JPH10304277A - Television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a user to listen to a sound by using an automatic gain control circuit even for a hearing aid circuit so as to emphasize a small sound level at a high frequency without a remarkable cost increase in the television receiver that employs the automatic gain control circuit to decrease a sound level difference. SOLUTION: The receiver is provided with a high-pass filter 1 that extracts a high frequency component, a 1st changeover means 2 and a 2nd changeover means 5 that select a signal depending on an application, an automatic gain control circuit 3 that amplifies or attenuates the signal at a preset amplification factor or attenuation factor, and a synthesis circuit 4 that synthesizes high frequency components, and the automatic gain control circuit 3 are used in common for two applications. Thus, a small sound level at a high frequency is emphasized without a remarkable cost increase to provide the television receiver where the sound is easily heard by the user.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for handling audio signals, such as a television receiver.

[0002]

2. Description of the Related Art In conventional audio signal processing of a device that handles audio such as a television receiver, automatic gain control is performed to reduce the audio level difference between different broadcasting stations or between a commercial (hereinafter referred to as CM) and a program. Circuits are often used. This is to control the gain of the output signal by varying the gain of the amplifier circuit in accordance with the level of the input signal of the audio signal.

On the other hand, in the field of hearing aids, it has been considered to use an automatic gain control circuit by dividing a band as shown in, for example, Japanese Patent Application Laid-Open No. 5-300595.

[0004]

A phenomenon that makes it difficult to hear small sounds in a high frequency range occurs with aging and is called presbycusis. When such an elderly person watches a television receiver, the volume is excessively increased in order to listen to a small sound in a high frequency of a frequency that is hard to hear, and the sound of other frequencies is also large. There is a problem that the sound becomes loud for both the viewer and the surrounding people.

Although it is easy to provide a hearing aid circuit separately from the audio signal processing circuit of the television receiver, there is a problem that the cost is greatly increased because a plurality of automatic gain control circuits are required.

[0006]

In order to solve the above-mentioned problems, a television receiver according to the present invention comprises an automatic gain control circuit, which has conventionally been used to reduce a difference in audio level between a CM and a program, by using a frequency control circuit. It is characterized in that it is used in common with a hearing aid circuit that emphasizes small sounds in the high frequency range and makes the sound easier to hear.

According to the present invention, it is possible to provide a television receiver that can emphasize small sounds in a high frequency range without significantly increasing the cost and that can easily hear sound.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A television receiver according to a first aspect of the present invention uses a television receiver in which an automatic gain control circuit is used to reduce a difference in audio level between broadcasting stations or between a CM and a program. Wherein the automatic gain control circuit emphasizes a low-frequency sound of an input audio signal and synthesizes and outputs the resultant signal with the audio signal. This has the effect of emphasizing a sound having a small volume and making it easier to hear the sound.

According to a second aspect of the present invention, there is provided a television receiver, comprising: a high-pass filter for inputting an audio output after detection output and extracting only a high-frequency portion; an output of the high-pass filter; First switching means for selecting an audio output after output, an automatic gain control circuit for receiving an output of the first switching means and outputting the output according to a preset input / output characteristic; and A synthesizing circuit for inputting and synthesizing an output and the audio output, and synthesizing and outputting; and a second switching unit for selecting and outputting the output of the synthesizing circuit and the output of the automatic gain control circuit. In addition, this configuration has the effect of emphasizing small high-frequency sounds without a significant increase in cost, making it easier to hear voices.

According to a third aspect of the present invention, there is provided a television receiver, comprising: a high-pass filter for inputting an audio output after detection output and extracting only a high-frequency portion; an output of the high-pass filter; A multiplexing circuit that time-division multiplexes the output audio output, an automatic gain control circuit that receives the output of the multiplexing circuit and outputs the output according to a preset input / output characteristic, and an output of the automatic gain control circuit. A separating circuit for separating the signal into two outputs, and a synthesizing circuit for inputting and synthesizing a signal output from the separating circuit. This has the effect that the voice can be easily heard by emphasizing, and at the same time, the voice signal that has just been subjected to the voice signal processing can be extracted.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) An example of a first embodiment of the present invention will be described with reference to FIGS. 1, 2 and 5. FIG. FIG. 1 shows a configuration of an audio signal processing circuit of a television receiver of the present invention, and FIG. 2 is a diagram showing an operation example of a television receiver using the audio signal processing circuit. FIG. 5 is a diagram showing output characteristics of an input signal and an output signal of the automatic gain control circuit.

In FIG. 1, a high-pass filter 1 allows only high-frequency signals to pass. The first switching means 2 selects and outputs either the output of the high-pass filter or the input signal. The automatic gain control circuit 3 changes the output level by performing preset amplification or attenuation in accordance with the level of the input signal. The combining circuit 4 combines the input signal and the output of the automatic gain control circuit. The second switching means 5 selects and outputs an output of the synthesis circuit or an output of the automatic gain control circuit.

The operation of the audio signal processing circuit of the television receiver according to the present invention configured as shown in FIG. 1 will be described. First, consider the case where the switching means 2 and the switching means 5 are connected on the lower side. At this time, the input signal is directly input to the automatic gain control circuit 3, and an output level corresponding to the level of the input signal as shown in FIG. 5 is obtained. As a result, the circuit works so as to suppress the loud sound to a small level, so that the level difference between the broadcasting stations of the television receiver or between the CM and the program can be suppressed. Then, this output is directly connected to the next circuit, and is reproduced as sound using a speaker or the like inside the television.

Next, consider a case where the switching means 2 and the switching means 5 are connected to the upper side. At this time, only a high frequency (for example, 2 KHz or more) is extracted by the high-pass filter 1 and the signal is input to the automatic gain control circuit 3. This is because the loss of hearing is noticeable at higher frequencies. Then, the automatic gain control circuit 3 obtains the output having the input / output characteristics shown in FIG. In other words, the circuit works by emphasizing the small sound of the high frequency and increasing the volume, and suppressing the volume of the large sound.
The sound is very easy to hear for elderly people with poor hearing. This is a recruitment phenomenon, that is, a small sound cannot be heard, but a loud sound has the same or worse discomfort as a normal hearing person. This is because a loud sound can be corrected by emphasizing it.

The output of the automatic gain control circuit 3 is combined with the input signal by the combining circuit 4 to obtain a sound in which the high frequency range is emphasized, and this output is directly connected to the next circuit. The sound is reproduced as sound using a speaker or the like inside the television.

If the input signal before synthesis contains a high-frequency component, so that the high frequency is emphasized too much, a low-pass filter may be inserted.

In the television receiver shown in FIG. 2, the remote controller 11 switches on / off the switch 2 or 5 of the audio signal processing circuit in addition to general functions such as channel switching of the television receiver. With the provision of the switch, the hearing aid circuit can be operated from a distance.

If the operation status is displayed on the screen during the operation, the correction circuit can be controlled while looking at the screen.

(Embodiment 2) An example of a second embodiment of the present invention will be described with reference to FIGS. 3, 4, 5, and 6. FIG.
FIG. 3 shows a configuration of an audio signal processing circuit of a television receiver according to the present invention, and FIG. 4 is a diagram showing an operation example of a television receiver using the audio signal processing circuit.
FIG. 5 is a diagram showing output characteristics of an input signal and an output signal of the automatic gain control circuit, and FIG. 6 is a waveform diagram of the configuration of the present embodiment.

The operation of the audio signal processing circuit of the television receiver configured as shown in FIG. 3 will be described. This circuit is realized using digital signal processing, and the input signal is an audio signal already converted into digital data.

First, a high frequency (for example, 2 KHz or more) is extracted by the high-pass filter 20. Next, in the multiplexing circuit 21, the output of the high-pass filter 20 and the input signal are time-division multiplexed. The multiplexing circuit 21 may be a general circuit in which the clock rate is doubled and arranged in order as shown in FIG. The output of the multiplexing circuit 21 is input to the automatic gain control circuit 23.

The automatic gain control circuit 23 can be realized by a table using a ROM, for example. That is, a value based on a table written in advance is output according to the level of the input signal. Here, the characteristics shown in FIG. 5 are set by digital data so as to function as an automatic gain control circuit.

The output of the automatic gain control circuit 22 is
3 and the original clock rate as shown in FIG.
Split into two signals. The synthesizing circuit 24 synthesizes the two signals output from the separating circuit 23, and can obtain a sound that is very audible to an elderly person whose hearing has declined.

