Light guide device and electronic device comprising the same

Abstract

Embodiments disclose 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 diffractive element unit disposed on the second substrate; a first reference mark disposed on the first substrate; and a second reference mark disposed on the second substrate, wherein the first reference mark and the second reference mark at least partially do not overlap in a stacking direction.

Description

Technical Field

[0001] The embodiments relate to a light guiding device and an electronic device including the light guiding device. Background Technology

[0002] Virtual Reality (VR) refers to a specific environment or situation that is similar to but not exactly the same as the real world, generated by artificial technologies such as computers, or to the technology itself.

[0003] Augmented Reality (AR) is a technology used to synthesize virtual objects or information with the real environment so that the synthesized virtual objects or information look like real objects or information existing in the real environment.

[0004] Mixed Reality (MR) is a technology used to combine the virtual and real worlds to create new environments or information. Specifically, MR is an experience where real and virtual objects interact with each other in real time.

[0005] In this context, the generated virtual environment or situation stimulates the user's five senses and allows the user to have a spatial and temporal experience similar to reality, freely traversing the boundary between reality and imagination. Furthermore, users can not only simply immerse themselves in such an environment, but also interact with objects realized within it by manipulating real devices or giving commands.

[0006] Recently, research on gear and devices used in these technological fields has been actively underway. However, the need to miniaturize these devices and improve their optical performance is growing. Summary of the Invention

[0007] [Technical Issues]

[0008] The embodiments provide a light guide device and an electronic device including the light guide device, wherein when using the light guide device for augmented reality (AR) and the electronic device including the light guide device, the light guide device and the electronic device including the light guide device are assembled more precisely by forming reference marks on the light guide device.

[0009] Alternatively, the implementation may provide a light guide device and electronic device in which the reference mark is invisible to the user's eye based on the refractive index and transmittance of the reference mark, thereby suppressing interference with user identification.

[0010] Alternatively, embodiments may provide a light guide device and electronic device that can accurately determine misalignment by applying reference marks (period, height, and width) according to the wavelength under which visual recognition is possible, and by allowing first and second reference marks spaced apart from each other to have the same or different shapes for each region.

[0011] The objectives to be addressed in the implementation are not limited to this, and the implementation may also include objectives or effects that can be understood from the solutions to the problem or implementation described below.

[0012] [Technical Solutions]

[0013] The light guide device according to the embodiment includes a first substrate, a first diffraction element unit disposed on the first substrate, a second substrate disposed spaced apart from the first substrate, a second diffraction element unit disposed on the second substrate, a first reference mark disposed on the first substrate, and a second reference mark disposed on the second substrate, wherein the first reference mark and the second reference mark do not overlap each other at least partially in the stacking direction.

[0014] Either the period of the first reference mark or the period of the second reference mark may be different from the period of either the first diffraction element unit or the second diffraction element unit.

[0015] Either the period of the first reference mark or the period of the second reference mark may be greater than the period of either the first diffraction element unit or the second diffraction element unit.

[0016] The wavelength bands with minimum transmittance for the first and second reference marks may differ from the diffraction wavelengths of each of the first and second diffraction element units.

[0017] The first and second reference marks can be positioned within the eye box.

[0018] The first reference mark and the first substrate may have a refractive index difference of 0 to 1.

[0019] The first reference mark and the first diffraction element unit can be made of the same material.

[0020] The second reference mark and the second diffraction element unit can be made of the same material.

[0021] The first reference mark, the second reference mark, the first diffraction element unit, and the second diffraction element unit may include polymers. , , and At least one of them.

[0022] The wavelength band with minimum transmittance of the first reference mark can be the same as the wavelength band with minimum transmittance of the second reference mark.

[0023] The first reference mark and the second reference mark can have different periods.

[0024] The stacking direction can be from the second substrate to the first substrate.

[0025] The first reference mark and the second reference mark may each include a first region and a second region having the same shape.

[0026] When the first region and the second region do not overlap each other at least partially in the stacking direction, the first diffraction element unit and the second diffraction element unit may be misaligned in a direction perpendicular to the stacking direction.

[0027] The first and second reference marks may include a third and a fourth region with different shapes.

[0028] When the third region and the fourth region overlap each other at least partially in the stacking direction, the first diffraction element unit and the second diffraction element unit may be at least partially misaligned in the stacking direction.

[0029] The first and second reference markers can have periods of 700 nm to 900 nm.

[0030] The first and second reference marks can have a refractive index of 1.7 to 2.7.

[0031] The first and second reference markers can have a height of 100 nm to 600 nm in the stacking direction.

[0032] The first diffraction element unit may include a first input diffraction element, a first transmission diffraction element, and a first output diffraction element, with light sequentially incident on the first input diffraction element, the first transmission diffraction element, and the first output diffraction element.

[0033] The second diffraction element unit may include a second input diffraction element, a second transmission diffraction element, and a second output diffraction element, with light sequentially incident on the second input diffraction element, the second transmission diffraction element, and the second output diffraction element.

[0034] [Beneficial Effects]

[0035] The implementation achieves a light guide device and an electronic device including the light guide device as follows: when using the light guide device for augmented reality (AR) and the electronic device including the light guide device, the light guide device and the electronic device including the light guide device are assembled more precisely by forming reference marks on the light guide device.

[0036] Alternatively, the implementation can realize a light guide device and electronic device in which the reference mark is invisible to the user's eye based on the refractive index and transmittance of the reference mark, thereby suppressing interference with user identification.

[0037] Additionally, the implementation can realize a light guide device and electronic device that can accurately determine misalignment by applying reference marks (period, height, and width) according to the wavelength under which visual recognition is possible, and by allowing first and second reference marks spaced apart from each other to have the same or different shapes for each region.

[0038] The various beneficial advantages and effects of the present invention are not limited to those described above, and can be more easily understood in the process of describing the specific embodiments of the present invention. Attached Figure Description

[0039] Figure 1 This is a block diagram illustrating the configuration of an electronic device for extended reality according to an embodiment of the present invention.

[0040] Figure 2 This is a perspective view of an electronic device for augmented reality according to an embodiment of the present invention.

[0041] Figure 3 This is a view of the projection device and the light guide device according to the embodiment.

[0042] Figure 4 This is an exploded view of the light guide device according to the embodiment.

[0043] Figure 5 This is a cross-sectional view used to describe the optical guide device according to the embodiment.

[0044] Figure 6 Plan view and cross-sectional view of reference marks in an optical guide device according to an embodiment are shown.

[0045] Figure 7 This is a view used to describe the positions of the first reference mark and the second reference mark in the light guide device according to the embodiment.

[0046] Figure 8 This is a view of the first reference mark in the light guide device according to the embodiment.

[0047] Figure 9 This is a view of the second reference mark in the light guide device according to the embodiment.

[0048] Figure 10 It is a graph showing the transmittance of each wavelength according to the conditions of the reference mark in the light guide device according to the embodiment.

[0049] Figure 11 It is a graph showing the transmittance of a reference mark for each wavelength according to a structure of a light guide device according to an embodiment.

[0050] Figure 12 It is a graph showing the transmittance of each wavelength of a reference mark in another structure of the optical guide device according to the embodiment.

[0051] Figure 13 This is a view showing the arrangement of reference marks in the light guide device according to an embodiment.

[0052] Figure 14 This is a view used to describe another example and position of the first and second reference marks in the light guide device according to the embodiment.

[0053] Figure 15 This is a view used to describe yet another example and position of the first and second reference marks in the light guide device according to the embodiment.

[0054] Figure 16 This is a view used to describe another example and position of the first and second reference marks in the light guide device according to the embodiment. Detailed Implementation

[0055] In the following description, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[0056] However, the spirit of the present invention is not limited to the few embodiments described and can be implemented using various other embodiments. Furthermore, within the scope of the spirit of the present invention, at least one component of an embodiment can be selectively coupled, replaced, and used to implement the spirit of the invention.

[0057] Furthermore, unless otherwise explicitly and specifically defined by the context, all terms used herein (including technical and scientific terms) are to be interpreted as having the meanings commonly used by those skilled in the art, and the meanings of commonly used terms, such as those defined in general dictionaries, will be interpreted by taking into account the contextual meaning of the relevant art.

[0058] Furthermore, the terminology used in the embodiments of this invention is for the purpose of describing the embodiments and is not intended to limit the invention.

[0059] In this specification, unless otherwise expressly indicated by the context, the singular form includes its plural form, and in the case of describing “at least one of A, B and C (or one or more of them)”, this may include at least one of all combinations that can be combined with A, B and C.

[0060] In addition, in the description of the components of the present invention, terms such as "first", "second", "A", "B", "(a)" and "(b)" may be used.

[0061] These terms are only used to distinguish one element from another, and the nature, order, etc., of the elements are not limited by these terms.

[0062] Additionally, it should be understood that when an element is referred to as being “connected or coupled” to another element, such a description can include both cases where the element is directly connected or coupled to the other element and cases where the element is connected or coupled to the other element via another element disposed between the element and the other element.

[0063] Additionally, when any element is described as being formed or disposed "above or below" another element, such a description includes both cases where the two elements are formed or disposed in direct contact with each other and cases where one or more other elements are located between the two elements. Furthermore, when an element is described as being disposed "above or below" another element, such a description can include cases where the one element is disposed on the upper or lower side relative to the other element.

[0064] Figure 1 This is a block diagram illustrating the configuration of an electronic device for extended reality according to an embodiment of the present invention.

[0065] Reference Figure 1 The electronic device 20 for extended reality 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. Because... Figure 1 The components shown are not essential for implementing the electronic device 20, and therefore the electronic device 20 described in this specification may include more or fewer components than those listed above.

[0066] More specifically, in the above components, the wireless communication unit 21 may include one or more modules capable of 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. Additionally, the wireless communication unit 21 may include one or more modules for connecting the electronic device 20 to one or more networks.

[0067] The wireless communication unit 21 may include at least one of a broadcast receiving module, a mobile communication module, a wireless Internet module, a short-range communication module, and a location information module.

[0068] Input unit 22 may include a camera or image input unit for inputting image signals, a microphone or audio input unit for inputting audio signals, and a user input unit (e.g., touch keys or buttons (mechanical keys)) for receiving information from the user. Voice or image data collected by input unit 22 can be analyzed and processed as user control commands.

[0069] The sensing unit 23 may include one or more sensors for detecting at least one of the following: information in the electronic device 20, information about the environment surrounding the electronic device 20, and user information.

[0070] For example, sensing unit 23 may include at least one of the following: proximity sensor, lighting sensor, touch sensor, accelerometer, magnetic sensor, G sensor, gyroscope sensor, motion sensor, red-green-blue (RGB) sensor, infrared sensor (IR sensor), finger scanning sensor, ultrasonic sensor, optical sensor (e.g., imaging device), microphone, battery gauge, environmental sensor (e.g., barometer, hygrometer, thermometer, radiation detection sensor, thermal detection sensor, or gas detection sensor), and chemical sensor (e.g., electronic nose, healthcare sensor, or biometric sensor).

[0071] Furthermore, in the electronic device 20 disclosed in this specification, information detected from at least two of these sensors can be combined and used.

[0072] Output unit 24 can be used to generate outputs related to visual, auditory, or tactile senses, and may include at least one of a display unit, an audio output unit, a tactile module, and an optical output unit. The display unit may form an interlayer structure with the touch sensor or may be integrally formed therewith to realize a touchscreen. The touchscreen can serve as a user input device that provides an input interface between the electronic device 20 for augmented reality and the user, and can also provide an output interface between the electronic device 20 for augmented reality and the user.

[0073] The interface unit 25 serves as a pathway for connecting to various types of external devices of the electronic device 20. Through the interface unit 25, the electronic device 20 can receive virtual reality or augmented reality content from external devices and can perform mutual interaction by exchanging various input signals, sensing signals, and data.

[0074] For example, interface unit 25 may include at least one of a wired / wireless headphone 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 input / output (I / O) port, a video I / O port, and a headphone port.

[0075] Additionally, memory 26 stores data to support various functions of electronic device 20. Memory 26 may store multiple applications (or programs) executed by electronic device 20, data for the operation of electronic device 20, and commands. At least some of these applications can be downloaded from an external server via wireless communication. Furthermore, at least some of these applications may be present on electronic device 20 from the time of manufacture for the basic functions of electronic device 20 (e.g., functions for receiving calls, making calls, receiving messages, and sending messages).

[0076] In addition to operations related to the application, 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 described above.

[0077] Furthermore, the control unit 27 can control at least some of the components by executing an application program stored in the memory 26, thereby providing the user with appropriate information or processing functions. In addition, to execute the application program, the control unit 27 can combine and operate at least two of the components included in the electronic device 20.

[0078] Alternatively, the control unit 27 can use a gyroscope sensor, gravity sensor, motion sensor, etc., included in the sensing unit 23 to detect movement of the electronic device 20 or the user. Alternatively, the control unit 27 can use a proximity sensor, illumination sensor, magnetic sensor, infrared sensor, ultrasonic sensor, optical sensor, etc., included in the sensing unit 23 to detect objects approaching the electronic device 20 or the user. Furthermore, the control unit 27 can detect user movement using sensors provided in a controller that operates in conjunction with the electronic device 20.

[0079] In addition, the control unit 27 can use the application stored in the memory 26 to perform the operation (or function) of the electronic device 20.

[0080] The power supply unit 28 can receive external or internal power under the control of the control unit 27 and supply power to each component included in the electronic device 20. The power supply unit 28 may include a battery, which may be provided in an embedded or replaceable form.

[0081] At least some of the above components can cooperate with each other to implement the operation, control, or control method of the electronic device according to the various embodiments described below. Furthermore, the operation, control, or control method of the electronic device can be implemented on the electronic device by executing at least one application program stored in memory 26.

[0082] In the following description, implementations of electronic devices described as examples of the present invention will be provided based on applications in wearable devices (e.g., virtual reality (VR) glasses / augmented reality (AR) glasses / mixed reality (MR) glasses). However, implementations of electronic devices according to the present invention may include mobile phones, smartphones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, slate PCs, tablet PCs, ultrabooks, and wearable devices. Besides head-mounted displays (HMDs), wearable devices may include smartwatches, contact lenses, VR / AR / MR glasses, etc.

[0083] Figure 2 This is a perspective view of an electronic device for AR according to an embodiment of the present invention.

[0084] like Figure 2 The electronic device shown, according to an embodiment of the present invention, may include a frame 100, a projection device 200, and a display unit 300.

[0085] The electronic device can be provided as an eyeglass-type electronic device (smart glasses). The eyeglass-type electronic device can be configured to be worn on the head, and for this purpose, it can include a frame (shell, housing, etc.) 100. The frame 100 can be formed of a flexible material for ease of wear.

