Patent ID: 7809037

Claim:
A laser array circuit comprising: a drive circuit including: a laser diode array including a plurality of laser diodes that emit light; a plurality of charge capacitors in which charge is accumulated; and a plurality of charge switching elements that cause the charge to accumulate in the plurality of charge capacitors; a laser diode driving switching element causing a current equivalent to the charge accumulated in one of the plurality of the charge capacitors to flow into a one of the plurality of the laser diodes scheduled to emit light so as to generate a pulsed light; and a tabular light-emitting board having a first side and a second side, wherein: the plurality of laser diodes, the plurality of charge capacitors, and the plurality of charge switching elements have a corresponding number of members; the laser diode driving switching element is used in common among the plurality of laser diodes; charge is sequentially accumulated in the one of the plurality of the charge capacitors associated with the one of the plurality of laser diodes scheduled to emit light, and the laser diode driving switching element is repeatedly turned on and off in order to cause additional ones of the plurality of laser diodes, among which the laser diode driving switching element is used in common, to emit light; the laser diode array and the plurality of charge capacitors are disposed on the light-emitting board such that wiring lengths linking the respective laser diodes included in the laser diode array and the plurality of charge capacitors associated with the plurality of laser diodes are equal; the laser diode array and the plurality of charge capacitors are disposed on the first side of the light-emitting board, and the laser diode driving switching element is disposed on the second side of the light-emitting board; and the laser diode array and the laser diode driving switching element overlap in a direction perpendicular to the first side of the light-emitting board.