EP0073916B2 - Circuit de commande individuelle de la couleur d'un caractère et son fond affiché sur un récepteur de télévision à couleurs ou un moniteur - Google Patents

Circuit de commande individuelle de la couleur d'un caractère et son fond affiché sur un récepteur de télévision à couleurs ou un moniteur Download PDF

Info

Publication number
EP0073916B2
EP0073916B2 EP19820106645 EP82106645A EP0073916B2 EP 0073916 B2 EP0073916 B2 EP 0073916B2 EP 19820106645 EP19820106645 EP 19820106645 EP 82106645 A EP82106645 A EP 82106645A EP 0073916 B2 EP0073916 B2 EP 0073916B2
Authority
EP
European Patent Office
Prior art keywords
character
color
font
background
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19820106645
Other languages
German (de)
English (en)
Other versions
EP0073916A3 (en
EP0073916A2 (fr
EP0073916B1 (fr
Inventor
Jesus Andres Saenz
Mark Edward Dean
David Allen Kummer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US06/292,074 external-priority patent/US4442428A/en
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0073916A2 publication Critical patent/EP0073916A2/fr
Publication of EP0073916A3 publication Critical patent/EP0073916A3/en
Publication of EP0073916B1 publication Critical patent/EP0073916B1/fr
Application granted granted Critical
Publication of EP0073916B2 publication Critical patent/EP0073916B2/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/02—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the way in which colour is displayed
    • G09G5/024—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the way in which colour is displayed using colour registers, e.g. to control background, foreground, surface filling

Definitions

  • This invention relates generally to color television, and, more particularly, to a circuit for independently controlling the colors of the font and background of character displayed on the cathode ray tube (CRT) screen employed in a conventional television receiver or monitor as used in a data processing system, such as a small personal computer, for displaying computer-generated alpha-numeric and graphic data.
  • CTR cathode ray tube
  • a data processing system such as a small personal computer, employing a conventional television receiver or a monitor for displaying characters in a color determined by computer-generated digital color signals
  • a conventional television receiver or a monitor for displaying characters in a color determined by computer-generated digital color signals
  • US Patent 4,149,152 described a circuit for controlling the color of dot elements in a raster scan display.
  • a data memory stores the state (on or off) of dot elements which are mapped onto the raster scan display.
  • At least one smaller auxiliary memory is provided to store one set of color information specifying the color of a plurality of contiguous dot elements when the dot states have one value and another set of color information specifying the color of the plurality of contiguous dot elements when the dot states have the other value.
  • This circuit needs an auxiliary memory with its specific circuitry.
  • Japanese unexamined application JA PUPA 52-27325 describes a system in which control of the font and background colours of characters is provided, the information for display being defined in terms of character codes and associated character attribute codes This system is, however, relatively complex, requiring a character/background colour extraction circuit for holding colour data, whereas character information codes are directly supplied to a dot signal generating circuit.
  • a circuit for providing control of the colors of the font and background displayed on the tube comprising: means for fetching from a random access memory character codes and character attribute codes containing character font color bits and character background bits; means responsive to a character code for generating character dots; means for applying to a multiplexer serial character dots selectively to gate font color bits and background color bits to a composite video signal generator to produce a composite video color signal; and means to apply said composite video signal to the cathode ray tube to display thereon a character having font and background colors in accordance with the gated bits, characterized in that: said means for fetching said character codes and character attribute codes comprises means for fetching, for a character for display, a character code and an associated attribute code for the character into
  • Figure 1 is a block diagram of a portion of a data processing system, such as a small personal computer, in which computer-generated digital color signals are used to control the color of alpha-numeric and graphic data displayed on the screen of a conventional TV receiver or monitor.
  • a data processing system such as a small personal computer, in which computer-generated digital color signals are used to control the color of alpha-numeric and graphic data displayed on the screen of a conventional TV receiver or monitor.
  • Figure 2 is a combined logic and circuit schematic diagram of the composite video generator of Figure 1.
  • Figure 3 illustrates the manner in which the color attribute byte is applied to the video information multiplexer to produce the independent font and background digital color signals.
  • Figure 4 is a timing diagram illustrating the times, within a character block, at which the respective font color and background color control signals are generated for a particular character.
  • Figure 1 is a block diagram of a portion of a data processing system, such as a personal computer, in which alpha-numeric ang graphic data, generated by a keyboard or other components of the system, are displayed on a cathode ray tube, such as a conventional television receiver or monitor.
  • a data processing system such as a personal computer
  • alpha-numeric ang graphic data generated by a keyboard or other components of the system
  • a cathode ray tube such as a conventional television receiver or monitor.
  • a central processing unit (CPU) 10 is connected to a three-state system bus 12 including a 8-bit data bus.
  • a character such as one entered by a keyboard coupled to the bus, is to be displayed on the cathode ray tube (CRT) of a conventional TV receiver 14 designed in accordance with the National Television Standards Committee (NTSC) standards.
  • a conventional CRT controller 16 such as a Motorola 6845 chip, controlled by CPU 10 via the bus 12, generates the CHARACTER ADDRESS on output line 18, CHARACTER SCAN on line 24, and the television frequency component on lines 20 and 22.
  • a -BLANK signal is produced on line 20, and the scanning pulses are produced on line 24 and applied to a character generator (ROM) 28.
  • ROM character generator
  • An 8-bit character code is fetched from a random access memory (RAM) 30 at the specified character address.
  • An 8-bit attribute code is also fetched, and four of these bits designate the color of the character to be displayed, i.e., the foreground color of the character, as opposed to the background color of the character.
  • the four character color bits are applied to a multiplexer (MUX) 32, such as a 74LS157 chip, which outputs the red (R), green (G), blue (B) and intensity (I) signals from which there is derived the composite video color signal to be applied to the TV receiver.
  • MUX multiplexer
  • Multiplexer 32 is under the control of the serial character dots from the 8-to-1 parallel-to-serial converter 34 connected to the output of the character generator 28.
  • the digital R, G, B and I signals on the output of multiplexer 32 are applied as inputs to a composite video generator 38 which produces the composite video color signal which can be used directly by a conventional composite monitor or, after being modulated by an R.F modulator 13, by TV receiver 14 to display the colored character, or as inputs to the drivers 40 of a conventional direct drive TV monitor which operates directly from the R, G, B and I signals without the RF modulation required by the TV receiver 14, but which requires externally supplied synchronizing and blanking signals.
  • Figure 2 is a logic and schematic circuit diagram of the composite video generator 38 of Figure 1, and functions directly to convert the R, G B and I digital color signals on the output of MUX 32 to a composite video color signal which can be utilized by the TV receiver 14 to display the character image having the color designated by a particular set of digital color signals.
  • a line is UP, i.e. has a logical value of 1 (+5 volts), when the indicated signal is present, and is DOWN, i.e. has the logical value of 0 (0 volt), when the signal does not exist.
  • the circuit of Figure 2 consists of three digital delay devices in the form of three 74LS74 edge-triggered D-type latches or flipflops 50, 52 and 54, each of which has a D input, a clock (CLK) input, a Q set output, and a Q reset output.
  • the outputs of the three latches are connected as six inputs to an 8-to-174LS151 multiplexer 56 to whose output Y are switched, under the control of digital color signals B, G, R applied to its SELECT terminals A, B and C, respectively, individual ones of the eight phase-shifted color subcarriers appearing on the eight inputs of the multiplexer.
  • the O input terminal of multiplexer 56 is grounded and represents the color black, and the white input is connected to +5 volts.
  • the S (strobe) terminal of the multiplexer chip 56 is not used and is grounded.
  • a 14.318 MHz clock signal from the system bus is applied to the CLK terminal of latches 50 and 52, and inverted and applied to the CLK terminal of latch 54.
  • the system clock signal is also divided by four in a frequency divider 58 to produce the 3.58 MHz (actually 3.5695) NTSC color subcarrier signal.
  • a delay of one clock period of the 14.318 MHz signal corresponds to a 90° phase shift of the 3.58 MHz subcarrier.
  • One-half of the 14.318 MHz clock period thus correspond to a 45° phase shift of the subcarrier.
  • the Q or 0° phase output of latch 50 is applied to the D input of latch 52, and the Q or 90° delay output of latch 52 is applied to the D input of latch 54.
  • the subcarrier signal is synchronized by the rising edges of the clock signal. Because of the inherent delay between the inputs and the outputs of such D-type latches, the zero phase output of latch 50, for example, will be slightly delayed from its D input. Thus, when the Q output of latch 50 is applied to the D input of latch 52, it will no be up for the first rising edge of the clock signal which is also applied to latch 52. Thus, the outputs of latch 52 will be delayed by ninety degrees relative to those of latch 50. Similarly, a 45° phase shift occurs between the outputs of latches 52 and 54, that is, when the Q output of latch 52 goes high, the Q output of latch 54 will go high one-half of the 14.318 MHz period later to produce the 45° phase shift. The same operation occurs for the Q outputs of latches 52 and 54.
  • the two outputs of latch or flip-flop 50 provide a 3.58 MHz color subcarrier signal at both, 0° phase shift (yellow, brown, burst) and also 180° phase shift (blue, bright blue).
  • Latch 52 delays the 0° phase shift signal from latch 50 and provides a 3.58 MHz signal at 90° phase shift (red, pink) and at 270° phase shift (cyan, bright cyan).
  • Latch 54 delays the 90° phase shift signal from latch 52 by 45°, and its outputs provide a 3.58 MHz signal at 135° phase shift (magneta, bright magenta) and at 315° phase shift (green, bright green).
  • phase-shifted subcarriers at the output Y of multiplexer 56 are passed through a buffer 50 and a 2.2 K resistor to the summing node 62 connected to the base of the NPN emitter-follower transistor 64 whose emitter-resistor output contains the composite video color signal which is applied through R.F. modulator 13 to the input terminals of the TV receiver 14.
  • Also connected to summing node 62 via corresponding buffer 66, 68 and 69 and corresponding summing resistors having ohmic values of 3.3K, 13K and 4.7K are the -SYNC and -BLANK signals from the CRT controller 16 and the +INTENSITY (1) signal from the color video control circuit or multiplexer 32 of Figure 1.
  • the OR gates 70 and 72 are used to select the 3.58 MHz 0° phase shift signal during BURST time to time to provide the color burst signal.
  • the -SYNC signal is a composite of the horizontal and vertical synchronizing pulses. In the steady state condition, i.e. when the T.V. screen is black, the Y output is 0, -SYNC is 1, -BLANK is 1, and I is 0.
  • Figure 3 shows the eight color attribute bits applied to the inputs of the 74LS151 multiplexer 32 to produce the red (R), green (G), blue (B) and intensity (I) digital color signals which are applied to the composite video generator 38 to produce the video composite color signal as described in detail with reference to Figure 2.
  • the intensity signal (I) produces a D.C level which produces "brighter” versions of the eight colors which are derived from the three basic colors of blue, green and red.
  • the eight character color attribute bits (four font or foreground color bits and four background color bits) are applied to the inputs of the multiplexer 32 and are selectively switched to the output lines of the multiplexer under the control of the serial character dots from the parallel to serial converter 34.
  • Figure 3 illustrates the format of the eight bit attribute code which is fetched from the RAM 30 and applied to the multiplexer 32.
  • Figure 4 illustrates the relative timing of the foreground (font) and the background color signals in the horizontal and vertical scannings of a CRT for a typical 7x7 character block for the character "A".
  • the shaded areas represent font or foreground times, and the unshaded areas represent background times.
  • the attribute byte also can be used to render a character invisible on the display screen by choosing the foreground (font) and background colors to be the same.
  • a separate DON'T DISPLAY code and hardware were required to prevent display of a character.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Controls And Circuits For Display Device (AREA)
  • Processing Of Color Television Signals (AREA)

