FIELD OF THE INVENTION
The present invention generally relates to the art of vibrators and, more particularly, to a linear vibrator for generating tactile sensation.
DESCRIPTION OF RELATED ART
Consumer products, such as mobile phones and portable multi-media players, generally include vibrators for generating tactile feedback. For example, a mobile phone has a vibrator for generating vibration while a call is called in, and a portable multi-media player has a touch screen having vibrators for getting tactile feedback.
A vibrator has a moving unit moving along a linear direction is called linear vibrator. Linear vibrators are widely used in consumer products and are disclosed in U.S. Pat. No. 6,466,682 B2 issued on Oct. 15, 2002, and U.S. Pat. No. 7,099,489 B2 issued on Aug. 29, 2006. The vibrator is mounted on a mounting surface of a printed circuit board, and the moving unit thereof is actuated to move along a direction perpendicular to the mounting surface. However, the movement along the direction perpendicular to the mounting surface increases the height of the vibrator.
So, it is necessary to provide a new vibrator for solving the problem mentioned above.
SUMMARY OF THE INVENTION
In one embodiment of the present invention, a linear vibrator is disclosed. The linear vibrator includes a housing having a base and a cover, a number of elastic members connected to the housing, a vibrating unit suspended in the housing by the elastic members, and a coil positioned in the housing. The base has a bottom wall and a plurality of sidewalls extending vertically from the bottom wall. The vibrating unit has a magnet assembly and vibrates along a direction parallel to the bottom wall.
Other features and advantages of the present invention will become more apparent to those skilled in the art upon examination of the following drawings and detailed description of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a linear vibrator in accordance with a first embodiment of the present invention;
FIG. 2 is an exploded view of the linear vibrator in FIG. 1;
FIG. 3 is top view of the linear vibrator, a cover thereof being removed away;
FIG. 4 is an isometric view of an elastic member of the linear vibrator;
FIG. 5 is a cross-sectional view of the linear vibrator along a line A-A in FIG. 3;
FIG. 6 is a schematic illustration showing how the vibrator woks; and
FIG. 7 is a schematic illustration of a linear vibrator in accordance with a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made to describe the preferred embodiments of the present invention in detail.
A linear vibrator is mounted on a printed circuit board for generating tactile vibration. Referring to FIGS. 1-3, a linear vibrator 10, in accordance with a first embodiment of the present invention, includes a cover 11, a base 12 forming a receiving space together with the cover 11, an annular coil 13, a plurality of elastic member 14, a weight 15, and a magnet assembly 16. The cover 11 and the base 12 corporately form a housing having the receiving space. The base 12 further defines a bottom wall 122 and a plurality of sidewalls 121 extending vertically from the bottom wall 122. When the vibrator 10 is mounted on the printed circuit board, the bottom wall 122 is attached and parallel to the printed circuit board.
The coil 13 is positioned on the bottom wall 122 and a pair of leads thereof is electrically connected to electrical pads 123 embedded in the bottom wall 122 for receiving current from external circuits. The elastic members 14 are positioned on the base 12, preferably on the sidewalls 121 of the base 12. The weight 15 is suspended in the receiving space by the elastic members 14. The weight 15 includes a main body 151 and a plurality of positioning portions 152 extending from the main body 151. The positioning portions 152 are used for assembling with the elastic members 14. The main body 151 defines a through hole 153 in a middle portion thereof for receiving the magnet assembly 16 therein. Thus, the magnet assembly 16, together with the weight 15, is suspended in the receiving space by the elastic members 14. In fact, the magnet assembly 16, as a vibrating unit, may be directly connected to the elastic members 14. In addition, if used, the weight can be made from materials having specific gravities higher than 7.8 g/cm3.
Referring to FIGS. 4-5, together with FIGS. 1-3, each of the elastic members 14 includes a fastening portion 141 fixed on the sidewall 121, an elastic arm substantially parallel to the fastening portion 141, and a mounting portion 144 extending from the elastic arm 142. The fastening portion 141 is connected to the elastic arm by a U-shape connecting portion 143. Preferably, the fastening portion 141 may include a first fastening part 141a and a second fastening part 141b substantially perpendicularly to the first fastening part 141a, by which the fastening portion 141 can be positioned on two adjacent sidewalls 121 of the base 12. The mounting portion 144 extends vertically from the elastic arm and extends far away from the fastening portion 141. Further, preferably, the mounting portion 144 may include an upper part 144a, a lower part 144b opposed from the upper part 144b, and a slot 144c between the upper part 144a and the lower part 144b. Accordingly, the elastic arm 142 can deform elastically along a direction X substantially perpendicularly to the first fastening part 141a. The positioning portion 152 of the weight 15 is at least partially received in the slot 144c of the mounting portion 144 of the elastic member 14, i.e., the positioning portion 152 is sandwiched between the upper part 144a and the lower part 144b. Therefore, the weight 15 is suspended in the receiving space by the elastic members 14.
The magnet assembly 16 in the through hole 153 has two halves, in which, one half 16a has magnetic poles opposite to those of the other half 16b, as shown in FIG. 5. Planes of magnetic poles of the magnet assembly 16 are parallel and face to the bottom wall 122 and are also parallel to the coil 13. The magnet assembly 16 is arranged above the coil 13. The coil 13 receives current from external circuit. At one moment, direction of the current passing through the left half of the coil is inward into the paper (labeled as ![]()
), and direction of the current passing through the right half of the coil is outward (labeled as {circle around (•)}). Magnetic lines of force are shown as dashed lines with arrows. According to Left-hand rule, direction of the electromagnetic force F1 applied on the left half coil is rightward, and direction of the electromagnetic force F2 applied on the right half coil is also rightward. Thus, the whole coil 13 is given a rightward total electromagnetic force which forces the coil 13 to move rightward. However, the coil is positioned on the bottom wall 122 and can't move by the force. As a result, the weight 15 suspended by the elastic members 14 is forced to move leftward by the reaction force F′. As direction and intensity of the current passing through the coil 13 is varied, the movement of the weight 15 is leftward or rightward, alternatively, which is called vibration. Direction of the vibration is parallel to the bottom wall 122 (shown as direction Y in FIG. 5).
FIG. 7 illustrates a linear vibrator in accordance with a second embodiment of the present invention. In the linear vibrator, two magnets 17, 18 are provided in the weight 15. One of the magnets has magnetic poles opposite to those of another. In fact, it is clearly that the two magnets can be regarded as a magnet assembly.
As the direction of vibration is parallel to the bottom wall, a height of the linear vibrator can be reduced.
While the present invention has been described with reference to a specific embodiments, 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 preferred embodiments 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
20100213773