[0086] The frame 100 is supported on the head and provides space for mounting various components. As shown, electronic components such as the projection device 200, user input unit 130, or audio output unit 140 can be mounted on the frame 100. In addition, lenses covering at least one of the left and right eyes can be detachably mounted on the frame 100.

[0087] As shown in the figure, the frame 100 may have the shape of glasses worn on the user's face, but the present invention is not necessarily limited to this. The frame 100 may also have the shape of goggles worn close to the user's face.

[0088] Frame 100 may include a front frame 110 having at least one opening and a Y-direction intersecting the front frame 110 (see [link]). Figure 2 A pair of side frames 120 extending upwards and parallel to each other.

[0089] In frame 100, the length DI in the X direction can be equal to or different from the length LI in the Y direction.

[0090] The projection device 200 is configured to control various electronic components installed in the electronic device. The projection device 200 may also be referred to as an "optical output device," "optical projection device," "light illumination device," "optical device," "projector," etc.

[0091] The projection device 200 can generate an image or a video of a series of images to be displayed to a user. The projection device 200 may include an image source panel for generating the image and a plurality of lenses for diffusing and converging the light generated by the image source panel.

[0092] The projection device 200 can be fixed to one of the two side frames 120. For example, the projection device 200 can be fixed inside or outside either side frame 120, or it can be integrally formed by being embedded inside either side frame 120. Alternatively, the projection device 200 can be fixed to the front frame 110 or disposed separately from the electronic device.

[0093] The display unit 300 can be implemented as a VR / AR / MR glasses type or an HMD type. An HMD is a type of display mounted on the head and directly displays images in front of the user's eyes. When the user wears the electronic device, the display unit 300 can be positioned to correspond to at least one of the left and right eyes to provide an image directly in front of the user's eyes. In this figure, the display unit 300 is positioned at the portion corresponding to the right eye to output an image toward the user's right eye. However, as described above, the invention is not limited thereto, and the display unit 300 can be positioned on both the left and right eyes.

[0094] The display unit 300 allows users to visually perceive the external environment and simultaneously displays images generated by the projection device 200 to the user. For example, the display unit 300 can use a prism to project images onto the display area.

[0095] The display unit 300 can be made transparent, allowing simultaneous viewing of the projected image and the conventional forward field of view (the range seen by the user's eyes). For example, the display unit 300 can be semi-transparent and can be formed from optical components including glass. For example, the display unit 300 can be a light guide or may include a light guide.

[0096] The display unit 300 can be inserted into and secured in an opening included in the front frame 110, or positioned on the rear surface of the opening (e.g., between the opening and the user) and secured to the front frame 110. Although the figure shows an example of the display unit 300 being positioned on the rear surface of the opening and secured to the front frame 110, the display unit 300 can be positioned and secured in one of a variety of locations on the frame 100.

[0097] like Figure 2 As shown, in the electronic device, when the projection device 200 allows image light to be incident on one side of the display unit 300, the image light is emitted through the display unit 300 to the other side, thereby allowing the user to view the image generated by the projection device 200.

[0098] Therefore, users can view the external environment through the opening in frame 100 and simultaneously view the image generated by projection device 200. In other words, the image output by display unit 300 can be seen overlapping with the normal field of view. Electronic devices can provide AR for displaying an image by using such display characteristics to overlay virtual images onto a real image or background.

[0099] In addition to this method, images generated from the external environment and the projection device 200 can be provided to the user with a time difference over a short period of time imperceptible to a human. For example, in one frame, the external environment can be provided to the person in one segment, and in another segment, the image from the projection device 200 can be provided to the person.

[0100] Alternative sites can provide both overlap and time difference.

[0101] Additionally, the projection device according to the embodiments may have the structure described below, or may have a structure that further includes a waveguide and / or glass. Furthermore, the projection device may include a digital light processing (DLP) projector or a projection device.

[0102] Figure 3 This is a view of the projection device and the light guide device according to the embodiment. Figure 4 This is an exploded view of the light guide device according to the embodiment.

[0103] Reference Figure 3 and Figure 4 In this embodiment, the light guide device 300 may or may not include the projection device 200.

[0104] First, the projection device 200 according to the embodiment may include a light source unit, a housing, a lens unit, an optical modulator, and a projection lens unit.

[0105] The housing may have a space or a housing recess in which each component of the projection device 200 is accommodated or disposed. The housing may be positioned at the outermost part of the projection device 200.

[0106] Furthermore, the housing may have an opening on one side. Therefore, each component described above can be assembled via the opening area or surface. The housing can have various shapes. For example, the housing may have a hexahedral structure. Therefore, the projection device according to the embodiment can be easily mounted on an electronic device. Additionally, the projection device according to the embodiment can be easily miniaturized or compacted.

[0107] The light source unit can be housed within the housing. The light source unit can be disposed adjacent to any of the outer surfaces of the housing.

[0108] A light source unit may include at least one light source. When multiple light sources are provided, the light sources may emit light with different wavelength bands or colors.

[0109] The lens unit may include at least one optical element (e.g., a lens). The lens unit can focus light. Due to this configuration, the loss of light emitted from the light source unit can be reduced, and the size of the projection device can be easily reduced.

[0110] Additionally, the lens unit may include a relay lens or similar element to align or alter the path of light. Furthermore, the lens unit can adjust the size of the illumination or image (the area of ​​maximum light) provided by the illumination system, or it can compensate for optical differences.

[0111] The lens unit may include elements that change the path of light (e.g., a prism).

[0112] For example, the lens unit may include a total internal reflection prism (TIR prism). The prism can change the direction of light travel as described above. That is, the prism can transmit and reflect light. Due to this configuration, miniaturization of the projection device according to the embodiment can be achieved.

[0113] An optical modulator can be positioned behind a prism. The optical modulator can reflect light passing through the prism back to the prism. The optical modulator can project images by reflecting incident light. For example, the optical modulator can transmit or project video or images based on image signals incident through a substrate, etc. In other words, the optical modulator can modulate the light emitted by the light source unit.

[0114] An optical modulator according to an embodiment may include a digital micromirror device (DMD). An optical modulator may include multiple small mirrors. An optical modulator may include various optical modulation devices such as liquid crystal on silicon (LCoS).

[0115] The projection lens unit can be positioned behind the prism. When light emitted by the optical modulator is reflected by the prism, the reflected light can enter the projection lens unit. The light described above can be projected by the projection lens unit. The projection lens unit can project the light emitted by the projection device onto a screen or waveguide (or display unit).

[0116] In this implementation, the projection lens unit can adjust the size of the image so that light is incident within the incident pupil diameter (EPD) of the waveguide or the like.

[0117] The projection device according to the embodiments may include an illumination system and a projection system (or projection system, projection unit, projection unit, projector unit, etc.).

[0118] An illumination system may include a light source unit, a lens unit, and a prism as components, and may receive source light (illumination light) and emit light in a predetermined direction. The illumination light may be transmitted or provided to an optical modulator of a projection system.

[0119] The projection system may include a prism, an optical modulator, and a projection lens unit. The projection system may include a prism as a component. In some embodiments, the prism may be an element of both the illumination system and the projection system.

[0120] Furthermore, the projection system may also include the illumination system described above. That is, the projection system can modulate the illumination light generated by the illumination system using an optical modulator, and emit or diffuse the modulated illumination light in a predetermined direction using a prism and projection lens unit.

[0121] An optical modulator can reflect illumination light into patterned light, and this patterned light can pass through the projection lens unit and be output to the outside of the projection device.

[0122] In addition, the output unit of the projection device and the input unit of the waveguide or wavelength guide (waveguide) or optical guide device can be positioned to correspond to each other.

[0123] According to an embodiment, the light guide device 300 may include a projection device 200, a substrate, and a diffraction element (diffraction element region). Alternatively, the light guide device 300 may include a substrate and a diffraction element (diffraction element region). Furthermore, the light guide device 300 may include an optical component 330. The diffraction element (diffraction element region) may be configured as at least one of transmissive or reflective types. For example, when the diffraction element is transmissive, the diffraction element region may be positioned on a surface of the substrate adjacent to the projector. When the diffraction element is reflective, the diffraction element region may be positioned on a surface of the substrate away from the projector. Furthermore, multiple diffraction element regions may exist on a single substrate, and each region may be configured as either reflective or transmissive.

[0124] The light guide device 300 according to an embodiment may include a first substrate 311 and first diffraction element units 312, 313 and 314. Furthermore, the light guide device 300 according to an embodiment may include a projection device 200 (hereinafter referred to as a projector). As described above, the light guide device 300 may have a structure separate from the projector 200.

[0125] 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 second diffraction element units 322, 323, and 324.

[0126] The light guide device 300 according to this 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. The second substrate 321, the second diffraction element units 322, 323, and 324, the first substrate 311, the first diffraction element units 312, 313, and 314, and the cover 330 (or optical component) may be stacked or arranged sequentially in the stacking direction. In addition, the light guide device 300 may also include a first reference mark RM1 disposed on the first substrate 311 and a second reference mark RM2 disposed on the second substrate 321.

[0127] The first diffraction element unit according to the embodiment may include a plurality of diffraction element regions. The first diffraction element unit may be disposed on the first substrate 311 and may have a nanoscale pattern. Therefore, the first diffraction element unit may be referred to as a "first pattern layer," "first pattern," etc. Hereinafter, the first diffraction element unit will be described interchangeably with the first pattern layer. The second diffraction element unit may be referred to as a "second pattern layer," "second pattern," etc. The diffraction element unit may be formed by various methods. For example, the diffraction element unit may be formed on the substrate by deposition.

[0128] Therefore, the first diffraction element unit can diffract and guide the incident light emitted from the projector 200. For example, the first diffraction element unit may include a first diffraction element region 312 and a second diffraction element region 314. Furthermore, the first diffraction element unit may include a third diffraction element region 313 positioned between the first diffraction element region 312 and the second diffraction element region 314. The first diffraction element region 312 may correspond to an "input coupler." The second diffraction element region 314 may correspond to an "output coupler." The third diffraction element region 313 may correspond to a folded grating.

[0129] The light guide device 300 can change the path of light output from the light output unit and incident on the light guide device 300, and then output the light to the outside again. The light can sequentially incident on the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314, and then be output to the outside again. The direction in which the light is incident on the light guide device 300 can be a first direction. The first direction can be the incident direction of the light or the opposite direction.

[0130] The first diffraction element region 312 is the first input diffraction element to which light is incident, the third diffraction element region 313 is the first transmission diffraction element to which light passes along a desired path, and the second diffraction element region 314 is the first output diffraction element from which light is emitted.

[0131] The fourth diffraction element region 322 is the second input diffraction element to which light is incident, the sixth diffraction element region 323 is the second transmission diffraction element to which light passes along the desired path, and the fifth diffraction element region 324 is the second output diffraction element from which light is emitted.

[0132] In this embodiment, the first substrate 311 can guide light emitted by the projector 200. The first substrate 311 can serve as a path for transmitted light. A first diffraction element region 312, a third diffraction element region 313, and a second diffraction element region 314 can be disposed on the first substrate 311. Light can undergo total internal reflection within the first substrate 311 to travel along the interior of the first substrate 311. The first substrate 311 can be a waveguide.

[0133] The first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 may be disposed on the first substrate 311 spaced apart from each other. The first substrate 311 may extend in a second direction perpendicular to the first direction in which light is incident. The first substrate 311 may have a refractive index of 1.4 to 2.0.

[0134] The first diffraction element region 312 can guide light incident onto the first substrate 311. That is, the first diffraction element region 312 can be used to guide light. Alternatively, the first diffraction element region 312 can receive light. That is, the first diffraction element region 312 can be used to guide light incident onto the first substrate 311.

[0135] Additionally, the first diffraction element region 312 can be disposed on the first substrate 311. Light can be incident on the light guide device 300 from the outside or from the projector 200 through the first diffraction element region 312, and can be transmitted along the first substrate 311 to the second diffraction element region 314 and the third diffraction element region 313. The first diffraction element region 312 can change the path of light by diffracting light.

[0136] The third diffraction element region 313 can be used to change the path of light. The third diffraction element region 313 can be disposed on the first substrate 311. The third diffraction element region 313 can change the path of incident light emitted 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 light.

[0137] The second diffraction element region 314 can be used to guide light to be emitted to the outside (e.g., to a user). The second diffraction element region 314 can be disposed 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 can emit the received light to the outside. The second diffraction element region 314 can change the path of light and emit the light to the outside. The second diffraction element region 314 can change the path of light by diffracting light. The second diffraction element region 314 can be disposed spaced apart from the first diffraction element region 312. The second diffraction element region 314 can emit light.

[0138] The first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 may include a plurality of protrusions. The plurality of protrusions may have predetermined widths, periods, and heights, and may be disposed on the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314. The plurality of protrusions may protrude along a first direction (or a stacking direction or a direction opposite to the stacking direction) on the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314. The plurality of protrusions may be spaced apart from each other in the vector direction of the 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 diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 may be varied. The width of a protrusion may be the width of the protrusion in the vector direction of the pattern including the protrusions. The period of a protrusion may be the interval between a side surface of a protrusion and a side surface of an adjacent protrusion in the vector direction of the pattern including the protrusions. The height of the protrusion can be the height of the protruding portion in the first direction. These protrusions can be configured with a predetermined pattern. Even when a background appears where the pattern orientation changes, the pattern (or protrusion) in the same area (diffraction element area or reference mark) can be configured in the same vector direction and can have the same diffraction vector. Furthermore, even within a single area, various diffraction vector patterns can be formed according to a grid.

[0139] In this embodiment, the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 may be formed of the same material or different materials. For example, the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 may be formed of the same material. The first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 may have a refractive index of 1.7 to 2.7.

[0140] Furthermore, the contours (boundary regions) of the first diffraction element region 312 and the third diffraction element region 313 do not overlap. When the contours overlap, a portion of the incident light emitted from the third diffraction element region 313 to the second diffraction element region 314 can be blocked, and therefore the image from the second diffraction element region 314 may not be emitted into the blocked area. Since efficiency decreases when the contours (boundary regions) of the first diffraction element region 312 and the third diffraction element region 313 overlap, it is preferable that the contours (boundary regions) of the first diffraction element region 312 and the third diffraction element region 313 do not overlap.

[0141] According to the embodiment, the third diffraction element region 313 may include a first region 313a adjacent to the second diffraction element region 314 and a second region 1320 that is in contact with the first region 313a and spaced apart from the second diffraction element region 314.

[0142] The first region 313a and the second region 1320 can be some regions of the third diffraction element region 313. The first region 313a and the second region 313b can be two regions separated from each other when the optical signal is observed along the stacking direction (or the first direction) of its incident optical signal. The first region 313a can be a region of the third diffraction element region 313 adjacent to the second diffraction element region 314. The first region 313a can be a region of the third diffraction element region 313 adjacent to the first diffraction element region 312. The second region 313b can be a region of the third diffraction element region 313 spaced apart from the second diffraction element region 314. The second region 313b can be a region of the third diffraction element region 313 spaced apart from the first diffraction element region 312. The separation distance between the first region 313a and the second diffraction element region 314 can be smaller than the separation 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 can be different from each other. The first region 313a and the second region 313b may each include multiple surfaces. Some surfaces of the first region 313a and some surfaces of the second region 313b may be in contact with each other.

[0143] The first region 313a includes a first pattern, and the first pattern includes a first protrusion projecting in a first direction. The second region 313b may include a second pattern and a second protrusion projecting in the first direction. The first and second protrusions may be portions projecting from the first region 313a and the second region 313b respectively in the first direction. The first direction may be the direction in which light from the projector is incident on the first diffraction element region 312. The first direction may be the incident direction of the light or the opposite direction. The first direction is perpendicular to the first substrate 311.

[0144] The first and second protrusions can be repeatedly arranged on the first region 313a and the second region 313b with a predetermined period, width, and height. A plurality of first protrusions can be arranged perpendicular to a first direction and spaced apart from each other in the vector direction of the first region 313a of the third diffraction element region 313. A plurality of second protrusions can 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 diffraction element region 313.

[0145] Furthermore, the first diffraction element region 312, the second diffraction element region 314, and the third diffraction element region 313 can be connected to or spaced apart from each other. For example, at least a portion of the first diffraction element region 312, the second diffraction element region 314, and the third diffraction element region 313 may include portions where the patterns are connected to each other. This configuration facilitates the fabrication of each of the first diffraction element regions 312, the second diffraction element region 314, and the third diffraction element region 313. Additionally, at least a portion of the first diffraction element region 312, the second diffraction element region 314, and the third diffraction element region 313 can be formed to be spaced apart from each other in different regions. That is, the first diffraction element region 312, the second diffraction element region 314, and the third diffraction element region 313 may not include portions where they are connected to each other. Therefore, light transmission other than diffraction through the pattern can be suppressed, thereby improving accuracy and efficiency.

[0146] Optical component 330 can be disposed on the first substrate 311, the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314. Optical component 330 can be disposed 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 optical component 330 and can be incident on the first diffraction element region 312. Optical component 330 can have the effect of protecting the interior of the light guide device 300. Optical component 330 can have a refractive index of 1.4 to 1.55. Optical component 330 can have, for example, a refractive index of about 1.5. Optical component 330 can be referred to as a "cover," "cover glass," etc.

[0147] Furthermore, in the following text, in the light guide device according to each embodiment, the stacking direction (first direction) will be described as the “S-axis direction” shown. The stacking direction (S-axis direction) may correspond to the direction from the first substrate 311 to the cover 330 or the direction from the second substrate 321 to the first substrate 311 or the cover 330.

[0148] 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 disposed below or on the lower surface of the first substrate 311. For example, the second substrate 321 may be positioned to be spaced apart from the lower portion of the first substrate 311.

[0149] The second substrate 321, the fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 can be disposed on the first substrate 311 at a distance from the projector 200. The second substrate 321, the fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 can overlap with the first substrate 311 in the first direction of light incidence. The fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 can be disposed between the first substrate 311 and the second substrate 321.

[0150] An optical component or cover 330 may be disposed 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 component 330 may be disposed 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 component 330 and can be incident on the first diffraction element region 312. The optical component 330 may have the effect of protecting the interior of the light guide device 300. The optical component 330 may have a refractive index of approximately 1.5.

[0151] As described above, the light guide device 300 can change the path of light output from the light output unit and incident on the light guide device 300, and output the light to the outside again. Specifically, the light can pass through the first diffraction element unit PT1 and the first substrate 311, and can be provided to the second substrate 321 and the second diffraction element unit PT2 disposed below the first substrate 311. Therefore, the light can sequentially incident on the fourth diffraction element region 322, the sixth diffraction element region 323 and the fifth diffraction element region 324, and then be output to the outside again.

[0152] The second substrate 321 can serve as a path for transmitted light. A fourth diffraction element region 322, a sixth diffraction element region 323, and a fifth diffraction element region 324 can be disposed on the second substrate 321. Light can undergo total internal reflection within the second substrate 321 to travel along its interior. The second substrate 321 may include a waveguide. The fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 can be disposed on the second substrate 321 spaced apart from each other. The second substrate 321 can be disposed along a second direction perpendicular to the first direction of light incidence. The first substrate 311 and the second substrate 321 can have a refractive index of 1.4 to 2.0.

[0153] The fourth diffraction element region 322 can be used as the path through which light is incident. The fourth diffraction element region 322 can be disposed 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 light.

[0154] The sixth diffraction element region 323 can be used to change the path of light. The sixth diffraction element region 323 can be disposed on the second substrate 321. The sixth diffraction element region 323 can change the path of incident light emitted through the fourth diffraction element region 322. The sixth diffraction element region 323 can change the path of light so that the light is directed towards the fifth diffraction element region 324. The sixth diffraction element region 323 can change the path of light by diffracting light.

[0155] The fifth diffraction element region 324 can serve as a path for light to pass through and be 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 can emit that light to the outside. The fifth diffraction element region 324 can change the path of light and emit that light to the outside. The fifth diffraction element region 324 can change the path of light by diffracting light.

[0156] 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 predetermined widths, periods, and heights, and may be disposed 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 spaced apart from each other in a vector direction perpendicular to the first direction of the pattern including the protrusions. Depending on the width, period, and height of the plurality of protrusions, the path of light after passing through the fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 may be varied. The width of a protrusion may be the width of the protrusion in the vector direction of the pattern including the protrusions. The period of a protrusion may be the interval between a side surface of a protrusion and a side surface of an adjacent protrusion in the vector direction of the pattern including the protrusions. The height of the protrusion can be the height of the protruding portion in the first direction. The first diffraction element region 312, the third diffraction element region 313, the second diffraction element region 314, the fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 can have a refractive index of 1.7 to 2.7. The refractive index of the first diffraction element region 312, the third diffraction element region 313, the second diffraction element region 314, the fourth diffraction element region 322, the sixth diffraction element region 323, and the fifth diffraction element region 324 can be greater than or equal to the refractive index of the first substrate 311 and the second substrate 321.

[0157] Furthermore, as described above, depending on whether the diffraction element unit is transmissive or reflective, the position of the diffraction element unit can be located on the upper or lower surface of the first substrate. For example, the first diffraction element region can be located on the lower surface of the first substrate 311 (the surface not facing the projector, i.e., the first surface). Additionally, optical components can be located between the projector 200 and the first substrate 311.

[0158] The stacking of the first substrate and the components disposed thereon, as well as the stacking of the second substrate and the components disposed thereon, can be performed by curing, insulating members (or intermediate layers or barrier members), etc.

[0159] The second substrate can guide light that has passed through the first substrate. For example, the wavelength or wavelength band (e.g., center wavelength) of the light guided by the first substrate and the light guided by the second substrate can be different.

[0160] In the light guide device 300, the first reference mark RM1 and the second reference mark M2 can be positioned on the corresponding substrate.

[0161] A first reference mark RM1 may be disposed on the first substrate 311. A second reference mark RM2 may be disposed on the second substrate 321. A detailed description of such reference marks will be provided below. The first reference mark RM1 is...

[0162] Figure 5 This is a cross-sectional view used to describe the optical guide device according to the embodiment. Figure 6 Plan view and cross-sectional view of reference marks in an optical guide device according to an embodiment are shown.

[0163] Reference Figure 5 and Figure 6 Each of the first reference mark RM1 and the second reference mark RM2 can be positioned to at least partially overlap with the diffraction element unit of each substrate in the horizontal direction.

[0164] The first reference mark RM1 may at least partially overlap with the first diffraction element unit PT1 in the horizontal direction. The second reference mark RM2 may at least partially overlap with the second diffraction element unit PT2 in the horizontal direction.

[0165] The first reference marker RM1 and the first diffraction element unit PT1 can be made of the same material. Similarly, the second reference marker RM2 and the second diffraction element unit PT2 can also be made of the same material. For example, the first reference marker RM1, the second reference marker RM2, the first diffraction element unit PT1, and the second diffraction element unit PT2 can comprise polymers, titanium dioxide (… ), hafnium dioxide ( ), aluminum oxide ( ) and silicon dioxide ( At least one of the following.

[0166] Because of this configuration, the increase or decrease in costs associated with the manufacture of the first reference mark RM1 and the second reference mark RM2 can be minimized, and the ease of manufacture can also be improved.

[0167] Furthermore, the first reference mark RM1 and the first diffraction element unit PT1 can be formed of different materials. Therefore, the refractive index difference between the first reference mark RM1 and the first substrate 311 can be minimized. For example, the refractive index difference between the first reference mark RM1 and the first substrate 311 can be in the range of 0 to 1.

[0168] Similarly, the second reference mark RM2 and the second diffraction element unit PT2 can be formed of different materials. Therefore, the refractive index difference between the second reference mark RM2 and the second substrate 321 can be minimized. For example, the refractive index difference between the second reference mark RM2 and the second substrate 321 can be in the range of 0 to 1.

[0169] Therefore, user identification or external user identification of the first reference marker RM1 and the second reference marker RM2 can be difficult. Thus, inconvenience caused by user identification, etc., can be prevented.

[0170] The first reference mark RM1 and the second reference mark RM2 can be diffraction elements, similar to diffraction elements in a diffraction element unit such as the first diffraction element unit PT1 and the second diffraction element unit PT2. For example, the first reference mark RM1 may include multiple protrusions. Similarly, the second reference mark RM2 may include multiple protrusions.

[0171] Multiple protrusions can form a pattern. That is, the first reference mark RM1 and the second reference mark RM2 can have a structure including a pattern. The first reference mark RM1 and the second reference mark RM2 can be diffraction elements or diffraction element regions. In the vector direction of the pattern including multiple protrusions, the multiple protrusions can be spaced apart from each other. Depending on the width W, period P, and height H of the multiple protrusions, the path of light after passing through the first diffraction element region 312, the third diffraction element region 313, and the second diffraction element region 314 can be changed differently. This can also be applied to the second diffraction element unit.

[0172] As an example, the first reference marker RM1 and the second reference marker RM2 can have a period of 700 nm to 900 nm.

[0173] Additionally, the first reference marker RM1 and the second reference marker RM2 can have a fill factor (FF) of 0.2 to 0.7. FF can be expressed as width W / period P. Furthermore, the height H of the first reference marker RM1 and the second reference marker RM2 can be in the range of 100 nm to 600 nm. The first reference marker RM1 and the second reference marker RM2 can have a refractive index of 1.7 to 2.7.

[0174] In this implementation, the transmittance of the first reference marker RM1 and the second reference marker RM2 in the visible light band can be higher than that of the first diffraction element unit and / or the second diffraction element unit in the visible light band. Due to this configuration, the first reference marker RM1 and the second reference marker RM2 can have high transmittance in the visible light band. Therefore, the first reference marker RM1 and the second reference marker RM2 can be invisible to the user, thereby preventing user identification. However, the first reference marker RM1 and the second reference marker RM2 can have low transmittance at specific wavelengths (e.g., 850 nm and 940 nm). Therefore, the first reference marker RM1 and the second reference marker RM2 can be easily identified by machine vision. For example, because the first reference marker RM1 and the second reference marker RM2 have low transmittance at their corresponding wavelengths, the areas where the first reference marker RM1 and the second reference marker RM2 are located may appear dark in images obtained by machine vision used for checking alignment, etc. Furthermore, the areas where the first reference marker RM1 and the second reference marker RM2 overlap each other in the stacking direction may appear even darker. Therefore, misalignment (rotation or movement) between the first substrate 311 and the second substrate 321 can be easily identified, or alignment can be easily determined to perform assembly.

[0175] Figure 7 This is a view used to describe the positions of the first reference mark and the second reference mark in the light guide device according to the embodiment. Figure 8 This is a view of the first reference mark in the light guide device according to the embodiment. Figure 9 This is a view of the second reference mark in the light guide device according to the embodiment. Figure 10 It is a graph showing the transmittance of each wavelength according to the conditions of the reference mark in the light guide device according to the embodiment.

[0176] Reference Figure 7 According to the implementation, the first reference mark RM1 and the second reference mark RM2 may at least partially not overlap each other in the stacking direction. Alternatively, the first reference mark RM1 and the second reference mark RM2 may have at least partially overlapping areas.

[0177] Specifically, the first reference mark RM1 and the second reference mark RM2 may each include a first region AR1 and a second region AR2 having the same shape. For example, the first reference mark RM1 may include the first region AR1. The second reference mark RM2 may include the second region AR2. The first region AR1 and the second region AR2 may have the same shape. For example, when the first region AR1 is circular, the second region AR2 may also be circular. Furthermore, the first region AR1 and the second region AR2 may overlap each other in the stacking direction.

[0178] Therefore, the first region AR1 of the first reference mark RM1 and the second region AR2 of the second reference mark RM2 may each have a region OV1 that overlaps with each other in the stacking direction on the first substrate 311 and the second substrate 321, respectively. In this case, the overlapping region OV1 may appear very dark in the image obtained by machine vision. The first reference mark RM1 and the second reference mark RM2 may overlap each other at least partially in the stacking direction. In particular, the first region AR1 and the second region AR2 may be in a state in which the first substrate or the second substrate is not moving in a direction perpendicular to the stacking direction. That is, it can be confirmed that the first region AR1 and the second region AR2 are in an aligned state in which one of the substrates (e.g., the first substrate) is not moving in a direction perpendicular to the stacking direction. In the following, the movement and rotation of the first reference mark RM1 will be described. Furthermore, it is easy to determine whether the first reference mark RM1 and the second reference mark RM2 are moved, thereby achieving precise assembly.

[0179] On the other hand, the first reference mark RM1 and the second reference mark RM2 may not overlap each other partially in the stacking direction. When the first region AR1 and the second region AR2 do not overlap each other at least partially in the stacking direction, the first diffraction element unit and the second diffraction element unit may be misaligned in a direction perpendicular to the stacking direction. Therefore, when the first region AR1 and the second region AR2 are at least partially misaligned in the stacking direction, the first substrate can be moved in a direction perpendicular to the stacking direction (horizontal direction) to prevent misalignment. Alternatively, when the first substrate and the second substrate are not parallel and one substrate is tilted, the substrates can be adjusted to be parallel to each other. Therefore, precise assembly can be performed with the first substrate and the second substrate aligned. Furthermore, misalignment can be easily prevented even when the first reference mark RM1 of the first substrate to be assembled is out of focus, and alignment can be easily determined even when the first substrate is not within the focal length of the imaging device. Therefore, damage to the individual diffraction element units can be prevented.

