发明名称 Aperture-limiting element and optical head utilizing the same
摘要 The optical head has a light source, a collimating lens, an aperture-limiting element and an objective lens in the mentioned order in the direction of progress of light emitted from the light source, and a photo-detecting system for detecting return light having been transmitted through the objective lens and reflected by an optical disk. The aperture-limiting element includes a plurality of stripe transparent electrodes spaced apart at a predetermined interval on an electro-optical crystal substrate, and a substantially circular non-electrode area lacking the stripe transparent electrodes at a center portion of the substrate. The aperture-limiting element can be constructed with a reduced number of components as compared with the prior art construction.
申请公布号 US6031809(A) 申请公布日期 2000.02.29
申请号 US19970986181 申请日期 1997.12.05
申请人 NEC CORPORATION 发明人 OHBA, AKITOMO
分类号 G11B7/135;G02F1/03;G11B7/00;G11B7/125;G11B7/20;(IPC1-7):G11B7/00 主分类号 G11B7/135
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