JP4626441B2 - Audio output control apparatus and audio output control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the operability and the quality of viewing and listening, without full blast of sound being output, when the power is turned on. <P>SOLUTION: The voice output controller measures the level of input volume of a voice signal when the power is on, as shown by 14, and predicts power value W when the voice is outputted to a speaker 4 from a voice amplifier 3, on the basis of the input volume level and gains of the voice amplifiers 2 and 3, as shown by 15. Then, up to the output volume level value of a user setting, according to the power value W of the voice output with respect to the speaker 4 as predicted, when the power is on, an increase in gain of the voice amplifier 2 is variably controlled. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to an audio output control apparatus and an audio output control method that perform automatic volume level control in a television receiver, for example.

  Conventionally, in a device such as a television receiver that controls the volume level of sound output from a speaker with an up / down key or the like, control is performed to always output the sound at the stored volume level when the power is turned off.

  FIG. 2A is a diagram showing a volume operation after canceling mute when the power is turned on. In FIG. 2A, when the power is turned on at time T1, and then the mute of the audio amplifier is released at time T2, the volume level is instantaneously increased to the user volume value Vu set by the user operation. Volume sound was output.

  Also, when the power is turned on, the volume level at the previous power-off is compared with the reference volume level. If the volume level at the previous power-off is greater than the reference volume level, the output volume level is forcibly reduced to the reference volume level. A volume control device has been proposed (see Patent Document 1).

Also proposed is a volume control circuit comprising a volume control circuit, a time constant circuit for controlling the output of the volume control circuit by a power supply control input, and an audio amplifier controlled by the output of the volume control circuit supplied through the time constant circuit. (See Patent Document 2).
JP 2002-16457 A JP-A-2-277306

  However, with the conventional control described above, it is not possible to know how much sound level is output when the power is turned on, and suddenly the sound is output at a large volume level, or in a quiet place once the power is turned on. Since sound is output at a predetermined volume level and then the volume level must be lowered, there is a disadvantage that the operability is lowered.

In addition, there was a disadvantage that the sound was suddenly too loud when the power was turned on again at night, especially at midnight, when the television was watched at a louder volume during the daytime.
Further, in the technique described in Patent Document 1, when the volume level at the time of the previous power-off is larger than the reference volume level, the output volume level is forcibly decreased to the reference volume level instantaneously. As a result, there is a disadvantage that viewing quality is lowered.

  In the technique described in Patent Document 2, the time constant circuit is operated when the power is turned on to slowly increase the volume, but this is for adjusting the increase in the volume level to the screen output of the cathode ray tube. The ascending control is not possible. For this reason, there is an inconvenience that the operability is lowered because an operation for raising and lowering the volume level has to be performed.

  Therefore, an object of the present invention is to provide an audio output control device and an audio output control method capable of improving operability and viewing quality without outputting a loud sound when the power is turned on. It is.

In order to solve the above problems and achieve the object of the present invention, the audio output control device of the present invention measures the input volume level of the audio signal when the power is turned on, and based on the input volume level and amplification factor of the audio signal. The control means for predicting the power value when the sound is output to the speaker, and variably controlling the volume increase rate according to the power value of the sound output predicted for the speaker when the power is turned on , and the user setting of the target value Storage means for storing several types of tables of volume increase rates with respect to the output volume level values according to the volume increase rates .
Here, the variable control of the volume increase rate by the control means is performed by switching the table stored in the storage means in accordance with the power value of the sound output to the speaker predicted when the power is turned on.

In addition, the audio output control method of the present invention measures the input volume level of the audio signal when the power is turned on, and calculates the power value when the audio is output to the speaker based on the input volume level and the amplification factor of the audio signal. The sound volume increase rate is variably controlled according to the power value of the sound output to the speaker predicted and predicted when the power is turned on.
Here, the variable control of the volume increase rate is performed by increasing the volume with respect to the user-set output volume level value as a target value, which is stored in the storage means according to the power value of the audio output to the speaker predicted when the power is turned on. This is done by switching the rate table.

The audio output control device and the audio output control method of the present invention, for example, in an audio output device such as a television receiver, target the volume increase rate of the audio output when the power is turned on according to the predicted power output value of the audio output to the speaker. There is a function to prevent sound output with a large volume by variably controlling to a value (gradual increase etc.).

According to the present invention, since the volume increase rate of the audio output when the power is turned on is variably controlled to the target value according to the predicted power output value of the audio output to the speaker, a loud sound can be output when the power is turned on. Therefore, operability and viewing quality can be improved.

Embodiments of the present invention will be described below with reference to the drawings as appropriate.
First, an outline of processing from measuring the input sound volume level of sound output to predicting the power value of sound output will be described.
FIG. 1 is a diagram illustrating signal processing for predicting the power value W of audio output.
In FIG. 1, a signal processing system of an audio system applied to this signal processing includes an audio switch 1 for switching channels of a plurality of audio signals from a sound source (not shown), and an output volume level of the audio signal from the sound source with a gain Gvol. And an audio amplifier 2 that amplifies the output volume level of the audio signal from the audio amplifier 2 with a gain Gamp, and a speaker 4 that outputs sound from the audio signal from the audio amplifier 3. Has been.
Here, for example, the gain Gvol of the audio amplifier 2 can variably control the output volume level up to the user volume value Vu set by the user operation. Also, for example, the gain Gamp of the audio amplifier 3 can be controlled to an output volume level set in advance according to the required specifications. Both the gain Gvol and the gain Gamp indicate the amplification factors of the audio amplifier 2 and the audio amplifier 3.

  The control unit that controls the signal processing for predicting the power value W of the audio output for the signal processing system described above, as shown at 14, is the input volume level Venv of the audio signal from the audio switch 1 when the power is turned on. , And as shown at 15, the power value W when the sound is output to the speaker 4 is predicted based on the input volume level Venv and the gains Gvol and Gamp.

  The control unit variably controls the increase in the gain Gvol of the audio amplifier 2 in accordance with the power value W of the audio output to the speaker 4 predicted when the power is turned on. That is, the output volume level up to the user volume value Vu (Gvol) set by the user operation is variably controlled.

  At this time, the controller performs mute 1 on the channel-switched audio signal from the audio switch 1 as shown by 11 and 12 on the audio signal output from the audio amplifier 3. As shown by, mute 2 is performed. As a result, the output of the audio signal is stopped for a certain period until the processing of the signal processing system is stabilized, and after the elapse of the certain period, the mute 1 indicated by 11 and the mute 2 indicated by 12 are canceled and the output of the audio signal is started.

  Here, as shown at 13, the release of mute 2 for the audio signal from the audio amplifier 3 indicated by 12 is delayed from the release of mute 1 for the audio signal from the audio switch 1 indicated by 11. During the period for measurement, the input volume level Venv of the audio signal from the audio switch 1 at the time of power-on indicated by 14 is measured.

  In this way, the control unit measures the input signal level Venv of the audio amplifier 2 and predicts the power value W of the audio output to the speaker 4 from this and the user volume value Vu (Gvol). It should be noted that there is a time difference for measurement between the cancellation of mute 2 for the audio amplifier 3 that outputs audio to the speaker 4 and the cancellation of mute 1 for the audio switch 1 to which the audio signal is input. The signal processing is performed by measuring the level Venv of the input signal 2 and predicting the power value W of the audio output.

Next, the signal processing for predicting the power value W of the audio output shown in FIG. 1 is performed, and then the increase in the gain Gvol is varied according to the power value W of the audio output for the speaker predicted when the power is turned on. A specific audio system configuration applied to the signal processing to be controlled will be described.
FIG. 3 is a block diagram of signal processing for predicting the power value W of the audio output. The audio switch 34 is the audio switch 1 of FIG. 1, the audio processor 35 is the audio amplifier 2 of FIG. 1, the audio amplifier 36 is the audio amplifier 3 of FIG. 1, the speaker 37 is the speaker 4 of FIG. A microcomputer (hereinafter referred to as a microcomputer) 39 and a memory (EEPROM (electrically erasable programmable read only memory)) 43 correspond to the control unit described in FIG. A TV 31, a VCR (video cassette recorder) 32, and a DVD (digital versatile disc) 33 are sound sources.

  In FIG. 3, the microcomputer 39 is provided with an envelope detection circuit 38. The envelope detection circuit 38 measures the input volume level Venv of the audio signal from the audio switch 34 when the power is turned on, and measures the input volume. The level Venv is supplied to the microcomputer 39.

  The microcomputer 39 predicts a power value W when sound is output to the speaker 37 based on the input volume level Venv and the gains Gvol and Gamp based on the input volume level Venv and the gains Gvol and Gamp. The functions include a sound output power value W calculation unit 41 that performs sound output and a volume increase control unit 42 that variably controls the increase in gain Gvol by table control in accordance with the power value W of sound output to the speaker 37 that is predicted when the power is turned on. is doing.

  The microcomputer 39 is provided with a memory (EEPROM) 43. The memory (EEPROM) 43 includes a user volume value Vu storage unit 44 that stores a table that can be variably controlled to increase the volume level up to the user volume value Vu. Here, the user volume value Vu is set by a user operation with respect to the gain Gvol of the audio processor 35. A plurality of tables are provided corresponding to the sound volume level and the power value W of the sound output.

  When the measured input volume level Venv of the audio signal from the audio switch 34 when the power is turned on is supplied from the envelope detection circuit 38 to the microcomputer 39, the Venv digitization processing unit 40 of the microcomputer 39 sets the numerical value of the input volume level Venv. Process. At this time, for example, as shown in FIG. 6, the Venv digitization processing unit 40 samples the measurement waveform of the input volume level Venv for a certain period, and generates a waveform including the peak 61 with respect to the average value 62 at the time of stabilization. Used for calculation.

  Next, the sound output power value W calculation unit 41 calculates the power value W when sound is output to the speaker 37 based on the input volume level Venv and the gains Gvol and Gamp, using the following equation (1). Predict. Here, R is the resistance value of the speaker 37.

[Equation 1]
W = Venv ² × 10 ^{(Gvol + Gamp) 10} / R

  The volume increase control unit 42 variably controls the increase in the gain Gvol by table control in accordance with the power value W of the audio output to the speaker 37 predicted when the power is turned on. At this time, the volume increase control unit 42 reads a table corresponding to the volume level and the power value W of the audio output from the user volume value Vu storage unit 44 of the memory (EEPROM) 43, and the audio processor according to the volume increase rate of this table. By performing volume control 47 on 35, the increase in gain Gvol is variably controlled to control the increase in volume.

  The microcomputer 39 performs measurement between the cancellation of the mute 2 for the audio amplifier 36 that outputs sound to the speaker 37 indicated by 48 and the release of the mute 1 for the audio switch 34 that inputs the audio signal 46 indicated by 46. Have a time difference for. Then, during this measurement period, a numerical process after the measurement of the input volume level Venv of the audio amplifier 35 is performed, and the power value W of the audio output is predicted.

  The microcomputer 39 controls channels and input switching of a plurality of audio signals from the TV 31, VCR 32 and DVD 33 by an input switch switching signal indicated by 45 for the audio switch 34.

In the present embodiment described above, an example in which the input volume level Venv is measured using an analog signal has been described. However, the same function can be realized even with data from a digital signal processing IC dedicated to audio processing.
The input sound volume level Venv for the audio processor 35 uses a peak value observed over several seconds. Here, for example, a peak observed for 3 seconds is taken every 0.2 seconds. The series of control operations described above are continuously executed after the power is turned on until the output volume level reaches the user volume value Vu (Gvol) set by the user operation.

Next, a description will be given of a volume control operation in which the volume control 47 is variably controlled by performing the volume control 47 on the audio processor 35 to variably control the volume increase.
FIG. 2B is a diagram showing a volume control operation after mute 2 is released when the power is turned on according to the present invention. In FIG. 2B, when the power is turned on at time T11 and then the mute 2 of the audio amplifier 36 is released at time T12, the volume level is increased at a rate corresponding to the power value W of the audio output until reaching the user volume value Vu. Is raised. As indicated by 21, when the volume level is small, the curve rise rate is high, so that the user volume value Vumin is controlled relatively quickly. On the other hand, as indicated by 22, when the volume level is high, the rate of increase of the curve is low, so that control is performed so as to reach the user volume value Vumax relatively late at time T 13 after T seconds.

  In this manner, the increase table of the gain Gvol of the audio processor 35 is switched according to the predicted audio output power value W with respect to the final user volume value Vu. As a result, when the predicted power value W of the audio output with respect to the final user volume value Vu increases, a table with a gentler slope is selected in order to reduce the rate of increase. The time until the volume value Vu increases as the power value W of the audio output increases.

FIG. 7 is a diagram illustrating an example of table control for variably controlling the increase in gain Gvol.
In FIG. 7, when the mute 2 of the audio amplifier 36 is released at the time T0 after the power is turned on, the increase control is being performed up to a% as shown at 71 at the time T21, and 72 at the time T22. As shown in FIG. 4, the increase control is being performed up to b (> a)%. Then, as indicated by 73, the volume level is increased at a rate of increase corresponding to the power value W of the audio output predicted up to the target user volume value Vu (100%) at the time Tn. At this time, if the viewer operates the volume key from the remote commander to the microcomputer 39 while the volume level is increasing, the increase control is canceled and the sound can be output at the volume level by the operation of the volume key at that time. Like that.

FIG. 8 is a diagram illustrating an example of a table control type for variably controlling the increase in gain Gvol.
In FIG. 8, 81 is a table for performing a rise control that results in a weak voice output that reaches a target value with a relatively high rise rate because the user volume value Vu is small, and 82 is a medium user volume value Vu. Therefore, 83 is a table for performing an increase control that achieves a medium voice output reaching a target value with a medium increase rate, and 83 is a target value with a relatively low increase rate because the user volume value Vu is large. It is a table for performing the raise control used as the strong audio | voice output which reaches | attains. 81 to 83 are tables for performing linear ascent control.
Here, the number of tables for performing linear increase control is about six kinds, and the maximum time to the target volume Vu is about 10 seconds.

Moreover, it is also possible to control using the table shown below as tables other than linear raise control.
84 is a relatively high rate of increase from the middle to the end of control while performing a rise control with a relatively high rise rate from the start of control and a weak sound output reaching the target value with respect to the user volume value Vu. It is a table for performing the raise control used as the strong audio | voice output which lowers and reaches | attains a target value. On the other hand, 85 increases relative to the user volume value Vu while gradually increasing from the start of control to a strong audio output that reaches a target value with a relatively low increase rate. It is a table | surface for performing the raise control used as the weak audio | voice output which makes a rate high and reaches | attains a target value. In addition, after 86 once performing an increase control that provides a strong sound output that reaches a target value by lowering the increase rate in the first half of the control relative to the user volume value Vu, the increase rate is relatively increased in the second half of the control. It is a table for performing the raise control used as the weak audio | voice output which reaches a target value. 84 to 86 are tables for performing an increase control of an arbitrary characteristic.

FIG. 4 is a flowchart showing the operation when the power is turned on. FIG. 4 shows the processing of the microcomputer 39.
In FIG. 4, when the power is turned on (step S1), the microcomputer 39 reads the user volume value Vu stored in the user volume value Vu storage unit 44 of the memory (EEPROM) 43 (step S2). The user volume value Vu is a value corresponding to the gain Gvol of the audio processor 35.

Here, the microcomputer 39 cancels the mute 1 after switching the input of the sound source to the audio switch 34 (step S3).
When the measured input volume level Venv of the audio signal from the audio switch 34 when the power is turned on is supplied from the envelope detection circuit 38 to the microcomputer 39, the Venv digitization processing unit 40 of the microcomputer 39 inputs the input volume level Venv. The numerical process is performed (step S4).

Next, the sound output power value W calculation unit 41 calculates the power value W when sound is output to the speaker 37 based on the input volume level Venv and the gains Gvol and Gamp (step S5).
At this time, the volume increase control unit 42 reads a table corresponding to the volume level and the power value W of the audio output from the user volume value Vu storage unit 44 of the memory (EEPROM) 43, and the audio processor according to the volume increase rate of this table. Volume control 47 is performed on 35 (step S6).

  Subsequently, the microcomputer 39 cancels mute 2 for the audio amplifier 36 that outputs sound to the speaker 37 (step S7). A time difference for measurement is given between the release of mute 1 for the audio switch 34 for inputting the audio signal shown in step S3, and after the measurement of the input volume level Venv of the audio amplifier 35 shown in step S5 during this measurement period. Numerical processing is performed to predict the power value W of the audio output.

  Then, the volume increase control unit 42 variably controls the increase in the gain Gvol of the audio processor 35 by table control in accordance with the power value W of the audio output to the speaker 37 predicted when the power is turned on (step S8).

  Here, the microcomputer 39 determines whether or not the viewer has operated the volume key from the remote commander to the microcomputer 39 during the volume increase (step S9). When the volume key is operated in step S9, the microcomputer 39 cancels the ascending control in step S8 so that the sound can be output with the volume by the operation of the volume key at that time (step S10).

  When the volume key is not operated in step S9, the microcomputer 39 determines whether or not the ascent control in step S8 is completed (step S11). When the ascending control is being performed, the microcomputer 39 returns to step S8, and steps S8 to S8. The processing and determination up to step S11 are repeated, and when the ascent control in step S8 is completed, the processing ends (step S12).

Next, control at the time of channel and input switching will be described.
At the time of channel switching or input switching in the audio switch 34 after the power is turned on, the input volume level Venv of the audio processor 35 cannot be measured because of the audio output response that it is necessary to continuously output audio. For this reason, the table for controlling the increase in the gain Gvol of the audio processor 35 uses a specified value regardless of the sound level, but the table to be used is changed depending on the input type. For example, in the case of external input such as a VCR 32 and a DVD 33, unlike the TV 31 in the same device, there is a possibility that an excessive input may be made.

FIG. 5 is a flowchart showing the operation at the time of channel switching. FIG. 5 shows the processing of the microcomputer 39.
In FIG. 5, when there is channel switching or input switching (step S21), the microcomputer 39 reads the user volume value Vu stored in the user volume value Vu storage unit 44 of the memory (EEPROM) 43 (step S22). . The user volume value Vu is a value corresponding to the gain Gvol of the audio processor 35.

Here, the microcomputer 39 cancels mute 1 after switching the input of the sound source to the audio switch 34 (step S23).
At this time, the envelope detection circuit 38, the Venv digitization processing unit 40, and the audio output power value W calculation unit 41 do not operate.

  At this time, the volume increase control unit 42 reads a fixed table corresponding to channel switching or input switching from the user volume value Vu storage unit 44 of the memory (EEPROM) 43, and the audio processor according to the volume increase rate of this table. Volume control 47 is performed on 35 (step S24).

  Subsequently, the microcomputer 39 cancels mute 2 for the audio amplifier 36 that outputs sound to the speaker 37 (step S25). At this time, a time difference for table selection is given to the cancellation of the mute 1 for the audio switch 34 for inputting the audio signal shown in step S23, and the table shown in step S524 is selected during this selection period.

  Then, the volume increase control unit 42 variably controls the increase in the gain Gvol by table control in accordance with the power value W of the audio output to the speaker 37 predicted when the power is turned on (step S26).

  Here, the microcomputer 39 determines whether or not the viewer operates the volume key from the remote commander to the microcomputer 39 during the volume increase (step S27). When the volume key is operated in step S27, the microcomputer 39 cancels the ascending control in step S26, so that the sound can be output with the volume by the operation of the volume key at that time (step S28).

  When the volume key is not operated in step S27, the microcomputer 39 determines whether or not the ascent control in step S26 is completed (step S29). When the ascending control is being performed, the microcomputer 39 returns to step S26 to perform steps S26 to S26. The process and determination up to step S29 are repeated, and when the ascent control in step S26 is completed, the process ends (step S30).

  As described above, even if the user volume value Vu or the input volume level Venv is biased, the control is performed so that the rate of increase in the volume level varies according to the power value W of the audio output. Therefore, it is possible to perform sound output with a stable volume increase characteristic that is not affected by the bias. For this reason, since a natural control becomes possible on a user's audibility, viewing environment improves.

In addition, by using a table with different slopes for increasing the volume level, when the output volume of the user volume value Vu is large, the user volume rises slowly, and the user can operate the volume key to stop the increase in the user volume. As a result, viewing quality is improved.
Further, when the user volume value Vu is small, the control speed can be divided according to the volume level because it rises quickly and does not deteriorate the audio output response in the normal use state.

In addition, since a table having an arbitrary characteristic can be prepared as a table for controlling the increase rate of the sound volume level, it is possible to change not only the increase rate due to the linear inclination but also the characteristic curve depending on the power value W of the audio output.
It goes without saying that this function can be selected only when it is desired to use it on a menu or the like.

  It goes without saying that the configuration can be appropriately changed within the scope of the gist of the present invention described in the claims, not limited to the above-described embodiment.

It is a figure which shows the signal processing for prediction of the electric power value W of an audio | voice output. It is a figure which shows the volume control operation | movement after the mute cancellation | release at the time of a power supply ON, FIG. 2A is conventional and FIG. 2B is this invention. It is a block diagram of the signal processing for prediction of the electric power value W of an audio | voice output. It is a flowchart which shows the operation | movement at the time of power-on. It is a flowchart which shows the operation | movement at the time of channel switching. It is a figure which shows the measurement waveform of the input volume level Venv. It is a figure which shows the example of table control. It is a figure which shows an example of a table control type.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Voice switch, 2, 3 ... Audio amplifier, 4 ... Speaker, 11 ... Mute 1, 12 ... Mute 2, 13 ... Measure Venv in mute 2 release delay period with respect to mute 1, 14 ... Measure input volume level Venv , 15: The power value W of the audio output is calculated from Gvol and GampVenv, 21: Curve with small output volume, 22 ... Curve with large output volume, 31 ... TV, 32 ... VCR, 33 ... DVD, 34 ... Audio switch, 35 DESCRIPTION OF SYMBOLS ... Audio processor, 36 ... Audio amplifier, 37 ... Speaker, 38 ... Envelope detection circuit, 39 ... Microcomputer, 40 ... Venv digitization processing unit, 41 ... Audio output power value W calculation unit, 42 ... Volume increase control unit, 43 ... Memory (EEPROM), 44 ... User volume value Vu storage unit

Claims (6)

In an audio output control device that controls to amplify an input volume level of an audio signal from a sound source with a predetermined amplification factor and outputs sound from a speaker,
Measure the input volume level of the audio signal when the power is turned on, predict the power value when the sound is output to the speaker based on the input volume level and the amplification factor, and predict the sound for the speaker predicted when the power is turned on Control means for variably controlling the volume increase rate according to the power value of the output ;
Storage means for storing several types of volume increase rate tables for user-set output volume level values as target values according to the volume increase rate ,
The variable control of the volume increase rate by the control means is performed by switching a table stored in the storage means according to the power value of the sound output to the speaker predicted when the power is turned on.
Audio output control device. A the power-on or later, the channel or input switching of a plurality of audio signals from the sound source, the variable control of the volume increase rate by the control means is carried out
The audio output control device according to 請 Motomeko 1. When the control means detects that the volume key is operated in the middle of the variable control of the volume increase rate, the control means cancels the variable control of the volume increase rate and outputs a sound at a volume specified by the volume key. To control
The voice output control device according to claim 1. The volume increase rate in the above table is variable until reaching the output volume level value set by the user.
The audio output control device according to 請 Motomeko 1. In the audio output control method for controlling the sound volume of the audio signal from the sound source to be amplified at a predetermined amplification factor and outputting sound from the speaker,
Measure the input volume level of the audio signal when the power is turned on,
Based on the input volume level and the amplification factor, predict the power value when sound is output to the speaker,
The volume increase rate is variably controlled according to the power value of the sound output to the speaker predicted when the power is turned on ,
Depending on the power value of the sound output to the speaker that is predicted when the power is turned on, the sound volume increase rate can be controlled by increasing the sound volume with respect to the user-set output sound volume level value that is the target value stored in the storage means. By switching rate table
Voice output control method. After the power is turned on, the above control operations are performed when the channels or inputs of a plurality of audio signals from the sound source are switched.
Audio output control method according to 請 Motomeko 5.

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