Abstract:
A display apparatus allowing a user positioned in a first direction to visually recognize a first image and allowing a user positioned in a second direction different from the first direction to visually recognize a second image includes: a display unit displaying a combined image formed by combining the first image with the second image; an irradiation unit irradiating the display unit displaying the combined image with irradiation light; a distribution unit distributing components corresponding to the first image of the irradiation light transmitted through the display unit to the first direction and distributing components corresponding to the second image of the irradiation light transmitted through the display unit to the second direction; and a cancellation unit cancelling luminance characteristics of the irradiation light distributed by the distribution unit.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application claims priority to Japanese Priority Patent Application JP 2012-056701 filed in the Japan Patent Office on Mar. 14, 2012, the entire content of which is hereby incorporated by reference. 
     BACKGROUND 
     The present disclosure relates to a display apparatus and an electronic apparatus, and particularly relates to a display apparatus and an electronic apparatus suitably applied when different pictures are displayed with respect to plural users positioned in different directions. 
     For example, there is a car navigation system to be mounted on an automobile which applies a display (hereinafter referred to as a dual-view display) capable of displaying a picture for navigation with respect to a driver driving the automobile in a driver&#39;s seat and displaying another picture with respect to a person sitting in a passenger&#39;s seat. 
       FIG. 1  shows an outline of the dual-view display. A dual-view display  1  can display an image “l” with respect to a user L positioned on the left side facing the dual-view display  1  and can display an image “r” different from the image “l” with respect to a user R positioned on the right side facing the display. Naturally, it is possible to display the same image with respect to the user L and the user R (see JP-A-2005-78092 (Patent Document 1)). 
       FIG. 2  shows a schematic cross-sectional view of the dual-view display  1  shown in  FIG. 1 . 
     The dual-view display  1  is provided with a parallax barrier  11 , a color filter  12 , a liquid crystal layer  13  and a backlight  14  sequentially from an upper layer to a lower layer direction. In the drawing, only portions concerning dual-view display are shown, and a polarization plate, electrodes and so on concerning driving of the liquid crystal layer  13  are not shown. 
     The parallax barrier  11  distributes irradiation light from the lower layer to a direction of the user L or a direction of the user R. The color filter  12  includes color material films of three primary colors R, G and B having a sub-pixel size. The liquid crystal layer  13  displays a combined image in which vertical-direction lines of the image “l” aimed at the user L and the image “r” aimed at the user R are alternately arranged in units of sub-pixels sectioned by R, G and B of the color filter  12 . The liquid crystal layer  13  on an upper layer side is uniformly irradiated by the backlight  14 . 
     In the dual-view display  1 , the combined image generated by the liquid crystal layer  13  reaches the user L and the user R by the irradiation light from the backlight  14  through the color filter  12  and the parallax barrier  11 . Accordingly, the user L can visually recognize the image “l” and the user R can visually recognize the image “r”. 
     SUMMARY 
       FIG. 3  shows a surface luminance distribution on the dual-view display  1  with respect to the user L. 
     That is, when an emitted direction of irradiation light at a position farther from the user L is θ 1  and an emitted direction of irradiation light at a position closer to the user L is θ 2  on the dual-view display  1 , the luminance of light is higher (brighter) at the position closer to the user L and the luminance of light is lower (darker) at the position farther from the user L. The surface luminance distribution on the dual-view display  1  with respect to the user R is the same as the above. Accordingly, it is difficult for the users to view a screen of the dual-view display  1  in a good condition. 
     Thus, a mechanism for allowing the surface luminance distribution on the screen of the dual-view display  1  viewed by the user to be uniform is necessary. 
     In view of the above, it is desirable to allow the surface luminance distribution on the screen visually recognized by the user to be uniform. 
     An embodiment of the present disclosure is directed to a display apparatus allowing a user positioned in a first direction to visually recognize a first image and allowing a user positioned in a second direction different from the first direction to visually recognize a second image, which includes a display unit displaying a combined image formed by combining the first image with the second image, an irradiation unit irradiating the display unit displaying the combined image with irradiation light, a distribution unit distributing components corresponding to the first image of the irradiation light transmitted through the display unit to the first direction and distributing components corresponding to the second image of the irradiation light transmitted through the display unit to the second direction, and a cancellation unit cancelling luminance characteristics of the irradiation light distributed by the distribution unit. 
     The cancellation unit may include an open-area ratio correction unit in which an open area ratio of an optical filter transmitting the irradiation light transmitted through the display unit is adjusted in accordance with coordinates. 
     The optical filter may be a color filter, and the open-area ratio correction unit may be a black matrix. 
     The black matrix may adjust the open-area ratio in units of sub-pixels or in units of pixels of the color filter in accordance with coordinates. 
     The cancellation unit may further include a luminance correction unit correcting a luminance signal of the combined image so as to cancel luminance characteristics of the irradiation light distributed by the distribution unit. 
     The cancellation unit may further include a color filter transmitting the irradiation light transmitted through the display unit, in which at least one of a film thickness and density is adjusted in accordance with coordinates. 
     The cancellation unit may further include an irradiation control unit controlling the irradiation unit so as to cancel luminance characteristics of the irradiation light distributed by the distribution unit. 
     In the embodiment of the present disclosure, components corresponding to the first image of the irradiation light transmitted through the display unit displaying the combined image are distributed to the first direction and components corresponding to the second image are distributed to the second direction. Then, luminance characteristics of the irradiation light to be distributed are cancelled. 
     Another embodiment of the present disclosure is directed to an electronic apparatus allowing a user positioned in a first direction to visually recognize a first image and allowing a user positioned in a second direction different from the first direction to visually recognize a second image, which includes an image combining unit combining the first image with the second image to generate a combined image, a display unit displaying the combined image, an irradiation unit irradiating the display unit displaying the combined image with irradiation light, a distribution unit distributing components corresponding to the first image of the irradiation light transmitted through the display unit to the first direction and distributing components corresponding to the second image of the irradiation light transmitted through the display unit to the second direction, and a cancellation unit cancelling luminance characteristics of the irradiation light distributed by the distribution unit. 
     In another embodiment of the present disclosure, the first image is combined with the second image to generate the combined image, components corresponding to the first image of the irradiation light transmitted through the display unit displaying the combined image are distributed to the first direction and components corresponding to the second image are distributed to the second direction. Then, luminance characteristics of the irradiation light to be distributed are cancelled. 
     According to the embodiment of the present disclosure, the surface luminance distribution on the screen visually recognized from both sides can be uniform. 
     According to another embodiment of the present disclosure, surface luminance distributions on different screens visually recognized by plural users respectively positioned in the right and left directions of the screen. 
     Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a view showing an outline of a dual-view display; 
         FIG. 2  is a schematic cross-sectional view of a related-art dual-view display; 
         FIG. 3  is a graph showing a surface luminance distribution of a screen seen from a user; 
         FIG. 4  is a schematic cross-sectional view of a display apparatus to which an embodiment of the present disclosure is applied; 
         FIGS. 5A to 5D  are views showing a first structure example of a black matrix of a color filter; 
         FIGS. 6A to 6D  are views showing a second structure example of the black matrix of the color filter; and 
         FIG. 7  is a view showing an adjustment example of the surface luminance distribution on the screen seen from the user. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as an embodiment) will be explained in detail with reference to the drawings. 
     [Structure Example of Display Apparatus] 
       FIG. 4  shows a schematic cross-sectional view of a display apparatus  20  according to the embodiment of the present disclosure. 
     The display apparatus  20  is applied to, for example, a car navigation system, a game machine and so on, displaying an image “l” with respect to a user L positioned on the left side facing the display apparatus  20 , and displaying an image “r” which is different from the image “l” with respect to a user R positioned on the right side facing the display apparatus  20 . Naturally, it is possible to display the same image with respect to the user L and the user R. 
     The display apparatus  20  is provided with a parallax barrier  21 , a color filter with BM (black matrix)  22 , a liquid crystal layer  23  and a backlight  24  sequentially from an upper layer to a lower layer direction. The display apparatus  20  is also provided with a combined image generation unit  31  and a backlight control unit  32 . 
     In the schematic cross-sectional view of the drawing, only portions concerning dual-view display are shown, and a polarization plate, electrodes and so on concerning driving of the liquid crystal layer  23  are not shown. 
     The parallax barrier  21  distributes irradiation light from the lower layer to a direction of the user L or a direction of the user R. It is also preferable to use a lenticular lens instead of the parallax barrier  21 . 
     The color filter with BM  22  includes color material films of three primary colors R, G and B having a sub-pixel size, in which an open area ratio is adjusted in accordance with a coordinate position by changing the size in a black matrix provided on the surface of them (the details will be explained later with reference to  FIGS. 5A to 5D ). 
     The liquid crystal layer  23  displays a combined image in which vertical-direction lines of the image “l” aimed at the user L and the image “r” aimed at the user R alternately appear in units of sub-pixels sectioned by R, G and B of the color filter with BM  22  based on a corrected signal of the combined image to be inputted from the combined image generation unit  31 . The liquid crystal layer  23  on an upper layer side is uniformly irradiated by the backlight  24  in accordance with control by the backlight control unit  32 . 
     The combined image generation unit  31  generates the signal of the combined image by alternately arranging vertical-direction lines of an image signal of the image “l” and an image signal of the image “r” inputted from the previous stage in units of sub-pixels sectioned by R, G and B of the color filter with BM  22 . 
     The backlight control unit  32  control the backlight  24  to allow the liquid crystal layer  23  on the upper layer side to be irradiated. Irradiation characteristics by the backlight  24  are the same as shown in  FIG. 3 . 
     [First Structure Example of Color Filter with BM  22 ] 
       FIGS. 5A to 5D  show a first structure example of the black matrix in the color filter with BM  22 .  FIGS. 5A to 5D  correspond to a case where the combined image displayed on the liquid crystal layer  23  is configured by vertical-direction lines of the image “l” and the image “r” alternately arranged in units of sub-pixels as shown in  FIG. 5A . 
     As shown in  FIG. 5B , concerning the BM for transmitting the image “l” aimed at the user L, the size of areas not covered with the BM (white areas surrounded by an black area in which any of R, G and B is written in the drawings) is changed so that an open area ratio of the BM is gradually reduced from a position farther from the user L to a position closer to the user L. Similarly, concerning the BM for transmitting the image “r” aimed at the user R, the size of areas not masked by the BM is changed so that the open area ratio is gradually increased from a position closer to the user R to a position farther from the user R. 
     Specifically, there is a method of changing a vertical size or a horizontal size of the areas not covered with the BM. 
       FIG. 5C  shows a case where the vertical size of the areas not covered with the BM is changed without changing the horizontal size of the areas.  FIG. 5D  shows a case where the horizontal size of the areas not covered with the BM is changed without changing the vertical size of the areas. When comparing the case of  FIG. 5D  with the case of  FIG. 5C  in the same coordinates, the open area ratio can be further increased in the case of  FIG. 5D . However, in the case of  FIG. 5D , the adjustment of the parallax barrier  21  will be necessary. 
     As shown in  FIG. 5C  or  FIG. 5D , it is possible to increase the open area ratio at the position farther from the user and to reduce the open area ratio at the position closer to the user by changing the size of the areas not covered with the BM, therefore, the surface luminance distribution on the screen seen by the user can be corrected to be uniform. 
     Incidentally, the display apparatus  20  shown in  FIG. 4  and the color filter with BM  22  shown in  FIGS. 5A to 5D  correspond to the case where the combined image displayed on the liquid crystal layer  23  is configured by the vertical-direction lines of the image “l” and the image “r” alternately arranged in units of sub-pixels. The present disclosure can be also applied to a case where the combined image is configured by the vertical-direction lines of the image “l” and the image “r” alternately arranged in units of pixels each having three sub-pixels of R, G and B. In such case, the position of the parallax barrier  21  differs from the case shown in  FIG. 4 . 
     [Second Structure Example of Color Filter with BM  22 ] 
       FIGS. 6A to 6D  show a second structure example of the black matrix of the color filter with BM  22 .  FIGS. 6A to 6D  correspond to a case where the combined image displayed on the liquid crystal layer  23  is configured by vertical-direction lines of the image “l” and the image “r” alternately arranged in units of pixels each having three sub-pixels of R, G and B as shown in  FIG. 6A . 
     As shown in  FIG. 6B , concerning the BM for transmitting the image “l” aimed at the user L, the size of areas not covered with the BM is changed so that the open area ratio of the BM is gradually reduced from a position farther from the user L to a position closer to the user L. Similarly, concerning the BM for transmitting the image “r” aimed at the user R, the size of areas not masked by the BM is changed so that the open area ratio is gradually increased from a position closer to the user R to a position farther from the user R. 
       FIG. 6C  shows a case where the vertical size of the areas not covered with the BM is changed without changing the horizontal size of the areas.  FIG. 6D  shows a case where the horizontal size of the areas not covered with the BM is changed without changing the vertical size of the areas. When comparing the case of  FIG. 6D  with the case of  FIG. 6C  in the same coordinates, the open area ratio can be further increased in the case of  FIG. 6D . 
     As explained above, characteristics in which the luminance of light is higher (brighter) at a position closer to the user and the luminance of light is lower (darker) at a position farther from the user shown in  FIG. 3  can be cancelled by gradually changing the open area ratio of the BM in the color filter with BM  22 . 
     Modification Example 
     It is also possible to correct an image signal of the combined image in addition to changing the open area ratio of the BM in the color filter with BM  22  as described above. 
     That is, the combined image generation unit  31  corrects the image signal of the image “l” inputted from the previous stage so that the luminance of pixels at coordinates farther from the user L becomes higher and the luminance of pixels at coordinates closer to the user L becomes lower. Similarly, the combined image generation unit  31  may correct the image signal of the image “r” inputted from the previous stage so that the luminance of pixels at coordinates farther from the user R becomes higher and the luminance of pixels at coordinates closer to the user R becomes lower. 
     It is also preferable to adjust the transmittance of irradiation light by changing the film thickness or density of color material films in the color filter with BM  22 . 
     It is also possible to specialize irradiation characteristics of the backlight  24  for the purpose of dual-view display, for example, so as to have two peaks as shown in  FIG. 7 . In this case, the open area ratio in the BM for transmitting the image “l” aimed at the user L is gradually changed in the order of large, small and large, not gradually reducing the open area ratio from the position farther from the user L to the position closer to the user L. Similarly, the open area ratio in the BM for transmitting the image “r” aimed at the user R is gradually changed in the order of small, large and small, not gradually increasing the open area ratio from the position closer to the user R to the position farther from the user R. 
     As described above, in the display apparatus  20  according to the embodiment of the present disclosure, it is possible to allow the surface luminance distribution of the image “l” visually recognized by the user L positioned on the left side facing the display apparatus  20  to be uniform as well as to allow the surface luminance distribution of the image “r” visually recognized by the user R positioned on the right side facing the display apparatus  20  to be uniform. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.