Long range optical pointing for video screens
First Claim
1. Apparatus for use in locating a spot on a video screen which is scanned in a raster, comprising:
- (a) an optical pointer including a photodetector responsive to light, a lens for focusing a portion of the image of a plurality of raster lines from the screen on the photodetector, and detection means responsive to the photodetector for providing an output signal pulse corresponding to the incidence of light from a raster line on the photodetector;
(b) signal processing means, responsive to the detected raster line output signal from the optical pointer and to the vertical and horizontal video signals controlling the display on the video screen for a frame of raster lines, for determining an averaged vertical and horizontal position with respect to the screen of the video image of a plurality of the detected raster lines incident on the photodetector during a frame of raster lines and providing an output signal indicative thereof.
1 Assignment
0 Petitions
Accused Products
Abstract
A long range optical pointing apparatus (10) is disclosed which can locate a spot (24) on a video screen (16) from a position several feet away from the screen. An optical pointer unit (11) focuses a portion of the raster lines traced over the video screen during one frame onto a photodetector (28), and provides an output pulse when a raster line is focused upon and detected by the photodetector. The detected raster line pulses are provided to a processing unit (13) which also receives the vertical and horizontal deflection signals from the video terminal (15). The processing circuitry (13) averages the positions of the group of raster line portions detected by the optical pointer unit to provide an averaged vertical and horizontal position for the area of the screen at which the pointer (11) is directed. The vertical and horizontal information provided by the processing circuitry can be used by a computer (19) to provide a cursor at the spot (24) on the video screen (16) to inform the user of the position on the screen at which he is pointing. The optical pointer unit (11) can be worn on the head of a user seated before the video terminal (15) so that communication with the computer (19) through the video screen can be accomplished with head pointing movements.
60 Citations
23 Claims
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1. Apparatus for use in locating a spot on a video screen which is scanned in a raster, comprising:
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(a) an optical pointer including a photodetector responsive to light, a lens for focusing a portion of the image of a plurality of raster lines from the screen on the photodetector, and detection means responsive to the photodetector for providing an output signal pulse corresponding to the incidence of light from a raster line on the photodetector; (b) signal processing means, responsive to the detected raster line output signal from the optical pointer and to the vertical and horizontal video signals controlling the display on the video screen for a frame of raster lines, for determining an averaged vertical and horizontal position with respect to the screen of the video image of a plurality of the detected raster lines incident on the photodetector during a frame of raster lines and providing an output signal indicative thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Apparatus for use in locating a spot on a video screen which is scanned in a raster, comprising:
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(a) an optical pointer including a lens focusing a portion of the video field from the screen and means for detecting a portion of the image as focused by the lens and providing a pulse signal when a raster line image is detected; (b) means for timing the pulses produced by the optical pointer from detected raster lines with respect to the horizontal synchronization signal of the video screen indicating the end of each horizontal raster line; and (c) means for averaging the times between the beginning of the detected raster pulses and the horizontal synchronization signals for a plurality of raster lines in a frame of raster lines to provide an estimate of the position of the detected portion of the screen. - View Dependent Claims (16, 17)
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18. Apparatus for use in locating a spot on a video screen which is scanned in a raster to provide a frame of background light intendity covering the screen, comprising:
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(a) an optical pointer including a lens focusing a portion of the video field from the screen and means for detecting a portion of the image as focused by the lens and providing a pulse output signal when each raster line passes through the detected portion of the image field; (b) means for timing a selected plurality of the pulses produced from detected raster lines with respect to the vertical synchronization signal of the video screen for each frame of the video image; and (c) means for averaging the times between the selected plurality of detected raster line pulses in a frame of raster lines and the vertical synchronization signal to provide an estimate of the average vertical position of the detected portion of the screen. - View Dependent Claims (19)
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20. A method of locating a particular spot on a video screen which is scanned in a raster, comprising the steps of:
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(a) focusing a portion of the video field from the screen; (b) detecting a portion of the focused image from the video screen and providing a pulse output signal when a raster line passes through the detected portion of the field; (c) timing the pulses produced from the detected raster lines with respect to the horizontal synchronization signal of the video screen indicating the end of each horizontal line; and (d) averaging the times between the beginning of detected raster line pulses and the horizontal synchronization signal for a plurality of raster lines in a frame of raster lines to provide an estimate of the position of the detected portion of the screen. - View Dependent Claims (21, 22)
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23. A method of locating a particular spot on a video screen, comprising the steps of:
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(a) scanning the screen in a raster to provide a frame of background light intensity covering the screen; (b) focusing a portion of the video field from the screen; (c) detecting a portion of the focused image from the video screen and providing a pulse output signal when each raster line passes through the detected portion of the field; (d) timing a selected plurality of the pulses produced from detected raster lines with respect to the vertical synchronization signal of the video screen for each frame of the video image; and (e) averaging the times between the selected plurality of detected raster line pulses and the vertical synchronization signal in a frame of raster lines to provide an estimate of the average vertical position of the detected portion of the screen.
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Specification