embodiment of the present invention, and FIG. 2 (A> is a perspective view showing a long box-shaped photomultiplier used in the device of the present invention). , FIG. 2(B) is a sectional view taken along the line II, FIG. 3 is a drive circuit diagram of the photomultiplier shown in the second factor, and FIG. 4(A) is a long length used in the device of the present invention. A perspective view showing the Venetian blind type photomultiplier of
The figure is a schematic diagram showing a photomultiplier in which a filter and a condenser are provided on the light receiving surface, Figure 7 is a perspective view showing a photomultiplier housed in a light-shielding case, and Figure 8 is a schematic diagram showing a photomultiplier housed in a light-shielding case. Loading the sheet into the equipment shown in the figure. A schematic diagram illustrating an example of carrying out, FIG. 9 is a perspective view showing a conventional light beam reading device, and FIG.
This figure is a side view showing another conventional light beam reading device, and FIG. 11 is a perspective view showing a conventional light beam scanning device. 1...Excitation light source 2...Excitation
Light generation 3...Rotating polygon II 4...Main scanning imaging lens 5...Photomultiplier 7...Sub scanning mirror 8...Stormative phosphor sheet 9...Sheet holding Means Figure 1 Figure 6 Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1) A light beam emitted from a beam light source is caused to scan in the main scanning direction on a sheet on which image information is recorded, and the light beam and the sheet are relative to each other in the main scanning direction. a light beam that is moved in a sub-scanning direction substantially perpendicular to the direction of the light beam to two-dimensionally scan the light beam over the sheet to generate light containing the image information, and detect this light to read the image information; In the reading device, a main scanning optical deflector is provided on the optical path of the optical beam emitted from the beam light source and deflects the optical beam, and a main scanning optical deflector is provided on the optical path of the optical beam deflected by the main scanning optical deflector. an imaging lens provided, a plane provided on the optical path of the light beam that has passed through the imaging lens, that reflects the light beam with a reflective surface, and that includes the optical path of the light beam that has passed through the imaging lens, or the plane; a sub-scanning mirror that rotates about a branch line between a plane parallel to the image forming lens and a plane perpendicular to the optical axis of the imaging lens; A light beam reader comprising: a sheet holding means for holding the sheet in an arcuate shape; and a light detection means rotating about a drive shaft that substantially coincides with a rotation axis of the sub-scanning mirror. Device. 2) The light beam reading device according to claim 1, wherein the sub-scanning mirror is a long mirror extending in the main scanning direction. 3) A patent claim characterized in that the light detection means is an elongated photomultiplier tube having a light receiving surface extending along the main scanning line on the sheet and disposed close to the sheet. The image information reading device according to item 1. 4) The sheet is a stimulable phosphor sheet on which radiation image information is stored and recorded, and the light beam generates stimulated luminescence according to the image information stored and recorded on the stimulable phosphor sheet. The image information reading device according to any one of claims 1 to 3, wherein the excitation light is excitation light, and the light detection means detects the stimulated luminescence light. .