Patent ID: 7924407

Claim:
An exposure device for forming circuit patterns onto a surface of an object, comprising: at least one spatial light modulator including a plurality of reflection elements being arranged in a matrix fashion; at least one optical source supplying exposure light to the reflection elements; and a bias voltage controller applying a bias voltage to the reflection elements; a control section monitoring an intensity of the exposure light; wherein when the bias voltage is a first voltage, the reflection elements are set to a first state in which the exposure light is delivered to the surface of the object; wherein when the bias voltage is not supplied, the reflection elements are set to a second state in which the exposure light is not delivered to the surface of the object and is not measured by the control section; and wherein when the bias voltage is a third voltage, the reflection elements are set to a third state in which the exposure light is not delivered to the surface of the object and is measured by the control section.