| 摘要 |
<p>The invention relates to an apparatus for equalizing the signal strengths of different scan lines which employs an attenuating mirror (32). The attenuating mirror (32) attenuates a laser beam and reflected light from an article at an attenuation which is different from the attenuation of another pattern mirror (34) so that reflected light from the one and the other pattern mirror (32,34) have intensities which are substantially equal, within a predetermined range of intensities having a low end equal to a signal-to-noise threshold and a high end equal to a saturation level. <IMAGE></p> |
