Light guide device and electronic device including same

Abstract

A light guide device according to an embodiment of the present invention comprises: an input diffraction element; a transmission diffraction element; and a substrate on which the input diffraction element and the transmission diffraction element are disposed, wherein the transmission diffraction element includes a first region and a second region formed by dividing the transmission diffraction element in two, the first region includes a first grating pattern, the height of the first grating pattern changes with distance from the input diffraction element, the second region includes a second grating pattern, the height of the second grating pattern also changes with distance from the input diffraction element, and the height of the first grating pattern and the height of the second grating pattern may be different from each other.

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, and more specifically, to a light guide device including a diffraction element for changing the direction of leaking light and an electronic device including the same.

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

[0003] Augmented Reality (AR) refers to a technology that superimposes virtual objects or information onto a real environment to make them appear as if they exist in the original environment.

[0004] Mixed Reality (MR) or Hybrid Reality refers to the creation of new environments or new information by combining the virtual world and the real world. In particular, it is called Mixed Reality when referring to the ability to interact in real time between things existing in the real world and the virtual world.

[0005] In this case, the created virtual environment or situation stimulates the user's five senses and enables spatial and temporal experiences similar to reality, thereby allowing the user to freely cross the boundary between reality and imagination. Furthermore, the user can not only simply immerse themselves in this environment but also interact with the elements implemented within it, such as by using actual devices to perform operations or issue commands.

[0006] Recently, active research has been conducted on equipment (gear, devices) used in these technological fields. In particular, these devices include diffraction elements that perform the functions of diffraction and / or total internal reflection of incident light. However, there is a problem in that increasing the diffraction efficiency of the diffraction element can lead to reduced light uniformity because light cannot be transmitted, while increasing the total internal reflection efficiency lowers the overall efficiency of the device; therefore, research is being conducted to resolve these issues.

[0007] The technical problem to be solved by the present invention is to provide a light guide device with improved light diffraction efficiency and uniformity of light output, and an electronic device including the same.

[0008] In addition, the technical problem that the present invention aims to solve is to provide a miniaturized light guide device and an electronic device including the same by improving the light diffraction efficiency and the uniformity of light output.

[0009] In addition to this, the technical problems that the present invention aims to solve are not limited to those described above, and other technical problems may exist.

[0010] A light guide device according to an embodiment of the present invention comprises an input diffraction element, a transfer diffraction element, and a substrate on which the input diffraction element and the transfer diffraction element are arranged. The transfer diffraction element comprises a first region and a second region formed by being divided into two parts. The first region comprises a first grating pattern, and the height of the first grating pattern changes in a direction away from the input diffraction element. The second region comprises a second grating pattern, and the height of the second grating pattern also changes in a direction away from the input diffraction element. The heights of the first grating pattern and the second grating pattern may be different from each other.

[0011] A light guide device according to an embodiment of the present invention further includes an output diffraction element, and the second region may be disposed between the first region and the output diffraction element.

[0012] In a light guide device according to an embodiment of the present invention, the transfer diffraction element includes a first side closest to the input diffraction element, a second side facing the first side, and a third side and a fourth side disposed between the first side and the second side and disposed to face each other, wherein the first region and the second region are distinguished by a first line, the first line is a line connecting the center of the first side and the center of the second side, and the length of the first side may be shorter than the length of the second side.

[0013] In a light guide device according to an embodiment of the present invention, the maximum height of the first grid pattern may be greater than the maximum height of the second grid pattern.

[0014] In a light guide device according to an embodiment of the present invention, the difference between the highest and lowest heights of the first grid pattern may be greater than the difference between the highest and lowest heights of the second grid pattern.

[0015] In a light guide device according to an embodiment of the present invention, the lowest height of the first grid pattern may be equal to or greater than the lowest height of the second grid pattern.

[0016] In a light guide device according to an embodiment of the present invention, among the regions into which the first region is divided into a plurality of parts, the region furthest from the input diffraction element may have the highest height of the first grating pattern.

[0017] In a light guide device according to an embodiment of the present invention, the region with the smallest height difference between the first grating pattern and the second grating pattern may be the region closest to the input diffraction element among the regions into which the first region is divided into multiple parts.

[0018] In a light guide device according to an embodiment of the present invention, the region with the largest height difference between the first grating pattern and the second grating pattern may be the region furthest from the input diffraction element among the regions into which the first region is divided into multiple parts.

[0019] In a light guide device according to an embodiment of the present invention, the height of the second grid pattern may be highest in the middle region or the region located next to the middle among the regions in which the second region is divided into a plurality of regions.

[0020] An electronic device according to an embodiment of the present invention includes a frame, a projection device, and a light guide device. The light guide device includes an input diffraction element, a transfer diffraction element, and a substrate on which the input diffraction element and the transfer diffraction element are arranged. The transfer diffraction element includes a first region and a second region formed by being divided into two parts. The first region includes a first grating pattern, and the height of the first grating pattern changes in a direction away from the input diffraction element. The second region includes a second grating pattern, and the height of the second grating pattern also changes in a direction away from the input diffraction element. The heights of the first grating pattern and the second grating pattern may be different from each other.

[0021] According to an embodiment of the present invention, a light guide device with improved light diffraction efficiency and uniformity of light output can be provided.

[0022] According to an embodiment of the present invention, the diffraction efficiency of light and the uniformity of light output are improved, thereby providing a miniaturized light guide device and an electronic device including the same.

[0023] In addition to these, the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0024] FIG. 1 is a block diagram showing the configuration of an electronic device including a light guide device according to an embodiment of the present invention.

[0025] FIG. 2 is a perspective view of an electronic device including a light guide device according to an embodiment of the present invention.

[0026] FIG. 3 is a schematic diagram of a light guide device according to an embodiment of the present invention.

[0027] FIG. 4 is a drawing showing the grating pattern of a diffraction element included in a light guide device according to an embodiment of the present invention.

[0028] FIGS. 5a to 5e show various examples to compare the uniformity and efficiency of an optical guide device according to the modulation dimension of a transfer diffraction element.

[0029] FIG. 6 is a drawing showing an optical guide device including a 6x2 divided transfer diffraction element according to one embodiment of the present invention.

[0030] Figures 7a and 7b show the distribution of diffraction efficiency and reflection efficiency according to the height of the grating pattern and the fill factor in a transfer diffraction element.

[0031] FIGS. 8A and 8B are graphs showing the change in height and efficiency according to each column of a transfer diffraction element according to an embodiment of the present invention.

[0032] FIGS. 9a and 9b are graphs showing the efficiency according to each column of a transfer diffraction element including a 7x2 region according to an embodiment of the present invention.

[0033] FIG. 10 is a diagram showing an example of a grating pattern of a diffraction element included in a light guide device according to an embodiment of the present invention.

[0034] FIG. 11 is a perspective view showing an example of a grating pattern in the transfer diffraction element of FIG. 9b.

[0035] FIG. 12a is a diagram showing the divided regions of the transfer diffraction element of FIG. 11, FIG. 12b is a side view of the first column of the transfer diffraction element, and FIG. 12c is a side view of the second column of the transfer diffraction element.

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0037] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0038] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0039] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0040] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0041] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0042] These terms are intended merely to distinguish a component from other components and are not limited by the essence, order, sequence, etc. of the component.

[0043] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0044] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0045] Extended Reality (XR) is a collective term for Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). VR technology provides real-world objects or backgrounds solely as CG images, AR technology provides virtual CG images superimposed on real-world images, and MR technology provides virtual objects mixed and combined with the real world.

[0046] MR technology is similar to AR technology in that it displays real-world objects and virtual objects together. However, there is a difference in that while virtual objects in AR technology are used to complement real-world objects, virtual objects and real-world objects are used as equals in MR technology.

[0047] XR technology can be applied to HMDs (Head-Mount Displays), HUDs (Head-Up Displays), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

[0048] Hereinafter, an electronic device providing augmented reality according to an embodiment of the present invention will be described. In particular, a projection device applied to augmented reality and an electronic device including the same will be described in detail.

[0049] FIG. 1 is a block diagram showing the configuration of an electronic device including a light guide device according to an embodiment of the present invention.

[0050] Referring to FIG. 1, an electronic device (10) including a light guide device may include a wireless communication unit (11), an input unit (12), a sensing unit (13), an output unit (14), an interface unit (15), a memory (16), a control unit (17), and a power supply unit (18), etc. Since the components illustrated in FIG. 1 are not essential for implementing the electronic device (10), the electronic device (10) described herein may have more or fewer components than those listed above.

[0051] More specifically, among the above components, the wireless communication unit (11) may include one or more modules that enable wireless communication between the electronic device (10) and a wireless communication system, between the electronic device (10) and another electronic device, or between the electronic device (10) and an external server. Additionally, the wireless communication unit (11) may include one or more modules that connect the electronic device (10) to one or more networks.

[0052] This wireless communication unit (11) 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.

[0053] The input unit (12) may include a camera or video input unit for inputting a video signal, a microphone or audio input unit for inputting an audio signal, and a user input unit for receiving information from a user (e.g., a touch key, a push key, etc.). Voice data or image data collected from the input unit (12) may be analyzed and processed into a user's control command.

[0054] The sensing unit (13) may include one or more sensors for detecting at least one of information within the electronic device (10), information about the surrounding environment surrounding the electronic device (10), and user information.

[0055] For example, the sensing unit (13) may include at least one of a proximity sensor, an illumination sensor, a touch sensor, an acceleration sensor, a magnetic sensor, a gravity sensor (G-sensor), a gyroscope sensor, a motion sensor, an RGB sensor, an infrared sensor (IR sensor: infrared sensor), a fingerprint sensor (finger scan sensor), an ultrasonic sensor, an optical sensor (e.g., a shooting means), 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 sensor, etc.). Meanwhile, the electronic device (10) disclosed in this specification may utilize information detected by at least two of these sensors in combination.

[0056] The output unit (14) is intended to generate output related to sight, hearing, or touch, 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 form a layered structure with the touch sensor or be formed integrally to implement a touch screen. Such a touch screen functions as a user input means that provides an input interface between the electronic device (10) and the user, and at the same time can provide an output interface between the electronic device (10) and the user.

[0057] The interface section (15) serves as a channel for various types of external devices connected to the electronic device (10). Through the interface section (15), the electronic device (10) can receive content from the external device and interact by exchanging various input signals, sensing signals, and data.

[0058] For example, the interface section (15) 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.

[0059] Additionally, the memory (16) stores data that supports various functions of the electronic device (10). The memory (16) can store a number of applications (application programs or applications) running on the electronic device (10), data for the operation of the electronic device (10), and instructions. At least some of these applications may be downloaded from an external server via wireless communication. Additionally, at least some of these applications may exist on the electronic device (10) from the time of shipment for the basic functions of the electronic device (10) (e.g., phone incoming and outgoing functions, message receiving and outgoing functions).

[0060] In addition to operations related to the application, the control unit (17) can generally control the overall operation of the electronic device (10). The control unit (17) can process signals, data, information, etc. that are input or output through the components described above.

[0061] Additionally, the control unit (17) can control at least some of the components by running an application program stored in the memory (16) to provide appropriate information to the user or process functions. Furthermore, the control unit (17) can operate at least two or more of the components included in the electronic device (10) in combination with each other to run the application program.

[0062] Additionally, the control unit (17) can detect the movement of the electronic device (10) or the user by using a gyroscope sensor, gravity sensor, motion sensor, etc. included in the sensing unit (13). Alternatively, the control unit (17) can detect an object approaching the electronic device (10) or the user by using a proximity sensor, light sensor, magnetic sensor, infrared sensor, ultrasonic sensor, light sensor, etc. included in the sensing unit (13). Furthermore, the control unit (17) can also detect the movement of the user through sensors provided in a controller that operates in conjunction with the electronic device (10).

[0063] In addition, the control unit (17) can perform the operation (or function) of the electronic device (10) using an application program stored in the memory (16).

[0064] The power supply unit (18) can supply power to each component included in the electronic device (10) by receiving external power or internal power under the control of the control unit (17). The power supply unit (18) includes a battery, and the battery may be provided in a built-in or replaceable form.

[0065] At least some of the above components may operate in cooperation with each other to implement the operation, control, or control method of an electronic device according to various embodiments described below. Additionally, the operation, control, or control method of an electronic device may be implemented on the electronic device by running at least one application program stored in memory (16).

[0066] FIG. 2 is a perspective view of an electronic device including a light guide device according to an embodiment of the present invention.

[0067] As illustrated in FIG. 2, an electronic device according to an embodiment of the present invention may include a frame (100), a project device (200), and a display unit (300).

[0068] The electronic device may be of the smart glass type. The smart glass type electronic device is configured to be wearable on the head of the human body and may be provided with a frame (case, housing, etc.) (100) for this purpose. The frame (100) may be formed of a flexible material to facilitate wearing.

[0069] The frame (100) is supported on the head and provides a space for mounting various components. As illustrated, electronic components such as a projector (200), a user input unit (130), or an audio output unit (140) may be mounted on the frame (100). Additionally, a lens covering at least one of the left and right eyes may be detachably mounted on the frame (100).

[0070] As shown in the drawing, the frame (100) may have the form of glasses worn on the face of the user, but is not necessarily limited thereto and may have the form of goggles worn in close contact with the user's face.

[0071] Such a frame (100) may include a front frame (110) having at least one opening, and a pair of side frames (120) that extend in the y direction (in FIG. 2) intersecting the front frame (110) and are parallel to each other.

[0072] The frame (100) may have the same or different length (D1) in the x direction and length (L1) in the y direction.

[0073] The projection device (200) is configured to control various electronic components equipped in an electronic device. The projection device (200) may be used interchangeably with 'light output device', 'light projection device', 'light irradiation device', 'optical device', etc.

[0074] The projection device (200) can generate an image or a continuous video of images that is displayed to the user. The projection device (200) may include an image source panel that generates an image and a plurality of lenses that diffuse and converge the light generated from the image source panel.

[0075] 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 formed integrally by being embedded inside one of the side frames (120). Alternatively, the project device (200) may be fixed to the front frame (110) or provided separately from the electronic device.

[0076] The display unit (300) can be implemented in the form of a head-mounted display (HMD). A head-mounted display refers to a display method that is mounted on the head and displays an image directly in front of the user's eyes. In order to provide an image directly 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 eye and the right eye. In this drawing, the display unit (300) is exemplified as being located in the part corresponding to the right eye so as to output an image toward the user's right eye. However, as described above, it is not limited to this and may be positioned on both the left eye and the right eye.

[0077] The display unit (300) can allow the user to visually perceive the external environment while simultaneously displaying an image generated by the projection device (200) to the user. For example, the display unit (300) can project an image onto a display area using a prism.

[0078] And the display unit (300) may be formed to be transparent so that the projected image and the general field of view in front (the range the user looks at through their eyes) can be seen simultaneously. For example, the display unit (300) may be translucent and may be formed of an optical member including glass.

[0079] The display unit (300) may be inserted into and fixed to an opening included in the front frame (110), or positioned on the back of the opening [i.e., between the opening and the user] and fixed to the front frame (110). Although the drawing illustrates an example where the display unit (300) is positioned on the back of the opening and fixed to the front frame (110), the display unit (300) may be positioned and fixed at various locations on the frame (100).

[0080] As shown in FIG. 2, when an image light for an image is incident on one side of a display unit (300) from a projection device (200), the image light is emitted through the display unit (300) to the other side, thereby allowing the image generated by the projection device (200) to be shown to the user.

[0081] Accordingly, the user can view the external environment through the opening of the frame (100) while simultaneously viewing the image generated by the projection device (200). That is, the image output through the display unit (300) can be seen overlapping with the normal field of view. The electronic device can utilize these display characteristics to provide Augmented Reality (AR), which superimposes a virtual image onto a real image or background to display it as a single image.

[0082] Furthermore, in addition to this operation, the external environment and the image generated by the projection device (200) may be provided to the user with a time difference for a short period that is not perceived by the user. For example, within a single frame, the external environment may be provided to the user in one section, and the image from the projection device (200) may be provided to the user in another section. Alternatively, both overlap and time difference may be provided.

[0083] The display unit below may be represented as a light guide device. The light guide device according to the embodiment may correspond to the display unit included in the electronic device described above.

[0084] The first direction below may correspond to the X-axis direction on the drawing, and the second direction may correspond to the Y-axis direction on the drawing. The first direction and the second direction may be directions perpendicular to each other. Additionally, the third direction may be the opposite direction to the second direction. The first direction, the second direction, and the third direction may be directions perpendicular to the optical axis direction.

[0085] FIG. 3 is a schematic diagram of a light guide device according to an embodiment of the present invention.

[0086] Referring to FIG. 3, the light guide device (300) according to the embodiment may include a substrate (310), an input diffraction element (320), a transfer diffraction element (330), and an output diffraction element (340). Additionally, the light guide device (300) may include a cover (350).

[0087] The light guide device (300) can change the path of the incident light output from the projector device (200) and output the light to the outside again. The light can be sequentially incident on an input diffraction element, a substrate, a transfer diffraction element, and an output diffraction element and output to the outside again. The direction of incidence of the light to the light guide device (300) may be a third direction. The third direction may mean the direction of incidence of the light or the opposite direction. Additionally, the third direction may mean the direction of the optical axis.

[0088] The substrate (310) can serve as a path for transmitting light. The substrate (310) can transmit light. An input diffraction element (320), a transfer diffraction element (330), and an output diffraction element (340) may be disposed on the substrate (310). Light may travel along the interior of the substrate (310) by total internal reflection within the substrate (310). The input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340) may be disposed spaced apart from each other on the substrate (310). The substrate (310) may be disposed in a second direction.

[0089] The input diffraction element (320) can serve as a path for incident light. The input diffraction element (320) can be placed on the substrate (310). Light can be incident from the outside through the input diffraction element (320) to the light guide device (300) and transmitted through the substrate (310). The input diffraction element (320) can change the path of light by diffracting the light. The input diffraction element (320) can be placed adjacent to the transfer diffraction element (330). Light diffracted from the input diffraction element (320) can be transmitted through the substrate (310) and reach the transfer diffraction element (330). Here, the input diffraction element (320) and the transfer diffraction element (330) are described as distinct separate diffraction elements, but the input diffraction element (320) and the transfer diffraction element (330) may be composed of a single diffraction element.

[0090] The transfer diffraction element (330) can change the path of light. The transfer diffraction element (330) can also be placed on the substrate (310) just like the input diffraction element (320). The transfer diffraction element (330) can change the path of light incident through the input diffraction element (320). The transfer diffraction element (330) can change the path of light so that it is directed toward the output diffraction element (340). The transfer diffraction element (330) can change the path of light by diffracting the light. The transfer diffraction element (330) can be placed between the input diffraction element (320) and the output diffraction element (340) in the path of light.

[0091] The output diffraction element (340) can serve as a path for light to be emitted. The output diffraction element (340) can also be placed on the substrate (310). Light can be emitted to the outside of the light guide device (300) through the output diffraction element (340). The output diffraction element (340) can receive light with a changed path from the transfer diffraction element (330) and emit it to the outside. The output diffraction element (340) can change the path of the light and emit it to the outside. The output diffraction element (340) can change the path of the light by diffracting the light.

[0092] In FIG. 3, an input diffraction element (320), a transfer diffraction element (330), and an output diffraction element (340) are shown disposed on a single substrate (310), but they may be disposed separately on multiple substrates. For example, the input diffraction element (320) and the transfer diffraction element (330) may be disposed on one substrate, and the output diffraction element (340) may be disposed on another substrate. The number of substrates included in the light guide device (300) may not be limited.

[0093] A cover (350) may be placed on a substrate (310), an input diffraction element (320), a transfer diffraction element (330), and an output diffraction element (340). The cover (350) may be placed adjacent to a projector device (200) on the substrate (310), the input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340). Light irradiated by the projector device (200) may pass through the cover (350) and be incident on the input diffraction element (320). The cover (350) may serve to protect the interior of the light guide device (300).

[0094] FIG. 4 is a drawing showing the grating pattern of a diffraction element included in a light guide device according to an embodiment of the present invention.

[0095] Referring to FIG. 4, the input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340) included in the light guide device may each have a grating pattern in which a plurality of protrusions are repeatedly arranged. The plurality of protrusions have a constant width, period, and height and may be arranged on the input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340). The plurality of protrusions may protrude in the direction of the optical axis on the input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340). The plurality of protrusions may be spaced apart in the vector direction of the pattern containing the protrusions. Depending on the width, period, and height of the plurality of protrusions, the path of light may change differently after passing through the input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340). The grating period (or period) of a diffraction element can be defined as the shortest distance between one side of a protrusion and one side of an adjacent protrusion. The grating period of a diffraction element can be the shortest distance between identical sides of a protrusion.

[0096] The grating vector of the diffraction element may consist of a direction and a magnitude, the direction may be the direction of separation of adjacent protrusions of the diffraction element, and the magnitude may be the grating period. The direction of the grating vector may be the angle (i.e., azimuth) that the grating vector makes with the first direction. The first direction is perpendicular to the optical axis direction and may be the direction in which the input diffraction element (320) is separated from the output diffraction element (340). For example, the first direction may be the horizontal direction in which the substrate is placed. The first direction may refer to the X-axis direction of FIG. 4.

[0097] The input diffraction element (320) may include a plurality of first protrusions (321). The grating period (λ1) of the input diffraction element (320), which is the magnitude of the grating vector of the input diffraction element (320), may be the shortest distance between one side of the first protrusion (321) and one side of the adjacent first protrusion (321). Additionally, the grating period (λ1) of the input diffraction element (320) may be the shortest distance between the same sides of adjacent first protrusions (321). The direction (φ1) of the grating vector of the input diffraction element (320) may be the direction of separation of the adjacent first protrusions (321) of the input diffraction element (320). The angle of the direction (φ1) of the grating vector of the input diffraction element (320) may be the angle formed by the grating vector of the input diffraction element (320) with the first direction.

[0098] The transfer diffraction element (330) may include a plurality of second protrusions (331). The grating period (λ2) of the transfer diffraction element (330), which is the magnitude of the grating vector of the transfer diffraction element (330), may be the shortest distance between one side of the second protrusion (331) and one side of the adjacent second protrusion (331). Additionally, the grating period (λ2) of the transfer diffraction element (330) may be the shortest distance between the same sides of adjacent second protrusions (331). The direction (φ2) of the grating vector of the transfer diffraction element (330) may be the direction of separation of the adjacent second protrusions (331) of the transfer diffraction element (330). The angle of the direction (φ2) of the grating vector of the transfer diffraction element (330) may be the angle formed by the grating vector of the transfer diffraction element (330) with the first direction.

[0099] The output diffraction element (340) may include a plurality of third protrusions (341). The grating period (λ3) of the output diffraction element (340), which is the magnitude of the grating vector of the output diffraction element (340), may be the shortest distance between one side of the third protrusion (341) and one side of the adjacent third protrusion (341). Additionally, the grating period (λ3) of the output diffraction element (340) may be the shortest distance between the same sides of adjacent third protrusions (341). The direction (φ3) of the grating vector of the output diffraction element (340) may be the direction of separation of the adjacent third protrusions (341) of the output diffraction element (340). The angle of the direction (φ3) of the grating vector of the output diffraction element (340) may be the angle formed by the grating vector of the output diffraction element (340) with the first direction.

[0100] In FIG. 4, each diffraction element is described as being composed of a single region and having a single grating pattern, but each diffraction element may be composed of multiple regions.

[0101] The present invention relates to a transfer diffraction element among a plurality of diffraction elements included in an optical guide device, and proposes a transfer diffraction element capable of increasing the efficiency and uniformity of the optical guide device.

[0102] A transfer diffraction element that may include multiple regions can be distinguished as one-dimensional modulation or two-dimensional modulation depending on how the multiple regions are divided.

[0103] FIGS. 5a to 5e show various examples to compare the uniformity and efficiency of an optical guide device according to the modulation dimension of a transfer diffraction element.

[0104] Specifically, in FIG. 5a, the transfer diffraction element (510) is configured as a single region. The uniformity of the light guide device including the transfer diffraction element (510) configured as a single region is distributed over a wide range, and the efficiency is relatively low. Here, efficiency represents the final efficiency of light entering the human eye. FIG. 5b shows the uniformity and efficiency of the light guide device including the transfer diffraction element (520) divided into a 3x1 region, FIG. 5c shows the uniformity and efficiency of the light guide device including the transfer diffraction element (530) divided into a 5x1 region, and FIG. 5d shows the uniformity and efficiency of the light guide device including the transfer diffraction element (540) divided into a 7x1 region. FIG. 5a to 5d show a light guide device including a one-dimensional modulated transfer diffraction element, and it can be seen from FIG. 5a to 5d that the efficiency does not exceed 0.0055 and the uniformity is not high. In other words, it can be seen that even if the number of regions of a one-dimensional modulated transfer diffraction element increases, there are limitations to the efficiency and uniformity of the optical guide device containing it.

[0105] FIG. 5e shows the uniformity and efficiency of a two-dimensional modulated transfer diffraction element and an optical guide device including it. In FIG. 5e, the transfer diffraction element (550) is divided into a 6x2 area. Looking at the graph showing the uniformity and efficiency in FIG. 5e, it can be seen that the uniformity of the optical guide device including the two-dimensional modulated transfer diffraction element does not change significantly compared to one-dimensional modulation, but the efficiency has increased.

[0106] The following describes the structure of a two-dimensional modulated transfer diffraction element capable of increasing efficiency. First, Figure 6 describes in detail a plurality of regions included in the two-dimensional modulated transfer diffraction element.

[0107] FIG. 6 is a drawing showing an optical guide device including a transfer diffraction element divided into a 6x2 region according to one embodiment of the present invention.

[0108] Referring to FIG. 6, the light guide device (600) may include an input diffraction element (610), a transfer diffraction element (620), and an output diffraction element (630). The input diffraction element (610) and the output diffraction element (630) are no different from those described in FIG. 4, so a description thereof is omitted here.

[0109] According to one embodiment, the shape of the transfer diffraction element (620) may be rectangular. Accordingly, the transfer diffraction element (620) may be composed of four sides. For convenience of explanation, the side closest to the input diffraction element (610) in the transfer diffraction element (620) may be referred to as the first side (621), the side furthest from it as the second side (622), the side furthest from the output diffraction element (630) as the third side (623), and the side closest to it as the fourth side (624). Accordingly, the first side (621) and the second side (622) may face each other, and the third side (623) and the fourth side (624) may face each other. In FIG. 6, the lengths of the sides may be in the order of the third side (623) being the longest, followed by the fourth side (624), the second side (622), and the first side (621), but are not limited thereto. Also, the line connecting the center of the first side (621) and the center of the second side (622) may be referred to as the first line (625). FIG. 6 shows the first line (625) connecting the center of the first side (621) and the second side (622), but the first line may be a line connecting the center of the input diffraction element (610) and the center of the second side (622). Alternatively, the first line may be a line connecting a point on the first side (621) and a point on the second side (622). That is, the first line (625) may be a line formed in the transfer diffraction element (620) in a direction extending from the input diffraction element (610) in a direction closer to it. Among the regions of the transfer diffraction element (620) divided by the first line (625), the region far from the output diffraction element (630) may be referred to as the first region or first column, and the region close to it may be referred to as the second region or second column. Additionally, the second line (626) may be a line vertically connected from the center of the output diffraction element (630) to the first line (625).Likewise, in FIG. 6, a second line (626) is shown perpendicularly connected to the first line (625) from the center of the output diffraction element (630), but the second line may be a line connecting the center of the output diffraction element (630) to the center of the line connecting the center of the input diffraction element (610) and the center of the second side (622). In this case, the second line may not be perpendicular to the first line, but may be within ±5% of perpendicular.

[0110] According to one embodiment, the third side (623) and the fourth side (624) of the transfer diffraction element (620) may be divided into six equal parts, and each point of the six divisions may be connected to form a transfer diffraction element (620) that includes a 6x2 region. Alternatively, the third side (623) and the fourth side (624) of the transfer diffraction element (620) may be arbitrarily divided into six parts, and each point may be connected to form a transfer diffraction element (620) that includes a 6x2 region. For example, the spacing between the arbitrarily divided six points may gradually widen or narrow. Alternatively, the transfer diffraction element (620) may be divided by a line parallel to the second line to include a 6x2 region. However, it is not limited thereto. The area divided by sequentially connecting points on the third side (623) and the fourth side (624) can be referred to as a row, and can be referred to as the first row, the second row, etc., in order of proximity to the input diffraction element (610). In FIG. 6, the third side (623) and the fourth side (624) are divided into six parts, but they can be divided into fewer or more parts.

[0111] Figure 6 describes a method for dividing regions of a transfer diffraction element. Below, a grating pattern within the transfer diffraction element is described to increase the efficiency of an optical guide device including the transfer diffraction element disclosed in Figure 6.

[0112] Figures 7a and 7b show the distribution of diffraction efficiency and reflection efficiency according to the height of the grating pattern and the fill factor in a transfer diffraction element.

[0113] Here, the grating material of the transfer diffraction element is TiO2, and the refractive indices of TiO2 are 2.542, 2.453, and 2.394 at wavelengths of light of 455 nm, 528 nm, and 621 nm, respectively, and the lattice period is 273.8 nm. The fill factor represents the ratio of the active region to the total region and can be calculated as shown in [Equation 1] below.

[0114] [Mathematical Formula 1]

[0115] fill factor = width of protruding part / period

[0116] The protruding parts and grid period are as described in Fig. 4, and the fill factor has a value between 0 and 1. The fill factor is also called the duty.

[0117] Referring to Figures 7a and 7b, the sum of the diffraction efficiency and the reflection efficiency is approximately 1. Here, reflection efficiency refers to the efficiency of total reflection when light diffracted once in a diffraction grating. When the height of the grating pattern is 150 nm or less, the high reflection efficiency is distinct, and the trends of the diffraction efficiency and the reflection efficiency are simple.

[0118] Accordingly, in the following embodiment, the trend of the height of the grating pattern that increases the diffraction efficiency of each column of the transfer diffraction element is confirmed so that the final efficiency of the light guide device is increased within a constant or similar range of fill factor.

[0119] In the first column, if the fill factor is greater than 0.2 and less than 0.3, the final efficiency of the light guide device increases as the height of the grating pattern increases in the range where the height of the grating pattern is greater than 20 nm and less than 150 nm. If the fill factor is greater than 0.3 and less than 0.5, the final efficiency of the light guide device increases as the height of the grating pattern increases in the range where the height of the grating pattern is greater than 20 nm and less than 120 nm. If the fill factor is greater than 0.5 and less than 0.6, the final efficiency of the light guide device increases as the height of the grating pattern increases in the range where the height of the grating pattern is greater than 20 nm and less than 100 nm. Finally, if the fill factor is greater than 0.6 and less than 0.8, the final efficiency of the light guide device increases as the height of the grating pattern increases in the range where the height of the grating pattern is greater than 20 nm and less than 150 nm.

[0120] In the second column, if the fill factor is less than 0.3, the change in height of the grating pattern with high final efficiency of the optical guide device increases and then decreases in the range where the height of the grating pattern is greater than 20 nm and less than 150 nm. If the fill factor is greater than 0.3 and less than 0.5, the change in height of the grating pattern with high final efficiency of the optical guide device increases and then decreases in the range where the height of the grating pattern is greater than 20 nm and less than 120 nm. If the fill factor is greater than 0.5 and less than 0.6, the change in height of the grating pattern with high final efficiency of the optical guide device increases and then decreases in the range where the height of the grating pattern is greater than 20 nm and less than 100 nm. Finally, if the fill factor is greater than 0.6 and less than 0.8, the change in height of the grating pattern with high final efficiency of the optical guide device increases and then decreases in the range where the height of the grating pattern is greater than 20 nm and less than 150 nm.

[0121] The minimum height of the grid pattern was set to 20 nm, but changing it to 10 nm did not affect the above results; however, if the maximum is greater than 150 nm, the total reflection efficiency may decrease, making it difficult to transmit light in the direction of light propagation.

[0122] In summary, in the first column, regardless of the fill factor, the final efficiency of the optical guide device may improve as the height of the grating pattern increases when the height is between 20 nm and 100 nm, but the final efficiency of the optical guide device may vary depending on the fill factor when the height is between 100 nm and 150 nm. In the second column, regardless of the fill factor, the final efficiency of the optical guide device may improve when the height of the grating pattern increases and then decreases when the height is between 20 nm and 100 nm, but the final efficiency of the optical guide device may vary depending on the fill factor when the height is between 100 nm and 150 nm.

[0123] In another embodiment, the trend of the fill factor of the grid pattern was confirmed, in which the final efficiency of the light guide device of each column is increased when the height of the grid pattern is fixed or similar at 150 nm or less.

[0124] In the first column, when the height of the grid pattern is greater than 20 nm and less than 100 nm, the final efficiency of the light guide device increases as the fill factor increases in the range where the fill factor is greater than 0.2 and less than 0.55. On the other hand, in the range where the fill factor is greater than 0.55 and less than 0.8, the final efficiency of the light guide device increases as the fill factor decreases.

[0125] If the height of the grid pattern in the first column is greater than 100 nm and less than 150 nm, and the fill factor is greater than 0.55, the final efficiency of the light guide device increases as the fill factor decreases. If the fill factor is greater than 0.4 and less than 0.55, the final efficiency of the light guide device increases as the fill factor increases. If the fill factor is less than 0.4, the final efficiency of the light guide device increases as the fill factor increases.

[0126] In the second column, when the height of the grating pattern is greater than 20 nm and less than 100 nm, the change in the fill factor that increases the final efficiency of the optical guide device increases in the range where the fill factor is greater than 0.2 and less than 0.55, and then decreases. In the range where the fill factor is greater than 0.55 and less than 0.8, the change in the fill factor that increases the final efficiency of the optical guide device decreases and then increases. However, when the fill factor is greater than 0.2 and greater than 0.55, a tendency may appear in which the fill factor increases and then decreases, or decreases and then increases.

[0127] In the second column, when the height of the grating pattern is greater than 100 nm and less than 150 nm, the change in the fill factor that increases the final efficiency of the optical guide device decreases and then increases in the range where the fill factor is greater than 0.55. In the range where the fill factor is less than 0.4, the change in the fill factor that increases the final efficiency of the optical guide device increases and then decreases. However, when the fill factor is greater than 0.4 and greater than 0.6, a tendency may appear in which the fill factor increases and then decreases, or decreases and then increases.

[0128] In another embodiment, the trend of the height and fill factor of the grid pattern was confirmed so that the final efficiency of the optical guide device of each column increases without fixing the height and fill factor when the height of the grid pattern is 150 nm or less.

[0129] In the first column, if the fill factor is greater than 0.2 and less than 0.3, the height of the grating pattern increases in the range greater than 20 nm and less than 150 nm, and the final efficiency of the optical guide device can be increased as the fill factor increases. If the fill factor is greater than 0.3 and less than 0.5, the height of the grating pattern increases in the range greater than 20 nm and less than 120 nm, and the final efficiency of the optical guide device can be increased as the fill factor increases. If the fill factor is greater than 0.5 and less than 0.6, the height of the grating pattern increases in the range greater than 20 nm and less than 100 nm, and the final efficiency of the optical guide device can be increased as the fill factor increases and then decreases, and the height of the grating pattern decreases in the range greater than 100 nm, and the final efficiency of the optical guide device can be increased as the fill factor increases. If the fill factor is greater than 0.6 and less than 0.8, the height of the grating pattern increases in the range greater than 20 nm and less than 150 nm, and if the fill factor decreases, the final efficiency of the light guide device can be increased.

