JP4280227B2 - Electronic keyboard instrument keyboard device - Google Patents

Description

  The present invention relates to a keyboard apparatus for an electronic keyboard instrument that is applied to an electronic keyboard instrument such as an electronic piano and determines the timing of sound generation and the sound volume according to the keystroke speed.

Conventional electronic keyboard instruments generally determine at what timing during the key stroke operation and the sound volume of the sound generation based on the keyboard speed at the time of key depression, that is, the keystroke speed.
As an apparatus for detecting a key depression of such an electronic keyboard instrument, for example, there is an apparatus described in JP-A-4-52693 and an apparatus described in JP-A-6-95676.
In the apparatus described in Japanese Patent Laid-Open No. 4-52693, two switches are provided in the depth direction of the key stroke for each key in order to bring the performance feeling of an electronic keyboard instrument key closer to that of an acoustic piano, The time from when the first switch was turned on to when the second switch was turned on was measured, and a sound signal corresponding to the measurement time was output.

Furthermore, in the apparatus described in Japanese Patent Laid-Open No. 6-95676, an analog switch such as a volume is provided for each key so that the performance feeling of the keys of the electronic keyboard instrument is brought close to that of an acoustic piano. The key stroke speed is calculated, the calculated stroke speed is compared with a predetermined critical speed, and a sound generation signal is output when the calculated stroke speed exceeds the critical stroke speed.
Japanese Patent Laid-Open No. 4-52693 JP-A-6-95676

However, in the former device in which two switches are provided in the depth direction of the key stroke, the detection position for sound generation when the key is pressed is determined from the relationship between the key stroke position and the switch installation position. It is limited to one place, and it has been difficult to bring the performance feeling of an electronic keyboard instrument close to the feeling of a desired keyboard instrument such as an acoustic piano.
In addition, since these switches are physically in contact with the contacts, contact failures are likely to occur, and no sound may be produced.

  In a device that detects the key stroke position by an analog switch such as the latter volume, the voltage value output from the analog switch is detected by an AD converter, and the difference between the current detection value and the previous detection value is determined for a predetermined time. Since the key stroke speed is calculated by dividing by the above, when calculating the key stroke speed more accurately, that is, with a finer period, it is necessary that the accuracy and resolution of the AD converter is not high. The difference between the detected values of the analog switch becomes zero, and the key stroke speed cannot be calculated. In this way, the higher the period of calculation, the higher the performance of the AD converter and the higher the cost.

Further, the output characteristic with respect to the stroke when the analog switch is pressed at a constant speed is not actually a straight line, but is non-linear as shown in FIG. 7, for example.
When a key of an electronic keyboard instrument using an analog switch with such characteristics is pressed at a constant speed, the difference in the detected value of the analog switch with respect to a predetermined stroke width is the detected value difference at the desired stage of the key stroke. At the end of the key stroke, the difference between the detected values of the analog switch with respect to the predetermined stroke width becomes the detected value difference B. When the key stroke speed is calculated using these detected value differences A and B, different speeds are calculated in the initial stage and the end stage of the key stroke, although the key stroke speed is actually constant. Therefore, when the output characteristic of the analog switch itself with respect to the stroke is non-linear, there is a problem that it is impossible to calculate an accurate key stroke speed.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an inexpensive keyboard device for an electronic keyboard instrument with a simple structure.

  The present invention provides a stroke position detecting means for detecting a stroke position of a key, and a first stroke position determining means for determining whether or not the key has passed a first detection point based on a detection result of the stroke position detecting means. Timer means for counting an elapsed time from when the key passes the first detection point, sound generation determination means for performing sound generation permission determination when the key reaches a predetermined stroke position, and timer means. A storage unit for storing a sound generation reference stroke position corresponding to the elapsed time, and the sound generation determination means includes a key stroke position detected by the stroke position detection means and a timer means for each elapsed time count by the timer means. Compared to the pronunciation reference stroke position corresponding to the elapsed time counted by the Stroke position of detected by the detecting means key when located in Oshikata direction side of the key, and shall make sound permission determination.

According to the present invention, for each count by the timer means, the key stroke position detected by the stroke position detecting means is compared with the sound generation reference stroke position to determine whether or not to sound at the current stroke position of the key. By performing the determination, it is only necessary to compare numerical values without performing complicated processing such as speed conversion, for example, so that it is possible to reduce the calculation processing load for sound generation permission determination.
Therefore, an inexpensive keyboard device for an electronic keyboard instrument can be obtained with a simple configuration without using a high-performance arithmetic processing unit (specifically, a CPU or the like).

Next, embodiments of the present invention will be described by way of examples.
In this embodiment, an electronic piano is used as the electronic keyboard instrument.
FIG. 1 shows the overall configuration of this embodiment.
The electronic piano 1 includes a plurality of keys (not shown), and each key is provided with a keyboard switch 10 (10A, 10B,...).
The keyboard switch 10 detects that a key has been pressed by the operator of the electronic piano 1, and uses a capacitive switch. This capacitance type switch is a non-contact type switch, has no defects such as contact fixing, and has high reliability.
As the installation position of the keyboard switch 10 on the key and the configuration of the capacitance type switch 10, for example, those described in JP-A-9-204846 and JP-A-2002-23758 can be used. Description of is omitted.
The key is assumed to have a hammer action function described in JP-A-2002-23758.

The keyboard switch 10 has a capacitance that changes in accordance with the amount of key press, and the capacitance change is detected by a capacitance detection circuit 11.
A detection result by the capacitance detection circuit 11 is output to the AD converter 12 as a detection voltage. The AD converter 12 converts the input analog detection voltage into a digital signal, and outputs the converted digital signal to the CPU 13.

The CPU 13 determines the key stroke position from the input signal.
Further, the CPU 13 includes a timer 15 that outputs a count signal at a predetermined time interval after the key stroke position passes the first detection point. The CPU 13 detects the stroke position of the key every time the count signal is output, and compares the stroke position with a tone generation processing map shown in FIG. Is output to the sound source 14 as a sounding signal.
The predetermined time interval of the count signal output from the timer 15 depends on the processing speed of the CPU constituting the timer function, and the time interval is a time required to process the key stroke detection at least once. . Further, the number of times the count signal is output corresponds to the elapsed time after the key stroke position passes the first detection point.

Further, the CPU 13 determines which keyboard switch of the plurality of keyboard switches 10 (10A, 10B...) Is to be detected, and outputs a key scan control signal to the keyboard switch 10.
As a result, the electrostatic capacitance is sequentially detected for all the keyboard switches 10 provided in the electronic piano 1, and it is possible to detect which key is currently pressed and to which position.
The sound source 14 is used for sound generation, and generates sound of a predetermined volume and a predetermined sound range based on a sound generation signal input from the CPU 13.
The storage unit 16 stores a sound generation process map used for sound generation determination processing by the CPU 13.

Next, pronunciation determination processing performed by the CPU 13 will be described.
FIG. 2 shows the relationship between the key stroke position and the first detection point and the second detection point, and FIGS. 3 and 4 show the flow of the sound generation determination process performed by the CPU 13. FIG. 5 shows a sound generation processing map, and FIG. 6 shows sound generation position characteristics.
Here, as shown in FIG. 2, the position at the normal time of the key (before the key is pressed) is the initial position, and the position where the key is pressed deepest is the deepest position. The CPU 13 uses the keyboard switch 10 to detect the key stroke position in a predetermined section from the initial position to the deepest position.

The sound generation process map shown in FIG. 5 used for the sound generation determination process is stored in advance in the storage unit 16 connected to the CPU 13.
In addition, the CPU 13 divides the stroke width from the initial key position to the deepest position into 128 steps, and uses a hexadecimal number to indicate where the key is located in the divided stroke width. It is assumed that the key is located at a deeper position (deepest position side) as the numerical value is larger.
The number of stroke width divisions is determined based on the minimum stroke width by which the CPU 13 can identify the key stroke position.

Similarly, the pronunciation reference stroke position is also expressed using hexadecimal numbers as shown in FIG.
Further, the CPU 13 controls the volume signal output to the sound source 14 in 128 steps, and a sound generation table representing the volume signal intensity is stored in the storage unit 16. The pronunciation table is also stored using hexadecimal numbers as shown in FIG.

  Each time the count signal is output from the timer 15, the CPU 13 detects the key stroke position as a second detection point, and the second detection point is more than the sound generation reference stroke position corresponding to the count signal output count shown in FIG. When the value is large (when it is the deepest position side), the numerical value described in the sound generation table is output to the sound source 14. When the second detection point does not exceed the sound generation reference stroke position, the sound generation signal is not sent to the sound source 14.

In this embodiment, the smaller the number of count signal outputs (the shorter the elapsed time), the deeper the sounding stroke position is set, and the larger the number of count signal outputs (the longer the elapsed time), the shallower the sounding stroke position. Set to position. When the keystroke speed is high, the sounding reference stroke position set at a deeper position is exceeded when the elapsed time from the start of counting by the timer is short, so that the key stroke position is deeper as shown in FIG. Pronunciation is performed at the position. On the other hand, when the keystroke speed is slow, sound is generated at a position where the key stroke position is shallow.
In this way, by changing the numerical value of the sound generation reference stroke position with respect to the count signal output count, it is possible to control to what position the key is pressed according to the keystroke speed.
Therefore, it is possible to obtain the touch characteristics of the keyboard of the desired keyboard instrument using this sound generation processing map.

  As shown in FIG. 3, when the key scan is started, the CPU 13 detects the key stroke position in step 100 using the keyboard switch 10 provided for the key to be subjected to the sound generation determination process. . Specifically, the capacitance of a predetermined keyboard switch that performs the sound generation determination process is detected by the capacitance detection circuit 11, and the detected voltage value detected by the capacitance detection circuit 11 is converted by the AD converter 12. The CPU 13 receives the converted value.

  In step 101, it is determined whether or not the key to be subjected to the sound generation determination process has moved from the initial position and made a sound by the current key operation (operation from when the key leaves the initial position until it returns to the initial position). to decide. If the key stroke position remains at the initial position or if the key has been stroked from the initial position but no sound is produced by the current key operation, the process proceeds to step 102. On the other hand, if the sound has already been generated by the operation of the key this time, the routine proceeds to step 108.

In step 102, it is determined whether or not the key stroke position detected in step 100 exceeds the first detection point (whether or not the key stroke position is on the deepest position side of the first detection point). If the first detection point has been exceeded, the process proceeds to step 103, and if not, the process proceeds to step 107.
If the first detection point for delay is set in step 115 to be described later, it is determined in step 102 whether or not the key stroke position exceeds the first detection point for delay.

In step 103, the timer 15 starts counting.
This start process is executed only when it is first determined that the first detection point has been exceeded in step 102 during the current key operation.
If it is determined at step 102 that the first stroke position has been exceeded for the second time or more during the current key operation, the process at step 103 is not performed.

In step 104, the stroke position of the key detected in step 100 is set as a second detection point, and the second detection point and the number of times counted by the timer 15 (the number of count signal outputs) are used. By referring to the sound generation processing map shown in FIG. 5, it is determined whether or not sound generation is performed at the current key stroke position.
Since it is determined in step 102 that the key stroke position exceeds the first detection point, here, the key stroke position detected in step 100 is the second detection point.

  Specifically, a pronunciation reference stroke position corresponding to the number of times of output of the count signal output from the timer 15 is extracted from the pronunciation process map shown in FIG. 5, and the extracted pronunciation reference stroke position and the second detection point are extracted. A comparison is made, and when the second detection point exceeds the sound generation reference stroke position (the second detection point is located on the deepest position side), it is determined that sound generation is performed, and the count signal output from the timer 15 is output. The numerical value described in the corresponding pronunciation table is extracted.

In step 105, a branching process for determining whether or not to sound is performed based on the determination result in step 104. If sounding is to be performed, the process proceeds to step 106, and if sounding is not to be performed, the process proceeds to step 114.
In step 106, the numerical value of the sound generation table extracted in step 104 is transmitted to the sound source 14 as a sound generation signal.
Note that the sound generation signal corresponds to the volume when sounding.
As a result, the sound source 14 produces a sound with a volume corresponding to the sound generation signal and a sound range corresponding to the key at the current stroke position of the key.

In step 107, a key scan control signal is output to the keyboard switch 10 to be detected next, and then preparation for detecting the stroke position of the key is made.
When all the processes are completed, the process returns to step 100 to repeat the above-described process and repeat the sound generation determination process for all keys.

If the sound is generated by the current key operation in step 101, it is determined in step 108 whether the key stroke position has returned to the initial position side from the sound generation OFF position.
The sound generation OFF position is set closer to the initial position than the first detection point, as shown in FIG.

When the key stroke position returns to the initial position side from the sound generation OFF position, the process proceeds to step 113, and when the key stroke position does not return to the initial position side from the sound generation OFF position, the process proceeds to step 109.
In step 113, a sounding OFF signal is output to the sound source 14, and the timer 15 stops counting. As a result, the sound produced by operating the key is stopped.
After transmitting the sound generation OFF signal in step 113, the process proceeds to step 107 and the above processing is repeated.

In step 109, it is determined whether or not the key stroke position detected in step 100 has returned to the initial position side from the reproducible return position and the key has advanced in the pushing direction side (deepest position side).
Here, as shown in FIG. 2, the range from the position on the predetermined width initial position side to the sounding OFF position from the deepest position is set as a re-soundable region, and the key strokes in the re-soundable region even after once sounding. It is assumed that the area can be sounded again when the position is located.
Further, the re-reproducible return position is set at the lower limit position (the deepest position) of the re-reproducible area.

Whether the key has advanced in the pressing direction is determined by comparing the stroke position detected in step 100 in the previous processing of the key with the stroke position of the key detected in step 100 this time. It is possible to determine which direction the traveling direction is.
If it is determined in step 109 that the key stroke position has returned to the initial position side from the reproducible return position and the key has advanced in the pushing direction side, the process proceeds to step 110; Proceed to 107.

In step 110, a first detection point for re-sounding is set.
In the present embodiment, the first detection point for re-sounding is set at the lower limit position (the position on the deepest position side) of the re-soundable region.
In step 111, it is determined whether or not the stroke position of the key detected in step 100 exceeds the first detection point for re-sounding (whether it is located deeper than the first detection point for re-sounding). If it exceeds the first detection point for re-sounding, the process proceeds to step 112, and if not, the process proceeds to step 107.

In step 112, the timer 15 newly starts counting.
This start process is executed only when it is determined for the first time that the first detection point for re-sounding has been exceeded in step 111 during the current key operation. If the timer 15 has already started counting by processing in another step, the count information of the timer related to the key is discarded.

After the processing in step 112, the process proceeds to step 104. Thereafter, the sound source 14 refers to the sound generation processing map of FIG. , Sounding at a predetermined volume.
By having the processing from step 108 to step 112 in this way, even when the operator presses the key and makes a sound and then presses the key again before returning it to the initial position, the sound is made (hereinafter, Called re-pronunciation after pronunciation).

If it is determined in step 104 that no sound is generated and the process proceeds to step 114 in the branching process in step 105, it is determined whether or not the key movement is an abnormal keystroke different from the normal keystroke operation.
Specifically, when the key stroke position exceeds the first detection point and the timer 15 starts counting, the key stroke position is determined to be abnormal when the key stroke position hardly changes for a long time.
This determination is performed using the count information by the timer 15, the current key stroke position, and a table for determining whether or not the key is abnormally pressed, and whether or not the storage unit 16 is abnormally keyed in advance. Holds a table to determine.
If it is determined that the key is abnormal, the process proceeds to step 115. If it is determined that the key is not abnormal, the process proceeds to step 107.

In step 115, a first detection point for delay is set.
The first detection point for delay is set at the same position as the first detection point for re-sounding in this embodiment.
In step 116, it is determined whether or not the stroke position of the key detected in step 100 exceeds the delay first detection point (whether it is located on the deepest position side of the delay first detection point). If the first detection point for delay is exceeded, the process proceeds to step 117, and if not, the process proceeds to step 107.

In step 117, the timer 15 newly starts counting.
This start process is executed only when it is determined in step 116 that the first detection point for re-sounding has been exceeded for the first time during the operation of the key. If the timer 15 has already started counting by processing in another step, the count information of the timer related to the key is discarded.

After the processing in step 117, the process proceeds to step 107, and thereafter, by referring to the sound generation processing map of FIG. 5 as described above based on the count signal that the timer 15 has started to output in step 117, the sound source 14 makes a predetermined volume. Perform pronunciation.
By having the processing from step 114 to step 117 in this way, sound can be generated even when the operator slowly presses the key halfway and then presses the key at a high speed.
In this embodiment, step 100 constitutes the stroke position detecting means in the present invention, and step 102 constitutes the first stroke position determining means in the present invention. Steps 103, 112, and 117 constitute timer means in the present invention, and the sound generation table constitutes volume data in the present invention. Step 104 constitutes sound generation determination means in the present invention.

In this embodiment, the key stroke position is detected as the second detection point by using the keyboard switch 10 for each count signal output from the timer 15, and the second detection point is shown in FIG. By comparing with the pronunciation reference stroke position included in the pronunciation processing map, it is determined whether or not to sound at the current stroke position of the key. Since it is possible to determine whether or not to generate sound only by performing comparison, it is possible to reduce the calculation processing burden of sound generation determination.
Therefore, a keyboard device for an electronic keyboard instrument can be realized with an inexpensive configuration without using a high-performance arithmetic processing unit (specifically, a CPU or the like).

Further, the amount of change during the key stroke is reduced by further reducing the time width of the count performed by the timer 15 and detecting the key stroke position as the second detection point for each count and comparing it with the pronunciation processing map. It is possible to perform a process for determining whether or not to pronounce the sound more precisely.
Further, at the keystroke detection timing for each count, the keystroke detection time and the timer count interval are not necessarily synchronized, and either one of the time or interval may be earlier. The timer 15 may be, for example, a single free-running timer, or may be stored by temporarily storing a plurality of necessary times in the storage unit 16 by arithmetic processing, or may be another method as long as the time can be measured.

In this way, the sound generation determination process can be performed more finely by reducing the count time width of the timer 15 without increasing the performance of the AD converter 12, so that the sound generation determination process can be performed more finely. A keyboard device for a keyboard instrument can be provided at low cost.
Further, in order to improve reliability, the detection order of keystrokes may be changed as necessary, or each detection point may be detected a plurality of times.
Further, by using a capacitive switch as the keyboard switch 10, there is no failure such as contact sticking, and the reliability of the keyboard device of the electronic keyboard instrument can be improved.

  Furthermore, when the key is advanced in the pushing direction after the key is sounded and the key stroke is returned to the re-soundable return position after the key operation has been performed, the processing in steps 108 to 112 is repeated. The first detection point for sound generation is set, the timer 15 starts a new count, and the sound generation determination is performed using the sound generation processing map. Even when the key is pressed again after the return, the sound can be re-sound, and the sound processing map is used even during the re-sound, so that a desired keyboard touch characteristic can be realized.

  If the key stroke position exceeds the first detection point and remains at that position for a predetermined time or longer, the first detection point for delay is set by the processing from step 114 to step 117, Since counting by the timer 15 is newly started and sound generation determination is performed using the sound generation processing map, even when the operator slowly presses the key halfway and then presses the key at a high speed, it is large. Sound can be produced at a volume, and a keyboard touch closer to the desired keyboard instrument can be realized.

