BE450084A - - Google Patents
Info
- Publication number
- BE450084A BE450084A BE450084A BE450084A BE450084A BE 450084 A BE450084 A BE 450084A BE 450084 A BE450084 A BE 450084A BE 450084 A BE450084 A BE 450084A BE 450084 A BE450084 A BE 450084A
- Authority
- BE
- Belgium
Links
Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; 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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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/54—Accessories
- G03B21/56—Projection screens
- G03B21/565—Screens allowing free passage of sound
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE434831A BE434831A (https=) | 1939-06-10 | 1939-06-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE450084A true BE450084A (https=) | 1943-05-31 |
Family
ID=3869809
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE434831A BE434831A (https=) | 1939-06-10 | 1939-06-10 | |
| BE450084A BE450084A (https=) | 1939-06-10 | 1943-04-09 |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE434831A BE434831A (https=) | 1939-06-10 | 1939-06-10 |
Country Status (1)
| Country | Link |
|---|---|
| BE (2) | BE434831A (https=) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO20130568A1 (no) * | 2013-04-24 | 2014-10-27 | Momentor Ans | Lerret |
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1939
- 1939-06-10 BE BE434831A patent/BE434831A/fr unknown
-
1943
- 1943-04-09 BE BE450084A patent/BE450084A/fr unknown
Also Published As
| Publication number | Publication date |
|---|---|
| BE434831A (https=) | 1939-07-08 |