Patent US3870820A successfully refreshed from Google Patents.
US3870820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microphone with different directional modes
Assignee: Victor Company of Japan Ltd
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Filing: 1973-06-29
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Granted: 1975-03-11
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Expires: 1993-06-29
Abstract
Abstract A built-in microphone for a tape recorder, comprising a diaphragm responsive to sound waves and sensing means behind it in the microphone case. The microphone case has at least one opening to admit the sound waves to impinge on the inner surface of the diaphragm so as to counteract the effect of the sound waves impinging on the outer surface of the diaphragm for unidirectional mode of operation. The openings can be closed for nondirectional mode of operation.
Inventors
- 👤 Tomohide Suzuki
- 👤 Toshio Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:23
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/38
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
171 words
In combination, a recording apparatus having a casing and a microphone having a housing with a larger diameter portion and a smaller diameter portion defining a shoulder portion therebetween, said apparatus casing having an opening receiving said smaller diameter portion slidably movable with respect to said casing, said shoulder portion having at least a first opening therein, a diaphragm mounted in said larger diameter portion of said housing and having a first major surface exposed to frontal soundwaves and a backside second major surface opposite to said first major surface, a sensor operatively coupled to said diaphragm, a backplate mounted in said larger diameter portion spaced from said second surface of said diaphragm and defining a spaCe between it and said shoulder, said backplate having therein at least a second opening communicating with said first opening through said space, whereby upon slidable movement of said smaller diameter portion away from said apparatus casing said second opening is uncovered and soundwaves impinge on said second surface through said first and second openings.
Claim 2
Dependent Claim
171 words
In combination, a recording apparatus having a casing and a microphone having a housing with a larger diameter portion and a smaller diameter portion defining a shoulder portion therebetween, said apparatus casing having an opening receiving said smaller diameter portion slidably movable with respect to said casing, said shoulder portion having at least a first opening therein, a diaphragm mounted in said larger diameter portion of said housing and having a first major surface exposed to frontal soundwaves and a backside second major surface opposite to said first major surface, a sensor operatively coupled to said diaphragm, a backplate mounted in said larger diameter portion spaced from said second surface of said diaphragm and defining a spaCe between it and said shoulder, said backplate having therein at least a second opening communicating with said first opening through said space, whereby upon slidable movement of said smaller diameter portion away from said apparatus casing said second opening is uncovered and soundwaves impinge on said second surface through said first and second openings.
Claim 3
Dependent Claim
171 words
In combination, a recording apparatus having a casing and a microphone having a housing with a larger diameter portion and a smaller diameter portion defining a shoulder portion therebetween, said apparatus casing having an opening receiving said smaller diameter portion slidably movable with respect to said casing, said shoulder portion having at least a first opening therein, a diaphragm mounted in said larger diameter portion of said housing and having a first major surface exposed to frontal soundwaves and a backside second major surface opposite to said first major surface, a sensor operatively coupled to said diaphragm, a backplate mounted in said larger diameter portion spaced from said second surface of said diaphragm and defining a spaCe between it and said shoulder, said backplate having therein at least a second opening communicating with said first opening through said space, whereby upon slidable movement of said smaller diameter portion away from said apparatus casing said second opening is uncovered and soundwaves impinge on said second surface through said first and second openings.
Claim 4
Dependent Claim
171 words
In combination, a recording apparatus having a casing and a microphone having a housing with a larger diameter portion and a smaller diameter portion defining a shoulder portion therebetween, said apparatus casing having an opening receiving said smaller diameter portion slidably movable with respect to said casing, said shoulder portion having at least a first opening therein, a diaphragm mounted in said larger diameter portion of said housing and having a first major surface exposed to frontal soundwaves and a backside second major surface opposite to said first major surface, a sensor operatively coupled to said diaphragm, a backplate mounted in said larger diameter portion spaced from said second surface of said diaphragm and defining a spaCe between it and said shoulder, said backplate having therein at least a second opening communicating with said first opening through said space, whereby upon slidable movement of said smaller diameter portion away from said apparatus casing said second opening is uncovered and soundwaves impinge on said second surface through said first and second openings.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |