Patent Application
20140119591
The present disclosure relates to transducers to be mounted in terminal equipment for converting electrical signals to audible sounds, and more particularly to a micro-speaker.
Sound which can be heard by a person's auditory sense is transmitted in the form of waves. The sound having the wave form moves air molecules and vibrates the tympanic membrane, thus allowing a person to hear the sound. In order to provide audible sounds, various kinds of speakers have been developed. The speaker is generally coupled to audio equipment or an amplifier for use as a large sound producing means for considerably amplifying volume. Alternatively, the speaker may be used as a small sound producing means having small size and volume.
As such, the small-sized speaker may be mounted to a small electronic product, such as a mobile phone, a PDA, or a notebook computer. As the wireless age begins, consumers want to consume various contents regardless of time and place and demand portability. In order to satisfy the consumers' desires, speakers are tending towards miniaturization and lightness.
A micro-speaker related to the present disclosure includes a case defining a sound hole, a frame attached to the case for forming a chamber, a magnetic circuit defining a magnetic gap, a diaphragm located in the chamber, and a voice coil attached to the bottom of the diaphragm. Typically, the magnetic circuit includes a yoke, a magnet positioned on the yoke, and a top plate attached to the magnet. The magnetic gap is formed between the yoke and the magnet, and the voice coil is suspended in the magnetic gap. While electrified, the voice coil will be activated to vibrate by the electromagnetic Ampere Force and further drives the diaphragm to vibrate, which converts the electrical signals to sound waves. However, as mentioned above, as the micro-spacer is designed smaller and thinner, no extra space is provided for the voice coil to vibrate with sufficient amplitude. In many cases, the voice coil even will collide to the bottom of the yoke so as to badly affect the frequency sound quality produced by the diaphragm.
U.S. patent application Ser. No. 13/057,048 provides a yoke made of iron or like as a magnetic member, the yoke including a bottom in substantially rectangular shape, a long sidewall and a short sidewall. Four yoke notched parts in round shape are formed by two adjacent sidewalls for coupling the yoke to a frame by corresponding four guide members brought into contact with the yoke notched parts, respectively. In fact, this type of construction does not provide an extra space for the voice coil to vibrate with sufficient amplitude.
Therefore, it is desirable to provide a micro-speaker which can overcome the above-mentioned problems.
Many aspects of the embodiment can be better understood with reference to the drawings mentioned above. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Reference will now be made to describe exemplary embodiments of the present disclosure in detail.
Referring to
In particularly, the frame 11, cooperatively with the cover 12 forming a housing, defines a chamber therebetween for receiving the yoke 15, the magnet 16, the pole plate 17, the voice coil 13 and the diaphragm 14 therein. One end of the voice coil 13 is connected directly or indirectly with the diaphragm 14, the other end of the voice coil 13 is at least partially received in the magnetic gap. The frame 11 further includes a fence 112 extending from inner sidewalls of the frame 11 and received in a hollow space 110 for embedding the pair of conductive terminals 18 in proper position so as to electrically connect with the leads 132 of the voice coil 13. In the embodiment, the leads 132 extend from the end far away from the diaphragm 14. While electrified, the voice coil 13 is activated to move by Lorenz Force, and accordingly, the diaphragm 14 is driven by the voice coil 13, which produces sound waves.
Referring to
Accordingly, each of the longitudinal sidewalls 154 further comprises a nick 157 formed by the main wall 155 and the auxiliary wall 156 for engaging with the positioning portion 111 for positioning the frame 11. Each of the two ends of the base wall 151 is provided with a groove 152 located between two main walls 15 and closed to the inclining portions 153. That is to say, two grooves 152 are located on two ends of the base wall 151 and near to the short boundary, respectively. The term “groove” here means to a rectilineal or arc-shaped trough without through hole. Consequently, the leads 132 are provided on the short-side of the voice coil 13 corresponding to the groove so that a part of the leads may be suspended in the groove 152 during vibration so as not to bump against the base wall 151 of the yoke 15.
Alternatively, the yoke 15 may be includes a closed-loop recess designed on the bottom of the yoke for providing an extra space to accommodate the voice coil 13 such that the voice coil 13 can oscillate freely relative to the frame 11.
While assembled, the voice coil 13 can be partially received in the magnetic gap and is suspended above the groove 152. In order not to limit the vibration of the voice coil 13 completely, the groove 152 is designed to have a width greater than that of the thickness of the voice coil 13. The leads 132 are used as a flexible wire electrical directly connected the conductive terminals 18. The flexible wire is sway with the vibration of the voice coil 13 such that it may be received in the groove 152 without contacts the yoke 15.
Consequently, while vibrating, the voice coil 13 is intermittently received in the magnetic gap for avoiding dump the base wall 151 of the yoke 15.
The shape of the yoke 11 is not restricted to rectangle as described in this embodiment. Referring to
While the present disclosure has been described with reference to the 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 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.
This application is a continuation-in-part of U.S. patent application Ser. No. 13/190,451, filed Jul. 25, 2011, entitled “micro-speaker”, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13190451 | Jul 2011 | US |
| Child | 14147133 | US |
