JPS6169265A - Multiscanning picture receiver - Google Patents

Abstract

PURPOSE:To obtain always a certain pin distortion compensating parabolic wave signal independently of a vertical frequency by using a control value, which makes the amplitude of saw tooth wave constant, to correct the amplitude of a signal obtained from a deflecting yoke. CONSTITUTION:A vertical synchronizing signal is supplied to an input terminal 100, and the saw tooth wave is generated through a saw tooth wave oscillator 61. This saw tooth wave is supplied to a vertical deflecting yoke 9 through an output circuit 67 after the output amplitude is controlled to a certain value independently of the frequency by a control circuit 101. The saw tooth wave from the middle point between a capacitor 68 and a resistor 69 is supplied to a multiplying circuit 102, and a control signal form the circuit 101 is supplied to the circuit 102, and the signal from the circuit 102 is outputted to an output circuit 104 through an integrating circuit 103. The control value which makes the amplitude of the saw tooth wave constant is used to correct the amplitude of the signal from the yoke 9, thereby obtaining always a certain pin distortion compensating parabolic wave signal independently of the vertical frequency.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable not only to reception of television broadcasting using the trial system, but also to reception of television broadcasting of a different broadcasting system, display of video signals from computers, etc. The present invention relates to a multi-scanning receiver capable of receiving video signals having different vertical frequencies and vertical deflection widths.

[Conventional technology]

For example, in an NTSC television signal, an image is formed with a vertical frequency of approximately 6011 z and a horizontal frequency of approximately 15.75 kHz. In contrast, the so-called CCIR
In this method, the vertical frequency is 50 Hz.

Furthermore, a conversion device has been proposed that doubles the number of scanning lines through arithmetic processing or the like to improve the quality of received and imaged images. When using this device, the signal output from this has a vertical frequency of, for example, 60Hz, and a horizontal frequency of approximately 31.5Hz.
It is set to kHz.

In addition, some so-called high-resolution display computer output signals have a horizontal frequency of about 25 kHz. Furthermore, in so-called high-definition televisions, the horizontal frequency is expected to be approximately 33.75 kHz.

A multi-scanning receiver has been proposed that allows a single device to receive various signals having different vertical and horizontal frequencies.

By the way, in conventional television receivers, so-called left and right pin distortion correction is performed as follows. In FIG. 7, a sawtooth wave with a vertical period is supplied to the input terminal (201'), and this signal is passed through the output circuit (202) to the vertical deflection yoke (203), the capacitor (204), and the resistor (205). It is fed into a series circuit for vertical deflection. This deflection yoke (203) and the capacitor (204)
) A signal in which a sawtooth wave is superimposed on a vertically synchronized parabolic wave signal is extracted. Also, the capacitor (
A sawtooth wave signal with a vertical period is extracted from the connection midpoint between the resistor 204) and the resistor <205). Therefore, the subtraction circuit (2
By taking these differences in step 06), a parabolic wave signal with a vertical period is obtained from this subtraction circuit (206'). By setting this signal to a predetermined level in the output circuit (207), left and right pin distortion correction signals are taken out to the output terminal (208).

However, in this device, for example, NTSC system and CC
When attempting to receive an IR television broadcast, the vertical frequency is changed from approximately 601 (Z) to 50 Hz. For example, 60
When changing from Hz to 50Hz, the amplitude is changed by 1.2 times. For this reason, if the adjustment is made so that correct correction is performed at 60Hz, for example, over-correction will occur at 50Hz, and for example, as shown in Figure 8A and B, 60H
What was correctly corrected at 50 Hz ends up causing distortion in the opposite direction.

Furthermore, when displaying computer output, for example, in conventional TV broadcast reception, so-called overscanning is performed in order to display the displayed image to fill the display screen, whereas with computer output, the display image is displayed to the fullest extent of the display screen. Underscanning is performed for complete display. For this reason, for example, as shown in Figure 9, in conventional television broadcasting, the vertical amplitude is determined by the number of horizontal scanning lines, whereas for example, the output of a computer with a horizontal frequency of 25 kHz requires vertical scanning, and the vertical amplitude is determined by the number of horizontal scanning lines. be changed.

In this case, the pin distortion correction signal mentioned above needs to be varied in response to the vertical amplitude.

[Problem that the invention seeks to solve]

A multi-scanning receiver as described above has been proposed. However, with this device, if left and right pin distortion correction is performed using the same configuration as used in conventional television receivers, it is not possible to perform appropriate pin distortion correction when the vertical frequencies are different. First, there was a problem that distortion occurred on the display screen depending on the frequency.

[Means for solving problems]

The present invention has a sawtooth wave oscillator (61) with a vertical period that detects the amplitude of an output signal and is controlled (101) so that this amplitude becomes a predetermined value, which is obtained from a vertical deflection yoke (9). The sawtooth wave oscillator (61) generates a vertically periodic sawtooth wave.
Calculation (102) using the control value to control (101'),
(103,) and parabolic wave signal for pin distortion correction (10
4) is a multi-scan receiver.

[Effect]

According to the above-mentioned device, since the amplitude of the signal obtained from the deflection yoke is corrected using a control value that keeps the amplitude of the sawtooth wave constant, the parabola for pin distortion correction is always constant regardless of the vertical frequency. wave signal can be obtained.

〔Example〕

First, a multi-scanning type receiver proposed by the applicant of the present application will be explained.

FIG. 4 shows an overall block diagram. In this figure, a typical television broadcast tuner or video tape recorder,
When receiving a normal video signal from a video disc player, satellite broadcast tuner, some personal combinations, -v, etc., the video signal supplied to the input terminal (1) is passed through the video processing circuit (2). The signals are supplied to an RGB processing circuit (3) to form three primary color signals. In addition, the video/RGB switching signal supplied to the input terminal (4) is supplied to the process circuit (3), whereby the three primary color signals from the selected video signal are sent to the cathode ray tube (6) through the output circuit (5). Supplied.

In addition, the video signal from the input terminal (1) is transferred to the sync separation circuit (
7], and the vertical and horizontal synchronization signals are separated.

Furthermore, the switching signal from the input terminal (4) is sent to the separation circuit (7).
The vertical synchronizing signal from the selected video signal is supplied to the vertical deflection circuit (8), and the formed vertical deflection signal is applied to the vertical deflection yoke (6) of the cathode ray tube (6).
9). Further, the horizontal synchronizing signal from the video signal selected by the separation circuit (7) is supplied to the AFC circuit αω, and the signal from this AFC circuit aω is transmitted to the horizontal oscillation circuit (1
1), and a normal control signal from the mode detection circuit (12) is also supplied to the oscillation circuit (11).

The signal from this oscillation circuit (11) is then supplied to the horizontal deflection circuit (13), and the formed horizontal deflection signal is supplied to the horizontal deflection yoke (14) of the cathode ray tube (6). Furthermore, the signal from the deflection circuit (13) is supplied to a high voltage generation circuit (15) such as a flyback transformer, and the generated high voltage is supplied to the high voltage terminal (16) of the cathode ray tube (6). portion is supplied to the AFC circuit αω.

Furthermore, the commercial power from the power input (17) is connected to the power supply circuit (1
8), and a normal voltage according to the signal from the detection circuit (12) is supplied to the horizontal deflection circuit (13). Also, commercial power from the power supply input (17) is supplied to another power supply circuit (19), and the voltage formed is supplied to other circuits.

This allows normal video signal reception. On the other hand, when receiving digital or analog ROB signals from some personal computers, so-called captain demodulators, teletext demodulators, or scan converters, input terminals (20R) (20G)
Digital RGB signals supplied to (20B > and input terminal (21R) (21G') (21B >
The analog RGB signal supplied to Ru.

Further, the digital synchronization signal from the input terminal (20S) and the analog synchronization signal from the input terminal (215) are selected by the changeover switch (23) and supplied to the synchronization separation circuit (7), and the input terminal (4) It is selected by a switching signal from , and is supplied to the vertical deflection circuit (8) and the AFC circuit QOI. Furthermore, the signal from the separation circuit (7) is transmitted to the mode detection circuit (12).
), a control signal corresponding to the frequency of the horizontal synchronization signal is formed, and the horizontal oscillation circuit (11) and the horizontal deflection circuit (13
) and the power supply circuit (18).

As a result, digital or analog RGB signals are received. Furthermore, when performing so-called superimposed image reception in which RGB signals are displayed superimposed on the above-mentioned normal video signal, the switching signal supplied to the input terminal (4) is set to RGB mode, and the input terminal ( 24)
Ys-fold signal indicating the position of the superimposed signal supplied to and Y indicating the superimposed range
The m signal is supplied to the RGB processing circuit (3), and switching between the video signal and the RGB signal is performed between these Ys and Ym signals.

Various signals are received in the manner described above.

Further, in the above-described apparatus, the horizontal deflection system is specifically configured as follows. In Figure 5, separation circuit (7)
A horizontal synchronizing signal from the horizontal synchronizing signal is supplied to a frequency-voltage conversion circuit (FVC) (31) constituting the mode detection circuit (12) to form a voltage according to the horizontal frequency. This voltage is supplied to a voltage controlled oscillator (VCO) (34) constituting the horizontal oscillation circuit (11) through a limiter circuit (32) that determines the lower limit and a buffer (B) amplifier (33). This V
The oscillation output of the CO (34) is supplied through a drive circuit (35) to a switching transistor (36) constituting the horizontal deflection circuit (13).

In addition, the voltage from the FVC (31) is passed through a limiter circuit (37) that determines the upper limit and a gain control (GC) amplifier (38) to the power supply circuit (18), such as a Y-Z type parametric power supply circuit (39). Supplied. The output voltage of this power supply circuit (39) is fed back to the amplifier (38) through the voltage dividing circuit (40) to stabilize the output voltage. This output voltage is supplied to the flybank transformer (41).

A transistor (36) is connected in series to this flyback transformer (41). Also, this transistor (36
) is connected in parallel with a series circuit of a damper diode (42), a resonant capacitor (43), a horizontal deflection yoke (14), and a figure-8 correction capacitor (44).

Further, the horizontal synchronization signal is supplied to the detection circuit (45) constituting the AFC circuit (101), and the transistor (36
) is supplied to a detection circuit (45) to form an AFC signal.

This signal is supplied to the control terminal of the VCO (34) through a low pass filter (LPF) (47).

Furthermore, a switch circuit (
Capacitors (49) and (50) are connected through 48). In addition, the capacitor (52) (53) is connected in parallel to the figure 8 correction capacitor (44) through the switch circuit (51).
) are connected. Further, the voltage from the FVC (31) is supplied to a comparator circuit (54) that compares it with values corresponding to voltages of 20 kHz and 30 kHz of the input horizontal frequency, for example.
) 1z or less, 20 to 30k) lz, 3-value comparison corresponding to each range of 30kHz or more is formed, and depending on this comparison output, the two built-in switch circuits (48) and (51) are selected. Control is performed so that both switches are turned off or one of them is turned on.

As a result, in this horizontal deflection system, the VCO (34
), an oscillation signal that varies from 15 to 34 kHz in synchronization with the input horizontal synchronizing signal is formed to perform horizontal deflection, and the power supply circuit (39) varies from 58 to 123 volts, for example, depending on the horizontal frequency. A voltage is generated to control the amplitude of the horizontal deflection to be constant. Also, the resonance capacitor (43) and the figure 8 correction capacitor (44)
) in parallel with the capacitor (4
9) (50), (52), and (53) are connected, and the characteristics of each are corrected.

Further, in the above-described apparatus, the vertical deflection system is specifically configured as follows. In FIG. 6, a vertical synchronizing signal from a separation circuit (7) is supplied to a sawtooth wave oscillator (61) constituting a vertical deflection circuit (8).
2) is charged and discharged by the current of the current source (63) to form a sawtooth wave. This sawtooth wave is supplied to a comparator circuit (64) to form a three-value comparison output indicating a predetermined voltage range and below or above it, and this comparison output is fed to an up/down counter (UDC) (65). Supplied to the control terminal.

A vertical synchronization signal is supplied to the counting terminal of this UDC (65). The count value of each UDC (65) (7) is supplied to a DA conversion circuit (DAC) (66), and the current source (63) is controlled by the converted analog value.

Therefore, a sawtooth wave whose peak value (amplitude) is controlled within a predetermined voltage range is extracted from the oscillator (61) regardless of the frequency of the vertical synchronization signal. This sawtooth wave is the output circuit (67)
is supplied to the vertical deflection yoke (9) through the vertical deflection yoke (9). Furthermore, a series circuit consisting of a capacitor (68) and a resistor (69) is connected in series to this deflection yoke (9).
) is connected in parallel with a voltage dividing circuit (7o). The divided voltage of this voltage dividing circuit (70) is supplied to the output circuit (67).

This provides a constant amplitude vertical deflection even if the vertical frequency changes. Further, by making one of the resistors constituting the voltage dividing circuit (7o) variable, the amplitude of the vertical deflection can be arbitrarily controlled.

Furthermore, another set of circuits (oscillator (71) to DAC (76)') consisting of an oscillator (61) to a DAC (66) is provided, and the output value of the DAC (76) of this circuit is used as a pin distortion correction signal forming circuit ( 77), and a vertically periodic parabolic wave signal from, for example, the connection midpoint between the deflection yoke (9) and the capacitor (68) is also supplied to the forming circuit (77) to form a pin distortion correction signal. . This signal is supplied to the pin distortion correction circuit.

In this manner, in the above-described apparatus, the necessary horizontal and vertical deflections are performed in accordance with various different horizontal and vertical frequencies, and various signals are received.

In this device, left and right pin distortion correction is performed as follows.

In FIG. 1, the input terminal (100) has a separation circuit (7
) is supplied with a vertical synchronization signal. This synchronization signal is supplied to the vertical sawtooth wave oscillator (61) to form a sawtooth wave as described above, and also to the comparison circuits (64) to D.
Control circuit (101) configured by AC (66) etc.
The output amplitude is made constant regardless of frequency. This sawtooth wave passes through the output circuit (67) to the vertical deflection yoke (9).
supplied to

In addition, a sawtooth wave from the connection midpoint between the capacitor (68) and the resistor (69) is supplied to a multiplication circuit (102), and a control signal from the above-mentioned control circuit (101) is supplied to this multiplication circuit (102). be done. The signal from the multiplication circuit (102) passes through the integration circuit (103) to the output circuit (10
4) and taken out to the output terminal (105).

In this circuit, when a sawtooth wave with a predetermined amplitude as shown in FIG. 2A at 60 Hz is supplied to the deflection yoke (9), a capacitor (68) is formed thereby.
The sawtooth wave from the midpoint of the connection between the resistor (69) and the resistor (69) passes through the multiplication circuit (102) and is integrated by the integration circuit (103) to form a parabolic wave signal for pin distortion correction as shown in FIG. 2B. .

On the other hand, if the frequency is set to 50Hz and a sawtooth wave with the same amplitude is further supplied to the deflection yoke (9) as shown in Figure 2C, the capacitor (68) and resistor (69) are connected. The amplitude of the sawtooth wave from the point is 60Hz-
If this is integrated as it is, a parabolic wave signal with an amplitude 1.2 times as large as that in the case of , is formed as shown in the second diagram. Here, in the control circuit (101), as shown in FIG. It is possible to set the amplitude of the wave to be the same and to integrate it to make the secret width of the parabolic wave signal No. 1.2 constant, as shown in Fig. 2F.

As a result, according to this circuit, regardless of the vertical frequency,
It is possible to always obtain left and right parabolic wave signals for correcting pin distortion with constant amplitude.

Furthermore, in the above circuit, when the vertical amplitude is adjusted by the voltage divider circuit (70), this adjustment is performed by the control circuit (101).
), the pin distortion correction signal is changed in response to this adjustment.

By the way, in the multi-scanning receiver mentioned above, the DAC
(76) has a control output of 1.2 when controlled by the oscillator (71). In that case, for example, the third
As shown in the figure, a capacitor (68
) is further subtracted from the difference signal from both ends of the signal (1
By subtracting the signal from the integrating circuit (103) in step 06), it is possible to obtain a parabolic wave signal for pin distortion correction that always has a constant amplitude regardless of the vertical frequency.

The above-mentioned device may obtain the control value from the sawtooth wave oscillator (61) of the vertical deflection circuit, or from an oscillator (71) which is separate and performs the same operation.

〔Effect of the invention〕

According to the present invention, since the amplitude of the signal obtained from the deflection yoke is corrected using a control value that makes the amplitude of the sawtooth wave constant, the parabolic wave for pin distortion correction is always constant regardless of the vertical frequency. Now you can get a signal.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an example of the present invention, FIGS. 2 to 6 are diagrams for explaining the same, and FIGS. 7 to 9 are diagrams for explaining a conventional apparatus. (100) is an input terminal, (101') is a control circuit, (1
02) is a multiplication circuit, (103) is an integration circuit, (104)
is an output circuit, and (105) is an output terminal. (,-' Same as Hidemori Matsukuma □11 Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] It has a sawtooth wave oscillator with a vertical period that detects the amplitude of the output signal and is controlled so that the amplitude becomes a predetermined value. A multi-scanning receiver that calculates a parabolic wave signal for pin distortion correction using control values.