JP6697156B2 - Volume control device - Google Patents

Description

  The present invention relates to a volume adjusting device that adjusts the volume of an audio signal.

  In a volume adjusting device that adjusts the volume of a stereo audio signal, a potentiometer (variable resistor) in which two variable resistors are linked by one rotating shaft may be used. When the volume is adjusted by dividing the audio signal by the variable resistance of the potentiometer, a so-called gang error may occur, which causes a difference in the output amount between the L channel and the R channel of the stereo audio signal. This is caused by the mutual deviation of potentiometers, and the deviation amount also varies from part to part. Since the deviation amount of the gang error differs depending on the adjustment position (rotation angle) of the potentiometer, the difference in the output amount between the L channel and the R channel differs depending on the adjustment amount of the sound volume.

  It is conceivable to use an electronic volume to reduce the gang error. However, considering the components required when an electronic volume is mounted (coupling capacitors for signal lines, bypass capacitors for power supplies, etc.), the area occupied by the board in the circuit configuration is greater than when directly dividing the audio signal with a potentiometer. The cost may increase. Further, if the specification value of the mutual deviation of the potentiometers is managed to be small, the yield as a component is affected, and therefore the feasibility is not accompanied.

  Patent Document 1 discloses a technique for correcting a gang error that occurs when two voltage controlled amplifiers are used.

Japanese Patent Laid-Open No. 09-244746

  As described above, when a potentiometer is used for volume adjustment, there is a problem that a gang error occurs.

  An object of the present invention is to reduce the occurrence of a gang error even when a potentiometer is used for volume adjustment.

  A volume adjusting device according to a first aspect of the present invention includes a correcting unit that corrects a signal, a potentiometer having a plurality of variable resistors, and a plurality of variable resistors that apply a predetermined potential voltage to the plurality of variable resistors. A storage unit that stores the partial pressure values of the storage unit in association with each other, and the storage unit stores the partial pressure value indicating the adjustment position of the potentiometer, which corresponds to the partial pressure value indicating the adjustment position of the potentiometer, which is stored in the storage unit. A control unit that controls the correction unit based on a ratio of a plurality of partial pressure values.

  In the present invention, the storage unit stores a plurality of divided voltage values of the plurality of variable resistors in association with each other when a voltage of a predetermined potential is applied to the plurality of variable resistors. Then, the control unit, based on the ratio of a plurality of partial pressure values stored in the storage unit, corresponding to the partial pressure value indicating the potentiometer adjustment position, excluding the partial pressure value indicating the potentiometer adjustment position, the correction is performed. Control the department. This reduces the occurrence of gang errors.

  A volume adjusting device according to a second aspect of the present invention is the volume adjusting device according to the first aspect, wherein the correction unit is a volume correction unit that corrects the volume of the left channel audio signal and the right channel audio signal, and the potentiometer. Is a uniaxial triple potentiometer having a first variable resistor for the left channel audio signal, a second variable resistor for the right channel audio signal, and a third variable resistor, and the storage section is the first variable resistor. A first divided voltage value by the first variable resistor and a second divided value by the second variable resistor when a voltage having a predetermined potential is applied to the resistor, the second variable resistor, and the third variable resistor. The pressure value and the third partial pressure value by the third variable resistor are stored in association with each other, and the control unit stores the adjustment position of the single-axis triple potentiometer stored in the storage unit. The sound volume correction unit is controlled based on a ratio of the first partial pressure value and the second partial pressure value corresponding to the three partial pressure value.

  According to the present invention, the storage unit includes the first variable resistance, the second variable resistance, and the third variable resistance, the first divided voltage value by the first variable resistance when the voltage of the predetermined potential is applied, and the first variable resistance, The second partial pressure value of the two variable resistors and the third partial pressure value of the third variable resistor are stored in association with each other. Then, the control unit, based on the ratio between the first partial pressure value and the second partial pressure value, which is stored in the storage unit and corresponds to the third partial pressure value indicating the adjustment position of the uniaxial triple potentiometer, Controls the volume correction unit. This reduces the occurrence of gang errors.

  A volume adjusting device according to a third aspect of the present invention is the volume adjusting device according to the second aspect, wherein the storage unit stores the first partial pressure value and the first partial pressure value when the uniaxial triple potentiometer is at a plurality of different adjustment positions. A second partial pressure value and the third partial pressure value are stored.

  A volume adjusting device according to a fourth aspect of the present invention is the volume adjusting device according to the second or third aspect, wherein the control unit adjusts the adjustment position of the single-axis triple potentiometer when the single-axis triple potentiometer is operated. The sound volume correction unit is controlled based on a ratio of the first partial pressure value and the second partial pressure value corresponding to the third partial pressure value shown.

  A volume adjusting device according to a fifth aspect of the present invention is the volume adjusting device according to any one of the second to fourth aspects of the present invention, wherein the power source for supplying the voltage of the predetermined potential and the signal source for the left channel audio signal can be switched. A first switch, the power source, and a signal supply source for a right channel audio signal, and a second switch capable of switching between the first power source and the right channel audio signal. One end of the first variable resistor is connected to the first switch. , The other end is connected to the ground, the second variable resistor has one end connected to the second switch, the other end connected to the ground, and the third variable resistor has one end connected to the power supply. It is connected, and the other end is connected to the ground.

  A volume adjusting device according to a sixth aspect of the present invention is the volume adjusting device according to any of the second to fifth aspects, further comprising: a third switch that connects or disconnects the output from the first variable resistor and the control unit. And a fourth switch that connects or disconnects the output from the second variable resistor and the control unit.

  A sound volume adjusting apparatus according to a seventh aspect of the present invention is the sound volume adjusting apparatus according to the first aspect, wherein the correction unit outputs a non-inverted left channel audio signal, an inverted left channel audio signal, and a non-inverted right channel audio signal. , A volume correction unit for correcting the volume of the inverted right channel audio signal, wherein the potentiometer comprises a fourth variable resistor for the non-inverted left channel audio signal and a fifth variable resistor for the inverted left channel audio signal. A uniaxial five-series potentiometer having a resistor, a sixth variable resistor for a non-inverted right channel audio signal, a seventh variable resistor for an inverted right channel audio signal, and an eighth variable resistor, wherein the storage unit Is the fourth variable resistor, the fifth variable resistor, the sixth variable resistor, the seventh variable resistor, and the eighth variable resistor, when a voltage of a predetermined potential is applied to the fourth variable resistor. A fourth partial pressure value of the fourth variable resistor, a fifth partial pressure value of the fifth variable resistor, a sixth partial pressure value of the sixth variable resistor, and a seventh partial pressure value of the seventh variable resistor, The eighth partial pressure value by the eighth variable resistor is stored in association with each other, and the control unit stores the eighth partial pressure value stored in the storage unit and indicating the adjustment position of the uniaxial five-series potentiometer. The sound volume correction unit is controlled based on the ratio of the fourth partial pressure value, the fifth partial pressure value, the sixth partial pressure value, and the seventh partial pressure value corresponding to ..

  According to the present invention, the storage unit is configured such that the fourth variable resistor, the fifth variable resistor, the sixth variable resistor, the seventh variable resistor, and the eighth variable resistor are provided with a voltage of a predetermined potential. 4th partial pressure value by variable resistance, 5th partial pressure value by 5th variable resistance, 6th partial pressure value by 6th variable resistance, 7th partial pressure value by 7th variable resistance, 8th variable The eighth partial pressure value by the resistance is stored in association with each other. Then, the control unit stores the fourth partial pressure value, the fifth partial pressure value, and the sixth partial pressure value, which are stored in the storage unit and correspond to the eighth partial pressure value indicating the adjustment position of the uniaxial five-series potentiometer. The volume correction unit is controlled based on the ratio with the seventh partial pressure value. This reduces the occurrence of gang errors.

  According to the present invention, the occurrence of gang errors is reduced.

It is a block diagram which shows the structure of the music reproducing apparatus which concerns on embodiment of this invention. It is a block diagram which shows the music reproducing apparatus in the case of acquiring the data for correcting a gang error. It is a block diagram which shows the music reproducing apparatus at the time of music reproduction.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a block diagram showing the configuration of the music reproducing device according to the present embodiment. The music reproducing device 1 (volume adjusting device) reproduces music based on the audio signal. In addition, in the present embodiment, a configuration relating to volume adjustment of an audio signal will be mainly described. The music reproducing device 1 includes a microcomputer 2, a D / A converter (hereinafter referred to as “DAC”) 3, a uniaxial triple potentiometer 4, and switches 5 to 8.

  The microcomputer 2 (control unit) includes hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input / output interface. The microcomputer 2 controls each part of the music reproducing device 1. The DAC 3 (volume correction unit) D / A converts the L channel and R channel digital audio signals into analog audio signals. The D / A converted L channel analog audio signal is output to the variable resistor VR1 of the uniaxial triple potentiometer 4. Further, the D / A converted R channel analog audio signal is output to the variable resistor VR2 of the uniaxial triple potentiometer 4. The DAC 3 has a function of correcting the volume of the audio signal.

  The uniaxial triple potentiometer 4 has variable resistors VR1 to VR3. The resistance values of the variable resistors VR1 to VR3 change according to a user operation. The variable resistor VR1 (first variable resistor) is for an analog audio signal of the L (left) channel. One end of the variable resistor VR1 is connected to the switch 5. The other end of the variable resistor VR1 is connected to the ground GND. The variable resistor VR1 divides the analog audio signal of the L channel. The L-channel analog audio signal divided by the variable resistor VR1 is output to the L-channel output terminal. The variable resistor VR2 (second variable resistor) is for an analog audio signal of the R (right) channel. One end of the variable resistor VR2 is connected to the switch 6. The other end of the variable resistor VR2 is connected to the ground GND. The variable resistor VR2 divides the R channel analog audio signal. The R channel analog audio signal divided by the variable resistor VR2 is output to the R channel output terminal.

  The variable resistor VR3 (third variable resistor) is a variable resistor for correcting a gang error. One end of the variable resistor VR3 is connected to a power supply VCC that supplies a voltage of a predetermined potential. The other end of the variable resistor VR3 is connected to the ground GND. The variable resistor VR3 divides the voltage from the power supply VCC. The divided voltage value by the variable resistor VR3 is output to the A / D port A / D3 of the microcomputer 2. The power supply VCC is also used as a power supply for supplying a power supply voltage to the microcomputer 2.

  The switch 5 (first switch) can switch between the power supply VCC and the L channel port of the DAC 3 that is the signal supply source of the L channel analog audio signal. The switch 6 (second switch) can switch between the power supply VCC and the R channel port of the DAC 3 that is a signal supply source of the R channel analog audio signal. The switch 7 (third switch) connects or disconnects the output of the variable resistor VR1 and the A / D port A / D1 of the microcomputer 2. The switch 8 (fourth switch) connects or disconnects the output of the variable resistor VR2 and the A / D port A / D2 of the microcomputer 2.

  When acquiring the data for correcting the gang error, the switch 5 connects the power supply VCC and the variable resistor VR1 as shown in FIG. The switch 6 connects the power supply VCC and the variable resistor VR2. The switch 7 is in the ON state, and connects the output of the variable resistor VR1 and the A / D port A / D1 of the microcomputer 2. The switch 8 is in the ON state, and connects the output of the variable resistor VR2 and the A / D port A / D2 of the microcomputer 2.

  The variable resistor VR1 divides the voltage from the power supply VCC. The voltage division value (first voltage division value) by the variable resistor VR1 is output to the A / D port A / D1 of the microcomputer 2. The variable resistor VR2 divides the voltage from the power supply VCC. The voltage division value (second voltage division value) by the variable resistor VR2 is output to the A / D port A / D2 of the microcomputer 2. The variable resistor VR3 divides the voltage from the power supply VCC. The voltage division value (third voltage division value) by the variable resistor VR3 is output to the A / D port A / D3 of the microcomputer 2. The microcomputer 2 stores the divided voltage value by the variable resistor VR1, the divided voltage value by the variable resistor VR2, and the divided voltage value by the variable resistor VR3 in association with each other in the ROM (storage unit).

  Further, the rotation angle (adjustment position) of the uniaxial triple potentiometer 4 is changed, and the voltage division value by the variable resistance VR1, the voltage division value by the variable resistance VR2, and the voltage division value by the variable resistance VR3 are associated with each other, It is stored in the ROM by the microcomputer 2. In this manner, the voltage division value by the variable resistance VR1, the voltage division value by the variable resistance VR2, and the voltage division value by the variable resistance VR3 are associated with each other for the entire variable range of the uniaxial triple potentiometer 4, and are associated with each other. 2, the ROM is stored. Therefore, the ROM stores the voltage division value by the variable resistance VR1, the voltage division value by the variable resistance VR2, and the voltage division value by the variable resistance VR3 when the uniaxial triple potentiometer 4 has a plurality of different rotation angles. is doing.

  The microcomputer 2 is based on the ratio of the voltage division value by the variable resistance VR1 and the voltage division value by the variable resistance VR2, which is stored in the ROM and corresponds to the variable resistance VR3 indicating the rotation angle of the uniaxial triple potentiometer 4. , DAC3 is controlled. Here, the ratio of the divided voltage value by the variable resistor VR1 and the divided voltage value by the variable resistor VR2 is the ratio of the signal levels of the L-channel analog audio signal and the R-channel analog audio signal. Therefore, in order to eliminate the signal level difference between the analog audio signal of the L channel and the analog audio signal of the R channel, a microcomputer is used according to the ratio of the voltage divided value by the variable resistor VR1 and the voltage divided value by the variable resistor VR2. 2 adjusts the gain of the DAC 3. For example, the gain for the L channel or the R channel of the DAC 3 is attenuated.

  At the time of reproducing music, as shown in FIG. 3, the switch 5 connects the L channel port of the DAC 3 and the variable resistor VR1. The switch 6 connects the R channel port of the DAC 3 and the variable resistor VR2. The switch 7 is in an off state, and disconnects the output of the variable resistor VR1 from the A / D port A / D1 of the microcomputer 2. Further, the switch 8 is in the off state, and shuts off the output of the variable resistor VR2 and the A / D port 2 of the microcomputer 2.

  When the uniaxial triple potentiometer 4 is operated, the microcomputer 2 corresponds to the divided voltage value by the variable resistance VR1 corresponding to the divided voltage value by the variable resistance VR3 output to the A / D port A / D3. The DAC 3 is controlled based on the ratio of the divided voltage value by the VR 2. The DAC 3 corrects the volume of the digital audio signal of the L channel and the R channel based on the setting made by the microcomputer 2. The DAC 3 D / A converts the L-channel digital audio signal into an analog audio signal. The L-channel analog audio signal D / A converted by the DAC 3 is output to the variable resistor VR 1 via the switch 5. The variable resistor VR1 divides the analog audio signal of the L channel. The L-channel analog audio signal divided by the variable resistor VR1 is output to the L-channel output terminal.

  The DAC 3 D / A converts the R channel digital audio signal into an analog audio signal. The R channel analog audio signal D / A converted by the DAC 3 is output to the variable resistor VR 2 via the switch 6. The variable resistor VR2 divides the R channel analog audio signal. The R channel analog audio signal divided by the variable resistor VR2 is output to the R channel output terminal.

  As described above, in the present embodiment, in the ROM, the variable resistor VR1, the variable resistor VR2, and the variable resistor VR3 are provided with a voltage division value by the variable resistor VR1 when a voltage of a predetermined potential is applied, and The divided voltage value by the resistor VR2 and the divided voltage value by the variable resistor VR3 are stored in association with each other. Then, the microcomputer 2 stores the divided voltage value by the variable resistance VR1 and the variable resistance VR2 corresponding to the divided voltage value by the variable resistance VR3 stored in the ROM, which indicates the rotation angle (adjustment position) of the uniaxial triple potentiometer 4. The DAC 3 is controlled based on the ratio with the partial pressure value by. This reduces the occurrence of gang errors.

  Although the embodiment of the present invention has been described above, the mode to which the present invention is applicable is not limited to the above-described embodiment, and as illustrated below, may be appropriately performed without departing from the spirit of the present invention. It is possible to make changes.

  In the above-described embodiment, the volume is adjusted by the uniaxial triple potentiometer 4. Not limited to this, when adjusting the volume of the balanced audio signal, the volume may be adjusted by a uniaxial five-series potentiometer.

  In this case, the DAC 3 has a non-inverting L (left) channel digital audio signal, an inverting L (left) channel digital audio signal, a non-inverting R (right) channel digital audio signal, and an inverting R digital signal. (Right) Correct the volume of the digital audio signal of the channel. The uniaxial five-series potentiometer includes a variable resistor (fourth variable resistor) for a non-inverted L (left) channel analog audio signal and a variable resistor (fifth variable resistor) for an inverted L (left) channel analog audio signal. ), A variable resistor (sixth variable resistor) for the non-inverted R (right) channel analog audio signal, and a variable resistor (seventh variable resistor) for the inverted R (right) channel analog audio signal. A variable resistor (eighth variable resistor) for correcting a gang error.

  The ROM includes a variable resistor for non-inverting L channel analog audio signals, a variable resistor for inverting L channel analog audio signals, a variable resistor for non-inverting R channel analog audio signals, and an inverting R channel. Voltage division value by non-inverted variable resistor for analog audio signal of L channel when voltage of predetermined potential is applied to variable resistor for analog audio signal of channel and variable resistor for correcting gang error And a divided value by a variable resistor for the inverted L channel analog audio signal, a divided value by a variable resistor for the non-inverted R channel analog audio signal, and a variable value for the inverted R channel analog audio signal. The voltage division value by the resistance and the voltage division value by the variable resistance for correcting the gang error are stored in association with each other.

  The microcomputer 2 is a non-inverted L-channel analog voice corresponding to the voltage division value by the variable resistor for correcting the gang error indicating the adjustment position (rotation angle) of the uniaxial five-series potentiometer stored in the ROM. The divided value by the variable resistor for the signal, the divided value by the variable resistor for the inverted L channel analog audio signal, the divided value by the variable resistor for the non-inverted R channel analog audio signal, and the inverted value The DAC 3 is controlled based on the ratio with the voltage division value of the variable resistor for the R channel analog audio signal.

  Further, the potentiometer may be a uniaxial quadruple potentiometer, a uniaxial 6 limb potentiometer, or the like.

  In the above-described embodiment, the divided voltage value of the variable resistor VR1, the divided voltage value of the variable resistor VR2, and the divided voltage value of the variable resistor VR3 are stored in the ROM of the microcomputer 2 in association with each other. Not limited to this, it may be stored in a memory outside the microcomputer 2.

  In the above-described embodiment, the DAC 3 corrects the volume in order to correct the gang error. Not limited to this, the volume may be corrected by another circuit. For example, the volume may be corrected by a DSP (Digital Signal Processor). The DSP is in the preceding stage of the DAC3, and the DSP outputs a digital audio signal to the DAC3. Which of the DSP and the DAC is to be used for correction may be determined based on whether or not fine level adjustment can be performed as a specification. Further, if controllable by the microcomputer 2, the volume may be corrected by an analog circuit.

  INDUSTRIAL APPLICATION This invention can be suitably employ | adopted for the volume control apparatus which adjusts the volume of an audio signal.

1 Music playback device (volume control device)
2 Microcomputer (control unit)
3 DAC (correction unit, volume correction unit)
4 Single axis triple potentiometer 5 Switch (1st switch)
6 switch (2nd switch)
7 switch (3rd switch)
8 switches (4th switch)

Claims (7)

A correction unit that corrects the signal,
A potentiometer having a plurality of variable resistors,
When a voltage of a predetermined potential is applied to the plurality of variable resistors, a storage unit that stores a plurality of divided voltage values by the plurality of variable resistors in association with each other,
Based on the ratio of the plurality of partial pressure values stored in the storage unit, corresponding to the partial pressure value indicating the adjustment position of the potentiometer, excluding the partial pressure value indicating the adjustment position of the potentiometer, the correction unit A control unit for controlling
A volume control device comprising: The correction unit is a volume correction unit that corrects the volume of the left channel audio signal and the right channel audio signal,
The potentiometer is
A first variable resistor for the left channel audio signal,
A second variable resistor for the right channel audio signal,
A single-axis triple potentiometer having a third variable resistance,
The storage unit has a first voltage division value of the first variable resistor when a voltage having a predetermined potential is applied to the first variable resistor, the second variable resistor, and the third variable resistor, A second partial pressure value by the second variable resistor and a third partial pressure value by the third variable resistor are stored in association with each other,
The control unit is a ratio of the first partial pressure value and the second partial pressure value, which is stored in the storage unit and corresponds to the third partial pressure value indicating the adjustment position of the uniaxial triple potentiometer. The volume adjusting device according to claim 1, wherein the volume correcting unit is controlled based on the above.   The storage unit stores the first partial pressure value, the second partial pressure value, and the third partial pressure value when the uniaxial triple potentiometer is at a plurality of different adjustment positions. The volume control device according to claim 2, wherein The controller controls the first partial pressure value and the second partial pressure value corresponding to the third partial pressure value indicating the adjustment position of the single-axis triple potentiometer when the single-axis triple potentiometer is operated. The volume adjusting device according to claim 2, wherein the volume correcting unit is controlled based on a ratio with a value. A first switch capable of switching between a power supply for supplying a voltage of the predetermined potential and a signal supply source for a left channel audio signal;
A second switch capable of switching between the power source and a signal supply source of a right channel audio signal,
One end of the first variable resistor is connected to the first switch, the other end is connected to the ground,
One end of the second variable resistor is connected to the second switch and the other end thereof is connected to the ground;
The volume adjusting device according to any one of claims 2 to 4, wherein one end of the third variable resistor is connected to the power source and the other end thereof is connected to the ground. A third switch that connects or disconnects the output from the first variable resistor and the control unit;
A fourth switch for connecting or disconnecting the output from the second variable resistor and the control unit;
The volume control device according to any one of claims 2 to 5, further comprising: The correction unit is a volume correction unit that corrects the volume of a non-inverted left channel audio signal, an inverted left channel audio signal, a non-inverted right channel audio signal, and an inverted right channel audio signal,
The potentiometer is
A fourth variable resistor for the non-inverting left channel audio signal,
A fifth variable resistor for the inverted left channel audio signal,
A sixth variable resistor for the non-inverted right channel audio signal,
A seventh variable resistor for the inverted right channel audio signal,
A uniaxial five-series potentiometer having an eighth variable resistance,
In the case where the storage unit applies a voltage of a predetermined potential to the fourth variable resistance, the fifth variable resistance, the sixth variable resistance, the seventh variable resistance, and the eighth variable resistance. A fourth voltage division value of the fourth variable resistance, a fifth voltage division value of the fifth variable resistance, a sixth voltage division value of the sixth variable resistance, and a seventh voltage division of the seventh variable resistance. A value and an eighth partial pressure value by the eighth variable resistor are stored in association with each other,
The control unit stores the fourth partial pressure value, the fifth partial pressure value, and the fifth partial pressure value stored in the storage unit, which correspond to the eighth partial pressure value indicating the adjustment position of the uniaxial five-series potentiometer. The volume adjusting device according to claim 1, wherein the volume correcting unit is controlled based on a ratio between a 6-partial pressure value and the seventh partial-pressure value.

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