JP3321820B2 - Audio output device and TV receiver provided with the device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio output device having an audio output function and a TV receiver provided with the audio output device.

[0002]

2. Description of the Related Art The digitization of music sources input to audio-visual equipment greatly expands the dynamic range of audio output. For example, in the case of classical music and the like, it is more realistic, delicate, and stiff than before. It is possible to play a performance with a certain depth.

[0003]

By the way, such an audio device is satisfactory for music lovers, but a person who is simply enjoying a music program or the like can use the audio device when the volume during the performance is low, for example. If you increase the volume level because you do not hear it well, the volume will be too loud when the volume increases, and conversely, if you reduce the volume level because it is loud when the volume is high, the volume will decrease. There is a problem that you will not be able to hear when you do. Also, even when watching a normal program, the volume of commercials entering between programs often increases suddenly, and if the volume level is lowered at that time, when the program starts again, Had a problem that the volume was too low to hear well.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a compressor for controlling an output audio level to a certain level in an audio circuit system is provided. When there is a large-level sound input, the output sound is controlled to be smaller than the input level, and the sound volume is controlled within a certain range.

[0005]

The compressor in the control unit controls the output sound in response to a large-level sound input and outputs the sound within a certain range. Even if there is a large-level audio input, excessive output can be prevented.

[0006]

An embodiment in which the audio output device of the present invention is used in a digital TV receiver will be described. FIG. 1 is a block diagram of a digital TV receiver, particularly an audio system circuit. 1 is an antenna terminal, 2 is an external input terminal for connecting a video deck or the like, 3 is a TV tuner for selecting a received radio wave, 4 is an intermediate frequency amplifier, 5 is an audio signal processor, 9 is the TV tuner 3, and an intermediate frequency. A system computer SC for controlling the amplifying unit 4, the audio signal processing unit 5, etc., a speaker 10; an operating unit 6 for controlling the volume and the like by the user; and 7 an infrared light receiving unit for inputting an operating signal from a remote commander operated by the user. , 8 indicate a demodulation unit.

[0007] A TV program of a broadcasting station is selected by a TV tuner 3, an audio signal component is separated in an intermediate frequency amplifier 4, and various signal processes are performed in an audio signal processor 5.
The audio signal of an external device such as a video deck connected to the external input terminal 2 is directly processed by the audio signal processing unit 5, and the audio signal is output from the speaker 10. The audio signal processing unit 5 controls the operation buttons of the operation unit 6 to increase or decrease the tone of the volume, and also performs digital signal processing for forming various sound effects such as a surround sound and a hall reverberation sound. . The video circuit system is omitted.

FIG. 2 functionally shows the inside of the audio signal processing unit 5 shown in FIG. 1, wherein 5a is a sample hold circuit, 5b is an A / D converter, 5c is an arithmetic unit,
5d indicates a D / A converter, and 5e indicates a low-pass filter.

Conventionally, a simple volume control performed by the arithmetic unit 5c is, as shown in FIG.
Output level output from the sound volume level and speaker of the converted digital signal by D converter is directly proportional, as is more inclination θ to user volume operation, changes, for example A, B, C, the so-called linear mode Met. Therefore, in the case of music with a wide dynamic range, when the output level is set to be higher with respect to the smaller input level, when the input level becomes higher, the output level becomes larger accordingly. Conversely, when the output level is reduced, there is a problem that the sound volume becomes insufficient at a low input level.
Therefore, when a music source signal with a wide dynamic range is input while listening to music lightly, it may not be possible to set the volume control to any point.

In such a case, the present invention sets the ratio between the input level and the output level as a non-linear mode curve as shown in FIG. 4. When the input is set to a large level, the volume is compressed so that the operation can be performed so that the inclination of θ2 is set to be small. Therefore, even if there is a large input, the output level can be suppressed more than the case of the linear mode shown in FIG.

In order to achieve the above-mentioned compression mode, for example, several kinds of nonlinear mode curves are represented by A,
B and C are stored as a ROM table inside the calculation unit 5c, and the slopes of the curves are A, B, and C from the ROM table based on the value set by the user's volume operation. By selecting one curve, the output level with respect to the input level can be controlled.

Further, as a method of volume control, for example, instead of having the ROM table, there is provided a mathematical formula for calculating the slope of the curve from the value of the volume set by the user. Sound may be output. Regarding the selection between the linear mode and the non-linear mode, a manual switch operated by the user is provided so that the user can freely switch according to his / her preference.

Although the present embodiment has been described with respect to a digital TV receiver, the audio output device of the present invention can be used for any audio equipment such as a car stereo, a radio cassette, an audio amplifier, and the like.

[0014]

As described above, the sound volume according to the present invention is
Audio output apparatus having a compressor, it is possible to compress the dynamic range in accordance with the volume that the user has been set, if you select the non-linear mode, set large user volume for small input levels When the input level suddenly increases, even if the state is changed, excessive output can be prevented, and the user's discomfort with the loud sound can be eliminated. Furthermore, since the output volume is controlled within a certain range,
There is an advantage that even if a large-level audio signal is suddenly input, the user can skip the hassle of turning down the volume of the volume. Further, when this apparatus is used in a TV receiver, it is possible to prevent the volume of a commercial entering between programs from suddenly increasing and causing discomfort even when the user is simply watching a normal program, and also to prevent the commercial from being uncomfortable. There is an advantage that the volume operation for a short period of time only can be omitted, and the volume does not need to be adjusted again when the program starts again.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital TV receiver according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a part of audio processing 5 of FIG.

FIG. 3 is a graph showing a dynamic range of a conventional digital TV receiver.

FIG. 4 is a graph showing a dynamic range of the digital TV receiver according to the embodiment of the present invention.

[Explanation of symbols]

 5a Sample hold line 5b A / D converter 5c Operation unit 5d D / A converter 5e Low pass filter

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-218227 (JP, A) JP-A-1-260908 (JP, A) JP-A-64-65910 (JP, A) JP-A-56- 79508 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H03G 5/00-11/08 H04N 5/60

Claims (2)

(57) [Claims] 1. A sound signal processing unit, the audio output apparatus having an audio output device such as a speaker, to control within a certain range the output volume level, and compressor circuit portion having an output characteristic of the non-linear, Li
An operation unit having a near mode / non-linear mode selection switch and an operation button capable of selecting the compressor output characteristic with respect to the input audio signal , wherein the compressor output characteristic is determined by an input level and an output level.
The ratio of the input level is large when the input level is small, and the input level is large.
An audio output device characterized in that it is set to be small in the case of force . 2. A TV capable of selecting a plurality of reception channels including digital audio such as HDTV and BS.
In the receiver, to control within a certain range of the output volume level, and compressor circuit portion having an output characteristic of the non-linear, Li
An operation unit having a near mode / non-linear mode selection switch and an operation button capable of selecting the compressor output characteristic with respect to the input audio signal , wherein the compressor output characteristic is determined by an input level and an output level.
The ratio of the input level is large when the input level is small, and the input level is large.
A TV receiver characterized in that it is set to be smaller in the case of force .