OPTICAL INFORMATION DETECTOR,申请号JP19840168893-传众专利搜索

OPTICAL INFORMATION DETECTOR

申请公布号：JPS6148137(A)

申请号：JP19840168893

申请日期：1984.08.14

申请公布日期：1986.03.08

申请人：

RICOH CO LTD

发明人：NISHINOMIYA MASANOBU;EMOTO MASAMI

分类号：G02B7/28;G11B7/09

主分类号：G02B7/28

摘要：PURPOSE:To detect more efficiently an information signal without lowering the accuracy of a track signal by constituting a light shield member used in common for a signal detection means with a photodetector having a 4-split mode and using an element closer to an opitcal axis as an information signal detection. CONSTITUTION:A track detection photodetector 8 is arranged at a position at right angles to the optical axis P2 and where its tip is projected from the P2 to improve the track detection accuracy, because the error if the track detection signal is neglected nearly when the amount of photodetection is >=60% depending on the relation between the detection amount of the reflected light and the track detection accuracy. Then the sum of signals outputted from small split elements 8a, 8b close to the optical axis P2 among the four split elements 8a-8d is adopted as an information signal. Further, the difference between the sum signals of two sets of the split elements 8a, 8c and the split elements 8b, 8d divided by a split line 1 is used as a track signal.