KR100269755B1 - Voltage generating method, voltage generating circuit and monitor device - Google Patents

Abstract

An object of the present invention is to provide a voltage generating method, a voltage generating circuit, and a monitor device for generating a voltage based on waveform data approximating a waveform of a voltage to be generated. The configuration of the present invention includes a memory 10 having a small storage capacity for storing waveform data for approximating a waveform of a parabola wave voltage to be generated, a CPU 11 for inputting waveform data read from the memory 10, And a digital / analog converter 13 for calculating the linear approximate waveform data by the CPU 11 based on the read waveform data and performing digital / analog conversion on the computed linear approximate waveform data output from the CPU 11 .

Description

A voltage generating method, a voltage generating circuit, and a monitor device (Voltage Generating Method, and Monitor Apparatus)

FIG. 1 is a block diagram showing a configuration of a voltage generating circuit according to the present invention. FIG.

FIG. 2 is a conceptual diagram of a data table of a memory. FIG.

FIG. 3 is a conceptual diagram of a case where the voltage of the parabola wave is linearly approximated. FIG.

FIG. 4 is a conceptual diagram of a case in which a parabola wave voltage is approximated by a curve. FIG.

5 is a flowchart showing control contents of the CPU.

6 is a block diagram showing the configuration of another embodiment of the voltage generating circuit according to the present invention.

7 is a conceptual view of a data table of a memory;

FIG. 8 is a block diagram showing a configuration of a waveform synthesizing section. FIG.

FIG. 9 is a conceptual diagram of a case in which a sinusoidal voltage is curve-approximated. FIG.

10 is a flowchart showing control contents of the CPU.

FIG. 11 is a waveform diagram of sinusoidal waves, sawtooth waves, and corrected sawtooth waves. FIG.

12 is an explanatory diagram of a display state of a display image;

FIG. 13 is an explanatory diagram of bobbin distortion of a display image; FIG.

FIG. 14 is a waveform diagram of a vertical parabola wave voltage. FIG.

15 is a block diagram of a conventional parabola wave voltage generating circuit.

FIG. 16 is a conceptual diagram of a data table in a memory. FIG.

17 is a flowchart showing control contents of the CPU;

DESCRIPTION OF THE REFERENCE NUMERALS

10: memory 11: CPU

12: adjustment control unit 13: digital / analog converter

16:

The present invention relates to a voltage generating method, a voltage generating circuit, and a monitor apparatus.

Bobbin distortion in which the horizontal width changes in the vertical direction is generated in the display image of the CRT 100 shown in FIG. 13 on the monitor device or the television receiver of the personal computer as indicated by the dotted line. In order to correct this bobbin distortion, a parabola wave voltage generating circuit for generating a vertical parabola wave voltage Vp as shown in Fig. 14 is incorporated.

FIG. 15 is a block diagram of a conventional vertical parabola wave voltage generating circuit for generating a parabola wave voltage by a digital signal. The memory 1 stores waveform data that linearly approximates a vertical parabola wave voltage (hereinafter referred to as parabola wave voltage) to be generated. When one parabola wave voltage is linearly approximated, the linear approximate waveform data requires 512 words. In case of 100 kinds of waveforms of the parabola wave, waveform data that linearly approximates each of the parabola wave voltages is required. Therefore, as shown in FIG. 16, the memory 1 is a data table having 512 words in the horizontal direction and 100 lines in the vertical direction.

The data table stores waveform data of 512 words in a linear approximation corresponding to the adjustment value for adjusting the outline of the display image. The waveform data read from the memory 1 is input to the CPU 2. [ The output signal of the outline adjustment section 3 that specifies the adjustment value for adjusting the outline of the display image is input to the CPU 2. [ The linear approximate waveform data read out from the memory 1 in accordance with the specified adjustment value is input to the digital / analog converter 4. The digital / analog converter 4 generates an analog parabola wave voltage by converting the input digital signal into an analog voltage, and the generated parabola wave voltage is input to the monitor device 5. [

Hereinafter, the operation of the parabola wave voltage generating circuit will be described simultaneously with the flowchart of FIG. 17 showing the control contents of the CPU 2. FIG. When the user corrects the adjustment value by correcting the outline of the display image, that is, correcting the bobbin distortion of the display image, the CPU 2 accepts the designated adjustment value for adjusting the outline of the display image (S1). The adjustment value designated here is set to "2 " (S2). A signal of the adjustment value is input to the CPU 2, and the CPU 2 outputs an address signal corresponding to the specified adjustment value to output linear approximate waveform data corresponding to the adjustment value "2" of the data table of the fifteenth 512 words of waveform data are read from the area of the adjustment value "2 " of the data table and received (S3).

Then, the CPU 2 inputs the received 512-word waveform data to the digital / analog converter 4 (S4). Then, the digital / analog converter 4 digitally / analog-converts the digital signal of the input linear approximate waveform data to generate an analog parabolic wave voltage, and inputs it to the monitor device 5. The bobbin distortion of the display image is corrected accordingly.

By the way, the memory for storing the linear approximate waveform data of the parabola wave voltage to be generated as described above requires a storage capacity of (512 words x 100 rows) x 2 bytes (where 1 word is 2 bytes) There is a problem that an expensive memory must be used for the wave voltage generating circuit. SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a voltage generating method, a voltage generating circuit, and a monitor apparatus that can use a storage unit having a small storage capacity.

A voltage generating method according to a first aspect of the present invention is a method of generating a voltage of a required waveform by a digital signal, comprising the steps of: reading waveform data from a storage unit that receives waveform data approximating a curve to be generated; Approximated waveform data of a voltage to be generated by the digital-to-analog converter, and generates analog voltage by digitally / analog-converting the calculated waveform data.

A voltage generating circuit according to a second aspect of the present invention is a voltage generating circuit for generating a voltage of a required waveform by a digital signal. The voltage generating circuit includes a storage unit storing waveform data for approximating a curve to be generated, Calculating means for calculating waveform data to be linearly approximated by the read waveform data, and digital / analog converting means for digital / analog converting the computed linear approximate waveform data.

The monitor device according to the third invention is characterized by including the voltage generating circuit according to the second aspect.

In the first invention, waveform data for approximating a curve to be generated is stored in a storage unit having a storage capacity of 5 words x 100 rows x 2 bytes, for example. And calculates linear approximate waveform data of a voltage to be generated based on the curve approximated waveform data read from the storage unit. When the digital signal of the computed linear approximate waveform data is subjected to digital / analog conversion, an analog voltage is generated. In the case of storing waveform data that linearly approximates a voltage to be generated, the storage capacity of the storage unit requires, for example, 512 words x 100 rows x 2 bytes.

Thus, a storage unit having a small storage capacity can be used.

In the second invention, waveform data for approximating a curve to be generated is stored in a storage unit. The number of waveform data that approximates the curve of the voltage to be generated is small and is smaller than the number of waveform data to be linearly approximated, and the storage unit does not need to have a large storage capacity. The curve approximate waveform data is read from the storage section and the linear approximate waveform data is calculated based on the read waveform data. An analog voltage is generated when the digital signal of the computed linear approximation waveform data is subjected to digital / analog conversion. Thus, a storage unit having a small storage capacity can be used.

In the third invention, linear approximate waveform data is calculated on the basis of waveform data that approximates a curve to be generated. The display state of the display image is controlled by the analog voltage obtained by digital / analog conversion of the calculated linear approximate waveform data. Thus, the display state of the display image can be adjusted.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments.

FIG. 1 is a block diagram showing the configuration of a voltage generating circuit according to the present invention. FIG. Approximated waveform data that can approximate the parabola wave voltage to be generated with a small number of waveform data are stored in the memory 10 in a data table of 5 words in the horizontal direction and 100 rows in the vertical direction, And stored in association with the adjustment value for adjusting the outline of the display image. The curve-approximated waveform data read from the memory 10 is input to the CPU 11. [

An output signal of the adjustment specifying section (12) for specifying an adjustment value for adjusting the outline of the display image is input to the CPU (11). The linear approximate waveform data calculated by the curve-approximated waveform data received by the CPU 11 is input to the digital-to-analog converter 13. The digital / analog converter 13 converts the digital signal of the input waveform data into an analog signal to generate an analog parabolic wave voltage. The parabolic wave voltage output from the digital / analog converter 13 is input to the monitor device 14 for displaying an image.

Fig. 3 is a conceptual diagram of a case in which the parabolic wave voltage to be generated is linearly approximated. In the case of linear approximation, as shown in Fig. 3, basically, one point in the X- Of waveform data is required. However, since the parabola wave voltage has many curved portions, when the known third-order spline interpolation is performed, as shown in the conceptual diagram of the curve approximation shown in FIG. 4, for example, five points a, Using the waveform data of b, c, d, and e, it is possible to reproduce a curve similarly approximating the parabolic wave pressure.

That is, by approximating the curve, it is possible to approximate the curve with less coordinate information. Therefore, as described above, waveform data of 5 words can be stored in the data table of the memory 10 with respect to one parabola wave voltage. Also, the same waveform data is stored for each of 100 kinds of parabola wave voltages. Therefore, the memory 10 needs to store data of (5x100) x 2 bytes (here, one word is two bytes). Therefore, when storing the linear approximate waveform data, the memory 10 stores 512 words x It is possible to use an inexpensive memory having a memory capacity of 100 lines × 2 bytes.

Next, the operation of the voltage generating circuit constructed as described above will be described concurrently with the flowchart of FIG. 5 showing the control contents of the CPU 11. FIG. When the user performs an operation to correct the contour of the display image, that is, to negate the bobbin distortion of the display image, the CPU 11 receives the adjustment value designated by the operation (S1). Here, the specified predetermined value is set to "2 " (S2). A signal of the adjustment value "2" is input to the CPU 11. The CPU 11 inputs an address signal corresponding to the designated fixed value to the memory 10, The curve approximated waveform data corresponding to the adjustment value "2 " is read from the table and received (S3).

That is, 5-word curve-approximated waveform data is read out from the area of the adjustment value "2" of the data table. Subsequently, based on the waveform data read by the CPU 11, the waveform data of the curve is calculated by the known third-order spline curve interpolation method (S4). The linearly approximated waveform data of the Y coordinate corresponding to the X coordinate 512 is calculated based on the waveform data of the continuously calculated curve (S5). The linearly approximated waveform data thus calculated are input to the digital / analog converter 13 as in the conventional case (S6). Then, the digital / analog converter 13 converts the digital signal of the input waveform data into an analog voltage and outputs an analog parabola wave voltage. When the parabola wave voltage is inputted to the monitor device 14, the outline of the display image of the monitor device 14 is adjusted by the parabola wave voltage and the display image of the contour corresponding to the specified adjustment value "2" is displayed.

Conventionally, since the waveform data for linearly approximating the parabola wave voltage is stored in the memory, it is necessary to use a memory having a very large storage capacity. However, when the parabola wave voltage is approximated to a curve, a small number of waveform data is stored in the memory Therefore, it is possible to use an inexpensive memory having a very small memory capacity. Thus, the cost of the parabola wave voltage generating circuit can be reduced.

FIG. 6 is a block diagram showing the configuration of another embodiment of the voltage generating circuit according to the present invention. FIG. The FIG. 6 is configured to generate a sawtooth voltage that corrects the vertical Linearity.

As shown in FIG. 7, the waveform data of one cycle of the curve approximation, which can approximate the sinusoidal voltage to be generated with a small number of waveform data, is stored in the memory 10A in 8 words in the horizontal direction and 100 words in the vertical direction In correspondence with the adjustment value for adjusting the vertical linearity of the display image in the data table of FIG. The curve approximated waveform data of the sine wave plotted in the memory 10A is input to the CPU 11. [

An output signal of the adjustment specifying section (12) for specifying an adjustment value for adjusting the vertical linearity of the display image is input to the CPU (11). The sinusoidally approximated waveform data read out from the memory 10A and calculated by the curve approximate waveform data received by the CPU 11 are input to the digital / analog converter 13A. The memory 10B stores waveform data of one cycle of the sawtooth voltage to be generated at the same cycle as the sine wave voltage. The waveform data of the sawtooth voltage read by the memory 10B and received by the CPU 11 is input to the digital / analog converter 13B. The digital / analog converter 13A converts the digital signal of the waveform data of the input sinusoidal wave into an analog signal to generate an analog sinusoidal voltage. The digital / analog converter 13B converts the digital signal of the waveform data of the input sawtooth wave into an analog signal to generate an analog sawtooth voltage.

The sinusoidal voltage output from the digital / analog converter 13A and the sawtooth voltage output from the digital / analog converter 13B are input to the waveform synthesizer 16. [ The waveform synthesizer 16 outputs the sawtooth voltage corrected by synthesizing the input sinusoidal voltage and the sawtooth voltage. The corrected sawtooth voltage outputted from the waveform synthesizer 16 is supplied to the monitor device 14 for displaying an image, Not shown in the figure.

FIG. 8 is a block diagram showing the configuration of the waveform synthesizer 16; FIG. The output side of the digital / analog converter 13A is connected to the negative input terminal (-) of the operational amplifier OA ₁ through the resistor R ₁ . A parallel circuit of the capacitor C ₁ and the resistor R ₂ is interposed between the negative input terminal (-) of the OP amplifier OA ₁ and the output terminal OP. The output terminal OP of OP AMP ₁ OA ₁ is connected to the OP AMP OA ₂ positive input terminal (+) through a series circuit of capacitor C ₂ and resistor R ₃ .

The output side of the digital / analog converter 13B is connected to the negative input terminal (-) of the operational amplifier OA ₃ through the resistor R ₄ . A parallel circuit of a capacitor C ₃ and a resistor R ₅ is interposed between the negative input terminal (-) of the operational amplifier OA ₃ and the output terminal OP and the negative input terminal (-) is connected to the positive input terminal (-) of the operational amplifier OA ₁ . Respectively. The positive input terminal (+) of the operational amplifier OA ₃ is grounded and the output terminal OP is connected to the positive input terminal (+) of the operational amplifier OA ₂ via the resistor R ₆ . The negative input terminal (-) of the operational amplifier OA ₂ is connected to the output terminal OP thereof and is connected to a vertical circuit (not shown) of the monitor device 14.

Fig. 9 is a conceptual diagram of a case in which a sinusoidal voltage to be generated is curve-approximated. As shown in Fig. 9, when the waveform data of the total 8 points j, k, l, m, o, p, q and r of the four points on the positive side and the negative side of the sine wave are used, Can be reproduced. That is, by approximating the curve, it is possible to approximate the curve with less coordinate information as in the case of the parabola wave voltage as described above. Therefore, waveform data of 8 words for one sinusoidal voltage can be stored in the data table of the memory 10A. The data table also stores waveform data for each of 100 kinds of sine wave voltages.

Therefore, since the memory 10A needs to store data of (8x100) x 2 bytes (one word is assumed to be two bytes in this case), the memory 10A stores the data in the case of storing the linear approximate pattern data 512 words x 100 rows x 2 bytes are needed, an inexpensive memory having a very small storage capacity can be used.

Next, the operation of the voltage generating circuit constructed as described above will be described concurrently with the flowchart of FIG. 10 showing the control contents of the CPU. When the user performs an operation to correct the vertical linearity of the display image, the CPU 11 accepts the adjustment value specified by the operation (S11). The adjustment value specified here is set to "2 " (S12). A signal of the adjustment value "2" is input to the CPU 11. The CPU 11 inputs the address signal corresponding to the designated adjustment value to the memory 10A, The curve approximate waveform data corresponding to the adjustment value "2 " is read from the table and received (S13). That is, 4-word curve-approximated waveform data is read from the area of the adjustment value "2" of the data table.

Subsequently, on the basis of the waveform data read by the CPU 11, the waveform data of the curve is calculated by a known third-order spline curve interpolation method (S14). The linear approximate waveform data of the Y coordinate corresponding to the X coordinate 512 is calculated based on the waveform data of the curve thus calculated (S15). Subsequently, the computed linear approximate waveform data is input to the digital / analog converter 13A as in the conventional case (S16). Subsequently, the CPU 11 inputs the same address signal as the address signal input to the memory 10A into the memory 10B, and reads and receives the waveform data of the sawtooth wave from the memory 10B (S17). Then, the waveform data of the received sawtooth wave is input to the digital / analog converter 13B (S18).

Then, the digital / analog converter 13A converts the digital signal of the waveform data of the inputted sinusoidal wave into an analog voltage and outputs the analog sinusoidal voltage V _{A shown} in FIG. 11 (a). The digital / analog converter 13B converts the digital signal of the waveform data of the input sawtooth wave to an analog voltage and outputs the analog sawtooth voltage V _{B shown} in FIG. 11 (b). These voltages are input to the waveform synthesizing section 16 and amplified separately according to the OP amplifiers OA ₁ and OA ₃ , respectively. Thereafter, the sinusoidal voltage and the sawtooth voltage are synthesized by the OP amplifier OA ₂ , And generates and outputs the sawtooth wave voltage V _C corrected by the illustrated sine wave voltage. Then, the corrected sawtooth voltage V _C has a waveform with a large voltage change at a time point corresponding to the half cycle of the sine wave voltage V _A.

Then, when the sawtooth voltage Vc thus determined is inputted to a vertical circuit (not shown) of the monitor device 14, the linearity of the display image of the monitor device 14 is corrected by the corrected sawtooth voltage, The spacing of the scanning lines L is increased due to the influence of the floating magnetic field in the vicinity of the center in the vertical direction of the display image in the CRT 100 as shown in Fig. 12 (a), and the linearity is deteriorated , The vertical linearity is corrected in accordance with the corrected adjustment value "2 " as shown in FIG. 12 (b), and an image with good linearity is displayed with the interval of the scanning lines L being constant.

Even when a sinusoidal voltage is generated as in the case of generating a parabola wave voltage, waveform data approximating a curve of a sinusoidal wave can be stored in a memory. In this case, too, an inexpensive memory having a very small storage capacity can be used, It is possible to avoid the cost reduction of the voltage generating circuit that generates one sawtooth voltage.

In addition, the curve approximated waveform data used in the present embodiment is 5 words or 8 words, and the point of the X coordinate is 512, but this is merely an example.

As described above, in the first invention, the curve approximated waveform data of the voltage to be generated is stored in the storage section, and the voltage is generated by calculating the linear approximate waveform data based on the curve approximated waveform data read from the storage section. It is possible to generate an inexpensive voltage using a memory having a small storage capacity.

Since the second aspect of the present invention stores the curved approximate waveform data of the voltage to be generated in the storage unit, it is possible to use an inexpensive storage unit having few waveform data for approximating the curve to be generated and having a small storage capacity, And the present invention exerts an excellent effect.

Claims (3)

A method for generating a voltage of a required waveform by a digital signal, comprising the steps of: reading waveform data from a storage unit storing waveform data approximating a curve of a voltage to be generated; calculating a linear approximation of a voltage to be generated by the read waveform data A step of calculating waveform data, and a step of digitally / analog-converting the calculated waveform data to generate an analog voltage. A voltage generation circuit for generating a voltage of a required waveform by a digital signal, comprising: a storage section for storing waveform data approximated to a curve of a voltage to be generated; means for reading out waveform data from the storage section; And a digital / analog conversion unit for performing digital / analog conversion on the computed linear approximate waveform data. A monitor device comprising a voltage generating circuit claimed in claim 2.