Display device and display method

A display device includes a display portion including sub-pixels, and a light control portion overlapping the display portion. The display portion includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel is shaped in a parallelogram, and inclined at a first angle of greater than or equal to 4° and less than or equal to 16° with respect to the second direction. The light control portion is inclined at a second angle substantially equivalent to arctan (2/9) with respect to the second direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-204701, filed Oct. 23, 2017, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device and a display method.

BACKGROUND

Recently, various display devices enabling stereoscopic view with the naked eyes have been proposed. In such display devices, achieving more natural stereoscopic view is required. In one example, a technology of combining a display panel, which simultaneously displays multiple images different from each other in a horizontal direction, and a lenticular lens has been known. According to this technology, when a viewer observes the display panel through the lenticular lens, images observed when a viewpoint is changed horizontally are switched, and a motion parallax can be obtained.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprising: a display portion comprising sub-pixels arranged in a first direction and a second direction orthogonal to the first direction, the sub-pixels adjacent to each other in the first direction displaying colors different from each other, the sub-pixels adjacent to each other in the second direction displaying a same color; and a light control portion overlapping the display portion, wherein: the display portion includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel, each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel is shaped in a parallelogram, and inclined at a first angle of greater than or equal to 4° and less than or equal to 16° with respect to the second direction, the light control portion is inclined at a second angle substantially equivalent to arctan(2/9) with respect to the second direction.

According to another embodiment, a display method of a display device comprising: a display portion comprising sub-pixels arranged in a first direction and a second direction orthogonal to the first direction, the sub-pixels adjacent to each other in the first direction displaying colors different from each other, the sub-pixels adjacent to each other in the second direction displaying a same color; and a light control portion overlapping the display portion, the display portion including a red sub-pixel, a green sub-pixel, and a blue sub-pixel, each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel being shaped in a parallelogram, and inclined at a first angle of greater than or equal to 4° and less than or equal to 16° with respect to the second direction, the light control portion being inclined at a second angle substantially equivalent to arctan(2/9) with respect to the second direction, wherein: the sub-pixels adjacent to each other in the first direction display images identified when the display portion is observed from different viewpoints, of the viewpoints arranged in order in an observation plane; the sub-pixels in a first row display images corresponding to viewpoints represented as (3n−2), where n is an integer greater than or equal to 1; the sub-pixels in a second row display images corresponding to viewpoints represented as (3n); and the sub-pixels in a third row display images corresponding to viewpoints represented as (3n−1).

Embodiments will be described hereinafter with reference to the accompanying drawings. The disclosure is merely an example, and proper changes within the spirit of the invention, which are easily conceivable by a skilled person, are included in the scope of the invention as a matter of course. In addition, in some cases, in order to make the description clearer, the widths, thicknesses, shapes, etc., of the respective parts are schematically illustrated in the drawings, compared to the actual modes. However, the schematic illustration is merely an example, and adds no restrictions to the interpretation of the invention. In addition, in the specification and drawings, structural elements which function in the same or a similar manner to those described in connection with preceding drawings are denoted by like reference numbers, and redundant detailed description thereof is omitted unless necessary.

First Configuration Example

FIG. 1is a cross-sectional view showing a first configuration example of a display device1of the present embodiment. In the drawing, a first direction X and a second direction Y are orthogonal to each other, and a third direction Z is orthogonal to the first direction X and the second direction Y. In the present specification, a direction toward a pointing end of an arrow indicating the third direction Z is referred to as “upper” or “above”, and a direction toward the opposite side from the pointing end of the arrow is referred to as “lower” or “below”. When such expressions as “a second member above a first member” and “a second member below a first member” are used, the second member may be in contact with the first member or may be separated from the first member. Further, it is assumed that an observation position at which the display device1is to be observed is at the pointing end side of the arrow indicating the third direction Z, and observing from the observation position toward an X-Y plane defined by the first direction X and the second direction Y is called a planar view.

The display device1comprises a display panel10, a light control device20, and an illumination device30. The display panel10is, for example, a liquid crystal panel. The display panel10comprises a first substrate11and a second substrate12. The second substrate12is located above the first substrate11. The light control device20is located above the display panel10. Although details will be described later, the light control device20comprises a plurality of light control portions. The light control device20is fixed to the display panel10by a transparent resin40. The illumination device30is located below the display panel10. A first polarizer51is bonded to a lower surface11B of the first substrate11. A second polarizer52is bonded to an upper surface20A of the light control device20.

Alternatively, the second polarizer52may be bonded to an upper surface12A of the second substrate12, or bonded to a lower surface20B of the light control device20. Further, the light control device20may be located between the first polarizer51and the first substrate11. Furthermore, the light control device20may be incorporated in the display panel10.

FIG. 2is a plan view showing a configuration example of the display panel10shown inFIG. 1. The display panel10comprises a display portion DA at a portion where the first substrate11and the second substrate12overlap one another in planar view. The display portion DA comprises a plurality of sub-pixels SP arrayed in the first direction X and the second direction Y. In one example, as the sub-pixels SP, the display portion DA comprises a red sub-pixel SPR which displays red, a green sub-pixel SPG which displays green, and a blue sub-pixel SPB which displays blue. InFIG. 2, the red sub-pixel SPR is shown by a pattern including vertical lines parallel to the second direction Y, the green sub-pixel SPG is shown by a pattern including horizontal lines parallel to the first direction X, and the blue sub-pixel SPB is shown by a lattice pattern. In the following explanation, when the color of the sub-pixel is not particularly referred to, the sub-pixel may be simply referred to as the sub-pixel SP. The first direction X may be referred to as a horizontal direction, and the second direction Y may be referred to as a vertical direction. The sub-pixels SP arranged in the first direction X form row, and the sub-pixels SP arranged in the second direction Y form column.

The sub-pixels SP adjacent to each other in the first direction X are sub-pixels displaying colors different from each other. The sub-pixels SP adjacent to each other in the second direction Y are sub-pixels displaying the same color. For example, the red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB are arranged in this order in the first direction X, and constitute a main pixel PX. The main pixels PX are arranged in the first direction X and the second direction Y.

The red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB are each formed as a parallelogram, and inclined at a first angle θ1of greater than or equal to 4° and less than or equal to 16° with respect to the second direction Y. Further, the red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB each have the same dimension, and have a width WX along the first direction X and a width WY along the second direction Y. For example, the width WY is approximately three times larger than the width WX.

In the display portion DA, the sub-pixels SP located in an odd-numbered row LA are inclined in a direction different from the sub-pixels SP located in an even-numbered row LB. However, the angle formed by the sub-pixel SP located in the odd-numbered row LA with respect to the second direction Y is the same as the angle formed by the sub-pixel SP located in the even-numbered row LB with respect to the second direction Y.

For example, the sub-pixels SP located in the odd-numbered row LA are all inclined clockwise at the first angle θ1with respect to the second direction Y. Meanwhile, the sub-pixels SP located in the even-numbered row LB are all inclined counterclockwise at the first angle θ1with respect to the second direction Y. Note that the sub-pixels SP located in the odd-numbered row LA may be inclined counterclockwise at the first angle θ1with respect to the second direction Y, and the sub-pixels SP located in the even-numbered row LB may be inclined clockwise at the first angle θ1with respect to the second direction Y.

FIG. 3is a cross-sectional view showing a configuration example of the light control device20shown inFIG. 1. The light control device20comprises a base21, and a plurality of light restriction elements22. The base21is a transparent substrate formed of glass or resin, etc. The light restriction element22restricts light beams entering the light restriction element22, and serves as a light control portion. In one example, the light restriction element22comprises a light shield element23overlapping the sub-pixels SP arranged in the first direction X, and an aperture24overlapping at least one sub-pixel SP. In other words, a plurality of light shield elements23are arranged in the first direction X at intervals corresponding to the aperture24. The optical density (OD value) of the light shield element23should preferably be 3 or more. The light shield element23may be formed of a metal material such as a compound containing chromium, molybdenum, or silver, or may be formed of a black resin material. In the present embodiment, as the light restriction element22, for example, an emulsion mask is used.

The light shield element23has a width W23, and the aperture24has a width W24. Note that each of the width W23and the width W24is a length along the first direction X. A width W22of one light restriction element22or a pitch of light restriction elements22corresponds to the sum of the width W23and the width W24.

The width W23is greater than the width W24. The light shield element23overlaps, for example, twenty-two sub-pixels SP. The aperture24overlaps, for example, one sub-pixel SP. The apertures24which are adjacent to each other in the first direction X overlap the sub-pixels SP of different colors. For example, the aperture24located on the left side inFIG. 3overlaps the red sub-pixel SPR, and the aperture24located on the right side inFIG. 3overlaps the blue sub-pixel SPB.

In the example illustrated inFIG. 3, although the width W24is greater than the width WX of the sub-pixel SP, the size of the width is not limited to this example. The width W24may be equal to the width WX, or the width W24may be less than the width WX. When the width W24is less than the width WX, the number of light beams transmitted through the light restriction element22can be reduced, and the resolution of an image to be viewed can be improved. Meanwhile, from the standpoint of suppressing reduction in luminance of the image to be viewed, the width W24should preferably be substantially equal to the width WX, which is the width of at least one sub-pixel.

FIG. 4is a plan view showing a configuration example of the light control device20shown inFIG. 3.

The light control device20comprises the light restriction elements22arranged in the first direction X. The light shield element23and the aperture24which constitute the light restriction element22extend in a direction different from the first direction X and the second direction Y. Each of the light shield elements23includes a pair of edges E23arranged in the first direction X. The edges E23are parallel to each other. The aperture24is located between the edges E23, which are opposed to each other, of the light shield elements23that are adjacent to each other in the first direction X.

The light restriction elements22overlap the display portion DA shown inFIG. 2, and linearly extend over the sub-pixels SP located in the odd-numbered rows LA and the sub-pixels SP located in the even-numbered rows LB. Each of the light restriction element22, the light shield element23, and the aperture24is inclined at a second angle62with respect to the second direction Y. The second angle θ2is smaller than the first angle81. In the present embodiment, an extending direction of each of the light restriction element22, the light shield element23, and the aperture24can be defined as an extending direction of the edge E23. Each of the edges E23is inclined at the second angle θ2(about 12.5°), which is substantially equivalent to arctan(2/9) with respect to the second direction Y. Note that the second angle θ2intended in this specification may be an angle formed clockwise with respect to the second direction Y, or may be an angle formed counterclockwise with respect to the second direction Y.

According to the first configuration example of the present embodiment, the light control device20overlaps the display panel10comprising the display portion DA shown inFIG. 2, and moreover, comprises the light restriction elements22(the light control portions), which are inclined at the second angle82substantially equivalent to arctan(2/9), with respect to the sub-pixels SP inclined at the first angle θ1of greater than or equal to 4° and less than or equal to 16°. By defining the above first angle θ1and the second angle θ2, occurrence of a moiré between regularly arranged sub-pixels SP and regularly arranged light restriction elements22can be suppressed, and the resolution can be improved.

Second Configuration Example

FIG. 5is a cross-sectional view showing a second configuration example of the display device1of the present embodiment. The display device1shown inFIG. 5comprises a light control device60different from the light control device20of the display device1shown inFIG. 1. The light control device60comprises a plurality of lenses61. The light control device60includes a lens surface60A and a flat surface60B. The flat surface60B of the light control device60is fixed to the second polarizer52by the transparent resin40. The second polarizer52is bonded to the upper surface12A of the second substrate12. Details of the light control device60will be described later.

Third Configuration Example

FIG. 6is a cross-sectional view showing a third configuration example of the display device1of the present embodiment. The display device1shown inFIG. 6is different from the display device1shown inFIG. 5in that the position of the light control device60is different. More specifically, the lens surface60A of the light control device60is in contact with the second substrate12. Preferably, the light control device60should be fixed to an outer circumference of the display panel10though not described in detail. The second polarizer52is bonded to the flat surface60B of the light control device60. Details of the light control device60will be described later.

FIG. 7is a cross-sectional view showing a configuration example of the light control device60shown inFIGS. 5 and 6. The light control device60comprising a plurality of lenses61is formed of, for example, transparent glass or resin. The lenses61function as light control portions. The lenses61overlap a plurality of sub-pixels SP arranged in the first direction X. Each of the lenses61has a width W61along the first direction X. The lens61overlaps, for example, twenty-three sub-pixels SP.

FIG. 8is a plan view showing a configuration example of the light control device60shown inFIGS. 5 and 6. In the light control device60, the lenses61are arranged in the first direction X. Each of the lenses61extends in a direction different from the first direction X and the second direction Y. Each of the lenses61includes a pair of edges E61arranged in the first direction X. The edges E61are parallel to each other.

The lenses61overlap the display portion DA shown inFIG. 2, and linearly extend over the sub-pixels SP located in the odd-numbered rows LA and the sub-pixels SP located in the even-numbered rows LB. As in the first configuration example, the lenses61are inclined at the second angle θ2with respect to the second direction Y. In the present embodiment, an extending direction of each of the lenses61can be defined as an extending direction of the edges E61. Each of the edges E61is inclined at the second angle θ2, which is substantially equivalent to arctan(2/9) with respect to the second direction Y.

According to the second configuration example and the third configuration example of the present embodiment, the light control device60overlaps the display panel10comprising the display portion DA shown inFIG. 2, and moreover, comprises the lenses61(the light control portions), which are inclined at the second angle θ2substantially equivalent to arctan(2/9), with respect to the sub-pixels SP inclined at the first angle θ1of greater than or equal to 4° and less than or equal to 16°. By defining the above first angle θ1and the second angle θ2, the same advantage as that of the first configuration example can be obtained.

<Specific Example of Light Control>

The light restriction element22and the lens61will be described below as a light control portion100.

FIG. 9is an illustration showing an example of a layout of the sub-pixels SP in the display portion DA.FIG. 10is an illustration showing the relationship between a viewpoint in a virtual observation plane VP and the sub-pixels SP to be observed. A unit matrix U comprises a plurality of sub-pixels SP arrayed in a matrix in the first direction X and the second direction Y. In the unit matrix U, in one example, twenty-three sub-pixels SP are arranged in the first direction X, and nine sub-pixels SP are arranged in the second direction Y. In other words, the unit matrix U comprises two hundred and seven (23*9=207) sub-pixels SP.

The numbers assigned to the respective sub-pixels SP inFIG. 9correspond to the numbers assigned to the viewpoints arranged in order counterclockwise in the observation plane VP shown inFIG. 10. In one example, sixty-nine viewpoints exist in the observation plane VP. InFIG. 9, the sub-pixels SP indicated by the same number are observed from the same viewpoint. In three rows arranged continuously in the second direction Y, the unit matrix U comprises sixty-nine (23*3=69) sub-pixels SP in total. These sixty-nine sub-pixels SP are observed from different viewpoints, respectively. In other words, the sixty-nine sub-pixels SP are observed from sixty-nine viewpoints, respectively.

For example, in the first row L1shown inFIG. 9, the sub-pixels SP observed from the viewpoints represented as (3n−2), where n is an integer greater than or equal to 1, are arranged. In the second row L2, the sub-pixels SP observed from the viewpoints represented as (3n) are arranged. In the third row L3, the sub-pixels SP observed from the viewpoints represented as (3n−1) are arranged. The fourth row L4and the seventh row L7comprise the sub-pixels SP arranged similarly to the first row L1. The fifth row L5and the eighth row L8comprise the sub-pixels SP arranged similarly to the second row L2. The sixth row L6and the ninth row L9comprise the sub-pixels SP arranged similarly to the third row L3.

Each of the sub-pixels SP in the first row L1, the fourth row L4, and the seventh row L7displays an image corresponding to the viewpoint represented as (3n−2). Each of the sub-pixels SP in the second row L2, the fifth row L5, and the eighth row L8displays an image corresponding to the viewpoint represented as (3n). Each of the sub-pixels SP in the third row L3, the sixth row L6, and the ninth row L9displays an image corresponding to the viewpoint represented as (3n−1).

In the sub-pixels SP of the three consecutive rows, one of the red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB to be observed from the same viewpoint is included. Further, in order to realize color display at the same viewpoint, a set of all of the red sub-pixel SPR, the green sub-pixel SPG, and the blue sub-pixel SPB is included in the sub-pixels SP of the nine consecutive rows.

More specifically, as regards the sub-pixels to be observed from the same viewpoint, the sub-pixel of a first color is included in one of the rows from the first row L1to the third row L3, and the sub-pixel of a second color different from the first color is included in one of the rows from the fourth row L4to the sixth row L6, and the sub-pixel of a third color different from the first color and the second color is included in one of the rows from the seventh row L7to the ninth row L9. In one example, when the display portion DA is observed from viewpoint1, the green sub-pixel SPG is included in the first row L1, the blue sub-pixel SPB is included in the fourth row L4, and the red sub-pixel SPR is included in the seventh row L7.

InFIG. 10, visual lines (i.e., lines of sight) V1to V67are depicted. Visual lines V1to V67may be assumed as light beams restricted by the light control portions100. Visual lines V1to V67are line segments connecting between viewpoints1to67and the sub-pixels SP of the first row L1, respectively, when the viewer's eye is assumed to be at the corresponding viewpoint in the observation plane VP.

Note that viewpoints2and3that are not illustrated exist between viewpoints1and4in the observation plane VP. Also, visual lines V2and V3that are not illustrated exist between visual lines V1and V4. Visual line V2is a line segment connecting between viewpoint2and the sub-pixel SP indicated as “2” in the third row L3. Visual line V3is a line segment connecting between viewpoint3and the sub-pixel SP indicated as “3” in the second row L2. As described above, sixty-nine viewpoints1to69exist in the observation plane VP, sixty-nine sub-pixels SP indicated as “1” to “69” exist in the display portion DA, and sixty-nine visual lines V1to V69exist between the observation plane VP and the display portion DA.

The twenty-three sub-pixels SP arranged in the first direction X display images when the display portion DA is observed from the viewpoints corresponding to these sub-pixels. The viewer who is present at the observation plane VP can view the sub-pixel SP through one of the visual lines V1to V69when the display portion DA is observed through the light control portions100. The viewpoint in the observation plane VP is different in the right eye and the left eye of the viewer. Accordingly, the viewer can recognize a parallax as a result of different images being observed at different viewpoints, and a stereoscopic effect of the image can be obtained. Further, when the viewer changes the viewpoint along the observation plane VP, images according to the sixty-nine viewpoints can be observed, respectively, and more natural stereoscopic effect can be obtained.

FIG. 11is a plan view showing the sub-pixels SP to be observed when the light restriction elements22are applied as the light control portions100. The light control device20overlaps the unit matrix U. The aperture24in the light restriction elements22extends linearly over the sub-pixels SP from the first row L1to the ninth row L9.

In the example illustrated inFIG. 11, in the sub-pixel SP, when the width WX is assumed as 1, the width WY is 3. The first angle θ1is 15°, and the second angle θ2is 12.5°. In a state in which the light control device20overlaps the unit matrix U, the aperture24overlaps each of the green sub-pixel SPG indicated as “1”, the blue sub-pixel SPB indicated as “1”, and the red sub-pixel SPR indicated as “1”. Accordingly, when the display portion DA is observed from viewpoint1shown inFIG. 10, the green sub-pixel SPG, the blue sub-pixel SPB, and the red sub-pixel SPR corresponding to this viewpoint can be observed.

FIG. 12is a plan view showing the sub-pixels SP to be observed when the lenses61are applied as the light control portions100. Each of the lenses61extends linearly over the sub-pixels SP from the first row L1to the ninth row L9.

In the example illustrated inFIG. 12, in the sub-pixel SP, when the width WX is assumed as 1, the width WY is 3. The first angle θ1is 15°, and the second angle θ2is 12.5°. In a state in which the light control device20overlaps the unit matrix U, the green sub-pixel SPG, the blue sub-pixel SPB, and the red sub-pixel SPR, which are all indicated as “1”, are located on the same straight line parallel to the extending direction of the lens61. Accordingly, when the display portion DA is observed from viewpoint1shown inFIG. 10, the green sub-pixel SPG, the blue sub-pixel SPB, and the red sub-pixel SPR corresponding to this viewpoint can be observed.

FIG. 13is an illustration showing a display example of a display device of a comparative example.FIG. 14is an illustration showing a display example of the display device1of the present embodiment.

The comparative example shown inFIG. 13corresponds to an example in which a display portion DA of a layout disclosed in FIG. 7 of JP 2005-316372 A overlaps the light control portions100of the present embodiment. Although the display portion DA displays a character string “ABODE”, when the display portion DA is observed through the light control portions100, it is difficult to recognize that character string.

According to the present embodiment shown inFIG. 14, when the display portion DA is observed through the light control portions100, the character string “ABODE” displayed on the display portion DA can be recognized, and a moire did not occur.

As explained above, according to the present embodiment, a display device and a display method capable of improving display quality can be provided.

The present invention is not limited to the embodiments described above but the constituent elements of the invention can be modified in various manners without departing from the spirit and scope of the invention. Various aspects of the invention can also be extracted from any appropriate combination of a plurality of constituent elements disclosed in the embodiments. For example, some structural elements may be deleted from the entire structural elements in the embodiments. Furthermore, structural elements described in different embodiments may be combined suitably.

An example of a display device which can be obtained from the structure disclosed in the present specification is noted as follows:

(1) A display device comprising:

a display portion comprising sub-pixels arranged in a first direction and a second direction orthogonal to the first direction, the sub-pixels adjacent to each other in the first direction displaying colors different from each other, the sub-pixels adjacent to each other in the second direction displaying a same color; and

a light control portion overlapping the display portion, in which:

the display portion includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel,

each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel is shaped in a parallelogram, and inclined at a first angle of greater than or equal to 4° and less than or equal to 16° with respect to the second direction,

the light control portion is inclined at a second angle substantially equivalent to arctan(2/9) with respect to the second direction.

(2) The display device according to (1), in which the light control portion is a light restriction element or a lens,

the light restriction element comprises a light shield element overlapping the plurality of sub-pixels arranged in the first direction, and an aperture overlapping at least one of the sub-pixels,

the lens overlaps the plurality of sub-pixels arranged in the first direction.

(3) The display device according to (1) or (2), in which in the display portion, the sub-pixels of one of an odd-numbered row and an even-numbered row are inclined clockwise at the first angle with respect to the second direction, and the sub-pixels of the other one of the odd-numbered row and the even-numbered row are inclined counterclockwise at the first angle with respect to the second direction.

(4) The display device according to (3), in which the light control portion is linearly extended over the sub-pixel in the odd-numbered row and the sub-pixel in the even-numbered row.

(5) The display device according to any one of (1) to (4) comprising:

a display panel comprising the display portion; and

a light control device comprising the light control portions arranged in the first direction.

(6) A display method of a display device comprising:

a display portion comprising sub-pixels arranged in a first direction and a second direction orthogonal to the first direction, the sub-pixels adjacent to each other in the first direction displaying colors different from each other, the sub-pixels adjacent to each other in the second direction displaying the same color; and

a light control portion overlapping the display portion,

the display portion including a red sub-pixel, a green sub-pixel, and a blue sub-pixel,

each of the red sub-pixel, the green sub-pixel, and the blue sub-pixel being shaped in a parallelogram, and inclined at a first angle of greater than or equal to 4° and less than or equal to 16° with respect to the second direction,

the light control portion being inclined at a second angle substantially equivalent to arctan(2/9) with respect to the second direction, in which:

the sub-pixels adjacent to each other in the first direction display images identified when the display portion is observed from different viewpoints, of the viewpoints arranged in order in an observation plane;

the sub-pixels in a first row display images corresponding to viewpoints represented as (3n−2), where n is an integer greater than or equal to 1;

the sub-pixels in a second row display images corresponding to viewpoints represented as (3n); and

the sub-pixels in a third row display images corresponding to viewpoints represented as (3n−1).