Patent ID: 7260049
Filing Date: 2007-08-21
Classification: G11B

Abstract:
1. A light receiving unit integrally comprising: a plurality of light receiving elements; and a processing circuit, wherein said processing circuit includes a plurality of current-to-voltage converters configured to convert current signals output from each of the light receiving elements into voltage signals, an adder configured to add the voltage signals to obtain an added voltage signal, and an attenuator configured to attenuate the added voltage signal or, an operation unit that includes the adder and the attenuator, and wherein the voltage signals output from the current-to-voltage converters and a voltage signal output from the attenuator or the operation unit are output from the light receiving unit, and wherein: the processing circuit includes an inversion circuit configured to generate a complementary signal having a waveform symmetrical to that of the voltage signal output from the attenuator or the operation unit about a reference voltage, and the complementary signal is also output from the light receiving unit.