STEREOSCOPIC DISPLAY DEVICE AND STEREOSCOPIC DISPLAY METHOD

FIELD

The present disclosure relates to a stereoscopic display device and a stereoscopic display method capable of performing a stereoscopic display employing a parallax barrier system.

BACKGROUND

Recently, display devices (stereoscopic display devices) that can realize a stereoscopic view have attracted attention. In the display of a stereoscopic view, a left-eye video and a right-eye video in parallax to each other (different viewpoints) are displayed. Thus, when an observer sees the left-eye video and the right-eye video with his or her left and right eyes, a stereoscopic video having a depth can be recognized. In addition, display devices are developed which can provide an observer with a more natural stereoscopic video by displaying three or more videos in parallax to each other.

Such stereoscopic display devices can be largely divided into a type for which it is necessary to use dedicated glasses and a type for which it is not necessary to use dedicated glasses. Since it is inconvenient for an observer to use dedicated glasses, the type for which it is not necessary to use dedicated glasses (in other words, a type that can form a stereoscopic view for naked eyes) is more preferable. As stereoscopic display devices that can form a stereoscopic view for naked eyes, stereoscopic display devices, for example, employing a parallax barrier system or a lenticular system are known. In the stereoscopic display device employing such a system, a plurality of videos (viewpoint videos) in parallax to one another are simultaneously displayed, and a video that is seen differs in accordance with the relative positional relationship (angle) between the display device and the viewpoint of an observer. In a case where a video having a plurality of viewpoints is displayed by the stereoscopic display device, the substantial resolution of the video becomes resolution that is acquired by dividing the resolution of the display device such as a CRT (Cathode Ray Tube) or a liquid crystal display device by the number of viewpoints. Accordingly, there is a problem in that the image quality deteriorates.

In order to solve such a problem, various considerations have been made. For example, in JP-A-2005-157033, a method for equivalently improving the resolution is proposed in which a time-divisional display is performed by switching between a transmitting state and a shielding state of each barrier in a time-divisional manner in a parallax barrier system.

However, in a case where the parallax barrier extends in the screen vertical direction, although the resolution in the screen horizontal direction can be improved, it is difficult to improve the resolution in the screen vertical direction. Thus, as a technique for enhancing a balance (resolution balance) between the resolution in the screen horizontal direction and the resolution in the screen vertical direction, a step barrier system has been developed. In such a step barrier system, the alignment direction (or extending direction) of openings of the parallax barrier or the axial direction of the lenticular lens is set to the diagonal direction of the screen, and one unit pixel is configured by sub pixels of a plurality of colors (for example, R (red), G (green), and B (blue)) aligned in one row so as to be adjacent to the diagonal direction.

SUMMARY

However, recently, improvement of the resolution together with improvement of the resolution balance regardless of the number of viewpoints is demanded.

Thus, it is desirable to provide a stereoscopic display device and a stereoscopic display method capable of suppressing deterioration of the resolution without degrading the resolution balance in a case where a stereoscopic display is performed using a plurality of viewpoint videos.

An embodiment of the present disclosure is directed to a display device including: a display unit that composes p (here, p is an integer equal to or greater than two) viewpoint videos that are spatially divided within one screen by sequentially displaying q (here, q is an integer that is equal to or greater than two and is equal to or less than p) display patterns that are divided in time; and an optical separation device that optically separates the p viewpoint videos configuring each one of the q display patterns displayed on the display unit. Here, the display unit includes a plurality of unit pixels each formed from a plurality of sub pixels displaying r types (here, r is an integer equal to or greater than three) of colors necessary for a color video display, the sub pixels of a same color are arranged in a same row in a screen vertical direction, and the sub pixels of different colors are sequentially arranged in a same row in a screen horizontal direction. In addition, in an arrangement pattern that configures the p viewpoint videos out of the q display patterns, a plurality of sub pixel rows each formed from a plurality of the sub pixels aligned in a diagonal direction are displayed in the screen horizontal direction for every p rows. The q display patterns composed within one screen are disposed at positions for which the unit pixels corresponding to each other overlap each other when the display patterns are relatively moved in parallel in the screen vertical direction. The optical separation device, for example, is a variable-type parallax barrier that includes a plurality of light transmitting portions that transmit light output from the display unit or light traveling toward the display unit and a plurality of light shielding portions that shield the light output from the display unit or the light traveling toward the display unit and is configured such that arrangement states of the plurality of light transmitting portions and the plurality of light shielding portions can be changed in accordance with the q display patterns.

Another embodiment of the present disclosure is directed to a display device including: a display unit that sequentially displays a plurality of viewpoint videos that are spatially divided in a plurality of display patterns that are divided in time; and an optical separation device that optically separates the plurality of viewpoint videos. Here, the display unit includes a plurality of unit pixels each formed from a plurality of the sub pixels aligned in a diagonal direction, and the plurality of display patterns are disposed at positions for which the unit pixels corresponding to each other overlap each other when the display patterns are relatively moved in parallel in a screen vertical direction.

Still another embodiment of the present disclosure is directed to a display method including: composing p (here, p is an integer equal to or greater than two) viewpoint videos that are spatially divided within one screen of a display unit by sequentially displaying q (here, q is an integer that is equal to or greater than two and is equal to or less than p) display patterns that are divided in time; and optically separating the p viewpoint videos configuring each one of the q display patterns displayed on the display unit by using an optical separation device. Here, as the display unit, a unit is used in which a plurality of unit pixels each formed from a plurality of sub pixels displaying r types (here, r is an integer equal to or greater than three) of colors necessary for a color video display are included, the sub pixels of a same color are arranged in a same row in a screen vertical direction, and the sub pixels of different colors are sequentially arranged in a same row in a screen vertical direction. In addition, in an arrangement pattern that configures the p viewpoint videos out of the q display patterns, a plurality of sub pixel rows each formed from a plurality of the sub pixels aligned in a diagonal direction are displayed in the screen horizontal direction for every p rows. Furthermore, the q display patterns are disposed at positions for which the unit pixels corresponding to each other overlap each other when the display patterns are relatively moved in parallel in the screen vertical direction. As the optical separation device, a variable-type parallax barrier may be used, which includes a plurality of light transmitting portions that transmit light output from the display unit or light traveling toward the display unit and a plurality of light shielding portions that shield the light output from the display unit or the light traveling toward the display unit and is configured such that arrangement states of the plurality of light transmitting portions and the plurality of light shielding portions can be changed in accordance with the q display patterns.

In the display device and the display method according to the embodiments of the present disclosure, in an arrangement pattern, which configures each viewpoint video that is spatially divided, out of a plurality of display patterns, a plurality of sub pixel rows aligned in the diagonal direction are displayed at a predetermined interval in the screen horizontal direction. By sequentially displaying the plurality of display patterns in a time-divisional manner, one composite video is formed in which the plurality of display patterns are integrated with respect to time at each viewpoint. In addition, in the plurality of display patterns, since the unit pixels corresponding to one another are present at positions overlapping one another when the display patterns are relatively moved in parallel in the vertical direction, the resolution in the vertical direction is improved.

In the display device and display method according to the embodiment of the present disclosure, a plurality of viewpoint videos that are spatially divided are composed within one screen by sequentially displaying a plurality of display patterns that are divided in time. Accordingly, compared to a case where each viewpoint video is displayed in a space-divisional manner by using one display pattern, a decrease in the resolution at the time of performing a stereoscopic display can be suppressed. In addition, since the plurality of display patterns that are composed within one screen are disposed at positions that allow the unit pixels corresponding to one another overlap with one another when the patterns are relatively moved in parallel in the screen vertical direction, the resolution at each viewpoint video in the vertical direction can be further improved. Here, by appropriately selecting the type of colors of the sub pixels, the number of the viewpoint videos, and the number of the display patterns, a balance between the resolution in the screen vertical direction and the resolution in the screen horizontal direction can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram illustrating the configuration of a stereoscopic display device according to a first embodiment of the present disclosure.

FIG. 2 is a block diagram illustrating circuits, which relate to display control, of the stereoscopic display device according to the first embodiment.

FIG. 3 is a plan view illustrating a sub pixel arrangement of a liquid crystal display panel of the stereoscopic display device according to the first embodiment.

FIGS. 4A and 4B are plan views illustrating examples of first and second display patterns that are displayed on the liquid crystal display panel illustrated in FIG. 1 and the like.

FIGS. 5A and 5B are plan views illustrating examples of first and second barrier patterns that are formed on a switching liquid crystal panel illustrated in FIG. 1 and the like.

FIGS. 6A and 6B are diagrams schematically illustrating the states of stereoscopic views in first and second display periods.

FIGS. 7A and 7B are plan views illustrating the arrangement patterns of sub pixels that configure a first viewpoint video according to the first embodiment.

FIG. 8 is a plan view illustrating a composite video that is recognized as the first viewpoint video according to the first embodiment.

FIG. 9 is a plan view illustrating an example of a first display pattern according to a second embodiment of the present disclosure.

FIG. 10 is a plan view illustrating an example of a second display pattern according to the second embodiment of the present disclosure.

FIG. 11 is a plan view illustrating an example of a third display pattern according to the second embodiment of the present disclosure.

FIG. 12 is a plan view illustrating a composite video that is recognized as a first viewpoint video according to the second embodiment.

FIGS. 13A and 13B are plan views illustrating examples of first and second display patterns according to a third embodiment of the present disclosure.

FIG. 14 is a feature diagram illustrating the relationship between the number of viewpoints and a resolution balance of a stereoscopic display device according to an example of the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present disclosure (hereinafter, referred to as embodiments) will be described in detail with reference to the accompanying drawings.

First Embodiment
Configuration of Stereoscopic Display Device

FIG. 1 illustrates the entire configuration of a stereoscopic display device according to a first embodiment of the present disclosure. FIG. 2 illustrates circuits, which relate to display control, of the stereoscopic display device. This stereoscopic display device, as illustrated in FIG. 1, includes a liquid crystal display panel 2, a back light 3 that is arranged on the rear side of the liquid crystal display panel 2, and a switching liquid crystal panel 1 that is arranged so as to face the display face side of the liquid crystal display panel 2. In addition, this stereoscopic display device, as illustrated in FIG. 2, includes a timing controller 21 that is used for controlling the display operation of the liquid crystal display panel 2 and a viewpoint video data output unit 23. Furthermore, the stereoscopic display device includes a timing controller 22 that is used for controlling the switching operation of the switching liquid crystal panel 1 and a barrier pixel data output unit 24.

FIG. 3 illustrates an example of the pixel arrangement of the liquid crystal display panel 2. The liquid crystal display panel 2 has a pixel structure in which a plurality of sub pixels of three colors including R (red), G (green), and B (blue) that are necessary for a color display are two dimensionally arranged. As illustrated in FIG. 3, a pixel arrangement is formed in which a sub pixel of each color periodically appears in the same row in the screen horizontal direction (X-axis direction), and sub pixels of the same color are aligned in the same row in the screen vertical direction (the Y-axis direction). The liquid crystal display panel 2 having such a pixel structure modulates light emitted from the back light 3 for each sub pixel, and thereby performing a two-dimensional image display. The liquid crystal display panel 2 displays parallax images for a stereoscopic display that are output from the viewpoint video data output unit 23 under the control of the timing controller 21.

In addition, in order to realize a stereoscopic view, different viewpoint videos are necessarily seen by a left eye 10L and a right eye 10R. Accordingly, at least two viewpoint videos for a right-eye video and a left-eye video are necessary. In a case where three or more viewpoint videos are used, a multi-eye view can be realized. In this embodiment, a case will be described in which four viewpoint videos (first to fourth viewpoint videos) are formed (in other words, the number of viewpoints is four), and observation is performed by using two viewpoint videos (here, the first and second viewpoint videos) among of them.

In the liquid crystal display panel 2, four viewpoint videos including view point videos for the right eye (the first viewpoint) and the left eye (the second viewpoint) are spatially divided, and q (here, q is an integer that is equal to or greater than two and is equal to or less than p) display patterns that are divided in time are sequentially displayed, whereby the four viewpoint videos and the q display patterns are composed so as to be displayed within one screen. Here, the liquid crystal display panel 2 alternately displays (time-division display) two types of display patterns, whereby the display positions of the four viewpoint videos are periodically switched between two states. Image data corresponding to each display pattern is output from the viewpoint video data output unit 23. Here, timing for displaying each display pattern is controlled by the timing controller 21.

FIGS. 4A and 4B illustrate first and second display patterns 20A and 20B as examples of two types of display patterns that are displayed in a time-division manner. As illustrated in FIGS. 4A and 4B, for example, a first sub pixel row formed from sub pixels to which reference numerals R1, G1, and B1 are assigned, a second sub pixel row formed from sub pixels to which reference numerals R2, G2, and B2 are assigned, a third sub pixel row formed from sub pixels to which reference numerals R3, G3, and B3 are assigned, and a fourth sub pixel row formed from sub pixels to which reference numerals R4, G4, and B4 are assigned extend in parallel with the diagonal direction so as to be periodically arranged in the screen horizontal direction. The sub pixels R1, G1, and B1 are constituent elements of a unit pixel 4A that displays a first viewpoint video (for example, a video for the right eye), the sub pixels R2, G2, and B2 are constituent elements of a unit pixel 4B that displays a second viewpoint video (for example, a video for the left eye). In addition, a unit pixel 4C formed from the sub pixels R3, G3, and B3 configures a third viewpoint video, and a unit pixel 4D formed from the sub pixels R4, G4, and B4 configures a fourth viewpoint video. As a result, the stripe-shaped first to fourth viewpoint videos extending in the diagonal direction are periodically arranged in the screen horizontal direction.

