US3889225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sonar display
Assignee: Westinghouse Canada Inc
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Filing: 1973-08-09
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Granted: 1975-06-10
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Expires: 1993-08-09
Abstract
Abstract A PPI display system for sonar is based upon a digital clock. This constant reference is used to generate analog values for the deflection of the PPI display tube. The arrangement adds particular convenience to the adjustment of range in response to temperature, orientation of display with respect to north calibration of various cursors and the generation of cursors.
Inventors
- 👤 George J Mckenzie
- 👤 Heinz W Ruther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:51
CPC Classifications
H; H03; H03K; H03K7/00; H03K7/06; G; G01; G01S; G01S7/00; G01S7/52; G01S7/56; G01S7/62; G01S7/6218; G01S7/6227; Y; Y10; Y10S; Y10S367/00; Y10S367/902
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
119 words
In a plan position information display system, a master clock source of pulses of a fixed frequency, a variable clock source of pulses of a frequency adjustable in accordance with a variable ambient condition, a read only memory for producing a cyclically variable digital output function when driven by the count of the pulses from said master clock, a digital multiplier for multiplying the digital output from said read only memory with the digital value of the pulses produced by said variable clock and a digital to analogue converter which converts thE digital output from said multiplier into an analogue value for deflecting the beam of a cathode ray tube in accordance with the digital output from said multiplier.
Claim 2
Dependent Claim
119 words
In a plan position information display system, a master clock source of pulses of a fixed frequency, a variable clock source of pulses of a frequency adjustable in accordance with a variable ambient condition, a read only memory for producing a cyclically variable digital output function when driven by the count of the pulses from said master clock, a digital multiplier for multiplying the digital output from said read only memory with the digital value of the pulses produced by said variable clock and a digital to analogue converter which converts thE digital output from said multiplier into an analogue value for deflecting the beam of a cathode ray tube in accordance with the digital output from said multiplier.
Claim 3
Dependent Claim
15 words
A system as claimed in claim 1 wherein said cyclically variable function is a sinusoid.
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) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |