| 摘要 |
An optical recording apparatus comprises a light source for emitting a light beam, a modulator for modulating the light beam with a signal to be recorded, and an optical system for conducting the light beam thus modulated through a specific light path. The light beam has a specific cross-sectional shape which is projected onto a recording medium. The optical system also includes a restricting plate having a slit or hole for restricting the cross-sectional shape of the modulated light beam to the specific shape. A pair of light detectors are irradiated by the modulated light beam of the restricted cross-sectional shape to detect the intensities of the light beam in the vicinity of two end parts. Any difference between the outputs of the two light detectors control the optical system, in response to the detected difference, so that the light intensity distribution of the modulated beam in the restricted cross-sectional shape is maintained symmetrical with respect to the center of light distribution.
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