Patent Publication Number: US-2015062161-A1

Title: Portable device displaying augmented reality image and method of controlling therefor

Description:
This application claims the benefit of the Korean Patent Application No. 10-2013-0102324, filed on Aug. 28, 2013, which is hereby incorporated by reference as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present specification relates to a portable device, and more particularly, to a portable device that an angle of view of a camera unit and an angle of view of a display unit are different from each other. 
     2. Discussion of the Related Art 
     An augmented reality technology of which a real object and a virtual object are mixed together enables a user to see a real image along with an augmented reality image and then provides additional information in addition to a sense of reality. For instance, if a user holds a camera of a smartphone to surroundings, such augmented reality images as a location of a nearby store, a telephone number, and the like are marked as a 3 dimensional image along with a real image. The augmented reality technology can be applied to a wearable computer as well. In particular, such a display put on a head as a head mounted display provides an augmented reality to a user in a manner of overlapping a real environment of which the user currently sees with an augmented reality image, a text, or the like. 
     An augmented reality image is detected by the camera unit and is generated in response to a marker displayed in the display unit. Yet, if an angle of view of the camera unit and that of the display unit are different from each other, the marker detected by the camera unit may not be displayed in the display unit. In this case, a method of processing and displaying the marker and an augmented reality image corresponding to the marker is required. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present specification is directed to an apparatus and method thereof that substantially obviate one or more problems due to limitations and disadvantages of the related art. 
     An object of the present specification is to provide a portable device displaying an augmented reality image and a method of controlling therefor. In particular, it is necessary for the portable device to provide a method of displaying an augmented reality image using a camera unit and a display unit having an angle of view different from each other in the present specification. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a portable device includes a camera unit configured to detect a marker existing within a first angle of view, a display unit configured to display an augmented reality image corresponding to the marker, wherein the display unit is configured to display an area corresponding to a second angle of view and wherein the second angle of view is less than the first angle of view, and a controller configured to control the camera unit and the display unit, if the marker is detected at an angle less than the first angle of view and larger than the second angle of view, the controller configured to display a first part of the augmented reality image corresponding to the marker, wherein the first part corresponds to a part of the augmented reality image positioned within the second angle of view. 
     To achieve these and other advantages and in accordance with the purpose of the present specification, as embodied and broadly described, according to one embodiment, a method of controlling a portable device includes the steps of configuring an angle of view of a camera unit as a first angle of view and an angle of view of a display unit as a second angle of view, wherein the second angle of view is less than the first angle of view, detecting a marker at an angle less than the first angle of view and larger than the second angle of view, and displaying a first part of an augmented reality image corresponding to the marker, wherein the first part corresponds to a part of the augmented reality image positioned within the second angle of view. 
     According to the present specification, a portable device can display an augmented reality image corresponding to a marker before the marker is displayed in a display unit. 
     According to the present specification, a portable device can control a camera unit and a display unit having an angle of view different from each other. 
     According to the present specification, a portable device can indicate a position of a marker corresponding to a not displayed augmented reality image. 
     According to the present specification, a portable device can display a marker detected outside of an angle of view of a display unit. 
     According to the present specification, a portable device can display an augmented reality image in a manner of changing a position of the augmented reality image according to a gaze or a gesture of a user. 
     It is to be understood that both the foregoing general description and the following detailed description of the present specification are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a diagram of a portable device and an angle of view of the portable device according to one embodiment of the present specification; 
         FIG. 2  is a diagram of a method of displaying an augmented reality image of a portable device according to one embodiment of the present specification; 
         FIG. 3  is a diagram of a method of displaying an augmented reality image of a portable device according to a different embodiment of the present specification; 
         FIG. 4  is a diagram of a method of displaying an indicator of a portable device according to one embodiment of the present specification for a marker or an augmented reality image; 
         FIG. 5  is a diagram of a method of moving and displaying an augmented reality image of a portable device according to one embodiment of the present specification; 
         FIG. 6  is a diagram of a method of moving and displaying an augmented reality image of a portable device according to a different embodiment of the present specification; 
         FIG. 7  is a block diagram of a portable device according to one embodiment of the present specification; 
         FIG. 8  is a flowchart for a method of controlling a portable device according to one embodiment of the present specification. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While the embodiments have been concretely described with reference to the attached diagrams and the contents written on the diagrams, a scope of claims may be non-restricted or non-limited to the embodiments. 
     Although terminologies used in the present specification are selected from general terminologies used currently and widely in consideration of functions, they may be changed in accordance with intentions of technicians engaged in the corresponding fields, customs, advents of new technologies and the like. Occasionally, some terminologies may be arbitrarily selected by the applicant(s). In this case, the meanings of the arbitrarily selected terminologies shall be described in the corresponding part of the detailed description of the specification. Therefore, terminologies used in the present specification need to be construed based on the substantial meanings of the corresponding terminologies and the overall matters disclosed in the present specification rather than construed as simple names of the terminologies. 
     In the present specification, a portable device may include a head mounted display, a smartphone, a smart pad, a tablet computer, a notebook, a music player, or a foldable display device. And, an augmented reality image of the present specification may include a graphic image, a text, a symbol, and an emoticon. 
       FIG. 1  is a diagram of a portable device and an angle of view of the portable device according to one embodiment of the present specification. The portable device can include a camera unit and a display unit. The camera unit included in the portable device can have a first angle of view and the display unit can have a second angle of view. 
     In this case, the angle of view of the camera unit may mean an area capable of being detected by an image sensor included in the camera unit. In particular, as the angle of view of the camera unit is wider, an optical image of a wider area can be detected and the optical image of the wider area can be converted to a digital image. And, the angle of view of the display unit may mean an area capable of being displayed in the display unit. For instance, when a camera unit of a smartphone is activated, an area displayed in a display unit of the smartphone can be defined as the angle of view of the display unit. And, when a head mounted display is activated, an area capable of displaying an image within a vision of a user by the head mounted display can be defined as the angle of view of the display unit. 
     In the present specification, the first angle of view of the camera unit and the second angle of view of the display unit may have a figure different from each other. In particular, in the following description, a case that the first angle of view of the camera unit exceeds the second angle of view of the display unit is explained. 
     The top of  FIG. 1  is a diagram of a smartphone, which is an example of the portable device. The portable device  11  can include a camera unit and a display unit  12 . The camera unit can include a first angle of view  13  and can convert an optical image to a digital image. The display unit  12  can include a second angle of view  14  and can display an area corresponding to the second angle of view  14  only among digital images of the first angle of view  13  taken by the camera unit. In particular, the display unit  12  can display a part of the digital images of the first angle of view taken by the camera unit. 
     The portable device  11  can detect a real object  15  within the first angle of view  13  using the camera unit. The real object may mean an actual object existing in a real space. The real object  15  can include a marker  16  of an augmented reality image. The marker  16  included in the real object  15  can be positioned within the first angle of view  13  and can be positioned outside of the second angle of view  14 . Hence, the portable device  11  can detect the marker  16  within the first angle of view  13  using the camera unit. On the contrary, the portable device  11  cannot display the marker  16  using the display unit. This is because the portable device can display the area corresponding to the second angle of view  14  only among the digital images of the first angle of view  13 . Since the marker  16  is positioned at the outside of the second angle of view  14  of the display unit  12 , the portable device  11  cannot display the marker  16  in the display unit  12 . 
     In order for the portable device  11  to display an augmented reality image in the display unit  12 , the marker  16  should be displayed in the display unit  12 . Hence, the portable device displays an image  17  of the real object only and does not display the augmented reality image. 
     The bottom of  FIG. 1  is a diagram of a head mounted display, which is an example of the portable device. The portable device  18  can include a camera unit and a display unit. The display unit of the head mounted display can include a projector projecting an optical image. The camera unit may have a first angle of view  13  and can convert the optical image to a digital image. In case that the portable device corresponds to the head mounted display, the portable device may include two display units for a pair of eyes. The display unit may have a second angle of view  14 . The portable device  18  can project or display a digital image using the second angle of view  14  smaller than the first angle of view  13 , which is detected by the camera unit. In particular, the portable device  18  can display an augmented reality image in a space narrower than a viewing angle of a user or the first angle of view capable of being detected by the camera unit. In other word, the portable device  18  can display an augmented reality image in an area smaller than the area capable of being seen by a user via the head mounted display. 
     The portable device can detect a real object  15  within the first angle of view  13  using the camera unit. The real object  15  can include a marker  16  of an augmented reality image. The marker  16  included in the real object  15  can be positioned within the first angle of view  13  and can be positioned outside of the second angle of view  14 . Hence, the portable device  18  can detect the marker  16  within the first angle of view  13  using the camera unit. On the contrary, the portable device  11  cannot display an augmented reality image in a position of which the marker  16  is detected using the display unit. This is because the portable device can display the augmented reality image in an area corresponding to the second angle of view  14  only among the area of the first angle of view  13 . Since the marker  16  is positioned at the outside of the second angle of view  14  of the display unit, the portable device  11  cannot display the augmented reality image corresponding to the marker  16  in the display unit. 
     In order for the portable device  11  to display an augmented reality image in the display unit, the marker  16  should be positioned at within the second angle of view. Hence, the portable device cannot display the augmented reality image in the display unit. 
       FIG. 2  is a diagram of a method of displaying an augmented reality image of a portable device according to one embodiment of the present specification. The portable device can include a camera unit and a display unit. The camera unit included in the portable device can have a first angle of view and the display unit can have a second angle of view. 
     In this case, the angle of view of the camera unit may mean an area capable of being detected by an image sensor included in the camera unit. In particular, as the angle of view of the camera unit is wider, an optical image of a wider area can be detected and the optical image of the wider area can be converted to a digital image. And, the angle of view of the display unit may mean an area capable of being displayed in the display unit. For instance, when a camera unit of a smartphone is activated, an area displayed in a display unit of the smartphone can be defined as the angle of view of the display unit. And, when a head mounted display is activated, an area capable of displaying an image within a vision of a user by the head mounted display can be defined as the angle of view of the display unit. 
     In the present specification, the first angle of view of the camera unit and the second angle of view of the display unit may have a figure different from each other. In particular, in the following description, a case that the first angle of view of the camera unit exceeds the second angle of view of the display unit is explained. 
     The top of  FIG. 2  is a diagram of a smartphone, which is an example of the portable device. The portable device  11  can include a camera unit and a display unit  12 . The camera unit can include a first angle of view  13  and can convert an optical image to a digital image. The display unit  12  can include a second angle of view  14  and can display an area corresponding to the second angle of view  14  only among digital images of the first angle of view  13  taken by the camera unit. In particular, the display unit  12  can display a part of the digital images of the first angle of view taken by the camera unit. 
     The portable device  11  can detect a real object  15  within the first angle of view  13  using the camera unit. The real object  15  can include a marker  16  of an augmented reality image. The marker  16  included in the real object  15  can be positioned within the first angle of view  13  and the second angle of view  14 . Hence, the portable device  11  detects the marker  16  within the first angle of view  13  using the camera unit and can display the marker  16  using the display unit. Since the marker is included within the second angle of view, the portable device can display an area corresponding to the second angle of view  14 . 
     The portable device  11  can display an augmented reality image  21  in response to the marker displayed in the display unit  12 . Although a user cannot see the augmented reality image  21  with the naked eye, the user can check the augmented reality image  21  via the display unit  12 . 
     The bottom of  FIG. 2  is a diagram of a head mounted display, which is an example of the portable device. The portable device  18  can include a camera unit and a display unit. The camera unit may have a first angle of view  13  and can convert the optical image to a digital image. In case that the portable device corresponds to the head mounted display, the portable device may include two display units for a pair of eyes. The display unit of the head mounted display can include a projector projecting an optical image. The display unit may have a second angle of view  14 . The portable device  18  can project or display a digital image using the second angle of view  14  smaller than the first angle of view  13 , which is detected by the camera unit. In particular, the portable device  18  can display an augmented reality image  21  in a space narrower than a viewing angle of a user or the first angle of view capable of being detected by the camera unit. In other word, the portable device  18  can display an augmented reality image in an area smaller than the area capable of being seen by a user via the head mounted display. 
     The portable device can detect a real object  15  within the first angle of view  13  using the camera unit. The real object  15  can include a marker  16  of an augmented reality image. The marker  16  included in the real object  15  can be positioned within the first angle of view  13  and the second angle of view  14 . Hence, the portable device  18  can detect the marker  16  within the first angle of view  13  using the camera unit. And, the portable device can display the augmented reality image  21  in the position of which the marker is detected using the display unit. The portable device can display the augmented reality image in the area included in the second angle of view  14  since the marker is positioned at within the second angle of view  14 . Since the marker  16  is positioned at within the second angle of view  14 , the portable device  11  can display the augmented reality image  21  corresponding to the marker  16  in the display unit. 
     The portable device  18  can display the augmented reality image  21  in response to the marker detected by the camera unit. Although a user cannot see the augmented reality image  21  with the naked eye, the user can check the augmented reality image  21  via the display unit of the portable device  18 . 
       FIG. 3  is a diagram of a method of displaying an augmented reality image of a portable device according to a different embodiment of the present specification. Before a marker enters into a second angle of view of the display unit, the portable device can display an augmented reality image corresponding to the marker. The portable device can detect the marker using a camera unit having a first angle of view wider than the second angle of view of the display unit. Hence, if the marker is positioned at within the first angle of view and is positioned at the outside of the second angle of view, the portable device can display the augmented reality image corresponding to the marker. The augmented reality image displayed in the portable device may correspond to at least a part of the augmented reality images included in the second angle of view. In the following description, although a smartphone is explained as an example, the following explanation can be applied to such various portable devices as a smart pad, a head mounted display, and the like. 
     The portable device  11  can include a camera unit and a display unit  12 . The camera unit can include a first angle of view  13  and can convert an optical image to a digital image. The display unit  12  can include a second angle of view  14  and can display an area corresponding to the second angle of view  14  only among digital images of the first angle of view  13  taken by the camera unit. In particular, the display unit  12  can display a part of the digital images of the first angle of view taken by the camera unit. 
     The portable device  11  can detect a real object  15  within the first angle of view  13  using the camera unit. The real object  15  can include a marker  16  of an augmented reality image. The marker  16  included in the real object  15  can be positioned within the first angle of view  13  and can be positioned outside of the second angle of view  14 . Hence, the portable device  11  can detect the marker  16  within the first angle of view  13  using the camera unit. On the contrary, the portable device  11  cannot display the marker  16  using the display unit. This is because the portable device can display the area corresponding to the second angle of view  14  only among the digital images of the first angle of view  13 . Since the marker  16  is positioned at the outside of the second angle of view  14  of the display unit  12 , the portable device  11  cannot display the marker  16  in the display unit  12   
     The portable device  11  can display an augmented reality image  21  before the detected marker is displayed in the display unit  12 . If the marker is detected within the first angle of view and the outside of the second angle of view by the camera unit, the portable device  11  can display the augmented reality image  21  corresponding to the detected marker. 
     A position of the augmented reality image  21  is determined based on a position of the marker. Referring to  FIG. 3 , since the marker  16  is positioned at the outside of the second angle of view, the augmented reality image  21  can be positioned at the outside of the second angle of view. Yet, in some cases, a part of the augmented reality image  21  can exist within the second angle of view according to a size of the augmented reality image. In particular, in case that the marker  16  is detected at the outside of the second angle of view, if at least a part of the augmented reality image  21  corresponding to the marker  16  is included within the second angle of view, the portable device can display the augmented reality image  21 . In this case, the displayed augmented reality image  21  may correspond to a part of the augmented reality image  21  included within the second angle of view. 
     As depicted in  FIG. 3 , if a part of the augmented reality image  21  is displayed, the portable device can count down a first timer. If the first timer ends, the portable device can eliminate a part of the augmented reality image  21  displayed in the display unit from the display unit. And, the portable device can display a part of the augmented reality image in a manner of gradually fading out while the first timer operates. If the marker positioned at the outside of the second angle of view enters into the inside of the second angle of view, the portable device can reset or hold the first timer. 
       FIG. 4  is a diagram of a method of displaying an indicator of a portable device according to one embodiment of the present specification for a marker or an augmented reality image. As mentioned earlier in  FIG. 2  and  FIG. 3 , the portable device can detect a marker within a first angle of view. If the detected marker deviates from the first angle of view, the portable device can eliminate an augmented reality image corresponding to the marker from a display unit. 
     If the detected marker deviates to the outside of the first angle of view, the portable device can display an indicator for the augmented reality image corresponding to the marker. The indicator can include a graphic image or a text indicating at least one selected from the group consisting of a position, a type, a direction, a distance, an angle, and an importance of the marker. When the marker is detected within the first angle of view, if at least a part of the augmented reality image corresponding to the marker is not positioned within a second angle of view, the portable device can display an indicator of the augmented reality image. The indicator can include a graphic image or a text indicating at least one selected from the group consisting of a position, a type, a direction, a distance, an angle, and an importance of the augmented reality image. 
     The portable device  11  can detect that the detected marker  16  moves to the outside of the first angle of view  13  of the camera unit. The portable device  11  can display the indicator  41  indicating a position of the marker in the display unit  12 . By doing so, a user can know a direction to which the portable device should be moved to detect the marker  16  using the indicator  41 . 
     The portable device  11  can detect how much the marker has moved to the outside of the first angle of view  13 . After the marker  16  is disappeared from the outside of the first angle of view  13 , the portable device  11  can calculate a moving path, a rotation angle, and the like of the portable device  11 . The portable device can determine how far the marker is away from the first angle of view using a calculation result. The portable device  11  can display the indicator according to the position of the marker  16 . For instance, if an arrow is used as the indicator, the portable device  11  displays the arrow in a manner that the arrow indicates a direction at which the marker  16  is positioned. The portable device can display the arrow in a manner of changing a length of the arrow according to a distance to the marker  16 . 
     The portable device  11  can determine whether the indicator is displayed according to the position of the marker  16 . If the marker  16  is separated from the portable device more than a first angle or a first distance, the indicator may not be displayed any more by the portable device  11 . If the marker moves more than the first angle or the first distance, the portable device  11  judges that a user does not have an intention to use the corresponding marker again and the indicator for the marker may not be displayed by the portable device. 
     As a different embodiment, the portable device  11  can detect that no part of the augmented reality image corresponding to the marker  16  detected within the first angle of view is positioned within the second angle of view. The portable device  11  can display the indicator  41  indicating the position of the augmented reality image in the display unit  12 . By doing so, a user can know a direction to which the portable device should be moved to display the augmented reality image using the indicator  41 . 
     The portable device  11  can detect how far the augmented reality image is away from the second angle of view  14 . The portable device  11  can calculate a position of the marker  16  and a first position of the augmented reality image corresponding to the marker. The first position of the augmented reality image may mean a position of the augmented reality image in a real space. The portable device can determine the position and direction of the augmented reality image based on the first position and a position in which the display unit displays. The portable device  11  can display the indicator according to the position and the direction of the augmented reality image. For instance, if an arrow is used as the indicator, the portable device  11  displays the arrow in a manner that the arrow indicates a direction at which the augmented reality image is positioned. The portable device can display the arrow in a manner of changing a length of the arrow according to a distance to the augmented reality image. 
     The portable device  11  can determine whether the indicator is displayed according to the position of the augmented reality image. If the augmented reality image is separated from the portable device more than a second angle or a second distance, the indicator may not be displayed any more by the portable device  11 . If the augmented reality image is positioned away from the portable device more than the second angle or the second distance, the portable device  11  judges that a user does not have an intention to use the corresponding augmented reality image and the indicator for the augmented reality image may not be displayed by the portable device. 
       FIG. 5  is a diagram of a method of moving and displaying an augmented reality image of a portable device according to one embodiment of the present specification. A position of an augmented reality image can be determined according to a position of a marker positioned at a real space. The augmented reality image is assigned to a constant first position if the marker does not move. If the display unit or the camera unit of the portable device faces the first position, the augmented reality image can be displayed in the portable device. The portable device of the present specification can display the augmented reality image assigned to the first position in a manner of moving the augmented reality image to a second position. 
     The left diagram of  FIG. 5  is a diagram of the portable device displaying a part of an augmented reality image  21 . The portable device  11  can include a camera unit having a first angle of view  13  and a display unit having a second angle of view  14 . The portable device  11  can detect a marker  16  within the first angle of view. If the marker  16  is detected at the outside of the second angle of view  14 , the marker is not displayed in the display unit. Yet, if at least a part of the augmented reality image  21  corresponding to the marker is included within the second angle of view, the portable device  11  can display the part of the augmented reality image. 
     Since the marker  16  is positioned at the outside of the second angle of view  14 , the portable device can display a part of the augmented reality image  21 . As depicted in the right of  FIG. 5 , the portable device can display the augmented reality image  21 , which is displayed in part, in a manner of moving the augmented reality image to a center part of the display area. By doing so, the portable device  11  can display a whole image of the augmented reality image  21 . 
     The portable device  11  can move a position of the displayed augmented reality image by detecting a touch input or a gesture of a user. The portable device can further include a sensor unit configured to detect the touch input or the gesture of the user. As depicted in the left of  FIG. 5 , the portable device can detect a touch input or a gesture input pointing the displayed part of the augmented reality image. The portable device can configure the pointed augmented reality image  21  as an interested object. The portable device  11  can move the position of the augmented reality image  21  configured as the interested object according to the touch input touching and dragging the augmented reality image  21 . A user selects the augmented reality image  21 , which is displayed in part, and then drags it to a center area of the display unit. By doing so, the user can check a whole image of the augmented reality image  21 . As mentioned in the foregoing description, the portable device can move the augmented reality image  21  assigned to the first position of the real space and display the augmented reality image. By doing so, the portable device can display the whole image of the augmented reality image  21 , which is displayed in part. 
     The portable device  11  can display the marker  16  corresponding to the augmented reality image  21 . Referring to the left of  FIG. 5 , since the marker  16  is positioned at the outside of the second angle of view  14 , the marker cannot be displayed in the display unit. Yet, the portable device  11  can display a copied image  51  of the marker detected by the camera unit in a manner of moving the copied image of the marker to the display unit. In particular, the portable device  11  can display the copied image  51  of the marker in a manner of moving the copied image of the marker from the external of the display area to the center part of the display area similar to displaying the augmented reality image  21  in a manner of moving the augmented reality image to the center part of the display unit. By doing so, the portable device can display the copied image  51  of the marker corresponding to the augmented reality image  21 . 
     In displaying the copied image of the marker in a manner of moving the copied image of the marker to the display unit, the portable device can use a time condition. In case that the marker is detected within the first angle of view and the outside of the second angle of view for more than a first time, the portable device can display an image  51  of the detected marker in the display unit. The portable device can further display the augmented realty image corresponding to the displayed marker. 
       FIG. 6  is a diagram of a method of moving and displaying an augmented reality image of a portable device according to a different embodiment of the present specification. The augmented reality image can be assigned to a first position in a real space according to a position of a corresponding marker. The first position to which the augmented reality image is assigned can be maintained without being changed although the portable device or a gaze of a user moves. Yet, the portable device of the present specification recognizes the gaze of the user and can move a position of the augmented reality image at which the user gazes. The portable device can include a gaze recognition camera. The portable device can detect a direction or an object at which the user gazes using the gaze recognition camera. The portable device can configure the object at which the user gazes as an interested object and can display the interested object in a manner of moving to the center of the display area. 
     Referring to the top of  FIG. 6 , the portable device  18  can include a camera unit and a display unit. The camera unit may have a first angle of view  13  and can convert an optical image to a digital image. The display unit may have a second angle of view  14  and can display an augmented reality image in an area corresponding to the second angle of view  14  among the area capable of being gazed by a user via the portable device. 
     The portable device  18  can detect a real object  15  within the first angle of view using the camera unit. The real object  15  can include a marker of the augmented reality image. The marker  16  included in the real object  15  is positioned within the first angle of view  13  and can be positioned at the outside of the second angle of view  14 . Hence, the portable device  18  can detect the marker  16  within the first angle of view  13  using the camera unit. 
     The portable device  18  can display an augmented reality image  21  corresponding to the detected marker  16 . A position of the augmented reality image  21  corresponding to the marker can be determined based on a position of the marker. Referring to the top of  FIG. 6 , since the marker  16  is positioned at the outside of the second angle of view, the augmented reality image  21  can be positioned at the outside of the second angle of view. Yet, in some cases, a part of the augmented reality image  21  can exist within the second angle of view  14  according to a size of the augmented reality image. In particular, a part of the augmented reality image  21  exists within the second angle of view  14  and a different part of the augmented reality image can exist outside of the second angle of view  14 . Hence, in case that the marker  16  is detected at the outside of the second angle of view, if at least a part of the augmented reality image  21  corresponding to the marker  16  is included in the inside of the second angle of view, the portable device can display the augmented reality image  21 . In this case, the displayed augmented reality image  21  may correspond to a part of the augmented reality image  21  included in the inside of the second angle of view. Consequently, although the marker  16  is detected at the outside of the second angle of view  14 , if the augmented reality image  21  corresponding to the marker  16  exists in the inside and the outside of the second angle of view  14 , the portable device can display a part of the augmented reality image  21  positioned within the second angle of view  14 . 
     Since the area capable of displaying the augmented reality image  21  displayed by the portable device  18  is limited to the inside of the second angle of view  14 , referring to the top of  FIG. 6 , the portable device  18  can display a part of the augmented reality image  21  included in the inside of the second angle of view  14  only. Hence, a user can check a part of the augmented reality image  21  only by a vision. 
     As depicted in the top of  FIG. 6 , if the augmented reality image  21  corresponding to the marker  16  exists in the inside and the outside of the second angle of view  14  although the marker  16  is detected at the outside of the second angle of view  14 , the portable device can display a part of the augmented reality image positioned at the inside of the second angle of view  14  only among the augmented reality image  21 . The portable device  18  can display a position of the augmented reality image  21  in a manner of moving the position of the augmented reality image based on a position of a gaze of a user  61 . If the gaze of the user  61  gazes at the augmented reality image  21 , which is displayed in part, the portable device  18  can move the augmented reality image to the inside of the second angle of view  14  as depicted in the bottom of  FIG. 6 . 
     The portable device can include a sensor unit configured to detect a gaze of a user. If the user gazes at the augmented reality image  21 , which is displayed in part, the portable device  18  can move a position of the augmented reality image to provide a whole image of the augmented reality image  21  to the user. Although the augmented reality image  21  is assigned to a first position based on a position of the marker  16 , the portable device can display the augmented reality image  21  in a manner of moving the augmented reality image from the first position to a second position for a convenience of the user. In this case, the second position may correspond to a center area of the display area of the portable device  18  or an area included in the inside of the second angle of view. Or, the second position may correspond to a position capable of minimizing a moving distance of the augmented reality image  21  and displaying a whole image of the augmented reality image  21 . 
     The portable device  18  can move the augmented reality image  21  to the second position only when the user gazes at the augmented reality image  21 , which is displayed in part, for more than a first time. 
     If the gaze of the user deviates from the augmented reality image displayed in the second position, the portable device  18  can eliminate the displayed augmented reality image. 
       FIG. 7  is a block diagram of a portable device according to one embodiment of the present specification. The portable device can include a display unit  101 , a camera unit  102 , and a controller  103 . 
     The display unit  101  can display at least one of a marker and an augmented reality image corresponding to the marker. The display unit  101  can display an image of a real object detected by the camera unit. The real object can include the marker. The display unit can display the augmented reality image corresponding to the marker in a manner of adding to the image of the real object. If the portable device corresponds to a head mounted display, the real object image may not be displayed. If the portable device corresponds to the head mounted display, the portable device can display the augmented reality image in an object of a real world of which a user sees via a see-through glass. The display unit may have a second angle of view and can display an image included in the second angle of view among the images generated by the camera unit. 
     According to embodiment, the display unit  101  can include at least one selected from the group consisting of an organic light-emitting diode (OLED), a liquid crystal display (LCD), an E-ink, a projector, and a flexible display. 
     The camera unit  102  is configured to take a picture of surroundings of the portable device and can generate an image of a real object with the captured surroundings. The image of the real object can include a marker. The camera unit  102  detects the marker included in the image of the real object and can deliver the marker to the controller. If the image of the real object includes a plurality of markers, the camera unit  102  detects a plurality of the markers and can deliver information on a plurality of the markers to the controller. The camera unit  102  may have a first angle of view and can generate the image of the real object included in the first angle of view. 
     Although it is not depicted in  FIG. 7 , the portable device can further include a storage unit. The portable device can store at least one of the marker and the augmented reality image corresponding to the marker, which is detected at an angle less than the first angle of view and larger than the second angle of view, in the storage unit. The portable device can display at least one of the marker and the augmented reality image in a manner of loading at least one of the stored marker and the stored augmented reality image even in a situation that the marker is not detected. The storage unit may not be included in the portable device according to embodiment. 
     Although it is not depicted in  FIG. 7 , the portable device can further include a sensor unit configured to recognize a gaze of a user. The portable device can determine whether the user gazes at a displayed augmented reality image using the sensor unit. And, the sensor unit can further detect a touch input or a gesture input of a user. The portable device detects a user input pointing a part of the augmented reality image using the sensor unit and can deliver information on the user input to the controller. The sensor unit may not be included in the portable device according to embodiment. 
     The controller  103  can control the display unit  101  and the camera unit  102  using the information delivered from the camera unit  102 . The controller  103  can detects a marker in an image displayed in the display unit  101  or in a digital image generated by the camera unit  102 . 
     If a marker is detected, the controller  103  can display an augmented reality image corresponding to the marker in addition to a real object image. As mentioned earlier in  FIG. 3 , if a marker is detected within the first angle of view and the outside of the second angle of view, the controller  103  can display an augmented reality image as well. In particular, the controller  103  can display the augmented reality image corresponding to the marker even in a case that the marker does not enter the second angle of view of the display unit yet and the marker is not displayed in the display unit. In this case, the controller  103  can display a part included in the second angle of view of the display unit  101  among the augmented reality images. 
     The controller  103  can move the augmented reality image displayed in part. As mentioned earlier in  FIG. 5  and  FIG. 6 , if an augmented reality image is displayed in the edge of the display unit, the controller  103  can display the augmented reality image in a center part of the display area in a manner of moving a position of the augmented reality image. By doing so, the portable device can enhance visibility of the augmented reality image and can display a whole area of the augmented reality image displayed in part. The controller  103  can move the augmented reality image in a manner of detecting a touch input, a gesture input, or a gaze input of a user. 
       FIG. 7  is a block diagram according to one embodiment. Blocks represented as being separated are depicted for elements of the portable device in a manner of being logically distinguished. Thus, the aforementioned elements of the portable device may be equipped with a single chip or a plurality of chips according to a design of the portable device. 
       FIG. 8  is a flowchart for a method of controlling a portable device according to one embodiment of the present specification. The portable device can set an angle of view of the camera unit and an angle of view of the display unit to a first angle of view and a second angle of view, respectively [S 10 ]. As mentioned earlier in  FIG. 1 , the camera unit of the portable device may have a first angle of view. The camera unit can detect a real object positioned within the first angle of view and a marker included in the real object. The portable device can convert an optical image sensed within the first angle of view to a digital image using the camera unit and can deliver information on the digital image to the controller. The display unit can display an area corresponding to an inside of the second angle of view among the digital images generated by the camera unit. In this case, the second angle of view may be less than the first angle of view. In particular, for a digital image of the first angle of view taken by the camera unit, the display unit can display an area corresponding to the second angle of view, which is a part of the first angle of view. If the portable device corresponds to a head mounted display, a part of the digital image captured by the camera unit may not be displayed. 
     The portable device can detect a marker [S 20 ]. As mentioned earlier in  FIG. 1  to  FIG. 3 , the portable device can detect the marker positioned within the first angle of view using the camera unit. The marker may correspond to an augmented reality image. 
     The portable device can determine whether the marker is positioned within the second angle of view of the display unit [S 30 ]. The portable device can determine whether a position of the marker detected within the first angle of view is the inside of the second angle of view. The second angle of view is an angle of view of the display unit. If the marker is positioned within the second angle of view, the portable device can display an image of the marker in the display unit. 
     The portable device can display an augmented reality image corresponding to the marker [S 40 ]. If the marker is positioned within the second angle of view of the display unit, the portable device can display an image of the marker. The portable device can display the augmented reality image corresponding to the marker. The portable device can display a whole area of the augmented reality image corresponding to the marker. 
     The portable device can determine whether a part of the augmented reality image is positioned within the second angle of view [S 50 ]. As mentioned earlier in  FIG. 3 , if the marker is positioned at the outside of the second angle of view of the display unit, the portable device cannot display the image of the marker. Although the portable device has detected the marker within the first angle of view, the image of the marker is not displayed in the display unit. The portable device can determine a first position of the augmented reality image corresponding to the marker. The first position of the augmented reality image may mean a position in a real space. The portable device can determine whether at least a part of the augmented reality image positioned at the first position is positioned within the second angle of view. 
     The portable device can display a part of the augmented reality image included within the second angle of view [S 60 ]. As mentioned earlier in  FIG. 3 , if a part of the augmented reality image is positioned within the second angle of view of the display unit, the portable device can display the augmented reality image. In this case, the displayed augmented reality image may correspond to a part of the augmented reality image positioned within the second angle of view. In particular, the portable device can display the augmented reality image included within the second angle of view of the display unit in advance before the marker is displayed in the display unit. By doing so, a user can know a direction at which the augmented reality image is positioned and a direction to which the portable device should be moved to see a whole area of the augmented reality image. 
     If no part of the augmented reality image is positioned within the second angle of view of the display unit, the portable device cannot display the augmented reality image. In particular, if the whole area of the augmented reality image is positioned at the outside of the second angle of view, the portable device cannot display the augmented reality image. Yet, as mentioned earlier in  FIG. 4 , if the marker is detected in the first angle of view and no part of the augmented reality image is included in the second angle of view, the portable device can display an indicator indicating a property of the augmented reality image. 
     As mentioned in the foregoing description, the portable device of the present specification can display the augmented reality image corresponding to the marker even in a situation that the marker is detected at the outside of the second angle of view of the display unit. The portable device can display the augmented reality image corresponding to the marker before the marker is displayed as well. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present specification without departing from the spirit or scope of the inventions. Thus, it is intended that the present specification covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.