JPH06160611A - Method for supporting color separation prism and color separation optical system constituted by using this method - Google Patents

Abstract

PURPOSE:To provide the method for supporting the color sepn. prism of simple constitution which makes color sepn. of the incident light from an image pickup lens and can make this light incident on the prescribed positions on an image pickup plane with high accuracy. CONSTITUTION:A metallic film is formed on the surface of the chamfered part formed at the corner part on the flanks of the prism holding an air gap therebetween among the plural prisms 1a, 1b, 1c of the color sepn. prism 1 having the plural prisms 1a, 1b, 1c which reflect incident luminous fluxes plural times and emit these luminous fluxes by color sepn. to plural color light rays. An adhesive surface 8 is then formed thereon by laminating a solder thin film thereon. Molten metal 10 is interposed between the adhesive surfaces 8 and the adhesive surface 9 of the prism to be adhered disposed opposite to the adhesive surface 8 and thereafter, the molten metal is melted by heating, by which the prisms 1a, 1b are fixed to each other.

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 the 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 A color separation prism conventionally 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 precision. It is required to be supported by a supporting 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, the 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 a prism base 3
It is fixed to the surface 1 by an adhesive such as epoxy or silicone. The supporting method shown in FIG.
There is no mechanical (for example, pin) reference between b and 31c and the prism base 31, and the prism base 31 is supported only by the strength of the adhesive.

[0006]

However, in the method of supporting the color separation prism 30 shown in FIG. 5, the prism base 31 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 30 are displaced, and when the color images are electrically combined by the television camera, the images are displaced and the resolution is lowered, resulting in a good image. There was a problem such as not being able to obtain.

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

[0010]

As a method for supporting a color separation prism of the present invention, among color separation prisms having a plurality of prisms that reflect incident light a plurality of times, perform color separation into a plurality of color lights, and emit the separated color lights. , A metal coating on the surface of the chamfered portion (tapered portion) formed on the corner of the side surface of the prism that sandwiches the air gap, and a solder thin film is laminated on the metal coating surface to form an adhesive surface. It is characterized in that the prisms are fixed to each other by interposing a molten metal between the facing adhesive surfaces of the prisms to be mounted and then heating and melting the molten metal.

In the color separation optical system of the present invention, the color separation prism having a plurality of prisms that reflect incident light a plurality of times, color-separate the light into a plurality of color lights, and emit the separated color lights. A chamfered portion (tapered portion) is provided at a corner of a side surface, a metal coating and an adhesive surface obtained by laminating a solder thin film on the metal coating surface are provided on the chamfered surface, and the adhesive surface faces the adhesive surface. The prisms to be mounted are arranged in this way, and a melting metal for heating and melting and fixing the prisms to each other is interposed between the both bonding surfaces.

[0012]

【Example】

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

In FIGS. 1 to 3, 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. There is.

1x, 1y and 1z are prisms 1a,
It is a light emission surface of 1b and 1c. L is the incident light that enters the color separation prism from the photographic 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. 3a, 3b,
Reference numerals 3c are solid-state image pickup elements, and prisms 1a, 1b,
The color filters 1a, 2b, 2c of 1c are fixed on the surfaces. Reference numeral 4 denotes a support member (substrate) that serves as a mounting reference for the color separation prism 1. This support member 4 is a prism 1a, 1
b, 1c, color filters 2a, 2b, 2c, etc., a material having a value substantially equal to the linear expansion coefficient of the optical member such as titanium,
The color separation prism 1 is made of permalloy, ceramics, or the like, and is in contact with a predetermined position of the incident surface 1a2 serving as a reference surface of the color separation prism 1.

4a is an adhesive for fixing the prism 1a to the support member 4, 6 is a tapered surface formed on the prism 1a, 7 is a tapered surface formed on the prism 1b, 8 is an adhesive surface provided on the tapered surface 6, Reference numeral 9 is an adhesive surface applied to the tapered surface 7. As will be described later, the adhesive surfaces 8 and 9 have a multilayer structure in which a metal coating is provided on the tapered surfaces 6 and 7, and a solder thin film is further laminated on the metal coating.

The adhesive surface 8 of the prism 1a and the adhesive surface 9 of the prism 1b are formed by a molten metal 1 such as solder interposed therebetween.
0 is heated from the outside to melt the solder and the like to bond and fix both. Reference numeral 11 denotes an optical filter held by a frame 12 in front of the entrance surface 1a2 of the prism 1a via a support member 4.

The metal coating provided on the bonding surfaces 8 and 9 of the prisms 1a and 1b has a three-layer structure. This metal coating is formed by using a prism (1a, 1b) as a substrate and applying a mask having an opening having the shape of the area to be adhered, and forming a chrome (C
r), the second layer is a binary vapor deposition of chrome and nickel N (Ni), and the third layer is a nickel vapor deposition layer, both of which are heated to about 250 ° C. and vapor deposited. Then, a solder thin layer is vapor-deposited on the metal coating surface at a substrate temperature of about 70 ° C. to form an adhesive surface.
The film thickness of this adhesive surface is changed according to the application, but the total thickness is about 0.2 to 0.9 μm. The solder thin layer may be laminated by a method other than vapor deposition.

In this embodiment, in order to support the color separation prism 1 at a predetermined position on the support member 4, first, the support member 4 is used.
The prism 1a is attached to the incident surface 1a by using a dedicated tool or mechanical positioning means (for example, a pin abutting surface).
2 is arranged as a reference, and the prism 1a is fixed to the support member 4 using an adhesive 4a. Further, the prisms 1a and the prisms 1b to which the prisms 1c have been bonded in advance are arranged so that the bonding surfaces 8 and 9 face each other, and a molten metal 10 such as cream solder is sandwiched between the bonding surfaces 8 and 9. To do.

Next, the bonding surfaces 8 and 9 of the prisms 1a and 1b are bonded and fixed by melting the molten metal 10 with a heating means such as a soldering iron, a halogen lamp and a laser.

In the above embodiments, three prisms are used as color separation prisms and the color separation is performed into three colors. However, it is a color separation prism composed of two prisms and separated into two arbitrary colors. May be. Example 2. Second Embodiment FIG. 4 is a cross-sectional view of a main part showing a second embodiment of the present invention. The same parts as those of the first embodiment shown in FIGS.

In FIG. 4, reference numeral 13 denotes a dustproof frame, which is made of a compressible material such as silicon rubber or sponge rubber, and is provided between the support member 4 and the entrance surface 1a2 of the prism 1a. It has a hole 13a that does not affect the luminous flux and other reflected light.

In the first embodiment, the prism 1a is fixed to the support member 4 with the adhesive 4a, and the prism 1a is fixed.
The molten metal such as the solder 10 was used to bond and fix between a and 1b, but in the second embodiment, the prism 1 with respect to the support member 4 is used.
The fixing of a and the fixing between the prism 1a and the prism 1b can be performed simultaneously.

[0024]

As described above, according to the present invention,
By fixing and supporting the color separation prism and the supporting member that supports the color separation prism using a molten metal such as solder, the incident light from the photographing lens is color-separated and is incident on a predetermined position on the imaging surface with high accuracy. It is possible to achieve a method of supporting a color separation prism having a simple structure that enables the above.

The present invention also uses a fusible metal such as solder to shorten the curing time at the time of bonding and to prevent other unnecessary force from being applied during bonding, thereby achieving high assembly accuracy. It is possible to obtain a color-separating optical system which is easily obtained, has less strength deterioration due to aging, and 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 view when seen from the direction of arrow B in FIG.

FIG. 3 is a vertical 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 1x, 1y, 1z Light Emitting Surface 8, 9 Bonding Surface 10 Molten Metal (Solder)

Claims (4)

[Claims] 1. 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, at a corner portion of a side surface of the prism that sandwiches an air gap among the plurality of prisms. A metal film is formed on the surface of the formed chamfer and a solder thin film is laminated on the surface of the metal film to form an adhesive surface, and a molten metal is formed between the adhesive surface of the prism to be mounted facing the adhesive surface. A method for supporting a color separation prism, characterized in that the prisms are fixed by interposing, and then melting the molten metal by heating. 2. The method for supporting a color separation prism according to claim 1, wherein both the metal film and the solder thin layer are formed by a vapor deposition method. 3. 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 plurality of color lights. Of the plurality of prisms, a corner portion of a side surface of the prism that sandwiches an air gap. A chamfered portion is provided on the chamfered portion, and a metal thin film and an adhesive surface on which a solder thin film is laminated on the metal thin film surface are provided on the chamfered portion, and between the adhesive surface of the prism to be mounted facing the adhesive surface. A color separation optical system characterized in that a molten metal for fixing prisms to each other is interposed between the two. 4. The color separation optical system according to claim 3, wherein both the metal film and the solder thin layer are formed by a vapor deposition method.