Fast serial data transmission using a CRT
First Claim
1. A method of serially transferring a sequence of data units to a portable information device, each data unit having one of a plurality of possible values, the method comprising the following steps:
- displaying sequential display frames on a frame-scanning graphics display device;
illuminating line segments within the display frames to represent the individual data units, each such line segment having a continuous length on the display device which produces an optical pulse of a corresponding duration;
encoding each possible data unit value as a different line segment length to produce an optical pulse for each data unit having a duration which is dependent on the value of the data unit.
2 Assignments
0 Petitions
Accused Products
Abstract
Disclosed herein is a system and method of serially transferring a sequence of data bits between a computer and a portable information device such as the Timex Data Link™ watch, using the CRT of the computer as a transmission medium. The computer is programmed to display sequential display frames on a frame-scanning graphics display device and to illuminate line segments within the display frames to represent individual data bits. Each line segment has a continuous length on the display device which produces an optical pulse of a corresponding duration. Each data bit is encoded as a different line segment length to produce an optical pulse for each data bit having a duration which is dependent on the value of the data bit. For example, a pulse representing a binary value of 0 has a duration which is relatively longer than that of a pulse representing a binary 1. A receiving device monitors the optical signal created by the CRT and detects rising signal edges. It interprets each rising edge as the beginning of a single bit. After detecting a rising edge, the receiving device waits for a pre-determined time and then samples the optical signal. If the pulse from the CRT is still present, the receiving device interprets the data bit as a binary 0. Otherwise, the receiving device interprets the data bit as a binary 1.
93 Citations
29 Claims
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1. A method of serially transferring a sequence of data units to a portable information device, each data unit having one of a plurality of possible values, the method comprising the following steps:
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displaying sequential display frames on a frame-scanning graphics display device; illuminating line segments within the display frames to represent the individual data units, each such line segment having a continuous length on the display device which produces an optical pulse of a corresponding duration; encoding each possible data unit value as a different line segment length to produce an optical pulse for each data unit having a duration which is dependent on the value of the data unit. - View Dependent Claims (2, 3)
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4. A method of serially transferring a sequence of data units to a portable information device, each data unit having one of a plurality of possible values, the method comprising the following steps:
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displaying sequential display frames on a frame-scanning graphics display device, each display frame comprising a plurality of available raster lines; identifying a plurality of line segments in the available raster lines, the individual line segments corresponding respectively to individual data units; dividing each line segment into at least first and second sub-segments; illuminating at least the first sub-segment of each line segment to produce an optical pulse of a minimum duration having a rising edge; if a particular data unit has a first of the possible values, discontinuing the illumination of the line segment corresponding to the particular data unit during the second sub-segment of said line segment; if the particular data unit does not have the first of the possible values, continuing to illuminate the corresponding line segment during its second sub-segment; unconditionally discontinuing the illumination after the second sub-segment of the corresponding line segment. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. A method of serially transferring a sequence of data units to a portable information device, each data unit having one of a plurality of possible values, the method comprising the following steps:
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displaying sequential display frames on a frame-scanning graphics display device, each display frame comprising a plurality of available raster lines; identifying a plurality of line segments in the available raster lines, the individual line segments corresponding respectively to individual data units; dividing each line segment into leading, trailing, and intermediate sub-segments; illuminating at least the leading sub-segment of each line segment to produce an optical pulse of a minimum duration having a rising edge; if a particular data unit has a first of the possible values, discontinuing the illumination of the line segment corresponding to the particular data unit during the intermediate and trailing sub-segments of said line segment; if the particular data unit does not have the first of the possible values, illuminating the corresponding line segment during its intermediate sub-segment and discontinuing the illumination during the trailing sub-segment. - View Dependent Claims (12, 13, 14)
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15. A method of receiving a serial transmission of data units in a portable information device, each data unit having one of a plurality of possible values, the method comprising the following steps:
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monitoring optical pulses generated by a frame-scanning graphics display device with an optical sensor; detecting the rising edges of the optical pulses; interpreting the rising edge of each optical pulse as the beginning of a corresponding data unit transmission; waiting a first pre-defined time from the rising edge of a particular optical pulse; after waiting the first pre-defined time from the rising edge, detecting whether the particular optical pulse has been discontinued; recording the data unit corresponding to the particular optical pulse as a first of the possible values only if the particular optical pulse has been discontinued after waiting the first pre-defined time. - View Dependent Claims (16, 17, 18)
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19. A system for serially transferring a sequence of data units to a portable information device, each data unit having one of a plurality of possible values, the system comprising:
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a frame-scanning graphics display device; means for displaying sequential display frames on the frame-scanning graphics display device; means for illuminating line segments within the display frames to represent the individual data units, each such line segment having a continuous length on the display device which produces an optical pulse of a corresponding duration; means for encoding each possible data unit value as different line segment length to produce an optical pulse for each data unit having a duration which is dependent on the value of the data unit. - View Dependent Claims (20, 21)
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22. A system for serially transferring a sequence of data units to a portable information device, each data unit having one of a plurality of possible values, the system comprising:
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a computer having a frame-scanning graphics display device for displaying sequential display frames, each display frame comprising a plurality of available raster lines which include a plurality of line segments corresponding respectively to individual data units, each line segment being divided into at least first and second sub-segments; the computer being programmed to; illuminate at least the first sub-segment of each line segment to produce an optical pulse of a minimum duration having a rising edge; if a particular data unit has a first of the possible values, discontinue the illumination of the corresponding line segment during its second sub-segment; if the particular data unit does not have the first of the possible values, continue to illuminate the corresponding line segment during its second sub-segment; unconditionally discontinue the illumination before the first sub-segment of the next line segment. - View Dependent Claims (23, 24, 25, 26, 27)
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28. A portable information device for receiving a serial transmission of data units, each data unit having one of a plurality of possible values, comprising:
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an optical sensor for monitoring optical pulses generated by a frame-scanning graphics display; internal logic configured to; detect rising edges of the optical pulses; interpret the rising edge of each optical pulse as the beginning of a corresponding data unit transmission; wait a pre-defined time from the rising edge of a particular optical pulse; after waiting the pre-defined time from the rising edge, detect whether the particular optical pulse has been discontinued; record the data unit corresponding to the particular optical pulse as a first of the possible values only if the particular optical pulse has been discontinued after waiting the pre-defined time. - View Dependent Claims (29)
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Specification