Patent ID: 7177242
Filing Date: 2007-02-13
Classification: G11B

Abstract:
1. A light receiving device having a condenser which generates condensed light, comprising: a first light receiving element, which receives the condensed light before the condensed light images; and a second light receiving element, which receives the condensed light after the condensed light images, wherein the first light receiving element and second light receiving element are disposed at positions equidistantly spaced from a focal point of the condensed light, and generate electrical signals based on light received by the light receiving elements, wherein each of the first light receiving element and second light receiving element includes: a first light receiving area, which receives a first portion of the condensed light which includes a optical axis of the condensed light; a second light receiving area, which receives a second portion of the condensed light which is located outside of the first portion of the condensed light; and a third light receiving area, which receives a third portion of the condensed light which is located outside of the second portion of the condensed light.