Method and apparatus for optically determining note characteristics from key motion in a keyboard operated musical instrument

• US 5,841,050 A
• Filed: 06/10/1996
• Issued: 11/24/1998
• Est. Priority Date: 02/27/1995
• Status: Expired due to Term

• Current Assignee: Sanwa Bank California (Bank of Montreal)
• Original Assignee: Burgett, Inc.
• Inventors: Lee, Charles R., Clift, Pamela K.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): HSIEH, SHIH YUNG
• Application Number:
  US08/658,486
• Time in Patent Office: 897 Days
• Field of Search: 84/461, 84/462, 84/645, 84/626, 84/658, 84/670, 84/236, 84/DIG. 7, 84/687, 84/718, 84/724
• US Class Current: 84/462
• CPC Class Codes: G10G 3/04 using electrical means
• CPC Class Codes: G10H 1/0553 using optical or light-responsive means
• CPC Class Codes: G10H 1/34 Switch arrangements, e.g. keyboards or mechanical switches specially adapted for electrophonic musical instruments

Abstract

A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned adjacent to the keys. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through. This overlapping of sensor board activation and reading, which is made possible by the preferred arrangement of the dual sensor banks as well as the data acquisition method employed, provides for a higher throughput of data conversion than has been heretofore achieved, and thus more efficient sensing and recording of musical expression information from keyboard instruments than has been previously attained.

Claims

1. An apparatus for determining motion characteristics of selected string striking means in a keyboard operated musical instrument having a plurality of string striking means, comprising:

(a) a plurality of sensor banks, each said sensor bank including a plurality of sensor boards, each said sensor board including a plurality of light emitters and corresponding light sensors, said light emitters and corresponding light sensors positioned adjacent said plurality of string striking means in said keyboard operated musical instrument, each said light sensor producing an output voltage responsive to intensity of sensed light reflected from a corresponding one of said plurality of string striking means in said keyboard operated musical instrument; and

(b) control means for addressing said sensor banks, addressing said sensor boards, activating said light emitters and said light sensors in said addressed sensor boards, acquiring voltage output data from said light sensors in said addressed sensor boards, sequencing between addressing a sensor bank and a sensor board in said addressed sensor bank, and determining motion characteristics of said plurality of string striking means from said acquired output voltage data.

2. An apparatus as recited in claim 1, further comprising means for recording said key motion characteristics on a machine readable storage media.

3. An apparatus for determining motion characteristics of selected string striking means in a keyboard operated musical instrument having a plurality of string striking means, comprising:

(a) first and second sensor banks, each said sensor bank including a plurality of sensor boards, each said sensor board including a plurality of light emitters and corresponding light sensors, said light emitters and corresponding light sensors positioned adjacent said plurality of string striking means in said keyboard operated musical instrument, each said light sensor producing an output voltage responsive to intensity of sensed light reflected from a corresponding one of said string striking means; and

(b) control means for addressing said first and second sensor banks, sequentially addressing said sensor boards in said sensor banks, activating said light emitters and said light sensors in said addressed sensor boards, acquiring voltage output data from said light sensors in said addressed sensor boards, alternating between addressing a sensor board in said first sensor bank and a sensor board in said second sensor bank, and determining motion characteristics of said string striking means from said acquired output voltage data.

4. An apparatus as recited in claim 3, further comprising means for recording said key motion characteristics on a machine readable storage media.

5. A method for determining motion characteristics of selected string striking means in a keyboard operated musical instrument having a plurality of string striking means, comprising the steps of:

(a) positioning a plurality of sensor boards adjacent to said plurality of string striking means, said sensor boards divided into a plurality of sensor banks, each said sensor board including a plurality of light emitting diodes, each said light emitting diode positioned adjacent to a corresponding one of said plurality of string striking means, each said sensor board including a plurality of photosensors, each said photosensor positioned adjacent to a corresponding light emitting diode and adjacent to said corresponding one of said plurality of string striking means;

(b) sequentially addressing said sensor banks;

(c) sequentially addressing said sensor boards;

(d) activating said light emitters and said light sensors in said addressed sensor boards;

(e) acquiring voltage output data from said light sensors in said addressed sensor boards, said voltage output data generated from sensed light reflected from said plurality of string striking means;

(f) sequencing between addressing a sensor bank and a sensor board in said addressed sensor bank; and

(g) determining motion characteristics of said plurality of string striking means from said acquired output voltage data.

6. A method as recited in claim 5, further comprising the steps of recording said key motion characteristics on a machine readable storage media.

7. A method for determining motion characteristics of selected string striking means in a keyboard operated musical instrument having a plurality of string striking means, comprising the steps of:

(a) positioning a plurality of sensor boards adjacent to said plurality of string striking means, said sensor boards divided into first and second sensor banks, each said sensor board including a plurality of light emitting diodes, each said light emitting diode positioned adjacent to a corresponding one of said plurality of string striking means, each said sensor board including a plurality of photosensors, each said photosensor positioned adjacent to a corresponding light emitting diode and adjacent to said corresponding one of said plurality of string striking means;

(b) sequentially addressing said sensor banks;

(c) sequentially addressing said sensor boards;

(d) activating said light emitters and said light sensors in said addressed sensor boards;

(e) acquiring voltage output data from said light sensors in said addressed sensor boards, said voltage output data generated from sensed light reflected from said plurality of string striking means;

(f) alternating between addressing a sensor board in said first sensor bank and a sensor board in said second sensor banks; and

(g) determining motion characteristics of said plurality of string striking means from said acquired output voltage data.

8. A method as recited in claim 7, further comprising the steps of recording said key motion characteristics on a machine readable storage media.