JP2019075341A - Image tube, and manufacturing method thereof - Google Patents

Abstract

To provide an image tube capable of making the distribution of the amount of alkaline metal uniform in a photoelectric conversion film, and to provide a manufacturing method thereof.SOLUTION: An image tube includes a package, an input part provided on one end side of the package, and having a fluorescent screen for converting the incident radiant ray into fluorescent light, and a photoelectric conversion film for converting the fluorescent light into an electron ray, an output part provided on the other end side of the package and converting the electron ray into fluorescent light, a first annular electrode provided between the input part and the output part, a second annular electrode provided between the first annular electrode and the output part, and having multiple holes penetrating in the thickness direction, and a connection part provided on the output part side of the second annular electrode, connected with a cylindrical introduction pipe, and internally having a space connecting the hole of the introduction pipe and the multiple holes.SELECTED DRAWING: Figure 2

Description

  Embodiments of the present invention relate to an image tube and a method of manufacturing the same.

There is an image tube for converting image information by radiation such as X-ray, γ-ray, and neutron beam into an optical image. The image tube is widely used as a so-called image intensifier (image intensifier) in medical diagnostic devices, industrial nondestructive inspection devices, and the like.
Such an image tube is provided with an envelope, an input unit, an electrode, an anode, an insulating unit, an output unit and the like. The input unit is provided inside the envelope and has a fluorescent film that converts incident radiation into fluorescence and a photoelectric conversion film that converts the converted fluorescence into an electron beam. Generally, the photoelectric conversion film is formed by reacting a film containing Sb (antimony) provided inside the envelope with Cs (cesium) which is an alkali metal. For example, the vapor of Cs is introduced into the gap between the inner wall of the envelope and the electrode from the introduction pipe provided in the insulating portion to supply the vapor of Cs to the film containing Sb.

However, if Cs vapor is introduced into the gap between the inner wall of the envelope and the electrode, the vapor may not be sufficiently diffused or its travel path may be complicated, resulting in the vapor reaching the film containing Sb. Unevenness is likely to occur in the distribution of the amount of If an in-plane distribution occurs in the amount of Cs in the formed photoelectric conversion film, uneven photosensitivity may occur and appear as a stain in the output image.
Therefore, a technique has been proposed in which Cs vapor is introduced into the inside of the annular electrode provided on the insulating portion side, and Cs vapor is supplied to the film containing Sb through the space on the central axis side of the envelope. There is.
However, there is room for improvement in making the distribution of the amount of alkali metal in the photoelectric conversion film uniform.

JP, 2014-89927, A

  The problem to be solved by the present invention is to provide an image tube capable of making the distribution of the amount of alkali metal in the photoelectric conversion film uniform, and a method of manufacturing the same.

  The image tube according to the embodiment includes an envelope, a fluorescent film provided on one end side of the envelope and converting incident radiation into fluorescence, and a photoelectric conversion film converting the fluorescence into an electron beam. And an output unit provided at the other end of the envelope, the output unit converting the electron beam into fluorescence, the input unit, and the output unit. A second annular electrode provided between the first annular electrode, the first annular electrode, and the output portion and having a plurality of holes penetrating the thickness direction, and the second annular electrode The connection part which is provided in the surface by the side of the above-mentioned output part, is connected with a cylindrical introductory pipe, and has a space which connects a hole of the introductory pipe and the plurality of holes inside is provided.

It is a schematic cross section for illustrating the image tube concerning this embodiment. It is a model perspective view for illustrating a steam guide part and the 3rd electrode. It is a model perspective view for illustrating a steam guide part. (A)-(c) is a schematic diagram for illustrating the physical relationship of the hole of an introductory pipe, and a plurality of holes. It is a schematic cross section for illustrating the formation method of a photoelectric conversion film. It is a model perspective view for illustrating the effect of a steam guide part.

Hereinafter, embodiments will be illustrated with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals and the detailed description will be appropriately omitted.
Further, in the following, as an example, the case of X-rays will be described as a representative example of radiation.
Therefore, other radiation can also be applied by replacing “X-ray” in the following embodiments with “other radiation”.

(Image tube)
FIG. 1 is a schematic cross-sectional view for illustrating an image tube 1 according to the present embodiment.
FIG. 2 is a schematic perspective view for illustrating the steam guiding portion 8 and the third electrode 43.
FIG. 3 is a schematic perspective view for illustrating the steam guiding portion 8.
As shown in FIG. 1, the image tube 1 is provided with an envelope 2, an input unit 3, an electrode 4, an anode 5, an output unit 6, an insulating unit 7, and a steam guiding unit 8.

