Speaker diaphragm, speaker, and electronic equipment and mobile device using the speaker
View Patent ↗A speaker diaphragm of the present invention is formed by mixing polylactic acid as a plant-derived resin, bamboo fibers and a natural binder. It is thereby possible to realize a speaker diaphragm capable of obtaining sufficient sound velocity, while having low environmental load and high sound quality.
1. A speaker diaphragm, comprising polylactic acid, bamboo fibers, granular bamboo charcoal which has been carbonized at a temperature of about 800° C., and a natural starch-based binder, wherein
the polylactic acid is a base resin, wherein the bamboo charcoal is blended in the resin,
a length of the bamboo fibers is not smaller than 0.2 mm and not larger than 5 mm,
a content of the bamboo fibers is 10 wt % to 30 wt %, a content of the binder is 1 wt % to 10 wt %, and a content of the polylactic acid and the granular bamboo charcoal is regarded as a remaining wt %.
2. The speaker diaphragm according to claim 1 , wherein the speaker diaphragm is formed by compounding the polylactic acid, the bamboo fibers, and the natural binder, and injection-molding the compound.
3. The speaker diaphragm according to claim 1 , wherein the natural binder is a starch-based binder.
4. The speaker diaphragm according to claim 1 , wherein the bamboo fibers are made finer into a microfibrillated state.
5. The speaker diaphragm according to claim 1 , wherein the polylactic acid, the bamboo fibers, and the natural binder are uniformly dispersed.
6. The speaker diaphragm according to claim 1 , wherein a specific gravity is not lower than 1.10 and not higher than 1.18.
7. A speaker, comprising:
a magnetic circuit;
a frame, coupled to the magnetic circuit;
a diaphragm, coupled to a periphery of the frame; and
a voice coil, coupled to the diaphragm and arranged in a magnetic gap formed by the magnetic circuit,
wherein the diaphragm comprises polylactic acid, bamboo fibers, granular bamboo charcoal which has been carbonized at a temperature of about 800° C. and a natural starch-based binder, wherein
the polylactic acid is a base resin, wherein the bamboo charcoal is blended in the resin,
a length of the bamboo fibers is not smaller than 0.2 mm and not larger than 5 mm,
a content of the bamboo fibers is 10 wt % to 30 wt %, a content of the starch-based binder is 1 wt % to 10 wt %, and
a content of the polylactic acid and the granular bamboo charcoal is regarded as a remaining wt %.
8. The speaker according to claim 7 , comprising a diaphragm formed by compounding the polylactic acid, the bamboo fibers, and the natural binder, and injection-molding the compound.
9. The speaker according to claim 7 , wherein the natural binder is a starch-based binder.
10. The speaker according to claim 7 , wherein the bamboo fibers are made finer into a microfibrillated state.
11. The speaker according to claim 7 , wherein the polylactic acid, the bamboo fibers, and the natural binder are uniformly dispersed.
12. The speaker according to claim 7 , wherein a specific gravity of the diaphragm is not lower than 1.10 and not higher than 1.18.
13. An electronic equipment, comprising a speaker and an amplifier circuit for driving the speaker, wherein
the speaker has a magnetic circuit; a frame, coupled to the magnetic circuit; a diaphragm, coupled to a periphery of the frame; and a voice coil, coupled to the diaphragm and arranged in a magnetic gap formed by the magnetic circuit,
the diaphragm comprises polylactic acid, bamboo fibers, granular bamboo charcoal which has been carbonized at a temperature of about 800° C. and a natural starch-based binder, wherein the polylactic acid is a base resin, and the bamboo charcoal is blended in the resin, and
a length of the bamboo fibers is not smaller than 0.2 mm and not larger than 5 mm,
a content of the bamboo fibers is 10 wt % to 30 wt %, a content of the starch-based binder is 1 wt % to 10 wt %, and a content of the polylactic acid and the granular bamboo charcoal is regarded as a remaining wt %.
14. A mobile device, comprising a speaker, an amplifier circuit for driving the speaker, and mobile means, wherein
the speaker has a magnetic circuit; a frame, coupled to the magnetic circuit; a diaphragm, coupled to a periphery of the frame; and a voice coil, coupled to the diaphragm and arranged in a magnetic gap formed by the magnetic circuit,
the diaphragm comprises polylactic acid, bamboo fibers, granular bamboo charcoal which has been carbonized at a temperature of about 800° C., and a natural starch-based binder, wherein the polylactic acid is a base resin, and the bamboo charcoal is blended in the resin, and
a length of the bamboo fibers is not smaller than 0.2 mm and not larger than 5 mm,
a content of the bamboo fibers is 10 wt % to 30 wt %, a content of the starch-based binder is 1 wt % to 10 wt %, and a content of the polylactic acid and the granular bamboo charcoal is regarded as a remaining wt %.
15. The speaker diaphragm according to claim 1 , wherein a content of the bamboo fibers is greater than a content of the natural binder.
16. The speaker diaphragm according to claim 1 , wherein a glass transition temperature of the starch-based binder is 85° C. to 130° C.
17. The speaker according to claim 7 , wherein a glass transition temperature of the starch-based binder is 85° C. to 130° C.
18. The electronic equipment according to claim 13 , wherein a glass transition temperature of the starch-based binder is 85° C. to 130° C.
19. The mobile device according to claim 14 , wherein a glass transition temperature of the starch-based binder is 85° C. to 130° C.