Method and apparatus for downloading information from a controllable light source to a portable information device
First Claim
1. The method of transmitting data from a transmitter to a receiver, said transmitter including a display screen made up of a plurality of pixels arranged in a two-dimensional array that is scanned repeatedly to produce a spatially and temporally variable, two-dimensional, light image on the screen, and said receiver including a photosensor, which is much smaller than said screen, for detecting light impinging on the photosensor, said method comprising the steps of:
- positioning the receiver so that the photosensor receives light from substantially the entirety of said screen;
operating the transmitter to modulate the light produced by said screen so that a plurality of successive light pulses emanate from said screen during each complete scanning of said screen, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels, said light pulses representing said data and being characterized by a predetermined pulse rate which is substantially greater than the rate at which complete scannings of said screen are performed; and
using the receiver to detect said light pulses via said photosensor and to thereby receive said data for use by said receiver.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for transferring data from a CRT (cathode ray tube) video display monitor on a personal computer to a portable information device such as a multifunction electronic wristwatch. The CRT video display has a video signal generator providing raster scanning of the screen and a program for formatting the binary coded data into blocks of serial data bits, with start bit and stop bit. The blocks of data are supplied to the video signal generator in synchronism with raster scanning of the screen so as to provide an integral number of one or more blocks of data for each vertical frame, and modulated to vary the brightness of the screen and provide light pulses corresponding to presence or absence of binary coded transmitter pulses. The portable information device is manipulated within line of sight of the CRT screen and has a photosensor to detect light pulses when the photosensor is directed toward the screen. Signals from the photosensor are amplified and filtered to remove ambient light source flicker and extraneous spurious light signals and to convert the receiver pulses to binary coded data blocks varying between high and low logic levels at a preselected pulse repetition rate. The portable information device stores the received data for further use.
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Citations
35 Claims
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1. The method of transmitting data from a transmitter to a receiver, said transmitter including a display screen made up of a plurality of pixels arranged in a two-dimensional array that is scanned repeatedly to produce a spatially and temporally variable, two-dimensional, light image on the screen, and said receiver including a photosensor, which is much smaller than said screen, for detecting light impinging on the photosensor, said method comprising the steps of:
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positioning the receiver so that the photosensor receives light from substantially the entirety of said screen; operating the transmitter to modulate the light produced by said screen so that a plurality of successive light pulses emanate from said screen during each complete scanning of said screen, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels, said light pulses representing said data and being characterized by a predetermined pulse rate which is substantially greater than the rate at which complete scannings of said screen are performed; and using the receiver to detect said light pulses via said photosensor and to thereby receive said data for use by said receiver. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Apparatus for transmitting data comprising:
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a transmitter having a display screen made up of a plurality of pixels arranged in a two-dimensional array that is scanned repeatedly to enable the screen to display a spatially and temporally variable, two-dimensional, light image; a receiver having a photosensor for producing an output signal indicative of the amount of light impinging on the photosensor, said photosensor being much smaller than said screen, and said receiver being positionable relative to said screen so that said photosensor receives light from substantially the entirety of said screen; said transmitter further including screen controls for causing said screen to emit a plurality of successive light pulses during each complete scanning of said screen, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels, said light pulses representing said data and being characterized by a pulse rate which is substantially greater than the rate at which complete scannings of said screen are performed; and said receiver further including circuitry for processing the output signal of said photosensor to detect said data represented by said light pulses and received by said receiver via said photosensor. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. The method of transmitting data from a transmitter to a receiver, said transmitter including a display screen made up of a plurality of pixels arranged in a two-dimensional array that is scanned repeatedly to produce a spatially and temporally variable, two-dimensional, light image on the screen, and said receiver including a photosensor, which is much smaller than said screen, for detecting light impinging on the photosensor, said method comprising the steps of:
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positioning the receiver so that the photosensor receives light from substantially the entirety of said screen; operating the transmitter to modulate the light produced by said screen so that a plurality of successive, substantially temporally non-overlapping light pulses emanate from the screen during each complete scanning of the screen, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels, said light pulses representing said data; and using the receiver to detect said light pulses via said photosensor and to thereby receive said data for use by said receiver. - View Dependent Claims (15, 16, 17, 18)
