| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light receiver which is applicable to an optical recording medium of multiple standards and can eliminate the troubles resulting from dark currents or stray light. <P>SOLUTION: The light receiver reads information by irradiating two kinds of optical recording mediums of a CD and a DVD with a laser beam and by receiving the light reflected on them. For a differential amplifier circuit 103, a bias resistor Rc, and a variable resistor Rf composing a trans-impedance amplifier circuit in this light receiver, a photodiode A1 for receiving the light reflected on the CD and a photodiode a1 receiving the light reflected on the DVD are connected through switches 101, 102 respectively to the non-inverting input terminal and the inverting input terminal of the differential amplifier circuit. When reproducing the CD, the photodiode A1 is connected to the inverting input terminal and the photodiode a1 to the non-inverting input terminal. When reproducing the DVD, the photodiode a1 is connected to the inverting input terminal and the photodiode A1 to the non-inverting input terminal. <P>COPYRIGHT: (C)2007,JPO&INPIT |
