Vehicle display device

Abstract

The present disclosure is applicable to the technical field related to display devices and, for example, relates to a vehicle display device applicable to the instrument panel of a vehicle. The vehicle display device according to a first aspect of the present disclosure may comprise: a light source; a waveguide disposed at 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 thereon and coupled to the waveguide on the main plane thereof, wherein the diffraction layer includes a plurality of domains repeatedly arranged, and the domains each include a first pattern for diffracting light of a first wavelength band, a second pattern for diffracting light of a second wavelength band, and a third pattern for diffracting light of a third wavelength band.

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] Therefore, a solution to these problems is required.

[0008] 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).

[0009] 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.

[0010] The technical problem to be solved by the present disclosure is to provide a vehicle display device that can easily adjust image uniformity when implementing a head-up display.

[0011] The technical problem to be solved by the present disclosure is to provide a vehicle display device capable of resolving the alignment problem that occurs when implementing a head-up display using a multilayer waveguide.

[0012] The technical problem to be solved by the present disclosure is to provide a vehicle display device capable of resolving the problem of reduced white balance that occurs when implementing a head-up display using a multilayer waveguide.

[0013] A vehicle display device according to the first 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 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.

[0014] A vehicle display device according to the second 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 a plurality of domains arranged repeatedly, and 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, wherein the incoupler region comprises a first region in which light is directly incident at an angle of a first angle region and emitted at a third angle; and a second region in which the light is re-incident and emitted at the third angle, and the first region and the second region may have different diffraction layer structures.

[0015] According to an embodiment of the present disclosure, the following effects are achieved.

[0016] First, when implementing a Head-up Display (HUD), a single-layer waveguide can be used to reduce light loss on the surface of the substrate forming the waveguide and the surface of the substrate adhesive material.

[0017] When implementing a head-up display, using a single-layer waveguide reduces light loss, thereby improving the brightness and image quality of the final output image.

[0018] When implementing a head-up display, the uniformity of the image can be easily adjusted.

[0019] The alignment problem that occurs when implementing a head-up display using a multilayer waveguide can be resolved.

[0020] The problem of degraded white balance that occurs when implementing a head-up display using a multilayer waveguide can be resolved.

[0021] Furthermore, according to another embodiment of the present disclosure, 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.

[0022] FIG. 1 is a schematic diagram showing one embodiment of a vehicle display device according to one embodiment of the present disclosure.

[0023] FIG. 2 is a plan view of a vehicle display device according to one embodiment of the present disclosure.

[0024] FIG. 3 is a schematic diagram showing the process of light propagation in a vehicle display device according to one embodiment of the present disclosure.

[0025] 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.

[0026] FIG. 5 is a schematic cross-sectional view showing an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0027] FIGS. 6 to 8 are schematic cross-sectional diagrams showing the characteristics of a vehicle display device according to an embodiment of the present disclosure as a function of the angle of incident light.

[0028] FIG. 9 is a schematic diagram showing diffraction and reflection characteristics in the incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0029] FIG. 10 is a schematic diagram showing diffraction and reflection regions in the incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0030] FIGS. 11 to 13 show subpixels of an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0031] FIG. 14 is a conceptual diagram showing the propagation of light in the incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0032] FIG. 15 is a conceptual diagram illustrating the light propagation process of a vehicle display device according to one embodiment of the present disclosure.

[0033] FIGS. 16 and 17 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.

[0034] FIGS. 18 to 20 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.

[0035] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components are assigned the same reference number regardless of drawing symbols, 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040]

[0041] FIG. 1 is a schematic diagram showing one embodiment of a vehicle display device according to one embodiment of the present disclosure.

[0042] 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.

[0043] For example, a head-up display (HUD) with augmented reality (AR) applied can be implemented using a vehicle display device (1).

[0044] 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.

[0045] 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.

[0046] 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).

[0047] 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 display (31) 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).

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] These anisotropic materials may include liquid crystal materials containing chiral dopants or reactive mesogen materials in which molecules cross-link with each other by ultraviolet light or temperature.

[0054] This will be discussed in detail later.

[0055]

[0056] FIG. 2 is a plan view of a vehicle display device according to one embodiment of the present disclosure. FIG. 3 is a schematic diagram showing the process of light propagation in a vehicle display device according to one embodiment of the present disclosure.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063]

[0064] 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.

[0065] 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.

[0066] 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).

[0067] 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.

[0068] 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.

[0069] 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).

[0070] 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˚.

[0071] 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).

[0072] 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.

[0073] 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).

[0074] 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).

[0075] 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.

[0076] 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.

[0077] 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).

[0078]

[0079] FIG. 5 is a schematic cross-sectional view showing an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0080] Referring to FIG. 5, the light source is incident on and emitted from the incoupler region (100) configured on the waveguide (400) and the light propagating therefrom is schematically shown.

[0081] In one embodiment, a light source having an incoupler region (100) and a unit size (a constant diameter (d_0); hereinafter defined as pupil) enters a waveguide (400) having a thickness d_g at a constant angle of incidence (θ a Light is incident with a first angle of incidence, and subsequently, light refracted by the refractive index (n_g) of the waveguide (400) is incident on the alignment film (101) and the anisotropic material (102) of the incoupler region (100) with an angle of incidence (θ_g; second angle of incidence). At this time, the refractive index of the alignment film (101) is (n_n) and the refractive index of the anisotropic material (102) is (n_ie, n_io). Here, since the anisotropic material (102) has diffraction or reflection characteristics depending on the wavelength region, the refractive index values ​​(ie, no) for each wavelength may be different from each other.

[0082] For example, light incident on an anisotropic material (102) with an angle of incidence (θ_g; second angle of incidence) is θ_g by the pattern design of each material β1 Diffraction or reflection occurs by an angle (first diffraction / reflection angle), and total reflection occurs on the lower surface (opposite surface of the main plane) of the waveguide (400) within the thickness (d_g) of the waveguide (400), and after moving by a distance d_1 of the waveguide (400), it is re-incident in the incoupler region (100).

[0083] At this time, the angle of incidence (θ) when light is re-incident after moving a distance d_1 of the waveguide (400). β2 ; The third angle of incidence) may be different from the second angle of incidence (θ_g) which is incident in the order of light source-waveguide (400)-alignment film (101) of the incoupler region (100). Therefore, the third angle of incidence (θ β2 The light incident on ) is θ in the incoupler region (100). β1 Diffraction or reflection can occur at an angle different from the angle (second angle of diffraction / reflection).

[0084] In this way, the incoupler region (100) may include a first region (P1; see FIG. 9) in which light is directly incident at an angle (θ_g; second incident angle) of a first angle region, and a second region (P3; see FIG. 9) in which the light is re-incident at an angle (θ_g; third incident angle) of a second angle region within the incoupler region (100). At this time, the first region (P1) and the second region (P3) may have different diffraction layer structures.

[0085] In other words, the incoupler region (100) may include a first region (P1) in which light is directly incident at an angle of a first angle region (e.g., 0 to 20 degrees) and a second region (P3) in which the light is re-incident at an angle of a second angle region (an angle range that is larger than the first angle region due to reflection / diffraction). As such, the second angle region may be larger than the first angle region.

[0086]

[0087] FIGS. 6 to 8 are schematic cross-sectional diagrams showing the characteristics of a vehicle display device according to an embodiment of the present disclosure as a function of the angle of incident light.

[0088] As described above, according to the present disclosure, by controlling the optical characteristics of light re-incident to the incoupler region (100), the quality of the image provided to the driver and passenger viewing the AR vehicle head-up display (HUD) as one embodiment can be improved.

[0089] Referring to FIGS. 6 to 8, the first diffraction / reflection angle (θ β1 The uniformity of the image provided to the viewer through the outcoupler area (300) can change depending on )

[0090] As illustrated, the area of ​​the image that is re-incident within the incoupler region (100) may vary depending on the distance (d_1) traveled by the incident light representing the image that is diffracted / reflected in the incoupler region (100). This travel distance (d_1) is the first diffraction / reflection angle (θ β1 It can vary depending on ), and this first diffraction / reflection angle (θ β1 ) is the angle of incidence of the incident light (θ a ; It can vary depending on the first angle of incidence.

[0091] For example, as in the case of FIG. 6, when the distance (d_1) traveled by the incident light that is diffracted / reflected in the incoupler region (100) is equal to the size of the incoupler region (100), i.e., the first diffraction / reflection angle is θ β11 In this case, the uniformity of the image may be reduced.

[0092] Meanwhile, as in the case of FIGS. 7 and 8, when the distance (d_1) traveled by the incident light diffracted / reflected in the incoupler region (100) becomes smaller than the size of the incoupler region (100), i.e., the first diffraction / reflection angle is θ β12 or θ β13 In this case, the uniformity of the image can be increased. In this case, the area of ​​re-incident light within the incoupler region (100) can gradually increase in inverse proportion to the first diffraction / reflection angle.

[0093] At this time, the image (light) re-incident within the incoupler region (100) has a different angle of incidence when incident into the incoupler region (100) compared to the light directly incident from the light source into the incoupler region (100). Therefore, when a material having general refractive index anisotropy is oriented as an alignment film, it is lost and disappears at a large rate, which can act as a primary factor in reducing the efficiency of the light.

[0094] Accordingly, the angle of incidence (θ) due to re-incidence into the incoupler region (100) β2 Design of alignment films and refractive index anisotropic materials that reflect the degree of overlap of light and light may be required.

[0095]

[0096] FIG. 9 is a schematic diagram showing diffraction and reflection characteristics in an incoupler region of a vehicle display device according to one embodiment of the present disclosure. FIG. 10 is a schematic diagram showing diffraction and reflection regions in an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0097] According to the present disclosure, the angle of incidence (θ) by re-incidence into the incoupler region (100) β2 The structural characteristics of the alignment film and refractive index anisotropic material reflecting the degree of overlap of ) and light are as follows.

[0098] (1) The region where light diffracted or reflected from the incoupler region (100) is re-incident to the incoupler region (100) may include a chiral refractive index anisotropic material that is cultured so that it can be divided into multiple regions.

[0099] (2) The total area of ​​the re-incident area may be 10% (N>1 / 10) or more of the total area of ​​the incoupler area (100).

[0100] (3) The incoupler region (100) can be configured as a multi-domain by dividing the wavelength of the incident light into a certain range and separating it into at least one subpixel region with different characteristics for each color.

[0101] (4) The subpixels of the direct incident region and the re-incident region can each be composed of an anisotropic material such that the angle of the light emitted (Θ_β1_R, Θ_β1_G, Θ_β1_B) is the same even though the angle of incidence (Θ_g, Θ_β2) and the orientation direction are different.

[0102] (5) Each material may have material design conditions as shown in Table 1 below.

[0103] (6) The angle of incidence and the angle of exit can each have the angle design conditions shown in Table 2 below.

[0104] Thickness Refractive Index Helical Pitch PB Pitch (Orientation Period) Anisotropic Material 0.1 µm or more ne, no Average Refractive Index = 1.3 ~ 3.0 ┃ne-no┃= 0.05~0.40 0.1 µm~2.0 µm (at least one of the subpixels has a different value) 0.1 µm~2.0 µm (at least one of the subpixels has a different value) Alignment Film Material 10 nm or more 1.2~2.5 Waveguide 0.1 mm or more 1.2~2.5

[0105] Air → Waveguide Waveguide → Alignment Layer Alignment Layer → Anisotropic Material Anisotropic Material → Alignment Layer Alignment Layer → Waveguide Angle of Incident: 0~±45˚ 0~±45˚ 0~±45˚ Angle of Exit (Absolute Value): 25˚ or more 25˚ or more

[0106] These subpixel regions may correspond to each pattern (120, 121, 122) described above.

[0107] As shown in Table 1, the anisotropic material is positioned on the alignment layer (101), the thickness of the anisotropic material is 0.1 μm or more, the thickness of the alignment layer (101) is 10 nm or more, and the thickness of the waveguide (400) may be 0.1 mm or more.

[0108] Meanwhile, the anisotropic material may have a helical pitch range of 0.1 to 2.0 μm or a PB pitch (orientation period) range.

[0109]

[0110] Referring to FIGS. 9 and 10, the incoupler region (100) is shown with a region (P1; first region) that is directly incident and a region (P3) that is totally reflected once in the waveguide (400). At this time, a region (P3; second region) in which light is re-incident exists adjacent to the first region (P1) that is directly incident due to the angle of incidence described above. Here, the first region (P1) may have a first area (A1). Meanwhile, the second region (P3) may have a second area (A2, A3).

[0111] This first region (P1) may include a multi-domain consisting of l*m subpixels. Meanwhile, the second region (P3) may include a multi-domain consisting of l*m*n subpixels.

[0112] For example, the first region (P1) is composed of a repeating structure (subpixel) divided into 1-1, ..., 1-m regions to ensure that the diffraction / reflection angles for each wavelength are the same, and the second region (P3) may be composed of 2-1-1, ..., 2-1-m regions, ..., 2-n-1, ..., 2-nm regions to improve efficiency and ensure image uniformity.

[0113] In this way, the incoupler region (100) may include a first region (P1) in which light is directly incident at an angle (angle of incidence) of a first angle region, and a second region (P3) in which such light is re-incident within the incoupler region (100). These first region (P1) and second region (P3) may have different diffraction layer structures.

[0114] For example, the incoupler region (100) may include a first region (P1) in which light is directly incident at an angle of a first angle region (e.g., a second angle of incidence) and a second region (P3) in which light is re-incident at an angle of a second angle region (a third angle of incidence that is reflected and larger than the second angle of incidence). In this way, the second angle region may be larger than the first angle region.

[0115] At this time, corresponding to the incident angle of the light source, the distance traveled by light due to reflection and diffraction (d_1) and the size of the second region (P3) where light is re-incident within the incoupler region (100) are determined, and such distance traveled (d_1) and the size of the second region (P3) may have an inverse relationship.

[0116] Here, the second region (P3) may include a second-1 region (A2) that causes the diffraction angle of light incident at the angle of the second angle region to be emitted at the third angle, and a second-2 region (A3) that causes the diffraction angle of light incident at the angle of the first angle region to be emitted at the third angle. Here, A2 and A3 represent the areas of the second-1 region and the second-2 region, respectively, and are used as symbols to designate each region. Similarly, the symbols P1 and A1 will be used interchangeably to describe the first region.

[0117] In this case, as an exemplary embodiment, the 2-2 region (A3) may have the same diffraction layer structure as the 1 region (P1). Additionally, the 3rd angle may be included within the 2nd angle region.

[0118] Accordingly, the second region (P3) can diffract or reflect light incident at the angle of the first angle region and light re-incident at the angle of the second angle region at the same angle.

[0119]

[0120] FIGS. 11 to 13 show subpixels of an incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0121] Referring to FIG. 11, in the first region (A1) illustrated in FIG. 9 and FIG. 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). Such first pattern (120), second pattern (121), and third pattern (122) may be repeatedly arranged on a waveguide (400).

[0122] 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).

[0123] Referring to FIG. 12, each anisotropic material (102) pattern in the 2-1 region (A2) illustrated in FIG. 9 and FIG. 10 may include a fourth pattern (123) having a diffraction layer capable of diffracting light of a first wavelength band (e.g., red light), a fifth pattern (124) having a diffraction layer capable of diffracting light of a second wavelength band (e.g., green light), and a sixth pattern (125) having a diffraction layer capable of diffracting light of a third wavelength band (e.g., blue light).

[0124] Referring to FIG. 12, in the second-2 region (A3) illustrated in FIG. 9 and FIG. 10, each anisotropic material (102) pattern may include a seventh pattern (126) having a diffraction layer capable of diffracting light of a first wavelength band (e.g., red light), an eighth pattern (127) having a diffraction layer capable of diffracting light of a second wavelength band (e.g., green light), and a ninth pattern (128) having a diffraction layer capable of diffracting light of a third wavelength band (e.g., blue light).

[0125] As an exemplary embodiment, as described above, these seventh pattern (126), eighth pattern (127) and ninth pattern (128) may each be identical to the first pattern (120), second pattern (121) and third pattern (122).

[0126]

[0127] FIG. 14 is a conceptual diagram showing the propagation of light in the incoupler region of a vehicle display device according to one embodiment of the present disclosure.

[0128] Referring to Fig. 14, the process in which directly incident light (k_di) and re-incident light (k_re) are diffracted or reflected at the same angle for each color of light and emitted as a single light (k1) is conceptually illustrated on the XZ plane defined above.

[0129] As one embodiment, as described above, a light source in an incoupler region (100) enters a waveguide (400) having a thickness d_g at a constant angle of incidence (θ a Light is incident with a first angle of incidence, and subsequently, light refracted by the refractive index (n_g) of the waveguide (400) is incident on the alignment film (101) and anisotropic material (102) of the incoupler region (100) with an angle of incidence (θ_g; second angle of incidence).

[0130] For example, light incident on an anisotropic material (102) is θ by the pattern design of each material β1 Diffraction or reflection occurs by an angle (first diffraction / reflection angle), and total reflection occurs on the lower surface (opposite surface of the main plane) of the waveguide (400) within the thickness (d_g) of the waveguide (400), and after moving by a distance d_1 of the waveguide (400), it is re-incident in the incoupler region (100).

[0131] This is because light of each color is diffracted or refracted by the first pattern (120), second pattern (121), and third pattern (122) located within the first region (A1), and the red light (R) is θ β1R It is emitted at an angle, and the green light (G) is θ β1G It is emitted at an angle, and the blue light (B) is θ β1B It can be emitted at an angle. In this case, θ β1R Angle, θ β1G Angle, and θ β1B The angles can be substantially within the same angle range. In this way, light of each color can be emitted at the same angle and propagated within the waveguide (400). Accordingly, all colors of light can be propagated uniformly using a single-layer waveguide (400).

[0132] Meanwhile, light re-incident within the incoupler region (100) may be incident with an angle of incidence (θ_β2) that is larger than the second angle of incidence (θ_g). This re-incident light of each color (RGB) is diffracted or refracted by the fourth pattern (123), fifth pattern (124), and sixth pattern (125) located within the second region (A2), so that the same θ β1R Angle, θ β1G Angle, and θ β1B It can be emitted at an angle.

[0133] In this way, light re-incident within the incoupler region (100) is also diffracted or reflected at the same angle for each color, and light of all colors can be propagated uniformly using a single-layer waveguide (400).

[0134]

[0135] FIG. 15 is a conceptual diagram illustrating the light propagation process of a vehicle display device according to one embodiment of the present disclosure. FIG. 16 and FIG. 17 are detailed diagrams illustrating the light propagation in an expander region of a vehicle display device according to one embodiment of the present disclosure.

[0136] Referring to FIG. 15, light incident through the incoupler region (100) can propagate to the expander region (200) with a pupil (P) of the same size.

[0137] As explained above, the characteristics of the subpixels by multi-domain can be applied equally to the expander area (200).

[0138] These expander regions (200) may have the following characteristics.

[0139] (1) The expander region (200) may have a structure in which the pupils overlap each other, with the area corresponding to the width of the re-incident region (P3) of the incoupler region (100) existing on the left and right. This expander region (200) may extend to the nth block along one direction of the incoupler region (100).

[0140] (2) The total area of ​​the multiple overlapping regions of the overlapping pupils may be 10% or more of the total area of ​​the incoupler region (100) (N>1 / 10).

[0141] (3) The number of pupils in the expander area (200) may be three or more. FIG. 15 shows an example where the number of pupils in the expander area (200) is six, but this is merely an example.

[0142] (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.

[0143] At this time, with reference to FIGS. 16 and 17, 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).

[0144] (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).

[0145] As such, the expander region (200) may include a third region for advancing light to the outside of the expander region (200) or to the outcoupler region (300), and a fourth region for advancing light within the expander region (200), although these are not clearly indicated on the drawing.

[0146] At this time, the third region may be a reflection region and the fourth region may be a diffraction region.

[0147]

[0148] FIGS. 18 to 20 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.

[0149] Referring to FIGS. 18 to 20, light propagated through the expander region (200) can be propagated to the outcoupler region (300) with a pupil (P) of the same size.

[0150] As explained above, the characteristics of the subpixels by multi-domain can be applied equally to the outcoupler area (300).

[0151] 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.

[0152] (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.

[0153] At this time, referring to FIGS. 18 to 20, 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).

[0154] 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.

[0155] 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.

[0156] (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).

[0157] (3) The number of pupils in the outcoupler region (300) may be 9 or more. FIG. 15 shows an example where the number of pupils in the outcoupler region (300) is 24, but this is merely an example.

[0158] 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.

[0159] According to the present disclosure, the optical properties, the orientation period of the alignment film, and the characteristics of the anisotropic material in each region can be summarized as shown in Tables 3 and 4 below. This is an exemplary embodiment, and various other design values ​​may be taken according to the principles of the present disclosure.

[0160] According to an embodiment of the present disclosure, this corresponds to a case where the number of regions for each grating optical element (incoupler, expander, outcoupler) and color on a single-layer waveguide (400) is designed to be relatively small.

[0161] As a result of this embodiment, compared to a mirrorless HUD using a diffractive optical element (DOE), the efficiency of the output light output from the outcoupler region toward the viewer can be improved by more than 30% compared to the incident light incident from the viewer's direction toward the incoupler region (Red 60% or more, Green and Blue 30% or more).

[0162] Direct Incident Region / 2-2 Region PB Pitch (Orientation Period) (nm) Thickness of Anisotropic Material (㎛) Helical Pitch of Anisotropic Material Red (R) 599 ~ 649 nm Incoupler Region 530 ~ 560 2.50 460 ~ 490 Expander Region 1000 ~ 1030 560 ~ 590 Outcoupler Region 590 ~ 620 440 ~ 470 Green (G) 495 ~ 545 nm Incoupler Region 440 ~ 470 370 ~ 400 Expander Region 600 ~ 630 440 ~ 470 Outcoupler Region 580 ~ 610 350 ~ 380 Blue (B) 430 ~ 480 nm Incoupler Region 385 ~ 415 310 ~ 340 Expander Region 465 ~ 495 340 ~ 370 Outcoupler Range 585 ~ 615 290 ~ 320

[0163] Re-incident region / 2-1 region PB Pitch (Orientation Period) (nm) Thickness of Anisotropic Material (㎛) Helical Pitch of Anisotropic Material Red (R) 599 ~ 649 nm Incoupler Region Infinity > 2.50 565 ~ 595 Expander Region Outcoupler Region Green (G) 495 ~ 545 nm Incoupler Region 435 ~ 465 Expander Region Outcoupler Region Blue (B) 430 ~ 480 nm Incoupler Region 345 ~ 375 Expander Region Outcoupler Region

[0164]

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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, and the diffraction layer includes a plurality of domains that are repeatedly arranged. The above domain is A first pattern that diffracts light in a first wavelength band; A second pattern that diffracts light in a second wavelength band; and A third pattern comprising diffracting light in a third wavelength band Vehicle display device.

2. In paragraph 1, 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.

3. In claim 1, the first pattern, the second pattern, and the third pattern comprise an anisotropic material that causes visible light, including light of the first wavelength band, light of the second wavelength band, and light of the third wavelength band, to be incident and diffracted within the same angular range. Vehicle display device.

4. In paragraph 3, the anisotropic material comprises a liquid crystal material containing a chiral dopant or a reactive mesogen material in which molecules cross-link with each other by ultraviolet light or temperature. Vehicle display device.

5. In claim 1, the diffraction layer Incoupler region where the above light source is incident; An expander region that expands the region of light incident from the incoupler region; and Includes an outcoupler region in which light expanded in the above expander region is formed into an image. Vehicle display device.

6. In Paragraph 5, The above incoupler region is A first region where light is directly incident at an angle of the first angle region; and The above includes a second region in which the light is re-incident within the incoupler region, and The first region and the second region have different diffraction layer structures. Vehicle display device.

7. In Paragraph 5, The above incoupler region is A first region where light is directly incident at an angle of the first angle region; and It includes a second region where the light is re-incident at an angle of the second angle region, and The second angle region is larger than the first angle region. Vehicle display device.

8. In Paragraph 7, Corresponding to the incident angle of the light source, the travel distance of the light due to reflection and diffraction and the size of the second region where the light is re-incident within the incoupler region are determined, and the travel distance and the size of the second region have an inverse relationship. Vehicle display device.

9. In Paragraph 6, The above second region is A 2-1 region that causes the diffraction angle of light incident at an angle in the 2nd angle region to be emitted at a 3rd angle; and A second-2 region comprising a second region that causes the diffraction angle of light incident at the angle of the first angle region to be emitted at the third angle. Vehicle display device 10. In Paragraph 9, The above 2-2 region has the same diffraction layer structure as the above 1 region. Vehicle display device.

11. In Paragraph 9, The above third angle is included within the above second angle region Vehicle display device.

12. In Paragraph 6, The area of ​​the second region is 10% or more of the total area of ​​the incoupler region. Vehicle display device.

13. In claim 5, the expander region is A third region for advancing light within the above-mentioned expander region; and A fourth region for advancing light to the outside of the expander region or to the outcoupler region. Vehicle display device.

14. In claim 5, at least one of the incoupler region, the expander region, and the outcoupler region is devoid of an anisotropic material, or comprises an isotropic material or a metal or oxide material having a reflectance of 30% or more. Vehicle display device.

15. In claim 5, at least one of the incoupler region, the expander region, and the outcoupler region has an area different from the remaining region. Vehicle display device.

16. In Paragraph 3, The above anisotropic material is located on the orientation film, and The thickness of the anisotropic material is 0.1 μm or more, the thickness of the alignment layer is 10 nm or more, and the thickness of the waveguide is 0.1 mm or more. Vehicle display device.

17. In Paragraph 3, The above anisotropic material has a helical pitch range of 0.1 to 2.0 μm, a PB pitch range greater than 0.1 μm, or an anisotropic material without a PB pitch. Vehicle display device.

18. In claim 5, the outcoupler region is A fifth region for propagating light within the above-mentioned outcoupler region; and Including a sixth area for external shooting Vehicle display device.

19. In claim 18, the fifth region is a reflection region and the sixth region is a diffraction region. Vehicle display device.

20. In claim 13, the third region is a reflection region and the fourth region is a diffraction region. Vehicle display device.

21. In paragraph 5, for each unit size at which the light source is incident in the incoupler region, the outcoupler region has nine or more unit sizes. Vehicle display device.

22. In Paragraph 21, At least some of the above nine or more unit sizes overlap each other, and In the above outcoupler region, the overlapping area of ​​the unit size is 10% or more of the unit size. Vehicle display device.

23. In Paragraph 1, The angle of incidence of the above light source is smaller than ±45˚ Vehicle display device.

24. 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, and the diffraction layer includes a plurality of domains that are repeatedly arranged. 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 forms an image. The above incoupler region is A first region in which light is directly incident at an angle of the first angle region and emitted at a third angle; and It includes a second region that causes the light to be re-incident and emitted at the third angle, and The first region and the second region have different diffraction layer structures. Vehicle display device.

25. In Paragraph 24, The above second region is A second-1 region that causes the diffraction angle of light incident at the angle of the second angle region to be emitted at the third angle; and A second-2 region comprising a second region that causes the diffraction angle of light incident at the angle of the first angle region to be emitted at the third angle. Vehicle display device.

26. In Paragraph 25, The above 2-2 region has the same diffraction layer structure as the above 1 region. Vehicle display device.

27. In Paragraph 25, The above third angle is included within the above second angle region Vehicle display device.

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