Patent Publication Number: US-2012039489-A1

Title: Volume control method and electronic device capable of automatic volume adjustment

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese Applications No. 099126745, filed on Aug. 11, 2010 and No. 100124239, filed on Jul. 8, 2011. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a control method, more particularly to a volume control method for adjusting volume of an electronic device. 
     2. Description of the Related Art 
     A television is currently an essential home appliance in modern life. However, when people are watching television, they often find that volume of the television is too loud or too small resulting from surrounding environment factors, for example: a mobile phone ringtone, such that they have to adjust the volume of the television manually. Nevertheless, they may miss important program content when adjusting the volume of the television. 
     Therefore, in order to overcome the aforementioned issue, a conventional volume adjustment technology may configure a television to automatically adjust volume of sound outputted thereby according to sound of its surrounding environment. However, according to the conventional volume adjustment technology, once the sound is determined as not outputted from the television, the sound is presumed to be noise from surrounding environment. Accordingly, when a user&#39;s mobile phone rings, the television may be configured to falsely determine the mobile phone ringtone to be noise and increase the volume of sound outputted thereby, such that the user has to manually decrease the volume of the television and that the user is disturbed from watching television. Furthermore, the conventional volume adjustment technology blindly configures the television to increase the volume of the television so as to mask noise from surrounding environment. Therefore, when audio signal in the surrounding environment is too strong, the television outputs higher sound volume correspondingly such that hearing of the user is damaged unconsciously. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide a volume control method capable of adjusting volume of an electronic device according to an external audio signal of an environment in which the electronic device is located. 
     Accordingly, the volume control method of the invention is to be performed by an electronic device for adjusting intensity of an output audio signal outputted from the electronic device according to an external audio signal of an environment in which the electronic device is located. The volume control method comprises: 
     (A) configuring the electronic device to receive the external audio signal; 
     (B) configuring the electronic device to compare a sound track of the external audio signal with a preset sound track and to make a first determination as to whether a degree of similarity between the two sound tracks reaches a preset ratio, the preset sound track being preferably a sound track of a ringtone of a user&#39;s mobile phone so as to determine whether the external audio signal of the environment in which the electronic device is located is the ringtone of the user&#39;s mobile phone; and 
     (C) configuring the electronic device to stop outputting the output audio signal when a result of the first determination is affirmative, i.e., the external audio signal is the ringtone of the user&#39;s mobile phone. 
     Preferably, the volume control method further comprises: 
     (D) configuring the electronic device to receive the external audio signal during a pause time of the output audio signal outputted from the electronic device when the result of the first determination is negative, i.e., the external audio signal is noise; and 
     (E) configuring the electronic device to adjust the intensity of the output audio signal according to the external audio signal received during the pause time such that the intensity of the output audio signal is higher than intensity of the external audio signal. 
     Moreover, the volume control method further comprises step (F) to be performed after step (C): 
     (F) configuring the electronic device to make a second determination as to whether a mute canceling command is received, 
     wherein step (A) is performed and the electronic device proceeds to output the output audio signal when a result of the second determination is affirmative, and 
     wherein step (C) is performed when the result of the second determination is negative. 
     Preferably, step (E) includes: 
     (E.1) configuring the electronic device to set a target intensity of the output audio signal higher than the intensity of the external audio signal with reference to an audio intensity look-up table; 
     (E.2) configuring the electronic device to adjust the intensity of the output audio signal according to the target intensity thereof; and 
     (E.3) configuring the electronic device to make a third determination as to whether the intensity of the output audio signal has reached the target intensity thereof, wherein steps (E.2) and (E.3) are repeated until a result of the third determination is affirmative. 
     Preferably, the volume control method further comprises steps (G) and (H) to be performed before step (A): 
     (G) configuring the electronic device to receive the external audio signal; and 
     (H) configuring the electronic device to adjust the intensity of the output audio signal according to the received external audio signal such that the intensity of the output audio signal is higher than intensity of the external audio signal. 
     Further, step (H) includes: 
     (H.1) configuring the electronic device to set a target intensity of the output audio signal higher than the intensity of the external audio signal with reference to an audio intensity look-up table; 
     (H.2) configuring the electronic device to adjust the intensity of the output audio signal according to the target intensity thereof; and 
     (H.3) configuring the electronic device to make a fourth determination as to whether the intensity of the output audio signal has reached the target intensity thereof, wherein step (A) is performed when a result of the fourth determination is affirmative, and wherein steps (H.2) and (H.3) are repeated when the result of the fourth determination is negative. 
     Another object of the present invention is to provide an electronic device capable of automatic volume adjustment and capable of performing the aforementioned volume control method. 
     Accordingly, the electronic device capable of automatic volume adjustment of the invention, comprises a memory unit, an audio output unit, an audio receiver unit, a control unit and a sound track comparison unit. 
     The memory unit is for storing a preset sound track. The audio output unit is for outputting an output audio signal. The audio receiver unit is for receiving an external audio signal of an environment in which the electronic device is located. The control unit is coupled to the memory unit, the audio output unit and the audio receiver unit. The soundtrack comparison unit is coupled to the control unit. The sound track comparison unit compares a sound track of the external audio signal with the preset sound track so as to determine whether a degree of similarity between the two sound tracks reaches a preset ratio. The control unit is configured to control the audio output unit to stop outputting the output audio signal when a result of determination made by the sound track comparison unit is affirmative. 
     An effect of the invention resides in that the electronic device is configured to receive the external audio signal of the environment in which the electronic device is located, to determine whether the external audio signal is a noise or a preset ringtone of a user&#39;s mobile phone, and to perform volume control correspondingly, so as to facilitate convenience in use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
         FIG. 1  is a flow chart illustrating a preferred embodiment of the volume control method according to an embodiment of the invention, in which processing procedures of an initial mode are shown in this flow chart; 
         FIG. 2  is a flow chart illustrating the preferred embodiment of the volume control method according to an embodiment of the invention, in which processing procedures of a working mode are shown in this flowchart; 
         FIG. 3  is a block diagram of an electronic device for performing the preferred embodiment of the volume control method; and 
         FIG. 4  is an audio intensity look-up table illustrating a relation between intensity of an external audio signal and intensity of an output audio signal outputted from the electronic device. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1  and  FIG. 2 , a preferred embodiment of a volume control method according to an embodiment of the invention is illustrated. The volume control method is to be performed by an electronic device  100  (as illustrated in  FIG. 3 ) for causing the electronic device  100  to adjust volume of sound outputted thereby, such that when external sound of an environment in which the electronic device  100  is located varies (for example, from a noisier daytime to a quieter nighttime), the electronic device  100  is capable of varying the volume of sound outputted thereby automatically such that users may listen to the sound with appropriate volume. In this embodiment, a television is given as an example of the electronic device  100 , but the electronic device  100  should not be limited thereto. 
     Referring to  FIG. 3 , the electronic device  100  comprises a memory unit  10 , an audio receiver unit  20 , a command receiver unit  30 , a control unit  40 , a sound track comparison unit  50 , an audio output unit  60  and a displayer unit  70 . 
     The memory unit  10  is for storing a preset soundtrack, and an audio intensity look-up table such as that shown in  FIG. 4 . In this embodiment, the preset sound track is a sound track of a mobile phone ringtone stored by a user in advance. The audio receiver unit  20  is a microphone for receiving an external audio signal of an environment in which the electronic device  100  is located. The command receiver unit  30  is for receiving a control command sent from peripheral equipment (not shown), such as a remote controller, operated by the user, for example, activate/cancel mute. The sound track comparison unit  50  is for comparing a sound track of the external audio signal received at the audio receiver unit  20  with the preset sound track stored in the memory unit  10 . The audio output unit  60  includes a speaker which is for outputting an output audio signal and is composed of other electronic components such as an audio decoder and a digital-to-analog converter (DAC). Since the feature of the invention does not reside in the detailed configuration of the audio output unit  60 , further details of the same are omitted herein for the sake of brevity. The displayer unit  70  is a liquid crystal displayer. The control unit  40  is coupled to the memory unit  10 , the audio receiver unit  20 , the command receiver unit  30 , the sound track comparison unit  50 , the audio output unit  60  and the displayer unit  70  for controlling operation of each component. 
     The following description explains how the electronic device  100  controls volume of sound outputted thereby according to external sound. Specifically, the electronic device  100  of the invention is operable in an initial mode ( FIG. 1 ) in which the electronic device  100  is just turned on, a mute mode in which no sound is outputted, and a working mode ( FIG. 2 ). 
     Referring to step S 10  in  FIG. 1 , the electronic device  100  is configured to operate in the initial mode when just turned on, and the control unit  40  is configured to make a first determination, with reference to a volume parameter recorded before the electronic device  100  was turned off, as to whether the electronic device  100  was configured to operate in the mute mode at the time the electronic device  100  was turned off. The control unit  40  is configured to stay in the mute mode (i.e., steps S 20  and S 30  are performed) when a result of the first determination is affirmative. Otherwise, step  40  is performed when the result of the first determination is negative. 
     In this embodiment, operation of the electronic device  100  in the mute mode is illustrated in steps S 20  and S 30 . In step S 20 , the control unit  40  is configured to control the audio output unit  60  to stop outputting the output audio signal, and simultaneously control the displayer unit  70  to display subtitles corresponding to current output images and characters of ‘mute’. 
     In step  30 , the control unit  40  is configured to make a second determination as to whether the command receiver unit  30  has received a mute canceling command. Step S 40  is performed when a result of the second determination is affirmative. Otherwise, steps S 20  and S 30  are repeated when the result of the second determination is negative. In this embodiment, when the command receiver unit  30  has received the mute cancelling command transmitted as a result of operation of the remote controller or pushing of a mute button (not shown) of the electronic device  100  by the user, the command receiver unit  30  is configured to send a control signal to the control unit  40  such that the control unit  40  is configured to in turn detect the external audio signal of the environment according to the control signal. 
     Specifically, in this embodiment, if the electronic device  100  had been operated in the mute mode at the time the electronic device  100  was turned off, the electronic device  100  is still configured to stay in the mute mode (step S 20 ) until the user cancels mute operation manually (step S 30 ) when the electronic device  100  is turned on anew. In other configurations of the invention, steps S 10  to S 30  are omitted and the control unit  40  is configured to perform step S 40  directly when the electronic device  100  is turned on, regardless of whether the electronic device  100  had been configured to operate in the mute mode or not before being turned off. 
     In step S 40 , the control unit  40  is configured to control the audio receiver unit  20  to receive the external audio signal of the environment in which the electronic device  100  is located, and to perform step S 50  thereafter. In step S 50 , the control unit  40  is configured to adjust intensity of the output audio signal outputted at the audio output unit  60  with reference to the audio intensity look-up table (see  FIG. 4 ) stored in the memory unit  10 . 
     Referring to  FIG. 4 , an abscissa of the audio intensity look-up table represents volume values associated with the intensity of the output audio signal. The volume values correspond to a volume bar (usually from 0 to 100) displayed on the displayer unit  70 . An ordinate of the audio intensity look-up table represents audio signal intensity measured in Decibel (dB). A curve L 1  of the audio intensity look-up table is a curve representing the intensity of the output audio signal which shall be outputted at the audio output unit  60 . A curve L 2  of the audio intensity look-up table is a curve representing intensity of the external audio signal received at the audio receiver unit  20 . In this embodiment, for ensuring that the user may still listen to the sound outputted from the electronic device  100  in a noisy environment, the intensity of the output audio signal outputted at the audio output unit  60  is required to be higher than the intensity of the external audio signal by a predefined intensity (in this embodiment, 3 dB). In other words, the curve L 1  is the curve L 2  shifted 3 dB upwardly. For example, when the intensity of the external audio signal is 70 dB, the intensity of the output audio signal outputted at the audio output unit  60  is 73 dB and the volume value corresponding to the volume bar displayed on the displayer unit  70  is 98. 
     Furthermore, step S 50  includes the following sub-steps: 
     In step S 51 , the control unit  40  is configured to set a target intensity of the output audio signal which is 3 dB higher than the intensity of the external audio signal with reference to an audio intensity look-up table. For example, if the intensity of the external audio signal is 60 dB, the target intensity is 63 dB. 
     In step S 52 , the control unit  40  is configured to adjust the intensity of the output audio signal outputted at the audio output unit  60  according to the target intensity thereof. Specifically, the intensity of the output audio signal outputted at the audio output unit  60  is increased from an initial intensity, and the displayer unit  70  is simultaneously configured to display the volume bar which has a length gradually increasing with rise of the intensity of the output audio signal. In this embodiment, the initial intensity is 30 dB and the volume value corresponding to the volume bar displayed on the displayer unit  70  is 10, such that the audio output unit  60  may be prevented from outputting excessive volume and reducing service life thereof when the electronic device  100  is just turned on. 
     In step S 53 , the control unit  40  is configured to make a third determination as to whether the intensity of the output audio signal outputted at the audio output unit  60  has reached the target intensity (63 dB) thereof. The audio output unit  60  is configured to maintain the intensity of the output audio signal at 63 dB and operate in the working mode when a result of the third determination is affirmative. Otherwise, steps S 52  and S 53  are repeated until the intensity of the output audio signal reaches the target intensity (63 dB) thereof when the result of the third determination is negative. 
     In summary, when the electronic device  100  is turned on, the audio output unit  60  is configured to gradually increase the intensity of the output audio signal from the initial intensity thereof (the volume value corresponding to the volume bar is 10) as long as the electronic device  100  had not been operated in the mute mode at the time the electronic device  100  was turned off. In this embodiment, the intensity of the output audio signal is increased at speed of 1 volume value corresponding to the volume bar per 500 ms until the intensity of the output audio signal reaches the target intensity thereof set by the control unit  40 . That is, when the electronic device  100  is turned on, steps S 10  to S 50  are performed first so as to adjust the intensity of the output audio signal from the initial intensity to the target intensity suitable for the surrounding environment, such that damage to the audio output unit  60  resulting from outputting excessive volume may be prevented when the electronic device  100  is just turned on. 
     Referring to  FIG. 2 , in the working mode, step S 100  is performed by the control unit  40 . In step S 100 , the control unit  40  is configured to control the audio receiver unit  20  to receive the external audio signal. Notably, the control unit  40  is configured to periodically (for example, at one-minute intervals) control the audio receiver unit  20  to receive the external audio signal, and each duration of receiving the external audio signal lasts 30 seconds. However, the actual configurations are not limited to the disclosure of this embodiment. 
     Subsequently, step S 200  is performed. In step S 200 , the sound track comparison unit  50  is configured to compare the sound track of the external audio signal with the preset sound track (i.e., the sound track of the mobile phone ringtone) stored in the memory unit  10  and to make a fourth determination as to whether a degree of similarity between the two soundtracks reaches a preset ratio (in this embodiment, 70% is given as an example of the preset ratio). The received external audio signal is deemed to be the mobile phone ring tone when a result of the fourth determination is affirmative. Accordingly, the control unit  40  is configured to perform step S 300  and operate in the mute mode. In step S 300 , the control unit  40  is configured to disable the audio output unit  60  from outputting the output audio signal temporarily, to control the displayer unit  70  to display the subtitles corresponding to the current output images and the characters of ‘mute’ so as to prevent the user from experiencing interference resulting from sound emitted by the electronic device  100  when answering the phone, and to perform step S 400  thereafter. Specifically, the sound track comparison unit  50  is configured to compare whether each byte of the sound track of the external audio signal is the same as a respective byte of the preset sound track, and to determine that the external audio signal is the mobile phone ringtone when a number of the same bytes occupies a total number of the bytes by the preset ratio (70%). It is noted that there are other ways to compare sound tracks, and the invention is not limited to the disclosure of the preferred embodiment. On the contrary, step S 500  is performed when the degree of similarity between the two sound tracks does not reach the preset ratio. 
     That is, since the external audio signal received at the audio receiver unit  20  may include the user&#39;s mobile phone ring tone and external noise, in step S 200 , the external audio signal is determined to be noise when the sound track comparison unit  50  determines that the degree of similarity between the sound track of the external audio signal and the preset sound track of the mobile phone is low (i.e., lower than 70%). 
     In step S 400 , the control unit  40  is configured to make a fifth determination as to whether the command receiver unit  30  has received the mute cancelling command transmitted as a result of operation of the remote controller or pushing of the mute button of the electronic device  100  by the user. Step S 100  is performed when a result of the fifth determination is affirmative. Otherwise, steps S 300  and S 400  are repeated when the result of the fifth determination is negative. 
     In step S 500 , the control unit  40  is configured to control the audio receiver unit  20  to receive the external audio signal during a pause time of the output audio signal outputted at the audio output unit  60 . The pause time mentioned herein is a break without any sound between sounds emitted from the television. During the pause time, the external audio signal received at the audio receiver unit  20  does not contain the output audio signal. That is, only sound other than that from the electronic device  100  is included in the external audio signal, such that the control unit  40  may determine intensity of the noise more precisely. 
     Therefore, step S 600  is performed after the audio receiver unit  20  has received the external audio signal. In step S 600 , the control unit  40  is configured to make a sixth determination as to whether the intensity of the external audio signal received at the audio receiver unit  20  has reached a maximum noise intensity, i.e., determining whether decibel of the intensity of the external audio signal is equal to decibel of the maximum noise intensity (for example, 73 dB). When a result of the sixth determination is affirmative, the noise of the environment in which the electronic device  100  is located has reached a maximum value of the audio intensity look-up table, and the audio output unit  60  may no longer output the output audio signal which has an intensity 3 dB higher than the intensity of the external audio signal. That is, referring to  FIG. 4 , when the intensity of the external audio signal has reached the maximum noise intensity (for example, 73 dB), the volume value corresponding to the volume bar of the electronic device  100  has reached 100 and may not be increased anymore. At this moment, for protecting the hearing of the user from damage resulting from excessive volume, the control unit  40  is configured to perform steps S 300  and S 400  and operate in the mute mode, so as to reduce overall environment volume and protect the hearing of the user simultaneously. Back to step S 600 , step S 700  is performed when the result of the sixth determination is negative. 
     In step S 700 , the control unit  40  is configured to make a seventh determination, according to the intensity (dB) of the audio signal outputted at the audio output unit  60 , as to whether the intensity of the output audio signal is higher than the intensity of the external audio signal by a predefined intensity, for example, 3 dB. This means that the noise of the environment where the user is at may not interfere with the user watching television when a result of the seventh determination is affirmative. Therefore, step S 701  is performed. In step S 701 , the intensity of the output audio signal outputted at the audio output unit  60  maintained. Otherwise, step S 800  is performed when the result of the seventh determination is negative. 
     In step S 800 , the control unit  40  is configured to make an eighth determination as to whether the command receiver unit  30  has received a volume control command from the remote controller. When a result of the eighth determination is affirmative, this means that the user desires to adjust volume of the electronic device  100  manually, and step  801  is thus performed. In step  801 , the control unit  40  is configured to adjust the intensity of the output audio signal outputted at the audio output unit  60  according to the volume control command, i.e., the intensity of the output audio signal is adjusted as desired by the user, and the flow ends. Back to step S 800 , step S 900  is performed when the result of the eighth determination is negative. In step S 900 , the control unit  40  is configured to adjust the intensity of the output audio signal outputted at the audio output unit  60  with reference to the audio intensity look-up table (referring to  FIG. 4 ) stored in the memory unit  10 . 
     Furthermore, step S 900  includes the following sub-steps: 
     In step S 901 , the control unit  40  is configured to set a target intensity of the output audio signal higher than the intensity of the external audio signal by, for example 3 dB, with reference to the audio intensity look-up table stored in the memory unit  10 . 
     In step S 902 , the control unit  40  is configured to adjust the intensity of the output audio signal according to the target intensity thereof. Specifically, step S 902  in the working mode is different from step S 52  in the initial mode. In the initial mode, the control unit  40  is configured to control the intensity of the output audio signal outputted at the audio output unit  60  to increase from the initial intensity. However, in the working mode, the control unit  40  is configured to control the intensity of the output audio signal outputted at the audio output unit  60  from a current intensity to the target intensity. That is, the intensity of the output audio signal outputted at the audio output unit  60  may be increased or decreased. 
     In step S 903 , the control unit  40  is configured to make a ninth determination as to whether the intensity (dB) of the output audio signal outputted at the audio output unit  60  has reached the target intensity (dB) thereof. When a result of the ninth determination is affirmative, the control unit  40  is configured to maintain the intensity of the output audio signal, to end the process flow, and to wait for next detection of the external audio signal of the environment. Otherwise, steps S 902  and S 903  are repeated when the result of the ninth determination is negative. 
     In summary, by means of the volume control method of the invention, the electronic device  100  is capable of automatically adjusting the intensity of the output audio signal outputted thereby according to the intensity of the noise (the external audio signal) of the environment in which the electronic device  100  is located. Therefore, the user is not required to manually adjust volume of the electronic device  100  resulting from variation in noise of the surrounding environment, so as to facilitate convenience in use. Moreover, the volume control method of the invention is further configured to control the electronic device  100  to operate in the mute mode automatically when the user&#39;s mobile phone is ringing, such that the user is prevented from experiencing interference of the sound emitted from the electronic device  100  when answering the phone. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.