In the first display pattern 20A illustrated in FIG. 4A and the second display pattern 20B illustrated in FIG. 4B, the positions of the unit pixels displaying the first to fourth viewpoint videos are different from each other. For example, the unit pixel 4A that is formed by the sub pixels R1, G1, and B1 to which the first viewpoint video is assigned in the first display pattern 20A becomes the unit pixel 4C formed from the sub pixels R3, G3, B3 to which the third viewpoint video is assigned in the second display pattern 20B. Similarly, the unit pixels 4B, 4C, and 4D to which the second, third, and fourth viewpoint videos are assigned in the first display pattern 20A become the unit pixels 4D, 4A, and 4B to which the fourth, first, and second viewpoint videos are assigned in the second display pattern 20B.

The switching liquid crystal panel 1 includes a plurality of pixels that are two dimensionally arranged and can perform a switching operation of switching between a light transmitting state and a non-light transmitting state for each pixel. The switching liquid crystal panel 1 realizes the function of a variable-type parallax barrier. The switching liquid crystal panel 1 forms a barrier pattern that is used for optically separating parallax images displayed on the liquid crystal display panel 2 for enabling a stereoscopic view. The switching liquid crystal panel 1 forms two types of barrier patterns corresponding to the first and second display patterns 20A and 20B illustrated in FIGS. 4A and 4B by periodically switching between two states.

FIGS. 5A and 5B illustrate examples of the two barrier patterns (the first and second barrier patterns 10A and 10B). Each one of the first and second barrier patterns 10A and 10B is a pattern that is formed by a shielding portion (light shielding portion) 11 that shield display image light transmitted from the liquid crystal display panel 2 and openings (light transmitting portions) 12 that transmit the display image light. FIG. 5A is a first barrier pattern 10A corresponding to the first display pattern 20A illustrated in FIG. 4A, and FIG. 5B is a second barrier pattern 10B corresponding to the second display pattern 20B illustrated in FIG. 4B. In other words, the first barrier pattern 10A optically separates the display image light so as to enable a stereoscopic view when each viewpoint video is displayed in the first display pattern 20A. On the other hand, the second barrier pattern 10B optically separates the display image light so as to enable a stereoscopic view when each viewpoint video is displayed in the second display pattern 20B. The arrangement position and the shape of the opening 12 in the first and second barrier patterns 10A and 10B are set such that light of different viewpoint videos are separately incident to the left and right eyes 10L and 10R of an observer when the observer views the stereoscopic display device from a predetermined position in a predetermined direction. In addition, in FIGS. 5A and 5B, the opening 12 has a stepped shape extending in the diagonal direction in correspondence with the first to fourth sub pixel rows.

The pixel data used for forming the first and second barrier patterns 10A and 10B on the switching liquid crystal panel 1 is output from the barrier pixel data output unit 24. In addition, timing (timing for switching between a state in which light emitted from each sub pixel is transmitted and a state in which the light is not transmitted) for forming each barrier pattern in the switching liquid crystal panel 1 is controlled by the timing controller 22. The image data of each display pattern displayed on the liquid crystal display panel 2 is output from the viewpoint video data output unit 23, and, at this time, a frame signal acquired when each display pattern is changed is output to the timing controller 22 through the barrier pixel data output unit 24. The timing controller 22 performs control based on the frame signal such that the timing for changing each barrier pattern is synchronized with the timing for changing each display pattern on the liquid crystal display panel 2.

[Operation of Stereoscopic Display Device]

According to this stereoscopic display device, on the liquid crystal display panel 2, each viewpoint video is displayed in the first and second display patterns 20A and 20B within one screen in a spatially divided manner, and the first and second display patterns 20A and 20B are periodically changed so as to be displayed. In other words, each viewpoint video is divided in space and time so as to be displayed on the liquid crystal display panel 2. On the switching liquid crystal panel 1, the first and second barrier patterns 10A and 10B are periodically formed so as to enable a stereoscopic view in synchronization with the switching between the first and second display patterns 20A and 20B.

FIG. 6A schematically illustrates the state of a stereoscopic view in a first display period T1 in the stereoscopic display device. FIG. 6B schematically illustrates the state of a stereoscopic view in a second display period T2 that is different from the first display period T1. Here, it is preferable that both the first and second display periods T1 and T2 are equal to or less than 1/60 seconds (60 Hz or higher). In the first display period T1, the first display pattern 20A (FIG. 4A) is displayed on the liquid crystal display panel 2, and the first barrier patterns 10A (FIG. 5A) is formed on the switching liquid crystal panel 1. On the other hand, in the second display period T2, the second display pattern 20B (FIG. 4B) is displayed on the liquid crystal display panel 2, and the second barrier patterns 10B (FIG. 5B) is formed on the switching liquid crystal panel 1.

In FIGS. 6A and 6B, the right eye 10R of the observer is set as the first viewpoint, and the left eye 10L is set as the second viewpoint. In the first display period T1, the first to fourth viewpoint videos are sequentially assigned to the sub pixel row that is formed from the sub pixels R1, G1, and B1, the sub pixel row that is formed from the sub pixels R2, G2, and B2, the sub pixel row that is formed from the sub pixels R3, G3, and B3, and the sub pixel row that is formed from the sub pixels R4, G4, and B4 so as to be displayed on the liquid crystal display panel 2 in accordance with the first display pattern 20A. Such a display is observed through the first barrier pattern 10A (FIG. 5A) formed on the switching liquid crystal panel 1. Accordingly, as illustrated in FIG. 6A, only light transmitted from the sub pixels R1, G1, and B1 that form the first viewpoint video is recognized by the right eye 10R. On the other hand, only light transmitted from the sub pixels R2, G2, and B2 that form the second viewpoint video is recognized by the left eye 10L. Accordingly, in the first display period T1, a stereoscopic image that is based on the first viewpoint video and the second viewpoint video is perceived. FIG. 6A is a schematic diagram illustrating the configuration of a cross-section perpendicular to the screen (XY plane) in an area VIA surrounded by broken lines illustrated in FIG. 4A.

In addition, in the second display period T2 following the first display period T1, the first to fourth viewpoint videos are sequentially assigned to the sub pixel row that is formed from the sub pixels R1, G1, and B1, the sub pixel row that is formed from the sub pixels R2, G2, and B2, the sub pixel row that is formed from the sub pixels R3, G3, and B3, and the sub pixel row that is formed from the sub pixels R4, G4, and B4 so as to be displayed on the liquid crystal display panel 2 in accordance with the second display pattern 20B. Such a display is observed through the second barrier pattern 10B (FIG. 5B) formed by the switching liquid crystal panel 1. Accordingly, as illustrated in FIG. 6B, only light transmitted from the sub pixels R1, G1, and B1 that form the first viewpoint video is recognized by the right eye 10R. On the other hand, only light transmitted from the sub pixels R2, G2, and B2 that form the second viewpoint video is recognized by the left eye 10L. Accordingly, also in the second display period T2, a stereoscopic image that is based on the first viewpoint video and the second viewpoint video is perceived. FIG. 6B is a schematic diagram illustrating the configuration of a cross-section perpendicular to the screen (XY plane) in an area VIB surrounded by broken lines illustrated in FIG. 4B.

FIG. 7A illustrates an arrangement pattern 20A1 of sub pixels configuring the first viewpoint video that can be visually recognized by the right eye 10R in the first display period T1. On the other hand, FIG. 7B illustrates an arrangement pattern 20B1 of sub pixels configuring the first viewpoint video that can be visually recognized by the right eye 10R in the second display period T2. Here, unit pixels of the arrangement pattern 20A1 and the arrangement pattern 20B1 that correspond to each other are disposed at positions overlapping each other when relatively being moved in parallel in the screen vertical direction. The sub pixel row displayed in one arrangement pattern 20A1 is located between the sub pixel rows displayed in the other arrangement pattern 20B1. For example, the pixel 4A1 of the arrangement pattern 20A1 is in a positional relationship of overlapping the pixel 4A2 of the arrangement pattern 20B1 when being moved in the screen vertical direction by two sub pixels.

Since the first and second display periods T1 and T2 are extremely short, the arrangement pattern 20A1 and the arrangement pattern 20B1 are recognized as one video overlapping each other by the observer. In other words, as illustrated in FIG. 8, a composite video 20R that is acquired by composing the arrangement pattern 20A1 of the sub pixels illustrated in FIG. 7A and the arrangement pattern 20B1 of the sub pixels illustrated in FIG. 7B is recognized by the observer as the first viewpoint video acquired from the right eye 10R. Accordingly, through the first display period T1 and the second display period T2, as a result, the first viewpoint video is displayed by using a half of the total sub pixels disposed on the liquid crystal display panel 2. Therefore, the spatial resolution of the display of the first viewpoint video is improved to be double the resolution of a case where a time-divisional display is not performed (a case where the first viewpoint video is displayed in a space divisional manner in accordance with only one display pattern). Here, since the unit pixels of the arrangement pattern 20A1 and the arrangement pattern 20B1 that correspond to each other are present at positions that are relatively moved from each other in parallel in the screen vertical direction, the resolution of the first viewpoint video in the screen vertical direction is improved so as to be doubled.

In this embodiment, the first viewpoint video is observed by the right eye 10R, and the second viewpoint video is observed by the left eye 10L, whereby a stereoscopic image is perceived. However, a stereoscopic image can be observed by arbitrarily combining any two of the first to fourth viewpoint videos.

Advantages of First Embodiment

As above, according to this embodiment, the first to fourth viewpoint videos that are spatially divided are composed within one screen by sequentially displaying the first and second display patterns 20A and 20B that are divided in time. Accordingly, compared to a case where each viewpoint video is displayed in a space divisional manner by using only one display pattern, the resolution of the stereoscopic display can be improved. Here, of the first and second display patterns 20A and 20B, since the unit pixels configuring each viewpoint video are present at positions that are relatively moved from each other in parallel in the screen vertical direction, the resolution of each viewpoint video in the vertical direction can be further improved. As a result, a high-precision stereoscopic video can be displayed while improving a balance between the resolution in the screen horizontal direction and the resolution in the screen vertical direction. In addition, according to this embodiment, since the sub pixel row displayed in one arrangement pattern 20A is located between the sub pixel rows displayed in the other display pattern 20B, the homogeneity of the resolution of the composite video 20R within the screen can be acquired.

Second Embodiment

Next, a stereoscopic display device according to a second embodiment of the present disclosure will be described. The same reference numeral is assigned to a constituent portion that is substantially the same as that of the stereoscopic display device according to the above-described first embodiment, and the description thereof will be appropriately omitted.

In the above-described first embodiment, the liquid crystal display panel 2 alternately displays (time-divisional display) two types of display patterns (the first and second display patterns 20A and 20B), whereby the display positions of the first to fourth viewpoint videos are periodically switched between two states. In contrast to this, according to this embodiment, as illustrated in FIGS. 9 to 11, the liquid crystal display panel 2 sequentially displays (time-divisional display) three types of display patterns, whereby the display positions of first to sixth viewpoint videos are periodically switched among three states. The three types of the display patterns are displayed on the liquid crystal display panel 2 in the order of the first display period T1, the second display period T2, and the third display period T3.

FIGS. 9 to 11 represent three types of display patterns (first to third display patterns 25A to 25C) that are displayed on the liquid crystal display panel 2 in a time-divisional manner. As illustrated in FIGS. 9 to 11, first to sixth sub pixel rows that configure the first to sixth viewpoint videos extend so as to be parallel to one another in the diagonal direction and are periodically arranged in the X-axis direction. The first sub pixel row is configured by the sub pixels R1, G1, and B1. Similarly, the second sub pixel row is configured by the sub pixels R2, G2, and B2, the third sub pixel row is configured by the sub pixels R3, G3, and B3, the fourth sub pixel row is configured by the sub pixels R4, G4, and B4, the fifth sub pixel row is configured by the sub pixels R5, G5, and B5, and the sixth sub pixel row is configured by the sub pixels R6, G6, and B6. As a result, the stripe-shaped first to sixth viewpoint videos extending in the diagonal direction are periodically arranged in the X-axis direction.

In the first display pattern 25A illustrated in FIG. 9, the second display pattern 25B illustrated in FIG. 10, and the third display pattern 25C illustrated in FIG. 11, the positions of the unit pixels displaying the first to sixth viewpoint videos are different from one another. Here, the first display pattern 25A is displayed in the first display period T1, the second display pattern 25B is displayed in the second display period T2, and the third display pattern 25C is displayed in the third display period T3.

In FIGS. 9 to 11, hatching is applied only for the sub pixels R1, G1, and B1 that configure the first viewpoint video in the illustration. In the first to third display patterns 25A, 25B, and 25C, the unit pixels corresponding to each other are disposed at positions overlapping each other when being relatively moved in parallel in the Y-axis direction. For example, the pixel 4A1 of the first display pattern 25A1 is in the positional relationship of overlapping the pixels 4A2 and 4A3 of the second and third display patterns 25B and 25C by being moved in the Y-axis direction by two sub pixels or four sub pixels.

Also in this embodiment, since the first to third display periods T1 to T3 are an extremely a short time period, the first to third display patterns 25A, 25B, and 25C that are displayed in a time-divisional manner are recognized as one video acquired by overlapping the display patterns by an observer. In other words, for example, as the first viewpoint video acquired from the right eye 10R, a composite video 25R as illustrated in FIG. 12 is recognized. Accordingly, through the first to third display periods T1 to T3, as a result, the first viewpoint video is displayed by using a half of the total sub pixels disposed on the liquid crystal display panel 2. Therefore, the spatial resolution of the display of the first viewpoint video is improved to be double the resolution of a case where a time-divisional display is not performed (a case where the first viewpoint video is displayed in a space-divisional manner in accordance with only one display pattern). Here, in the first to third display patterns 25A, 25B, and 25C, the unit pixels that correspond to each other are present at positions that are relatively moved from each other in parallel in the screen vertical direction, and accordingly, the resolution of the first viewpoint video in the screen vertical direction is improved to be doubled. This similarly applies to the second to sixth viewpoint videos.

As above, according to this embodiment, the first to sixth viewpoint videos that are spatially divided are composed within one screen by sequentially displaying the first to third display patterns 25A to 25C that are divided in time. Accordingly, compared to a case where each viewpoint video is spatially divided by using one display pattern, the resolution at the time of displaying a stereoscopic view can be improved. Here, of the first to third display patterns 25A to 25C, the unit pixels configuring each viewpoint video are present at positions relatively moved in parallel in the screen vertical direction, and accordingly, the resolution of each viewpoint video in the vertical direction can be further improved. As a result, a high-precision stereoscopic video can be displayed while improving a balance between the resolution in the screen horizontal direction and the resolution in the screen vertical direction.

Third Embodiment

Next, a stereoscopic display device according to a third embodiment of the present disclosure will be described. The same reference numeral is assigned to a constituent portion that is substantially the same as that of the stereoscopic display device according to the above-described first embodiment, and the description thereof will be appropriately omitted.

In the above-described first embodiment, the liquid crystal display panel 2 alternately displays (time-divisional display) two types of display patterns (the first and second display patterns 20A and 20B), whereby the display positions of the first to fourth viewpoint videos are periodically switched between two states. In contrast to this, according to this embodiment, as illustrated in FIGS. 13A and 13B, the liquid crystal display panel 2 sequentially displays (time-divisional display) two types of display patterns, whereby the display positions of the first and second viewpoint videos are periodically switched between two states.

FIGS. 13A and 13B represent two types of display patterns (first and second display patterns 26A to 26B) that are displayed on the liquid crystal display panel 2 in a time-divisional manner. As illustrated in FIGS. 13A and 13B, first and second sub pixel rows that configure the first and second viewpoint videos extend so as to be parallel to each other in the diagonal direction and are alternately arranged in a repetitive manner in the X-axis direction. The first sub pixel row is configured by the sub pixels R1, G1, and B1, and the second sub pixel row is configured by the sub pixels R2, G2, and B2. As a result, the stripe-shaped first and second viewpoint videos extending in the diagonal direction are alternately arranged in the X-axis direction.

In the first display pattern 26A illustrated in FIG. 13A and the second display pattern 26B illustrated in FIG. 13B, the position of the unit pixel displaying the first viewpoint video and the position of the unit pixel displaying the second viewpoint video are interchanged. Here, the first display pattern 26A is displayed in the first display period T1, and the second display pattern 26B is displayed in the second display period T2.

Also in this embodiment, since the first and second display periods T1 to T2 are an extremely a short time period, the first and second display patterns 26A and 26B that are displayed in a time-divisional manner are recognized as one video acquired by overlapping both the display patterns by an observer. Accordingly, through the first and second display periods T1 and T2, consequently, the first viewpoint video and the second viewpoint video are respectively displayed by using all the sub pixels disposed on the liquid crystal display panel 2. Therefore, the spatial resolution of the display of the first and second viewpoint videos does not decrease.

EXAMPLES

Specific examples of the present disclosure will be described in detail.

Generally, according to the step barrier system, there are cases where, while the resolution balance at a specific number of viewpoints is improved, it is difficult to acquire sufficient resolution balance at the other numbers of viewpoints. For example, in the case of a stripe-shaped viewpoint video that is formed by sub pixels of a plurality of colors sequentially arranged in the diagonal direction and is divided in space and time, compared to the original two-dimensional display image, resolution deterioration as illustrated in the following Equations (1) and (2) occurs. Here, D denotes the number of display patterns displayed in a time-divisional manner, C denotes the number of types of colors of sub pixels, RV denotes a resolution deterioration index in the vertical direction, RH denotes a resolution deterioration index in the horizontal direction, and OP denotes the number of viewpoints. Here, a two-dimensional display panel is assumed to have a configuration in which sub pixels of the same color are aligned in the vertical direction, and sub pixels of different colors are sequentially aligned in the horizontal direction in a repetitive manner.

RV=D/OP (1)

RH=C/OP (2)

Here, when the resolution balance index K is defined as Equation (3), in a case where the resolution deterioration index RV in the vertical direction and the resolution deterioration index RH in the horizontal direction are the same, in other words, in a case where K=0, the best resolution balance is acquired. It can be stated that the resolution balance deteriorates as the resolution balance index K increases.

K=|log(RH/RV)| (3)

By rewriting Equation (3) based on Equations (1) and (2), the following equation is formed.

K=|log(C/D)| (4)

Thus, in this example, in a case where a stereoscopic video is displayed by sub pixels of three colors, a change in the resolution balance from that of the original two-dimensional display image is calculated. More specifically, changes in the resolution balance index K according to the number of viewpoints are acquired for a comparative example, Example 1, and Example 2 that satisfy the following conditions. The results are illustrated in FIG. 14. In addition, in display patterns that are divided in time, unit pixels corresponding to each other are configured so as to be located at positions overlapping each other when being relatively moved in parallel in the screen vertical direction.

Comparative Example
Case where Only a Space-Divisional Display is Performed, but a Time-Divisional Display is not Performed (D=1)
Example 1
Case where a Time-Divisional Display with the Number (OP/2) Of Divisions that is a Half of the Number (the Number Of Viewpoints OP) of Viewpoint Videos is Performed Together With a Space-Divisional Display
Example 2
Case where Time-Divisional Display with the Number of Divisions that is the Same as the Number OP of Viewpoints is Performed Together with a Space-Divisional Display

As illustrated in FIG. 14, in the comparative example in which only the space-divisional display is performed, a complete resolution balance can be acquired in a case where the number OP of viewpoints is nine, and as the number OP of viewpoints becomes farther from nine, the resolution balance index K further increases (in other words, the resolution balance deteriorates). In contrast to this, it can be understood that, in a case where the number OP of viewpoints is twice the number of display patterns (Example 1), the resolution balance is better than that of the comparative example when the number of viewpoints OP is four or six, and, in a case where the number OP of viewpoints is the same as the number of display patterns (Example 2), the resolution balance is better than that of the comparative example when the number OP of viewpoints is two, three, or four.

As above, the embodiments of the present disclosure have been described. However, the present disclosure is not limited to the above-described embodiments, and various changes can be made therein. For example, in the above-described embodiments, a case has been described in which the unit pixel of the two-dimensional display unit is configured by sub pixels of three colors R (red), G (green), and B (blue). However, in the present disclosure, the unit pixel may be configured by sub pixels of four or more colors (a combination of R (red), G (green), B (blue), and W (white) or Y (yellow)).

In addition, in the embodiment of the present disclosure, the number of viewpoint videos, the number of display patterns, and the combination thereof are not limited to those described in the above-described embodiments and the like. In other words, the display unit according to the embodiment of the present disclosure may compose p (here, p is an integer equal to or greater than two) viewpoint videos that are spatially divided within one screen by sequentially displaying q (here, q is an integer that is equal to or greater than two and is equal to or less than p) display patterns that are divided in time. Accordingly, it is preferable that the variable-type parallax barrier according to the embodiment of the present disclosure is configured such that arrangement states of a plurality of light transmitting portions and a plurality of light shielding portions can be changed in accordance with the q display patterns, and the p viewpoint videos configuring each one of the q display patterns displayed on the display unit are optically separated so as to enable a stereoscopic view at p viewpoints.

In addition, in the above-described embodiments, the variable-type parallax barrier as the optical separation device, the liquid crystal display panel as the two-dimensional display unit, and the back light as the light source are sequentially arranged from the observer side. However, the present disclosure is not limited thereto, and for example, the two-dimensional display unit, the optical separation device, and the light source may be sequentially arranged from the observer side. In such a case, as the two-dimensional display unit, for example, a transmissive-type liquid crystal display may be used.

Furthermore, in the above-described embodiments, a color liquid crystal display using the back light as the display unit has been described as an example. However, the present disclosure is not limited thereto. For example, a display using an organic EL device or a plasma display may be used.

In addition, in the above-described embodiments, although the shape of the opening in the barrier pattern is configured as a step shape, the present disclosure is not limited thereto. For example, the shape of the opening may be a stripe shape extending in the diagonal direction.

Furthermore, in the above-described embodiments, although the variable-type parallax barrier is used as the optical separation device, the present disclosure is not limited thereto. For example, a liquid crystal lens or a lenticular lens that applies an optical operation for transmitted light may be used as the optical separation device. The liquid crystal lens is formed by inserting a liquid crystal layer between one pair of transparent electrode substrates arranged so as to face each other with a predetermined gap interposed therebetween, and switching can be electrically performed between a state in which there is no lens effect and a state in which there is a lens effect in accordance with the state of a voltage applied between the one pair of transparent electrode substrates. Here, by appropriately adjusting the application voltage in the in-plane direction in accordance with a display pattern displayed on the display unit, the same effect as that of the variable-type parallax barrier can be acquired. The lenticular lens is formed by aligning a plurality of cylindrical lenses in one-dimensional direction. By changing the position of the lenticular lens in the screen horizontal direction with respect to the display unit, the same effect as that of the variable-type parallax barrier can be acquired.

The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2010-234798 filed in the Japan Patent Office on Oct. 19, 2010, the entire content of which is hereby incorporated by reference.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

STEREOSCOPIC DISPLAY DEVICE AND STEREOSCOPIC DISPLAY METHOD

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