JPH046265Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a channel selection display device capable of displaying a search display and a channel display during a search, for example in a television receiver having an electronic tuner.

BACKGROUND ART AND PROBLEMS THEREOF For example, in a television receiver having an electronic tuner, a channel selection operation, so-called search, can be performed automatically by sequentially changing the channel selection voltage. In this case, if an operation is performed to perform a search, but it is unclear whether or not the search is actually being performed, the user will be extremely anxious.
Therefore, if some method were used to display the search and also the channel displaying which side is being searched, when searching,
It is safe for users.

Purpose of the invention The present invention has been made in view of these points, and is designed to display a search display and a channel display during a search.

Summary of the invention In order to achieve the above object, the tuning display device according to the invention includes an oscillator and a light emitting element, the oscillation period of the oscillator is changed according to the tuning voltage, and the oscillation output of the oscillator is used during a search. The light emitting element is driven.

The present invention is structured as described above, and when searching,
Since the light emitting element flashes light, a search display is performed, and since the cycle of the flashing light is changed according to the channel selection voltage, a channel display is performed.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to FIG. In this example, channels are displayed only when searching for the UHF band.

In the figure, reference numeral 1 denotes an electronic tuner, to which a high frequency signal is supplied from an antenna 2. The intermediate frequency signal from the tuner 1 is amplified by an intermediate frequency amplifier 3 and then supplied to a video detection circuit (not shown).

Further, 4U, 4V _L , and 4V _H are connection switches for band switching, respectively, and the DC voltage +B supplied to the power supply terminal 5 is connected to these connection switches 4U, 4V L, and 4V H, respectively.
It is supplied to the tuner 1 as a band switching voltage through 4V _L and 4V _H. In this case, when the connection switches 4U, 4V _L , and 4V _H are turned on, the tuner 1 is switched to the UHF band, VHF low band, and VHF high band, respectively.

Reference numeral 6 denotes, for example, an automatic return type connection switch for starting a search, and the DC voltage +B supplied to the power supply terminal 5 is passed through this connection switch 6 to R.
-S is supplied to the set side of the flip-flop 7. The signal obtained at the Q terminal of flip-flop 7 is supplied to channel selection voltage generation circuit 8. Then, the tuning voltage V _c is supplied from the generating circuit 8 to the tuner 1 . Further, the intermediate frequency signal from the video intermediate frequency amplifier 3 is supplied to the station detection circuit 9.
When a station is detected in the station detection circuit 9, a high level "1" signal is output from its output side, and this is supplied to the reset side of the flip-flop 7.

In this case, when the connection switch 6 is turned on, the flip-flop 7 is placed in the set state, and a high level "1" signal is obtained at its Q terminal, and the generation circuit 8
The tuning voltage Vc from tuner 1 is changed sequentially.
is in the search state. When the tuner 1 selects a station, a high level "1" signal is supplied from the station detection circuit 9 to the reset side of the flip-flop 7, and the flip-flop 7 is placed in the reset state, and its Q terminal is set to a low level. A signal of "0" is obtained, the change in the tuning voltage V _c from the generating circuit 8 is stopped, and the tuner 1 is placed in the tuning state.

The above is a conventionally known channel selection circuit, and next, the channel selection display device of this example will be described.

In FIG. 1, numeral 10 is a terminal to which the tuning voltage V _c from the generation circuit 8 described above is supplied.
This terminal 10 is grounded through a series circuit of resistors 11 and 12, and the voltage obtained at the connection point P of these resistors 11 and 12 is supplied to the base of an npn transistor 13. The collector of this transistor 13 is connected to the power supply terminal 5, and its emitter is grounded through a series circuit of resistors 14 and 15 and also through a series circuit of resistors 16 and 17. The voltage available at the connection point Q of resistors 14 and 15 is supplied to the base of an npn transistor 18. Further, the voltage obtained at the connection point R between the resistors 16 and 17 is supplied to the base of the npn transistor 19.

In this case, in the UHF band, when the tuning voltage V _c supplied to the terminal 10 becomes V ₁ or higher and when tuning is performed by searching 40 channels or more as shown in FIG. Resistors 14, 15, etc. are selected so as to obtain a voltage sufficient to turn on the resistors 14 and 15. Similarly, in the UHF band, the tuning voltage V _c becomes V ₂ or more, and the second
As shown in the figure, when searching and selecting 60 or more channels, the resistor 16 is connected to the connection point R so that a voltage sufficient to turn on the transistor 19 is obtained.
and 17th prize will be selected.

The emitters of transistors 18 and 19 are connected to each other, and their common connection point is grounded via the collector-emitter of npn transistor 20.

Also, resistors 21 and 2 are connected between the power supply terminal 5 and the ground.
Two series circuits are connected. The collectors of transistors 18 and 19 are connected to each other via resistors 23 and 24, respectively, and their common connection point is connected to connection point S of resistors 21 and 22 via diode 25. This connection point S is a diode 26
and is grounded via a series circuit of resistor 27.

Further, 28 is a terminal to which the switching voltage supplied to the tuner 1 via the connection switch 4U is supplied via the resistor 29, and this terminal 28 is connected to the resistor 3.
0 to the base of the transistor 20, and is connected to the diode 2 via the diode 31.
6 and the connection point of resistor 27.

In addition, the connection point S is the PUT that constitutes the oscillator 32.
(Programmable Unijunction Transistor) Connected to the gate of 33. Further, a series circuit of resistors 34, 35 and a capacitor 36 is connected between the power supply terminal 5 and the ground, and a connection point T between the resistors 34 and 35 is connected to the anode of the PUT 33. Also, the cathode of PUT33 is resistor 37
grounded via.

In this case, PUT33 has its anode voltage,
That is, when the voltage V _T obtained at the connection point T is lower than its gate voltage, that is, the voltage V _S obtained at the connection point S, there is no conduction, and the capacitor 36 is charged.
When the voltage V _T becomes higher than the voltage V _S , conduction occurs, and at this time, the charge in the capacitor 36 is transferred to the resistor 35→
PUT33 anode-cathode → resistor 37 →
Discharged through the ground path. When the charge in the capacitor 36 is discharged, the voltage V _T becomes lower than the voltage V _S and the PUT 33 becomes non-conductive. Like this PUT3
3 oscillates by repeating conduction and non-conduction. In this case, as is clear from the above, the lower the voltage V _S is, the more
Since the voltage V _T becomes higher than the voltage V _S and the time until the PUT 33 becomes conductive becomes shorter, the oscillation period becomes shorter.

Further, the oscillation output obtained at the connection point between the cathode of the PUT 33 and the resistor 37 is supplied to the base of the transistor 38 for driving the light emitting diode. The emitter of this transistor 38 is grounded, and its collector is connected to the cathodes of light emitting diodes 39U, 39V _L and 39V _H. Furthermore, the switching voltage supplied to the tuner 1 via the connection switches 4U, 4V _L and 4V _H for band switching is applied to the anodes of the light emitting diodes 39U, 39V _L and 39V _H via resistors 40, 41 and 42, respectively. is supplied to In this case, the light emitting diodes 39U, 39
V _L and 39 V _H are designed to emit light in, for example, green, red, and yellow.

Further, 43 is a terminal to which a signal obtained from the Q terminal of the flip-flop 7 is supplied;
3 is connected to the connection point T via a diode 44.

This example is configured as described above and operates as follows.

First, when the connection switch 4U is turned on and the tuner 1 is set to the UHF band, the light emitting diode 39
DC voltage +B is applied to the anode of U. Also, since DC voltage +B is applied to the terminal 28,
Transistor 20 is turned on, diode 26 is turned off, and resistor 27 is disconnected from the circuit. Then, when the connection switch 6 is turned on and the search is started, the terminal 4
A high level "1" signal is supplied to the oscillator 3, the diode 44 is rendered non-conductive, and the oscillator 32 is activated. Here, when the tuning voltage V _c is less than V ₁ , 14 ~
During the period in which the 39th channel is being searched, both transistors 18 and 19 are turned off. Therefore, during this period, the voltage V _S at the connection point S is
₂ , and the oscillation period of the oscillator 32 is γ ₁ , for example, 1200 msec, as shown in FIG.
becomes. Therefore, during this period, the light emitting diode 39U
flashes in green with a period of γ ₁ . Also,
During the period when channel selection voltage V _c is V ₁ or higher and channels 40 to 59 are being searched, transistors 18 and 19
are placed in the on and off states, respectively. Therefore, during this period, the voltage V _S at the connection point S is
and 23 parallel circuits, and the oscillation period of _{the oscillator 32 is γ 2 (<γ 1 ) ,} for example _, 600 msec, as shown in FIG. Therefore, during this period, the light emitting diode 39U flashes green light with a period of γ ₂ . Also, the tuning voltage V _c is V ₂
During the period in which the 60th to 83rd channels are being searched, both transistors 18 and 19 are turned on. Therefore, the voltage at the connection point S during this period is
V _S is V _S3 (<V _S2 ) determined by the parallel circuit of resistors 22, 23, and 24, and the oscillation period of the oscillator 32 is γ ₃ (<γ ₂ ), for example, as shown in FIG.
It will be 230msec. Therefore, during this period, the light emitting diode 39U flashes green light with a period of γ ₃ .

On the other hand, when a tuner is selected by the tuner 1, the flip-flop 7 is placed in a reset state, a low level "0" signal is obtained at its Q terminal, and the tuner 1 is placed in a tuned state. At this time, terminal 4
3 is supplied with a low level "0" signal, the diode 44 is rendered conductive, the voltage V _T at the connection point T remains at the low level "0", and the oscillator 32 is rendered inactive. Therefore, when the tuner 1 selects a channel, the light emitting diode 39U stops blinking and emitting light.

Next, when the connection switch _4VL is turned on and the tuner 1 is set to the VHF low band, a DC voltage +B is applied to the anode of the light emitting diode _39VL . Further, since the DC voltage +B is no longer applied to the terminal 28, the transistor 20 is turned off, the diode 26 is turned on, and the resistor 27 is connected in parallel with the resistor 22. When the connection switch 6 is turned on and a search is started, a high level "1" signal is supplied to the terminal 43, and the oscillator 32 is put into operation. In this case, the transistor 20 is turned off, and the voltage V _S at the connection point S becomes V _S4 determined by the parallel circuit of the resistors 22 and 27, regardless of the level of the channel selection voltage V _c , and the oscillation period of the oscillator 32 is γ ₄ , for example 600msec
becomes. Therefore, during a search in the VHF low band, the light emitting diode 39V _L flashes red light with a period of γ ₄ . On the other hand, when a channel is selected by the tuner 1, the oscillator 32 is brought into a non-operating state, so that the light emitting diode _39VL ceases to flash and emit light.

Next, when the connection switch _4VH is turned on and the tuner 1 is set to the VHF high band, a DC voltage +B is applied to the anode of the light emitting diode _39VH . In this case, in the same way as when tuner 1 is set to VHF low band, when searching,
The light emitting diode 39V _H blinks and emits yellow light with a period of γ ₄ , and when tuned by the tuner 1, the light emitting diode 39V _H stops blinking and emits light.

According to this example, when searching, the light emitting diode 39U, 39V _L , or 39V _H blinks and emits light to indicate that it is the search time, and when a channel is selected, the blinking light stops and it is displayed that the channel has been selected. Ru. Also, when searching for the UHF band,
The period of blinking light emission of the light emitting diode 39U changes depending on the channel band being searched, and the channel band is displayed. In addition, the UHF band,
In VHF low band and VHF high band, light emitting diodes 39U, 39V _L and 3
9V _H flashes and these light emitting diodes 3
Band switching display is performed by 9U, 39V _L and 39V _H.

In the above embodiment, the channel is displayed only when searching for the UHF band, but it is of course possible to display the same channel in the VHF low band and high band. It is. Also,
In the above embodiment, the channel display displays three channel bands, but it is also possible to display channel bands in more detail.

Effects of the Invention As is clear from the embodiments described above, according to the present invention, when searching, the light emitting element blinks and emits light, so that it is displayed that it is the search time, and when a channel is selected, the blinking and light emission stops. It will be displayed that the call was made. Furthermore, since the period of blinking light emission of the light emitting element changes depending on the channel band being searched, the channel band being searched is roughly displayed. Especially when the number of channels is large, such as the UHF band (14 channels to 83 channels), the channel band being searched (for example, 14 to 40 channels) is used instead of the individual channel number being searched.
The invention of the present invention, which roughly displays three bands of channels, 40 to 60 channels, and 60 to 83 channels, is effective.

[Brief explanation of the drawing]

Fig. 1 is a connection diagram showing one embodiment of the present invention;
3 and 3 are diagrams for explaining the example in FIG. 1, respectively. 1 is an electronic tuner, 6 is a connection switch for starting a search, 8 is a tuning voltage generation circuit, 32 is an oscillator,
39U, 39V _L and 39V _H are light emitting diodes, respectively.

Claims (1)

[Claims for Utility Model Registration] 1. An oscillator whose oscillation period can be changed according to a channel selection voltage and a light emitting element, and the light emitting element is activated by the output of the oscillator during a channel search period from one station to the next station. A channel selection display that is driven to change the blinking cycle of the light emitting element in accordance with the channel selection voltage, and roughly displaying the channel band being searched according to the blinking cycle of the light emitting element during the search period. Device. 2. The channel selection display device according to claim 1, wherein the light emitting element also serves as a light emitting element for band switching.