Automotive display device

Abstract

The present disclosure is applicable to the technical field associated with display devices and relates to, for example, an automotive display device that can be applied to an instrument panel in an automobile. The automotive display device according to one aspect disclosed herein comprises: a light source; a waveguide disposed on one side of the light source; and a diffraction layer which is arranged on the waveguide, and which is struck by visible light emitted from the light source and causes the light to be coupled on a principal plane of the waveguide. The diffraction layer includes: an incoupler region on which the light source is incident; an expander region which expands a region of light incident from the incoupler region; and an outcoupler region in which the light expanded in the expander region is formed into an image, wherein, when the sizes of unit regions having identical optical characteristics in the incoupler region, the expander region, and the outcoupler region are denoted as A, B, and C, respectively, the condition A≥B≥C may be satisfied.

Description

Vehicle display device

[0001] The present disclosure relates to a vehicle display device applicable to the field of display device technology, for example, applicable to a vehicle instrument panel.

[0002] The application of Head-Up Displays (HUDs) is increasing significantly to enhance driver safety and comfort while driving. HUDs can display instrument panel information, such as vehicle speed, fuel level, and engine RPM, as well as navigation information. In addition to this data, a wider range of information can be provided through the application of augmented reality.

[0003] Automotive HUD systems are predominantly mirror-based, but these optical systems are very bulky. Consequently, mirrorless Augmented Reality (AR) HUD systems are being introduced.

[0004] To implement a HUD optical system that does not use such mirrors, development is underway to reduce volume by introducing a diffraction optical element (DOE) grating structure on a waveguide substrate.

[0005] However, DOE grating optical systems that do not use mirrors also primarily use three waveguides to propagate light corresponding to the wavelength ranges of red, green, and blue light, respectively, due to the wavelength dispersion characteristics and differences in diffraction angles for each wavelength in the wavelength range of incident light (visible light region).

[0006] As such, using three waveguides not only increases material costs but also makes it difficult to align or compensate for optical path differences according to the wavelength range of the three waveguides and the thickness of the waveguide adhesive, which can lead to a decrease in white balance.

[0007] The technical problem to be solved by the present disclosure is to provide a vehicle display device that can reduce light loss on the surface of a substrate forming a waveguide and the surface of a substrate adhesive material by using a one-layer waveguide when implementing a head-up display (HUD).

[0008] The technical problem to be solved by the present disclosure is to provide a vehicle display device capable of improving the brightness and image quality of the final output image by reducing optical loss through the use of a one-layer waveguide.

[0009] The technical problem to be solved by the present disclosure is to provide a vehicle display device capable of improving the color and brightness uniformity of an image (video) that is propagated / radiated while propagating light in a display.

[0010] The technical problem to be solved by the present disclosure is to provide a vehicle display device capable of efficiently propagating / radiating light within the expander region and the outcoupler region, and further improving the color and brightness uniformity of the light.

[0011] A vehicle display device according to one aspect of the present disclosure comprises: a light source; a waveguide disposed on one side of the light source; and a diffraction layer arranged on the waveguide such that visible light emitted from the light source is incident and coupled on the main plane of the waveguide, wherein the diffraction layer comprises an incoupler region into which the light source is incident, an expander region that expands the region of light incident from the incoupler region, and an outcoupler region in which the light expanded in the expander region is formed into an image, and wherein the sizes of unit regions having the same optical characteristics within the incoupler region, the expander region, and the outcoupler region are denoted as A, B, and C, respectively, the rule A ≥ B ≥ C can be satisfied.

[0012] As an exemplary embodiment, a plurality of cells having a unit size into which a light source is incident in the incoupler region are provided in the expander region and the outcoupler region, and at least some of the plurality of cells may include a reflection region and a diffraction region.

[0013] As an exemplary embodiment, the sizes of the reflection region and the diffraction region may differ from each other in adjacent cells in at least one direction.

[0014] As an exemplary embodiment, the size of the reflection region and the diffraction region may vary along at least one direction.

[0015] As an exemplary embodiment, the size of the diffraction region may increase as it moves away from the incoupler region.

[0016] As an exemplary embodiment, the length directions of the unit regions (subpixels) of the incoupler region, the expander region, and the outcoupler region may differ from each other in at least some parts.

[0017] As an exemplary embodiment, the length direction of the unit area of ​​the expander region may be different from the length direction of the unit area of ​​the outcoupler region.

[0018] As an exemplary embodiment, the length direction of the unit area of ​​the outcoupler region may be formed diagonally with respect to the length direction of the unit area of ​​the expander region.

[0019] As an exemplary embodiment, at least some of the incoupler region, the expander region, and the outcoupler region may include a structure or material consisting of a void space or an organic or inorganic material.

[0020] As an exemplary embodiment, the organic or inorganic material may include a refractive index isotropic material with the same refractive index depending on the direction, a refractive index anisotropic material with a different refractive index depending on the direction, and a metal or oxide material with a reflectance of 30% or more.

[0021] As an exemplary embodiment, the refractive index anisotropic material may include a reactive mesogen, a UV-reactive material, a thermal-reactive material, a chiral dopant, or a liquid crystal.

[0022] As an exemplary embodiment, the diffraction layer comprises a plurality of domains arranged repeatedly, and the domains may include a first pattern that diffracts light of a first wavelength band; a second pattern that diffracts light of a second wavelength band; and a third pattern that diffracts light of a third wavelength band.

[0023] As an exemplary embodiment, the first wavelength band may correspond to a red wavelength band, the second wavelength band may correspond to a green wavelength band, and the third wavelength band may correspond to a blue wavelength band.

[0024] A vehicle display device according to another aspect of the present disclosure comprises a light source; a waveguide disposed on one side of the light source; and a diffraction layer arranged on the waveguide such that visible light emitted from the light source is incident and coupled on the main plane of the waveguide, wherein the diffraction layer comprises an incoupler region into which the light source is incident, an expander region that expands the region of light incident from the incoupler region, and an outcoupler region in which the light expanded in the expander region is formed into an image, and the length directions of the unit regions of the incoupler region, the expander region, and the outcoupler region may differ from each other in at least some parts.

[0025] According to one embodiment of the present disclosure, the following effects are achieved.

[0026] First, by using a one-layer waveguide in a vehicle display device, light loss at the surface of the substrate forming the waveguide and the surface of the substrate adhesive material can be reduced.

[0027] By using a one-layer waveguide in a vehicle display device, light loss is reduced, thereby improving the brightness and image quality of the final output image.

[0028] In a vehicle display device, the uniformity of the image can be easily adjusted.

[0029] In automotive display devices, the color and brightness uniformity of the image (video) being propagated / radiated while emitting light from the display can be improved.

[0030] In a vehicle display device, light can be efficiently propagated / radiated within the expander area and outcoupler area, and the color and brightness uniformity of the light can be further improved.

[0031] Furthermore, according to another embodiment of the present invention, there are additional technical effects not mentioned herein. Those skilled in the art will understand this from the full context of the specification and drawings.

[0032] FIG. 1 is a schematic diagram showing one embodiment of a vehicle display device according to one embodiment of the present disclosure.

[0033] FIG. 2 is a plan view of a vehicle display device according to one embodiment of the present disclosure.

[0034] FIG. 3 is a cross-sectional view schematically illustrating the process of light propagation in a vehicle display device according to one embodiment of the present disclosure.

[0035] FIG. 4 is a conceptual diagram showing the reflection and diffraction characteristics of a vehicle display device according to one embodiment of the present disclosure.

[0036] FIG. 5 is a conceptual diagram showing the pattern structure of a vehicle display device according to one embodiment of the present disclosure.

[0037] FIG. 6 is a plan view showing a part of the incoupler area of ​​a vehicle display device according to one embodiment of the present disclosure.

[0038] FIG. 7 is a plan view showing a part of the expander area of ​​a vehicle display device according to one embodiment of the present disclosure.

[0039] FIG. 8 is a plan view showing a part of the outcoupler area of ​​a vehicle display device according to one embodiment of the present disclosure.

[0040] FIG. 9 is a figure showing examples of diffraction and reflection patterns of a vehicle display device according to one embodiment of the present disclosure.

[0041] FIG. 10 is a schematic cross-sectional view showing a subpixel of an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0042] FIG. 11 is a conceptual diagram showing the propagation of light in a display of a vehicle display device according to one embodiment of the present disclosure.

[0043] FIGS. 12 and FIGS. 13 are detailed diagrams showing the propagation of light in an expander region of a vehicle display device according to one embodiment of the present disclosure.

[0044] FIGS. 14 to 16 are detailed drawings showing the propagation of light in the outcoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0045] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are assigned the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not inherently possess distinct meanings or roles.

[0046] Furthermore, in describing the embodiments disclosed in this specification, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the embodiments disclosed in this specification. Additionally, it should be noted that the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and should not be interpreted as limiting the technical concept disclosed in this specification.

[0047] Furthermore, for the convenience of explanation, each drawing is described, but it is also within the scope of the present invention that a person skilled in the art implements other embodiments by combining at least two drawings.

[0048] Furthermore, when elements such as layers, regions, or substrates are referred to as existing "on" other components, it can be understood that this means they exist directly on the other elements or that there may be an intermediate element between them.

[0049] However, those skilled in the art will readily understand that the configuration according to the embodiments described in this specification may be applied to displayable devices, even in the form of new products developed in the future.

[0050]

[0051] FIG. 1 is a schematic diagram showing one embodiment of a vehicle display device according to one embodiment of the present disclosure.

[0052] Referring to FIG. 1, an example is shown in which a vehicle head-up display (HUD) is implemented using a vehicle display device (1) according to one embodiment of the present disclosure.

[0053] For example, a head-up display (HUD) with augmented reality (AR) applied can be implemented using a vehicle display device (1).

[0054] The application of such head-up displays is increasing significantly to enhance driver safety and comfort while driving. Head-up displays can show instrument panel information, such as vehicle speed, fuel level, and engine RPM, as well as navigation information. In addition to this data, a wider range of information can be provided through the application of augmented reality.

[0055] A vehicle display device (1) may largely include a light source (20) and a display (10) disposed on one side of the light source (20) that implements an image as light emitted from the light source (20) propagates within a waveguide.

[0056] Here, the light source (20) can be located in the same direction (transmitting type) or opposite direction (reflecting type) as the diffraction layer described below.

[0057] Referring to FIG. 1, a virtual instrument panel image (30) can be formed using the front transparent glass (windshield; 40) of a vehicle by light emitted from a vehicle display device (1).

[0058] At this time, a virtual view image (30) can be formed on the outside of the windshield (40) at a distance equal to the distance between the eyebox (31; eyebox) and the windshield (40). At this time, since the image (30) is displayed as a virtual image through the windshield (40), the driver can simultaneously see the actual object on the other side of the windshield (40).

[0059] As schematically illustrated in FIG. 1, a vehicle display device (1) may include a display (10) having an anisotropic material and structure that allows light of three primary colors emitted from a light source (20) to propagate by internal total reflection at the same angle within a single layer waveguide.

[0060] Such a display (10) is arranged on a waveguide (400; see FIG. 3) and includes a diffraction layer that allows visible light emitted from a light source (20) to be incident and coupled on the main plane of the waveguide (400), and such a diffraction layer may include a plurality of domains that are repeatedly arranged.

[0061] At this time, a plurality of domains may include a first pattern that diffracts light of a first wavelength band, a second pattern that diffracts light of a second wavelength band, and a third pattern that diffracts light of a third wavelength band.

[0062] Here, the first wavelength band corresponds to the red wavelength band, the second wavelength band corresponds to the green wavelength band, and the third wavelength band may correspond to the blue wavelength band.

[0063] The first pattern, the second pattern, and the third pattern may include an anisotropic material that causes visible light, including light of a first wavelength band, light of a second wavelength band, and light of a third wavelength band, to be incident and diffracted within the same angle range.

[0064] These anisotropic materials may include liquid crystal materials containing chiral dopants or reactive mesogen (RM) materials in which molecules cross-link with each other by ultraviolet light or temperature.

[0065] This will be discussed in detail later.

[0066]

[0067] FIG. 2 is a plan view of a vehicle display device according to one embodiment of the present disclosure. FIG. 3 is a cross-sectional view schematically showing the process of light propagation in a vehicle display device according to one embodiment of the present disclosure.

[0068] FIG. 2 schematically shows a planar view of a vehicle display device (1). Hereinafter, this planar view is defined as the XY plane. Meanwhile, FIG. 3 shows the process of light propagating through a cross-section of a vehicle display device (1). This planar view (cross-section) is defined as the XZ plane.

[0069] Referring to FIG. 2, a vehicle display device (1) may include an incoupler region (100) into which a light source is incident, an expander region (200) that expands the region of light incident from the incoupler region (100), and an outcoupler region (300) into which the light expanded in the expander region (200) forms an image.

[0070] For example, the incoupler region (100), the expander region (200), and the outcoupler region (300) include a diffraction layer that is coupled on the main plane of the waveguide, and this diffraction layer may include a plurality of domains that are repeatedly arranged.

[0071] FIG. 3 conceptually illustrates a basic structure in which an alignment layer (101, 201, 301) and an anisotropic material (102, 202, 302) are applied at respective locations corresponding to the incoupler region (100), expander region (200), and outcoupler region (300) on the main plane of a one-layer waveguide (400; waveguide) to align the optical axis direction of the anisotropic material (long axis direction of the liquid crystal director) to a design value.

[0072] Referring to FIG. 3, a display (10) having an anisotropic material and structure that allows light of three primary colors emitted from a light source (20) to propagate by internal total reflection at the same angle within a single layer waveguide.

[0073] For example, light of three primary colors including red (R), green (G), and blue (B) emitted from a light source (20) can pass through a waveguide (400) and be incident on an alignment layer (101, 201, 301) and an anisotropic material (102, 202, 302). The light thus incident can first be emitted after diffraction or reflection by the physical property values ​​of the anisotropic material set in the incoupler region (100). The light thus emitted undergoes total reflection in the waveguide (400) and is incident and emitted again to the expander region (200) and the outcoupler region (300), and finally, an image (O) is output in the outcoupler region (300) so that the image becomes visible to the observer's eye.

[0074]

[0075] FIG. 4 is a conceptual diagram showing the reflection and diffraction characteristics of a vehicle display device according to one embodiment of the present disclosure.

[0076] Referring to FIG. 4, an alignment layer (101) may be positioned on the main plane (for example, the upper plane in FIG. 4) of a single-layer waveguide (400), and an anisotropic material (102) pattern formed according to the characteristics of the alignment layer (101) may be positioned.

[0077] The anisotropic material (102) pattern may include a first pattern (120) capable of diffracting light of a first wavelength band (e.g., red light), a second pattern (121) capable of diffracting light of a second wavelength band (e.g., green light), and a third pattern (122) capable of diffracting light of a third wavelength band (e.g., blue light). Such first pattern (120), second pattern (121), and third pattern (122) may be repeatedly arranged on a waveguide (400).

[0078] Such first pattern (120), second pattern (121), and third pattern (122) can be implemented by a diffraction layer that is coupled on the main plane of the waveguide (400). Such a diffraction layer may include a plurality of domains that are repeatedly arranged.

[0079] For example, the first wavelength band may correspond to the red (R) wavelength band, the second wavelength band may correspond to the green (G) wavelength band, and the third wavelength band may correspond to the blue (B) wavelength band.

[0080] Light incident on the pattern of an anisotropic material (102) through the waveguide (400) can be diffracted or reflected by the first pattern (120), the second pattern (121), and the third pattern (122) and emitted at the same angle. The light diffracted or reflected at the same angle in this way can be propagated by total internal reflection within the waveguide (400). Therefore, using a single-layer waveguide (400), light of the three primary colors (RGB) can be propagated by internal total internal reflection within the single-layer waveguide (400).

[0081] The incident light may include light in the red (R) wavelength band, the green (G) wavelength band, and the blue (B) wavelength band. The incident light may be incident on the waveguide (400) with an angle of incidence (θ_in). This incident light may be refracted on the lower side of the waveguide (400) and propagate within the waveguide (400) with a first angle of refraction (θ_GLS). The first angle of refraction (θ_GLS) may correspond to the angle of refraction refracted by the refractive index between the light source (incident light) and the waveguide (400; for example, a glass material). For example, the angle of incidence of the light source may be less than ±45˚.

[0082] Light propagated inside the waveguide (400) with a first angle of refraction (θ_GLS) can be refracted at a second angle of refraction (θ_N) in the alignment layer (101). The second angle of refraction (θ_N) may correspond to the angle of refraction refracted by the refractive index between the waveguide (400; for example, glass material) and the alignment layer (101).

[0083] Light having a second refraction angle (θ_N) can be diffracted by the first pattern (120), the second pattern (121), and the third pattern (122), respectively, and then emitted to the alignment film (101) with a diffraction angle (θ_RN). At this time, each diffraction angle (θ_RN) can have substantially the same angle or the same angle range.

[0084] Afterwards, the red light (R), green light (G), and blue light (B) diffracted by each of the first pattern (120), second pattern (121), and third pattern (122) can be refracted again by the waveguide (400) and propagate along the waveguide (400) with each refraction angle (θ_R, θ_G, θ_B).

[0085] Although the anisotropic material (102) pattern having such a first pattern (120), second pattern (121), and third pattern (122) has been described mainly for the incoupler region (100), it is obvious that it can be applied in the same way to the expander region (200) and the outcoupler region (300).

[0086] Generally, to implement a vehicle AR head-up display (HUD) as illustrated in FIG. 1, an incoupler area (100), an expander area (200), and an outcoupler area (300) or the corresponding optical element may be configured.

[0087] Conventionally, due to differences in diffraction angles for different wavelengths, three or three layers of waveguides are required for red light (R), green light (G), and blue light (B), or two or two layers of waveguides are required according to the design of a certain range of wavelengths.

[0088] However, according to the present disclosure, a pattern and structure of an anisotropic material may be provided such that light can be propagated by internal total reflection within a single layer waveguide (400) at the same angle even if the colors of the light are different, such as red light (R), green light (G), and blue light (B).

[0089]

[0090] FIG. 5 is a conceptual diagram showing the pattern structure of a vehicle display device according to one embodiment of the present disclosure.

[0091] Referring to FIG. 5, FIG. 5(a) shows a part of the incoupler region (100) of the diffraction layer, FIG. 5(b) shows a part of the expander region (200) of the diffraction layer, and FIG. 5(c) shows a part of the outcoupler region (300) of the diffraction layer.

[0092] FIG. 6 is a plan view showing a part of the incoupler region of a vehicle display device according to one embodiment of the present disclosure. FIG. 7 is a plan view showing a part of the expander region of a vehicle display device according to one embodiment of the present disclosure. FIG. 8 is a plan view showing a part of the outcoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0093] Hereinafter, with reference to FIGS. 5 to 8, the pattern structure of a vehicle display device (1) according to one embodiment of the present disclosure will be described in detail.

