JPH10274975A - Crt display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image distortion correcting device with easy circuit constitution, small memory capacity and capable of obtaining a required image state even when signals of plural modes are received respectively. SOLUTION: An image size and a distortion are adjusted to an optimum image in an adjustment mode as a reference, and the data are stored in a memory 3, and distortive information in the adjustment mode becomes the reference data, and only total two pieces of a piece each in respective distortions regardless of a deflection frequency and the image size are stored in the memory 3. The maximum size control data in the adjustment mode become the reference data also, and the maximum size at this time is made a reference maximum size (Hr), and the data of a horizontal size Hs and the maximum size HSm are adjusted at every mode to be stored, and are obtained by imparting a synchronizing signal S to a CPU 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a CRT display device for receiving an image signal formed by a plurality of different synchronization signals, and more particularly to a CRT display device provided with image distortion correction means.

[0002]

2. Description of the Related Art A conventional CRT display apparatus corrects horizontal deflection by applying amplitude modulation of a vertical cycle to the displayed image in order to cause left and right image distortion in a display image due to the geometrical characteristics of a horizontal deflection circuit. It is necessary to change the amount of distortion correction, which is the amount of change in the modulation, in accordance with each deflection frequency, and it is necessary to change the amount according to the image size due to geometrical properties. The deflection current ip is proportional to the amplitude. However, since the proportionality constant is different between the upper part and the central part of the screen, if the amplitude Hc at the central part of the screen and the proportionality constant are Kc, Hc = Kc · ip (1)

The deflection current ip is determined by the voltage VL between both ends of the deflection yoke, the scanning period Ts and the deflection yoke inductance Lh. Hc = (Kc / Lh) TsTVL = (Kc / Lh) VL {(1 / fh) -Tr} (2)

Further, Kc, Lh and Tr are constants,
In order to keep Hc constant, it is necessary to change VL in accordance with the change in fh, and let Ht be the amplitude at the top of the screen without distortion correction, and take the difference from the center Hc of the screen, Assuming that the optimal distortion correction amount is EW, EW = Ht−Hc = Kt · Hc
(Kt is a constant), and the ratio of the optimum distortion correction amount of the screen amplitude H1 to EW1 and the optimum distortion correction amount of the screen amplitude H2 to EW2 is EW2 = (H2 / H1) EW1 (3). Also needs to adjust the distortion correction amount.

Therefore, a CRT display device capable of receiving a plurality of different synchronization signal modes stores all the correction amounts for each synchronization signal mode because the amount of left and right image distortion varies depending on the synchronization signal mode and the image amplitude state. The correction amount follows the change in the horizontal deflection frequency and the image amplitude. As shown in FIG. 3, the host system 1, the CPU 2, the memory 3, and the D / D output the synchronization signal S and the image signal D.
From the outputs of the A converter 4 and the D / A converter 4, Equation (2),
(3) a tracking circuit 108 for adjusting the distortion correction signal by performing the correction, a control circuit 5 for controlling the deflection voltage of the deflection circuit 6 based on the signal adjusted by the tracking circuit 108, and a control circuit 5 for controlling the deflection voltage. The control circuit 5 includes a deflection circuit 6 for performing deflection and a CRT 7 for displaying an image signal D. The control circuit 5 generates a correction signal from the distortion correction signal adjusted by the tracking circuit 108, a distortion waveform and size control. It comprises an amplifier 52 for amplifying a signal and a voltage converter 53 for adjusting the deflection voltage B of the deflection circuit 6 based on the output of the amplifier 52.

The operation of this conventional CRT display device is shown in FIG.
As shown in (1), when correcting the mode 1 as the first step, the synchronization signal S is input, the CPU 2 determines the mode, reads the data 1 to 4 shown in FIG. The frequency is obtained from the synchronizing signal S input to the CPU 2 and supplied to the following circuit 108 through the D / A converter 4 to adjust the deflection voltage B to operate the deflection circuit 6. When the mode is changed to mode 2, the synchronization signal S is input as in the first step, and the CPU 2 determines the mode, and the data 1 and 2 shown in FIG.
5 and 6 are read from the memory 3 and input to the tracking circuit 108 through the D / A converter 4, and the tracking circuit 108 changes the distortion correction signal according to the horizontal deflection frequency and the horizontal size signal, and outputs the output to the waveform generator 51. In order to obtain the best image even when the mode is changed in the same manner as in the first step, a memory capacity for distortion correction is increased, and a circuit for causing the distortion correction amount to follow the deflection frequency or image size is added. Or

[0007]

However, the conventional CRT display device requires a follow-up circuit to maintain an optimal image state. Therefore, when the number of parts is increased and the image amplitude is changed, the distortion is reduced. Since the correction amount does not change with it, an optimal image cannot be obtained at each image amplitude, and it takes time to readjust the distortion correction amount every time the image amplitude changes, and when the number of signals increases, There is a problem that the capacity of the memory increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a CRT display device having a small memory capacity by receiving image signals in a plurality of synchronization signal modes in an optimum image state.

