JPS58194230A - Image tube and production process thereof - Google Patents

Abstract

PURPOSE:To provide the captioned device with the merits of the optical fiber flux board and, enhance the transfer efficiency thereof so as to obtain the high- grade image, by forming the phosphor surface acting as the output surface on the internal surface of an optical fiber flux board hving a specified board thickness, and by connecting and fixing the external surface's peripheral part of the fiber flux board, except the necessary effective diametral part, to a supporting ring which is strong in strength. CONSTITUTION:In the vicinity of the output window 1b in a vacuum enclosure 1, an output surface 16 is disposed where an output phosphor surface 10 is formed on the internal surface of an optical fiber flux board 17 whose board thickness is less than 1.5mm., and said output surface 16 is fixed to the supporting ring 18. The mechanical strength of this supporting ring 18 is stronger than that of the optical fiber flux board 17, and the effective diameter of a central hole 19 is made larger than the output image diameter. The peripheral part's surface of the optical fiber flux board 17 opposite to the phosphor surface 10 is connected and stuck to this supporting ring 18 by means of an adhesive 20. In this way, an image tube having enhanced transfer efficiency and high-grade image and further possessing the merits of the optical fiber flux board can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image tube using an optical fiber bundle plate as the output surface substrate, and a method for manufacturing the same.

Technical Background and Problems of C Party In general, image tubes, such as Xa* photomultiplier tubes, are widely used in medical applications, mainly in industrial non-destructive testing, in combination with X-ray industrial televisions. This type of X@fluorescence multiplier tube is constructed as shown in FIG. 1, and has an input surface 1 disposed inside the input side of a vacuum envelope 1 mainly made of glass. - Inside the output side of the vacuum envelope 1, an anode 3 is disposed and an output surface 2 is provided, and a focusing electrode 5 is further disposed along the side wall inside the vacuum envelope 1. There is. The input direction l
is the output 1ill of the substrate 6 made of spherical At (concave surface 1
A CsI input fluorescent surface 1 is formed on the input fluorescent surface 1, and a photocathode 8 is further formed on this input fluorescent surface 1. Further, the output [1of] is formed by forming an output fluorescent surface 10 on a substrate 9. In operation, when X1s (not shown) passes through a subject (not shown) t, it is changed by the subject's X@transmittance and excites the input fluorescence ifi]7. The excitation light of the input fluorescent surface 1 gives energy t to the photocathode 8 formed on the inner surface of the input fluorescent light TJjJ1, and the photoelectric surface 1lf18
Release Shimiko. This electron is anode 31 Kato electrode 5
The electron beam is acceleratedly dyed onto the output fluorescent surface 10 by the action of an electron lens, which causes the output fluorescent surface 10 to emit light. In this process, electrons are multiplied, and a much brighter image is obtained on the output phosphor surface 10 than that obtained on the input phosphor surface 7.

By the way, as one example of using an optical fiber bundle plate as a holding substrate for the output fluorescent surface of the above-mentioned X@fluorescence multiplier tube,
There is a method disclosed in Japanese Utility Model Publication No. 14405/1983, in which an optical fiber bundle plate is attached directly to the output window as part of the vacuum envelope, and an output fluorescent surface is formed on the inner surface. be. As shown in FIG. 2, this method relies on direct optical coupling with an image pickup tube 12 equipped with an optical fiber bundle plate 1. method is required. As shown in Fig. 1, the accelerating voltage is usually zero or low for the photocathode 8, and 20 kV to 20 kV for the anode 3.
Apply a high voltage of 30 kVO. However, when the optical fiber bundle plate 14 is used as shown in Figure #p, 2, the withstand voltage characteristics of the optical fiber bundle plate J4 are poor, so if the anode 3 is set to a high voltage, discharge occurs inside the optical fiber bundle plate 14. This will cause damage.

