TW276390B - Double four quadrant angle position detector - Google Patents

Abstract

A double four quadrant angle position detector comprises: one first four quadrant direction detector with first photo detector pair and second photo detector pair, and the sensitive area of above first photo detector pair and second photo detector pair have the same area symmetrically allocated on four sides of first square, in which two sensitive area of the above first photo detector pair are allocated on opposite sides of the above first square for generating the first short photo circuit, and two sensitive area of the above second photo detector pair are allocated on the other opposite sides of the above first square for generating the second short photo circuit; one second four quadrant direction detector with third photo detector pair and fourth photo detector pair, and the sensitive area of above third photo detector pair and fourth photo detector pair have the same area symmetrically allocated on four sides of second square that has the same center as the above first square and is larger than the first square, and sensitive area of the above first four quadrant direction detector does not overlap with the above second's, in which two sensitive area of the above third photo detector pair are allocated on opposite sides of the above second square for generating the third short photo circuit, and two sensitive area of the above fourth photo detector pair are allocated on the other opposite sides of the above second square for generating the fourth short photo circuit; one detector for detecting image angle position based on the above first short photo current, the second short photo current, the third short photo current, the fourth short current.