JPH02273711A - Optical component - Google Patents

Abstract

PURPOSE:To fix the gap part of a joint surface with an adhesive low in viscosity and to prevent flaring by forming grooves in or nearby a coupling surface. CONSTITUTION:Plural rectangular, V-shaped, or round grooves which are wider and deeper than air gap size are worked in or nearby the joint surface 6a between prisms 1a and 1a' over the entire periphery. The prisms 1a and 1a' are assembled while an air gap 5a is left between the opposite surfaces 7a and 7a' of the prisms 1a and 1a' with spacers 3a, etc., and a black opaque adhesive 2a with low viscosity is applied outside the joint surface 6a. Consequently, the adhesive with the low viscosity is usable and the fixation area becomes wide, so the fixation strength is improved greatly and excessive reflected light is absorbed to prevent the flaring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical component used in an optical system of an optical instrument.

Conventional technology Optical components used in optical systems of conventional optical instruments are assembled and adjusted by forming a gap (hereinafter referred to as an air gap) between opposing surfaces using a spacer, etc. A high viscosity adhesive was applied from the outside and it stuck.

That is, FIG. 3 is an example of a color separation prism used in a conventional optical system. Opposing surfaces of prisms 1°, 1°, 7°, 7. An air gap of 5 degrees (0.02 to 0.05 mm) is formed by using spacers 3 degrees, etc., and the parts are assembled and adjusted and fixed with adhesive 2C. Solid-state imaging devices 8° and 8° are fixed to the exit surface and are accurately positioned with respect to the optical axis 9.

Problems to be Solved by the Invention However, when a low-viscosity adhesive is applied to the outside of the joint surface, the adhesive flows into the air gear part necessary for the optical path system due to capillary action.

For this reason, low viscosity adhesives cannot be used, and high viscosity adhesives have been applied from the outside of the bonding surfaces. However, since the adhesive has a high viscosity, the adhesive tends to enter the gap between the surfaces to be fixed.As a result, only the outside of the prism is fixed, and the fixed area becomes narrow, resulting in a weak bonding force.

Therefore, when subjected to temperature changes during use (changes can occur in the range of -40°C to 70°C), the parts and adhesives expand and contract, making it easy for the joined parts to move relative to each other, causing the parts to emit radiation. Since the position of each solid-state image sensor attached to the surface is shifted with respect to the optical axis, a relative position shift of the image occurs. Furthermore, since the bonding surfaces are fixed with a colorless and transparent adhesive, excess reflected light tends to reach the solid-state image sensor, causing flare.

That is, FIG. 2 (aL (b) shows a conventional example in which a spacer 3 is placed on the opposing surfaces 7b, 7b- of the prisms 1b, lb-.
FIG. 2B is an enlarged front view and a plan view of a joint portion in which an air gap 5b is formed with the adhesive 2b, etc., and the bonded portion is fixed with the adhesive 2b.

With this structure, the bonding area of the bonding surface 8b is narrow and the high viscosity adhesive 2bL cannot be used, so the adhesive 2b does not enter the gap between the bonding surfaces 6, resulting in a narrow bonding area and weak bonding force.

In view of this, the present invention enables the use of a low-viscosity adhesive, allows the gap portion of the bonding surfaces to be fixed, and creates a structure that allows the bonding area of the bonding surfaces to be widened, thereby realizing strong bonding force and creating a flare. The purpose is to provide an optical component that can prevent this.

Means for Solving the Problems The present invention provides a single row or multiple rows of grooves on or near the joint surface in an optical component in which an air gap is provided between opposing surfaces of a member and the joint surface at the outer edge is fixed with an adhesive. will be established. Further, the depth and width of the groove are made larger than the air gap dimension. Further, the joint surfaces are fixed with a low viscosity black opaque adhesive.

Function: According to the present invention, by providing a single row or multiple rows of grooves on or near the joint surface, the surface area of the joint surface is increased, so that the fixing area is increased. When a low-viscosity black opaque adhesive is applied to the outside of the joint surface, the adhesive enters the gap between the joint surfaces by capillary action. At this time, by making the width and depth of the groove larger than the air gap dimension, the groove serves as a reservoir for the adhesive and prevents the low-viscosity, black, opaque adhesive from flowing into the air gear, which is necessary as an optical path system. Strongly fixes the joint surface.

The black opaque adhesive evenly fills the joint surface and acts as a mask to prevent flare by absorbing excess reflected light. The bonding surface between the adhesive and the member is intricately formed by a single row or multiple rows of grooves, thereby preventing moisture from entering from the bonding surface.

Examples Examples of the present invention will be described below with reference to the drawings.

FIG. 1(a) is an enlarged front view of a joint portion of a prism according to the present invention, and FIG. 1(b) is a plan view thereof. Joint surfaces of prisms t, ls-8. Or in the vicinity thereof, a plurality of rows of grooves 4 are machined over the entire circumference, each having a width and depth larger than the air gap size, and having a rectangular, square, or round shape.

Opposing surfaces 71.7 of prisms t,,i,-. The air gap 5. is created by the spacer 31 etc. are assembled and prepared using a low viscosity black opaque adhesive 2. (For example, low viscosity UV resin mixed with black powder, etc.) on the joint surface 6. Apply to the outside of the Adhesive 2. The bonding surface 6. It enters into the gap part of. The poetry 4 acts as a glue reservoir, and the glue 2. does not enter through the groove 4, so the air gap 5, which is necessary for the optical path system. can be easily formed. Also, joint surfaces in limited spaces6. As the surface area becomes wider due to the grooves 4, the adhesion area force (widens).Then, the low viscosity black opaque adhesive 2 fills the bonding surface θ uniformly all around the groove 4.

It goes without saying that the present invention is applicable not only to prisms but also to other optical components.

As described in detail, the present invention allows the use of a low-viscosity adhesive and widens the bonding area, thereby greatly improving the bonding strength and preventing relative displacement of images due to the environment. In addition, wavelength fluctuations can be suppressed by preventing the entry of moisture, which has a large effect on wavelength fluctuations, and at the same time, the black opaque adhesive acts as a mask, absorbing excess reflected light and preventing flare.

[Brief explanation of drawings]

FIG. 10(a) is a front view of an enlarged cross-section of an optical component according to an embodiment of the present invention in which the joint surfaces are fixed, and FIG.
FIG. 2(b) is a plan view of an enlarged cross section of the optical component according to the same embodiment with the bonding surface fixed; FIG. 2(a) is a front view of an enlarged cross section of the conventional prism with the bonding surface fixed; Figure (b
) is a plan view of an enlarged cross-section of the same prism with its bonded surface fixed, and FIG. 3 is a cross-sectional view of a conventional color separation prism. DESCRIPTION OF SYMBOLS 1... Prism, 2... Adhesive, 3... Spacer, 4... Groove, 5... Air gap, 6... Bonding surface.

Claims (3)

[Claims] (1) An optical component in which a gap is provided between surfaces where members face each other and a joint surface at the outer edge is fixed with an adhesive, characterized in that a single row or multiple rows of grooves are provided at or near the joint surface. parts. (2) The optical component according to claim 1, wherein the groove has a groove depth and a groove width larger than the gap size. (3) The optical component according to claim 1, wherein the adhesive that fixes the joint surfaces is black and opaque.