DE2135050A1 - Raster generator - Google Patents

Description

Raster generator

The invention relates to a raster generator for mapping representations, characters, letters and the like.

In known raster generators, a cathode ray is mostly deflected step by step so that certain raster points appear a phosphor screen can be selectively excited. To reinforce the individual raster point display, a specific one is used here Dwell time of the exciting cathode ray required. Since the advancement speed of the cathode ray but is constant, the dwell time determines the rate of advance also for not to be excited grid points. So there is an unnecessary loss of time.

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It is the object of the invention to avoid this unnecessary loss of time.

The object is, starting from a raster generator in which a plurality is modulated halftone dots selectively exciting, portable energy beam by intensity level signals time-dependent clock pulses achieved in that connected to a pulse clock and Int ens it ät Snive au- w signals receiving means for In the absence of an intensity level signal, the continuation of the pulses is generated synchronously with the pulse pulses and, when an intensity level signal occurs, the continuation of the pulses is delayed by a certain dwell time.

Further favorable configurations emerge from the following description and the subclaims.

Figure 1 shows the arrangement of the invention partly in perspective, mostly as a block diagram;

FIG. 2 shows the beam deflection in a grid with 5 × 7 grid pointsj.

FIG. J shows the representation as an example of a raster display of the letter B;

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Figures 4a and 4b show the clock pulses and intensity level signals for a well-known., and

FIGS. 5a and 5b for the raster generator according to the invention.

FIG. 1 shows a raster generator with a cathode ray tube 11, the front of which is coated with a continuous layer of phosphor. Certain, e.g. B. a 5x7 Matrix forming grid points of the phosphor layer are selectively by the z. B. generated by a cathode ray hole anode and from the deflection coils 13 from raster point to raster point switched cathode ray selectively excited.

To advance the cathode ray, a suitable one containing the digital counter 14 and the digital / analog converter 15 is generated Circuit an addressing signal. When switching of the counter 14 from stage to stage, the transducer 15 generates increasing deflection currents, which via the deflection amplifier 16 to the Deflection coils 13 are given, so represent an addressing signal advancing the cathode ray.

FIG. 2 shows an example of the scanning of the raster from raster point to raster point by the cathode ray which indicates certain points is reinforced and thereby a raster image,

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ζ. B. the letter "B" according to Figure 3 in one Grid with 5x7 grid points.

The gain for displaying a raster point is regulated by an intensity level signal applied to the electrode energy source 17. This signal is z. B. at the output of a digital computer, or a magnetic tape, memory, or derglei- ψ chen tapped in time-dependent relationship with the clock pulses.

So far, the cathode ray has been advanced to the next raster point with each clock pulse of FIG. 4a and through a The intensity level signal of FIG. 4b is selectively amplified at certain points. In the program shown, e.g. B. the first, fourth, fifth, seventh, eighth, ninth and twelfth grid point excited, while the second, third, sixth, The tenth and eleventh raster points remain unamplified, but the cathode ray also at the raster points that are not to be excited lingers exactly as long as at the grid points to be excited.

According to the invention, this Zext waste is eliminated. The intensity level signals are in a time-dependent relationship to the very rapid clock pulse sequence 5a taken from the pulse generator 18 5b generated and together with the clock pulses

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entered into a logic circuit. This generates switching impulses, the "in the absence of an intensity level signal synchronous to the Clock pulses are, on the other hand, when an intensity level signal occurs for the clock pulses by a "certain dwell time are delayed. According to FIG. 1, the logic circuit contains the clock pulses in the absence of an intensity level signal Letting UAND gate 19, the output of which with the OR gate 20 connected is. The continuation pulses are given from the output of the gate 20 to the counter 14 and counted there. To delay the incremental pulses are used by a reversing amplifier 21, a NAHD gate 22 and a counter 25 when an intensity level signal occurs lets the gate 22 clock pulses in the counter 23 · Bach-dem this z. B. has counted six pulses, it generates its output is passed into the counter 14 via the OR gate 20 Incremental pulse. Counter 2 $ works as a delay device for the switching pulse, which only occurs after a certain dwell time after the occurrence of the first clock pulse the deflection voltage for the cathode ray advances.

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Claims (6)

Patent claims Ill raster generator in which a multitude of raster points selectively exciting, moving energy beam is modulated time-dependently by intensity level signals to form pulses, characterized in that means connected to a pulse clock (18) and receiving the intensity level signals synchronously in the absence of an intensity level signal port switching pulses generate with the clock pulses and delay the incremental pulses by a certain dwell time when an intensity level signal occurs. 2. Raster generator according to claim 1, characterized in that that the incremental pulses are given into an addressing signal generator, which in turn generates the energy beam from the raster point advances to grid point according to a specified pattern. 3 raster generator according to claim 1, characterized in that "that the means generating the incremental pulses consist of a logic circuit with two coincidence circles (19» 20, 14 or 22, 20, 14) and one connected to one of the coincidence circles Retarders (23) exist. 109084/1763 4-, raster generator according to claim 3 »characterized in that that the delay consists of a counter (23) "whose output delivers an incremental pulse delayed by a "certain dwell time 5. Raster generator according to claim 2, characterized in that the addressing generator consists of one of the incremental pulses
counting counter (14-) and a digital-to-analog converter (15) "connected to this and generating a deflection signal. 6. Raster generator according to any one of the preceding claims, characterized in that the movable energy radiation is provided with a phosphor layer and on a cathode ray tube connected to a deflection circuit is generated. 109884/1763