CROSS-REFERENCE TO RELATED APPLICATION
This application claims foreign priority benefits under 35 U.S.C. §119 of Chinese Patent Application Serial No. 200820095582.6, filed on Jul. 18, 2008, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an earphone, and more particular to an earpiece for communications and hearing aids.
BACKGROUND
An earphone, or earpiece, is often used with portable digital products such as MP3 players, mobile phones, personal digital assistants (PDA) and laptop computers. An earpiece generates sound through magnetic fields generated around the earpiece. A schematic of magnetic fields generated by a conventional earpiece is illustrated by FIG. 1.
Referring to FIG. 1, the earpiece (not numbered) includes a magnet 110, which is comprised of two parallel magnets 102 and 104. The north and south poles of the magnets 102 and 104 set up a first magnetic field on an axis A. Since the magnets 102 and 104 are permanent magnets, the first magnetic field is constant and uniform. A magnetic force associated with the first magnetic field is perpendicular to the axis A. The earpiece also includes a balanced armature 130, which comprises a stationary portion 130a, an extending portion 130b and an arc portion 130c. The stationary portion 130a is connected to the frame (not shown) of the earpiece. The extending portion 130b is capable of moving about the arc portion 130c. When the extending portion 130b is centered in the first magnetic field, no net force is exerted on it.
The earpiece further comprises a coil 120. When a current passes through the coil 120, a second magnetic field is created on an axis B. The direction of the second magnetic field is perpendicular to that of the first magnetic field, i.e., axis B is perpendicular axis A. A magnetic force associated with the second magnetic field is perpendicular to the axis B. Accordingly, a net magnetic force may be generated to cause the extending portion 130b to rotate about the arc portion 130c. The extending portion 130b then transmits movement to a diaphragm 140 via a connecting rod 150. Vibration of the diaphragm 140 generates sound in the earpiece. Because the net magnetic force is in a different direction than the moving direction of the extending portion 130b, the efficiency of the magnetic energy is reduced.
BRIEF SUMMARY
According to one exemplary embodiment of the invention, an earpiece for communications comprises a frame, a vibration system disposed in the frame and a magnetic field system disposed in the frame. The vibration system includes a vibrating armature, a diaphragm and a connecting rod. The magnetic field system includes a magnet to generate a first magnetic field on a first axis and a coil to generate a second magnetic field on a second axis. One of the magnet and the coil is connected to the frame. The first and the second magnetic fields produce a net magnetic force to cause the vibration system to move. The first axis is parallel to the second axis.
According to another exemplary embodiment of the invention, an earpiece for communications comprises a frame, a vibration system and a magnetic field system. The vibration system includes a vibrating armature, a diaphragm and a connecting rod. The vibrating armature has a stationary portion and an extending portion. The stationary portion is connected to the frame. One end of the extending portion is connected to the stationary portion to form an arc portion and the other end of the extending portion is capable of movement. The magnetic field system includes a magnet to generate a first magnetic field on a first axis and a coil to generate a second magnetic field on a second axis. One of the magnet and the coil is connected to the frame through the stationary portion. The first and the second magnetic fields produce a net magnetic force to cause the extending portion to vibrate. The extending portion transmits vibration to the diaphragm through the connecting rod. The first axis is parallel to the second axis.
According to another exemplary embodiment of the invention, an earpiece for communications comprises a frame, a vibration system and a magnetic field system. The magnetic field system includes a magnet to generate a first magnetic field on a first axis and a coil to generate a second magnetic field on a second axis. The first and the second magnetic fields share a same space within the frame and cause the vibration system to move. The first axis is parallel to the second axis.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. The embodiments illustrated in the figures of the accompanying drawings herein are by way of example and not by way of limitation. In the drawings:
FIG. 1 illustrates a schematic of magnetic fields generated by a conventional earpiece;
FIG. 2 illustrates a cross-section view of an earpiece according to one exemplary embodiment of the present invention;
FIG. 3 illustrates a schematic of magnetic fields generated by the earpiece shown in FIG. 2;
FIG. 4 illustrates a cross-section view of an earpiece according to another exemplary embodiment of the present invention;
FIG. 5 illustrates a cross-section view of an earpiece according to another exemplary embodiment of the present invention;
FIG. 6 illustrates a cross-section view of an earpiece according to another exemplary embodiment of the present invention; and
FIG. 7 illustrates a cross-section view of an earpiece according to another exemplary embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 2 illustrates a cross-section view of an earpiece 200 according to one exemplary embodiment of the present invention. The earpiece 200 comprises a frame 1, a magnetic field generation system 4 and a vibration system 6. The magnetic field generation system 4 comprises a permanent magnet 10 to produce a first magnetic field between the two poles of the magnet. The direction of the first magnetic field is along an axis A. The magnetic field generation system 4 may further comprise a coil 20. When an electric current passes through the coil 20, a second magnetic field around the coil 20 is generated on an axis B. Both magnetic fields are generated inside the frame 1 and share the same space. A schematic of the magnetic fields generated by the magnet 10 and the coil 20 respectively on axes A and B are illustrated in FIG. 3. As shown in FIG. 3, the axis A is parallel to the axis B. The net magnetic force is in a direction perpendicular to the axes A and B. The net magnetic force moves one of the magnet 10 and the coil 20.
Referring again to FIG. 2, the vibration system 6 comprises a vibrating armature 30, a diaphragm 40 and a connecting rod 50. The vibrating armature 30 includes a stationary portion 302 and an extending portion 304. The stationary portion 302 is connected to the frame 1. One end of the extending portion 304 is connected to the stationary portion 302 to form an arc portion 306. The other end is not held in place. The diaphragm 40 is disposed in the proximity of an outlet (not numbered) of the frame 1 where sound is projected outward. The diaphragm 40 is operatively coupled to the vibrating armature 30 by the connecting rod 50. In one embodiment, the coil 20 and magnet 10 are disposed in series with the diaphragm 40.
In various embodiments, one of the magnet 10 and the coil 20 is connected to the frame 1 by the stationary portion 302. For convenience and brevity, the one which is connected to the frame 1 is called a “fixed element.” The other one of the magnet 10 and the coil 20 is connected to the extending portion 304 and may move under the net magnetic force. This element is termed “moving element.”
As illustrated in FIG. 2, a coil pole 208 is at least partially surrounded by the coil 20. The coil pole 208 is connected to the frame 1 through the stationary portion 302. Thus, in this embodiment, the coil 20 is the fixed element. The magnet 10 is connected to the extending portion 304 which is not held in place by the frame. Accordingly, in this embodiment, the magnet 10 is the moving element.
Referring to FIG. 3, the axis B is parallel to the axis A, so the net magnetic force may be in the same direction as the movement of the moving element which is perpendicular to the axes A and B. Since the second magnetic field is constantly changing along with the current, a two-way magnetic force perpendicular to the axes A and B may be achieved that causes the magnet 10 and the extending portion 304 to vibrate about the arc portion 306. As a result, the connecting rod 50 may carry the vibration from the extending portion 304 to the diaphragm 40. In one embodiment, the coil 20 and magnet 10 are disposed in series with the diaphragm 40 relative to the movement of the vibrating system.
FIGS. 4-7 illustrate various exemplary embodiments of the present invention. In these embodiments, the extending portion 304 has different shapes. As shown in FIG. 4, the extending portion 304 is formed in two approximately “U” shapes having arms 304a, 304b and 304c. The arm 304a is connected to the connecting rod 50. The arm 304c serves as the coil pole which is at least partially surrounded by the coil 20. The arm 304b is connected to the stationary portion 302 to form the arc portion 306. Since the magnet 10 is connected to the frame 1 through the stationary portion 302, the magnet 10 is the fixed element in this embodiment. The coil 20 is the moving element. The movement of the coil 20 may cause the arm 304a to vibrate in a direction perpendicular to the axes A and B when electric current passes through the coil 20. As a result, the arm 304a transmits vibration to the diaphragm 40 through the connecting rod 50 to generate sound.
FIG. 5 illustrates another exemplary embodiment of the present invention. In this embodiment, the magnet 10 is the fixed element and the coil 20 is the moving element. The extending portion 304 has a similar shape as shown in FIG. 4. The arm 304a functions in the same way as earlier described. However, the arm 304b serves as the coil pole and is surrounded at least partially by the coil 20. The arm 304c is connected to the stationary portion 302 to form the arc 306. When current passes through the coil 20, the net magnetic force causes the coil 20 to move in a direction perpendicular to the axes A and B, thereby causing the arm 304a to move or vibrate, about the arc 306.
Referring to FIG. 6, the coil 20 is the fixed element connected to the frame 1 via the stationary portion 302. The magnet 10 is the moving element. The extending portion 304 forms approximately a “U” shape. The magnet 10 may be placed on either side of the U shape portion of the extending portion 304. In this embodiment, the magnet 10 is placed to the side of the U shape closer to the connecting rod 50. When current passes through the coil 20, magnetic fields generated by the magnet 10 and the coil 20 have two parallel axes A and B. The net magnetic force moves the magnet 10 in a direction perpendicular to the axes A and B, thereby creating vibration. The extending portion 304 then carries the vibration to the diaphragm 40 via the connecting rod 50.
With reference to FIG. 7, similar to the structure illustrated in FIG. 6, the coil 20 is the fixed element. The magnet 10 is the moving element. The shape of the extending portion 302 is similar to that of FIG. 6. In this embodiment, the magnet 10 is placed on a different side of the U shape. When the net magnetic force is applied to the magnet 10, it makes the extending portion 304 vibrate about the arc 306 and causes the diaphragm 40 to move via the connecting rod 50.
It will be appreciated by those skilled in the art that changes could be made to the examples described above without departing from the broad inventive concept. It is understood, therefore, that this invention is not limited to the particular examples disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
Patent Application
20100014700
