KR20070113891A - Method and apparatus for controlling audio signal of image display device - Google Patents

Abstract

An apparatus and a method for adjusting an audio signal of an image display device are provided to detect the level of an audio signal received from an external appliance and compare the level of the detected audio signal with a reference level, thereby adjusting the level of the audio signal. An audio signal input module(100) inputs an audio signal from an external appliance. A controller determines an input source of the audio signal, compares the level of the audio signal with a previously stored reference level, and compensates for the audio signal according to the comparison result. A prescaler(130) compensates for the level of the audio signal input through the audio signal input module(100) according to the control signal of the controller. An audio signal output module(180) is used to provide an audio signal compensated through the prescaler(130) to the user.

Description

Method and apparatus for controlling audio signal of image display device

In order to better understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

1 is a block diagram illustrating an audio signal processing apparatus of a video display device according to the related art.

2 is a block diagram illustrating an audio signal adjusting apparatus of an image display device according to an exemplary embodiment of the present invention.

3 is a flowchart illustrating a step-by-step method of adjusting an audio signal of an image display device according to an exemplary embodiment of the present invention.

           <Explanation of symbols for the main parts of the drawings>

100: audio signal input unit

102 and 104: first and second input terminals 110 and 170: switching unit

120: A / D converter 130: prescaler

140: control unit 142: audio level detection unit

144: microcomputer 150: memory

160: RF signal input unit 162: tuner

164: RF signal processing unit 180: audio signal output unit

182: volume control 184: D / A converter

186: speaker 190: key input unit

192: IR transmitter 194: IR receiver

The present invention relates to an image display device, and more particularly, to an apparatus and method for adjusting an audio signal of an image display device for adjusting the size of an audio signal input through an external device.

Generally, a TV is included in a video display device, and such TV is tuned to a demodulated broadcast signal according to a channel selected by a user among broadcast signals transmitted from a broadcasting station, and separated into a voice and a video, and then processed through a corresponding voice and image processing. And a video device output through a speaker.

In recent years, as a video display device has been developed with the development of TV technology, a method of transmitting broadcast signals has been developed, and accordingly, interest in digital TVs using digital transmission methods has increased. Digital TVs transmit analog broadcast signals in digital form, minimizing the effects of noise and facilitating the reproduction of the original image.

Such an image display device has added additional functions as a way to enhance the convenience of the viewer. As one of such additional functions, the video display device is connected to various external devices through an external input / output terminal on the back thereof to enable the use of video and Internet information from an external device in addition to watching TV. The user can adjust the audio signal to be output at an appropriate level of volume desired by the user when viewing information from such an external audio / video device through a television.

However, the magnitude of an audio signal input from an external device to an external input / output terminal of an image display device is not constant. This is due to the specification of the external device, the degree of aging and the adjustment by the user. For this reason, the user had to adjust the size of the external audio signal to a desired volume when using information from an external device. These problems are also confirmed through conventional image display apparatuses having external input / output terminals.

1 is a block diagram illustrating an audio signal processing apparatus of a video display device according to the related art.

If the viewer is watching a broadcast input from the tuner 16, the viewer may designate the volume of the audio signal to be output through the key input unit 28. The microcomputer 12 receives the volume data input from the key input unit 28 and stores the volume data value in the storage unit 14. In addition, the microcomputer 12 assigns an adjustment amount (gain value) of the audio signal to the volume controller 22 based on the received volume data value of the key data type. The volume controller 22 increases or decreases the volume of the audio signal input from the RF signal processor 18 or the prescaler 10 according to the adjustment amount of the microcomputer. The audio signal adjusted from the volume controller 22 is converted into an analog audio signal output by the digital-to-analog converter (hereinafter referred to as "D / A converter") 24, and then the speaker 26 Is provided to the user.

The external audio signal supplied to the first or second input terminals 2 and 4 through an external device is switched 6 and an analog-to-digital converter (hereinafter referred to as an "AD converter") (8) Supply to the free scaler (10) via the. The prescaler 10 amplifies the audio data from the A-D converter 8 at a constant amplification rate. The audio data amplified by the prescaler 10 is transmitted to the user via the switching unit 20, the volume controller 22, the D-A converter 24, and the speaker 26.

The audio signal transmitted to the user through this path is not constant in size, so that the output is often too small or too large.

 Due to the change in the audio signal input through such an external device, not only can the user be surprised but also the user has to deal with the inconvenience of frequently adjusting the volume of the audio signal to be output. In addition, the audio circuit portion of the television may be damaged.

In addition, even if the volume is adjusted according to the size of the audio signal input through the external device, the output of the audio signal occurs due to the difference and the maker of the external device.

In this respect, the audio signal supplied to the video display device from the external device needs to be adjusted to have a constant size.

Accordingly, an object of the present invention is to provide an apparatus and method for adjusting an audio signal of an image display device that can automatically adjust the size of an audio signal input through an external device.

In order to achieve the above object, an audio signal adjusting apparatus of an image display device according to an embodiment of the present invention determines an audio signal input unit for inputting an audio signal from an external device, an input source of an input audio signal, and the corresponding audio signal. A control unit for outputting a control signal to compensate for an audio signal level according to a result of comparing the signal level with a previously stored reference level, and compensating the size of the audio signal input through the audio signal input unit according to the control signal of the control unit It comprises a prescaler for, and an audio signal output unit for providing a user with an audio signal compensated through the prescaler is characterized by.

Preferably, the control unit includes an audio level detector for detecting a level of an audio signal input from the audio signal input unit, a memory for storing a reference level value, a level value of the detected audio signal from the audio level detector, and the memory. And a microcomputer for outputting an adjustment signal to the prescaler by determining a gain value by comparing the reference level values stored in the control unit.

More preferably, the audio level detector detects a peak value for a predetermined time of the audio signal input through the audio signal input unit.

More preferably, the audio signal input unit includes an external device input terminal for inputting an audio signal from an external device, and a switching unit for selectively outputting audio signals input from the external device input terminal.

More preferably, it comprises a key input unit for inputting a user's command and a control unit for outputting a control signal so that the user can select a desired audio preference through the switching unit in response to the command from the key input unit. There is this.

More preferably, selectively outputting an RF signal input unit for inputting a high frequency signal received through an antenna (or a transmission line), an RF audio signal input from the RF signal input unit, and an audio signal input from the prescaler It is configured to include a switching unit for its features.

An audio signal adjusting method of an image display device according to an exemplary embodiment of the present invention includes determining an input source of an input audio signal, detecting a signal level of a corresponding audio signal when the determined input source is an external device, and detecting Compensating the signal level according to a comparison result of the audio signal level with a preset reference audio signal level; In addition, the method includes outputting a corresponding audio signal at the compensated signal level.

Preferably, the determining of the input source may include determining whether one of an audio signal received through an antenna, an audio signal received through an external device, and an audio signal previously stored in a storage medium.

More preferably, the step of detecting the audio signal level is a step of detecting a peak level value of an audio signal input through an external device as a result of the determination.

More preferably, the compensating of the audio signal level may include comparing the detected audio signal level value with a preset standard level value and adjusting the size of an audio signal input from the audio signal input unit. And determining whether the reference level values coincide with each other and if the audio data level value and the reference signal level value do not match and the audio data level value is larger than the reference level value, the audio input through the external device. Attenuating the magnitude of the signal and if the audio data level value and the reference level value do not match, and the level value of the audio data is smaller than the reference level value, increasing the size of the audio signal input through the external device. It is a stage and it is characterized.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 2 is a block diagram illustrating an audio signal adjusting apparatus of an image display device according to an exemplary embodiment of the present invention.

Referring to FIG. 2, when a user manipulates a key such as channel selection and volume adjustment using a remote controller or the like, the IR transmitter 192 transmits data on the manipulated key in the form of infrared ray (IR). . The IR receiver 194 receives the key data signal in the infrared form input from the IR transmitter 192 and restores the key data signal. The key data restored by the IR receiver 194 is transferred to the microcomputer 144. The microcomputer 144 analyzes the input key data and outputs a control signal to each unit.

The RF signal input unit 160 receives a television broadcast signal. The RF signal input unit 160 includes a tuner 162 and an RF signal processor 164. The tuner 162 extracts and outputs a high frequency signal existing in a bandwidth (channel) specified by a user among high frequency signals received through an antenna (or a transmission line). The RF signal processor 164 demodulates the tuned high frequency signal input from the tuner 162 and outputs demodulated audio data.

The audio signal input unit 100 inputs an audio signal from an external device. The audio signal input unit 100 includes first and second input terminals 102 and 104. The first input terminal 102 is a terminal for inputting an audio signal from an external device such as a PC, and the second input terminal 104 is a terminal for inputting an audio signal from an external audio / video device.

The switching unit 110 selectively outputs audio signals input from the audio signal input unit 100. That is, the user operates the key button by using the IR transmitter 192 used as the remote controller. The IR transmitter 192 converts the key data for the manipulated key button into an infrared form and transmits the key data to the IR receiver 194. The IR receiver 194 converts the input infrared key signal into key data and transmits the received key signal to the microcomputer 144. The microcomputer 144 analyzes key data input from the IR receiver 194 and outputs a selection signal so that the user can select a desired input port through the switching unit 110. The switching unit 110 selects and outputs an input port desired by a user from among the first and second input terminals according to the selection signal of the microcomputer 144.

An analog-to-digital converter (ADC) (hereinafter, referred to as an "A / D converter") 120 converts an analog audio signal input from the switching unit 110 into digital audio data.

The memory 150 detects a peak value input for a predetermined time of a standard audio signal 500mV when a professional manufactures the product, and stores the detected value. The memory 150 is a ROM that allows a user to modify contents in the memory. The memory 150 may be an EEPROM capable of repeatedly erasing or writing a program again using a voltage higher than normal. In addition, the memory 150 may be replaced with a ROM and a switch inside the microcomputer 144.

The controller 140 controls the operations of the sub-units in the digital television receiver, and also outputs a control signal for adjusting an audio signal input through an external device. The controller 140 includes an audio level detector 142 and a microcomputer 144. The audio level detector 142 detects the level of audio data input from the A / D converter 120. In other words, the audio level detector 142 detects a peak value of the audio signal level input for a predetermined time. The microcomputer 144 controls the prescaler 130 based on the audio level value input from the audio level detector 142 to maintain a constant size of audio data to be output from the prescaler 130. This determines the amount of scaling of the audio data.

That is, the microcomputer 144 compares the level value of the audio data input from the audio level detector 142 with the reference level value stored in the memory 150. The microcomputer 144 determines how much the audio data inputted from the A / D converter 120 through the prescaler 130 is to be increased or decreased, that is, the amount of adjustment according to the comparison result. In other words, when the level value of the audio data is lower than the reference level value as a result of the comparison, an adjustment amount of the audio data size is output to amplify the audio data input from the A / D converter 120 by a certain amount, and the audio If the level value of the data and the level value of the reference signal do not match, and the level value of the audio data is larger than the reference level value, an adjustment amount is output to attenuate the audio data input from the A / D converter 120 by how much. . Unlike the method of directly controlling the gain of the prescaler 130, the microcomputer 144 may control the gain of the prescaler 130 via a writeable ROM (eg, an EEPROM). Can be. In this case, the microcomputer 144 may obtain an advantage of reducing the program load.

The prescaler 130 amplifies or attenuates audio data input from the A / D converter 120 according to the adjustment amount of the microcomputer 144. That is, the prescaler 130 increases / decreases the level value of the audio data by a gain ratio equal to the difference between the level value of the audio data and the reference level value according to the adjustment amount of the microcomputer 144.

The switching unit 170 selectively outputs audio data input from the prescaler 130 and audio data input from the RF signal input unit 160. That is, the user manipulates a key button for selecting an audio signal using the IR transmitter 192 used as a remote controller. The IR transmitter 192 converts the key data for the manipulated key button into an infrared form, and then transmits the infrared data to the IR receiver 194. The IR receiver 194 restores the input infrared key data signal to key data, and then transfers the restored key data to the microcomputer 144. The microcomputer 144 analyzes key data input from the IR receiver 194 and outputs a selection signal so that a user can select desired audio data through the switching unit 170. The switching unit 170 selects and outputs audio data desired by a user among audio data input from the prescaler 130 and the RF signal input unit 160 according to the selection signal of the microcomputer 144.

The audio signal output unit 180 is a device for providing an audio signal input from the switching unit 170 to a user. The audio signal output unit 180 includes a volume controller 182, a digital-to-analog converter 184, and a speaker 186. The volume controller 182 adjusts the volume of audio data input from the switching unit 170. That is, when the user inputs the desired volume data by using the key input unit 190, the key input unit 190 transmits the received volume data to the microcomputer 144. The microcomputer 144 analyzes the volume data input from the key input unit 190 and outputs an adjustment signal to adjust the volume of the audio data to a volume value desired by the user. The volume controller 182 adjusts the volume of audio data input from the switching unit 170 according to the adjustment signal of the microcomputer 144.

A digital analog converter (DAC) 184 converts the audio data input from the volume controller 182 into an outputable analog audio signal. The speaker 186 provides an analog audio signal input from the D / A converter 184 to the user.

As described above, if the audio signal level value input from the external device is compared with the reference level value stored in the memory 150 and the two values do not match, the level value of the input audio signal is adjusted by the difference of the reference level value. Determine the amount.

3 is a flowchart illustrating a step-by-step method of adjusting an audio signal of an image display device according to an exemplary embodiment of the present invention. For convenience, FIG. 3 will be described in detail in conjunction with FIG. 2.

The audio level detector 142 detects the level value of the audio data input from the A / D converter 120 at predetermined intervals and transfers the detected level value of the audio data to the microcomputer 144. The microcomputer 144 analyzes the detection value of the audio data input through the audio level detector 142 and checks for the existence of an audio signal input through an external device (step S210). After performing step S210, when the detected audio data value is less than 0-5 mV, it is determined that there is no audio signal input through an external device. If there is no audio signal input through the external device, the microcomputer 144 outputs a selection signal to select the audio data input from the RF signal input unit 160 through the switching unit 170 (S220). step).