[0094] As described above, a vehicle display device (1) according to an embodiment may include a light source (20; see FIG. 1) and a display (10) disposed on one side of the light source (20) to create an image as light emitted from the light source (20) propagates within a waveguide (400). The diffraction layer of the display (10) may include an incoupler region (100), an expander region (200), and an outcoupler region (300).

[0095] Such a display (10) may include a waveguide (400) disposed on one side of a light source (20), and a diffraction layer arranged on the waveguide (400) such that visible light emitted from the light source (20) is incident and coupled on the main plane of the waveguide (400).

[0096] In other words, the diffraction layer may include an incoupler region (100) into which a light source (20) is incident, an expander region (200) that expands the region of light incident from the incoupler region (100), and an outcoupler region (300) into which the light expanded in the expander region (200) forms an image.

[0097] This diffraction layer may include a plurality of patterns (120, 121, 122 / 220, 221, 222 / 320, 321, 322) that diffract light of different wavelength bands.

[0098] First, referring to FIG. 5(a) and FIG. 6, the incoupler region (Incoupler; 100) may include a first pattern (120) capable of diffracting light of a first wavelength band (e.g., red light) in a diffraction layer configured in the display (10), a second pattern (121) capable of diffracting light of a second wavelength band (e.g., green light), and a third pattern (122) capable of diffracting light of a third wavelength band (e.g., blue light).

[0099] These first pattern (120; RM1), second pattern (121; RM2), and third pattern (122; RM3) can form a block (1 Block). As described above, the first pattern (120; RM1), second pattern (121; RM2), and third pattern (122; RM3) can each diffract red light, green light, and blue light.

[0100] In this way, a block, which is a unit structure capable of diffracting red, green, and blue light, can be defined as a pixel. At this time, each pattern (120, 121, 122; unit area) can be defined as a subpixel. For example, a diffraction layer has a unit area having the same optical characteristics capable of diffracting light of a single wavelength band, and this can be defined as a subpixel. Therefore, the terms (unit) structure, (unit) block, and pixel may be used interchangeably below. Additionally, the terms (unit) pattern, (unit) area, and subpixel may be used interchangeably.

[0101] Referring to FIG. 5(a) and FIG. 6, two unit blocks (103, 104), that is, two pixels (103, 104), are shown. Here, each unit area (RM1, RM2, RM3) in the incoupler area (100) may have a stripe shape. For example, the subpixels (RM1, RM2, RM3) in the incoupler area (100) may have a stripe shape. Here, the size of the unit area (RM1, RM2, RM3) in the incoupler area (100) is indicated by A. This size A can be defined as the subpixel pitch.

[0102] FIGS. 5(a) and FIGS. 6 illustrate an exemplary embodiment in which each unit area (RM1, RM2, RM3) in the incoupler region (100) has a stripe shape, but each unit area (RM1, RM2, RM3) may have various other shapes. In such cases, the size of the unit area (RM1, RM2, RM3) may correspond to the shorter length among the width, height, diagonal, and diameter of the unit area.

[0103] Referring to FIG. 6, the arrangement order of the first to third unit regions in adjacent blocks (103, 104) may differ from one another. For example, the order of each unit region (pattern; RM1, RM2, RM3) of the diffraction layer in the first block (103) may differ from the order of each unit region (RM1, RM2, RM3) of the diffraction layer in the second block (104). For example, in the first block (103), unit areas (RM1, RM2, RM3) may be arranged in one direction in the order of the first pattern (120; RM1), the second pattern (121; RM2), and the third pattern (122; RM3), and in the second block (104), unit areas (RM1, RM2, RM3) may be arranged in one direction in the order of the second pattern (121; RM2), the third pattern (122; RM3), and the first pattern (121; RM1).

[0104] When forming each pattern (RM1, RM2, RM3), there is a possibility that parts of the anisotropic material forming each pattern (RM1, RM2, RM3) may mix with each other at the boundaries of each pattern (RM1, RM2, RM3), which may lead to the possibility of color mixing during the diffraction of light in the diffraction layer. However, the probability of color mixing may be reduced as the arrangement order of the first unit region to the third unit region is different.

[0105] In this way, by changing the arrangement order of the first to third unit regions, the diffraction and reflection efficiency of the image (video) propagated / radiated while propagating light, and the uniformity of color and brightness can be improved.

[0106] Figure 6 shows two adjacent blocks (103, 104), but it goes without saying that the incoupler region (100) can contain a large number of blocks.

[0107] In the incoupler region (100), a plurality of blocks (103, 104) can function as diffraction regions and reflection regions. For example, a plurality of blocks including a first block (103) and a second block (104) may correspond to diffraction regions and reflection regions.

[0108] The refractive index anisotropic material constituting the diffraction region may include at least one of a reactive mesogen (RM), a UV-reactive material, a thermal-reactive material, a chiral dopant, or a liquid crystal.

[0109] Next, referring to FIG. 5(b) and FIG. 7, the expander region (Expander; 200) may include a first pattern (220) capable of diffracting light of a first wavelength band (e.g., red light) in a diffraction layer configured in the display (10), a second pattern (221) capable of diffracting light of a second wavelength band (e.g., green light), and a third pattern (222) capable of diffracting light of a third wavelength band (e.g., blue light).

[0110] These first pattern (220; RM4), second pattern (221; RM5), and third pattern (222; RM6) can form a block (1 Block). For example, the first pattern (220; RM4), second pattern (221; RM5), and third pattern (222; RM6) can be repeated several times to form a block.

[0111] As described above, the first pattern (220; RM4), the second pattern (221; RM5), and the third pattern (222; RM6) can each diffract red light, green light, and blue light.

[0112] In this way, a block that is a unit structure capable of diffracting red light, green light, and blue light can be defined as a pixel. At this time, each pattern (220, 221, 222; unit area) can be defined as a subpixel.

[0113] For example, the diffraction layer has a unit region having the same optical properties capable of diffracting light of one wavelength band, and this can be defined as a subpixel. In this embodiment, a pixel may have a structure in which a first pattern (220; RM4), a second pattern (221; RM5), and a third pattern (222; RM6) are repeated three times. For example, in the expander region (200), a pixel may be composed of nine subpixels.

[0114] Referring to FIG. 5(b) and FIG. 7, two pixels (203, 204) are shown. Here, each unit area (RM4, RM5, RM6) in the expander area (200) may have a stripe shape. For example, the size and direction of the stripe shape of each unit area (RM4, RM5, RM6) in this expander area (200) may differ from the size and direction of the stripe shape of each unit area (RM1, RM2, RM3) in the incoupler area (100).

[0115] For example, the size of the stripe shape of each unit area (RM4, RM5, RM6) in the expander area (200) may be smaller than the size of the stripe shape of each unit area (RM1, RM2, RM3) in the incoupler area (100). For example, the length direction of the stripe shape of each unit area (RM4, RM5, RM6) in the expander area (200) may be perpendicular to the length direction of the stripe shape of each unit area (RM1, RM2, RM3) in the incoupler area (100).

[0116] Here, the size of the unit area in the expander area (200) is denoted as B. This size B can be defined as a subpixel pitch.

[0117] In FIG. 5(b) and FIG. 7, each unit area in the expander area (200) is exemplarily shown having a stripe shape, but each unit area may have various other shapes. In such cases, the size of the unit area may correspond to the shorter of the width, height, diagonal, and diameter of the unit area.

[0118] Referring to FIG. 7, the arrangement order of the first to third unit regions in one block (203 or 204) may differ from one another. For example, the order of the first three unit regions (RM4, RM5, RM6) of the diffraction layer in the first block (203) may differ from the arrangement order of the next three unit regions (RM4, RM5, RM6).

[0119] For example, in the first block (203), the first three unit regions (RM4, RM5, RM6) of the diffraction layer may be arranged in one direction in the order of the first pattern (220; RM4), the second pattern (221; RM5), and the third pattern (222; RM6), and the next three unit regions (RM4, RM5, RM6) may be arranged in one direction in the order of the second pattern (221; RM5), the third pattern (220; RM4), and the third pattern (222; RM6).

[0120] As explained above, by changing the arrangement order of the first to third unit regions, the diffraction and reflection efficiency of the image (video) propagated / radiated while propagating light, and the color and brightness uniformity can be improved.

[0121]

[0122] Figure 7 shows two adjacent blocks (203, 204), but it goes without saying that the expander area (200) can contain a large number of blocks.

[0123] In the expander region (200), a plurality of blocks (203, 204) can function as diffraction regions and reflection regions.

[0124] For example, in the first block (203), the first three unit regions (RM4, RM5, RM6) may correspond to the diffraction region (205), and the remaining region (E1) may correspond to the reflection region (206). Meanwhile, in the second block (204), the first six unit regions (RM4, RM5, RM6, RM5, RM4, RM6) may correspond to the diffraction region (205), and the remaining region (E2) may correspond to the reflection region (206).

[0125] As such, the sizes of the diffraction region (205) and the reflection region (206) may differ from each other in adjacent blocks (203, 204). The functions of these diffraction region (205) and reflection region (206) will be described in detail later.

[0126] For example, the size of the diffraction region (205) and the reflection region (206) may vary along at least one direction in the expander region (200). For example, the size of the diffraction region (205) in the expander region (200) may increase as it moves away from the incoupler region (100). Conversely, the size of the reflection region (206) in the expander region (200) may decrease as it moves away from the incoupler region (100). This will be described in detail later.

[0127] As described above, the refractive index anisotropic material constituting the diffraction region (205) may include at least one of a reactive mesogen (RM), a UV-reactive material, a thermal-reactive material, a chiral dopant, or a liquid crystal.

[0128] Meanwhile, the reflection area (206) may include a refractive index isotropic material with the same refractive index depending on the direction, a refractive index anisotropic material with a different refractive index depending on the direction, and a metal or oxide material with a reflectivity of 30% or more.

[0129] These reflective areas (206) may include structures or materials consisting of empty spaces or organic and inorganic materials.

[0130] Next, referring to FIG. 5(c) and FIG. 8, the outcoupler region (Outcoupler; 300) may include a first pattern (320) capable of diffracting light of a first wavelength band (e.g., red light) in a diffraction layer configured in the display (10), a second pattern (321) capable of diffracting light of a second wavelength band (e.g., green light), and a third pattern (322) capable of diffracting light of a third wavelength band (e.g., blue light).

[0131] These first pattern (320), second pattern (321), and third pattern (322) can form a block (1 Block). For example, the first pattern (320), second pattern (321), and third pattern (322) can be repeated several times to form a block.

[0132] As described above, the first pattern (320), the second pattern (321), and the third pattern (322) can each diffract red light, green light, and blue light.

[0133] In this way, a block that is a unit structure capable of diffracting red light, green light, and blue light can be defined as a pixel. At this time, each pattern (320, 321, 322; unit area) can be defined as a subpixel.

[0134] For example, the diffraction layer has a unit region having the same optical properties capable of diffracting light of one wavelength band, and this can be defined as a subpixel. In this embodiment, a pixel may have a structure in which the first pattern (320), the second pattern (321), and the third pattern (322) are repeated four times.

[0135] Referring to FIG. 5(c) and FIG. 8, the outcoupler area (300) is illustrated with six pixels (O11 to O23) defined as OM1, OM2, OM3 in the vertical direction and O1L, O2L in the horizontal direction. For example, the outcoupler area (300) may have M×L pixels.

[0136] Reference numerals 303 and 304 indicate each pixel within the outcoupler area (300). Here, each unit area (320, 321, 322) in the outcoupler area (300) may have a stripe shape in which small square shapes are connected diagonally to the unit pixel area. For example, the size and direction of the stripe shape of each unit area (320, 321, 322) in the outcoupler area (300) may differ from the size and direction of the stripe shape of each unit area (RM1, RM2, RM3) in the incoupler area (100) and / or the stripe shape of each unit area (RM4, RM5, RM6) in the expander area (200).

[0137] Here, if a single stripe shape formed by such small square shapes extending diagonally across a unit pixel area is defined as a single subpixel, for example, one pixel in the outcoupler area (300) can be composed of 81 subpixels.

[0138] For example, the size of the stripe shape of each unit area (320, 321, 322) in the outcoupler area (300) may be smaller than the size of the stripe shape of each unit area (RM1, RM2, RM3) in the incoupler area (100) and / or the size of the stripe shape of each unit area (RM4, RM5, RM6) in the expander area (200).

[0139] For example, the longitudinal direction of the stripe shape of each unit area (320, 321, 322) in the outcoupler area (300) may form a diagonal direction with respect to the longitudinal direction of the stripe shape of each unit area (RM1, RM2, RM3) in the incoupler area (100) and / or the stripe shape of each unit area (RM4, RM5, RM6) in the expander area (200).

[0140] In this way, for example, the length direction of the unit area (320, 321, 322) of the outcoupler area (300) may be different from the length direction of the unit area (RM4, RM5, RM6) of the expander area (200). For example, the length direction of the unit area (320, 321, 322) of the outcoupler area (300) may be formed diagonally with respect to the length direction of the unit area (RM4, RM5, RM6) of the expander area (200).

[0141] Here, the size of the unit area in the outcoupler area (300) is denoted by C. This size C can be defined as a subpixel pitch. In this case, the size of this unit area may correspond to the shorter of the width, height, diagonal, and diameter of the unit area.

[0142] FIGS. 5(c) and FIGS. 8 illustrate an exemplary embodiment in which each unit area (320, 321, 322) in the outcoupler area (300) has a stripe shape in which small square shapes are connected diagonally with respect to the unit pixel area, but each unit area may have various other shapes. For example, each unit area (320, 321, 322) in the outcoupler area (300) may be formed as a stripe shape having a certain width in a diagonal direction with respect to the unit pixel area.

[0143] Referring to FIG. 8, the arrangement order of the first unit region (320) to the third unit region (322) in one block (303 or 304) may be the same. According to an embodiment, the arrangement order of the first unit region (320) to the third unit region (322) in one block (303 or 304) may be different from each other. For example, the order of the first three unit regions (320, 321, 322) of the diffraction layer in one block (303 or 304) may be different from the arrangement order of the next three unit regions (320, 321, 322).

[0144] Figure 8 shows six adjacent blocks (O11 to O23), but it goes without saying that the outcoupler region (300) can contain a large number of blocks. For example, the outcoupler region (300) can have M×L pixels.

[0145] Here, in the outcoupler region (300), a plurality of blocks (O11 to O23) can function as diffraction regions and reflection regions. For example, each block may include a diffraction region (305) and a reflection region (306).

[0146] In one block (303; O21), the part marked 306 may correspond to a reflection area, and the remaining area may correspond to a diffraction area (305).

[0147] As such, the sizes of the diffraction region (305) and the reflection region (306) may differ from each other in adjacent blocks (303, 304). The functions of these diffraction region (305) and reflection region (306) will be described in detail later.

[0148] For example, the size of the diffraction region (305) and the reflection region (306) may vary along at least one direction in the outcoupler region (300). For example, the size of the diffraction region (305) in the outcoupler region (300) may increase as it moves away from the expander region (200). Conversely, the size of the reflection region (306) in the outcoupler region (300) may decrease as it moves away from the expander region (200). This will be described in detail later.

[0149] As described above, the refractive index anisotropic material constituting the diffraction region (305) may include at least one of a reactive mesogen (RM), a UV-reactive material, a thermal-reactive material, a chiral dopant, or a liquid crystal.

[0150] Meanwhile, the reflection area (306) may include a refractive index isotropic material with the same refractive index depending on the direction, a refractive index anisotropic material with a different refractive index depending on the direction, and a metal or oxide material with a reflectivity of 30% or more.

[0151] These reflective areas (306) may include structures or materials consisting of empty spaces or organic and inorganic materials.

[0152] In this way, at least some of the incoupler region (100), expander region (200), and outcoupler region (300) may correspond to a reflection region. For example, at least some of the incoupler region (100), expander region (200), and outcoupler region (300) may include a structure or material consisting of a void space or an organic or inorganic material.

[0153] As described above, according to an embodiment of the present disclosure, when the sizes of unit regions (subpixels) having the same optical characteristics within the incoupler region (100), expander region (200), and outcoupler region (300) are denoted as A, B, and C, respectively, the rule A ≥ B ≥ C can be satisfied.

[0154] By such rules, the color and brightness uniformity of the image (video) being propagated / radiated while propagating light from the display (10) can be improved.

[0155] In addition, as described above, the size of the reflection area (206, 306) can gradually decrease as it moves away from the incoupler area (100) in each cell. Accordingly, light can be efficiently propagated / radiated within the expander area (200) and the outcoupler area (300), and the uniformity of the color and brightness of the light can be further improved.

[0156]

[0157] FIG. 9 is a diagram showing examples of diffraction and reflection patterns of a vehicle display device according to one embodiment of the present disclosure. FIG. 10 is a schematic cross-sectional view showing a subpixel of an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0158] Referring to FIGS. 9 and 10, each anisotropic material (102) pattern may include a first pattern (120) having a diffraction layer capable of diffracting light of a first wavelength band (e.g., red light), a second pattern (121) having a diffraction layer capable of diffracting light of a second wavelength band (e.g., green light), and a third pattern (122) having a diffraction layer capable of diffracting light of a third wavelength band (e.g., blue light). Each pattern may have a shape according to the orientation period (PB pitch) of the alignment film.

[0159] A first pattern (120) corresponding to light of a first wavelength band may have a shape as illustrated in FIG. 9(a). This first pattern (120) may have a first PB pitch (PB Pitch 1). For example, as illustrated, the first pattern (120) may have a pattern shape having the first PB pitch that is repeatedly arranged on a plane (alignment film; 110).

[0160] A second pattern (121) corresponding to light of the second wavelength band may have a shape as illustrated in FIG. 9(b). This second pattern (121) may have a second PB pitch (PB Pitch 2). For example, as illustrated, the second pattern (121) may have a pattern shape having the second PB pitch that is repeatedly arranged on a plane (alignment film; 111). Here, the light of the second wavelength band may have a shorter wavelength band than the light of the first wavelength band. Accordingly, the second PB pitch may be smaller than the first PB pitch.

[0161] A third pattern (122) corresponding to light of the third wavelength band may have a shape as illustrated in FIG. 9(c). This third pattern (122) may have a third PB pitch (PB Pitch 3). For example, as illustrated, the pattern shape having the third PB pitch of the third pattern (122) may be repeatedly arranged on a plane (alignment film; 112). Here, the light of the third wavelength band may have a shorter wavelength band than the light of the second wavelength band. Accordingly, the third PB pitch may be smaller than the second PB pitch.

[0162] The characteristics of the patterns (220, 221, 222) of the expander region (200) and the characteristics of the patterns (320, 321, 322) of the outcoupler region (300) may be the same as or have the same tendency as the characteristics of the patterns (120, 121, 122) of the incoupler region (100).

[0163] Meanwhile, the reflection pattern (206) functioning as a reflection layer may be the same for the entire plane (alignment layer; 110, 111, 112). That is, the PB pitch of the reflection pattern (206) may be infinite. The reflection pattern (306) of the outcoupler region (300) may have the same characteristics or the same tendency as the reflection pattern (206) of the incoupler region (100).

[0164] Referring to FIG. 10, as described above, each anisotropic material (102) pattern may include a first pattern (120) having a diffraction layer capable of diffracting light of a first wavelength band (e.g., red light), a second pattern (121) having a diffraction layer capable of diffracting light of a second wavelength band (e.g., green light), and a third pattern (122) having a diffraction layer capable of diffracting light of a third wavelength band (e.g., blue light). Such first pattern (120), second pattern (121), and third pattern (122) may be repeatedly arranged on a waveguide (400).

[0165] These first pattern (120), second pattern (121), and third pattern (122) may be located on the first alignment layer (110), second alignment layer (111), and third alignment layer (112), respectively. For example, the first pattern (120), second pattern (121), and third pattern (122) may be formed according to the characteristics of the first alignment layer (110), second alignment layer (111), and third alignment layer (112).

[0166] The anisotropic material (102) forming a plurality of patterns (120, 121, 122) has a helical structure in a direction perpendicular to the orientation film (101) and can have a helical pitch of a defined range.

[0167]

[0168] FIG. 11 is a conceptual diagram showing the propagation of light in a display of a vehicle display device according to one embodiment of the present disclosure.

[0169] Referring to FIG. 11, the propagation directions of diffracted light and reflected light are shown. For example, in the incoupler region (100), diffracted light and reflected light can propagate in the same direction.

[0170] Referring to FIG. 11, the expander region (200) may include a plurality of regions in the longitudinal direction. Each of these regions may correspond to a cell having a unit size (pupil) into which a light source is incident.

[0171] For example, in a display (10), a light source having a unit size (a certain diameter; hereinafter defined as a pupil) is incident on a waveguide (400) having a certain thickness at a certain angle of incidence (a first angle of incidence), and then light refracted by the refractive index (n_GLS; see FIG. 4) of the waveguide (400) is incident on an alignment film (101) and an anisotropic material (102) of the incoupler region (100) at an angle of incidence (a second angle of incidence). Here, the anisotropic material (102) may have diffraction or reflection characteristics depending on the wavelength range.

[0172] Meanwhile, the outcoupler region (300) may be extended in one direction relative to the longitudinal direction of the expander region (200) to form a plane of a certain size. For example, the outcoupler region may include M regions (OM1 to OML; see FIG. 5) in the first direction (longitudinal direction in FIG. 11) and L regions in the second direction (transverse direction in FIG. 11). Likewise, each region may correspond to a cell having a unit size (pupil) into which a light source is incident.

[0173] For example, in the expander region (200), reflected light can be propagated in the direction indicated by the solid line, that is, in the length direction of the expander region (200), and diffracted light can be propagated in the direction indicated by the dotted line, that is, in a direction perpendicular to the length direction of the expander region (200) (outcoupler region direction).

[0174] For example, in the outcoupler area (300), reflected light is propagated in the direction indicated by the solid line, that is, in the plane direction of the outcoupler area (300), and diffracted light can be propagated in the direction indicated by the dotted line, that is, in a direction perpendicular to the plane direction of the outcoupler area (300) (direction toward the viewer).

[0175] The process of such light propagation will be described in detail later with reference to the drawings.

[0176] As described above, at least some of the plurality of cells may include reflection regions and diffraction regions. The sizes of these reflection regions and diffraction regions may differ from each other in adjacent cells in at least one direction.

[0177] For example, in the expander area (200), the size of the reflection area (206) in one cell (207) may differ from the size of the reflection area (206) in an adjacent cell (207).

[0178] For example, the size of the diffraction region (205) and the reflection region (206) in the expander region (200) can vary along at least one direction.

[0179] Referring to FIG. 11, as an exemplary embodiment, the size of the diffraction region (205) may increase as it moves away from the incoupler region (100). In this case, for example, the cell (207) located at the outermost end may be composed only of the diffraction region (205) without having a reflection region (206).

[0180] For example, in the outcoupler area (300), the size of the reflection area (306) in one cell (307) may differ from the size of the reflection area (306) in an adjacent cell (307).

[0181] For example, the size of the diffraction region (305) and the reflection region (306) in the outcoupler region (300) can vary along at least one direction.

[0182] Referring to FIG. 11, as an exemplary embodiment, the size of the diffraction region (305) may increase as it moves away from the expander region (200). In this case, for example, the cell (307) located at the outermost row may be composed only of the diffraction region (305) without having a reflection region (306).

[0183] As such, the embodiment illustrated in FIG. 11 is an example designed to use 8 cells in the expander region (200) and 64 cells in the outcoupler region (300) with a single waveguide (400). Here, the ratio of the diffraction region in the last cell can be set to 100% and the ratio of the reflection region to 0% so that the optical loss rate is minimized when the diffraction efficiency of the expander region (200) and the outcoupler region (300) is 50% relative to the incident light amount.

[0184]

[0185] FIGS. 12 and FIGS. 13 are detailed diagrams showing the propagation of light in an expander region of a vehicle display device according to one embodiment of the present disclosure.

[0186] Hereinafter, the process of light propagation in the display (10) will be explained in detail with reference to FIGS. 11 to 13.

[0187] Light incident through the incoupler region (100) can propagate to the expander region (200) with a pupil of the same size.

[0188] As explained above, the characteristics of the subpixel (unit size) by the multi-domain can be applied equally to the expander area (200).

[0189] These expander regions (200) may have the following characteristics.

[0190] (1) The expander region (200) may have a structure in which pupils overlap each other, with an area corresponding to the width of the re-incident region of the incoupler region (100) existing on the left and right. This expander region (200) may extend to the Mth block along one direction of the incoupler region (100). One pupil may be located in the corresponding block.

[0191] (2) The total area of ​​the overlapping multiple regions of the overlapping pupils may be 10% or more of the total area of ​​the incoupler region (100) (N>1 / 10).

[0192] (3) The number of pupils in the expander area (200) may be three or more. FIG. 11 shows an example where the number of pupils in the expander area (200) is eight, but this is merely an example.

[0193] (4) The interior of one pupil is a Bragg diffraction or reflection region (third region), and ±1 st It can be divided into order (1st order) diffraction regions (4th region). At this time, each region can be further divided into subpixel regions for each color.

[0194] At this time, with reference to FIGS. 12 and 13, light emitted from the third region travels within the expander region (200) (k1, k3; reflected light), and light emitted from the fourth region can propagate to the outcoupler region (300) (k2; diffracted light).

[0195] (5) The size of the fourth region can be larger the further the pupil is from the incoupler region (100) compared to the pupil closer to the incoupler region (100).

[0196] As such, the expander region (200) may include a third region for advancing light within the expander region (200) and a fourth region for advancing light to the outside of the expander region (200) or to an outcoupler region (300), although these are not clearly indicated in the drawing.

[0197] At this time, the third region may be a reflection region (206) and the fourth region may be a diffraction region (205).

[0198]

[0199] FIGS. 14 to 16 are detailed drawings showing the propagation of light in the outcoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0200] Referring to FIGS. 14 to 16, light propagated through the expander region (200) can be propagated to the outcoupler region (300) with a pupil of the same size.

[0201] As explained above, the characteristics of the subpixel (unit size) by multi-domain can be applied equally to the outcoupler area (300).

[0202] When a pupil with areas that overlap each other on the left and right sides in the expander region (200) is incident on the outcoupler region (300), the outcoupler region (300) may have the following characteristics.

[0203] (1) Within the outcoupler area (300), one pupil can be divided into a fifth area and a sixth area, just like the expander area (200), and each area can be further divided into subpixel areas for each color.

[0204] At this time, referring to FIGS. 14 to 16, light emitted from the fifth region travels within the outcoupler region (300) (k5; reflected light), and light emitted from the sixth region can be propagated toward the viewer (k4; diffracted light).

[0205] Here, the fifth region is the Bragg diffraction or reflection region, and the sixth region is ±1 st It can be an order (1st order) diffraction region.

[0206] The fifth region of the outcoupler region (300) generates light that travels within the outcoupler region (300), and the sixth region can generate light that is emitted outside the waveguide (400) so that a viewer can perceive the image.

[0207] At this time, the fifth region may be a reflection region (306) and the sixth region may be a diffraction region (305).

[0208] (2) The total area of ​​multiple overlapping regions of the overlapping pupil may be 10% or more of the total pupil area (N=1 / 10 or more).

[0209] (3) The number of pupils in the outcoupler region (300) may be 9 or more. FIG. 11 shows an example where the number of pupils in the outcoupler region (300) is 64, but this is merely an example.

[0210] At least some of these nine or more unit sizes overlap each other, and the overlapping area of ​​the unit sizes in the outcoupler area (300) may be 10% or more of the unit sizes.

[0211]

[0212] The above description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention.

[0213] Accordingly, the embodiments disclosed in this invention are intended to explain, not limit, the technical concept of the invention, and the scope of the technical concept of the invention is not limited by these embodiments.

[0214] The scope of protection of the present invention shall be interpreted by the claims below, and all technical ideas within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0215] According to the present disclosure, a display device applicable to a vehicle's instrument panel or to augmented reality (AR) or virtual reality (VR) can be provided.

Claims

1. In a vehicle display device, Light source; A waveguide disposed on one side of the above light source; It includes a diffraction layer arranged on the waveguide, wherein visible light emitted from the light source is incident and coupled on the main plane of the waveguide. The above diffraction layer It includes an incoupler region into which the light source is incident, an expander region that expands the region of light incident from the incoupler region, and an outcoupler region in which the light expanded in the expander region forms an image. For a unit region (pixel) having the same optical characteristics within the incoupler region, the expander region, and the outcoupler region, where the shorter lengths among the width, height, diagonal, and diameter are denoted as A, B, and C, respectively, the rule A ≥ B ≥ C is satisfied. Vehicle display device.

2. In claim 1, a plurality of cells having a unit size (pupil) into which a light source is incident in the incoupler region are provided in the expander region and the outcoupler region, and At least some of the plurality of cells above include a reflection region and a diffraction region. Vehicle display device.

3. In paragraph 2, the sizes of the reflection region and the diffraction region are different in adjacent cells in at least one direction. Vehicle display device.

4. In paragraph 2, the sizes of the reflection region and the diffraction region vary along at least one direction Vehicle display device.

5. In paragraph 2, the size of the diffraction region increases as it moves away from the incoupler region Vehicle display device.

6. In claim 1, the length directions of the unit regions of the incoupler region, the expander region, and the outcoupler region are different in at least some parts. Vehicle display device.

7. In paragraph 6, the length direction of the unit area of ​​the expander region is different from the length direction of the unit area of ​​the outcoupler region. Vehicle display device.

8. In claim 6, the length direction of the unit area of ​​the outcoupler region is formed diagonally with respect to the length direction of the unit area of ​​the expander region. Vehicle display device.

9. In claim 1, at least some of the incoupler region, the expander region, and the outcoupler region comprise a structure or material having a void space or being an organic or inorganic material. Vehicle display device.

10. In claim 9, the organic or inorganic material comprises a refractive index isotropic material with the same refractive index depending on the direction, a refractive index anisotropic material with a different refractive index depending on the direction, and a metal or oxide material having a reflectance of 30% or more. Vehicle display device.

11. In paragraph 10, the refractive index anisotropic material comprises a reactive mesogen, a UV-reactive material, a thermal-reactive material, a chiral dopant, or a liquid crystal. Vehicle display device.

12. In Paragraph 1, The above diffraction gratings include a plurality of domains arranged repeatedly, and The above domain is A first pattern having a grating period corresponding to light of a first wavelength band; A second pattern having a grating period corresponding to light of a second wavelength band; and A third pattern having a grating period corresponding to light of a third wavelength band Vehicle display device.

13. In paragraph 12, the first wavelength band corresponds to the red wavelength band, the second wavelength band corresponds to the green wavelength band, and the third wavelength band corresponds to the blue wavelength band. Vehicle display device.

14. In a vehicle display device, Light source; A waveguide disposed on one side of the above light source; It includes a diffraction layer arranged on the waveguide, wherein visible light emitted from the light source is incident and coupled on the main plane of the waveguide. The above diffraction layer It includes an incoupler region into which the light source is incident, an expander region that expands the region of light incident from the incoupler region, and an outcoupler region in which the light expanded in the expander region forms an image. The length directions of the unit regions of the incoupler region, the expander region, and the outcoupler region are different in at least some parts. Vehicle display device.

15. In claim 14, for a unit area (pixel) having the same optical characteristics within the incoupler area, the expander area, and the outcoupler area, where the shorter lengths among the width, height, diagonal, and diameter are denoted as A, B, and C, respectively, the rule A ≥ B ≥ C is satisfied. Vehicle display device.

Images