In the case where the high frequency component is excessively emphasized because the input signal before synthesis contains a high frequency component, a circuit configuration may be adopted in which the signal is synthesized with a signal into which a low-pass filter is inserted. Good. Also, the automatic gain control circuit has no problem even if it is a variable amplifier circuit using an integration circuit for detection.

As described above, the output in which the automatic gain control circuit operates on all the band components is used for the purpose of suppressing the level difference between the television broadcasting stations or between the CM and the program, and the automatic gain control circuit operates on the high frequency component. The output can be used to make corrections for the elderly. Since these two outputs can be obtained at the same time, various usages are possible.

For example, if the output of the synthesizing circuit 23 can be output to the outside using an earphone terminal or the like, it is possible to reproduce the sound separately from the sound reproduced by the internal speaker. In addition, as shown in FIG. 4, if it is possible to output to an external receiver 33 by radio waves or infrared rays instead of terminals, it is possible to reproduce sound at the ear without having to worry about wiring. Become.

If the user can select which signal is to be reproduced by the speaker inside the television, it is possible to select a desired sound according to the situation.

If a switch is provided on the television remote controller as shown in FIG. 2, the correction circuit can be turned on and off from a place remote from the television.

In FIG. 4, a television 30 is a television receiver of the present invention, and usually has an internal speaker 31.
The sound is played from. Therefore, if the external terminal 32 is provided so that the output of the hearing aid circuit is output to the outside, the sound corrected separately from the sound of the normal television receiver is heard using an external speaker or headphones. It becomes possible. Further, if this external terminal is a wireless output device such as an FM or infrared ray and is received by the speaker 33 at hand, it is not necessary to worry about wiring. Further, the signal output from the internal speaker 31 can be switched between a normal signal and a corrected signal.

[0030]

As described above, according to the present invention, the conventional CM
The automatic gain control circuit, which was used to mitigate the audio level difference between the program and the program, is shared with a hearing aid circuit that emphasizes low-frequency sounds in the high frequency range and makes it easier to hear the audio. It is possible to provide a television receiver in which the sound can be easily heard without the elderly person who can hardly hear the small sound in the high frequency range without making the sound unnecessarily loud.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an audio signal processing circuit of a television receiver according to a first embodiment of the present invention.

FIG. 2 is a view showing the concept of the television receiver and a remote controller.

FIG. 3 is a block diagram showing a configuration of an audio signal processing circuit of a television receiver according to a second embodiment of the present invention;

FIG. 4 is an exemplary view showing the concept of an output method of the television receiver.

FIG. 5 is an input / output characteristic diagram of an automatic gain control circuit of the television receiver.

FIG. 6 is a waveform chart for explaining the operation of the television receiver.

[Explanation of symbols]

 1,20 high-pass filter 2,5 switching means 3,22 automatic gain control circuit 4,24 synthesizing circuit 5 switching means 10,30 television receiver 11 remote control transmitter 21 multiplexing circuit 23 separation circuit 31 internal speaker 32 output Terminal 33 Hand speaker

Claims (3)

[Claims] 1. A television receiver in which an automatic gain control circuit is used to reduce a difference in audio level between broadcast stations or between a CM and a program. A television receiver characterized by emphasizing a sound having a small volume and synthesizing the sound signal and outputting the synthesized signal. 2. A high-pass filter for inputting an audio output after detection output and extracting only a high-frequency portion, and a first for selecting an output of the high-pass filter and an audio output after the detection output.
Switching means, an automatic gain control circuit that receives the output of the first switching means and outputs the output according to a preset input / output characteristic, and inputs and synthesizes the output of the automatic gain control circuit and the audio output. A synthesis circuit for outputting
A television receiver comprising: a second switching unit that selects and outputs an output of the synthesis circuit and an output of the automatic gain control circuit. 3. A high-pass filter for inputting an audio output after detection output and extracting only a high-frequency portion, and a multiplexing circuit for time-division multiplexing the output of the high-pass filter and the audio output after detection output. An automatic gain control circuit that receives an output of the multiplexing circuit and outputs the output according to a preset input / output characteristic, a separation circuit that separates the output of the automatic gain control circuit into two outputs, And a synthesizing circuit for inputting and synthesizing a signal output from the television receiver.