[0130] In the second column, if the fill factor is greater than 0.2 and less than 0.3, the height of the lattice pattern may increase and then decrease as the height of the lattice pattern increases and then decreases, or the fill factor may increase. Alternatively, if the height of the lattice pattern increases, the fill factor may increase and then decrease.

[0131] In the second column, if the fill factor is greater than 0.3 and less than 0.5, as the height of the grid pattern increases and then decreases, the fill factor may also increase and then decrease, or the fill factor may increase. Alternatively, as the height of the grid pattern increases, the fill factor may increase and then decrease.

[0132] In the second column, if the fill factor is greater than 0.5 and less than 0.6, the fill factor may increase or decrease as the height of the grid pattern increases and then decreases in the range where the height of the grid pattern is greater than 20 nm and less than 100 nm. In the range where the height of the grid pattern is 100 nm or more, the fill factor may increase or decrease as the height of the grid pattern increases and then decreases or decreases and then increases.

[0133] In the second column, if the fill factor is greater than 0.6 and less than 0.8, the height of the grid pattern may increase and then decrease, or increase as the height of the grid pattern increases and then decreases, or increase. Alternatively, if the height of the grid pattern increases, the fill factor may decrease and then increase.

[0134] Below, we examine an embodiment in which the diffraction efficiency improves according to the change in height of the grating pattern confirmed in FIG. 7a and FIG. 7b.

[0135] FIGS. 8A and 8B are graphs showing the change in height and efficiency according to each column of a transfer diffraction element according to an embodiment of the present invention.

[0136] Specifically, [Table 1] is a table of Fig. 8a, and [Table 2] is a table of Fig. 8b. According to Fig. 8a and [Table 1], the height of the first column gradually increases as it moves away from the input diffraction element, and the height of the second column increases as it moves away from the input diffraction element, and then decreases. Referring to [Table 1], the height of the first row in the first column may be the same as the height of the first row in the second column. The row with the highest height in the second column may be the fourth row, which is located behind the middle of the second column.

[0137] Row 123456 1st Column 10598698104112 2nd Column 101424483216

[0138] (Unit: nm)

[0139] Looking at Figure 8b and [Table 2], which show the efficiency at this time, it can be seen that in the first column, the efficiency gradually increases as it moves away from the input diffraction element, while in the second column, it increases as it moves away from the input diffraction element and then decreases. Similarly, the path with the highest efficiency in the second column may be the fourth path, which is located further back than the middle. Here, the efficiency in Figure 8b and [Table 2] refers to the first-order diffraction efficiency of the transfer diffraction element.

[0140] Row 123456 1st Column 1.5435.5046.1549.8151.2352.83 2nd Column 1.543.008.322513.673.89

[0141] (unit: %)

[0142] For reference, the grating material of the transfer diffraction element in FIG. 8a and FIG. 8b is TiO2, and the period may be 273.8 nm, the width 192 nm, and the azimuth angle 57.5 degrees.

[0143] Figures 8a and 8b divide the rows into 6, but they can also be divided into 3. In this case, in each column of Figures 8a and 8b, two rows become one row, and the height of the row in the first column gradually increases, and in the second column, the height of the row increases in the first and second rows but decreases in the third row.

[0144] Figures 8a and 8b show the height and efficiency according to the path of each column of a transfer diffraction element covering a 6x2 region, and Figures 9a and 9b show the efficiency according to the path of each column of a transfer diffraction element covering a 7x2 region.

[0145] Specifically, FIGS. 9a and 9b are graphs showing the efficiency according to each column of a transfer diffraction element including a 7x2 region according to an embodiment of the present invention.

[0146] The grating material of the transfer diffraction elements in Fig. 9a and Fig. 9b is TiO2, and the azimuth angle is the same at 57.5 degrees. The period of the transfer diffraction element in Fig. 9a is 268.6 nm and the width is 188.1 nm, while the period of the transfer diffraction element in Fig. 9b is 273.8 nm and the width is 192 nm.

[0147] Tables 3 and 4 respectively show the height and efficiency of the furnaces for each column of the transfer diffraction element in Fig. 9a. Similar to the transfer diffraction elements in Figs. 8a and 8b, the height of the first column gradually increases as it moves away from the input diffraction element, while the height of the second column increases as it moves away from the input diffraction element and then decreases. Referring to Table 3, the height of the first furnace in the first column may be higher than the height of the first furnace in the second column. In the second column, the furnace with the highest height is the fifth furnace, which may be located behind the middle of the second column. The difference between the highest and lowest heights of the first column is greater than the difference between the highest and lowest heights of the second column.

[0148] Row 1 2 3 4 5 6 7 1st Column 2 4.0 28.0 30.0 31.0 33.0 36.0 40.0 2nd Column 2 0.0 20.0 22.0 27.0 31.0 30.0 20.0

[0149] (Unit: nm)

[0150] Looking at [Table 4], which shows the efficiency at this time, it can be seen that in the first column, the efficiency gradually increases as it moves away from the input diffraction element, and in the second column, it increases as it moves away from the input diffraction element and then decreases. Similarly, the 5th column, which is the part after the middle, may have the highest efficiency in the second column.

[0151] Row 1234567 1st Column 8.310.9 12.313.014.4 16.5 19.4 2nd Column 5.95.97.110.213.012.35.9

[0152] (unit: %)

[0153] Tables 5 and 6 represent the height and efficiency of the furnaces for each column of the transfer diffraction element in Fig. 9b, respectively. Similar to the transfer diffraction elements in Figs. 8a and 8b, the height of the first column gradually increases as it moves away from the input diffraction element, while the height of the second column increases as it moves away from the input diffraction element and then decreases. Referring to Table 5, the height of the first furnace in the first column is the same as the height of the first furnace in the second column. The furnace with the highest height in the second column is the fourth furnace, which may be an intermediate furnace in the second column. The height of the furnace with the highest height in the first column is greater than the height of the furnace with the highest height in the second column. The difference between the highest and lowest heights in the first column is greater than the difference between the highest and lowest heights in the second column.

[0154] Row 1234567 Column 1 30506090100110120 Column 2 30507080604030

[0155] (Unit: nm)

[0156] Looking at [Table 6], which shows the efficiency at this time, it can be seen that in the first column, the efficiency gradually increases as it moves away from the input diffraction element, and in the second column, it increases as it moves away from the input diffraction element and then decreases. Similarly, the furnace with the highest efficiency in the second column may be the middle, fourth furnace.

[0157] Row 1234567 1st Column 12.2926.4933.1347.5150.3152.4654.10 2nd Column 12.2926.4938.9943.8033.1319.3812.29

[0158] (unit: %)

[0159] FIG. 10 is a drawing showing an example of a plan view of a grating pattern of a diffraction element included in a light guide device according to an embodiment of the present invention.

[0160] Specifically, among the diffraction elements included in the light guide device, the transfer diffraction element may be the transfer diffraction element of FIG. 9b. Compared to FIG. 4, the grating patterns of the input diffraction element and the output diffraction element may be identical or similar. In the case of the transfer diffraction element, FIG. 4 is shown as containing a single grating pattern, but in FIG. 10, the column of the transfer diffraction element is divided into 2 and the row into 7, so that the grating pattern may be different for each divided region. As previously explained, the period and azimuth angle of the grating pattern in each region within the transfer diffraction element may be constant, and only the height of the protrusions and the fill factor of the grating pattern may differ. However, since the fill factor is constant in FIG. 9b, the width of the protruding parts may be different in order to make the grating pattern of the transfer diffraction element different.

[0161] FIG. 11 is a perspective view showing an example of a grating pattern in the transfer diffraction element of FIG. 9b.

[0162] Referring to FIG. 11, the fill factor of each region included in the transfer diffraction element may be the same, and the height of the grating pattern may differ. In the first column, the height of the grating pattern of each row increases as it moves away from the input diffraction element, and in the second column, the height of the grating pattern of each row increases as it moves away from the input diffraction element and then decreases. For better understanding, this is illustrated in more detail in FIG. 12a to 12c.

[0163] FIG. 12a is a diagram showing divided regions of the transfer diffraction element of FIG. 11, FIG. 12b is a side view of the grating pattern in the first column of the transfer diffraction element, and FIG. 12c is a side view of the grating pattern in the second column of the transfer diffraction element.

[0164] Referring to FIG. 12a, the transfer diffraction element (1200) may include a 7x2 area. As described in FIG. 6, the 7x2 area included in the transfer diffraction element (1200) may be divided by a line connecting the center of the nearest and farthest sides of the input diffraction element among the sides constituting the transfer diffraction element (1200) and a line sequentially connecting any 6 points of the nearest and farthest sides of the output diffraction element. The area divided by the line connecting the center of the nearest and farthest sides of the input diffraction element among the sides constituting the transfer diffraction element (1200) may be the first column and the second column, and the area divided by the line sequentially connecting any 6 points of the nearest and farthest sides of the output diffraction element among the sides constituting the transfer diffraction element (1200) may be the first column, the second column, ..., the seventh column.

[0165] Referring to FIGS. 12b and 12c, the grating patterns within the same row may be identical. That is, the grating period, height, and azimuth angle may be identical. However, different rows may have the same grating period and azimuth angle, but the height of the grating pattern may differ from one another. In FIG. 12b, which is a side view of the grating pattern in the first column, the height of the grating pattern may gradually increase as the position of the row moves further away from the input diffraction element, and in FIG. 12c, which is a side view of the grating pattern in the second column, the height of the grating pattern may gradually increase and then decrease as the position of the row moves further away from the input diffraction element. In the first column, the row with the highest grating pattern height may be the seventh row, which is the last row, and in the second column, the row with the highest grating pattern height may be the fourth row, which is the middle row.

[0166] Although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. Input diffraction element; Transfer diffraction element; and A substrate having the input diffraction element and the transfer diffraction element disposed thereon, The above-mentioned transfer diffraction element includes a first region and a second region formed by dividing into two, and The first region includes a first grating pattern, and the height of the first grating pattern changes in a direction away from the input diffraction element, and The second region includes a second grating pattern, and the height of the second grating pattern also changes in a direction away from the input diffraction element, and A light guide device in which the heights of the first grid pattern and the second grid pattern are different.

2. In Paragraph 1, It further includes an output diffraction element, and The above second region is a light guide device disposed between the above first region and the above output diffraction element.

3. In Paragraph 1, The above transfer diffraction element has a first side closest to the input diffraction element and a second side facing the first side, It includes a third side and a fourth side positioned between the first side and the second side and positioned to face each other, The above first region and the above second region are distinguished by a first line, and The first line above is a line connecting the center of the first side and the center of the second side, and A light guide device in which the length of the first side is shorter than the length of the second side.

4. In Paragraph 3, A light guide device in which the maximum height of the first grid pattern is greater than the maximum height of the second grid pattern.

5. In Paragraph 3, A light guide device in which the difference between the highest and lowest heights of the first grid pattern is greater than the difference between the highest and lowest heights of the second grid pattern.

6. In Paragraph 3, A light guide device in which the lowest height of the first grid pattern is equal to or greater than the lowest height of the second grid pattern.

7. In Paragraph 3, A light guide device in which, among the regions in which the first region is divided into multiple regions, the region furthest from the input diffraction element has the highest height of the first grating pattern.

8. In Paragraph 7, A light guide device in which the region with the smallest height difference between the first grating pattern and the second grating pattern is the region closest to the input diffraction element among the regions into which the first region is divided into multiple regions.

9. In Paragraph 7, A light guide device in which the region with the largest height difference between the first grating pattern and the second grating pattern is the region furthest from the input diffraction element among the regions into which the first region is divided into multiple regions.

10. Project device; and Includes a light guide device, The above light guide device is, Input diffraction element; Transfer diffraction element; and A substrate having the input diffraction element and the transfer diffraction element disposed thereon, The above-mentioned transfer diffraction element includes a first region and a second region formed by dividing into two, and The first region includes a first grating pattern, and the height of the first grating pattern changes in a direction away from the input diffraction element, and The second region includes a second grating pattern, and the height of the second grating pattern also changes in a direction away from the input diffraction element, and An electronic device in which the heights of the first grid pattern and the second grid pattern are different.

Images