Therefore, the field 3 is set to zero potential, and a negative ^ is applied to the photocathode 811iI.
It is necessary to apply a voltage of -20 to -30 kV. The focusing electrode 5 applies a normal voltage of several 6 volts to the photocathode 8, but as a result, a high negative voltage is also applied to the focusing electrode 5. Therefore, as shown in FIG. 2, if the input window Jm of the vacuum envelope 1 is made of metal, the input window 1a should also be covered with an insulator 15. 15, the shape is larger and the weight also increases. Furthermore, in order to maintain vacuum tightness, the thickness of the optical fiber bundle plate 14 must be 3.0 mm or more. On the other hand, Japanese Patent Laid-Open No. 53-24770 proposes that the optical fiber bundle plate be housed inside a vacuum envelope and that an output fluorescent surface be formed on the optical fiber bundle plate to improve the contrast. This method is the second
As shown in the figure, it cannot be directly connected to the image pickup tube U equipped with the optical fiber bundle plate 1, and a lens system is required. It can be done in the same way as a multiplier tube. However, when using an optical fiber bundle plate, this publication does not mention measures against optical defects in the optical fiber bundle plate, which is the most serious problem in image quality, and does not mention that optical fibers with a small diameter In the current situation where it is almost impossible to make a bundle without the defects described below, it is difficult to believe that it is appropriate. That is, the optical defects of the optical fiber bundle plate include cranes and distortions. These flaws appear as black dots or black edges due to optical fiber breakage or devitrification, resulting in areas where light is not transmitted, or uneven distribution of the absorber. On the other hand, distortion occurs when the fiber bundle is twisted during the manufacturing process of the optical fiber bundle plate. When the fiber bundle is tilted, the positional relationship of each point of the image generated on the M plane is shifted. In order to reduce these optical defects, the probability of defects occurring inside the fiber bundle is reduced by making the optical fiber bundle plate thinner. Therefore, Utility Model 11855-
As shown in Japanese Patent No. 47153, there is a method of attaching an optical fiber bundle plate to a glass plate and polishing it to 1.0 or less.

However, the contents of the publication cannot be said to fully take advantage of the effect of using the optical fiber bundle plate to improve contrast, and the light spreads during the process of passing from the optical fiber bundle into the glass. Speed up transmission efficiency.

[Purpose of the invention]

An object of the present invention is to provide an image tube that has the features of an optical fiber bundle plate, eliminates defects, and provides high-quality MS, and a method for manufacturing the same.

[Summary of the invention]

The present invention provides an image tube in which an input surface is provided on the input side in a vacuum envelope, an anode and an output surface are provided on the output side, and a focusing electrode is arranged along the 1# wall. Optical iI1 with a plate thickness of 1.5cm or less. An output fluorescent surface is formed on the inner surface of the #1 bundle plate (9, and the peripheral part of the outer surface of the optical fiber bundle plate is made of iron optical fiber bundle plate).The required output image diameter is formed on a mechanically strong support ring. The image tube is bonded and fixed with adhesive, leaving the effective diameter part necessary to obtain the image tube.

In addition, the present invention provides a support ring T-jointed to the periphery of one side of a thick optical fiber bundle plate, excluding the effective diameter portion, and then a support ring T-jointed to the other side of the optical fiber bundle plate with a thickness of 15 mm or less. After sanding,
This is a method of manufacturing an image tube in which a fluorescent surface is formed on the polished surface.

[Invention C) @Example]

This invention improves the vicinity of the output surface in order to eliminate the above-mentioned conventional drawbacks, and only the vicinity of the output surface will be explained. That is, as described above, defects in the optical fiber bundle plate can be alleviated by making it thinner, but on the other hand, the mechanical strength becomes extremely weak, making it impossible to withstand the process of forming the output fluorescent surface. Therefore, the image tube of this invention, for example,
The main parts of a fluorescent multiplier tube are constructed as shown in the TSA diagram.
The same parts as in FIG. 1 are denoted by the same reference numerals, and an output surface 16 is disposed near the output window 1b inside the vacuum envelope l. This output surface L1 is connected to the optical fiber bundle plate 17 as shown in FIG.
An output fluorescent surface io is formed on one surface (facing inward) of the support ring 18, and is fixed to a support ring 18. In this case, the support ring 18 has a stronger mechanical strength than the optical fiber bundle plate 11, and the center hole 19 has an effective diameter larger than the output image diameter. And this support $
At 18, the peripheral portion of the other surface of the optical fiber bundle plate 12 (the surface opposite to the output/light surface 10) is bonded and bonded with an adhesive 20. In this state, even if the optical fiber bundle plate 17 has a thickness of 1.5 mm or less (for example, even if the thickness is reduced to 0.2 mm), the support @18
Since the periphery is held in place, the mechanical strength is strong, and the strength is sufficient for handling when forming an output fluorescent surface.

The material of the support ring II is preferably a material that has thermal expansion characteristics matching that of the optical fiber bundle plate 17, and the inventor's experiments have shown that the material used for the support ring II is iron, Ni, Kel alloy, glass used as a material for manufacturing the optical fiber bundle plate 11, or the like. Good results were obtained using a glass medium with similar composition.

Further, the adhesive 20 for joining the optical fiber bundle plate 1r and the support fJ11g is preferably fused glass. Powdered crystallized glass to fused glass with nitrocellulose and acetic acid! It can be bonded by dissolving it in a chill mixture, applying it to the support ring 18, drying it, placing the optical fiber bundle plate 11 on it, and heating it to 450°C in the air while applying a load of 5 to 20/ex2 in the adhesion direction. Yes, nine.

