Abstract:
Disclosed is a mobile terminal comprising: a case for mounting electronic components therein; a light source located within the case, for laterally emitting light; and a light guide unit in which light emitted from the light source is incident on the lateral side, wherein the light guide unit comprises a base module and a reflective film, which is coated on the outer side of the base module and includes a first opening formed on the side facing the light source and a second opening formed in the direction of the front side, wherein the case includes a light transmission unit in a portion facing the second opening of the reflective film and wherein the reflective film encloses the lateral side of the mobile terminal so that even the lateral leakage of light can be blocked.

Description:
CROSS-REFERENCE TO THE RELATED APPLICATIONS 
     This application is the National Phase of PCT International Application No. PCT/KR2013/010272, filed on Nov. 13, 2013, which claims priority under 35 U.S.C. §119(a) to Patent Application No. 10-2013-0113149, filed in the Republic of Korea on Sep. 24, 2013, all of which are hereby expressly incorporated by reference into the present application. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the present invention relate to a mobile terminal including a light guide unit with a simple structure and a method for manufacturing the mobile terminal. 
     Discussion of the Related Art 
     Terminals may be generally classified as mobile/portable terminals or stationary terminals according to their mobility. Mobile terminals may also be classified as handheld terminals or vehicle mounted terminals according to whether or not a user can directly carry the terminal. 
     As such functions become more diversified, the mobile terminal can support more complicated functions such as capturing images or video, reproducing music or video files, playing games, receiving broadcast signals, and the like. By comprehensively and collectively implementing such functions, the mobile terminal may be embodied in the form of a multimedia player or device. 
     Many components have to be mounted in the mobile terminal for diverse functions. Accordingly, the sizes of the internal components have to become small and the manufacturing price has to be lowered. In addition, the processes required to fabricate such a mobile terminal have to be simplified. 
     A conventional light guide unit  10  shown in  FIG. 15  includes a light guide film  11 , a white film  13  and a reflection film  14  bonded to upper and lower surfaces of the light guide film  11 , respectively, using bond  12  and a printed circuit board  185  and a case  109  bonded to the white film, using a double-sided tape  15 . 
     To dispose several layers  11 ,  13  and  14 , adhesive  12  and  15  has to be applied several times, thereby complicating processes and increasing expense and thickness. There is one advantage that light escapes in a lateral direction as shown in  FIG. 15 . 
     SUMMARY OF THE INVENTION 
     To overcome the disadvantages, an object of the present invention is to provide a mobile terminal which is able to be manufactured easily, with a slim thickness, by simplifying a structure of a light guide unit used in emitting light such as a button, an indicator and the like. 
     To achieve these objects and other advantages and in accordance with the purpose of the embodiments, as embodied and broadly described herein, a mobile terminal includes a case having electronic components mounted therein; a light source arranged in the case and configured to emit light in a lateral direction; and a light guide unit configured to have the light emitted from the light source incident thereon, wherein the light guide unit comprises a base module; and a reflection film coated on an outer surface of the base module and comprising a first opening fotined in a surface facing the light source and a second opening formed toward a front surface of the light guide unit, and the case comprises a light transmission unit facing the second opening of the reflection film. 
     The light guide unit may have an area projected in a lateral direction, corresponding to the second opening of the reflection film. 
     The height of the second opening formed in the reflection film may be smaller than the height of the light guide unit. 
     A plurality of uneven portions may be formed in a bottom surface of the light guide unit. 
     One or more of the second opening and the light transmission may be formed in a character or figure shape. 
     The mobile terminal may further comprise a white sheet disposed between a front surface of the light guide unit and the case. 
     One or more of the corners of the light guide unit may cut away obliquely. 
     The reflection film may be formed by coating tin or aluminum in a non-conductive vapor metallization (NCVM) method. 
     In another aspect of the present disclosure, a method for manufacturing a light guide unit comprises steps of injection-molding a transparent injection mold comprising a temporary fixing unit and a plurality of base modules having one surface of which a predetermined portion is connected to the temporary fixing unit and the other surfaces exposed outside; coating a reflection film on a surface of the transparent injection mold; partially removing the reflection film formed in the front surface of the transparent injection mold; and cutting away a connecting portion between the base module and the temporary fixing unit. 
     The connecting portion may be thinner than the base module. 
     The plurality of the base modules may be arranged in a line. 
     The temporary fixing unit may be a bar type, and the plurality of the base modules are connected to right and left portions of the temporary fixing unit. 
     The injection molding step may inject injection solution to a mold having a cavity formed corresponding to the shape of the transparent injection mold, and a plurality of unevenness may be formed in the mold, corresponding to the uneven portions formed in the bottom surface of the base module. 
     The mold may be a detachable assembly mold having the unevenness detachable there from. 
     The reflection film coating step may coat tin or aluminum according to non-conductive vapor metallization (NCVM). 
     The step of partially removing the reflection film may be performed according to laser etching. 
     In a further aspect of the present disclosure, a method for manufacturing a light guide unit includes steps of injection-molding a transparent injection mold comprising a temporary fixing unit and a plurality of base modules having one surface of which a predetermined portion is connected to the temporary fixing unit and the other surfaces exposed outside; coating a reflection film on a surface of the transparent injection mold; partially removing the reflection film formed in the front surface of the transparent injection mold; forming a light guide unit by cutting away a connecting portion between the base module and the temporary fixing unit; disposing a light source facing a cut-away portion of the light guide unit and the light guide unit to make the laser-processed portion toward a front surface; and coupling a front case to the rear case to locate a light transmission unit in the laser-processed portion. 
     According to at least one of the embodiments of the present disclosure, the reflection film may cover even the lateral surface of the light guide unit and even the light escaping in a lateral direction may be guided. 
     Moreover, no adhesive layer needs to be disposed and the processes may be simplified. The overall thickness of the light guide unit can be reduced and the plurality of the light guide units may be manufactured at one time. Accordingly, the production cost can be lowered. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating one example of a mobile terminal in accordance with one embodiment of the present disclosure; 
         FIG. 2  is a perspective diagram illustrating one example of the mobile terminal in accordance with one embodiment of the present disclosure, viewed in front; 
         FIG. 3  is a sectional diagram illustrating a light guide unit of the mobile terminal in accordance with one embodiment of the present disclosure; 
         FIG. 4  is a perspective diagram of  FIG. 3 ; 
         FIG. 5  is a flow chart illustrating a method for manufacturing a light guide unit in accordance with another embodiment of the present disclosure; 
         FIGS. 6 through 9  are diagrams illustrating one example of a method for manufacturing the light guide unit according to  FIG. 5 ; 
         FIGS. 10 through 13  are perspective diagrams illustrating diverse examples of the light guide unit of the mobile terminal in accordance with one embodiment of the present disclosure; 
         FIG. 14  is a sectional diagram illustrating a mold for manufacturing the light guide unit of  FIG. 13 ; and 
         FIG. 15  is a sectional diagram illustrating a conventional light guide unit. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Different vibrations can be output in a manner of being synthesized together or can be output in sequence. 
     The haptic module  153  is able to generate various tactile effects as well as the vibration. For instance, the haptic module  153  generates the effect attributed to the arrangement of pins vertically moving against a contact skin surface, the effect attributed to the injection/suction power of air though an injection/suction hole, the effect attributed to the skim over a skin surface, the effect attributed to the contact with electrode, the effect attributed to the electrostatic force, the effect attributed to the representation of hold/cold sense using an endothermic or exothermic device and the like. 
     The haptic module  153  can be implemented to enable a user to sense the tactile effect through a muscle sense of finger, arm or the like as well as to transfer the tactile effect through a direct contact. Optionally, at least two haptic modules  153  can be provided to the mobile terminal  100  in accordance with the corresponding configuration type of the mobile terminal  100 . 
     The memory  170  is generally used to store various types of data to support the processing, control, and storage requirements of the mobile terminal  100 . Examples of such data include program instructions for applications operating on the mobile terminal  100 , contact data, phonebook data, messages, audio, still pictures (or photo), moving pictures, etc. In addition, a recent use history or a cumulative use frequency of each data (e.g., use frequency for each phonebook, each message or each multimedia) can be stored in the memory unit  160 . Moreover, data for various patterns of vibration and/or sound output in case of a touch input to the touchscreen can be stored in the memory unit  160 . 
     The memory  170  may be implemented using any type or combination of suitable volatile and non-volatile memory or storage devices including hard disk, random access memory (RAM), static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk, multimedia card micro type memory, card-type memory (e.g., SD memory, XD memory, etc.), or other similar memory or data storage device. In addition, the mobile terminal  100  is able to operate in association with a web storage for performing a storage function of the memory  160  on Internet. 
     The interface unit  160  is often implemented to couple the mobile terminal  100  with external devices. The interface unit  160  receives data from the external devices or is supplied with the power and then transfers the data or power to the respective elements of the mobile terminal  100  or enables data within the mobile terminal  100  to be transferred to the external devices. 
     The interface unit  160  may be configured using a wired/wireless headset port, an external charger port, a wired/wireless data port, a memory card port, a port for coupling to a device having an identity module, audio input/output ports, video input/output ports, an earphone port and/or the like. 
     The identity module is the chip for storing various kinds of information for authenticating a use authority of the mobile terminal  100  and can include User Identify Module (UIM), Subscriber Identify Module (SIM), Universal Subscriber Identity Module (USIM) and/or the like. A device having the identity module (hereinafter called ‘identity device’) can be manufactured as a smart card. Therefore, the identity device is connectible to the mobile terminal  100  via the corresponding port. 
     When the mobile terminal  100  is connected to an external cradle, the interface unit  170  becomes a passage for supplying the mobile terminal  100  with a power from the cradle or a passage for delivering various command signals input from the cradle by a user to the mobile terminal  100 . Each of the various command signals input from the cradle or the power can operate as a signal enabling the mobile terminal  100  to recognize that it is correctly loaded in the cradle. 
     The controller  180  may control the overall operations of the mobile terminal  100 . For example, the controller  180  may performs the control and processing associated with voice calls, data communications, video calls, etc. The controller  180  may include a multimedia module  181  that provides multimedia playback. The multimedia module  181  may be configured as part of the controller  180 , or implemented as a separate component. 
     Moreover, the controller  180  is able to perform a pattern (or image) recognizing process for recognizing a writing input and a picture drawing input carried out on the touchscreen as characters or images, respectively. 
     The power supply unit  190  provides power required by the various components for the mobile terminal  100 . The power may be internal power, external power, or combinations thereof. 
     A battery may include a built-in rechargeable battery and may be detachably attached to the terminal body for a charging and the like. A connecting port may be configured as one example of the interface unit  160  via which an external charger for supplying a power of a battery charging is electrically connected. 
     Various embodiments described herein may be implemented in a computer-readable medium using, for example, computer software, hardware, or some combination thereof. 
     For a hardware implementation, the embodiments described herein may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a selective combination thereof. Such embodiments may also be implemented by the controller  180 . 
     For a software implementation, the embodiments described herein may be implemented with separate software modules, such as procedures and functions, each of which perform one or more of the functions and operations described herein. The software codes can be implemented with a software application written in any suitable programming language and may be stored in memory such as the memory  170 , and executed by a controller or processor, such as the controller  180 . 
       FIG. 2  is a perspective diagram of one example of a mobile terminal, viewed in front. 
     The illustrated mobile terminal  100  includes a bar-type terminal body. The examples presented herein are not limited to the bar type terminal body. The examples are applicable to diverse structures including a slide type, a folder type, a swing type, swivel type and the like. Those types have two or more bodies coupled to each other to relatively move. 
     The body of the mobile terminal  100  includes a case  101  and  102  defining an exterior appearance of the mobile terminal. In the illustrated example, the case may include a front case  101  and a rear case  102  cooperatively defining an inner space. The inner space formed between the front case  101  and the rear case  102  may accommodate various electronic components. 
     Other configurations are possible. For example, electronic components may be mounted in a surface of the rear case  102 . Examples of the electronic components mounted in the surface of the rear case  102  include a battery loadable and unloadable by a user, a USIM card, a memory card and the like. In this instance, the rear case  102  may further include a back cover  103  for covering the surface. The back cover  103  may be configured as a detachable unit detached by the user easily and smoothly. When the back cover  103  is detached by the user, the surface of the rear case  102  is exposed. 
     The back cover  103  is attached to the rear case, a lateral surface of the rear case  102  may be partially exposed. When the back cover  103  is small, a rear surface of the rear case  102  may be also partially exposed. If covering an overall area of the rear surface of the rear case  102 , the back cover  103  may have an opening for exposing the camera or the audio output module outside. 
     The case  101 ,  102  and  103  may be formed by injection-molding synthetic resin or made of metal, for example, stainless steel (STS) and titanium (Ti). 
     In the case  101  and  102  may be arranged a display unit  151 , an audio output module  152 , a camera  121 , a user input unit  130 ,  131  and  132 , a microphone  122 , an interface unit  160  and the like. 
     The display unit  151  occupies most area of the front case  101 . The audio output module  152  and the camera  121  are arranged in an area adjacent to one of ends of the display unit  151 . The user input unit  131  and the microphone  122  are arranged in an area adjacent to the other end of the display unit  151 . The user input unit  132 , the interface unit  160  and the like are arranged in lateral surfaces of the front case  101  and the rear case  102 . An ear jack  155  may be further provided in a predetermined area of the mobile terminal to connect an external sound output device such as an earphone by inserting a plug. A proximity sensor  141  is also shown. 
     The user input unit  130  is implemented for the user to input commands and the commands are processed by the controller to control the operation of the mobile terminal  100 . The user input unit  130  may include a plurality of manipulation units  131 ,  132  and  133  and the plurality of the manipulation units  131 ,  132  and  133  may be called as a manipulating portion. 
     The information input by first and second manipulation units  131  and  132  may be diversely preset. For example, the first manipulation unit  131  is implemented for the user to input commands such as start, end, scroll and the like. The second manipulation unit  132  is implemented for the user to input commands such as volume adjusting of the sound output from the audio output module  152 . The third manipulation unit  133  is implemented for the user to input commands such as touch recognition mode activation/deactivation of the display unit  151 . 
     The manipulation units  131 ,  132  and  133  may be implemented in a form of a button type for recognizing inputs when the user applies a certain pressure. As an alternative example, the manipulation units  131 ,  132  and  133  may include a touch sensor for recognizing inputs by only using the user&#39;s touch. 
     The manipulation unit may emit light for the user to press the button of the manipulation unit even in a dark place. A light source  250  ( FIG. 3 ) such as a light emitting diode (LED) is used even for an indicator configured to display a state of the mobile terminal  100 . In this instance, if the light source  250  directly emits light forwards, a strong light might reach the user&#39;s eyes and it can be a disadvantage. Moreover, if the light source  250  is arranged in a direction to the thickness of the mobile terminal  100 , there is another disadvantage of a thick mobile terminal  100 . 
     To solve such disadvantages, a light guide unit for emitting light forwards uniformly may be used. However, a conventional light guide unit  10  is configured with various layers as mentioned above and has a disadvantage of a complex manufacturing process and another disadvantage of a high expense. A light guide unit  210  is formed in the form of injection molding and metal layer coating, thereby simplifying the structure of the light guide unit  210  and reducing the overall thickness, with a low manufacture cost. 
       FIG. 3  is a sectional diagram illustrating a light guide unit of the mobile terminal in accordance with one embodiment of the present disclosure and  FIG. 4  is a perspective diagram of  FIG. 3 . 
     Referring to  FIGS. 3 and 4 , the light guide unit  210  of the present disclosure may include a base module  211  made in the form of injection molding; and a reflection film  215  coated on a surface of the base module  211 . The reflection film  215  has a first opening  215   a  formed in a lateral surface for light to be incident thereon from the light source  250  and a second opening  215   b  formed forwards. Accordingly, the light incident via the first opening  215   a  from the lateral surface may travel in the light guide unit  210  and reflects on the reflection film  215 , to be emitted forwards via the second opening  215   b.    
     Different from a conventional light guide unit, the lateral surface is blocked and the light escaped from the lateral surface is minimized enough to enhance efficiency of light guidance. Moreover, no auxiliary shielding film has to be provided to shield the light escaping via the lateral surface. 
     The reflection film  215  of the present disclosure is formed by coating a metallic material, for example, tin (SN) or aluminum (Al) in the form of Non-conductive Vacuum Metallization. In other words, the reflection film  215  is coated by Mon-conductive Vacuum Metallization and the polish of the reflection film  215  is improved such that the light incident on the lateral surface of the light guide unit  210  can be reflected as if reflected on a mirror. Non-conductive Vacuum Metallization may perform more glossy coating, compared with other coating methods, and enhance reflectivity. 
     A white sheet  230  is disposed on the light guide unit  210  and an adhesive tape  220  is attached to a backside of the light guide unit  210 , thereby being disposed on the printed circuit board  185 . The white sheet is functioned to scatter the light emitted from the light guide unit  210  and to change and emit the light into a soft light. 
     As shown in  FIG. 4 , the white sheet  230  is larger than the light guide unit  210  to cover even a top surface of the light source  250 . The scattered light not incident on the light guide unit  210  may be prevented from emitting forwards directly. 
     A case  109  located in a front or forward direction where the second opening  215   b  is formed (an upper surface in the drawing) is configured as a light transmission unit  109 ′ to emit the light. When a portion of the case facing the second opening  215   b  has a window glass  109 , printing is partially performed and the light transmission unit  109 ′ may be formed in a bezel  109 ″ of the window glass  109  for light to transmit. 
     The base module  211  is formed by injection molding. The reflection film  215  is coated by the non-conductive vacuum metallization and disposed on the base module  211 . After that, the reflection film  215  is partially removed by a laser etching method and the opening  215   b  is then formed. The injection molding method and the non-conductive vacuum metallization method may form a product with a large area easily, such that the production cost of the light guide unit  210  can be lowered. 
     Hereinafter, a method for manufacturing the light guide unit  210  will be described, referring to  FIGS. 5 through 9 .  FIG. 5  is a flow chart illustrating a method for manufacturing a light guide unit in accordance with another embodiment of the present disclosure.  FIGS. 6 through 9  are diagrams illustrating one example of a method for manufacturing the light guide unit  210  according to  FIG. 5 . 
     As shown in  FIGS. 5 and 6 , a transparent injection mold  200  having a plurality of base modules  211  is formed by the injection molding method (S 10 ). The injection molding method injects and hardens injection solution in a mold. Mass production can be possible, using the injection molding. Several base modules  211  may be fabricated at one time, using the injection molding method as shown in  FIG. 6 . 
     A temporary fixing unit  212  connecting the base modules  211  with each other may serve as a passage of the injection solution and the temporary fixing unit  212  is removed finally. Accordingly, the temporary fixing unit  212  is only connected to each of the base modules  211  and the appearance of the temporary fixing unit  212  is not limited. The temporary fixing unit may be formed in a rectangular shape of a plate as shown in  FIG. 6  or in a shape of several bars as shown in  FIG. 7 . 
     The base modules  211  may be connected to right and left portions of the bar-shaped temporary fixing unit  212  like leaves hanging on a branch. Temporary fixing portions  212 ′ may be further provided to connect several temporary units  212  with each other. 
     A connecting portion  213  for connecting the base modules  211  with the temporary fixing unit  212  may have a certain thickness which is equal to the thickness of the base module  211  and the temporary fixing unit  212  as shown in the example of  FIG. 11 . As an alternative example shown in  FIG. 7 , the connecting portion  213  may be thinner to enlarge the area of coating the reflection film  215  in a step of coating the reflection film  215  which will be described later. 
     The base modules  211  are used after separated from the temporary fixing unit  212 . It is preferred that the base modules  211  are arranged in a line to cut away several base modules  211  at one time. 
     After the transparent injection mold  200  including the base module  211  and the temporary fixing unit  212  is injection-molded, tin or aluminum is coated by the non-conductive vapor metallization (NCVM) method and the reflection film  215  is formed (S 20 ). As shown in  FIG. 8 , the non-conductive vapor metallization method enables the reflection film  215  coated on the overall area of the surface. 
     Accordingly, the reflection film  215  coated on the front surface is partially laser-etched to form the second opening  215   b  and the second opening  215   b  is formed (S 30 ). 
     As an alternative example, the transparent injection mold  200  is injected to have a projected area corresponding to the second opening  215  and the reflection film  215  is coated. After that, the projected area is cut away and then the second opening  215   b  shown in  FIG. 9  is formed. As another alternative example, only the area corresponding to the second opening  215   b  is shielded and the other area is coated to form the second opening  215   b.    
     After the second opening  215   b  is formed, each of the connecting portions  213  are cut away and then the light guide units  210  are fabricated one by one as shown in  FIG. 10  (S 40 ). As shown in  FIG. 10 , the first opening  215   a  may be formed in the surface having the connecting portion  213  cut away there from, without forming the reflection film  215 . 
     As shown in  FIGS. 11 and 12 , the second opening  215   b  may be formed in a shape of a character or a figure. When the connecting portion  213  is thinner than the base module  211  as shown in  FIG. 7 , the first opening  215   a  is less high than the light guide unit  210  as shown in  FIGS. 11 and 12 . 
     The light guide unit may be cut away close to the base module  211  as shown in  FIG. 12  or it may be cut away only to leave the connecting portion  213  as shown in  FIG. 11 . A corner of the light guide unit  210  shown in  FIG. 12  is cut away obliquely to form a dull angle. The light is not collected in the corners but induced to the second opening  215   b.    
     An uneven portion  214  may be formed in a bottom of the base module  211  shown in  FIG. 13 . When the uneven portion  214  is formed in the bottom of the base module  211 , the light is scattered to the front surface (or forwards) and guided toward the second opening  215   b . The uneven portion  214  formed in the bottom of the base module  211  may be formed by forming unevenness in the mold  50  in the injection molding. At this time, the unevenness of the mold  50  may be a replaceable type shown in  FIG. 14  illustrating a cross section of the mold  50  to fabricate the light guide unit  210  of  FIG. 13 . 
     The light guide unit  210  manufactured in the method described above is fixed to the printed circuit board  185 , using the double-sided tape  220 , as shown in  FIG. 3 . The light guide unit  210  may be mounted to have the second opening  215   b  toward the light transmission unit  109 ′ of the case of the mobile terminal  100 . In case the light transmission unit  109 ′ is functioned as the user input unit  130 , a touch sensor may be further provided in the back side of the window glass  109 . 
     As described above, according to one or more of the embodiments of the present disclosure, the reflection film  215  may cover even the lateral surface of the light guide unit and even the light escaping in a lateral direction may be guided. Moreover, no adhesive layer needs to be disposed and the processes may be simplified. The overall thickness of the light guide unit can be reduced and the plurality of the light guide units  210  may be manufactured at one time. Accordingly, the production cost can be lowered. 
     Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. 
     As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be considered broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds, are therefore intended to be embraced by the appended claims.