The envelope 2 has a tubular shape, and maintains the internal atmosphere in a state in which the internal pressure is reduced below atmospheric pressure. In this case, the inside of the envelope 2 is high vacuum (for example, about 10 ⁻⁴ Pa or less).
One end of the envelope 2 is closed by the entrance window 21.
The other end side of the envelope 2 is closed by the output portion 6 and the insulating portion 7.
The material of the envelope 2 can be, for example, metal.

The input unit 3 is provided at one end of the envelope 2 and converts incident X-rays into fluorescence, and further converts the converted fluorescence into electron beams.
The input unit 3 is provided inside the envelope 2 and in the vicinity of the entrance window 21.
The input unit 3 includes an incident substrate 31, a fluorescent film 32, and a photoelectric conversion film 33.
The incident substrate 31 is provided on the incident window 21 side. The surface on the incident window 21 side of the incident substrate 31 is an X-ray incident surface. X-rays, which are radiation, are incident on the incident substrate 31. Further, the incident substrate 31 functions as a cathode. The incident substrate 31 can be made of, for example, aluminum or the like. The thickness of the incident substrate 31 can be, for example, about 1 mm.

  The fluorescent film 32 is provided on the side of the incident substrate 31 opposite to the incident window 21 side. The fluorescent film 32 converts X-rays incident through the incident substrate 31 into fluorescent light (visible light). The fluorescent film 32 contains, for example, cesium iodide (CsI).

  The photoelectric conversion film 33 is provided on the side of the fluorescent film 32 opposite to the incident substrate 31 side. The photoelectric conversion film 33 faces the inside of the envelope 2. The fluorescence converted by the fluorescent film 32 is incident on the photoelectric conversion film 33. The photoelectric conversion film 33 converts the incident fluorescence into an electron beam. The photoelectric conversion film 33 can be formed by reacting a film containing antimony (Sb) with a vapor of an alkali metal such as cesium (Cs), potassium (K), sodium (Na) or the like in a vacuum. In general, the photoelectric conversion film 33 can be an Sb-Cs film. The details of the method of forming the photoelectric conversion film 33 will be described later.

The electrode 4 is provided inside the envelope 2 and between the input unit 3 and the output unit 6.
The electrode 4 has a first electrode 41, a second electrode 42, and a third electrode 43. The first electrode 41, the second electrode 42, and the third electrode 43 can be formed of, for example, a metal.
The shapes of the first electrode 41 and the second electrode 42 can be cylindrical. The first electrode 41, the second electrode 42, the third electrode 43, and the anode 5 described later can be provided to be coaxial.

The first electrode 41 is provided closest to the input unit 3. The second electrode 42 is provided between the first electrode 41 and the third electrode 43.
The second electrode 42 focuses the electron beam emitted from the input unit 3.
The second electrode 42 controls the focal position of the electron beam emitted from the input unit 3. The second electrode 42 can be an electrode for focusing.
In the case of the image tube 1 illustrated in FIG. 1, although one first electrode 41 and one second electrode 42 are provided, the first electrode 41 and the second electrode 42 are provided. The number can be changed as appropriate.
Although not shown, the first electrode 41 and the second electrode 42 are fixed to the inner wall of the envelope 2 via an insulating member.

The third electrode 43 is provided closest to the output unit 6. The third electrode 43 controls an irradiation area at the output unit 6 of the electron beam emitted from the input unit 3. The third electrode 43 can be an electrode for changing the field of view.
The third electrode 43 has a support portion 43a, a first annular electrode 43b, a second annular electrode 43c, and a fixing portion 43d.

The support portion 43a can have a tubular shape.
The first annular electrode 43 b has a plate shape. The planar shape of the first annular electrode 43 b can be, for example, an annular shape. The outer peripheral edge of the first annular electrode 43 b is provided at the end of the support 43 a on the input unit 3 side.
The second annular electrode 43 c is provided between the first annular electrode 43 b and the output unit 6.
The second annular electrode 43c has a plate shape. The planar shape of the second annular electrode 43c can be, for example, an annular shape. The outer peripheral edge of the second annular electrode 43c is provided at the end of the support 43a on the output unit 6 side. Further, a plurality of holes 43c1 penetrating in the thickness direction is provided in a region where the steam guide portion 8 of the second annular electrode 43c is provided. The number of holes 43c1 is not particularly limited, as long as two or more holes 43c1 are provided.
The fixing portion 43d can have a tubular shape. The end of the fixing portion 43d on the input portion 3 side is provided on the inner peripheral edge of the second annular electrode 43c. The vicinity of the end portion on the output portion 6 side of the fixed portion 43 d is fused to the inner cylindrical portion 71 of the insulating portion 7.

