JPS60241340A - External speaker device for television receiver - Google Patents

Abstract

PURPOSE:To reduce an unnatural auditive feeling by detecting the sound level difference between two channels or prescribed frequency out-band components of sound signals at least. CONSTITUTION:When a television receiver 10 receives a stereo broadcast and stereo sound signals are supplied to input terminals INL and INR, the level difference between these stereo sound signals is detected by a level difference detecting circuit 9 and is supplied to a switch circuit 6, and stereo signals are supplied to external speakers 8a and 8b if this level difference is higher than a prescribed level. If a monaural broadcast is received or the level difference signal does not exist during reception of the stereo broadcast, signals obtained in an HPF12a and an LPF12b are supplied to switch circuits 6 and 11 through an OR circuit 13, and sound signals of two channels are supplied to external speakers 8a and 8b.

Description

[Detailed description of the invention] 1L1 The present invention relates to an external speaker device for a television receiver.

There is a television receiver equipped with a built-in audio multiplex decoder to support television audio multiplex broadcasts such as uJL stereo broadcasts and bilingual broadcasts. By the way, some television receivers with a built-in audio multiplex decoder can only reproduce monaural sound from the built-in speaker, and such television receivers are provided with an external audio output terminal for stereo reproduction. Therefore, as shown in FIG. 1, the television reception f! By providing an external speaker device 4 to the external audio output terminal 3 of J1, stereo broadcasting can be enjoyed.

In this case, since the external speaker device can be placed arbitrarily apart from the television receiver, there is an advantage that a better stereo effect can be obtained than in a television receiver capable of stereo reproduction using built-in speakers.

However, even when such an external speaker device is used, the best listening position for stereo reproduced sound is limited to some extent, and the localization of the sound source becomes unnatural at positions other than that position. This has the disadvantage that it gives a very unnatural hearing sensation, especially when announcement sounds are used even in stereo broadcasts, and when listening to monaural broadcasts using an external speaker device.

11 animals 1'' An object of the present invention is to provide an external speaker device for a television receiver that reduces unnatural hearing sensations.

The external speaker device for a television receiver according to the invention of Application 1 detects the level difference between the audio signals of at least two channels outputted from the external audio output terminal of the television receiver, and when the detected level is equal to or higher than a predetermined level. a detection means for generating a detection signal; and at least two detection means only during the generation period of the detection signal.
and switch means for supplying the audio signal of the channel to an external speaker. Further, the external speaker device for a television receiver according to the second aspect of the present application is a detection means for detecting components outside a predetermined frequency band of at least two channels of audio signals output from an external audio output terminal of the television receiver, and generating a detection signal when detected. and a switch means for supplying at least two channels of signals to an external speaker only during the generation period of the detection signal.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 5.

In the external speaker device which is an embodiment of the invention of Application 1 shown in FIG. is provided.

The switch circuit 6 has two interlocking switches 6a and 6b, an audio amplifier 7a is connected to the input terminal INL via the switch 6a, and an audio amplifier 7b is connected to the input terminal JNR via the switch 6b. .

The audio amplifier 7a drives the L-ch external speaker 8a, and the audio amplifier 7b drives the R-ch external speaker 8b. Further, a level difference detection circuit 9 consisting of a differential amplifier is connected to the input terminals INL and INR. The level difference detection circuit 9 detects and outputs the signal level difference supplied from the input terminals INL and INR. The level difference is supplied to the switch circuit 6 via the level averaging circuit 14, and when the output level of the level averaging circuit 14 is above a predetermined level, the switches 6a and 6b are turned on.

A television receiver 41t10 is connected to the input terminals INL and INR, and the television receiver 1o has a built-in audio multiplex decoder and monaural reproduction speaker (not shown), and the L- The L-ch and R-ah audio signals are output from the ah and R-ah external audio output terminals 0UTL' and 0LJTR.

In this configuration, the L-ah audio signal from the external audio output terminal 0LITL is sent to the input terminal INL, and the R-ch audio signal from the external audio output terminal 0UTR is sent to the input terminal JNR.
is supplied to Now, the television receiver 10 receives stereo broadcasting, and the L-ah and R-ch stereo audio signals obtained by the audio multiplex decoder are sent to the input terminals INL and JN.
When the stereo audio signal level difference is detected by the level difference detection circuit 9 and supplied to the switch circuit 6 via the level averaging circuit 14. When the output level of the level averaging circuit 14 is equal to or higher than a predetermined level, a detection signal is generated, and the detection signal turns on the switches 6a and 6b, so the L-ch detection signal is the switch 6a.
The R-ch detection signal is supplied to the audio amplifier 7b via the switch 6b. Therefore, stereo reproduction sound can be obtained from the external speakers 8a and 8b. At this time, playback sound is also obtained from the built-in speaker of the television receiver 1o, but this playback sound is L-c
Since it is the sum of the detection signals of h and R-ah, it does not adversely affect the stereo reproduction sound from the external speakers 8a and 8b.

Next, when the television receiver 10 is receiving monaural broadcasting and when receiving stereo broadcasting, if -ch, R=c
When the detection signal levels of h are almost equal, no output is obtained from the level difference detection circuit 9, so the switches 5a and 6b are turned off. Therefore, the reproduced sound is not output from the external speakers 8a and 8b, and the reproduced sound is output only from the built-in speakers of the television receiver 10.

FIG. 3 shows another embodiment of the invention of Box 1 of the present application. In this figure, the same parts as in FIG. 2 are indicated by the same symbols, and the television receiver 10 has an earphone output terminal 0UTE.
This earphone output terminal 0UTE is for TV reception 1.
110 in the signal line to the built-in speaker. In addition, the earphone output terminal 0LITE has an input terminal IN.
A switch circuit 11 is connected through E, and the switch circuit 11 has a switch 11a that turns on and off the signal line to the built-in speaker.When the output level of the level averaging circuit 14 is above a predetermined level, the switch 11a is turned off. - Close. Therefore, when there is a level difference of more than a predetermined level between the audio signal levels of L-(ih and R-ch, and the switches 6, a, and 6b are on, the switch 11a is turned off, and the built-in speaker of the television receiver 1110 is The signal line is cut off.Therefore, the reproduced sound with a stereo effect is output only from the external speakers 8a and 8b, and the reproduced sound with only a monaural effect is output only from the built-in speaker.

FIG. 4 shows an embodiment of the invention of Box 2 of the present application.

In this figure, the same parts as in FIG. 2 or 3 are indicated by the same reference numerals, and a filter circuit 12a is connected to the input terminal INL, and a filter circuit 12b is connected to the input terminal INR.
are connected to each other. The filter circuits 12a and 12b are composed of an HPF (bypass filter) and an LPF (low pass filter), and generate a detection signal when signal outputs are obtained from the HPF and the LPF. Filter circuit 12a, 1
The output signal units 2b are supplied to a switch circuit 6.11 via an OR circuit 13.

Other configurations of the external speaker device according to the invention of Box 2 include a level difference detection circuit 9 and a level averaging circuit 14.
Since it is the same as that in FIG. 3 except that it is not provided, the explanation here will be omitted.

In general, the frequency spectra of audio signals for music that is preferably played in stereo and announcement sounds that are desirable to be played in monaural are different. Fifth
As shown by the broken line B in Figure 5 (ω), the spectrum is narrower than that of music. Therefore, the filter characteristics of the filter circuits 12a and 12b are as shown in Figure 5+b+. It has a characteristic that prevents passage.

Now, the television receiver 10 receives a stereo broadcast, and L-c
The stereo audio signals of h and R-ch are input to the input terminal INL,
When the stereo audio signal is supplied to JNR, if it is a wideband audio signal such as music or live broadcast interruption,
A detection signal is generated from at least one of the filter circuits 128.12b. Since the detection signal turns on the switches 6a and 6b, the L-ch audio signal is supplied to the audio amplifier 7a via the switch 6a, and the R'-ch audio signal is supplied to the audio amplifier 7b via the switch 6b, and is then externally supplied. Stereo reproduction sound is output from the speakers 8a and 8b.

Next, L-ah and R- received by the television receiver 10
If the audio signal of the channel is an audio signal such as an announcement sound,
Since no audio signal is obtained from the filter circuits 12a and 12b, the switches 6a and 6b are turned off. Therefore, no reproduced sound is output from the external speakers 8a and 8b, and only reproduced sound is output from the built-in stereo of the television receiver 1o.

--l As described above, in the external speaker device of the invention in Box 1, the sound reproduced from the external speaker is only when the level difference between the audio signals of at least two channels output from the television receiver is equal to or higher than the predetermined level. Output. Further, in the external loudspeaker device of the invention in Box 2, components outside the predetermined frequency band of at least two channels of audio signals output from the television receiver are detected, and reproduced sound is output from the external speaker only when detected. Therefore, even when receiving stereo broadcasts, for programs such as music or live broadcasts that require a stereo effect, stereo playback sound is output from the external speakers, and it is more natural to obtain monaural sounds such as announcement sounds. In the case of an auditory program, monaural playback sound is output only from the built-in speakers of the television receiver. Therefore, the unnatural hearing sensation is reduced compared to the conventional method.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a connection state between a television receiver and an external speaker device, Fig. 2 is a block diagram showing an embodiment of the invention in Box 1, and Fig. 3 is another embodiment of the invention in Box 1. FIG. 4 is a block diagram showing an embodiment of the invention in Box 2, and FIG. 5 is a waveform diagram for explaining the operation of the filter circuit in the device shown in FIG. Explanation of symbols of main parts 1.10...Television receiver 3.0UTL, 0UTR...External audio output terminal 4...External speaker device 6.11... ...Switch circuits 7a, 7b...Audio amplifiers 8a, 8b...
...Speaker 9 ...Level difference detection circuit Applicant Pioneer Co., Ltd. Agent Patent attorney Motohiko Fujimura

Claims (2)

[Claims] (1) An external speaker device for receiving at least two channels of audio signals output from a television receiver capable of receiving stereo broadcasts and obtaining stereo playback sound through external speakers, the device comprising: a detection means for detecting a level difference between the two and generating a detection signal when the detection level is equal to or higher than a predetermined level; and a switch means for supplying the at least two channels of audio signals to the external speaker only during a period in which the detection signal is generated. An external speaker device comprising: (2) An external speaker device for receiving at least two channels of audio signals output from a television receiver capable of receiving stereo broadcasts to obtain stereo playback sound through external speakers, the external speaker device receiving at least two channels of audio signals output from a television receiver capable of receiving stereo broadcasts, The device is characterized by comprising a detection means for detecting a component outside a predetermined frequency band and generating a detection signal when detected, and a switch means for supplying the at least two channels of audio signals to the external speaker only during the period in which the detection signal is generated. external speaker device.