Patent US4130830A successfully refreshed from Google Patents.
US4130830A
Expired / Lapsed
US
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Method and apparatus for homogeneous exposure of video display screen
Assignee: Midway Games West Inc
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Filing: 1977-09-14
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Granted: 1978-12-19
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Expires: 1997-09-14
Abstract
Abstract A homogeneous screen exposure method for a video display tube used in a video game which may be exposed for prolonged periods to a fixed pattern is provided by utilizing the motion counters of the game which normally provide for a moving ball, for example, to generate a moving checkerboard pattern with which the fixed playfield pattern is exclusively ORed.
Inventors
- 👤 Richard B. Derickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:03
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/66; H04N5/68
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
75 words
A method of exposing the entire viewing area of a video display screen to the same amount of luminance where the screen normally displays a fixed pattern for prolonged periods of time comprising the following steps: generating a signal for providing a moving pattern across said screen; exclusively ORing said moving pattern signal with a signal corresponding to said fixed pattern; and driving said video display screen with the logical result of the previous step.
Claim 2
Independent Claim
75 words
A method of exposing the entire viewing area of a video display screen to the same amount of luminance where the screen normally displays a fixed pattern for prolonged periods of time comprising the following steps: generating a signal for providing a moving pattern across said screen; exclusively ORing said moving pattern signal with a signal corresponding to said fixed pattern; and driving said video display screen with the logical result of the previous step.
Claim 3
Dependent Claim
16 words
A method as in claim 1 where said moving pattern has a 50% luminance duty cycle.
Claim 4
Dependent Claim
51 words
A method as in claim 1 where the video display screen includes an image forming beam driven by horizontal and vertical position counter means for providing a moving object and where said generating step includes exclusively ORing outputs of said horizontal and vertical position counters to generate said moving pattern signal.
Claim 5
Dependent Claim
31 words
A method as in claim 3 where said counter outputs correspond to a fraction of the total count of said counter means to form a moving pattern which is checkerboard like.
Claim 6
Dependent Claim
37 words
A method as in claim 3 where said fixed pattern includes a color component provided by a color signal said method including the step of exclusively ORing such signal with an output of one of said counters.
Claim 7
Dependent Claim
35 words
A method as in claim 1 where said fixed pattern includes a color component provided by a color signal said method including the step of complementing said color signal in accordance with said moving pattern.
Claim 8
Dependent Claim
125 words
Apparatus for exposing the entire viewing area of a video display screen to the same amount of luminance where the screen normally displays a fixed pattern for prolonged periods of time comprising: position counter means for moving an object formed by a beam traversing said video display screen along a path across said screen; first gating means responsive to a state of said position counter means corresponding to a fraction of the total count of said counter means for producing a signal representative of a checkerboard like pattern moving across said screen; and second gating means responsive to said checkerboard pattern signal and to a signal representative of said fixed pattern for changing the luminance of said fixed pattern in accordance with said moving checkerboard.
Claim 9
Dependent Claim
125 words
Apparatus for exposing the entire viewing area of a video display screen to the same amount of luminance where the screen normally displays a fixed pattern for prolonged periods of time comprising: position counter means for moving an object formed by a beam traversing said video display screen along a path across said screen; first gating means responsive to a state of said position counter means corresponding to a fraction of the total count of said counter means for producing a signal representative of a checkerboard like pattern moving across said screen; and second gating means responsive to said checkerboard pattern signal and to a signal representative of said fixed pattern for changing the luminance of said fixed pattern in accordance with said moving checkerboard.
Claim 10
Dependent Claim
135 words
Apparatus for exposing the entire viewing area of a video display screen to the same amount of luminance where the screen normally displays a fixed pattern for prolonged periods of time comprising: horizontal and vertical position counter means for moving an object formed by a beam traversing said video display screen along a path across said screen; parity logic means responsive to, (a) a binary state of the horizontal counter means corresponding to a fraction of its total count, (b) a binary state of the vertical counter means corresponding to a fraction of its total count, and (c) a digital signal representation of said fixed pattern, for generating a luminance signal for said video display screen of one type for odd parity of (a), (b), and (c) and of the opposite type for even parity.
Claim 11
Dependent Claim
135 words
Apparatus for exposing the entire viewing area of a video display screen to the same amount of luminance where the screen normally displays a fixed pattern for prolonged periods of time comprising: horizontal and vertical position counter means for moving an object formed by a beam traversing said video display screen along a path across said screen; parity logic means responsive to, (a) a binary state of the horizontal counter means corresponding to a fraction of its total count, (b) a binary state of the vertical counter means corresponding to a fraction of its total count, and (c) a digital signal representation of said fixed pattern, for generating a luminance signal for said video display screen of one type for odd parity of (a), (b), and (c) and of the opposite type for even parity.
Claim 12
Dependent Claim
20 words
Apparatus as in claim 8 where said luminance signal is relatively black for odd parity and white for even parity.
References Cited (Backward Citations)
US3441668A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |