| 摘要 |
PURPOSE:To extremely increase the control range of the sectional form of a bit, and to stabilize exposure quality by generating the bit by irradiating the surface of an optical information recording medium by an incident beam transmitted through a dot matrix type optical element. CONSTITUTION:A liquid crystal plate 8 as the dot matrix type optical element is arranged just before an objective lens 5 on an optical path along which laser light emitted from an ion gas laser 1 advances toward an optical master disk 6. This plate 8 is of two-dimensional matrix structure (X,Y axes) provided with a diaphragm function and a shutter function, and the laser intensity distribu tion of the incident beam and the form the bit can be freely controlled by the plate 8. Namely, since even the distribution of the quantity of light of the incident beam can be controlled, and various kinds of exposure patterns can be generated by the control result, the control range of the sectional form of the bit can be increased extremely compared with a traditional device. |
