Patent ID: 7920609

Claim:
An exposure device for making exposure of a subject to be exposed by laser light, comprising: a main controller responsible for overall control of the operation of said exposure device; a laser emitter for emitting laser light; and a laser controller for controlling the emission of laser light from said laser emitter on receipt of an instruction for control given from said main controller, said laser controller being configured as a circuit board capable of independently being changed, said laser controller having a memory into which error control information for controlling variations of a controlling factor due to a circuit error of said circuit board is stored prior to the provision of said-circuit board to said exposure device, on receipt of an instruction for control given from said main controller to cause the emission of laser light in a predetermined amount of light, said laser controller determining a condition of emission of laser light based on said error control information stored in said memory to cause said laser emitter to emit laser light under said condition, wherein said laser emitter includes a photoelectric converter for detecting laser light emitted at said laser emitter, and outputting a monitor current of a current value responsive to an amount of the detected laser light, said laser controller performs feedback control for controlling light emission at said laser emitter based on said current value of said monitor current output by said photoelectric converter, wherein said laser controller includes: a control circuit for converting said current value of said monitor current to a voltage level, and outputting the voltage level; a reference voltage output element for outputting a reference voltage to be employed as a criterion for said feedback control; and a comparison circuit for making comparison between a voltage level output from said control circuit and said reference voltage to output a feedback signal based on a result of said comparison, and said error control information is used to control reference voltage in said feedback control based on said circuit error.