Patent ID: 7224648

Claim:
An optical recording and reproduction apparatus, comprising: a light receiving element detecting an amount of reflected light of a light beam from an optical disc and outputting an electric signal in accordance with the amount of reflected light; an amplifier unit amplifying said electric signal output from said light receiving element; an analog-digital converter converting said electric signal output from said amplifier unit to a digital signal; an error signal generation portion subjecting said electric signal output from said analog-digital converter to arithmetic processing so as to generate a focus error signal and a tracking error signal; and a control unit outputting first and second control signals for adjusting offset and gain for said electric signal output from said amplifier unit; wherein said control unit detects said electric signal output from said analog-digital converter, and outputs the first control signal for providing said electric signal with the offset so that a direct current component in said electric signal is equal to a median in a dynamic range of said analog-digital converter and the second control signal for adjusting the gain so that output amplitude of said electric signal is within the dynamic range of said analog-digital converter, and said amplifier unit adjusts the offset and the gain for said electric signal in accordance with said first and second control signals and inputs amplified said electric signal to said analog-digital converter.