FIELD OF THE INVENTION
The present invention relates to electromagnetic transducers, and more specifically to an electromagnetic transducer using a single magnet to provide multiple functions.
DESCRIPTION OF RELATED ART
A typical electromagnetic transducer has only one simple function. Inputted electric energy causes the sound coil and a magnet of the electromagnetic transducer to produce a coupling effect and to further move a vibration panel. When the vibration panel is vibrated, air molecules contacting the vibration panel are excited to produce a variable dense-disperse wave (longitudinal wave). The amount of variation of the dense-disperse wave is the waveform of sound pressure audible to human ears.
However, the electromagnetic transducer can only produce a magnetic loop to convert electric energy into sound energy without any other added functions. Therefore, while installed in an electronic telecommunication apparatus (for example, a cellular phone), two component parts are required to achieve sound producing and vibration functions. In recent years, it has been the market tendency to make electronic apparatus thinner and smaller and to provide electronic telecommunication apparatus with user-friendly operation interfaces. When designing the electromagnetic transducer, which is a key component for electronic telecommunication apparatus, factors of high performance, low consumption of power, flat and compact outer appearance, and low cost should be taken into account.
So, it is necessary to provide a new multifunctional vibrating actuator for solving the problem mentioned above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustrative cross-sectional view of an electromagnetic transducer according to an exemplary embodiment of the present invention;
FIG. 2 is an illustrative isometric view of a suspension of the electromagnetic transducer actuator;
FIG. 3 is an illustrative isometric view of a yoke of the electromagnetic transducer;
FIG. 4 is an illustrative isometric view of a magnet of the electromagnetic transducer; and
FIG. 5 is an illustrative isometric view of a weight of the electromagnetic transducer.
DETAILED DESCRIPTION OF THE EMBODIMENT
Reference will now be made to describe the exemplary embodiment of the present invention in detail.
Referring to FIG. 1 through FIG. 5, an electromagnetic transducer 100 comprises a holder 1 forming a hollow space 11, a suspension 2 assembled with the holder 1, a vibrating member 3 suspended in the hollow space 11 by the suspension 2 and defining a magnetic gap 31, a diaphragm 4 arranged facing the vibrating member 3 with a periphery thereof fixed to the holder 1, and a voice coil 5 attached to a lower surface of the diaphragm 4 with a part thereof inserted into the magnetic gap 31 of the vibrating member 3.
Referring to FIGS. 1, 3 and 4, the vibrating member 3 defines a magnetic circuit part 32 and a weight 36 assembled with the magnetic circuit part 32. The magnetic circuit part 32 comprises a yoke 33, a magnet 34 receiving in the yoke 33 and a pole plate 35 attached to a top surface of the magnet 34. Referring to FIG. 4, the yoke 33 defines four first linear portions 331 and four first arc portions 332 each smoothly connecting two adjacent first linear portions 331. Referring to FIG. 5, the magnet 34 defines four second linear portions 341 and four second arc portions 342 each smoothly connecting the two adjacent second linear portions 341. It is optional that each arc portion is configured to be a part of a circle. In the present exemplary embodiment, the vibrating member is a type of two-piece and the weight 36 is separated with the yoke. In fact, the weight 36 may be an integral part of the vibrating member.
Referring to FIG. 2, the suspension 2 defines an inner ring portion 21, an outer ring portion 22 surrounding the inner ring portion 21, and at least a pair of connecting portions 23 disposed between and connecting the inner ring portion 21 and the outer ring portion 22. The inner ring portion 21 of the suspension 2 defines four first straight segments 211 and four first arcuate segments 212 each smoothly connecting with two adjacent first straight segments 211. The outer ring portion 22 of the suspension 2 includes four second straight segments 221 and four second arcuate segments 222 each smoothly connecting with two adjacent second straight segments 221. Each connecting portion 23 defines a first end 231 connected to the inner ring portion 21, a second end 232 connected to the outer ring portion 22, and a middle portion 233 extending between and connecting with the first and second ends 231, 232. The middle portion 233 of the suspension 2 is parallel to the straight segments 211, 221 between which the middle portion 233 is located.
Referring to FIG. 2 and FIG. 3, the suspension 2 further defines at least a pair of fastening portions 24 projecting from the inner ring portion 21 toward a center of the suspension 2, and the yoke 33 defines a pair of securing portion 333 for engaging with the fastening portions 24 for assembling the suspension 2 with the yoke 33 firmly.
Referring to FIGS. 1 and 5, the weight 36 defines a surrounding wall 361 forming a first gap 61 with an inner side of the holder 1 and a plurality flanges 362 projecting from the surrounding wall 361 towards the inner side of the holder 1 for forming a second gap 62 with the inner side of the holder 1, the first gap 61 being communicated with the second gap 62. It is optional that a width of the second gap 62 is more than 0 but not more than 0.2 mm and the first gap 61 is more than 0.2 mm.
Referring to FIG. 1, the voice coil 5 is partially inserted into the magnetic gap 31 and spaced apart from the yoke 33 and magnet 34 at a predetermined distance.
The outline of the diaphragm 4 is similar to the suspension 2.
According to the electromagnetic transducer, providing sound producing and vibration functions, the outline of the suspension is rectangular with rounded corners. And the outlines of the magnetic circuit part, the diaphragm and the suspension are same to each other. The magnetic flux density exerting on the diaphragm is equal. Thus, the vibrating of the diaphragm is stable and balanced.
The present invention meets the electronic telecommunication apparatus's current design focus, which is characterized in being thinner, smaller, and shorter, and greatly reducing material cost and assembly cost.
While the present invention has been described with reference to the specific embodiment, the description of the invention is illustrative and is not to be construed as limiting the invention. Various of modifications to the present invention can be made to the exemplary embodiment by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.
Patent Application
20110274288