[0180] The first reference marker RM1 and the second reference marker RM2 may include a third region AR3 and a fourth region AR4 with different shapes. For example, the first reference marker RM1 may include the third region AR3, and the second reference marker RM2 may include the 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 each other in the stacking direction. Therefore, the third region AR3 and the fourth region AR4 may have different shapes.

[0181] As an implementation, the third region AR3 and the fourth region AR4 may have a region OV2 that at least partially overlaps with each other in the stacking direction. In this case, the first diffraction element unit and the second diffraction element unit may be at least partially misaligned in the stacking direction. When the third region AR3 and the fourth region AR4 at least partially overlap each other in the stacking direction, the first substrate may be moved in a direction perpendicular to the stacking direction (horizontal direction) or rotated about the stacking direction as an axis to prevent misalignment. Alternatively, when the first substrate and the second substrate are not parallel and one substrate is tilted, the substrates may be adjusted to be parallel to each other. Therefore, precise assembly can be performed with the first substrate and the second substrate aligned. In this way, rotational errors occurring between the first substrate and the second substrate (or between the first diffraction element unit and the second diffraction element unit) and movement errors occurring between the first substrate and the second substrate (or between the first diffraction element unit and the second diffraction element unit) due to movement in the horizontal direction can be easily identified by the third region AR3 and the fourth region AR4.

[0182] Furthermore, at least one of the first reference mark RM1 and the second reference mark RM2 may have a period different from the period of either the first diffraction element unit or the second diffraction element unit. For example, at least one of the first reference mark RM1 and the second reference mark RM2 may have a period larger than the period of either the first diffraction element unit or the second diffraction element unit.

[0183] For example, the periods of the first reference mark RM1 and the second reference mark RM2 may be different from the periods of the first diffraction element unit and the second diffraction element unit. The periods of the first reference mark RM1 and the second reference mark RM2 may be greater than the periods of the first diffraction element unit and the second diffraction element unit.

[0184] Furthermore, due to this period difference, the wavelength bands with minimum transmittance for the first reference mark RM1 and the second reference mark RM2 can differ from the diffraction wavelengths of the first and second diffraction element units. The wavelength band with minimum transmittance may not be a visible light wavelength band.

[0185] Due to this configuration, the reference markers and diffraction element units can have different periods, and therefore different transmittances for each wavelength of light. In particular, since the wavelength bands with the lowest transmittance differ from each other, marker recognition and image recognition can be achieved in different wavelength bands. For example, light can be diffracted and guided by the first and second diffraction element units in the visible light region, and the first and second reference markers can have high transmittance in the visible light region, thereby minimizing user identification of the reference markers. Furthermore, the user can more accurately visually identify the image provided by the projector. Additionally, the flexibility in the arrangement of multiple combiners (i.e., the first substrate (including the first diffraction element unit) and the second substrate (including the second diffraction element unit)) can be increased. For example, the first and second reference markers can be disposed inside or outside the eyepiece.

[0186] Further reference Figure 8 and Figure 9 The first reference marker RM1 and the second reference marker RM2 can differ from each other in at least one of their period, width, and height. The first reference marker RM1 and the second reference marker RM2 can have the same height. For example, the height H1 of the protrusion (or pattern) of the first reference marker RM1 can be equal to 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 can be different from the period P2 and / or width W2 of the protrusion (or pattern) of the second reference marker RM2. Due to this configuration, misalignment identification or precise assembly via machine vision can be performed in various wavelength bands. That is, compatibility with reference markers can be improved.

[0187] Furthermore, as another example, the first reference marker RM1 and the second reference marker RM2 can have the same period, width, and height. For example, the first reference marker RM1 and the second reference marker RM2 can have the same height, width, and period. For example, the height (width and period) of the protrusion (or pattern) of the first reference marker RM1 can be equal to the height (width and period) of the protrusion (or pattern) of the second reference marker RM2. Therefore, the wavelength band with the lowest transmittance of the first reference marker RM1 can be the same as the wavelength band with the lowest transmittance of the second reference marker RM2. Due to this configuration, misalignment between the first reference marker RM1 and the second reference marker RM2 can be identified more clearly in the wavelength band with the lowest transmittance. That is, misalignment identification via machine vision can be performed more efficiently. Therefore, misalignment identification and assembly accuracy can be improved.

[0188] The vector directions of the patterns of the first reference mark and the second reference mark can be the same.

[0189] Further reference Figure 10 OP1 corresponds to the reference marker with a period of 900 nm, a width of 630 nm, and a height of 200 nm. OP2 corresponds to the reference marker with a period of 800 nm, a width of 160 nm, and a height of 200 nm.

[0190] The wavelength corresponding to the minimum transmittance of OP1 is approximately 850 nm. The wavelength corresponding to the minimum transmittance of OP2 is approximately 950 nm. In this case, in machine vision, the application of OP1 and / or OP2 can be considered based on the wavelength used for visual recognition (e.g., the light-receiving wavelength band of the image sensor).

[0191] For example, when the wavelength at which visual recognition is possible is 950 nm, the first and second reference markers of OP1 can be applied. Therefore, misalignment can be more easily identified.

[0192] When the wavelength at which visual recognition is possible is 850 nm, the first and second reference markers of OP2 can be applied. Therefore, misalignment can be more easily identified.

[0193] In addition, when the wavelengths under which visual recognition can be performed are in the range of 950 nm and 850 nm, OP1 and OP2 can be applied to the first reference mark and the second reference mark.

[0194] Therefore, when two or more combiners (i.e., a first substrate and a second substrate on which patterned layers or diffraction element units are formed) are aligned, positional and rotational errors can be more easily identified, thereby achieving precise assembly. Thus, the light guide device according to the embodiment may include a first reference mark and a second reference mark, the first and second reference marks being spaced apart from each other and having regions that at least partially do not overlap each other in the stacking direction. Alternatively, the light guide device may include a first reference mark and a second reference mark, the first and second reference marks being spaced apart from each other and having regions that at least partially overlap each other in the stacking direction.

[0195] Figure 11 It is a graph showing the transmittance of a reference mark for each wavelength according to a structure of a light guide device according to an embodiment. Figure 12 It is a graph showing the transmittance of each wavelength of a reference mark in another structure of the optical guide device according to the embodiment.

[0196] exist Figure 11 and Figure 12In this context, "single" indicates a graph showing the transmittance of each wavelength in either the first or second reference mark under the same conditions (width, period, and height), or in a region where the first and second reference marks do not overlap in the stacking direction. "Overlapping" indicates a graph showing the case where the first and second reference marks overlap in the stacking direction under the same conditions (width, period, and height).

[0197] Reference Figure 10 and Figure 11 When the wavelength at which the applied visual recognition can be performed is 950 nm, the first and second reference marks of OP1 can be applied. Therefore, since the transmittance of the areas overlapping each other in the stacking direction is reduced to 25% or less, rotational or movement errors can be identified more clearly. Thus, misalignment can be identified more easily.

[0198] Reference Figure 10 and Figure 12 When the wavelength at which the applied visual recognition can be performed is 850 nm, the first and second reference marks of OP2 can be applied. Therefore, since the transmittance of the areas overlapping each other in the stacking direction is reduced to approximately 25%, rotational or movement errors can be identified more clearly. Thus, misalignment can be identified more easily.

[0199] In this way, in the light guide device according to the embodiment, the conditions (period, height, and width) of the reference mark are changed according to the wavelength under which visual recognition is possible, and different shapes (areas) are provided, thereby suppressing user recognition and accurately determining misalignment.

[0200] Figure 13 This is a view showing the arrangement of reference marks in the light guide device according to an embodiment.

