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US3866210A
Expired / Lapsed
US
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X-y alphanumeric character generator for oscilloscopes
Assignee: National Aeronautics and Space Administration
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Filing: 1973-09-14
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Granted: 1975-02-11
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Expires: 1993-09-14
Abstract
Abstract A method and apparatus is disclosed by which any general purpose external trigger laboratory oscilloscope can be utilized to display alphanumeric characters. Each character to be displayed is composed of a plurality of segments appearing at various segment positions in various segment rows to define a conventional matrix, various ones of the segments being displayed during each horizontal sweep of the oscilloscope trace. In between character segments to be displayed, or when no display is desired, the trace is effectively blanked by a vertical clamping voltage so as to position the oscilloscope trace in an off-screen position. The ''''clamping'''' technique of the invention, i.e., biasing the oscilloscope trace to an off-screen position when no character segment is to be displayed, eliminates the necessity of providing Z-axis modulation to effect blanking.
Inventors
- 👤 Donald C Lokerson
- 👤 Ronald E Boston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:19
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/002; G01; G01R; G01R13/00; G01R13/02; G01R13/20; G01R13/22
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
201 words
An alphanumeric character generator for generating characters on the screen of a general purpose oscilloscope of the type having an external horizontal sweep trigger input and a vertical deflection input, said character generator comprising: means for generating a vertical clamping voltage of a value to vertically bias the oscilloscope trace in an off-screen position; means for generating a vertical deflection voltage of a value to vertically position the oscilloscope trace at a level on-screen corresponding to a desired level of a horizontal row of segments of characters to be generated; means for sequentially generating a plurality of control signals, each representative of a different character segment of a plurality of segments to be successively displayed in predetermined segment positions along a horizontal row on the oscilloscope screen during a horizontal sweep of the oscilloscope trace; and gate means coupled to each said generaTing means responsive to each control signal for selectively and successively presenting to the vertical deflection input of the oscilloscope either said vertical clamping voltage or said vertical deflection voltage; whereby character segments are displayed by successively moving the oscilloscope trace between the off-screen vertical position and the on-screen vertical position during a horizontal sweep of the oscilloscope trace.
Claim 2
Dependent Claim
201 words
An alphanumeric character generator for generating characters on the screen of a general purpose oscilloscope of the type having an external horizontal sweep trigger input and a vertical deflection input, said character generator comprising: means for generating a vertical clamping voltage of a value to vertically bias the oscilloscope trace in an off-screen position; means for generating a vertical deflection voltage of a value to vertically position the oscilloscope trace at a level on-screen corresponding to a desired level of a horizontal row of segments of characters to be generated; means for sequentially generating a plurality of control signals, each representative of a different character segment of a plurality of segments to be successively displayed in predetermined segment positions along a horizontal row on the oscilloscope screen during a horizontal sweep of the oscilloscope trace; and gate means coupled to each said generaTing means responsive to each control signal for selectively and successively presenting to the vertical deflection input of the oscilloscope either said vertical clamping voltage or said vertical deflection voltage; whereby character segments are displayed by successively moving the oscilloscope trace between the off-screen vertical position and the on-screen vertical position during a horizontal sweep of the oscilloscope trace.
Claim 3
Dependent Claim
137 words
a character generator as defined in claim 1, wherein each fully completed character to be displayed is composed of a matrix of a plurality of segments disposed in selected segment positions along a plurality of different horizontal rows, each horizontal row being vertically displaced from one another on the oscilloscope screen; and wherein said means for generating said vertical deflection voltage generates a deflection voltage having a staircase wave form, each step of the wave form being of a value corresponding to the level of a respective different horizontal segment row during successive horizontal sweeps of the oscilloscope trace; said character generator further comprising trigger means for periodically generating a horizontal sweep trigger signal; and timing means for effecting synchronous operation of said vertical deflection voltage generating means, said trigger means, and said control signal generating means.
Claim 4
Dependent Claim
96 words
a character generator as defined in claim 2, wherein said plurality of horizontal rows in which a fully completed character is displayed comprises a character line, and wherein a plurality of character lines are displayed, each character line being vertically displaced from one another on the oscilloscope screen; adjusting means being provided for said vertical deflection voltage generator to shift the values of the staircase wave form generated thereby such that the wave form is of a value to position the oscilloscope trace at a level on-screen corresponding to the level of each respective character line.
Claim 5
Independent Claim
144 words
A method of generating alphanumeric character segments on the screen of a general purpose oscilloscope of the type having an external horizontal sweep trigger input and a vertical deflection input, said method comprising the steps of: biasing the oscilloscope trace to an off-screen vertical position; generating a horizontal sweep trigger signal; and sequentially generating a train of spaced square wave vertical deflection pulses during each horizontal sweep of the oscilloscope trace, each pulse and the spacing therebetween being representative of the existence and position of a different character segment to be displayed, each said deflection pulse being of a value so as to position the top of each corresponding oscilloscope trace pulse from an off-screen position to a lvel which is visible on the oscilloscope screen, only the top of each oscilloscope trace pulse thereby being visible, thus giving the appearance of a dash.
Claim 6
Independent Claim
144 words
A method of generating alphanumeric character segments on the screen of a general purpose oscilloscope of the type having an external horizontal sweep trigger input and a vertical deflection input, said method comprising the steps of: biasing the oscilloscope trace to an off-screen vertical position; generating a horizontal sweep trigger signal; and sequentially generating a train of spaced square wave vertical deflection pulses during each horizontal sweep of the oscilloscope trace, each pulse and the spacing therebetween being representative of the existence and position of a different character segment to be displayed, each said deflection pulse being of a value so as to position the top of each corresponding oscilloscope trace pulse from an off-screen position to a lvel which is visible on the oscilloscope screen, only the top of each oscilloscope trace pulse thereby being visible, thus giving the appearance of a dash.
Claim 7
Dependent Claim
68 words
The method defined in claim 4, wherein during each successive horizontal sweep of the oscilloscope trace, the value of the vertical deflection pulses is altered to position the top of each oscilloscope trace pulse generated during a respective horizontal sweep at a different on-screen level corresponding to the desired level of a respective row of character segments, a plurality of character segment rows defining a complete character display.
References Cited (Backward Citations)
US3524022A
Cited
US3786481A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |