JPS63174485A - Television receiver - Google Patents

Abstract

PURPOSE:To execute vivid audio reproducing at the time of reproducing music and to execute a clear reproducing at the time of reproducing an announcement, etc., by making voice frequency characteristic a wide band when inputting external sounds or receiving a stereophonic broadcast. CONSTITUTION:Video output signals from a video disk, a VTR and a 8 mm VTR are supplied to input terminals 3, 4 and 5 and audio output signals from them are supplied to the input terminals 6, 7 and 8. And also the audio output signals from an audio tuner, a cassette tape recorder and a CD player are respectively supplied to the input terminals 9, 10 and 11. The respective audio output signals are switched to be selected with a switching signal from a microcomputer 14 in a switching circuit 2, and supplied to an audio output circuit 27 through a tone quality control circuit 26. When the input sound signals are external inputs or when the stereophonic broadcast is received, a D/A converter 30 transmits a control signal to the tone quality control circuit 26 in order to obtain the with band frequency characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a television receiver having an external audio input terminal.

[Summary of the invention]

In a television receiver having an external audio input terminal, the present invention provides a wideband audio frequency characteristic when inputting external audio or receiving a stereo broadcast, and changes the audio frequency characteristic to a narrow band when receiving primary and secondary broadcasts or receiving a broadcast that is not an audio multiplex broadcast. This enables powerful audio playback when playing music, etc.
This allows clear reproduction of announcements and the like.

[Conventional technology]

Optimal sound quality characteristics when reproducing audio signals on a television receiver vary depending on the type of input audio signal. For example, if the input audio signal is from a music program, a wider band will allow for higher quality and more powerful playback. On the other hand, if the input audio signal is based on analance, for example, if the band is set too wide, the signal will become unlistenable.

As described above, the optimal sound quality characteristics vary depending on the type of input audio signal. Therefore, it is preferable that the sound quality characteristics of a television receiver be set according to the type of input audio signal.

[Problem that the invention seeks to solve]

However, with conventional television receivers, the sound quality characteristics are determined by the volume settings for adjusting treble and bass.
Even if the type of input audio signal changes, the treble,
The sound quality characteristics will not change unless you change the bass adjustment volume. For this reason, in conventional television receivers, in order to perform optimal sound quality adjustment, the user has to adjust the treble and bass adjustment volume every time the type of input audio signal changes. It is necessary to reset the settings to the desired state.

Therefore, an object of the present invention is to provide a television receiver that can change sound quality characteristics depending on the type of input audio signal.

Means for Solving Problem c] The present invention is characterized in that, in a television receiver having an external audio input terminal, the audio frequency characteristics are wideband when inputting external audio or when receiving stereo broadcasting. It is a television receiver.

[Effect]

When a stereo broadcast control channel signal is detected,
Alternatively, when the external input is selected by the source switching circuits 1 and 2, the audio frequency characteristics are wideband. when no control channel signal is detected, or
When the main and sub audio control channel signals are detected,
The audio frequency characteristics are considered to be narrowband.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

The present invention is used in a television receiver that is equipped with a high-output audio output circuit, is provided with an audio-only input terminal, and can be connected to various video devices and to which various audio devices can be connected.

In FIG. 1, 1 is a video source switching circuit;
2 is an audio source switching circuit. The source switching circuit 1 is supplied with the video signals from the input terminals 3.4.5 and also with the output of the video intermediate frequency amplification and video detection circuit 12. The source switching circuit 2 is supplied with the audio signal from the input terminal 6.7.8 and the audio signal from the input terminal 9.10.11, as well as the output of the audio multiplex decoder 13. Input terminals 3.4.5 are supplied with video signals output from various video devices, respectively, and input terminals 6.7.8
are respectively supplied with audio signals output from the video equipment. Audio signals output from various audio devices are supplied to input terminals 9, 10, and 11, respectively. That is, for example, input terminals 3.4.5 are supplied with video output signals of a video disc, VTR, and 8 mm VTR, respectively, and input terminals 6.7.8 are supplied with their audio output signals, respectively. Ru. Input terminal 9
．． 10 and 11 are supplied with audio output signals of an audio tuner, a cassette chip recorder, and a compact disc player, respectively.

The source switching circuits 1 and 2 are supplied with a source switching signal from the microcomputer 14. The microconpeak 14 receives an input from a key switch 15 and also receives an input from a commander 17 via a light receiving section 16 . By operating the key switch 15 or the commander 17, a source switching signal is generated from the microcomputer 14. As a result, a desired one is selected from among various video equipment, audio equipment, and television broadcasts connected to the television receiver.

Note that the audio input signal is a stereo input, and there are audio input terminals for a left channel and a right channel, but to simplify the explanation, only the audio input terminal for one channel is shown.

When television broadcasting is selected, the signal received by the tuner circuit 21 is supplied to the video intermediate frequency amplification and video detection circuit 12. For example, frequency 4.5
The audio signal detected from the MHz beat component is supplied to the audio intermediate frequency amplification circuit 22 . The output of the video intermediate frequency amplification and video detection circuit 12 is supplied to the video signal processing circuit 23 via the source switching circuit 1. The video signal is demodulated in the video signal processing circuit 23, and the output of the video signal processing circuit 23 is supplied to the CRT display 25 via the adding circuit 24. On the other hand, audio intermediate frequency amplification circuit 2
The output of 2 is supplied to the audio multiplex decoder 13, and the audio signal is demodulated. The output of the audio multiplex decoder 13 is supplied to the sound quality control circuit 26 via the source switching circuit 2. The output of the sound quality control circuit 26 is supplied to an audio output circuit 27.

The signal amplified by the audio output circuit 27 is supplied to speakers 28A and 28B.

If one of the video devices is selected, the video signal from the input terminal 3.4.5 is transferred to the source switching circuit 1.
The audio signal from the input terminal 6.7.8 is supplied to the sound quality control circuit 26 via the source switching circuit 2. The output of the video signal processing circuit 23 is supplied to a CRT display 25 via an adder circuit 24. The output of the sound quality control circuit 26 is supplied to the audio output circuit 27, and the output of the audio output circuit 27 drives the speakers 28A and 28B.

When one of the audio devices is selected, the audio signal from the input terminal 9, 10, 11 is supplied to the sound quality adjustment circuit 26 via the source switching circuit 2, and the output of the sound quality adjustment circuit 26 is used as the audio output. It is supplied to the circuit 27. The output of the audio output circuit 27 causes the speakers 28A and 2
8B is driven.

A display signal is generated from a display generation circuit 29 to the adder circuit 24 . The display generation circuit 29 is supplied with the output of the microcomputer 14 . The display signal from the display generation circuit 29 is superimposed on the output signal of the video signal processing circuit 23 in the adder circuit 24, and various information is displayed on the CRT display 2.
5 is displayed on the screen.

Note that when an audio device is selected, no video signal is supplied to the video signal processing circuit 23. At this time, a display indicating that the audio device is selected is displayed on the CRT display 25. At this time, video-related operations may be accompanied.

The microcomputer 14 generates a source switching signal, and also generates image quality control data and sound quality control data based on commands from the key switch 15 or commander 17. Image quality adjustment data such as color tone, color depth, brightness, sharpness, etc. generated by the microcomputer 14 is converted into an analog control voltage by the D/A converter 30 and supplied to the video signal processing circuit 23. Audio control data such as sound quality generated by the microcomputer 14 is converted into an analog control voltage by the D/A converter 30 and supplied to the sound quality control circuit 26. Image quality is adjusted in the video signal processing circuit 23 using an analog control voltage from the D/A converter 30. D in the sound quality control circuit 26
The sound quality is adjusted by the analog control voltage from the /A converter 30.

The frequency characteristics of the sound quality control circuit 26 are as follows when receiving external input or stereo broadcasting, unless the sound quality is specifically adjusted.
As shown by the solid line a in Figure 2, the frequency is 20Hz to 20k.
The characteristic is flat for audio signals up to Hz, and in other cases, the characteristic is rounded in the high range, as shown by the broken line in FIG.

In other words, in audio multiplex broadcasting, as shown in Figure 3, the subcarrier is approximately 55.125 kHz, which is 3.5 times the horizontal scanning frequency, and the frequency is 922.5 kHz in primary and secondary audio broadcasting.
A control channel signal AM-modulated with a sine wave having a frequency of 982.5 kHz is sent during stereo broadcasting. This control channel signal is detected by the audio multiplex decoder 13. This detection signal is supplied to the microcomputer 14.

The microcomputer 14 generates sound quality control data in response to this detection signal. When a stereo broadcast control channel signal is detected, or when external input is selected by source switching circuits 1 and 2, the sound quality is controlled so that the audio frequency characteristics are as shown by the solid line a in FIG. Data is from microcomputer 14
/A given to Konhak 30. When a control channel signal is not detected during television reception, or when a control channel signal for primary and secondary audio is detected, the sound quality control data is changed to the micro level so that the audio frequency characteristics become the characteristics shown by the broken line in Figure 2. computer 14 to D
/A converter 30.

〔Effect of the invention〕

According to this invention, when it is desired to perform powerful audio playback, such as when receiving a stereo broadcast or when external input is selected by the source switching circuits 1 and 2, the audio frequency characteristics are widened, and when receiving the main and sub-audio, etc., the audio frequency characteristics are narrowed when clear audio reproduction is performed and the audio frequency characteristics are straddled. In this way, according to the present invention, optimal sound quality characteristics are automatically set according to the input audio signal.

[Brief explanation of the drawing]

1H is a block diagram of an embodiment of the invention, the 2nd leap is a frequency characteristic diagram used to explain an embodiment of the invention, and FIG. 3 is a spectrum diagram used to explain audio multiplex broadcasting. Explanation of main symbols in the drawings 1.2: Source switching circuit, 13: Audio multiplex decoder, 14: Microcombeater, 26: Sound quality control circuit. Agent: Patent Attorney Masatoshi Sugiura) Measurement Rebuttal, 1
Figure 2 of 11, Figure 3 of Hz at the beginning of the test.

Claims (1)

[Scope of Claim] A television receiver having an external audio input terminal, characterized in that the audio frequency characteristic is wideband when inputting external audio or when receiving stereo broadcasting.