BE474660A - - Google Patents
Info
- Publication number
- BE474660A BE474660A BE474660DA BE474660A BE 474660 A BE474660 A BE 474660A BE 474660D A BE474660D A BE 474660DA BE 474660 A BE474660 A BE 474660A
- Authority
- BE
- Belgium
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
- H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
- H04R1/345—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means for loudspeakers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
Landscapes
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US691279A US2483231A (en) | 1946-08-17 | 1946-08-17 | Loud-speaking telephone set with low acoustic coupling |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE474660A true BE474660A (ru) |
Family
ID=24775892
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE474660D BE474660A (ru) | 1946-08-17 |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US2483231A (ru) |
| BE (1) | BE474660A (ru) |
| FR (1) | FR949759A (ru) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2580439A (en) * | 1949-09-07 | 1952-01-01 | Bell Telephone Labor Inc | Directional acoustic system |
| US3069508A (en) * | 1958-05-02 | 1962-12-18 | Ericsson Telefon Ab L M | Telephone instrument |
| WO2011042019A1 (en) * | 2009-10-07 | 2011-04-14 | Sl Audio A/S | Dipole loudspeaker with diffuse rear radiation |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2114680A (en) * | 1934-12-24 | 1938-04-19 | Rca Corp | System for the reproduction of sound |
| FR856727A (fr) * | 1938-06-24 | 1940-08-03 | Telefunken Gmbh | Système permettant d'éviter les réactions acoustiques dans les installations de diffusion de parole |
| US2177769A (en) * | 1938-12-24 | 1939-10-31 | Frank I Du Frane Company Inc | Loud-speaking intercommunicating system |
| US2208160A (en) * | 1939-10-19 | 1940-07-16 | Harold J Mccreary | Communication system |
| US2381174A (en) * | 1942-11-16 | 1945-08-07 | Brush Dev Co | Communication system |
| US2385279A (en) * | 1943-01-27 | 1945-09-18 | Bell Telephone Labor Inc | Distant talking loud-speaker telephone system |
-
0
- BE BE474660D patent/BE474660A/xx unknown
-
1946
- 1946-08-17 US US691279A patent/US2483231A/en not_active Expired - Lifetime
-
1947
- 1947-07-19 FR FR949759D patent/FR949759A/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR949759A (fr) | 1949-09-08 |
| US2483231A (en) | 1949-09-27 |