US4024385A
Expired / Lapsed
US
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Second difference function generator
Assignee: Raytheon Co
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Filing: 1976-02-09
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Granted: 1977-05-17
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Expires: 1996-02-09
Abstract
Abstract High accuracy function calculating apparatus using a minimum of components and storage locations. Second difference values of the function to be generated are stored in a read-only memory which is addressed by an incrementable and reversible address counter. A first accumulator circuit connected to the output of the read-only memory calculates the first difference values of the function. A second accumulator coupled to the output of the first accumulator calculates the values of the desired function. The apparatus is used to advantage in radar azimuth converter applications as well as in general purpose function calculating applications.
Inventors
- 👤 Gerald P. Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:27
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/22; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/295; G06F; G06F1/00; G06F1/02; G06F1/03; G06F1/035
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
160 words
In combination: data storage means; means for sequentially addressing said data storage means; first adder means; means for coupling outputs of said data storage means to first inputs of said first adder means; first register means coupled to outputs of said first adder means, second inputs of said first adder means being coupled to outputs of said first register means; second adder means having first inputs coupled to said inputs of said first register means; second register means coupled to outputs of said second adder means, second inputs of said second adder means being coupled to outputs of said second register means; means for multiplying the number represented by said outputs of said second register by a predetermined number; means for sequentially accumulating the number represented by outputs of said multiplying means; means for converting outputs of said accumulating means to an analog voltage; and means for deflecting the beam of a cathode-ray tube in accordance with said analog voltage.
Claim 2
Dependent Claim
160 words
In combination: data storage means; means for sequentially addressing said data storage means; first adder means; means for coupling outputs of said data storage means to first inputs of said first adder means; first register means coupled to outputs of said first adder means, second inputs of said first adder means being coupled to outputs of said first register means; second adder means having first inputs coupled to said inputs of said first register means; second register means coupled to outputs of said second adder means, second inputs of said second adder means being coupled to outputs of said second register means; means for multiplying the number represented by said outputs of said second register by a predetermined number; means for sequentially accumulating the number represented by outputs of said multiplying means; means for converting outputs of said accumulating means to an analog voltage; and means for deflecting the beam of a cathode-ray tube in accordance with said analog voltage.
Claim 3
Dependent Claim
12 words
The combination of claim 1 wherein said addressing means comprises a counter.
Claim 4
Dependent Claim
15 words
The combination of claim 1 wherein said data storage means comprises a read only memory.
Claim 5
Dependent Claim
19 words
The combination of claim 3 wherein second difference values of a function are stored in said read only memory.
Claim 6
Dependent Claim
16 words
The combination of claim 4 further comprising means for initializing said first and second register means.
Claim 7
Dependent Claim
12 words
The combination of claim 4 wherein said function comprises a trigonometric function.
Claim 8
Dependent Claim
13 words
The combination of claim 6 wherein said trigonometric function comprises a sine function.
Claim 9
Dependent Claim
13 words
The combination of claim 6 wherein said trigonometric function comprises a cosine function.
Claim 10
Dependent Claim
215 words
In combination: means for providing a binary count in response to a sequence of input pulses; a read-only memory, said read-only memory being addressed by said count providing means, said read-only memory containing values representing second differences of 45° of a sine function and 45° of a cosine function, each of said values comprising two binary bits; at least one first accumulator means, inputs of said first accumulator means being coupled to outputs of said read-only memory, and said first accumulator means producing first difference values from said second difference values; at least one second accumulator means, inputs of said second accumulator means being coupled to outputs of said first accumulator means, said second accumulator means producing values of a sinusoidal function from said first difference values; means for initializing said first and second accumulator means to predetermined values; said values of said sinusoidal function being accurate to 18 ± 1/2 binary places; means for multiplying said values of said sinusoidal function by a predetermined number; at least one third accumulator means, inputs of said third accumulator means being coupled to outputs of said multiplying means; means for converting outputs of said third accumulating means to an analog voltage; and means for deflecting the beam of a cathode-ray tube in accordance with said analog voltage.
Claim 11
Dependent Claim
215 words
In combination: means for providing a binary count in response to a sequence of input pulses; a read-only memory, said read-only memory being addressed by said count providing means, said read-only memory containing values representing second differences of 45° of a sine function and 45° of a cosine function, each of said values comprising two binary bits; at least one first accumulator means, inputs of said first accumulator means being coupled to outputs of said read-only memory, and said first accumulator means producing first difference values from said second difference values; at least one second accumulator means, inputs of said second accumulator means being coupled to outputs of said first accumulator means, said second accumulator means producing values of a sinusoidal function from said first difference values; means for initializing said first and second accumulator means to predetermined values; said values of said sinusoidal function being accurate to 18 ± 1/2 binary places; means for multiplying said values of said sinusoidal function by a predetermined number; at least one third accumulator means, inputs of said third accumulator means being coupled to outputs of said multiplying means; means for converting outputs of said third accumulating means to an analog voltage; and means for deflecting the beam of a cathode-ray tube in accordance with said analog voltage.
Claim 12
Dependent Claim
30 words
The combination of claim 9 wherein said values in said read-only memory comprise values representing the first 45° of the sine function and the first 45° of the cosine function.
Claim 13
Dependent Claim
17 words
The combination of claim 10 wherein said first and second accumulator means are each two in number.
Claim 14
Dependent Claim
40 words
The combination of claim 11 wherein said initializing means initializes said first accmulator means to the first difference of one of said sine and cosine functions and initializes said second accumulator means to the first value of said sinusoidal function.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |