US4002897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Opto-acoustic telephone receiver
Assignee: AT&T Inc
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Filing: 1975-09-12
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Granted: 1977-01-11
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Expires: 1995-09-12
Abstract
Abstract An opto-acoustic telephone receiver, for converting optical signals propagating in an optical fiber waveguide into audible acoustic signals, includes an optical absorption cell having a volume of the order of 10 - 3 cm 3 , acoustically coupled to the narrow end of a tapered acoustic tube whose wide end can be acoustically coupled to a human ear.
Inventors
- 👤 David Allmond Kleinman
- 👤 Donald Frederick Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:43
CPC Classifications
H; H04; H04R; H04R23/00; H04R23/008
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
97 words
Apparatus which comprises a. a hollow chamber of the order of 0.001 cm 3 in volume, b. a first aperture in said chamber for the entry of light signals; c. light absorbing means for absorbing the light located in said chamber; and d. a second aperture in said chamber for the exit of acoustic signals into a hollow tube in accordance with the light signals, said acoustic signals having been generated in the chamber and said hollow tube adapted for acoustically transmitting said acoustic signals from a relatively narrow input end to a relatively wide output end.
Claim 2
Dependent Claim
97 words
Apparatus which comprises a. a hollow chamber of the order of 0.001 cm 3 in volume, b. a first aperture in said chamber for the entry of light signals; c. light absorbing means for absorbing the light located in said chamber; and d. a second aperture in said chamber for the exit of acoustic signals into a hollow tube in accordance with the light signals, said acoustic signals having been generated in the chamber and said hollow tube adapted for acoustically transmitting said acoustic signals from a relatively narrow input end to a relatively wide output end.
Claim 3
Dependent Claim
28 words
Apparatus according to claim 1 in which said volume is in the range of about 5 × 10.sup. -4 to about 2.5 × 10.sup. -3 cm 3 .
Claim 4
Dependent Claim
19 words
Apparatus according to claim 1 in which the chamber has an aperture for the insertion of an optical fiber.
Claim 5
Dependent Claim
93 words
Apparatus according to claim 1 which further comprises: the hollow tube of tapered inside cross section whose narrow end has an inside cross section of the order of 0.01 cm 2 and whose wide end has an inside cross section of the order of 1.0 cm 2 , the length of said tube being of the order of 100 cm, the narrow end being acoustically coupled to the second aperture of the chamber, and said tapering being such that the inside cross section area varies monotonically from the narrow to the broad end.
Claim 6
Dependent Claim
38 words
Apparatus according to claim 4 in which the tube has an inside circular cross section of radius equal to about 0.04 cm at the narrow end and of radius equal to about 0.09 cm at the wide end.
Claim 7
Dependent Claim
16 words
Apparatus according to claim 4 in which the length of the tube is about 85 cm.
Claim 8
Dependent Claim
19 words
Apparatus according to claim 4 in which the chamber is acoustically coupled to the tube by a loaded diaphragm.
Claim 9
Dependent Claim
31 words
Apparatus according to claim 4 in which the wide end of the tube is coupled to an ambient atmosphere by a diaphragm and a perforated screen mutually defining a volume therebetween.
Claim 10
Dependent Claim
19 words
Apparatus according to claim 4 in which the chamber has an aperture for the insertion of an optical fiber.
Claim 11
Dependent Claim
45 words
Apparatus according to claim 4 in which the narrow end of the tube is acoustically coupled to the chamber by a hollow channel of length of the order of 2 cm and a substantially uniform cross section of the order of 0.001 cm 2 .
Claim 12
Dependent Claim
123 words
Apparatus for converting an optical signal to an acoustic signal which comprises: a. a hollow chamber of the order of 10.sup. -3 cm 3 in volume having a first aperture for the insertion of an optical waveguide and a second aperture for acoustic coupling; b. a tapered hollow acoustic tube of the order of 100 cm in length having a first end of narrow inside cross-section area of the order of 10.sup. -2 cm 2 coupled acoustically to the second aperture of the chamber and a second end of wide inside cross-section area of the order of 1 cm 2 for acoustic coupling to a human ear, the inside cross section of said tube varying monotonically from the narrow to the wide end.
Claim 13
Dependent Claim
123 words
Apparatus for converting an optical signal to an acoustic signal which comprises: a. a hollow chamber of the order of 10.sup. -3 cm 3 in volume having a first aperture for the insertion of an optical waveguide and a second aperture for acoustic coupling; b. a tapered hollow acoustic tube of the order of 100 cm in length having a first end of narrow inside cross-section area of the order of 10.sup. -2 cm 2 coupled acoustically to the second aperture of the chamber and a second end of wide inside cross-section area of the order of 1 cm 2 for acoustic coupling to a human ear, the inside cross section of said tube varying monotonically from the narrow to the wide end.
Claim 14
Dependent Claim
20 words
Apparatus according to claim 11 in which the waveguide is an optical fiber which is inserted in the first aperture.
Claim 15
Dependent Claim
19 words
Apparatus according to claim 11 in which the second end is acoustically coupled by means of an acoustic diaphragm.
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) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |