EP0170816A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Digital display system employing a raster scanned display tube
Assignee: International Business Machines Corp
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Filing: 1985-06-05
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Granted: —
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Expires: 2005-06-05
Abstract
Abstract A digital display system includes a monitor arranged to receive digital display data and synchronising signals to develop displays on a cathode ray tube. The monitor is switched between different line structure and/or colour definition modes in response to the polarity of one of the vertical or horizontal synchronising signals trains. A circuit receives this train to provide control signals to the horizontal time base and/or a colour signal code converter. The time base control signal, in accordance with its binary value, controls the frequency of the time base. The colour converter, in response to the control signals, either passes colour signals received in parallel over six input lines without change to the cathode ray tube drive circuits or converts colour signals on four of the input lines to output signals on the six lines to the drive circuits.
Inventors
- 👤 Darwin Preston Rackley
- 👤 Jesus Andres Saenz
- 👤 Paul Stewart Yosim
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:37
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/27; G; G09; G09G; G09G1/00; G09G1/06; G09G1/14; G09G1/16; G09G1/165; G09G1/167; G09G1/28; G09G1/285
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
In or for a display system, a raster scan cathode tube display unit, adapted to be coupled to receive data signals defining the data to be displayed and horizontal and vertical synchronising signals and arranged to develop a raster scan display on the cathode ray tube of the unit, the display unit incorporating control circuitry responsive to input signals, when received,to switch the frequency of at least one of the time bases produced for generating the raster and thereby to alter the line structure of the display, characterised in that the control circuitry is so responsive to the polarity of at least one of the horizontal and the vertical synchronising signal trains.
Claim 2
Dependent Claim
112 words
In or for a display system, a raster scan cathode tube display unit, adapted to be coupled to receive data signals defining the data to be displayed and horizontal and vertical synchronising signals and arranged to develop a raster scan display on the cathode ray tube of the unit, the display unit incorporating control circuitry responsive to input signals, when received,to switch the frequency of at least one of the time bases produced for generating the raster and thereby to alter the line structure of the display, characterised in that the control circuitry is so responsive to the polarity of at least one of the horizontal and the vertical synchronising signal trains.
Claim 3
Dependent Claim
35 words
A display unit as claimed in claim 1 wherein the control circuitry includes a slow response, relative to the synchronising signal rate, intergrator, the output of which defines the polarity of the synchronising signals received.
Claim 4
Dependent Claim
108 words
A display unit as claimed in claim 1 or claim 2, wherein the received data signals are digital colour signals and are received. together with the synchronising signals from a computer display adapter, in parallel form on different lines from the adapter, the control circuitry being responsive to the polarity of the synchronising signals on at least one of the synchronising signal lines to generate digital control signals coupled to control the frequency of at least one of the time base generators and to, where appropriate, invert received sychronising signals applied to the time base generators so that the polarity of the sychronising signals so applied is constant.
Claim 5
Dependent Claim
120 words
A digital display system including a display unit as claimed in claim 3 and a display adapter connected thereto, in which system, the display adapter is arranged to provide the parallel digital colour signals on either all of the different data lines or on less than all of the different lines with the polarity of the synchronising signals on the at least one line varying in correspondence with the different colour signal formats provided, and the display unit includes logic means, responsive to the generated digital control signals and connected to receive the colour signals, to provide digital colour output signals on all of a fixed number of output lines in response to the colour signals and the control signals.
Claim 6
Dependent Claim
80 words
A digital display system as claimed in Claim 4 in which the output lines correspond in number to the different lines from the adapter and the logic means is adapted to pass the colour signals from the adapter unchanged to the output lines when the colour signals are in one format and to encode the colour signals on less than all of the different lines into output signals on all the output lines when the colour signals are another format.
Claim 7
Dependent Claim
18 words
A digital display system as claimed in Claim 5 in which the logic means comprise a read-only memory.
Claim 8
Dependent Claim
60 words
I. A digital display system according to Claim 2 or any Claim appendant thereto, in which the logic means comprises an exclusive NOR circuit or an exclusive OR circuit, depending on which polarity of synchronising signals are designed to respond, to combine the received synchronising signals with the integrated polarity signal level to regenerate sychronising signals of a constant polarity.
References Cited (Backward Citations)
No citation records indexed.
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