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
Application number
BE450084A
Other languages
French (fr)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed filed Critical
Publication of BE450084A publication Critical patent/BE450084A/fr

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
    • 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)
BE450084A 1939-06-10 1943-04-09 BE450084A (ko)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
BE434831A BE434831A (ko) 1939-06-10 1939-06-10

Publications (1)

Publication Number Publication Date
BE450084A true BE450084A (ko) 1943-05-31

Family

ID=3869809

Family Applications (2)

Application Number Title Priority Date Filing Date
BE434831A BE434831A (ko) 1939-06-10 1939-06-10
BE450084A BE450084A (ko) 1939-06-10 1943-04-09

Family Applications Before (1)

Application Number Title Priority Date Filing Date
BE434831A BE434831A (ko) 1939-06-10 1939-06-10

Country Status (1)

Country Link
BE (2) BE434831A (ko)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO20130568A1 (no) 2013-04-24 2014-10-27 Momentor Ans Lerret

Also Published As

Publication number Publication date
BE434831A (ko) 1939-07-08

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