Patent US4273467A successfully refreshed from Google Patents.
US3849698A
Expired / Lapsed
US
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Electromechanical sweep generating system with the utilization of photocells
Assignee: SRI International Inc
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Filing: 1973-04-25
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Granted: 1974-11-19
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Expires: 1993-04-25
Abstract
Abstract An electrical waveform is generated which is sinusoidal relative to the angular position of a shaft which rotates in a single direction by means of an optically sensed, or scanned, patterned disk affixed to the shaft to rotate in synchronism with it. The pattern on the disk primarily comprises uniformly spaced parallel lines on its face. In addition, a half revolution sensor such as a peripheral band having halves of differing optical properties is used. A first photocell scans the lines on the disk as it is rotated to count the number of lines and a second photocell scans the half revolution indicator, e.g., the peripheral band (outside track) of the disk. The first photocell produces a series of pulses indicative of the number of lines scanned and the second photocell produces an output which indicates when all of the lines on the face have been counted once and provides interlace between alternate counts. The number of lines scanned is added until they have all been counted once to produce the increasing half of the sinusoidal wave and then they are subtracted until they have all been counted a second time to produce the decreasing half of the sinusoidal wave. The sequence is repeated continuously to provide the desired waveform which is used as the vertical deflection voltage for a display device. Each line counted is also used to generate a horizontal sweep voltage for the display device so that in spite of the sinusoidal character of the vertical deflection, the lines composing the raster of the display are evenly and uniformly spaced.
Inventors
- 👤 H Frohbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:05
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/52; G01S7/52017; G01S7/52053; G01S7/52057; H; H03; H03K; H03K4/00; H03K4/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
193 words
Apparatus for generating synchronizing signals in synchronism with a rotating device comprising: disk means; means for rotatably supporting said disk means to be driven in synchronism with said rotating device; said disk means having parallel, equally spaced lines of one color alternate with parallel, equally spaced lines of a second color covering a face thereof and having a marking of one color extending over half of the perimeter of said face and a marking of another color extending over the other half of the perimeter of said face; a first photodetector means adjacent to said disk means and spaced at a predetermined radial distance from the center thereof for generating first signals responsive to the lines of said disk means; a second photodetector means adjacent said disk means positioned for generating second signals responsive to one of the colors on the perimeter of said disk means; first means responsive to said first signals for generating ramp signals synchronous with each first signal; and second means responsive to said first and second signals for generating an analog voltage which increases in the presence of second signals and decreases in the absence of second signals.
Claim 2
Dependent Claim
193 words
Apparatus for generating synchronizing signals in synchronism with a rotating device comprising: disk means; means for rotatably supporting said disk means to be driven in synchronism with said rotating device; said disk means having parallel, equally spaced lines of one color alternate with parallel, equally spaced lines of a second color covering a face thereof and having a marking of one color extending over half of the perimeter of said face and a marking of another color extending over the other half of the perimeter of said face; a first photodetector means adjacent to said disk means and spaced at a predetermined radial distance from the center thereof for generating first signals responsive to the lines of said disk means; a second photodetector means adjacent said disk means positioned for generating second signals responsive to one of the colors on the perimeter of said disk means; first means responsive to said first signals for generating ramp signals synchronous with each first signal; and second means responsive to said first and second signals for generating an analog voltage which increases in the presence of second signals and decreases in the absence of second signals.
Claim 3
Dependent Claim
36 words
Apparatus as recited in claim 1 wherein said first means responsive to said first signals for generating ramp signals comprises ramp generator means to which said first signals are applied for generating ramp signals responsive thereto.
Claim 4
Dependent Claim
106 words
Apparatus as recited in claim 1 wherein said second means responsive to said first and second signals for generating an analog voltage comprises: up-down counter means; means for applying the output of said second photocell means to said up-down counter means to enable it to count up in response to second signals and down in the absence of second signals; means for applying first signals to said up-down counter means to be counted; digital-to-analog counter means for converting the output of said up-down counter means to an analog voltage; and means for applying said second signals to said digital-to-analog voltage means as a least significant bit.
Claim 5
Dependent Claim
50 words
A system as recited in claim 1 wherein there is included a cathode ray tube means; means to apply said ramp signals to said cathode ray tube means as horizontal deflection voltages; and means to apply said analog signal to said cathode ray tube means as a vertical deflection voltage.
Claim 6
Dependent Claim
286 words
Apparatus for generating synchronizing signals in synchronism with a rotating device comprising disk means; means for rotatably supporting said disk means to be driven synchronously with said rotating device; said disk means having parallel, equally spaced lines of one color alternate with parallel equally spaced lines of a second color covering a face thereof and having a marking of one color extending over half of the perimeter of said face and a marking of another color extending over the other half of the perimeter of said face; a first photodetector means adjacent to said disk means and spaced at a predetermined radial distance from the center thereof for generating first signals responsive to the lines on said disk means; a second photodetector means adjacent said disk means positioned for generating second signals responsive to one of the colors on the perimeter of said disk means; up-down counter means; means for applying the output of said first photocell to said up-down counter means to cause it to count in response thereto; means for applying the output of the second pHotocell to said up-down counter means to cause it to count up when said second photodetector means is viewing one color on the perimeter of said disk and to count down when said second photodetector means is viewing said another color on the perimeter of said disk; means for converting the output of said up-down counter means to an analog voltage synchronous with the angular position of said rotating device; and means for generating ramp voltage responsive to each output of said first photocell which causes said up-down counter means to count in a manner synchronous with each line of said one color detected by said first photocell.
