| 摘要 |
<p>1500544 Facsimile apparatus XEROX CORP 7 April 1975 [8 April 1974] 14152/75 Heading H4F A xerographic facsimile transceiver of the type described in Specification 1,429,161 in which a mirror 31 is selectively positioned in a scanned laser beam to deflect the beam to scan a document via slit 14, the reflected light being detected by a photosensor 39, and in which with the mirror 31 out of the scanned laser beam path the laser beam (now modulated) is scanned over a xerographic drum 16, is provided with the added feature of a beam splitter 26 which when inserted in the scanned laser beam path converts the facsimile transceiver into an office document copier with the video signal obtained from the photosensor 39 fed back to modulate the laser or laser beam while it is simultaneously scanning both the document to be copied and the xerographic drum 16. The photosensor output video signal is applied to the inverting input of an operational amplifier to the non-inverting input of which a reference signal is applied, the resulting difference signal being applied to modulate the laser or the laser beam so that the intensity of the light reflected by the document on to the photosensor is maintained substantially constant.</p> |
