US3695154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable aperture photoexposure device
Assignee: Gerber Systems Corp
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Filing: 1970-09-15
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Granted: 1972-10-03
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Expires: 1990-09-15
Abstract
Abstract In a photoexposure device for exposing lines on a photosensitive surface a rectangular aperture is used to form a rectangular spot of light projected onto the photosensitive surface and moved thereover to generate a line. During the exposure of a given line, the light spot is moved relative to the photosensitive surface in accordance with a velocity program which includes an acceleration stage at the beginning of the line, a deceleration stage at the end of the line, and possibly a constant velocity stage between the acceleration and deceleration stages. The width of the light spot, as measured in the direction of its travel, is varied in accordance with its velocity relative to the photosensitive surface to obtain distinct definition of the line at its ends and to obtain a substantially uniform exposure of the line along its length despite the changes in the velocity of the light spot. In one embodiment a pair of blades sliding in perpendicular directions form a variable aperture to determine the size and shape of the light spot. In another embodiment the source of light is a cathode ray tube, and the shape of the projected light spot is determined by the image on the face of the tube.
Inventors
- 👤 Ronald B Webster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:22
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70383; G03F7/704; G03B; G03B9/00; G03B9/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
134 words
A photoexposure device for exposing a line on a photosensitive surface by means of a light spot moved thereover, said photoexposure device comprising means for supporting a workpiece having a photosensitive surface, a projecting device for projecting a light spot onto the photosensitive surface of a workpiece supported by said supporting means, and means for moving said light spot relative to said photosensitive surface for exposing a line thereon, said projecting device including a light source, aperture means defining a rectangular aperture illuminated by said light source, means for projecting an image of said aperture onto said photosensitive surface to form said light spot, and means for varying the size of said aperture in only one dimension thereof in response to changes in the speed of said light spot relative to said photosensitive surface.
Claim 2
Dependent Claim
134 words
A photoexposure device for exposing a line on a photosensitive surface by means of a light spot moved thereover, said photoexposure device comprising means for supporting a workpiece having a photosensitive surface, a projecting device for projecting a light spot onto the photosensitive surface of a workpiece supported by said supporting means, and means for moving said light spot relative to said photosensitive surface for exposing a line thereon, said projecting device including a light source, aperture means defining a rectangular aperture illuminated by said light source, means for projecting an image of said aperture onto said photosensitive surface to form said light spot, and means for varying the size of said aperture in only one dimension thereof in response to changes in the speed of said light spot relative to said photosensitive surface.
Claim 3
Dependent Claim
118 words
A photoexposure device as defined in claim 1 further characterized by said means for varying the size of said aperture in one dimension thereof in response to changes in the speed of said light spot relative to said photo-sensitive surface being such that the variation of said size in said one dimension corresponds to changes in the size of said light spot in the dimension parallel to its path of movement relative to said photosensitive surface and such that said size of said one dimension is decreased as said speed of said light spot is decreased and is increased as said speed of said light spot is increased over a given range of speeds of said light spot.
Claim 4
Dependent Claim
43 words
A photoexposure device as defined in claim 2 further characterized by means for varying the size of said aperture in the other dimension thereof to vary the width of the line exposed on said photosensitive surface by movement of said light spot thereover.
Claim 5
Dependent Claim
121 words
A photoexposure device as defined in claim 1 further characterized by said aperture means including a base plate having an opening therein, a first blade partially covering said opening and having an edge defining one edge of said aperture, and means supporting said blade for movement relative to said base plate in a direction perpendicular to said one edge thereof, said means for varying the size of said aperture in one dimension thereof in response to changes in the speed of said light spot reLative to said photosensitive surface including means for moving said first blade in the direction perpendicular to said one edge thereof in response to changes in the speed of said light spot relative to said photosensitive surface.
Claim 6
Dependent Claim
91 words
A photoexposure device as defined in claim 4 further characterized by said aperture means further including a second blade partially covering said opening in said base plate and having one edge thereof arranged perpendicular to said one edge of said first blade, means supporting said second blade for movement relative to said base plate in the direction perpendicular to its said one edge, and means for moving said second blade in said direction perpendicular to said one edge thereof to vary the size of said aperture in the other dimension thereof.
Claim 7
Dependent Claim
225 words
A photoexposure device as defined in claim 1 further characterized by said light source comprising a cathode ray tube having an output face, and said aperture means comprising a pair of fixed masks positioned adjacent said output face and collectively defining two spaced parallel edges between which said output face is unobstructed by said fixed masks, and second mask means positioned adjacent said output face and defining two spaced parallel edges oriented perpendicular to said spaced edges of said fixed masks and between which latter edges said output face is unobstructed by said second mask means so that said spaced edges of said fixed masks and said spaced edges of said second mask means collectively define a rectangular aperture adjacent said output face, and said means for varying the size of said aperture in one dimension thereof in response to changes in the speed of said light spot relative to said photosensitive surface comprising means for sweeping the beam of said cathode ray tube back and forth across said aperture in a direction generally perpendicular to said spaced edges of said second mask means to illuminate a portion of said aperture in the dimension thereof perpendicular to said spaced edges of said fixed masks and the length of which illuminated portion is dependent on the speed of said light spot relative to said photosensitive surface.
Claim 8
Dependent Claim
76 words
A photoexposure device as defined in claim 6 further characterized by said second mask means including at least one blade defining one of said spaced edges of said second mask means and movable relative to the face of said cathode ray tube in the direction perpendicular to said latter edge, and means for moving said at least one blade relative to said face of said cathode ray tube in said direction perpendicular to said latter edge.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |