KR810002159Y1 - Television receiver operating mode selector - Google Patents

Abstract

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Description

A television receiver

1 is a circuit diagram according to a conventional example.

2 is a front view of the apparatus operation unit according to a conventional example.

3 is a circuit diagram according to the present invention.

4 is a front view of the apparatus operation unit according to the present invention.

5 is a circuit diagram showing an example of a gate circuit.

6 is a waveform diagram for explaining the operation of FIG.

The present invention relates to a television receiver having a state switching device for switching a television reception signal and an external signal from a video tape recorder or the like to be sent to a water pipe.

An example of this type of television receiver is shown in FIG. In FIG. 1, a TV signal of a general television broadcast is received by the antenna 1, tuned to the tuner 2 and the tuner 3, amplified by the intermediate frequency amplifier 4, detected by the video detector 5, and the switching terminal a and the external output of the switching switch 8. Applied to terminal 01. When the switching switch 8 is switched to the terminal a, the T.V signal from the video detector 5 is applied to the water pipe CRT 7 via the video amplifier 6. The switching switch 8 is for switching between the T.V signal applied to the terminal a and the external signal applied to the terminal b. As an external signal, a signal from a video tape recorder (VTR) or a television camera is generally used. In the figure, the case of VTR is shown and the switching terminal b is connected to the VTR9 through the external input terminal 02.

The external output terminal 01 is connected to the input terminal of the VTR 9.

The tuner 2 is a voltage controlled type, and the channel of predetermined frequency can be selected by changing the voltage applied between the terminals of the internal reactance element (for example, the varicap) 20.

Tuning device 3 is to apply the voltage corresponding to the channel to be selected to element 20 of tuner 2, and the tuning switches 301, 302 ..., switching transistors 311, 312 ..., and the preset resistors 321, 322 ..., Tuning channel display neon lamps 331,332 ..., diodes 341,342 ..., and tuning IC 30. The tuning IC 30 sequentially turns on each of the switching transistors 301, 302, ..., when a predetermined voltage (for example, + B _L power supply voltage) is applied to the terminal C. For example, the pulse generator 31, It consists of a counter circuit 32, a decoder circuit 33, etc. This can also be configured using a ring counter circuit.

Referring to the channel selection operation, when any channel, for example, the first channel, is tuned, only the first transistor 311 is in the ON state, and the other transistors 312 and the like are in the OFF state.

At this time, the output voltage of each of the variable resistors 321, 322 ... is the lowest as the predetermined predetermined voltage of only the variable resistor 321, and the other variable resistors 322, etc. are all + B _H power supply voltages.

Therefore, only diode 341 is conductive, other diodes 342, etc. are non-conducting, and a predetermined preset voltage from variable resistor 322 is applied to variable reactance element 20 of tuner 2.

At this time, only neon lamp 331 is on and all other neon lamps 322 are off.

Next, when the switch 302 of another predetermined channel, for example, the third channel, is turned on, the transistor 312 is in the OFF state, so that the + B _H power supply voltage is applied to the point A through the variable resistor 322 and the switch 302. Since this point A is connected to the + B _L power supply (+ B _L <+ B _H ) through the resistor 34 and the diode 35, approximately + B _L power supply voltage is applied to the point C. At this time, the tuning IC 30 is operated to turn ON the switching transistors 311,312 ... one by one. The estimated time of this ON operation is about 0.7 ms, which is shorter than the time when the switch 302 is turned ON by human manual operation, so that all transistors 311, 312 ... can be turned on at least once. In this way, while the switch 302 is ON, the transistors 311 and the like are sequentially turned ON, and when the transistor 312 connected in parallel with the switch 302 is turned ON, the voltage at the point A becomes zero and the voltage at the point C becomes zero. Therefore, the operation of the tuning IC 30 is stopped, the transistor 312 is held in the O state, and the second channel is selected.

An example of the operation part of such a T.V receiver is shown in FIG. The operation buttons 201, 202, ... for channel selection are, for example, push buttons for automatic return, and the respective switches 301, 302. It corresponds to. In other words, if a desired one of the operation buttons 201 and 202 is pressed, the corresponding one of the switches 301, 302 ... is turned ON. The neon lamps 331, 332 ... in FIG. 1 are disposed behind the channel display units 231, 232 ... to display the tuned channels. These operation buttons 201, 202 ... channel indicators 231, 232 ... and not shown, but since the power switch capacity adjustment buttons are frequently used, they are discharged by being exposed to the front side of the TV receiver. It is often covered by a part of the side plate or the back plate of a TV receiver.

This is mainly because it is effective for enhancing the appearance aesthetics.

In FIG. 2, the portion 200 surrounded by the dotted line is covered by the lid. In this part 200, the preset knobs 221, 222 ... corresponding to the preset variable resistors 321, 322 ... in FIG. 1 and the slide switch 28, etc. corresponding to the switch 8 in FIG.

However, the channel selection operation buttons 201, 202 ... and the switch 28 for switching the T.V reception state and the VTR regeneration state are separately arranged and have a different operation form, which results in a poor operability. For example, when the VTR is used without a connection, the T.V reception image does not appear on the screen even if the switch 28 for state switching is switched on the VTR side. In such a case, if the switch 28 is hidden by a lid or the like, the user may be mistaken for a malfunction of the T.V receiver. When the VTR is connected and used, the operation mode between the state switching operation and the channel switching fragment is different, resulting in poor operability and inconvenient transition of T.V reception to arbitrary channel selection in VTR reproduction.

The present invention is aimed at providing a television receiver having high operability of state switching and hardly causing misoperation.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a circuit diagram of a TV receiver according to an embodiment of the present invention, and FIG. 4 is a front view of an operation unit of the TV receiver, and the same parts as those in FIGS. 1 and 2 described above are given the same reference numerals. would.

First, in FIG. 3, the T.V signal from the video detector 5 is applied to the external output terminal 01 and the input terminal of the gate circuit 82. An external signal (VTR signal in the drawing) from the external input terminal 02 is applied to the input terminal of the gate circuit 82. These gate circuits 81, 82 are all connected to CTR 7 through video amplifier 6. The external machine VTR

The state switching signal from the state (TV / VTR) switching circuit 10 is applied to the control terminals of the gate circuits 81 and 82. The state switching circuit 10 selects a flip-flop (hereinafter referred to as FF) 11 which outputs a state switching signal in reverse phase to each other, a switch 12 which gives a trigger signal for inverting the operation of the FF11, TV fixing and TV / VTR switching. It has a selector switch 13 to be selected and neon lamps 141 and 142 for status display. In addition, the trigger signal that the switch gives to the FF of 12 can be transmitted remotely using, for example, a remote control unit.

The operation part of this T.V receiver is comprised as FIG. 4, for example. The channel selection operation buttons 201, 202 ..., the channel display sections 231, 232 ..., and the tuning knobs 221, 222 ..., etc. are the same as those in FIG.

The state selection operation button 120 is disposed at a predetermined position in the row of the channel selection operation buttons 201, 202, for example, the upper position. The operation button 120 is, for example, a push button for automatic return and corresponds to the switch 12.

It is also possible to use a contact electrode of a quench switch as the operation buttons 120, 201, 202, and so on. The T.V state display unit 121 and the VTR state display unit 122 are disposed in the vicinity of the state selection operation button 120, and the neon lamps 141 and 142 are disposed behind the display units 121 and 122, respectively. Further, a slide switch 130 for selecting one of T.V fixing and T.V / VTR switching is disposed at a predetermined position of the portion 200 covered by the lid. This slide switch 130 corresponds to the changeover switch 13.

Referring to the following operation, first, when the slide switch 130 is moved to the T.V fixed side, the switch 13 in FIG. 3 is switched to the terminal a side, and the + B voltage is always applied to the control terminal of the gate circuit 81. FIG. FF11 does not work because there is no power supply. Therefore, only the gate circuit 81 conducts, so that the T.V signal from the video detector 5

Next, when the slide switch 130 is moved to the T.V / VTR switching state side, the switch 13 is switched to terminal b, and the + B power supply voltage is applied to FF11. At this time, the point E voltage becomes slower than the point D voltage because of the time constant circuit of the resistor 113 and the capacitor 114. For this reason, transistor 112 is turned on first, the point E voltage decreases, transistor 11 is turned off, and the point D voltage becomes approximately + B power supply voltage. This point D voltage is applied to the control terminal of the gate circuit 81 as a state switching signal through the diode 151. Therefore, the T.V signal from the video detector 5 is applied to the video amplifier 6 through the gate circuit 81. At this time, the transistor 143 is turned on and the neon lamp 141 for displaying the T.V state lights up. As described above, when the switch 12 is turned on by operating the operation button 120 when the transistor 11 of the FF 11 is OFF and 112 are in the ON state, the F point is grounded through the parallel circuit of the capacitor 122 and the resistor 123. The voltage at the point F varies with the current flowing through the capacitor 122, but becomes approximately the magnitude of the + B power supply divided by the resistors 123 and 124. Since the point D voltage was approximately + B supply voltage, diode 153 would conduct and the point D voltage would drop to the point F voltage.

Since the capacitor 115 is charged by the + B power supply, the base voltage of the transistor 112 is lowered by approximately + B voltage than the voltage at point D, and becomes the negative voltage. At this time, the transistor 112 is turned off and the voltage at the point E rises to turn the transistor 111 on. When the operation button 120 stops operation (pressing, etc.), the switch 12 automatically returns to the OFF state. Therefore, the point E voltage becomes approximately + B power supply voltage, and this point E voltage is supplied to the control terminal of the gate circuit 82 through the diode 152. Is approved. Therefore, the VTR signal from VTR 9 is sent to the video amplifier 6 through the gate circuit 82. At this time, the transistor ON44 turns on the neon lamp 142 for displaying the VTR diode.

Since a relatively large capacitor 121 is connected to the point F at which the trigger signal is input in this circuit 10, the impulse voltage generated by the discharge in the CRT tube is absorbed, and malfunction is prevented. In addition, the variation of the + B power supply is compensated by the capacitor 125.

Examples of the resistance values R113, R117 ... of the resistors 113, 117 ... of the capacitors, and the capacitance values C114, C115 ... of the capacitors 114, 115, of the capacitors 113, 117 ... of the capacitors 113, 117 ..., respectively, are represented by R113 = 180Ω, R117 = 1000Ω, R118. = 820 Ω, R123 = 100 kΩ, R124 = 100 kΩ, C114 = 10 µF, C115, C116 = 0.015 µF, C121 = 0.01 µF, C122 = 10 µF, C125 = 10 µF.

As the gate circuits 81 and 82, for example, a circuit as shown in Fig. 5 is used. Examples of the resistance values R812, R813 ... of the resistors 812, 813 ... of the gate circuits 81, 82, and the capacitance values C815, C816 ... of the capacitors 815, 816 ... of the gate circuits 81, 82 are R812, R822 = 1000? , R813, R823 = 33kΩ R814 = 10kΩ, R824 = 12kΩ, C815, C825 = 4.7μF, C816, C826 = 10μF.

Now, a case where the above-described points D and E of FF11 are connected to these gate circuits 81 and 82 without going through the diodes 151 and 152 will be considered with reference to FIG.

First, when transistor 111 of FF11 in FIG. 4 is OFF and transistor 112 is in the steady state of ON, point D voltage is approximately + B and point E voltage is 0 (ground potential).

At this time, the voltage B ₁ (the base voltage of the transistor 811) of the gate circuit 81 of FIG. 5 is at a predetermined voltage V _B1 (corresponding to a divided voltage of approximately resistance 814). Split voltages corresponding to capacitors 813 and 814 are applied, respectively, and predetermined charges are accumulated. The B ₂ point voltage of the gate circuit 82 (the base voltage of the transistor 821) is zero, and the accumulated charges of the capacitors 825 and 826 are also zero.

When FF11 is inverted in this state, the D point voltage becomes D and the E point voltage becomes approximately + B. At this time, the accumulated discharge of the capacitors 815 and 816 is discharged to the gate circuit 81, but ₁ is discharged.

On the other hand, in the gate circuit, the B ₂ point voltage is charged to the capacitor 826 through the resistors 822 and 823 (and the capacitor 825) so that the B ₂ point voltage slowly rises to the predetermined voltage V _R2 .

Therefore, the voltage changes at these B ₁ and B ₂ points are shown in FIG. 6, and the operation of the transistors 811 and 831 is not exactly reversed, but a change occurs in the current IC flowing through the output resistor 61, which affects the video amplifier 6 and the like. For this reason, as the video signal, the black DC level rises for a while, the beam current flows excessively, and the screen is brightened. In the audio signal, the speaker noise appears due to the DC level change.

Here, the transients are suppressed (see dotted line in FIG. 6) by preventing diodes 151 and 152 from being connected between the points D and E to the gate circuits 81 and 82, respectively.

As is clear from the above description, when only TV reception is performed without connecting the VTR, when the switch 13 is switched to terminal a with the slide switch 130 fixed to the TV, the TV reception status is always independent of the operation of the operation switching button 120. Obtained. When the VTR is connected, the slide switch 130 is moved to the T.V / VTR switching state side, and the switch 13 is switched to the terminal b so that the state switching operation button 120 is operated to easily switch the state of T.V reception and VTR regeneration.

This state switching is performed by the operation form like channel selection, and operability is extremely favorable. In addition, the switched state is displayed by the display units 121 and 122 so that no malfunction occurs.

Claims (1)

As described in the text and illustrated in the drawings, the channel selection operation button and the state switching operation button arranged in the operation unit of the television receiver and the state of the normal television signal reception state and the state switchable state are shown. In a television receiver equipped with a switch for selecting, a switching circuit comprising a known flip-flop and a flip-flop trigger switch inverted by the operation of the state switching operation button when the state switching is possible, and the flip-flop A television receiver, comprising: a gate circuit for transmitting a predetermined signal to a water pipe by an output.