Patent Publication Number: US-2005141725-A1

Title: Apparatus for correcting sound for video display appliance and method thereof

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to a video display appliance, and more particularly to an apparatus for correcting sound for a video display appliance and a method thereof that performs a sound correction according to the characteristics of sound fed back from the video display appliance.  
      2. Description of the Related Art  
      Generally, video display appliances are installed in diverse environments, and thus their sound characteristics may diversely be changed accordingly. That is, even if the sound characteristic of a video display appliance was well set when the video display appliance was designed, it may be changed in accordance with the change of its use environment or installation condition.  
       FIG. 1  is a block diagram illustrating the construction of a conventional video display appliance, and  FIG. 2  is a flowchart illustrating a sound correcting method for the conventional video display appliance.  
      The conventional video display appliance, as illustrated in  FIG. 1 , includes a tuner  11  for selecting a broadcasting signal received through an antenna, a DeMUX (Demultiplexer)  12  for separating the broadcasting signal received through the tuner  11  into video signal, audio signal and additional information, a video signal processing unit  13  for receiving and processing the video signal separated through the DeMUX  12  to display the processed video signal through a display unit  14 , an audio signal processing unit  15  for receiving and processing the audio signal separated through the DeMUX  12  to output the processed audio signal through a speaker  16 , a key input unit  17  for inputting a user&#39;s command, a memory  18  for storing various kinds of operation-related menus, and a control unit  19  for outputting a control  9  signal according to the user&#39;s command input through the key input unit  17 .  
      According to the conventional video display appliance as constructed above, if a user selects a desired channel through the tuner  11  after the user inputs a ‘power-on’ command through the key input unit  17 , a broadcasting signal received through the channel selected by the user is input to the DeMUX  12  and separated into video signal, audio signal and additional information through the DeMUX  12 .  
      The video signal separated through the DeMUX  12  is processed by the video signal processing unit  13 , and then displayed through the display unit  14 . Meanwhile, the audio signal separated through the DeMUX  12  is processed by the audio signal processing unit  15 , and then output through the speaker  16  as sound.  
      The sound correcting method for the conventional video display appliance will be explained with reference to  FIG. 2 .  
      If the user inputs the ‘power-on’ command, the received broadcasting signal is separated into the video signal, audio signal and additional information, and the video signal and the audio signal are processed and output as image and sound, respectively (steps S 11  and S 12 ).  
      In this state, if the user desires the change of sound volume, the user may change the sound volume on a sound volume change menu (steps S 13  and S 14 ).  
      If a ‘power-off’ command is input in this state, the operation of the video display appliance is terminated (step S 15 ).  
      The conventional video display appliance as described above, however, is not provided with any function for automatically performing a proper sound correction with respect to the sound characteristic that is changed according to the installation environment of the video display appliance. Accordingly, the sound is reproduced in a state that the sound characteristic set when the video display appliance was designed is maintained as it is, and this may cause the sound of a specified band to be improperly amplified and output through the speaker  16  according to the installation environment of the video display appliance. The sound output as above is liable to have distorted band characteristics, and this may cause the user to feel awkward in listening to the sound or to be displeased with the sound.  
      In this case, the user may display a menu for correcting the sound characteristic on the display screen through the key input unit  17 , and adjust the sound characteristic to a desired state though the menu. However, it is difficult and inconvenient for the user to do such adjustment.  
      The distortion of the sound characteristic as described above mostly occurs in the band of bass. The smaller the installation space of the video display appliance is and the more reflecting objects exist around the video display appliance, the greater the bass is amplified. This causes an output human voice to be unclear, and the clarity of sound deteriorates.  
      If the user reduces the sound volume to overcome the above-described problem, this merely causes the reduction of the whole sound strength, but the problems caused by the excessively amplified bass sound is not solved.  
      Because the user cannot accurately know how to adjust in order to solve the problems caused by the excessively amplified bass sound, it is still difficult for the user to listen to the output sound the characteristic of which is properly set.  
     SUMMARY OF THE INVENTION  
      The present invention is directed to an apparatus for correcting sound for a video display appliance and a method thereof that substantially obviate one or more problems due to limitations and disadvantages of the related art.  
      It is an object of the present invention to provide an apparatus for correcting sound for a video display appliance and a method thereof that senses the change of the sound characteristics of the video display appliance and performs an automatic sound correction according to the change of the sound characteristics.  
      To achieve this and other objects and advantages in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an apparatus for correcting sound for a video display appliance having a tuner for selecting a broadcasting signal, a demultiplexer for separating the received broadcasting signal into video and audio signals and a speaker for outputting the sound, which comprises a key input unit for inputting a user&#39;s command, a sound sensing unit for sensing bass/middle/treble ranges of sound output through the speaker if a ‘power-on’ command is input through the key input unit, a memory for storing reference sound levels of the bass/middle/treble ranges of the sound preset according to installation environment characteristics of the video display appliance, and a control unit for comparing the sound levels of the bass/middle/treble ranges of the sound sensed through the sound sensing unit with the reference sound levels of the bass/middle/treble ranges of the sound, correcting sound characteristics according to a result of comparison, and feeding the corrected sound characteristics back to the audio signal processing unit.  
