| 摘要 |
PURPOSE:To secure the linearity of a scanning line while permitting deviation in oscillation wavelength from designed wavelength and to perform photoscanning operation by allowing >=1 reflecting medium provided between a deflection point of a laser light by a deflecting member and a surface to be scanned to be adjusted in an oscillatory state. CONSTITUTION:Laser light L' from a semiconductor laser 10 is collimated by a collimator lens 11 and the sectional shape of the luminous flux is in an elliptic shape L2 which is long in an Y direction. The laser light L' is incident on a cylindrical lens 4' through a quarter-wavelength plate 12 and an aperture 13, and then incident on a hologram grating disk 1 as a deflecting member through a plane mirror 5. The deflected light reaches the surface 9 to be scanned through a plane mirror 6, ftheta lens 7, and cylindrical lens 8. The plane mirror 6 is adjustable in the oscillatory state around an axis perpendicular to the figure plane at a point R, and if the wavelength of laser oscillation of the semiconductor laser 10 deviates from the designed wavelength, the tilt angle of the plane mirror 6 is varied according to the deviation quantity DELTAlambda to vary the angle of reflection, making the main scanning line as linear as possible. |