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19. Apparatus for transmitting data comprising:
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a transmitter having a display screen made up of a plurality of pixels arranged in a two-dimensional array that is scanned repeatedly to enable the screen to display a spatially and temporally variable, two-dimensional, light image; a receiver having a photosensor for producing an output signal indicative of the amount of light impinging on the photosensor, said photosensor being much smaller than said screen, and said receiver being positionable relative to said screen so that said photosensor receives light from substantially the entirety of said screen; said transmitter further including screen controls for causing said screen to emit a plurality of successive, substantially temporally non-overlapping light pulses during each complete scanning of said screen, each of said light pulses being produced by sequentially illuminating a subplurality of said pixels, said light pulses representing said data; and said receiver further including circuitry for processing the output signal of said photosensor to detect said data represented by said light pulses and received by said receiver via said photosensor. - View Dependent Claims (20, 21, 22, 23, 24)
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25. The method of using a display screen of a transmitter to transmit data from the transmitter to a receiver which is positioned to view substantially the entirety of said screen, said screen made up of a plurality of pixels arranged in a two-dimensional array and being scanned repeatedly by a modulatable scanning signal to produce a spatially and temporally variable, two-dimensional, light image on the screen, said screen having a plurality of substantially parallel lines that are scanned successively at a predetermined line scanning rate to produce a complete scanning of said screen each time all of said lines have been scanned, said method comprising the step of:
modulating said scanning signal so that the screen emits a plurality of successive, substantially temporally non-overlapping light pulses during each complete scanning of the screen, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels, said light pulses representing said data and being characterized by a predetermined pulse rate which is substantially less than the line scanning rate of said screen. - View Dependent Claims (26, 27)
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28. A transmitter having a display screen for transmitting data from the transmitter to a receiver which is positionable to view substantially the entirety of said screen, said transmitter comprising:
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said display screen being made up of a plurality of pixels arranged in a two-dimensional array and being scanned repeatedly by a modulatable scanning signal to produce a spatially and temporally variable, two-dimensional, light image on the screen, said screen having a plurality of substantially parallel lines that are scanned successively at a predetermined line scanning rate to produce a complete scanning of said screen each time all of said lines have been scanned; and screen controls for modulating said scanning signal so that said screen emits a plurality of successive, substantially temporally non-overlapping light pulses during each complete scanning of the screen, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels, said light pulses representing said data and being characterized by a predetermined pulse rate which is substantially less than the line scanning rate of said screen. - View Dependent Claims (29, 30)
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31. The method of using a receiver to receive data transmitted by a transmitter via a plurality of successive light pulses emitted by a display screen of said transmitter, said display screen made up of a plurality of pixels arranged in a two-dimensional array and being capable of producing a spatially and temporally variable, two-dimensional, light image, said receiver including a photosensor, which is much smaller than said screen, for producing an output signal indicative of the amount of light impinging on the photosensor, said method comprising the steps of:
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positioning the receiver so that the photosensor can receive substantially all light emanating from said screen; detecting said light pulses via said photosensor, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels; and processing the output signal of said photosensor to detect said data represented by said light pulses. - View Dependent Claims (32)
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33. A receiver for receiving data transmitted by a transmitter via a plurality of successive light pulses emitted by a display screen of said transmitter, said display screen made up of a plurality of pixels arranged in a two-dimensional array and being capable of producing a spatially and temporally variable, two-dimensional, light image, said receiver comprising:
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a photosensor for producing an output signal indicative of the amount of light impinging on the photosensor, said photosensor being much smaller than said screen and being positionable relative to said screen so that said photosensor receives light from substantially the entirety of said screen; and circuitry for processing the output signal of said photosensor to detect said data represented by said light pulses and received by said receiver via said photosensor, each of said light pulses being produced by sequentially illuminating a sub-plurality of said pixels. - View Dependent Claims (34, 35)
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Specification