Patent ID: 7760780

Claim:
A laser diode driving device comprising: a light amount-detecting unit adapted to detect an amount of light emitted from a laser diode; a light amount-determining unit adapted to determine an amount of light to be emitted from the laser diode; a light amount control unit adapted to control the laser diode to emit light in the light amount determined by said light amount-determining unit; and a bias current value-determining unit adapted to determine a bias current value based on results of light emission performed by the laser diode in three or more light amounts determined by said light amount-determining unit, wherein said bias current value-determining unit determines the bias current value through comparison between (a) a first bias current value obtained from a first line calculated through two points corresponding to electric current values associated with two of the three or more light amounts, and (b) a second bias current value obtained from a second line calculated through two points corresponding to electric current values associated with two of the three or more light amounts, and wherein a point of the two points associated with the first line is different than a point of the two points associated with the second line.