JPS5826452Y2 - image intensifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image intensifier tube comprising an input window with a charging cathode, an electro-optical imaging electrode, and an output window.

An image intensifier tube of this kind is known from US Pat. No. 3,660,668.

However, in the image intensifier tube described therein, shocks or temperature fluctuations, for example, may cause the image intensifier tube to shift in position with respect to the optical system on the entrance side, which tends to prevent accurate image formation, and is also disposed at the input window or on the entrance side. There are drawbacks such as damage to the first surface of the optical system and the inability to firmly mount the image intensifier tube.

The object of the present invention is to provide an image intensifier tube capable of alleviating these deficiencies, comprising: an airtight container with an input window; a charging cathode; - a set of electro-optical imaging electrodes; In the image intensifier tube, an upright ring is provided, and the upright ring is attached to the airtight container so as to be adjacent to the input window, and the end face of the upright ring is positioned at a predetermined distance from the input surface of the input window. Position the abutment surface accurately on the
The input window and the upright ring are constructed of members having a coefficient of thermal expansion such that the relative displacement between the input window and the abutment surface of the upright ring is minimized when there is a temperature change, and image intensification is achieved. The device is characterized in that an elastic member is provided for elastically mounting the tube airtight container inside the outer container.

By mounting as in the present invention, a shock-resistant structure can be obtained in a simple manner, and distortion of the image intensifier tube due to temperature fluctuations can be considerably alleviated.

In a preferred embodiment of the invention, the upright ring is constructed by disposing a metal ring on top of a molten glass ring.

The axial dimension of the input window, the axial dimension of the upright ring that combines the glass nong and the metal ring, and the thermal expansion of both are mutually optimally selected.

In another preferred embodiment, an abutment surface is provided on the input window side of the outer container to which the image intensifier tube is resiliently mounted.

The invention will be explained with reference to the drawings.

The accompanying drawings illustrate the construction of an exemplary image intensifier tube of the present invention comprising an upright ring with an abutting surface.

As shown in the drawings, the image intensifier tube of the present invention includes an outer container 1;
It comprises an image intensifier tube 2 having an input window 3, preferably an optical fiber, an output window 4 and a cylindrical airtight container 5.

The input window 3 is provided with a charging cathode 7 on its inner wall 6, which is preferably concave.

A channel plate type multiplier 8 is provided near the output window 4, and its input surface is designated 9 and its output surface is designated 10.

A set of electro-optical imaging electrodes 11 and 12 is provided between the photocathode 7 and the channel plate multiplier 8, forming an image of the charging cathode 7 on the channel plate multiplier 8 and thus on the output window 4. do.

The electrical conductivity of commonly used charged cathodes is such that they qualify as electro-optical imaging electrodes.

In addition, if it cannot be recognized as an electrode, an electrode that is transparent to the radiation to be measured can be added.

A light emitting layer 13 is provided inside the output window 4.

In an image intensifier tube without a channel plate multiplier, the light emitting layer 13 replaces the input surface 9 of the channel plate multiplier.

The airtight container 5 is formed with an inwardly extending wall 14 on which an upright ring 15 is provided.

This upright ring is secured to the wall 14 by, for example, welding or sealing.
Can be installed on.

Viewed axially, the abutment surface 16 of the upright ring 15 is precisely ground.

In the illustrated example, the upright ring 15 is cut in two parts, 17 being a fused glass ring and 18 being a ring which is preferably metal.

In this case, the glass ring 17 also functions as an electrical insulator for the photocathode 7.

The metal ring 18 is similar to the jacket of the image intensifier tube, for example made of Fuernico and coated with a glass-metal bond or seal 1.
It is connected to the glass ring 17 by 9.

The input window 3 is also connected to the wall 14, but the side facing the outside of the image intensifier tube is the manpower surface 21.

This input surface 21 and the abutment surface 16 of the upright ring 15 may lie exactly in one plane, or this input surface 21 may be moved a precisely defined short distance from the abutment surface 16. shift.

In particular, by constructing the input window 3 and the upright ring 15 from materials with suitable axial dimensions and a suitable coefficient of thermal expansion, it is possible to maintain the position of the input surface 21 and the abutment surface 16 even under temperature fluctuations. Prevent the relative relationship with the position from changing.

By using the abutment surface 16 as a reference surface, the distance between the entrance surface of the input window and the entrance side optical system attached to the input window of an image intensifier tube, for example, can be maintained at a predetermined distance at all times during operation.

Rather than projecting the image to be intensified onto the input surface by the input optical system, as is the case when using a fiber optic window,
Even when projecting onto the charging cathode itself, as in the case of using an ordinary glass window, the position of the photocathode 7 can be fixed in the same way.

When attaching the image intensifier tube 2 to the outer container 1, it is preferable to interpose an elastic member 23 in the middle.

In an actual image intensifier tube, this elastic material is an electrically insulating rubber and fills the entire space, although it may also form a cavity for accommodating at least a portion of the power circuit (not shown).

For example, attachment of other parts such as the entrance side optical system can be carried out by a pressure bonding method.

In this case, the reference surface 16 functions as an abutment surface which is pressed against the element to be mounted by the elasticity of the rubber, so that the input surface 21 of the input window assumes the desired position.

The pressure can be generated, for example, by pressing on the end face 26 of the outer container 1.

Such a mounting legally prevents the input window 3 from being damaged and allows the input window 3 to be mounted at a very short distance or at a precisely defined long distance as desired.

Variations in the axial length of the input window 3 are absorbed by the upright ring 15 so that the input surface 21 of the input window 3 remains at a constant distance from the photocathode surface 7.

Although usually not so necessary, in some cases a similar mounting member as described above may be provided on the exit side of the image intensifier tube.

This is the case, for example, when an output image of an image intensifier tube is captured in a television image pickup tube.

The image intensifier tube of the present invention is particularly suitable for use in night vision instruments for detecting images with very low radiation levels.

By suitably choosing the charging cathode, in particular by adding a scintillation layer to it, the image intensifier tube can be adapted to different radiations.

Although the invention has been described as comprising a fiber optic input window 3 and a channel plate multiplier 8, one or the other is not necessarily an essential requirement of the invention, and the invention is not limited thereto. do not have.

The advantage of the fiber optic manual window is that it can be used with a flat input surface as a reference.

The reason is that by projecting the input image onto it, the support surface of the charging cathode is adapted to the optimal imaging conditions of the electro-optical imaging electrode, without taking into account the geometry of the image plane of the input optics. This is because it can be done.

When using a uniform input window, it is desirable to optimally match the output image plane of the entrance optical system to the photocathode plane, but this condition may be inconsistent in this case.

In the case of these input windows, it must first of all be ensured that the photocathode surface is fixed relative to the reference surface even in the case of temperature fluctuations.

The position of the abutting surface relative to the reference surface is determined at the same time by the structure of the part to be attached.

The effects of the present invention described above are as follows.

(1) The end face of the upright ring 15 is used as the abutting face 16, this face is accurately positioned with respect to the input face 21 of the input window 3, and the coefficients of thermal expansion of the upright ring 15 and the input window 3 are appropriately selected. Since the axial deviation between the two is minimized, the deviation between the image intensifier tube and other components attached to the upright ring 15, such as the optical system, is extremely small even under temperature fluctuations. .

(2) When attaching other members to the entrance surface side of the image intensifier tube, the upright ring 15
Since it is attached to the abutment surface 16 of the input window 3, the input window 3 can be protected from damage, and other members can also be protected from damage.

(3) When the incident surface side of the image intensifier tube is connected to another member, the abutment surface 16 of the upright ring 15 abuts against this other member, so that the whole can be firmly and firmly connected.

(4) Since the elastic member 23 is interposed between the airtight container 5, which is the main body of the image intensifier tube, and the outer container 1, when the entrance surface side of the image intensifier tube is brought into contact with another member, the upright ring 15 is By pressing the outer container 1 toward the incident surface by hitting it against another member, an elastic force is applied to the upright ring 15, thereby ensuring the collision and providing relief against fluctuations.

[Brief explanation of drawings]

The accompanying drawing is a cross-sectional view of an exemplary image intensifier tube of the present invention having an upright ring with an abutting surface. 1...Outer container, 2...Image intensifier tube, 3
...Manpower window, 4...Output window, 5...
... Airtight container, 6 ... Concave inner wall, 7 ...
...Photocathode, 8...Channel plate multiplier, 9...Input surface, 10...Output surface,
11.12...Electron-optical imaging electrode, 13...
...Light emitting layer, 14...Wall part, 15...
...Upright non-stick, 16...Abutment surface (end surface), 1
7...Glass ring, 18...Metal ring, 19...Connection part, 21...Input surface of human powered window, 23... Elastic member, 26...
··End face.

Claims (1)

[Scope of utility model registration request] 1. An image intensifier tube comprising an airtight enclosure having an input window, a photocathode, a set of electro-optic imaging electrodes, and an output window, with an upright ring positioned adjacent the input window. Installed in an airtight container, the end face of this upright ring,
An abutment surface is positioned precisely at a predetermined distance from the input surface of the input window, and the input window and upright ring are arranged such that the abutment surface of the input window and the upright ring is An image intensifying tube comprising a member having a coefficient of thermal expansion that minimizes relative positional displacement, and comprising an elastic member for elastically mounting an airtight container of the image intensifying tube within an outer container. 2. The manual window is a fiber window, and the fiber window and the upright ring are arranged in axial dimensions and thermally such that the mutual positional deviation between the end face of the upright ring and the surface of the fiber window is minimized in the case of temperature fluctuations. Utility model registration claim 1 characterized by being constructed using a member having an expansion coefficient
Image intensifier tube as described in section.