JP6350789B2 - Signal processing apparatus, electronic musical instrument, signal processing method and program - Google Patents

Description

The present invention relates to a signal processing device, an electronic musical instrument, a signal processing method, and a program that cancel out temperature drift of an output stage without temperature compensation and eliminate the need for a dead zone of an operator.

  In an electronic musical instrument, a rotary operator such as a pitch bender or a modulation wheel or a slider operator is provided as an operator for modifying generated musical sounds in real time. A variable resistor (volume resistor) is used for such an operator. When the resistance value of the variable resistor changes due to the operation of the operator (turning operation or sliding operation), the corresponding operation signal (output voltage signal) is level-shifted via a known emitter follower circuit. After that, it is supplied to the AD converter.

  In the emitter follower circuit, a temperature drift is known in which the base-emitter voltage of the bipolar transistor constituting the circuit changes according to the temperature. As a technique for suppressing this temperature drift, for example, Patent Document 1 includes a current source circuit serving as a temperature compensation unit, and a resistor connected from the current source circuit to the emitter so as to cancel the temperature drift of the base-emitter voltage. A technique for supplying current to the element is disclosed.

Japanese Patent Laid-Open No. 11-97942

  By the way, in the technique disclosed in Patent Document 1 described above, when temperature compensation is performed in consideration of transistor manufacturing variations, temperature compensation means (currents) are used to suppress temperature drift including voltage changes caused by the manufacturing variations. Source circuit) must be individually adjusted and lacks versatility.

  For this reason, in the electronic musical instrument described above, it is handled as an operation signal level-shifted at the output stage (emitter follower circuit) without temperature compensation, that is, an operation signal including temperature drift. That is, the maximum value and the minimum value of the operation signal generated by the operation of the operation element are converted in consideration of a range that varies due to temperature drift. Specifically, ranges corresponding to fluctuations due to temperature drift are provided as dead zones on the upper end side and the lower end side of the movable range of the operation element. The presence of such a dead zone adversely affects the operation feeling of the operation element. Therefore, in other words, there is a problem that it is impossible to cancel the temperature drift of the output stage without making temperature compensation and to eliminate the dead zone of the operator.

The present invention has been made in view of such circumstances, and a signal processing apparatus, electronic musical instrument, and signal processing that can cancel out the temperature drift of the output stage and eliminate the need for the dead zone of the operator without performing temperature compensation. It aims to provide a method and program.

In order to achieve the above object, the signal processing apparatus of the present invention includes: an output unit that performs level conversion on each of a plurality of input signals; and a plurality of signals that are output from the output unit. A detecting means for detecting a temperature drift level generated in the output means, and a temperature drift level detected by the detecting means for each of the signals other than the one signal among the plurality of signals output from the output means. And a detecting means for correcting temperature drift caused by the output means based on a signal set in response to an on / off switch operation among a plurality of signals output from the output means. It is characterized by detecting the level .

Further, the signal processing method of the present invention includes:
An output process of level-converting and outputting each of a plurality of input signals;
A detection process for detecting a temperature drift level generated in the output process from one signal among a plurality of signals output in the output process;
A correction step of correcting each of the other signals excluding the one signal out of the plurality of signals output in the output step based on the temperature drift level detected in the detection step. To do.

Furthermore, the program of the present invention
On the computer,
An output step for level-converting and outputting each of a plurality of input signals,
A detection step of detecting a temperature drift level generated in the output step from one signal among the plurality of signals output in the output step;
A correction step of correcting each of the other signals excluding the one signal out of the plurality of signals output in the output step based on the temperature drift level detected in the detection step; Features.

  In the present invention, the temperature drift of the output stage can be canceled without temperature compensation, and the dead zone of the operating element can be eliminated.

1 is a block diagram illustrating an overall configuration of an electronic musical instrument 100 including a signal processing device according to a first embodiment of the present invention. It is a block diagram which shows the structure of the operation part 11 by 1st Embodiment. It is a flowchart which shows operation | movement of a main routine. It is a flowchart which shows the operation | movement of initialization. It is a flowchart which shows the operation | movement of a switch process. It is a flowchart which shows the operation | movement of a slide SW process. It is a flowchart which shows the operation | movement of a keyboard process. It is a block diagram which shows the structure of the operation part 11 by 2nd Embodiment. It is a flowchart which shows the operation | movement of initialization by 2nd Embodiment. It is a flowchart which shows the operation | movement of the slide SW process by 2nd Embodiment. It is a flowchart which shows the operation | movement of the slide SW process by 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
A. Configuration of Electronic Musical Instrument 100 FIG. 1 is a block diagram showing an overall configuration of an electronic musical instrument 100 including a signal processing device according to the first embodiment of the present invention. In this figure, the keyboard 10 generates keyboard information including a key-on / key-off signal, a key number, a velocity, and the like corresponding to a key release / release operation. The keyboard information generated by the keyboard 10 is converted into a note-on / note-off event by the CPU 13 and then supplied to the sound source unit 16.

  The operation unit 11 includes various switches such as a timbre selection switch for selecting a tone color of a generated musical tone in addition to a power switch for powering on / off the apparatus power supply, and generates a switch event of a type corresponding to the switch operation. To do. The operation unit 11 includes a wheel operator (pitch bender, modulation wheel) and a slider operator for modifying the musical sound generated by the sound source 16 in real time.

  Here, with reference to FIG. 2, the principal part structure of the signal processing apparatus of 1st Embodiment with which the operation part 11 is provided is demonstrated. In this figure, only the variable resistance element VR (ch1) is shown for simplification of the drawing, but actually, the variable resistance element VR (ch1) is provided for each of the input channels ch1 to ch7 of the analog multiplexer 11a. ˜VR (ch7) is provided.

  The variable resistance elements VR (ch1) to VR (ch7) change in resistance values according to the rotation operation of the wheel operation element or the sliding operation of the slider operation element, and an operation signal (output voltage) whose level changes in accordance with this change. Signal) to the corresponding input channel of the analog multiplexer 11a. The analog multiplexer 11a outputs signals supplied to the input channels ch1 to ch8 in a time-sharing manner under the control of the CPU 13. A ground level signal is input to the input channel ch8 of the analog multiplexer 11a.

  The emitter follower circuit 11b performs level conversion on the signals of the input channels ch1 to ch8 that are time-division output from the analog multiplexer 11a and supplies the signals to the AD converter 11c. The level data of the input channels ch1 to ch8 subjected to AD conversion by the AD converter 11c is supplied to the CPU 13.

  As will be described later, the CPU 13 first acquires the level data of the input channel ch8 as reference level data, and thereafter, every time the level data of the input channel ch8 is output in a time-sharing manner, the level data is fetched and used as a reference. The difference from the level data, that is, the temperature drift level is calculated. Then, the calculated temperature drift level is subtracted from the level data of the other input channels ch1 to ch7 corresponding to the operation signal. Thereby, the temperature drift included in each level data of the input channels ch1 to ch7 is canceled.

  Next, the description of the overall configuration of the electronic musical instrument 100 will be continued with reference to FIG. 1 again. In FIG. 1, the display unit 12 displays a parameter setting state and an operation state of each part of the musical instrument on the screen based on a display control signal supplied from the CPU 13. The CPU 13 sets the operation state of each part of the musical instrument based on various switch events supplied from the operation unit 11 and instructs the sound source unit 16 to generate musical sound waveform data W based on the keyboard information supplied from the keyboard 10.

  Further, as described above, the CPU 13 first acquires and stores the level data of the input channel ch8 as the reference level data, and then takes in the level data of the input channel ch8 to obtain the difference from the reference level data, that is, the temperature drift level. The calculated temperature drift level is subtracted from each level data of the other input channels ch1 to ch7 corresponding to the operation signal to cancel the temperature drift. The CPU 13 instructs the sound source 16 to modify the generated musical sound according to the level data of the input channels ch1 to ch7 in which the temperature drift is canceled.

  The ROM 14 stores various control programs loaded on the CPU 13. The various control programs include a main routine, which will be described later, and initialization, switch processing, and keyboard processing that constitute the main routine. The switch process includes a slide volume process and other switch processes.

  The RAM 15 temporarily stores various register / flag data used for the processing of the CPU 13. The sound source unit 16 includes a plurality of sound generation channels configured by a well-known waveform memory reading method, generates musical tone waveform data W according to note-on / note-off events supplied from the CPU 13, and controls the operation unit 11. The musical tone waveform data W being generated is modified in accordance with the turning operation or sliding operation. The sound system 17 converts the musical sound waveform data W output from the sound source 16 into an analog musical sound signal, performs filtering such as removing unnecessary noise from the musical sound signal, and amplifies this to generate sound from the speaker. Let

B. Operation Next, operations of the electronic musical instrument 100 having the above-described configuration will be described with reference to FIGS. 3 to 7 for the main routine executed by the CPU 13, the initialization process, the switch process, and the keyboard process that constitute the main routine. .

(1) Operation of Main Routine FIG. 3 is a flowchart showing the operation of the main routine executed by the CPU 13. When the CPU 13 executes the main routine in response to the power-on of the electronic musical instrument 100, the process proceeds to step SA1 shown in FIG. 3, and initialization processing for initializing various registers and flags is executed. Details of the initialization process will be described later.

  Subsequently, in step SA2, a slide volume process for canceling the temperature drift from the operation signal and other switch processes for generating a switch event corresponding to the operated switch type are executed. Details of the slide volume process will be described later.

  Next, in step SA3, a note-on / note-off event is generated based on the keyboard information generated in response to the key release operation of the keyboard 10 and is sent to the sound source 16, and a musical tone of the pitch of the pressed key is generated. The keyboard processing is executed to cause the musical tone of the pitch of the released key to be muted. In step SA4, for example, other processing such as adding a user-designated effect to the generated tone is executed, and then the processing returns to step SA2. Thereafter, the steps SA2 to SA4 are repeatedly executed until the electronic musical instrument 100 is powered off.

(2) Operation of Initialization Processing FIG. 4 is a flowchart showing the operation of initialization processing executed by the CPU 13. When the initialization process is executed via step SA1 (see FIG. 3) of the main routine described above, the CPU 13 proceeds to step SB1 shown in FIG. 4 to set “−1” in the register drift_base, and in the subsequent step SB2 , The initial value is set in the register drift_val. Next, in step SB3, “8” is set to the channel number ch. The channel number ch specifies the input channel of the analog multiplexer 11a. In step SB4, initial values are set in the other registers and flags, and the present process ends.

(3) Operation of Switch Process FIG. 5 is a flowchart showing the operation of the switch process executed by the CPU 13, and FIG. 6 is a flowchart showing the operation of the slide volume process executed by the CPU 13. When the switch process is executed via step SA2 (see FIG. 3) of the main routine described above, the CPU 13 executes the slide volume process (described later) via step SC1 shown in FIG. The process proceeds to execute other switch processing that generates a switch event corresponding to the switch type to be operated. Hereinafter, the operation of the slide volume processing according to the gist of the present invention will be described in detail.

  When the slide volume process is executed via step SC1, the CPU 13 proceeds to step SD1 shown in FIG. In step SD1, the level data (AD conversion value) of the input channel of the analog multiplexer 11a specified by the channel number ch is stored in the register value (ch).

  In the situation where this process is executed first, since the channel number ch is initially set to “8” in step SB3 of the above-described initialization process (see FIG. 4), the ground level of the input channel ch8 is set in step SD1. Data is stored in register value (ch).

  Subsequently, in step SD2, it is determined whether or not the channel number ch is “8”. As described above, in the situation where this process is executed first, the channel number ch is initially set to “8”, so the determination result is “YES”, and the flow proceeds to step SD3. In step SD3, it is determined whether or not the value of the register drift_base is “−1”.

  In the situation where this process is executed first, the value of the register drift_base is initially set to “−1” in step SB1 of the above-described initialization process (see FIG. 4). The process proceeds to step SD4. In step SD4, the value of the register value (ch) acquired in step SD1, that is, the ground level data is stored in the register drift_base as reference level data.

  Thereafter, the process proceeds to step SD6, where the channel number ch is incremented and incremented, and in the subsequent step SD7, it is determined whether or not the incremented channel number ch exceeds the maximum value “8”. In the situation where this process is executed first, the stepped channel number ch is “9” and exceeds the maximum value “8”, so the determination result in step SD7 is “YES”, and the process proceeds to step SD8. The channel number ch is reset to the initial value “1”, and this process ends.

  Thus, after the ground level data of the input channel ch8 of the analog multiplexer 11a is stored in the register drift_base as the reference level data, this process is executed again through the main routine.

  Then, in step SD1, the level data of the input channel ch1 of the analog multiplexer 11a is stored in the register value (ch), and in the subsequent step SD2, it is determined whether or not the channel number ch is “8”. Since the channel number ch is “1”, the determination result is “NO”, and the process proceeds to step SD9.

  In step SD9, the value of the register drift_val is subtracted from the level data of the register value (ch), and the result is stored in the register value (ch). Note that, in a situation where all the level data of the input channels ch1 to ch8 have not been captured, the value of the register drift_val is an initial value set in step SB2 of the above-described initialization process (see FIG. 4).

  Next, in step SD10, the tone generator 16 is instructed to modify the musical sound assigned to the channel number ch based on the value of the register value (ch). For example, when the operator of the input channel ch1 is a pitch bender, the sound source 16 is instructed to change the pitch (pitch) of a musical sound that is being generated on the sound generation channel to which the pitch bender is assigned according to the pitch bender operation amount. .

  Thereafter, the process proceeds to step SD6, where the channel number ch is incremented and incremented. In the subsequent step SD7, it is determined whether or not the incremented channel number ch exceeds the maximum value “8”. If the incremented channel number ch does not exceed the maximum value “8”, the determination result is “NO”, and the process returns to step SD1. Thereafter, the processing of steps SD1, SD2, SD9, SD10, SD6, SD7 is repeated for the input channels ch2 to ch7.

  When the incremented channel number ch becomes “8”, the determination result in step SD2 is “YES”, and the process proceeds to step SD3 to determine whether or not the value of the register drift_base is “−1”. However, since the reference level data is already stored in the register drift_base, the determination result here is “NO”, and the process proceeds to step SD5.

  In step SD5, the temperature drift level obtained by subtracting the reference level data of the register drift_base from the ground level data of the input channel ch8 stored in the register value (ch) is stored in the register drift_val. Thereafter, the process proceeds to step SD6, where the channel number ch is incremented and stepped.

  Subsequently, in step SD7, it is determined whether or not the stepped channel number ch exceeds the maximum value “8”. In this case, the stepped channel number ch is “9”, and therefore the determination result is “9”. "YES" is determined, the process proceeds to step SD8, the channel number ch is reset to the initial value "1", and this process is terminated.

  Thus, after the temperature drift level is stored in the register drift_val and this process is executed again through the main routine, the above steps SD1, SD2, SD9, SD10, SD6, SD7 are performed for the input channels ch1 to ch7. By repeating the above process, the temperature drift level is subtracted from each level data of the input channels ch1 to ch7, and according to each level data of the input channels ch1 to ch7 in which the temperature drift is canceled, the corresponding channel number ch is set. The sound source 16 is instructed to modify the assigned musical sound. Then, when the ground level data of the input channel ch8 is newly taken in, the temperature drift level of the register drift_val is updated based on the above step SD5, and this processing is finished.

  As described above, in the slide volume processing, the level data of the input channel ch8 is first acquired as the reference level data, and thereafter, every time the level data of the input channels ch1 to ch8 is output in a time-sharing manner, The ch8 level data (ground level data) is taken in, and the difference from the reference level data, that is, the temperature drift level is calculated. Then, the calculated temperature drift level is subtracted from the level data of the other input channels ch1 to ch7 corresponding to the operation signal, thereby canceling out the temperature drift included in the level data of the input channels ch1 to ch7. It has become.

(4) Operation of Keyboard Processing FIG. 7 is a flowchart showing the operation of keyboard processing executed by the CPU 13. When this process is executed via step SA3 (see FIG. 3) of the main routine described above, the CPU 13 proceeds to step SE1 shown in FIG. 7 and detects the presence / absence of a key-on / key-off signal for each key on the keyboard 10. A key scan is performed, and in a subsequent step SE2, a key change is determined based on the key scan result in step SE1. If no key release operation is performed and no key change occurs, it is determined that there is no key change, and this process is terminated.

  When a key-on signal generated in response to the key depression is detected, the process proceeds to step SE3 via step SE2 to search for the number CH of the empty channel in which sound generation is stopped from among the plurality of sound generation channels provided in the sound source 16. . Next, in steps SE4 to SE5, note-on events (CH) assigned to the empty channel numbers CH searched in step SE3 are determined based on the key pressing number and velocity in the keyboard information generated by the keyboard 10 in response to the key pressing. The created note-on event (CH) is sent to the sound source 16 and the process is completed. As a result, the sound source 16 generates a musical sound according to the note-on event (CH) from the empty channel CH.

  On the other hand, when the key-off signal generated in response to the key release is detected, the process proceeds to step SE6 via step SE2 and a musical tone having the same pitch as the key release number is selected from the plurality of sound generation channels provided in the sound source 16. The number CH of the sounding channel that is occurring is searched. Subsequently, in step SE7, a note-off event (CH) assigned to the sound channel number CH searched in step SE6 is created based on the key release number in the keyboard information generated by the keyboard 10 in response to the key release. Then, the process proceeds to step SE5, where the created note-off event (CH) is sent to the sound source 16 and the present process ends. As a result, the sound source 16 mutes the musical sound that is being generated on the sound generation channel (CH).

  As described above, in the first embodiment, the signal processing of the input channels ch1 to ch8 that are time-division output from the analog multiplexer 11a is shifted to a predetermined level by the emitter follower circuit 11b and supplied to the AD converter 11c. In the apparatus, the level data of the input channel ch8 to be grounded is first obtained as reference level data, and thereafter, every time the level data of the input channel ch8 is output in a time-sharing manner, the level data is fetched and the reference level is obtained. The difference from the data, that is, the temperature drift level is calculated. Then, the calculated temperature drift level is subtracted from the level data of the other input channels ch1 to ch7 corresponding to the operation signal to cancel out the temperature drift included in these level data, and therefore output without temperature compensation. It becomes possible to eliminate the dead zone of the operating element by canceling out the temperature drift of the stage.

[Second Embodiment]
In the first embodiment described above, the input channel ch8 of the analog multiplexer 11a is occupied for ground input, the temperature drift level is detected from the change over time in the level data of the input channel ch8, and the detected temperature drift level is used as the operation signal. Is subtracted from each level data of the other input channels ch1 to ch7, so that the temperature drift included in each level data of the input channels ch1 to ch7 is canceled.

  On the other hand, in the second embodiment, when one of the input channels of the analog multiplexer 11a cannot be occupied for ground input, the input channel to which the on / off switch is assigned is used as the input for detecting the temperature drift level. It is a form used as a channel. Hereinafter, such a second embodiment will be described with reference to FIGS.

(1) Configuration of Operation Unit 11 FIG. 8 is a block diagram illustrating a configuration of the operation unit 11 according to the second embodiment. In this figure, the same reference numerals are given to the same components as those in the first embodiment (see FIG. 2), and the description thereof is omitted. The operation unit 11 illustrated in FIG. 8 has a configuration in which the input channel ch8 to which the on / off switch prev_sw is assigned among the input channels ch1 to ch8 of the analog multiplexer 11a is used as an input channel for temperature drift level detection.

  In the above configuration, when the on / off switch prev_sw is set to OFF when the electronic musical instrument 100 is powered on, the CPU 13 acquires the level data of the input channel ch8 that becomes the H level corresponding to the power supply voltage Vcc as the reference level data CH8_H1. . On the other hand, when the on / off switch prev_sw is set to ON when the electronic musical instrument 100 is turned on, the CPU 13 acquires the level data of the input channel ch8 that is L level corresponding to the ground level as the reference level data CH8_L1.

  When the input channel scan is completed and the level data of the input channel ch8 is time-divisionally output, if the on / off switch prev_sw of the input channel ch8 is set to OFF, the CPU 13 acquires the level data CH8_H2 of the input channel ch8. Then, the temperature drift level calculated from the difference (CH8_H1-CH8_H2) from the reference level data CH8_H1 is subtracted from the level data of the input channels ch1 to ch7 that are output in a time-sharing manner, and included in these level data. Compensates for temperature drift.

  On the other hand, when the level data of the input channel ch8 is output in a time-sharing manner after the input channel scan is complete, if the on / off switch prev_sw of the input channel ch8 is set to ON, the CPU 13 acquires the level data CH8_L2 of the input channel ch8. Then, the temperature drift level calculated from the difference (CH8_L1-CH8_L2) from the reference level data CH8_L1 is subtracted from the level data of the input channels ch1 to ch7 that are output in a time-sharing manner, and included in these level data. Compensates for temperature drift.

  Next, operations of initialization processing and slide volume processing that implement the operations of the second embodiment outlined above will be described. Since other processes are the same as those in the first embodiment described above, description of the operation is omitted.

(2) Operation of Initialization Processing According to Second Embodiment FIG. 9 is a flowchart showing the operation of initialization processing according to the second embodiment. As in the first embodiment described above, when this process is executed via step SA1 (see FIG. 3) of the main routine, the CPU 13 proceeds to step SF1 shown in FIG. 9 to set the on / off switch prev_sw to the on / off setting state. In response, “1” or “0” is set to the flag prev_sw_stat. That is, when the on / off switch prev_sw is set to off, “1” is set to the flag prev_sw_stat, while when the on / off switch prev_sw is set to on, “0” is set to the flag prev_sw_stat.

  Subsequently, “0” is set in the flag PF. The flag PF is “0” when the level data of the input channel ch8 is acquired as the reference level data, and “1” when the level data of the input channel ch8 including the temperature drift is acquired. Next, in step SF3, an initial value is set in the register drift_val. In step SF4, “8” is set to the channel number ch. The channel number ch specifies the input channel of the analog multiplexer 11a. Thereafter, in step SF5, initial values are set in other register flags, and this process is terminated.

(3) Operation of Slide Volume Processing According to Second Embodiment FIGS. 10 to 11 are flowcharts showing the operation of slide volume processing according to the second embodiment. As in the first embodiment described above, when this process is executed via step SA2 (see FIG. 3) of the main routine and step SC1 (see FIG. 5) of the switch process, the CPU 13 performs step SG1 shown in FIG. Then, the level data (AD conversion value) of the input channel ch of the analog multiplexer 11a designated by the channel number ch is stored in the register value (ch).

  Subsequently, in step SG2, it is determined whether or not the channel number ch is “8”. In the situation where this process is executed first, the channel number ch is initially set to “8” in step SF4 of the above-described initialization process (see FIG. 9), so the determination result is “YES”, and step SG3 Proceed to

  In step SG3, the level data of the input channel ch8 in the state where the value of the register value (ch) is not less than the threshold value Vth and the flag prev_sw_stat is “1”, that is, the on / off switch prev_sw is set to off. Is at the H level corresponding to the power supply voltage Vcc. Hereinafter, the description of the operation will be divided into a case where the on / off switch prev_sw is set to off and a case where the on / off switch prev_sw is set to on.

a. When the ON / OFF switch prev_sw is set to OFF If the ON / OFF switch prev_sw is set to OFF, the determination result at Step SG3 is “YES”, and the process proceeds to Step SG4 to determine whether or not the flag PF is “0”. to decide. In a situation where this process is executed first, the flag PF is set to “0” in step SF2 of the above-described initialization process (see FIG. 9), so the determination result is “YES” and the flow proceeds to step SG5.

  In step SG5, the value of the register value (ch), that is, the level data of the input channel ch8 that becomes H level corresponding to the power supply voltage Vcc is stored in the register CH8_H1 as reference level data. Hereinafter, the content of the register CH8_H1 is referred to as reference level data CH8_H1. Next, in step SG6, the flag PF is set to “1” and the process proceeds to step SG7.

  In step SG7, the channel number ch is incremented to be incremented, and in the subsequent step SG8, it is determined whether or not the incremented channel number ch has exceeded the maximum value “8”. In the situation where this process is executed first, the stepped channel number ch is “9” and exceeds the maximum value “8”, so the determination result in step SG8 is “YES”, and the process proceeds to step SG9. The channel number ch is reset to the initial value “1”, and this process ends.

  As described above, after obtaining the reference level data CH8_H1 when the on / off switch prev_sw is set to OFF, the stepped channel number ch becomes “8” again, and the ON / OFF switch prev_sw is set to OFF at that time. Suppose that it was done. Then, the determination results in steps SG2 and SG3 are both “YES”, and the process proceeds to step SG4. In step SG4, since the reference level data CH8_H1 has already been acquired, the flag PF is set to “1”. Therefore, the determination result is “NO”, and the process proceeds to step SG12.

  In step SG12, the value of the register value (ch), that is, the level data of the input channel ch8 that becomes the H level corresponding to the power supply voltage Vcc is stored in the register CH8_H2. Hereinafter, the content of the register CH8_H2 is referred to as level data CH8_H2. Subsequently, in step SG13, the temperature drift level is calculated from the difference (CH8_H1-CH8_H2) between the reference level data CH8_H1 and the level data CH8_H2, and stored in the register drift_val.

  Thereafter, the process proceeds to step SG7 described above, where the channel number ch is incremented and incremented. In the subsequent step SG8, the incremented channel number ch becomes “9” and exceeds the maximum value “8”. Becomes “YES”, the flow proceeds to step SG 9, the channel number ch is reset to the initial value “1”, and this processing ends.

  As described above, the temperature drift level is calculated from the difference (CH8_H1−CH8_H2) between the reference level data CH8_H1 and the level data CH8_H2 and stored in the register drift_val. When the level data is sequentially acquired as the register value (ch), the determination result of the above step SG2 becomes “NO”, the process proceeds to step SG10, and the temperature drift of the register drift_val from the level data of the register value (ch). The level is subtracted, and the subtraction result is stored in the register value (ch).

  Next, in step SG11, the tone generator 16 is instructed to modify the musical sound assigned to the channel number ch based on the value of the register value (ch) from which the temperature drift level has been canceled (subtracted). For example, when the operator of the input channel ch1 is a pitch bender, the sound source 16 is instructed to change the pitch (pitch) of a musical sound that is being generated on the sound generation channel to which the pitch bender is assigned according to the pitch bender operation amount. .

  Thereafter, the process proceeds to step SG7, where the channel number ch is incremented and incremented, and in the subsequent step SG8, it is determined whether or not the incremented channel number ch exceeds the maximum value “8”. If the incremented channel number ch does not exceed the maximum value “8”, the determination result is “NO”, and the process returns to step SG1. Thereafter, the processes of steps SG1, SG2, SG10, SG11, SG7, and SG8 described above are repeated for input channels ch2 to ch7.

b. When the on / off switch prev_sw is set to on When the on / off switch prev_sw is set to on, the determination result at step SG3 is “NO”, the process proceeds to step SG14 shown in FIG. 11, and the flag PF is “0”. Judge whether there is. In the situation where this process is executed first, the flag PF is set to “0” in step SF2 of the above-described initialization process (see FIG. 9), so the determination result is “YES” and the flow proceeds to step SG15.

  In step SG15, the value of the register value (ch), that is, the level data of the input channel ch8 that is L level corresponding to the ground level is stored in the register CH8_L1 as reference level data. Hereinafter, the content of the register CH8_L1 is referred to as reference level data CH8_L1. Next, in step SG16, the flag PF is set to “1”, and the process proceeds to step SG7 shown in FIG.

  In step SG7, the channel number ch is incremented to be incremented, and in the subsequent step SG8, it is determined whether or not the incremented channel number ch has exceeded the maximum value “8”. In the situation where this process is executed first, the stepped channel number ch is “9” and exceeds the maximum value “8”, so the determination result in step SG8 is “YES”, and the process proceeds to step SG9. The channel number ch is reset to the initial value “1”, and this process ends.

  As described above, after obtaining the reference level data CH8_L1 when the on / off switch prev_sw is set to on, the stepped channel number ch becomes “8” again, and the on / off switch prev_sw is set to on at that time. Suppose that it was done. Then, the determination result of step SG2 is “YES”, the determination result of step SG3 is “NO”, and the process proceeds to step SG14 shown in FIG. In step SG14, since the reference level data CH8_L1 has already been acquired, the flag PF is set to “1”. Therefore, the determination result is “NO”, and the flow proceeds to step SG17.

  In step SG17, the value of the register value (ch), that is, the level data of the input channel ch8 that is L level corresponding to the ground level is stored in the register CH8_L2. Hereinafter, the content of the register CH8_L2 is referred to as level data CH8_L2. Subsequently, in step SG18, the temperature drift level is calculated from the difference (CH8_L1-CH8_L2) between the reference level data CH8_L1 and the level data CH8_L2, and stored in the register drift_val.

  Thereafter, the process proceeds to the above-described step SG7 (see FIG. 10), the channel number ch is incremented and incremented, and in the subsequent step SG8, the incremented channel number ch becomes “9” and the maximum value “8” is set. Therefore, the determination result is “YES”, the process proceeds to step SG9, the channel number ch is reset to the initial value “1”, and this process is terminated.

  As described above, the temperature drift level is calculated from the difference (CH8_L1−CH8_L2) between the reference level data CH8_L1 and the level data CH8_L2 and stored in the register drift_val. When the level data is sequentially acquired as the register value (ch), the determination result of the above step SG2 becomes “NO”, the process proceeds to step SG10, and the temperature drift of the register drift_val from the level data of the register value (ch). The level is subtracted, and the subtraction result is stored in the register value (ch).

  Next, in step SG11, the tone generator 16 is instructed to modify the musical sound assigned to the channel number ch based on the value of the register value (ch) from which the temperature drift level has been canceled (subtracted). For example, when the operator of the input channel ch1 is a pitch bender, the sound source 16 is instructed to change the pitch (pitch) of a musical sound that is being generated on the sound generation channel to which the pitch bender is assigned in accordance with the pitch bender operation amount. .

  Thereafter, the process proceeds to step SG7, where the channel number ch is incremented and incremented, and in the subsequent step SG8, it is determined whether or not the incremented channel number ch exceeds the maximum value “8”. If the incremented channel number ch does not exceed the maximum value “8”, the determination result is “NO”, and the process returns to step SG1. Thereafter, the processes of steps SG1, SG2, SG10, SG11, SG7, and SG8 described above are repeated for input channels ch2 to ch7.

  As described above, in the second embodiment, among the input channels ch1 to ch8 of the analog multiplexer 11a, the input channel ch8 to which the on / off switch prev_sw is assigned is used as an input channel for temperature drift level detection. When the on / off switch prev_sw is set to OFF, the level data of the input channel ch8 that is at the H level corresponding to the power supply voltage Vcc is first obtained as the reference level data CH8_H1, and thereafter, the input channel scan is input in a round. When the level data of the channel ch8 is time-divisionally output, if the on / off switch prev_sw of the input channel ch8 is set to off, the level data CH8_H2 of the input channel ch8 is acquired.

  Then, the temperature drift level calculated from the difference (CH8_H1-CH8_H2) between the reference level data CH8_H1 and the level data CH8_H2 is subtracted from the level data of the input channels ch1 to ch7 that are output in a time-division manner thereafter. Since the temperature drift included in the data is canceled, the temperature drift of the output stage can be canceled without compensating for the temperature, and the dead zone of the operator can be made unnecessary.

  On the other hand, if the on / off switch prev_sw is set to on at the beginning of startup, the level data of the input channel ch8 that is L level corresponding to the ground level is first acquired as the reference level data CH8_L1, and thereafter the input channel scan is performed. When the level data of the input channel ch8 is output in a time-sharing manner, if the on / off switch prev_sw of the input channel ch8 is set on, the level data CH8_L2 of the input channel ch8 is acquired.

  Then, the temperature drift level calculated from the difference (CH8_L1-CH8_L2) between the reference level data CH8_L1 and the level data CH8_L2 is subtracted from the level data of the input channels ch1 to ch7 that are output in a time-division manner thereafter. Since the temperature drift included in the data is canceled, the temperature drift of the output stage can be canceled without compensating for the temperature, and the dead zone of the operator can be made unnecessary.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to it, It is included in the invention described in the claim of this-application, and its equivalent range. Hereinafter, each invention described in the scope of claims at the beginning of the present application will be additionally described.

(Appendix)
[Claim 1]
Output means for level-converting and outputting each of a plurality of input signals;
Detecting means for detecting a temperature drift level generated in the output means from one signal among a plurality of signals output from the output means;
Correction means for correcting each of the signals other than the one signal out of the plurality of signals output from the output means based on the temperature drift level detected by the detection means. A signal processing device.

  The correction means subtracts the temperature drift level detected by the detection means from each of other signals excluding the one signal among a plurality of signals output from the output means. The signal processing apparatus according to 1.

[Claim 3]
3. The signal processing apparatus according to claim 1, wherein the detection unit detects a temperature drift level generated in the output unit from a signal input to ground from a plurality of signals output from the output unit. .

[Claim 4]
The detection means includes
Of the plurality of signals output from the output means, a first acquisition means for acquiring the level of the ground input signal as reference level data;
Second acquisition for acquiring level data of a signal input to ground among a plurality of signals output from the output means each time a predetermined time has elapsed since the first acquisition means acquired reference level data. Means,
Temperature drift calculating means for calculating a temperature drift level from a difference between the acquired level data and the reference level data acquired by the first acquiring means each time the second acquiring means acquires level data; The signal processing apparatus according to claim 1, wherein the signal processing apparatus is a signal processing apparatus.

[Claim 5]
The detection means detects a temperature drift level generated in the output means based on a switch signal set to either an H level or an L level according to an on / off switch operation among a plurality of signals output from the output means. The signal processing apparatus according to claim 1, wherein the signal processing apparatus is detected.

[Claim 6]
The detection means includes
First obtaining means for obtaining, as reference level data, a level of a switch signal set to OFF among a plurality of signals output from the output means;
A second time for acquiring the level data of the switch signal set to OFF among the plurality of signals output from the output means each time a predetermined time elapses after the first acquisition means acquires the reference level data. Acquisition means;
Temperature drift calculating means for calculating a temperature drift level from a difference between the acquired level data and the reference level data acquired by the first acquiring means each time the second acquiring means acquires level data; The signal processing apparatus according to claim 5, wherein

[Claim 7]
The detection means includes
First acquisition means for acquiring, as reference level data, the level of the switch signal set to ON among the plurality of signals output from the output means;
A second time for acquiring the level data of the switch signal set to ON among the plurality of signals output from the output means each time a predetermined time elapses after the first acquisition means acquires the reference level data. Acquisition means;
Temperature drift calculating means for calculating a temperature drift level from a difference between the acquired level data and the reference level data acquired by the first acquiring means each time the second acquiring means acquires level data; The signal processing apparatus according to claim 5, wherein

[Claim 8]
A method performed in a signal processing device, comprising:
An output process of level-converting and outputting each of a plurality of input signals;
A detection process for detecting a temperature drift level generated in the output process from one signal among a plurality of signals output in the output process;
A correction step of correcting each of the other signals excluding the one signal out of the plurality of signals output in the output step based on the temperature drift level detected in the detection step. Signal processing method.

[Claim 9]
On the computer,
An output step for level-converting and outputting each of a plurality of input signals,
A detection step of detecting a temperature drift level generated in the output step from one signal among the plurality of signals output in the output step;
A correction step of correcting each of the other signals excluding the one signal out of the plurality of signals output in the output step based on the temperature drift level detected in the detection step; A featured program.

DESCRIPTION OF SYMBOLS 10 Keyboard 11 Operation part 11a Analog multiplexer 11b Emitter follower circuit 11c AD converter 12 Display part 13 CPU
14 ROM
15 RAM
16 Sound source section 17 Sound system 100 Electronic musical instrument

Claims (11)

Output means for level-converting and outputting each of a plurality of input signals;
Detecting means for detecting a temperature drift level generated in the output means from one signal among a plurality of signals output from the output means;
Correction means for correcting each of the other signals excluding the one signal among the plurality of signals output from the output means based on the temperature drift level detected by the detection means , and
The detection unit detects a temperature drift level generated in the output unit based on a signal set according to an on / off switch operation among a plurality of signals output from the output unit. . The output means converts an analog signal indicating an operation amount of the operation element into a digital signal and outputs the digital signal,
2. The signal processing apparatus according to claim 1, further comprising control means for controlling the generation of a musical sound based on the digital signal corrected by the correction means. The output means converts an operation amount of an operator that instructs modification to a musical sound generated by a sound source from an analog signal to a digital signal and outputs the converted signal.
3. The signal processing apparatus according to claim 2, wherein the control means performs control so as to modify a musical sound generated by a sound source based on the digital signal corrected by the correction means.   The correction means subtracts the temperature drift level detected by the detection means from each of other signals excluding the one signal among a plurality of signals output from the output means. The signal processing device according to any one of 1 to 3.   The said detection means detects the temperature drift level produced in the said output means from the signal input into the earth | ground among the several signals output from the said output means, The said any one of Claim 1 thru | or 4 characterized by the above-mentioned. Signal processing equipment. The detection means includes
Of the plurality of signals output from the output means, a first acquisition means for acquiring the level of the ground input signal as reference level data;
Second acquisition for acquiring level data of a signal input to ground among a plurality of signals output from the output means each time a predetermined time has elapsed since the first acquisition means acquired reference level data. Means,
Temperature drift calculating means for calculating a temperature drift level from a difference between the acquired level data and the reference level data acquired by the first acquiring means each time the second acquiring means acquires level data; The signal processing device according to claim 1, wherein the signal processing device is a signal processing device. The detection means includes
First obtaining means for obtaining, as reference level data, a level of a switch signal set to OFF among a plurality of signals output from the output means;
A second time for acquiring the level data of the switch signal set to OFF among the plurality of signals output from the output means each time a predetermined time elapses after the first acquisition means acquires the reference level data. Acquisition means;
Temperature drift calculating means for calculating a temperature drift level from a difference between the acquired level data and the reference level data acquired by the first acquiring means each time the second acquiring means acquires level data; The signal processing device according to claim 1, wherein the signal processing device is a signal processing device. The detection means includes
First acquisition means for acquiring, as reference level data, the level of the switch signal set to ON among the plurality of signals output from the output means;
A second time for acquiring the level data of the switch signal set to ON among the plurality of signals output from the output means each time a predetermined time elapses after the first acquisition means acquires the reference level data. Acquisition means;
Temperature drift calculating means for calculating a temperature drift level from a difference between the acquired level data and the reference level data acquired by the first acquiring means each time the second acquiring means acquires level data; The signal processing device according to claim 1, wherein the signal processing device is a signal processing device. An electronic musical instrument comprising the signal processing device according to any one of claims 1 to 8 ,
An electronic musical instrument further comprising control means for controlling the generation of a musical sound based on the signal corrected by the correction means. A method performed in a signal processing device, comprising:
Output processing for level-converting and outputting each of a plurality of input signals;
Among a plurality of signals output by the output processing, the detection processing for detecting the temperature drift levels resulting from one of the signal in the output process,
A correction process for correcting each of the other signals excluding the one signal among the plurality of signals output in the output process based on the temperature drift level detected in the detection process , and
In the signal processing method , the detection process detects a temperature drift level generated in the output process based on a signal set according to an on / off switch operation among a plurality of signals output in the output process. . On the computer,
Output processing for level-converting and outputting each of a plurality of input signals;
Among a plurality of signals output by the output processing, the detection processing for detecting the temperature drift levels resulting from one of the signal in the output process,
Correction processing for correcting each of the other signals excluding the one signal among the plurality of signals output in the output processing based on the temperature drift level detected in the detection processing , and
The detection process detects a temperature drift level generated in the output process based on a signal set according to an on / off switch operation among a plurality of signals output in the output process .

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