JPH028315Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a display device that can rotate displayed characters one character at a time.

[Background of the invention and problems with conventional technology]

When displaying graphics on a cathode ray tube display using a computer, it is convenient to display characters such as dimensions along with the graphics. The displayed text must be rotated at least every 90 degrees in relation to the graphic.

As one of the conventional techniques for rotating a display, Japanese Patent Application Laid-Open No. 50-32894 discloses that X and Y output signals from a symbol generator and cos θ and sin θ signals (θ: rotation angle)
An apparatus is disclosed for supplying four multipliers with four multipliers and adding the output signals of these multipliers and X and Y coordinate signals. According to this conventional device, displayed characters can be rotated by any angle, but it requires four multipliers and a circuit that generates cosine and sine signals.
The configuration is complex and expensive.

In addition, as another prior art, Japanese Patent Application Laid-Open No. 52-47327 discloses that the display direction is controlled by a 3-bit deformation tag of the figure data from the memory, and the figure data is supplied to a line segment generator and displayed. Discloses a device that controls graphics in eight different orientations. However, since this conventional device uses a display processor, a program for that purpose is also required, making the design complicated.

However, read-on memory (ROM) that stores patterns of characters, especially kanji, e.g.
MB83256 series ICs have recently been commercially available. This ROM stores character patterns in the form of a dot matrix and is suitable for raster scanning type display devices. However, when the entire display screen is raster scanned, it is easy to rotate the entire display, but it is difficult to rotate the displayed characters one character at a time because control is complicated. Also, this ROM
It is difficult to apply this to the above-mentioned prior art, or the configuration becomes complicated.

A conventional technique using character pattern memory in this manner is disclosed in Japanese Patent Laid-Open No. 147441/1983. In this prior art, the read address of the character pattern memory and the output multiplexer of the character pattern memory are controlled to rotate the displayed characters. However, since the read address signal and the multiplexer control signal are multi-bit digital signals, processing of these signals accompanying rotation must be performed for each bit, making the configuration of the rotation control circuit complicated. It was hot.

[Purpose of invention]

Therefore, one of the objects of the present invention is to provide a display device that can rotate displayed characters one character at a time with a simple configuration.

Another object of the present invention is to provide a display device capable of displaying rotatable characters as well as vector display of figures and the like.

[Summary of the idea]

According to the display device of the present invention, raster scanning is performed character by character, character pattern signals are read out as luminance signals from the memory circuit (ROM) in 1 pixel (pixel) units in synchronization with this raster scanning, and the cathode ray tube Display characters on CRT). The display position of characters is controlled by superimposing a position signal on a scanning signal.
Further, in order to rotate the displayed characters, the scanning signals are selectively exchanged between the vertical and horizontal axes, or the polarity is selectively reversed. Further, by stopping the generation of the scanning signal and controlling the position signal, other information such as graphics can be easily displayed as a vector. Then,
With a simple configuration, displayed characters can be rotated in units of characters.

[Embodiment of the invention] Hereinafter, a preferred embodiment of the invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram of a preferred embodiment of the present invention. Clock generator 10 is, for example, a crystal oscillator, and generates a clock signal of a predetermined frequency.
The counter 12 counts this clock signal and supplies the lower bit group of the counted digital output signal to a digital-to-analog (D/A) converter 14 and the upper bit group to a D/A converter 16. Since the counting digital output signal is increased by one step by the clock signal, the D/A converters 14 and 16
The respective analog output signals A and B from the second -
As shown in FIG. 1, a high-frequency and low-frequency slope wave (scanning signal: actually a staircase wave, but for convenience, it is assumed to be a slope wave) is obtained. Note that the frequency ratio of the scanning signals A and B is determined in consideration of raster scanning of character display. The analog multiplexer 18 converts the scanning signals A and B applied to the inputs X and Y into one of the outputs X0 to X3 and Y, depending on the rotating digital information.
Selectively output from one of 0 to Y3. amplifier 2
The inverting input terminal of 0 is connected to the output terminals X2 and Y1 of the multiplexer 18 through a resistor 22, and the non-inverting input terminal is connected to the multiplexer 1 through a resistor 24.
Connect to output terminals X0 and Y3 of 8. Resistor 22
The left end of is grounded through resistor 26, and resistor 24
Both ends of are grounded through resistors 28 and 30, respectively. Further, a parallel circuit of a resistor 32 and a phase compensation capacitor 34 is inserted into the negative feedback path of the amplifier 20. Similarly, the inverting input of amplifier 36 is connected to resistor 3.
8 to the outputs X1 and Y0 of the multiplexer 18, and the non-inverting input is connected to the outputs X3 and Y2 of the multiplexer 18 through a resistor 40. The left end of resistor 38 is grounded via resistor 42, and both ends of resistor 40 are grounded via resistors 44 and 46, respectively. Further, a parallel circuit of a resistor 48 and a phase compensation capacitor 50 is inserted in the negative feedback path of the amplifier 36. Note that the resistors 22, 24,
Since the values of 30, 32, 38, 40, 46 and 48 are equal to, for example, 10 kilohms, amplifiers 20 and 36 have a gain of 1 due to the input terminals providing the input signal.
It works as an inverting amplifier or a non-inverting amplifier.

The position digital information is latched by a latch circuit 52 and the horizontal and vertical components are provided to D/A converters 54 and 56, respectively. Analog adder 58 receives horizontal scanning signal X from amplifier 20 and D/A converter 54
Amplifier 6 adds the horizontal position analog signals from
2 to the horizontal coil of the electromagnetic deflection coil 66. This electromagnetic deflection coil 66 deflects the electron beam of the CRT 64. In addition, the analog adder 6
8 is the vertical scanning signal Y and D/A from the amplifier 36
The vertical position analog signals from transducer 56 are summed and provided via amplifier 70 to the vertical coil of electromagnetic deflection coil 66 . Summers 58 and 68 may be conventional operational amplifiers, and electrostatic deflection plates may be provided within CRT 64 in place of electromagnetic deflection coil 66.

The ROM 72 as a storage circuit is, for example, an MB83256 series IC as described above, and stores kanji (character) patterns as a dot matrix. The decoder 74 decodes the character digital information and selects a character pattern in the ROM 72.
Further, each dot information of the selected character pattern from the ROM 72 is read out in synchronization with raster scanning for one character by the count digital output signal of the counter 12. That is, the address of the ROM 72 is specified by the digital output signals of the counter 12 and the decoder 74. Shift register 76 receives the clock signal from clock generator 10, converts the parallel digital signal from ROM 72 into a serial digital signal, and converts the serial digital signal through amplifier 78.
It is supplied to the control grid of the CRT 64 to perform brightness control. Note that the above-mentioned character information, rotation information, and position information are sent from a computer or the like.

Next, the operation shown in FIG. 1 will be explained. If the rotation information is, for example, "00", the input terminals X and Y of the multiplexer 18 are coupled to the output terminals X0 and Y0, respectively.
The scanning signals A and B from the D/A converters 14 and 16 are thus applied to the non-inverting input of the amplifier 20 and the inverting input of the amplifier 36, respectively.
The scanning signals X and Y from 0 and 36 become signals as shown in FIG. 2-2. That is, the scanning signal X remains the scanning signal A, and the scanning signal Y remains the scanning signal B.
It is the inverted version of . These scanning signals X and Y
Therefore, the raster scan for one character is R in Figure 2-2.
The characters, such as "toku", are displayed as shown in D in the figure. Note that since the scanning signals X and Y are superimposed on the position information, when the position information represents a point 80 on the display screen of the CRT 64 as shown in FIG.
The text is displayed at the top right 82 of this point 80.

Further, when the rotation information is "11", the scanning signals A and B are transmitted to the inverting input terminal of the amplifier 36 and the amplifier 2, respectively.
0, the scanning signals X and Y become the inverted scanning signals B and A as shown in FIGS. 2-3. Therefore, the raster scan for one character is
The display will be as shown in Figure 3R, and the displayed characters will be rotated 90 degrees as shown in Figure 3D. When the location information indicates point 84 in FIG. 3, the text is displayed at 86 to the lower right of point 84.

If the rotation information is "10", multiplexer 18
The inputs X and Y of are coupled to the outputs X2 and Y2, respectively, and the scanning signals X and Y remain the inverted scanning signal A and the scanning signal B, respectively, as shown in FIGS. 2-4. At this time, if the position information indicates point 88 in FIG.
The display is shown in the lower left 90 of FIG. 2-4 as shown in FIG.

Further, when the rotation information is "01", the input terminals X and Y of the multiplexer 18 are output terminals X3 and Y, respectively.
3, the scanning signals X and Y become scanning signals B and A, respectively, as shown in FIGS. 2-5. When the position information indicates a point 92 in FIG. 3, raster scanning for one character is performed at the upper left 94 of this point 92 as shown in FIG. 2-5R, and the display becomes as shown in FIG. 2-5D. This display is 270 degrees or minus 90 degrees in the case of Figure 2-2.
It has been rotated a degree.

In this way, the rotation information allows the display to be rotated for each character. Further, the display position can be arbitrarily controlled using position information. Further, as long as the counting of the counter 12 is not stopped and the scanning numbers X and Y (ie, A and B) are not generated, an arbitrary vector display can be performed based on the position information.

[Effect of idea]

As mentioned above, according to the present invention, all processing associated with character rotation is performed using analog signals.
For horizontal and vertical processing, it is only necessary to process analog signals on one signal line, and the configuration is simpler than when processing rotation using a multi-bit digital signal. That is, the raster scan for one character is performed, and the high-frequency and low-frequency scanning signals are selectively inverted or interchanged on the vertical and horizontal axes, so that the displayed character can be rotated in units of 90 degrees. Furthermore, the position of displayed characters can be controlled arbitrarily by simply superimposing (adding) position information on the scanning signal. Furthermore, since the rotation of characters can be controlled only by a multiplexer, the configuration is simple.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a preferred embodiment of the present invention, Figs. 2-1 to 2-5 are waveform charts and display diagrams explaining the operation of Fig. 1, and Fig. 3 is the operation of Fig. 1. FIG. 10: Clock generator, 12: Counter, 1
4, 16: D/A converter, 18: Multiplexer, 20, 36: Amplifier, 58, 68: Adder,
64: Cathode ray tube, 72: Memory circuit.

Claims (1)

[Claims for Utility Model Registration] A clock generator that generates a clock signal, a counter that counts the clock signal, and a counter that converts the upper bit group and lower bit group of the counting digital output signal of the counter into analog signals, respectively. first and second digital-to-analog converters; first and second amplifiers each having an inverting input terminal and a non-inverting input terminal, and having equal gains for signals supplied to the inverting input terminal and the non-inverting input terminal, respectively; , converting the analog output signal of the first digital-to-analog converter into the first and second digital-to-analog converters according to the rotation information.
The analog output signal of the second digital-to-analog converter is selectively supplied to one inverting input terminal or non-inverting input terminal of the amplifier, and the analog output signal of the second digital-to-analog converter is supplied to the other inverting input terminal or non-inverting input terminal of the first and second amplifiers. a first adder for adding the output signal of the first amplifier to the horizontal position analog signal; and a second adder for adding the output signal of the second amplifier to the vertical position analog signal. an adder; a storage circuit for storing character patterns and addressed by the character information and the counting digital output signal of the counter; and an electron beam being directed horizontally and vertically by the output signals of the first and second adders, respectively. A display device comprising a cathode ray tube that is deflected and whose brightness is controlled by an output signal of the storage circuit.