DE2114665A1 - Circuit arrangement for a display device operating in video line mode, controllable by digital codes - Google Patents

Description

Licentia Patent-Verwaltungs-GmbH 6000 Frankfurt (Main) 7.0, Theodor-Stern-Kai 1

Constance, March 1, 1971 PT-KN Whs / lo

Circuitry for a video line mode working, controllable by digital codes

Display device

The invention relates to a circuit arrangement for a video line mode operating by digital codes Controllable display device with a character image points via a light button signal transmitter in selected image point grid times character generator generating a character window in each case, the window format being determined by a horizontal pixel counter and a video line counter is determined, as well as with switching means for generating others from pixels constructed representations

Known viewing devices with which a video presentation is prepared Characters as well as other representations, in particular lines, are possible, use for these others Representations an image repetition memory in which the individual pixels of the representations in their position in

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must be stored in a manner corresponding to the video grid (see S.Davis "Computer Data Displays", Prentice-Hall Inc., Englewood Cliffs, NJ. 1969, p. 329; U.S. Patent 3,396,377). This requires storage and storage effort, e.g. on the part of an electronic system that provides the pixel coordinates Calculator.

The aim of the invention is to improve that on In a simpler way, lines such as straight lines in particular, which at the same time use characters as subdivision or underline lines should appear, can be generated.

The circuit arrangement according to the invention for a display device of the type mentioned in the introduction is characterized by at least one between a code reception register and the Light button signal generator parallel to the character generator with a light button circuit with a detector for a no character determining code value, its detection signal in connection with signals from the horizontal pixel counter and / or the video line counter while from the character generator unoccupied pixel times are generated, brings about a light key signal.

In particular, it is provided that the light sensing circuit delay devices contains, by the effect of which the healing button appears delayed.

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In a further implementation of the invention, a resettable holding element which can be set by a detector signal is for Maintaining a light key signal during a sequence of horizontal pixel times is provided, and furthermore a, Detector for a code value, the detection signal of which is effective as a signal for resetting the holding element

It can also be provided that the setting and / or reset time for the holding element is additionally determined by coincidence with a signal from the horizontal pixel counter. _v fi -

In a preferred embodiment, the circuit arrangement according to the invention is characterized by a first light button with a first detector, the detection signal of which is a light button signal in each case with at least one count of the horizontal pixel counter brings about, and a second light probe circuit with a second detector whose detection signal is about a holding element brings about a light key signal for at least one count of the video character counter, in addition to a reset circuit with a third detector, the detection signal of which brings about the resetting of the holding element

Provision is also made for the arrangement of downshift means for Resetting of the holding element by a video line end signal, wherein the reset switching means can preferably be switched off.

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It can be provided that a certain count of the horizontal pixel counter determines both the point in time of setting and resetting of the holding element as well as the point in time of the light button signal brought about by a detection signal from the first detector.

An exemplary embodiment is shown below with the aid of the drawing the invention explained in more detail.

In the drawing, 1 is a circulating memory, which can be, for example, a feedback path or a drum track, and in which bit patterns fed by a data source circulate, which contain consecutive, for example, 8-part codes. The circulating memory 1 can be assigned to a line of characters to be displayed on the screen of a display device, with the same type of circulating memory being assigned to other character lines to be displayed, which can be successively connected to an accumulator register 2, come into effect in the same way and in their entirety form a frame repetition memory. To understand the invention, it is sufficient to consider essentially only one horizontal strip of the screen in which a line of characters is to be located. Characters are to be built up in this horizontal strip in the manner of the television picture from light-scanned points of video lines' with the aid of a character generator 3, in each case in a window, of which. Height of the width of the horizon, containing e.g. 24 video lines

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valley strip and its width e.g. 8 pixel times

speaks. In order to maintain the mutual spacing of the characters and the lines of text, some are at least Pixel times and video lines of the window lying a window edge cannot be occupied by the character generator 3.

If a character line is to be filled with characters, the circulating memory 1 is corresponding to those to be formed Characters sorted in their order, the individual characters determining codes taken one after the other and (under Retention in the circular memory) entered in the discharge register 2, from where they are each by a character clock TZ be transferred to a control register 5 via a gate 4- aas recognition circuits of the character generator 3 are connected. In this way the code sequence for each Video line of the horizontal strip offered again, the character generator 3 has the effect that he in each Video line the line points required to build up the character determined by the respective code via a Light button signal generator, here in the form of an OR gate 6, light button. For this purpose, the character generator 3 the respective status of a video line counter 7 communicated via connections not shown, which the video lines of the Counting the horizontal strip.

In the example shown, the bright point pattern is generated in each video line in such a way that the font

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character generator 3 a corresponding bit pattern in which, for example, L »means light and .0 - dark, via a gate 8 parallel in a shift register 9 enters, from which it is then immediately pushed out (to the left in the drawing) by a Shift clock TS, the impulses of which determine the pixel times. When pushing out, the Bit value 0, with all subsequent shift clock pulses the bit value L is shifted from the right end of the shift register 9 b.er from a correspondingly designed additional point in the drawing (9) · In this way, according to one of the The number of shift clock pulses corresponding to the window width in the shift register 9 does not occur during the generation of the image point Occurring bit pattern - in the example the pattern OLIiLLLLL in the points (1) to (8) -, which is detected by a detector 10 with the effect that the detection signal ST the shift clock TS switches off and the register 9 clears · The arrangement with the shift register 9 also has the function of a Horizontal pixel counter, whereby under "pixel" all possible (light or dark keyed) pixels are understood. Instead of this arrangement, a common, in particular, binary counter that counts the pixel times and also successively for output gates of the character generator 3 provides. If the key is to be brightly at a pixel time, this is done in the illustrated embodiment by shifting an L value to an input of the OR gate 6, which thereby generates a light test pulse issues. .

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The character generator 3 is required for the provision of a pixel bit pattern to be entered in the shift register 9 on the basis of a recognized writing · character code, a processing time. This is provided by the fact that after a character code has been entered in the control register 5 by a 'character clock pulse - in the drawing with TZ (1) denotes - the query of the pixel bit pattern via the gate 8 by the following, denoted in the drawing with TZ (2) Character clock pulse occurs (which at the same time fetches the next character code in control register 5) Generation of a character bright point pattern is therefore one compared to the supply of the character code around the time Window width delayed

It is now planned, in addition to the characters, also line representations to be generated on the screen in the form of horizontal and / or vertical straight lines, so that e.g. underlines made, frames or form divisions or other orthogonal figures can be displayed.

To this end, the circulating Save 1 at appropriate, also the window time assigned locations are determined by the data source in the data flow is written codes that determine no characters, but "Graphikkodes ¹¹ are · As such a code are provided here ¹¹ VL""vertical line a code BHL * beginning of a horizontal line and a code

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EHL β end of a horizontal line. These codes remain in the character generator 3 has no effect.

Is through a. Character clock pulse TZ (1) instead of a character code If the code VL is entered in the control register 5, it is recognized by a detector 11, the recognition signal of which is fed to an input of an AND gate "12". The output of the AND gate 12 is connected to a point - in the drawing point (3) - of the shift register 9, so, that, when activated, it sets this position to "L". This activation happens through the second input of the and gate 12 applied subsequent character clock pulse TZ (2), which, like every TZ pulse, starts the shift clock TS. A bright point is thus generated via the OR gate 6 at the pixel time "3" of the window, and the result is that there this process is repeated for each video line in the window, a vertical line running through the entire height of the window Line. Since in the corresponding window of an adjacent horizontal strip there is also a vertical line through feed of the code VL can be generated, the vertical line can be continued over a desired number of horizontal strips will.

A vertical line of double thickness can be obtained in that the output of the undgate 12 to two adjacent ones Digits - e.g. (3) and (4-) - of the shift register 9.

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is closed, a double line is obtained by connecting the output of 12 to points that are further apart - e.g. (3) and (5) As can be easily seen, one can also provide that the representations, such as vertical thin, thick or double lines are selectively generated by several Helltastkreise as 11, beregister with suitable connections to the rail ¹ "and the" set parallel 9 12 Each detector circuit is responsive to its own code.

In the case described above, a window width is made available for the vertical line (s). But it is also possible to display the vertical line (s) together with a character in a window. For this it is intended that the code to be entered in the control register 5 is extended by one bit position that is generated by the character generator 3 is not queried, but is evaluated in the devices shown in dashed lines in the drawing. From the additional bit position 13, the value of the bit contained is queried by the detector line 14. A Binary value, e.g. 0 »has no effect, while the other binary value, e.g. L, activates one input of an AND gate 15. Its output is to a position that cannot be occupied by the character generator 3 - e.g. position (7) - of the shift register 9 connected to set this position to "L" when activated. Activation happens when the aforementioned Input of the AND gate 15 is activated, by activating

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tion of the second input, the character clock pulse, TZ (2). When the window is then pushed out, a bright point is generated via the OR gate 6 at the pixel time (7) of the drawing window, and since this happens in every video line of the window, a vertical line that extends over the height of the window is created, either alone if the main part of the control register 5 does not contain a character code, or, if one is present in the main part of the register 5, next to the character, its pixel sub-pattern in another area - e.g. positions (1) to (5) - of the shift register is entered and pushed out by video line and occupy only part of the video lines of the window. Again, the vertical line can be continued over any number of the possible horizontal stripes by adding the additional bit "L ¹¹ " to the codes for the windows lying one below the other, and there may or may not be a symbol next to the line in each of these windows, depending on the code, which is entered for the respective character line in addition to the said bit "L" in the control register 5. Of course, when using the method of the additional bit, the activated output of the AND gate 15 could simultaneously have several positions in the shift register - outside the position range that can be occupied by the character generator 3 - Use "L" values if the window is sufficiently wide.

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The codes BHL and EHL are used to generate horizontal lines, and it was useful to be able to underline characters in a video line area of each window, which is below the window area that can be occupied by the character generator 3. Is entered in the control register 5 by a character clock pulse TZ ( 1) the code BHL is entered, it is recognized in a detector 16, and the recognition signal is fed to the set input of a clocked bistable flip-flop circuit 1? a signal to the set input of another clocked bistable multivibrator 18, which is then set by the next character clock pulse TZ (3), i.e. with a delay of two window widths Another entrance of the Undgatters 19 is through the Vid eoline counter 7 activated via a counter reading detector 20 only when a counter reading is assigned to a video line running in the aforementioned area below the character area (there can also be several counter readings that meet the stated condition). It is assumed that there are video lines 16-23, for example, in the lower edge area free of characters, and that the detector 20 responds to the counter readings "21" and "22". Furthermore, it is assumed for the following that the now treated horizontal line light circle

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is provided together with a vertical line light touch circle, which runs over the elements 11 and 12 as in the drawing. ,

When the flip-flop 18 is set and the video line 21 is started, two inputs of the AND gate 19 are activated. The shift register 9 can at most only one via the AND gate 12 in the position (3) set L-value, which generates a vertical line pixel. The third entrance of the AND gate 19 is connected to a detector 21 which, at the pixel time "3" (at which the named L bit, if present, is pushed out) by recognizing the bit pattern OOOOOOliL in positions (1) to (8) of the shift register 9 responds » The detection signal of the detector 21 then activates the output of the AND gate 19, creating a bistable multivibrator 22 is set. Their output signal in the set state activates the second input of the OR gate 6 and generates a light button signal via this, which remains as long as the flip-flop 22 is set. The result in the Video line 21 resulting light-scanned horizontal line begins, as can be seen from the above, 2 window width times plus 3 pixel times after entering the code BHL in control register 5 »Was during the (third) Window width time a vertical line L bit in position (3) of the Shift register 9, then the horizontal line attaches to this vertical line, extending from this to the right.

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It will then be for a subsequent window width time Code EHL entered in control register 5. This is recognized by a detector 23, whose recognition signal is immediately an input of an AND gate 24 activated, the second input also by the counter position signal "21" of the Video line counter 7 is activated. A detector 25 is connected to a third input of the Ur.d ^ atters 24, which is shown in example treated here as well as the detector 21 responds at the pixel time "3", and its detection signal the third; Input of the AND gate 24 activated, so that this gate, ve-r-n also seir.e two other inputs are activated its output emits a signal which resets the flip-flop circuit 22 via an OR gate 26. The one in video line 21 The normal-scanned horizontal line ends here, specifically at a point in time through which the right-hand end of this line passes is added to a vertical line again, provided that this is created in the window containing this point in time.

With the assumption made that the detector 20 also on the. Video line counter reading "22" responds, repeat the processes described in the 22nd video line, during which the codes BHL and EHL yes in the same time sequence again be entered in the control register 5. This reinforces the horizontal line. You also knew as Double lines are represented by the detector 20 responding to the video line counters "20" and "22", for example,

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or as a thin line by just looking at a video line counter appeals to.

"V; -> r reset lines, not shown, can be used by the flip-flop 17 by the beginning of the output signal of the set Flip-flop 18 and flip-flop 18 by the beginning of the output signal of the set flip-flop 22 reset will.

The delays provided in the light probe circles serve several purposes. The delay by one character clock interval after the detection of a code VL in the detector 11 or an additional hit L in the control register location 13 takes into account the fact that the characters composing a character Bit patterns from the character generator 3 appear with a delay of one character clock interval. The delay at two character intervals in which the code BHL The processing light circle serves the purpose of underlining a character sequence of the code sequence that generates it to be able to add the code BHL. The delay is necessary because then the code of the first character of the sequence a character clock interval is recorded in the control register after the code BHL, and again a character clock interval passes before the mark is written. The delay in the action of the code EHL has only a few pixel times to the rim that if the aforementioned character code sequence of

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Code EHL is appended, the underlining ends in the same window as the last character in the sequence appears. The additional delay in the action of the code BHL by a few pixel times as well as the delay of the Effect of the code EHL around a few pixel times are used, as explained, to adapt the position of the beginning and end of a horizontal line to the position of a veitical line, for which a position in the window interior is provided. The number of Pixel times by which the effect of the code EHL is delayed and the effect of the code BHL is additionally delayed be chosen differently for the two codes, and for this purpose are in the drawing at the third inputs of the AND gate 19 and 24 each have a detector 21 and 25 connected (while for the case described above where the pixel time delays for BHL and EHL are the same, only one would have been sufficient) · For example, in the event that in a vertical double line can be generated in a window, the pixel times for BHL and EHL are chosen so that one horizontal line begins on the right line of such a double line and on the left line of such a double line ends.