[0201] Reference Figure 13 As described above, the first and second reference marks can have high transmittance in the visible light range, and thus minimize user identification of the reference marks. Furthermore, the user can more accurately visually identify the image provided by the projector. In this way, the first and second reference marks can have high transmittance in the visible light range, and therefore can be positioned in areas other than the region where the diffraction element unit is located.

[0202] For example, the first reference mark may be disposed in a region other than the first diffraction element units 312, 313 and 314. That is, the first reference mark may be disposed on the first substrate 311 without overlapping with the first diffraction element units 312, 313 and 314 in the stacking direction.

[0203] Similarly, the second reference mark can be disposed in the region other than the second diffraction element units 322, 323 and 324. That is, the second reference mark can be disposed on the second substrate 321 without overlapping with the second diffraction element units 322, 323 and 324 in the stacking direction.

[0204] In other words, the first reference mark and the second reference mark can be positioned in region PA1, which is located outside the eyebox and spaced apart from the diffraction element unit.

[0205] As a modification example, the first and second reference marks can also be positioned within region PA2 inside the eyebox. For example, the first and second reference marks can be positioned in areas or locations that do not affect image delivery. Additionally, within the eyebox, conditions (period, height, and width) different from those of the second diffraction element region (or fifth diffraction element region) can be set between the protrusions of the second diffraction element region (or fifth diffraction element region).

[0206] Therefore, the light guide device according to the embodiment can provide increased design freedom for the reference mark.

[0207] As a modification example, the first and second reference marks can be positioned outside the eyepiece. For example, the first and second reference marks can be positioned in region PA1. Furthermore, at least a portion of them can be identifiable by the user in the visible light region. Therefore, in addition to machine vision, the first and second reference marks can also be used as alignment marks during assembly. Thus, ease of manufacturing can be improved.

[0208] Figure 14 This is a view used to describe another example and position of the first and second reference marks in the light guide device according to the embodiment. Figure 15 This is a view used to describe yet another example and position of the first and second reference marks in the light guide device according to the embodiment. Figure 16 This is a view used to describe another example and position of the first and second reference marks in the light guide device according to the embodiment.

[0209] Figures 14 to 16 Examples of first and second reference markers are shown, based on various examples.

[0210] As described above, the first and second reference marks according to the embodiments may include a first region and a second region that overlap each other in the stacking direction, and a third region and a fourth region that do not overlap each other in the stacking direction.

[0211] Reference Figure 14 According to the embodiments, the first and second reference marks may respectively include a third region AR3 and a fourth region AR4 that do not overlap with each other at least partially in the stacking direction.

[0212] The first reference marker RM1 may include the third region AR3. The second reference marker RM2 may include the fourth region AR4.

[0213] When there is no misalignment (when aligned), the third region AR3 and the fourth region AR4 may appear slightly darker in the image obtained through machine vision. For example... Figure 12 As shown, approximately 50% of the transmitted light can appear in images obtained through machine vision.

[0214] When misalignment exists, the third region AR3 and the fourth region AR4 may have a region OV2 that at least partially overlaps with each other in the stacking direction. That is, the first diffraction element unit and the second diffraction element unit may be at least partially misaligned in the stacking direction. In this way, since the third region AR3 and the fourth region AR4 at least partially overlap each other in the stacking direction, the first substrate can be moved in a direction perpendicular to the stacking direction (horizontal direction) or rotated about the stacking direction as an axis to more easily prevent misalignment.

[0215] Reference Figure 15 According to the embodiments, the first and second reference marks may each be included in a third region in the stack that at least partially do not overlap with each other. and the fourth region The first reference marker RM1 may include the third region. The second reference mark RM2 may include the fourth region. .

[0216] In this case, with Figure 14 The situation shown is different, in the fourth region. The area can be set to be larger than the third region. The area is large. Therefore, since the reference mark is formed with a large area, the rotation of the first or second substrate in the stacking direction can be identified more clearly. The description of the cases where misalignment is absent and present is the same as the description of the cases described above.

[0217] In other words, as described above, when misalignment exists, the third region... and the fourth region It can have regions that at least partially overlap each other in the stacking direction. In other words, in this case, the degree of rotation about the stacking direction as an axis can be identified more clearly, thus making it easier to prevent misalignment between the first and second diffraction element units.

[0218] Reference Figure 16 According to the embodiments, the first and second reference marks may each be included in a third region in the stack that at least partially do not overlap with each other. and the fourth region The first reference marker RM1 may include the third region. The second reference mark RM2 may include the fourth region. .

[0219] In this case, with Figure 14 The situation shown is different, in the fourth region. and the third region At least one region in the equation can be formed as a closed loop. For example, the fourth region. and the third region It can be formed as a closed loop. In particular, the various regions can be arranged to intersect each other. Therefore, not only can the movement of the reference mark be identified more clearly, but its rotation can also be identified more clearly. The descriptions of the cases where misalignment is absent and present are the same as those described above.

[0220] In other words, as described above, when misalignment exists, the third region... and the fourth region It can have regions that at least partially overlap each other in the stacking direction. That is, in this case, the degree of rotation about the stacking direction as an axis can be more clearly identified, thereby making it easier to prevent misalignment between the first diffraction element unit and the second diffraction element unit.

[0221] The features, structures, effects, etc., described above in the embodiments are included in at least one embodiment, but are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc., exemplified in each embodiment can be combined, modified, and implemented in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, content related to these combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0222] Although the invention has been described with reference to embodiments, these are merely examples and are not intended to limit the embodiments. Those skilled in the art will understand that various modifications and applications not illustrated above are possible without departing from the essential characteristics of these embodiments. For example, each component specifically shown in the embodiments can be implemented using modifications. Furthermore, differences related to modifications and applications should be interpreted as including within the scope of the embodiments as defined in the appended claims.

Claims

1. A light guiding device, comprising: First substrate; A first diffraction element unit disposed on the first substrate; A second substrate is configured to be spaced apart from the first substrate; A second diffraction element unit disposed on the second substrate; A first reference mark is disposed on the first substrate; as well as A second reference mark is disposed on the second substrate. Wherein, the first reference mark and the second reference mark do not overlap each other at least partially in the stacking direction.

2. The optical guide device according to claim 1, wherein, The period of the first reference mark and the period of the second reference mark are different from the period of either the first diffraction element unit or the second diffraction element unit.

3. The optical guide device according to claim 2, wherein, The period of the first reference mark and the period of the second reference mark are both greater than the period of either the first diffraction element unit or the second diffraction element unit.

4. The optical guide device according to claim 1, wherein, The wavelength bands with minimum transmittance of the first and second reference marks are different from the diffraction wavelengths of each of the first and second diffraction element units.

5. The optical guide device according to claim 1, wherein, The first reference mark and the second reference mark are positioned inside the eye box.

6. The optical guide device according to claim 1, wherein, The first reference mark and the first substrate have a refractive index difference of 0 to 1.

7. The optical guide device according to claim 1, wherein, The first reference mark and the first diffraction element unit are made of the same material.

8. The optical guide device according to claim 1, wherein, The second reference mark and the second diffraction element unit are made of the same material.

9. The optical guide device according to claim 1, wherein, The first reference mark, the second reference mark, the first diffraction element unit, and the second diffraction element unit comprise polymers. , , and At least one of them.

10. The light guide device according to claim 1, wherein, The wavelength band with minimum transmittance of the first reference mark is the same as the wavelength band with minimum transmittance of the second reference mark.

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