[0009]

In order to solve the above-mentioned problems, a CRT display device according to the present invention comprises: a host system for transmitting an image signal based on a plurality of different synchronization signals; and a host system for transmitting an image signal. C to display image signal
RT, a memory in which reference distortion information and reference amplitude information serving as display references for image signals displayed on the CRT are stored in advance, and distortion information from the reference distortion information and reference amplitude information based on the deflection frequency of the synchronization signal. And a CPU that calculates amplitude information, a D / A converter that converts each information calculated by the CPU into an analog voltage and sends out a distortion correction signal and a size control signal, and a signal output from the D / A converter. A waveform generator that generates a distortion correction waveform from the distortion correction signal, an amplifier that amplifies the distortion correction waveform generated by the waveform generator and the size control signal, and outputs a deflection voltage based on an output signal from the amplifier. A control circuit having a voltage converter, and a deflection circuit for deflecting the image signal by the deflection voltage output from the control circuit. And butterflies.

In order to solve the above-mentioned problems, a CRT display device according to the present invention uses left and right pincushion distortion information and trapezoid distortion information obtained by setting the image signal as the reference distortion information, And the memory for storing the amplitude information obtained by the setting as the reference amplitude information.

[0011]

Next, a CRT display device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a CR according to an embodiment of the present invention.
It is a block diagram of a T display device.

FIG. 2 shows a CR according to an embodiment of the present invention.
It is a memory structure figure of T display device.

As shown in FIG. 1, a CRT display device according to an embodiment of the present invention transmits a video signal D based on a plurality of different synchronization signals S, and transmits the video signal D from the host system 1. A CRT 7 for displaying the image signal D, a memory 3 in which reference distortion information and reference amplitude information as a display reference of the image signal D displayed on the CRT 7 are stored in advance, and a reference distortion based on the deflection frequency of the synchronization signal S. CPU 2 that calculates distortion information and amplitude information from the information and the reference amplitude information, and converts each information calculated by the CPU 2 into an analog voltage to convert distortion information EW, TR
A D / A converter 4 for transmitting P and size control signals HS and HSM; a waveform generator 51 for generating a distortion correction waveform from the distortion correction signals EW and TRP output from the D / A converter 4; An amplifier 5 for amplifying the distortion correction waveform generated by the waveform generator 51 and the size control signals HS and HSM.
2, a control circuit 5 having a voltage converter 53 that outputs a deflection voltage B in accordance with an output signal from the amplifier 52;
The image signal D is generated by the deflection voltage B output from the control circuit 5.
And a deflection circuit 6 for deflecting the light.

A CRT according to an embodiment of the present invention
The memory 3 of the display device stores the image signal D as shown in FIG.
Are used as reference distortion information, and the image signal D
Are stored as the reference amplitude information.

Next, a CRT according to an embodiment of the present invention will be described.
The operation of the display device will be described with reference to the drawings.

The operation of the CRT display device according to one embodiment of the present invention, as shown in FIG.
In the reference adjustment mode, the image size and the distortion are adjusted to the optimum image, and the data is stored in the memory 3. The distortion information in the adjustment mode becomes the reference data. As shown in FIG. Irrespective of this, it means the storage of only two in total for each distortion, and the maximum size control data in the adjustment mode also becomes the reference data. The maximum size at this time is set as the reference maximum size Hr, and the horizontal size Hs, The data of the maximum size HSm is adjusted and stored for each mode, and is obtained by giving the synchronization signal S to the CPU 2.

As a second step, when the mode is changed from the mode 1 to the mode 2, control is performed such that the distortion correction amount is optimal even if the deflection frequency changes with the reference maximum size Hr. EW = G3 ・ k3 ・ D30 ・ Ts0 = G
3 · k3 · D3 (fh) · Ts Left and right pincushion distortion at the reference maximum size Hr D3 (fh) = D30 · (Ts0) / Ts (F1) After changing the frequency under the same image size conditions as the adjustment mode Is also for calculating data so as to obtain the same image as in the adjustment mode.

As a third step, in the case of performing control according to the maximum size HSm data, in order to eliminate the influence of the image size on the image distortion correction amount, the same image size as the mode adjusted optimally, that is, the reference maximum size Hr, The ratio to the actual maximum size HSm after the mode change is multiplied by the distortion correction, and the maximum reference size Dr after the mode change is obtained by performing a correction operation on the frequency from the data of the reference mode, and VLref = a11 · D0 + b11 Dr = a11 · VLref · (1 / Ts) + b12 (F2) The same as the adjustment mode even after the mode is changed from the size reference data D0 of the maximum size of the adjustment mode as the reference first. The reference maximum size data Dr capable of maintaining the maximum size is calculated, and a change amount ΔH from the actual maximum size data D1 after the mode change and the calculation result Dr to the reference maximum size Hr is calculated. m is obtained, △ HSm = G1 · k1 · (Dr-D1) · Ts ··· (F3) ratio calculation of the maximum size HSm reference maximum size Hr and reality. HSm = Hr- △ HSm (HSm / Hr) = 1-[{G1 · k1 (Dr-D1) Ts} / Hr] (F4)

As a fourth step, the horizontal size change amount △
In the case of performing control using HS data, image size control is performed in addition to the above-described maximum size HSm data and horizontal size HSm.
In order to control the data and correct the distortion using the horizontal size HS data, an operation of calculating the amount of change in image size ΔHS by the horizontal size HS data is performed, and ΔHS = G2 · k2 · D2 · Ts. (F5) As a result, the image size is obtained by subtracting the variable size △ HS from the maximum size HSm, and the control for the distortion correction amount may be performed by calculating the ratio between the changed image size and the maximum size in each mode. HS = HSm- △ HS (HS / HSm) = 1-[{G2 ・ k2 ・ D2 ・ Ts} / HSm] ・ ・ ・ (F6)

As a fifth step, when performing control to apply each correction to the reference distortion correction amount, the maximum size HSm and the reference maximum are compared with the frequency distortion correction at the reference maximum size Hr obtained by the equation (F1). The expression (F4) for the ratio between the size Hr and the expression (F6) for the ratio between the horizontal size HS and the maximum size HSm is multiplied. D3out = D3 (fh) (HS / HSm) (HSm / Hr) = D30 (Ts0 / Ts) <1-[{G2 ・ k2 ・ D2 ・ Ts} / HSm]><1-[{G1 / k1 (Dr -D1) Ts} / Hr]> (F7) The result of the distortion correction data obtained by this calculation is represented by D
By giving to the control circuit 5 through the / A converter 4,
Even when the mode or the size is changed, the same image as that at the time of the adjustment is obtained.

Although the second to fifth steps have been described with respect to the pincushion distortion, the same calculation is also performed for the trapezoidal distortion. In the present invention, the optimum image state is obtained even when a plurality of synchronization signal modes are received. Is maintained.

[0023]

As described above, according to the CRT display device of the present invention, if there is a change in the frequency or size of the synchronizing signal of the image signal, it is set by calculating the state change. Even if the user changes the image according to his / her preference, the state can be maintained irrespective of the image size or the received signal, and since the distortion correction data is only the reference data, the adjustment time can be reduced, and the tracking circuit can be implemented. There is an effect that the number of parts becomes unnecessary and the number of parts can be reduced.

According to the CRT display device of the present invention,
Since the adjusted and stored data is used for the calculation,
Since the error caused by the circuit components can be absorbed and only the reference data is stored, the memory capacity can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a CRT display device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a memory structure of a CRT display device according to an embodiment of the present invention;

FIG. 3 is a block diagram of a conventional CRT display device.

[Explanation of symbols]

 Reference Signs List 1 host system 2 CPU 3 memory 4 D / A converter 5 control circuit 6 deflection circuit 7 CRT 51 waveform generator 52 amplifier 53 voltage converter D image signal S synchronization signal EW, TRP distortion correction signal HS, HSM size control signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 3/223 H04N 3/223 3/23 3/23 Z // G09G 5/12 G09G 5/12

Claims (2)

[Claims] A host system for transmitting an image signal based on a plurality of different synchronization signals; a CRT for displaying the image signal transmitted from the host system; and a display reference for the image signal displayed on the CRT. A memory that stores reference distortion information and reference amplitude information in advance; a CPU that calculates distortion information and amplitude information from the reference distortion information and reference amplitude information based on the deflection frequency of the synchronization signal; and a CPU that is calculated by the CPU. D / A that converts information into an analog voltage and sends out a distortion correction signal and a size control signal
A converter, a waveform generator for generating a distortion correction waveform from the distortion correction signal output from the D / A converter, and an amplifier for amplifying the distortion correction waveform generated by the waveform generator and the size control signal. A control circuit having a voltage converter that outputs a deflection voltage according to an output signal from the amplifier; and a deflection circuit that deflects the image signal using the deflection voltage output from the control circuit. CRT display device. 2. The pincushion distortion information and the trapezoid distortion information obtained by setting the image signal are used as the reference distortion information, and the amplitude information obtained by setting the image signal is stored as the reference amplitude information. 2. The CRT display device according to claim 1, wherein said CRT display device comprises said memory.