  The anode 5 is provided inside the envelope 2 and between the third electrode 43 and the output unit 6. The anode 5 accelerates the electron beam focused by the second electrode 42 and the third electrode 43. The anode 5 has a funnel shape, and the opening on the output unit 6 side is larger than the opening on the input unit 3 side. The anode 5 is provided at the output section 6 and surrounds the fluorescent film 63. The anode 5 can be formed of, for example, a metal. The anode 5 can be electrically connected to the fixing plate 62.

The output unit 6 is provided to close the end of the insulating unit 7 on the side opposite to the envelope 2 side. The output unit 6 converts the electron beam accelerated by the anode 5 into fluorescent light (visible light), and emits it to the outside of the image tube 1 as a visible light image.
The output unit 6 includes a face plate 61, a fixing plate 62, a fluorescent film 63, and a metal back film 64.
The face plate 61 has a plate shape and is formed of a light transmitting material such as glass.
The fixing plate 62 has an annular shape, and the vicinity of the inner peripheral edge is fused to the side of the face plate 61. The outer peripheral edge side of the fixing plate 62 has a bent shape, and the vicinity of the end is fused to the inner cylindrical portion 71 of the insulating portion 7. The fixing plate 62 can be made of, for example, metal.

  The fluorescent film 63 is provided on the surface of the face plate 61 on the incident window 21 side. The fluorescent film 63 converts the electron beam incident through the metal back film 64 into fluorescent light (visible light) and emits it as a visible light image. The fluorescent film 63 can include, for example, a green phosphor made of aluminum, ZnS: Al, Cu containing copper as an activating material, or the like.

  The metal back film 64 covers the fluorescent film 63. The metal back film 64 emits excess electrons remaining in the fluorescent film 63 through the fixing plate 62. That is, the metal back film 64 prevents the charging of the fluorescent film 63. The metal back film 64 can be formed of, for example, aluminum or an aluminum alloy. The thickness of the metal back film 64 can be, for example, about 200 nm to 350 nm.

The insulating portion 7 has an insulating property. The insulating portion 7 can be formed of, for example, glass or the like. The insulating unit 7 is provided between the envelope 2 and the output unit 6.
The insulating portion 7 has an inner cylindrical portion 71, an outer cylindrical portion 72, a support portion 73, and an introduction portion 74.
The inner cylindrical portion 71 has a tubular shape.
The outer cylindrical portion 72 has a tubular shape.
The support portion 73 has a plate shape, and has a hole penetrating in the thickness direction at the center. The inner peripheral end of the support portion 73 is connected to the outer side surface of the inner cylindrical portion 71. The outer peripheral end of the support portion 73 is connected to the inner side surface of the outer cylindrical portion 72.
The introduction portion 74 protrudes outward from the surface of the support portion 73 on the output portion 6 side. The introduction portion 74 has a tubular shape. One end of the introduction portion 74 is connected to a hole provided in the support portion 73. The other end of the introducer 74 is closed.

As shown in FIGS. 1 to 3, the steam guiding portion 8 has a connecting portion 81, an introducing pipe 82, and a flange 83.
The connection portion 81 has a box shape, and an end portion on the second annular electrode 43 c side is open. The connection portion 81 is provided on the surface of the second annular electrode 43c on the output portion 6 side, and covers the plurality of holes 43c1 provided in the second annular electrode 43c. The connection portion 81 extends along the outer peripheral edge of the second annular electrode 43c. The planar shape of the connection portion 81 may be an annular shape, or may be a part of an annular ring as shown in FIG. The planar shape of the connection portion 81 can be appropriately changed according to the positional relationship between the introduction pipe 82 and the plurality of holes 43c1.
Further, although the case where the end on the second annular electrode 43c side is opened is illustrated, the end on the second annular electrode 43c side is closed, and a hole is provided at a position corresponding to the plurality of holes 43c1. You can also do so.
That is, the connection portion 81 may be connected to the tubular introduction pipe 82 and has a space for connecting the hole 82 a of the introduction pipe 82 and the plurality of holes 43 c 1 inside.