Claims (3)

1. Dans un système de traitement de données comprenant une unité de commande d'un tube cathodique et également un multiplexeur pour produire des signaux d'information vidéo en vue d'afficher des données colorées sur l'écran d'affichage d'un tube cathodique dans un récepteur ou un moniteur de télévision, un circuit permettant de commander les couleurs de la police de caractères et du fond affichés sur le tube, ce circuit comprenant :
   des moyens pour extraire d'une mémoire à accès direct (30), des codes de caractères et des codes d'attributs de caractères contenant des bits de couleur de police de caractères et des bits de fond de caractères;
   des moyens (28) répondant à un code de caractère pour produire des points de caractères;
   des moyens pour appliquer sélectivement à un multiplexeur (32) des points de caractères en série pour transférer des bits de couleurs de police de caractères et des bits de couleur de fond à un générateur de signaux d'information vidéo composites pour produire un signal de couleur vidéo composite; et
   des moyens pour appliquer ledit signal vidéo composite au tube cathodique afin d'y afficher un caractère ayant des couleurs de police de caractères et de fond en accord avec les bits transférés, caractérisé en ce que
   lesdits moyens pour extraire lesdits codes de caractères et lesdits codes d'attributs de caractères comprennent des moyens pour extraire, pour un caractère à afficher, un code de caractère et un code d'attribut associé pour le caractère, de manière à les introduire dans une bascule bistable servant à verrouiller le code de caractères et le code d'attribut de caractère associé pour le caractère, ce qui permet d'obtenir une commande indépendante de la police et du fond pour un caractère.
2. Circuit selon la revendication 1, caractérisé en ce que lesdits moyens d'application desdits points de caractères en série comprennent un convertisseur série-parallèle (34).
3. Circuit selon la revendication 1 ou 2, caractérisé en ce qu'il comporte en outre des moyens pour rendre identiques lesdits bits de couleur de police de caractères et de fond.
EP19820106645 1981-08-12 1982-07-23 Circuit de commande individuelle de la couleur d'un caractère et son fond affiché sur un récepteur de télévision à couleurs ou un moniteur Expired EP0073916B2 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US29206781A 1981-08-12 1981-08-12
US292074 1981-08-12
US292067 1981-08-12
US06/292,074 US4442428A (en) 1981-08-12 1981-08-12 Composite video color signal generation from digital color signals

Publications (4)

Publication Number Publication Date
EP0073916A2 EP0073916A2 (fr) 1983-03-16
EP0073916A3 EP0073916A3 (en) 1984-06-06
EP0073916B1 EP0073916B1 (fr) 1988-05-25
EP0073916B2 true EP0073916B2 (fr) 1992-01-29

Family

ID=26967136

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19820106645 Expired EP0073916B2 (fr) 1981-08-12 1982-07-23 Circuit de commande individuelle de la couleur d'un caractère et son fond affiché sur un récepteur de télévision à couleurs ou un moniteur

Country Status (4)

Country Link
EP (1) EP0073916B2 (fr)
DE (1) DE3278546D1 (fr)
HK (1) HK4290A (fr)
SG (1) SG62089G (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4591842A (en) * 1983-05-26 1986-05-27 Honeywell Inc. Apparatus for controlling the background and foreground colors displayed by raster graphic system
DE3486472T2 (de) 1983-12-26 1999-11-25 Hitachi Ltd Graphisches Musterverarbeitungsgerät und Verfahren
CA2098743A1 (fr) * 1993-06-18 1994-12-19 Yvan Gosselin Systeme de marquage automatique pour le jeu de quilles

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3668686A (en) * 1969-06-06 1972-06-06 Honeywell Inc Control apparatus
US4149152A (en) * 1977-12-27 1979-04-10 Rca Corporation Color display having selectable off-on and background color control
US4310838A (en) * 1978-10-04 1982-01-12 Sharp Kabushiki Kaisha Instruction controlled audio visual system
FR2477745A1 (fr) * 1980-03-04 1981-09-11 Thomson Brandt Dispositif d'affichage graphique en couleurs

Also Published As

Publication number Publication date
EP0073916A3 (en) 1984-06-06
SG62089G (en) 1990-01-26
HK4290A (en) 1990-01-25
EP0073916A2 (fr) 1983-03-16
DE3278546D1 (en) 1988-06-30
EP0073916B1 (fr) 1988-05-25

Similar Documents

Publication Publication Date Title
US4442428A (en) Composite video color signal generation from digital color signals
CA1229441A (fr) Circuit de conversion de signaux couleur
US4437092A (en) Color video display system having programmable border color
US4420770A (en) Video background generation system
US5559954A (en) Method & apparatus for displaying pixels from a multi-format frame buffer
CA1219388A (fr) Systeme d'affichage video a choix de formats d'images-ecrans
EP0158902B1 (fr) Visualisation monochrome d'images en couleur
EP0419765B1 (fr) Extension de fenêtre pour télévision en couleurs et correction de surbalayage pour dispositifs d'affichage de graphique de trame à haute définition
US4908700A (en) Display control apparatus for displacing and displacing color image data
US4262302A (en) Video display processor having an integral composite video generator
US4303912A (en) Digitally controlled composite color video display system
US4724431A (en) Computer display system for producing color text and graphics
KR970000824B1 (ko) 디지탈 화상 합성 장치
JP2578170B2 (ja) 画像表示装置
US4720803A (en) Display control apparatus for performing multicolor display by tiling display
US4833462A (en) Raster-scanned cathode ray tube display with cross-hair cursor
EP0433881B1 (fr) Système de chargement dynamique de palettes pour un affichage basé sur des éléments d'image
US3944999A (en) Colour display apparatus
US4827251A (en) Display control system with control of background luminance or color data
EP0073916B2 (fr) Circuit de commande individuelle de la couleur d'un caractère et son fond affiché sur un récepteur de télévision à couleurs ou un moniteur
KR20000048934A (ko) 그래픽 온-스크린 디스플레이 시스템
GB2168181A (en) Video interface
GB2104356A (en) Control of character and background colour on video display unit of data processing system
EP0073338A2 (fr) Couleur du bord programmable pour un appareil à T.R.C. ou un récepteur de télévision couleur
US5072214A (en) On-screen display controller

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19830621

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): DE FR GB IT

17Q First examination report despatched

Effective date: 19870108

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19880525

REF Corresponds to:

Ref document number: 3278546

Country of ref document: DE

Date of ref document: 19880630

ET Fr: translation filed
PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: LOEWE OPTA GMBH

Effective date: 19890224

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19910625

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19910723

Year of fee payment: 10

PUAH Patent maintained in amended form

Free format text: ORIGINAL CODE: 0009272

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT MAINTAINED AS AMENDED

27A Patent maintained in amended form

Effective date: 19920129

AK Designated contracting states

Kind code of ref document: B2

Designated state(s): DE FR GB IT

EN3 Fr: translation not filed ** decision concerning opposition
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19920619

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19920624

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19930401

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19930723

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930723