In addition, after performing step S210, when the detected audio data value is “5 mV or more”, the microcomputer 144 determines that an audio signal input through an external device exists. If there is an audio signal input through the external device, the microcomputer 144 outputs a selection signal to select the audio signal input from the audio signal input unit 100 through the switching unit 110 (step S230). ). The analog audio signal input from the switching unit 110 is converted into digital audio data through the A / D converter 120. The audio level detector 142 detects a level value of audio data input from the A / D converter 120 (step S240).

After performing step S240, the audio level detector 142 transmits the detected level value of the audio data to the microcomputer 144. The microcomputer 144 compares the audio data level value input from the audio level detector 142 with the reference level value stored in the memory 150 (operation S250). In addition, the microcomputer 144 checks whether the two values match (step S260).

After performing step S230, if the two values do not match, the microcomputer 144 outputs an adjustment signal by the difference between the two values. That is, when the level value of the audio data is lower than the reference level value, an adjustment amount is output to amplify the audio data input from the A / D converter 120 to some extent, and when the level value of the audio data is higher than the reference level value, The amount of adjustment is output to attenuate the audio data input from the A / D converter 120 by how much. The prescaler 130 increases / decreases the size of the audio data input from the A / D converter 120 according to the adjustment amount of the microcomputer 144 (step S270).

After performing step S220, when the two values coincide in step S260 and after performing step S270, the audio data input to the user is provided to the user through the audio signal output unit 180 (step S280).

As described above, the present invention detects a level of an audio signal input through an external device, compares the detected audio level value with a reference level value, and determines an adjustment amount of the audio signal by a difference between the two values. Increase / decrease

As a result, even if the audio signal level input through the external device is different, the same audio size can be output, thereby preventing consumer claims due to sudden changes in the audio signal, it is possible to reduce the damage of the audio amplifier and speakers.

In addition, even if the user does not adjust the volume according to the change of the audio signal, which is cumbersome, the audio signal can be automatically adjusted according to a preset condition, thereby providing convenience to the user and providing more accurate audio output. Therefore, the user can be satisfied.

Claims (10)

An audio signal input unit for inputting an audio signal from an external device; A controller for determining an input source of an input audio signal and outputting a control signal to compensate for the audio signal level according to a result of comparing the signal level of the corresponding audio signal with a previously stored reference level; A prescaler for compensating the magnitude of an audio signal input through the audio signal input unit according to a control signal of the controller; And, And an audio signal output unit for providing a user with an audio signal compensated through the prescaler. The method of claim 1, The controller may include an audio level detector for detecting a level of an audio signal input from the audio signal input unit. A memory for storing a reference level value; And, An image including a microcomputer for outputting an adjustment signal to the prescaler by comparing a level value of the audio signal detected by the audio level detector with a reference level stored in the memory to determine a gain value by the difference between the two values Audio signal adjusting device of the display device. The method of claim 2, And the audio level detector detects a peak value for a predetermined time of an audio signal input through the audio signal input unit. The method of claim 1, The audio signal input unit may include an external device input terminal for inputting an audio signal from an external device; And And a switching unit for selectively outputting audio signals input from the external device input terminal. The method of claim 4, wherein A key input unit for inputting a user command; And And a control unit for outputting a control signal in response to a command from the key input unit, so that a user can select a desired audio preference through the switching unit. The method of claim 1, An RF signal input unit for inputting a high frequency signal received through an antenna (or a transmission line); And a switching unit for selectively outputting an RF audio signal input from the RF signal input unit and an audio signal input from the prescaler. Determining an input source of an input audio signal; Detecting a signal level of a corresponding audio signal when the determined input source is an external device; Compensating the signal level according to a result of comparing the detected audio signal level with a preset reference audio signal level; And, And outputting a corresponding audio signal at the compensated signal level. The method of claim 7, wherein Determining the input source is And determining one of an audio signal received through an antenna, an audio signal received through an external device, and an audio signal pre-stored in a storage medium. The method of claim 7, wherein Detecting the audio signal level Detecting the peak level of the audio signal input through the external device as a result of the determination. The method of claim 7, wherein Compensating the audio signal level The step of adjusting the size of the audio signal input from the audio signal input unit by comparing the detected audio signal level value with a preset standard level value determines whether the detected audio level value and the reference level value match. Wow, Attenuating the magnitude of the audio signal input through the external device if the audio data level value and the reference signal level value do not match and the audio data level value is larger than the reference level value; And if the audio data level value and the reference level value do not match and the level value of the audio data is smaller than the reference level value, increasing the size of the audio signal input through the external device. Adjusting the audio signal of a video display device.

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