Abstract:
A 3D image display device includes a display panel, a barrier, a controller, and a barrier driver. The barrier includes: a first substrate; a plurality of first electrodes disposed on the first substrate and extended in a first direction; a plurality of second electrodes respectively disposed between adjacent first electrodes; a second substrate opposing the first substrate; a plurality of third electrodes disposed on the second substrate and extended in a second direction crossing the first direction; a plurality of fourth electrodes respectively disposed between adjacent third electrodes; and a liquid crystal layer disposed between the first and second substrates. The barrier driver receives a barrier control signal from the controller, and applies a reference voltage to the first electrodes, the second electrodes, the third electrodes, and/or the fourth electrodes, and applies a liquid crystal driving voltage to one or more other ones of the first to fourth electrodes.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2005-0018210 filed on Mar. 4, 2005 in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a barrier device and a 3D image display device using the same for displaying a 3D image by using binocular disparity. More particularly, the present invention relates to a barrier device and a 3D image display device using the same, which are able to change barrier shape. 
     2. Description of the Related Art 
     In general, people perceive a stereoscopic effect physiologically and experientially. In three-dimensional image display technology, a stereoscopic effect of an object is produced by using binocular parallax, which is a primary factor in recognizing a stereoscopic effect at a short distance. Stereoscopic images are viewed by a stereoscopic method that involves wearing of spectacles or by an autostereoscopic method that does not involve wearing of spectacles. 
     The stereoscopic method is classified into an anaglyph method that involves wearing of spectacles having blue and red lenses on respective sides, a polarization method that involves wearing of polarizing spectacles having different polarization directions, and a time-division method that involves wearing of spectacles including an electronic shutter synchronized with intervals by which a frame is repeated time-divisionally. As such, each stereoscopy method requires the inconvenience of wearing the spectacles, and causes difficulty of viewing objects other than the stereoscopic image. Accordingly, the autostereoscopic method that does not involve wearing of spectacles has been actively developed. 
     The typical autostereoscopy methods generally obtain a stereoscopic effect by separating left-eye and right-eye images using a barrier. 
     In the barrier, opaque regions and transparent regions are repeatedly arranged, and an image display panel is formed of pixels corresponding to a right eye, and pixels corresponding to a left eye. 
     An observer sees an image displayed on the image display panel through the transparent regions of the barrier. Here, the left eye and the right eye of the observer respectively see different regions of the image display panel, even though the image may pass through the same transparent region. 
     There are two types of arrangements for the opaque regions and the transparent regions of the barrier. They are a stripe type arrangement and a zigzag type arrangement. In the stripe type barrier, the opaque regions and the transparent regions, which are extended in one direction, are formed alternately. The stripe type barrier has disadvantages in that a horizontal resolution is at most half of a vertical resolution, and a displayed image gives a burden to the observer&#39;s eyes because a vertical stripe pattern appears in the displayed image. Recently, display devices capable of rotating its screen between a vertically long portrait screen mode and a horizontally long landscape screen mode have been developed. Specifically, the landscape screen mode is typically used for playing games, watching TV or motion pictures, and using the screen to see wide pictures captured by a built-in digital camera. However, the barrier is manufactured to be suitable for only one of the portrait and landscape modes. Therefore, the 3D images are not available on a screen of the landscape mode when a barrier for the portrait mode is combined with the display device. 
     To solve this problem, a zigzag type barrier, in which the opaque regions and the transparent regions are arranged in the zigzag shape, has been developed. 
     However, the zigzag type barrier has a drawback of a narrow viewing angle whereas it has improved horizontal resolution. Also, though it may be available for both of the portrait mode screen and the landscape mode screen, when the screen is changed to the landscape mode while the display mode of the barrier is fixed, a 3D image may not be displayed correctly depending on the position of left eye pixels and right eye pixels of the display panel, and the position of opaque regions and transparent regions of the barrier. 
     For those reasons, it has been difficult to popularize the 3D image display device. Accordingly, it is highly desirable to develop a barrier that is adaptive to display 3D images in various schemes. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention is to provide barrier devices, 3D image display devices, and driving methods thereof. 
     The barrier devices, the 3D image display devices, and the driving method thereof according to the exemplary embodiments of the present invention have a feature in that a pattern of a barrier can be changed according to the user&#39;s choice. 
     An exemplary 3D image display device according to an embodiment of the present invention includes a display panel, a barrier, a controller, and a barrier driver. 
     The display panel displays an image corresponding to an input video signal. 
     The barrier is arranged in correspondence to the display panel. The barrier includes: a first substrate; a plurality of first electrodes disposed on the first substrate and extended in a first direction; a plurality of second electrodes respectively disposed between adjacent ones of the first electrodes on the first substrate; a second substrate opposing the first substrate; a plurality of third electrodes disposed on the second substrate and extended in a second direction crossing the first direction; a plurality of fourth electrodes respectively disposed between adjacent ones of the third electrodes on the second substrate; and a liquid crystal layer disposed between the first substrate and the second substrate. 
     The controller generates a barrier control signal for determining a pattern of the barrier. 
     The barrier driver applies, based on the barrier control signal, a reference voltage to the first electrodes, the second electrodes, the third electrodes, and/or the fourth electrodes, and applies a liquid crystal driving voltage to the first electrodes, the second electrodes, the third electrodes and/or the fourth electrodes to which the reference voltage is not applied. 
     The barrier control signal may determine the pattern of the barrier to be a stripe shape or a zigzag shape. 
     The barrier driver, in response to the barrier control signal for the stripe shape, may apply the reference voltage to the first electrodes and the second electrodes, and may apply the liquid crystal driving voltage to the third electrodes or the fourth electrodes. 
     The barrier driver, in response to the barrier control signal for the zigzag shape, may apply the reference voltage to the first electrodes and the third electrodes, and may apply the liquid crystal driving voltage to the second electrodes and the fourth electrodes. 
     The reference voltage may be a ground voltage, and the liquid crystal driving voltage may be an alternating voltage between a positive voltage and a negative voltage with a predetermined frequency. 
     The display panel may be convertible between a portrait mode and a landscape mode, and the barrier control signal may be determined with reference to the modes in which the display panel is being driven. 
     An exemplary barrier device according to another embodiment of the present invention is used for a 3D image display panel for displaying a 3D image by using a binocular disparity. 
     The barrier device includes a barrier, a barrier driver, and a controller. 
     The barrier includes: a first substrate on which a plurality of first electrodes and a plurality of second electrodes are disposed; a second substrate on which a plurality of third electrodes and a plurality of fourth electrodes are disposed; and a liquid crystal layer disposed between the first substrate and the second substrate. 
     The barrier driver applies a first driving voltage to the first electrodes, the second electrodes, the third electrodes, and/or the fourth electrodes, and applies a second driving voltage to the first electrodes, the second electrodes, the third electrodes, and/or the fourth electrodes to which the first driving voltage is not applied. 
     The controller generates a barrier control signal for determining a pattern of the barrier and transmits the barrier control signal to the barrier driver. 
     An exemplary driving method for a 3D image display device according to a further embodiment of the present invention includes steps a), b), c), and d) below. 
     Here, the barrier includes a first substrate and a second substrate. 
     On the first substrate, a plurality of first electrodes are disposed, the first electrodes being extended in a first direction and being apart from each other by a predetermined gap, and a plurality of second electrodes are respectively disposed between adjacent ones of the first electrodes. 
     On the second substrate, a plurality of third electrodes are disposed, the third electrodes being extended in a second direction crossing the first direction and being apart from each other by a predetermined gap, and a plurality of fourth electrode are respectively disposed between adjacent ones of the third electrodes. 
     In the a), a first driving voltage is applied to the first electrodes and the second electrodes, while a second driving voltage is concurrently applied to the third electrodes or the fourth electrodes. 
     In the b), an image corresponding to the video signal is displayed on the display panel. 
     In the c), the first driving voltage is applied to the first electrodes and the third electrodes, while the second driving voltage is concurrently applied to the second electrodes and the fourth electrodes. 
     In the d), an image corresponding to the video signal is displayed on the display panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a block diagram of a 3D image display device according to an exemplary embodiment of the present invention. 
         FIG. 2  illustrates a cross-sectional view of a barrier according to a first exemplary embodiment of the present invention. 
         FIG. 3A  illustrates a structure of electrodes formed on a first substrate. 
         FIG. 3B  illustrates a structure of electrodes formed on a second substrate. 
         FIG. 4A  and  FIG. 4B  show that a voltage is applied to each electrode of the barrier according to the first exemplary embodiment of the present invention. 
         FIG. 4C  illustrates a barrier driven in a stripe shape according to the first exemplary embodiment of the present invention. 
         FIG. 5A  and  FIG. 5B  show that a voltage is applied to each electrode of the barrier according to the first exemplary embodiment of the present invention. 
         FIG. 5C  illustrates a barrier driven in a zigzag shape according to the first exemplary embodiment of the present invention. 
         FIG. 6  shows a barrier driven in a stripe shape according to the second exemplary embodiment of the present invention. 
         FIG. 7  shows a barrier driven in a zigzag shape according to the second exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Certain exemplary embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings. 
     In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
       FIG. 1  shows a block diagram of a 3D image display device according to an exemplary embodiment of the present invention. 
     The 3D image display device includes a controller  100 , a barrier driver  200 , a barrier  300 , a display panel driver  400 , and a display panel  500 . 
     The controller  100  generates a barrier control signal and a display panel control signal and respectively transmits them to the barrier driver  200  and the display panel driver  400  after receiving an image signal (R, G, and B data), a horizontal synchronization signal (H_sync), and a vertical synchronization signal (V_sync). 
     The display panel driver  400  drives the display panel  500  using the control signal received from the controller  100 . In further detail, the display panel driver  400  drives the display panel  500  so as to normally display the inputted image signal (R, G, and B data) on the display panel  500 . Any suitable image display panel may be used as the display panel  500 . In more detail, the display panel  500  is capable of displaying a 3D image by dividing a left eye image and a right eye image corresponding to the input 3D image signal (R, G, and B data). As the display panel  500 , any suitable one of various display panels can be used, for example, a liquid crystal display panel, a plasma display panel, and a light emitting display panel, etc. 
     The barrier driver  200  drives the barrier  300  using the control signal received from the controller  100 . In more detail, the barrier driver  200  drives the barrier  300  to have the stripe shape (or pattern) or zigzag shape (or pattern) in accordance with the display mode of the barrier  300  determined by the controller  100 . 
     The barrier  300  may have an electrode format of a stripe type or a zigzag type (similar to a checkerboard pattern). Such a structure and a format of the barrier  300  will be describe in reference to  FIG. 2 ,  FIG. 3A  and  FIG. 3B . 
       FIG. 2  illustrates a cross-sectional view of a barrier according to a first exemplary embodiment of the present invention.  FIG. 3A  illustrates a structure of electrodes formed on a first substrate  301 , and  FIG. 3B  illustrates a structure of electrodes formed on a second substrate  302 . 
     As shown in  FIG. 2 , the barrier  300  includes the first substrate  301 , and the second substrate  302 , which are arranged with a predetermined space or gap therebetween. In the present exemplary embodiment, the first substrates  301  and the second substrate  302  may use substrates of a rectangular shape having a pair of short sides and a pair of long sides. 
     Electrodes  304 ,  305 ,  306 ,  307 ,  308  and  309  for driving a liquid crystal  303  placed between the first substrate  301  and the second substrate  302  are formed on surfaces of the first substrate  301  and the second substrate  302  that face each other. The electrodes  304 ,  305 ,  306 ,  307 ,  308  and  309  can be formed of transparent material such as indium tin oxide (ITO). Hereinafter, the electrodes will be described in detail. 