In the embodiment, when re-sounding after sounding or when it is determined that the key is abnormally pressed, it is determined whether to sound or not based on the sounding processing map shown in FIG. In this case, it is possible to obtain the touch characteristics of the keyboard of the desired keyboard instrument by performing the sound generation process using another sound generation process map different from the normal time.
Alternatively, in the case of re-sounding after sounding or an abnormal keystroke determination, two switches are provided in the depth direction of the key stroke as in the conventional example without using the sounding processing map, and the first switch It is also possible to determine whether or not to generate sound based on the time from when ON is turned on until the second switch is turned on.
Further, the storage unit 16 stores a plurality of pronunciation processing maps corresponding to touch characteristics of a keyboard such as a piano or an organ (which sound volume is to be generated at which stroke position after the key is pressed) and is sounded by a changeover switch or the like. By enabling the process map to be switched, a desired keyboard touch characteristic can be obtained simply by the operator selecting the sound generation process map.

Furthermore, the first detection point for re-sounding and the first detection point for delay are set to the re-soundable return position. However, the present invention is not limited to this, and calculation is performed so as to approximate the touch characteristics of the key of the desired keyboard instrument. It is also possible to set to the position obtained by the above, or to set the position obtained experimentally.
Also, the setting of the upper limit position and the lower limit position of the re-soundable area can be changed.
Alternatively, by combining the pronunciation processing map described above with the key hammer action function that realizes the key touch characteristics of the desired keyboard instrument, the operator's performance sensation is made closer to that of the desired keyboard instrument. Can do.

In the embodiment, the electronic piano is used as the electronic keyboard instrument. However, the present invention can be applied to any instrument having a keyboard.
Further, although the capacitance type switch is used as the keyboard switch 10, an analog type switch such as a volume may be used instead.

It is a figure which shows the whole structure in an Example. It is a figure which shows the positional relationship of each detection point with respect to the stroke position of a key. It is a figure which shows the flow of a pronunciation determination process. It is a figure which shows the flow of a pronunciation determination process. It is a figure which shows a pronunciation process map. It is a figure which shows a pronunciation position characteristic. It is a figure which shows the output characteristic of an analog switch.

Explanation of symbols

1 Electronic Piano 10, 10A, 10B Keyboard Switch 11 Capacitance Detection Circuit 12 AD Converter 13 CPU
14 sound source 15 timer 16 storage unit

Claims (5)

Stroke position detecting means for detecting the stroke position of the key;
First stroke position determining means for determining whether the key has passed the first detection point based on a detection result of the stroke position detecting means;
Timer means for counting an elapsed time from when the key passes the first detection point;
A sounding determination means for performing sounding permission determination when the key reaches a predetermined stroke position;
A storage unit for storing a pronunciation reference stroke position corresponding to the elapsed time counted by the timer means;
The sound generation determination means calculates a key stroke position detected by the stroke position detection means and a sound generation reference stroke position corresponding to the elapsed time counted by the timer means for each elapsed time count by the timer means. A keyboard device for an electronic keyboard instrument, characterized in that, when the key stroke position detected by the stroke detection means is located closer to the key pressing direction than the sound generation reference stroke position, the sound generation permission determination is performed. . The storage unit further corresponds to the elapsed time counted by the timer means, and stores sound volume data of sound produced by the electronic keyboard instrument,
The sound generation determination means further extracts sound volume data corresponding to the elapsed time counted by the timer means at the time of sound generation permission determination from the storage unit simultaneously with the sound generation permission determination. A keyboard device for electronic keyboard instruments. The keyboard device for an electronic keyboard instrument according to claim 1, wherein at least one of the pronunciation reference stroke position and the volume data stored in the storage unit can be changed. 4. The keyboard device for an electronic keyboard instrument according to claim 1, wherein the stroke position detecting means detects a stroke position of the key using a capacitance type switch. 5. The keyboard device for an electronic keyboard instrument according to claim 1, wherein a hammer action function is added to the key.

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