JP4122787B2 - Electronic image converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic image conversion apparatus that converts a display on a fluorescent screen into electrical information using a solid-state imaging device, and more particularly to an electronic image conversion apparatus that can suitably measure an electrical waveform even during high-intensity observation. .
[0002]
[Prior art]
Conventionally, in order to measure an electrical waveform, an electronic image conversion device that converts a display on a phosphor screen into an electrical signal by a solid-state imaging device has been developed. For example, Japanese Patent Laid-Open No. 2-156162 describes a specific example thereof. An electronic image conversion device is disclosed. The configuration of this electronic image conversion apparatus will be described with reference to FIG.
[0003]
The electronic image conversion apparatus includes an electron gun unit 2 that generates an electron beam B and a deflecting unit 3 in a housing 1 that is kept in a vacuum inside. A B light receiving conversion unit 4 is provided. In the electron gun section 2, a cathode 5, a control grid 6, an acceleration electrode 7, a focusing electrode 8 and an astig electrode 9 are arranged so as to coincide with the electron beam axis, and the deflection section 3 has a vertical deflection plate 10 and a horizontal plate. A deflection plate 11 is disposed.
[0004]
Further, in the light receiving conversion unit 4 provided at the rear end of the housing 1, a downstream acceleration electrode 12 is provided downstream of the electron beam B, and a fluorescent screen 13 is provided on the back side of the electrode. On the opposite side of the phosphor screen 13 as viewed from the electron gun section 2, an optical fiber plate 15 having a transparent conductive film 17 in close contact with the output end face is attached to the glass plate section 14 formed at the end of the housing 1. It is supported through a frit (powder glass) 16.
[0005]
Then, the solid-state imaging device 18 is disposed in close proximity to or in close contact with the transparent conductive film 17 formed in close contact with the output end face of the optical fiber plate 15 via a transparent resin 19. Further, the transparent conductive film 17 is grounded through a conductive wire. Reference numeral 20 in the figure indicates a package of the solid-state imaging device 18.
[0006]
[Problems to be solved by the invention]
In this electronic image conversion apparatus, the electron beam B emitted from the electron gun unit 2 is deflected by the deflecting unit 3 and accelerated by a high voltage applied to the post-projection acceleration electrode 12. The electron beam B is projected onto the fluorescent screen 13 to generate fluorescence and display an electrical signal. This display information is transmitted to the solid-state imaging device 18 through the optical fiber plate 15 with a small optical transmission loss, where it is converted into an electrical signal, and further, the converted electrical signal is recorded.
[0007]
However, in recent years, a solid-state imaging device having a microlens on the imaging surface may be used. When an electric signal waveform is observed with high luminance by using such an electronic image conversion apparatus, the observed signal waveform periphery becomes bright, and the observed original signal waveform may become unclear. This has been a major obstacle to measurement at high brightness. The phenomenon that the original signal waveform is obscured as seen during the measurement of high luminance is considered to occur due to the following reasons.
[0008]
Therefore, FIG. 5 shows a specific example of a solid-state imaging device provided with a microlens on the imaging surface used in recent years. FIG. 5 shows a partially enlarged view of the output portion of the optical fiber plate 15 in the conventional electronic image conversion apparatus. Portions common to those shown in FIG. 4 are given the same reference numerals, and descriptions thereof are omitted.
[0009]
When an electrical signal is to be observed with high brightness using a conventional electronic image conversion device, the amount of the electron beam B is increased, and the phosphor screen 13 emits light with high brightness. The light emitted from the fluorescent screen 13 enters the optical fiber plate 15 and enters the microlens 21 of the solid-state imaging device 18 according to the optical paths L _{1 to} L ₃ . A plurality of light receiving elements 23 are arranged as solid-state imaging elements 18 at positions corresponding to the plurality of lens portions of the microlens 21. Further, a metal light shielding plate 22 having openings at the positions of the plurality of light receiving elements 23 is disposed on the back surface of the microlens 21.
[0010]
Since the light in the optical path L ₂ is incident on the top of the microlens 21, the light travels straight and reaches the light receiving element 23. On the other hand, the light in the optical path L ₁ does not go to the light receiving element 23 but reaches the metal light shielding portion 22. Originally, the light in the optical path L ₁ should be refracted by the microlens 21 and reach the light receiving element 23 according to the optical path L ₁₁ , similarly to the optical path L ₂ .
[0011]
This is due to the following reason. In the conventional electronic image conversion apparatus, a transparent resin 19 having a refractive index greater than 1 is provided between the microlens 21 of the solid-state imaging device 18 and the optical fiber plate 15 in which the transparent conductive film 17 is formed in close contact with the output end face. Is provided. The refractive index n of the transparent resin 19 is generally 1.4 to 1.6. On the other hand, the microlenses 21 of the solid-state imaging device 18 also, for example, often are made of a resin such as a resist, a refractive index n ₀ is known to be 1.4 to 1.6.
[0012]
Thus, between the transparent resin film 19 and the microlens 21, since not take a large refractive index difference, for example, light incident along the optical path L ₁ is most refracted by the microlens 21 of the solid-state imaging device 18 without being, if originally place to go along the optical path L _11, resulting in straight along the optical path L _12. For this reason, the light in the optical path L ₁ does not reach the light receiving element 23 but reaches the metal light shielding portion 22.
[0013]
Generally, the metal material of the metal light-shielding part 22 is aluminum. Therefore, most of the light reaching the metal light-shielding portion 22 is diffusely reflected without being absorbed. The irregularly reflected light L _D is returned to the phosphor screen 13 side through the fiber optic plate 15. However, post acceleration electrode 12, since it is generally formed of an aluminum film, in turn, irregularly reflected light L _D is diffusely reflected again by the post-acceleration electrode 12.
[0014]
Its re irregularly reflected light L _R is returned to the solid-state imaging device 18 side in the same optical path as light traveling along the optical path L ₁ to L _3, and reaches the light receiving element 23 and the metal light-shielding portion 22,. This means that this multiple irregular reflection is repeated until the irregular reflection light _LR is attenuated. Therefore, the light generated on the fluorescent screen 13 corresponding to the observed electrical signal is diffused to the light receiving element 23 located in the periphery.
[0015]
Therefore, when the electrical signal waveform is observed with high luminance by a conventional electronic image conversion device having a solid-state image sensor having a microlens on the imaging surface, the multiple diffuse reflection phenomenon described above occurs. As a result, the periphery of the observed signal waveform became bright, and the observed original signal waveform was unclear.
[0016]
Therefore, an object of the present invention is to suppress the multiple diffuse reflection of incident light and prevent the peripheral portion of the observed signal waveform from becoming bright even when the electrical signal is observed at a high luminance. It is an object of the present invention to provide an electronic image conversion apparatus that can clearly observe only the image.
[0017]
[Means for Solving the Problems]
In order to achieve this object, in the electronic image conversion apparatus of the present invention , a means for generating an electron beam, a phosphor screen that emits light when the electron beam is projected, and an entire light emitting side of the phosphor screen are in close contact with each other. A transparent conductive film, an optical fiber plate that is in close contact with the transparent conductive film , the light enters , and a solid-state imaging device that is disposed on the output end face side of the optical fiber plate and has a microlens , A high voltage was applied to the transparent conductive film.
[0018]
The solid-state imaging element includes a plurality of light receiving elements, and a metal light shielding portion having an opening for the light receiving elements is disposed.
[0019]
Further, the microlens is integrally formed with a plurality of lenses corresponding to the light receiving element, and seals gas in a gap formed between the output end face of the optical fiber plate and the microlens, The gas was dry air or dry inert gas.
[0020]
A light-shielding film that absorbs the light is formed between the lenses arranged corresponding to the light-receiving elements.
[0021]
Further, the solid-state imaging device has a plurality of light-receiving elements, a metal light-shielding portion having an opening for the light-receiving elements is arranged, and a package for housing the solid-state imaging device is the optical fiber plate The solid-state imaging device is arranged to be opposed to the output end face of the optical fiber plate.
[0022]
A transparent conductive film is formed in close contact with the output end face of the optical fiber plate, and the transparent conductive film is grounded.
[0023]
[Action]
In the present invention, the configuration in which the solid-state imaging device having the microlens on the imaging surface is in close contact with the optical fiber plate without using the transparent resin enables the lens action of the microlens to be effective. The transparent conductive film formed on the input end face of the optical fiber plate has a function as a post-acceleration electrode that gives a potential sufficient for the phosphor screen to emit light sufficiently, and has a function to prevent irregular reflection. It has a function of preventing re-diffuse reflection of irregularly reflected light, and it is possible to clearly observe only the original signal waveform even in electrical signal measurement at high luminance.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an electronic image conversion apparatus according to the present invention will be described below in detail with reference to the drawings.
[0025]
FIG. 1 shows a configuration relating to an example of an electronic image conversion apparatus of the present embodiment.
[0026]
In this embodiment, the electron beam B radiated from the electron gun unit 2 is deflected by the deflecting unit 3, and high speed is applied to the electrons by the high voltage applied to the transparent conductive film 24 formed on the optical fiber plate input end face. It projects on the phosphor screen 13 and displays an electrical signal. This display information is transmitted to a solid-state image sensor 18 having a microlens on the imaging surface using an optical fiber plate 15 with a small optical transmission loss, and is converted into a recording or an electrical signal. The solid-state image sensor 18 having a microlens on the imaging surface is held in close contact with the fiber plate 15 having the transparent conductive film 17 formed on the output end surface. The solid-state image sensor 18 is housed in a solid-state image sensor package 20, and this close contact state is maintained by bonding the solid-state image sensor package 20 and the side wall of the fiber plate 15 via a support plate 25. Yes.
[0027]
The transparent conductive film 24 formed on the input end face of the optical fiber plate and the transparent conductive film 17 formed on the output end face are formed by, for example, a sputtering method having a thickness of about 1 [μm] and a sheet resistance of about 100 [Ω / sq.]. The transparent conductive film 17 formed of the formed ITO film and formed on the output end face is grounded via a conductive line. The solid-state imaging device package 20 and the side wall of the fiber plate 15 are bonded to each other through the support plate 25 by using an epoxy adhesive and cured in an atmosphere of dry air.
[0028]
As described above, by adopting the configuration according to the present embodiment, when an electrical signal is observed with high luminance, it is possible to prevent the peripheral portion of the observed signal waveform from becoming bright, and only the original signal waveform can be clearly observed. The reason is as follows.
[0029]
FIG. 2 is a partially enlarged view of the light receiving conversion unit 4 in the electronic image conversion apparatus of the present embodiment. Portions common to FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
[0030]
When an electronic signal is to be observed with high brightness using the electronic image conversion apparatus of the present embodiment, the amount of the electron beam B is increased to cause the phosphor screen 13 to emit light with high brightness. The light emitted from the fluorescent screen 13 passes through the transparent conductive film 24 on the incident side, enters the optical fiber plate 15, and follows the optical path of any one of the optical paths L _{1 to} L _4. Is incident on. When the light takes the optical path L ₃ , the light is incident on the head portion of the microlens 21, so that the light travels straight and reaches the light receiving element 23. Also in the case of entering along the optical path L ₄ , as in the case of the optical path L ₃ , the light reaches the light receiving element 23 and does not reach the metal light shielding part 22.
[0031]
This is due to the following reason. In the present embodiment, there is a gap 26 between the microlens 21 of the solid-state image sensor 18 and the optical fiber plate 15 in which the transparent conductive film 17 is formed in close contact with the output end face. Sealed. The refractive index n ₁ of this dry air is 1.0. Accordingly, since the refractive index n ₀ of the microlens 21 of the solid-state image sensor is 1.4 to 1.6, the light in the optical path L ₄ is refracted by the microlens 21 of the solid-state image sensor, and the optical path L ₃ and Similarly, it can reach the light receiving element 23, and irregular reflection by the metal light shielding part 22 can be significantly suppressed.
[0032]
Furthermore, in the present embodiment, since the transparent conductive film 24 formed on the input end face of the optical fiber plate 15 is used as a post-acceleration electrode that provides a potential sufficient to allow the phosphor screen 13 to emit light sufficiently, It does not have a high reflectivity like an aluminum film. Therefore, among the optical paths L _{1 to} L ₄ , for example, the light incident on the optical path L ₁ is incident on the lens function invalid portion of the microlens 21 of the solid-state imaging device 18, but the light is the metal light shielding unit 22. Is irregularly reflected.
[0033]
However, the irregularly reflected light returns to the fluorescent screen 13 side through the optical fiber plate 15, but is irregularly reflected again because the transparent conductive film 24 does not have a high reflectance like the conventional aluminum film. Therefore, re-diffuse reflection can be greatly suppressed.
[0034]
On the other hand, the light generated by the phosphor screen 13, for example, in the case where it is incident on the optical path L ₂ is a lens action due to the large difference in refractive index between the microlens 21 and the gap 26 of the solid-state imaging device 18, The light incident on the optical path L ₂ is refracted, travels along the optical path L ₂₁ , and reaches the light receiving element 23. Therefore, the signal waveform can be clarified even during high-intensity observation with the amount of electron beam B increased.
[0035]
Therefore, even when an electrical signal is observed at high luminance, multiple diffuse reflection is suppressed, and only light corresponding to the originally observed electrical signal is applied to the light-receiving element of the solid-state imaging device having a microlens on the imaging surface. Therefore, it is possible to prevent the periphery of the observed signal waveform from becoming bright due to multiple diffuse reflections, and to clearly observe only the original signal waveform.
[0036]
Next, an electronic image conversion apparatus according to a second embodiment of the present invention will be described.
[0037]
FIG. 3 is a partially enlarged view of the light receiving conversion unit 3 of the electronic image conversion apparatus according to the second embodiment, as in the case shown in FIG. Portions common to those in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted.
[0038]
The second embodiment is different from the first embodiment in that a light-shielding film 27 made of a light-shielding substance is formed in a recess between the lens portion of the microlens 21 of the solid-state imaging device 18. . For the light shielding film 27, a toner generally used in a wet plate making machine or the like is used as a light shielding material. For example, it is formed by a spin coating method under conditions of 3000 [rpm] and 30 [s].
[0039]
According to this spin coating method, the light shielding film 27 can be formed on the surface of the microlens 21 in a portion other than the lens portion. The light shielding film 27 is obtained by drying and fixing the coating film at 50 [° C.] and 1 [h]. The process of forming the light shielding film 27 is performed before the solid-state imaging device package 20 and the side wall of the fiber plate 15 are bonded via the support plate 25 of FIG.
[0040]
According to the second embodiment, when an electrical signal is observed with high brightness, it is possible to further prevent the peripheral portion of the observed signal waveform from becoming brighter than in the first embodiment, and to further reduce only the original signal waveform. It is observable with clarity.
[0041]
In the first embodiment, among the optical paths L _{1 to} L ₄ , for example, light incident on the lens action invalid portion of the microlens 21 of the solid-state imaging device 18 along the optical path L ₁ is transmitted by the metal light shielding unit 22. Although it was irregularly reflected and returned to the fluorescent screen 13 side through the optical fiber plate 15, in the second embodiment, since the light shielding film 27 is formed on the concave surface between the lens portions of the microlens 21, the optical path L _The light incident on the lens action invalid portion of the microlens 21 of the solid-state imaging device along ₁ is absorbed by the light shielding film 27. Therefore, the light incident along the optical path L ₁ does not reach the metal light shielding unit 22. In addition, the light is not irregularly reflected by the metal light shielding portion 22.
[0042]
On the other hand, when the light generated on the fluorescent screen 13 is incident along the optical paths L _{2 to} L ₄ , the lens portion of the microlens 21 is not covered with the light-shielding film 27, so that the lens portion is Since it has a lens action, it is incident on the light receiving element 23.
[0043]
Therefore, even when an electrical signal is observed at a high luminance, multiple diffuse reflection is further suppressed, and the light receiving portion of the solid-state imaging device having a microlens on the imaging surface corresponds to the originally observed electrical signal. Only the light is allowed to reach and the peripheral portion of the observed signal waveform due to multiple diffuse reflection is prevented from becoming bright, and only the original signal waveform can be observed more clearly.
[0044]
The transparent conductive film used in the first and second embodiments are not limited to the ITO film, generally well known, Sn0 ₂ film, Au film, obtained similar effects with Ti0 ₂ film or the like It is done.
[0045]
Further, the bonding using the epoxy adhesive or the like between the solid-state imaging device package 20 and the side wall of the optical fiber plate 15 via the support plate 25 is not limited only to curing in an atmosphere of dry air. Any material can be used as long as the refractive index in the gap 26 is maintained at about 1.0. For example, the material may be cured in an atmosphere of an inert gas such as dry N ₂ .
[0046]
In the second embodiment described so far, an example is shown in which a gap is provided between the optical fiber plate and the microlens of the solid-state imaging device, and a gas such as dry air is sealed in the gap. When the transparent resin is sealed in this gap, even if the light shielding film according to the second embodiment is applied, it is possible to prevent the observed peripheral portion of the signal waveform from becoming bright due to multiple irregular reflections.
[0047]
【The invention's effect】
As described above, the configuration in which the optical fiber plate and the solid-state imaging device having the microlens on the imaging surface are brought into close contact with each other without using a transparent resin enables the lens action of the microlens to be effective, and the light shielding of the solid-state imaging device In addition, the structure in which the light-shielding film is formed on the concave surface between the microlenses prevents light from being incident on the metal light-shielding part of the solid-state imaging device, and the optical fiber. -The transparent conductive film formed on the input end face of the plate functions as an electrode that provides a potential sufficient for the phosphor screen to emit light sufficiently, and has the function of preventing re-diffuse reflection of irregularly reflected light from the metal light-shielding part. Even in electrical signal measurement at high brightness, only the original signal waveform can be clarified and observed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an electronic image conversion apparatus according to the present invention.
FIG. 2 is a partially enlarged configuration diagram of the electronic image conversion apparatus according to the first embodiment of the present invention.
FIG. 3 is a partially enlarged configuration diagram of an electronic image conversion apparatus according to a second embodiment of the present invention.
FIG. 4 is a configuration diagram of a conventional electronic image conversion apparatus.
FIG. 5 is a partially enlarged configuration diagram of a conventional electronic image conversion apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Electron gun part 3 ... Deflection part 4 ... Light reception conversion part 5 ... Cathode 6 ... Control grid 7 ... Acceleration electrode 8 ... Convergence electrode 9 ... Astig electrode 10 ... Vertical deflection plate 11 ... Horizontal deflection plate 12 ... Later stage Accelerating electrode 13 ... Fluorescent screen 14 ... Glass plate part 15 ... Optical fiber plate 16 ... Frit 17 and 24 ... Transparent conductive film 18 ... Solid-state image sensor 19 ... Transparent resin 20 ... Solid-state image sensor package 21 ... Micro lens 22 ... Metal light shielding part 23 ... light receiving element 25 ... support plate 26 ... gap 27 ... light shielding material

Claims (8)

Means for generating an electron beam;
A phosphor screen from which the electron beam is projected to emit light;
A transparent conductive film adhered to the entire light emitting side of the phosphor screen;
An optical fiber plate that is in close contact with the transparent conductive film and on which the light is incident;
A solid-state imaging device disposed on the output end face side of the optical fiber plate and having a microlens ,
An electronic image conversion apparatus, wherein a high voltage is applied to the transparent conductive film.   The electronic image conversion apparatus according to claim 1, wherein the solid-state imaging element includes a plurality of light receiving elements, and a metal light-shielding portion having an opening for the light receiving elements is disposed. The microlenses, the light receiving elements a plurality of lenses corresponding to is integrally formed, and characterized by forming a gap between the output end face of said fiber optic plate and the microlens according to claim 1 or 2 The electronic image conversion apparatus described in 1.   The electronic image conversion apparatus according to claim 3, wherein dry air or dry inert gas is sealed in the gap.   5. The electronic image conversion apparatus according to claim 3, wherein a light shielding film is formed between the microlenses arranged corresponding to the light receiving elements.   The electronic image conversion apparatus according to claim 5, wherein the light shielding film is formed of a material that absorbs the light and blocks the light. The package for housing the solid-state imaging device is held on a side wall of the optical fiber plate via a support plate, and the solid-state imaging device is disposed opposite to an output end face of the optical fiber plate. The electronic image conversion apparatus as described in any one of thru | or 6 . The fiber optic plate transparent conductive film to the output end face of the adhesion formed, an electronic image conversion apparatus according to any one of claims 1 to 7, characterized in that grounded transparent conductive film.

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