Patent ID: 7440002

Claim:
An optical scanning apparatus which comprises: a light source which emits a light beam; a first and a second deflection mirror surfaces which are disposed for free pivoting about main scanning/deflection axes which are independent of and parallel to each other; and a mirror driver which drives the first and the second deflection mirror surfaces and makes the first and the second deflection mirror surfaces pivot about the main scanning/deflection axes so that the light beam from the light source is deflected by the first deflection mirror surface and the deflected light beam is further deflected by the second deflection mirror surface, wherein the first deflection mirror surface is structured so that when driven to pivot in a first resonance frequency band including a first resonance frequency at which the deflection angle of the light beam deflected by the first deflection mirror surface becomes the largest, owing to resonance, wherein a resonance frequency band is a band of which a resonance frequency becomes 70.7% of its maximum peak, the first deflection mirror surface deflects the light beam at a larger deflection angle than when driven to pivot at a frequency outside the first resonance frequency band, wherein the second deflection mirror surface is structured so that when driven to pivot in a second resonance frequency band including a second resonance frequency at which the deflection angle of the light beam deflected by the second deflection mirror surface becomes the largest, owing to resonance, the second deflection mirror surface deflects the light beam at a larger deflection angle than when driven to pivot at a frequency outside the second resonance frequency band, wherein the second resonance frequency is higher than the first resonance frequency, and a high-frequency side of the first resonance frequency band and a low-frequency side of the second frequency band partially overlap, and wherein the mirror driver drives the first and the second deflection mirror surfaces and makes the first and the second deflection mirror surfaces pivot at a frequency which is higher than the first resonance frequency and lower than the second resonance frequency.