KR820000442B1 - Tuning voltage display device for a color television receiver with an electronic tuner - Google Patents

Abstract

The display device uses a diode to control an associated primary color output TR(transistor) so that a specific color is intensely reproduced. A diode is associated with each of 3 primary color outputs TRs(81,82,83) which provide an output for switching in accordance with received bands of TV signals. These associated switches are provided between the electronic tuner(3,4) and the power source for the circuitry. The diode associated with each primary color output TR is on-off controlled by a pulse so a predetermined pluse width is generated following the termination of a period responsive to the magnitude of the tuning voltage.

Description

Tuning voltage display on color television receivers with fully tuned tuner

1 is a circuit diagram showing an embodiment of a tuning voltage display device of a color television receiver equipped with an autotuning tuner according to the present invention.

2 is a view showing the shape of the pattern generated in accordance with the tuning voltage.

3 is a voltage waveform diagram of an essential part of FIG. 1;

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuning voltage display device of a television receiver for displaying the tuning voltage of an electronically tuned tuner on a screen. In a television receiver equipped with a fully tuned tuner, the display of the reception channel needs to display the reception band together with the display of the tuning voltage. 1975.9.26 issued "Funkschau 1975. Heft 20" P51 to 53, the channel number of the lower and upper channels of the reception band and the upper channel on the left and right vertical center of the display screen, An example is shown in which a receiving bar whose length changes in accordance with the tuning voltage is displayed between the displayed both numbers.

In this way, the display of the reception channel using the display screen is excellent because it does not require the next display element and the display itself is large and easy to see, but the display of the reception band uses letters. It is complicated and expensive.

In addition, since the display is carried out in green and monochrome, letters must be read in order to determine the reception band, which is annoying.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tuning voltage display device of an electronic tuning tuner that enables screen display of a receiving channel to be performed by a simple circuit.

In order to achieve the above object, in the present invention, in a color television receiver equipped with an autotuning tuner and configured to generate a pattern that changes in accordance with the tuning voltage, at least a part of the color of the pattern of the pattern changes in accordance with a reception band. It was made possible.

Hereinafter, the drawings will be described in detail.

In FIG. 1, reference numeral 3 denotes a VHF fully tuned tuner, and 4 denotes a UHF fully automatic tuner. Switches 51, 52 and 53 of the band changer 50 are turned on and off in the reception band. The operating voltage is supplied to the tuning tuner (3) (4).

Two band switching switches 51 and 52 are connected to the VHF fully tuned tuner, 4, so that the VHF reception band has a low band (1 to 3 channels) and a high band (4). This is because it is divided into 12 channels). When the switches 51, 52 and 53 are turned on, the reception bands become the VHF low band, the VHF high band and the UHF band, respectively.

The tuning voltage generator 10 generates, at its output terminal 11, a direct current voltage varying from 0 to the breakdown voltage of the zener diode 12, and the direct current voltages are VHF and UHF as tuning voltages. It is supplied to the fully tuned tuners 3 and 4, and is also supplied to the input terminal 201 of the pattern generator 200.

The pattern generator 200 generates a strip 2 extending in a vertical direction on the display screen 1 of the color image tube 90 as shown in FIG.

The pattern generator 200 operates so that the horizontal position of the band 2 corresponds to the magnitude of the tuning voltage supplied to the input terminal 201.

The color of the band 2 is controlled by the color setter 300 so as to be red, green, and blue, respectively, when the reception band is the VHF low band, the VHF high band, or the UHF band.

Red, green, and blue color difference signals from the color difference signal generator 60, the luminance signal generator 70, and the color difference signal generator 60 and luminance signals from the luminance signal generator 70 are matrixed. The primary color signal generator 80 and the color image tube 90 that generate the primary color signal of blue are the same as the VHF and UHF fully tuned tuners 3 and 4, the band switch 50 and the tuned voltage generator 10. It is the same as that found in a typical color television receiver with a fully tuned tuner. The resistors 16 and diodes 19 and 22 operate as gate circuits when the switch 51 is in the ON state, that is, when the VHF low band is being received, and the gates are switched in accordance with the ON and OFF of the transistor 25. Dogs, lungs. Circuits of resistors 17, diodes 20, 23, and circuits of resistors 18, diodes 21, 24 receive the VHF highband when the switch 52 is ON. And when the switch 53 is in the ON state, that is, when the UHF band is being received, respectively, it operates as a gate circuit. The primary color output transistors 81, 82, 83 are strongly biased only when the gate circuits connected to the bases of the primary color transistors 81, 82, 83 are closed.

For example, when receiving the VHF low band as in the case of the illustrated state, the transistor 25 turns off and the diode 19 turns on, whereby the base current of the red output transistor 81 is increased. Is increased, and red is thus strongly reproduced.

At this time, since the switches 52 and 53 are turned off, the diodes 20 and 21 connected to the green output transistor 82 and the blue output transistor 83 are together with the transistor 25. ) Is off even if) is off.

Therefore, the base currents of the green output transistor 82 and the blue transistor 83 are not affected by the ON and OFF of the transistor 25 in this case. The period in which the transistor 25 is OFF coincides with the period in which the band 2 is scanned. Therefore, the color of the band 2 is received in the VHF low band reception, VHF high band reception, and UHF band reception. Each time becomes red, green and blue.

Portions other than the strip 2 are normal reproduced images suitable for the received signals of the tuners 3 and 4.

The circuit constituted by the transistors 26 to 28 is a monostable multivibrator circuit for determining which horizontal position on the screen the band 2 is displayed in accordance with the height of the tuning voltage.

This circuit is a normal monostable multivibrator circuit when the transistor 26 and the resistor 29 are replaced with one resistor. If there is no trigger input supplied to the input terminal 202, the transistor is a conductive transistor ( 28) is stable in the blocking state.

The transistor 26 constitutes a constant current circuit whose current level is controlled by the tuning voltage of the fully tuned tuner 3, 4. The current flowing through the transistor 26 is determined by the value of the resistor 29, the voltage of the power supply line (+ 12V), and the voltage divided by the resistors 30 and 31.

When the tuning voltage is high, the base potential of the transistor 26 is also high and the collector current of the transistor 26 is reduced.

On the contrary, when the tuning voltage is low, the collector current of the transistor 26 increases.

If the circuit constant is determined so that the collector current of the transistor 26 at the maximum point of the tuning voltage is a base current sufficient to saturate the transistor 27, the transistor is independent of the tuning voltage value when there is no trigger pulse. The transistor 27 is in a conductive state, and the transistor 28 is in a blocking state, thereby stabilizing.

Next, the operation of each part when the trigger pulse enters the horizontal period will be described.

3 shows the voltage waveforms of the respective parts when the screen display circuit is operating in a horizontal cycle, wherein (a) shows voltage waveforms (b) and (c) of the input terminal 202, respectively, the base of the transistor 28, The voltage waveforms of the collector, (d) and (e) are the base of the transistor 27, the voltage waveforms of the collector, (f) and (g) are the base of the transistor 25 and the voltage waveform of the collector, respectively (h). Is a diagram showing the voltage waveform of the base of the red output transistor 81. FIG.

When the horizontal retrace pulse 250 enters the trigger terminal at the input terminal 202, the transistor 28, which has been shut off until then, becomes a conductive state. Then, since the collector potential (Fig. 3c) of the transistor 28 is lowered, the base potential (Fig. 3d) of the transistor 27 is also lowered, and the transistor 27 is turned off.

When the transistor 27 is turned off, the collector potential (Fig. 3e) of the transistor 27 rises, so that the base current of the transistor 28 flows through the resistor 33, and the horizontal from the input terminal 202 is increased. Even when the retrace pulse 50 disappears, the conduction state of the transistor 28 and the interruption state of the transistor 27 are maintained.

The above operation takes place immediately after the trigger input comes in. At this time, the base potential of the transistor 27 becomes negative as shown in FIG. 3d. However, since the capacitor 34 discharges by the constant current circuit constituted by the transistor 26, the potential gradually rises. Turn off. When the base potential of the transistor 27 becomes negative positive and becomes a base voltage (normally about 0.7 V) that causes the transistor 27 to conduct, the transistor 27 becomes conductive and the collector potential of the transistor 27 (the 3e also down).

When the collector potential of the transistor 27 falls, the base current of the transistor 28 does not flow, and the collector voltage (FIG. 3c) of the transistor 28 starts to rise, so that the capacitor ( A charging current flows in 34).

Thus, the transistor 27 is in a conductive state instantaneously.

The period T in which the transistor 27 is turned off is determined by the discharge rate of the capacitor 34, i.e., all positions of the constant current source composed of the transistor 26, and the higher the tuning voltage, the smaller the current difference of the constant current source. The period T becomes longer.

Since the waveform shown in FIG. 3E is differentiated between the capacitor 36 and the resistor 35, the negative pulse 252 shown in FIG. 3F is obtained. For this reason, the positive pulse 254 shown in FIG. 3g disappears in the collector of the transistor 25 which controls the opening and closing of the gate circuit. The time when the positive pulse 254 is generated is immediately after the period T in which the transistor 27 is turned off, and the higher the tuning voltage, the later it becomes.

In addition, since the pulse width of the negative pulse 252 is determined by the time constants of the condenser 36 and the resistor 35, the pulse width of the positive pulse 254 is also determined by the time constant, and the constant value T ' to be.

Therefore, the transistor 25 turns off only a certain period T 'after a period T in response to the high and low tuning voltages at the time of the generation of the horizontal synchronization pulse 250. As shown in FIG. 1, when the switch 51 is turned on because the VHF low band is received, and the switches 52 and 53 are turned off, the diode 19 is turned on in the period T '. 81 is strongly biased in the period T ', and red is strongly reproduced in T'.

Since the period T 'is a horizontal period, the strong red reproduction is also a horizontal synchronization, and the band 2 in the vertical direction in FIG. 2 becomes red.

In addition, since the occurrence of the period T 'is delayed as the tuning voltage is higher, the horizontal position of the band 2 is shifted to the right as the tuning voltage is higher. Since the switch 52 is turned on at the time of VHF high band reception, the diode 20 is turned on at a horizontal period, the band 2 is turned green, and the switch 53 is turned on when the UHF band is received. ) Becomes the horizontal period ON, and the band 2 becomes blue.

In addition, the switch 340 of the pattern generator 200 is for erasing the display of the tuning voltage. When the switch 340 is turned off, the transistor 25 is always ON, and the diodes 19 and 20 are used. (21) is always OFF.

In the embodiment of Fig. 1, red, green, and blue colors are generated depending on the reception band, but it is easy to configure different colors depending on the reception band.

For example, when the diodes of which the anode and the cathode are connected to the base of the anode 19 and the exposure force transistor 82 are respectively provided, the color of the band 2 at the time of low band reception becomes yellow.

It is also possible to use a vertical retrace pulse instead of the horizontal retrace pulse 250 supplied to the input terminal.

In this case, the capacitance values of the capacitors 34, 36, 37 must be increased in accordance with the vertical synchronization.

In this case, the band 2 is in the horizontal direction, and the band in the horizontal direction moves in the vertical direction in accordance with the tuning voltage.

In addition, various circuits can be considered as a circuit for determining the period T according to the tuning voltage.

For example, an integrating circuit for converting a horizontal retrace pulse into a sawtooth wave, an overlapping circuit for removing a direct current from a sawtooth voltage obtained at the output of the integrating circuit, and superimposing a DC voltage whose value changes in accordance with the tuning voltage, and the reference voltage source. And the output voltage of the superimposed circuit and the reference voltage, and can be configured as a pulse generating circuit which generates a pulse at the moment when the sawtooth voltage crosses the reference voltage.

In addition, in the composite receiver in which the electronically tuned radio receiver and the color television receiver are combined, the radio receiver tuning voltage can be displayed on the same screen.

Claims (1)

Fully tuned tuner, band designation means for designating a reception band received by the fully tuned tuner, tuned voltage generation means for supplying a tuned voltage to the tuned tuner, color image reproduction means, and color image reproduction according to color information. Pattern generating means and band connected between the driving means for generating a color image in the means, the tuning voltage generating means and the driving stage, and controlling the driving stage so that the color image reproducing means generates a pattern changing in accordance with the tuning voltage. A tuning voltage display device of a color television receiver having an automatic tuning tuner connected between the designation means and the driving stage, the color image reproducing means being a color generating means for controlling the driving stage so as to generate a color changing in accordance with a specified band.

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