Light guide device, optical element, and manufacturing method therefor

Abstract

Disclosed in an embodiment is a light guide device comprising: a first substrate; and a first input diffractive element, a first transmission diffractive element and a first output diffractive element which are disposed on the first substrate and on which light is sequentially incident, wherein the first transmission diffractive element includes a first region and a second region, which is in contact with the first region and is adjacent to the first output diffractive element, the first region of the first transmission diffractive element includes a first protrusion protruding in a first direction, the second region includes a second protrusion protruding in the first direction, and the width of the first protrusion of the first region of the first transmission diffractive element is different from the width of the second protrusion of the second region of the transmission diffractive element.

Description

Light guide device, optical element and manufacturing method thereof

[0001] The embodiments relate to a light guide device, an optical element and a method for manufacturing the same.

[0002] Virtual Reality (VR) refers to a specific environment or situation, or the technology itself, that is similar to reality but not real, created using artificial technology such as computers.

[0003] Augmented Reality (AR) is a technology that synthesizes virtual objects or information into the real environment to make them appear as objects that exist in the original environment.

[0004] Mixed reality (MR) or hybrid reality refers to the creation of new environments or information by merging the virtual and real worlds. In particular, it refers to real-time interaction between real and virtual worlds.

[0005] At this time, the created virtual environments and situations stimulate the user's five senses, allowing them to experience spatial and temporal experiences similar to reality, freely moving between reality and imagination. Furthermore, users can not only immerse themselves in these environments, but also interact with the objects embodied within them, using real devices to control and command them.

[0006] Recently, active research has been conducted on the gear and devices used in these fields. However, the need for miniaturization and improved optical performance of these devices is emerging.

[0007] Additionally, diffractive AR glasses consist of a diffractive element that diffracts an image from a light source and a waveguide that acts as a path for the image to travel. The diffractive element that makes up diffractive AR glasses is composed of a combination of structures with a period smaller than the wavelength of visible light (350 nm to 700 nm) to efficiently diffract an image composed of visible light.

[0008] Traditionally, diffractive elements coated with metal films have been used to effectively couple light information incident from the outside at a wide angle to a waveguide. However, when the metal film is exposed to the air, the metal surface naturally oxidizes, which can alter the metal's plasmon frequency or weaken its surface plasmon characteristics, thereby losing its original metallic properties and hindering efficient coupling. To protect the metal film, methods such as atomic layer deposition (ALD) or physical vapor deposition (PVD) can be used to form an oxide film. However, this method suffers from the drawback of reduced productivity due to the additional process involved. Furthermore, ALD requires high temperatures (150 to 250°C) for deposition, which can lead to deformation of diffractive elements made of polymers, making it difficult to apply. Therefore, a method that can protect thin metal films from the external environment with a small number of manufacturing steps is needed.

[0009] The embodiment provides a light guide device with improved diffraction efficiency.

[0010] Additionally, a light guide device with improved uniformity is provided.

[0011] The embodiment provides a method for manufacturing a metal thin film capable of protecting a diffractive element with a small number of manufacturing steps.

[0012] In addition, a metal thin film that can protect the diffraction element more effectively is provided.

[0013] In addition, a method for manufacturing a metal thin film is provided that can maximize the gap plasmon effect by minimizing the transfer of the metal thin film to the side of the diffraction structure.

[0014] The problem to be solved in the embodiment is not limited to this, and it can be said that the purpose or effect that can be understood from the solution or embodiment of the problem described below is also included.

[0015] A light guide device according to an embodiment comprises: a first substrate; and a first input diffractive element, a first transmission diffractive element, and a first output diffractive element, which are arranged on the first substrate and onto which light is sequentially incident, wherein the first transmission diffractive element includes a first region adjacent to the first output diffractive element and a second region contacting the first region and spaced apart from the first output diffractive element, wherein the first region of the first transmission diffractive element includes a first protrusion protruding in a first direction, and the second region includes a second protrusion protruding in the first direction, and a width of the first protrusion of the first region of the first transmission diffractive element may be different from a width of the second protrusion of the second region of the first transmission diffractive element.

[0016] The second region of the first transmission diffraction element includes six surfaces, and the number of surfaces of the first region of the first transmission diffraction element may be greater than the number of surfaces of the second region.

[0017] The first region of the first transmission diffraction element may be arranged to surround a first side adjacent to the first input diffraction element of the second region of the first transmission diffraction element and a second side adjacent to the first side.

[0018] The shortest distance between the first input diffraction element and the first region of the first transmission diffraction element may be shorter than the shortest distance between the first input diffraction element and the second region of the first transmission diffraction element.

[0019] The second region of the first transmission diffraction element includes a third side surface spaced apart from the first side surface and adjacent to the second side surface, and a width of the third side surface may be greater than a width of the first side surface.

[0020] The width of the second side of the second region of the first transmission diffraction element may be greater than the widths of the first side and the third side.

[0021] The width of the first protrusion of the first region of the first transmission diffraction element may be wider than the width of the second protrusion of the second region of the first transmission diffraction element.

[0022] A light guide device according to an embodiment includes a second substrate, and a second transmission diffractive element disposed on the second substrate includes a third region and a fourth region, the third region of the second transmission diffractive element includes a third protrusion protruding in the first direction, the fourth region includes a fourth protrusion protruding in the first direction, and a width of the third protrusion of the third region of the second transmission diffractive element may be different from a width of the fourth protrusion of the fourth region of the second transmission diffractive element.

[0023] The width of the third protrusion of the third region of the second transmission diffraction element may be wider than the width of the fourth protrusion of the fourth region of the second transmission diffraction element.

[0024] The period of the first region of the first transmission diffraction element disposed on the first substrate may be shorter than the period of the third region of the second transmission diffraction element disposed on the second substrate.

[0025] The periods of the first region of the first transmission diffraction element and the second region of the first transmission diffraction element may be the same, and the periods of the third region of the second transmission diffraction element and the fourth region of the second transmission diffraction element may be the same.

[0026] The above period may be the shortest distance between the same side of the most adjacent protrusions when viewed from above.

[0027] The first transmission diffraction element includes a first surface adjacent to the first input diffraction element, a second surface adjacent to the first output diffraction element, a third surface arranged to face the first surface, and a fourth surface arranged to face the second surface, and the first output diffraction element can overlap an extension line of the first surface and an extension line of the third surface.

[0028] The above first emission diffraction element may not overlap with the extension line of the second surface of the above first transmission diffraction element.

[0029] The first input diffractive element is arranged between an extension line of the second face of the first transmission diffractive element and an extension line of the fourth face of the first transmission diffractive element, and an outline of the first input diffractive element may not overlap with the extension line of the second face of the first transmission diffractive element and the extension line of the fourth face of the first transmission diffractive element.

[0030] The first transmission diffraction element includes a first side and a second side which are boundaries between the first region of the first transmission diffraction element and the second region of the first transmission diffraction element, and the first side and the second side may be regions having a pattern of the first region of the first transmission diffraction element and a pattern of the second region of the first transmission diffraction element.

[0031] The second side surface of the first transmission diffraction element is between an extension line of a vector from the center of the first input diffraction element and an extension line of the fourth surface of the first transmission diffraction element, the first input diffraction element includes a pattern having a constant directionality, and the extension line of the vector of the first input diffraction element may be a line extended in a direction perpendicular to the pattern direction of the first input diffraction element.

[0032] The first surface of the first transfer diffraction element may be positioned between the first input diffraction element and the third surface between the first transfer diffraction element, and the first side surface of the first transfer diffraction element may be positioned between the first surface of the first transfer diffraction element and the third surface between the first transfer diffraction element.

[0033] The second surface of the first transmission diffraction element is located between the fourth surface of the first transmission diffraction element and the first output diffraction element, and an extension line of a vector from the center of the first input diffraction element is located between the second surface of the first transmission diffraction element and the second side surface of the second region of the first transmission diffraction element, and the first input diffraction element includes a pattern having a constant directionality, and the extension line of the vector of the first input diffraction element may be a line extending in a direction perpendicular to the pattern direction of the first input diffraction element.

[0034] The first region of the first transmission diffraction element may include eight faces, and two of the eight faces may be the first side of the second region of the first transmission diffraction element and the second side of the second region of the first transmission diffraction element.

[0035] One of the six surfaces of the second region of the first transmission diffraction element may be a surface adjacent to the first substrate as a lower surface of the second region of the first transmission diffraction element, and the other may be a surface facing a cover disposed on the first substrate as an upper surface of the second region of the first transmission diffraction element.

[0036] One of the eight surfaces of the first region of the first transmission diffraction element may be a lower surface of the first region of the first transmission diffraction element and a surface adjacent to the first substrate, and the other may be an upper surface of the first region of the first transmission diffraction element and a surface facing a cover disposed on the first substrate.

[0037] The pattern of the first region of the first transmission diffraction element may be composed of the first protrusion, and the pattern of the second region of the first transmission diffraction element may be composed of the second protrusion.

[0038] An optical element according to an embodiment includes a substrate; a diffractive element disposed on the substrate and including a plurality of unit structures; and a metal thin film disposed on the plurality of unit structures and including a plurality of unit bodies, wherein the diffractive element can be disposed to contact all surfaces of the plurality of unit bodies.

[0039] The above plurality of units may include a curved surface, and the curved surface may be arranged toward the diffractive element.

[0040] The above plurality of units include an upper surface arranged with the curved surface, and the upper surface can be spaced apart from the outer surface of the diffractive element by a certain distance.

[0041] The above diffractive element includes a plurality of recesses between the plurality of unit structures, and the metal thin film can be arranged adjacent to the upper surface of the plurality of unit structures and the lower surface of the plurality of recesses.

[0042] The diffractive element includes a first region where the plurality of unit structures are located and a second region located between the first region, and the metal thin film may be adjacent to the first upper surface among the first upper surface and the first lower surface of the first region in the first region, and may be adjacent to the second upper surface among the second upper surface and the second lower surface of the second region in the second region.

[0043] The distance between the metal thin film and the upper surface of the plurality of unit structures may be smaller than the distance between the metal thin film and the lower surface of the plurality of unit structures.

[0044] The plurality of units may be spaced apart in a first direction, and the diffractive element may be arranged between the plurality of units to be spaced apart from each other in the first direction.

[0045] The thickness of the metal thin film in the second direction perpendicular to the first direction may be 5 nm to 50 nm.

[0046] The height of the above plurality of unit structures in the second direction may be 30 nm to 500 nm.

[0047] A method for manufacturing an optical element according to an embodiment includes the steps of depositing a metal thin film on a stamp; applying a resin on a substrate; pressing the stamp against the resin to form a diffractive element; and curing the diffractive element; wherein, in the depositing step, the metal thin film may include a plurality of units forming a spaced apart from each other.

[0048] The step of depositing a metal thin film on the stamp includes a step of depositing the metal thin film on the stamp using a physical vapor deposition (PVD) method, and the thickness of the metal thin film may be 5 nm to 50 nm.

[0049] The step of depositing a metal film on the above stamp is performed at a vacuum level of 5*10 - 6 torr or less, deposition rates can be run at 1 to 3 Å / s.

[0050] The step of forming the diffractive element may include the step of protruding the resin so that it comes into contact with the metal thin film.

[0051] The step of forming the diffractive element and the step of curing the diffractive element include a step of curing the diffractive element using ultraviolet rays or heat, and can be performed in a nitrogen (N2) or argon (Ar) gas atmosphere.

[0052] When the above diffraction element is cured using ultraviolet rays, the wavelength of the ultraviolet rays is 365 nm and the energy density is 1 to 30 J / cm 2 It could be.

[0053] When the above diffraction element is hardened using heat, it is performed at a temperature higher than the glass transition temperature, and can be performed at a temperature of 40 to 300°C.

[0054] The above resin can cover the entire surface of the above metal film.

[0055] According to an embodiment, a light guide device with improved diffraction efficiency can be provided.

[0056] In addition, a light guide device with improved uniformity can be provided.

[0057] According to an embodiment, a method for manufacturing a metal thin film capable of protecting a diffractive element can be provided with a small number of manufacturing steps.

[0058] In addition, a metal thin film that can protect a diffraction element more effectively can be provided.

[0059] In addition, a method for manufacturing a metal thin film can be provided that can maximize the gap plasmon effect by minimizing the transfer of the metal thin film to the side of the diffraction structure.

[0060] The various advantageous and beneficial effects of the present invention are not limited to the above-described contents, and will be more easily understood in the course of explaining specific embodiments of the present invention.

[0061] Figure 1 is a schematic diagram of a first substrate according to an embodiment.

[0062] Fig. 2 is a cross-sectional view of a first substrate according to an embodiment.

[0063] Figure 3 is an enlarged view of the first region and the second region of the first substrate according to the embodiment.

[0064] Figures 4 to 6 are cross-sectional views of a first substrate according to an embodiment.

[0065] Figure 7 is an enlarged view of the first side and the second side according to the embodiment.

[0066] Figure 8 is a schematic diagram of the first side and the second side according to the embodiment.

[0067] Figure 9 is an enlarged view of the first side and the second side according to the embodiment.

[0068] Fig. 10 is a drawing showing a vector of a pattern of a diffraction element of a light guide device according to an embodiment.

[0069] Fig. 11 is a schematic diagram of a light guide device according to another embodiment.

[0070] Figure 12 is an enlarged view of the third and fourth regions according to the embodiment.

[0071] Figures 13 to 15 are cross-sectional views of a second substrate according to an embodiment.

[0072] Fig. 16 is an enlarged view of a diffraction element of a light guide device according to an embodiment as viewed from above.

[0073] Fig. 17 is a cross-sectional view of the diffraction pattern vector direction of the first substrate diffraction element of the light guide device according to the embodiment.

[0074] Fig. 18 is an enlarged view of a diffraction element of a light guide device according to an embodiment as viewed from above.

[0075] Fig. 19 is a cross-sectional view of the diffraction pattern vector direction of the second substrate diffraction element of the light guide device according to the embodiment.

[0076] FIGS. 20A to 20C are cross-sectional views of light guide devices according to various embodiments.

[0077] Fig. 21 is a block diagram showing the configuration of an extended reality electronic device according to an embodiment.

[0078] Fig. 22 is a perspective view of an augmented reality electronic device according to an embodiment.

[0079] Fig. 23 is a conceptual diagram of an optical element according to an embodiment.

[0080] Fig. 24 is an enlarged view of an optical element according to an embodiment.

[0081] Figure 25 is a flowchart of a method for manufacturing an optical element according to an embodiment.

[0082] Figures 26 to 30 are drawings showing a method for manufacturing an optical element according to an embodiment.

[0083] Figures 31 to 33 are graphs showing the diffraction efficiency of optical elements.

[0084] Figure 34 is an enlarged image of a metal film deposited on a stamp.

[0085] Figure 35 is a drawing showing the configuration of a camera module according to an embodiment of the present invention.

[0086] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0087] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0088] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0089] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0090] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0091] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

[0092] These terms are intended only to distinguish one component from another, and are not intended to limit the nature, order, or sequence of the component.

[0093] And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, it may include not only cases where the component is directly connected, coupled or connected to the other component, but also cases where the component is 'connected', 'coupled' or 'connected' by another component between the component and the other component.

[0094] Additionally, when described as being formed or arranged "above or below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below", it can include the meaning of a downward direction as well as an upward direction based on one component.

[0095] Fig. 1 is a schematic diagram of a light guide device according to an embodiment.

[0096] Referring to FIG. 1, a light guide device (1000) according to an embodiment may include a first substrate (1100), a first input diffractive element (1200), a first transmission diffractive element (1300), a first output diffractive element (1400), and a cover (not shown) for protecting the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400).

[0097] The light guide device (1000) can change the path of light that is output from the light output unit and then output the light to the outside again. The light can sequentially enter the first input diffraction element (1200), the first transmission diffraction element (1300), and the first output diffraction element (1400) and be output to the outside again. The direction in which the light enters the light guide device (1000) may be the first direction. The first direction may mean the direction in which the light enters or the opposite direction.

[0098] A first substrate (1100) can serve as a path for transmitting light. A first input diffractive element (1200), a first transmission diffractive element (1300), and a first output diffractive element (1400) can be arranged on the first substrate (1100). The light can be totally reflected inside the first substrate (1100) and travel along the inside of the first substrate (1100). The first substrate (1100) can include a waveguide. The first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400) can be arranged spaced apart from each other on the first substrate (1100). The first substrate (1100) can be arranged in a second direction perpendicular to a first direction in which light is incident. The refractive index of the first substrate (1100) may be 1.77 to 1.81.

[0099] The first input diffraction element (1200) can serve as a path through which light is incident. The first input diffraction element (1200) can be placed on the first substrate (1100). Light can be incident from the outside onto the light guide device (1000) through the first input diffraction element (1200) and transmitted through the first substrate (1100). The first input diffraction element (1200) can change the path of light by diffracting the light.

[0100] The first transmission diffraction element (1300) can serve to change the path of light. The first transmission diffraction element (1300) can be arranged on the first substrate (1100). The first transmission diffraction element (1300) can change the path of light incident through the first input diffraction element (1200). The first transmission diffraction element (1300) can change the path of light so that it is directed toward the first output diffraction element (1400). The first transmission diffraction element (1300) can change the path of light by diffracting the light.

[0101] The first exit diffraction element (1400) can serve as a path through which light is emitted. The first exit diffraction element (1400) can be disposed on the first substrate (1100). Light can be emitted to the outside of the light guide device (1000) through the first exit diffraction element (1400). The first exit diffraction element (1400) can receive light whose path has been changed from the first transmission element (1300) and emitted the light to the outside. The first exit diffraction element (1400) can change the path of the light and emitted it to the outside. The first exit diffraction element can change the path of the light by diffracting the light.

[0102] The first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400) may include a plurality of protrusions. The plurality of protrusions may have a constant width, period, and height and may be arranged on the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400). The plurality of protrusions may protrude in a first direction on the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400). The plurality of protrusions may be arranged to be spaced apart from each other in a vector direction of a pattern including the protrusions. Depending on the width, period, and height of the plurality of protrusions, the path of light may be changed differently after passing through the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400). The width of the protrusion may refer to the width in the vector direction of the pattern including the protrusion of the protrusion. The period of the protrusion may refer to the interval in the vector direction of the pattern including the protrusion between one side of the protrusion and the same side of an adjacent protrusion. The height of the protrusion may refer to the height of the portion protruding in the first direction of the protrusion. The refractive index of the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400) may be 1.80 to 1.86.

[0103] Fig. 2 is a cross-sectional view of a light guide device according to an embodiment, and Fig. 3 is an enlarged view of a first region and a second region according to an embodiment.

[0104] Referring to FIGS. 2 and 3, the outline (boundary area) of the first input diffractive element (1200) and the outline (boundary area) of the first transmission diffractive element (1300) do not overlap each other. If they overlap, some of the light incident from the first transmission diffractive element (1300) to the first output diffractive element (1400) is blocked, so that an image may not be output from the first output diffractive element (1400) in the blocked area. If the outline (boundary area) of the first input diffractive element (1200) and the outline (boundary area) of the first transmission diffractive element (1300) overlap each other, efficiency decreases, so it is preferable that the outline (boundary area) of the first input diffractive element (1200) and the outline (boundary area) of the first transmission diffractive element (1300) do not overlap each other.

[0105] The first transmission diffraction element (1300) according to the embodiment may include a first region (1310) adjacent to the first emission diffraction element (1400) and a second region (1320) in contact with the first region (1310) and spaced apart from the first emission diffraction element (1400).

[0106] The first region (1310) and the second region (1320) may refer to a portion of the first transmission diffraction element (1300). The first region (1310) and the second region (1320) may be two regions that are divided from each other when the first transmission diffraction element (1300) is viewed in a first direction in which an optical signal is incident. The first region (1310) may be a region adjacent to the first output diffraction element (1400) of the first transmission diffraction element (1300). The first region (1310) may be a region adjacent to the first input diffraction element (1200) of the first transmission diffraction element (1300). The second region (1320) may be a region spaced apart from the first output diffraction element (1400) of the first transmission diffraction element (1300). The second region (1320) may be a region spaced apart from the first input diffraction element (1200) of the first transmission diffraction element (1300). The distance between the first region (1310) and the first output diffraction element (1400) may be smaller than the distance between the second region (1320) and the first output diffraction element (1400). The shapes or areas of the first region (1310) and the second region (1320) may be different from each other. The first region (1310) and the second region (1320) may each include a plurality of surfaces. Some surfaces of the first region (1310) and some surfaces of the second region (1320) may be in contact with each other.

[0107] The first region (1310) includes a first pattern, and the first pattern includes a first protrusion (1311) protruding in a first direction. The second region (1320) may include a second pattern and a second protrusion (1321) protruding in the first direction. The first protrusion (1311) and the second protrusion (1321) may be portions protruding in the first direction from the first region (1310) and the second region (1320), respectively. The first direction may be a direction in which light from the projector is incident on the first input diffraction element (1200). The first direction may mean the direction in which light is incident or the opposite direction. The first direction means a direction perpendicular to the first substrate (1100). Fig. 3 is an enlarged view of the first region (1310) and the second region (1320) when viewed from the front. Referring to FIG. 3, the first protrusions (1311) and the second protrusions (1321) may be arranged repeatedly with a predetermined period, width, and height on the first region (1310) and the second region (1320). The plurality of first protrusions (1311) may be arranged perpendicular to the first direction and spaced apart from each other in the vector direction of the first region pattern (1310) of the first transmission circuit element (1300). The plurality of second protrusions (1321) may be arranged perpendicular to the first direction and spaced apart from each other in the vector direction of the second region pattern (1320) of the first transmission circuit element (1300).

[0108] The width (w1) of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be different from the width (w2) of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300). The first protrusion (1311) may have a constant width (w1) and period (T1). In addition, the second protrusion (1321) may have a constant width (w2) and period (T2). The width (w1) of the first protrusion (1311) may mean the width in the vector direction of the pattern of the first region (1310) of the first transmission diffraction element (1300) of the first protrusion (1311). The period (T1) of the first protrusion (1311) may refer to the distance between one side of two adjacent first protrusions (1311). The period (T1) of the first protrusion (1311), which is the distance between one side of two adjacent first protrusions (1311), refers to the shortest distance between one side of two adjacent first protrusions (1311). The width (w2) of the second protrusion (1321) may refer to the width in the vector direction of the pattern of the second region (1320) of the first transmission diffraction element (1300) of the second protrusion (1321). The period (T2) of the second protrusion (1321) may refer to the distance between one side of two adjacent second protrusions (1321). The interval between one side of two adjacent second protrusions (1321), which is the period (T2) of the second protrusion (1321), means the shortest distance between one side of two adjacent first protrusions (13121). The width (w1) of the first protrusion (1311) of the first region (1310) is different from the width (w2) of the second protrusion (1321) of the second region (1320), so that the diffraction efficiency of light passing through the first region (1310) of the first transmission diffraction element (1300) and light passing through the second region (1320) of the first transmission diffraction element (1300) can be different.By making the diffraction efficiency of the light passing through the first region (1310) of the first transmission diffraction element (1300) different from that of the light passing through the second region (1320) of the first transmission diffraction element (1300), the uniformity of the intensity of the light passing through each of the first region (1310) and the second region (1320) and output from the first output diffraction element (1400) can be improved.

[0109] The width (w1) of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be narrower than the width (w2) of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300). For example, the width (w1) of the first protrusion (1311) of the first region (1310) may be 84 nm. Additionally, for example, the width (w2) of the second protrusion (1321) of the second region (1320) may be 180 nm. The width (w1) of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) is narrower than the width (w2) of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300), thereby increasing the diffraction efficiency of light in the second region (1320) positioned far from the first input diffraction element (1200) and the first output diffraction element (1400), thereby improving the uniformity of the intensity of light passing through each portion of the first region (1310) and the second region (1320) and outputting to the first output diffraction element (1400).

[0110] Fig. 4 is a cross-sectional view of a light guide device according to an embodiment.

[0111] Referring to FIG. 4, the second region (1320) of the first transmission diffraction element (1300) includes six faces, and the number of faces of the first region (1310) of the first transmission diffraction element (1300) may be greater than the number of faces of the second region (1320). The first region (1310) of the first transmission diffraction element (1300) includes eight faces.

[0112] The second region (1320) of the first transmission diffraction element (1300) may include six faces. One of the six faces is a lower surface of the second region (1320) of the first transmission diffraction element (1300) that is adjacent to the first substrate (1100), and the other face is a upper surface of the second region (1320) of the first transmission diffraction element (1300) that faces a cover (3000) that is arranged on the first substrate (1100). The second region (1320) of the first transmission diffraction element (1300) may have a polygonal shape formed by a plurality of faces when viewed in the first direction. The second region (1320) may have a rectangular shape including four faces when viewed in the first direction. The first region (1310) may have a polygonal shape formed by a plurality of faces when viewed from the first direction. The number of faces of the first region (1310) may be greater than the number of faces of the second region (1320). For example, the first region (1310) may have a hexagonal shape including eight faces. One of the eight faces is a face adjacent to the first substrate (1100) as a lower surface of the first region (1310) of the first transmission diffraction element (1300), and the other face is a face facing the cover (3000) disposed on the first substrate (1100) as an upper surface of the first region (1310) of the first transmission diffraction element (1300). The second region (1320) of the first transmission diffraction element (1300) includes six surfaces, and the number of surfaces of the first region (1310) of the first transmission diffraction element (1300) is greater than the number of surfaces of the second region (1320), so that the first region (1310) can be arranged over a wider range to surround the periphery of the second region (1320). By increasing the diffraction efficiency of light in a wide area located far from the first input diffraction element (1200) of the first transmission diffraction element (1300), the uniformity of light output can be improved.

[0113] The first region (1310) of the first transmission diffraction element (1300) can be arranged to surround the first side (S1) adjacent to the first input diffraction element (1200) of the second region (1320) of the first transmission diffraction element (1300) and the second side (S2) adjacent to the first side (S2).

[0114] The second region (1320) of the first transmission diffraction element (1300) may include a first side surface (S1) and a second side surface (S2). The first side surface (S1) and the second side surface (S2) may be included in a plurality of side surfaces when the second region (1320) is viewed in the first direction. The first side surface (S1) and the second side surface (S2) may be two adjacent side surfaces of the second region (1320). The first region (1310) of the first transmission diffraction element (1300) may be arranged to surround the first side surface (S1) and the second side surface (S2) of the second region (1320). The first region (1310) may be in contact with the first side surface (S1) and the second side surface (S2). The two sides of the first region (1310) may be in contact with the first side surface (S1) and the second side surface (S2), respectively. The first side (S1) of the second region (1320) may be a side adjacent to the first input diffractive element (1200). The second side (S2) of the second region (1320) may be a side adjacent to the first output diffractive element (1400). The first region (1310) of the first transmission diffraction element (1300) is arranged to surround the first side (S1) adjacent to the first input diffraction element (1200) of the second region (1320) of the first transmission diffraction element (1300) and the second side (S2) adjacent to the first side (S2), so that the second region (1320) is arranged farther away from the first input diffraction element (1200) and the first output diffraction element (1400) than the first region (1310), and the first region (1310) can be arranged close to the first input diffraction element (1200) and the first output diffraction element (1400). Ultimately, the second region (1320) can improve the uniformity of the output light by increasing the diffraction efficiency of the region positioned far from the first input diffraction element (1200) and the first output diffraction element (1400).

[0115] The shortest distance (d1) between the first input diffraction element (1200) and the first region (1310) of the first transmission diffraction element (1300) may be shorter than the shortest distance (d2) between the first input diffraction element (1200) and the second region (1320) of the first transmission diffraction element (1300).

[0116] The first region (1310) is arranged to surround the first side surface (S1) closest to the first input diffractive element (1200) of the second region (1320), so that the first region (1310) can be arranged closer to the first input diffractive element (1200) than the second region (1320). As a result, the shortest distance (d1) between the first input diffractive element (1200) and the first region (1310) is shorter than the shortest distance (d2) between the first input diffractive element (1200) and the second region (1320), so that the second region (1320) can increase the diffraction efficiency of the region that is arranged farther away from the first input diffractive element (1200), thereby improving the uniformity of the output light.

[0117] The second region (1320) of the first transmission diffraction element (1300) includes a third side (S3) that is spaced apart from the first side (S1) and adjacent to the second side (S2), and the width (a3) ​​of the third side (S3) may be greater than the width (a1) of the first side (S1).

[0118] The second region (1320) of the first transmission diffraction element (1300) may include a third side surface (S3). The third side surface (S3) may be a surface spaced apart from the first side surface (S1) and adjacent to the second side surface (S2). The third side surface (S3) may be a surface arranged to face the first side surface (S1). The third side surface (S3) may be a surface that is furthest away from the first input diffraction element (1200). The third side surface (S3) may form a portion of an outer surface of the first transmission diffraction element (1300). The width (a3) ​​of the third side surface (S3) may be greater than the width (a1) of the first side surface (S1). The width (a3) ​​of the third side (S3) is larger than the width (a1) of the first side (S1), so that the second region (1320) can be widely arranged in an area far from the first input diffraction element (1200), and ultimately, the diffraction efficiency of the area far from the first input diffraction element (1200) can be increased, thereby improving the uniformity of the output light.

[0119] The width (a2) of the second side (S2) of the second region (1320) of the first transmission diffraction element (1300) may be greater than the widths (a1, a3) of the first side (S1) and the third side (S3).

[0120] The second side (S2) may be adjacent to the first side (S1) and the third side (S3). The second side (S2) may be arranged in a direction away from the first input diffractive element (1200). The width (a2) of the second side (S2) is greater than the widths (a1, a3) of the first side (S1) and the third side (S3), so that the second region (1320) may be arranged widely up to an area disposed far from the first input diffractive element (1200) of the first transmission diffractive element (1300), and ultimately, the diffraction efficiency of the area disposed far from the first input diffractive element (1200) may be increased, thereby improving the uniformity of the output light.

[0121] Fig. 5 is a cross-sectional view of a light guide device according to an embodiment.

[0122] Referring to FIG. 5, the first transmission diffraction element (1300) includes a first surface (F1) adjacent to the first input diffraction element (1200), a second surface (F2) adjacent to the first output diffraction element (1400), a third surface (F3) arranged to face the first surface (F1), and a fourth surface (F4) arranged to face the second surface (F2), and the first output diffraction element (1400) can overlap with an extension line (l1) of the first surface and an extension line (l3) of the third surface.

[0123] The first transmission diffraction element (1300) may include a first surface (F1), a second surface (F2), a third surface (F3), and a fourth surface (F4). The first surface to the fourth surface (F1, F2, F3, F4) may be outer surfaces of the first transmission diffraction element (1300) when the first transmission diffraction element (1300) is viewed in a first direction. The first surface (F1) may be a surface adjacent to the first input diffraction element (1200). The first surface (F1) may be an outer surface of the first transmission diffraction element (1300) that has the smallest distance from the first input diffraction element (1200). The first surface (F1) may be in contact with the second surface (F2) and the fourth surface (F4). The second surface (F2) may be a surface adjacent to the first output diffraction element (1400). The second surface (F2) may be an outer surface of the first transmission diffraction element (1300) having the smallest separation distance from the first output diffraction element (1400). The second surface (F2) may be in contact with the first surface (F1) and the third surface (F3). The third surface (F3) may be a surface arranged to face the first surface (F1). The third surface (F3) may be an outer surface having the largest separation distance from the first input diffraction element (1200) among the first to fourth surfaces (F1, F2, F3, F4) of the first transmission diffraction element (1300). The third surface (F3) may be in contact with the second surface (F2) and the fourth surface (F4). The fourth surface (F4) may be a surface arranged to face the second surface (F2). The fourth surface (F4) may be an outer surface having the largest distance from the first emission diffraction element (1400) among the first to fourth surfaces (F1, F2, F3, F4) of the first transmission diffraction element (1300). The fourth surface (F4) may be in contact with the first surface (F1) and the third surface (F3).

[0124] The first emission diffraction element (1400) may overlap with the extension line (l1) of the first surface and the extension line (l3) of the third surface. The extension line (l1) of the first surface may refer to a line extended in the direction in which the first surface (F1) faces when the first surface (F1) is viewed from the first direction. The extension line (l3) of the third surface may refer to a line extended in the direction in which the third surface (F3) faces when the third surface (F3) is viewed from the first direction. A part of the first emission diffraction element (1400) may be arranged between the extension line (l1) of the first surface and the extension line (l3) of the third surface. A part of the first emission diffraction element (1400) may be arranged outside the extension line (l1) of the first surface and the extension line (l3) of the third surface. The first exit diffraction element (1400) can be in contact with at least the extension line (l1) of the first side and the extension line (l3) of the third side. The extension line (l1) of the first side can be in contact with the first exit diffraction element (1400) or overlap with the first exit diffraction element (1400). The extension line (l3) of the third side can be in contact with the first exit diffraction element (1400) or overlap with the first exit diffraction element (1400). By arranging the first exit diffraction element (1400) so as to be positioned outside the extension line (l1) of the first side and the extension line (l3) of the third side, all light transmitted from the first transmission diffraction element (1300) can be emitted to the outside through the first exit diffraction element (1400). Ultimately, the light output efficiency of the light guide device (1000) can be improved.

[0125] The first emission diffraction element (1400) may not overlap with the extension line (l2) of the second surface of the first transmission diffraction element (1300). The extension line (l2) of the second surface may refer to a line extended in the direction in which the second surface (F2) faces when the second surface (F2) is viewed from the first direction. The extension line (l2) of the second surface may be arranged to intersect the extension line (l1) of the first surface and the extension line (l3) of the third surface. The first emission diffraction element (1400) may be arranged to be spaced apart from the first transmission diffraction element (1300) by a certain distance or more so as not to overlap with the extension line (l2) of the second surface. The first exit diffraction element (1400) is positioned so as not to overlap with the extension line (l2) of the second surface of the first transmission diffraction element (1300), so that all light transmitted from the first transmission diffraction element (1300) can reach the first exit diffraction element (1400) and be emitted to the outside. Consequently, the light output efficiency of the light guide device (1000) can be improved.

[0126] FIG. 6 is an enlarged view of the first side and the second side according to the embodiment, FIG. 7 is a schematic view of the first side and the second side according to the embodiment, and FIG. 8 is an enlarged view of the first side and the second side according to the embodiment.

[0127] Referring to FIGS. 5 to 8, the first side (S1) and the second side (S2) may be regions having a first pattern of a first region (1310) of a first transmission diffraction element (1300) and a second pattern of a second region (1310) of the first transmission diffraction element (1300).

[0128] The first side (S1) and the second side (S2) may correspond to the boundary between the first region (1310) and the second region (1320). The first side (S1) and the second side (S2) correspond to the boundary between the first region (1310) and the second region (1320) and may include the shape of a surface or a shape of a line. Based on the first side (S1) and the second side (S2), one side may have the first pattern of the first region (1310), and the other side may have the second pattern of the second region (1320). The pattern may be determined by the period, width, or height of the protrusions of the first region (1310) and the second region (1320). The first side (S1) and the second side (S2) may be regions where the first pattern of the first region (1310) and the second pattern of the second region (1320) are mixed. Fig. 6 is an enlarged photograph of a portion where the first side (S1) and the second side (S2) meet, and an enlarged cross-section thereof. Referring to Fig. 6, the patterns of the first transmission diffraction elements (1300) on both sides of the first side (S1) and the second side (S2) may be different. In addition, referring to the AA' cross-section of Fig. 6, the first side (S1) and the second side (S2) may have a mixture of a pattern of a first region (1310) and a pattern of a second region (1320). The patterns of the first side (S1) and the second side (S2) may be different from the patterns of the first region (1310) and the second region (1320) because the first pattern of the first region (1310) and the second pattern of the second region (1320) are mixed. Fig. 7 is a cross-sectional view showing several embodiments of the patterns of the first side (S1) and the second side (S2) of the first transmission diffraction element (1300). The shapes of the patterns of the first side (S1) and the second side (S2) of the first transmission diffraction element (1300) may be the same as the embodiment of Fig. 7. The protrusions of the patterns of the first side (S1) and the second side (S2) of the first transmission diffraction element (1300) may be inclined surfaces or may be vertical surfaces.The upper surfaces of the protrusions of the patterns of the first side (S1) and the second side (S2) of the first transmission diffraction element (1300) may be inclined surfaces or may be horizontal surfaces. The patterns of the first side (S1) and the second side (S2) of the first transmission diffraction element (1300) may be in the form of different protrusions spaced apart from each other, or in the form of different protrusions contacting each other. Fig. 8 may be an enlarged photograph of a portion where the first side (S1) and the second side (S2) of the first transmission diffraction element (1300) meet and an enlarged photograph of the second side (S2). Referring to Fig. 8, the patterns of the first transmission diffraction element (1300) on both sides may be different based on the first side (S1) and the second side (S2).

[0129] The characteristics of the patterns of the first side (S1) and the second side (S2) of the first transmission diffraction element (1300) shown in FIGS. 6 to 8 also appear identically in the first side (S'1) and the second side (S'2) of the second transmission diffraction element (2300) described later.

[0130] Fig. 9 is a cross-sectional view of a light guide device according to an embodiment.

[0131] Referring to FIG. 9, the first input diffraction element (1200) is positioned between an extension line (l2) of the second face of the first transmission diffraction element (1300) and an extension line (l4) of the fourth face of the first transmission diffraction element (1300), and the outline of the first input diffraction element (1200) may not overlap with the extension line (l2) of the second face of the first transmission diffraction element (1300) and the extension line (l4) of the fourth face of the first transmission diffraction element (1300).

[0132] The first input diffraction element (1200) may be arranged between an extension line (l2) of the second face of the first transfer diffraction element (1300) and an extension line (l4) of the fourth face of the first transfer diffraction element (1300). The extension line (l4) of the fourth face may refer to a line extended in the direction in which the fourth face (F4) faces when the fourth face (F4) is viewed in the first direction. The first input diffraction element (1200) may be arranged between an extension line (l2) of the second face of the first transfer diffraction element (1300) and an extension line (l4) of the fourth face of the first transfer diffraction element (1300) so that all light incident through the first input diffraction element (1200) may be transmitted to the first transfer diffraction element (1300).

[0133] The outline of the first input diffraction element (1200) may not overlap with the extension line (l2) of the second surface of the first transmission diffraction element (1300) and the extension line (l4) of the fourth surface of the first transmission diffraction element (1300). The first input diffraction element (1200) may be positioned within a certain distance from the first transmission diffraction element (1300) between the extension line (l2) of the second surface and the extension line (l4) of the fourth surface, so as not to overlap with the extension line (l2) of the second surface and the extension line (l4) of the fourth surface. The outline of the first input diffraction element (1200) is arranged so as not to overlap with the extension line (l2) of the second side and the extension line (l4) of the fourth side, so that the first input diffraction element (1200) and the first transmission diffraction element (1300) can be arranged close to each other, and the efficiency of the transmitted light can be increased, ultimately improving the light output efficiency of the light guide device (1000).

[0134] The outline of the first input diffractive element (1200) and the first surface (F1) of the first transmission diffractive element (1300) do not overlap each other. If they overlap, a portion of the light incident from the first transmission diffractive element (1300) to the first output diffractive element (1400) is blocked, and an image may not be output from the first output diffractive element (1400) in the blocked area. If the outline of the first input diffractive element (1200) and the first surface (F1) of the first transmission diffractive element (1300) overlap each other, a blocked area is generated, which reduces efficiency. Therefore, it is preferable that the outline of the first input diffractive element (1200) and the first surface (F1) of the first transmission diffractive element (1300) do not overlap each other.

[0135] The first transmission diffraction element (1300) may include a first side surface (S1) and a second side surface (S2), which are boundaries between the first region (1310) of the first transmission diffraction element (1300) and the second region (1320) of the first transmission diffraction element (1300).

[0136] The first transmission diffraction element (1300) may include a first side surface (S1) and a second side surface (S2). The first side surface (S1) and the second side surface (S2) may be boundaries between a first region (1310) and a second region (1320). The first side surface (S1) may be a boundary between the first region (1310) and the second region (1320) adjacent to the first input diffraction element (1200). The second side surface (S2) may be a boundary between the first region (1310) and the second region (1320) adjacent to the first output diffraction element (1400).

[0137] Fig. 10 is a drawing showing a vector of a pattern of a diffraction element of a light guide device according to an embodiment.

[0138] Referring to FIGS. 9 and 10, the second side surface (S2) of the first transmission diffraction element (1300) may be between the vector extension line (l7) of the pattern of the first input diffraction element (1200) passing through the center of the first input diffraction element (1200) and the extension line (l4) of the fourth side of the first transmission diffraction element (1300), and the vector extension line (l7) of the pattern of the first input diffraction element (1200) passing through the center of the first input diffraction element (1200) means a line drawn in a direction perpendicular to the pattern direction of the first input diffraction element (1200).

[0139] The first input diffraction element (1200) has a pattern, and the pattern of the first input diffraction element (1200) includes a certain tendency and directionality. The vector of the pattern of the first input diffraction element (1200) means a direction perpendicular to the pattern direction of the first input diffraction element (1200). In the embodiment, the vector of the pattern of the first input diffraction element (1200) has -50°, which is an angle formed with the x-axis when the horizontal direction of the first output diffraction element (1400) is defined as the x-axis and the vertical direction as the y-axis.

[0140] According to the embodiment, the vector of the pattern of the first input diffraction element (1200) is -50°, the vector of the pattern of the first transmission diffraction element (1300) is -107.5°, and the vector of the pattern of the first output diffraction element (1400) is 15°.

[0141] The center of the first input diffraction element (1200) may refer to the center of a circle of the first input diffraction element (1200) when the first input diffraction element (1200) is viewed from the first direction. The second region (1320) may be arranged between the extension line (l7) of the vector passing through the center of the first input diffraction element (1200) and the extension line (l4) of the fourth surface. Accordingly, the first side surface (S1) and the second side surface (S2), which are boundaries between the first region (1310) and the second region (1320), may be arranged between the extension line (l7) of the vector passing through the center of the first input diffraction element (1200) and the extension line (l4) of the fourth surface. In addition, the first side surface (S1) and the second side surface (S2) may overlap the extension line (l7) of the vector at the center of the first input diffraction element (1200). However, the first side (S1) and the second side (S2) cannot be placed between the extension line (l7) of the vector passing through the center of the first input diffraction element (1200) and the extension line (l2) of the second surface. The first side surface (S1) and the second side surface (S2) of the first transmission diffraction element (1300) are arranged between the extension line (l7) of the vector passing through the center of the first input diffraction element (1200) and the extension line (l4) of the fourth surface of the first transmission diffraction element (1300), so that the second region (1320) can be arranged between the extension line (l7) of the vector from the center of the first input diffraction element (1200) and the extension line (l4) of the fourth surface, and ultimately, the diffraction efficiency of a portion spaced far from the first output diffraction element (1400) of the first transmission diffraction element (1300) can be increased, thereby improving the uniformity of the output light.

[0142] Fig. 11 is a schematic diagram of a light guide device according to another embodiment.

[0143] Referring to FIG. 11, the light guide device (2000) according to the embodiment may further include a second substrate (2100), a second input diffractive element (2200), a second transfer diffractive element (2300), a second output diffractive element (2400), and a cover (3000) in addition to the first substrate (1100), the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400) described above.

[0144] The second substrate (2100), the second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400) may be arranged on the lower surface of the first substrate (1100). The second substrate (2100), the second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400) may be arranged on the first substrate (1100) spaced apart from the light output unit (10). The second substrate (2100), the second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400) may overlap the first substrate (1100) in the first direction in which light is incident. A second input diffractive element (2200), a second transmission diffractive element (2300), and a second output diffractive element (2400) may be disposed between a first substrate (1100) and a second substrate (2100). A cover (3000) may be disposed on the first substrate (1100), the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400). The cover (3000) may be disposed adjacent to the light output unit (10) on the first substrate (1100), the first input diffractive element (1200), the first transmission diffractive element (1300), and the first output diffractive element (1400). Light may pass through the cover (3000) and enter the first input diffractive element (1200). The cover (3000) may have the effect of protecting the interior of the light guide device (2000). The refractive index of the cover (3000) may be about 1.5.

[0145] The second substrate (2100) can serve as a path for transmitting light. A second input diffractive element (2200), a second transmission diffractive element (2300), and a second output diffractive element (2400) can be arranged on the second substrate (2100). The light can be totally reflected inside the second substrate (2100) and travel along the inside of the second substrate (2100). The second substrate (2100) can include a waveguide. The second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400) can be arranged spaced apart from each other on the second substrate (2100). The second substrate (2100) can be arranged in a second direction that is perpendicular to a first direction in which light is incident. The refractive index of the first substrate (1100) and the second substrate (2100) may be 1.77 to 1.81.

[0146] The second input diffraction element (2200) can serve as a path through which light is incident. The second input diffraction element (1200) can be placed on the second substrate (2100). Light can be incident through the second input diffraction element (1200) and transmitted through the second substrate (2100). The second input diffraction element (2200) can change the path of light by diffracting the light.

[0147] The second transmission diffraction element (2300) can change the path of light. The second transmission diffraction element (2300) can be placed on the second substrate (2100). The second transmission diffraction element (2300) can change the path of light incident through the second input diffraction element (2200). The second transmission diffraction element (2300) can change the path of light so that it is directed toward the second output diffraction element (2400). The second transmission diffraction element (2300) can change the path of light by diffracting the light.

[0148] The second exit diffraction element (2400) can serve as a path through which light is emitted. The second exit diffraction element (2400) can be disposed on the second substrate (2100). Light can be emitted to the outside of the light guide device (2000) through the second exit diffraction element (2400). The second exit diffraction element (2400) can receive light whose path has been changed from the second transmission element (2300) and emitted the light to the outside. The second exit diffraction element (2400) can change the path of the light and emitted it to the outside. The second exit diffraction element can change the path of the light by diffracting the light.

[0149] The second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400) may include a plurality of protrusions. The plurality of protrusions may have a constant width, period, and height and may be arranged on the second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400). The plurality of protrusions may protrude in a first direction on the second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400). The plurality of protrusions may be arranged to be spaced apart from each other in a vector direction of a pattern including protrusions that is perpendicular to the first direction. Depending on the width, period, and height of the plurality of protrusions, the path of light may be changed differently after passing through the second input diffractive element (2200), the second transmission diffractive element (2300), and the second exit diffractive element (2400). The width of the protrusion may refer to the width in the vector direction of the pattern including the protrusion of the protrusion. The period of the protrusion may refer to the interval in the vector direction of the pattern including the protrusion between one side of the protrusion and one side of an adjacent protrusion. The height of the protrusion may refer to the height of the portion protruding in the first direction of the protrusion. The refractive index of the first input diffractive element (1200), the first transmission diffractive element (1300), the first exit diffractive element (1400), the second input diffractive element (2200), the second transmission diffractive element (2300), and the second exit diffractive element (2400) may be 1.80 to 1.86. The refractive indices of the first input diffractive element (1200), the first transmission diffractive element (1300), the first output diffractive element (1400), the second input diffractive element (2200), the second transmission diffractive element (2300), and the second output diffractive element (2400) may be equal to or greater than the refractive indices of the first substrate (1100) and the second substrate (2100).

[0150] Figure 12 is an enlarged view of the third and fourth regions according to another embodiment.

[0151] Referring to FIG. 12, the second transmission diffraction element (2300) may include a third region (2310) and a fourth region (2320). The third region (2310) and the fourth region (2320) may refer to a portion of the second transmission diffraction element (2300). The third region (2310) and the fourth region (2320) may be two regions that are separated from each other when the second transmission diffraction element (2300) is viewed in a first direction in which an optical signal is incident. The third region (2310) may be a region adjacent to the second output diffraction element (2400) of the second transmission diffraction element (2300). The third region (2310) may be a region adjacent to the second input diffraction element (2200) of the second transmission diffraction element (2300). The fourth region (2320) of the second transmission diffraction element (2300) may be a region spaced apart from the second output diffraction element (2400). The fourth region (2320) of the second transmission diffraction element (2300) may be a region spaced apart from the second input diffraction element (2200). The distance between the third region (2310) and the second output diffraction element (2400) may be smaller than the distance between the fourth region (2320) and the second output diffraction element (2400). The shapes or areas of the third region (2310) and the fourth region (2320) may be different from each other. The third region (2310) and the fourth region (2320) may each include a plurality of surfaces. Some surfaces of the third area (2310) and some surfaces of the fourth area (2320) may be in contact with each other.

[0152] Figures 13 to 15 are cross-sectional views of a second substrate according to an embodiment.

[0153] Referring to FIG. 13, the shortest distance (d'1) between the second input diffraction element (2200) and the third region (2310) of the second transmission diffraction element (2300) may be shorter than the shortest distance (d'2) between the second input diffraction element (2200) and the fourth region (2320) of the second transmission diffraction element (2300).

[0154] The relationship between the first side (S'1) and the third side (S'3) of the fourth region (2320) of the second substrate (2300) has the same effect as the relationship between the first side (S1) and the third side (S3) of the second region (2310) of the first substrate (1300). The relationship between the width (a'3) of the third side (S'3) of the fourth region (2320) of the second substrate (2300) and the width (a'1) of the first side (S'1) has the same effect as the relationship between the width (a3) ​​of the third side (S3) of the second region (1320) of the first substrate (1300) and the width (a1) of the first side (S1).

[0155] Referring to FIG. 14, the second transmission diffraction element (2300) includes a first surface (F'1) adjacent to the second input diffraction element (2200), a second surface (F'2) adjacent to the second output diffraction element (2400), a third surface (F'3) arranged to face the first surface (F'1) of the second transmission diffraction element (2300), and a fourth surface (F'4) arranged to face the second surface (F'2) of the second transmission diffraction element (2300), and the second output diffraction element (2400) can overlap with an extension line (l'1) of the first surface and an extension line (l'3) of the third surface.

[0156] Fig. 9 can be equally applied to the second transmission diffraction element (2300). The second input diffraction element (2200) is arranged between the extension line (l'2) of the second face of the second transmission diffraction element (2300) and the extension line (l'4) of the fourth face of the second transmission diffraction element (2300), and the outline of the second input diffraction element (2200) may not overlap with the extension line (l'2) of the second face of the second transmission diffraction element (2300) and the extension line (l'4) of the fourth face of the second transmission diffraction element (2300).

[0157] The second input diffraction element (2200) may be arranged between an extension line (l'2) of the second face of the second transmission diffraction element (2300) and an extension line (l'4) of the fourth face of the second transmission diffraction element (2300). The extension line (l'4) of the fourth face of the second transmission diffraction element (2300) may refer to a line extended in a direction in which the fourth face (F'4) of the second transmission diffraction element (2300) faces when the fourth face (F'4) of the second transmission diffraction element (2300) is viewed in the first direction. The second input diffraction element (2200) is arranged between the extension line (l'2) of the second face of the second transfer diffraction element (2300) and the extension line (l'4) of the fourth face of the second transfer diffraction element (2300), so that all light incident through the second input diffraction element (2200) can be transmitted to the second transfer diffraction element (2300).

[0158] The outline of the second input diffractive element (2200) may not overlap with the extension line (l'2) of the second face of the second transfer diffractive element (2300) and the extension line (l'4) of the fourth face of the second transfer diffractive element (2300). The second input diffractive element (2200) may be arranged within a certain distance from the second transfer diffractive element (2300) between the extension line (l'2) of the second face of the second transfer diffractive element (2300) and the extension line (l'4) of the fourth face of the second transfer diffractive element (2300), so as not to overlap with the extension line (l'2) of the second face of the second transfer diffractive element (2300) and the extension line (l'4) of the fourth face of the second transfer diffractive element (2300). The outline of the second input diffraction element (2200) is arranged so as not to overlap with the extension line (l'2) of the second surface of the second transmission diffraction element (2300) and the extension line (l'4) of the fourth surface of the second transmission diffraction element (2300), so that the second input diffraction element (2200) and the second transmission diffraction element (2300) can be arranged close to each other, and the efficiency of the transmitted light can be increased, ultimately improving the light output efficiency of the light guide device (1000).

[0159] The outline of the second input diffractive element (2200) and the first surface (F'1) of the second transmission diffractive element (2300) do not overlap each other. If they overlap, a portion of the light incident from the second transmission diffractive element (2300) to the second output diffractive element (2400) is blocked, and an image may not be output from the second output diffractive element (2400) in the blocked area. If the outline of the second input diffractive element (2200) and the first surface (F'1) of the second transmission diffractive element (2300) overlap each other, a blocked area is generated, which reduces efficiency. Therefore, it is preferable that the outline of the second input diffractive element (2200) and the first surface (F'1) of the second transmission diffractive element (2300) do not overlap each other.

[0160] The second transmission diffraction element (2300) may include a first side surface (S'1) and a second side surface (S'2), which are boundaries between the third region (2310) of the second transmission diffraction element (2300) and the fourth region (2320) of the first transmission diffraction element (2300).

[0161] The second transmission diffraction element (2300) may include a first side surface (S'1) and a second side surface (S'2). The first side surface (S'1) and the second side surface (S'2) of the second transmission diffraction element (2300) may be a boundary surface of a third region (2310) and a fourth region (2320). The first side surface (S'1) of the second transmission diffraction element (2300) may be a boundary surface of a third region (2310) and a fourth region (2320) adjacent to the second input diffraction element (2200). The second side surface (S'2) of the second transmission diffraction element (2300) may be a boundary surface of a third region (2310) and a fourth region (2320) adjacent to the second output diffraction element (2400).

[0162] The first side surface (S1) of the first transmission diffraction element (1300) overlaps with the first side surface (S'1) of the second transmission diffraction element (2300) in the first direction, and the second side surface (S2) of the first transmission diffraction element (1300) overlaps with the second side surface (S'2) of the second transmission diffraction element (2300) in the first direction.

[0163] Referring to FIG. 15, the fourth region (2320) may be positioned between an extension line (l'7) of a vector passing through the center of the second input diffraction element (2200) and an extension line (l'4) of the fourth surface of the second transmission diffraction element (2300). The center of the second input diffraction element (2200) may refer to the center of a circle shape of the second input diffraction element (2200) when the second input diffraction element (2200) is viewed from the first direction. Accordingly, the first side surface (S'1) and the second side surface (S'2) of the second transfer diffraction element (2300), which are the boundaries between the third region (2310) and the fourth region (2320), may be arranged between the extension line (l'7) of the vector passing through the center of the second input diffraction element (2200) and the extension line (l'4) of the fourth surface of the second transfer diffraction element (2300). In addition, the first side surface (S'1) and the second side surface (S'2) of the second transfer diffraction element (2300) may overlap the extension line (l'7) of the vector at the center of the second input diffraction element (2200). However, the first side (S'1) and the second side (S'2) of the second transmission diffraction element (2300) cannot be placed between the extension line (l'7) of the vector passing through the center of the second input diffraction element (2200) and the extension line (l'2) of the second surface of the second transmission diffraction element (2300). The first side surface (S'1) and the second side surface (S'2) of the second transmission diffraction element (2300) are arranged between the extension line (l'7) of the vector passing through the center of the second input diffraction element (2200) and the extension line (l'4) of the fourth surface of the second transmission diffraction element (2300), so that the fourth region (2320) can be arranged between the extension line (l'7) of the vector passing through the center of the second input diffraction element (2200) and the extension line (l'4) of the fourth surface of the second transmission diffraction element (2300), and ultimately, the diffraction efficiency of a portion of the second transmission diffraction element (2300) that is far away from the second output diffraction element (2400) can be increased, thereby improving the uniformity of the output light.

[0164] The first input diffractive element (1200) may overlap with the second input diffractive element (2200) in the first direction, and the first input diffractive element (1200) may have a shape that is 1:1 symmetrical with the second input diffractive element (2200) in the first direction. The first transfer diffractive element (1300) may overlap with the second transfer diffractive element (2300) in the first direction, and the first transfer diffractive element (1300) may have a shape that is 1:1 symmetrical with the second transfer diffractive element (2300) in the first direction. The first region (1310) of the first transmission diffraction element (1300) overlaps with the third region (2310) of the second transmission diffraction element (2300) in the first direction, and the first region (1310) of the first transmission diffraction element (1300) may have a shape that is 1:1 symmetrical with the third region (2310) of the second transmission diffraction element (2300) in the first direction. The first output diffraction element (1400) overlaps with the second output diffraction element (2400) in the first direction, and the first output diffraction element (1400) may have a shape that is 1:1 symmetrical with the second output diffraction element (2400) in the first direction.

[0165] The third region (2310) of the second transmission diffraction element (2300) may include a third protrusion (2311) protruding in the first direction, and the fourth region (2320) may include a fourth protrusion (2321) protruding in the first direction. The third protrusion (2311) and the fourth protrusion (2321) may be portions protruding in the first direction from the third region (2310) and the fourth region (2320), respectively. The first direction may be a direction in which light is incident. The first direction may mean the direction in which light is incident or the opposite direction. Fig. 11 is an enlarged view of the third region (2310) and the fourth region (2320) when viewed from the front. Referring to FIG. 11, the third protrusion (2311) and the fourth protrusion (2321) may be arranged repeatedly with a certain period, width, and height on the third region (2310) and the fourth region (2320). The plurality of third protrusions (2311) may be arranged to be spaced apart from each other in the vector direction of the pattern of the third region (2310) of the second transmission diffraction element (2300). The plurality of fourth protrusions (2321) may be arranged to be spaced apart from each other in the vector direction of the pattern of the third region (2310) of the second transmission diffraction element (2300).

[0166] The width (w3) of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) may be different from the width (w4) of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300). The third protrusion (2311) may have a constant width (w3) and period (T3). In addition, the fourth protrusion (2321) may have a constant width (w4) and period (T4). The width (w3) of the third protrusion (2311) may refer to the width in the vector direction of the pattern of the third region (2310) of the second transmission diffraction element (2300) of the third protrusion (2311). The period (T3) of the third protrusion (2311) may refer to the distance between one side of two adjacent third protrusions (2311). The period (T3) of the third protrusion (2311) may refer to the distance between one side of two adjacent third protrusions (2311). The period (T3) of the third protrusion (2311) may refer to the shortest distance between one side of two adjacent third protrusions (2311). The width (w4) of the fourth protrusion (2321) may refer to the width in the vector direction of the pattern of the third area (2320) of the second transmission diffraction element (2300) of the fourth protrusion (2321). The period (T4) of the fourth protrusion (2321) may refer to the distance between one side of two adjacent fourth protrusions (2321). The period (T4) of the fourth protrusion (2321) may mean the shortest distance between one side of two adjacent fourth protrusions (2321). The width (w3) of the third protrusion (2311) of the third region (2310) may be different from the width (w4) of the fourth protrusion (2321) of the fourth region (2320), so that the diffraction efficiency of the light passing through the third region (2310) of the second transfer diffraction element (2300) and the light passing through the fourth region (2320) of the second transfer diffraction element (2300) may be different.By making the diffraction efficiency of the light passing through the third region (2310) of the second transmission diffraction element (2300) different from that of the light passing through the fourth region (2320) of the second transmission diffraction element (2300), the uniformity of the intensity of the light passing through each of the third region (2310) and the fourth region (2320) and output to the second output diffraction element (2400) can be improved.

[0167] The width (w3) of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) may be wider than the width (w4) of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300). For example, the width (w3) of the third protrusion (2311) of the third region (2310) may be 265 nm. Additionally, for example, the width (w4) of the fourth protrusion (2321) of the fourth region (2320) may be 178 nm. The width (w3) of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) is wider than the width (w4) of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300), thereby increasing the diffraction efficiency of light in the fourth region (2320) positioned far from the second input diffraction element (2200) and the second output diffraction element (2400), thereby improving the uniformity of the intensity of light passing through each part of the third region (2310) and the fourth region (2320) and outputting to the second output diffraction element (2400). The design values ​​of the width (w3) of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) and the width (w4) of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300) may be within a range of ±15% due to process errors and measurement errors.

[0168] Referring to FIG. 3 and FIG. 12, the period (T1) of the first region (1310) of the first transmission diffraction element (1300) disposed on the first substrate (1100) may be shorter than the period (T3) of the third region (2310) of the second transmission diffraction element (2300) disposed on the second substrate (2100). The period may be the shortest distance between the same side surfaces of the most adjacent protrusions when the diffraction element is viewed from the top. The period (T1) of the first region (1310) may be the shortest distance in the vector direction of the pattern of the first region (1310) of the first transmission diffraction element (1300) between the same two side surfaces of two adjacent first protrusions (1311). The period (T3) of the third region (2310) may be the shortest distance in the vector direction of the pattern of the third region (2310) of the second transmission diffraction element (2300) between the same two sides of the two adjacent third protrusions (2311). For example, the period (T1) of the first region (1310) may be 300 nm. Also, for example, the period (T3) of the third region (2310) may be 425 nm. Since the period (T1) of the first region (1310) of the first transmission diffraction element (1300) is shorter than the period (T3) of the third region (2310) of the second transmission diffraction element (2300), the first region (1310) of the first transmission diffraction element (1300) can diffract visible light of a shorter wavelength range than the third region (2310) of the second transmission diffraction element (2300). Since the first region (1310) and the third region (2310) can diffract visible light of different wavelength ranges, the light guide device (2000) can transmit and output light of different wavelength ranges with optimal diffraction efficiency through the two substrates, respectively. As a result, the output efficiency and uniformity of light can be improved.

[0169] The periods (T1, T2) of the first region (1310) of the first transmission diffraction element (1300) and the second region (1320) of the first transmission diffraction element (1300) may be the same, and the periods (T3, T4) of the third region (2310) of the second transmission diffraction element (2300) and the fourth region (2320) of the second transmission diffraction element (2300) may be the same. For example, the period (T1) of the first region (1310) and the period (T2) of the second region (1320) may be 300 nm. Also, for example, the period (T3) of the third region (2310) and the period (T4) of the fourth region (2320) may be 425 nm. Since the period (T1) of the first region (1310) and the period (T2) of the second region (1320) are the same, and the period (T3) of the third region (2310) and the period (T4) of the fourth region (2320) are the same, each region of the same transmission diffraction element can transmit light of the same wavelength range. Since each region of the same transmission diffraction element transmits light of the same wavelength range, the diffraction efficiency of light can be controlled by adjusting the width of each region under the same conditions, and thus the uniformity of the output light can be improved. All design values ​​described above, such as the periods (T1, T2) of the first region (1310) of the first transmission diffraction element (1300) and the second region (1320) of the first transmission diffraction element (1300), and the periods (T3, T4) of the third region (2310) of the second transmission diffraction element (2300) and the fourth region (2320) of the second transmission diffraction element (2300), may be within a range of ±5% due to process errors and measurement errors.

[0170] Fig. 16 is an enlarged view of a top view of a diffraction element of a light guide device according to an embodiment, and Fig. 17 is a cross-sectional view of a pattern vector direction of a diffraction element of a first substrate of a light guide device according to an embodiment. That is, it is a cross-sectional view of a first substrate diffraction element as viewed from the diffraction pattern vector direction of a second substrate diffraction element.

[0171] Referring to FIGS. 16 and 17, the directions of the patterns of the first region (1310) and the second region (1320) of the first transmission diffraction element (1300) of the light guide device (1000) may be the same. In addition, the directions of the patterns of the first input diffraction element (1200) and the first output diffraction element (1400) of the light guide device (1000) may be different.

[0172] The directions of the patterns of the first region (1310) and the second region (1320) are the same, so that light can be diffracted and transmitted in the same direction. The first region (1310) and the second region (1320) can transmit light in the same direction so that it reaches the first output diffraction element (1400). The directions of the patterns of the first input diffraction element (1200) and the first output diffraction element (1400) are different, so that the first input diffraction element (1200) can diffract light so that it reaches the first transmission diffraction element (1300), and the first output diffraction element (1400) can diffract light so that it outputs it to the outside.

[0173] The period (Ti1) of the first input diffractive element (1200) may be 305 nm to 360 nm. For example, the period (Ti1) of the first input diffractive element (1200) may be 322 nm. The width (wi1) of the protrusion (1210) of the first input diffractive element (1200) may be 109 nm to 169 nm. For example, the width (wi1) of the protrusion (1210) of the first input diffractive element (1200) may be 139 nm. The vector of the pattern direction of the first input diffractive element (1200) may be -70° to -45°. For example, the vector of the pattern direction of the first input diffractive element (1200) may be -50°. The first direction height of the protrusion (1210) of the first input diffractive element (1200) may be 117 nm to 177 nm. For example, the first direction height of the protrusion (1210) of the first input diffractive element (1200) may be 147 nm. The protrusion (1210) of the first input diffractive element (1200) may be designed to be inclined in the vector direction of the pattern of the first input diffractive element (1200).

[0174] Referring to FIG. 17, the angle (θ1) at which the protrusion (1210) of the first input diffractive element (1200) is inclined in the vector direction of the pattern of the first input diffractive element (1200) may be 35° to 45° based on the first direction. For example, the angle at which the protrusion (1210) of the first input diffractive element (1200) is inclined in the vector direction of the pattern of the first input diffractive element (1200) may be 40° based on the first direction. The design values ​​of the period (Ti1) of the first input diffractive element (1200) and the vector of the pattern direction of the first input diffractive element (1200) and the angle (θ1) at which the protrusion (1210) of the first input diffractive element (1200) is inclined in the vector direction of the pattern of the first input diffractive element (1200) may be within a range of ±5% due to process errors and measurement errors. The first direction height design value of the protrusion (1210) of the first input diffraction element (1200) may be within the range of ±15% due to process error and measurement error.

[0175] The period (T1) of the first region (1310) of the first transmission diffraction element (1300) may be 283 nm to 335 nm. For example, the period (T1) of the first region (1310) of the first transmission diffraction element (1300) may be 300 nm. The width (w1) of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be 54 nm to 114 nm. For example, the width (w1) of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be 84 nm. The direction vector of the pattern of the first region (1310) of the first transmission diffraction element (1300) may be -120° to -95°. For example, the direction vector of the pattern of the first region (1310) of the first transmission diffraction element (1300) may be -107.5°. The first direction height of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be 25 nm to 45 nm. For example, the first direction height of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be 35 nm. Referring to FIG. 14, the first direction reference slope of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be -5° to 5°. For example, the first direction reference inclination of the first protrusion (1311) of the first region (1310) of the first transmission diffraction element (1300) may be 0°.

[0176] The period (T2) of the second region (1320) of the first transmission diffraction element (1300) may be 283 nm to 335 nm. For example, the period (T2) of the second region (1320) of the first transmission diffraction element (1300) may be 300 nm. The width (w2) of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300) may be 150 nm to 210 nm. For example, the width (w2) of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300) may be 180 nm. The direction vector of the pattern of the second region (1320) of the first transmission diffraction element (1300) may be -120° to -95°. For example, the vector of the pattern direction of the second region (1320) of the first transmission diffraction element (1300) may be -107.5°. The first direction height of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300) may be 25 nm to 45 nm. For example, the first direction height of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300) may be 35 nm. Referring to FIG. 14, the first direction reference slope of the second protrusion (1321) of the second region (1320) of the first transmission diffraction element (1300) may be -5° to 5°. For example, the first The slope relative to the direction can be 0˚.

[0177] The period (To1) of the first exit diffraction element (1400) may be 305 nm to 360 nm. For example, the period (To1) of the first exit diffraction element (1400) may be 322 nm. The width (wo1) of the protrusion (1410) of the first exit diffraction element (1400) may be 109 nm to 169 nm. For example, the width (wo1) of the protrusion (1410) of the first exit diffraction element (1400) may be 139 nm. The vector in the pattern direction of the first exit diffraction element (1400) may be 10° to 35°. For example, the vector in the pattern direction of the first exit diffraction element (1400) may be 15°. The first direction height of the protrusion (1410) of the first output diffraction element (1400) may be 117 nm to 177 nm. For example, the first direction height of the protrusion (1410) of the first output diffraction element (1400) may be 147 nm. Referring to FIG. 17, the angle (θ4) at which the protrusion (1410) of the first output diffraction element (1400) is inclined in the vector direction of the pattern of the first output diffraction element (1400) may be 45° to 35° with respect to the first direction. For example, the angle (θ4) at which the protrusion (1410) of the first output diffraction element (1400) is inclined in the vector direction of the pattern of the first output diffraction element (1400) may be 40° with respect to the first direction. All design values ​​described above may be within the range of ±5% due to process errors and measurement errors.

[0178] Fig. 18 is an enlarged view of a top view of a diffraction element of a second substrate of a light guide device according to another embodiment, and Fig. 19 is a cross-sectional view of a diffraction pattern vector direction of a second substrate diffraction element of a light guide device according to another embodiment. That is, it is a cross-sectional view of the second substrate diffraction element as seen from the diffraction pattern vector direction of the second substrate diffraction element.

[0179] Referring to FIGS. 18 and 19, the directions of the patterns of the third region (2310) and the fourth region (2320) of the second transmission diffraction element (2300) of the light guide device (2000) may be the same. In addition, the directions of the patterns of the second input diffraction element (2200) and the second output diffraction element (2400) of the light guide device (2000) may be different.

[0180] The directions of the patterns of the third region (2310) and the fourth region (2320) are the same, so that light can be diffracted and transmitted in the same direction. The third region (2310) and the fourth region (2320) can transmit light in the same direction so that it reaches the second output diffraction element (2400). The directions of the patterns of the second input diffraction element (2200) and the second output diffraction element (2400) are different, so that the second input diffraction element (2200) can diffract light so that it reaches the second transmission diffraction element (2300), and the second output diffraction element (2400) can diffract light so that it outputs it to the outside.

[0181] The period (Ti2) of the second input diffractive element (2200) may be 411 nm to 489 nm. For example, the period (Ti2) of the second input diffractive element (2200) may be 457 nm. The width (wi2) of the protrusion (2210) of the second input diffractive element (2200) may be 138 nm to 198 nm. For example, the width (wi2) of the protrusion (2210) of the second input diffractive element (2200) may be 168 nm. The vector of the pattern direction of the second input diffractive element (2200) may be -70° to -45°. For example, the vector of the pattern direction of the second input diffractive element (2200) may be -50°. The first direction height of the protrusion (2210) of the second input diffraction element (2200) may be 145 nm to 205 nm. For example, the first direction height of the protrusion (2210) of the second input diffraction element (2200) may be 175 nm. Referring to FIG. 19, the angle (θ'1) at which the protrusion (2210) of the second input diffraction element (2200) is inclined in the pattern direction of the second input diffraction element (2200) may be -35° to -45° with respect to the first direction. For example, the angle (θ'1) at which the protrusion (2210) of the second input diffraction element (2200) is inclined in the vector direction of the pattern of the second input diffraction element (2200) may be -40° with respect to the first direction.

[0182] The period (T3) of the third region (2310) of the second transmission diffraction element (2300) may be 382 nm to 455 nm. For example, the period (T3) of the third region (2310) of the second transmission diffraction element (2300) may be 425 nm. The width (w3) of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) may be 235 nm to 295 nm. For example, the width (w3) of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) may be 265 nm. The vector of the direction of the pattern of the third region (2310) of the second transmission diffraction element (2300) may be -120° to -95°. For example, the vector of the direction of the pattern of the third area (2310) of the second transmission diffraction element (2300) may be -107.5°. The first direction height of the third protrusion (2311) of the third area (2310) of the second transmission diffraction element (2300) may be 25 nm to 45 nm. For example, the first direction height of the third protrusion (2311) of the third area (2310) of the second transmission diffraction element (2300) may be 35 nm. The first direction reference slope of the third protrusion (2311) of the third area (2310) of the second transmission diffraction element (2300) may be -5° to 5°. For example, the first direction reference inclination of the third protrusion (2311) of the third region (2310) of the second transmission diffraction element (2300) may be 0°.

[0183] The period (T4) of the fourth region (2320) of the second transmission diffraction element (2300) may be 382 nm to 455 nm. For example, the period (T4) of the fourth region (2320) of the second transmission diffraction element (2300) may be 425 nm. The vector of the pattern direction of the fourth region (2320) of the second transmission diffraction element (2300) may be -120° to -95°. For example, the vector of the pattern direction of the fourth region (2320) of the second transmission diffraction element (2300) may be -107.5°. The first direction height of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300) may be 32 nm to 52 nm. For example, the first direction height of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300) may be 42 nm. The first direction reference inclination of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300) may be -5° to 5°. For example, the first direction reference inclination of the fourth protrusion (2321) of the fourth region (2320) of the second transmission diffraction element (2300) may be 0°.

[0184] The period (To2) of the second emission diffraction element (2400) may be 411 nm to 489 nm. For example, the period (To2) of the second emission diffraction element (2400) may be 457 nm. The width (wo2) of the protrusion (2410) of the second emission diffraction element (2400) may be 150 nm to 210 nm. For example, the width (wo2) of the protrusion (2410) of the second emission diffraction element (2400) may be 180 nm. The vector of the pattern direction of the second emission diffraction element (2400) may be 10° to 35°. For example, the vector of the pattern direction of the second emission diffraction element (2400) may be 15°. The first direction height of the protrusion (2410) of the second output diffraction element (2400) may be 145 nm to 205 nm. For example, the first direction height of the protrusion (2410) of the second output diffraction element (2400) may be 175 nm. Referring to FIG. 16, the angle (θ'4) at which the protrusion (2410) of the second output diffraction element (2400) is inclined in the vector direction of the pattern of the second output diffraction element (2400) may be 45° to 35° with respect to the first direction. For example, the angle (θ'4) at which the protrusion (2410) of the second output diffraction element (2400) is inclined in the vector direction of the pattern of the second output diffraction element (2400) may be 40° with respect to the first direction.

[0185] Among all the design values ​​described above, the design values ​​of the vectors of the period and pattern direction may be within a range of ±5% due to process errors and measurement errors, and the height in the first direction of the protrusion, the angle inclined in the vector direction of the pattern including the protrusion, and the width of the protrusion may be within a range of ±15% due to process errors and measurement errors.

[0186] The diffractive elements of FIGS. 16 to 19 may be schematic diagrams of diffractive elements of a light guide device according to an embodiment. The diffractive elements of FIGS. 16 to 19 may be different from the diffractive elements of the light guide device according to an embodiment.

[0187] FIGS. 20A to 20C are cross-sectional views of light guide devices according to various embodiments.

[0188] The field of view (FoV) can vary depending on the width of the light incident on the first input diffractive element. The width of the light incident on the first input diffractive element can vary depending on the width of the first input diffractive element. The area of ​​the first transmission diffractive element can vary depending on the FoV.

[0189] The vector of the pattern of the first input diffractive element or the first output diffractive element refers to a direction perpendicular to the pattern direction of the first input diffractive element or the first output diffractive element. This is the angle formed with the x-axis when the horizontal direction of the first input diffractive element or the first output diffractive element is defined as the x-axis and the vertical direction as the y-axis.

[0190] The relative height of the first input diffractive element and the first output diffractive element may be the difference in height between the center of the first input diffractive element and the center of the first output diffractive element. This may be a value obtained by subtracting the y-axis position of the first output diffractive element from the y-axis position of the first input diffractive element, when the horizontal direction of the first input diffractive element or the first output diffractive element is defined as the x-axis and the vertical direction as the y-axis.

[0191] Referring to FIG. 20a, the FoV (FoV1) of the light guide device according to the embodiment may be 30°, the vector (i1) of the pattern of the first input diffractive element may be -45°, the vector (o1) of the pattern of the first output diffractive element may be 35°, and the relative height (h1) of the first input diffractive element and the first output diffractive element may be -2.5 mm.

[0192] Referring to FIG. 20b, the FoV (FoV2) of the light guide device according to the embodiment may be 30°, the vector (i2) of the pattern of the first input diffractive element may be -50°, the vector (o2) of the pattern of the first output diffractive element may be 15°, and the relative height (h2) of the first input diffractive element and the first output diffractive element may be -7.5 mm.

[0193] Referring to FIG. 20c, the FoV (FoV3) of the light guide device according to the embodiment may be 30°, the vector (i3) of the pattern of the first input diffractive element may be -75°, the vector (o3) of the pattern of the first output diffractive element may be 10°, and the relative height (h3) of the first input diffractive element and the first output diffractive element may be -12.5 mm.

[0194] When the FoV of the light guide device is 30˚, the vector of the pattern of the first input diffractive element may be about -70˚ to -45˚, the vector of the pattern of the first output diffractive element may be about 10˚ to 35˚, and the relative height of the first input diffractive element and the first output diffractive element may be about -5 mm to -13 mm.

[0195] When the FoV of the light guide device increases, the width of the first transmission diffraction element and the size of the first output diffraction element may increase. When the FoV of the light guide device increases, if the vector of the pattern of the first input diffraction element is kept the same, the size of the first transmission diffraction element increases, so the size of the relative height of the first input diffraction element and the first output diffraction element may decrease to prevent the first transmission diffraction element and the first output diffraction element from overlapping. When the size of the relative height of the first input diffraction element and the first output diffraction element decreases, the vector of the pattern of the first output diffraction element may increase.

[0196] Fig. 21 is a block diagram showing the configuration of an extended reality electronic device according to an embodiment.

[0197] Referring to FIG. 21, the extended reality electronic device (20) may include a wireless communication unit (21), an input unit (22), a sensing unit (23), an output unit (24), an interface unit (25), a memory (26), a control unit (27), and a power supply unit (28). The components illustrated in FIG. 18 are not essential for implementing the electronic device (20), and thus, the electronic device (20) described in this specification may have more or fewer components than the components listed above.

[0198] More specifically, among the above components, the wireless communication unit (21) may include one or more modules that enable wireless communication between the electronic device (20) and a wireless communication system, between the electronic device (20) and another electronic device, or between the electronic device (20) and an external server. In addition, the wireless communication unit (21) may include one or more modules that connect the electronic device (20) to one or more networks.

[0199] This wireless communication unit (21) may include at least one of a broadcast reception module, a mobile communication module, a wireless Internet module, a short-range communication module, and a location information module.

[0200] The input unit (22) may include a camera or video input unit for inputting video signals, a microphone or audio input unit for inputting audio signals, and a user input unit (e.g., a touch key, a mechanical key, etc.) for receiving information from a user. Voice data or image data collected from the input unit (22) may be analyzed and processed into a user's control command.

[0201] The sensing unit (23) may include one or more sensors for sensing at least one of information within the electronic device (20), information about the surrounding environment surrounding the electronic device (20), and user information.

[0202] For example, the sensing unit (23) may include at least one of a proximity sensor, an illumination sensor, a touch sensor, an acceleration sensor, a magnetic sensor, a G-sensor, a gyroscope sensor, a motion sensor, an RGB sensor, an infrared sensor (IR sensor), a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor (e.g., a photographing device), a microphone, a battery gauge, an environmental sensor (e.g., a barometer, a hygrometer, a thermometer, a radiation detection sensor, a heat detection sensor, a gas detection sensor, etc.), and a chemical sensor (e.g., an electronic nose, a healthcare sensor, a biometric recognition sensor, etc.). Meanwhile, the electronic device (20) disclosed in the present specification may utilize information sensed by at least two or more of these sensors in combination.

[0203] The output unit (24) is for generating output related to visual, auditory, or tactile sensations, and may include at least one of a display unit, an audio output unit, a haptic module, and an optical output unit. The display unit may be formed as a touch screen by forming a mutual layer structure with a touch sensor or by forming an integral structure. This touch screen may function as a user input means that provides an input interface between the augmented reality electronic device (20) and the user, and at the same time, may provide an output interface between the augmented reality electronic device (20) and the user.

[0204] The interface unit (25) serves as a passageway for various types of external devices connected to the electronic device (20). Through the interface unit (25), the electronic device (20) can receive virtual reality or augmented reality content from the external device, and can perform mutual interaction by exchanging various input signals, sensing signals, and data.

[0205] For example, the interface unit (25) may include at least one of a wired / wireless headset port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device equipped with an identification module, an audio I / O (Input / Output) port, a video I / O (Input / Output) port, and an earphone port.

[0206] In addition, the memory (26) stores data that supports various functions of the electronic device (20). The memory (26) can store a plurality of application programs (or applications) that run on the electronic device (20), data for the operation of the electronic device (20), and commands. At least some of these application programs can be downloaded from an external server via wireless communication. In addition, at least some of these application programs can exist on the electronic device (20) from the time of shipment for the basic functions of the electronic device (20) (e.g., call receiving and making functions, message receiving and making functions).

[0207] In addition to operations related to the application program, the control unit (27) typically controls the overall operation of the electronic device (20). The control unit (27) can process signals, data, information, etc. input or output through the components discussed above.

[0208] In addition, the control unit (27) can control at least some of the components by driving an application program stored in the memory (26) to provide appropriate information to the user or process a function. Furthermore, the control unit (27) can operate at least two or more of the components included in the electronic device (20) in combination with each other to drive the application program.

[0209] In addition, the control unit (27) can detect the movement of the electronic device (20) or the user by using a gyroscope sensor, gravity sensor, motion sensor, etc. included in the sensing unit (23). Alternatively, the control unit (27) can detect an object approaching the electronic device (20) or the user by using a proximity sensor, a light sensor, a magnetic sensor, an infrared sensor, an ultrasonic sensor, a light sensor, etc. included in the sensing unit (23). In addition, the control unit (27) can also detect the movement of the user by using sensors provided in a controller that operates in conjunction with the electronic device (20).

[0210] Additionally, the control unit (27) can perform operations (or functions) of the electronic device (20) using an application program stored in the memory (26).

[0211] The power supply unit (28) supplies power to each component included in the electronic device (20) by receiving external or internal power under the control of the control unit (27). The power supply unit (28) includes a battery, and the battery may be provided in a built-in or replaceable form.

[0212] At least some of the above components may cooperate with each other to implement the operation, control, or control method of the electronic device according to various embodiments described below. In addition, the operation, control, or control method of the electronic device may be implemented on the electronic device by driving at least one application program stored in the memory (26).

[0213] Fig. 22 is a perspective view of an augmented reality electronic device according to an embodiment.

[0214] As illustrated in FIG. 22, an electronic device according to an embodiment may include a frame (100), a projector device (200), and a display unit (300).

[0215] The electronic device may be provided as a glass type (smart glass). The glass type electronic device is configured to be worn on the head of the human body and may include a frame (case, housing, etc.) (100) for this purpose. The frame (100) may be formed of a flexible material to facilitate wearing.

[0216] The frame (100) is supported by the head and provides a space for mounting various components. As illustrated, electronic components such as a projector device (200), a user input unit (130), or an audio output unit (140) may be mounted on the frame (100). In addition, a lens covering at least one of the left and right eyes may be detachably mounted on the frame (100).

[0217] The frame (100) may have a shape of glasses worn on the face of the user's body as shown in the drawing, but is not necessarily limited thereto, and may also have a shape of goggles or the like worn in close contact with the user's face.

[0218] Such a frame (100) may include a front frame (110) having at least one opening, and a pair of side frames (120) extending in the y direction (in FIG. 2) intersecting the front frame (110) and being parallel to each other.

[0219] The frame (100) may have the same or different length (DI) in the x direction and length (LI) in the y direction.

[0220] The project device (200) is provided to control various electronic components provided in an electronic device. The project device (200) may be used interchangeably with 'optical output device', 'optical projector device', 'light irradiation device', 'optical device', etc.

[0221] The projector device (200) can generate an image or a video of a sequence of images that are displayed to the user. The projector device (200) can include an image source panel that generates an image and a plurality of lenses that diffuse and converge light generated from the image source panel.

[0222] The project device (200) may be fixed to one of the two side frames (120). For example, the project device (200) may be fixed to the inside or outside of one of the side frames (120), or may be integrally formed by being built into the inside of one of the side frames (120). Alternatively, the project device (200) may be fixed to the front frame (110) or may be provided separately from the electronic device.

[0223] The display unit (300) may be implemented in the form of a head-mounted display (HMD). The HMD form refers to a display method that is mounted on the head and directly displays an image in front of the user's eyes. When the user wears the electronic device, the display unit (300) may be positioned to correspond to at least one of the left and right eyes so that the image can be directly displayed in front of the user's eyes. In this drawing, the display unit (300) is positioned in a portion corresponding to the right eye so as to output an image toward the user's right eye. However, as described above, the present invention is not limited thereto and may be positioned for both the left and right eyes.

[0224] The display unit (300) can allow the user to visually perceive the external environment while simultaneously displaying images generated by the projector device (200). For example, the display unit (300) can project images onto the display area using a prism.

[0225] The display unit (300) may be formed to be translucent so that the projected image and the general field of view in front (the range that the user sees through his eyes) can be viewed simultaneously. For example, the display unit (300) may be translucent and formed of an optical member including glass.

[0226] And the display unit (300) can be inserted into and fixed to an opening included in the front frame (110), or can be positioned on the back surface of the opening, that is, between the opening and the user, and fixed to the front frame (110). In the drawing, an example in which the display unit (300) is positioned on the back surface of the opening and fixed to the front frame (110) is shown, but the display unit (300) can be positioned and fixed to various positions of the frame (100).

[0227] As illustrated in FIG. 22, when the electronic device projects image light from the projector device (200) onto one side of the display unit (300), the image light is emitted to the other side through the display unit (300), thereby allowing the user to see the image generated from the projector device (200).

[0228] Accordingly, the user can view the external environment through the opening of the frame (100) and simultaneously view the image generated by the projector device (200). That is, the image output through the display unit (300) can be seen to overlap with the general field of view. By utilizing these display characteristics, electronic devices can provide augmented reality (AR) that superimposes a virtual image on a real image or background and shows it as a single image.

[0229] Furthermore, in addition to these operations, images generated from the external environment and the projector device (200) may be provided to the user with a time difference for a short period of time that is not recognized by the user. For example, within a single frame, the external environment may be provided to the user during one section, and images from the projector device (200) may be provided to the user during another section.

[0230] Alternatively, both overlap and time difference may be provided.

[0231] Additionally, the projector device according to the embodiment may have a structure described below, or may be formed of a structure further including a waveguide or / and glass in the structure. Additionally, the projector device may include a DLP (Digital Light Processing) projector or a projector device.

[0232] Fig. 23 is a conceptual diagram of an optical element according to an embodiment.

[0233] Referring to FIG. 23, an optical element (3000) according to an embodiment may include a substrate (3100), a diffractive element (3200), and a metal thin film (3300).

[0234] The optical element (3000) may include a substrate (3100). The substrate (3100) may transmit an optical signal that has passed through the diffractive element (3200). The optical signal may be reflected and travel along the inner surface of the substrate (3100) after being incident on the substrate (3100). The substrate (3100) may include a waveguide.

[0235] The optical element (3000) may include a diffractive element (3200). The diffractive element (3200) may diffract incident light to change the path of the incident light. The diffractive element (3200) may include a plurality of unit structures (3210). The diffractive element (3200) may have a structure in which a plurality of unit structures (3210) having a constant height, constant period, and constant width are repeatedly arranged. When an optical signal is incident on the diffractive element (3200), diffraction may occur, thereby changing the path of the optical signal. The period of the unit structure of the diffractive element (3200) may be smaller than the wavelength of visible light (350 nm to 700 nm). When an optical signal is incident on the diffractive element (3200), diffraction may not occur, and there may be a component of the optical signal that is transmitted. The transmittance of an optical signal passing through a diffractive element (3200) may vary depending on the polarization component and wavelength of the optical signal. The diffractive element (3200) may be placed on a substrate (3100). The diffractive element (3200) may be placed in contact with a metal thin film (3310). The diffractive element (3200) may include a resin.

[0236] The diffractive element (3200) may include a plurality of unit structures (3210). The unit structures (3210) may be protruding portions of the diffractive element (3200). The unit structures (3210) may be protrusions protruding from one surface of the diffractive element (3200). The plurality of unit structures (3210) may be arranged with a constant period, constant height, and constant width. The plurality of unit structures (3210) may be arranged in a first region (A1) of the diffractive element (3200). The plurality of unit structures (3210) may be arranged to be spaced apart from each other in a first direction. The plurality of unit structures (3210) may protrude in a second direction perpendicular to the first direction. The height of the plurality of unit structures (3210) in the second direction may be 30 nm to 500 nm. The period of the plurality of unit structures (3210) may be 300 nm to 600 nm. The fill factor of the plurality of unit structures (3210) may be 20% to 80%.

[0237] The diffractive element (3200) may include a plurality of recesses (R) between a plurality of unit structures (3210). The recesses (R) may be portions arranged between the unit structures (3210) of the diffractive element (3200). The plurality of recesses (R) may be arranged with a constant period, constant height, and constant width. The plurality of recesses (R) may be arranged in a second region (A2) of the diffractive element (3200). The plurality of recesses (R) may be arranged to be spaced apart from each other in a first direction. The plurality of recesses (R) may be sunken in a second direction.

[0238] The diffractive element (3200) may include a first region (A1) in which a plurality of unit structures (3210) are positioned, and a second region (A2) positioned between the first region (A1). The first region (A1) may be a portion where the plurality of unit structures (3210) of the diffractive element (3200) are positioned. The first region (A1) may be positioned with a constant period, a constant height, and a constant width. The first region (A1) may include a first upper surface (a1) and a first lower surface (b1). The second region (A2) may be a portion overlapping with a recess (R) of the diffractive element (3200). The second region (A2) may be positioned with a constant period, a constant height, and a constant width.

[0239] The optical element (3000) may include a metal thin film (3300). The metal thin film (3300) may improve the coupling performance of the diffractive element (3200). The metal thin film (3300) may be disposed inside the diffractive element (3200). The metal thin film (3300) may be disposed adjacent to the upper surface of the diffractive element (3200). The metal thin film (3300) may be disposed in a plurality of unit structures (3210) of the diffractive element (3200). The metal thin film (3300) may be disposed in the first region (A1) and the second region (A2) of the diffractive element (3200). The metal thin film (3300) may be disposed adjacent to the first upper surface (a1) of the first region (A1). The metal thin film (3300) may be disposed adjacent to the second upper surface (a2) of the second region (A2). The metal thin film (3300) may be disposed at a predetermined distance in the second direction from the first upper surface (a1) or the second upper surface (a2). The metal thin film (3300) may be disposed adjacent to the upper surfaces of the plurality of unit structures (3210) and the lower surfaces of the plurality of recesses (R). The distance between the metal thin film (3300) and the upper surfaces of the plurality of unit structures (3210) may be smaller than the distance between the metal thin film (3300) and the lower surfaces of the plurality of unit structures (3210). The thickness of the metal thin film (3300) in the second direction may be 5 nm to 50 nm.

[0240] Fig. 24 is an enlarged view of an optical element according to an embodiment.

[0241] Referring to FIG. 24, the metal thin film (3300) of the optical element (3000) according to the embodiment may include a plurality of units (3310).

[0242] The metal thin film (3300) may include a plurality of units (3310). The plurality of units (3310) may constitute the metal thin film (3300). The plurality of units (3310) may be arranged to be spaced apart from each other in a first direction. The plurality of units (3310) may be arranged so that all surfaces are in contact with the diffractive elements (3200). The diffractive elements (3200) may be arranged to surround all surfaces of the plurality of units (3310). Each of the plurality of units (3310) may include a top surface (S) and a curved surface (C). The top surface (S) of the plurality of units (3310) may be a surface adjacent to the top surface of the diffractive element (3200). The curved surface (C) of the plurality of units (3310) may be arranged with the top surface (S) and may be a surface facing the diffractive element (3200). The upper surfaces (S) of the plurality of units (3310) may be arranged at a certain distance from the outer surfaces of the diffraction elements (3200). The diffraction elements (3200) may be arranged to surround all surfaces of the plurality of units (3310), so that the metal thin film (3300) may not be exposed to the outside. Since the metal thin film (3300) is not exposed to the outside, the metal thin film (3300) may be prevented from coming into contact with the air and being naturally oxidized.

[0243] Figure 25 is a flowchart of a method for manufacturing an optical element according to an embodiment.

[0244] Referring to FIG. 25, a method for manufacturing an optical element according to an embodiment (S1000) may include a step of depositing a metal thin film on a stamp (S1100), a step of applying a resin on a substrate (S1200), a step of pressing the stamp onto the resin to form a diffractive element (S1300), and a step of hardening the diffractive element (S1400).

[0245] Figures 26 to 30 are drawings showing a method for manufacturing an optical element according to an embodiment.

[0246] Referring to FIG. 26, a method for manufacturing an optical element according to an embodiment may include a step of manufacturing a stamp (20) using a master (10) having a defined diffraction pattern. The master (10) may have a defined pattern of a diffraction element of an optical element to be manufactured. A stamp (20) may be manufactured using the master (10). The stamp (20) may include a polymer compound replicated from the master (10). The polymer compound may include polydimethylsiloxane (PDMS), perfluoropolyether (PFPE), and polyurethane acrylate (PUA). The stamp (20) may include a support (21). The support (21) may support the polymer compound. The support (21) may include polyethylene terephthalate (PET).

[0247] Referring to FIG. 27, a method for manufacturing an optical element according to an embodiment may include a step of depositing a metal thin film (3300) on a stamp (20). The metal thin film (3300) may be deposited on the lower surface of the stamp. The metal thin film (3300) may be deposited using a physical vapor deposition (PVD) method. The thickness of the metal thin film (3300) may be 5 nm to 50 nm. The thickness of the metal thin film (3300) may be lower than the height of the diffraction element. The metal thin film (3300) may include a plurality of units forming a spaced apart space from each other. The step of depositing the metal thin film (3300) on the stamp (20) may be performed under a vacuum of 5*10 - 6torr or less, the deposition rate can be performed at 1 to 3 Å / s. When depositing a metal thin film (3300) on a stamp (20), a thermal evaporator can be used. When using a thermal evaporator, a low density between metal units can be formed during deposition of the metal thin film (3300). When depositing a metal thin film (3300) on a stamp (20), an e-beam evaporator can be used. When using an e-beam evaporator, the deposition can be performed at a deposition rate of 3 Å / s or more.

[0248] Referring to FIG. 28, a method for manufacturing an optical element according to an embodiment may include a step of applying a resin (3200) on a substrate (3100). The substrate (3100) may include a waveguide. The resin (3200) may include a resin for nanoimprinting.

[0249] Referring to FIG. 29, a method for manufacturing an optical element according to an embodiment may include a step of pressing a stamp (20) onto a resin (3200) to form a diffraction element (3200). The stamp (20) may be placed on a substrate (3100) to which a resin (3200) is applied. The resin (3200) pressed by the stamp (20) may be replicated as a diffraction pattern of the stamp (20) due to a capillary phenomenon. In this case, the process may be performed in a nitrogen (N2) or argon (Ar) gas atmosphere to prevent oxidation of the metal thin film (3300). The step of pressing the stamp (20) onto the resin (3200) to form a diffraction element (3200) may include a step of protruding the resin (3200) so as to contact the metal thin film (3300). The metal film (3300) may include a plurality of units that form a spaced apart space between each other, and the resin (3200) may protrude to fill the spaced apart space between the plurality of units. In addition, the diffraction element (3200) may be formed so that the resin (3200) comes into contact with all outer surfaces of the metal film (3300). The resin (3200) may cover the entire surface of the metal film (3300). By preventing the metal film (3300) from being exposed to the outside, the metal film (3300) may be prevented from being naturally oxidized by contact with the air. According to the step of forming the diffraction element (3200) by pressing the stamp (20) onto the resin (3200), a separate step of manufacturing a metal oxidation prevention film is not required, and the diffraction element may be prevented from being deformed due to high temperatures, etc.

[0250] In addition, the method for manufacturing an optical element according to the embodiment may include a step of curing the diffractive element (3200). The diffractive element (3200) may be cured using ultraviolet light or heat. When the diffractive element (3200) is cured using ultraviolet light, the wavelength of the ultraviolet light is 365 nm and the energy density is 1 to 30 J / cm. 2It can be. When hardening the diffraction element (3200) using heat, it is performed at a temperature higher than the glass transition temperature, and can be performed at a temperature of 40°C to 300°C. When hardening the diffraction element (3200), the pressure can be performed at 0.1 MPa to 15 MPa.

[0251] Figure 30 shows an optical element manufactured including a metal thin film (3300).

[0252] Figures 31 to 33 are graphs showing the diffraction efficiency of optical elements.

[0253] Fig. 31 shows the diffraction efficiency of an optical element when a metal thin film is not deposited, Fig. 32 shows the diffraction efficiency of an optical element when a metal thin film is deposited and then naturally oxidized, and Fig. 33 shows the diffraction efficiency of an optical element when a metal thin film is deposited according to an embodiment. The graphs of Figs. 31 to 33 show the diffraction efficiency according to the ratio of the first diffraction of an optical signal incident on an optical element. The x-axis and the y-axis of the graphs of Figs. 31 to 33 may be axes indicating a diffracted surface after the optical signal passes through the diffractive element. The graph of Fig. 31 may be a graph showing the diffraction efficiency when the filling factors of the diffractive element are 30%, 55%, and 80%, respectively, from the left. The graphs of Figs. 32 and 33 may be graphs showing the diffraction efficiency when the thicknesses of the metal thin films are 20 nm, 30 nm, and 40 nm, respectively, from the left. Referring to FIGS. 31 to 33, when a metal thin film is deposited according to an embodiment, the diffraction efficiency of an optical element can be increased.

[0254] Figure 34 is an enlarged image of a metal film deposited on a stamp.

[0255] Referring to Fig. 34, in a method for manufacturing an optical element, a metal thin film may be deposited on a stamp. The bright area may be a metal thin film deposited on a protruding portion of the stamp, and the dark area may be a metal thin film deposited on a non-protruding portion of the stamp.

[0256] A vehicle system (or environment) according to an embodiment may include a vehicle, a passenger (driver), and an electronic device. While the electronic device is described below as a device separately installed within the vehicle (1), the present invention is not limited thereto. For example, the electronic device may be implemented as a component of the vehicle.

[0257] A vehicle may include a body and various devices for moving the body (e.g., wheels, a drive unit for driving the wheels, a starter for starting the drive unit, an engine for generating power and transmitting the generated power to the drive unit, a steering unit for controlling the direction of the vehicle, an accelerator for controlling the speed of the vehicle, etc.). In addition, the vehicle may include various electrical systems. For example, the electrical system may include an engine control unit for controlling the engine, a temperature control unit for controlling the temperature inside the vehicle, a light control unit for controlling the lights according to external conditions, etc.

[0258] In particular, the vehicle may include a communication interface capable of communicating with an electronic device, and may include an additional processor for analyzing data transmitted through the communication interface and performing preset functions based on the analysis results.

[0259] The processor may be implemented, for example, as the aforementioned engine control unit or motor control unit. The communication interface may support at least one of various communication methods, such as CAN communication, which supports data transmission and reception within the vehicle, or wired communication via a cable connected to an electronic device. As an example, the vehicle may receive images acquired by an electronic device or analysis results of the images, and perform a designated function based on the received results.

[0260] According to an embodiment, an electronic device may be connected to a camera module to acquire an image of a driver, analyze the acquired image, and then perform various set function processing (e.g., deceleration processing, turning on or off emergency lights, controlling a horn, controlling vehicle vibration, controlling window opening and closing, etc.) based on the analysis results. In addition to this function processing, various other function processing may be additionally implemented.

[0261] And the driver, as a person who can sit in the driver's seat and control the steering device, can be the subject of video capture by an electronic device. In the present invention, the electronic device acquires an image of a driver seated in the driver's seat as a representative example, but the present invention is not limited thereto. For example, the monitoring system can be applied to acquire images of not only the driver but also passengers seated in the passenger seat or other seats, and to adjust the image acquisition method according to various behaviors of the passengers. In this regard, at least one electronic device can be arranged in the vehicle. For example, a camera module and an electronic device can be arranged to acquire an image of a driver seated in the driver's seat that only supports driver monitoring.

[0262] Alternatively, if monitoring capabilities for the driver and passengers are supported, multiple electronic devices may be placed within the vehicle to enable image acquisition of the driver and passenger seats.

[0263] An electronic device can receive image information about the driver's face via a camera module. Accordingly, the electronic device can determine the driver's drowsiness, etc., in a predetermined manner and provide various feedback (e.g., an alarm) in response. For example, the electronic device can determine the driver's drowsiness based on the user's eye track, iris size, or size changes. Furthermore, the electronic device can receive image information about the driver's hands as well as the user's face from the camera module. Therefore, the electronic device can easily determine the driver's hands-off status. In other words, a driver monitoring system with a hands-off monitoring function can be implemented. This allows the driver's concentration and drowsiness to be easily determined based on various driver movements resulting from the driver's hands-off.

[0264] The camera module can be positioned within the vehicle to easily capture images of occupants. For example, it can be positioned in various locations within the vehicle, such as the windshield (e.g., where the head-up display is positioned), the underside of the windshield, the dashboard, or the instrument panel, to capture images of a subject seated in the driver's seat. Furthermore, the camera module can be positioned in locations that are difficult for occupants to easily perceive.

[0265] Additionally, a camera module connected to an electronic device can be positioned at a specific location within the vehicle to receive image information about passengers other than the driver. For example, there may be at least one camera module, and the camera module may be positioned in a rearview mirror (or rearview mirror) or similar location to detect all passengers other than the driver. This allows the camera module to generate an image of all passengers.

[0266] This allows the camera module to generate image information about other occupants in the vehicle, not just the driver. Furthermore, the electronic device can receive image information including occupants other than the driver. This configuration facilitates the implementation of a monitoring system for not only the driver but also other occupants.

[0267] A camera module according to an embodiment may include a light source unit, a light guide device, a light receiving unit, and a control unit.

[0268] First, the light source can output light according to a control signal. Finally, the light output from the light source can be irradiated onto an object. Then, the light irradiated onto the object can be reflected and provided to the light receiving unit.

[0269] The light source unit may include at least one light source. The at least one light source may emit light of a predetermined wavelength range or light having a predetermined central wavelength. Furthermore, the light source unit may emit light in a predetermined pattern based on a pre-designed algorithm. The light source unit may output light under the control of the control unit.

[0270] Hereinafter, output light or incident light refers to light output from a light source and provided to an object, and input light or reflected light refers to light output from a light source, reaches an object, is reflected from the object, and is input to a light receiving unit. That is, from the object's perspective, output light can be incident light, and input light can be reflected light.

[0271] At least one light source of the light source unit can output light of a predetermined wavelength band. For example, the wavelength of the light output from the light source may be infrared light of 770 nm to 3000 nm. Additionally, the wavelength of the light output from the light source may be visible light of 380 nm to 770 nm. Furthermore, the light source of the light source unit may emit light outside the wavelength range described above. In particular, the light source may irradiate light of a specific wavelength band so as not to be harmful to passengers such as the driver and other passengers in the vehicle, as described above, or irradiate light of a specific energy or lower so as not to be harmful.

[0272] The light source may include a light emitting diode (LED), an organic light emitting diode (OLED), a laser diode (LD), a vertical-cavity surface-emitting laser (VCSEL), a plasma lamp, a fluorescent lamp, a xenon lamp, a halogen lamp, a neon lamp, etc. It may output a wavelength of about 800 nm to 1000 nm, for example, a wavelength of about 850 nm or about 940 nm.

[0273] The light guide device can be positioned adjacent to the light source and the light receiver. The light guide device can guide light emitted from the light source and transmit it to an object. In addition, the light guide device can guide light reflected from the object back to the light receiver. In this way, the light guide device can be configured to control the light and direct it along a desired path. In other words, the light guide device can both transmit light to the object and receive reflected light. Accordingly, the light guide device can be configured to help the light in the camera module accurately reach the sensor or guide it along a specific path so that optical information can be accurately transmitted.

[0274] Such light guide devices may be made of materials such as glass, polymer, or silicone. The light guide devices may also include various other light-guiding materials.

[0275] The light guide device can transmit light in a desired direction using diffraction. Accordingly, the light guide device may include optical elements for determining the path of light on a substrate, which is a waveguide. The optical elements may include various elements that operate based on diffraction.

[0276] As an example, the light guide device may include a diffractive element, which is a holographic optical element (HOE). The light guide device may include an input diffractive element, an input / output diffractive element, and an output diffractive element, as described below. For example, the input diffractive element, the input / output diffractive element, and the output diffractive element may be formed of a holographic optical element.

[0277] Holographic optical elements use interference patterns generated by laser interference to diffract light (or light), allowing them to control light of a specific wavelength or diffract it in a desired direction. This diffraction process is governed by Bragg's Law, and the diffraction angle can be determined based on the wavelength of the light and the structure of the holographic optical element.

[0278] A holographic optical element can be composed of an interference pattern recorded on a transparent substrate. As described above, the transparent substrate is a waveguide and can be made of various materials, such as glass, plastic, or polymer. The interference pattern of the holographic optical element can be precisely designed within or on the substrate to guide light in a specific direction. Furthermore, holographic optical elements can be categorized into transmissive, which diffracts light as it passes, and reflective, which diffracts light as it reflects. Therefore, the holographic optical element can be positioned variably on the substrate. These holographic optical elements enable precise control of light, resulting in high-resolution images. Furthermore, holographic optical elements can support high-speed data transmission in optical communications through wavelength separation and combination. Furthermore, holographic optical elements are lighter and thinner than conventional lenses or mirrors, enabling the provision of miniaturized camera modules. A detailed description of the diffractive elements in the light guide device—the input diffractive element, the input / output diffractive element, and the output diffractive element—will be provided below.

[0279] The light receiving unit can receive light transmitted through the light guide device. The light receiving unit can include an image sensor. The image sensor can receive light reflected from an object. Accordingly, the image sensor can detect the light and convert it into an electrical signal. For example, the image sensor can convert the electrical signal to generate a digital image. The image sensor can include a charge-coupled device (CCD), a complementary metal-oxide-semiconductor (CMOS), an indium gallium arsenide (InGaAs) sensor, a mercury cadmium telluride (HgCdTe) sensor, a microbolometer, etc. The light receiving unit may also include an image sensor that receives light of various wavelength bands other than those described above or as examples.

[0280] The light receiver may be positioned adjacent to the light guide device, similar to the light source. Alternatively, an additional lens may be positioned between the light receiver and the light guide device. This can also be applied to the area between the light source and the light guide device.

[0281] The control unit can control the operation of the light source and light receiver. Furthermore, the control unit can generate depth information based on the image generated by the light receiver, or transmit and receive image information with other electronic devices, such as vehicles. This control unit can control the operation within the camera module and communicate with processors within external electronic devices, such as vehicles.

[0282] The control unit may include a processor, a microcontroller (MCU), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc., and may also be implemented in the form of an application processor (AP) of various electronic devices.

[0283] Figure 35 is a drawing showing the configuration of a camera module according to an embodiment of the present invention.

[0284] Figure 35a shows a state in which light incident from the outside enters the light receiving unit (500) through the light guide device (400), and Figure 35b shows a state in which light irradiated from the light source unit (600) is emitted to the outside through the light guide device (400).

[0285] Referring to FIG. 35, the light guide device (400) may include a cover (401), a first substrate (410), a first input diffraction element (420), a first transmission diffraction element (430), a first input / output diffraction element (440), and a first output diffraction element (450).

[0286] The first input diffractive element (420), the first transmission diffractive element (430), the first input / output diffractive element (440), and the first output diffractive element (450) may be arranged on a first substrate (410) which is a waveguide. The first input diffractive element (420), the first transmission diffractive element (430), the first input / output diffractive element (440), and the first output diffractive element (450) may be either a transmissive type or a reflective type, and may be positioned on either one surface (e.g., an upper surface) or the other surface (e.g., a lower surface) of the first substrate (410).

[0287] And the first input diffraction element (420), the first transmission diffraction element (430), the first input / output diffraction element (440), and the first output diffraction element (450) are diffraction elements as described above, and can be spaced apart from each other.

[0288] The first input diffraction element (420) diffracts light provided from the light source unit (600) and guides it to the first substrate (410), and the light guided into the first substrate (410) can be provided to the first input / output diffraction element (440) through the first transmission diffraction element (430). The first input / output diffraction element (440) diffracts light guided from the first input diffraction element (420) to the first substrate (410) onto an object, and diffracts light reflected from the object and guides it into the substrate (410). The first output diffraction element (450) diffracts light reflected from the object and guided to the substrate (410) by the first input / output diffraction element (440) and guides or provides it to the light receiving unit (500). At this time, the light diffracted by the first emitting diffraction element (450) and guided to the light receiving unit (500) may be incident on the light receiving unit (500) and converted into image information. In the case of a light guide device according to another embodiment, the first transmission diffraction element (430) may not be included.

[0289] The light guide devices of FIGS. 1 to 20 can be applied to the light guide device (400) of FIG. 35a. In this case, the first input diffraction element (1200) of FIG. 1 corresponds to the first input / output diffraction element (440) of FIG. 35a, the first transmission diffraction element (1300) of FIG. 1 corresponds to the first transmission diffraction element (430) of FIG. 35a, and the first output diffraction element (1400) of FIG. 1 corresponds to the first output diffraction element (350) of FIG. 35a. In conclusion, the light guide device of the camera module according to the embodiment can include the light guide devices of FIGS. 1 to 20 not only when light irradiated from the light source unit (600) is emitted to the outside through the light guide device (400), but also when light incident from the outside is incident to the light receiving unit (500) through the light guide device (400). Accordingly, a light guide device and camera module can be provided that more easily generate images of passengers, etc., within a vehicle.

[0290] In addition, the optical elements of FIGS. 23 to 34 can be applied to the light guide device (400) of FIG. 35a. In this case, the substrate (3100) of FIG. 23 may correspond to the first substrate (410) of FIG. 35a, and the diffractive element (3200) of FIG. 23 may correspond to the first input / output diffractive element (440) of FIG. 35a. Ultimately, the light guide device of the camera module according to the embodiment may include the optical elements of FIGS. 23 to 34 not only when light irradiated from the light source unit (600) is emitted to the outside through the light guide device (400), but also when light incident from the outside is incident to the light receiving unit (500) through the light guide device (400). Accordingly, a light guide device and a camera module that can more easily generate images for passengers, etc. in a vehicle, etc. can be provided.

[0291] Although the above description focuses on examples, these are merely examples and do not limit the present invention. Those skilled in the art will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be construed as being included within the scope of the present invention defined in the appended claims.

Claims

1. First substrate; and A first input diffraction element arranged on the first substrate and onto which light is sequentially incident, including a first transmission diffraction element and a first emission diffraction element, The first transmission diffraction element includes a first region adjacent to the first emission diffraction element and a second region in contact with the first region and spaced apart from the first emission diffraction element, The first region of the first transmission diffraction element includes a first protrusion protruding in a first direction, and the second region includes a second protrusion protruding in the first direction. A light guide device in which the width of the first protrusion of the first region of the first transmission diffraction element is different from the width of the second protrusion of the second region of the first transmission diffraction element.

2. In paragraph 1, The second region of the first transmission diffraction element includes six surfaces, A light guide device in which the number of surfaces of the first region of the first transmission diffraction element is greater than the number of surfaces of the second region.

3. In paragraph 1, A light guide device in which the first region of the first transmission diffraction element is arranged to surround a first side adjacent to the first input diffraction element of the second region of the first transmission diffraction element and a second side adjacent to the first side.

4. In paragraph 1, A light guide device in which the shortest distance between the first input diffractive element and the first region of the first transmission diffractive element is shorter than the shortest distance between the first input diffractive element and the second region of the first transmission diffractive element.

5. In paragraph 3, The second region of the first transmission diffraction element includes a third side surface spaced apart from the first side surface and adjacent to the second side surface, An optical guide device wherein the width of the third side is greater than the width of the first side.

6. In paragraph 5, A light guide device in which the width of the second side of the second region of the first transmission diffraction element is greater than the widths of the first side and the third side.

7. In paragraph 3, A light guide device in which the width of the first protrusion of the first region of the first transmission diffraction element is narrower than the width of the second protrusion of the second region of the first transmission diffraction element.

8. In paragraph 7, Including a second substrate, The second transmission diffraction element disposed on the second substrate includes a third region and a fourth region, The third region of the second transmission diffraction element includes a third protrusion protruding in the first direction, and the fourth region includes a fourth protrusion protruding in the first direction. A light guide device in which the width of the third protrusion of the third region of the second transmission diffraction element is different from the width of the fourth protrusion of the fourth region of the second transmission diffraction element.

9. In paragraph 8, A light guide device in which the width of the third protrusion of the third region of the second transmission diffraction element is wider than the width of the fourth protrusion of the fourth region of the second transmission diffraction element.

10. In paragraph 8, A light guide device in which the period of the first region of the first transmission diffraction element disposed on the first substrate is shorter than the period of the third region of the second transmission diffraction element disposed on the second substrate.

Images