Sound output system

• US 5,988,314 A
• Filed: 12/15/1993
• Issued: 11/23/1999
• Est. Priority Date: 12/09/1987
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Negishi, Hirokazu
• Primary Examiner(s): Lee, Eddie C.
• Application Number:
  US08/166,984
• Time in Patent Office: 2,169 Days
• Field of Search: 181/144, 181/145, 181/153, 181/154, 181/155, 181/191, 181/192, 181/194, 181/195, 181/199, 181/146, 181/151
• US Class Current: 181/144
• CPC Class Codes: H04R 1/345 for loudspeakers
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• CPC Class Codes: H04S 1/00 Two-channel systems H04S5/00, H04S7/00 take precedence

Abstract

A sound output system has a pair of right and left speakers and a pair of audio mirrors for respectively controlling directivities of sounds which are output from the pair of speakers. The shapes or arrangement of the pair of audio mirrors are adjusted such that a difference between arrival times of the sounds which are respectively output from the pair of speakers can be compensated by a sound pressure difference due to the Haas effect in a predetermined area. Alternative means are phase difference, dipole, and asymmetrical horn loading.

Claims

1. A stereophonic sound output system comprising:

a pair of left and right speakers, each speaker having a cabinet, a diaphragm contained in the cabinet and a conical or part conical sound mirror spaced from the diaphragm with an apex of the sound mirror coinciding with a rim of the diaphragm so as to define a direction in which sound is preferentially radiated towards a listening area, said diaphragm being arranged on a surface of the cabinet which is opposite to the sound mirror; and

a sound control material which is inserted between the surface of the cabinet and the sound mirror in a predetermined angular area where sound energy is not directly radiated towards the listening area so as to control the directional distribution of acoustic energy radiated towards the listening area by blocking acoustic energies which are reflected in unnecessary directions, said sound control material filling a space between the surface of the cabinet and the sound mirror in the predetermined angular area.

2. A system according to claim 1, wherein said pair of speakers are pistonic motion speakers.

3. A system according to claim 1, wherein the speakers are spaced apart along a base line of a triangle and centers of the directions of sounds which are respectively output from said pair of speakers are directed towards an apex of the triangle by said audio mirrors, the centers of the directions of said sounds being at 45°

or less to said base line.

4. A system according to claim 1, wherein the speakers are such as to output predominantly median and high tones and further comprising right and left speakers for outputting predominantly low tones.

5. A system according to claim 1, wherein said

sound control material has an outer cylindrical surface a diameter of which corresponds to that of the sound mirror.

6. A system according to claim 1, wherein said sound control material has a part-cylindrical shape and an axis of the sound control material is coincident with an axis of the sound mirror.