Light guide device and electronic device comprising same

Abstract

An embodiment discloses a light guide device comprising: a first substrate; a first diffractive element unit disposed on the first substrate; a second substrate spaced apart from the first substrate; a second diffraction element unit disposed on the second substrate; a first reference marker disposed on the first substrate; and a second reference marker disposed on the second substrate, wherein the first reference marker and the second reference marker do not overlap at least partially in a stacking direction.

Description

Light guide device and electronic device including the same

[0001] The present invention relates to a light guide device and an electronic device including 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] The embodiment provides a light guide device and an electronic device including the same, which enable more precise assembly by forming a reference marker on the light guide device when using the light guide device used for AR (Augmented Reality) and the like and an electronic device including the same.

[0008] Additionally, the embodiment can provide a light guide device and electronic device in which the reference marker is not visible to the user's eyes depending on the refractive index and transmittance of the reference marker, thereby suppressing interference with user perception.

[0009] In addition, the embodiment can provide a light guide device and electronic device that can accurately determine misalignment by applying conditions (period, height, width) of a reference marker according to a wavelength that can be recognized by vision, and having first and second reference markers spaced apart having the same or different shapes for each area.

[0010] 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 implementation form of the problem described below is also included.

[0011] An optical guide device according to an embodiment includes: a first substrate; a first diffractive element portion disposed on the first substrate; a second substrate spaced apart from the first substrate; a second diffractive element portion disposed on the second substrate; a first reference marker disposed on the first substrate; and a second reference marker disposed on the second substrate; wherein the first reference marker and the second reference marker do not overlap at least partially in a stacking direction.

[0012] Either the period of the first reference marker or the period of the second reference marker may be different from the period of either the first diffraction element portion or the second diffraction element portion.

[0013] Either the period of the first reference marker or the period of the second reference marker may be greater than the period of either the first diffraction element portion or the second diffraction element portion.

[0014] The wavelength band having the minimum transmittance in the first reference marker and the second reference marker may be different from the diffraction wavelength of the first diffraction element portion and the second diffraction element portion.

[0015] The first reference marker and the second reference marker may be located within the eye box.

[0016] The first reference marker and the first substrate may have a refractive index difference of 0 to 1.

[0017] The first reference marker and the first diffraction element may have the same material.

[0018] The second reference marker and the second diffraction element may have the same material.

[0019] The first reference marker, the second reference marker, the first diffraction element portion, and the second diffraction element portion may include at least one of polymer, TiO2, HfO2, Al2O3, and SiO2.

[0020] The wavelength band having the minimum transmittance in the first reference marker and the wavelength band having the minimum transmittance in the second reference marker may be the same.

[0021] The first reference marker and the second reference marker may have different periods.

[0022] The above lamination direction may be a direction from the second substrate toward the first substrate.

[0023] The first reference marker and the second reference marker may each include a first region and a second region having the same shape.

[0024] If the first region and the second region do not overlap at least partially in the stacking direction, the first diffractive element portion and the second diffractive element portion may be misaligned along a direction perpendicular to the stacking direction.

[0025] The first reference marker and the second reference marker may include a third region and a fourth region having different shapes.

[0026] If the third region and the fourth region overlap at least partially in the stacking direction, the first diffractive element portion and the second diffractive element portion may be misaligned at least partially in the stacking direction.

[0027] The first reference marker and the second reference marker may have a period of 700 nm to 900 nm.

[0028] The first reference marker and the second reference marker may have a refractive index of 1.7 to 2.7.

[0029] The first reference marker and the second reference marker may have a height of 100 nm to 600 nm in the stacking direction.

[0030] The above first diffractive element section may include a first input diffractive element, a first transmission diffractive element, and a first output diffractive element onto which light is sequentially incident.

[0031] The above second diffractive element section may include a second input diffractive element, a second transmission diffractive element, and a second output diffractive element onto which light is sequentially incident.

[0032] The embodiment implements a light guide device and an electronic device including the same, which enable more precise assembly by forming a reference marker on the light guide device when using the light guide device used for AR (Augmented Reality) and the like and an electronic device including the same.

[0033] In addition, the embodiment can implement a light guide device and electronic device in which the reference marker is not visible to the user's eyes depending on the refractive index and transmittance of the reference marker, thereby suppressing interference with user perception.

[0034] In addition, the embodiment can implement a light guide device and electronic device that can accurately determine misalignment by applying conditions (period, height, width) of a reference marker according to a wavelength that can be recognized by vision, and having first and second reference markers that are spaced apart have the same or different shapes for each area.

[0035] 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.

[0036] FIG. 1 is a block diagram showing the configuration of an extended reality electronic device according to an embodiment of the present invention.

[0037] Figure 2 is a perspective view of an augmented reality electronic device according to an embodiment of the present invention;

[0038] Figure 3 is a drawing of a project device and a light guide device according to an embodiment;

[0039] Figure 4 is an exploded drawing of a light guide device according to an embodiment;

[0040] Fig. 5 is a cross-sectional view illustrating a light guide device according to an embodiment;

[0041] Figure 6 is a plan view and a cross-sectional view of a reference marker in a light guide device according to an embodiment;

[0042] FIG. 7 is a drawing illustrating the positions of the first reference marker and the second reference marker in the light guide device according to the embodiment;

[0043] FIG. 8 is a drawing of a first reference marker in a light guide device according to an embodiment;

[0044] FIG. 9 is a drawing of a second reference marker in a light guide device according to an embodiment;

[0045] Fig. 10 is a graph of the transmittance by wavelength according to the conditions of the reference marker in the light guide device according to the embodiment.

[0046] Fig. 11 is a graph of the transmittance by wavelength according to the reference marker of one structure in the light guide device according to the embodiment.

[0047] Fig. 12 is a graph of the transmittance by wavelength according to reference markers of different structures in a light guide device according to an embodiment.

[0048] Fig. 13 is a drawing showing the arrangement position of a reference marker in a light guide device according to an embodiment;

[0049] FIG. 14 is a drawing illustrating another example and position of a first reference marker and a second reference marker in a light guide device according to an embodiment;

[0050] FIG. 15 is a drawing illustrating another example and position of a first reference marker and a second reference marker in a light guide device according to an embodiment;

[0051] FIG. 16 is a drawing illustrating another example and position of a first reference marker and a second reference marker in a light guide device according to an embodiment.

[0052] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] FIG. 1 is a block diagram showing the configuration of an extended reality electronic device according to an embodiment of the present invention.

[0062] Referring to FIG. 1, 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. 1 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.

[0063] 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.

[0064] The 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.

[0065] 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.

[0066] 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.

[0067] 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.).

[0068] Meanwhile, the electronic device (20) disclosed in this specification can utilize information sensed by at least two of these sensors in combination.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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).

[0076] Additionally, the control unit (27) can perform operations (or functions) of the electronic device (20) using an application program stored in the memory (26).

[0077] The power supply unit (28) receives external power or internal power under the control of the control unit (27) and supplies power to each component included in the electronic device (20). The power supply unit (28) includes a battery, and the battery may be provided in a built-in or replaceable form.

[0078] 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).

[0079] Hereinafter, an electronic device described as an example of the present invention will be described based on an embodiment applied to a wearable device (e.g., VR / AR / MR Glass). However, embodiments of the electronic device according to the present invention may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a slate PC, a tablet PC, an ultrabook, and a wearable device. In addition to a head-mounted display (HMD), the wearable device may include a smart watch, a contact lens, VR / AR / MR Glass, and the like.

[0080] FIG. 2 is a perspective view of an augmented reality electronic device according to an embodiment of the present invention.

[0081] As illustrated in FIG. 2, an electronic device according to an embodiment of the present invention may include a frame (100), a projector device (200), and a display unit (300).

[0082] 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.

[0083] 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).

[0084] 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.

[0085] 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.

[0086] The frame (100) may have the same or different length (DI) in the x direction and length (LI) in the y direction.

[0087] The projector device (200) is provided to control various electronic components provided in an electronic device. The projector device (200) may be used interchangeably with 'optical output device', 'optical projector device', 'light irradiation device', 'optical device', 'projector', etc.

[0088] 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.

[0089] 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.

[0090] The display unit (300) may be implemented in the form of VR / AR / MR Glasses or a Head Mounted Display (HMD). The HMD form refers to a display method that is mounted on the head and directly shows 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 provided in front of the user's eyes. In this drawing, the display unit (300) is positioned in a part corresponding to the right eye so as to output an image toward the user's right eye. However, as described above, the display unit (300) is not limited thereto and may be positioned for both the left and right eyes.

[0091] 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.

[0092] 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 or her eyes) can be viewed simultaneously. For example, the display unit (300) may be translucent and may be formed of an optical member including glass. For example, the display unit (300) may be a light guide device or may include a light guide device.

[0093] 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 side of the opening (e.g., between the opening and the user) and fixed to the front frame (110). In the drawing, the display unit (300) is positioned on the back side of the opening and fixed to the front frame (110) as an example, but the display unit (300) can be positioned and fixed to various positions of the frame (100).

[0094] As illustrated in FIG. 2, 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).

[0095] 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.

[0096] Furthermore, in addition to these operations, images generated by 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.

[0097] Alternatively, both overlap and time difference may be provided.

[0098] Additionally, the projector device according to the embodiment may have a structure described below, or may be configured with a structure further including a waveguide and / or glass. Additionally, the projector device may include a DLP (Digital Light Processing) projector or a projector device.

[0099] FIG. 3 is a drawing of a project device and a light guide device according to an embodiment, and FIG. 4 is an exploded drawing of a light guide device according to an embodiment.

[0100] Referring to FIGS. 3 and 4, in the present embodiment, the light guide device (300) may or may not include a projector device (200).

[0101] First, the project device (200) according to the embodiment may include a light source unit, a housing, a lens unit, a light modulator, and a projection lens unit.

[0102] The housing may have a space or housing groove in which each component of the project device (200) is accommodated or placed. The housing may be located at the outermost side of the project device (200).

[0103] Additionally, the housing may have an open structure on one side. Accordingly, each of the aforementioned components may be assembled through the open area or surface. The housing may have various shapes. For example, the housing may have a hexahedral structure. Accordingly, the project device according to the embodiment can be easily mounted on an electronic device. Furthermore, the project device according to the embodiment can be easily miniaturized or compacted.

[0104] The light source unit may be positioned within the housing. The light source unit may be positioned adjacent to any one of the outer surfaces of the housing.

[0105] The light source unit may include at least one light source. If there are multiple light sources, the light sources may emit light of different wavelength bands or colors.

[0106] The lens unit may be composed of at least one optical element (e.g., a lens). The lens unit may focus light. This configuration may reduce the loss of light emitted from the light source unit and facilitate a reduction in the volume of the projector device.

[0107] Additionally, the lens unit can align or change the path of the light beam, including a relay lens, etc. Additionally, the lens unit can adjust the size of the light or image (maximum area of ​​the light beam) provided by the illumination system, or compensate for optical differences.

[0108] And the lens unit may include an element that changes the optical path (e.g., a prism, etc.).

[0109] For example, the lens unit may include a total internal reflection prism (TIR prism). The prism can change the direction of light propagation as described above. That is, the prism can transmit and reflect light. This configuration allows for miniaturization of the projector device according to the embodiment.

[0110] An optical modulator may be placed at the rear end of the prism. The optical modulator can re-emit light transmitted through the prism. The optical modulator can project an image by reflecting the incident light. For example, the optical modulator can emit or project an image or image based on an incident image signal through a substrate or the like. In other words, the optical modulator can modulate the light emitted from the light source.

[0111] The optical modulator according to the embodiment may include a digital micromirror device (DMD). The optical modulator may include a plurality of small mirrors. The optical modulator may include various optical modulation devices, such as an Lcos.

[0112] The projection lens unit may be positioned at the rear end of the prism. When light emitted from the light modulator is reflected by the prism, the light reflected by the prism may be incident on the projection lens unit. The light described above may be projected from the projection lens unit. The projection lens unit may project the light emitted from the projector device onto a screen or waveguide (or display unit).

[0113] In an embodiment, the projection lens unit can adjust the size of the image so that light enters within the effective aperture diameter (entrance pupil diameter, EPD) of the waveguide or the like.

[0114] A project device according to an embodiment may include an illuminating system and a projecting system (or a projecting system, a projecting unit, a projection unit, a projection unit, etc.).

[0115] This lighting system includes a light source, a lens, and a prism as components, and can receive light from a light source (illumination light) and emit light in a predetermined direction. The illumination light can be transmitted to or provided to a light modulator of a projection system.

[0116] The projection system may include a prism, a light modulator, and a projection lens. The projection system may include the prism as a component. In an embodiment, the prism may be an element of both the illumination system and the projection system.

[0117] Furthermore, the projection system may further include the above-described illumination system. That is, the projection system may modulate illumination light generated in the illumination system through a light modulator and emit or diverge the light in a predetermined direction through a prism and a projection lens unit.

[0118] The light modulator reflects the illumination light into patterned light, and the patterned light can pass through the projection lens section and be output to the outside of the projector device.

[0119] Additionally, the output of the project device and the input of the waveguide or wavelength guide (waveguide) or light guide device can be positioned correspondingly.

[0120] And according to an embodiment, the light guide device (300) may include a projector device (200), a substrate, and a diffractive element (diffractive element region). Alternatively, the light guide device (300) may include a substrate and a diffractive element (diffractive element region). Furthermore, the light guide device (300) may include an optical member (330). The diffractive element (diffractive element region) may be formed of at least one of a transmissive type and a reflective type. For example, when the diffractive element is a transmissive type, the diffractive element region may be located on a surface of the substrate adjacent to the projector. And when the diffractive element is a reflective type, the diffractive element region may be located on a surface of the substrate that is disposed far from the projector. Furthermore, a plurality of diffractive element regions may exist on one substrate, and each region may be formed of either a reflective type or a transmissive type.

[0121] The light guide device (300) according to the embodiment may include a first substrate (311) and a first diffractive element portion (312, 313, 314). Furthermore, the light guide device (300) according to the embodiment may include a projector (hereinafter referred to as a projector) (200). As described above, the light guide device (300) may have a structure separate from the projector (200).

[0122] The light guide device (300) may include a first substrate (311), a first diffraction element region (312), a third diffraction element region (313), a second diffraction element region (314), a second substrate (321) and a second diffraction element portion (322, 323, 324).

[0123] The light guide device (300) according to the present embodiment may include the first substrate (311), the first diffraction element region (312), the third diffraction element region (313), the second diffraction element region (314), the second substrate (321), the fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324) described above. In addition, the second substrate (321), the second diffraction element portion (322, 323, 324), the first substrate (311), the first diffraction element portion (312, 313, 314), and the cover (or optical member, 330) may be sequentially stacked or arranged in the stacking direction. Furthermore, the light guide device (300) may further include a first reference marker (RM1) disposed on a first substrate (311) and a second reference marker (RM2) disposed on a second substrate (321).

[0124] And the first diffractive element portion according to the embodiment may include a plurality of diffractive element regions. The first diffractive element portion is disposed on the first substrate (311) and may have a nano-scale pattern. Accordingly, the first diffractive element portion may be referred to as a 'first pattern layer', a 'first pattern', etc. Hereinafter, the first diffractive element portion will be described interchangeably with the first pattern layer. The second diffractive element portion may be referred to as a 'second pattern layer', a 'second pattern', etc. And the diffractive element portion may be formed by various methods. For example, the diffractive element portion may be formed on the substrate by deposition.

[0125] And through this, the first diffraction element section can guide by diffracting light incident from the projector (200). For example, the first diffraction element section can include a first diffraction element region (312) and a second diffraction element region (314). Furthermore, the first diffraction element section can include a third diffraction element region (313) located between the first diffraction element region (312) and the second diffraction element region (314). The first diffraction element region (312) can correspond to an 'in-coupler'. The second diffraction element region (314) can correspond to an 'out-coupler'. The third diffraction element region (313) can correspond to a folding grating.

[0126] The light guide device (300) 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 diffraction element region (312), the third diffraction element region (313), and the second diffraction element region (314) and be output to the outside again. The direction in which the light is incident to the light guide device (300) can be the first direction. The first direction can mean the direction in which the light is incident or the opposite direction.

[0127] The first diffraction element region (312) is a first input diffraction element into which light is incident, the third diffraction element region (313) is a first transmission diffraction element through which light is transmitted along a desired path, and the second diffraction element region (314) is a first output diffraction element through which light is emitted.

[0128] And the fourth diffraction element region (322) is a second input diffraction element through which light is incident, the sixth diffraction element region (323) is a second transmission diffraction element through which light is transmitted along a desired path, and the fifth diffraction element region (324) is a second output diffraction element through which light is emitted.

[0129] In an embodiment, the first substrate (311) can guide the light emitted from the projector (200). The first substrate (311) can serve as a path for transmitting the light. The first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314) can be arranged on the first substrate (311). The light can be totally reflected within the first substrate (311) and travel along the interior of the first substrate (311). The first substrate (311) can be a waveguide.

[0130] And the first diffraction element region (312), the third diffraction element region (313), and the second diffraction element region (314) may be spaced apart from each other on the first substrate (311). The first substrate (311) may extend in a second direction perpendicular to the first direction in which light is incident. The refractive index of the first substrate (311) may be 1.4 to 2.0.

[0131] The first diffraction element region (312) can guide light to enter the first substrate (311). That is, the first diffraction element region (312) can serve as a light guide. Alternatively, the first diffraction element region (312) can receive light. That is, the first diffraction element region (312) can serve as a guide to enter the first substrate (311).

[0132] Additionally, the first diffractive element region (312) may be arranged on the first substrate (311). Light may be incident from the outside or the projector (200) through the first diffractive element region (312) onto the light guide device (300) and may be transmitted along the first substrate (311) to the second diffractive element region (314) and the third diffractive element region (313). In addition, the first diffractive element region (312) may change the path of the light by diffracting the light.

[0133] The third diffraction element region (313) can play a role in changing the path of light. The third diffraction element region (313) can be arranged on the first substrate (311). The third diffraction element region (313) can change the path of light incident through the first diffraction element region (312). The third diffraction element region (313) can change the path of light and guide the light toward the second diffraction element region (314). The third diffraction element region (313) can change the path of light by diffracting the light.

[0134] The second diffraction element region (314) can serve to guide light to be emitted to the outside (e.g., a user, etc.). The second diffraction element region (314) can be arranged on the first substrate (311). Light can be emitted to the outside of the light guide device (300) through the second diffraction element region (314). The second diffraction element region (314) can receive light whose path has been changed from the third diffraction element region (313) and emitted it to the outside. The second diffraction element region (314) can change the path of the light and emitted it to the outside. The second diffraction element region (314) can change the path of the light by diffracting the light. The second diffraction element region (314) can be arranged to be spaced apart from the first diffraction element region (312). And the second diffraction element region (314) can emit light.

[0135] The first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314) 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 diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314). The plurality of protrusions may protrude in a first direction (or in a stacking direction or a direction opposite to the stacking direction) on the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314). 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 after passing through the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314) may be changed differently. The width of a protrusion may refer to the width in the vector direction of the pattern including the protrusion of the protrusion. The period of a 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 a protrusion may refer to the height of a portion protruding in the first direction of the protrusion. These protrusions may be arranged to have a predetermined pattern. Even if the background appears to change the direction of the pattern in the drawing, in the same area (diffraction element area or reference marker), the patterns (or protrusions) are arranged in the same vector direction and may have the same diffraction vector. Furthermore, even in one area, various diffraction vector patterns may be present depending on the grid.

[0136] In an embodiment, the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314) may be formed of the same material or different materials. For example, the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314) may be formed of the same material. In addition, the refractive indices of the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314) may be 1.7 to 2.7.

[0137] Furthermore, the outline (boundary area) of the first diffraction element region (312) and the outline (boundary area) of the third diffraction element region (313) do not overlap each other. If they overlap, some of the light incident from the third diffraction element region (313) to the second diffraction element region (314) is blocked, so that the blocked area may not produce an image from the second diffraction element region (314). If the outline (boundary area) of the first diffraction element region (312) and the outline (boundary area) of the third diffraction element region (313) overlap each other, efficiency decreases, so it is preferable that the outline (boundary area) of the first diffraction element region (312) and the outline (boundary area) of the third diffraction element region (313) do not overlap each other.

[0138] The third diffraction element region (313) according to the embodiment may include a first region (313a) adjacent to the second diffraction element region (314) and a second region (1320) in contact with the first region (313a) and spaced apart from the second diffraction element region (314).

[0139] The first region (313a) and the second region (1320) may refer to a portion of the third diffraction element region (313). The first region (313a) and the second region (313b) may be two regions that are divided from each other when the third diffraction element region (313) is viewed in the stacking direction (or the first direction) in which the optical signal is incident. The first region (313a) may be a region adjacent to the second diffraction element region (314) of the third diffraction element region (313). The first region (313a) may be a region adjacent to the first diffraction element region (312) of the third diffraction element region (313). The second region (313b) may be a region spaced apart from the second diffraction element region (314) of the third diffraction element region (313). The second region (313b) may be a region spaced apart from the first diffraction element region (312) of the third diffraction element region (313). The distance between the first region (313a) and the second diffraction element region (314) may be smaller than the distance between the second region (313b) and the second diffraction element region (314). The shapes or areas of the first region (313a) and the second region (313b) may be different from each other. The first region (313a) and the second region (313b) may each include a plurality of surfaces. Some surfaces of the first region (313a) and some surfaces of the second region (313b) may be in contact with each other.

[0140] The first region (313a) includes a first pattern, and the first pattern includes a first protrusion protruding in a first direction. The second region (313b) may include a second pattern and a second protrusion protruding in the first direction. The first protrusion and the second protrusion may be portions protruding in the first direction from the first region (313a) and the second region (313b), respectively. The first direction may be a direction in which light from the projector is incident on the first diffractive element region (312). 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 (311).

[0141] The first protrusion and the second protrusion may be arranged repeatedly with a certain period, width, and height on the first region (313a) and the second region (313b). The plurality of first protrusions may be arranged perpendicular to the first direction and spaced apart from each other in the vector direction of the first region (313a) of the third diffractive element region (313). The plurality of second protrusions may be arranged perpendicular to the first direction and spaced apart from each other in the vector direction of the second region (313b) of the third diffractive element region (313).

[0142] In addition, the first diffraction element region (312), the second diffraction element region (314), and the third diffraction element region (313) may be connected to each other or spaced apart from each other. For example, at least some of the first diffraction element region (312), the second diffraction element region (314), and the third diffraction element region (313) may have a portion that is connected to each other between patterns. According to this configuration, the manufacturing of each of the first diffraction element region (312), the second diffraction element region (314), and the third diffraction element region (313) may be easy. In addition, at least some of the first diffraction element region (312), the second diffraction element region (314), and the third diffraction element region (313) may be formed spaced apart from each other. That is, the first diffraction element region (312), the second diffraction element region (314), and the third diffraction element region (313) may not have any interconnected portions. As a result, other light transmissions than diffraction due to the pattern can be suppressed, thereby improving accuracy and efficiency.

[0143] And the optical member (330) can be arranged on the first substrate (311), the first diffraction element region (312), the third diffraction element region (313), and the second diffraction element region (314). The optical member (330) can be arranged adjacent to the projector (200) on the first substrate (311), the first diffraction element region (312), the third diffraction element region (313), and the second diffraction element region (314). Light can pass through the optical member (330) and enter the first diffraction element region (312). The optical member (330) can have an effect of protecting the inside of the light guide device (300). The refractive index of the optical member (330) can be 1.4 to 1.55. The refractive index of the optical member (330) can be, for example, about 1.5. The optical member (330) may be called a ‘cover’, ‘cover glass’, etc.

[0144] Furthermore, in the light guide device according to each embodiment below, the stacking direction (first direction) is described as the illustrated 'S-axis direction'. In addition, the stacking direction (S-axis direction) may correspond to the direction from the first substrate (311) toward the cover (330) or the direction from the second substrate (321) toward the first substrate (311) or the cover (330).

[0145] The second substrate (321), the fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324) may be positioned on the lower or bottom surface of the first substrate (311). For example, the second substrate (321) may be positioned spaced apart from the lower surface of the first substrate (311).

[0146] The second substrate (321), the fourth diffractive element region (322), the sixth diffractive element region (323), and the fifth diffractive element region (324) may be arranged on the first substrate (311) and spaced apart from the projector (200). The second substrate (321), the fourth diffractive element region (322), the sixth diffractive element region (323), and the fifth diffractive element region (324) may overlap the first substrate (311) along the first direction in which light is incident. The fourth diffractive element region (322), the sixth diffractive element region (323), and the fifth diffractive element region (324) may be arranged between the first substrate (311) and the second substrate (321).

[0147] An optical member or cover (330) may be disposed on the first substrate (311), the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314). The optical member (330) may be disposed adjacent to the projector (200) on the first substrate (311), the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314). Light may pass through the optical member (330) and enter the first diffractive element region (312). The optical member (330) may have the effect of protecting the interior of the light guide device (300). The refractive index of the optical member (330) may be about 1.5.

[0148] And, as described above, the light guide device (300) can change the path of the light output from the light output unit and output the light to the outside again. In particular, the light can pass through the first diffraction element unit (PT1) and the first substrate (311) and be provided to the second substrate (321) and the second diffraction element unit (PT2) under the first substrate (311). Accordingly, the light can be sequentially incident on the fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324) and output to the outside again.

[0149] The second substrate (321) can serve as a path for transmitting light. A fourth diffraction element region (322), a sixth diffraction element region (323), and a fifth diffraction element region (324) can be arranged on the second substrate (321). The light can travel along the interior of the second substrate (321) by totally reflecting the interior of the second substrate (321). The second substrate (321) can include a waveguide. The fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324) can be arranged spaced apart from each other on the second substrate (321). The second substrate (321) can be arranged in a second direction perpendicular to the first direction in which light is incident. The refractive indices of the first substrate (311) and the second substrate (321) can be 1.4 to 2.0.

