1. Technical Field
The present invention relates to an electronic device with a phononic crystal structure.
2 Description of Related Art
Many kinds of electronic devices, such as projectors, personal computers, have been widely used in daily life. Electronic devices usually employ a fan to dissipate heat. Generally, the fan generates a loud noise during functioning, which makes cause discomfort to the users.
Therefore, a new electronic device is desired to overcome the above mentioned problems.
Many aspects of the embodiments can be better understood with references to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Embodiments will now be described in detail below with reference to the drawings.
Referring to
The housing 10 includes a bottom plate 14, a side plate 12 connected with the bottom plate 14. The bottom plate 14 includes a surface 142. The side plate 12 defines a heat-dissipating opening 20 therein.
The fan 70 is disposed on the surface 142 of the bottom plate 14 and is received in the housing 10. The fan 70 is configured for dissipating heat from the electronic device 10.
The phononic crystal structure 40 is formed on the surface 142 of the bottom plate 14. The phononic crystal structure 40 is positioned between the fan 70 and the side plate 12, and is adjacent to the heat-dissipating opening 20. The phononic crystal structure 40 is configured for abating noises (i.e., reducing an intensity of the noises) generated by electronic components (for example, the fan 70) within the electronic device 100.
The phononic crystal structure 40 includes a substrate 44 and a plurality of bars 42 extending from the substrate 44. The substrate 44 is fixedly mounted on the surface 142 of the bottom plate 14. The bars 42 are periodically arranged in a two-dimensional crystal lattice. In the present embodiment, the two-dimensional crystal lattice includes a plurality of interconnected squares in an array. A lattice constant of crystal lattice is a length b of a side of the square.
Each of the bars 42 has a central axis (not shown), and each central axis is substantially perpendicular to the surface 142 of the bottom plate 14. Each bar 42 can be circular, elliptical, square, or regular hexagonal in cross-section. In the present embodiment, each bar 42 is circular in cross-section. Whether each bar 42 is hollow or not does not affect the efficiency of abating the noises of the phononic crystal structure 40. Accordingly, in the present embodiment, each bar 42 is hollow, so that less material is used in the phononic crystal structure 40 and the cost is decreased. Each bar 42 is comprised of iron, stainless steel, or aluminum alloy.
An outer diameter of each bar 42 is 2 R, and a filling ratio f of the phononic crystal structure 40 can be calculated according to the following equation: f=πR2/b2. When the filling ration f is large, the phononic crystal structure 40 can abate the noise with a high frequency. It is to be noted that the phononic crystal structure 40 can further include a plurality of bars (not shown) arranged in a two-dimensional crystal lattice with a lattice constant different from the lattice constant b, so that the noises with a wide frequency range can be abated by the phononic crystal structure 40.
It should be noted that the substrate 44 and the plurality of bars 42 can be formed integrally. It should also be noted that the substrate 44 of the phononic crystal structure 40 can be eliminated and the plurality of bars 42 are directly formed on the surface 142 of the bottom plate 14.
The phononic crystal structure 40 abates most of the noises in the electronic device 100. As a result, the electronic device 100 is quiet when in operation. Furthermore, a gap between adjacent bars facilitates heat-dissipating via the heat-dissipating opening 20.
While certain embodiments have been described and exemplified above, various other embodiments from the foregoing disclosure will be apparent to those skilled in the art. The present invention is not limited to the particular embodiments described and exemplified but is capable of considerable variation and modification without departure from the scope of the appended claims.
Number | Date | Country | Kind |
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200810301613.3 | May 2008 | CN | national |