Abstract:
Disclosed is a portable terminal having a display device arranged on the front side of the housing of the portable terminal, and an optical touch pad arranged on the rear side of the housing, wherein a user can operate the touch screen with the thumb and operate the touch pad on the rear side of the housing with the index finger or another finger in a state in which the user grasps the portable terminal.

Description:
CLAIM OF PRIORITY 
     This application claims the priority under 35 U.S.C. §119(a) of an application entitled “Portable Terminal With Optical Touch Pad And Method For Controlling Data In The Same” filed in the Korean Intellectual Property Office on Dec. 16, 2010 and assigned Serial No. 10-2010-0128991, the contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a portable terminal having an input device comprised of an optical touch pad, and a method for controlling data in the portable terminal using the optical touch pad. 
     2. Description of the Related Art 
     In general, a portable terminal provides various functions from a communication function, such as voice and data communication, to a multimedia function, such as storage of various information items to enjoy games/moving pictures. Such portable terminals include a digital diary, a palm PC (personal computer), a portable game machine, a moving picture/music reproducer, a cellular phone, and a notebook PC. 
     Recently, other new functions such as a security function enabling banking business, a multimedia function, and a simple business function have become popular. 
     With a conventional mobile communication terminal, it was sufficient to conduct voice and data communication with only a keypad having numeric input keys, call/end keys, menu selection keys, movement keys, etc. However, as the multimedia function as well as the communication function has become advance in a portable terminal, a need to enlarge a display device in such a portable terminal has grown. However, the enlargement of a display device in a portable terminal pose a problem in the miniaturization effort. To this end, some portable terminals are not provided with a separate keypad by implementing a touch screen. 
     Portable terminals, which are provided with a touch screen as a display device, are generally bar-type terminals, wherein input, menu search or the like can be conducted mainly by operating the touch screen. One or more physical keys may be arranged at a side of the touch display device to navigate the main menu or to return to the previous screen. 
     However, a key arranged at the side of a display device is a drawback in miniaturizing the size of the portable terminal. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an aspect of the present invention provides a portable terminal with an optical touch pad, which can contribute to the miniaturization of a portable terminal. 
     Another aspect of the present invention provides a portable terminal having an optical touch pad for enabling an input action to be executed on the rear side of the portable terminal. 
     Another aspect of the present invention provides a portable terminal having an optical touch pad capable of diversifying an input device. 
     In accordance with an aspect of the present invention, a portable terminal includes a display device installed on a front side of a housing, and an optical touch pad installed at least on the rear side of the housing, wherein the display device is formed by a touch screen. 
     In accordance with another aspect of the present invention, a method of controlling data in a portable terminal with an optical touch pad on the rear side of a housing includes: determining whether the touch pad is operated in a current mode of the portable terminal, and executing a function for controlling the data of the current mode in accordance with the operation of the touch pad. 
     According to the teachings of present invention, since a display device is arranged on the front side of the housing of the portable terminal, and an optical touch pad is arranged on the rear side of the housing, it is not required to provide a physical key at a side of the display device. As a result, the omission of side keys contributes to the enlargement of a display device or miniaturization of a portable terminal. Moreover, a user can operate the touch screen with the thumb and operate the touch pad on the rear side of the housing with the index finger or another finger in a state in which the user grasps the portable terminal, thus providing alternate convenient way of manipulating and navigating the content of a portable terminal by holding up the terminal using only one hand so that the user faces the display screen. 
     Furthermore, if an optical touch pad is provided in a state in which the optical touch pad is rectilinearly movable to a certain extent while maintaining its function, it will be possible to implement a function of a physical key by adding a separate switch member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view showing a portable terminal in accordance with an embodiment of the present invention; 
         FIG. 2  is a perspective view showing the rear side of the portable terminal shown in  FIG. 1 ; 
         FIG. 3  is a perspective view showing an optical touch pad of the portable terminal shown in  FIG. 2 ; 
         FIG. 4  is an exploded perspective view of the optical touch pad shown in  FIG. 3 ; 
         FIG. 5  is a side view of a rear case of the optical touch pad shown in  FIG. 3 ; 
         FIG. 6  shows the optical touch pad shown in  FIG. 3  in a state in which the optical touch pad is installed in a terminal; 
         FIG. 7  shows a configuration of a portable terminal in accordance with an embodiment of the present invention; 
         FIG. 8  is a flowchart showing a process for controlling data in the portable terminal shown in  FIG. 7  using an optical touch pad; and 
         FIGS. 9   a  to  9   d  are views for describing the process shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same elements will be designated by the same reference numerals although they are shown in different drawings. For the purposes of clarity and simplicity, a detailed description of known functions and configurations incorporated herein will be omitted as it may make the subject matter of the present invention unclear. 
     Referring to  FIGS. 1 and 2 , a portable terminal  100  in accordance with an embodiment of the present invention includes a display device  102  provided on the front side of a housing  101 , and an optical touch pad  103  provided on the rear side  101   a  of the housing  101  as an input device. The display device  102  is configured by a touch screen, so that the entirety of the front side of the housing  101  may be used as a space for mounting the display device  102 . 
     The optical touch pad  103  may be installed to be rectilinearly movable on the housing  101 , and may be used as a physical key. 
     In operation, when a user grasps the housing  101  of the terminal  100 , the user&#39;s fingers operating the touch pad will be generally positioned on the upper rear side  101   a  of the housing  101 . Therefore, it is desired to arrange the touch pad  103  over the rear side  101   a  and the top side  101   b . However, it should be noted that the touch pad  103  may be arranged at other location of the rear side  101   a  of the housing  101  in accordance with the teachings of the present invention. 
     Now, the configuration of the touch pad  103  will be described in more detail with reference to  FIGS. 3 to 6 . 
     The touch pad  103  includes a front case  133 , a sensor module  131 , and a rear case  135 . The front case  133  has a periphery, which is adapted to be arranged as a part of the outer area of the housing  101 . That is, the housing  101  is formed with an opening (not shown) over the rear side  101   a  and the top side  101   b , and the front case  133  is provided to close the opening, thereby completing the outer surface area of the housing  101 . 
     The sensor module  131  is provided with an optical sensor  131   b  at the outer part of its body  131   a . When configuring the sensor module  131 , it is not necessary to provide a separate body. However, in order to stably connect a power source and a signal transmission line to the optical sensor  131   b , the body  131   a  is arranged on the optical sensor  131 . The present embodiment illustrates a configuration in which a flexible printed circuit board  131   c  is used as the signal transmission line. The flexible printed circuit board  131   c  is wired to extend from the optical sensor  131   b  and through the body  131   a.    
     The rear case  135  is adapted to receive the sensor module  131 , more specifically the optical sensor  131   b  and to stably anchor the sensor module  131  to the front case  133 , wherein the rear case  135  is engaged with the inner periphery of the front case  133 . The rear case  135  is formed with a reception recess  135   a  for receiving the sensor module  131 , and a slit  135   b  extending through the rear case  135  to the outside of the rear case  135  is formed in the reception recess  135   a . If the sensor module  131  is received in the reception recess  135   a , the flexible printed circuit board  131   c  is wired to the outside of the rear case  135  through the slit  135   b.    
     If the rear case  135  is joined to the front case  133  in a state in which the sensor module  131  is received in the rear case  135 , the touch pad  103  is completed as a module type. The optical sensor  131   b  is opposed to the inner periphery of the front case  133 . When installing the touch pad  103  to the housing  101 , the optical sensor  131   b  is obliquely positioned in relation to the rear side  101   a  of the housing  101 , more preferably to be oriented toward the corner between the rear side  101   a  and the top side  101   b . That is, the sensing direction of the optical sensor  131   b  is obliquely arranged in relation to the rear side  101   a  of the housing  101 . Through this arrangement, the optical sensor  131   b  can sense more precisely the user&#39;s operation of the touch pad  103 , more specifically on the front case  133 . 
     As shown in  FIG. 6 , the touch pad  103 , more specifically the front case  133  is arranged as a part of the outer area of the housing  101 , and the sensor module  131  received in the rear case  135 , which is positioned within the interior of the housing  101 . 
     A main board  117  is arranged in the interior of the housing  101 , and the main board  117  is equipped with a connector  118  for connecting the optical sensor  131   b , more specifically the flexible printed circuit board  131   c . The flexible printed circuit board  131   c  is bent at a proper position within the interior of the housing  101 , and an end of the flexible printed circuit board is connected to the connector  118 . 
     As a result, the touch pad  103  is installed on the housing  101  to be capable of providing a screen scroll function or the like. In addition, depending on the operation mode of the terminal  100 , the touch pad  103  may be used for adjusting volume or controlling screen brightness. A detail description of different touch pad functions during a plurality of operation modes will be explained later in details with reference to  FIG. 8 . 
     Upon being installed to be rectilinearly movable on the housing  101  as described above, the touch pad  103  can be used as a physical type key. In order to use the touch pad  103  as a physical key, an actuation protrusion  135   c  protruding laterally is formed on the rear case  135 , and a switch member  119  is provided in the housing  101  as shown in  FIGS. 5 and 6 . 
     A tact switch fixed on the main board  117  is exemplified as the switch member  119 , and the actuation protrusion  135   c  is positioned facing to the switch member  119 . The touch pad  103  is rectilinearly movable on the housing  101  of the terminal  100  in the longitudinal direction of the housing  101 , so that, as the touch pad  103  is rectilinearly moved, the actuation protrusion  135   c  actuates the switch member  119 . 
     In arranging such a physical key, it is not necessary to arrange a tact switch as the switch member  119 . For example, it is possible to arrange the touch pad  103 , more specifically the front case  133  only on the rear side of the housing  101 , and arrange a dome switch between the rear case  135  and the main board  117  as the switch member. In such an embodiment, the main board  117 , the dome switch and the touch pad  103  will form a stack configuration, and the touch pad  103  may be arranged to be rectilinearly movable in the direction of the thickness of the housing  101  (in  FIG. 6 , in the vertical direction). In the configuration shown in  FIG. 6 , it is possible to arrange a dome switch at an area where the rear case  135  and the main board  117  are opposed to each other, so that the dome switch can be used as a physical key. 
       FIG. 7  shows a configuration of a portable terminal in accordance with an embodiment of the present invention. 
     Referring to  FIG. 7 , an RF unit  223  conducts a wireless communication function of the portable terminal. The RF unit  223  includes a RF transmitter for up-converting frequency of transmitted signals and amplifying the transmitted signals, and an RF receiver for low noise-amplifying received signals and down-converting the frequency of the received signals. A data processing unit  220  includes a transmitter for coding and modulating the transmitted signals, and a receiver for demodulating and decoding the received signals. That is, the data processing unit  220  may consist of a MODEM and a CODEC. Here, the CODEC includes a data CODEC for processing packet data and an audio CODEC for processing audio signals. An audio processing unit  225  serves to reproduce received audio signals that are outputted from the audio CODEC of the data processing unit  220 , or to transmit the transmitted audio signals, which are produced from a microphone, to the audio CODEC of the data processing unit  220 . 
     A memory  230  may consist of program memories and data memories. The program memories may store programs for controlling the ordinary operations of the portable terminal, and programs for controlling data of the current mode in accordance with the operation of the optical touch pad provided in the portable terminal. 
     A control unit  210  serves to control the overall operations of the portable terminal. 
     In accordance with the present embodiment, the control unit  210  controls data displayed or executed in the current mode of the portable terminal in accordance with the operation of the touch pad. 
     In accordance with the present embodiment, if the current mode is the standby mode, the control unit  210  performs control in such a manner that a background screen change function is executed in accordance with the operation of the touch pad  103 , wherein the operation of the touch pad  103  may be a touch movement in a corresponding direction among four directions of up, down, left and right. 
     In the standby mode, the background screen and icons may be displayed all together, wherein since the background layer and the icon layer are separated from each other, it is possible to change the background screen to another background screen in accordance with the operation of the touch pad  103 . 
     In accordance with the present embodiment, if the current mode is a video communication mode, the control unit  210  may perform control in such a manner that the volume or brightness adjusting function is executed in accordance with the operation of the touch pad  103 , wherein the operation of the touch pad  103  may be a touch movement in a corresponding direction among four directions of up, down, left and right. 
     In accordance with the present embodiment, if the current mode is an internet mode, the control unit  210  may perform control in such a manner that the mouse function is executed in accordance with the operation of the touch pad  103 , wherein the operation of the touch pad  103  may be a touch movement in a corresponding direction among four directions of up, down, left and right. 
     In accordance with the present embodiment, if the current mode is a specific mode, the control unit  210  may perform control in such a manner that a data scroll function or a specific function is executed in accordance with the operation of the touch pad  103 . 
     In such a case, the operation of the touch pad  103  for the data scroll may be a touch movement in a corresponding direction among four directions of up, down, left and right, and the operation of the touch pad  103  for executing the specific function may be a single touch. 
     In addition, the specific function may be a home key function, a back key function or an enter key function. 
     In addition, the control unit  110  may control the data of the current mode in accordance with the operation of the touch pad  130  regardless of the position of the portable terminal, i.e. regardless of the transversal mode or longitudinal mode. 
     As shown in  FIG. 2 , the optical touch pad  103  is arranged over the rear side and the top side of the housing of the portable terminal. The touch pad  103  may be operated by a touch movement in a corresponding direction among four directions of up, down, left and right, and a single touch, wherein the data displayed in the current mode of the portable terminal can be controlled in accordance with the operation of the touch pad  103 . 
     A camera unit  240  photographs image data, and includes a camera sensor for converting photographed optical signals into electric signals, and a signal processing unit for converting the analog image signals photographed by the camera sensor into digital data. Here, it is assumed that the camera sensor is a CCD or CMOS sensor, and the signal processing unit may be implemented by a DSP (Digital Signal Processor). In addition, the camera sensor and the signal processing unit may be implemented in a one-piece type, or implemented separately. 
     An image processing unit  250  performs ISP (Image Signal Processing) for displaying image signals outputted from the camera unit  240  on a touch screen  260 , wherein the ISP executes various functions, such as gamma correction, interpolation, spatial change, image effect, image scale, AWB, AE and AF. Therefore, the image processing unit  250  processes image signals outputted from the camera unit  240  in a frame unit, and outputs the frame image data to be suitable for the feature and size of the touch screen  160 . In addition, the image processing unit  250  includes an image CODEC, and serves to compress the frame image data displayed on the touch screen  260  in a preset method, or to recover the compressed frame image data to the original frame image data. The image CODEC may be JPEG CODEC, MPEG4 CODEC, or Wavelet CODEC. Assuming that the image processing unit  250  has an OSD (On Screen Display) function, the image processing unit  250  may output on screen data in accordance with a displayed screen size under the control of the control unit  210 . 
     The touch screen  260  may be operated as input and output units, wherein when it is operated as the display unit, the touch screen  260  displays image signals outputted from the image processing unit  250  as a screen, and displays user data outputted from the control unit  210 . In addition, when being operated as the input unit, the touch screen  260  may display keys for inputting numeric and character information items, and function keys for setting various functions. 
     In accordance with the present embodiment, the touch screen  260  may display data controlled through the operation of the touch pad in the current mode. 
     The operations for controlling data in the above-mentioned portable terminal using an optical touch pad will be described in detail with reference to  FIGS. 8 and 9 . 
       FIG. 8  is a flowchart showing a process of controlling data using an optical touch pad in a portable terminal in accordance with an embodiment of the present invention, and  FIGS. 9   a  to  9   d  are views for describing the process shown in  FIG. 8 . 
     Referring to  FIGS. 7 and 8 , if the current mode of the portable terminal is the standby mode, the control unit  201  senses this in step  801  and determines the operation of the touch pad  103 . In the standby mode, if the touch movement is produced on the touch pad in a corresponding direction among four directions of up, down, left and right, the control unit  201  senses this in step  802 , and proceeds with step  803 , in which a function to change the background screen displayed on the touch screen  260  to another background screen is executed. 
     In step  803 , the control unit performs control in such a manner that each time a touch movement in a corresponding direction among four directions of up, down, left and right is produced on the touch pad  103 , the images stored in the memory  230  are sequentially displayed. 
       FIG. 9   a  shows that the background screen of the touch screen is changed each time a touch movement in a corresponding direction among four directions of up, down, left and right is produced on the touch screen during the standby mode. 
     In the standby mode, icons may be displayed together with the background screen, wherein since the background layer and the icon layer are separated from each other, it is possible to change the background screen to another background screen in accordance with the operation of the touch pad  103 . 
     If the current mode is the video communication mode, the control unit  210  senses this in step  804 , and determines the operation of the touch pad  103 . If a touch movement in a corresponding direction among the four directions of up, down, left and right is produced on the touch pad  103  in the video communication mode, the control unit  210  senses this in step  805 , and proceeds with step  806 , in which the volume adjusting function or the screen brightness control function is executed. 
     In step  806 , if a touch movement in the up or down direction is produced on the touch pad in accordance with setting, the control unit  210  may execute volume-up or volume-down, and if a touch movement in the left or right direction is produced on the touch pad, the control unit  210  may control the screen brightness in accordance with set values so that the screen is displayed lightly or darkly. Alternatively, if a touch movement in the left or right direction is produced on the touch pad in accordance with setting, the control unit  210  may execute volume-up or volume-down, and if a touch movement in the up or down direction is produced on the touch pad, the control unit  210  may control the screen brightness in accordance with set values so that the screen is displayed lightly or darkly. 
       FIG. 9   b  shows that up/down adjusting of volume is executed each time a touch movement in a corresponding direction among the four directions of up, down, left and right is produced on the touch pad  103  during the video communication mode. 
     In addition,  FIG. 9   c  shows that the screen brightness is controlled each time a touch movement in a corresponding direction among the four directions of up, down, left and right is produced on the touch pad  103  during the video communication mode. 
     If the current mode is the internet mode, the control unit  210  senses this in step  807 , and determines the operation of the touch pad  103 . If a touch movement in a corresponding direction among the four directions of up, down, left and right is produced on the touch pad  103  during the internet mode, the control unit senses this in step  807 , and proceeds with step  809  in which a mouse function is executed. 
     In step  809 , the control unit  110  may perform control in such a manner that an activated banner function is moved or the cursor displayed on the screen is moved to a corresponding position through a touch movement in a corresponding direction among the four directions of up, down, left and right on the touch pad  103 . 
     If the current mode is a specific mode, the control unit  210  senses this in step  810 , and determines the operation of the touch pad  103 . If a touch movement in a corresponding direction among the four directions of up, down, left and right is produced on the touch pad  103  when the specific mode displays data, the control unit senses this in step  811 , and proceeds with step  812 , in which the scroll function for the data in the corresponding direction of the touch movement is executed. 
       FIG. 9   d  shows that image data is scrolled upward or downward when a touch movement in the up or down direction is produced on the touch pad  103  while the image data is being displayed in the specific mode. 
     If a single touch is produced on the touch pad  103  in the specific mode, the control unit  210  senses this in step  813 , and performs a specific set function. 
     The specific function may be a home key function, a back key function or an enter key function. 
     Although it is described by way of an example in the present embodiment that the set specific function is executed when a single touch is produced on the touch pad  103  in the specific mode, the specific mode may include the standby mode, the video communication mode, and the interne mode. 
     In addition, the operations as shown in  FIG. 8  may control the data of the current mode in accordance with the operation of the touch pad  130 , regardless of the position of the portable terminal, i.e. regardless of the transverse or longitudinal mode. 
     The above-described methods according to the present invention can be implemented in hardware, firmware or as software or computer code that can be stored in a recording medium such as a CD ROM, an RAM, a floppy disk, a hard disk, or a magneto-optical disk or computer code downloaded over a network originally stored on a remote recording medium or a non-transitory machine readable medium and to be stored on a local recording medium, so that the methods described herein can be rendered in such software that is stored on the recording medium using a general purpose computer, or a special processor or in programmable or dedicated hardware, such as an ASIC or FPGA. As would be understood in the art, the computer, the processor, microprocessor controller or the programmable hardware include memory components, e.g., RAM, ROM, Flash, etc. that may store or receive software or computer code that when accessed and executed by the computer, processor or hardware implement the processing methods described herein. In addition, it would be recognized that when a general purpose computer accesses code for implementing the processing shown herein, the execution of the code transforms the general purpose computer into a special purpose computer for executing the processing shown herein. 
     While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.