Patent Application
20090214068
This patent generally relates to transducers and in particular to a directional microphone adapted to operate with a plurality of openings.
One type of a directional transducer, e.g., microphone, for converting an acoustic signal into an electrical signal includes a cavity formed within a housing. A diaphragm within the housing divides the cavity into a back volume and a front volume. A front port communicates with the front volume, and a rear port communicates with the back volume. Placing an acoustic resistance, such as a screen, a channel, or a porous material, in the rear port creates a time-delay structure to modify the time it takes a sound signal arriving at the rear port to strike the diaphragm and hence modifies the directionality characteristics of the microphone. To create a second-time delay structure, the rear and front ports may be physically spaced apart so that a sound signal traveling through the front port and the front volume and also traveling through the rear port and the back volume strike the diaphragm at different times. However, if the microphone is built with both first and second time-delay structures, i.e, first time-delay structure in the rear port and the second time-delay structure in the front port, the internal time delay for the sound signal to travel through the rear port may equal to the internal time delay for the sound signal to travel through the front port. In this case, the sound signals strike the diaphragm simultaneously and the sound pressure is canceled and no electric signal is generated.
For a more complete understanding of the disclosure, reference should be made to the following detailed description and accompanying drawings wherein:
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein
While the subject matter of this patent is susceptible to various modifications and alternative forms, certain embodiments are shown by way of example in the drawings and these embodiments will be described in detail herein. It will be understood, however, that this disclosure is not intended to limit the invention to the particular forms described, but to the contrary, the invention is intended to cover all modifications, alternatives, and equivalents falling within the spirit and scope of the invention defined by the appended claims. Throughout the following detailed description, similar reference numbers refer to respective similar elements in all figures of the drawings.
The transducer 100 may be a receiver, a speaker or a microphone. Two or more transducers 100 may be combined, and in combinations may be a combined receiver and microphone, combined multiple microphones or combined multiple receivers, depending on the desired applications. In the embodiment shown, the transducer 100 is a directional microphone. The transducer 100 may include a housing 101 including a top housing portion 102 and a bottom housing portion 104. Housing portions 102 and 104 each have an end wall 102a and 104a, respectively, at an opening end thereof. A disk or plate-like structure 110 is fixedly coupled to the housing portions 102 and 104 between the end walls 102a and 104a. The structure 110 may have the form of a substantially annular ring and may correspond to the configuration of the housing 101.
The structure 110 may include a first surface 110a, a second surface 110b, and a plurality of openings 112, e.g. notches formed in a peripheral edge 115 of the structure 110. The openings 112 allow acoustic signals, e.g., sounds to pass from above and below the structure 110. With the end walls 102a, 104b of the housings 102, 104 joined to the first and second surfaces 110a, 110b of the structure 110 adjacent to the openings 112 by any suitable technique to form a complete housing, the openings 112 existing along an inside surface 117 (as shown
The transducer 100 further includes a flex circuit assembly 106 and at least one terminal pad 108, three are illustrated, electrically coupled to the flex circuit assembly 106 to permit connecting of the transducer 100 to an external device (not shown). The external device may be a printed circuit board (PCB), a transducer, a portion of an electronic device or an electronic device. The flex circuit assembly 106 may be attached to any surface of the housing 101 as long as the flex circuit assembly 106 does not block the openings 112. As shown, the flex circuit assembly 106 is attached to the top housing portion 102 but it may as easily be attached to the bottom housing portion 104.
It will be appreciated that numerous variations to the above-mentioned approaches are possible. Variations to the above approaches may, for example, include performing the above steps in a different order. Further, the openings 112 may be formed directly on the top housing portion 102 or the bottom portion 104 without introducing the structure 110. For example, the openings 112 may be formed on the side wall 150a or 150b (as shown in
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention. It should also be understood that, unless a term is expressly defined in this patent using the sentence “As used herein, the term ‘______’ is hereby defined to mean . . . ” or a similar sentence, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning. Unless a claim element is defined by reciting the word “means” and a function without the recital of any structure, it is not intended that the scope of any claim element be interpreted based on the application of 35 U.S.C. §112, sixth paragraph.
This patent claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/031,483 filed Feb. 26, 2008, the disclosure of which is hereby expressly incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61031483 | Feb 2008 | US |
