JP2013120958A - Mobile type electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a sound pressure level of a mobile phone having a loudspeaker.SOLUTION: A main sound hole 3 is provided on one flat plate part 2 of a housing 1, and sub-sound holes 6, 7 are provided on both side walls 3, 4 of the housing 1. Resonance tubes 21, 31 having plural air chambers 25, 35 are provided between vent holes 17, 18 provided on both sides of a rear air chamber 16 of a loudspeaker unit 11 and the sub-sound holes 6, 7. When sounds from a loudspeaker 14 are issued from the main sound hole 3, resonance sounds resonating with the sounds issued from the loudspeaker 14 are issued from the sub-sound hole 6 or 7, due to resonance phenomenon of the resonance tubes 21, 31. Thereby, a sound pressure level can be improved.

Description

  The present invention relates to a portable electronic device such as a cellular phone.

  A speaker unit used in a conventional cellular phone or the like is provided with a piezoelectric diaphragm in the center between a case and a cover provided thereon, and is composed of a space between the piezoelectric diaphragm and the cover. The front air chamber communicated with the outside through a sound hole provided in the cover, and the rear air chamber composed of a space between the piezoelectric diaphragm and the case communicated with the outside through an open hole provided in the case. There are some (see, for example, Patent Document 1). In this speaker unit, the air in the front air chamber vibrates due to the vibration of the piezoelectric diaphragm, and this air vibration leaks to the outside through the sound hole, thereby emitting sound.

JP 2008-199266 A (FIG. 8)

  However, in the above conventional speaker unit, the air in the front air chamber vibrates due to the vibration of the piezoelectric diaphragm, and this air vibration leaks to the outside through the sound hole, thereby only emitting sound. Therefore, there is a problem that the sound pressure level has a limit.

  Therefore, an object of the present invention is to provide a portable electronic device that can increase the sound pressure level.

  A portable electronic device according to the present invention includes a housing having a main sound hole and a sub sound hole, and a front air chamber, a speaker, and a rear space that are provided inside the sound hole portion of the housing and communicate with the main sound hole. A speaker unit having a vent hole communicating with the air chamber and the rear air chamber, and a resonance tube provided between the auxiliary sound hole of the housing and the vent hole of the speaker unit, To do.

  According to the present invention, the sound pressure level can be increased.

Sectional drawing of the principal part of the mobile telephone as one Embodiment of this invention. The figure shown in order to demonstrate a sound pressure level frequency characteristic.

  FIG. 1 is a cross-sectional view of a main part of a mobile phone as an embodiment of the present invention. This mobile phone includes a housing 1. Main sound holes 3 made of circular holes are provided at a plurality of locations in a predetermined region of the flat plate portion 2 of the housing 1. A left side secondary sound hole 6 and a right side secondary sound hole 7, which are circular holes, are provided at predetermined positions on the left side wall 4 and the right side wall 5 of the housing 1.

  A speaker unit 11 is provided inside the main sound hole 3 of the flat plate portion 2 of the housing 1. The speaker unit 11 includes a bottomed cylindrical frame 12. The upper surface of the peripheral wall portion of the frame 12 is fixed to the inner surface of the main sound hole 3 portion of the flat plate portion 2 of the housing 1 via an adhesive (not shown).

  A speaker 14 is provided at the center inside the frame 12. The speaker 14 may be an electrodynamic type using a magnetic circuit, or may be a piezoelectric type using a piezoelectric film. A space between the speaker 14 and the main sound hole 3 of the flat plate portion 2 of the housing 1 is a front air chamber 15. The front air chamber 15 communicates with the main sound hole 3. A space between the speaker 14 and the bottom of the frame 12 is a rear chamber 16. A left vent hole 17 and a right vent hole 18 are provided in the frame 12 on the left and right sides of the rear air chamber 16.

  A left resonance tube 21 is provided between the left auxiliary sound hole 6 and the left vent hole 17. The left resonance tube 21 is provided with a partition plate 24 having a circular hole 23 in the central portion at left and right end portions of a tube 22 having a circular cross section and a predetermined plurality of locations inside the tube, for example, three locations, and adjacent partition plates 23. The four air chambers 25 are provided between them. The length of the four air chambers 25 in the left-right direction gradually increases from the right side to the left side.

  A right resonance tube 31 is provided between the right auxiliary sound hole 7 and the right vent hole 18. The right resonance tube 31 is provided with a partition plate 34 having a circular hole 33 at a central portion at left and right end portions of a tube 32 having a circular cross section and a predetermined plurality of locations, for example, three locations therein, and adjacent partition plates 33. It has a structure in which four air chambers 35 are provided therebetween. The lengths of the four air chambers 35 in the left-right direction gradually increase from the left side toward the right side.

  The left and right lengths of the air chambers 25 of the left resonance tube 21 and the air chambers 35 of the right resonance tube 31 are all different. That is, the length in the left-right direction of each air chamber 25 of the left resonance tube 21 and each air chamber 35 of the right resonance tube 31 is a length corresponding to each of a plurality of preset frequencies.

  Here, as described above, the four air chambers 25 of the left resonance tube 21 are arranged so that the length in the left-right direction gradually increases from the right side to the left side. Is not limited to this, and may be any arrangement. Further, as described above, the four air chambers 35 of the right resonance tube 31 are arranged so that the length in the left-right direction gradually increases from the left side to the right side. The arrangement of the four air chambers 35 is as follows. The arrangement is not limited to this, and any arrangement may be used.

  Now, in this mobile phone, when the speaker 14 vibrates, the air in the front air chamber 15 vibrates accordingly, and this air vibration leaks to the outside from the main sound hole 3 and is thereby emitted. Further, the air in the rear air chamber 16 vibrates in response to the vibration of the speaker 14, and this air vibration leaks to the outside through the left vent hole 17, the left resonant tube 21 and the left auxiliary sound hole 6, and the right vent It leaks to the outside through the pores 18, the right resonance tube 31 and the right auxiliary sound hole 7.

  In this case, among the plurality of air chambers 25 and 35 of the left resonance tube 21 and the right resonance tube 31, respectively, the length in the left-right direction is a length corresponding to the frequency of the speaker 14 at that time. A resonance phenomenon occurs in the air chamber, and a resonance sound is emitted from the left auxiliary sound hole 6 or the right auxiliary sound hole 7. Therefore, a sound is emitted from the main sound hole 3 and a resonance sound is emitted from the left side auxiliary sound hole 6 or the right side auxiliary sound hole 7, and the sound pressure level can be increased by an amount corresponding to the resonance sound.

  As a result, as an example, as shown in FIG. 2, the sound pressure level when sound is emitted only from the main sound hole 3 is indicated by a dotted line, whereas the sound pressure level when resonance sound is emitted is This is indicated by a solid line and is generally higher than the case indicated by a dotted line. Further, it becomes possible to complement the sound thickness level at a specific frequency, and a flat sound pressure level frequency characteristic can be obtained.

  The present invention is not limited to a mobile phone, and is also applicable to an electronic device such as a portable terminal device such as a PHS (Personal Handyphone System) and a PDA (Personal Data Assistance, Personal Digital Assistance). be able to.

  Hereinafter, various aspects of the present invention will be collectively described as supplementary notes.

(Appendix 1)
The invention of Supplementary Note 1 includes a housing having a main sound hole and a sub sound hole, and a front air chamber, a speaker, a rear air chamber, A portable electronic device comprising: a speaker unit having a vent hole communicating with a rear air chamber; and a resonance tube provided between the auxiliary sound hole of the housing and the vent hole of the speaker unit. Equipment.

(Appendix 2)
The invention of appendix 2 is characterized in that, in the invention of appendix 1, the main sound hole is provided in one flat plate portion of the casing, and the secondary sound hole is provided in a side wall of the casing. It is a portable electronic device.

(Appendix 3)
The invention according to appendix 3 is the invention according to appendix 2, in which the secondary sound holes are respectively provided on the side walls on both sides of the casing, the vent holes are provided on both sides of the speaker unit, and the resonance tube is 2 A portable electronic device.

(Appendix 4)
The invention of appendix 4 is the portable electronic device according to any one of appendices 1 to 3, wherein the resonance tube has a plurality of air chambers having different lengths.

(Appendix 5)
The invention of appendix 5 is the portable electronic device according to the invention of appendix 4, wherein the length of each air chamber of the resonance tube is a length corresponding to a preset frequency.

DESCRIPTION OF SYMBOLS 1 Case 2 One flat plate part 3 Main sound hole 4 Left side wall 5 Right side wall 6 Left side sub sound hole 7 Right side sound hole 11 Speaker unit 12 Frame 14 Speaker 15 Front air chamber 16 Rear air chamber 17 Left vent hole 18 Right vent hole 21 Left resonance tube 25 Air chamber 31 Right resonance tube 35 Air chamber

Claims (5)

  A housing having a main sound hole and a sub sound hole, and a front air chamber, a speaker, a rear air chamber, and a rear air chamber that are provided inside the sound hole portion of the housing and communicate with the main sound hole. A portable electronic device comprising: a speaker unit having a vent hole; and a resonance tube provided between the auxiliary sound hole of the housing and the vent hole of the speaker unit.   The portable electronic device according to claim 1, wherein the main sound hole is provided in a flat plate portion of the casing, and the sub sound hole is provided in a side wall of the casing.   In the invention according to claim 2, the secondary sound holes are respectively provided on side walls on both sides of the housing, the vent holes are provided on both sides of the speaker unit, and the two resonance tubes are provided. A portable electronic device.   4. The portable electronic device according to claim 1, wherein the resonance tube has a plurality of air chambers having different lengths.   5. The portable electronic device according to claim 4, wherein the length of each air chamber of the resonance tube is a length corresponding to a preset frequency.

Images