Light beam scanning device generating a stable synchronizing signal
AssigneeFuji Photo Film Co., Ltd.
InventorAtsushi Suganuma
Life of this patent
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Abstract
A light beam scanning device includes a reference grid plate, a resonant light deflector for deflecting a light beam to cause the light beam to scan the reference grid plate through an f.theta. lens for thereby enabling the reference grid plate to produce a pulse signal, and a PLL circuit for generating a synchronizing signal from the pulse signal to read or record image information. The reference grid plate has slits defined at intervals, the slit intervals in that area of the reference grid plate which produces a pulse signal that is not directly contributed to the recording or reading of the image information being progressively smaller toward an end of the reference grid plate according to the scanning speed of the light beam.
Claims5
A light beam scanning device comprising:
- means for generating a light beam;
- a reference grid plate;
- an f.theta. lens;
- a resonant light deflector for detecting said light beam to cause the light beam to scan said reference grid plate through said f.theta. lens for thereby enabling said reference grid plate to produce a pulse signal;
- a PLL circuit for generating a synchronizing signal from said pulse signal to read or record image information;
- and
- said reference grid plate having slits defined at intervals, the slit intervals in that area of said reference grid plate which produces a pulse signal that is not directly contributed to the recording or reading of the image information being progressively smaller toward an end of said reference grid plate according to the scanning speed of the light beam.
Dependencies are inferred from the claim text.