Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
  • G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
• • 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
  • G09G5/22—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the display of characters or indicia using display control signals derived from coded signals representing the characters or indicia, e.g. with a character-code memory
  • G09G5/24—Generation of individual character patterns
  • G09G5/28—Generation of individual character patterns for enhancement of character form, e.g. smoothing
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
  • G06K2215/0002—Handling the output data
  • G06K2215/002—Generic data access
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K2215/00—Arrangements for producing a permanent visual presentation of the output data
  • G06K2215/0002—Handling the output data
  • G06K2215/0077—Raster outputting to the print element(s)

Definitions

• the invention relates to a circuit arrangement for controlling an image display device according to the preamble of claim 1.
• a device for controlling a matrix printer or a matrix display device according to the preamble of claim 1 contains a control unit for reading out pixel information from a character memory.
• a character stored in the character memory with a certain width can be read out in different character widths for image reproduction.
• the respective character width is determined by a logic circuit.
• a character generator is contained in the device which controls the image reproduction device.
• characters of a specific form defined by attributes are stored.
• the character memory is read out line by line.
• the value 0 is read out at places where there is no character information and the value 1 is read out at locations where there is character information.
• This value 1 corresponds to information in the form of an I pulse which, depending on the cutoff frequency of the character generator, has a certain steepness of the rising and falling edge. In unfavorable cases it can happen that a pulse does not reach its setpoint. A pulse that does not reach its target value or just reaches it, then leads to a reduced contrast of the pixel with the image background in the image display device. If a large number of pixels with reduced contrast appear in a character, this leads to poor image reproduction of the displayed character.
• the present invention is therefore based on the object of improving the display of characters on an image display device in a simple and inexpensive manner.
• FIG. 1 shows a block diagram of the circuit arrangement according to the invention with image display device
• FIG. 2 shows a field for a character in a character memory according to the prior art
• FIG. 3 shows a field for a character in a character memory with an increased number of columns
• FIG. 4a shows a detail from the character spotting animal according to FIG. 2,
• FIG. 4b shows a target pulse for a pixel of a character memory according to FIG. 4a
• FIG. 4c shows an actual pulse for a pixel of a character memory according to FIG. 4a
• FIG. 5a shows a section of a character memory according to FIG. 3,
• FIG. 5b shows a target pulse for a pixel of a character memory according to FIGS. 5a and
• 5c shows an actual pulse for a pixel of a character memory according to FIG. 5a.
• a control unit C for an image display device BW receives data D in coded form.
• the control unit C uses a character memory ZM to convert the data D into pulses which are fed to the image display unit BW and displayed there.
• the character memory ZM is structured in a matrix in rows ZE and columns SP (see FIG. 2). For each character Z, fields with a certain number of columns and rows are reserved in the character memory ZM.
• a field for a character Z of a known character memory ZM consists of sixteen lines ZE and nine columns SP.
• a character Z here the capital letter A, is stored in the field of the character memory ZM in the form of information.
• a pixel P is activated when a logical 1 is read from the character memory ZM when addressing a specific column SP and a specific row ZE. If, on the other hand, a logical 0 is read, no pixel P is activated at this point.
• the character Z which represents the capital letter A
• the following pixels P are set in the corresponding section of the character memory ZM: columns SP / lines ZE
• FIG. 3 shows a corresponding field of a character memory ZM according to the invention, in which the character Z for the capital letter A is stored.
• This field comprises sixteen rows ZE and eighteen columns SP.
• the number of columns SP is accordingly increased by a factor of 2 compared to the character memory ZM according to FIG.
• the following pixels are set for the capital letter A in the character memory ZM according to the invention: columns SP / lines ZE
• a pixel P of a character Z of a known character memory ZM is stored in the character memory ZM according to the invention in the row direction multiplied by more than the column factor in the character memory ZM.
• the column factor is 2 and the pixel P is stored multiplied by a factor of 3 in the row direction (row 6).
• each pixel P is multiplied in the line direction by the gap factor. Only the last pixel of such a row ZE shows the multiplication of a pixel P by more than the column factor.
• the pixel P which is located at the intersection of the eighth column SP and the ninth row ZE in FIG. 2, is stored tripled in FIG. 3 in the intersection points of the ninth row ZE with the fifth, sixth and seventh column SP.
• the second, third and fourth column SP and the sixth, seventh and eighth row ZE comprises the second, third and fourth column SP and the sixth, seventh and eighth row ZE. If, for example, the sixth line ZE is read out at a certain clock frequency, then the rectangular target pulse PS shown in FIG. 4b should be read from the second column SP and output to the image display device BW. However, the actual pulse PI shown in FIG. 4c actually reaches the image display device BW. This actual pulse PI has flattened rising and falling edges and does not reach the desired height H of the desired pulse PS. Even if the desired height H is to be reached, the needle-like actual pulse PI directed to the image display device BW generates a point with little contrast, which is difficult to recognize on the image display device BW designed in the form of a cathode ray tube.
• a target pulse PS shown in FIG Has 1 1/2 times the width of the desired pulse PS shown in FIG. 4b.
• the clock frequency is increased by the column factor, ie by a factor of 2.
• the actual pulse PI resulting from the reading which is shown in FIG. 5c, reaches the target height H completely and is significantly broadened compared to the actual pulse PI shown in FIG. 4c. If this broadened actual pulse PI is supplied to the image display device BW, then this image display device BW can reproduce the section of the character Z under consideration with increased contrast and thus with increased quality.
• the image reproduction device BW is not subjected to an increased video frequency compared to the known prior art.
• the maximum video frequency results from the ketir value of the readout time for two columns SP of a row ZE and, in the circuit arrangement according to the invention, from the reciprocal of the time for reading out four adjacent columns SP of a row ZE.
• the image display devices BW used in the prior art can therefore continue to be used.
• these image display devices BW have a better image display quality.
• Even the control C can remain unchanged, provided that it is able to deliver a clock frequency that is increased by the column factor, for example by inserting a corresponding crystal.
• Customary character memories ZM can also continue to be used. However, if there are not previously unused storage spaces available, the number of characters Z stored in the character memory ZM must be reduced by the column factor.

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

Applications Claiming Priority (3)

Publications (1)

Family

ID=6461268

Family Applications (1)

Country Status (3)

Family Cites Families (5)

• 1992
  • 1992-06-17 DE DE19924219925 patent/DE4219925C1/de not_active Expired - Fee Related
• 1993
  • 1993-06-09 WO PCT/DE1993/000501 patent/WO1993025993A1/de not_active Application Discontinuation
  • 1993-06-09 EP EP93912577A patent/EP0646270A1/de not_active Ceased

Non-Patent Citations (1)

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