JP2014112926A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus capable of efficiently suppressing the deterioration of a sound pressure and the increase of the distortion rate.SOLUTION: An electronic apparatus includes a piezoelectric element and a panel, and the panel curves so as to fit the expansion or curve of the piezoelectric element.

Description

  The present invention relates to an electronic device that vibrates a panel by applying a predetermined electrical signal (audio signal) to a piezoelectric element, and transmits the vibration of the panel to a human body to transmit air conduction sound and bone conduction sound to a user. Regarding equipment.

  Patent Document 1 describes an electronic device such as a mobile phone terminal that transmits air conduction sound and bone conduction sound to a user. According to Patent Document 1, air conduction sound is sound transmitted to the auditory nerve of a user by vibration of air that is caused by vibration of an object being transmitted to the eardrum through the external auditory canal. Have been described. Patent Document 1 describes that bone conduction sound is sound transmitted to the user's auditory nerve through a part of the user's body (for example, cartilage of the outer ear) that contacts the vibrating object. ing.

  In the telephone set described in Patent Document 1, it is described that a short plate-like vibrating body made of a piezoelectric bimorph and a flexible material is attached to the outer surface of a housing via an elastic member. Further, in Patent Document 1, when a voltage is applied to the piezoelectric bimorph of the vibrating body, the piezoelectric material expands and contracts in the longitudinal direction, causing the vibrating body to bend and vibrate, and the user contacts the vibrating body with the auricle. It is described that air conduction sound and bone conduction sound are transmitted to the user.

JP 2005-348193 A

  In the electronic device described in Patent Document 1, a vibrating body is attached to the outer surface of a housing such as a mobile phone terminal. For this reason, it is necessary to touch a small vibrating body protruding from the outer surface of the housing to the ear, and there are cases where the usability is poor. Therefore, by placing the vibrating body on the back surface (inner surface) of a panel such as a mobile phone terminal and deforming the panel due to deformation of the vibrating body, air conduction sound is generated with respect to the object (ear) that contacts the panel. It is assumed that the bone conduction sound is transmitted.

  However, in Patent Document 1 described above, no consideration has been given to various problems that occur when the panel is deformed.

  An object of the present invention is to solve a problem in an electronic device that vibrates a panel and to provide a good electronic device.

  A first electronic device of the present invention includes a piezoelectric element and a panel, and the panel is bent in accordance with expansion or contraction or bending of the piezoelectric element.

  Preferably, when the panel is bent, the antinode generated directly above the piezoelectric element in the longitudinal direction of the piezoelectric element is larger than the antinode generated other than immediately above the piezoelectric element.

  Preferably, when the panel is curved, the antinodes generated immediately above the piezoelectric elements in the longitudinal direction of the piezoelectric elements are larger than the antinodes generated near both ends of the panel.

  A second electronic device according to the present invention includes a piezoelectric element, a panel that supports the piezoelectric element, and a housing that holds the panel. In the longitudinal direction of the piezoelectric element, the piezoelectric element is directly above the piezoelectric element. In the electronic device in which the panel is bent by the piezoelectric element so as to be raised highest as compared with the surroundings, and a contact part of the human body in contact with the panel vibrates and transmits sound, the panel and the casing A cushioning material is disposed between the two.

  Preferably, both the piezoelectric element and the buffer material are arranged on one end side in one direction in a plan view of the panel.

  Preferably, the buffer material becomes thinner as it moves away from the piezoelectric element toward the other end.

  Preferably, the cushioning material is bonded to only one of the panel and the casing.

  Suitably, the said housing | casing contains the sheet metal as an insert member.

  Preferably, the piezoelectric element has a rectangular shape in plan view, and the cushioning material is disposed outside the end in the longitudinal direction of the piezoelectric element.

  Suitably, the said housing | casing is comprised from the 1st housing | casing part and the 2nd housing | casing part located inside the said 1st housing | casing part and containing the said sheet metal.

  Suitably, the said buffer material is arrange | positioned rather than the said piezoelectric element in the other end direction in the said one direction of the said panel.

  Preferably, the display unit is held on the panel, and the cushioning material is in contact with the display unit.

  Preferably, the buffer material is in a pressed state before vibration of the piezoelectric element.

  Preferably, the housing has a rectangular shape in plan view, and the length of one of the two opposing sides is equal to or longer than the length from the antitragus to the lower leg of the antiaural ring.

  Preferably, in the case, the length of the other two sides facing each other is equal to or longer than the length from the tragus to the antiaural ring.

  Preferably, the panel constitutes part or all of any one of a display unit, an input unit, and a cover of the display unit.

  Preferably, the fixed portion of the piezoelectric element in the panel is located outside an overlapping area with the display unit in plan view of the panel.

  ADVANTAGE OF THE INVENTION According to this invention, the subject in the electronic device which vibrates a panel can be solved, and a favorable electronic device can be provided.

It is a figure which shows the functional block of the principal part of the electronic device which concerns on one Embodiment of this invention. It is a figure which shows the suitable shape of a panel. It is a figure which shows schematically the principal part of the mounting structure of the electronic device which concerns on 1st Embodiment. It is a figure which shows an example of the vibration of the panel of the electronic device which concerns on 1st Embodiment. It is a figure which shows the frequency characteristic regarding the sound pressure of the electronic device which concerns on 1st Embodiment. It is a figure which shows the frequency characteristic regarding the distortion of the electronic device which concerns on 1st Embodiment. It is a figure which shows schematically the principal part of the mounting structure of the electronic device which concerns on 2nd Embodiment. It is a figure which shows an example of the vibration of the panel of the electronic device which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing functional blocks of a main part of an electronic device 1 according to an embodiment of the present invention. The electronic device 1 is, for example, a mobile phone terminal, and includes a wireless communication unit 5, a panel 10, a display unit 20, a piezoelectric element 30, an input unit 40, and a control unit 50. The wireless communication unit 5 has a known configuration and is wirelessly connected to a communication network via a base station or the like.

  The panel 10 is a touch panel that detects contact or a cover panel that protects the display unit 20. The panel 10 is made of, for example, glass or a synthetic resin such as acrylic. The shape of the panel 10 may be a plate shape. The panel 10 may be a flat plate or a curved panel whose surface is smoothly inclined. When the panel 10 is a touch panel, the touch of a user's finger, pen, stylus pen, or the like is detected. As a detection method of the touch panel, any method such as a capacitance method, a resistance film method, a surface acoustic wave method (or an ultrasonic method), an infrared method, an electromagnetic induction method, and a load detection method can be used.

  The display unit 20 is a display device such as a liquid crystal display, an organic EL display, or an inorganic EL display. The display unit 20 is provided on the back side of the panel 10. For example, the display unit 20 is disposed on the back surface of the panel 10 by a joining member (for example, an adhesive). Alternatively, the display unit 20 is separated from the panel 10 and supported by the housing of the electronic device 1.

  The piezoelectric element 30 is an element that expands or contracts or curves in accordance with an electromechanical coupling coefficient of a constituent material by applying an electric signal (voltage). For these elements, for example, those made of ceramic or quartz are used. The piezoelectric element 30 may be a unimorph, bimorph, or multilayer piezoelectric element. The stacked piezoelectric element includes a stacked bimorph element in which bimorphs are stacked (for example, 16 layers or 24 layers are stacked). The laminated piezoelectric element is composed of a laminated structure of a plurality of dielectric layers made of, for example, PZT (lead zirconate titanate) and electrode layers arranged between the plurality of dielectric layers. Unimorphs expand and contract when an electrical signal (voltage) is applied, and bimorphs bend when an electrical signal (voltage) is applied.

  The piezoelectric element 30 is disposed on the back surface of the panel 10 (the surface on the inner side of the electronic device 1). The piezoelectric element 30 is attached to the panel 10 by a joining member (for example, double-sided tape). The piezoelectric element 30 may be attached to the panel 10 via an intermediate member (for example, a sheet metal). The piezoelectric element 30 is disposed on the back surface of the panel 10 and is separated from the surface on the inner side of the housing by a predetermined distance. The piezoelectric element 30 may be separated from the surface on the inner side of the housing by a predetermined distance even in a stretched or curved state. That is, the distance between the piezoelectric element 30 and the inner surface of the housing is preferably larger than the maximum deformation amount of the piezoelectric element 30.

  The input unit 40 receives an operation input from a user, and includes, for example, an operation button (operation key). In addition, when the panel 10 is a touch panel, the panel 10 can also accept the operation input from a user by detecting the contact from a user.

  The control unit 50 is a processor that controls the electronic device 1. The control unit 50 applies a predetermined electrical signal (a voltage corresponding to an audio signal of a call partner's voice or a ringing melody or music including music, etc.) to the piezoelectric element 30. Note that the acoustic signal may be based on music data stored in an internal memory, or music data stored in an external server or the like may be reproduced via a network.

  When an electrical signal is applied to the piezoelectric element 30, the piezoelectric element 30 expands or contracts or curves in the longitudinal direction. At this time, the panel 10 to which the piezoelectric element 30 is attached is deformed in accordance with the expansion or contraction or bending of the piezoelectric element 30, and the panel 10 vibrates. Here, the maximum voltage of the electric signal applied to the piezoelectric element 30 by the control unit 50 is higher than ± 5 V, which is an applied voltage of a so-called panel speaker for the purpose of conducting sound by air conduction sound instead of vibration sound, for example. , ± 15V. As a result, even when the user presses the panel 10 against his / her body with a force of 3N or more (5N to 10N), for example, the panel 10 is caused to generate sufficient bending vibration, and the user's body Vibration sound can be generated through a part (eg, cartilage of the outer ear). Note that how much applied voltage is used can be appropriately adjusted according to the fixing strength of the panel 10 to the casing or the support member or the performance of the piezoelectric element 30.

  The panel 10 bends and vibrates not only in the attachment region to which the piezoelectric element 30 is attached, but also in the region away from the attachment region. The panel 10 has a plurality of locations that vibrate in a direction intersecting the main surface of the panel 10 in the vibrating region, and the amplitude value of the vibration is increased from positive to negative with time in each of the plurality of locations. Or vice versa. At a certain moment, the panel 10 vibrates in such a manner that a portion having a relatively large vibration amplitude and a portion having a relatively small vibration amplitude are distributed randomly or periodically throughout the panel 10 at first glance. That is, vibrations of a plurality of waves are detected over the entire panel 10. Even when the user presses the panel 10 against his / her body with a force of 5N to 10N, for example, the control unit 50 does not attenuate the piezoelectric element 30 in order to prevent the above-described vibration of the panel 10 from being attenuated. The maximum voltage to be applied may be ± 15V. Therefore, the user can hear the sound by bringing his / her ear into contact with a region away from the above-described region where the piezoelectric element 30 is attached, for example, the center of the panel 10.

  Here, the panel 10 may be approximately the same size as the user's ear. The panel 10 may be larger than the user's ear, as shown in FIG. In this case, when the user listens to the sound, the entire ear is easily covered with the panel 10 of the electronic device 1, so that it is difficult for ambient sounds (noise) to enter the ear canal. Panel 10 is an area wider than an area having a length corresponding to the distance from the lower leg of the anti-annulus (lower anti-limb) to the anti-tragus and a width corresponding to the distance from the tragus to the anti-annulus. Should just vibrate. The panel 10 preferably has a length corresponding to the distance between a portion near the upper leg of the ankle ring (upper pair leg) in the ear ring and the earlobe, and a distance between the tragus and a portion near the ear ring in the ear ring. It suffices that a region having a width corresponding to is vibrated. The region having the above length and width may be a rectangular region, or may be an elliptical shape having the above length as the major axis and the above width as the minor axis. The average size of Japanese ears can be found by referring to the Japanese human body size database (1992-1994) created by the Human Life Engineering Research Center (HQL). If the panel 10 is larger than the average size of Japanese ears, the panel 10 is considered to be large enough to cover the entire foreign ear. By having the dimensions and shapes as described above, the panel 10 can cover the user's ears, and is tolerant of misalignment when applied to the ears.

  The electronic device 1 can transmit air conduction sound and vibration sound via a part of the user's body (for example, cartilage of the outer ear) to the user by the vibration of the panel 10. Therefore, when outputting a sound having a volume equivalent to that of a conventional dynamic receiver, the sound transmitted to the periphery of the electronic device 1 due to the vibration of the air due to the vibration of the panel 10 is less than that of the dynamic receiver. Therefore, it is suitable, for example, when listening to a recorded message on a train or the like.

  In addition, since the electronic device 1 transmits vibration sound due to the vibration of the panel 10, even if the user wears an earphone or a headphone, for example, the user can touch the electronic device 1 to contact the earphone or the headphone. Sounds can be heard through headphones and body parts.

The electronic device 1 transmits sound to the user by the vibration of the panel 10. Therefore, when the electronic device 1 does not include a separate dynamic receiver, it is not necessary to form an opening (sound outlet) for sound transmission in the housing, and the waterproof structure of the electronic device 1 can be simplified. In addition, when the electronic device 1 is provided with a dynamic receiver, the sound emission port is preferably closed by a member that allows gas to pass but not liquid. An example of the member that allows gas to pass but not liquid is Gore-Tex (registered trademark).
(First embodiment)
FIG. 3 is a diagram schematically showing a main part of the mounting structure of the electronic device 1 according to the first embodiment. 3A is a front view, and FIG. 3B is a cross-sectional view taken along the line bb in FIG. 3A. FIG.3 (c) is sectional drawing along the cc line in Fig.3 (a). The electronic device 1 shown in FIG. 3 is a smartphone in which a substantially rectangular glass plate is arranged on the front surface of a housing 60 (for example, a metal or resin case) as the panel 10 in a plan view.

  The panel 10 constitutes, for example, a capacitive touch panel, and is supported (held) on the housing 60 via a joining member 70. The display unit 20 is bonded to the panel 10 via a bonding member 70 on the back surface excluding the upper portion on one end side in the longitudinal direction, which is one direction in plan view. Further, the piezoelectric element 30 is bonded to the upper back surface on one end side in the longitudinal direction of the panel 10 via a bonding member 70 and supported by the panel 10. That is, as illustrated in FIG. 3A, the fixed portion of the piezoelectric element 30 is located outside the overlapping region between the panel 10 and the display unit 20 in plan view. The piezoelectric element 30 has a substantially rectangular shape in plan view, and is bonded so that its long side is along the short side of the panel 10. The bonding member 70 is an adhesive having a thermosetting property or an ultraviolet curable property, a double-sided tape, or the like, and may be, for example, an optical elastic resin that is a colorless and transparent acrylic ultraviolet curable adhesive.

  FIG. 4 is a diagram illustrating an example of vibration of the panel 10 of the electronic device 1 according to the first embodiment. In the electronic device 1 according to the first embodiment, the display unit 20 is attached to the panel 10. For this reason, the other end side of the panel 10 is less likely to vibrate compared to one end side of the panel 10 to which the piezoelectric element 30 is attached (hereinafter also referred to as a main vibration unit). Therefore, sound leakage due to vibration of the other end side of the panel 10 on the other end side of the panel 10 can be reduced.

  In FIG. 3, the input unit 40 is supported by the housing 60 on the other end side in the longitudinal direction of the panel 10. In addition, a microphone mouthpiece 41 is formed in the input unit 40 as indicated by a broken line. That is, the piezoelectric element 30 is disposed at the upper part on one end side of the substantially rectangular casing 60, and the mouthpiece 41 is formed at the lower part on the other end side.

  The housing 60 includes a rear case (first housing portion) 62 and a front case (second housing portion) 61 located inside thereof. The rear case 62 is detachable from the front case 61. The front case 61 is configured to have a recess 63. Similarly, the rear case 62 is configured to have a recess 64. The front case 61 and the rear case 62 are not limited to a concave shape, and can be configured in an appropriate shape.

  The front case 61 is configured so as to include a sheet metal 80 as an insert member. The panel 10, the display unit 20, the piezoelectric element 30, and the input unit 40 are disposed in the recess 63 of the front case 61.

  A buffer material 90 is disposed between the display unit 20 and the sheet metal 80. The buffer material 90 reduces the interference of the display unit 20 that bends and vibrates with the vibration of the piezoelectric element 30 with (contacts with) the sheet metal 80. That is, the cushioning material 90 is disposed between the panel 10 and the front case 61 which is a part of the housing, and interference between the panel 10 and the front case 61 is reduced. The buffer material is a material of SCF (Super Critical Fluid), a foam material, or the like, for example, sponge or polystyrene foam.

  The buffer material 90 is joined to the display unit 20 via the joining member 70. Further, the cushioning material 90 is in contact with the sheet metal 80 without using a joining member. Note that the cushioning material 90 and the sheet metal 80 may not be in contact with each other, and there may be a gap between the cushioning material 90 and the sheet metal 80. The buffer material 90 is not limited to being bonded to the display unit 20 instead of the sheet metal 80, and the buffer material 90 may be bonded to only one of the display unit 20 and the sheet metal 80.

  The thickness of the buffer material 90 can be set so as to decrease as it moves away from the piezoelectric element 30 toward the other end, that is, away from the main vibration part. As the region is further away from the main vibration part, the vibration is reduced, and the display unit 20 is less likely to come into contact with the sheet metal 80. Therefore, the buffer material 90 can be made thinner. Note that the display unit 20 and the sheet metal 80 are not arranged in parallel as shown in FIG. 3B in accordance with the shape of the cushioning material 90, and the display unit is moved away from the piezoelectric element 30 in the other end direction. The electronic device 1 can also be configured so that the gap between the metal plate 20 and the sheet metal 80 is small.

