US3634593A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Key-operating mechanisms for electronic musical instruments
Assignee: Nippon Gakki Co Ltd
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Filing: 1970-10-29
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Granted: 1972-01-11
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Expires: 1990-10-29
Abstract
Abstract In an electronic musical instrument having a plurality of keys which are selectively depressed to generate tone signals of predetermined pitches, each key is provided with a piezoelectric element for producing a pulsating signal having a voltage level varied directly with the depressive force applied upon the key and an electrical circuitry for controlling the volume and/or tone color of the reproduced musical sound in response to the voltage level of the pulsating signal.
Inventors
- 👤 Takehiko Nagano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:35
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/055; G10H1/0556; G10D; G10D13/00; G10D13/01; G10D13/08; G10D13/09
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
107 words
A key-operating mechanism for an electronic musical instrument having a plurality of keys which are selectively operated to generate tone signals of different tone pitches and piezoelectric elements each for each key, each key including a mechanism for striking the associated piezoelectric element with a force corresponding to the depressive force applied thereon to produce a pulsating signal having a voltage level varied directly with the depressive force, a rectifier for rectifying the pulsating signal generated by said piezoelectric element and an electric circuitry to control at least one of the volume and tone color of the reproduced musical sound in accordance with the rectified pulsating signal.
Claim 2
Dependent Claim
107 words
A key-operating mechanism for an electronic musical instrument having a plurality of keys which are selectively operated to generate tone signals of different tone pitches and piezoelectric elements each for each key, each key including a mechanism for striking the associated piezoelectric element with a force corresponding to the depressive force applied thereon to produce a pulsating signal having a voltage level varied directly with the depressive force, a rectifier for rectifying the pulsating signal generated by said piezoelectric element and an electric circuitry to control at least one of the volume and tone color of the reproduced musical sound in accordance with the rectified pulsating signal.
Claim 3
Dependent Claim
59 words
The key-operating mechanism according to claim 1 wherein said striking mechanism comprises a swinging arm pivotally mounted under said key, a spring to urge said swinging arm to a position remote from said piezoelectric element, and means to drive said swinging arm to strike said piezoelectric element with a force corresponding to the depressive force applied upon said key.
Claim 4
Dependent Claim
89 words
The key-operating mechanism according to claim 1 wherein said striking mechanism comprises a substantially L-shaped swinging member including a rigid member and a leaf spring which are interconnected into said L-shape means to pivotally mount said L-shaped swinging member under said key, a weight secured to said leaf spring to hold said rigid member substantially in parallel relation with said key, and means for driving said swInging member with a force proportional to the depressive force applied to said key thus causing said weight to strike said piezoelectric element.
Claim 5
Dependent Claim
72 words
The key-operating mechanism according to claim 1 wherein said swinging arm comprises a leaf spring fixed at one end to extend substantially in parallel with said key, a weight secured to the free end of said leaf spring and means to deflect downwardly said leaf spring when said key is depressed thus causing said weight to strike said piezoelectric element with a force corresponding to the depressive force applied to said key.
Claim 6
Dependent Claim
82 words
The key-operating mechanism according to claim 1 wherein said striking mechanism comprises a catch secured to said key, a leaf spring with one end fixed and the other end caught by said catch, and a weigh secured to said leaf spring at a point intermediate the ends thereof whereby when said key is depressed said weight is caused to strike said piezoelectric element by the flexure of said leaf spring with a force corresponding to the depressive force applied to said key.
Claim 7
Dependent Claim
75 words
The key-operating mechanism according to claim 1 wherein said striking mechanism comprises a driving member secured to the lower side of said key, a stationary cushion confronting said driving member, a leaf spring with one end fixed and a piezoelectric element secured to said leaf spring between said driving member and said cushion whereby said piezoelectric element is struck by said driving member with a force proportional to the depressive force applied to said key.
Claim 8
Dependent Claim
45 words
The key-operating mechanism according to claim 1 wherein said striking mechanism comprises a driving member secured to the lower surface of said key, a plunger located under said driving member for supporting said piezoelectric element and compression spring urging said plunger toward said driving member.
Claim 9
Dependent Claim
91 words
The key-operating mechanism according to claim 1 wherein said electric circuitry comprises a rectifier for rectifying said pulse signal generated by said piezoelectric element, a capacitor charged by the output from said rectifier, a variable resistance element whose resistance is varied in accordance with the terminal voltage of said capacitor, and an amplifier to amplify the tone signal generated when said key is operated and passed through said variable resistance element so as to vary the volume of said tone signal in accordance with the depressive force applied to said key.
Claim 10
Dependent Claim
82 words
The key-operating mechanism according to claim 1 wherein said electric circuitry comprises a rectifier for rectifying said pulse signal generated by said piezoelectric element, a capacitor charged by the output from said rectifier, and a tone-coloring filter including a variable resistance element whose resistance is varied in accordance with the terminal voltage of said capacitor whereby to control the tone color of the tone signal generated by the depression of said key in accordance with the resistance variation of said resistance element.
Claim 11
Dependent Claim
17 words
The key-operating mechanism according to claim 8 wherein said variable resistance element is an active circuit element.
Claim 12
Dependent Claim
22 words
The key-operating element according to claim 9 wherein said variable resistance element included in said tone-coloring filter is an active circuit element.
Claim 13
Dependent Claim
23 words
The key-operating mechanism according to claim 2 wherein said swinging arm includes a roller driven by said key when the key is depressed.
Claim 14
Dependent Claim
76 words
The key-operating mechanism according to claim 2 wherein the lower end of said swinging arm is pivotally connected to a supporting arm, a roller is mounted on the upper end of said swinging arm, and said roller is normally urged against said driving means by means of a spring whereby when said key is operated said roller is caused to strike said piezoelectric element with a force proportional to the depressive force applied on said key.
References Cited (Backward Citations)
US3507970A
Cited
US3564105A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |