[Related Applications]

[0001]

The present Application for Patent claims priority to Japanese Patent Application No. 2012-244546, entitled "Three-Dimensional Display Device," filed November 6, 2012, assigned to the assignee hereof and hereby expressly incorporated by reference herein. [Field of Technology]

[0002]

The present invention relates to a three-dimensional display device.

[Prior Art]

[0003] A MEMS display (Micro Electro Mechanical System display) is a display that is anticipated to replace the liquid crystal display (Referencing Patent Citation 1). This display differs from the liquid crystal shutter system that is used for deflecting light in that a window through which the light passes is opened and closed through a mechanical shutter system. Specifically, a shutter is provided for each pixel on a TFT (Thin Film Transistor) substrate whereon TFTs are formed, and the shutter is caused, through electrostatic force, to move in the horizontal direction, to display an image by opening and closing an opening portion. [Prior Art Citation]

[Patent Citation]

[0004]

[Patent Citation 1] Japanese Unexamined Patent Application Publication 2008-197668

[Summary of the Invention]

[Problem Solved by the Present Invention]

[0005]

In recent years products that respond to the demand for three-dimensional displays of images have been developed, and liquid crystal display devices that are provided with parallax barrier liquid crystal panels, for naked-eye viewing, are known in small-and midsized devices for mobile telephones and mobile information terminals. A parallax barrier liquid crystal panel is stacked on top of a liquid crystal display panel, making it difficult to reduce the thickness of the display device, and reducing optical efficiency, and there is also a problem in that the number of components is large when compared to the structure for displaying a two-dimensional image, thus increasing the cost. [0006]

The object of the present invention is to provide a three-dimensional display device that can be made thinner, that has superior optical efficiency, and that does not increase the number of parts when compared to a structure for displaying a two-dimensional image. [Means for Solving the Problem]

[0007]

(1) A three-dimensional display device according to the present invention comprises: a first substrate a first light blocking film formed on the first substrate; a second substrate disposed so as to face the first substrate with a gap therebetween; a second light blocking film that is formed on the second substrate; a plurality of shutters and respective driving portions for driving the shutters disposed between the first substrate and the second substrate; and a backlight disposed so as to emit light toward the first substrate from the second substrate, wherein: the first light blocking film has a plurality of first fixed openings for forming a plurality of pixels, wherein one pixel is formed from a pair of a right opening that is formed from at least one first fixed opening and a left opening that is formed from at least one other first fixed opening; the second light blocking film has a plurality of second fixed openings that are positioned with their centers shifted with respect to the centers of the first fixed openings; light that passes through one of the plurality of second fixed openings travels obliquely to a right opening and/or a left opening; light directed respectively to the right opening or to the left opening is controlled to be passed or be blocked by a shutter; and light that has passed through the right opening and light that has passed through the left opening travel in directions that are away from each other on the outside of the first substrate. In this invention, the light that passes through the right-side opening advances in a different oblique direction than the light that passes through a left-side opening, so that the left and right eyes of a person will perceive different two-dimensional images, so that the brain will construct a three-dimensional space based on the two two-dimensional images. This enables the device to be made thinner than a structure wherein a parallax barrier liquid crystal panel is stacked on top of a liquid crystal display panel, has superior optical efficiency because there is no passage through a liquid crystal, and has the same structure as a display for displaying a two- dimensional image, and thus there is no increase in the number of components.

[0008]

(2) In a three-dimensional display device as set forth in (1), light that travels in different directions through the same second fixed opening may pass respectively through the right opening and the left opening. [0009]

(3) A three-dimensional display device as set forth in (1) or (2), may be such that the plurality of first fixed openings and the plurality of second fixed openings are each longer in one direction than in another.

[0010]

(4) A solid-state display device as set forth in (3) may be such that the plurality of first fixed openings is formed so as to each be longer in the same direction; and the plurality of second fixed openings is formed so as to each be longer in the same direction in which the plurality of first fixed openings are longer.

[001 1]

(5) A solid-state display device as set forth in (4) may be such that at least one of the first fixed openings that forms a right opening and at least one of the first fixed openings that forms a left opening are disposed with a gap therebetween, and each is formed so as to be longer in the direction that is perpendicular to the gap.

[0012]

(6) A three-dimensional display device as set forth in (3) may be such that the plurality of pixels includes first pixels and second pixels; either the first pixels or the second pixels are used in displaying an image, and the others are controlled so that the light emanating from them is blocked; the first pixels are formed from first right openings and first left openings; the second pixels are formed from second right openings and second left opening; at least one first fixed opening that forms a first right opening and at least one first fixed opening that forms a first left opening are disposed with a gap therebetween in a X direction and are shifted with respect to each other in a Y direction that is perpendicular to the X direction, and each is formed so as to be longer in the Y direction than in the X direction; and at least one first fixed opening that forms a second right opening and at least one first fixed opening that forms a second left opening are disposed with a gap therebetween in a Y direction and are shifted with respect to each other in a X direction, and each is formed so as to be longer in the X direction than in the Y direction.

[0013]

(7) A three-dimensional display device as set forth in (3) may be such that the plurality of pixels includes n sets of pixels; when one of the n sets of pixels is used in displaying an image, the other pixels are controlled so as to block the light; the n sets of pixels are formed from n pairs of right openings and left openings; and each of the pairs of right openings and left openings are disposed with gaps therebetween along one of n lines that are positioned rotated around a point with angles of 180°/n from each other.

[Brief Descriptions of the Drawings]

[0014]

FIG. 1 is a schematic cross-sectional diagram of a three-dimensional display device according to an embodiment according to the present invention.

FIG. 2 is a diagram for explaining the shapes and arrangements of the first fixed openings and the second fixed openings.

FIG. 3 is a perspective diagram of a shutter and a driving portion thereof.

FIG. 4 is a schematic diagram of a three-dimensional display device according to a first modified example of the embodiment according to the present invention.

FIG. 5 is a schematic diagram of a three-dimensional display device according to a second modified example of the embodiment according to the present invention.

FIG. 6 is a schematic diagram of a three-dimensional display device according to a third modified example of the embodiment according to the present invention.

[Most Preferred Form for Carrying Out the Invention]

[0015]

An embodiment according to the present invention will be explained below in reference to the drawings.

[0016]

FIG. 1 is a schematic cross-sectional diagram of a three-dimensional display device according to an embodiment according to the present invention. The three-dimensional display device has a first substrate 10 (for example, a glass substrate). The first substrate 10 is a circuit substrate or a TFT (Thin Film Transistor) substrate whereon thin film transistors or interconnections, or the like, not shown, are formed. A first light blocking film 12 is formed on the first substrate 10. The first light blocking film 12 has a plurality of first fixed openings 16, for forming a plurality of pixels 14 (referencing FIG. 2).

[0017]

A second substrate 18 (for example, a glass substrate) is disposed so as to face the first substrate 10 with a gap therebetween. A second light blocking film 20 is formed on the second substrate 18. The second light blocking film 20 has a plurality of second fixed openings 22. The second fixed openings 22 are located so that the centers thereof are shifted from all of the first fixed openings 16. Note that the first fixed openings 16 and the second fixed openings 22 may be shifted so as to not overlap whatsoever, or may instead have the end portions thereof overlapping, as illustrated in FIG. 1 and FIG. 2.

[0018]

FIG. 2 is a diagram for explaining the shapes and arrangements of the first fixed openings 16 and the second fixed openings 22. The plurality of first fixed openings 16 are formed so as to each be longer in some direction (for example, the same direction). A single pixel 14 is formed from a pair that is at least one right opening RO that is made from a first fixed opening 16 and another at least one left opening LO that is made from another first fixed opening 16. The at least one first fixed opening 16 that forms the right opening RO and the at least one first fixed opening 16 that forms the left opening LO are disposed with a gap therebetween. The first fixed openings 16 are longer in the direction that is perpendicular to this gap.

[0019]

A plurality of second fixed openings 22 are formed so as to be longer in some direction (for example, the same direction). Each of the plurality of second fixed openings 22 is formed so as to be longer in the same direction as the direction in which the plurality of first fixed openings 16 are longer. The spacing between adjacent second fixed openings 22 is larger than the spacing between adjacent right openings RO and left openings LO.

[0020]

As illustrated in FIG. 1, the three-dimensional display device has a backlight 24. The backlight 24 is stacked on the second substrate 18. This causes the backlight 24 to emit light from the second substrate 18 toward the first substrate 10. The respective light that passes through the second fixed openings 22 advances obliquely in the direction of a right opening RO and/or a left opening LO. The light that passes through the right opening RO and the light that passes through the left opening LO travel in directions that separate from each other on the outside of the first substrate 10. The light that passes through the right opening RO and the light that passes through the left opening LO each respectively travels in respective directions that mutually approach each other from separate second fixed openings 22, to travel in directions that mutually separate from each other after intersecting.

[0021]

A plurality of shutters 26 are provided between the first substrate 10 and the second substrate 18. A plurality (a large number) of shutters 26 are provided on the first substrate 10. The shutters 26 are provided on, for example, thin film transistors or interconnections, or the like, not shown. [0022]

FIG. 3 is a perspective diagram of a shutter and of the driving portion thereof. The shutter 26 is made from an inorganic material. A shutter 26 is supported by first springs 28, so as to be suspended from the first substrate 10. The shutter 26 is supported by a plurality of first springs 28. A first spring 28 is secured to the first substrate 10 by a first anchor portion 30. The first spring 28 is made from a material that can deform elastically. The first spring 28 has a plate shape wherein the thickness is thin, and is disposed so that the direction of thickness thereof is directed in a crosswise direction (a direction that is parallel to the plane of the first substrate 10), with its own crosswise direction directed in the vertical direction (the direction that is perpendicular to the plane of the first substrate 10). This makes it possible to deform in the crosswise direction, which is the direction of thickness of the first spring 28. The shutter 26 is supported on the first spring 28 so as to be able to move in the direction indicated by the arrow in FIG. 3.

[0023]

Second springs 34, supported by second anchor portions 32, are provided on the first substrate 10. The second springs 34 are also made from a material that can deform elastically. A second spring 34 is disposed with the direction of thickness thereof directed in a crosswise direction (a direction that is parallel to the plane of the first substrate 10), with its own crosswise direction thereof directed in the vertical direction (the direction that is

perpendicular to the plane of the first substrate 10). This enables the second spring 34 to deform in the crosswise direction, which is the direction of thickness of the second spring 34. Moreover, the second spring 34 is formed in a looped shape, where a band portion that extends from the second anchor portion 32 is bent so as to fold back, to return to the same second anchor portion 32.

[0024]

The second spring 34 faces the first spring 28 on the side that is further away from the shutter 26 than the first spring 28. When a voltage is applied to the second anchor portion 32, the first spring 28 is pulled toward the second spring 34 by the electrostatic attraction produced through the potential difference with the first spring 28. When the first spring 28 is pulled closer, the shutter 26 is also pulled closer. That is, the first spring 28 and the second spring 34 form a driving portion 36 for mechanically driving the shutter 26. The driving portion 36 is formed from the same material as at least a portion of the shutter 26. [0025]

As illustrated in FIG. 1 , the lights that are directed respectively toward the right opening RO and the left opening LO each have the passage or blockage thereof controlled by one of the shutters 26. The shutter 26 for the right opening RO and the shutter 26 for the left opening LO correspond to a single pixel 14, where an image is displayed through a large number of pixels 14. For this reason, a plurality (a large number) of shutters 26 are provided. The shutter 26 and the driving portion 36 are disposed in a display region for displaying an image depending on whether or not light passes through the left opening RO and the right opening LO, and the timing of the emissions.

[0026]

In the present embodiment, the light that passes through the right opening RO and the light that passes through the left opening LO travel in different oblique directions. The light that passes through the right opening RO enters into the right eye (the eye on the left side when facing), and the light that passes through the left opening LO enters into the left eye (the eye on the right side when facing). Given this, the left and right eyes perceive different two- dimensional images, and the brain constructs a three-dimensional space based on the two two-dimensional images. As a result, in comparison to the structure wherein a parallax barrier liquid crystal panel is layered on a liquid crystal display panel, the device can be made thinner, the light efficiency is superior, due to not passing through the liquid crystal, and the number of parts is not increased due to having the same structure as that for displaying a two- dimensional image.

[0027]

The first substrate 10 and the second substrate 18 are secured together, with a gap therebetween, by a seal material 38, illustrated in FIG. 1. The seal material 38 tightly seals together the mutually facing surfaces of the first substrate 10 and the second substrate 18. A space is sealed, by the seal material 38, between the first substrate 10 and the second substrate 18. The space is filled with a liquid 40 (for example, an oil, such as silicone oil). The shutter 26 and the driving portion 36 are disposed in the liquid 40. The vibration due to the motion of the shutter 26 and the driving portion 36 can be suppressed by the liquid 40, and adhesion of the first spring 28 and the second spring 34 can also be prevented thereby. When the first substrate 10 and the second substrate 18 are made out of glass, then the use of a liquid 40 that has an index of refraction that is near to that of glass makes it possible to reduce reflections of light at the interfaces with the first substrate 10 and the second substrate 18 through the filling with the liquid 40. [0028]

FIG. 4 is a schematic cross-sectional diagram of a three-dimensional display device according to a first modified example of the embodiment according to the present invention. In this example, lights that travel in different directions through the second fixed opening 122 pass through the respective right opening RO and left opening LO. In this example as well, the light that passes through the right opening RO and the light that passes through the left opening LO travel in different oblique directions, enabling different two-dimensional images to be perceived by the left and right eyes. In this way, there is no need for a one-to-one correspondence between the right opening RO and the left opening LO and the second fixed opening 122.

[0029]

FIG. 5 is a schematic cross-sectional diagram of a three-dimensional display device according to a second modified example of an embodiment according to the present invention. In this example, a plurality of pixels 214 includes first pixels 242 and second pixels 244. When either the first pixels 242 or the second pixels 244 are used in displaying an image, the light of the others is controlled by shutters 26 (referencing FIG. 1) so as to be blocked. The first pixel 242 is formed from a first right opening RO 1 and a first left opening LO 1. At least one first fixed opening 216 that forms a first right opening RO 1 , and at least one first fixed opening 216 that forms a first left opening LO 1 are disposed with a gap therebetween in the X direction and shifted in the Y direction, which is perpendicular to the X direction, and each is shaped so as to be longer in the Y direction.

[0030]

The second pixel 244 is formed from a second right opening R02 and a second left opening L02. At least one first fixed opening 216 that forms a second right opening R02, and at least one first fixed opening 216 that forms a second left opening L02 are disposed with a gap therebetween in the Y direction and are shifted with respect to each other in the X direction, and each is shaped so as to be longer in the X direction.

[0031]

In this example, the three-dimensional display device enables a three-dimensional display by the first pixels 242 if disposed so that the X axis is horizontal, and enables a three- dimensional display by the second pixels 244 if disposed so that the Y axis is horizontal. That is, the display is possible even if the three-dimensional display device is rotated, centered on one point of the display screen, by 90° either to the left or to the right. [0032]

FIG. 6 is a schematic diagram of a three-dimensional display device according to a third modified example of an embodiment according to the present invention. In this example, the plurality of pixels 3 14 include n sets of pixels (which, in the example in FIG. 6, are first pixels 346, second pixels 348, third pixels 350, and fourth pixels 352). When one of the n sets of pixels 3 14 is used in an image display, the light for the remaining pixels 3 14 is controlled by the shutters 26 (referencing FIG. 1) so as to be blocked. Each of the pixels 314 is formed from a pair of a right opening RO and a left opening LO.

[0033]

The right opening RO and the left opening LO of a first pixel 346 are disposed with a gap therebetween along a line Li. The right opening RO and the left opening LO of a second pixel 348 are disposed with a gap therebetween along a line L2. The right opening RO and the left opening LO of a third pixel 350 are disposed with a gap therebetween along a line L ₃ . The right opening RO and the left opening LO of a fourth pixel 352 are disposed with a gap therebetween along a line L ₄ .

[0034]

That is, each of the pairs of right openings RO and left opening LO are disposed, with gaps therebetween, along one of n lines Li, L ₂ , L ₃ , or L ₄ , which are at positions that are rotated around and centered on a point at angles of 180°/n from each other.

[0035]

In the example illustrated in FIG. 6, the three-dimensional display device enables a three- dimensional display through the first pixels 346 if oriented so that the line i is horizontal, a three-dimensional display through the second pixels 348 if oriented so that the line L2 is horizontal, a three-dimensional display through the third pixels 350 if oriented so that the line L3 is horizontal, and a three-dimensional display through the fourth pixels 352 if oriented so that the line L ₄ is horizontal. That is, the three-dimensional image display is possible even if the three-dimensional display device is rotated by 45°, 90°, or 135°, either to the left or to the right, around a point on the display screen.

[0036]

The present invention is not limited to the embodiments set forth above, but rather may be modified in a variety of ways. Moreover, the structure explained in the embodiments can be replaced with other structures that are essentially identical, other structures that provide identical effects of operations, or other structures that achieve the same object.

[Explanation of Codes] [0037]

10: First Substrate

12: First Light Blocking Film

14: Pixel

16: First Fixed Opening

18: Second Substrate

20: Second Light Blocking Film

22: Second Fixed Opening

24: Backlight

26: Shutter

28: First Spring

30: First Anchor Portion

32: Second Anchor Portion

34: Second Spring

36: Driving Portion

38: Seal Material

40: Liquid

122: Second Fixed Opening

214: Plurality of Pixels

216: First Fixed Opening

242: First Pixel

244: Second Pixel

314: Pixel

346: First Pixel

348: Second Pixels

350: Third Pixel

352: Fourth Pixel

RO: Light Opening

LO: Left Opening

ROl : First Right Opening

LOl : First Left Opening

R02: Second Right Opening

L02: Second Left Opening

Li, L ₂ , L ₃ , L ₄ : Lines