JP2018194806A - Display device - Google Patents

Abstract

To provide a display device that can prevent a non-video area from being visually recognized, the non-video area resulting from a non-pixel area present between pixels of a video source.SOLUTION: An optical sheet 20 has unit shapes 21a that are formed in a convex shape or a concave shape, and the unit shapes 21a are arranged at least in a specific arrangement direction in a sheet surface orthogonal to a thickness direction of the optical sheet 20. The optical sheet 20 diffuses light in an arrangement direction of the unit shapes 21a, and diffusion of light diffused by the optical sheet 20 has directivity with respect to the direction in the sheet surface of the optical sheet 20.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a display device that displays an image to an observer.

2. Description of the Related Art Conventionally, a head-mounted display device, a so-called head mounted display (HMD), that allows an observer to observe an image from an image source such as an LCD (Liquid Crystal Display) or an organic EL display through an optical system has been proposed. (For example, patent document 1). Such a head-mounted display device enlarges image light projected from an image source by an optical system such as a lens and displays a clear image to an observer.
A video source used in such a display device is provided with a plurality of pixel regions constituting a video and non-pixel regions that are provided between the pixel regions and do not contribute to video display. When the image light emitted from such an image source is enlarged by a lens, not only the image constituted by the pixel area, but also the non-image area caused by the non-pixel area is enlarged, and only the image is obtained. In some cases, the non-video area may be visually recognized by the observer, which may hinder the display of a clear video.

Special table 2011-509417 gazette

  The subject of this invention is providing the display apparatus which can suppress that the non-image area | region resulting from the non-pixel area | region which exists between the pixels of an image source originates.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

  According to a first aspect of the present invention, there is provided an image source (11) that emits image light, a lens (12) that expands and emits the image light toward an observer, the image source (11), and the lens (12). An optical sheet (20) disposed between the optical sheet (20), and the diffusion of the light diffused by the optical sheet (20) has a direction in which the diffusion is greatest with respect to the direction in the sheet plane of the optical sheet (20). It is a display device (1) having the property.

  According to a second invention, in the display device (1) according to the first invention, the diffusion of the light diffused by the optical sheet (20) has a diffusion angle in a direction in which the diffusion is the largest and a diffusion angle in the direction in which the diffusion is the smallest. It is a display device (1) characterized by being 10 times or more of the diffusion angle.

  According to a third invention, in the display device (1) according to the first invention or the second invention, the optical sheet (20) has a unit shape (21a) formed in a convex shape or a concave shape. The unit shapes (21a) are arranged in a specific arrangement direction at least in the sheet plane orthogonal to the thickness direction of the optical sheet (20), and the optical sheet (20) is formed of the unit shape (21a). The light diffuses in the arrangement direction, and the unit shape (21a) extends in a first direction in the sheet surface orthogonal to the thickness direction of the optical sheet (20), and the first shape in the sheet surface The second direction orthogonal to the direction is arranged as the specific arrangement direction, and the direction in which the diffusion of the light diffused by the optical sheet (20) is the largest is the specific arrangement direction. The display device (1) to be used.

  According to a fourth invention, in the display device (1) according to any one of the first to third inventions, the video source (11) is configured by arranging a plurality of pixels side by side, The direction in which the center distance between the pixels is closest is defined as the first proximity arrangement direction, which is different from the first proximity arrangement direction, and is next to the first proximity arrangement direction. A direction in which the center distances are close to each other is defined as a second adjacent arrangement direction, which is different from the first adjacent arrangement direction and the second adjacent arrangement direction, and is next to the second adjacent arrangement direction. A direction in which the center distance between pixels is close is defined as a third proximity arrangement direction, and is a direction different from the first proximity arrangement direction to the third proximity arrangement direction, and the third proximity arrangement direction The one where the center distance between the pixels is next to Is defined as the fourth adjacent arrangement direction, an integer of 3 or more is N, and the following pixel is a direction different from the first adjacent arrangement direction to the Nth adjacent arrangement direction, and is the pixel next to the Nth adjacent arrangement direction. The direction in which the center distance between the pixel and the pixel is close is defined as the (N + 1) th adjacent arrangement direction, and the direction with the largest diffusion has an angle within ± 2 degrees with respect to the Nth adjacent arrangement direction. The center distance in the direction corresponding to the direction in which the diffusion is largest among the center distances between the pixels in the Nth adjacent arrangement direction is the center between the pixels in the first adjacent arrangement direction. The display device (1) is characterized by being within 7 times the distance.

  According to a fifth invention, in the display device (1) according to the fourth invention, the direction in which the diffusion is the largest is an angle of ± 5 degrees or more with respect to the first adjacent arrangement direction and the second adjacent arrangement direction. The display device (1) is characterized by being arranged with

  According to a sixth aspect of the present invention, in the display device (1) according to the fourth aspect of the present invention, the direction in which the diffusion is greatest is arranged with an angle of ± 10 degrees or more with respect to the first adjacent arrangement direction. The display device (1) is characterized in that the display device (1) is arranged with an angle of ± 5 degrees or more with respect to the second adjacent arrangement direction.

  According to a seventh invention, in the display device (1) according to the fourth invention, the direction in which the diffusion is the largest is the same direction as the Nth adjacent arrangement direction. It is.

  According to an eighth aspect of the present invention, in the display device (1) according to the fourth aspect of the present invention, a straight line drawn in a direction along the direction in which the diffusion is the largest and passing through the outermost diameter portion of the pixel. When the video source (11) is virtually divided into a region including the pixel and a region not including the pixel, the area ratio of the region including the pixel is 80% or more. A display device (1) characterized in that a direction in which the diffusion is greatest is provided.

  According to a ninth aspect, in the display device (1) according to the eighth aspect, a direction in which the diffusion is the largest is provided so that an area ratio of a region including the pixels is 100%. A display device (1) characterized by the following.

  According to a tenth aspect of the present invention, in the display device (1) according to the fourth aspect of the invention, the video source (11) is configured by arranging the pixels of a plurality of colors side by side, and in the direction in which the diffusion is the largest. The display device (1) is characterized in that pixels of different colors are included and arranged.

  An eleventh aspect of the invention is the display device (1) according to any one of the first to tenth aspects of the invention, wherein the optical sheet (20) is on the image source (11) side with respect to the direction in which the diffusion is the largest. When the half-value angle of the transmitted light that is incident from the surface of the light at an incident angle of 0 ° and is emitted to the viewer side is α, and the diffusion angle at which the luminance of the transmitted light is 1/20 of the maximum luminance is β, β ≦ The display device (1) is characterized by satisfying 5 × α.

と定義し、前記単位形状（２１ａ）が形成された界面と前記映像源（１１）の表示層との間の距離をＬ１とし、前記第Ｎ近接配列方向のいずれかの近接配列方向うち、前記拡散が最も大きい方向に最も近い方向について、その近接配列方向を規定している画素配列ピッチをＰＰとしたとき、５≦θａｖｅ１×Ｌ１／ＰＰ≦６０を満たすこと、を特徴とする表示装置（１）である。 According to a twelfth aspect, in the display device (1) according to any one of the first to eleventh aspects, the luminance at the diffusion angle θ of the unit shape (21a) is I ₁ (θ), When the distance between the lens (12) and the interface on which the unit shape (21a) is formed is K1, and the effective radius of the lens (12) is R3, the average diffusion angle θave1 of the unit shape (21a) The

The distance between the interface on which the unit shape (21a) is formed and the display layer of the video source (11) is L1, and among the adjacent arrangement directions of the Nth adjacent arrangement directions, A display device (1) satisfying 5 ≦ θave1 × L1 / PP ≦ 60, where PP is the pixel array pitch that defines the adjacent array direction in the direction closest to the direction with the largest diffusion. ).

  A thirteenth invention is the display device (1) according to the twelfth invention, characterized in that 23 ≦ θave1 × L1 / PP ≦ 35 is satisfied.

  In a fourteenth aspect of the present invention, in the display device (1) according to the fourth aspect, the unit shape (21a) is parallel to the thickness direction of the optical sheet (20) and parallel to the direction in which the diffusion is greatest. The cross-sectional shape in a simple cross-section is formed in a substantially arc shape, the pitch at which the unit shapes (21a) are arranged is P1, and the radius of curvature of the arc shape of the cross-sectional shape of the unit shape (21a) is R1. Of the refractive indexes of the regions adjacent to each other through the interface on which the unit shape (21a) is formed, the refractive index having a higher refractive index is defined as na, and the refractive index having a refractive index lower than na is defined as nb. And the distance between the interface on which the unit shape (21a) is formed and the display layer of the image source (11) is L1, and an index representing the degree to which the image light is diffused by the unit shape (21a) Diffusion degree D1 as , D1 = (P1 / R1) × (1− (nb / na)) × L1, and among the adjacent arrangement directions of the Nth adjacent arrangement directions, the direction closest to the specific arrangement direction, The display device (1) is characterized in that 1.0 ≦ D1 / PP ≦ 2.0 is satisfied, where PP is a pixel array pitch that defines the proximity array direction.

  A fifteenth aspect of the invention is the display device (1) according to the fourteenth aspect of the invention, wherein 1.2 ≦ D1 / PP ≦ 1.7 is satisfied.

  According to a sixteenth aspect of the present invention, in the display device (1) according to any one of the first to fifteenth aspects, a pitch at which the unit shapes (21a) are arranged is P1, and the unit shape (21a) A display device (1), wherein 0.001 ≦ P1 / L1 ≦ 0.05 is satisfied, where L1 is a distance between the interface on which the film is formed and the display layer of the video source (11). It is.

  According to a seventeenth aspect, in the display device (1) according to any one of the first to sixteenth aspects, the video source (11) is configured by arranging a plurality of pixels side by side. In an image displayed in a state where the image source and the optical sheet are arranged, a spread width (W) of a light emitting area (EA) that is a range in which light from one of the pixels spreads by a diffusion action of the optical sheet is: It is defined as the distance between the two most distant points (t1, t2), which is 1/5 of the maximum value of the light amount in the direction in which the light emission area is the largest, and the spread width is arranged closest to the image. The display device (1) is characterized by being 0.5 to 5 times the center distance between pixels.

  According to an eighteenth aspect of the present invention, in the display device (1) according to the seventeenth aspect of the invention, the spread width (W) is arranged along the direction in which the spread of the light emitting area (EA) is the largest in the video. The display device (1) is characterized in that it is equal to or less than a center distance between pixels.

  According to a nineteenth aspect of the present invention, in the display device (1) according to the seventeenth aspect or the eighteenth aspect, the direction in which the center distance between the pixels is the closest is defined as the first adjacent arrangement direction, A direction different from the first adjacent arrangement direction, and a direction in which the center distance between the pixels is next to the first adjacent arrangement direction is defined as a second adjacent arrangement direction, and the first adjacent arrangement direction A direction different from the direction and the second adjacent arrangement direction, and a direction in which a center distance between the pixels is next to the second adjacent arrangement direction is defined as a third adjacent arrangement direction, A direction that is different from the first adjacent arrangement direction to the third adjacent arrangement direction and in which the center distance between the pixels is next to the third adjacent arrangement direction is defined as a fourth adjacent arrangement direction. An integer greater than or equal to 3 is assumed to be N, and hereinafter, A direction different from the array direction to the Nth adjacent array direction, and a direction in which the center distance between the pixels is next to the Nth adjacent array direction is defined as the (N + 1) th adjacent array direction; In the display device (1), the direction in which the light emitting area (EA) is most widened is at an angle of ± 5 degrees or more with respect to the first adjacent array direction and the second adjacent array direction. is there.

  According to a twentieth aspect of the present invention, in the display device (1) according to the nineteenth aspect of the invention, the direction in which the light emitting area (EA) is the largest is an angle within ± 2 degrees with respect to the Nth adjacent arrangement direction. It is a display device (1) characterized by doing.

  According to a twenty-first aspect, in the display device (1) according to any one of the seventeenth aspect to the twentieth aspect, the light emitting area (EA) is unidirectionally formed by a diffusion action of the optical sheet (20). The display device (1) is characterized by spreading.

  According to a twenty-second aspect of the present invention, in the display device (1) according to any one of the seventeenth to twenty-first aspects, the direction in which the light emitting area (EA) is the largest is the direction of the optical sheet (20). It is a display apparatus (1) characterized by being parallel to the arrangement direction of the unit shape (21a).

  According to a twenty-third aspect, in the display device (1) according to any one of the first to twenty-second aspects, the optical sheet (20) is composed of two or more different layers, The display device (1) is characterized in that the unit shape (21a) is formed at the interface between the different layers.

  In a twenty-fourth aspect of the present invention, in the display device (1) according to any one of the first to twenty-third aspects, a difference in refractive index is provided between the optical sheet (20) and the video source (11). The display device (1) is characterized in that the gap is filled with a filler for reducing the above.

  A twenty-fifth aspect of the invention is the display device (1) according to any one of the first to twenty-fourth aspects of the invention, wherein the optical sheet (20) comprises a reflection suppressing layer, a hard coat layer, and an antistatic layer. And a display device (1) characterized by comprising at least one layer of an antifouling layer.

  According to a twenty-sixth aspect of the invention, in the display device (1) according to any one of the first to twenty-fifth aspects of the invention, the pixel array of the image source (11) is a diamond pen tile array. The display device (1).

  In a twenty-seventh aspect of the present invention, in the display device (1) according to any one of the first to twenty-sixth aspects, the video source (11) is configured such that the ratio of the light emitting area in the video display area is 50% or less. It is a display device (1) characterized by being.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which can suppress that the non-video area | region resulting from the non-pixel area | region which exists between the pixels of a video source originates in it can be provided.

It is a figure explaining the head mounting type display apparatus 1 of this embodiment. FIG. 1 is a view of the display device 1 as viewed from above in the vertical direction. It is the figure which looked at the optical sheet 20, the holding | maintenance part, and the image source 11 used for the display apparatus 1 of this embodiment from the observer side (-Y side). It is a figure explaining the detail of the optical sheet 20 used for the display apparatus 1 of this embodiment. It is a figure which shows the relationship between the brightness | luminance and diffusion angle of the optical sheet 20 used for the display apparatus 1 of this embodiment. It is a figure which shows the example of the image displayed by the display apparatus 1 of this embodiment. It is a figure explaining the display apparatus 5 of a comparative example. It is a figure which shows distance K1, distance L1, and effective radius R3 of the lens 12. FIG. It is a figure explaining the specific arrangement direction of optical sheet 20 with an example of pixel arrangement of picture source 11. FIG. The figure which showed typically a mode that the optical sheet 20 diffuses the image light L when the optical sheet 20 is arrange | positioned by making the specific arrangement direction (SZ direction) of the optical sheet 20 correspond with the 3rd proximity arrangement direction DL3. is there. The figure which showed typically a mode that the optical sheet 20 diffused the image light L when the optical sheet 20 is arrange | positioned by making the specific arrangement direction (SZ direction) of the optical sheet 20 correspond with the 1st adjacent arrangement direction DL1. is there. It is a figure which shows the result of having evaluated the appearance of the image observed visually by arrange | positioning the angle (delta) which shows the specific arrangement direction (SZ direction) of the optical sheet 20 gradually changing. It is a figure explaining another fixed form of the optical sheet. It is a figure explaining the light emission area of one pixel. It is a figure explaining the breadth width W of the light emission area EA.

Embodiments of the present invention will be described below with reference to the drawings. In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding.
In the present specification, numerical values such as dimensions and material names of each member to be described are examples of the embodiment, and are not limited thereto, and may be appropriately selected and used.
In this specification, terms that specify shape and geometric conditions, for example, terms such as parallel and orthogonal, are strictly meanings, have similar optical functions, and can be regarded as parallel and orthogonal It also includes a state having an error of.
In the present specification, the sheet surface is a sheet-like member that indicates a surface in the planar direction of the sheet when viewed as the entire sheet.

(Embodiment)
FIG. 1 is a diagram illustrating a head-mounted display device 1 according to this embodiment. FIG. 1 is a view of the display device 1 as viewed from above in the vertical direction.
In the drawings shown below including FIG. 1 and the following description, the vertical direction (vertical direction) is set to the Z direction in a state where the viewer wears the display device 1 on the head for easy understanding. Let the horizontal direction be the X direction and the Y direction. Moreover, among this horizontal direction, let the thickness direction of the optical sheet 20 be Y direction, and let the left-right direction orthogonal to the thickness direction be X direction. The −Y side in the Y direction is the observer side, and the + Y side is the video source side (back side).

FIG. 2 is a view of the optical sheet 20, the holding unit 32, and the video source 11 used in the display device 1 of the present embodiment as viewed from the viewer side (−Y side).
In FIG. 2, in addition to the XYZ direction described above, SX is shown as a symbol indicating a second direction rotated (tilted) by an angle δ around the Y axis (in the XZ plane). -SY (Y) -SZ is shown. Note that the SY direction coincides with the Y direction described above. The direction of SX-SY-SZ is provided to indicate the direction (tilt) of the optical sheet 20.

FIG. 3 is a diagram illustrating details of the optical sheet 20 used in the display device 1 of the present embodiment. Fig.3 (a) is sectional drawing in a cross section parallel to the horizontal surface (SX-SY surface) of the optical sheet 20, FIG.3 (b) is b section sectional drawing of Fig.3 (a). FIG. 3C is a diagram showing details of the portion c in FIG. 3A, and FIG. 3D is a diagram showing details of the portion d in FIG. 3B.
FIG. 4 is a diagram illustrating the relationship between the luminance and the diffusion angle of the optical sheet 20 used in the display device 1 of the present embodiment.
FIG. 5 is a diagram illustrating an example of an image displayed by the display device 1 of the present embodiment.
FIG. 6 is a diagram illustrating a display device 5 of a comparative example. FIG. 6A is a diagram illustrating the configuration of the display device 5 of the comparative example, and corresponds to FIG. In FIG. 6A, only the video source 51 and the lens 52 are shown as the display device 5 for easy understanding. FIG. 6B is a diagram illustrating an example of an image displayed by the display device 5 of the comparative example.

The display device 1 is a so-called head mounted display (HMD) that is attached to the head of an observer and displays an image in front of the eyes of the observer. As shown in FIG. 1, the head-mounted display device 1 according to the present embodiment includes an image source 11, a lens 12, and an optical sheet 20 inside a housing 30. By wearing the head in front of the observer's eyes, the image displayed on the image source 11 can be visually recognized by the observer's eye E through the optical sheet 20 and the lens 12.
In FIG. 1, the display device 1 will be described with reference to an example in which an image is displayed on the observer's eyes E1 and E2. However, the display device 1 is not limited to this example. It is good also as a form arrange | positioned with respect to the eye E1, and displaying an image | video with respect to the eye E1.

The housing 30 is a rectangular box-shaped housing that is horizontally long in the left-right direction, and a holding unit 31 that holds the image source 11, a holding unit 32 that holds the optical sheet 20 (20 </ b> A, 20 </ b> B), and a lens inside thereof. 12 (12A, 12B) is provided. The housing 30 can be attached to the observer's head with, for example, a belt (not shown).
The holding unit 31 is a member that holds the video source 11, and corresponds to the display surface 11 a side of the video source 11 and to the eyes E (E 1, E 2) and the lenses 12 (12 A, 12 B) of the observer. The opening 311 (311A, 311B) is provided at the position to be operated. In the present embodiment, the video source 11 is detachably held by the holding unit 31 (that is, the display device 1). The video light L emitted from the video source 11 enters the lens 12 (12A, 12B) through the opening 311 (311A, 311B).

  The holding unit 32 is a member that is positioned closer to the observer side (−Y side) than the holding unit 31 and the image source 11 and holds the optical sheet 20. In the holding part 32, the optical sheet 20 (20A, 20B) is fitted and held in the opening part 321 (321A, 321B) provided at a position corresponding to the opening part 311 (311A, 311B).

The optical sheet 20 has a unit shape as will be described later. In the optical sheet 20, the arrangement direction of the unit shapes (the direction orthogonal to the extending direction in the sheet surface) is a specific pixel direction of the pixel arrangement in the video source 11 (first proximity arrangement direction, second proximity arrangement direction). , The third adjacent arrangement direction, the fourth adjacent arrangement direction, the fifth adjacent arrangement direction, the sixth adjacent arrangement direction, and the seventh adjacent arrangement direction). Although the specific pixel direction will be described later, the optical sheet 20 can be arranged facing a specific arrangement direction (a direction having a specific angle with respect to the specific pixel direction) with respect to the holding unit 32. As described above, the convex portion 20a as the positioning shape is fitted into the concave portion 321a as the positioning shape provided in the opening 321 of the holding portion 32.
In FIG. 2, the SX direction and the SZ direction are shown together, and this direction coincides with the extending direction and the arrangement direction of the unit shapes of the optical sheet 20. In the example of FIG. 2, the optical sheet 20 is disposed to be inclined (rotated) with respect to the X direction and the Y direction by an angle δ.
In this embodiment, the outer shape of the optical sheet 20 is basically a circle as shown in FIG. 2, but for example, the shape of the optical sheet 20 is a polygonal shape and mounted (rotation in the XY plane). You may make it prescribe | regulate the position of a direction.

  The holding unit 32 and the above-described holding unit 31 are integrally movable in the Y direction and can be fixed at a desired position in the Y direction. Therefore, the distance (position in the Y direction with respect to the lens 12) between the image source 11 and the optical sheet 20 and the lens 12 can be adjusted (focus adjustment is possible) according to the visual acuity of the observer. In addition, not only this but the holding | maintenance part 31 and the holding | maintenance part 32 are good also as a form by which the position of the Y direction was fixed.

  The holding unit 33 is a member that is positioned closer to the observer side (−Y side) than the holding unit 32 and the optical sheet 20 and holds the lens 12 (12A, 12B). The holding portion 33 has an opening 331 (331A, 331B) at a position corresponding to the optical sheet 20 (20A, 20B), and the lens 12 (12A, 12B) is located in the opening 331 (331A, 331B). It is fitted and held.

The video source 11 is a display element that emits video light L and displays an image on the display surface 11a. For example, a transmissive liquid crystal display device, a reflective liquid crystal display device, an organic EL, or the like may be used. it can. As the video source 11 of this embodiment, for example, an organic EL display having a diagonal of 5 inches is used.
The video source 11 is held by the holding unit 31 such that the display surface 11a is on the viewer side (−Y side).
In the present embodiment, the display device 1 has an example in which one video source 11 is provided. However, the display device 1 is not limited to this, and for example, corresponds to lenses 12A and 12B and observer's eyes E1 and E2, which will be described later. It is good also as a form provided with two video sources which do.

The lenses 12 (12A, 12B) are convex lenses that magnify the image light L emitted from the image source 11 and emit it to the viewer side. In the present embodiment, the image source 11 and the optical sheet 20 (20A, 20B) are arranged closer to the viewer (−Y side). The lens 12 is made of glass or resin with high translucency.
A reflection suppression layer 12 a is formed on the surface of the lens 12 on the image source side (back side, + Y side). The antireflection layer 12a is coated with a material having a general antireflection function (for example, magnesium fluoride (MgF ₂ ), silicon dioxide (SiO ₂ ), fluorine optical coating agent, etc.) with a predetermined film thickness. The image source of the lens 12 may be provided with a layer exhibiting a reflection suppressing function by having a moth-eye structure having a minute concavo-convex shape formed at a pitch smaller than the wavelength of light on the surface on the light incident side. Alternatively, they may be integrally laminated on the side.

By providing such a reflection suppressing layer 12a, the light incident on the lens 12 is reflected on the image source side of the lens 12, travels toward the optical sheet 20, and is reflected again on the surface of the optical sheet 20 to become stray light. This can be suppressed and the contrast and brightness of the video can be improved.
Further, the reflection suppressing layer 12 a may be further provided on the surface of the lens 12 on the viewer side (−Y side). By further providing a reflection suppression layer 12a at this position, when image light is emitted from the lens 12, it can be prevented from being reflected at the interface between the lens 12 and air and becoming stray light in the lens 12, and image contrast. Etc. can be improved.

As shown in FIG. 1, the optical sheet 20 is disposed between the video source 11 and the lens 12. The optical sheet 20 is a light-transmitting sheet having a diffusion function for slightly diffusing the image light L emitted from the image source 11.
In the present embodiment, lenses 12A and 12B and optical sheets 20A and 20B are provided corresponding to the observer's eyes E1 and E2, respectively. However, the present invention is not limited to this. For example, one optical sheet 20 that is large enough to cover the area of the lenses 12A and 12B may be arranged on the image source side (back side, -Y side) from the lens 12. Good. However, even when the optical sheet 20 is configured as a single sheet, the optical sheet 20 can be arranged in a predetermined direction with respect to the holding unit 32 (a direction having an angle with respect to the specific pixel direction described above). Configure as follows.

Conventionally, the head-mounted display device 5 (hereinafter referred to as a comparative display device 5) that is mainly used has a configuration that does not include the optical sheet 20 as shown in FIG. 6A. Yes, the image light L emitted from the image source 51 is enlarged by the lens 52 and the image is displayed to the observer.
A display such as an organic EL used for the video source 51 and the video source 11 has a plurality of pixel areas G1 that form an image on the display portion thereof, and does not contribute to the formation of an image between the pixel areas G1. A non-pixel region G2 is provided. Therefore, in the display device 5 of the comparative example, when the image displayed by the image light L emitted from the image source 51 is enlarged through the lens 52, as shown in FIG. In addition to the image F1 caused by the above, the non-image region F2 caused by the non-pixel region G2 is also enlarged. In addition, the non-video area F2 is also clearly visible to the observer, which may hinder clear video display.

On the other hand, in the display device 1 of the present embodiment, by providing the optical sheet 20 described above, the image light emitted from the image source 11 is slightly diffused, and the diffused image is displayed as shown in FIG. It is possible to suppress the non-image area F2 caused by the non-pixel area G2 from being visually recognized by the observer.
5 and 6 show a form in which rectangular pixel regions G1 are arranged side by side in the X direction and the Z direction for easy understanding.

As shown in FIG. 3, the optical sheet 20 of the present embodiment includes a reflection suppression layer 24, a first optical layer 21, and a second optical layer 22 stacked in order from the image source side (back side, + Y (SY) side). Has been. The optical sheet 20 has a plurality of unit shapes 21 a formed at the interface between the first optical layer 21 and the second optical layer 22.
The first optical layer 21 is a layer that is located on the image source side (+ Y (SY) side) from the second optical layer 22 in the thickness direction (Y (SY) direction) of the optical sheet 20 and has light transmittance. is there. The image source side surface of the first optical layer 21 is formed substantially flat. As shown in FIG. 3B, a plurality of convex unit shapes 21 a are formed on the surface on the viewer side (−Y (SY) side) of the first optical layer 21. The unit shape 21a is convex on the viewer side (−Y (SY) side).

  This unit shape 21a extends in the SX direction along the image source side surface of the first optical layer 21, and is in the SX direction (hereinafter referred to as a specific arrangement as appropriate) perpendicular to the extending direction (SX direction). A lenticular lens shape in which the cross-sectional shape in a plane (SY-SZ plane) parallel to the SZ direction and the thickness direction is formed in a substantially arc shape. Here, the “substantially arc shape” means not only a perfect circular arc but also a curved shape including a part such as an ellipse or an ellipse.

  The second optical layer 22 is a light-transmitting layer located on the most observer side (−Y (SY) side) of the optical sheet 20. An observer-side surface 22a of the second optical layer 22 is a surface from which image light transmitted through the optical sheet 20 is emitted, and is formed to be substantially flat. As shown in FIG. 3B, the image source side (+ Y (SY) side) surface of the second optical layer 22 has a shape that follows the unit shape 21a.

  As viewed from the thickness direction of the optical sheet 20 (the normal direction of the sheet surface, the Y (SY) direction), the SZ direction (specific arrangement direction) is arranged to form a specific angle with respect to the Z direction. Yes. The optical sheet 20 has a light diffusion effect in the SZ direction (specific arrangement direction), but has almost no light diffusion effect in the SX direction orthogonal to the SZ direction. Therefore, the SZ direction (specific arrangement direction) is the direction in which the diffusion is the largest. In the application of the present embodiment, the diffusion of light diffused by the optical sheet 20 is such that the diffusion angle in the direction with the largest diffusion (the SX direction) is 10 times or more the diffusion angle in the direction with the smallest diffusion (the SX direction). Is desirable. As a result, directivity is generated in the diffused light, and it is possible to obtain an effect specific to the present application by appropriately arranging the relationship between the pixel arrangement and the specific arrangement direction of the optical sheet 20. Details regarding the specific arrangement direction (SZ direction) of the optical sheet 20 will be described later.

Assume that the relationship between the luminance and diffusion angle of light that has passed through an interface in which a plurality of unit shapes of the optical sheet 20 are arranged is as shown in FIG. It is assumed that the diffusion angle θ is a component in the range of −φ to + φ. If the component of light diffused in this range is used as an index of the degree of diffusion at the interface, it is possible to evaluate the appropriate diffusion effect as an interface in which a plurality of unit shapes are arranged.
Further, if the pixel arrangement pitch PP in which the pixel region G1 of the video source 11 is arranged changes, the degree of necessary diffusion action also changes, so this pixel arrangement pitch PP is also an important parameter.
Furthermore, if the distance between the lens 12 and the interface formed with a plurality of unit shapes of the optical sheet 20 changes, the effect that the interface formed with a plurality of unit shapes diffuses the image light L also changes.

Therefore, the luminance at the diffusion angle θ by the interface on which the unit shape 21a is formed is I ₁ (θ), and the distance between the lens 12 and the interface on which the unit shape 21a is formed is K1, and the effective of the lens 12 is When the radius is R3, the average diffusion angle θave1 of the interface where the unit shape 21a is formed is defined by the following formula for components in the range of −φ to + φ.

The distance between the interface on which the unit shape 21a is formed and the display layer 11e of the video source 11 is L1, the pixel arrangement pitch in which the pixel regions G1 are arranged is PP, and θave1 × L1 / PP depends on the unit shape 21a. It is set as an index indicating the degree to which the non-image area F2 that causes the non-pixel area G2 from being visually recognized by the observer due to the action of diffusing the image light L, that is, an index of the blurring degree.
Note that the pixel arrangement pitch PP of the pixel region G1 of the video source 11 used in the display device 1 is 400 to 500 ppi (pixel per inch), and in this embodiment, PP = 0.0508 mm (500 ppi).

FIG. 7 is a diagram showing the distance K1, the distance L1, and the effective radius R3 of the lens 12. In FIG.
The unit shape 21 a is a shape that is convex in the thickness direction (Y direction, SY direction) of the optical sheet 20. In addition, a plurality of lenses can be used as the lens 12. Therefore, for the distance K1 between the lens 12 and the interface on which a plurality of unit shapes 21a are formed, from the position where the average height of the unit shapes 21a is reached to the center of the lens 12 (the main point if it is a single lens). Distance.

Further, when the image source 11 is an organic EL display, for example, as illustrated in FIG. 7, the transparent substrate 11 b, the transparent electrode 11 c, the organic hole transport layer 11 d, and the organic light emitting layer ( A plurality of layers are laminated such as a display layer 11e, an organic electron transport layer 11f, and a metal electrode 11g. The non-pixel region G2 is formed in the display layer 11e.
Therefore, the above-described distance L1 is preferably set from the display layer 11e to a position that is the average height of the unit shapes 21a.

A plurality of types of optical sheets 20 were created by changing various parameters, and the actual appearance was evaluated. As a result, the degree of suppressing the non-image area F2 from being visually recognized by the observer and θave1 × L1 / PP There is a good correlation between them.
5 ≦ θave1 × L1 / PP ≦ 60 (Formula 1)
When the above formula is satisfied, it is possible to observe a good image in which the non-image area F2 is not easily seen by the observer, the pixel area G1 (pixel) is not independently seen, and the image is not excessively blurred. It was.
In addition, when the following stricter conditions are satisfied, an optimum image can be observed.
23 ≦ θave1 × L1 / PP ≦ 35 (Expression 2)

When θave1 × L1 / PP is less than 5, the observer sees the pixel area G1 (pixels) independently, and the non-video area F2 is noticeable. When θave1 × L1 / PP is 5 or more, it is recognized that the pixel region G1 cannot be seen independently due to the diffusion action, and the non-video region F2 is difficult to visually recognize. If θave1 × L1 / PP is 23 or more, the pixel region G1 (pixel) is optimally blurred, and the observer can hardly confirm the non-image region F2.
Also, if θave1 × L1 / PP exceeds 35, the pixel region G1 cannot be seen independently, but the image sharpness is slightly lowered as compared with the case where 23 or more and 35 or less are satisfied. When θave1 × L1 / PP is larger than 60, the pixel region G1 is not noticeable to the observer, but the resolution of the image is lowered, the sharpness thereof is significantly impaired, and details cannot be confirmed. Become.
Therefore, it is preferable to satisfy the above (Formula 1), and it is more preferable to satisfy (Formula 2).

  Further, by considering the relative positional relationship among the optical sheet 20, the image source 11, and the lens 12, the non-image area F2 caused by the non-pixel area G2 due to the action of diffusing the image light L by the optical sheet 20 is provided. Can be set as an index indicating the degree to which the viewer is prevented from being visually recognized.

Here, the refractive index having the higher refractive index among the refractive indexes of the regions adjacent to each other (the first optical layer 21 (unit shape 21a) and the second optical layer 22) via the interface on which the unit shape 21a is formed. Let na be the refractive index with a refractive index lower than na. At this time, the diffusivity D1 as an index representing the degree to which the image light L is diffused by the unit shape 21a is expressed as follows:
D1 = (P1 / R1) × (1- (nb / na)) × L1
Can be defined as

  This diffusivity D1 represents the degree to which light is diffused at the interface where the unit shape 21a is formed. If the ratio between the pixel arrangement pitch PP in which the pixel area G1 is arranged and the diffusivity D1, that is, D1 / PP, is obtained, the interface on which the unit shape 21a is formed is caused by the non-pixel area G2 and the non-video area. It can be used as an index representing the degree to which F2 is prevented from being visually recognized by the observer.

Next, when various parameters were changed to create a plurality of types of optical sheets 20 and the actual appearance was evaluated, the degree of suppression of the non-image area F2 being visually recognized by the observer and D1 / PP There is a good correlation between them, and when the following expression is satisfied, the non-video region F2 is not easily seen by the observer, the pixel region G1 (pixel) is not seen independently, and the video is not too blurred. No good image could be observed.
1.0 ≦ D1 / PP ≦ 3.0 (Formula 3)
If D1 / PP is less than 1.0, the pixel region G1 (pixel) is seen independently by the observer, and the non-video region F2 is also visually recognized by the observer. In addition, when D1 / PP is larger than 3.0, the viewer visually recognizes the image as blurred. Therefore, it is preferable to satisfy the above (Formula 3).

Further, if the following conditions are satisfied, an optimal image in which the non-image area F2 is hardly visually recognized, the pixel area G1 (pixel) is not independently viewed, and the image is not excessively blurred. It was possible to observe.
1.2 ≦ D1 / PP ≦ 2.0 (Formula 4)

  In this way, by defining the range of the D1 / PP value at the interface with respect to the optical sheet 20, the display device 1 of the present embodiment uses the image light L emitted from the image source 11 in the arrangement direction of the unit shapes 21a. It can be slightly diffused (in the SZ direction). Thereby, the display device 1 can display a clear image to the observer and can suppress the non-image area F2 of the image source 11 from being visually recognized due to the minute diffusion of the image light L.

  If the cross-sectional shape of the unit shape 21a is an elliptical shape or a partial shape of an ellipse and is not a complete arc, the shape is approximated by an arc and the radius of the arc shape is calculated as R1. That's fine.

Next, the relationship between the arrangement pitch P1 of the unit shape at the interface where the unit shape 21a is formed and the distance L1 between the interface and the display layer 11e will be described.
The optical sheet 20 has a preferable arrangement pitch P1 of the unit shapes 21a depending on the distance L1 between the image source 11 and the display layer 11e. This is because when the optical sheet 20 is close to the display layer 11e, moire tends to occur between the pixel (pixel region G1) and the unit shape, and when the optical sheet 20 is far from the display layer 11e, diffraction tends to occur. is there.
It is preferable that the arrangement pitch P1 and the distance L1 of the unit shapes 21a satisfy the following expressions.
0.005 ≦ P1 / L1 ≦ 0.05 (Formula 5)
Moreover, it is more preferable to satisfy | fill the following formula | equation.
0.01 ≦ P1 / L1 ≦ 0.03 (Formula 6)
In the present embodiment, P1 / L1 = 0.02, which satisfies the above preferable range and more preferable range.

When P1 / L1 is smaller than 0.005, the distance between the unit shape 21a and the pixel (display layer 11e) is too large, the parallelism of the light incident on the optical sheet 20 is increased, or the pitch of the unit shape 21a is increased. May become too small, and the unit shape 21a may have a large influence of diffraction, making it impossible to obtain necessary characteristics.
When P1 / L1 is greater than 0.05, the distance between the unit shape 21a and the pixel (display layer 11e) is too short, and moire is likely to occur between the pixel and the unit shape 21a.
Therefore, it is preferable that P1 / L1 satisfies the above range.

Further, in the optical sheet 20 of the present embodiment, the half-value angle of the transmitted light that is incident at an incident angle of 0 ° from the surface on the image source side and is emitted to the viewer side with respect to a specific arrangement direction is α, and the brightness of the transmitted light is Is preferably formed so as to satisfy β ≦ 5 × α, where β is a diffusion angle at which 1/20 of the maximum luminance is β.
Here, the half-value angle α of the optical sheet 20 means that the light luminance is the maximum value in the arrangement direction and the extending direction of the unit shapes from the observation position on the sheet surface of the optical sheet 20 where the light luminance is the maximum value. The angle that has the largest absolute value among the observation angles that are half the value. Further, the diffusion angle β is set to 1/20 of the maximum value in the arrangement direction and the extending direction of the unit shape from the observation position on the sheet surface of the optical sheet 20 where the luminance of the light becomes the maximum value. The angle with the largest absolute value among the observation angles.

If the diffusion angle β is larger than 5 × α, the range in which the low-brightness video light is diffused becomes too wide, which is not desirable because the sharpness of the video is reduced.
Further, from the viewpoint of more effectively achieving the effect of making the non-image area F2 caused by the non-pixel area G2 inconspicuous, the diffusion angle β is more or less equal to the half-value angle α. desirable.

  Further, the optical sheet 20 of the present embodiment has a refractive index difference between adjacent optical layers, that is, a first refractive index difference Δn1 that is a refractive index difference between the first optical layer 21 and the second optical layer 22 is 0. .005 ≦ Δn1 ≦ 0.2.

  If the first refractive index difference Δn1 is less than 0.005, the refractive index difference between the optical layers becomes too small, and it is difficult for the image light to be refracted between the optical layers, so that a sufficient diffusion effect is exhibited. It is not desirable because it disappears. On the other hand, when the first refractive index difference Δn1 is larger than 0.2, the refraction of the light between the optical layers becomes too large, and the image light transmitted through the optical sheet becomes unclear, which is not desirable.

  In this way, the range of the half-value angle α and the diffusion angle β of the optical sheet 20 and the range of the first refractive index difference Δn1 of the layers adjacent to each other with the surface on which the unit shape 21a is formed as an interface are defined. Thus, the display device 1 of the present embodiment can slightly diffuse the video light L emitted from the video source 11 in the SZ direction or the SX direction. Thereby, the display device 1 displays a clear image to the observer, and suppresses the non-image region F2 caused by the non-pixel region G2 of the image source 11 from being noticeable due to the minute diffusion of the image light L. can do.

The first optical layer 21 is made of PC (polycarbonate) resin, MS (methyl methacrylate / styrene) resin, acrylic resin, or the like having high light transmittance.
In addition, the second optical layer 22 is formed from a highly light transmissive urethane acrylate resin, an ultraviolet curable resin such as an epoxy acrylate resin, or the like. In this embodiment, the second optical layer 22 has a refractive index higher than that of the first optical layer 21. It is formed with a low refractive index.

  When the cross-sectional shape of the unit shape 21a in the SY-SZ cross section is formed in an arc shape, as shown in FIG. 3D, the arrangement pitch of the unit shapes 21a in the SZ direction is P1, and the unit shape 21a The unit shape 21a is desirably formed in the range of 0.05 ≦ P1 / R1 ≦ 1.9, where R1 is the radius of curvature of the arc-shaped cross-sectional shape in the SY-SZ cross section.

  Thus, by forming the arrangement pitch P1 and the radius of curvature R1 of the unit shapes 21a in the above-described range, the display device 1 efficiently and evenly diffuses the image light emitted from the image source 11 in the SZ direction. be able to.

Further, the optical sheet 20 of the present embodiment is provided with a reflection suppressing layer 24 on the image source side (back side, + SY side) of the first optical layer 21.
The reflection suppression layer 24 is, for example, a material having a general antireflection function (for example, magnesium fluoride (MgF ₂ ), silicon dioxide (SiO ₂ ), in the same manner as the reflection suppression layer 12 a provided on the image source side of the lens 12. ₂ ), a fluorine-based optical coating agent, etc.) may be provided by coating with a predetermined film thickness. In addition, when the image source 11 is fixed to the display device and cannot be removed, the moth-eye structure having a minute uneven shape formed at a pitch smaller than the wavelength of the light is provided on the light incident side surface. Thus, a layer exhibiting a reflection suppressing function may be integrally laminated on the image source side of the optical sheet 20.

By providing the reflection suppression layer 24 on the image source side of the optical sheet 20, the brightness of the image due to the light incident on the optical sheet 20 being reflected by the image source side surface of the optical sheet 20 toward the image source 11 side. Can be suppressed.
Further, by providing the reflection suppressing layer 24 on the image source side of the optical sheet 20, the light incident on the optical sheet 20 is reflected by the surface of the optical sheet 20 on the image source side and travels toward the image source 11 side. It is possible to prevent stray light from being reflected again on the display surface 11a and improve the contrast of the image.

The antireflection layer 24 may be further provided on the surface of the optical sheet 20 on the viewer side (−Y (SY) side). By further providing the reflection suppressing layer 24 at this position, when image light is emitted from the optical sheet 20, it can be reflected at the interface between the optical sheet 20 and air, and can be suppressed to become stray light in the optical sheet 20, The contrast of the video can be improved.
A layer having a hard coat function, an antistatic function, an antifouling function, or the like may be provided on the image source side (+ Y (SY) side) of the optical sheet 20. By providing such a layer, when the image source 11 is detachable from the housing 30, the optical sheet 20 may be damaged or soiled when the image source 11 is removed from the housing 30. Therefore, it is possible to suppress the hindrance to visual recognition of the video.

In the display device 1 of the present embodiment, as described above, since the optical sheet 20 is located on the image source side (+ Y (SY) side) from the lens 12, the image source 11 can be attached to and detached from the housing 30. When the image source 11 is removed from the housing 30 in a certain display device 1, the lens 12 is not damaged or soiled by foreign matter such as dust or dust that has entered the housing. Further, even when the image source side of the optical sheet 20 is contaminated with foreign matter or the like, it is possible to wipe off the unit shape without damaging it.
In particular, the antireflection layer having a moth-eye structure has a high antireflection effect, but it is important that the antireflection layer is provided at a position where an observer's finger or the like cannot be touched because it easily breaks. In the display device 1 of the present embodiment, since the optical sheet 20 is positioned on the image source side (+ Y (SY) side) with respect to the lens 12, such a reflection suppressing layer is provided on the observer side of the optical sheet 20 or the lens 12. It can be provided on the image source side or the like, so that a higher reflection suppression effect can be obtained and the contrast and brightness of the image can be improved.

Next, an operation until the image light L emitted from the image source 11 reaches the observer's eyes E (E1, E2) will be described.
As shown in FIG. 1, the image light L emitted from the image source 11 is incident on the image source side (+ Y (SY) side) surface of the optical sheet 20 (20A, 20B). The image light L incident on the optical sheet 20 is transmitted through the first optical layer 21 and slightly diffused by the unit shape 21a at the interface between the first optical layer 21 and the second optical layer 22. The light passes through the second optical layer 22.
The video light L transmitted through the second optical layer 22 is emitted from the surface on the viewer side (−Y (SY) side) of the optical sheet 20.
The video light L that has passed through the optical sheet 20 enters the lens 12 (12A, 12B). Then, the image light L is enlarged by the lens 12 and emitted to the observer side (−Y (SY) side).

Next, a description will be given of a specific arrangement direction (SZ direction) of the optical sheets 20 that is inclined with respect to the image source 11 by an angle δ.
FIG. 8 is a diagram for explaining a specific arrangement direction of the optical sheet 20 together with an example of a pixel arrangement of the video source 11.
As described above, the main purpose of providing the optical sheet 20 is to prevent the non-pixel region G2 (see FIG. 6) between the pixels from being noticeable when the image source 11 is enlarged and observed. That is. This phenomenon tends to be particularly noticeable in the organic EL display. This is because in the organic EL display, the ratio of the light emitting area (pixel area) in the video display area tends to be low. In particular, when the ratio of the light emitting area (pixel area) in the video display area of the video source 11 is 50% or less, particularly 30% or less, the effect of the optical sheet 20 is more exhibited. In the case of the present embodiment shown in FIG. 8, the proportion of the light emitting area (pixel area) in the video display area of the video source 11 is about 20%.

As a pixel arrangement in the organic EL display, a diamond pen tile arrangement shown in FIG. 8 is known. In this diamond pen tile arrangement, the pixels are arranged in a square lattice pattern in a direction inclined 45 degrees with respect to the vertical and horizontal directions of the rectangular display area. In the diamond pen tile arrangement, the number of green (G) is twice the number of red (R) and blue (B). In FIG. 8, the shape and size of each pixel of red (R), green (G), and blue (B) are shown by imitating the actual shape and size. The letters R, G, and B indicating colors are attached. Pixels having the same shape and size indicate pixels of the same color. That is, a small square pixel is a red (R) pixel, a large square pixel is a blue (B) pixel, and a round pixel is a green (G) pixel. is there.
In the present specification, a diamond pen tile array configured in a square array (the same vertical and horizontal intervals) in the 45 degree direction will be described as an example. For example, a pixel array having slightly different intervals in the vertical and horizontal directions will be described. The present invention can be similarly used for these elements. Therefore, the invention disclosed in the claims and the specification of the present application is not limited to the one applied to the diamond-pentile arrangement of the square arrangement.

  In such a pixel arrangement, attention is paid to the distance between the center positions of the respective pixels regardless of the difference in the emission colors (R, G, B). In the diamond pen tile arrangement, the pixels are arranged at equal intervals if the color difference is eliminated, and any pixel may be used as a reference. In the example of FIG. 8, the red (R) pixel at the bottom of the figure is used as a reference. The following seven directions were defined by the distance between the pixel centers (center distance) (hereinafter, the distance between the pixels is the distance between the centers).

(First proximity arrangement direction DL1)
The direction in which the distance between the pixel centers is the closest from the appropriately selected reference pixel is defined as the first adjacent arrangement direction DL1. The angle formed by the first adjacent arrangement direction DL1 and the Z direction is 45 degrees.
Note that the reference pixel is set in the description for easy understanding, and it is not necessary to determine one pixel as the reference.

(Second adjacent arrangement direction DL2)
A direction that is different from the first adjacent arrangement direction and in which the center distance between the pixels is next to the first adjacent arrangement direction is defined as the second adjacent arrangement direction. The angle formed by the second adjacent arrangement direction DL2 with the Z direction is 0 degree.

(Third adjacent arrangement direction DL3)
A direction that is different from the first adjacent arrangement direction and the second adjacent arrangement direction and in which the center distance between the pixels is next to the second adjacent arrangement direction is defined as the third adjacent arrangement direction. The angle formed by the third adjacent arrangement direction DL3 and the Z direction is 18.4 degrees.

(Fourth adjacent arrangement direction DL4)
A direction that is different from the first adjacent arrangement direction to the third adjacent arrangement direction and in which the center distance between the pixels is next to the third adjacent arrangement direction is defined as a fourth adjacent arrangement direction. The angle formed by the fourth adjacent arrangement direction DL4 and the Z direction is 26.6 degrees.

(Fifth adjacent arrangement direction DL5)
A direction that is different from the first adjacent arrangement direction to the fourth adjacent arrangement direction and in which the center distance between the pixels is next to the fourth adjacent arrangement direction is defined as the fifth adjacent arrangement direction. The angle formed by the fifth adjacent arrangement direction DL5 and the Z direction is 11.3 degrees.

(Sixth adjacent arrangement direction DL6)
A direction that is different from the first adjacent arrangement direction to the fifth adjacent arrangement direction and in which the center distance between the pixels is next to the fifth adjacent arrangement direction is defined as a sixth adjacent arrangement direction. The angle formed by the sixth adjacent arrangement direction DL6 with the Z direction is 31.0 degrees.

(Seventh adjacent arrangement direction DL7)
A direction that is different from the first adjacent arrangement direction to the sixth adjacent arrangement direction and in which the center distance between the pixels is next to the sixth adjacent arrangement direction is defined as the seventh adjacent arrangement direction. The angle formed by the seventh adjacent arrangement direction DL7 and the Z direction is 8.1 degrees.

(Eighth adjacent arrangement direction DL8)
A direction that is different from the first adjacent arrangement direction to the seventh adjacent arrangement direction and in which the center distance between the pixels is next to the seventh adjacent arrangement direction is defined as an eighth adjacent arrangement direction. The angle formed by the seventh adjacent arrangement direction DL7 and the Z direction is 33.7 degrees.

(9th adjacent arrangement direction DL9)
A direction that is different from the first proximity arrangement direction to the eighth proximity arrangement direction and in which the center distance between the pixels is next to the eighth proximity arrangement direction is defined as the ninth proximity arrangement direction. The angle formed by the eighth adjacent arrangement direction DL8 and the Z direction is 23.2 degrees.

(Nth adjacent arrangement direction)
In FIG. 8, only the ninth proximity arrangement direction DL9 is illustrated, but an integer greater than or equal to 3 is N, which is a direction different from the first proximity arrangement direction to the Nth proximity arrangement direction, and the Nth proximity arrangement direction. Next, the direction in which the center distance between the pixels is close can be generalized and defined as the (N + 1) th adjacent arrangement direction. Even in the Nth adjacent arrangement direction, if the condition is satisfied, it can be used effectively in relation to a specific arrangement direction. However, in the following description, for ease of understanding, the description will be made using the first adjacent arrangement direction DL1 to the ninth adjacent arrangement direction DL9 shown in FIG.

  Here, the nine directions from the first adjacent arrangement direction to the ninth adjacent arrangement direction will be described from the Z direction to the counterclockwise direction as shown in FIG. 8 for easy understanding. However, these directions also exist in a line-symmetrical direction with a straight line in the Z direction as a symmetry axis and in a line-symmetrical direction with these two directions as further a straight line in the X direction as a symmetry axis. Accordingly, nine directions from the first proximity arrangement direction to the ninth proximity arrangement direction can be set in four directions. The same applies to the Nth adjacent arrangement direction.

  By arranging the specific arrangement direction (SZ direction) of the optical sheet 20 in an appropriate angular relationship with respect to the nine directions from the first adjacent arrangement direction to the ninth adjacent arrangement direction, a clear image is obtained for the observer. It was found that the non-video region F2 of the video source 11 can be suppressed from being visually recognized by the minute diffusion of the video light L.

FIG. 9 schematically illustrates how the optical sheet 20 diffuses the image light L when the optical sheet 20 is arranged with the specific arrangement direction (SZ direction) of the optical sheet 20 aligned with the third adjacent arrangement direction DL3. FIG.
As described above, the optical sheet 20 diffuses the video light L with respect to the arrangement direction (SZ direction) of the unit shapes 21a, but has almost no diffusing action with respect to the direction orthogonal to the arrangement direction (SX direction). . Therefore, the diffusion of light diffused by the optical sheet 20 as in the diffusion ranges DR, DG, and DB shown in FIG. 9 has directivity with respect to the direction in the sheet plane of the optical sheet 20. If the direction of the directivity, that is, the arrangement direction (SZ direction) of the unit shapes 21a becomes an appropriate direction as in the example of FIG. 9, the non-video area F2 of the video source 11 is formed as shown in FIG. It can be suppressed that the image light diffused in the corresponding region spreads and the non-image region F2 of the image source 11 is visually recognized.

FIG. 10 schematically illustrates how the optical sheet 20 diffuses the image light L when the optical sheet 20 is arranged with the specific arrangement direction (SZ direction) of the optical sheet 20 aligned with the first adjacent arrangement direction DL1. FIG.
Compared to the previous case of FIG. 9, in the case of FIG. 10, since the range in which the video light L is diffused is not properly aligned, there is an area where the non-video area F <b> 2 of the video source 11 is visually recognized. The beneficial effect by providing the optical sheet 20 is not large enough.

  Thus, it is very important what direction the specific arrangement direction (SZ direction) of the optical sheets 20 is. Therefore, the angle δ indicating the specific arrangement direction (SZ direction) of the optical sheets 20 was gradually changed and arranged to visually evaluate the appearance of the observed image. The evaluation criteria for this visual evaluation are whether or not the non-image area F2 of the image source 11 is suppressed from being visually recognized and whether or not the image can be clearly observed.

FIG. 11 is a diagram illustrating a result of visual evaluation of the appearance of an observed image by gradually changing and arranging an angle δ indicating a specific arrangement direction (SZ direction) of the optical sheets 20. The circles in FIG. 11 indicate that the non-image area F2 of the image source 11 can be suppressed from being visually recognized and a clear image can be observed. The Δ mark indicates that it is usable, although it is inferior to the ○ mark. The x mark indicates that the non-video region F2 of the video source 11 is not suppressed from being visually recognized, or the video is unclear.
From FIG. 11, it can be said that the optical sheet 20 is desirably disposed in the range of the angle δ from 8 degrees to 25 degrees, and more desirably disposed in the range of the angle δ from 8 degrees to 18 degrees. However, this numerical range is based on the premise that the image source 11 having a diamond pen tile arrangement is used. From the viewpoint of suppressing the non-image area F2 from being visually recognized, it is desirable to define a specific arrangement direction (SZ direction) of the optical sheet 20 from the arrangement of the pixels.

  That is, the orientation of the optical sheet 20 determines whether or not the effectiveness of the optical sheet 20 is exhibited in relation to the pixel arrangement. Therefore, based on the result of FIG. 11, how is the specific arrangement direction (SZ direction) of the optical sheet 20 with respect to the seven directions from the first adjacent arrangement direction to the seventh adjacent arrangement direction described above? Specifically, it should be specified as follows.

The specific arrangement direction of the optical sheet 20 is the third adjacent arrangement direction DL3, the fourth adjacent arrangement direction DL4, the fifth adjacent arrangement direction DL5, the sixth adjacent arrangement direction DL6, or the seventh. It is desirable that the adjacent arrangement direction DL7, the eighth adjacent arrangement direction DL8, and the ninth adjacent arrangement direction DL9 are arranged with an angle within ± 2 degrees.
By arranging the optical sheet 20 in this way, a clear image can be displayed to the observer, and the non-image area F2 of the image source 11 can be prevented from being visually recognized due to the slight diffusion of the image light L. be able to.

In addition, it is desirable that the optical sheet 20 be arranged such that the specific arrangement direction has an angle of ± 5 degrees or more with respect to the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2.
More preferably, the optical sheet 20 is arranged such that the specific arrangement direction has an angle of ± 10 degrees or more with respect to the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2. It is good to arrange with an angle of ± 5 degrees or more.
If the optical sheet 20 is arranged in this way, it is possible to avoid an inappropriate arrangement as shown in FIG. 10, a clear image can be displayed to the observer, and the image light L can be displayed. It is possible to suppress the non-video region F2 of the video source 11 from being visually recognized due to slight diffusion.

Furthermore, the optical sheet 20 has a specific arrangement direction in which the third adjacent arrangement direction DL3, the fourth adjacent arrangement direction DL4, the fifth adjacent arrangement direction DL5, the sixth adjacent arrangement direction DL6, and the seventh adjacent arrangement direction. It is desirable that the direction is the same as one of the directions DL7.
By arranging the optical sheet 20 in this way, a clear image can be displayed to the observer, and the non-image area F2 of the image source 11 can be prevented from being visually recognized due to the slight diffusion of the image light L. be able to.

The optical sheet 20 is a straight line drawn in a direction along the specific arrangement direction, and a virtual line that passes through the outermost diameter portion of the pixel is drawn into an area including the pixel and an area not including the pixel. In particular, when the video source 11 is divided, it is desirable that the specific arrangement direction is provided so that the area ratio of the region including the pixels is 80% or more, more preferably 100%. The area ratio of the region including the pixel will be described with reference to FIG. FIG. 10 shows a case where the optical sheet 20 is arranged such that the specific arrangement direction (SZ direction) of the optical sheet 20 coincides with the first adjacent arrangement direction DL1. In this case, it can be virtually divided into the regions PB1, PB2, PB3, and PB4 shown in FIG. 10 by a straight line drawn in a direction along a specific arrangement direction. In the figure, portions other than the regions indicated as regions PB1, PB2, PB3, and PB4 are repetitions of regions PB1, PB2, PB3, and PB4. The ratio of the widths of these regions is PB1: PB2: PB3: PB4 = 15: 15: 13: 15. Therefore, in the example of FIG. 10, the area ratio of the region including the pixels = (13 + 15) / (15 + 13 + 15 + 15) = 48%.
Similarly, when the area ratio of the region including the pixel is obtained in the other direction, it is 64% in the second adjacent arrangement direction DL2, and is 100% in the third adjacent arrangement direction DL3 to the seventh adjacent arrangement direction DL7. Become.
In this way, if the optical sheet 20 is arranged so that the area ratio of the region including the pixels is 80% or more or 100%, a clear image can be displayed to the observer, and the image light can be displayed. It is possible to suppress the non-video area F2 of the video source 11 from being visually recognized by the slight diffusion of L.

  In addition, the optical sheet 20 is desirably arranged so as to include pixels of different colors in the direction along the specific arrangement direction. This is because, if the direction is only for pixels of the same color, lines of the same color are diffused and the appearance is not good.

Furthermore, among the center distances between the pixels in any direction from the third proximity array direction to the seventh proximity array direction, the center distance in the direction corresponding to the specific array direction is the pixel in the first proximity array direction. It is desirable that the distance is within 7 times the center distance between the pixel and the pixel. In FIG. 8, the distance between the pixel centers is also indicated by a symbol. The example in FIG. 8 will be described as follows.
First adjacent arrangement direction DL1: CD1 / CD1 = 1.0
Second adjacent arrangement direction DL2: CD2 / CD1 = 1.4
Third adjacent arrangement direction DL3: CD3 / CD1 = 2.2
Fourth adjacent arrangement direction DL4: CD4 / CD1 = 3.2
Fifth adjacent arrangement direction DL5: CD5 / CD1 = 3.6
Sixth adjacent arrangement direction DL6: CD6 / CD1 = 4.1
Seventh adjacent arrangement direction DL7: CD7 / CD1 = 5.0
Eighth adjacent arrangement direction DL8: CD8 / CD1 = 5.1
Ninth adjacent arrangement direction DL9: CD9 / CD1 = 5.4
As described above, in this embodiment, any direction satisfies the above condition of 7 times or less.
If the center distance in the direction corresponding to the specific array direction exceeds seven times the center distance between the pixels in the first adjacent array direction, the diffusion action of the optical sheet 20 becomes insufficient, and the adjacent pixels This is because the non-video region F2 between the two may be visually recognized, and on the other hand, if the diffusion action is enhanced, a clear video cannot be obtained.

Next, the light diffusing action of the optical sheet 20 will be described from the viewpoint of the spread of light emitted from the pixels.
The light emitted from one pixel provided in the video source 11 has its light range (hereinafter referred to as a light emitting area) expanded mainly by the diffusion action of the optical sheet 20. As described above, since the direction in which the optical sheet 20 diffuses light has directivity, the direction in which the light emitting area expands due to the diffusion action of the optical sheet 20 also has directivity.
FIG. 13 is a diagram illustrating a light emitting area of one pixel. FIG. 13A is an observation image obtained by enlarging an image displayed by the image source 11 with a digital microscope or the like without using the lens 12 and the optical sheet 20, and shows a state of light emitted from one pixel. . FIGS. 13B and 13C are observation images obtained by enlarging an image displayed with a digital microscope or the like in a state where the image source 11 and the optical sheet 20 are combined and arranged without using the lens 12. Yes, it shows the state of light emitted by one pixel.

  When the light emitted from the pixel does not pass through the optical sheet 20 or the like, as shown in FIG. 13A, the light emitting area EA0 is observed as a shape close to the shape of the light emitting portion of the pixel (for example, a circular shape). Is done. Then, by receiving the diffusing action of the optical sheet 20, the light emitted from the pixels is spread most greatly in a specific arrangement direction (SZ direction, arrangement direction of the unit shapes 21a), as shown in FIG. Further, the light emitting area EA is observed as a shape that is most widened in one direction along a specific arrangement direction. The direction in which the light emitting area EA is expanded is equal to the direction in which the diffusion is the largest.

In addition, as the distance between the optical sheet 20 and the pixel (display layer 11e) of the image source 11 is shorter, the arrangement pitch P1 of the unit shapes 21a of the optical sheet 20 is preferably smaller from the viewpoint of obtaining an appropriate diffusion action. Therefore, when the optical sheet 20 is disposed close to the pixels, such as being stacked on the display surface 11a of the image source 11, compared with the case where the optical sheet 20 is disposed away from the image source 11, the optical sheet 20 The ratio of the amount of emitted light that is diffused and emitted by diffraction in the unit shape 21a is large.
In this case, as shown in FIG. 13C, the light emitting area EA is in a state where the light emitting area EA spreads most in one direction along a specific arrangement direction (SZ direction), and a region with a large amount of light generated by diffraction (bright). (Region) is observed in multiple grains.

FIG. 14 is a diagram for explaining the spreading width W of the light emitting area EA. Each graph shown in FIG. 14 shows the distribution of the light quantity in the direction (SZ direction) in which the light emitting area EA is greatly expanded, the vertical axis shows the light quantity, and the horizontal axis shows the position in the SZ direction.
The graph shown in FIG. 14A is an example of the light amount distribution of one light emitting area EA0 in an observation image obtained by enlarging an image displayed by the image source 11 with a digital microscope or the like without using the lens 12 and the optical sheet 20. Show. Each graph shown in FIGS. 14B and 14C is an observation image obtained by enlarging an image displayed with a digital microscope or the like in a state where the image source 11 and the optical sheet 20 are combined and arranged without using the lens 12. 2 shows an example of the light amount distribution of one light emitting area EA. The graph shown in FIG. 14B is an example in the case where the ratio of the diffusion action due to refraction at the interface of the unit shape 21a is high in the light emitted from the optical sheet 20, and the graph shown in FIG. This is an example of the case where the ratio of the diffusion action due to diffraction by the unit shape 21a is high in the light emitted from the optical sheet 20.

As shown in FIGS. 14B and 14C, the spread width W of the light emitting area EA of one pixel is an optical sheet in an image displayed in a state where the image source 11 and the optical sheet 20 are arranged in combination. 20 is defined as the distance between the two most distant points t1 and t2, which is 1/5 of the maximum value of the light amount in the direction (SZ direction) in which the light emitting area EA is the largest.
In addition, the spread width W is 0.5 times or more and 5 times the center distance between the pixels that are closest to each other in the above-described video (that is, the center distance between the pixels in the first adjacent arrangement direction DL1). The following is preferable.

It should be noted that, in an image displayed in a state where the image source 11 and the optical sheet 20 are combined and arranged, the maximum value of the light amount in the light emitting area EA, the value that is 1/5 of the maximum value, the positions of the two points t1 and t2, The distance between the two points t1 and t2 is a video signal (coordinate information and signal intensity in the image) in the observation image of the light emitting area EA obtained by enlarging the image with a digital microscope or the like and enlarging the image with a CCD camera or the like. From this, the correlation between the position in the light emitting area EA and the brightness can be detected and calculated.
Further, the center distance between the pixels in the first adjacent arrangement direction DL1 in the image displayed in a state where the image source 11 and the optical sheet 20 are arranged in combination is the image without using the lens 12 and the optical sheet 20. The image displayed by the source 11 can be calculated from an observation image obtained by similarly enlarging and capturing the image. Note that the center distance between the pixels in the first adjacent arrangement direction DL1 is also based on an observation image obtained by similarly enlarging and photographing an image displayed in a state where the image source 11 and the optical sheet 20 are combined. Although it can be calculated, in order to ensure accuracy, it is desirable to calculate from an observation image obtained by enlarging and capturing the image displayed by the image source 11 in the same manner.

  When the spread width W is less than the above range, it is not preferable because the non-image area is enlarged between the light emitting areas of adjacent pixels, and the non-image area is easily visible in the usage state of the display device 1. On the other hand, when the spread width W is larger than the above range, the light emitting areas of adjacent pixels are largely overlapped, and the blur of the video is increased, and the sharpness of the video is greatly decreased. Therefore, the spread width W is preferably within the above range.

Further, the spread width W satisfies the above range, and further, in the image displayed in a state where the image source 11 and the optical sheet 20 are arranged in combination, the direction in which the spread of the light emitting area EA is the largest (in the optical sheet 20). It is preferable that the distance is equal to or less than the center distance between the pixels arranged closest to each other in a specific arrangement direction (SZ direction).
If the spread width W is larger than the center distance between the pixels arranged closest to each other in the direction in which the spread of the light emitting area EA is the largest (the specific arrangement direction of the optical sheet 20, the SZ direction), In some cases, the light emitting areas of the matching pixels (the range in which the light emitted from the adjacent pixels spreads) overlap, leading to blurring of the image. Therefore, it is preferable that the spreading width W further satisfies the above range.

Further, the direction in which the light emitting area EA expands most is equal to the specific arrangement direction (SZ direction) of the optical sheet 20, and as described above, ± with respect to the first adjacent arrangement direction DL1 and the second adjacent arrangement direction DL2. It is desirable that the optical sheet 20 be arranged so as to form an angle of 5 degrees or more.
If the optical sheet 20 is arranged in this way, it is possible to avoid an inappropriate arrangement in which the non-image area F2 is visually recognized as a streak as shown in FIG. 10, and a clear image is displayed to the observer. In addition, it is possible to suppress the non-video region F2 of the video source 11 from being visually recognized due to the minute diffusion of the video light L.

Further, the direction in which the light emitting area EA expands most is equal to the specific arrangement direction (SZ direction) of the optical sheet 20, and as described above, the third adjacent arrangement direction DL3, the fourth adjacent arrangement direction DL4, or The angle within ± 2 degrees with respect to the fifth adjacent arrangement direction DL5 or the sixth adjacent arrangement direction DL6 or the seventh adjacent arrangement direction DL7 or the eighth adjacent arrangement direction DL8 and the ninth adjacent arrangement direction DL9 It is desirable to have
By arranging the optical sheet 20 in this way, a clear image can be displayed to the observer, and the non-image area F2 of the image source 11 can be prevented from being visually recognized due to the slight diffusion of the image light L. be able to.

  In the display device 1 including the image source 11 in which the pixel arrangement is a diamond pen tile arrangement, the optical sheet 20 is arranged by changing the angle δ indicating a specific arrangement direction (the arrangement direction of the unit shapes 21a, the SZ direction), When the appearance of the observed image is visually evaluated, as shown in FIG. 11 and the like, it is preferable to arrange the optical sheet 20 in the range of the angle δ from 8 degrees to 25 degrees, and the angle δ is from 8 degrees to 18 degrees. It is further desirable to arrange in a range of degrees.

Then, the display device 1 arranges the optical sheet 20 so that the angle δ satisfies the above-described range, and further displays a light emitting area in an image displayed with the image source 11 and the optical sheet 20 combined. By setting the spread width W of EA to 0.5 to 5 times the center distance between the pixels in the first adjacent arrangement direction DL1, the non-image area F2 is visually recognized and the pixel area G1 (pixel) is independent. It is possible to suppress the appearance and display a good image.
Further, in the above image, the spread width W is equal to or less than the center distance between the pixels closest to each other in the direction in which the spread of the light emitting area EA is the largest (the specific arrangement direction of the optical sheet 20, the SZ direction). Thus, the display device 1 can further enhance the above-described effects and display a good image with less blur.

Here, as an example, the direction (SZ direction) in which the spread width W due to the diffusion action of the optical sheet 20 satisfies the above-described preferable range and the light emitting area EA is expanded most by the optical sheet 20 is the fifth adjacent arrangement direction DL5. The display device 1 matched with the above-mentioned is prepared and observed at the observation position (the position of the eye E of the observer when the display device 1 is used and the focal point of the image light L by the lens 12). It was possible to suppress F2 from being visually recognized, to suppress the pixel region G1 (pixel) from being viewed independently, and to view a good image.
Further, in this display device 1, when the spread width W due to the diffusing action of the optical sheet 20 is less than the preferred range, and a larger one than the preferred range is prepared and observed at the observation position, the non-image area F2 is visually recognized. The pixel region G1 (pixel) is observed independently, or the blur of the image is increased and the sharpness is greatly reduced, and thus a good image cannot be visually recognized.

Next, the spreading width W satisfies the preferred range as described above, and the direction in which light is most spread by the third adjacent arrangement direction DL3 or the seventh adjacent arrangement direction DL7 and the optical sheet 20 (the arrangement direction of unit shapes 21a (SZ direction). )) And the display device 1 were prepared, and when an image was visually recognized at the observation position, a good image was also visually recognized.
Further, in these display devices 1, those in which the spread width W due to the diffusion action of the optical sheet 20 is less than the preferred range and those that are larger than the preferred range are prepared, and the image displayed at the observation position is visually confirmed as described above. However, the non-image area F2 is visually recognized, and the pixel area G1 (pixel) is observed independently, or the image is greatly blurred and the sharpness is greatly decreased. I couldn't.

FIG. 12 is a diagram for explaining another fixing form of the optical sheet 20. FIG. 12 is a view seen from the same direction as FIG.
The optical sheet 20 does not have to be provided independently corresponding to the left and right eyes, and may have an irregular shape in which the left and right regions are connected as shown in FIG. Moreover, the optical sheet 20 is good also as a rectangular shape as shown in FIG.12 (b). With such a shape, it becomes easy to arrange the SX direction and the SZ direction of the optical sheet 20 so as to be inclined by a predetermined angle δ with respect to the X direction and the Z direction. In addition, even if it is a form like FIG. 12, since it is symmetrical shape, in order to prevent the mistake at the time of an assembly, the parameter | index which shows the direction of the optical sheet 20 may be provided, or you may make it asymmetrical shape.

  As described above, according to the present embodiment, the display device 1 can slightly diffuse the video light L emitted from the video source 11, displays a clear video to the observer, and the pixel region G1. Can not be seen independently, and the non-image area F2 caused by the non-pixel area G2 of the image source 11 can be suppressed from being viewed by the observer.

(Deformation)
The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the scope of the present invention.

(1) In the embodiment, the unit shape 21a has been described by giving an example in which the cross-sectional shape is an arc-shaped lenticular lens shape. For example, the unit shape may be a triangular shape, a polygonal shape, or a shape formed by a curve other than the arc shape.

(2) In the embodiment, the optical sheet 20 has been described with an example in which the optical sheet 20 is disposed with a gap between the image source 11 and the optical sheet 20. For example, the optical sheet 20 may be arranged without a gap between the optical source 20 and the image source 11. In this case, for example, the gap may be filled with a filler that reduces the refractive index difference.

(3) In the embodiment, the optical sheet 20 has been described with an example in which the second optical layer 22 is laminated on the first optical layer 21 provided with the unit shape 21a. For example, the second optical layer 22 may be omitted.

(4) In the embodiment, the video source 11 may be fixed in advance to the display device 1 and not attachable / detachable.

(5) In the embodiment, the optical sheet 20 has been described with an example including only a unit shape of a lenticular lens shape extending in one direction. For example, two different unit shapes that are orthogonal to each other may be provided in the same optical sheet, or may be used separately.

  In addition, although embodiment and a deformation | transformation form can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited by the embodiments described above.

DESCRIPTION OF SYMBOLS 1 Display apparatus 11 Image source 11a Display surface 11b Transparent substrate 11c Transparent electrode 11d Organic hole transport layer 11e Display layer 11f Organic electron transport layer 11g Metal electrode 12 Lens 12A Lens 12B Lens 12a Antireflection layer 20 Optical sheet 20A Optical sheet 20B Optical Sheet 20a Convex portion 21 First optical layer 21a Unit shape 22 Second optical layer 22a Observer-side surface 24 Antireflection layer 30 Housing 31 Holding portion 32 Holding portion 33 Holding portion 51 Video source 52 Lens 311 Opening portion 321 Opening portion 321a Recess 331 Opening EA Light emitting area

The optical sheet 20 has a unit shape as will be described later. In the optical sheet 20, the arrangement direction of the unit shapes (the direction orthogonal to the extending direction in the sheet surface) is a specific pixel direction of the pixel arrangement in the video source 11 (first proximity arrangement direction, second proximity arrangement direction). , The third adjacent arrangement direction, the fourth adjacent arrangement direction, the fifth adjacent arrangement direction, the sixth adjacent arrangement direction, and the seventh adjacent arrangement direction). Although the specific pixel direction will be described later, the optical sheet 20 can be arranged facing a specific arrangement direction (a direction having a specific angle with respect to the specific pixel direction) with respect to the holding unit 32. As described above, the convex portion 20a as the positioning shape is fitted into the concave portion 321a as the positioning shape provided in the opening 321 of the holding portion 32.
In FIG. 2, the SX direction and the SZ direction are shown together, and this direction coincides with the extending direction and the arrangement direction of the unit shapes of the optical sheet 20. In the example of FIG. 2, the optical sheet 20 is disposed to be inclined (rotated) with respect to the X direction and the Z direction by an angle δ.
In this embodiment, the outer shape of the optical sheet 20 is basically a circle as shown in FIG. 2, but for example, the shape of the optical sheet 20 is a polygonal shape, and the mounting direction (rotation in the XZ plane) is performed. You may make it prescribe | regulate the position of a direction.

In such a pixel arrangement, attention is paid to the distance between the center positions of the respective pixels regardless of the difference in the emission colors (R, G, B). In the diamond pen tile arrangement, the pixels are arranged at equal intervals if the color difference is eliminated, and any pixel may be used as a reference. In the example of FIG. 8, the red (R) pixel at the bottom of the figure is used as a reference. The following nine directions were defined by the distance between the pixel centers (center distance) (hereinafter, the distance between the pixels is the distance between the centers).

Claims (27)

An image source that emits image light; and
A lens that magnifies and emits the image light to the viewer side;
An optical sheet disposed between the image source and the lens;
With
The diffusion of light diffused by the optical sheet is a display device having a direction in which the diffusion is greatest with respect to the direction in the sheet surface of the optical sheet and having directivity. The display device according to claim 1,
The diffusion of light diffused by the optical sheet is such that the diffusion angle in the direction with the largest diffusion is 10 times or more the diffusion angle in the direction with the smallest diffusion,
A display device. The display device according to claim 1 or 2,
The optical sheet has a unit shape formed in a convex shape or a concave shape,
The unit shapes are arranged in a specific arrangement direction in the sheet surface orthogonal to the thickness direction of the optical sheet,
The optical sheet diffuses light in the arrangement direction of the unit shapes,
The unit shape extends in a first direction in a sheet plane orthogonal to the thickness direction of the optical sheet, and a second direction orthogonal to the first direction in the sheet plane is the specific arrangement direction. Are arranged as
The direction in which the diffusion of the light diffused by the optical sheet is the largest is the specific arrangement direction,
A display device. The display device according to any one of claims 1 to 3,
The video source is configured by arranging a plurality of pixels side by side,
The direction in which the center distance between the pixels is closest is defined as the first proximity arrangement direction,
A direction different from the first adjacent arrangement direction, and a direction in which a center distance between the pixels is next to the first adjacent arrangement direction is defined as a second adjacent arrangement direction,
A direction that is different from the first adjacent arrangement direction and the second adjacent arrangement direction, and in which the center distance between the pixels is next to the second adjacent arrangement direction is defined as a third adjacent arrangement direction. Prescribe,
A direction that is different from the first adjacent arrangement direction to the third adjacent arrangement direction and in which the center distance between the pixels is next to the third adjacent arrangement direction is defined as a fourth adjacent arrangement direction. Prescribe,
An integer greater than or equal to 3 is assumed to be N. Hereinafter, the first adjacent arrangement direction is different from the Nth adjacent arrangement direction, and the center distance between the pixels is next to the Nth adjacent arrangement direction. Is defined as the (N + 1) th adjacent arrangement direction,
The direction with the largest diffusion is arranged with an angle within ± 2 degrees with respect to the Nth adjacent arrangement direction,
Of the center distances between the pixels in the Nth adjacent arrangement direction, the center distance in the direction corresponding to the direction in which the diffusion is greatest is within 7 times the center distance between the pixels in the first adjacent arrangement direction. Being
A display device. The display device according to claim 4,
The direction in which the diffusion is greatest is arranged with an angle of ± 5 degrees or more with respect to the first adjacent arrangement direction and the second adjacent arrangement direction,
A display device. The display device according to claim 4,
The direction in which the diffusion is greatest is arranged with an angle of ± 10 degrees or more with respect to the first adjacent arrangement direction, and has an angle of ± 5 degrees or more with respect to the second adjacent arrangement direction. Being arranged,
A display device. The display device according to claim 4,
The direction in which the diffusion is greatest is the same direction as the Nth adjacent arrangement direction;
A display device. The display device according to claim 4,
A straight line drawn in a direction along the direction in which the diffusion is greatest, and a line passing through the outermost diameter portion of the pixel is drawn to virtually include a region including the pixel and a region not including the pixel. When the video source is divided, the direction in which the diffusion is the largest is provided so that the area ratio of the region including the pixels is 80% or more,
A display device. The display device according to claim 8, wherein
A direction in which the diffusion is the largest is provided so that an area ratio of a region including the pixels is 100%;
A display device. The display device according to claim 4,
The video source is configured by arranging the pixels of a plurality of colors side by side,
In a direction along the direction in which the diffusion is the largest, pixels of different colors are included and arranged,
A display device. The display device according to any one of claims 1 to 10,
In the optical sheet, the half-value angle of the transmitted light that is incident at an incident angle of 0 ° from the surface on the image source side and is emitted to the viewer side with respect to the direction in which the diffusion is greatest is α, When the diffusion angle that is 1/20 is β,
satisfy β ≦ 5 × α,
A display device. The display device according to any one of claims 1 to 11,
When the luminance at the diffusion angle θ of the unit shape is I ₁ (θ), the distance between the lens and the interface on which the unit shape is formed is K1, and the effective radius of the lens is R3, the unit The average diffusion angle θave1 of the shape is

And the distance between the interface on which the unit shape is formed and the display layer of the video source is L1,
When the pixel arrangement pitch defining the adjacent arrangement direction is set to PP for the direction closest to the direction with the largest diffusion among the adjacent arrangement directions of any of the Nth adjacent arrangement directions,
5 ≦ θave1 × L1 / PP ≦ 60
Meeting,
A display device. The display device according to claim 12,
23 ≦ θave1 × L1 / PP ≦ 35
Meeting,
A display device. The display device according to claim 4,
The unit shape is formed in a substantially arc shape in a cross section in a cross section parallel to the thickness direction of the optical sheet and parallel to the direction in which the diffusion is the largest.
The pitch at which the unit shapes are arranged is P1, the radius of curvature of the arc shape of the cross-sectional shape of the unit shape is R1, and the refractive indexes of the regions adjacent to each other through the interface on which the unit shapes are formed. Of these, the refractive index having a higher refractive index is denoted by na, the refractive index having a refractive index lower than na is denoted by nb, and the distance between the interface on which the unit shape is formed and the display layer of the image source is L1. As a diffusivity D1 as an index indicating the degree to which the image light is diffused by the unit shape,
D1 = (P1 / R1) × (1- (nb / na)) × L1
And define
When the pixel arrangement pitch defining the adjacent arrangement direction is set to PP for the direction closest to the direction with the largest diffusion among the adjacent arrangement directions of any of the Nth adjacent arrangement directions,
1.0 ≦ D1 / PP ≦ 2.0
Meeting,
A display device. The display device according to claim 14, wherein
1.2 ≦ D1 / PP ≦ 1.7
Meeting,
A display device. The display device according to any one of claims 1 to 15,
When the pitch at which the unit shapes are arranged is P1, and the distance between the interface where the unit shapes are formed and the display layer of the video source is L1,
0.005 ≦ P1 / L1 ≦ 0.05
Meeting,
A display device. The display device according to any one of claims 1 to 16,
The video source is configured by arranging a plurality of pixels side by side,
In an image displayed in a state where the image source and the optical sheet are arranged, the width of the light emitting area, which is a range in which light from one pixel spreads by the diffusion action of the optical sheet, is the widest of the light emitting area. It is defined as the distance between the two most distant points that is 1/5 of the maximum value of the light quantity in the large direction.
The spread width is not less than 0.5 times and not more than 5 times the center distance between the pixels arranged closest to each other in the image;
A display device. The display device according to claim 17,
The spread width is equal to or less than a center distance between pixels arranged along a direction in which the spread of the light emitting area is the largest in the video,
A display device. The display device according to claim 17 or 18,
The direction in which the center distance between the pixels is closest is defined as the first proximity arrangement direction,
A direction different from the first adjacent arrangement direction, and a direction in which a center distance between the pixels is next to the first adjacent arrangement direction is defined as a second adjacent arrangement direction,
A direction that is different from the first adjacent arrangement direction and the second adjacent arrangement direction, and in which the center distance between the pixels is next to the second adjacent arrangement direction is defined as a third adjacent arrangement direction. Prescribe,
A direction that is different from the first adjacent arrangement direction to the third adjacent arrangement direction and in which the center distance between the pixels is next to the third adjacent arrangement direction is defined as a fourth adjacent arrangement direction. Prescribe,
An integer greater than or equal to 3 is assumed to be N. Hereinafter, the first adjacent arrangement direction is different from the Nth adjacent arrangement direction, and the center distance between the pixels is next to the Nth adjacent arrangement direction. Is defined as the (N + 1) th adjacent arrangement direction,
The direction in which the spread of the light emitting area is the largest is an angle of ± 5 degrees or more with respect to the first adjacent arrangement direction and the second adjacent arrangement direction;
A display device. The display device according to claim 19,
The direction in which the light emitting area expands most is at an angle within ± 2 degrees with respect to the Nth adjacent arrangement direction;
A display device. The display device according to any one of claims 17 to 20,
The light emitting area is spread in one direction by the diffusion action of the optical sheet,
A display device. The display device according to any one of claims 17 to 21,
The direction in which the light emitting area is most expanded is parallel to the arrangement direction of the unit shapes of the optical sheet,
A display device. The display device according to any one of claims 1 to 22,
The optical sheet is composed of two or more different layers, and the unit shape is composed of an interface between the different layers;
A display device. The display device according to any one of claims 1 to 23,
The gap between the optical sheet and the image source is filled with a filler that reduces a difference in refractive index,
A display device. The display device according to any one of claims 1 to 24,
The optical sheet includes at least one of a reflection suppressing layer, a hard coat layer, an antistatic layer, and an antifouling layer;
A display device. The display device according to any one of claims 1 to 25,
The pixel array of the image source is a diamond pen tile array,
A display device. The display device according to any one of claims 1 to 26,
In the video source, the proportion of the light emitting area in the video display area is 50% or less,
A display device.

Images