Furthermore, in addition to bath-coated glass, a disc-shaped aluminum foil can be inserted into the joint between the optical fiber bundle plate 17 and the support ring 18 and bonded by heat and pressure. Another method is to use an alkaline silicate adhesive, as it does not require vacuum tightness at the joint.
It was also possible to use inorganic adhesives such as silica sol adhesives and phosphorus w1 salt adhesives.

In the above-mentioned optical fiber bundle plate, it is necessary to specify the diameter of the single fibers from the viewpoint of resolution. That is, if the single fiber diameter is D■, the spatial frequency is ft, and the image transmission ability of the optical fiber bundle plate is expressed as F(1) as a change in imm to a sine wave input, then
F(f) is as follows.

Here, Jl is a first-order Bessel function. Normally, image tubes have poor quality IiIIIigI! In order to obtain this, it is preferable that the modulation rate is 30 tp/■ and the modulation depth is 50 or more.

Calculating "(1)" of the optical fiber bundle plate from this point, it is necessary that D, that is, the single fiber diameter, is 10 μm or less. Also, as the output image diameter of the image tube increases, the brightness decreases.
Since a lens with a large diameter is required to transmit an image to the lens, good results were obtained when the effective diameter of the optical fiber bundle plate in this invention was 50 mm or less.

In the above description, the support ring 18Fi is fixed to the molten metal electrode 3, but the support mIJ may be closely fixed to the inner surface of the output window 1b of the vacuum envelope 1.

Next, a method for manufacturing an image tube according to the present invention will be explained. First, an optical fiber bundle plate having a plate thickness of 2.0 haze is joined to the support ring 18, and then the surface of the optical fiber bundle plate opposite to the support 18111 is polished.

In this polishing, it was possible to finish with a very good yield up to 1.5, but as shown in FIG. By holding the optical fiber bundle plate J1, the plate thickness could be reduced to α2■.

Of course, this inclusion 21 is removed after polishing. Initially, when the thickness of the optical fiber bundle board to be pasted was 2.0 or more, it was easy to handle during pasting.

〔Effect of the invention〕

According to this invention, while having the features of an optical fiber bundle board, the defects thereof are removed, and moreover, a high-quality l! A IIi image can be obtained.

[Brief explanation of drawings]

The tXI diagram is a schematic diagram showing a general X@fluorescence multiplier tube.
FIG. 2 is a sectional view showing a conventional image tube and image pickup tube combined device using an optical fiber bundle plate, and FIG. 3 is an image tube (X-ray fluorescence multiplier tube) according to an embodiment of the present invention. 4 is an enlarged sectional view of a part of FIG. 3, and FIG. 5 is a cross-sectional view showing a modification of the manufacturing method of the present invention.
It's evil. 1...Vacuum outside H device, mutual...input restraint, 3...anode,
5... Focusing electrode, 10... Output fluorescent surface, 16...
Output surface, 17... Optical fiber bundle plate, 18... Support ring,
X a...Adhesive. Applicant's agent Patent attorney Takeshi Suzue 7 Figure 1 Figure 2 - 13 Figure 4 Figure 6 5 Figure 5

Claims (5)

[Claims] (1) In an image tube in which an input surface is provided on the input side in a vacuum envelope, an anode and an output surface are provided on the output side, and a focusing electrode is provided on the side wall, the output surface is a plate. Thickness 1,5
■An output fluorescent surface is formed on the inner surface of the following optical fiber bundle plate, and the peripheral part of the outer surface of the optical fiber bundle plate is attached to a supporting ring having a strong mechanical strength than the optical fiber bundle plate to form the desired output image. An image tube characterized in that it is bonded and fixed with an adhesive leaving an effective diameter portion necessary to obtain the diameter. (2) The single fiber diameter of the optical fiber bundle plate is 10 srm or less] and the effective diameter is 50 srm or less.
The image tube described in item 1. (3) The image tube according to claim 1, which is made of any one of the above-mentioned support wire made of nickel-based all-wire, Cera-t, glass, or glass. (4) Kaminichi adhesive is a patented product made of either molten glass, Cerabax thread inorganic adhesive, or Hiro aluminum foil.
Image t of the first product description of the range of pI calculation. (5) Join and fix the support fJI to one side of the thick optical fiber bundle plate except for the effective diameter part, and then make the other side of the optical fiber bundle plate 1.5 mm thick or less. A method for manufacturing an image tube, characterized in that after polishing, an output fluorescent surface is formed on the polished surface. (671) The method for manufacturing an image tube according to claim 5, wherein the thickness of the optical fiber bundle plate before distribution and polishing is 2.0 mm or more.