JPS62161264A - Photomultiplier and picture information reader - Google Patents

Abstract

PURPOSE:To improve light collecting efficiency by providing a filter to a long photodetecting face via a conductive liquid. CONSTITUTION:The scanning position on a stimulable phosphor sheet 3 which excitation light 1a is irradiated is subject to stimulate in response to the picture information stored and recorded thereupon. The long photomultiplier 5 whose photodetecting face 52 has a filter 10 is provided near the stimulable phosphor sheet as a photodetection means detecting the stimulated luminescent light emitted from a scanning position. The filter 10 is provided to the photomultiplier 5 whose photodetecting face 52 in a plane via a conductive liquid 16, which is nonvolatile and less volatile and highly viscous preferably, and silicone oil, fludic paraffin, water or water solution is used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photomultiplier tube equipped with a filter, and an image information reading device for reading image information of a radiation image information shade using the photomultiplier tube. Yes.

[Technical Background of the Invention] Conventionally, a light beam such as a laser beam is scanned two-dimensionally on a sheet on which image information is recorded, and the image information obtained by irradiating the beam light onto the sheet is obtained. An image information reading device that reads image information recorded on a sheet by detecting the contained light (e.g., reflected light, transmitted light, emitted light) using a photodetecting means equipped with a photomultiplier tube, etc. is now in widespread practical use. has been done.

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 (Japanese Patent Laid-Open No. 55
-12429, 56-11395, 56-11
There is a radiation image information reading device used in Japanese Patent No. 397 (disclosed in publications such as No. 397).

In other words, when a certain type of phosphor is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), a portion of this radiation energy is accumulated in the phosphor, causing the phosphor to It is known that when irradiated with excitation light such as ijf visual light, a phosphor exhibits stimulated luminescence depending on the accumulated energy, and a phosphor exhibiting this property is called a 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 exposes this stimulable phosphor sheet to a laser beam. The system generates stimulated luminescence light by scanning with excitation light such as the above, and the resulting stimulated luminescence light is read photoelectrically to obtain an image signal.

An example of the above radiation image information reading device is shown in FIG.
This will explain the system.

Excitation light 10 with constant intensity emitted from excitation light @1101
1a is made incident on the galvanometer mirror 102, and by this galvanometer mirror.

The laser beam is deflected and irradiated onto the stimulable phosphor sheet 1O3 so that the laser beam performs main scanning (scanning in the direction of arrow A) in the width direction of the stimulable phosphor sheet 103 placed below the galvanometer mirror. ll4i exhaustible phosphor sheet 10
3 is placed, for example, on the endless belt device 109 and conveyed in the direction of arrow B, so that the main scanning is repeated at an angle almost perpendicular to this sub-scanning, and the stimulable phosphor sheet)
Two-dimensional scanning is performed by the excitation light 101a over the entire surface of 103°.

The stimulable phosphor sheet irradiated with the excitation light 101a emits stimulated luminescence according to the image information recorded in the storage tank,
The emitted light enters the light condenser 104 from the incident end surface 104a of a transparent light condenser 104, the incident end surface 104a of which is formed parallel to the main scanning line set near the stimulable phosphor sheet.

This light collector 104 has a front end i'1l104b located near the stimulable phosphor sheet 103 which is formed into a planar shape, and which gradually becomes cylindrical toward the rear end. 104c has a substantially cylindrical shape and is coupled to a photomultiplier 105 provided on the exit end surface 104d, so that the stimulated luminescent light entering from the entrance end surface 104a is collected at the rear end 104C. and is transmitted to the photomultiplier 105 via a filter (not shown) that selectively transmits the stimulated luminescent light.

In the photomultiplier 105, the stimulated luminescent light is
After being converted into an hypochondriacal signal, the obtained electrical signal is sent to an image information reading circuit 106 for processing, and then, for example, a CRT 10.
7 as a visible image, or a magnetic tape 10.
8 or directly as a hard copy on a photographic material.

