FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
VEHICLE-MOUNTED AUDIO APPARATUS;
PANASONIC CORPORATION, A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501, JAPAN
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

DESCRIPTION
Technical Field
The present invention particularly relates to an audio apparatus mounted on an automobile, wherein the audio apparatus has a vibration-type speaker in a housing and acoustic holes arranged in an external front surface and an upper surface or a lower surface of the housing.
Background Art
A conventional audio apparatus has acoustic holes provided on the upper surface (see Patent Literature 1). Since this audio apparatus has a vibration-type speaker having a cone-type vibration plate capable of outputting sounds ranging from high audio frequencies to low audio frequencies, the vibration-type speaker is arranged to face the upper surface so that the audio apparatus is configured to accommodate a larger vibration-type speaker therein.
Citation List Patent Literature
PTL 1
Japanese Patent Application Laid-Open No. 2004-15149

Summary of Invention Technical Problem
However, when acoustic holes are provided only on the upper surface facing the vibration-type speaker like the conventional audio apparatus, a sound wave emitted from the back surface of the vibration plate is confined within the housing. For this reason, the air resistance increases, and it is difficult to produce sound waves in low audio frequencies in particular. The vibration plate generates sound waves by vibrating air using vibration of a sound wave generation section. Therefore, when sound waves having the same length of are output, the wavelength of the sound wave in front of the vibration plate and the wavelength of the sound wave at the back of the vibration plate have a positive phase and a negative phase, respectively. In other words, when the wavelengths of the positive phase and the negative phase coexist in the housing, the wavelengths thereof interfere with each other to cancel each other. As a result, there is a problem in that the output of the sound wave from the audio apparatus is reduced.
An object of the present invention is to reduce air resistance confined within the housing and to prevent reduction in the output of the sound wave caused by cancellation of the positive phase and negative phase sound waves emitted from the vibration plate.
Solution to Problem
In an audio apparatus according to the present invention, a sound wave is discharged through a first acoustic hole of a housing in accordance with vibration of a vibration-type speaker, and a sound wave discharged from a back surface of the vibration-type speaker is discharged

through a second acoustic hole disposed in an operation panel.
Advantageous Effects of Invention
According to the present invention, the acoustic holes are provided on the upper surface or the lower surface and a side surface of the audio apparatus, and a sound wave of positive phase and a sound wave of negative phase emitted from the vibration plate of the vibration-type speaker are output from the vibration-type speaker so that the sound wave of positive phase and the sound wave of negative phase do not cancel each other within the housing. This can prevent decrease in the output of the sound wave including low audio frequencies.
Brief Description of Drawings
FIG. 1 is a perspective view illustrating an audio apparatus according to Embodiment 1 of the present invention;
FIG.2 is a front view thereof;
FIG.3 is a back view thereof;
FIG.4 is a top view thereof;
FIG.5 is a bottom view thereof;
FIG.6 is a right side view thereof;
FIG.7 is a left side view thereof;
FIG.8 is a cross sectional view taken along A-A of FIG.2;
FIG.9 is a cross sectional view taken along B-B of FIG.4;
FIG. 10 is a figure schematically illustrating the audio apparatus arranged in a center console of a vehicle;
FIG. 11 is perspective view when an operation panel of the audio

apparatus is detached;
FIG. 12 is a perspective view showing a back surface of the operation panel;
FIG. 13 is a front view illustrating an audio apparatus according to Embodiment 2 of the present invention;
FIG.14 is a back view thereof;
FIG. 15 is a top view thereof;
FIG. 16 is a bottom view thereof;
FIG. 17 is a right side view thereof;
FIG.18 is left side view thereof;
FIG.19 is a cross sectional view taken along C-C of FIG.13;
FIG.20 is a figure schematically illustrating the audio apparatus arranged in a center console of a vehicle;
FIG.21 is a perspective view illustrating the audio apparatus; and
FIG.22 is a perspective view illustrating the audio apparatus when a flash memory is attached to the operation panel.
Description of Embodiments
(Embodiment 1)
A vehicle-mounted audio apparatus according to Embodiment 1 of the present invention will be hereinafter described with reference to FIGS.l to 12.
A perspective view, a front view, a back view, a top view, a bottom view, a right side view, and a left side view of the audio apparatus according to Embodiment 1 of the present invention are shown in FIGS. 1 to 7, respectively. FIG.8 is a cross sectional view taken in the vertical direction along line A-A as shown in FIG.2.

In the above drawings, vibration-type speaker 20 of audio apparatus 1 is made by integrally forming sound wave generation section 23 including magnet section 21 and voice coil section 22 and cone-type vibration plate 24 connected to sound wave generation section 23 for propagating sound wave to the outside. Edge section 25 is provided at an external peripheral section of cone-type vibration plate 24.
Substrate 30 has hole 31 for holding sound wave generation section 23 of vibration-type speaker 20, and is electrically connected to vibration-type speaker 20.
Audio apparatus 1 has housing 40 for covering vibration plate 24 of vibration-type speaker 20 and the sides of vibration-type speaker 20 held by substrate 30. Housing 40 has an opening section (not shown) at one of side surfaces and first acoustic hole 41 on the upper surface. First acoustic hole 41 of housing 40 is made in the upper surface and has substantially the same diameter as vibration-type speaker 20. First acoustic hole 41 passes the sound wave generated by vibration-type speaker 20. First acoustic hole 41 has a mesh structure or a slit structure, which easily pass the sound wave. Protruding section 42 is provided on the external peripheral section of first acoustic hole 41 in housing 40 in such a manner that protruding section 42 protrudes downward from the inside of the upper surface. Housing 40 is made of a resin so as to prevent resonance with the sound wave.
Audio apparatus 1 has operation panel 50 attached to the opening section of housing 40. Second acoustic holes 51 are provided at the right and left of the operation panel 50, and second acoustic holes 51 pass the sound wave of vibration-type speaker 20. In addition, audio apparatus 1 includes volume knob 52 for adjusting the volume, operation

button 53, and display panel 54 that displays the channel name of radio and the like. Therefore, audio apparatus I can change and output the channel of radio broadcast, change the volume, and the like. The sound source of audio apparatus 1 is not limited to radio broadcast. The sound source may be flash memory 60, a CD, or a DVD explained later.
FIG.9 is a cross sectional view taken in the vertical direction along line B-B as shown in FIG.4. How the sound wave is output from vibration-type speaker 20 will be explained using the cross sectional view of FIG.9.
Vibration-type speaker 20 faces the upper surface of housing 40, and the edge section 25 of cone-type vibration plate 24 is in contact with protruding section 42 disposed on the inside of the upper surface of housing 40. Accordingly, the sound wave emitted from the front surface of vibration-type speaker 20 is output through first acoustic hole 41 in the upper surface of housing 40. On the other hand, the sound wave emitted from the back surface of cone-type vibration plate 24 is output through second acoustic holes 51 in operation panel 50 disposed on the front surface of audio apparatus 1.
FIG. 10 is a figure schematically illustrating audio apparatus 1 arranged in a center console in the vehicle. Only operation panel 50 of audio apparatus 1 is protruding to the front surface. A driver manipulates volume knob 52 and operation button 53 of operation panel 50, thereby changing the channel of radio and adjusting the volume.
Since audio apparatus 1 is embedded in the center console in the vehicle, the sound wave that is output from the upper surface of audio apparatus 1 hits a vehicle-mounted apparatus such as an air conditioner provided in the center console. As a result, the sound wave is absorbed

or dispersed. On the other hand, the sound wave emitted from the back side of cone-type vibration plate 24 is output through second acoustic holes 51 of operation panel 50, and directly reaches a passenger.
In this configuration, the first and second acoustic holes 41,51 are sufficiently ensured. Therefore, the air resistance in housing 40 can be reduced, and this can prevent the interference between the sound wave of the positive phase and the sound wave of the negative phase which are emitted from the front and the back of cone-type vibration plate 24 of vibration-type speaker 20. Therefore, the apparatus can output the sound wave which can be easily listened to by the passenger without reducing the output of the sound source.
FIG.ll is perspective view when operation panel 50 of audio apparatus 1 is detached. As shown in FIG.ll, operation panel 50 can be detached from housing 40.
FIG. 12 is a perspective view showing the back surface of operation panel 50. As shown in FIG.12, insertion opening 70 may be provided in the back surface of operation panel 50 so that an auxiliary storage device such as flash memory 60 can be connected. In this case, operation panel 50 can be connected to audio apparatus 1 while flash memory 60 is inserted to insertion opening 70 to make connection.
In this configuration, flash memory 60 can be connected without defiling the appearance of operation panel 50. Music and the like stored in flash memory 60 can be played by audio apparatus 1.
(Embodiment 2) Subsequently, a vehicle-mounted audio apparatus according to Embodiment 2 of the present invention will be explained with reference to FIGS. 13 to 22.

In Embodiment 2, description about the same configuration and operation as those of Embodiment 1 is omitted.
A front view, a back view, a top view, a bottom view, a right side view, and a left side view of the audio apparatus according to Embodiment 2 of the present invention are shown in FIGS. 13 to 18, respectively. FIG. 19 is a cross sectional view taken in the vertical direction along line C-C as shown in FIG. 13.
In the above drawings, audio apparatus 110 has housing 140 for covering vibration plate 124 of vibration-type speaker 120 and the sides of vibration-type speaker 120 held by substrate 30. Housing 140 has an opening section (not shown) at one of side surfaces and first acoustic hole 141 on the bottom surface.
In this configuration, a sound wave is discharged from first acoustic hole 141 of housing 140 (the bottom surface of audio apparatus 110) in accordance with the vibration of vibration-type speaker 120, and the sound wave discharged from the back surface of vibration-type speaker 120 is discharged through second acoustic holes 151 provided in operation panel 150.
First acoustic hole 141 is made in the bottom surface of housing 140 and has the same diameter as vibration-type speaker 120. First acoustic hole 141 has a structure in which vibration-type speaker 120 of Embodiment 1 of the present invention is arranged in the opposite direction.
In this configuration, since audio apparatus 110 is embedded in the center console as shown in FIG.20, the sound wave that is output from the bottom surface of audio apparatus 110 hits a vehicle-mounted apparatus such as an air conditioner provided in the center console. As a

result, the sound wave is absorbed or dispersed. Like Embodiment 1, the acoustic holes are sufficiently ensured. Therefore, the air resistance in housing 140 can be reduced, and this can prevent the interference between the positive phase and the negative phase which are emitted from the front and the back of cone-type vibration plate 124 of vibration-type speaker 120. Therefore, the apparatus can output the sound wave which can be easily listened to by the passenger without reducing the output of the sound source.
When the apparatus is arranged in an upper portion of the center console, audio apparatus 110 in which vibration-type speaker 120 faces the bottom surface like Embodiment 2 can better prevent the interference between the positive phase and the negative phase which are emitted from the front and the back of cone-type vibration plate 124 of vibration-type speaker 120 than audio apparatus 1 of Embodiment 1. Therefore, in the sound wave that is output from second acoustic holes 151 of operation panel 150, the interference can be reduced between the sound waves in the opposite phases emitted from vibration-type speaker 120, and the apparatus can provide the sound wave which can be easily listened to by the passenger.
F1G.21 is a perspective view illustrating audio apparatus 110 according to Embodiment 2 of the present invention. In this audio apparatus 110, operation panel 150 cannot be detached from audio apparatus 110. In this case, as shown in FIG.22, insertion opening 170 to which flash memory 160 can be connected can be provided on a side surface of a thick portion 180 rising from operation panel 150. At this occasion, insertion opening 170 is arranged to face the right side surface or the left side surface of audio apparatus 110, so that when flash memory

160 is inserted, flash memory 160 can be connected to the front surface of audio apparatus 110 so that flash memory 160 does not protrude therefore. In this configuration, flash memory 160 does not disturb manipulation when a driver manipulates operation panel 150.
Industrial Applicability
As described above, the audio apparatus according to the present invention is useful as the audio apparatus that can be embedded into the center console of the vehicle.
Reference Signs List
1, 11 0 Audio apparatus
20, 120 Vibration-type speaker
23, 123 Sound wave generation section
24, 124 Vibration plate

30, 130 Substrate
31, 131 Hole

40, 140 Housing
41, 141 First acoustic hole
42, 142 Protruding section

50, 150 Operation panel
51, 151 Second acoustic hole 60, 160 Flash memory
70, 170 Insertion opening 180 Thick portion

We Claim :
Claim 1 An audio apparatus comprising:
a vibration-type speaker that includes a sound wave generation section and a vibration section propagating a sound wave generated by the sound wave generation section to an outside;
a substrate that holds the sound wave generation section of the vibration-type speaker, and is electrically connected to the sound wave generation section;
a housing that covers at least the vibration section of the vibration-type speaker and a side of the substrate at the vibration-type speaker, has an opening section in one of side surfaces, and has a first acoustic hole being provided in at least one of an upper position and a lower position of the sound wave generation section; and
an operation panel attached to the opening section of the housing, and has a second acoustic hole,
wherein the vibration-type speaker is in contact with an upper surface inside of the first acoustic hole disposed in the housing, a sound wave is discharged through the first acoustic hole of the housing in accordance with vibration of the vibration-type speaker, and a sound wave discharged from a back surface of the vibration-type speaker is discharged through the second acoustic hole disposed in the operation panel.
Claim 2 The audio apparatus according to claim 1, wherein the
operation panel can be detached from the housing, and an auxiliary storage device can be connected to a back surface of the operation panel.
Claim 3 The audio apparatus according to claim 1, wherein the

housing is made of a resin.
Claim 4 The audio apparatus according to claim 1, wherein the
operation panel has a thick portion rising from the opening section of the housing toward an outside, and an auxiliary storage device insertion opening through which an auxiliary storage device can be detached is provided in the thick portion.