      Preferably, the sound sensing unit comprises a microphone.  
      Preferably, the sound sensing unit is installed on a specified position of a front of the video display appliance.  
      Preferably, the sound sensing unit measures the sound levels of the bass/middle/treble ranges of the sound that are output through the speaker, reflected according to the installation environment characteristics of the video display appliance, and then input to the sound sensing unit.  
      Preferably, the control unit calculates a sound difference value between the sensed sound levels of the middle/bass ranges, and if the calculated sound difference value is not equal to a preset reference value, corrects the sound characteristics of the middle/bass ranges so that the sound difference value becomes equal to the preset reference value. Additionally, the control unit calculates a sound difference value between the sensed sound levels of the middle/treble ranges, and if the calculated sound difference value is not equal to a preset reference value, corrects the sound characteristics of the middle/treble ranges so that the sound difference value becomes equal to the preset reference value.  
      In another aspect of the present invention, there is provided an apparatus for correcting sound for a video display appliance having a speaker for outputting the sound, which comprises a memory for storing reference values of sound differences between sound levels of middle/bass ranges of the sound and reference values of sound differences between sound levels of middle/treble ranges of the sound among the sound levels of the bass/middle/treble ranges of the sound preset according to installation environment characteristics of the video display appliance, a sound sensing unit for sensing bass/middle/treble ranges of the sound output through the speaker, and a control unit for calculating a sound difference value between the sound levels of the middle/bass ranges among the sound levels of the bass/middle/treble ranges of the sound sensed through the sound sensing unit, and if the calculated sound difference value is not equal to the preset reference value of the sound difference between the sound levels of the middle/bass ranges of the sound, correcting the sound characteristics of the middle/bass ranges so that the sound difference value between the sound levels of the middle/bass ranges becomes equal to the preset reference value, the control unit further calculating a sound difference value between the sound levels of the middle/treble ranges among the sound levels of the bass/middle/treble ranges of the sound, and if the calculated sound difference value is not equal to the preset reference value of the sound difference between the sound levels of the middle/treble ranges of the sound, correcting the sound characteristics of the middle/treble ranges so that the sound difference value between the sound levels of the middle/treble ranges becomes equal to the preset reference value.  
      Preferably, the sound sensing unit comprises a microphone.  
      Preferably, the sound sensing unit is installed on a specified position of a front of the video display appliance.  
      Preferably, the sound sensing unit measures the sound levels of the bass/middle/treble ranges of the sound that are output through the speaker, reflected according to the installation environment characteristics of the video display appliance, and then input to the sound sensing unit.  
      In still another aspect of the present invention, there is provided a method for correcting sound for a video display appliance having a tuner for selecting a broadcasting signal, a demultiplexer for separating the received broadcasting signal into video and audio signals and a speaker for outputting the sound, which comprises the steps of reproducing and outputting through the speaker bass/middle/treble range of the audio signal separated through the demultiplexer if a user inputs a ‘power-on’ command, sensing the bass/middle/treble ranges of the sound output through the speaker, and comparing sound levels of the sensed bass/middle/treble ranges of the sound with reference sound levels of the bass/middle/treble ranges of the sound stored in a memory and correcting sound characteristics of the output sound according to a result of comparison.  
      Preferably, the sound sensing step senses the sound input through a microphone.  
      Preferably, the microphone is installed on a specified position of a front of the video display appliance.  
      Preferably, the sound sensing step measures the sound levels of the bass/middle/treble ranges of the sound that are output through the speaker, reflected according to the installation environment characteristics of the video display appliance, and then input to the sound sensing unit.  
      Preferably, the step of correcting the sound characteristics comprises the sub-steps of calculating a sound difference value between the sensed sound levels of the middle/bass ranges, if the calculated sound difference value is not equal to a preset reference value, correcting the sound characteristics of the middle/bass ranges so that the sound difference value becomes equal to the preset reference value, calculating a sound difference value between the sensed sound levels of the middle/treble ranges, and if the calculated sound difference value is not equal to a preset reference value, correcting the sound characteristics of the middle/treble ranges so that the sound difference value becomes equal to the preset reference value. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
       FIG. 1  is a block diagram illustrating the construction of a conventional video display appliance;  
       FIG. 2  is a flowchart illustrating a sound correcting method for the conventional video display appliance;  
       FIG. 3  is a block diagram illustrating the construction of a sound correcting apparatus for a video display appliance according to the present invention; and  
       FIG. 4  is a flowchart illustrating a sound correcting method for a video display appliance according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Reference will now be made in detail to the preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts.  
       FIG. 3  is a block diagram illustrating the construction of a sound correcting apparatus for a video display appliance according to the present invention, and  FIG. 4  is a flowchart illustrating a sound correcting method for a video display appliance according to the present invention.  
      The sound correcting apparatus for a video display appliance, as illustrated in  FIG. 3 , includes a tuner  11  for selecting a channel broadcasting signal desired by a user among broadcasting signals received through an antenna, a DeMUX  12  for separating the channel broadcasting signal selected through the tuner  11  into video signal, audio signal and additional information, a video signal processing unit  13  for receiving and processing the video signal input from the DeMUX  12  to display the processed video signal through a display unit  14 , a key input unit  17  for inputting a user&#39;s command, an audio signal processing unit  104  for receiving and processing the audio signal input from the DeMUX  12  to output the processed audio signal through a speaker  16 , a sound sensing unit  101  for sensing bass/middle/treble ranges of the sound output through the speaker and then reflected according to installation environment characteristics of the video display appliance, a memory  103  for storing reference sound levels of the bass/middle/treble ranges of the sound preset according to the installation environment characteristics of the video display appliance, and a control unit  102  for outputting a control signal according to the user&#39;s command input through the key input unit  17 , comparing the sound levels of the bass/middle/treble ranges of the sound sensed through the sound sensing unit  101  with the reference sound levels of the bass/middle/treble ranges of the sound stored in the memory  103 , and correcting sound characteristics of the output sound according to a result of comparison to feed the corrected sound characteristics back to the audio signal processing unit  104 .  
      Here, the sound sensing unit  101  comprises a microphone, and is installed on a specified position of a front of the video display appliance.  
      The operation of the sound correcting apparatus for a video display appliance as constructed above will now be explained.  
      If the user selects a desired channel through the tuner  11  after the user inputs a ‘power-on’ command through the key input unit  17 , a broadcasting signal received through the channel selected by the user is input to the DeMUX  12 . The broadcasting signal input to the DeMUX  12  is separated into video signal, audio signal and additional information.  
      The video signal separated through the DeMUX  12  is processed by the video signal processing unit  13 , and then displayed through the display unit  14 . Meanwhile, the audio signal separated through the DeMUX  12  is processed by the audio signal processing unit  104 , and then output through the speaker  16  as sound.  
      The sound output through the speaker is sensed through the sound sensing unit  101 , and the sound characteristics of the sensed sound are measured. The measured sound characteristics are input to the control unit  102 , and compared with the reference sound characteristic levels pre-stored in the memory  103  to correct the sound characteristics.  
      Accordingly, even if the user does not directly correct the sound characteristics, the sound is reproduced to most suitably meet the installation environment characteristics of the video display appliance.  
      Hereinafter, the sound correcting method for a video display appliance according to the present invention will be explained with reference to  FIG. 4 .  
      If the user inputs the ‘power-on’ command, the bass/middle/treble ranges of the sound are processed through the audio signal processing unit  104 , and then output to the speaker  16  (steps S 101 -S 102 ).  
      The bass/middle/treble ranges of the sound, which are output through the speaker and reflected according to the installation environment characteristics of the video display appliance, are sensed by the sound sensing unit  101  (step S 103 ).  
      Then, a first calculated value that is a sound difference value between the sensed sound levels of the middle/bass ranges is calculated (step S 104 ), and then it is judged whether the first calculated value is equal to a first preset reference value (step S 105 ).  
      If the first calculated value is not equal to the first reference value as a result of judgment at step S 105 , the sound characteristics of the middle/bass ranges are corrected so that the sound difference value becomes equal to the first reference value (step S 106 ).  
      Additionally, a second calculated value that is a sound difference value between the sensed sound levels of the middle/treble ranges is calculated (step S 107 ).  
      Then, it is judged whether the second calculated value is equal to a second preset reference value (step S 108 ).  
      If the second calculated value is not equal to the second reference value as a result of judgment at step S 108 , the sound characteristics of the middle/treble ranges are corrected so that the sound difference value becomes equal to the second reference value (step S 109 ).  
      As described above, according to the sound correcting apparatus and method for a video display appliance according to the present invention, the sound characteristics of the output sound that match the sound balance suitable for the human ears are measured through the sound sensing unit  101  installed on the front of the video display appliance, and stored in the memory  103  as the reference values of the bass/middle/treble ranges of the sound.  
      The bass/middle/treble ranges of the sound that are output from the speaker and then reflected by the reflecting objects existing around the video display appliance are sensed by the sound sensing unit  101 , and then compared with the reference values stored in the memory  103 , and the bass/middle/treble ranges of the sound are automatically corrected according to the result of comparison.  
      Accordingly, the sound correcting apparatus and method for a video display appliance according to the present invention has the following effects.  
      First, because the sound output through the speaker of the video display appliance is automatically corrected in accordance with the change of the sound characteristics of the reflected sound in the installation space of the video display appliance, the sound can be reproduced under the condition of the optimum sound characteristic without the necessity of the user&#39;s manual correction work.  
      Second, because the sound is reproduced under the optimum sound characteristic, the clarity of the sound can be maintained.  
      Third, by preventing the bass sound from being excessively amplified, the howling of the sound caused by the excessively amplified bass sound in the installation space can be prevented in advance.  
      The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to bc illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.