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US 4,053,903 AGranted
Scanning rate and intensity control for optical scanning apparatus
AssigneeGTE Sylvania Incorporated
InventorThomas W. Schultz
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AssigneeGTE Sylvania Incorporated
InventorThomas W. Schultz
Estimating the term…
In an optical scanning exposure system for manufacturing cathode ray tubes having a faceplate with an inner surface layer of photosensitive material and an adjacent apertured mask wherein the exposure system includes a light source providing a light beam, an angle of incidence deflector means for deflecting the light beam at an angle related to the angle of incidence of an electron beam, means for imaging the light beam, and a means for scanning the light beam in a predetermined fashion over the apertured mask to expose the photosensitive material, a control system having a means for storing information representative of the angle of incidence of a light beam and the rate of scanning of a light beam between a matrix of positional locations on the faceplate, a scan rate means for controlling the rate of horizontal and vertical light beam scanning, an encoder means providing light beam positional information to the storage means, and an angle of incidence control means for activating the angle of incidence deflector means in accordance with angular information of the storage means. Other aspects of the invention include controlling the integral with respect to time of the light beam intensity to effect uniform photosensitive material exposure, controlling movement of the effective light beam source to control the size and shape of the exposure area, and controlling the overlapping and overscanning of the light beam scanning to minimize stripes of unexposed photosensitive material and to provide uniform exposure at the edges of the faceplate.
In a control system for use with an optical scanning exposure system in manufacturing cathode ray tubes having a faceplate with a layer of photosensitive material thereon, said optical scanning exposure system including a light source with a wavelength spectrum for exposing the photosensitive material, means for scanning the faceplate with a light beam, and means for deflecting the light beam at an angle related to the angle of incidence of an electron beam in a cathode ray tube, and said electrical control system including an angle of incidence and scan rate memory means, a scan rate means for controlling scanning of the light beam, and an angle of incidence deflection control means for controlling the angle of incidence of the light beam, the improvement comprising means for controlling the integral with respect to time of the light beam intensity at each exposed region of photosensitive material on the faceplate of the cathode ray tube to provide a predetermined amount of exposure at predetermined positional locations across the surface of the faceplate.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
By photographic processes: devices for carrying out the processes, e.g. light houses
Electric discharge tubes or discharge lamps
Term ended 11 Oct 1994 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
A concurrently filed application entitled "Optical Scanning Apparatus for Photolithography of a Color Cathode Ray Tube Having An Aperture Mask" bears U.S. Ser. No. 699,109 and is filed in the name of John Schlafer. Therein, a method and apparatus for fabricating a cathode ray tube by an optical scanning technique is provided and fully detailed.
Also, concurrently filed applications directed to Optical Scanning Apparatus include: "Overlap and Overscan Exposure Control System" bearing U.S. Ser. No. 699,054 filed in the name of Mahlon B. Fisher and G. Norman Williams; "Exposure Area Control For An Optical Scanning System of Manufacturing Cathode Ray Tubes" bearing U.S. Ser. No. 699,046 in the name of Thomas W. Schultz; "Control System For An Optical Scanning Exposure System For Manufacturing Cathode Ray Tubes" bearing U.S. Ser. No. 699,045 filed in the name of Thomas W. Schultz; and "Optical Scanning Apparatus and Method For Manufacturing Cathode Ray Tubes" filed in the names of G. Norman Williams, Robert F. Wilson, and John Schlafer bearing U.S. Ser. No. 699,110.
The present invention relates to a system for controlling an optical scanning exposure system suitable to the manufacture of cathode ray tubes and more particularly to a control system for storing information representative of the angle of incidence of a light beam at a matrix of points and scan rate information intermediate the points of the matrix and for applying the stored information to an optical scanning system to effect a proper rate and angle of scanning and deflection of a light beam which is imaged on a layer of photosensitive material affixed to the faceplate of a cathode ray tube.
FIG. 1 is a block diagram illustrating a control system for an optical scanning exposure system suitable to the manufacture of cathode ray tubes;
FIG. 2 is a symbolic illustration to assist in the explanation of the control system of FIG. 1;
FIG. 3 is an explanatory diagram for explaining one form of interpolator apparatus of FIG. 1; and
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in conjunction with the accompanying drawings.
Referring to the drawings, FIG. 1 is a block diagram illustration of a system for controlling an optical scanning exposure system suitable to the manufacture of cathode ray tubes. As detailed in the cross referenced application, an optical scanning exposure system includes a light source 7, preferably a laser, which directs a light beam 9 onto a beam forming optics configuration 11. The formed light beam is applied to an angle of incidence deflector means 13 which alters the path of the light beam in a manner affecting its angle of arrival at the CRT faceplate but does not seriously alter the position at which it strikes the faceplate.
This angular altered light beam is applied to an imaging optic system 15 wherein the light beam is correctly imaged and applied to a horizontal and vertical scanning means 17. The horizontal and vertical scanning means 17 is directed in a predetermined horizontal and vertical scanning path and causes the light beam to scan an apertured mask 19 adjacent a layer of photosensitive material 21 affixed to the inner surface of the faceplate 23 of a cathode ray tube.