     As shown in  FIG. 2  and  FIG. 3A , a plurality of first electrodes  304  formed on the first substrate  301  are arranged in a first direction of the first substrate  301  (i.e., the first direction corresponds to the short side of the first substrate  301 , X-axis direction in  FIG. 3A ). The first electrodes  304  are formed on the first substrate  301  in a stripe pattern with a predetermined interval between each pair of neighboring electrodes. The first connecting electrode  305  is extended in a second direction (i.e., a direction crossed with the first direction, Y-axis direction in  FIG. 3A ) on the first substrate  301 , and is coupled to one end of each of the first electrodes  304 . The first electrodes  304  and the first connecting electrode  305  form a first electrode set set  1 . 
     Similarly, on the first substrate  301 , a second electrode set set  2  including second electrodes  306  and a second connecting electrode  307  is also formed. In more detail, a plurality of the second electrodes  306  formed on the first substrate  301  are arranged in the first direction of the first substrate  301  (i.e., X-axis direction in  FIG. 3A ). The second electrodes  306  are formed in the stripe pattern, and are respectively placed between the first electrodes  304 . The second connecting electrode  307  is extended in the second direction (i.e., the direction crossed with the first direction, Y-axis direction in  FIG. 3A ) on the first substrate  301 , and is coupled to one end of each of the second electrodes  306 . 
     The first electrode set set  1  and the second electrode set set  2  substantially cover an entire area, which corresponds to the display area of the display panel  500 , except predetermined intervals provided between the first electrodes  304  and the second electrodes  306 . 
     Similarly, as shown in  FIG. 2  and  FIG. 3B , a third electrode set set  3  and a fourth electrode set set  4  are formed on the surface of the second substrate  302  that faces the first substrate  301 . 
     The third electrode set set  3  includes a plurality of third electrodes  308  arranged in a vertical direction (i.e., Y-axis direction in  FIG. 3B ) of the second substrate  302 , and a third connecting electrode  310  coupled to the third electrodes  308 . The fourth electrode set  4  includes a plurality of fourth electrodes  309  arranged in a vertical direction of the second substrate  302 , and a fourth connecting electrode  311  coupled to the fourth electrodes  309 . 
     Here, the third electrodes  308  and the fourth electrodes  309  are arranged in the vertical Y-axis direction in a stripe pattern. In other words, when the first substrate  301  and the second substrate  302  are assembled together, the first electrodes  304  and the second electrodes  306 , and the third electrodes  308  and the fourth electrodes  309  cross over with each other at 90 degrees. 
     The third electrode set set  3  and the fourth electrode set set  4  substantially cover an entire area, which corresponds to the display area of the display panel  500 , except predetermined intervals provided between the third electrodes  308  and the fourth electrodes  309 . 
     A driving method for the barrier  300  driven by the barrier driver  200  according to the first exemplary embodiment of the present invention will be described in detail, with references to  FIG. 4A ,  FIG. 4B ,  FIG. 4C  and  FIG. 5A ,  FIG. 5B ,  FIG. 5C . 
     In the following description, it is assumed that liquid crystal of the barrier  300  is in a normally black state. When in a normally white state, the opaque regions and the transparent regions are provided inversely to those in the normally black state. In other words, the opaque regions and the transparent regions are switched. 
     A case where the barrier driver  200  drives the barrier  300  in a stripe type arrangement or format will be described with references to  FIG. 4A  to  FIG. 4C . 
       FIG. 4A  and  FIG. 4B  show voltages to be applied to the electrodes of the barrier  300 , and  FIG. 4C  shows the barrier that is driven in a stripe type arrangement. 
     As shown in  FIG. 4A  and  FIG. 4B , the barrier driver  200  applies a reference voltage (i.e., a first driving voltage) to the first electrode set set  1  and the second electrode set set  2  of the first substrate  301 , and applies a liquid crystal driving voltage (i.e., a second driving voltage) to one of the third electrode set set  3  and the fourth electrode set set  4  of the second substrate  302 . In the present exemplary embodiment, the case where the liquid crystal driving voltage is applied to the fourth electrode set set  4  will be described below, but it is of course possible that the liquid crystal driving voltage is applied to the third electrode set set  3 . Here, the reference voltage can be the ground voltage, and as shown in  FIG. 4B , the liquid crystal driving voltage can be a square wave voltage that alternates between a positive voltage and a negative voltage with a predetermined frequency. 
     By driving like this, the first and second electrode sets set  1  and set  2  that substantially cover the display area of the first substrate  301  perform as common electrodes, and the fourth electrode set set  4  of the second substrate  302  performs as driving electrodes for the liquid crystal. Because the liquid crystal of the barrier  300  is in a normally black state, regions corresponding to the fourth electrodes become transparent regions, and regions corresponding to the third electrodes become opaque regions. Accordingly, as shown in  FIG. 4C , the barrier  300  is driven to have a stripe shape, in which the transparent regions are extended in the Y-axis direction. 
     Next, the case where the barrier driver  200  drives the barrier  300  in a zigzag type arrangement or format will be described with reference to  FIG. 5A  to  FIG. 5C . 
       FIG. 5A  and  FIG. 5B  show that a voltage is applied to each electrode of the barrier, and  FIG. 5C  illustrates the barrier  300  that is driven to have a zigzag shape (similar to a checkerboard pattern). 
     As shown in  FIG. 5A  and  FIG. 5B , the barrier driver  200  applies a reference voltage to the second electrode set set  2  of the first substrate  301  and the third electrode set set  3  of the second substrate  302 , and applies a liquid crystal driving voltage to the first electrode set set  1  of the first substrate  301  and the fourth electrode set set  4  of the second substrate  302 . 
     By driving like this, because a voltage difference does not occur in overlapped regions of the second electrodes  306  and the third electrodes  308  to which the reference voltage is applied, the overlapped regions of the second electrodes  306  and the third electrodes  308  will become opaque regions when the barrier  300  is in a normally black state. Similarly, because a voltage difference does not occur in overlapped regions of the first electrodes  304  and the fourth electrodes  309  to which the liquid crystal driving voltage is applied, the overlapped regions of the first electrodes  304  and the fourth electrodes  309  will become opaque regions when the barrier  300  is in the normally black state. 
     On the other hand, a voltage difference occurs in overlapped regions of the second electrodes  306  and the fourth electrodes  309  such that the liquid crystal is driven, because the reference voltage is applied to the second electrodes  306  and the liquid crystal driving voltage is applied to the fourth electrodes  309 . Accordingly, the overlapped regions of the second electrodes  306  and the fourth electrodes  309  will become transparent regions. Similarly, a voltage difference occurs in overlapped regions of the first electrodes  304  and the third electrodes  308  such that the liquid crystal is driven, because the liquid crystal driving voltage is applied to the first electrodes  304  and the reference voltage is applied to the third electrodes  308 . Accordingly, the overlapped regions of the first electrodes  304  and the third electrodes  308  will become transparent regions. 
     As described above, because the opaque regions that intercept light are formed in the zigzag shape, a barrier having the zigzag shape (similar to a checkerboard pattern) which is able to increase resolution in a horizontal direction can be provided. 
     A driving method for the barrier  300  driven by the barrier driver  200  according to the second exemplary embodiment of the present invention will be described in detail with references to  FIG. 6  and  FIG. 7 . 
     The first exemplary embodiment of the present invention provides a driving method for the barrier when the image is displayed in the portrait mode in which the screen is longer in the vertical direction. The second exemplary embodiment of the present invention provides another driving method for the barrier when the image is displayed in the landscape mode in which the screen is longer in the horizontal direction. Therefore,  FIG. 6  and  FIG. 7  are figures that are rotated by 90 degrees of  FIG. 4C  and  FIG. 5 , such that X-axis indicates the vertical direction, and Y-axis indicates the horizontal direction. 
       FIG. 6  shows the barrier  300  that is driven to have a stripe shape according to the second exemplary embodiment of the present invention. 
     The barrier driver  200  applies the liquid crystal driving voltage to one of the first electrode set set  1  and the second electrode set set  2  of the first substrate  301 . For example, the barrier driver  200  applies the liquid crystal driving voltage to the second electrode set set  2 , and applies the reference voltage to the third electrode set set  3  and the fourth electrode set set  4  of the second substrate  302 . 
     By driving like this, the third and fourth electrode sets set  3  and set  4  that substantially cover the display area of the second substrate  302  perform as common electrodes, and the second electrode set set  2  of the first substrate  301  performs as liquid crystal driving electrodes. Here, regions for the second electrodes become the transparent regions, and regions for the first electrodes become the opaque regions, when the liquid crystal of the barrier  300  is in a normally black state. 
     As shown in  FIG. 6 , the barrier  300  has the stripe pattern in which the transparent regions are extended in the X-axis direction. Therefore, the barrier  300  is driven in an appropriate form for the landscape mode screen which is rotated 90 degrees from the portrait mode screen shown in  FIG. 4C . 
       FIG. 7  shows the barrier  300  that is driven to have a zigzag shape according to the second exemplary embodiment of the present invention. 
     The barrier driver  200  applies the reference voltage to the second electrode set set  2  of the first substrate  301  and the fourth electrode set set  4  of the second substrate  302 , and applies liquid crystal driving voltages to the first electrode set set  1  of the first substrate  301  and the third electrode set set  3  of the second substrate  302 . 
     By driving like this, as shown in  FIG. 7 , a voltage difference does not occur in overlapped regions of the second electrodes  306  and the fourth electrodes  309 , because the reference voltage is applied to both the second electrodes  306  and the fourth electrodes  309 . Accordingly, the overlapped regions of the second electrodes  306  and the fourth electrodes  309  will become opaque regions. Similarly, a voltage difference does not occur in overlapped regions of the first electrodes  304  and the third electrodes  308 , because the liquid crystal driving voltage is applied to both the first electrodes  304  and the third electrodes  308 . Accordingly, the overlapped regions of the first electrodes  304  and the third electrodes  308  will become opaque regions. 
     Meanwhile, a voltage difference occurs in overlapped regions of the second electrodes  306  and the third electrodes  308 , thereby driving the liquid crystal, because the reference voltage is applied to the second electrodes  306  and the liquid crystal driving voltage is applied to the third electrodes  308 . Accordingly, the overlapped regions of the second electrodes  306  and the third electrodes  308  will become transparent regions. Similarly, a voltage difference occurs in overlapped regions of the first electrodes  304  and the fourth electrodes  309 , thereby driving the liquid crystal, because the liquid crystal driving voltage is applied to the first electrodes  304  and the reference voltage is applied to the fourth electrodes  309 . Accordingly, the overlapped regions of the first electrodes  304  and the fourth electrodes  309  will become transparent regions. 
     As shown in  FIG. 7 , the barrier  300  has a zigzag pattern. Therefore, the barrier  300  is driven in an appropriate form for the landscape mode screen which is rotated 90 degrees from the portrait mode screen shown in  FIG. 5C . 
     In addition, the position of the transparent regions and the opaque regions may be controlled by shifting the electrodes to which the reference voltage or liquid crystal driving voltage is applied. Thereby, an optimal or suitable 3D image can be selectively provided according to the user&#39;s position. 
     According to exemplary embodiments of the present invention, the stripe type barrier and zigzag type barrier can be selectively provided by controlling the voltages to be applied to the electrodes differently. 
     In addition, a barrier appropriate or suitable for not only the portrait mode but also the landscape mode can be applied to a mobile 3D display device. 
     While this invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims and equivalents thereof.