JPS63142304A - Crystal optical filter - Google Patents

Abstract

PURPOSE:To improve the moisture resistance of a crystal optical filter and to make it usable at a place of high humidity by bonding a crystal plate to an optical glass plate with a photosetting epoxy adhesive. CONSTITUTION:Optical glass plates 6 are inserted between crystal plates 2, 4, 8 and bonded to each other using as photosetting epoxy resin as adhesive agent 3, 5, 7. Thus, the resistance of the optical glass plate 6 to moisture is improved because the principal face of the optical glass plate 6 does not contact directly with external air. Moreover, since the adhesive used therefor is photosetting type, the management of work is performed conveniently and the hardening time is shortened; thus the quality of the product is made stationary and the number of man-hour is lessened. Accordingly, crystal optical filters having high performance and small variation of quality are obtd. at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a crystal optical filter used in the optical system of video cameras and camera-integrated videos.

2. Description of the Related Art Conventionally, an image pickup tube has been generally used as an image pickup device for video cameras and camera-integrated videos. In addition, a stripe filter for color separation is deposited on the face plate of the image pickup tube, so that a color image can be obtained with a single image pickup tube. However, with this stripe filter, when an object whose so-called spatial frequency is close to the interval between the stripe filters is photographed, light interferes and a false color signal is generated. For this reason, a crystal optical filter was placed just before the stripe filter to prevent false color signals. In conventional image pickup tubes, a single crystal plate fulfilled the role of a crystal optical filter, but
After CAN and MO8 type solid-state image sensors began to be used, multiple crystal plates were bonded together to improve the characteristics and make the crystal optical filter more sophisticated. In some cases, the optical glass used for color correction was attached to the outside of the crystal, or in a different configuration, leaving its surface exposed. Furthermore, colorless and transparent adhesives such as photocurable acrylic or polybutadiene adhesives have been used.

Problems to be Solved by the Invention However, the conventional crystal optical filter described above has the following problems.

(1) Useful optical glasses have particularly poor moisture resistance.

(2) With photocurable acrylic or polybutadiene adhesives, the adhesive itself corrodes due to moisture.

(3) Epoxy adhesives have good moisture resistance, but conventional adhesives are two-component and not photocurable, making them difficult to mass-produce due to complicated work management and long curing times.

Means for Solving the Problems In order to solve the above problems, the present invention has a structure in which an optical glass plate is sandwiched between crystal plates and bonded together using a light-curing epoxy adhesive. .

Effect: With the above structure, the photocurable epoxy adhesive can improve moisture resistance and can be used in places with high humidity. Furthermore, since a photocurable adhesive is used, work management is simple and the curing time is short.

The embodiment drawings are perspective views showing the configuration of an embodiment of the present invention. In FIG. 1, 2, 4.8 are crystal plates, 6 is an optical glass plate, and a crystal optical filter 1 is obtained by bonding these plates with a photocurable epoxy adhesive 3, 5.7.

Next, the operation of the above embodiment will be explained. In the above embodiment, when the optical glass plate 6 is bonded to the crystal plate 4.8, the main surface of the optical glass plate 6 does not come into direct contact with the outside air, so that the moisture resistance of the optical glass plate 6 is improved.

As described above, according to the above embodiment, the crystal optical filter 1 can be heated to 100% under high temperature and humidity resistant conditions of 60'C and 96% humidity.
Almost 100% of the initial properties (adhesion strength and transmittance of each part) can be maintained for 0 hours.

Effects of the Invention As is clear from the above embodiments, the present invention has the advantage that the moisture resistance of the crystal optical filter is improved. Furthermore, since the adhesive used is a light-curing type, work management is easy and curing time can be shortened, resulting in stable quality, reduced man-hours, and excellent mass production. has.

Therefore, due to these advantages, a high-performance crystal optical filter with little variation in quality can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the crystal optical filter of the present invention. 1...Crystal optical filter, 2, 4.8...
...Crystal plate, 6...Optical glass plate, 3,5.
7... Light curing epoxy adhesive.

Claims (2)

[Claims] (1) A crystal optical filter in which a crystal plate and an optical glass plate are bonded together using a photocurable epoxy adhesive. (2) Claim 1, in which an optical glass plate is sandwiched between a plurality of crystal plates and bonded together with a photocurable epoxy adhesive.
Quartz optical filter described in section.