Claims
- 1. In an electronic musical instrument having a keyboard including a plurality of keys, an apparatus responsive to the depression of a key for controlling a tone signal corresponding to said key in accordance with the speed of key depression, comprising:
- (a) a key switch associated with said key and having a movable contact, a make contact and a break contact, the movable contact being normally held in engagement with the break contact and moved into enagagement with the make contact upon depression of the key;
- (b) a capacitor;
- (c) a charging circuit for charging the capacitor during a preassigned length of time following the movement of the movable contact of the key switch out of engagement with the break contact and before engagement with the make contact upon depression of the key;
- (d) first discharge means for causing the capacitor to discharge at a first predetermined rate during the interval from the charging of the capacitor to the engagement of the movable contact of the key switch with the make contact;
- (e) second discharge means for causing the capacitor to discharge at a second predetermined rate after the engagement of the movable contact of the key switch with the make contact; and
- (f) means responsive to a terminal voltage of the capacitor when the movable contact of the key switch comes into engagement with the make contact, which terminal voltage is a function of the key depression speed, for controlling the tone signal corresponding to the depressed key in accordance with said key depression speed.
- 2. The apparatus according to claim 1, wherein said responsive means includes means for controlling the amplitude of said tone signal to become large when the key depression speed becomes high.
- 3. The apparatus of claim 1 or 2, wherein the second discharge means include voltage divider means having a plurality of voltage dividing points to voltage-divide the terminal voltage of said capacitor and means for sequentially coupling the respective voltage dividing points with said responsive means following the engagement of the movable contact of the key switch with the make contact.
- 4. The apparatus of claims 1 or 2, further comprising third discharge means for causing the capacitor to discharge at a third predetermined rate after the movable contact of the key switch moves out of engagement with the make contact upon release of the key.
- 5. The apparatus of claim 4, wherein said third discharging is larger than said second discharging rate.
- 6. The apparatus of claim 5, wherein said first discharging rate is between said third and second discharging rates in magnitude.
- 7. The system of claim 5, wherein the third discharge means includes damper means for permitting the capacitor to discharge at said second predetermined rate even after the movable contact of the key switch moves out of engagement with the make contact upon release of the key.
- 8. In an electronic musical instrument having a keyboard including a plurality of keys, an apparatus responsive to the depression of a key for controlling a tone signal corresponding to said key in accordance with the speed of key depression, comprising:
- (a) switch means for producing a voltage pulse having a duration which is a function of the speed of depression of the key;
- (b) a capacitor;
- (c) a charging circuit for charging the capacitor during a predetermined period in response to the initiation of the voltage pulse;
- (d) a first discharge means for causing the capaictor to discharge at a first predetermined rate during an interval initiated by the charging of the capacitor and terminated in response to the termination of the voltage pulse;
- (e) a second discharge means for causing the capacitor to discharge at a second predetermined rate after the terminaton of the voltage pulse; and
- (f) a means responsive to a terminal voltage of the capacitor after the termination of the switch means voltage pulse, which terminal voltage is a function of the key depression speed, for controlling the tone signal corresponding to the depressed key in accordance with said key depression speed.
- 9. The apparatus according to claim 8, wherein said responsive means includes means for controlling the amplitude of said tone signal to become large when the key depression speed becomes high.
- 10. The apparatus of claim 8 or 9, wherein the second discharge means includes voltage divider means having a plurality of voltage dividing points to voltage-divide the terminal voltage of said capacitor, and means for sequentially coupling the respective voltage dividing points with said responsive means following the termination of the switch means voltage pulse.
- 11. The apparatus of claims 8 or 9, further comprising third discharge means for causing the capacitor to discharge at a third predetermined rate after the depression of the key is terminated.
- 12. The apparatus of claim 11, wherein said third discharging rate is faster than said second discharging rate.
- 13. The apparatus of claim 12, wherein said first discharging rate is between said third and second discharging rates in magnitude.
- 14. The apparatus of claim 12, wherein the third discharge means includes damper means for permitting the capacitor to discharge at said second predetermined rate even after the depression of the key is terminated.
- 15. In an electronic musical instrument having a keyboard including a plurality of keys, an apparatus responsive to the depression of a key by manual actuation, for controlling a tone signal corresponding to said key in accordance with the speed of key depression, comprising:
- (a) switch means, responsive to the manual actuation of a key, for producing a voltage pulse having a duration which is a function of the speed of depression of the key;
- (b) a capacitor;
- (c) a charging circuit for charging the capacitor to a predetermined level, in response to the depression of the key;
- (d) first discharge means for discharging the capacitor at a first predetermined rate during a first interval having a duration which is a function of the switch means voltage pulse duration wherein the terminal voltage of the capacitor at the end of the interval is a function of the speed of depression of the key;
- (e) second discharge means for discharging the capacitor at a second predetermined rate after the first predetermined rate interval; and
- (f) means responsive to the terminal voltage of the capacitor, for controlling the tone signal corresponding to the depressed key in accordance with the discharging terminal voltage of the capacitor and thereby in accordance with the key depression speed.
- 16. The apparatus of claim 15 wherein the charging circuit includes a voltage source, a first transistor switch operably connecting the voltage source to the capacitor and means responsive to the voltage pulse, for turning the transistor switch on for a second predetermined interval thereby charging the capacitor to the predetermined level.
- 17. The apparatus of claim 16, wherein the transistor turn on means includes a monostable circuit which is triggered by the rise of the voltage pulse and produces a second voltage pulse having a duration sufficient to turn on the transistor switch for the second predetermined interval.
- 18. The apparatus of claim 16 wherein the first discharge means comprises a discharge path, a second transistor switch operably connecting the discharge path to the capacitor and a second means, responsive to the voltage pulse, for turning on the second transistor switch for said first interval wherein the capacitor is discharged through the discharge path during the first interval.
- 19. In an electronic musical instrument having a keyboard including a plurality of keys, an apparatus responsive to the depression of a key for controlling a tone signal corresponding to said key in accordance with the speed of key depression, comprising:
- (a) switch means for producing a voltage pulse having a duration which is a function of the speed of depression of the key;
- (b) a capacitor and a charging circuit for charging the capacitor to a voltage level which is a function of the switch means voltage pulse duration and hence the key depression speed;
- (c) discharge means for discharging the capacitor after said voltage level is achieved; and
- (d) means responsive to the discharging capacitor voltage for controlling the tone signal in accordance with the capacitor voltage and thereby in accordance with the key depression speed.
- 20. A touch responsive control apparatus for a keyboard electronic musical instrument, comprising:
- a switch mechanically movable from a first position to a second position upon depression of a key in said keyboard,
- a capacitor,
- charging means for rapidly charging said capacitor to a first level upon initial movement of said switch away from said first position upon depression of a key, and
- discharging means for then discharging said capacitor at a fixed rate until said switch reaches said second position during said key depression,
- the resultant voltage on said capacitor being indicative of the speed of depression of said key.
Priority Claims (1)
Number |
Date |
Country |
Kind |
54-155786 |
Nov 1979 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 210,345, filed Nov. 25, 1980, and now abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (1)
Number |
Date |
Country |
48-42932 |
Dec 1973 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
210345 |
Nov 1980 |
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