US3750133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Home television receiver modified to operate as video terminal
Assignee: RCA Corp
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Filing: 1971-07-30
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Granted: 1973-07-31
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Expires: 1991-07-30
Abstract
Abstract A video terminal includes the deflection, power supply, video, and synchronization circuits of a commercial, home television receiver. The deflection yoke of the receiver is rotated through 90* to provide fast vertical rather than fast horizontal sweeps. The fast sweep frequency is approximately doubled to improve resolution along the rows of the characters displayed. The bandwidth of the receiver is increased to improve resolution in the fast sweep direction. The fast sweep retrace period, the slow sweep retrace period, and the frame repetition period of the receiver are not changed.
Inventors
- 👤 W Helbig
- 👤 W Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:56
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/06; G09G1/14; G09G1/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
85 words
A method of modifying a commercial television receiver of the type having fast horizontal sweeps, each consisting of an active portion which can be viewed on the screen of the television display means and a retrace portion, and a frame repetition frequency; comprising the steps of: changing the fast sweep direction to the vertical direction; and increasing the fast sweep frequency by reducing the duration of the active portion of the fast sweep without changing the fast sweep retrace duration, or the frame repetition frequency.
Claim 2
Independent Claim
85 words
A method of modifying a commercial television receiver of the type having fast horizontal sweeps, each consisting of an active portion which can be viewed on the screen of the television display means and a retrace portion, and a frame repetition frequency; comprising the steps of: changing the fast sweep direction to the vertical direction; and increasing the fast sweep frequency by reducing the duration of the active portion of the fast sweep without changing the fast sweep retrace duration, or the frame repetition frequency.
Claim 3
Dependent Claim
30 words
The method of claim 1, where the step of increasing the frequency consists of increasing it by a factor of approximately n, where n is an integer greater than 1.
Claim 4
Independent Claim
129 words
A method of modifying a commercial home television receiver of the type having: a kinescope, a kinescope deflection yoke, and means supplying slow and fast sweep signals to said yoke for rapidly deflecting the electron beam across the screen of said kinescope along successive horizontal lines, each horizontal fast sweep including an active portion which can be made visible on the screen and a retrace portion; comprising the steps of: rotating the yoke through an angle of approximately 90*; and increasing the fast sweep frequency by a factor of approximately n by reducing the duration of the active portion of the fast sweep without changing the duration of the retrace portion of the fast sweep or changing the slow sweep frequency, where n is an integer greater than 1.
Claim 5
Independent Claim
129 words
A method of modifying a commercial home television receiver of the type having: a kinescope, a kinescope deflection yoke, and means supplying slow and fast sweep signals to said yoke for rapidly deflecting the electron beam across the screen of said kinescope along successive horizontal lines, each horizontal fast sweep including an active portion which can be made visible on the screen and a retrace portion; comprising the steps of: rotating the yoke through an angle of approximately 90*; and increasing the fast sweep frequency by a factor of approximately n by reducing the duration of the active portion of the fast sweep without changing the duration of the retrace portion of the fast sweep or changing the slow sweep frequency, where n is an integer greater than 1.
Claim 6
Dependent Claim
8 words
The method of claim 3, where n 2.
Claim 7
Dependent Claim
20 words
The method of claim 3, further including the step of increasing the bandwidth of the receiver to improve its resolution.
Claim 8
Dependent Claim
23 words
The method of claim 5 wherein the step of increasing the bandwidth of the receiver includes by-passing the television receiver color filter trap.
Claim 9
Dependent Claim
26 words
The method of claim 5, wherein the step of increasing the bandwidth of the receiver includes adjustment of the tuning of the television receiver video amplifier.
Claim 10
Dependent Claim
177 words
A video terminal comprising, in combination; a display assembly comprising the video, synchronization, vertical and horizontal deflection circuits, power supply circuits and kinescope of a home television receiver interconnected in conventional fashion but with the kinescope yoke rotated through an angle of approximately 90* to provide fast vertical rather than fast horizontal sweeps, and with the tuned circuit for the horizontal oscillator of said horizontal deflection circuit including circuit elements of a value to produce horizontal sweeps at a frequency approximately double the normal sweep frequency, and with the bandwidth of said receiver having a value to permit each fast trace to include at least 200 resolution elements along the displayable portion of said sweep; and character generator means coupled to said display assembly for supplying the successive bits for intensity modulating the electron beam of the kinescope as it sweeps in the vertical direction to produce, in a plurality of successive sweeps, a column of characters, said character generator means including means supplying bits which always retain the same value for at least 2 bit intervals.
Claim 11
Dependent Claim
177 words
A video terminal comprising, in combination; a display assembly comprising the video, synchronization, vertical and horizontal deflection circuits, power supply circuits and kinescope of a home television receiver interconnected in conventional fashion but with the kinescope yoke rotated through an angle of approximately 90* to provide fast vertical rather than fast horizontal sweeps, and with the tuned circuit for the horizontal oscillator of said horizontal deflection circuit including circuit elements of a value to produce horizontal sweeps at a frequency approximately double the normal sweep frequency, and with the bandwidth of said receiver having a value to permit each fast trace to include at least 200 resolution elements along the displayable portion of said sweep; and character generator means coupled to said display assembly for supplying the successive bits for intensity modulating the electron beam of the kinescope as it sweeps in the vertical direction to produce, in a plurality of successive sweeps, a column of characters, said character generator means including means supplying bits which always retain the same value for at least 2 bit intervals.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |