Patent Publication Number: US-2010124945-A1

Title: Mobile terminal having touch screen panel

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY 
     The present application is related to and claims priority to an application entitled “MOBILE TERMINAL HAVING TOUCH SCREEN PANEL” filed in the Korean Intellectual Property Office on Nov. 19, 2008 and assigned Serial No. 10-2008-0114963, the contents of which are incorporated herein by reference. 
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a mobile terminal having a touch screen panel, and more particularly, to a mobile terminal having a touch screen panel that can prevent an erroneous operation of a detection sensor for detecting the approach of an external object. 
     BACKGROUND OF THE INVENTION 
     In general, a mobile terminal is an electronic device that enables a user to freely use a function, such as wireless communication, network connection, and digital broadcasting reception, almost regardless of time and location. Recently, mobile terminals have been developed to perform functions such as Internet connection and digital broadcasting reception as well as a communication function. Further, functions such as document writing and a game player are added to the mobile terminal. 
     Nowadays, the mobile terminal has a small size and thickness according to a user request. According to such a trend, interest has increased in new input devices for solving a problem of a conventional button type input device occupying a great bulk. Particularly, an input method using a touch screen different from a conventional input method has been highlighted. 
     In general, a touch screen is an input device that forms an interface between an information communication device using various displays and a user, and enables the user to directly contact a screen using an input tool, such as a finger or a touch pen. Because the user can easily touch the touch screen using the input tool, the touch screen can be used in various appliances, such as an automated teller machine (ATM), personal digital assistant (PDA), and mobile phone, and in many fields, such as in a bank, government and public offices, and for sightseeing and traffic guidance information devices. 
     Various types of touch screens have been developed, such as a resistance film type, capacitance type, supersonic wave type, infrared ray type, and surface elastic wave type. Because the resistance film type touch screen is cheap and can use various input tools, such as a finger and a touch pen, the resistance film type touch screen is widely used. 
     In a mobile phone terminal that includes a touch screen, when using an audio communication function, the user holds the mobile terminal to the user&#39;s ear in order to perform a communication. If the user&#39;s ear or cheek touches the touch screen of the mobile terminal, the mobile terminal may erroneously recognize this as the input of a user instruction and may perform a corresponding erroneous operation. Therefore, in order to prevent such an erroneous operation, a proximity sensor detects the approach of the user&#39;s ear or cheek, thereby preventing an erroneous operation of the touch screen. 
     In general, in the resistance film type touch screen, an upper panel and a lower panel are divided by a spacer. The upper panel includes an upper substrate and an upper conductive film, and the lower panel includes a lower substrate and a lower conductive film. However, because the lower substrate for supporting the upper substrate is made of a transparent material such as a plastic substrate, light emitted from a proximity sensor is diffusedly reflected in the lower substrate, and thus a problem may occur that a detection sensor for detecting the approach of the user&#39;s ear or cheek is erroneously operated. 
     Therefore, a mobile terminal having a touch screen panel that can prevent an erroneous operation of a detection sensor for detecting the approach of an external object is desired. 
     SUMMARY OF THE INVENTION 
     To address the above-discussed deficiencies of the prior art, it is a primary object to provide a mobile terminal that includes a touch screen panel that can prevent an erroneous operation of a detection sensor for detecting the approach of an external object. 
     In accordance with an aspect of the present invention, a mobile terminal includes: a touch screen panel installed in an upper surface of a display unit formed in an upper surface of the mobile terminal. The touch screen panel includes an upper panel and a lower panel disposed opposite each other; and a detection unit installed in the touch screen panel beneath the lower panel thereof for detecting an approach of an external object and for determining whether to allow or invalidate an input of a manipulation instruction from a user through the touch screen panel. A portion of the touch screen panel at which the detection unit is positioned does not include the lower panel of the touch screen panel. 
     Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
         FIG. 1  illustrates a perspective view of a configuration of a general slide type mobile terminal; 
         FIG. 2  illustrates a cross-sectional view of a structure of a general resistance film type touch screen panel; 
         FIG. 3A  illustrates a cross-sectional view of a structure of a detection unit and a touch screen panel around the detection unit in a mobile terminal having a touch screen panel according to an exemplary embodiment of the present invention; and 
         FIG. 3B  illustrates a plan view of the detection unit in the mobile terminal having the touch screen panel of  FIG. 3A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 through 3B , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged_mobile communications device. 
     In the following description, for convenience of description, a mobile terminal according to an exemplary embodiment of the present invention is described as a mobile communication terminal; however, the present invention is not limited thereto. The mobile terminal according to the present exemplary embodiment has a resistance film type touch screen panel and may be an information and communication device or a multimedia device, such as a mobile communication terminal, mobile phone, Personal Digital Assistant (PDA), smart phone, International Mobile Telecommunication 2000 (IMT-2000) terminal, Code Division Multiple Access (CDMA) terminal, Wideband Code Division Multiple Access (WCDMA) terminal, Global System for Mobile Communication (GSM) terminal, General Packet Radio Service (GPRS) terminal, Enhanced Data GSM Environment (EDGE) terminal, Universal Mobile Telecommunication (UMTS) terminal, digital broadcasting terminal, and applications thereof. 
       FIG. 1  illustrates a perspective view of a configuration of a general slide type mobile terminal. 
     Referring to  FIG. 1 , a general mobile terminal  1  includes an upper case  10  including a display unit  11  in an upper surface, and a lower case  20  including a key input unit  21 . The upper case  10  can move by sliding along the lower case  20 . In this case, either the upper case  10  or the lower case  20  includes a sliding unit (not shown) for guiding the upper case  10  to move by sliding operation. 
     The display unit  11  includes a touch screen, and performs a function of a user interface for outputting a desired screen to a user and for receiving an instruction from the user. The display unit  11  can use a Liquid Crystal Display (LCD), an Organic Light Emitting Diode (OLED), a Thin Film Transistor (TFT), an electrophoresis technology, and a Laser Induced Thermal Image (LITI) technology. The LCD is an electric device for changing and transmitting electrical information occurring in various devices using the change of a transmittance of liquid crystal, according to a voltage applied, to visible information. The OLED is formed of a self light emitting type organic material using an electroluminescence phenomenon that emits light when a current flows to a fluorescent organic compound. 
     The key input unit  21  that is configured to receive a manipulation instruction from the user is formed in an upper surface of the lower case  20 , and the lower case  20  is exposed to the outside by sliding the upper case  10 .  FIG. 1  illustrates an example in which an entire upper surface of the upper case  10  is formed with the display unit  11 , however an auxiliary key input unit (not shown) that receives a manipulation instruction from the user can be formed in a lower end portion or a side portion of the upper case  10 . The auxiliary key input unit can be formed with a minimum number of function keys necessary for receiving input from the user when the lower case  20  is covered by the upper case  10 . 
     The mobile terminal  1  includes a receiver  12  provided in an upper end portion of the upper case  10  to output a sound signal and a transmitter  22  provided in a lower end portion of the lower case  20  to input a voice signal. The user can hear a voice signal received from another party using the receiver  12  and transmit a voice signal to another party using the transmitter  22 . 
     Further, a detection unit  13  is provided in an upper surface of the upper case  10 .  FIG. 1  illustrates an example in which the detection unit  13  is installed in an upper end portion of the upper case  10  adjacent to the receiver  12 , however the detection unit  13  may be installed adjacent to a lower part of the display unit  11 . The detection unit  13  detects an approach of an external object, and subsequently either allows or invalidates an input through a touch screen panel  100  (shown in  FIG. 2 ). If no detection unit  13  was provided, when the user holds the mobile terminal  1  to their ear in order to perform a communication, if the user&#39;s ear or cheek touches a touch screen of the mobile terminal  1 , the mobile terminal  1  may recognize this as the input of a user instruction and may erroneously operate. Therefore, in the present invention, when the user holds the mobile terminal  1  to their ear in order to perform a communication, the detection unit  13  detects this state and invalidates an input through the touch screen panel  100 , thereby preventing an erroneous operation of the touch screen. A structure of the detection unit  13  is described later in detail with reference to  FIGS. 3A and 3B . 
     As shown in  FIG. 1 , the present invention can be applied to the slide type mobile terminal  1  having the display unit  11  of a touch screen form in an upper surface of the upper case  10 . Here, the mobile terminal  1  may be various portable electronic devices, such as a mobile phone, wireless receiver, and digital broadcasting receiver. 
       FIG. 2  illustrates a cross-sectional view of a structure of a general resistance film type touch screen panel. 
     Referring to  FIG. 2 , a resistance film type touch screen panel  100  includes an upper panel  110  and lower panel  120  installed in an upper surface of the display unit  11  and disposed opposite each other, and a spacer  130  for separating the upper panel  110  and the lower panel  120 . The upper panel  110  includes an upper substrate  111  having flexibility for deformation when a manipulation instruction is input by a user, and a transparent upper conductive film  112  coated on a lower surface of the upper substrate  111 . The lower panel  120  includes a lower substrate  122  installed at a lower part of the lower panel  120  and for supporting the upper substrate  111 , and a transparent lower conduction film  121  coated on an upper surface of the lower substrate  122 . 
     The upper substrate  111  is formed with a film made of a polymer resin having flexibility for deformation when a manipulation instruction is input by the user, for example, when a predetermined force is applied by the user. Further, the upper substrate  111  may be made of a transparent material transmitting light. Preferably, the upper substrate  111  comprises a transparent material such as a Polyethylene Terephthalate (PET) film. In order to protect the upper surface of the upper substrate  111 , a coating film (not shown) may be formed on the upper surface of the upper substrate  111 . 
     The lower substrate  122  may be formed with a transparent substrate. Preferably, the lower substrate  122  is a plastic substrate or a glass substrate and can support the upper substrate  111  formed with a film having flexibility. 
     The upper conductive film  112  is coated on a lower surface of the upper substrate  111 , for example, a surface facing towards the lower substrate  122 . The upper conductive film  112  can be a transparent conductive film, such as an Indium Tin Oxide (ITO) film. An upper electrode (not shown) electrically connected to the upper conductive film  112  can be disposed at edges of the upper conductive film  112 . The lower surface of the upper substrate  111  can be bonded to the upper surface of the upper conductive film  112  using an optical adhesive  113 . 
     The transparent lower conductive film  121  is coated on an upper surface of the lower substrate  122 , for example, on a surface facing towards the upper substrate  111 , and preferably an ITO film is used, as in the upper conductive film  112 . A lower electrode (not shown) electrically connected to the lower conductive film  121  can be disposed at edges of the lower conductive film  121 . The upper surface of the lower substrate  122  can be bonded to the lower surface of the lower conductive film  121  using an optical adhesive  123 . 
     A plurality of upper electrode guide lines (not shown) electrically connected to an upper electrode connected to the upper conductive film  112  and a plurality of lower electrode guide lines (not shown) connected to a lower electrode connected to the lower conductive film  121  can be formed in the lower substrate  122 . In this case, the upper electrode, lower electrode, upper electrode guide line, and lower electrode guide line can be made of a material having excellent conductivity. Further, the upper electrode, lower electrode, upper electrode guide line, and lower electrode guide line can be designed to have various patterns and dispositions. 
     The spacer  130  that separates the upper substrate  111  and the lower substrate  122  by a predetermined gap can be formed in an upper surface of the lower conductive film  121  or in a lower surface of the upper conductive film  122 . Preferably, the spacer  130  includes a plurality of dot spacers  131  formed in an upper surface of the lower conductive film  121  or in a lower surface of the upper conductive film  112 . The plurality of dot spacers  131  comprise an insulative resin material, such as epoxy and acrylic resin. Further, an air gap  132  can be formed between the plurality of dot spacers  131 . Therefore, the plurality of dot spacers  131  can uniformly sustain a gap between the upper substrate  111  and the lower substrate  122 . When the plurality of dot spacers  131  are formed in the upper surface of the lower conductive film  121  and a predetermined force is applied by the user to the upper substrate  111 , the plurality of dot spacers  131  can contact with the upper conductive film  112 . Alternatively, if the plurality of dot spacers  131  are formed in the lower surface of the upper conductive film  112 , the plurality of dot spacers  131  can contact with the lower conductive film  121 . In both cases, when the upper electrode connected to the upper conductive film  112  and the lower electrode connected to the lower conductive film  121  are electrically connected, an electrical signal is detected according to a resistance value of a touched position, and the touched position can be determined using a magnitude of the detected electrical signal. When the user applies a force to the upper substrate  111 , because the plurality of dot spacers  131  are separately disposed, the upper substrate  111  and the lower substrate  122  are prevented from touching at positions other than the touched position. 
     In order to bond the upper panel  110  and the lower panel  120 , an adhesive agent  133 , for example an optical adhesive or adhesive tape, can be applied along an edge of opposing surfaces between the upper panel  110  and the lower panel  120 . Further, the touch screen panel  100  can be bonded to an upper surface of the display unit  11  at the lower surface of the lower substrate  122  through a separate adhesive layer. 
       FIG. 2  illustrates a structure of the touch screen panel  100 , however the touch screen panel  100  is not limited thereto, and any structure of a resistance film type touch screen film  100  can be applied. 
       FIG. 3A  illustrates a cross-sectional view of a structure of the detection unit  13  and the touch screen panel  100  around the detection unit  13  in the mobile terminal  1  according to an exemplary embodiment of the present invention.  FIG. 3B  illustrates a plan view of the detection unit  13  in the mobile terminal  1  of  FIG. 3A . 
     Referring to  FIG. 3A , the touch screen panel  100  is divided into a detection area A at which the detection unit  13  is positioned and a touch area B for receiving a manipulation instruction from a user. For convenience of description,  FIG. 3A  illustrates an enlarged structure of the touch screen panel  100 . 
     As described in  FIG. 1 , the detection unit  13  is installed at a position at an upper end portion of the mobile terminal  1 , for example adjacent to the receiver  12 . The detection unit  13  includes a detection sensor  200  for detecting the approach of an external object  30 , and light transmittance units  114  and  115  formed in an upper surface of the upper panel  110  at a position corresponding to that at which the detection sensor  200  is positioned. 
     As shown in  FIG. 3A , the detection sensor  200  includes a light emitting unit  210 , light receiving unit  220 , and shielding film  230 , and is installed in the detection area A beneath the touch screen panel  100 . The detection sensor  200  detects the approach of the external object  30  and either allows or invalidates the input of a user instruction through the touch screen panel  100 . 
     The light emitting unit  210  performs a function of emitting light to the outside in order to measure a proximity distance to an external object, and the light receiving unit  220  performs a function of receiving light reflected from an external object. The shielding film  230  prevents light emitted from the light emitting unit  210  from directly entering the light receiving unit  220 , thereby preventing an erroneous operation of the detection sensor  200 . Preferably, the detection sensor  200  uses a proximity sensor, such as an infrared sensor for detecting whether the external object  30  approaches within a detection area of a predetermined distance using infrared rays. In this case, the light emitting unit  210  of the detection sensor  200  is formed with a Light Emitting Diode (LED) for emitting infrared rays. 
       FIG. 3A  illustrates a case where the light emitting unit  210  and the light receiving unit  220  of the detection sensor  200  are physically separated by the shielding film  230  provided between the light emitting unit  210  and the light receiving unit  220 , however a structure of the detection sensor  200  is not limited thereto and can be changed. For example, the light emitting unit  210  and the light receiving unit  220  may be integrally formed in the detection sensor  200 . 
     As shown in  FIG. 3A , in the mobile terminal  1  that includes the touch screen panel  100  according to the present exemplary embodiment, at a portion of the touch screen panel  100  at which the detection unit  13  is positioned, the lower panel  120  of the touch screen panel  100  can be removed. Specifically, the lower substrate  122  and the lower conductive film  121  corresponding to the portion of the touch screen panel  100  at which the detection unit  13  is positioned are removed. 
     As shown in  FIG. 3A , by removing the lower substrate  122  and the lower conductive film  121  of the lower panel  120  from the detection area A at which the detection sensor  200  is positioned, the spacer  130  for separating the lower panel  120  from the upper panel  110  is also removed. In this case, because in addition to the plurality of dot spacers  131 , the air layer  132  is formed in the spacer  130  between the upper panel  110  and the lower panel  120 , internal contamination due to the adhesive agent  133  can be prevented. 
     As described above, the lower substrate  122  forming the lower panel  120  of the resistance film type touch screen panel  100  is a transparent plastic substrate or a glass substrate. When the detection sensor  200  is installed in a lower part of the touch screen panel  100 , if the lower panel of the touch screen panel  100  was not to be removed from the portion thereof at which the detection sensor  200  is positioned, some of the light emitted from the light emitting unit  210  of the detection sensor  200  would be diffusedly reflected from the transparent lower substrate  122  before approaching the external object  30  and would enter the light receiving unit  220  of the detection sensor  200 , and thus, the detection sensor  200  may incorrectly recognize this as the approach of the external object  30  and may erroneously operate. 
     However, in the mobile terminal  1  having the touch screen panel  100  according to the present exemplary embodiment, by removing the lower panel  120  of the touch screen panel  100  from the portion thereof at which the detection sensor  200  is positioned, diffused reflection of light that may occur due to a transparent support substrate forming the lower panel  120  can be reduced, thereby preventing an erroneous operation of the detection unit  13  for detecting the approach of the external object  30 . 
     Further, in the portion of the touch screen panel  100  at which the detection sensor  200  is positioned, by removing the lower panel  120  of the touch screen panel  100 , the detection sensor  200  installed beneath the touch screen panel  100  can be installed closer to the touch screen panel  100  by a thickness of the removed lower panel  120 . That is, as shown in  FIG. 3A , by removing the lower panel  120 , a space corresponding to the thickness of the lower panel  120  can be created at a lower part of the touch screen panel  100 , and thus the detection sensor  200  can be moved upwards into the space. 
     Therefore, a proximity distance within which an external object detected by the detection sensor  200  can be increased, and an angle between light emitted from the light emitting unit  210  of the detection sensor  200  and light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200  can be increased. Further, because a proximity distance within which an object can be detected by the detection sensor  200  is increased, for an equivalent position of the external object  30  relative to the touch screen panel  100 , i.e., at an equivalent proximity distance, power consumption required for operating the detection sensor  200  can be reduced. 
     Referring again to  FIG. 3A , light transmittance units  114  and  115  are formed in an upper surface of the touch screen panel  100  corresponding to the portion of the touch screen panel  100  at which the detection sensor  200  is positioned. Preferably, as shown in  FIG. 3A , the light transmittance units  114  and  115  are formed in the upper substrate  111  forming the upper panel  110  corresponding to the portion thereof at which the detection sensor  200  is positioned. The light transmittance units  114  and  115  are formed in a light transmittance path taken by light emitted from the light emitting unit  210  of the detection sensor  200  and by light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200 , and at least one light transmittance unit can be formed.  FIGS. 3A and 3B  illustrate a case where two circular light transmittance units  114  and  115  are formed, respectively, in a portion of the touch screen panel  100  through which light emitted from the light emitting unit  210  of the detection sensor  200  passes, and a portion of the touch screen panel  100  through which light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200  passes. However, the quantity and shape of the light transmittance units  114  and  115  are not limited thereto. 
     In order to increase a transmittance of light emitted from the light emitting unit  210  of the detection sensor  200  and light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200 , the light transmittance units  114  and  115  can be formed transparently. However, when the light transmittance units  114  and  115  are formed transparently, a problem arises that the inside of the mobile terminal  1  is exposed to the outside. In this case, a black-based pigment (or ink) may be used to coat the light transmittance units  114  and  115 . However, this then creates a further problem that a transmittance of light, for example, infrared rays emitted from the light emitting unit  210  of the detection sensor  200  and light reflected from the external object  30  entering the light receiving unit  220  of the detection sensor  200 , may deteriorate. Further, although not shown, in order to save power of the mobile terminal  1 , an illumination sensor can be installed to enable adjustment of lighting of the display unit  11  according to a current light level external to the mobile terminal  1 , and it then becomes necessary to approximately adjust a transparency of the light transmittance units  114  and  115  in order to detect an amount of light entering the illumination sensor. 
     Therefore, the light transmittance units  114  and  115  can be formed using a black pigment and a transparent pigment in consideration of a transmittance of light emitted from the light emitting unit  210  of the detection sensor  200  and light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200 . In this case, a mixing ratio of a black pigment and a transparent pigment can be determined in consideration of a transmittance of light necessary for operation of the detection sensor  200  and a transmittance of light necessary for operation of the illumination sensor. 
     In the present exemplary embodiment, in which the detection sensor  200  is an Infrared Ray (IR) sensor, a 0.6% black pigment in which a black pigment and a transparent pigment are mixed with a ratio of approximately 6:994 is used, and as an experimental result with the 0.6% black pigment, a high transmittance value of infrared rays of about 75% was obtained. This mixing ratio of a black pigment and a transparent pigment is for illustration only and can be changed according to a condition such as a transmittance of light used for operation of the detection sensor  200 , a transmittance of light used for operation of the illumination sensor, and a degree of exposure to the outside. 
     In this way, in the mobile terminal  1  that includes the touch screen panel  100  according to the present exemplary embodiment, the light transmittance units  114  and  115  formed in a light transmittance path taken by light emitted from the light emitting unit  210  of the detection sensor  200  and by light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200  can be formed using a black pigment and a transparent pigment. A transmittance of light emitted from the light emitting unit  210  of the detection sensor  200  and a transmittance of light reflected from the external object  30  and entering the light receiving unit  220  of the detection sensor  200  can thereby be increased, and hence a transmission ability of the detection sensor  200  can be increased. Further, a problem that the inside of the mobile terminal  1  is exposed to the outside through the light transmittance units  114  and  115  of the detection unit  13  can be prevented. 
     In the present invention, a slide type mobile terminal is illustrated for example purposes, however the present invention is not limited thereto. The present invention can be applied to a rotating type mobile terminal, or to a combination type mobile terminal of a slide type mobile terminal and a rotating type mobile terminal. 
     As described above, in a mobile terminal that includes a touch screen panel according to an exemplary embodiment of the present invention, by removing a lower panel of a touch screen panel from a portion of the touch screen panel at which a detection sensor is positioned, diffused reflection of light, which may otherwise occur due to a transparent support substrate forming the lower panel, can be reduced, thereby preventing an erroneous operation of a detection unit for detecting the approach of an external object. 
     Further, because a detection sensor installed beneath the touch screen panel can be installed closer to the touch screen panel by a thickness of the removed lower panel, a proximity distance within which an external object can be detected by the detection sensor can be increased, and power consumption required for operating the detection sensor at an equivalent proximity distance can be reduced. 
     Further, because the detection sensor installed beneath the touch screen panel can be installed closer to the touch screen panel by a thickness of the removed lower panel, an angle between light emitted from a light emitting unit of the detection sensor and light reflected from an external object and entering a light receiving unit of the detection sensor can be greatly increased. 
     Further, by forming a light transmittance unit in an upper surface of an upper panel of the touch screen panel corresponding to a portion thereof at which the detection sensor is positioned by mixing a black pigment and a transparent pigment, a transmittance of light emitted from the light emitting unit of the detection sensor and a transmittance of light reflected from the external object and entering the light receiving unit of the detection sensor can be increased, and thereby accuracy of the detection sensor can be increased and a problem that the inside of the mobile terminal is exposed to the outside can be prevented. 
     Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.