The introduction tube 82 has a tubular shape, and protrudes from the surface of the connection portion 81 opposite to the second annular electrode 43 c side. One end of the introduction pipe 82 is connected to a hole which penetrates the surface of the connection portion 81 on the opposite side to the second annular electrode 43 c side in the thickness direction. That is, the hole 82 a of the introduction pipe 82 is connected to the internal space of the connection portion 81.
The flange 83 has an annular shape and is provided at the other end of the introduction pipe 82. As shown in FIG. 1, the flange 83 is provided in parallel to the support portion 73. A gap can be provided between the flange 83 and the support portion 73. When the insulating portion 7 (support portion 73) is formed of glass, the surface accuracy and the dimensional accuracy become worse as compared with a general machined product. Therefore, in order to prevent the end of the introduction pipe 82 from coming into contact with the support portion 73, a gap is provided between the end of the introduction pipe 82 and the support portion 73. However, if a gap is provided, the amount of alkali metal vapor leakage may increase. In the present embodiment, since the flange 83 is provided at the end of the introduction pipe 82, leakage of alkali metal vapor can be suppressed.
In this case, assuming that the gap is S and the width of the flange 83 is W, it is preferable to set “W ≧ 3S”. In this way, the leak of the alkali metal vapor can be effectively suppressed.

FIGS. 4A to 4C are schematic views for illustrating the positional relationship between the hole 82 a of the introduction pipe 82 and the plurality of holes 43 c 1.
In addition, in FIG. 4 (a)-(c), the case where two holes 43c1 are provided is illustrated as an example.
The plurality of holes 43c1 can be provided at arbitrary positions in a plan view (as viewed from the central axis direction of the image tube 1). However, the plurality of holes 43c1 are provided at positions not overlapping the holes 82a of the introduction pipe 82. If the plurality of holes 43c1 do not overlap the holes 82a of the introduction pipe 82, it becomes easy to equalize the amount of alkali metal vapor released from each of the plurality of holes 43c1. As a result, it becomes easy to obtain a sufficient diffusion effect, so it becomes easy to make the distribution of the amount of alkali metal in the photoelectric conversion film 33 uniform.

  In the examples illustrated in FIGS. 4A to 4C, the same number of holes 43c1 are provided on both sides of the hole 82a, but the number of holes 43c1 provided on one side is large or one side The hole 43c1 may be provided only in the

  However, as shown in FIGS. 4A and 4B, it is preferable to provide a plurality of holes 43c1 so that the distances from the holes 82a are equal. In this case, when forming the photoelectric conversion film 33, it becomes easy to equalize the amount of alkali metal vapor released from each of the two holes 43c1.

  Further, as shown in FIGS. 4A and 4C, it is preferable to provide two holes 43c1 facing each other with the center 43c2 of the second annular electrode 43c interposed therebetween. In this way, when forming the photoelectric conversion film 33, alkali metal vapor can be released from a distant position, so diffusion of alkali metal vapor inside the envelope 2 and hence photoelectric conversion film It becomes easy to make the distribution of the amount of alkali metal at 33 uniform.

Further, the size and shape of the plurality of holes 43c1 may be the same or different.
The number, arrangement, size, shape, and the like of the plurality of holes 43c1 can be appropriately determined based on the diffusivity of the alkali metal vapor described later.
The number, arrangement, and the like of the plurality of holes 43c1 can be appropriately determined by performing experiments and simulations.
In addition, the detail regarding discharge | release of the vapor | steam of the alkali metal at the time of forming the photoelectric conversion film 33 etc. is mentioned later.

(Method of manufacturing image tube)
Next, a method of manufacturing the image tube 1 will be described.
In addition to the formation method of the photoelectric conversion film 33, known techniques can be applied. Therefore, the method for forming the photoelectric conversion film 33 will be described below.
The photoelectric conversion film 33 is destroyed when exposed to the atmosphere. Therefore, the photoelectric conversion film 33 is formed inside the envelope 2 in a vacuum atmosphere. The photoelectric conversion film 33 is generally formed using Sb and Cs which is an alkali metal. Since Sb can maintain a stable metal state in the atmosphere, the Sb source can be incorporated into the inside of the envelope 2 together with the electrode 4 when the electrode 4 is assembled into the inside of the envelope 2. However, alkali metals such as Cs react violently and oxidize when exposed to the atmosphere. Therefore, in formation of the photoelectric conversion film 33, using hexavalent chromium like cesium chromate which can maintain the stable state in air | atmosphere as a material is also considered. For example, in order to form the photoelectric conversion film 33, cesium chromate or the like can be incorporated into the inside of the envelope 2. However, in this case, cesium chromate, which is hexavalent chromium, remains in the inside of the envelope 2. Hexavalent chromium is a substance whose use is restricted because it places a large burden on the human body and the environment.
Therefore, in the method for forming the photoelectric conversion film 33 according to the present embodiment, alkali metal vapor is introduced into the inside of the envelope 2 to react Sb with the alkali metal vapor. In this way, hexavalent chromium does not remain inside the envelope 2.

  Here, the alkali metal vapor introduced into the interior of the envelope 2 diffuses in the vacuum atmosphere as a molecular flow. Therefore, most of the introduced alkali metal vapor adheres to the inner wall of the envelope 2 and the electrode 4 without impinging on other gas molecules inside the envelope 2. Thereafter, the deposited alkali metal vapor separates from the inner wall of the envelope 2 and adheres to the inner wall of the envelope 2 again. Thus, the alkali metal vapor diffuses inside the envelope 2 by repeating adhesion and detachment to the inner wall of the envelope 2 and the electrode 4. Therefore, the distribution of alkali metal vapor reaching the input section 3 (photoelectric conversion film 33) is affected by the shape and arrangement of the electrodes 4, the shape of the inner wall of the envelope 2, the introduction position of the alkali metal vapor, and the like. .

  Here, if there is unevenness in the distribution of the amount of alkali metal vapor reaching the input portion 3, there is a possibility that the photoelectric conversion characteristics may partially change. In addition, if a stain occurs on the photoelectric conversion film 33, the product becomes a defective product. In this case, when the introduction port for introducing the alkali metal vapor is directly visible when viewed from the input unit 3 side, the alkali metal vapor excessively reaches immediately above the introduction port or in the vicinity thereof. As a result, the distribution of the amount of alkali metal vapor tends to be uneven. Therefore, the photoelectric conversion characteristics are partially changed, and stains are easily generated in the photoelectric conversion film 33.

In this case, an introduction port may be provided at a position where alkali metal vapor adheres to the electrode 4 and the like once, and alkali metal vapor may repeat adhesion and detachment to diffuse the inside of the envelope 2. However, the shape and the arrangement of the electrodes 4 are determined by the requirements such as the function as an electron lens and the structural strength. There is also a restriction on the position where the introduction port can be provided. Therefore, it is difficult to make the positional relationship between the electrode 4 and the inlet and the shape of the electrode 4 optimal for the diffusion of the alkali metal vapor.
For example, when the introduction port is provided at a position where the alkali metal vapor is introduced into the gap between the inner wall of the envelope 2 and the second electrode 42, the alkali metal vapor is once attached to the second electrode 42. The second electrode 42 separates from the second electrode 42 and adheres to the inner wall of the envelope 2, and thereafter, reaches the input unit 3 while repeating detachment and adhesion. In this way, the alkali metal vapor introduced from the inlet does not reach the input section 3 directly. However, the alkali metal vapor will reach the input 3 with insufficient diffusion. Therefore, the amount of alkali metal vapor reaching the specific region increases, and the photoelectric conversion characteristics of the region become different from those of the surroundings.

  Further, the alkali metal vapor is introduced into the internal space of the third electrode 43 (the annular space defined by the support portion 43a, the first annular electrode 43b, and the second annular electrode 43c), and the envelope 2 is formed. The alkali metal vapor can also reach the input unit 3 through the space on the central axis side of the. In this way, the alkali metal vapor diffuses in the space on the central axis side of the envelope 2. However, simply introducing alkali metal vapor into the inner space of the third electrode 43 may not provide a sufficient diffusion effect.

Therefore, a steam guiding unit 8 is provided in the image tube 1 according to the present embodiment.
FIG. 5 is a schematic cross-sectional view for illustrating the method of forming the photoelectric conversion film 33. As shown in FIG.
FIG. 6 is a schematic perspective view for illustrating the operation of the steam guiding unit 8.
As shown in FIG. 5, when the photoelectric conversion film 33 is formed, the end of the introduction portion 74 on the opposite side to the support portion 73 side is not closed, and the steam generator 100 is connected. The steam generator 100 generates an alkali metal vapor and supplies the generated alkali metal vapor to the vapor guide 8 via the introduction unit 74. In addition, when formation of the photoelectric conversion film 33 is complete | finished, the edge part of the introducing | transducing part 74 is sealed. For example, the end of the introduction portion 74 can be heated and melted, and the hole of the introduction portion 74 can be sealed with the melted material.

  As shown in FIG. 6, the alkali metal vapor introduced into the inside of the connection portion 81 through the hole 82a of the introduction pipe 82 diffuses inside the connection portion 81, and the two electrodes 43c1 to the third electrode 43 Introduced into the interior space of That is, since alkali metal vapor can be introduced into the internal space of the third electrode 43 from a distant position, alkali metal vapor is introduced into the interior of the envelope 2 from the remote position of the third electrode 43 can do. As a result, a sufficient diffusion effect can be obtained, so that the distribution of the amount of alkali metal in the photoelectric conversion film 33 can be made uniform.

Further, if the position of the hole 43c1 is changed, the position at which the alkali metal vapor is introduced into the internal space of the third electrode 43, and further, the position at which the alkali metal vapor is introduced to the inside of the envelope 2 is changed. be able to.
Although the case where the two holes 43c1 are provided is illustrated, as described above, the number, the arrangement, the size, the shape, and the like of the holes 43c1 can be appropriately changed in consideration of the diffusion of steam.

The two holes 43c1 are provided at positions not overlapping the holes 82a of the introduction pipe 82. If the two holes 43c1 do not overlap the holes 82a of the introduction pipe 82, it will be easy to equalize the amount of alkali metal vapor released from each of the two holes 43c1. As a result, it becomes easy to obtain a sufficient diffusion effect, so it becomes easy to make the distribution of the amount of alkali metal in the photoelectric conversion film 33 uniform.
As described above, in the method of manufacturing an image tube according to the present embodiment, alkali metal vapor is introduced from the alkali metal generator 100 into the space inside the connection portion 81 via the introduction tube 82, Alkali metal vapor is released from the plurality of holes 43c1 of the two annular electrodes 43c.

  While certain embodiments of the present invention have been illustrated, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in other various forms, and various omissions, replacements, changes, and the like can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof. In addition, the embodiments described above can be implemented in combination with each other.

  Reference Signs List 1 image tube, 2 envelope, 3 input unit, 4 electrode, 5 anode, 6 output unit, 7 insulation unit, 8 vapor guide unit, 31 incidence substrate, 32 fluorescent film, 33 photoelectric conversion film, 41 first electrode , 42 second electrode, 43 third electrode, 43a support portion, 43b first annular electrode, 43c second annular electrode, 43c1 hole, 43d fixing portion, 81 connection portion, 82 inlet tube, 82a hole, 83 Flange, 100 steam generator

Claims (5)

An envelope,
An input unit provided on one end side of the envelope and having a fluorescent film for converting incident radiation into fluorescence, and a photoelectric conversion film for converting the fluorescence into an electron beam;
An output section provided at the other end of the envelope for converting the electron beam into fluorescence;
A first annular electrode provided between the input unit and the output unit;
A second annular electrode provided between the first annular electrode and the output section and having a plurality of holes penetrating in the thickness direction;
A connecting portion provided on a surface of the second annular electrode on the output portion side, connected to a cylindrical introducing pipe, and having therein a space connecting a hole of the introducing pipe and the plurality of holes;
Image tube with.   The image tube according to claim 1, wherein the plurality of holes and the holes of the introduction tube do not overlap in a plan view.   The image tube according to claim 1 or 2, wherein an annular flange is provided at an end of the introduction tube opposite to the connection portion side. It further comprises a cylindrical support,
An outer peripheral edge of the first annular electrode is provided at one end of the support portion,
The image tube according to any one of claims 1 to 3, wherein an outer peripheral edge of the second annular electrode is provided at the other end of the support. A method of manufacturing an image tube according to any one of claims 1-4,
A method of manufacturing an image tube, wherein alkali metal vapor is introduced from an alkali metal generator into a space inside the connection portion through an introduction pipe, and the alkali metal vapor is released from the plurality of holes of the second annular electrode.

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