JP2870227B2 - Method for supporting color separation prism and color separation optical system using the same - Google Patents

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 and a video camera, and a color separation optical system using the same, and more particularly, to imaging of a television camera and 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 light of B, G, and R or arbitrary two-color light 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, a color separation prism 30 is composed of three prisms 31a, 31b, 31c, and a known dichroic film is applied to the reflection surface of each prism, thereby converting incident light into three color lights of B, G, and R. The color has been separated.

Generally, a prism 31b and a prism 31c are used.
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 epoxy-based or silicon-based adhesive. In the supporting method shown in the figure, there is no mechanical (for example, pin) reference between the prisms 31a, 31b, 31c and the prism base 31, and the supporting is performed by the strength of only the adhesive.

[0005]

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

For this reason, 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, a shift occurs in the optical axis of each color light separated by the color separation prism, and when each color image is electrically combined by a television camera, the image is shifted to lower the resolving power and a good image is obtained. There was a problem that it could not be obtained.

According to the present invention, the prism constituting the color separation prism and a supporting member for supporting the color separation prism are fixed and supported by using a molten metal such as solder, so that the incident light from the photographing lens is color-separated and the image pickup surface is obtained. It is an object of the present invention to provide a method of supporting a color separation prism having a simple configuration that can be made to be incident on an upper predetermined position with high accuracy, and a color separation optical system using the same.

[0009]

As a method of supporting a color separation prism according to the present invention, a plurality of color separation prisms having a plurality of prisms for reflecting an incident light beam a plurality of times, separating the light into a plurality of color lights, and emitting the light are provided. Forming a metal coating on a polished entrance surface, reflection surface, or part of the exit surface of at least one of the prisms, and an adhesive surface formed by laminating a solder thin layer on the metal coating surface; Is attached to a support member having a support portion that can be welded such that the adhesive surface of the prism faces the support portion of the support member, and a molten metal is provided between the support portion and the adhesive surface. The prism is fixed to the supporting member by heating and melting the molten metal.

The color separation optical system according to the present invention includes at least one of a plurality of prisms of a color separation prism having a plurality of prisms for reflecting an incident light beam a plurality of times, separating the light into a plurality of color lights, and emitting the light. A part of the polished entrance surface, reflection surface, or exit surface of one of the prisms is formed of a metal film and an adhesive surface obtained by laminating a thin solder layer on the metal film surface, and serves as a support member for supporting the one prism. Has a support portion to which solder can be welded, and the prism and the support member are fixed to each other by a molten metal provided between the support portion of the support member and the bonding surface of the prism. .

[0011]

FIG. 1 is a schematic side view of a first embodiment of the present invention, and FIG.
1 is a schematic view when viewed from the direction B in FIG. 1, and FIG.
It is the schematic which showed only one side in the -A cross section for the left-right symmetry.

In FIG. 1, reference numeral 1 denotes a color separation prism having three prisms 1a, 1b, and 1c, and a known dichroic film for color separation is applied to a reflection surface between the prisms. 1X, 1Y, 1Z are prisms 1a, 1b, 1 respectively.
The light exit surface (exit surface) c, 1a1 is the light incident surface (incident surface) of the prism 1a, and 1b1 is the light incident surface (incident surface) of the prism 1b. L is incident light that enters the color separation prism 1 from a not-shown photographing lens. Reference numerals 2a, 2b, and 2c denote color filters for color trimming.
1b, 1c are bonded to the light exit surfaces (exit surfaces) 1X, 1Y, 1Z.

Reference numerals 3a, 3b, and 3c denote solid-state image sensors, respectively, which are color filters 2a, 2 of prisms 1a, 1b, and 1c.
b, 2c. 4 is a color separation prism 1
Is a supporting member (substrate) serving as a mounting reference.

The supporting member 4 includes prisms (1a, 1b, 1).
c) and a material having a value approximately equal to the linear expansion coefficient of an optical member such as a color filter (2a, 2b, 2c), such as titanium, permalloy, and ceramics;
The color separation prism 1 is in contact with a predetermined position of an incident surface 1a1 serving as a reference surface. Reference numerals 5a, 5b, 6a, and 6b denote support portions of a part of the support member 4, respectively.

The supporting portions 5a and 5b are capable of melting molten metal such as solder for fixing the prism 1a to the supporting member 4. The support portions 6a and 6b connect the prism 1b to the support member 4
A molten metal such as solder for fixing to the surface can be melted.

Reference numeral 7 denotes a tap through which the color separation prism 1 is attached to a camera housing (not shown). 8
Reference numerals a and 8b denote adhesive surfaces formed on the incident surface 1a1 of the prism 1a, and reference numerals 9a and 9b denote adhesive surfaces formed on the incident surface 1b1 of the prism 1b, all of which are formed on polished flat surfaces. I have. Adhesive surfaces 8a, 8b, 9a, 9b
Has a multilayer structure in which a metal coating is provided on a part of the incident surface as described later, and a thin solder layer is further laminated on the metal coating surface.

The solder is provided in the gap between the bonding surfaces 8a and 8b of the prism 1a and the support portions 5a and 5b of the support member 4 and the gap between the bonding surfaces 9a and 9b of the prism 1b and the support portions 6a and 6b of the support member 4, respectively. The molten metal 10a, 10b is sandwiched and heated from the outside to melt the solder and bond and fix both.

Reference numeral 11 denotes an optical filter, which is held by a frame 12 via a support member 4 in front of the entrance surface 1a1 of the prism 1a. Reference numeral 13 denotes a dust-proof frame, which is made of a compressible material such as silicon rubber or sponge rubber, and is provided in a gap between the support member 4 and the incident surface 1a1 of the prism 1a. Has no holes.

Incidentally, the bonding surfaces 8a, 8a of the prism 1a (1b)
The metal films provided on 8b, 9a and 9b have a three-layer structure. The metal film is covered with a mask having an opening in the shape of the region to be bonded using the prism 1a (1b) as a substrate. The first layer is chromium (Cr) deposited, and the second layer is a binary deposited layer of chrome and nickel (Ni). The third layer is a nickel vapor-deposited layer, which is formed by heating the substrate to about 250 ° C. and vapor-depositing it. Thereafter, the temperature of the substrate is set to about 7 on the metal coating surface.
A thin solder layer is deposited at 0 ° C., thereby forming an adhesive surface.

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

In this embodiment, in order to support the color separating prism 1 at a predetermined position on the support member 4, first, a special tool or a mechanical positioning means (for example, a pin abutting surface) or the like is used for the support member 4. 1a and the two prisms 1b and 1c that have been bonded in advance to the entrance surface 1a of the prism 1a.
1 is arranged as a reference.

At this time, the bonding surface 8 of the prism 1a (1b)
a, 8b (9a, 9b) and support portions 5a, 5 of support member 4
b (6a, 6b) are arranged to face each other. Then, the bonding surfaces 8a, 8b (9a, 9b) and the support portions 5a, 5b (6
a, 6b) in the gap with molten metal 10a such as cream solder
(10b) is inserted. Next, the molten metal 10a, 10b is heated by a heating means such as a soldering iron, a halogen lamp, and a laser.
Are fused and fixed to each other.

FIG. 4 is a sectional view of a main part of a second embodiment of the present invention. In the figure, the same elements as those shown in FIGS. 1 to 3 are denoted by the same reference numerals.

In the first embodiment, the prism 1 previously bonded is used.
The support member 4 is bonded and fixed by providing an adhesive surface on the incident surface 1b1 of the prism 1b of the prisms 1b and 1c. In this embodiment, the same metal coating as described above is applied to the incident surface 1c1 of the prism 1c of the prisms 1b and 1c. And a thin solder layer to form an adhesive surface. Then, the bonding surfaces 9a1 and 9b1 and the supporting portion are bonded by using the solder 10b, thereby forming the prism 1c.
And the support member 4 are bonded and fixed.

In the above embodiment, the adhesive surface is provided on the incident surface of the prism. However, the same effect can be obtained by providing the reflective surface or the emission surface which is polished and has good flatness.

In each of the embodiments described above, the case where three prisms are used as color separation prisms to perform color separation into three colors has been described. However, a two-color separation prism consisting of two prisms that performs color separation into two arbitrary colors is used. There may be.

[0027]

According to the present invention, as described above, the polished flat surface of the prism constituting the color separation prism and the supporting member for supporting the same are fixed using molten metal such as solder. A method of supporting a color separation prism having a simple configuration capable of performing color separation of incident light from a photographing lens by supporting and allowing the light to enter a predetermined position on an imaging surface with high accuracy, and a color separation optical system using the same. Can be achieved.

The present invention also uses a fusible metal such as solder, thereby shortening the curing time during bonding and preventing the application of other unnecessary forces during bonding.
High assembling accuracy can be easily obtained, and furthermore, there is such a feature that the strength is not easily reduced due to aging, and it is durable against environmental changes and mechanical external forces.

[Brief description of the 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 a direction B in FIG. 1;

FIG. 3 is a schematic cross-sectional view taken along line AA of FIG. 1;

FIG. 4 is a schematic cross-sectional view of Embodiment 2 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, 1c1 entrance surface 1X, 1Y, 1Z light exit surface 2a, 2b, 2c color filter 3a, 3b, 3c solid-state imaging device 4 support member 5a, 5b, 6a, 6b Support portions 8a, 8b, 9a, 9b Adhesive surfaces 10a, 10b Molten metal (solder)

Claims (4)

(57) [Claims] 1. A color separation prism having a plurality of prisms for reflecting an incident light beam a plurality of times to separate light into a plurality of color lights and emit the light, and a polished incident surface or reflecting surface of at least one of the plurality of prisms. An adhesive surface formed by laminating a metal coating and a thin solder layer on the metal coating surface on a part of the emission surface, and attaching the one prism to a support member having a support portion to which solder can be welded. Is mounted so as to face the support portion of the support member, a molten metal is provided between the support portion and the adhesive surface, and then the molten metal is heated and melted, thereby attaching the prism to the support member. A method for supporting a color separation prism, characterized in that the color separation prism is fixed. 2. The method according to claim 1, wherein the metal film and the solder thin layer are both formed by a vapor deposition method. 3. A polished incident surface or reflection of at least one of the plurality of prisms of a color separation prism having a plurality of prisms for reflecting an incident light beam a plurality of times to separate the light into a plurality of color lights and emit the light. A part of the surface or the emission surface is composed of a metal film and an adhesive surface in which a thin solder layer is laminated on the metal film surface, and a supporting member for supporting the one prism has a supporting portion to which solder can be welded. A color separation optical system, wherein the prism and the support member are fixed to each other by a molten metal provided between a support portion of the support member and an adhesion surface of the prism. 4. The color separation optical system according to claim 3, wherein said metal coating and said solder thin layer are both formed by a vapor deposition method.