In the above device, the photodetection means for detecting stimulated luminescence light includes the photomultiplier 105 and the light condenser 104.
However, the condenser provided in the conventional device collects the stimulated luminescence light that enters from the sunken incident end surface 104a along the main scanning line in the main scanning direction by total reflection. In order to transmit the light to the photomultiplier, which has a small width, it is large as shown in the figure, and there is a problem in that the entire reading device equipped with such a light condenser becomes large.

In addition, the light concentrator has a shape in which a light-guiding sheet-like member such as an acrylic plate is shaped such that one end corresponding to the incident end face is linear and the other end corresponding to the exit end face is aligned with the light receiving surface of the photomultiplier (for example, , cylindrical shape), processing is difficult and processing costs are high, which raises the problem of increasing the manufacturing cost of the device. moreover,
As mentioned above, the stimulated luminescence light that is transmitted through a large condenser by total reflection may pass through the condenser without being totally reflected at an angle. Large-sized light collectors also have problems in light collection efficiency.

In view of the above-mentioned problems, the applicant of the present application has been able to detect light emitted from a sheet without using a large and complex-shaped light condenser, thereby reducing size and manufacturing costs. has already filed an application for an invention for an image information reading device that can greatly improve light collection efficiency (
(Japanese Patent Application No. 59-156255), the present invention provides an image information reading device as described above, in which the light detection means has a light receiving surface extending along the main scanning line and is disposed close to the sheet. A long photoelectron #! It is characterized by being a 1x tube. When using the long photomultiplier tube described above, it is also possible to use a long reflective optical element that reflects the light emitted from the sheet toward the light-receiving surface of the photomultiplier tube. We have already filed an application for the IJJ that we clarified (Japanese Patent Application No. 59-156256, No. 59-156)
No. 257).

Further, this elongated photomultiplier tube has a slit extending in the main scanning direction that allows passage of a light beam for main scanning, in which the light receiving surface of the photomultiplier tube is located on the inner surface, and An application has already been filed (Japanese Patent Application No. 59-156258) claiming that the invention can be used in a configuration including an integrating cylinder having an opening that is open on the portion including the main scanning line.

[Object of the invention] Book 9. An object of the present invention is to provide a device which is a further improvement on the invention of an image information reading device using a photodetecting means including a long photomultiplier tube, which was previously filed by the applicant.

Another object of the present invention is to provide an elongated photomultiplier tube equipped with a filter that can be suitably used in the above-mentioned image information reading device and the like.

``Summary of the Invention'' The present invention provides a main scanning means for main scanning a sheet on which image information is recorded with a light beam and generating light including the image information from the sheet; Sub-scanning means that performs sub-scanning by moving in a direction substantially perpendicular to the main-scanning direction.

and an image information reading device comprising a light detection means for detecting light emitted from the sheet.

The light detection means has a light-receiving surface extending along the main scanning line, and a light-guiding liquid is provided on the light-receiving surface by a filter that selectively transmits part or all of the light emitted from the sheet. An image information reading device is characterized in that it is a long photomultiplier tube provided through a photomultiplier tube.

Further, the non-emission 151 is a long photomultiplier tube characterized in that a filter is provided on the long light-receiving surface via a light-guiding liquid.

[Detailed description of the invention] A long photomultiplier tube according to the present invention is provided with a filter on its light-receiving surface via a light guide liquid, and the long photomultiplier tube is provided with a filter through a light-guiding liquid. Any device, system, etc. that can be used in combination with the above can be used in any system. However, the long photomultiplier tube of the present invention is
Since the present invention is particularly useful in an image information reading device that reads image information such as radiation image information, the following description will focus on the mode of use in this device.

That is, by preparing a long photomultiplier tube whose light-receiving surface is equipped with a filter via the light-guiding liquid of the present invention, and arranging it at a position close to the sheet movement position of the image information reading device. The light emitted from the sheet, such as stimulated luminescence light, can be made to efficiently enter the light receiving surface of the photomultiplier tube without using a conventional large and complicated light condenser.

The elongated photomultiplier tube in the device of the present invention has a shape in which its light-receiving surface is provided along the main scanning line, and the light emitted from the scanning position can be detected at any position in the main scanning direction. means something. It is particularly desirable that the length of the light-receiving surface of this long photomultiplier tube is longer than the reading scanning width on the sheet, but it may be slightly shorter than that.

In particular, as described below, when placing a B-shaped light condenser on the light receiving surface through a filter, the length of the light receiving surface is longer than the reading scanning width on the sheet by devising the shape of the light condensing body. Even if it is somewhat short, efficient light detection is possible. Moreover, arranging the photomultiplier tube close to the moving position of the sheet means that the photomultiplier tube is arranged so that the light emitted from the scanning position is directly and efficiently incident on the light receiving surface through a filter. of,
In addition to positioning it close to the sheet, it is also recommended to provide a very thin light condenser close to the filter on the light receiving surface.
It also means that the photomultiplier tube is placed slightly away from the sheet, so that the photomultiplier tube is placed slightly away from the sheet.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image information reading device and embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an outline of a radiation image information reading device that is an example of the present invention. FIG. 2 is a perspective view (A) of a long photomultiplier tube to which no filter is bonded, and a cross-sectional view (B) taken along the line II. FIG. 4 is a perspective view (A) and a cross-sectional view CB along the line H-■ of another elongated photomultiplier tube to which no filter is bonded.

Excitation light 1a emitted from excitation light source 1 enters galvanometer mirror 2, is reflected and deflected, and passes over stimulable phosphor sheet 3, which is conveyed in the direction of arrow B by endless belt device 9, which is a sub-scanning means, in the direction of arrow A. Main scan in the direction. The scanning position on the stimulable phosphor sheet 3 irradiated with the excitation light 1a emits stimulated light according to the image information stored there. As a photodetecting means for detecting the stimulated luminescence light emitted from this scanning position, in the apparatus of the present invention, a long photoelectronic device with a filter 10 bonded to the light receiving surface 52 is used in the vicinity of the photostimulable phosphor sheet. Multiplier tube (photomultiplier) 5
is provided.

It is particularly preferable that the photomultiplier 5 has its light receiving surface 52 arranged along the main scanning line, so that stimulated luminescence emitted from any position in the main scanning direction is efficiently incident on the inside of the light receiving surface 52. , the length of the light receiving surface 52 is the length of the sheet 3
The reading scan width is greater than the above reading scan width. 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) for processing, and then output as a visible image on a CRT or on a magnetic tape. It is recorded in

Conventional photomultipliers are generally divided into several types depending on the structure of the electrodes in the multiplier part provided inside that multiplies a minute photocurrent to an appropriate level, but the elongated photomultiplier of the present invention can be created by extending these various photomultipliers in a direction perpendicular to their sides.

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 photo multiplier 5
A photocathode (photocathode) 53 that emits photoelectric f- is provided in a main body 51 made of glass or the like and having a vacuum inside, facing a long light-receiving surface 52. Below this photocathode 53, a plurality of ( A multiplier section 67 is provided in which a combination of quarter-cylindrical electrodes (dynodes) 54 to 66 having a secondary electron emission effect (in this example, 13 pieces) is provided. A shield electrode 68 is provided opposite to the dynode 66 at the bottom end of the multiplier 67, and an anode 69 is further disposed within the shield electrode 68 to collect the electron flow multiplied in the multiplier and take it out as a signal. has been done.

These electrodes are electrically connected in correspondence with the ends f- and l of the four groups of ends 70, the number of which corresponds to the number of electrodes provided on the opposite side of the light-receiving surface 52, respectively. The dynodes 53 to 65 and the shield electrode 66 are fixedly held within the main body 51 by a support member 71 made of an insulator.

FIG. 3 shows an electric circuit 80 for driving the photomultiplier 5 and extracting the photoelectric output, and parts corresponding to each part of the photomultiplier 5 are given a reference number. A negative high voltage is applied to the photoelectric jJi 53 via a negative high voltage application end 'l-81. Further, the negative high voltage applied to the negative high voltage ignition terminal 81 is applied to the breeta resistance group 82.
The voltages are divided by and applied to tie nodes 53 to 65, respectively. Further, the shield electrode 68 is grounded,
The positive terminal 8i69 is grounded through a resistor 83 and is input to the - terminal of the amplifier 84. The other terminal of the amplifier 54 is grounded, and photoelectrically converted image information is taken out as an electrical signal from an output terminal f-85.

FIGS. 4A and 4B show another photomultiplier 15 used in the present invention, which has an electrode structure generally referred to as a Venetian blind type. This photomultiplier 15 has a main body 151 having 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 166 is formed by making a large number of U-shaped cuts in a single conductive plate and bending the plate to form a blind shape. A shield electrode 168 is fixed below this multiplier 167 with a pin 173 via an insulating member 172, and an anode 16 is fixed within 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. Incidentally, the output of the light 1 may be taken out by using exactly the same circuit as the circuit shown in FIG. 3.

In addition, the elongated photomultiplier used in the present invention is a photomultiplier equipped with a multiplier section made of other types of electrodes or a multiplier section formed by combining a plurality of types of electrodes. It is possible to create by extending .

In this way, the reading device described in L has a long photomultiplier whose light-receiving surface is arranged along the main scanning line, and is arranged close to the stimulable phosphor sheet. Since there is no need for a light condenser that has a large and complicated shape and is expensive to manufacture, it is possible to downsize the entire device and reduce manufacturing costs. In addition, the scanning position where the 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 light collection efficiency is lower than when the stimulated luminescence light is transmitted by a condenser. It is also possible to increase

The elongated photomultiplier tube used in the present invention is a elongated photomultiplier tube characterized in that a filter is provided on its light-receiving surface via a light-guiding liquid.

The positional relationship between the light-receiving surface of the photomultiplier and the filter provided through the light-guiding liquid is schematically shown in 514th (a) and (b).

FIG. 5(a) shows a state in which the filter 10 is provided to the photomultiplier 5 whose light-receiving surface 52 is a mosaic surface via the light-guiding liquid 16, and FIG. A photomultiplier 15 having a curved light-receiving surface 52 is shown equipped with a filter 10 via a light-guiding liquid 16.

Note that when the light guide liquid 16 has a high affinity for the light receiving surface and the filter surface and the cohesive force of the light guide liquid is crystallized, the light guide liquid 16 itself will cause the light reception F(ti and the filter surface to The surface may be joined.

In addition, in order to prevent volatilization or deterioration of the light guide liquid 16,
Alternatively, in order to realize the bonding between the light-receiving surface 52 and the surface of the filter 10, a retainer 17 as shown in FIG. A sheet, protective film, protective plate, etc. may be provided.

Furthermore, as shown in FIG. 5(d), a container 18 with a transparent IJJ bottom and a filter 10 attached to the bottom is filled with a light-guiding liquid 16, and the photo-transfer is placed in contact with the light-guiding liquid. The configuration may be such that the light receiving surface 52 of the multiplier 5 is arranged to face the filter IO. In this case, the container may have a bottom surface that functions as a filter.

It is also possible to partially adhere the filter to the light-receiving surface of the photomultiplier with adhesive, and then fill the gap between the remaining filter and the light-receiving surface of the photomultiplier with a light-guiding liquid. This is very effective when the filter and photomultiplier have different coefficients of thermal expansion and cannot be bonded over the entire surface.

The light guide liquid used for the above purpose is preferably nonvolatile or low volatility and high viscosity, and examples thereof include silicone oil and liquid paraffin. Alternatively, an aqueous liquid such as water or an aqueous solution can also be used.

If the length of the photomultiplier in the main scanning direction is somewhat shorter than the reading scanning width on the stimulable phosphor sheet 3, as shown in FIG. The photomultiplier 5 is configured to spread out from the light receiving surface 52 of the photomultiplier 5 toward the photostimulable phosphor sheet 3, and the stimulated luminescent light from the entire reading scanning width on the sheet 3 is efficiently directed to the light receiving surface 52 of the photomultiplier 5. You may also be able to guide them.

