JP2004364269

Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2004364269
PROBLEM TO BE SOLVED: To provide a sound reproduction device capable of reproducing a
high-quality sound while giving the user a feeling that sound is being reproduced from display
means. SOLUTION: The present invention is a sound reproduction device provided with a display
means, a substrate, a vibration panel, and at least one electroacoustic transducer. The display
means displays an image on the display surface. The substrate forms a first space with the
display surface of the display means, and is made of a material that transmits visible light. The
vibration panel is disposed on the side opposite to the display device with respect to the
substrate, forms a second space with the substrate, and is made of a material that transmits
visible light. The electroacoustic transducer emits sound into the second space. [Selected figure]
Figure 1
Sound reproduction device
[0001]
The present invention relates to a sound reproduction apparatus, and more particularly to a
sound reproduction apparatus having a display means and acoustically driving a transparent
vibration panel.
[0002]
Heretofore, a sound reproducing apparatus has been considered in which sound is reproduced
from a display screen.
11-05-2019
1
For example, there is a sound reproducing apparatus which vibrates a transparent vibration
panel provided on the front of a display screen to emit sound (see, for example, Patent Document
1). Hereinafter, this sound reproducing apparatus will be described with reference to FIG.
[0003]
FIG. 11 is an external perspective view of a television set provided with a conventional sound
reproduction device. In FIG. 11, the television set includes a cabinet 1, a cathode ray tube 2, a
front panel 3, a driver 4 and an acoustic slit 5. The front panel 3 is attached to the front of the
cathode ray tube 2. The front panel 3 is made of a material having high light transmittance, such
as glass or transparent acrylic. The driver 4 is an electromagnetic speaker and is directly
connected to the back of the front panel 3. A plurality of acoustic slits 5 (four in FIG. 11) are
provided on the outer peripheral portion of the Braun tube 2. The television set shown in FIG. 11
reproduces sound by a method in which a transparent vibration panel is directly driven by a
driver.
[0004]
The operation of the sound reproduction apparatus shown in FIG. 11 will be described. When an
electrical signal is applied to the driver 4, the driver 4 vibrates. Since the driver 4 is directly
attached to the front panel 3, the vibration of the driver 4 is mechanically transmitted to the
front panel 3, so that the front panel 3 vibrates. That is, if the electrical signal applied to the
driver 4 is an audio signal, acoustic reproduction of audio is performed from the front panel 3
attached to the front of the cathode ray tube 2. Further, since the front panel 3 is a material
having a high light transmittance, the front panel 3 does not disturb the image reproduced by the
Braun tube 2. Therefore, simultaneous playback of video and sound is possible by the television
set shown in FIG.
[0005]
When the volume of the space between the front panel 3 and the cathode ray tube 2 is small, the
air pressure of the space is increased, so that there is a problem that the reproduction limit of the
bass range in the acoustic reproduction is increased. The acoustic slit 5 is provided for the
purpose of preventing this problem. Since the back surface sound of the front panel 3 passes
11-05-2019
2
through the acoustic slit 5 and is emitted into the cabinet 1, the acoustic slit 5 does not raise the
air pressure in the space.
[0006]
Further, although the sound reproducing apparatus shown in FIG. 11 is used for a television set,
there is also a sound reproducing apparatus used for a portable telephone (see, for example,
Patent Document 2). The sound reproducing apparatus vibrates the outer case by a driver
directly attached to the outer case of the mobile phone to reproduce sound. Hereinafter, this
sound reproducing apparatus will be described with reference to FIG.
[0007]
FIG. 12 is an external view of a portable telephone provided with a conventional sound
reproducing apparatus. In FIG. 12, the mobile phone includes an outer case 10, an antenna 11, a
sound board 12, a driver 13, and a display screen 14. The sound board 12 is disposed on the
front upper portion of the outer case 10, and is formed so that the outer peripheral portion is
thin although not shown. The driver 13 is directly attached to the back side of the sound board
12. The display screen 14 is provided on the front of the outer case 10 below the sound board
12.
[0008]
The operation of the sound reproduction apparatus shown in FIG. 12 will be described. When an
electrical signal is applied to the driver 13, the vibration of the driver 13 is directly transmitted
to the sound board 12 formed in the outer case 10. As a result, the sound is reproduced by the
sound board 12 vibrating. Patent No. 2021497 JP, 8-275293, A
[0009]
In the sound reproducing apparatus shown in FIG. 11, the driver 4 needs to be attached so as not
to get in the way of the display screen of the cathode ray tube 2, so it is attached near the end of
the front panel 3. However, in the sound reproducing apparatus adopting the method of driving
11-05-2019
3
the front panel 3 directly by the driver 4, when the driver 4 is attached near the end of the front
panel 3, the sound quality of the reproduced sound is deteriorated.
