Abstract:
There is provided a vibrator including: a housing including an internal space; an elastic member mounted within the internal space so as to be elastically deformed; and a piezo actuator mounted on one surface of the elastic member, wherein the elastic member includes a reinforcement emboss protruding toward a surface opposite to a surface on which the piezo actuator is mounted in a portion on which the piezo actuator is mounted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2013-0077285 filed on Jul. 2, 2013, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a vibrator. 
         [0004]    2. Description of the Related Art 
         [0005]    A vibrator, a device converting electrical energy into mechanical vibrations using the principle of the generation of electromagnetic force, is mounted in a mobile phone, or the like, to be used for silently notifying a user of call reception. In addition, as the market for mobile devices such as mobile phones, and the like, has rapidly expanded and various additional functions have been added to mobile devices, a mobile device having a small size and high quality has been required. In this situation, the need for developing a vibrator having novel structure capable of overcoming disadvantages of existing products and significantly improved quality has increased. 
         [0006]    Further, as the release onto the market of smartphones, among other mobile phones, has rapidly increased, a touchscreen scheme has been adopted for use therewith, such that the adoption of vibration motors has increased in order to generate vibrations to provide feedback when a user touches a smartphone. Vibrational performance required when a touchscreen is touched is as follows. First, as the amount of vibrations generation at the time of the touch is increased to be greater than that of vibrations generated at the time of call reception, an operation lifespan is required to be increased. Second, in order to increase user satisfaction when a user is provided with vibrations at the time of a touch, a vibration response speed needs to be increased in accordance with a touch speed of the screen. 
         [0007]    As a product capable of implementing the characteristics as described above, there is provided a piezo haptic actuator. Such a piezo haptic actuator uses the principle of a converse piezoelectric effect, which generates displacement of a piezo element when a voltage is applied thereto, and vibratory force is generated by allowing a mass body provided on a moving element to move by the generated displacement. 
         [0008]    A vibrator having such a structure may be characterized in that a frequency band width allowing for vibration force to be obtained at a predetermined level or more is wider, such that stable vibrational characteristics may be implemented, and vibrations having a high or a low frequency, rather than a single frequency, may be variously used within a predetermined frequency range. In addition, since rapid operational response characteristics may be implemented, the vibrator as described above may be suitable for implementing haptic vibrations in mobile devices such as mobile phones, and the like. 
         [0009]    Meanwhile, the piezo element generating the vibration as described above may be mounted on an elastic member to vibrate, but there may be a problem in that the elastic member may be damaged by inertial force of amass body mounted on the elastic member when external impacts are applied thereto (particularly, in an axial direction). 
       SUMMARY OF THE INVENTION 
       [0010]    An aspect of the present invention provides a vibrator capable of preventing an elastic member from being damaged. 
         [0011]    According to an aspect of the present invention, there is provided a vibrator including: a housing including an internal space; an elastic member mounted within the internal space so as to be elastically deformed; and a piezo actuator mounted on one surface of the elastic member, wherein the elastic member includes a reinforcement emboss protruding toward a surface opposite to a surface on which the piezo actuator is mounted in a portion on which the piezo actuator is mounted. 
         [0012]    The reinforcement emboss may be continuously provided in a length direction of the elastic member. 
         [0013]    The reinforcement emboss may be provided so as to be shorter than the piezo actuator in a length direction. 
         [0014]    The elastic member may include a bottom plate having the piezo actuator is mounted on a surface thereof and an extension plate extended in a height direction from both edges of the bottom plate in a width direction. 
         [0015]    The extension plate may include a connection part having one end connected to the bottom plate and extended in the height direction from a central portion of the bottom plate in the length direction and a support plate part provided in the length direction at the other end of the connection part to guide a mass body. 
         [0016]    The reinforcement emboss may be provided so as to be shorter than the piezo actuator in the length direction and longer than a length between both ends of the connection part in the length direction. 
         [0017]    The reinforcement emboss may be provided so that both ends thereof are positioned outwardly from both ends of the connection part in the length direction, respectively. 
         [0018]    The reinforcement emboss may have a rectangular shape. 
         [0019]    The reinforcement emboss may have a triangular shape. 
         [0020]    The reinforcement emboss may have a round shape. 
         [0021]    At least one pair of the reinforcement embosses may be provided in a width direction. 
         [0022]    According to another aspect of the present invention, there is provided a vibrator including: a housing including an internal space; an elastic member mounted within the internal space; and a piezo actuator mounted on one surface of the elastic member to deform the elastic member, wherein the elastic member includes a bottom plate having the piezo actuator is mounted on a surface thereof, a connection part having one end connected to the bottom plate and extended in the height direction from a central portion of the bottom plate in a length direction, and a support plate part provided in the length direction at the other end of the connection part to guide a mass body, the bottom plate including a reinforcement emboss in the length direction so as to prevent a portion connected to the connection part in the bottom plate from being damaged. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0024]      FIG. 1  is a cross-sectional view of a vibrator according to an embodiment of the present invention; 
           [0025]      FIG. 2  is an exploded perspective view of the vibrator according to the embodiment of the present invention; 
           [0026]      FIG. 3  is a perspective view of an upper case of the vibrator according to the embodiment of the present invention; 
           [0027]      FIG. 4  is a perspective view of a lower case of the vibrator according to the embodiment of the present invention; 
           [0028]      FIG. 5  is a plan view and a perspective view illustrating an elastic member of the vibrator according to the embodiment of the present invention; 
           [0029]      FIG. 6  is a bottom perspective view illustrating a piezo element of the vibrator according to the embodiment of the present invention; 
           [0030]      FIG. 7  is a bottom perspective view illustrating a mass body of the vibrator according to the embodiment of the present invention; 
           [0031]      FIG. 8  is a perspective view illustrating a shape of a mass body cover of the vibrator according to the embodiment of the present invention; 
           [0032]      FIG. 9  is a perspective view illustrating a circuit board of the vibrator according to the embodiment of the present invention; and 
           [0033]      FIGS. 10A through 11C  are views illustrating various examples of the elastic member of the vibrator according to the embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0034]    Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements. 
         [0035]    A vibrator  100  according to an embodiment of the present invention may be a vibrator has a shape in which a mass body is adhered to a piezo element by interposing a cushioning material having adhesive force between the mass body disposed to face the piezo element and the piezo element. In this case, the piezo element is installed on a surface (for example, an upper surface) of an elastic member, such that a problem such as damage to the piezo element due to contact with the elastic member when external impacts are applied thereto may be solved. 
         [0036]      FIG. 1  is a cross-sectional view of a vibrator according to an embodiment of the present invention, and  FIG. 2  is an exploded perspective view of the vibrator according to the embodiment of the present invention. 
         [0037]    Referring to  FIGS. 1 and 2 , the vibrator  100  may include a housing  120  including an upper case  122  and a lower case  130 , an elastic member  140 , a piezo element  160 , a mass body  180 , and a circuit board  200 . 
         [0038]    The housing  120  may include the upper and lower cases  122  and  130 . In addition, the upper case  122  may have a box shape having an internal space, and the lower case  130  may have a plate shape.  FIG. 3  is a perspective view illustrating the upper case  122  of the housing  120 . 
         [0039]    In addition, as described above, the upper case  122  may have the box shape. That is, the upper  122  case may be configured of a front plate  123 , side plates  124  and  125 , a rear plate  129 , and an upper plate  126 . Further, at least one of both side plates  124  and  125  may be formed to have a length shorter than those of the front plate  123  and the rear plate  129  in a height direction to thereby form an opening. 
         [0040]    In addition, a plurality of grooves  127  for coupling with the lower case  130  may be formed in the front plate  123  and the rear plate  129 . 
         [0041]    Further, vent holes  128  for movement of air may be formed in the upper plate  126 . 
         [0042]    Here, terms with respect to directions will be defined. A length direction refers to an X direction of  FIG. 3 , and a width direction refers to a Y direction of  FIG. 3 . In addition, a height direction refers to a Z direction of  FIG. 3 . Further, the terms defined as described above will be equally used below. That is, in describing each configuration, terms used therefor will refer to the same directions as those described above. 
         [0043]      FIG. 4  is a perspective view of the lower case of the vibrator according to the embodiment of the present invention. 
         [0044]    The lower case  130  may have the plate shape as shown in  FIG. 4 . In addition, both end portions of the lower case  130  may be provided with protrusion parts  132  supporting both end portions of the elastic member  140  (See  FIG. 1 ). The protrusion part  132  may be formed by denting and have a square pillar shape. However, this is only an example, and the present invention is not limited thereto. 
         [0045]    In addition, the both end portions of the lower case  130  may be provided with coupling wall parts  136  increasing coupling force with the upper case  122  (See  FIG. 3 ). 
         [0046]    Meanwhile, both side surfaces of the lower case  130  may be formed with a plurality of grooves  138  corresponding to the grooves  127  of the upper case  122  (See  FIG. 3 ). 
         [0047]      FIG. 5  is a plan view and a perspective view illustrating the elastic member of the vibrator according to the embodiment of the present invention. 
         [0048]    Referring to  FIG. 5 , the elastic member  140  may include a bottom plate  142  and extension plates  144 . First, the bottom plate  142  of the elastic member  140  will be described. The bottom plate  142  may include a plurality of support protrusions  142   a  and  142   b  formed therefrom in order to install the piezo element  160  (See  FIG. 1 ). Two support protrusions  142   a  may support both side surfaces of the piezo element  160 , and the other support protrusions  142   b  may support the remaining two side surfaces (a front surface and a rear surface) except for both side surfaces of the piezo element  160 . Therefore, the piezo element  160  may be installed at a predetermined position, and separation of the piezo element  160  from the bottom plate  142  may be prevented. 
         [0049]    In addition, the bottom plate  142  may include opening parts  142   c  formed therein in order to electrically connect the circuit board  200  (See  FIG. 1 ) and the piezo element  160  to each other. 
         [0050]    Further, a plurality of auxiliary elastic deformation holes  142   d  for reducing strength may be formed between the opening parts  142   c  and both end portions of the bottom plate  142  so that elastic deformation of the bottom plate  142  may be easily performed. That is, the auxiliary elastic deformation hole  142   d , which is a hole formed so that elastic deformation of portions adjacent to both end portions of the bottom plate  142  may be easily performed, may be provided in plural, and a shape thereof may also be variously changed. 
         [0051]    Further, both end portions of the bottom plate  142  may be provided with support parts  142   e  supported by the protrusion parts  132  of the lower case  122  (See  FIG. 4 ). 
         [0052]    In addition, the extension plate  144  may include a support plate part  146  contacting a front surface and a rear surface of the mass body  180  and a connection part  148  connecting the support plate part  146  and the bottom plate  142  to each other. 
         [0053]    The connection part  148  may be extended from a front surface and a rear surface of the bottom plate  142 . Further, the connection part may be configured of first and second connection parts  148   a  and  148   b  disposed to be spaced apart from each other by a predetermined interval. 
         [0054]    In addition, the support plate part  146  may be extended in a length direction of the mass body  180 . 
         [0055]    Further, a lower end of the support plate part  146  may be provided with at least one support jaw  146   a  protruding so as to support the mass body  180  or a mass body cover  170  at a lower portion thereof. The support jaw  146   a  may limit movement of the mass body  180  in the height direction. The mass body  180  or the mass body cover  170  may be coupled to the support plate part  146  by an additional bonding method such as an adhesive bonding method, a welding method, or the like, in a state in which the mass body  180  or the mass body cover  170  is caught by the support jaw  146   a.    
         [0056]    Meanwhile, portions connected to the first and second connection parts  148   a  and  148   b  in the bottom plate  142  may be damaged by external force applied to the vibrator  100 . Particularly, in the case in which force is applied to the vibrator  100  in an axial direction, the portions connected to the first and second connection parts  148   a  and  148   b  in the bottom plate  142  may be easily damaged. The reason is that bending of the bottom plate  142  may not be appropriately performed in the portions connected to the first and second connection parts  148   a  and  148   b  in the bottom plate  142  due to the first and second connection parts  148   a  and  148   b , such that stress is concentrated on the portions, which causes damage. 
         [0057]    Therefore, in the present invention, the elastic member  140  may include a reinforcement emboss  145  protruding from a surface opposite to a surface on which the piezo actuator  160  is mounted in a central portion on which the piezo actuator  160  is mounted. That is, the reinforcement emboss  145  may be formed by pressing at least some of one surface of the elastic member  140  toward the other surface thereof. 
         [0058]    The reinforcement emboss  145  may be continuously provided in a length direction of the elastic member and may be shorter than the piezo actuator  160  in the length direction. In addition, the reinforcement emboss  145  may be provided so as to be longer than a length between both ends of the first and second connection parts  148   a  and  148   b  in the length direction. That is, the reinforcement emboss  145  may be provided so that both ends thereof are positioned outwardly from both ends of the first and second connection parts  148   a  and  148   b  in the length direction, respectively. The reason is to prevent the portions connected to the first and second connection parts  148   a  and  148   b  in the bottom plate  142  from being damaged. 
         [0059]      FIGS. 10A through 11C  are views illustrating various examples of the elastic member of the vibrator according to the embodiment of the present invention. 
         [0060]    Referring to  FIGS. 10A through 10C , a shape of the reinforcement emboss of the elastic member according to the embodiment of the present invention is shown. The reinforcement emboss shown  FIGS. 10A through 10C  may be provided along the bottom plate  142  of the elastic member  140  in the length direction. Here, a pair of the reinforcement embosses may be spaced apart from each other in the width direction and provided in parallel. However, the present invention is not limited thereto. That is, one or at least three reinforcement embosses may be provided. In this case,  FIG. 10A  shows an example of a reinforcement emboss  142   a  provided in a rectangular shape,  FIG. 10B  shows an example of a reinforcement emboss  142   b  provided having a triangular shape, and  FIG. 10C  shows an example of a reinforcement emboss  142   b  provided having a round shape. 
         [0061]    Next, referring to  FIGS. 11A through 11C , a shape of the reinforcement emboss of the elastic member according to another embodiment of the present invention is shown.  FIGS. 11A through 11C  show an example of a reinforcement emboss doubly provided in the bottom plate  142  of the elastic member  140 . That is, the reinforcement emboss may be doubly formed by performing primary compression on one surface of the bottom plate  142  and then performing secondary compression on the other surface of the primarily compressed portion. Here, the primarily compressed portion may basically have a rectangular shape, and the secondarily compressed portion may have a rectangular shape ( FIG. 11A ), a triangular shape ( FIG. 11B ), or a round shape ( FIG. 11C ) according to the embodiments. 
         [0062]      FIG. 6  is a bottom perspective view illustrating a piezo element of the vibrator according to the embodiment of the present invention. 
         [0063]    Referring to  FIG. 6 , the piezo element  160  may be fixedly installed onto the bottom plate  142  (See  FIG. 5 ) of the elastic member  140  (See  FIG. 5 ) as described above and have a rectangular parallelepiped shape. 
         [0064]    In addition, a bottom surface of the piezo element  160  may be provided with an electrode  162 . The electrode  162  may protrudes from the bottom surface of the piezo element  160  and be configured of a positive (+) electrode  162   a  and a negative (−) electrode  162   b.    
         [0065]      FIG. 7  is a bottom perspective view illustrating a mass body of the vibrator according to the embodiment of the present invention. 
         [0066]    Referring to  FIG. 7 , the mass body  180  may have a bar shape. In addition, a bottom surface of the mass body  180  may be provided with a contact prevention groove  182  facing the piezo element  160  (See  FIGS. 1 and 6 ). 
         [0067]    Meanwhile, both end portions of the piezo element  160  may be provided with stopper parts  184  for limiting displacement of the mass body  180  at the time of elastic deformation of the elastic member  140  (See  FIG. 4 ). That is, the stopper part  184  contact the end portion of the bottom plate  142  of the elastic member  140 , such that displacement of the mass body  180  may be limited. Therefore, a contact between the mass body  180  and an internal region of the both end portions of the bottom plate  142  may be prevented. 
         [0068]    Meanwhile, the mass body may include a support jaw insertion grooves  186  formed therein so as to be disposed between the stopper part  184  and the contact prevention groove  182  of the mass body  180 . The mass body  180  may be installed on the elastic member  160  so that the support jaw  146   a  of the elastic member  140  is inserted into the support jaw insertion groove  186 . In addition, an installation position of the mass body  180  in the height direction may be restricted by the support jaw  146   a.    
         [0069]    Meanwhile, the bottom surface of the mass body  180  may provided with an inclination surface  188  from the contact prevention groove  182  of the mass body  180 . The inclination surface  188  may be formed to have an inclination capable of preventing a contact with the bottom plate  142  at the time of the elastic deformation of the elastic member  140 . In other words, the inclination surface  188  may be formed to have an inclination equal to or less than an absolute value of an inclination of the bottom plate  142  when the bottom plate  142  is maximally deformed at the time of the elastic deformation of the bottom plate  142 . 
         [0070]    In addition, the bottom surface of the mass body  180  may be provided with a cover seat part  189  installed in a groove shape in a mass body cover  170  to be described below. Movement of the mass body  180  in the length direction may be restricted by the cover seat part  189 . 
         [0071]      FIG. 8  is a perspective view illustrating a shape of a mass body cover of the vibrator according to the embodiment of the present invention. 
         [0072]    Referring to  FIG. 8 , the mass body cover  170  may be provided in a shape in which the mass body  180  may be inserted therein. That is, the mass body  180  cover may include a bottom plate  172  and an installation plate  173  supporting the bottom surface of the mass body  180  and a support plate  175  extended from the bottom plate  172  and the installation plate  173  toward the side surface of the mass body  180 . The support plate  175  may be configured of front and rear support plates  176  and  177  supporting the front and rear surfaces of the mass body  180  and an end support plate  178  supporting the end portion thereof. Here, the end support plate  178  may protrude from end portions of the front and rear support plates  176  and  177  in the length direction toward the end surface of the mass body  180 . 
         [0073]    Meanwhile, the cover seat part  189  of the mass body  180  may be positioned on the installation plate  173 . 
         [0074]    In addition, although the bottom plate  172  and the installation plate  173  are discontinuously shown in the length direction in  FIG. 8 , the present invention is not limited thereto. The bottom plate  172  and the installation plate  173  may be provided integrally with each other to be continuously provided in the length direction. 
         [0075]      FIG. 9  is a perspective view illustrating a circuit board of the vibrator according to the embodiment of the present invention. 
         [0076]    Referring to  FIG. 9 , the circuit board  200  may be connected to the piezo element  160  (See  FIG. 1 ) and vibrated integrally with the elastic member  140 . To this end, the circuit board  200  may include a piezo element connection part  202 . Further, the piezo element connection part  202  may include insertion holes  204  formed therein so that the electrodes  162  (See  FIG. 5 ) of the piezo element  160  are inserted thereinto. 
         [0077]    Meanwhile, the piezo element connection part  202  may be inserted into the opening part  142   c  formed in the bottom plate  142  (See  FIG. 4 ) of the elastic member  140 . 
         [0078]    Therefore, solder for connecting the piezo element  160  and the circuit board  200  to each other may be disposed in the opening part  142   c  of the bottom plate  142 , thereby suppressing the thickness from being increased by the solder. 
         [0079]    Further, the piezo element connection part  202  may be stepped from a body  206 . To this end, the piezo element connection part  202  and the body  206  may be connected to each other by an inclination part  205 . In addition, the inclination part  205  may be formed with a support protrusion insertion hole  205   a  into which the support protrusion  142   a  of the bottom plate  142  is inserted. 
         [0080]    In addition, the body  206  may include a plurality of holes and grooves formed therein so as to be smoothly vibrated integrally with the bottom plate  142 . 
         [0081]    Further, the circuit board  200  may include a power connection terminal  208   a  formed thereon and an external exposure part  208  exposed to the outside of the upper case  122  (See  FIG. 1 ). The external exposure part  208  may be stepped from the body  206 . 
         [0082]    As set forth above, according to the present invention, damage to the elastic member may be prevented by adding the simple configuration. 
         [0083]    While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.