The apparatus of the present invention has been explained above using a radiation image information reading apparatus using a stimulable phosphor sheet as an example, but the apparatus of the present invention may also be applied to image information reading apparatuses other than the above-mentioned radiation image information reading apparatus. It goes without saying that effects such as miniaturization of the device and reduction of manufacturing costs can be achieved in any device.

[Effects of the Invention] According to the image information reading device of the present invention, by providing a photomultiplier equipped with a long filter close to the sheet, it is possible to use a conventional large-sized and complicated-shaped light condenser. The light emitted from the sheet can be detected without

Therefore, it is possible to downsize the entire device and reduce manufacturing costs, and it is also possible to increase the efficiency of condensing light emitted from the sheet.

Furthermore, since light is guided between the light-receiving surface of the long photomultiplier tube of the present invention and the filter via a light-guiding liquid, the light is Light loss due to insufficient adhesion at the bonding surface between the surface and the light-guiding solid material layer, and the bonding surface between the light-guiding solid material layer and the filter, or the light-receiving surface of the photomultiplier tube or the filter. Light loss caused by reflection on the surface is effectively reduced.

Furthermore, since the light-guiding material of the present invention is a liquid, it has the advantage that the desired light-guiding can be achieved almost unaffected by the shape of the surface to be bonded, that is, the shape of the light-receiving surface of the photomultiplier tube and the filter surface. be.

[Brief explanation of drawings]

FIG. 1 shows J! of a radiation image information reading device according to an embodiment of the present invention. It is a perspective view showing the main points. FIG. 2(A) is a perspective view (shown with the filter removed) of a long box-shaped photomultiplier used in the device of the present invention, and FIG. 2(B) is an I
-I line sectional view. :JrJ3 diagram is the photomultiplier shown in Figure 2.
FIG. FIG. 4(A) is a perspective view (shown with the filter removed) of a long Venetian blind type photomultiplier used in the device of the present invention;
IJA diagram (B) is a sectional view taken along the line ■-■. FIGS. 5(a), (b), (C), and (d) are schematic diagrams showing the configuration of a photomultiplier tube in which a filter according to the present invention is bonded to a light-receiving surface, respectively. FIG. 6 is a perspective view (shown with the filter removed) showing an example in which a long photomultiplier used in the device of the present invention is provided with a light condenser. It is a perspective view showing an outline of an image information reading device. 1a: Excitation light 3 Bistimulable phosphor sheet 5.15: Photomultiplier tube (photomultiplier) 52.152: Light receiving surface 10: Filter ll: Collection Light body 16: Light-guiding liquid 17: Protective equipment 18: Container with transparent bottom Patent applicant: Fuji Photo Film Co., Ltd. Representative: Patent attorney: Yasushi Yanagawa (Man) (b)
(C) Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. An elongated photomultiplier tube characterized in that a filter is provided on the elongated light-receiving surface via a light-guiding liquid. 2. The photomultiplier tube according to claim 1, wherein the light-receiving surface is a curved surface. 3. The photomultiplier tube according to claim 1, wherein the light-guiding liquid is an oily liquid. 4. The photomultiplier tube according to claim 3, wherein the oily liquid is silicone oil or liquid paraffin. 5. Main scanning means for main-scanning a sheet on which image information is recorded with a light beam to generate light containing the image information from the sheet; and a main scanning means for main-scanning a sheet on which image information is recorded, and generating light containing the image information from the sheet; An image information reading device comprising a sub-scanning means that performs sub-scanning by moving in a vertical direction, and a light detection means that detects light emitted from the sheet, wherein the light detection means extends along a main scanning line. A long photomultiplier tube having a light-receiving surface and a filter that selectively transmits part or all of the light emitted from the sheet on the light-receiving surface via a light-guiding liquid. An image information reading device characterized by the following. 6. The sheet is a stimulable phosphor sheet on which radiation image information is accumulated and recorded, and the light beam emits stimulable luminescent light according to the image information accumulated and recorded on the stimulable phosphor sheet. 6. The image information reading device according to claim 5, wherein the photodetecting means detects the stimulated luminescent light.