JPH0572465A - Method for supporting color separating prism and color separating optical system using this method - Google Patents

Abstract

PURPOSE:To obtain the supporting method for a color separating prism which can support the color separating prism consisting of plural prisms with high accuracy in the prescribed position of a supporting member and the color separating optical system using this method. CONSTITUTION:The prisms 1a, 1b formed with metallic films and adhesive surfaces 8, 9 laminated with thin solder layers on the surfaces of the metallic films on a part of the flanks of the faces among the plural prisms 1a to 1c of the color separating prism 1 having the plural prisms1a to 1c which reflect an incident luminous flux plural times and separates the luminous flux to plural color light rays are mounted to the supporting member 4 having supporting parts 5, 6 which can be welded by soldering in such a manner that the adhesive surfaces 8, 9 of the prisms 1a, 1b face the supporting parts 5, 6 of the supporting member 4. Meltable metals are provided between the supporting parts 5, 6 and the adhesive surfaces 8, 9 and thereafter, the meltable metals are heated to melt, by which the prisms 1a, 1b are fixed to the supporting member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supporting a color separation prism suitable for a color separation system such as a color television camera or a video camera, and a color separation optical system using the same, and more particularly to imaging for a television camera or a video camera. In the apparatus, a color separation prism composed of a plurality of prisms for separating incident light into, for example, three color lights of B, G and R, or into any two color lights is supported at a predetermined position with high accuracy and stability. The present invention relates to a color separation prism supporting method and a color separation optical system using the same.

[0002]

2. Description of the Related Art Conventionally, a color separation prism used in a color separation system of a television camera, a video camera or the like is designed so that a light beam passing through the color separation prism is incident on a predetermined position of an image pickup means with high accuracy. It is required to be supported by a support member.

FIG. 5 is a schematic view of a conventional method for supporting a color separation prism. In the figure, the color separation prism 30 is composed of three prisms 31a, 31b and 31c, and the reflecting surface of each prism is provided with a known dichroic film, whereby incident light is divided into three color lights of B, G and R. The colors are separated.

Generally, prisms 31b and 31c
Are fixed with an adhesive, and the prism 31a and the prism 31b are configured with a slight gap therebetween. The color separation prism 30 is fixed to the prism base 31 with an adhesive such as an epoxy-based or silicon-based adhesive. In the supporting method shown in the figure, there is no mechanical (for example, a pin) reference between the prisms 31a, 31b, 31c and the prism base 31, and the prisms 31a, 31b, 31c are supported only by the strength of the adhesive.

[0005]

In the method of supporting the color separation prism shown in FIG. 5, the prism base is supported by using an epoxy or silicon adhesive.

Therefore, the prism may be displaced due to environmental conditions (for example, temperature change) or mechanical conditions (for example, vibration, impact, etc.), and the relative positional relationship with the prism base 31 may change.

As a result, the optical axes of the respective color lights separated by the color separation prism are displaced, and when the color images are electrically combined by the television camera, the images are displaced and the resolution is lowered, so that a good image is formed. There was a problem that it could not be obtained.

According to the present invention, the prism constituting the color separation prism and the supporting member for supporting the prism are fixedly supported by using a molten metal such as solder to color-separate the incident light from the taking lens to obtain an image pickup surface. It is an object of the present invention to provide a method for supporting a color separation prism having a simple structure capable of highly accurately incident on the above predetermined position, and a color separation optical system using the same.

[0009]

As a method for supporting a color separation prism of the present invention, a plurality of color separation prisms having a plurality of prisms that reflect an incident light beam a plurality of times to perform color separation into a plurality of color lights and emit the color lights are described. The prism has a metal coating on a part of its side surface, and a prism having an adhesive surface on which a thin solder layer is laminated on the metal coating surface. Is mounted so as to face the supporting portion of the supporting member, a molten metal is provided between the supporting portion and the adhesive surface, and then the molten metal is heated and melted to move the prism to the supporting member. It is characterized by being fixed to.

In the color separation optical system of the present invention, at least one of the plurality of prisms of a color separation prism having a plurality of prisms that reflect an incident light beam a plurality of times to perform color separation into a plurality of color lights and emit the color lights. A part of the side surface of each prism is composed of a metal coating and an adhesive surface in which a thin solder layer is laminated on the surface of the metal coating. The supporting member for supporting the one prism has a supporting portion to which solder can be welded. It is characterized in that the prism and the supporting member are fixed to each other by a molten metal provided between the supporting portion of the supporting member and the bonding surface of the prism.

[0011]

1 is a schematic side view of Embodiment 1 of the present invention, and FIG.
1 is a schematic view when viewed from the direction B in FIG. 1, and FIG. 3 is A in FIG.
It is a schematic diagram showing only one of the -A cross-sections for symmetry.

In the figure, reference numeral 1 denotes a color separation prism having three prisms 1a, 1b and 1c, and a reflecting surface between the prisms is provided with a known dichroic film for color separation. 1X, 1Y, 1Z are prisms 1a, 1b, 1
A light exit surface of c is a side surface of the prism 1a that does not pass an effective light beam, and a side surface 1b1 is a side surface of the prism 1b. L is incident light that enters the color separation prism 1 from a photographing lens (not shown). Reference numerals 2a, 2b and 2c are color filters for color trimming, and are adhered to the light emitting surfaces 1X, 1Y and 1Z of the prisms 1a, 1b and 1c, respectively.

Reference numerals 3a, 3b and 3c respectively denote solid-state image pickup devices, which are color filters 2a and 2 of the prisms 1a, 1b and 1c.
It is fixed on the surfaces b and 2c. 4 is a color separation prism 1
It is a support member (board) that serves as a mounting reference.

The support member 4 is a prism (1a, 1b, 1
c) and color filters (2a, 2b, 2c) and other materials having a value substantially equal to the linear expansion coefficient of the optical member, such as titanium, permalloy, and ceramics,
The color separation prism 1 is in contact with a predetermined position of an entrance surface 1a2 that serves as a reference surface. Reference numerals 5 and 6 are support portions of a part of the support member 4, respectively.

The supporting portion 5 is capable of melting molten metal such as solder for fixing the prism 1a to the supporting member 4.
The supporting portion 6 is capable of melting molten metal such as solder for fixing the prism 1b to the supporting member 4.

Reference numeral 7 denotes a tap, through which the color separation prism 1 is attached to a camera housing (not shown). Reference numeral 8 is an adhesive surface formed on the side surface 1a1 of the prism 1a, and 9 is an adhesive surface formed on the side surface 1b1 of the prism 1b. As will be described later, the adhesive surfaces 8 and 9 have a multilayer structure in which a metal film is provided on the prism surface, and a thin solder layer is further laminated on the metal film surface.

Molten metal 10 such as solder is placed in the gap between the adhesive surface 8 of the prism 1a and the supporting portion 5 of the supporting member 4 and in the gap between the adhesive surface 9 of the prism 1b and the supporting portion 6 of the supporting member 4, respectively.
By inserting a and 10b and heating them from the outside, the solder is melted and both of them are bonded and fixed.

Reference numeral 11 denotes an optical filter, which is held by a frame 12 in front of the entrance surface 1a2 of the prism 1a via a support member 4. A dust-proof frame 13 is made of a compressible material such as silicon rubber or sponge rubber, and is provided in the gap between the support member 4 and the side surface 1a1 of the prism 1a, and does not affect the photographing light flux or other reflected light. It has holes.

The bonding surface 8 of the prism 1a (1b)
The metal coating provided in (9) has a three-layer structure. The metal film is covered with a mask having an opening in the shape of the adhered area using the prism 1a (1b) as a substrate, the first layer is chromium (Cr) vapor-deposited, and the second layer is chrome and nickel (Ni).
The binary vapor deposition layer and the third layer are nickel vapor deposition layers, both of which are formed by heating the substrate to about 250 ° C. and vapor deposition.
Then, a solder thin layer is vapor-deposited on the surface of the metal film at a substrate temperature of about 70 ° C., thereby forming an adhesive surface.

Although the thickness of the adhesive surface varies depending on the application, the total thickness is about 0.2 μm to 0.9 μm.
The solder thin layer may be laminated by a method other than vapor deposition.

In order to support the color separation prism 1 at a predetermined position on the supporting member 4 in this embodiment, first, a prism is formed on the supporting member 4 by using a dedicated tool or a mechanical positioning means (for example, a pin abutting surface). 1a and the two prisms 1b and 1c that have been adhered in advance are the incident surface 1a of the prism 1a.
Place 2 as the reference.

At this time, the bonding surface 8 of the prism 1a (1b)
(9) and the supporting portion 5 (6) of the supporting member 4 are arranged so as to face each other. Then, a molten metal 10a (10b) such as cream solder is inserted into the gap between the adhesive surface 8 (9) and the supporting portion 5 (6). Then, the molten metals 10a and 10b are melted by a heating means such as a soldering iron, a halogen lamp, and a laser to bond and fix them.

FIG. 4 is a sectional view of the essential portions of Embodiment 2 of the present invention. In the figure, the same elements as those shown in FIGS. 1 to 3 are designated by the same reference numerals.

In the first embodiment, the side faces of the prisms 1a and 1b are provided with adhesive surfaces and the supporting members are directly adhered and fixed, but in the present embodiment, the side faces of the prisms 1a, 1b and 1c are made of the same material or wire as the prism. A member 14 having a coefficient of expansion that is substantially equal is bonded. Then, the same metal coating and solder thin layer as described above are formed on the member 14 to form the adhesive surfaces 8 and 9. Then, the adhesive surfaces 8 and 9 and the supporting portion are connected to the solders 10a and 1
0b is used to bond the prisms 1a and 1b.
And the support member 4 are adhered and fixed.

In each of the above embodiments, the case where three prisms are used as color separation prisms and color separation is performed into three colors has been described. However, a two-color separation prism that is formed by two prisms and performs color separation into any two colors is described. It may be.

[0026]

According to the present invention, as described above, the prism constituting the color separation prism and the supporting member for supporting the prism are fixedly supported by using a molten metal such as solder, so that the incident light from the photographing lens can be obtained. It is possible to achieve a method for supporting a color separation prism having a simple structure capable of performing color separation on the image pickup surface and allowing the light to be incident on a predetermined position on the imaging surface with high accuracy, and a color separation optical system using the method.

The present invention also uses a fusible metal such as solder to shorten the curing time during bonding and to prevent other unnecessary forces from being applied during bonding.
It has the features that high assembly accuracy can be easily obtained, that the strength does not decrease with age, and that it is durable against environmental changes and mechanical external forces.

[Brief description of drawings]

FIG. 1 is a schematic side view of a first embodiment of the present invention.

FIG. 2 is a schematic diagram when viewed from the direction B in FIG.

3 is a schematic cross-sectional view taken along the line AA of FIG.

FIG. 4 is a schematic sectional view of a second embodiment of the present invention.

FIG. 5 is a perspective view of a main part of a conventional color separation optical system.

[Explanation of symbols]

 1 Color separation prism 1a, 1b, 1c Prism 1a1, 1b1 Side surface 1X, 1Y, 1Z Light emission surface 2a, 2b, 2c Color filter 3a, 3b, 3c Solid-state image sensor 4 Support member 5, 6 Support part 8, 9 Adhesive surface 10a, 10b Molten metal (solder)

Claims (6)

[Claims] 1. A metal coating on a part of a side surface of a plurality of prisms of a color separation prism having a plurality of prisms that reflect an incident light beam a plurality of times to perform color separation into a plurality of color lights for emission, and the metal. A prism provided with an adhesive surface in which a thin solder layer is laminated on the coating surface is attached to a supporting member having a supporting portion to which solder can be welded so that the adhesive surface of the prism faces the supporting portion of the supporting member, A method for supporting a color separation prism, wherein a molten metal is provided between a support portion and the adhesive surface, and then the molten metal is heated and melted to fix the prism to the support member. 2. The method for supporting a color separation prism according to claim 1, wherein both the metal coating and the solder thin layer are formed by a vapor deposition method. 3. The method for supporting a color separation prism according to claim 1, wherein the support member is made of a material having a coefficient of linear expansion substantially equal to that of a glass material such as titanium, permalloy or ceramics. 4. A part of a side surface of at least one of the plurality of prisms of the color separation prism having a plurality of prisms that reflect an incident light beam a plurality of times to perform color separation into a plurality of color lights and emit the color lights. The support member for supporting the one prism has a support portion to which solder can be welded, the support member including a coating film and an adhesive surface obtained by laminating a thin solder layer on the metal coating surface. A color separation optical system characterized in that the prism and the supporting member are fixed to each other by a molten metal provided between a supporting portion and a bonding surface of the prism. 5. The color separation optical system according to claim 4, wherein both the metal coating and the solder thin layer are formed by a vapor deposition method. 6. The color separation optical system according to claim 4, wherein the support member is made of a material having a linear expansion coefficient substantially equal to that of a glass material such as titanium, permalloy or ceramics.