[0010]
Furthermore, since the front panel 3 has a role as a protective panel for protecting the cathode
ray tube 2 together with a role as a vibrating panel that emits sound, an appropriate strength is
required. Therefore, the front panel 3 needs to be thick to a certain extent. Therefore, the weight
of the front panel 3 is increased, so that the vibration of the front panel 3 by the driver 4 is
reduced, and the reproduction sound pressure is reduced. Therefore, in the sound reproduction
apparatus shown in FIG. 11, the efficiency of the reproduction sound pressure to the driver is
very low as compared with a normal speaker.
[0011]
On the other hand, the sound reproducing apparatus shown in FIG. 12 can not be applied to a
recent cellular phone in which the enlargement of the display screen is strongly required.
Specifically, in the sound reproducing apparatus shown in FIG. 12, since the display screen 14
and the sound board 12 are arranged at different positions, the sound board 12 is in the way and
the enlargement of the display screen 14 is limited. . Furthermore, since the position of the
display screen 14 is different from the position at which the sound is reproduced, it is not
possible to give the user a feeling that the sound is reproduced from the display screen 14.
[0012]
Therefore, an object of the present invention is to provide a sound reproduction device capable
of reproducing a high-quality sound while giving the user a feeling that sound is being
reproduced from the display means.
[0013]
In order to solve the above-mentioned subject, the present invention has the following
composition.
11-05-2019
4
That is, the present invention is a sound reproduction device provided with display means, a
substrate, a vibration panel, and at least one electroacoustic transducer. The display means
displays an image on the display surface. The display means is a concept including a picture or a
picture on which an image is drawn, in addition to a display device such as a liquid crystal
display device. The substrate forms a first space with the display surface of the display means,
and is made of a material that transmits visible light. The vibrating panel is disposed on the side
opposite to the display means with respect to the substrate, forms a second space with the
substrate, and is made of a material that transmits visible light. The electroacoustic transducer
emits sound into the second space.
[0014]
Typically, the substrate is provided with a sound hole, and the electro-acoustic transducer emits
sound to the second space through the sound hole.
[0015]
In addition, the sound reproducing apparatus may further include a case having an opening
covered by the vibration panel.
The case contains therein a substrate, display means and an electroacoustic transducer.
[0016]
Also, the vibration panel may be configured by a touch panel.
[0017]
In addition, the sound reproduction apparatus may further include an antenna for receiving a
signal and a signal processing unit.
The signal processing means performs predetermined signal processing on the signal received by
the antenna, and inputs the signal subjected to the signal processing to the electroacoustic
transducer.
11-05-2019
5
[0018]
The sound reproduction apparatus may also include two electro-acoustic transducers. At this
time, when the signal received by the antenna includes a signal indicating a reception sound, the
signal processing means inputs the signal to one of the electroacoustic transducers, and the
reception sound is a signal received by the antenna. If a signal other than the signal indicating is
included, the signal is input to the other electroacoustic transducer.
[0019]
According to the invention, the vibrating panel is acoustically driven by the sound emitted from
the electro-acoustic transducer to the second space. When the vibration panel is acoustically
driven in this manner, the mounting position of the electroacoustic transducer does not affect the
reproduction of sound. Therefore, the sound quality does not deteriorate due to the mounting
position of the electroacoustic transducer. In addition, since the electro-acoustic transducer can
be freely disposed, the electro-acoustic transducer does not get in the way of the display means,
and the user can be given a feeling that the sound is being reproduced from the display means.
[0020]
First Embodiment First, a sound reproducing apparatus according to a first embodiment of the
present invention will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a diagram
showing the configuration of the sound reproduction device according to the first embodiment.
FIG. 1 (a) is a plan view of the sound reproduction apparatus, and FIG. 1 (b) is a cross-sectional
view of the sound reproduction apparatus taken along the line A-B. The sound reproducing
apparatus according to the first embodiment is realized as a mobile terminal device such as a
mobile phone or a PDA.
[0021]
In FIG. 1, the sound reproducing apparatus includes an outer case 20, a display device 21, a
substrate 22, a vibrating panel 23, a spacer 24, and an electroacoustic transducer 26. The
display device 21 is, for example, a liquid crystal display device. The substrate 22 and the
11-05-2019
6
vibration panel 23 are made of a material that transmits visible light. The substrate 22 is made
of, for example, glass or acrylic resin. The vibrating panel 23 is made of, for example, acrylic
resin or PET (polyethylene terephthalate).