  When the thickness of the buffer material 90 is larger than the gap between the display unit 20 and the sheet metal 80, the buffer material 90 is disposed between the display unit 20 and the sheet metal 80 in a pressed state before the vibration of the piezoelectric element 30. The The pressed state means a state where the cushioning material 90 is compressed and deformed. In addition, when the thickness of the buffer material 90 is the same as the gap between the display unit 20 and the sheet metal 80, the buffer material 90 may be disposed between the display unit 20 and the sheet metal 80 without being compressed. it can.

  In the present embodiment, the cushioning material 90 is disposed on one end side in the same manner as the piezoelectric element 30 disposed on one end side in the longitudinal direction of the panel 10. That is, as shown in FIG. 3A, the buffer material 90 is disposed around the piezoelectric element 30.

  In the present embodiment, the buffer material 90 is disposed outside the end in the longitudinal direction of the piezoelectric element 30. That is, as shown in FIG. 3A, the buffer material 90 is arranged on the outer peripheral side of the panel 10 with respect to the piezoelectric element 30 in the longitudinal direction of the piezoelectric element 30.

  In the present embodiment, the buffer material 90 is arranged in the other end direction in one direction (longitudinal direction) of the panel 10 rather than the piezoelectric element 30. That is, as shown in FIG. 3A, the buffer material 90 is disposed on the input unit 40 side that is disposed on the other end side with respect to the piezoelectric element 30.

  Various electronic components are arranged between the bottom of the recess 63 of the front case 61 and the bottom of the recess 64 of the rear case 62. In FIG. 3B, a circuit board 130 in which electronic components (processor, memory, etc.) necessary for realizing the function of the control unit 50 are incorporated, and a battery (battery) 150 for driving the electronic device 1 are provided. , Disposed in the recess 64.

  FIG. 5 is a diagram illustrating frequency characteristics related to the sound pressure of the electronic apparatus 1 according to the first embodiment. In FIG. 5, the frequency characteristic 170 when the buffer material 90 is not disposed between the display unit 20 and the sheet metal 80, and the frequency when the buffer material 90 is disposed between the display unit 20 and the sheet metal 80. Each characteristic 171 is shown. The horizontal axis represents frequency [Hz], and the vertical axis represents A characteristic sound pressure level [dBA]. As shown in FIG. 5, for example, in the frequency band of 300 to 1000 [Hz], the sound pressure level is increased by about 5 to 10 [dBA] due to the arrangement of the buffer material 90.

  FIG. 6 is a diagram illustrating frequency characteristics related to the distortion rate of the electronic apparatus 1 according to the first embodiment. The distortion rate represents the degree of distortion of the vibration waveform and is defined as the ratio of harmonics to the fundamental wave. The smaller the distortion rate, the smaller the ratio of harmonics to the fundamental wave and the better the sound quality. In FIG. 6, the frequency characteristic 180 when the buffer material 90 is not disposed between the display unit 20 and the sheet metal 80, and the frequency when the buffer material 90 is disposed between the display unit 20 and the sheet metal 80. Each characteristic 181 is shown. The horizontal axis represents frequency [Hz], and the vertical axis represents distortion rate [%]. As shown in FIG. 6, for example, in the frequency band of 300 to 1000 [Hz], the distortion rate is reduced by about 4 to 24 [%] due to the arrangement of the buffer material 90.

  Thus, according to the electronic apparatus 1 according to the present embodiment, the panel 10 is deformed due to the deformation of the piezoelectric element 30 attached to the back surface of the panel 10, and the longitudinal direction in which the piezoelectric element 30 is bonded. Sufficiently vibrates from one end side to the vicinity of the center. Therefore, the user brings a part of the user's body (for example, cartilage of the outer ear) into contact with at least a part of the upper region from the center of the panel 10, thereby causing air conduction sound and vibration due to vibration of the panel 10. I can hear the sound. Accordingly, air conduction sound and vibration sound can be transmitted to the user without causing the vibrating body to protrude from the outer surface of the housing 60, so that a very small vibrating body compared to the housing is brought into contact with the human body. The usability is improved as compared with the electronic device described in 1. In addition, since it is not necessary to put the user's ears on the piezoelectric element itself, the piezoelectric element 30 itself is not easily damaged. Further, when the case 60 is deformed instead of the panel 10, the user tends to drop the terminal when generating vibration, whereas when the panel 10 is vibrated, Things are hard to happen.

  In the present embodiment, the display unit 20 and the piezoelectric element 30 are joined to the panel 10 by the joining member 70. Thereby, the piezoelectric element 30 can be attached to the panel 10 in a state in which the degree of freedom of deformation of the piezoelectric element 30 is hardly hindered. The joining member 70 can be a non-heating type curable adhesive. Accordingly, there is an advantage that thermal stress shrinkage hardly occurs between the display unit 20 and the piezoelectric element 30 and the panel 10 at the time of curing. Moreover, the joining member 70 can be a double-sided tape. Thereby, there exists an advantage that the shrinkage stress like the time of use of an adhesive agent is hard to apply between the display part 20 and the piezoelectric element 30, and the panel 10. FIG. Further, since the panel 10 is also joined to the housing 60 by the joining member 70, the same effect can be obtained.

  In the present embodiment, a cushioning material 90 is disposed between the display unit 20 and the sheet metal 80. Thereby, it can reduce that the display part 20 which carries out a curved vibration with the vibration of the piezoelectric element 30 interferes with the sheet metal 80. Therefore, it is possible to reduce a decrease in sound pressure and an increase in distortion caused by the vibration of the panel 10. Since the interference between the display unit 20 and the sheet metal 80 can be suppressed or reduced, the gap between the display unit 20 and the sheet metal 80 can be reduced, and the electronic device 1 can be thinned.

  In the present embodiment, both the piezoelectric element 30 and the buffer material 90 are arranged on one end side in one direction in a plan view of the panel 10. Since the region (main vibration part) of the panel 10 to which the piezoelectric element 30 is attached vibrates most greatly, the display unit 20, the sheet metal 80, and the plate member 80 are efficiently arranged by arranging the buffer material 90 on the same side as the piezoelectric element 30. Interference can be suppressed or reduced.

  In the present embodiment, the cushioning material 90 is bonded only to the display unit 20 and is only in contact with the sheet metal 80. By not adhering the cushioning material 90 to both the display unit 20 and the sheet metal 80, generation of tension via the cushioning material 90 is prevented between the display unit 20 and the sheet metal 80, and the bending vibration of the panel 10 is more than necessary. Inhibition can be reduced.

  In the present embodiment, the front case 61 includes a sheet metal 80 as an insert member. The sheet metal 80 can reduce the thickness while maintaining the strength of the electronic device 1.

In the present embodiment, the buffer material 90 is disposed outside the end portion in the longitudinal direction of the piezoelectric element 30. Since main vibration, which is large vibration, is generated on the inner side of the end portion of the piezoelectric element 30, the buffer material 90 is disposed on the outer side, so that it is possible to reduce the obstruction of desired vibration more than necessary.
(Second Embodiment)
FIG. 7 is a diagram illustrating a mounting structure of the electronic device 1 according to the second embodiment. 7 (a) is a front view, FIG. 7 (b) is a cross-sectional view taken along line bb in FIG. 7 (a), and FIG. 7 (c) is taken along line cc in FIG. 7 (a). It is sectional drawing. The electronic device 1 shown in FIG. 7 includes a folding panel in which a cover panel (acrylic plate) that protects the display unit 20 is disposed as the panel 10 on the front surface of the upper housing 60a, and the input unit 40 is disposed on the lower housing 60b. Mobile phone terminal. The display unit 20, the piezoelectric element 30, and the circuit board 130 are disposed in the recess 65 of the housing 60a. In FIG. 7C, the piezoelectric element 30 and the reinforcing member 100 that are visible between the two cushioning members 90 are not shown for clarity of the drawing.

  In the second embodiment, the reinforcing member 100 is disposed between the panel 10 and the piezoelectric element 30. The reinforcing member 100 is a resin plate including, for example, a resin plate, sheet metal, or glass fiber. That is, the electronic device 1 according to the second embodiment has a structure in which the piezoelectric element 30 and the reinforcing member 100 are bonded by the bonding member 70, and the reinforcing member 100 and the panel 10 are bonded by the bonding member 70.

  In the second embodiment, the display unit 20 is not bonded to the panel 10 but is supported by the housing 60a. That is, the electronic device 1 according to the second embodiment has a structure in which the display unit 20 is separated from the panel 10 and the display unit 20 and the housing 60a are coupled via the circuit board 130. Note that the housing 60a can be configured to include a sheet metal, similarly to the front case 61 of the first embodiment.

  A cushioning material 90 similar to that of the first embodiment is disposed between the panel 10 and the display unit 20 (housing 60a). The panel 10 and the cushioning material 90 are joined via the joining member 70, and the display unit 20 and the cushioning material 90 are in contact without going through the joining member. Similarly to the first embodiment, the panel 10 and the cushioning material 90 may contact each other without a joining member, and the display unit 20 and the cushioning material 90 may be joined via the joining member.

  FIG. 8 is a diagram illustrating an example of vibration of the panel 10 of the electronic device 1 according to the second embodiment. In the electronic device 1 according to the second embodiment, the panel 10 is an acrylic plate having a lower rigidity than the glass plate, and the display unit 20 is not bonded to the back surface of the panel 10. Compared to the electronic apparatus 1 according to the first embodiment, the amplitude generated by the piezoelectric element 30 is increased. In addition, the panel 10 vibrates not only in the attachment region to which the piezoelectric element 30 is attached, but also in a region away from the attachment region. For this reason, the user can hear the vibration sound by bringing his / her ear into contact with an arbitrary position of the panel 10 in addition to the air conduction sound through the air.

  Thus, according to the electronic apparatus 1 according to the present embodiment, the reinforcing member 100 and the panel 10 are deformed due to the deformation of the piezoelectric element 30 attached to the panel 10 via the reinforcing member 100, and the deformation is performed. The air conduction sound and the vibration sound are transmitted to the object in contact with the panel 10. Thereby, the air conduction sound and the vibration sound can be transmitted to the user without placing the vibration body itself on the ear. The piezoelectric element 30 is attached to the surface of the panel 10 on the inner side of the housing 60a. For this reason, air conduction sound and vibration sound can be transmitted to the user without causing the vibrating body to protrude from the outer surface of the housing 60a. In addition, the panel 10 is deformed to transmit air conduction sound and vibration sound not only in the attachment region to which the piezoelectric element 30 is attached, but also in any part of the panel 10. For this reason, the user can hear the vibration sound by bringing his / her ear into contact with an arbitrary position of the panel 10 in addition to the air conduction sound through the air.

  In the present embodiment, by arranging the reinforcing member 100 between the piezoelectric element 30 and the panel 10, for example, when an external force is applied to the panel 10, the external force is transmitted to the piezoelectric element 30 and the piezoelectric element 30 is The possibility of breakage can be reduced. Moreover, even if the panel 10 is brought into strong contact with the human body, the vibration of the panel 10 can be hardly attenuated. In addition, by disposing the reinforcing member 100 between the piezoelectric element 30 and the panel 10, the resonance frequency of the panel 10 is lowered, and the acoustic characteristics in the low frequency band are improved. Instead of the reinforcing member 100, a plate-like weight may be attached to the piezoelectric element 30 by the joining member 70.

  In the present embodiment, a cushioning material 90 is disposed between the panel 10 and the display unit 20. Thereby, it can reduce that the panel 10 which carries out a curved vibration with the vibration of the piezoelectric element 30 interferes with the display part 20. FIG.

  In the present embodiment, the cushioning material 90 is bonded only to the panel 10 and is only in contact with the display unit 20. By not adhering the cushioning material 90 to both the panel 10 and the display unit 20, it is possible to prevent generation of tension between the panel 10 and the display unit 20 via the cushioning material 90, and to cause the panel 10 to vibrate more than necessary. Inhibition can be reduced.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each member, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of components, steps, etc. can be combined into one or divided. is there.

  For example, when the panel 10 and the display unit 20 are configured not to overlap each other, the piezoelectric element 30 may be disposed at the center of the panel 10. When the piezoelectric element 30 is disposed in the center of the panel 10, the vibration of the piezoelectric element 30 is evenly transmitted to the entire panel 10 to improve the quality of the air conduction sound, and the user can listen to various positions of the panel 10. The vibration sound can be recognized even if it is touched. A plurality of piezoelectric elements 30 may be mounted.

  In the electronic device 1 described above, the piezoelectric element 30 is attached to the panel 10, but may be attached to a location different from the panel 10. For example, in the first embodiment, the piezoelectric element 30 may be attached to a rear case 62 that is attached to the housing 60 and covers the battery 150. Since the rear case 62 is often attached to a surface different from the panel 10 in the electronic device 1 such as a mobile phone terminal, according to such a configuration, the user can place a part of the body (for example, an ear on the surface different from the panel 10). ) To hear the sound. In this case, the cushioning material 90 is disposed between the rear case 62 that bends and vibrates by the piezoelectric element 30 and a portion that can contact the rear case 62 (for example, the battery 150).

  Further, the panel 10 can constitute a part or all of any of a display panel, an operation panel, a cover panel, and a lid panel for making the rechargeable battery removable. In particular, when the panel 10 is a display panel, the piezoelectric element 30 is disposed outside the display area for the display function. As a result, there is an advantage that the display is hardly disturbed. The operation panel includes the touch panel of the first embodiment. In addition, the operation panel includes a sheet key that is a member that constitutes one surface of the operation unit side body, in which, for example, a key top of an operation key is integrally formed in a foldable mobile phone terminal.

  In the first embodiment and the second embodiment, the bonding member for bonding the panel 10 and the piezoelectric element 30 and the bonding member for bonding the panel 10 and the housing 60 (60a) have the same reference numerals. The bonding member 70 has been described. However, the joining member used in the first embodiment and the second embodiment may be appropriately different depending on the member to be joined.

DESCRIPTION OF SYMBOLS 1 Electronic device 5 Wireless communication part 10 Panel 20 Display part 30 Piezoelectric element 40 Input part 41 Mouthpiece 50 Control part 60, 60a, 60b Case 61 Front case (2nd case part)
62 Rear case (first housing)
63, 64, 65 Recess 70 Joint member 80 Sheet metal 90 Buffer material 100 Reinforcement member 130 Circuit board 150 Battery

Claims (17)

A piezoelectric element;
A panel, and
An electronic device in which the panel is bent in accordance with expansion or contraction or bending of the piezoelectric element.   2. The electronic device according to claim 1, wherein when the panel is bent, an antinode generated immediately above the piezoelectric element in a longitudinal direction of the piezoelectric element is larger than an antinode generated other than immediately above the piezoelectric element.   3. The electronic device according to claim 2, wherein when the panel is bent, an antinode generated immediately above the piezoelectric element in a longitudinal direction of the piezoelectric element is larger than an antinode generated near both ends of the panel. A piezoelectric element;
A panel for supporting the piezoelectric element;
A housing for holding the panel,
In the longitudinal direction of the piezoelectric element, the panel is bent by the piezoelectric element so that the portion directly above the piezoelectric element protrudes highest compared with the surrounding area, and the contact portion of the human body that is in contact with the panel vibrates. In electronic devices that convey sound,
An electronic device in which a cushioning material is disposed between the panel and the housing.   The electronic device according to claim 4, wherein both the piezoelectric element and the buffer material are arranged on one end side in one direction in a plan view of the panel.   The electronic device according to claim 5, wherein the buffer material becomes thinner as it moves away from the piezoelectric element toward the other end.   The electronic device according to any one of claims 4 to 6, wherein the cushioning material is bonded to only one of the panel and the housing.   The electronic device according to claim 4, wherein the housing includes a sheet metal as an insert member.   The electronic device according to claim 6, wherein the piezoelectric element has a rectangular shape in a plan view, and the buffer material is disposed outside an end portion in a longitudinal direction of the piezoelectric element.   The electronic device according to claim 8, wherein the housing includes a first housing portion and a second housing portion that is located inside the first housing portion and includes the sheet metal.   The electronic apparatus according to claim 9, wherein the cushioning material is disposed in the other end direction in the one direction of the panel rather than the piezoelectric element.   The electronic device according to claim 4, wherein a display unit is held on the panel, and the buffer material is in contact with the display unit.   The electronic device according to claim 4, wherein the buffer material is in a pressed state before the vibration of the piezoelectric element.   14. The housing according to claim 4, wherein the casing has a rectangular shape in plan view, and the length of one of the two opposite sides is equal to or longer than the length from the antitragus to the lower leg of the antiaural ring. The electronic device as described in the paragraph.   The electronic device according to claim 14, wherein a length of the opposite two sides of the casing is equal to or longer than a length from the tragus to the anti-aural ring.   The electronic device according to any one of claims 4 to 15, wherein the panel constitutes part or all of a display unit, an input unit, and a cover of the display unit.   The electronic device according to claim 16, wherein the fixed portion of the piezoelectric element in the panel is located outside an overlapping area with the display unit in a plan view of the panel.