JP2870228B2 - 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. An adhesive surface of the prism on a support member having a support portion to which solder can be welded to a prism provided with a metal coating on a part of the side surface of the prism and an adhesive surface formed by laminating a thin solder layer on the metal coating surface 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. It is characterized by being fixed to.

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 side surface of one prism is composed of a metal coating and an adhesive surface in which a thin solder layer is laminated on the metal coating surface, and a supporting member for supporting the one prism has a supporting portion to which solder can be welded. The prism and the support member are fixed 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 c, 1a1 is a side surface of the prism 1a through which no effective light beam passes, and 1b1 is a side 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, which are bonded to the light exit surfaces 1X, 1Y, and 1Z of the prisms 1a, 1b, and 1c, respectively.

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 1a2 which is a reference surface. Reference numerals 5 and 6 denote support portions of a part of the support member 4, respectively.

The support portion 5 is capable of melting molten metal such as solder for fixing the prism 1a to the support 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 denotes an adhesive surface formed on the side surface 1a1 of the prism 1a, and reference numeral 9 denotes an adhesive surface formed on the side surface 1b1 of the prism 1b. The bonding 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 as described later.

The gap between the bonding surface 8 of the prism 1a and the support portion 5 of the support member 4 and the gap between the bonding surface 9 of the prism 1b and the support portion 6 of the support member 4 are respectively filled with molten metal 10 such as solder.
The solder is melted by sandwiching a and 10b and heating from the outside, and both are bonded and fixed.

Reference numeral 11 denotes an optical filter, which is held by a frame 12 through a support member 4 in front of the entrance surface 1a2 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 side surface 1a1 of the prism 1a, and does not affect a photographing light beam or other reflected light. Has holes.

The bonding surface 8 of the prism 1a (1b)
The metal film provided in (9) has a three-layer structure. The metal film is coated 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 chrome and nickel (Ni).
The second and third layers are nickel vapor deposition layers, both of which are formed by heating the substrate to about 250 ° C. and vapor deposition.
Thereafter, a thin solder layer is deposited on the metal coating surface at a temperature of the substrate of about 70 ° 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.
2 is set as a reference.

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

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, an adhesive surface is provided on the side surfaces of the prisms 1a and 1b, and the support member is directly bonded and fixed. In this embodiment, the same material or wire as the prism is applied to the side surfaces of the prisms 1a, 1b and 1c. The members 14 having substantially equal expansion coefficients are bonded. Adhesive surfaces 8 and 9 are formed by forming the same metal coating and solder layer on the side of the member 14, that is, the prism. Then, the bonding surfaces 8, 9 and the support portion are bonded using the solders 10a, 10b, and thereby the prisms 1a, 1b and the support member 4 are bonded and fixed.

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

[0026]

According to the present invention, the prism constituting the color separation prism and the supporting member for supporting the same are fixed and supported by using a molten metal such as solder as described above, so that the incident light from the photographing lens can be obtained. Can be color-separated, and a color separation prism supporting method and a color separation optical system using the color separation prism can be achieved with a simple configuration that can be incident on a predetermined position on the imaging surface with high accuracy.

Also, the present invention uses a fusible metal such as solder, thereby shortening the curing time during bonding and preventing other unnecessary forces from being applied 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 side surface 1X, 1Y, 1Z light emission surface 2a, 2b, 2c color filter 3a, 3b, 3c solid-state imaging device 4 support member 5, 6 support portion 8, 9 bonding surface 10a, 10b molten metal (solder)

Claims (6)

(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 metal coating on a part of a side surface of the plurality of prisms; A prism provided with an adhesive surface in which a thin solder layer is laminated on the coating surface is mounted on a support member having a support portion to which solder can be welded so that the adhesive surface of the prism faces the support portion of the support member, A method for supporting a color separation prism, comprising: providing a molten metal between a support portion and the bonding surface; and then heating and melting the molten metal to fix the prism to the support member. 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. The method according to claim 1, wherein said 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. 4. A color separation prism having a plurality of prisms that reflect an incident light beam a plurality of times to separate the light into a plurality of color lights and emit the light, and a part of a side surface of at least one of the plurality of prisms is made of metal. A supporting member for supporting the one prism, having a supporting portion to which solder can be welded; and a supporting member for supporting the one prism. A color separation optical system, wherein the prism and the support member are fixed to each other with a molten metal provided between a support portion and an adhesive surface of the prism. 5. The color separation optical system according to claim 4, wherein said metal film and said thin solder layer are both formed by a vapor deposition method. 6. The color separation optical system according to claim 4, wherein said 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.