[0022]
In FIG. 1, the outer case 20 has an opening of substantially the same size as the display device
21, and the display device 21 is installed so as to close the opening. That is, the periphery of the
display device 21 is connected to the opening. The display device 21 is disposed inside the outer
case 20. The substrate 22 is disposed outside the display device 21 (left side in FIG. 1) with
respect to the outer case 20. A first space is formed between the display device 21 and the
substrate 22. The peripheral portion of the substrate 22 is connected to the outer case 20. The
vibrating panel 23 is disposed on the outer side (left side in FIG. 1) of the substrate 22 with
respect to the outer case 20. That is, the vibration panel 23 is disposed to face the display device
21 with respect to the substrate 22. The substrate 22 and the vibration panel 23 are fixed to
each other by the spacer 24 at their peripheral portions. As a result, a second space is formed
between the substrate 22 and the vibration panel 23. Further, sound holes 27 are provided in the
substrate 22 and the outer case 20. The electroacoustic transducer 26 is disposed on the side
opposite to the second space 25 with respect to the substrate 22. The electroacoustic transducer
26 is connected to the outer case 20 so as to close the sound hole 27. In other embodiments, the
electroacoustic transducer 26 may be directly connected to the substrate 22. The electroacoustic transducer 26 is disposed inside the outer case 20 in the same manner as the display
device 21.
[0023]
FIG. 2 is a cross-sectional view of the electro-acoustic transducer 26 shown in FIG. In FIG. 2, the
electroacoustic transducer 26 includes a bowl-shaped yoke 40, a magnet 41, a plate 42, a voice
coil 44, a diaphragm 45, and a frame 46. The frame 46 is connected to the outer case 20 at the
outer peripheral portion of the sound hole 27 so as to close the sound hole 27. The outer
peripheral lower surface (the surface on the right side in FIG. 2) of the yoke 40 is fixed to the
central portion of the frame 46. The magnet 41 is provided at the center of the yoke 40. The
plate 42 is disposed on the top surface of the magnet 41. The yoke 40 and the plate 42 are
disposed such that a magnetic air gap 43 is generated between the inner circumferential surface
of the yoke 40 and the outer circumferential surface of the plate 42. The outer peripheral portion
of the diaphragm 45 is fixed to the frame 46. The voice coil 44 is fixed to the diaphragm 45 so as
to be inserted into the magnetic gap 43.
11-05-2019
7
[0024]
The operation of the sound reproducing apparatus configured as shown in FIGS. 1 and 2 will be
described. When an electrical signal is applied to the voice coil 44 inserted into the magnetic gap
43 of the electroacoustic transducer 26, a driving force is generated in the voice coil 44. A sound
is generated by the diaphragm 45 coupled to the voice coil 44 vibrating by the driving force. The
sound radiated from the diaphragm 45 propagates from the sound hole 27 to the second space
25. As a result, the vibration panel 23 vibrates by the sound pressure of the second space 25.
That is, the vibration panel 23 is acoustically driven to vibrate. Thus, the sound is emitted from
the vibration panel 23. As described above, when the vibration panel 23 is acoustically driven,
the sound is propagated through the second space, so the mounting position of the electroacoustic transducer 26, which is a driver, affects the sound quality of the reproduced sound. I
will not give. Therefore, the mounting position of the electro-acoustic transducer 26 can be freely
designed, and the deterioration of the reproduction sound can be prevented.
[0025]
In addition, when the outer peripheral part of the vibration panel 23 is fixed by the spacer 24,
the vibration panel 23 vibrates so that vibration panel 23 itself may bend. In addition, when the
spacer 24 is configured by a suspension made of an elastic body, the vibrating panel 23 itself
vibrates so as to perform a piston movement. In the present invention, the vibrating panel 23
may vibrate so as to bend the vibrating panel 23 itself, or may vibrate so as to perform a piston
movement.
[0026]
When the vibration panel 23 vibrates due to the sound pressure of the sound radiated to the
second space 25, the same sound pressure is applied to the substrate 22 as in the case of the
vibration panel 23. Therefore, similar to the vibration panel 23, a force that causes the substrate
22 to vibrate acts by the sound pressure. Here, when the substrate 22 vibrates, the energy of the
sound radiated to the second space 25 is dispersed to the vibration panel 23 and the substrate
22. Therefore, in this case, the sound pressure level reproduced from the vibration panel 23 is
lower than that in the case where the substrate 22 does not vibrate. In other words, the energy
for the vibration of the vibration panel 23 is taken away by the vibration of the substrate 22, so
11-05-2019
8
that the vibration of the vibration panel 23 is reduced. From the above, it is necessary to prevent
the substrate 22 from vibrating due to the sound pressure of the second space 25.
[0027]
As a method for preventing the vibration of the substrate 22, it is conceivable to increase the
thickness of the substrate 22 so that the substrate 22 has sufficient strength. However,
increasing the thickness of the substrate 22 will increase the thickness of the acoustic
reproduction device. In particular, it is not preferable to increase the thickness of the substrate
22 in a portable terminal device for the purpose of downsizing and weight reduction. Further, as
another method for preventing the vibration of the substrate 22, it is also conceivable to stick the
substrate 22 closely to the display screen of the display device 21 with an adhesive. However,
when the substrate 22 and the display screen are bonded, the light transmittance is reduced by
the bonding layer, and the image quality of the display screen is degraded. Therefore, it is
necessary to provide a first space 28 between the substrate 22 and the display screen as shown
in FIG.
[0028]
Therefore, in the first embodiment, the vibration of the substrate 22 is suppressed by sealing the
first space 28. The acoustic stiffness of the air in the first space 28 suppresses the vibration of
the substrate 22. By making the first space 28 substantially a closed space, the vibration of the
substrate 22 can be suppressed even if the thickness of the substrate 22 is equal to or less than
that of the vibration panel 23. As a result, the reduction in the sound pressure of the vibration
panel 23 due to the vibration of the substrate 22 can be prevented.
[0029]
Since the substrate 22 and the vibration panel 23 are transparent materials, the display screen of
the display device 21 can be viewed from the outside of the sound reproduction device. In
addition, since the electroacoustic transducer 26 is disposed on the side of the display device 21,
the electroacoustic transducer 26 does not block the display screen.
[0030]
11-05-2019
9
As described above, according to the sound reproduction device according to the first
embodiment, it is possible to give the user a feeling that the sound is being reproduced from the
display device without degrading the sound quality of the reproduction sound. In addition, by
making the first space substantially sealed, it is possible to prevent a decrease in reproduced
sound pressure. Furthermore, since the substrate can be made thinner by forming the first and
second spaces, the sound reproducing apparatus can be made thinner.
[0031]
The sound reproducing apparatus according to the first embodiment can be manufactured
separately from the three components of the substrate 22, the vibration panel 23, and the spacer
24. That is, while assembling these three components, the main-body part other than these
components is manufactured. Then, by attaching a component in which these three components
are assembled to the main body portion, the sound reproduction apparatus can be easily
manufactured. Further, in the sound reproduction device according to the first embodiment,
since the display screen of the display device is covered by the substrate 22 and the vibration
panel 23, the display screen can be protected more reliably compared to the configuration
without the substrate 22. it can.
[0032]
In the first embodiment, the external shape of the electroacoustic transducer 26 is a round shape,
but may be an ellipse or a rectangle. By making the external shape of the electroacoustic
transducer 26 elliptical or rectangular, the display screen of the display device 21 can be made
larger.
[0033]
Second Embodiment Next, a sound reproducing apparatus according to a second embodiment
will be described with reference to FIGS. In the second embodiment, a sound reproduction
apparatus implemented as a mobile phone will be described. FIG. 3 is a plan view partially
showing the mobile phone according to the second embodiment with a notch. FIG. 4 is a block
diagram of a mobile phone according to the second embodiment.
11-05-2019
10
[0034]
In FIG. 3 and FIG. 4, the mobile phone 100 includes the outer case 101, the antenna 102, the
display device 103, the substrate 104, the vibration panel 105, the spacer 106, the
electroacoustic transducer 110, the signal processing unit 111, and the signal amplification unit
112. Have. In FIG. 3, the outer case 101 incorporates an electric circuit and the like included in
the mobile phone 100. The antenna 102 is attached to the outer case 101. In FIG. 3, a part of the
vibration panel 105 is shown with a notch. Further, in FIG. 4, the signal processing unit 111 is
connected to the antenna 102 and the signal amplification unit 112. The signal amplification unit
112 is connected to the signal processing unit 111 and the electroacoustic transducer 110. The
configuration of the sound reproduction device 113 shown by a dotted line in FIG. 4 is the same
as that of the first embodiment except for the outer shape of the outer case 101.
[0035]
Next, the operation of the mobile phone 100 according to the second embodiment will be
described. The signal received by the antenna 102 is input to the signal processing unit 111.
Here, it is assumed that a reception signal indicating a reception sound which is a speech of the
transmitter is received by the antenna 102. The signal processing unit 111 performs
predetermined signal processing on the signal input from the antenna 102. For example,
processing for extracting a reception signal from the input signal is performed. The signal
subjected to the signal processing is amplified by the signal amplification unit 112 and applied to
the electroacoustic transducer 110. Similar to the first embodiment, the sound is emitted from
the vibration panel 105 by applying the electric signal to the electro-acoustic transducer 110. As
described above, the vibration panel 105 operates as a receiver that is a speaker for receiving
sound reproduction. The vibration panel 105 vibrates substantially uniformly due to the sound
pressure in the second space 109, so a receiver with a wide listening range is able to hear the
reception sound regardless of the position of the vibration panel 105. realizable.
[0036]
Next, the effect of the first space 108 in the second embodiment will be described with reference
to FIG. FIG. 5 is a view showing a measuring apparatus for measuring the receiver characteristics
of the sound reproduction apparatus according to the second embodiment. In FIG. 5, the
11-05-2019
11
measurement apparatus includes a measurement cover 120, an acoustic coupler 122, and a
measurement microphone 123. The measurement cover 120 is attached to the vibrating panel
105 so as to form an enclosed space 121 with the vibrating panel 105. The acoustic coupler 122
has the acoustic characteristics of the ear conforming to the International Standard IEC
(International Electrotechnical Commision). In the measurement apparatus shown in FIG. 5, the
sound radiated from the vibration panel 105 is guided to the acoustic coupler 122 via the
enclosed space 121, and the sound pressure frequency characteristic is measured by the
measurement microphone 123.
[0037]
FIG. 6 is a diagram showing the result of measuring the sound pressure frequency characteristics
of the sound reproducing device by the measuring device shown in FIG. In FIG. 6, the vertical axis
is the sound pressure of the sound emitted from the sound reproducing apparatus, and the
horizontal axis is the frequency of the sound. Here, the electroacoustic transducer 110 is an
electrodynamic speaker with a diameter of 10 mm, the substrate 104 is a transparent acrylic
material with a material thickness of 0.65 mm, the vibrating panel 105 has a length of 60 × 40
mm, a thickness of 0. It is a transparent PET material of 190 mm. The gap width of the first space
108 is 0.5 mm, the gap width of the second space 109 is 0.2 mm, and the gap width of the
closed space 121 in front of the vibrating panel 105 is 0.2 mm.
[0038]
I shown in FIG. 6 indicates the sound pressure frequency characteristics when the first space 108
exists on the back surface of the substrate 104. Further, II shown in FIG. 6 shows the sound
pressure frequency characteristics when the first space 108 is not present on the back surface of
the substrate 104. If the first space 108 does not exist, the substrate 104 vibrates due to the
sound pressure emitted from the electroacoustic transducer 110 to the second space 109. Since
the acoustic energy for vibrating the vibrating panel 105 is consumed by this, the sound pressure
radiated from the vibrating panel 105 is reduced. On the other hand, when the first space 108
exists, the acoustic stiffness of the air in the first space 108 is large, and the vibration of the
substrate 104 is suppressed. That is, in this case, although the substrate 104 has a thin material
thickness of 0.65 mm, it acts as a rigid body. As a result, the sound pressure level becomes
higher by about 3 to 10 dB in the frequency band of 1 kHz or less than when the first space 108
is not present. As described above, it is understood that the provision of the first space 108 can
significantly improve the loss of acoustic energy by the substrate 104.
11-05-2019
12
[0039]
As described above, the same effect as that of the first embodiment can be obtained by the
mobile phone 100 according to the second embodiment. In the second embodiment, the signal
applied to the electroacoustic transducer 110 has been described as a reception signal. Here, an
incoming signal indicating an incoming call, a music signal, an audio signal, or a signal indicating
a sound effect of a game may be received by the antenna 102, and these signals may be applied
to the electroacoustic transducer 110. At this time, the vibration panel 105 functions as a
loudspeaker for reproducing a ring tone, music, voice, or a game sound effect. Further, when the
mobile phone 100 according to the second embodiment has a videophone function, the face of
the other party of the conversation is displayed on the display screen, and the speaking voice is
reproduced by the vibrating panel 105. In addition, in the conventional sound reproduction
apparatus which is the structure which attached the driver to the outer case directly, in order to
reproduce ¦ regenerate a sound by sufficient sound pressure, it was necessary to use most of the
outer case as a vibration surface. Therefore, the space for attaching the display device is limited,
and a large display screen can not be used (see FIG. 12). On the other hand, in the second
embodiment, since the vibration panel 105 is acoustically driven, a mobile phone equipped with
a large display screen that can not be realized by the conventional mobile phone can be realized.
[0040]
Third Embodiment Next, a sound reproduction device according to a third embodiment will be
described with reference to the drawings. The sound reproduction device according to the third
embodiment is realized as a portable terminal device as in the first embodiment. The sound
reproducing apparatus according to the third embodiment is configured to include two electroacoustic transducers.
[0041]
FIG. 7 is a diagram showing a sound reproduction device according to the third embodiment. 7
(a) is a plan view of the sound reproduction device, and FIG. 7 (b) is a cross-sectional view of the
sound reproduction device taken along the line C-D. In FIG. 7, the sound reproducing apparatus
includes an outer case 130, a display device 131, a substrate 132, a vibrating panel 134, a
spacer 140, a first electroacoustic transducer 136, and a second electroacoustic transducer 138.
In the third embodiment, the first sound hole 137 and the second sound hole 139 are provided
11-05-2019
13
in the substrate 132 and the outer case 130. The first and second electroacoustic transducers
136 and 138 are disposed opposite to the second space 135 with respect to the substrate 132.
The first electroacoustic transducer 136 is connected to the outer case 130 so as to close the
first sound hole 137. The second electroacoustic transducer 138 is connected to the outer case
130 so as to close the second sound hole 139. The configuration other than the configuration of
the first and second electroacoustic transducers 136 and 138 and the first and second sound
holes 137 and 139 is the same as that of the first embodiment. Further, the operating principle
of vibrating the vibrating panel 134 by applying an electric signal to at least one of the first and
second electroacoustic transducers 136 and 138 is the same as that of the first embodiment.
[0042]
Also, the mobile terminal device according to the third embodiment can be used as a mobile
phone as shown in the second embodiment. FIG. 8 is a block diagram of the case where the
mobile terminal device according to the third embodiment is used as a mobile phone. In FIG. 8,
the mobile phone includes an acoustic reproduction device 150, an antenna 151, a signal
processing unit 152, a first signal amplification unit 153, and a second signal amplification unit
154. The sound reproduction device 150 is a sound reproduction device shown in FIG. The signal
processing unit 152 is connected to the antenna 151 and the first and second signal
amplification units 153 and 154. The first signal amplification unit 153 is connected to the first
electroacoustic transducer 136. The second signal amplification unit 154 is connected to the
second electroacoustic transducer 138.
[0043]
Next, the operation of the mobile phone shown in FIG. 8 will be described. The antenna 151
receives a signal sent from a mobile phone base station. The signal includes an incoming signal, a
receiving signal indicating a receiving sound, an acoustic signal such as music, or an image signal
such as moving image or character information. The signal received by the antenna 151 is
subjected to signal processing in the signal processing unit 152, and is input to one of the first
and second signal amplification units 153 and 154. Here, when the reception signal is included
in the signal received by the antenna 151, the signal processing unit 152 outputs the reception
signal subjected to the signal processing to the first signal amplification unit 153. Thus, the
received signal is amplified by the first signal amplifier 153 and applied to the first
electroacoustic transducer 136. At this time, the vibrating panel 134 operates as a receiver. On
the other hand, when the signal received by the antenna 151 includes a signal other than the
reception signal, the signal processing unit 152 outputs the signal subjected to the signal
11-05-2019
14
processing to the second signal amplification unit 154. Here, the signals other than the incoming
call signal are, for example, the above-mentioned acoustic signal, an incoming call signal
indicating that there is an incoming call, a music signal downloaded from the Internet, and the
like. These signals are amplified by the second signal amplifier 154 and applied to the second
electroacoustic transducer 138. At this time, the vibration panel 134 operates as a loud speaker.
[0044]
Generally, in the case of an electroacoustic transducer operated as a receiver, the lowest
resonance frequency of the vibration system is set around 250 Hz to 550 Hz in consideration of
sound leakage from the ear. Since the receiver is assumed to listen closely to the ear, the input
signal to the electroacoustic transducer operated as a receiver is as small as 40 mW or less.
Therefore, even if the lowest resonance frequency of the electroacoustic transducer is low, the
large amplitude of the vibration system does not cause abnormal noise or destruction. On the
other hand, a signal with a large value of 200 mW or more is applied to a loudspeaker for loudspeaking that reproduces louder sound than the receiver. Therefore, it is difficult to make the
lowest resonance frequency of the electroacoustic transducer operating as a loudspeaker for
loudspeaker very low, and the electroacoustic transducer operating as a loudspeaker for
loudspeaker can reproduce a large sound pressure level. Require a stable structure and shape.
From the above, it is difficult to use different acoustic reproductions with different applications of
a receiver and a loudspeaker for a single electro-acoustic transducer. Here, in the third
embodiment, a configuration is adopted in which each of the electro-acoustic transducer
operated as a receiver and the electro-acoustic transducer operated as a loudspeaker for
loudspeaker is provided. Therefore, the configuration of the third embodiment is more practical
than the configuration of the second embodiment in which one electro-acoustic transducer
performs both the operation of the receiver and the speaker for sound amplification.
[0045]
Note that the user usually listens to the received sound reproduced by the receiver by bringing
the ear close to the vibrating panel. On the other hand, melody sound and the like reproduced by
the speaker for loud sound are reproduced with louder sound than the received sound.
Therefore, when the user brings the portable terminal close to the ear to listen to the receiving
sound, a loud melody sound may be reproduced, and the reproduced melody sound may impair
the user's hearing. Here, in the third embodiment, since two electroacoustic transducers are
arranged at different positions according to the application, there is little direct influence from
the electroacoustic transducers, and one electroacoustic transducer can be obtained. It is more
11-05-2019
15
secure than the second embodiment used.
[0046]
Fourth Embodiment Next, a sound reproducing apparatus according to a fourth embodiment will
be described with reference to FIG. The sound reproduction device according to the fourth
embodiment is realized as a portable terminal device as in the first embodiment. In the sound
reproduction device according to the fourth embodiment, the vibration panel and the substrate
are configured by a touch panel.
[0047]
FIG. 9 is a view showing a sound reproduction device according to the fourth embodiment. FIG. 9
(a) is a plan view in which a part of the sound reproduction device is cut away, and FIG. 9 (b) is a
cross-sectional view of the sound reproduction device taken along the line E-F.
[0048]
In FIG. 9, the sound reproducing apparatus includes an outer case 159, a display device 160, a
substrate 161, a first transparent electrode 162, a vibration panel 164, a second transparent
electrode 165, a spacer 166, resistance value detection electrodes 168 to 171, And an
electroacoustic transducer 173.
[0049]
The sound reproducing apparatus according to the fourth embodiment differs from the sound
reproducing apparatus according to the first embodiment in that it further includes first and
second transparent electrodes 162 and 165, and resistance value detection electrodes 168 to
171. It is.
The first transparent electrode 162 is connected to the substrate 161 so as to face the second
space 167. The second transparent electrode 165 is connected to the vibrating panel 164 so as
to face the second space 167. The resistance value detection electrodes 168 and 169 are
provided on the short side of the spacer 166. Further, resistance value detection electrodes 168
11-05-2019
16
and 169 are provided between the spacer 166 and the second transparent electrode 165.
Therefore, the resistance value detection electrodes 168 and 169 are in contact with the second
transparent electrode 165. On the other hand, the resistance value detection electrodes 170 and
171 are provided on the long side of the spacer 166. Resistance value detection electrodes 170
and 171 are provided between the spacer 166 and the first transparent electrode 162.
Therefore, the resistance value detection electrodes 170 and 171 are in contact with the first
transparent electrode 162.
[0050]
The sound reproducing apparatus according to the fourth embodiment is the sound reproducing
apparatus according to the first embodiment in that the sound hole 172 provided in the
substrate 161, the first transparent electrode 162, and the outer case 159 is rectangular. It is
different from Except for the above points, the configuration of the sound reproducing apparatus
according to the fourth embodiment is the same as the configuration of the sound reproducing
apparatus according to the first embodiment.
[0051]
Further, the operation of reproducing the sound by the vibration of the vibration panel 164 of
the sound reproducing apparatus is the same as that of the first embodiment. Here, in the sound
reproduction device according to the fourth embodiment, a touch panel is configured by the first
and second transparent electrodes 162 and 165 and the resistance value detection electrodes
168 to 171. That is, when the vibrating panel 164 is pressurized by the pen or the finger of the
user, the first transparent electrode 162 and the second transparent electrode 165 come in
contact with each other. Coordinates indicating the contact position are detected as a change in
resistance value by the resistance value detection electrodes 168 and 169 and the resistance
value detection electrodes 170 and 171. The operation of the sound reproducing apparatus is
controlled based on the detected coordinates. Although not shown in FIG. 9, an operation menu,
an icon, and the like are displayed on the display screen of the display device 160.
[0052]
As described above, in the fourth embodiment, the touch panel, which is an input device, can be
combined with the vibration panel for reproducing sound, and sound is reproduced from the
11-05-2019
17
touch panel without blocking the image on the display screen. A playback device can be realized.
The detection method of the touch panel is not limited to the method using a change in electric
resistance, and may be a method using light, capacitance, or the like.
[0053]
Although the circuit for processing the signal detected by the touch panel, the circuit for
controlling the sound reproducing apparatus by the signal, and the like are mounted in the sound
reproducing apparatus shown in FIG. Since it is not related to the detailed description and
explanation will be omitted.
[0054]
As described above, according to the present invention, it is possible to give the user a feeling
that the sound is being reproduced from the display device without degrading the sound quality
of the reproduction sound.
Further, by making the first space substantially sealed, it is possible to prevent a decrease in the
reproduction sound pressure and to make the sound reproduction device thin.
[0055]
In addition, if the sound reproducing apparatus according to the present invention is applied to a
mobile telephone and the vibration panel is disposed on the display screen of the mobile
telephone, the vibration panel can be operated as a receiver for receiving sound reproduction. It
becomes. At this time, since the reception sound is reproduced from the front of the vibration
panel, it becomes possible to listen in a wide range of the vibration panel surface, and it is
possible to realize a mobile phone in which the reception sound can be easily heard by elderly
people in particular. It is also possible to operate the vibration panel as a loudspeaker by
increasing the level of the input signal applied to the sound reproduction apparatus. This makes
it possible to have a conversation while viewing an image like a videophone. In addition, since the
radiation plane of the image and the sound is the same plane, it is possible to give the user a
feeling that the sound is coming out of the image, and to realize the sound reproduction device
that is optimal for simultaneous reproduction of the sound and the video Can.
11-05-2019
18
[0056]
Furthermore, by using the surface film of the touch panel also as the vibration panel, it is
possible to realize a portable terminal device in which the input device and the sound
reproducing device are integrated.
[0057]
In the first to fourth embodiments, the structure of the electrodynamic speaker is shown as an
example of the electroacoustic transducer 26. However, the electroacoustic transducer 26 may
be of any type.
The electro-acoustic transducer 26 may have any function of emitting sound from the
diaphragm, and the transducer type may be any type such as an electromagnetic type, a
piezoelectric type, and an electrostatic type.
[0058]
In the present invention, sealing the first space does not necessarily mean that the first space
is completely sealed. The first space 28 may be a substantially enclosed space. Hereinafter, this
will be described with reference to FIG.
[0059]
FIG. 10 is a diagram showing sound pressure frequency characteristics of the sound reproduction
device according to the present invention. FIG. 10 shows the result of measurement of the sound
radiated from the vibration panel of the sound reproduction apparatus according to the second
embodiment by the sound coupler shown in FIG. In FIG. 10, the size of each of the substrate and
the vibration panel is 40 × 60 mm, and the material thickness is 0.2 mm. Moreover, the solid
line shown in FIG. 10 is the sound pressure frequency characteristic when the pore is not
provided in the first space. The dotted line shown in FIG. 10 is the sound pressure frequency
characteristic when the pore having a diameter of 1 mm is provided in the first space. The
dashed-dotted line shown in FIG. 10 is a sound pressure frequency characteristic at the time of
providing a pore with a diameter of 2 mm in the first space.
11-05-2019
19
[0060]
As apparent from FIG. 10, when the pores are provided in the first space, it is understood that the
sound pressure is lower in the band of 400 Hz or less than in the case where the pores are not
provided. This is because the acoustic stiffness of the first space is reduced by the pores, and the
force to suppress the vibration of the substrate 104 is reduced. Here, when the diameter of the
pore is 1 mm, although the sound pressure level is lowered in the low frequency band of 300 Hz
or less, the sound pressure level does not decrease in the band of 300 Hz or higher. Considering
the case where the sound reproducing apparatus is realized as a portable telephone, the band
necessary for reproducing the received sound is a frequency band higher than 300 Hz.
Therefore, in the example of FIG. 10, there is no problem even if there is a pore having a
diameter of about 1 mm in the first space when operating as a receiver of the mobile phone. As
described above, it is desirable that the first space is completely sealed, but sufficient effects can
be obtained even if the first space is opened to some extent. In FIG. 5, the acoustic coupler is an
acoustic load to suppress the vibration of the vibration panel 105. Therefore, in FIG. 5, the
substrate 104 is considered to be easily vibrated as compared with the case without the acoustic
coupler. That is, since there is no acoustic coupler when using a portable telephone normally, it is
considered that the influence of the pore is actually smaller than in the case of FIG. In
consideration of the above, it is considered that there may be no problem even if the pore size is
1 mm or more in diameter in practice.
[0061]
In the first to fourth embodiments, the sound reproducing apparatus is realized as a portable
terminal device which is a portable electronic device. However, the sound reproducing device
according to the present invention may be a game machine, a personal computer, or the like. The
present invention is also applicable to stationary electronic devices such as televisions.
[0062]
Moreover, in the first, second, and fourth embodiments, the number of the electroacoustic
transducers and the number of the sound holes is one, but as described in the third embodiment,
the number of the electroacoustic transducers and the number of the sound holes are plural. May
be
Also, in the case where there are a plurality of electroacoustic transducers and sound holes, the
11-05-2019
20
sound can be reproduced at a large volume by applying the same signal to all the electroacoustic
transducers. Also, stereo signals may be applied to the two electroacoustic transducers.
[0063]
In another embodiment, a poster, a picture or the like on which an image is drawn may be used
instead of the display device. For example, if the sound reproducing apparatus is applied to a
photo frame, it is possible to give the user a feeling that sound is being reproduced from the
photo.
[0064]
The sound reproducing apparatus of the present invention can be used as a portable terminal
device such as a portable telephone or a PDA, and can also be used for a stationary personal
computer or a television.
[0065]
FIG. 2 is a cross-sectional view of the electro-acoustic transducer shown in FIG. 1 showing the
configuration of the sound reproducing apparatus according to Embodiment 1. FIG. 2 is a plan
view partially showing the mobile phone according to Embodiment 2 with a notch. FIG. 5 is a
block diagram of the mobile phone according to the second embodiment of the present
invention. FIG. 5 shows a measuring device for measuring the receiver characteristics of the
sound reproducing device according to the second embodiment. The figure which shows the
sound reproduction apparatus which concerns on mode 3 The block diagram at the time of
utilizing the portable terminal device which concerns on Embodiment 3 as a mobile telephone
The figure which shows the sound reproduction apparatus which concerns on Embodiment 4 The
sound reproduction apparatus which concerns on this invention Figure showing sound pressure
frequency characteristics External appearance perspective view of a television set equipped with
a conventional sound reproducing apparatus External view of a portable telephone equipped
with a conventional sound reproducing apparatus
Explanation of sign
[0066]
Reference Signs List 20, 101, 130, 159 Outer case 21, 103, 131, 160 Display 22, 104, 132, 161
Substrate 23, 105, 134, 164 Vibrating panel 24, 106, 140, 166 Spacer 26, 110, 136, 138 , 173
11-05-2019
21
Electroacoustic transducer
11-05-2019
22

Download Report