Direction and frequency independent column of electro-acoustic transducers
First Claim
1. An electro-acoustic transducer comprising (2K+1) transducer units with substantially identical directivity patterns (k being an integer wherein 2≦
- k≦
4), said transducer units being situated in line at equal distances (d1) from each other and being connected to a common electrical transmission channel, each transducer unit including a transducer and an amplitude control device for adjusting the conversion factor of the associated transducer unit, transducer units which are disposed symmetrically relative to a central transducer unit having conversion factors of equal value, the phase shifts in the transducer units being equal, but the phase shift in one of every two of those transducer units which are situated at equal odd multiples of the distance (d1) from the central transducer unit differing by 180°
from one another, the conversion factors being selected to produce a substantially frequency and direction-independent conversion of the sound waves when an index x (x being an interger in the range of l to k+1) is assigned to a plurality of the transducer units, the index 1 being assigned to one of the extreme transducer units, consecutive indices to consecutive adjacent transducer units, proceeding from said extreme transducer unit to the central transducer unit with the highest index assigned to the central transducer unit, and wherein the ratios between the conversion factors Ax assigned to the transducer units satisfy the equation A1 ;
A2 ;
A3 ;
A4 ;
A5 =1;
2n;
2n2 ;
n3 -n;
1/4(n4 -1)-2n2, wherein n has a value not equal to zero.
1 Assignment
0 Petitions
Accused Products
Abstract
An electro-acoustic arrangement comprising a plurality of transducer units including five, seven or nine equally spaced transducers situated in line with the transducers connected to a transmission channel via individual amplitude control devices. The amplitude control devices are adjusted so that the ratios between the conversion factors of the transducer units viewed from end to end are 1:2n:2n2 :-2n:1 for five transducers to produce an output signal substantially independent of direction and/or frequency. The invention also relates to a combination of five, seven or nine of the foregoing arrangements situated adjacent each other or in line at equal distances with further amplitude control devices connected to a transmission channel. The amplitude control devices are adjusted so that the ratios between the conversion factors of the arrangements, viewed from end to end, form a special relationship.
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Citations
20 Claims
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1. An electro-acoustic transducer comprising (2K+1) transducer units with substantially identical directivity patterns (k being an integer wherein 2≦
- k≦
4), said transducer units being situated in line at equal distances (d1) from each other and being connected to a common electrical transmission channel, each transducer unit including a transducer and an amplitude control device for adjusting the conversion factor of the associated transducer unit, transducer units which are disposed symmetrically relative to a central transducer unit having conversion factors of equal value, the phase shifts in the transducer units being equal, but the phase shift in one of every two of those transducer units which are situated at equal odd multiples of the distance (d1) from the central transducer unit differing by 180°
from one another, the conversion factors being selected to produce a substantially frequency and direction-independent conversion of the sound waves when an index x (x being an interger in the range of l to k+1) is assigned to a plurality of the transducer units, the index 1 being assigned to one of the extreme transducer units, consecutive indices to consecutive adjacent transducer units, proceeding from said extreme transducer unit to the central transducer unit with the highest index assigned to the central transducer unit, and wherein the ratios between the conversion factors Ax assigned to the transducer units satisfy the equation A1 ;
A2 ;
A3 ;
A4 ;
A5 =1;
2n;
2n2 ;
n3 -n;
1/4(n4 -1)-2n2, wherein n has a value not equal to zero. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- k≦
Specification