Claim 7
Dependent Claim
286 words
Apparatus for generating synchronizing signals in synchronism with a rotating device comprising disk means; means for rotatably supporting said disk means to be driven synchronously with said rotating device; said disk means having parallel, equally spaced lines of one color alternate with parallel equally spaced lines of a second color covering a face thereof and having a marking of one color extending over half of the perimeter of said face and a marking of another color extending over the other half of the perimeter of said face; a first photodetector means adjacent to said disk means and spaced at a predetermined radial distance from the center thereof for generating first signals responsive to the lines on said disk means; a second photodetector means adjacent said disk means positioned for generating second signals responsive to one of the colors on the perimeter of said disk means; up-down counter means; means for applying the output of said first photocell to said up-down counter means to cause it to count in response thereto; means for applying the output of the second pHotocell to said up-down counter means to cause it to count up when said second photodetector means is viewing one color on the perimeter of said disk and to count down when said second photodetector means is viewing said another color on the perimeter of said disk; means for converting the output of said up-down counter means to an analog voltage synchronous with the angular position of said rotating device; and means for generating ramp voltage responsive to each output of said first photocell which causes said up-down counter means to count in a manner synchronous with each line of said one color detected by said first photocell.
Claim 8
Dependent Claim
57 words
A system as recited in claim 5 wherein said means for converting the count of said up-down counter means to an analog voltage comprises a digital-to-analog converter to which the count of said up-down counter means is applied; and means for applying the output of said second photocell to said digital-to-analog converter as a least significant bit.
Claim 9
Dependent Claim
50 words
A system as recited in claim 5 wherein there is included a cathode ray tube means; means to apply said ramp signals to said cathode ray tube means as horizontal deflection voltages; and means to apply said analog signal to said cathode ray tube means as a vertical deflection voltage.
Claim 10
Independent Claim
101 words
An apparatus for generating electrical waveforms in synchronism with the movements of a device which follows a regular, repetitive motion said apparatus comprising disk means; means for rotatably supporting said disk means in synchronism with the regular, repetitive motion of said device; and said disk means having parallel, equally spaced lines of one color alternate with parallel, equally spaced lines of a second color covering a face thereof and having a marking of one color extending over half of the perimeter of said face and a marking of another color extending over the other half of the perimeter of said face.
Claim 11
Independent Claim
101 words
An apparatus for generating electrical waveforms in synchronism with the movements of a device which follows a regular, repetitive motion said apparatus comprising disk means; means for rotatably supporting said disk means in synchronism with the regular, repetitive motion of said device; and said disk means having parallel, equally spaced lines of one color alternate with parallel, equally spaced lines of a second color covering a face thereof and having a marking of one color extending over half of the perimeter of said face and a marking of another color extending over the other half of the perimeter of said face.
Claim 12
Dependent Claim
100 words
Apparatus as recited in claim 8 wherein there is provided a decoding means, said decoding means including scanning means for scanning the said equally spaced lines provided on said disk means and generating an electrical waveform in response to the number of lines counted, and means to cause said electrical waveform to increase as one half of the said equally spaced lines on said disk means is counted and decrease when the other half of said equally spaced lines is counted, whereby the said electrical waveform is substantially sinusoidal with respect to the angular position of said rotatable disk means.
Claim 13
Dependent Claim
148 words
Apparatus for generating synchronizing signals in synchronism with a rotating device comprising disk means; means for rotatably supporting said disk means to be driven in synchronism with said rotating device; said disk means having parallel, equally spaced lines of one color alternate with parallel, equally spaced lines of a second color covering a face thereof; photodetector means adjacent to said disk means and spaced at a predetermined radial distance from the center thereof for generating first signals responsive to the lines of said disk means; second signal generating means for generating second signals responsive to half revolutions of said disk means; first means responsive to said first signals for generating ramp signals synchronous with each first signal; and second means responsive to said first and second signals for generating an analog voltage which increases in the presence of second signals and decreases in the absence of second signals.
Claim 14
Dependent Claim
148 words
Apparatus for generating synchronizing signals in synchronism with a rotating device comprising disk means; means for rotatably supporting said disk means to be driven in synchronism with said rotating device; said disk means having parallel, equally spaced lines of one color alternate with parallel, equally spaced lines of a second color covering a face thereof; photodetector means adjacent to said disk means and spaced at a predetermined radial distance from the center thereof for generating first signals responsive to the lines of said disk means; second signal generating means for generating second signals responsive to half revolutions of said disk means; first means responsive to said first signals for generating ramp signals synchronous with each first signal; and second means responsive to said first and second signals for generating an analog voltage which increases in the presence of second signals and decreases in the absence of second signals.
Claim 15
Dependent Claim
36 words
Apparatus as recited in claim 10 wherein said first means responsive to said first signals for generating ramp signals comprises ramp generator means to which said first signals are applied for generating ramp signals responsive thereto.
Claim 16
Dependent Claim
107 words
Apparatus as recited in claim 10 wherein said second means responsive to said first and second signals for generating an analog voltage comprises: up-down counter means; means for applying the output of sAid second signal generating means to said up-down counter means to enable it to count up in response to second signals and down in the absence of second signals; means for applying first signals to said up-down counter means to be counted; digital-to-analog counter means for converting the output of said up-down counter means to an analog voltage; and means for applying said second signals to said digital-to-analog voltage means as a least significant bit.
Claim 17
Dependent Claim
65 words
Apparatus as recited in claim 10 wherein said disk means also has a centrally located circular area divided in two halves by a diameter with one half being of one color and the other half of another color and said second signal generating means includes a second photodetector means positioned to be responsive to one of the colors on the said centrally located circular area.
Claim 18
Dependent Claim
69 words
Apparatus as recited in claim 10 wherein said second signal generating means includes a second disk means mounted to rotate with said first disk means and being divided in two halves by a diameter with one half being of one color and the other half of another color and also including a second photodetector means positioned to be responsive to one of the colors on the said second disk.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |