US3614743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable stroke character generator
Assignee: Digital Equipment Corp
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Filing: 1969-01-14
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Granted: 1971-10-19
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Expires: 1989-01-14
Abstract
Abstract Each character to be displayed by a cathode-ray tube is assigned unique control and mask words. A portion of the assigned mask word designates one of a plurality of predetermined masks best suited for generation of a character; each mask defining a unique plurality of character stroke endpoints. The control word determines which of the various character strokes defined by a mask are to be executed by the CRT beam, while the remaining portion of the mask word determines which of the executed character strokes are to be visible.
Inventors
- 👤 Murray Ruben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:18
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/06; G09G1/08
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
308 words
The method of generating a font of characters for display on the screen of a cathode-ray tube, said method comprising the steps of A. storing 1. a plurality of masks, a. each mask consisting of coordinate address data for positioning the cathode-ray tube beam to a unique plurality of stroke endpoints, b. the endpoints of each mask being allotted a numbering sequence, 2. a control word assigned to each character, a. each control word consisting of a plurality of bits with each bit associated with a different endpoint of a particular mask, and 3. a mask word assigned to each character, each mask word having a. a first part designating a particular one of said masks, and b. a second part consisting of a plurality of bits, each associated with a different one of those bits of the commonly assigned control word having a first logical significance; B. accepting a character to be generated; C. locating the storage location of the control and mask words assigned to a character to be generated; D. locating on the basis of the first part of the assigned mask word the storage location of the first endpoint coordinate address data of the designated mask; E. retrieving the assigned control word from storage; F. interpreting a first bit of the assigned control word to determine its logical significance; G. when said first bit is determined to be of a first logical significance, retrieving the coordinate address data of the associated mask endpoint and supplying it to cathode-ray tube control circuitry; H. retrieving the assigned mask word; and I. interpreting the bit of the assigned mask word associated with said first bit of the assigned control word to determine the intensity of the beam as it executes a stroke to the endpoint whose coordinate address data was supplied to the cathode-ray tube control circuitry.
Claim 2
Independent Claim
308 words
The method of generating a font of characters for display on the screen of a cathode-ray tube, said method comprising the steps of A. storing 1. a plurality of masks, a. each mask consisting of coordinate address data for positioning the cathode-ray tube beam to a unique plurality of stroke endpoints, b. the endpoints of each mask being allotted a numbering sequence, 2. a control word assigned to each character, a. each control word consisting of a plurality of bits with each bit associated with a different endpoint of a particular mask, and 3. a mask word assigned to each character, each mask word having a. a first part designating a particular one of said masks, and b. a second part consisting of a plurality of bits, each associated with a different one of those bits of the commonly assigned control word having a first logical significance; B. accepting a character to be generated; C. locating the storage location of the control and mask words assigned to a character to be generated; D. locating on the basis of the first part of the assigned mask word the storage location of the first endpoint coordinate address data of the designated mask; E. retrieving the assigned control word from storage; F. interpreting a first bit of the assigned control word to determine its logical significance; G. when said first bit is determined to be of a first logical significance, retrieving the coordinate address data of the associated mask endpoint and supplying it to cathode-ray tube control circuitry; H. retrieving the assigned mask word; and I. interpreting the bit of the assigned mask word associated with said first bit of the assigned control word to determine the intensity of the beam as it executes a stroke to the endpoint whose coordinate address data was supplied to the cathode-ray tube control circuitry.
Claim 3
Dependent Claim
30 words
a control word assigned to each character, a. each control word consisting of a plurality of bits with each bit associated with a different endpoint of a particular mask, and
Claim 4
Dependent Claim
30 words
a control word assigned to each character, a. each control word consisting of a plurality of bits with each bit associated with a different endpoint of a particular mask, and
Claim 5
Dependent Claim
38 words
feeding the coordinate address data of the mask endpoint associated with the interpreted stroke control data bit to the cathode-ray tube pursuant to executing a Beam stroke thereto if said interpreted bit is of said first logical significance.
Claim 6
Dependent Claim
38 words
feeding the coordinate address data of the mask endpoint associated with the interpreted stroke control data bit to the cathode-ray tube pursuant to executing a Beam stroke thereto if said interpreted bit is of said first logical significance.
Claim 7
Dependent Claim
18 words
if the character display is completed, immediately proceeding to the generation of the next character to be displayed.
Claim 8
Dependent Claim
18 words
if the character display is completed, immediately proceeding to the generation of the next character to be displayed.
Claim 9
Dependent Claim
52 words
The method defined in claim 1, and A. determining when said first bit of the assigned control word is of a second logical significance, and then B. interpreting the next bit in sequence of the assigned control word without retrieving the endpoint coordinate address data associated with said first control word bit.
Claim 10
Dependent Claim
18 words
interrupting said test cycle when it is determined that a beam stroke is not to be executed, and
Claim 11
Dependent Claim
18 words
interrupting said test cycle when it is determined that a beam stroke is not to be executed, and
Claim 12
Dependent Claim
24 words
initiating the display of an executed beam stroke when an interpreted bit of said selected display control data is of a first logical significance.
Claim 13
Dependent Claim
24 words
initiating the display of an executed beam stroke when an interpreted bit of said selected display control data is of a first logical significance.
Claim 14
Dependent Claim
6 words
immediately initiating a new test cycle.
Claim 15
Dependent Claim
6 words
immediately initiating a new test cycle.
Claim 16
Dependent Claim
50 words
The method defined in claim 2, and A. sensing the remaining bits in sequence from said first bit Of the assigned control word to determine the logical significance thereof, and B. when said remaining bits are all of a second logical significance, immediately accept a next character to be generated.
Claim 17
Dependent Claim
214 words
a mask word assigned to each character, each mask word having a. a first part designating a particular one of said masks, and b. a second part consisting of a plurality of bits, each associated with a different one of those bits of the commonly assigned control word having a first logical significance; B. accepting a character to be generated; C. locating the storage location of the control and mask words assigned to a character to be generated; D. locating on the basis of the first part of the assigned mask word the storage location of the first endpoint coordinate address data of the designated mask; E. retrieving the assigned control word from storage; F. interpreting a first bit of the assigned control word to determine its logical significance; G. when said first bit is determined to be of a first logical significance, retrieving the coordinate address data of the associated mask endpoint and supplying it to cathode-ray tube control circuitry; H. retrieving the assigned mask word; and I. interpreting the bit of the assigned mask word associated with said first bit of the assigned control word to determine the intensity of the beam as it executes a stroke to the endpoint whose coordinate address data was supplied to the cathode-ray tube control circuitry.
Claim 18
Dependent Claim
214 words
a mask word assigned to each character, each mask word having a. a first part designating a particular one of said masks, and b. a second part consisting of a plurality of bits, each associated with a different one of those bits of the commonly assigned control word having a first logical significance; B. accepting a character to be generated; C. locating the storage location of the control and mask words assigned to a character to be generated; D. locating on the basis of the first part of the assigned mask word the storage location of the first endpoint coordinate address data of the designated mask; E. retrieving the assigned control word from storage; F. interpreting a first bit of the assigned control word to determine its logical significance; G. when said first bit is determined to be of a first logical significance, retrieving the coordinate address data of the associated mask endpoint and supplying it to cathode-ray tube control circuitry; H. retrieving the assigned mask word; and I. interpreting the bit of the assigned mask word associated with said first bit of the assigned control word to determine the intensity of the beam as it executes a stroke to the endpoint whose coordinate address data was supplied to the cathode-ray tube control circuitry.
Claim 19
Dependent Claim
60 words
The method defined in claim 3 wherein the coordinate address data of consecutive mask endpoints of each said mask is stored in consecutive storage locations, said method further including; A. establishing a marker register containing a storage address for accessing endpoint coordinate address data; and B. incrementing said marker register pursuant to interpreting each bit of the assigned control word.
Claim 20
Dependent Claim
75 words
The method defined in claim 1; and A. executing, under the control of the mask and control words assigned to the characters to be generated as the initial executed stroke of each character to be generated, an indexing stroke moving the beam from the endpoint of the last-executed stroke of the previously generated character to the endpoint corresponding to the starting point for the first stroke of the next character to be generated and displayed.
Claim 21
Independent Claim
29 words
A method of generating a font of characters for display on the screen of a cathode-ray tube, said method comprising the steps of: A. providing a plurality of masks,
Claim 22
Independent Claim
29 words
A method of generating a font of characters for display on the screen of a cathode-ray tube, said method comprising the steps of: A. providing a plurality of masks,
Claim 23
Dependent Claim
36 words
The method defined in claim 6, wherein said testing step is performed as a succession of test cycles, one test cycle being normally devoted to each stroke endpoint of said selected one mask in predetermined sequence.
Claim 24
Dependent Claim
14 words
The method defined in claim 7, wherein said testing step includes the steps of:
Claim 25
Dependent Claim
47 words
The method defined in claim 8, wherein said testing step further includes the step of: 1interpreting said selected display control data during the concluding portion of each uninterrupted test cycle to determine if the beam stroke to be executed to said particular endpoint is to be displayed.
Claim 26
Dependent Claim
14 words
The method of claim 9, wherein said testing step further includes the steps of:
Claim 27
Dependent Claim
138 words
The method defined in claim 6, wherein each said stroke control data is in the form of a unique digitally encoded control word, and each said mask identification data and each said display control data are combined as first and second parts, respectively, of a unique digitally encoded mask word, one of said control words and one of said mask words being assigned to each character of the font, and wherein the method further includes the step of: A. storing all of said mask and control words and all of said coordinate address data of each said mask in a memory; B. said testing step includes retrieving from the memory the selected mask and control words and the coordinate address data of those endpoints of said selected one mask to which a beam stroke is to be executed.
Claim 28
Dependent Claim
90 words
The method defined in claim 11, wherein said testing step is performed as a succession of test cycles, one test cycle being normally devoted to each stroke endpoint of said selected one mask in predetermined sequence, and wherein said selected control word is retrieved from the memory at the beginning of each test cycle, and said mask word and the coordinated address data of a particular endpoint are retrieved from the memory during the concluding portion of a test cycle only if a beam stroke is to be executed thereto.
Claim 29
Dependent Claim
87 words
The method defined in claim 11, wherein the stroke endpoints of each said mask are numbered in sequence and the coordinate address data of consecutively numbered stroke endpoints are stored in consecutive address locations in the memory, and wherein said testing step is performed as a succession of test cycles, one test cycle being normally devoted to each stroke endpoint of said selected one mask in numbered sequence, said method further includes the steps of: A. establishing a marker on the basis of said selected one mask,
Claim 30
Dependent Claim
65 words
The method defined in claim 11 which further includes the step of: A. providing a character position register in the memory containing coordinate address data establishing a reference position for the beam in each character space on the screen where a character is to be displayed; B. said testing step includes adding the mask endpoint coordinate address data to said reference position coordinate address data.
Claim 31
Dependent Claim
78 words
The method defined in claim 6, and A. executing, pursuant to the generation of each character and under the control of said selected one mask and said selected stroke and display control data, an invisible first beam stroke moving the beam from the endpoint of the last executed stroke for the previously displayed character to the mask endpoint corresponding to the starting point for the first visible beam stroke of the next character to be generated and displayed.
Claim 32
Dependent Claim
51 words
The method defined in claim 7, wherein said selected stroke control data includes a plurality of bits, each bit associated with a different endpoint of said selected mask, said bits being coded a first logical significance when a stroke is to be executed to their associated endpoints, said testing step including
Claim 33
Dependent Claim
45 words
The method defined in claim 16, wherein said selected display control data includes a plurality of bits, each said display control data bit associated with a different bit of said selected stroke control data coded in said first logical significance, said testing step further including
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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) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |