JPS6181082A - Multiscanning type image receiving device - Google Patents

Abstract

PURPOSE:To enable display at a horizontal deflection position according to video signals by providing a device that controls the horizontal deflection position and a device to preset this controlling value in a horizontal AFC loop and switching the presetting device according to selection of video signals. CONSTITUTION:A series circuit of resistances 101, 102 and a capacitor 103 in a horizontal AFC loop. Switching signals from input terminals 4, 24 are made to 1 or 0 according to selected signals, and a switching circuit 107 is controlled by a selection controlling circuit 109. When an arbitrary attenuator 108 is connected through the switching circuit 7 in this device, if, for instance, a signal from a voltage dividing circuit 46 is as A in the figure, the signal is changed as B or C in the figure by sliding the attenuator 108 to the grounding side or reverse side. Accordingly, by determining attenuators 108a-108c arbitrarily, phase of detection signal supplied to an AFC circuit is controlled at will, and the horizontal deflection position is controlled to desired position.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to reception of television broadcasts of different broadcasting formats, display of video signals from computers, etc., in addition to reception of regular television broadcasting. The present invention relates to a multi-scanning receiver capable of receiving video signals with different horizontal frequencies and horizontal deflection positions.

[Conventional technology]

For example, in an NTSC TV signal, the vertical frequency is approximately 60Hz and the horizontal frequency is approximately 15.75kHz.
(An elephant is formed.In contrast, G1 so-called C
In the CIR method, the vertical frequency is 50 Hz).

In addition, a conversion device has been proposed which doubles the number of scanning lines through arithmetic processing or the like to improve the quality of the received image. 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 24 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, when displaying video signals such as ordinary television signals, the center of the effective screen is set at a predetermined timing with respect to the synchronization signal, and this is the center of the display surface. Adjustments have been made to the horizontal deflection position, etc. so that the

However, in so-called output video signals from computers, the synchronizing signal width and the position of the effective screen are not constant. Therefore, in order to display such a signal, it is necessary to readjust the horizontal deflection position each time a manual switch is performed, which makes the operation extremely complicated. Or I had no choice but to put up with the slight movement of the screen and watch.

Also, the delay time in the video processing system differs between a normal composite video signal and an RGB signal, and if synchronization separation is normally performed in the previous stage,
This also causes the screen position to shift.

[Problem that the invention seeks to solve] Multi-scanning light as described @! machine is proposed.

However, in this device, the normal Te1,
When displaying video signals such as TV broadcasting,
When displaying a high-resolution video signal from a user, there is a problem in that the position of the displayed screen must be changed.

[Means for solving problems]

The present invention provides a plurality of types of video signals (1).

(20), (21) and select these video signals (3).

+71. (22), (23) and display (6
) A multi-scanning type machine (in a multi-scanning machine, a control means for controlling the horizontal deflection position (
101).

(102) and 2 to preset these control values respectively.
The above presetting means (107), (10B) are provided, and the video signal selection +41, (,2
4), the preset means is switched (106) so that display is performed at the horizontal deflection position according to the selected video signal.

[Effect]

According to the above-described device, the normal horizontal deflection position can be automatically changed to another position. Therefore, there is no need to readjust the horizontal deflection position every time the input video signal is switched, and various video signals can be displayed extremely well.

〔Example〕

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

Figure 3 shows the overall block diagram. In this figure, a typical television broadcast tuner or video tape recorder,
When receiving normal video signals from a video disc player, satellite broadcast tuner, some personal computers, etc., the video signal supplied to the input terminal (11 passes through the video processing circuit (2)) and converts into RGB. It is supplied to a process 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.

Further, the video signal from the input terminal (1) is supplied to the synchronization portion M+1 circuit (7), and vertical and horizontal synchronization signals are separated. Furthermore, the switching signal from the input terminal (4) is transmitted to the separation circuit (
7), whereby the vertical synchronizing signal from the selected video signal is supplied to the vertical deflection circuit (8), and the formed vertical deflection signal is supplied to the vertical deflection yoke (9) of the cathode ray tube (6). be done. Further, the horizontal synchronizing signal from the video signal selected by the separation circuit (7) is supplied to the AFC circuit QO), the signal from this AFC circuit QO) is supplied to the horizontal oscillation circuit (11), and the mode detection circuit (1
The current control signal from 2) is 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). Further, the signal from the deflection circuit (13) is supplied to a high voltage generation circuit (15) such as a flyback transformer, and the generated low voltage is supplied to the high voltage terminal (16) of the cathode ray tube (6). is supplied to the AFC circuit (101).

Furthermore, commercial power from the power source (17) is supplied 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). In addition, the commercial power from the power supply input (17) is connected to other power supply circuits (17).
9) and the voltage formed is supplied to other circuits.

This allows normal video signal reception. On the other hand, when receiving analog or digital RGB signals from some personal computers, so-called captain demodulators, teletext high-speed devices, or scan converters, input terminals (20R) (20G) are used.
The analog RGB signal supplied to the switch (20B') and the digital RGB signal supplied to the input terminals (21R) (21G) (21B) are
2), and is selected by the analog/digital switching signal from the input terminal (24) and is connected to the RGB process circuit (3).
), and is selected by the switching signal from the input terminal (4) and supplied to the output circuit (5).

In addition, the analog synchronization signal from the input terminal (20S>) and the digital synchronization signal from the input terminal (21S) are supplied to the changeover switch (23), and are selected by the changeover signal from the input terminal (24) for synchronization separation. The signal is supplied to the circuit (7), selected by the switching signal from the input terminal (4), and supplied to the vertical deflection circuit (8) and the AFC circuit 0ω.The signal from the separation circuit (7) is further supplied to the mode detection circuit ( 12), a control signal corresponding to the frequency of the horizontal synchronization signal is formed, and the control signal is supplied to the horizontal oscillation circuit (11), horizontal deflection circuit (13), and power supply circuit (18).

As a result, digital or analog RGB signals are received. Furthermore, when performing so-called superimposed image reception in which an RGB signal is displayed by receiving the above-mentioned normal video signal, the switching signal supplied to the input terminal (4) is set to RGB mode, and the input terminal (25)
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 YssYm 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 4, 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). The oscillation output of this VCO (34) is supplied through a drive circuit (35) to a switching transistor (36) constituting a horizontal deflection circuit (13).

In addition, the voltage from the FVC (31) is passed through a limiter circuit (37) that determines the upper and lower limits and a gain control (QC) 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 a flyback transformer (41).

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

In addition, the horizontal synchronization signal constitutes the AFC circuit detection circuit (
45), and a signal from the voltage dividing circuit (46) provided in series with the transistor (36) is supplied to the detection port I.
I (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. The voltage from the generator 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.
A three-value comparison output corresponding to each range of Hz or less, 20 to 30kHz, and 30kHz or more is formed, and according to this comparison output, each of the 2 (flit) switches built in the switch circuits (48) and (51) is activated. Control is performed so that both are turned off or one of them is turned on.

As a result, in this horizontally deflected yarn, ■C0 (34
) generates an oscillation signal that varies from 15 to 34 kHz in synchronization with the human-powered horizontal synchronization signal to perform horizontal deflection, and at the same time, the power supply circuit (39) generates an oscillation signal varying from 58 to 123 volts depending on the horizontal frequency. A variable 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 Figure 5, minute 1 i, ? 'l'1 circuit (") A vertical interval signal from 0 to 0 is supplied to a sawtooth wave oscillator (61) constituting a vertical deflection circuit (°), and for example, a capacitor (62) is charged with a current from a current source (63). A sawtooth wave is formed by discharging.This sawtooth wave is supplied to a comparator circuit (64) to form a three-value comparison output indicating a predetermined electrification range and below or above it. Down counter (tJpc) (65)
is supplied to the control terminal of A vertical synchronizing signal is supplied to the counting terminal of this tJDc (65). This tJDc (65
) is supplied to the DA conversion circuit CDAC) (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 capacitor (68) and a resistor are connected in series with this deflection yoke (9)! A series circuit of (69) is connected and this resistor (69
)' A voltage dividing circuit (7o) is connected in parallel to )'. The divided voltage output of this voltage dividing circuit (70) is output.
14 power circuit (67).
) This ensures that vertical deflection always has a constant amplitude even if the vertical frequency changes. In addition, a voltage dividing circuit (70
) by making one of the resistors 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 connected to a bin 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 bin distortion correction signal. This signal is supplied to the pin distortion correction circuit.

In this way, in the device described above, the necessary horizontal and vertical deflections are carried out depending on the different horizontal and on-duty frequencies, as well as the reception of various signals.

In this device, switching of the horizontal deflection position is performed as follows.

In Figure 1, the horizontal AFC loop voltage divider circuit (46)
and the detection circuit (45), the resistor (101) (10
2) A series circuit of a capacitor (103) is provided.

Both ends of this resistor (101) are connected to a series circuit of a resistor (104) and a capacitor (105), and a capacitor (106).
) are connected to the switch circuit (107), and each attenuator (
108a) (108b) (108c).

Further, a switching signal from the input terminal (41 (24)) is supplied to the selection control circuit (109).The switching signal supplied to the input terminal (4) is, for example, "1" when selecting a video signal; It is set to “0” when selecting an RGB signal,
The switching signal supplied to the input terminal (24) is, for example, '1' when selecting an analog signal, and '0' when selecting a digital signal.

Then, in this selection control circuit (109), a switch circuit (
107) is, for example, a when the terminal (4) is "1", and b1 when the terminal (4) is "0" and the terminal (24) is "l".
Terminal (41,'l("0'" and terminal (24) is "
o'', switching control is performed as shown in C.

In this device, when an arbitrary attenuator (108) is connected via a switch circuit (107),
For example, if the signal from the voltage divider circuit (46) is as shown in Fig. 2A, by sliding the attenuator (108) to the ground side, the signal will change as shown in B, and by sliding it to the opposite side. By moving, it changes like C.

Therefore, in this device, each attenuator (
By arbitrarily defining 108a) to (108c), the phase of the detection signal supplied to the AFd circuit αψ can be arbitrarily controlled, thereby controlling the horizontal deflection position to a desired position.

This allows the horizontal deflection position to be changed, for example, when an analog signal or a digital signal supplied from a computer is selected, and this change can be arbitrarily set for each of the analog signal and digital signal. Further, this change can be automatically performed in conjunction with the selection of the video signal.

In the above example, the attenuator (108a) connected when selecting a video signal may be semi-fixed and may be set to a desired value at the time of manufacturing or the like.

Further, in the above example, there are two types of RGB signals from the computer, analog and digital, but it is also possible to have two inputs of either one, or to be able to select a plurality of inputs for each.

The vertical deflection position may also be changed in conjunction with the above-described change in the horizontal deflection position. This vertical deflection position can be controlled by arbitrarily delaying the synchronizing signal.

〔Effect of the invention〕

According to the present invention, an arbitrary horizontal deflection position is preset in addition to the normal horizontal deflection position, and the horizontal deflection position can be automatically changed to this preset horizontal deflection position in accordance with the selection of an input signal. Therefore, there is no need to readjust the horizontal deflection position every time the video signal is manually switched, and various video signals can now be displayed extremely well.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an example of the present invention, and FIGS. 2 to 5 are diagrams for explaining the same. (41 (24) are switching signal input terminals, (46) is a voltage divider circuit, (101) (102) (104) are resistors, (103) (105) (106) are capacitors, (107) is a switch circuit , (108a) ~(1
08c) is an attenuator, and (109) is a selection control circuit.

Claims (1)

[Claims] In a multi-scanning receiver that is supplied with a plurality of types of video signals and can select and display these video signals, a horizontal AFC loop includes a control means for controlling the horizontal deflection position, and a control means for controlling the horizontal deflection position, and a control means for controlling the horizontal deflection position, respectively. Two or more presetting means for presetting are provided, and the presetting means are switched according to the selection of the video signal, so that display is performed at the horizontal deflection position according to the selected video signal. Multi-scan receiver.