[0150] The fourth diffraction element region (322) can serve as a path through which light is incident. The fourth diffraction element region (322) can be arranged on the second substrate (321). Light can be incident through the fourth diffraction element region (322) and transmitted through the second substrate (321). The fourth diffraction element region (322) can change the path of light by diffracting the light.

[0151] The sixth diffraction element region (323) can play a role in changing the path of light. The sixth diffraction element region (323) can be arranged on the second substrate (321). The sixth diffraction element region (323) can change the path of light incident through the fourth diffraction element region (322). The sixth diffraction element region (323) can change the path of light so that it is directed toward the fifth diffraction element region (324). The sixth diffraction element region (323) can change the path of light by diffracting the light.

[0152] The fifth diffraction element region (324) can serve as a path through which light is emitted. The fifth diffraction element region (324) can be disposed on the second substrate (321). Light can be emitted to the outside of the light guide device (300) through the fifth diffraction element region (324). The fifth diffraction element region (324) can receive light whose path has been changed from the sixth diffraction element region (323) and emit the light to the outside. The fifth diffraction element region (324) can change the path of the light and emit it to the outside. The fifth diffraction element region (324) can change the path of the light by diffracting the light.

[0153] The fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324) may include a plurality of protrusions. The plurality of protrusions may have a constant width, period, and height and may be arranged on the fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324). The plurality of protrusions may protrude in a first direction on the fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324). The plurality of protrusions may be arranged to be spaced apart from each other in a vector direction of a pattern including the 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 fourth diffraction element region (322), the sixth diffraction element region (323), and the fifth diffraction element region (324). The width of the protrusion may refer to the width of the pattern including the protrusion of the protrusion in the vector direction. 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 indices of the first diffractive element region (312), the third diffractive element region (313), the second diffractive element region (314), the fourth diffractive element region (322), the sixth diffractive element region (323), and the fifth diffractive element region (324) may be 1.7 to 2.7. The refractive indices of the first diffractive element region (312), the third diffractive element region (313), the second diffractive element region (314), the fourth diffractive element region (322), the sixth diffractive element region (323), and the fifth diffractive element region (324) may be equal to or greater than the refractive indices of the first substrate (311) and the second substrate (321).

[0154] Furthermore, as described above, depending on whether the projector is a transmissive or reflective type, the diffractive element portion may be positioned on the upper or lower surface of the first substrate. For example, the first diffractive element region may be positioned on the lower surface (the surface not facing the projector, the first surface) of the first substrate (311). In addition, an optical member may be positioned between the projector (200) and the first substrate (311).

[0155] And the lamination between the first substrate and the upper component and the second substrate and the upper component can be performed by curing and an insulating member (or intermediate layer, blocking member), etc.

[0156] And the second substrate can guide the light transmitted from the first substrate. For example, the wavelength or wavelength band (e.g., center wavelength) of the light guided from the first substrate and the second substrate can be different.

[0157] In the light guide device (300), the first reference marker (RM1) and the second reference marker (M2) can be positioned on each substrate.

[0158] The first reference marker (RM1) may be placed on the first substrate (311). And the second reference marker (RM2) may be placed on the second substrate (321). A detailed description of these reference markers will be described later. The first reference marker (RM1)

[0159] Fig. 5 is a cross-sectional view illustrating a light guide device according to an embodiment, and Fig. 6 is a plan view and a cross-sectional view of a reference marker in the light guide device according to an embodiment.

[0160] Referring to FIGS. 5 and 6, the first reference marker (RM1) and the second reference marker (RM2) can be positioned to overlap at least partially in the horizontal direction with the diffractive element portion of each substrate.

[0161] The first reference marker (RM1) may overlap at least partially in the horizontal direction with the first diffractive element portion (PT1). And the second reference marker (RM2) may overlap at least partially in the horizontal direction with the second diffractive element portion (PT2).

[0162] The first reference marker (RM1) and the first diffractive element portion (PT1) may have the same material. In addition, the second reference marker (RM2) and the second diffractive element portion (PT2) may have the same material. For example, the first reference marker (RM1), the second reference marker (RM2), the first diffractive element portion (PT1), and the second diffractive element portion (PT2) may include at least one of a polymer, titanium dioxide (TiO2), hafnium dioxide (HfO2), aluminum trioxide (Al2O3), and silicon dioxide (SiO2).

[0163] By this configuration, the increase or decrease in cost due to the production of the first reference marker (RM1) and the second reference marker (RM2) can be minimized, and the ease of manufacturing can also be improved.

[0164] Additionally, the first reference marker (RM1) and the first diffractive element (PT1) may be made of different materials. Accordingly, the difference in refractive index between the first reference marker (RM1) and the first substrate (311) can be minimized. For example, the difference in refractive index between the first reference marker (RM1) and the first substrate (311) may be 0 to 1.

[0165] Likewise, the second reference marker (RM2) and the second diffractive element (PT2) may be made of different materials. Accordingly, the difference in refractive index between the second reference marker (RM2) and the second substrate (321) can be minimized. For example, the difference in refractive index between the second reference marker (RM2) and the second substrate (321) may be 0 to 1.

[0166] As a result, user or external user recognition of the first reference marker (RM1) and second reference marker (RM2) may be difficult. Therefore, inconveniences arising from user recognition, etc., can be prevented.

[0167] In addition, the first reference marker (RM1) and the second reference marker (RM2) may be diffractive elements, such as the diffractive elements of the diffractive element portion, such as the first diffractive element portion (PT1) and the second diffractive element portion (PT2). For example, the first reference marker (RM1) may include a plurality of protrusions. In addition, the second reference marker (RM2) may include a plurality of protrusions.

[0168] And the plurality of protrusions can form a pattern. That is, the first reference marker (RM1) and the second reference marker (RM2) can be formed with a structure having a pattern. And the first reference marker (RM1) and the second reference marker (RM2) can be a diffractive element or a diffractive element region. Along the vector direction of the pattern formed by the plurality of protrusions, the plurality of protrusions can be arranged to be spaced apart from each other. Depending on the width (W), period (P), and height (H) of the plurality of protrusions, the path of the light can be changed differently after passing through the first diffractive element region (312), the third diffractive element region (313), and the second diffractive element region (314). This can be equally applied to the second diffractive element portion.

[0169] As an example, the first reference marker (RM1) and the second reference marker (RM2) may have a period of 700 nm to 900 nm.

[0170] Additionally, the first reference marker (RM1) and the second reference marker (RM2) may have a fill factor (FF) of 0.2 to 0.7. The fill factor (FF) may be width (W) / period (P). Furthermore, the first reference marker (RM1) and the second reference marker (RM2) may have a height (H) of 100 nm to 600 nm. In addition, the first reference marker (RM1) and the second reference marker (RM2) may have a height (H) of 1.7 to 2.7.

[0171] In an embodiment, the transmittance of the first reference marker (RM1) and the second reference marker (RM2) in the visible light band may be higher than the transmittance of the first diffractive element portion and / or the second diffractive element portion in the visible light band. By this configuration, the first reference marker (RM1) and the second reference marker (RM2) may have high transmittance in the visible light band. Therefore, they may not be noticeable to the user, thereby preventing user recognition. However, the first reference marker (RM1) and the second reference marker (RM2) may have low transmittance at specific wavelengths (e.g., 850 nm, 940 nm). Therefore, the first reference marker (RM1) and the second reference marker (RM2) may be easily identified by machine vision. For example, since the first reference marker (RM1) and the second reference marker (RM2) have low transmittance at the corresponding wavelength, the area where the first reference marker (RM1) and the second reference marker (RM2) are located may appear dark in an image obtained through machine vision for inspection such as alignment. Furthermore, the area where the first reference marker (RM1) and the second reference marker (RM2) overlap in the stacking direction may appear darker. Through this, misalignment (rotation or movement) between the first substrate (311) and the second substrate (321) can be easily distinguished, or the alignment can be easily identified to perform assembly.

[0172] FIG. 7 is a drawing illustrating the positions of a first reference marker and a second reference marker in a light guide device according to an embodiment, FIG. 8 is a drawing of a first reference marker in a light guide device according to an embodiment, FIG. 9 is a drawing of a second reference marker in a light guide device according to an embodiment, and FIG. 10 is a graph of transmittance by wavelength according to conditions of reference markers in a light guide device according to an embodiment.

[0173] Referring to FIG. 7, according to an embodiment, the first reference marker (RM1) and the second reference marker (RM2) may not overlap at least partially in the stacking direction. In addition, the first reference marker (RM1) and the second reference marker (RM2) may have an area in which they overlap at least partially.

[0174] Specifically, the first reference marker (RM1) and the second reference marker (RM2) may include a first region (AR1) and a second region (AR2) of the same shape, respectively. For example, the first reference marker (RM1) may include a first region (AR1). And the second reference marker (RM2) may include a second region (AR2). And the first region (AR1) and the second region (AR2) may have the same shape. For example, when the first region (AR1) is a circle, the second region (AR2) may also be a circle. Furthermore, the first region (AR1) and the second region (AR2) may overlap in the stacking direction.

[0175] Accordingly, the first region (AR1) of the first reference marker (RM1) and the second region (AR2) of the second reference marker (RM2) may have regions (OV1) that overlap in the stacking direction on the first substrate (311) and the second substrate (321), respectively. At this time, the overlapping region (OV1) may appear very dark in an image through machine vision. The first reference marker (RM1) and the second reference marker (RM2) may overlap at least partially in the stacking direction. In particular, the first region (AR1) and the second region (AR2) may be in a state where the first substrate or the second substrate does not move in a direction perpendicular to the stacking direction. That is, it can be confirmed that the alignment state is such that one substrate (e.g., the first substrate) does not move in a direction perpendicular to the stacking direction. Hereinafter, the movement and rotation of the first reference marker (RM1) will be described as references. Furthermore, by easily determining whether the first reference marker (RM1) and the second reference marker (RM2) are moving, precise assembly can be enabled.

[0176] In contrast, the first reference marker (RM1) and the second reference marker (RM2) may not partially overlap in the stacking direction. If the first region (AR1) and the second region (AR2) do not overlap at least partially in the stacking direction, the first diffractive element portion and the second diffractive element portion may be misaligned along a direction perpendicular to the stacking direction. Accordingly, if the first region (AR1) and the second region (AR2) are misaligned at least partially along the stacking direction, the first substrate can be moved in a direction perpendicular to the stacking direction (horizontal direction) to prevent misalignment. Alternatively, if the first substrate and the second substrate are not aligned and one substrate is tilted, the substrates can be adjusted to be aligned with each other. Through this, precise assembly can be performed in an aligned state between the first substrate and the second substrate. Furthermore, misalignment can be easily prevented even when the first reference marker (RM1) of the first substrate to be assembled is not in focus, and alignment can be easily recognized even when the first substrate is not within the focal length of the camera. Accordingly, damage to each diffraction element can be prevented.

[0177] And the first reference marker (RM1) and the second reference marker (RM2) may include a third region (AR3) and a fourth region (AR4) of different shapes. For example, the first reference marker (RM1) may include a third region (AR3). The second reference marker (RM2) may include a fourth region (AR4). The third region (AR3) and the fourth region (AR4) may have different shapes. For example, on the same plane, the third region (AR3) and the fourth region (AR4) may not overlap each other. In other words, when aligned, the third region (AR3) and the fourth region (AR4) may not overlap in the stacking direction. Therefore, the third region (AR3) and the fourth region (AR4) may have different shapes.

[0178] In an embodiment, the third region (AR3) and the fourth region (AR4) may have an area (OV2) that overlaps at least partially in the stacking direction. In this case, the first diffractive element portion and the second diffractive element portion may be misaligned at least partially in the stacking direction. When the third region (AR3) and the fourth region (AR4) overlap at least partially along the stacking direction, misalignment can be prevented by moving the first substrate in a direction perpendicular to the stacking direction (horizontal direction) or rotating the first substrate about its axis in the stacking direction. Alternatively, when the first substrate and the second substrate are not aligned and one substrate is tilted, the substrates can be adjusted to be aligned with each other. Through this, precise assembly can be performed in an aligned state between the first substrate and the second substrate. In this way, the rotational error that occurs between the first substrate and the second substrate (or the first diffraction element portion and the second diffraction element portion) or the translational error that occurs between the first substrate and the second substrate (or the first diffraction element portion and the second diffraction element portion) in the horizontal direction can be easily recognized through the third region (AR3) and the fourth region (AR4).

[0179] Additionally, at least one of the first reference marker (RM1) and the second reference marker (RM2) may have a period different from that of either the first diffractive element portion or the second diffractive element portion. For example, at least one of the first reference marker (RM1) and the second reference marker (RM2) may have a period greater than that of either the first diffractive element portion or the second diffractive element portion.

[0180] For example, the periods of the first reference marker (RM1) and the second reference marker (RM2) may be different from the periods of the first diffractive element portion and the second diffractive element portion. The periods of the first reference marker (RM1) and the second reference marker (RM2) may be greater than the periods of the first diffractive element portion and the second diffractive element portion.

[0181] Furthermore, due to this periodic difference, the wavelength bands having minimum transmittance in the first reference marker (RM1) and the second reference marker (RM2) may differ from the diffraction wavelengths of the first and second diffractive element sections. In addition, the wavelength bands having minimum transmittance may not be within the visible light wavelength band.

[0182] By this configuration, since the reference marker and the diffractive element unit have different periods, the transmittance of light according to the wavelength of the reference marker and the diffractive element unit can be different from each other. In particular, since the wavelength bands having the minimum transmittance are different from each other, marker recognition and image recognition can be implemented in different wavelength bands. For example, light is diffracted and guided by the first diffractive element unit and the second diffractive element unit in the visible light region, and the first reference marker and the second reference marker have high transmittance in the visible light region, so that the user's recognition of the reference marker can be minimized. Furthermore, at the same time, the user can more accurately visually recognize the image provided from the projector. In addition, the degree of freedom in the arrangement of the plurality of combiners, that is, the first substrate (including the first diffractive element unit) and the second substrate (including the second diffractive element unit), can be improved. For example, the first reference marker and the second reference marker can be arranged inside or outside the eye-box.

[0183] Referring further to FIGS. 8 and 9, the first reference marker (RM1) and the second reference marker (RM2) may differ from each other in at least one of a period, a width, and a height. The first reference marker (RM1) and the second reference marker (RM2) may have the same height. For example, the height (H1) of the protrusion (or pattern) of the first reference marker (RM1) may be the same as the height (H2) of the protrusion (or pattern) of the second reference marker (RM2). However, the period (P1) and / or width (W1) of the protrusion (or pattern) of the first reference marker (RM1) may be different from the period (P2) and / or width (W2) of the protrusion (or pattern) of the second reference marker (RM2). By this configuration, misalignment recognition or precise assembly can be performed through machine vision in various wavelength bands. In other words, compatibility with respect to the reference markers can be improved.

[0184] In addition, as another example, the first reference marker (RM1) and the second reference marker (RM2) may have the same period, width, and height. For example, the first reference marker (RM1) and the second reference marker (RM2) may have the same height, width, and period. For example, the height (width, period) of the protrusion (or pattern) of the first reference marker (RM1) may be the same as the height (width, period) of the protrusion (or pattern) of the second reference marker (RM2). Accordingly, the wavelength band having the minimum transmittance in the first reference marker (RM1) and the wavelength band having the minimum transmittance in the second reference marker (RM2) may be the same. By this configuration, the misalignment between the first reference marker (RM1) and the second reference marker (RM2) can be more clearly recognized in the wavelength band having the minimum transmittance. In other words, misalignment recognition through machine vision can be performed more effectively. Therefore, misalignment recognition and assembly accuracy can be improved.

[0185] And the vector directions of the pattern of the first reference marker and the second reference marker may be the same.

[0186] Referring further to FIG. 10, OP1 is a case where the period from the reference marker is 900 nm, the width is 630 nm, and the height is 200 nm. And OP2 is a case where the period from the reference marker is 800 nm, the width is 160 nm, and the height is 200 nm.

[0187] The wavelength of minimum transmittance for OP1 is approximately 850 nm. The wavelength of minimum transmittance for OP2 is approximately 950 nm. At this time, application of OP1 and / or OP2 can be considered depending on the wavelength for vision recognition in machine vision (e.g., the wavelength range of the image sensor's light reception).

[0188] For example, if the wavelength capable of vision recognition is 950 nm, the first reference marker and the second reference marker with OP1 applied can be applied. This makes it easier to recognize misalignment.

[0189] And when the wavelength capable of vision recognition is 850 nm, the first reference marker and the second reference marker with OP2 applied can be applied. This makes it easier to recognize misalignment.

[0190] Additionally, when the wavelengths capable of vision recognition are 950 nm and 850 nm, OP1 and OP2 can be applied to the first reference marker and the second reference marker.

[0191] Accordingly, when aligning two or more combiners, i.e., first and second substrates on which pattern layers or diffractive elements are formed, it is easier to distinguish positional and rotational errors, so that precise assembly can be implemented. Accordingly, the light guide device according to the embodiment may include a first reference marker and a second reference marker that are spaced apart from each other and have an area in which at least a portion does not overlap in the stacking direction. In addition, the light guide device may include a first reference marker and a second reference marker that are spaced apart from each other and have an area in which at least a portion overlaps in the stacking direction.

[0192] FIG. 11 is a graph of the transmittance by wavelength according to a reference marker of one structure in a light guide device according to an embodiment, and FIG. 12 is a graph of the transmittance by wavelength according to a reference marker of another structure in a light guide device according to an embodiment.

[0193] In FIGS. 11 and 12, 'single' is a graph for transmittance by wavelength in an area where neither the first reference marker nor the second reference marker under the same conditions (width, period, height) nor the first reference marker and the second reference marker overlap in the stacking direction, and 'overlapped' is a graph for a case where the first reference marker and the second reference marker under the same conditions (width, period, height) overlap in the stacking direction.

[0194] Referring to Figures 10 and 11, when the wavelength for which applied vision recognition is possible is 950 nm, the first and second reference markers with OP1 applied can be applied. Accordingly, the transmittance for the overlapping region in the stacking direction is reduced to 25% or less, so that the recognition of rotational or translational errors can be more clearly performed. This makes it easier to recognize misalignment.

[0195] Referring to Figures 10 and 12, when the wavelength for which applied vision recognition is possible is 850 nm, the first and second reference markers with OP2 applied can be applied. Accordingly, the transmittance for the overlapping region in the stacking direction is reduced to approximately 25%, so that the recognition of rotational or translational errors can be more clearly achieved. This makes it easier to recognize misalignment.

[0196] In this way, the light guide device according to the embodiment accurately determines misalignment while suppressing user recognition by changing the conditions (period, height, width) of the reference marker and having a different shape (area) depending on the wavelength that can be recognized by vision.

[0197] Fig. 13 is a drawing showing the arrangement position of a reference marker in a light guide device according to an embodiment.

[0198] Referring to Fig. 13, as described above, the first and second reference markers have high transmittance in the visible light range, which can minimize the user's perception of the reference markers. Furthermore, the user can visually perceive the image provided by the projector more accurately. Thus, since the first and second reference markers have high transmittance in the visible light range, they can be positioned except in areas where the diffractive element is positioned.

[0199] For example, the first reference marker may be placed in an area other than the first diffractive element portion (312, 313, 314). That is, the first reference marker may be placed on the first substrate (311) so as not to overlap with the first diffractive element portion (312, 313, 314) in the stacking direction.

[0200] Likewise, the second reference marker may be placed in an area other than the second diffractive element portion (322, 323, 324). That is, the second reference marker may be placed on the second substrate (321) so as not to overlap with the second diffractive element portion (322, 323, 324) in the stacking direction.

[0201] That is, the first reference marker and the second reference marker can be located in an area (PA1) outside the eye box and spaced apart from the diffractive element.

[0202] As a variation, the first and second reference markers may also be positioned within the inner region (PA2) of the eye box. For example, the first and second reference markers may be positioned in a region or location that does not affect image presentation. Furthermore, within the eye box, the second diffractive element region (or the fifth diffractive element region) may have different conditions (period, height, width) between the protrusions of the second diffractive element region (or the fifth diffractive element region).

[0203] Accordingly, the light guide device according to the embodiment can provide improved design freedom of the reference marker.

[0204] Alternatively, the first and second reference markers may be positioned outside the eye box. For example, the first and second reference markers may be positioned within the area (PA1). Furthermore, at least some of the markers may be recognizable by the user in the visible light range. Therefore, in addition to machine vision, they may also be used as alignment marks during assembly. This may improve manufacturing efficiency.

[0205] FIG. 14 is a drawing illustrating another example and position of a first reference marker and a second reference marker in a light guide device according to an embodiment, FIG. 15 is a drawing illustrating another example and position of a first reference marker and a second reference marker in a light guide device according to an embodiment, and FIG. 16 is a drawing illustrating another example and position of a first reference marker and a second reference marker in a light guide device according to an embodiment.

[0206] Figures 14 to 16 illustrate examples of first reference markers and second reference markers according to various examples.

[0207] The first reference marker and the second reference marker according to the embodiment may include first and second regions overlapping in the stacking direction and third and fourth regions non-overlapping in the stacking direction, as described above.

[0208] Referring to FIG. 14, the first reference marker and the second reference marker according to the embodiment may each include a third region (AR3) and a fourth region (AR4) that are at least partially non-overlapping in the stacking direction.

[0209] The first reference marker (RM1) may include a third area (AR3), and the second reference marker (RM2) may include a fourth area (AR4).

[0210] In the absence of misalignment (if aligned), the third region (AR3) and the fourth region (AR4) may appear slightly dark in the machine vision image. Based on Fig. 12, approximately 50% of the transmitted light may appear in the machine vision image.

[0211] In the case of misalignment, the third region (AR3) and the fourth region (AR4) may have an area (OV2) that overlaps at least partially in the stacking direction. That is, the first diffractive element portion and the second diffractive element portion may be misaligned at least partially in the stacking direction. In this way, in the case where the third region (AR3) and the fourth region (AR4) overlap at least partially along the stacking direction, the misalignment can be more easily prevented by moving the first substrate in a direction perpendicular to the stacking direction (horizontal direction) or rotating the stacking direction about its axis.

[0212] Referring to FIG. 15, the first reference marker and the second reference marker according to the embodiment may each include a third region (AR3') and a fourth region (AR4') that are at least partially non-overlapping in the stacking direction. The first reference marker (RM1) may include the third region (AR3'). And the second reference marker (RM2) may include the fourth region (AR4').

[0213] At this time, unlike in Fig. 14, the area of ​​the fourth region (AR4') can be set to be larger than the area of ​​the third region (AR3'). Accordingly, since the reference marker is formed with a large area, the rotation of the first or second substrate relative to the stacking direction can be more clearly recognized. The description of cases where there is and is not misaligned is the same as described above.

[0214] That is, as described above, in the case of misalignment, the third region (AR3') and the fourth region (AR4') may have an area (OV2') that overlaps at least partially in the stacking direction. That is, at this time, the degree of rotation about the stacking direction can be more clearly recognized, and thus misalignment of the first diffractive element portion and the second diffractive element portion can be more easily prevented.

[0215] Referring to FIG. 16, the first reference marker and the second reference marker according to the embodiment may each include a third region (AR3'') and a fourth region (AR4'') that are at least partially non-overlapping in the stacking direction. The first reference marker (RM1) may include the third region (AR3''). And the second reference marker (RM2) may include the fourth region (AR4'').

[0216] At this time, unlike in Fig. 14, at least one of the fourth region (AR4'') and the third region (AR3'') can be formed as a closed loop. For example, the fourth region (AR4'') and the third region (AR3'') can be formed as a closed loop. In particular, each region can be arranged to intersect. Accordingly, not only the movement of the reference marker but also the rotation can be more clearly recognized. The description of the cases with and without misalignment is the same as described above.

[0217] That is, as described above, in the case of misalignment, the third region (AR3'') and the fourth region (AR4'') may have at least a partially overlapping region in the stacking direction. That is, in this case, the degree of rotation about the stacking direction can be more clearly recognized, and thus misalignment of the first diffractive element portion and the second diffractive element portion can be more easily prevented.

[0218] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the embodiments.

[0219] Although the above description focuses on examples, these are merely examples and are not intended to limit the examples. 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 examples. 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 interpreted as being included within the scope of the embodiments set forth in the appended claims.

Claims

1. First substrate; A first diffraction element portion arranged on the first substrate; A second substrate spaced apart from the first substrate; A second diffraction element portion disposed on the second substrate; a first reference marker disposed on the first substrate; and a second reference marker disposed on the second substrate; A light guide device in which the first reference marker and the second reference marker do not overlap at least partially in the stacking direction.

2. In paragraph 1, A light guide device in which one of the period of the first reference marker and the period of the second reference marker is different from the period of one of the first diffractive element portion and the second diffractive element portion.

3. In paragraph 2, An optical guide device wherein one of the period of the first reference marker and the period of the second reference marker is greater than the period of one of the first diffractive element portion and the second diffractive element portion.

4. In paragraph 1, A light guide device in which the wavelength band having the minimum transmittance in the first reference marker and the second reference marker is different from the diffraction wavelength of the first diffraction element portion and the second diffraction element portion.

5. In paragraph 1, The above first reference marker and the above second reference marker are light guide devices located within the eye box.

6. In paragraph 1, The above first reference marker and the first substrate are light guide devices having a refractive index difference of 0 to 1.

7. In paragraph 1, A light guide device in which the first reference marker and the first diffraction element portion have the same material.

8. In paragraph 1, A light guide device in which the second reference marker and the second diffraction element portion have the same material.

9. In paragraph 1, A light guide device, wherein the first reference marker, the second reference marker, the first diffraction element portion, and the second diffraction element portion comprise at least one of polymer, TiO2, HfO2, Al2O3, and SiO2.

10. In paragraph 1, The wavelength band having the minimum transmittance in the first reference marker and the wavelength band having the minimum transmittance in the second reference marker are the same light guide devices.

Images