Claims
- 1. A key position computing apparatus for a player piano comprising:
- (a) sensing means provided on each key for measuring a characteristic operating signal representing a distance between a reference plane and a key surface for each key, and for outputting a value of the characteristic operating signal;
- (b) gain adjusting means for adjusting a gain of the value of the characteristic operating signal output from the sensing means to a constant value;
- (c) linearizing means for approximating the value of the characteristic operating signal output from the sensing means with a linearized output signal;
- (d) memory means for storing computer programs to compute a relationship between the linearized output signal output from the linearizing means and the distance between the reference plane and the key surface;
- (e) programmable memory means for storing the value of the characteristic operating signal of the sensing means for each key; and
- (f) computing means for computing the relationship between the linearized output signal from the linearizing means and the distance from the reference plane to the key surface of each key, thereby permitting a continual monitoring and a real time dynamic reproduction of a musical performance.
- 2. The key position computing apparatus as claimed in claim 1,
- wherein the sensing means comprises:
- an unitized reflecting type photo-interruptor (RPI) system including a light source for emitting a beam of light to the key surface of each key; and a light sensor for receiving the emitted beam of light reflected from the key surface of each key, and
- wherein the sensing means further generates a output signal in accordance with a distance x between the reference plane and the key surface of each key.
- 3. The key position computing apparatus as claimed in claim 2, wherein the RPI system generates an output signal which varies as an exponential function of the distance x.
- 4. The key position computing apparatus as claimed in claim 1, wherein the gain adjusting means includes a voltage control amplification device which varies an amplification factor in accordance with a signal supplied from an external source.
- 5. The key position computing apparatus as claimed in claim 1, wherein the linearizing means computes linear tangential expressions to approximate an exponential function.
- 6. The key position computing apparatus as claimed in claim 1, wherein the computing means and the gain adjusting means comprise an unitized device having a dedicated program which provides a real time digital computation of positional changes exhibited by each key during the musical performance.
- 7. A method for key position computing for a player piano comprising the steps of:
- selecting a first mode for initialization and testing or a second mode for computing a key position;
- wherein said first mode comprises the steps of;
- (a) generating a reference electrical signal,
- (b) detecting a reference electrical signal value of the reference electrical signal with a sensor,
- (c) computing a reference distance using the detected reference signal value according to a distance between a reference plane and a surface of a key,
- (d) storing the reference electrical signal value detected by the detecting step in a computer memory, and
- (e) computing a gain of a position computing circuit using a mathematical relationship and the stored reference signal value, and computing a correction factor for the gain of the position computing circuit,
- wherein said second mode comprises the steps of;
- (f) generating and detecting a new reference electrical signal generated according to a new distance between the reference plane and the surface of the key,
- (g) adjusting the gain of the new reference electrical signal to an adjusted value by the correction factor,
- (h) linearizing the detected new reference electrical signal to a linearized signal of new distance between the reference plane and the surface of the key.
- 8. The method of key position computing as claimed in claim 7, wherein the second mode may be repeated without repeating the first mode.
- 9. The method of key position computing as claimed in claim 7, wherein there is an additional step (d') repeating steps (a) through (d) for a second reference electrical signal according to a second distance between the reference plane and the surface of the key, and wherein step (e) uses both stored values of the reference signals with the mathematical relationship.
- 10. The method of key position computing as claimed in claim 9, wherein the second mode may be repeated without repeating the first mode.
- 11. The method of key position computing as claimed in claim 9, wherein the correction factor is stored in the computer memory.
- 12. The method of key position computing as claimed in claim 7, wherein the first mode is performed automatically.
- 13. The method of key position computing as claimed in claim 7, wherein the first mode is performed manually.
- 14. A method for key position computing for a player piano comprising the steps of:
- initializing by:
- (a) generating a reference electrical signal,
- (b) detecting a reference electrical signal value of the reference electrical signal with a sensor,
- (c) computing a reference distance using the detected reference signal value according to a distance between a reference plane and a surface of a key,
- (d) storing the reference electrical signal value detected by the detecting step in a computer memory,
- (e) computing a gain of a position computing circuit using a mathematical relationship and the stored reference signal values, and computing a correction factor for the gain of the position computing circuit, and
- computing a new key position by:
- (g) generating a detecting a new reference electrical signal generated according to a new distance between the reference plane and the surface of the key,
- (h) adjusting the gain of the new reference electrical signal to an adjusted value by the correction factor,
- (i) computing the new key position using the new reference electrical signal, and
- (j) linearizing the detected new reference electrical signal to a linearized signal of new distance between the reference plane and the surface of the key.
- 15. The method of key position computing as claimed in claim 14, wherein there is an additional step (d') repeating steps (a) through (d) for a second reference electrical signal according to a second distance between the reference plane and the surface of the key, and wherein step (e) uses both stored values of the reference signals with the mathematical relationship.
- 16. The method of key position computing as claimed in claim 15, wherein computing a new key position may be repeated without repeating the initializing steps.
- 17. The method of key position computing as claimed in claim 15, wherein the correction factor is stored in the computer memory.
- 18. The method of key position computing as claimed in claim 14, wherein the initializing steps are performed automatically.
- 19. The method of key position computing as claimed in claim 14, wherein the initializing steps are performed manually.
- 20. The key position computing apparatus as claimed in claim 3, wherein the linearizing means computes linear tangential expressions to approximate the exponential function.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-20030 |
Jan 1990 |
JPX |
|
Parent Case Info
This is a continuation in part application of the U.S. patent application U.S. Ser. No 07/647,440 filed Jan. 29, 1991, now abandoned.
US Referenced Citations (5)
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
647440 |
Jan 1991 |
|