It should also be mentioned that the detection signals of the detectors 11, 14, 16, 25 decay with a small delay so that they are still effective while a new code is already being fed into the control register 5 by the subsequent character clock TZ.
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According to what has been explained above, it should be clear that depending on the Position of the area in the window that can be filled with characters, horizontal lines also above or above and below of the characters and, when using the additional bit method, vertical lines also to the left or left and right of the character could be generated in the window.

In the event that a code BHL but no code EHL appears for a horizontal strip, it is provided that the Flip-flop 22 by a video line end pulse (used for the transition to the next video line is always required), or optionally not. The video line end pulse ZE is fed to an input of an AND gate 27, the output of which is connected to the reset via the OR gate 26 z input of the flip-flop 22 is connected. At the other input of the AND gate 27, either L or 0 can be applied. If L is applied, if no code EHL has appeared, the video line end pulse ZE resets the flip-flop, i.e. a light horizontal line started in a video line ends at the end of this line. Is at the other entrance of the And gate O is applied, the pulse ZE cannot generate an output signal from the gate. The set toggle switch 22 remains set with the effect that the light line started in the video line in the corresponding video line of the subsequent horizontal strip or also further subsequent horizontal strips, optionally with the top one

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Horizontal stripe starting again after jumping back, is continued until the EHL code in the control register is entered and the horizontal line in that strip ends. So you have it in your hand areas required by supplying only one BHL and EHL code to line the total image area or several fonts underline character lines with a selectable beginning and end.

As is easy to see, lines that run through light-keyed characters go through, which is mostly inexpedient will be.

* i light circle like 11, 12 could also be easy as well To see, for the generation of oblique lines, it would be sufficient to connect the points of the output of the AND gate 12 via gates controlled by the video line counter 7 step by step.

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Claims (8)

21U665 Pat en t a η s ρ r ü'c h e 1, circuit arrangement for a working in video line mode, Display device controllable by digital codes with a character image point via a light button signal transmitter in selected pixel raster times each of a drawing window generating character generator, the window format by a horizontal pixel counter and a video line counter is determined, as well as with switching means for generating other ones made up of pixels Representations,. characterized by at least one key circle lying between a code reception register (5) and the light key signal generator (6) parallel to the character generator (3) with a detector (11 or 14 or 16 or 23) for a code value which does not determine any character, its recognition signal in connection with signals which are generated by the horizontal pixel counter (9) and / or the video line counter (7) during pixel times not occupied by the character generator, brings about a light key signal. 2. A circuit arrangement according to claim 1, characterized in that the light sensing circuit contains delay devices (12 or 15 or 17-25), by the effect of which the light test signal appears to be delayed. KN 69/60 ' 209841/0943 3 «Circuit arrangement according to claim 1 or 2, characterized by a resettable holding element (22) which can be set by a detector signal and for maintaining a light button signal during a sequence of horizontal pixel times. 4. Circuit arrangement according to claim 3t "' characterized by a detector (23) for a code value whose detection signal is effective as a signal for resetting the holding member (22). 5. Circuit arrangement according to claim 3 and / or 4, characterized in that the setting and / or setting time for the holding element is additionally determined by coincidence with a signal from the horizontal pixel counter (9), 6. Circuit arrangement according to claim 1 or one of the following, characterized by a first light probe circuit with a Ezw 14- first detector (11/5, whose detection signal is a light button signal each with at least one count of the horizontal pixel counter (9) brings about, and- a second light probe circuit with a second detector (16), its detection signal A light test signal via a holding element (22) with at least one count of the video character counter (7) brings about, in addition to a reset circuit with a third detector (23), the detection signal of which the reset of the Holding member brings about. KN 69/60 209841/0943 7. Circuit arrangement according to claim 4 or 6, characterized by Euckstellschaltmittel (27, 26) for resetting the holding member (22) by a video line end signal .. 8. Circuit arrangement according to claim 7 » characterized in that the reset switching means can be switched off. Circuit arrangement according to Claims 5 and 6, characterized in that a certain count of the horizontal pixel counter (9) both the time of setting and resetting of the holding element (22) and the time of the light button signal brought about by a detection signal from the first detector OO certainly. KN 69/60 209SA1 / 0943