Abstract:
A security display apparatus is provided including an image processor which reverses a normal image to create a reverse image which is a negative of the normal image, and a display unit which displays the normal image and the reverse image. The display apparatus further includes glasses which filter the reverse image such that the reverse image is blocked from a user by the glasses and the normal image is transmitted to the user through the glasses.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Korean Patent Application No. 10-2012-0000059, filed on Jan. 2, 2012 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses consistent with exemplary embodiments relate to a security display apparatus, and more particularly to a security display apparatus which provides a secured image using a display apparatus capable of realizing a three-dimensional image. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, in the use of a display apparatus in a public place, people within a visible distance can see content displayed on a screen, bringing up the issue of invasion of privacy. Infringement of privacy is even more serious in display apparatuses used in public institutions for immigration inspections at airports or for an identity check. 
         [0006]    In this respect, a display apparatus is required to have a secured display function. 
         [0007]    One illustrative example of a display apparatus having a secured display function is an apparatus provided with an encoding/decoding function used to present a secured image. The display apparatus includes a display outputting an encoded image and exclusive glasses decoding the encoded image into a visible image. 
         [0008]    The display apparatus with this configuration enables a user wearing the exclusive glasses to watch the secured image output from the display but presents an unrecognizable image to a user with the naked eye, thereby maintaining security. 
         [0009]    However, such a display apparatus requires an encoding function embedded in the display and include the exclusive glasses having a decoding function, thus complicating the configuration and causing increase in product costs. 
         [0010]    Further, as one illustrative example of a liquid crystal display (LCD) having a secured display function, there is a display apparatus having a structure in which a polarizing plate serving as an analyzer is omitted from a pair of polarizing plates disposed to face each other with an LCD panel interposed therebetween. 
         [0011]    In this case, when watching an image displayed in the display apparatus, a user not wearing polarizing glasses sees a white screen but only a user wearing polarizing glasses serving as an analyzer can watch effective images, thereby maintaining security. 
         [0012]    However, since the display apparatus does not include a polarizing plate for an analyzer, which is an essential component, a user inconveniently must wear the polarizing glasses even to watch images when security is not needed. Further, since the display apparatus involves a modification to a basic structure, such a configuration is not applied to display apparatuses already being used. In addition, the display apparatus allows a user wearing glasses with mere polarizing properties, such as sunglasses, to see content, thus providing lax security. 
       SUMMARY 
       [0013]    Accordingly, one or more exemplary embodiments provide a security display apparatus which is constructed to provide a secured image viewable only by a user wearing glasses with predetermined settings using a display apparatus capable of realizing a 3D image. 
         [0014]    A security display apparatus according to an aspect of an exemplary embodiment permits a user to view a secured image using general glasses without involving a change to essential components or using exclusive glasses with a decoding function. Accordingly, the security display apparatus may have a compact structure and reduced manufacturing costs as compared with a conventional security display apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and/or other exemplary aspects and advantages will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings, in which: 
           [0016]      FIG. 1  is a perspective view schematically illustrating a security display apparatus according to an exemplary embodiment. 
           [0017]      FIG. 2  is a block diagram of the display apparatus of  FIG. 1 . 
           [0018]      FIG. 3  is a flowchart illustrating a process of the security display apparatus realizing a secured image. 
           [0019]      FIGS. 4A to 4C  illustrate a process of realizing a secured image by constructing a normal image and a reverse image in a side-by-side mode among 3D display modes. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0020]    Below, exemplary embodiments will be described in detail with reference to accompanying drawings so as to be easily realized by a person having ordinary knowledge in the art. One of skill in the art would understand that exemplary embodiments may be embodied in various forms without being limited to the embodiments specifically set forth herein. Descriptions of well-known parts are omitted for clarity and conciseness, and like reference numerals refer to like elements throughout. 
         [0021]      FIG. 1  is a perspective view schematically illustrating a security display apparatus according to an exemplary embodiment, and  FIG. 2  is a block diagram of the display apparatus of  FIG. 1 . 
         [0022]    Referring to  FIGS. 1 and 2 , the security display apparatus according to the present embodiment includes a display  100 , capable of realizing a three-dimensional (3D) image, and 3D glasses. In addition, the display apparatus may further include a wireless control device  300 . 
         [0023]    The present embodiment is described with respect to a display apparatus that realizes a 3D image using active shutter glasses as an illustrative example. In this case, shutter glasses  200  are provided as the 3D glasses. 
         [0024]    The display  100  displays a 3D image including a left-eye image and a right-eye image. The display  100  displays left-eye and right-eye images in different spatially frames, and a user wearing the shutter glasses  200  may visually recognize separate images as 3D images by a left shutter  221  and a right shutter  225  opening and closing. 
         [0025]    The display  100  includes an image signal reception unit  110  receiving an image signal from an image source, an image processor  120  processing a received image signal, a display unit  130  displaying an image, and a light receiving and emitting unit  140  receiving and emitting light for a control signal from and to a peripheral device. 
         [0026]    The display  100  may be configured as a portable device which receives a 3D image signal from an image source and displays the signal, e.g., a television, a monitor, and a mobile phone. 
         [0027]    The image processor  120  reverses a normal image input to realize a secured image to generate a reverse image. The reverse image may be generated by any one of an image board, a traffic control board (T-con board) and a logic board, which constitute the image processor  120 , reversing the normal image with respect to a contrast ratio. Here, the input normal image is a two-dimensional (2D) image which is not divided into left-eye and right-eye images, different from in realizing a 3D image. 
         [0028]    Further, the image processor  120  outputs one of a left-eye image and a right-eye image as a normal image and outputs the other thereof as a reverse image. For example, the image processor  120  outputs a left-eye image as the normal image, and a right-eye image as the reverse image. 
         [0029]    The display unit  130  displays an image based on an image signal processed by the image processor  120 . The display unit  130  may include a liquid crystal display (LCD) panel including a liquid crystal layer, an organic light emitting diode (OLED) display including a light emitting layer of an organic material and a plasma display panel (PDP), and a panel driver driving these panels. 
         [0030]    The light receiving and emitting unit  140  generates light for a synchronizing signal and irradiates the light to the shutter glasses  200  so that the left shutter  221  and the right shutter  225  of the shutter glasses  200  open and close in synchronization with an image displayed on the display unit  130 . Also, the light receiving and emitting unit  140  receives light for a control signal from the wireless control device  300 . 
         [0031]    The wireless control device  30  includes a device body  310  and a signal transmission unit  320  installed in the device body  310  and transmitting a control signal to the light receiving and emitting unit  140  of the display  100 . Further, the wireless control device  300  may include a controller  350  controlling the signal transmission unit  320  and a battery unit  360  supplying electric power to the wireless control device  300 . Here, the signal transmission unit  320  may include an infrared transmitter transmitting infrared light to perform infrared communication with the light receiving and emitting unit  140 . 
         [0032]    The shutter glasses  200  include a glasses body  210  and the left and right shutters  221  and  225  installed in the glasses body  210  and opening and closing in synchronization with left-eye and right-eye images displayed on the display  100 . Further, the shutter glasses  200  may further include a mode setting unit  225  to set an image among left-eye and right-eye images for each of the left shutter  221  and the right shutter  225  to synchronize with to open and close. 
         [0033]    Generally, to watch 3D images, the mode setting unit  229  sets the left shutter  221  to synchronize with a left-eye image and the right shutter  225  to synchronize with a right-eye image. In this case, the left shutter  221  is shut when a right-eye image is displayed on the display  100 , and it transmits an image when a left-eye image is displayed. That is, the left shutter  221  blocks a right-eye image and transmits a left-eye image. The right shutter  225  operates in the other way. That is, the right shutter  225  blocks a left-eye image and transmits a right-eye image. 
         [0034]    Further, in order to realize a secured display, the shutter glasses  200  as the 3D glasses filter a reverse image to view a normal image among images displayed on the display unit  130 . To this end, the shutter glasses  200  are set by the mode setting unit  229  so that both the left shutter  221  and the right shutter  25  transmit only an image providing a normal image (left-eye image in  FIG. 4A ). That is, both the left shutter  221  and the right shutter  225  transmit an image when a left-eye image (normal image) is displayed on the display  100 , but they block an image when a right-eye image (reverse image) is displayed. 
         [0035]    The shutter glasses  200  include a light receiving unit  230 , an optical element  240 , and a controller  250  controlling these components, which are installed in the glasses body  210 , in addition to the glasses body  210  and the left and right shutters  221  and  225 . Moreover, the shutter glasses  200  may include a shutter driver  220  driving the left and right shutters  221  and  225  and a battery unit  260 . 
         [0036]    The light receiving unit  230  receives light for a control signal irradiated from the display  100 , converts the light into a control signal, and outputs the signal to the shutter driver  220 . Here, the control signal may be a synchronizing signal for controlling the left and right shutters  221  and  225 . The light receiving unit  230  includes a light receiving element  231  receiving incident light and a light collecting lens  235  collecting light entering the light receiving element  231 . Here, the light receiving element  231  may include an infrared receiver receiving infrared light in a range of 790 to 890 nm. 
         [0037]    The shutter driver  220  performs auto gain control on an input synchronizing signal to drive the left shutter  221  and the right shutter  225 . The shutter driver  220  divides the synchronizing signal, delays divided synchronizing signals, or changes a phase of a signal. The left shutter  221  and the right shutter  225  may be provided as liquid crystal shutter glasses and open and close by drive of the shutter driver  220 . 
         [0038]    Hereinafter, a process of the security display apparatus realizing a secured image is described with reference to the drawings. 
         [0039]    Referring to  FIG. 3 , it is determined whether a secured image mode is realized in the display apparatus capable of realizing a 3D image (S 10 ), and then the image processor  120  generates a reverse image if realizing the secured image mode (S 20 ). Then, the image processor  120  forms a 2D normal image input to the display  100  and the reverse image generated by the image processor  120  as a left-eye image (L image) and a right-eye image (R image), respectively (S 30 ). 
         [0040]    Here, the normal image and the reverse image as the left-eye image and the right-eye image, respectively, may be configured in any one mode of 3D display modes. That is, the normal image and the reverse image may be realized as the left-eye image and the right-eye image in any one mode among a side-by-side mode, a top-and-bottom mode, a checker board mode, and a sequential frame mode. 
         [0041]      FIGS. 4A to 4C  illustrate a process of realizing a secured image by constructing a normal image and a reverse image in a side-by-side mode among 3D display modes. 
         [0042]      FIG. 4A  illustrates an example of an image realized in a side-by-side mode in which the normal image forms a left-eye image and the reverse image forms a right-eye image. When forming a screen in this manner and then driving the display apparatus in a 3D image mode, the normal image and the reverse image expand in a width direction of the display apparatus and are alternately displayed in a time-shared mode. 
         [0043]    In this case, a user wearing 3D glasses with settings for both the left shutter  221  and the right shutter  255  to transmit a left-eye image can see the left-eye image N 1  as shown in  FIG. 4B , thus watching a secured image normally. However, a user not wearing the exclusive glasses or a user wearing 3D glasses with settings for viewing a 3D image sees a gray image P 1  formed by combination of the normal image and the reverse image as shown in  FIG. 4C , thereby preventing the secured image from being disclosed. 
         [0044]    That is, referring to  FIG. 3 , depending on wearing L-exclusive glasses (S 40 ), a user wearing the L-exclusive glasses can watch the normal image (S 50 ), whereas a user not wearing the L-exclusive glasses can watch only a grey screen (S 60 ). 
         [0045]    Although the security display apparatus described with reference to  FIGS. 1 and 2  has been described with the shutter glasses including the mode setting unit  229  as 3D glasses, various changes and modifications of 3D glasses may be provided, without being particularly limited. 
         [0046]    For example, shutter glasses as 3D glasses may include a glasses body and left and right shutters installed in the glasses body and opening and closing in synchronization with an image corresponding to a normal image displayed on the display among the left-eye and right-eye images. That is, the shutter glasses may be configured in a structure in which the left and right shutters transmit a normal image only without use of a mode setting unit. 
         [0047]    Further, the security display apparatus may include polarizing glasses as 3D glasses. In this case, the display unit further includes a polarizing filter allowing the left-eye image and the right-eye image to have different polarizing properties. Here, the polarizing glasses transmit a certain polarized image corresponding to a normal image displayed on the display among the left-eye image and the right-eye image. 
         [0048]    As described above, the security display apparatus according to the present embodiment displays a normal image as one of left-eye and right-eye images and a reverse image as the other thereof, so that only a user wearing 3D glasses enabling both eyes to satisfy requirements for seeing a normal image is allowed to watch a secured image. 
         [0049]    Although a few exemplary embodiments have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the inventive concept, the scope of which is defined in the appended claims and their equivalents.