Light control circuit of optical disc system

Abstract From the Canadian patent

A light control circuit of an optical disc system for controlling light from a light emitting element at a read power level even if a write data operation is performed. The light control circuit includes a light control circuit, a superimposedly energizing circuit for providing a light for data write and a subtraction circuit for subtracting a predetermined current from a light sensing element. A light control circuit may further include a reference value setting circuit for automatically finding and determining reference values of a read power level, a write power level, and a subtraction value. The reference values may be defined with respect to an origin of the characteristic of the …