GB1405884A - Raster-scanned display devices - Google Patents
Raster-scanned display devicesInfo
- Publication number
- GB1405884A GB1405884A GB5002471A GB5002471A GB1405884A GB 1405884 A GB1405884 A GB 1405884A GB 5002471 A GB5002471 A GB 5002471A GB 5002471 A GB5002471 A GB 5002471A GB 1405884 A GB1405884 A GB 1405884A
- Authority
- GB
- United Kingdom
- Prior art keywords
- vector
- tan
- vectors
- line scan
- store
- 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
Links
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
- G09G5/20—Function-generator circuits, e.g. circle generators line or curve smoothing circuits
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)
- Image Generation (AREA)
Abstract
1405884 Cathode-ray tube displays GECELLIOTT AUTOMATION Ltd 27 Oct 1972 [27 Oet 1971] 50024/71 Heading H4T Vectors are displayed on a raster scanned cathode-ray tube by intensity modulation of the beam under the control of video signals derived from input digital signals and quantized into a plurality of discrete brightness levels. These are then utilized to produce a progressive increase and decrease of brightness level in each raster line and results in each vector trace (e.g. forming part of a graphical symbol) having a substantially unstepped appearance, especially for near-horizontal lines. Fig. 1, shows the overall scheme which has provision for the display of vectors and of circles, the latter, however, being produced at constant brightness level. The vectors can only be positioned on a restricted area of the screen each vector being represented by digital data specifying; the starting point, (measured from the start of the area) Xo; the number of the line scan (counted from the top of the area) in which the starting point occurs, Yo; the number of the line scan in which the end point occurs, Y1 and the tangent of the angle which the vector makes with the vertical, tan #. This data is loaded into a random access memory M1 (Fig. 3a), which can store data for a maximum of sixteen vector, during field retrace periods and the parameters of any selected vector may be modified by addressing the appropriate word (16 words each of 59 bits) and writing in the modified parameters. Figs. 3a and 3b together form the vector generator which includes a further random access memory M2 having a capacity of 512 words each of six bits B1 to B6, 512 being the notional number of horizontal video elements in the restricted area of the screen. In the general operation of the system the portion of the vector generator shown in Fig. 3a processes the input data in order of decreasing values of tan 0 and supplies an eight-bit binary output "T" which is equal to tan # when the integral part of the latter is greater than unity and equal to 1 (unity) when the integral part is less than unity. The "T" output together with X co-ordinate information is supplied to the portion shown in Fig. 3b which then operates to store in the memory (video store) M2 information specifying a complete line scan in terms of the start or end points of three discrete brightness unit (BU) levels which may occur in each video element. These levels are 1/3 BU for ¢ tan #, 2/3 BU for ¢ tan 0, full BU for tan 0, 2/3 BU for ¢ tan 0 and 1/3BU for ¢ tan 0 and such levels may be either "ON" or "OFF''. These levels which occur in sequence in each raster line and apply to vectors which make an angle 0 greater than 45 degrees with the vertical are produced in terms of the count in counters 30, 31, 32 and are converted to video (bright-up) signals in circuit 33 and employed for intensity control of the beam of the display tube. When, however, # is less than 45 degrees some of the video elements may overlap and where this occurs it is arranged that the higher brightness level overrides the lower one. Thus, in Fig. 2 the sequence of brightness levels follows that set out above for a vector such as P (# greater than 45 degrees) whereas in the case of vector Q (0 less than 45 degrees) the brightness level for line scan B has the sequence, 2/3 BU, full BU and 1/3 BU and for line scan C the sequence 1/3BU, full BU and 2/3 BU. Fig. 4a shows, schematically, a portion of the memory M2 storing the discrete brightness levels for the line scan portion A-A of Fig. 2 and Fig. 4b shows the corresponding video signal. Although data for sixteen vectors may be stored in M1 data for only eight vectors can be processed in the time available and so only eight vectors can be displayed in any given line scan. The store M2 may comprise two halves each containing 256 6 bit words the two halves being addressed alternately when writing into or reading out of the store. Alternatively, the store M2 may comprise two separate stores each capable of storing a complete line scan, the contents of one being read-out whilst the processing of data to update the other is being performed, the roles of the two stores being interchanged during alternate line scans. In a further arrangement the store M2 may comprise an associated memory divided into six stores two for each level of bright-up, (Fig. 5, not shown). Schematic circuit digrams of parts of Figs. 3a and 3b are described with reference to Figs. 6 and 7 (not shown) and flow diagrams representing the operating logic of Fig. 7 are shown in Figs. 8a, 8b and 8c (not shown).
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5002471A GB1405884A (en) | 1971-10-27 | 1971-10-27 | Raster-scanned display devices |
US00301090A US3812491A (en) | 1971-10-27 | 1972-10-25 | Raster-scanned display devices |
JP47107054A JPS4852335A (en) | 1971-10-27 | 1972-10-25 | |
FR7238093A FR2166929A5 (en) | 1971-10-27 | 1972-10-26 | |
DE2252556A DE2252556C2 (en) | 1971-10-27 | 1972-10-26 | Apparatus for generating a video signal for input into a raster-scanned display device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5002471A GB1405884A (en) | 1971-10-27 | 1971-10-27 | Raster-scanned display devices |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1405884A true GB1405884A (en) | 1975-09-10 |
Family
ID=10454364
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB5002471A Expired GB1405884A (en) | 1971-10-27 | 1971-10-27 | Raster-scanned display devices |
Country Status (5)
Country | Link |
---|---|
US (1) | US3812491A (en) |
JP (1) | JPS4852335A (en) |
DE (1) | DE2252556C2 (en) |
FR (1) | FR2166929A5 (en) |
GB (1) | GB1405884A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4280186A (en) * | 1978-07-07 | 1981-07-21 | Tokyo Shibaura Denki Kabushiki Kaisha | Exposure apparatus using electron beams |
Families Citing this family (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3902476A (en) * | 1974-04-02 | 1975-09-02 | Unirad Corp | Scanning display for sampled data |
NL7407660A (en) * | 1974-06-07 | 1975-12-09 | British Broadcasting Corp | FORMATION OF DOT-MATRIX SYMBOLS ON A TELE-VISION DISPLAY DEVICE. |
GB1564433A (en) * | 1976-09-03 | 1980-04-10 | Smiths Industries Ltd | Display systems |
US4127850A (en) * | 1974-10-03 | 1978-11-28 | Smiths Industries Limited | Scanning display apparatus |
US3918039A (en) * | 1974-11-07 | 1975-11-04 | Rca Corp | High-resolution digital generator of graphic symbols with edging |
US3987284A (en) * | 1974-12-03 | 1976-10-19 | International Business Machines Corporation | Conic generator for on-the-fly digital television display |
US4119956A (en) * | 1975-06-30 | 1978-10-10 | Redifon Flight Simulation Limited | Raster-scan display apparatus for computer-generated images |
GB1522375A (en) * | 1975-08-07 | 1978-08-23 | Texas Instruments Ltd | Method and apparatus for displaying alphanumeric data |
IL51719A (en) * | 1976-04-08 | 1979-11-30 | Hughes Aircraft Co | Raster type display system |
US4145754A (en) * | 1976-06-11 | 1979-03-20 | James Utzerath | Line segment video display apparatus |
GB1586169A (en) * | 1976-11-15 | 1981-03-18 | Elliott Brothers London Ltd | Display apparatus |
JPS5399728A (en) * | 1977-02-12 | 1978-08-31 | Nippon Telegr & Teleph Corp <Ntt> | Straight line drawing method |
JPS53121424A (en) * | 1977-03-31 | 1978-10-23 | Nippon Telegr & Teleph Corp <Ntt> | Straight line drawing method |
JPS5946397B2 (en) * | 1977-09-09 | 1984-11-12 | 株式会社日立製作所 | Variable precision trend graph display device |
US4158200A (en) * | 1977-09-26 | 1979-06-12 | Burroughs Corporation | Digital video display system with a plurality of gray-scale levels |
JPS5453833A (en) * | 1977-10-07 | 1979-04-27 | Nippon Telegr & Teleph Corp <Ntt> | Arc description method |
JPS5468119A (en) * | 1977-11-11 | 1979-06-01 | Hitachi Ltd | Trend graph display unit |
JPS54122026A (en) * | 1978-03-15 | 1979-09-21 | Nec Corp | Pattern display system |
US4262290A (en) * | 1978-05-12 | 1981-04-14 | Smiths Industries Limited | Display systems |
US4241341A (en) * | 1979-03-05 | 1980-12-23 | Thorson Mark R | Apparatus for scan conversion |
US4300136A (en) * | 1979-05-10 | 1981-11-10 | Nippon Electric Co., Ltd. | Display pattern preparing system |
US4298867A (en) * | 1979-07-06 | 1981-11-03 | System Concepts, Inc. | Cathode ray tube character smoother |
FR2479622B1 (en) * | 1980-03-28 | 1985-08-23 | Sfena | METHOD OF SMOOTHING CURVES GENERATED BY TELEVISION SCANNING |
US4458330A (en) * | 1981-05-13 | 1984-07-03 | Intergraph Corporation | Banded vector to raster converter |
US4679039A (en) * | 1983-11-14 | 1987-07-07 | Hewlett-Packard Company | Smoothing discontinuities in the display of serial parallel line segments |
US5216756A (en) * | 1989-09-29 | 1993-06-01 | Nihon Kohden Corporation | Luminance interspersion type waveform display apparatus |
JP4963680B2 (en) * | 2008-03-27 | 2012-06-27 | 株式会社メガチップス | Image processing device |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE339580B (en) * | 1967-12-06 | 1971-10-11 | Standard Radio & Telefon |
-
1971
- 1971-10-27 GB GB5002471A patent/GB1405884A/en not_active Expired
-
1972
- 1972-10-25 US US00301090A patent/US3812491A/en not_active Expired - Lifetime
- 1972-10-25 JP JP47107054A patent/JPS4852335A/ja active Pending
- 1972-10-26 DE DE2252556A patent/DE2252556C2/en not_active Expired
- 1972-10-26 FR FR7238093A patent/FR2166929A5/fr not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4280186A (en) * | 1978-07-07 | 1981-07-21 | Tokyo Shibaura Denki Kabushiki Kaisha | Exposure apparatus using electron beams |
Also Published As
Publication number | Publication date |
---|---|
JPS4852335A (en) | 1973-07-23 |
US3812491A (en) | 1974-05-21 |
FR2166929A5 (en) | 1973-08-17 |
DE2252556A1 (en) | 1973-05-03 |
DE2252556C2 (en) | 1982-05-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB1405884A (en) | Raster-scanned display devices | |
EP0023217B1 (en) | Data processing system for color graphics display | |
US4425559A (en) | Method and apparatus for generating line segments and polygonal areas on a raster-type display | |
CA1200027A (en) | Video overlay system having interactive color addressing | |
US4823120A (en) | Enhanced video graphics controller | |
US4398189A (en) | Line buffer system for displaying multiple images in a video game | |
US4751502A (en) | Display controller for displaying a cursor on either of a CRT display device or a liquid crystal display device | |
EP0098868B1 (en) | Apparatus for controling a color display | |
US4420770A (en) | Video background generation system | |
US4070662A (en) | Digital raster display generator for moving displays | |
US4668947A (en) | Method and apparatus for generating cursors for a raster graphic display | |
US4570161A (en) | Raster scan digital display system | |
WO1983002510A1 (en) | Method and apparatus for filling polygons displayed by a raster graphic system | |
US5371519A (en) | Split sort image processing apparatus and method | |
US3955189A (en) | Data display terminal having data storage and transfer apparatus employing matrix notation addressing | |
US4835526A (en) | Display controller | |
US4757309A (en) | Graphics display terminal and method of storing alphanumeric data therein | |
US4093996A (en) | Cursor for an on-the-fly digital television display having an intermediate buffer and a refresh buffer | |
US3883728A (en) | Digital vector generator | |
US4231032A (en) | Variable accuracy trend graph display apparatus | |
EP0202426A2 (en) | Raster scan digital display system | |
US4777486A (en) | Video signal receiver for computer graphics system | |
US3987284A (en) | Conic generator for on-the-fly digital television display | |
USRE31977E (en) | Digital computing system having auto-incrementing memory | |
GB1303181A (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |