Patent ID: 8208359
Filing Date: 2012-06-26
Classification: C08G,G02B,G11B,H01L

Abstract:
1. An optical head for use in an optical information recording and reproducing device for recording or reproducing information with respect to an information recording medium using laser light, the optical head comprising: an objective lens for (i) condensing laser light to be emitted from a laser light source and (ii) irradiating the laser light onto the information recording medium; a detection lens for condensing reflection light from the information recording medium; and a light receiving element for receiving the reflection light condensed by the detection lens, wherein the light receiving element includes (i) a light receiving chip and (ii) a resin protector for protecting the light receiving chip, the light receiving chip having (i) a light receiving cell for converting the received light into a photocurrent and (ii) an electrode connected to the light receiving cell, wherein the objective lens, the detection lens, and the resin protector are made of a silicon resin cured material obtained by subjecting a silicon resin composition containing a caged-silsesquioxane compound to a curing treatment, and wherein the caged-silsesquioxane compound contains at least one kind selected from the group consisting of silsesquioxane compounds expressed by the general formulas (1) through (3), and partially polymerized products thereof: where, in the formulas (1) through (3), A is a group having a carbon-carbon unsaturated bond, B is a substituted or non-substituted saturated alkyl group or hydroxyl group, B 1 is a substituted or non-substituted saturated alkyl group or hydroxyl group, or a hydrogen atom, R 1 to R 6 are each individually a functional group selected from a lower alkyl group, a phenyl group, and a lower arylalkyl group, m and t are each a number selected from 6, 8, 10, and 12, n is an integer from 1 to (m−1), p is an integer from 1 to (m−n), q is an integer from 0 to (m−n−p), r is an integer from 2 to t, and s is an integer from 0 to (t−r).