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US 4,717,925 AGranted
Optical scanner without extra convergent lens
AssigneeRicoh Company, Ltd.
InventorsIsamu Shibata, Kazuyuki Shimada
Life of this patent
Estimating the term…
Abstract
An optical scanner for use with a laser printer, a laser display or the like includes an optical deflector for directly scanning a photoconductive drum with a beam which is emitted from a semiconductor laser and to be focused as a minute spot on the drum. The frequency of an image scanning clock is continuously varied as an approximation to scanning speeds of a spot which is produced by the deflector. The intensity of the beam is controlled by an intensity control circuit.
Claims6
An optical scanner comprising:
- converging means for focusing a light beam issuing from a light source onto an object to be scanned as a minute spot;
- optical deflecting means interposed between said converging means and said object for deflecting the light beam to scan the object with there being no converging lens between said deflecting means and said object to be scanned;
- and
- frequency varying means supplied with an information signal for generating an image scanning clock in order to transfer the information signal to the light source and continuously varying frequency of the image scanning clock in proportion to a scanning speed at which the deflecting means scans the object with a scanning spot, thereby compensating for scanning distortion.
1 more element
Dependencies are inferred from the claim text.