# US 2018/0322853 A1 · Hammer Velocity Measurement System

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- Number: US 2018/0322853 A1
- Document ID: US20180322853A1
- Status: Published application
- Kind: A1
- Application number: 16/032,608
- Filed: 2018-07-11
- Published: 2018-11-08
- Earliest claimed: 2014-10-02
- Assignees: Steinway, Inc.
- Applicants: Steinway, Inc.
- Inventors: Richard Shepherd
- Web page: https://patentgrep.com/patent/US20180322853A1

## CPC

- G10G 3/04: using electrical means
- G10C 3/18: Hammers
- G10F 1/02: Pianofortes with keyboard
- G10H 1/14: during execution {(voice controlled instruments G10H5/005)}
- G10H 1/34: Switch arrangements, e.g. keyboards or mechanical switches specially adapted for electrophonic musical instruments
- G10H 1/344: {Structural association with individual keys (electrically operated wind-actuated organs G10B3/22)}
- G10H 2220/271: Velocity sensing for individual keys, e.g. by placing sensors at different points along the kinematic path for individual key velocity estimation by delay measurement between adjacent sensor signals
- G10H 2220/305: using a light beam to detect key, pedal or note actuation
- G10G: REPRESENTATION OF MUSIC; RECORDING MUSIC IN NOTATION FORM; ACCESSORIES FOR MUSIC OR MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR, e.g. SUPPORTS (music stands A47B; non-musical aspects of musical toy instruments A63H5/00; metronomes G04F5/02; teaching music G09B15/00)
- G10C: PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS (automatic musical instruments G10F)
- G10F: AUTOMATIC MUSICAL INSTRUMENTS (non-musical aspects of toy instruments A63H5/00; sound recording or reproducing G11B; working in association with recording or reproducing apparatus G11B31/02)
- G10H: ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE

## Abstract

A system 100, for determining the velocity of a hammer 120 of a keyboard instrument, with a light transceiver 140 and processing circuitry 160. The light transceiver 140 being configured to transmit a light signal to a hammer 120 to measure a hammer velocity, receive a reflected light signal from the hammer 120 indicative of the velocity of the hammer 120 and send an electrical signal to the processing circuitry 160, where the electrical signal is based on the reflected light signal from the hammer 120. The processing circuitry 160 being configured to receive and process the electrical signal so that a time interval between the electrical signal passing through a first trigger point and a second trigger point and the velocity of the hammer 120 can be determined.

## Claims

### Claim at position 1

-20. (canceled)

### Claim 21

A method for determining a velocity of a hammer of a keyboard instrument, the method comprising:
transmitting a light signal to a hammer;
receiving a reflected light signal from the hammer indicative of a position of the hammer as the hammer moves between a rest position and a strike position;
generating an electrical signal based on the reflected light signal received from the hammer;
determining a time interval between the electrical signal passing through a first trigger point representative of a first hammer position and a second trigger point representative of a second hammer position; and
determining a velocity of the hammer based on the time interval,
wherein i) the first hammer position corresponds to a first hammer height above the rest position, or ii) the second hammer position corresponds to a second hammer height below the strike position, the second hammer height being in close proximity to the strike position.

### Claim 22 (depends on 21)

The method of claim 21, wherein processing circuitry is configured to:
receive and process the electrical signal;
determine the time interval between the electrical signal passing through the first trigger point and the second trigger point; and
determine the velocity of the hammer based on the time interval.

### Claim 23 (depends on 22)

The method of claim 22, wherein the processing circuitry is configured to:
store information related to a third trigger point; and
determine a time at which the electrical signal passes through the third trigger point, wherein:
the third trigger point is representative of a third hammer position at a third hammer height, and
the third hammer height corresponds to a time at which a damper of the keyboard instrument is no longer in contact with a string associated with the hammer.

### Claim 24 (depends on 22)

The method of claim 22, wherein a light transceiver is configured to transmit the light signal and receive the reflected light signal.

### Claim 25 (depends on 24)

The method of claim 24, wherein the light transceiver and the processing circuitry together form a hammer module, wherein the keyboard instrument comprises several hammer modules arranged to form a group module, wherein each hammer module in the group module is physically interconnected to an adjacent hammer module.

### Claim 26 (depends on 25)

The method of claim 25, wherein the group module is mounted on a printed circuit board, and the printed circuit board is configured to magnetically couple to a corresponding group of hammers.

### Claim 27 (depends on 26)

The method of claim 26, wherein the corresponding group of hammers comprises a saddle magnetically attractive to the printed circuit board and configured to magnetically couple thereto.

### Claim 28 (depends on 27)

The method of claim 27, wherein the saddle includes a pair of alignment members configured to engage with a corresponding pair of cut-outs on the printed circuit board when the printed circuit board is magnetically coupled to the saddle.

### Claim 29 (depends on 28)

The method of claim 28, wherein the cut-outs and the alignment members are positioned such that a longitudinal axis of the light transceiver of each hammer module is aligned with a hammer axis of a corresponding hammer of the group when the alignment members are engaged with the cut-outs.

### Claim 30 (depends on 29)

The method of claim 29, wherein the longitudinal axis of each light transceiver runs between a center of a light source and a center of a photo transistor to minimize cross-talk between neighboring hammer modules.

### Claim 31 (depends on 28)

The method of claim 28, wherein the alignment members comprise heads of fasteners that affix the saddle to flanges of the group of hammers.

### Claim 32 (depends on 25)

The method of claim 25, wherein light transceivers of adjacent hammer modules are configured to be positioned at different relative points along lengths of adjacent hammers corresponding to the adjacent hammer modules.

### Claim 33 (depends on 21)

The method of claim 21, wherein the first hammer position and the second hammer position are separated by a distance of 3-7 mm.

### Claim 34 (depends on 33)

The method of claim 33, wherein the distance between the first hammer position and the second hammer position is chosen such that a difference between a velocity of the hammer at the first hammer position and a velocity of the hammer at the second hammer position is minimized.

### Claim 35 (depends on 34)

The method of claim 34, wherein the second hammer height is 0.1-1.0 mm below the strike position in which the hammer makes contact with a string associated with the hammer.

### Claim 36 (depends on 21)

The method of claim 21, wherein the second hammer height is 0.1-1.0 mm below the strike position.

### Claim 37 (depends on 21)

The method of claim 21, further comprising:
setting the hammer to the first hammer height;
storing the first trigger point on a first sample-and-hold device;
setting the hammer to the second hammer height; and
storing the second trigger point on a second sample-and-hold device.

### Claim 38 (depends on 37)

The method of claim 37, wherein the first trigger point and the second trigger point are voltages supplied by a light transceiver that transmits the light signal and receives the reflected light signal.

### Claim 39 (depends on 37)

The method of claim 37, further comprising:
setting the hammer to a third hammer height; and
storing a third trigger point on a third sample-and-hold device,
wherein the third hammer height corresponds to a time at which a damper of the keyboard instrument is no longer in contact with a string associated with the hammer.

### Claim 40 (depends on 21)

The method of claim 21, wherein the light signal is a visible light signal or an infra-red light signal.