Light guide device and electronic device including same

Abstract

According to an embodiment of the present invention, the light guide device comprises an input diffraction element, a transfer diffraction element, and a substrate on which the input diffraction element and the transfer diffraction element are disposed. The transfer diffraction element includes two separately formed regions (a first region and a second region). The first region includes a first grating pattern. The height of the first grating pattern gradually decreases in a direction away from the input diffraction element. The second region includes a second grating pattern. The height of the second grating pattern may also decrease and then increase in a direction away from the input diffraction element.

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 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] At this time, the created virtual environment or situation stimulates the user's five senses and allows the user to freely cross the boundary between reality and imagination by enabling spatial and temporal experiences similar to reality. In addition, 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 gradually decreases 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 may also decrease in a direction away from the input diffraction element and then increase.

[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] The light guide device according to an embodiment of the present invention comprises a transfer diffraction element including 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 lower than or equal to the maximum height of the second grid pattern.

[0014] In the 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 among the regions in which the second region is divided into a plurality of regions.

[0015] In a light guide device according to an embodiment of the present invention, the height of the second grid pattern may be symmetrical with respect to the middle region among the regions in which the second region is divided into a plurality of regions.

[0016] In a light guide device according to an embodiment of the present invention, the grid period, azimuth angle, and width of the first grid pattern and the second grid pattern may be the same.

[0017] In a light guide device according to an embodiment of the present invention, the width / grid period of the first grid pattern and the second grid pattern may be 0.5 to 0.6.

[0018] In a light guide device according to an embodiment of the present invention, the height of the first grating pattern and the second grating pattern may be 100 to 150 nm.

[0019] In a light guide device according to an embodiment of the present invention, the height of the first grating pattern and the height of the second grating pattern may be the same in the direction closest to the input diffraction element.

[0020] 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, wherein the width of the protrusion / grid period of the first grating pattern decreases and then increases in a direction away from the input diffraction element. The second region comprises a second grating pattern, wherein the width of the protrusion / grid period of the second grating pattern also decreases and then increases in a direction away from the input diffraction element. The height of the protrusion of the first grating pattern and the height of the protrusion of the second grating pattern may be fixed.

[0021] In a light guide device according to an embodiment of the present invention, the grid period of the first grid pattern may be fixed and the width of the protrusion of the first grid pattern may be changed, or the width of the protrusion of the first grid pattern may be fixed and the grid period of the first grid pattern may be changed.

[0022] In a light guide device according to an embodiment of the present invention, the grid period of the second grid pattern may be fixed and the width of the protrusion of the second grid pattern may be changed, or the width of the protrusion of the second grid pattern may be fixed and the grid period of the second grid pattern may be changed.

[0023] 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.

[0024] 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.

[0025] In an optical guide device according to an embodiment of the present invention, the width / grid period of the protrusion of the first grid pattern may be smallest in the middle of the area among the areas in which the first area is divided into a plurality of regions, or in the area located further than the middle relative to the input transmission element.

[0026] In an optical guide device according to an embodiment of the present invention, the width / grid period of the protrusion of the second grid pattern may be smallest in the middle of the area among the areas in which the second area is divided into multiple regions, or in the area located further than the middle relative to the input transmission element.

[0027] In a light guide device according to an embodiment of the present invention, the smallest value of the width / grid period of the protrusion of the second grid pattern may be greater than the smallest value of the width / grid period of the protrusion of the first grid pattern.

[0028] In a light guide device according to an embodiment of the present invention, the largest value of the width / grid period of the protrusion of the second grid pattern may be greater than or equal to the largest value of the width / grid period of the protrusion of the first grid pattern.

[0029] In a light guide device according to an embodiment of the present invention, among the regions in which the first region is divided into a plurality of areas, the width / grid period of the protrusion of the first grid pattern in the first region based on the input transmission element may be greater than the width / grid period of the protrusion of the first grid pattern in the last region.

[0030] In a light guide device according to an embodiment of the present invention, among the regions in which the second region is divided into multiple regions, the width / grid period of the protrusion of the second grid pattern in the first region based on the input transmission element may be greater than the width / grid period of the protrusion of the second grid pattern in the last region.

[0031] In a light guide device according to an embodiment of the present invention, the height of the protrusion of the first grid pattern and the height of the protrusion of the second grid pattern may be the same.

[0032] In a light guide device according to an embodiment of the present invention, the width / grid period of the protrusion of the first grid pattern and the width / grid period of the protrusion of the second grid pattern can each be changed from 0.55 to 0.8.

[0033] 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.

[0034] According to an embodiment of the present invention, a light guide device with improved uniformity of light output can be provided without lowering the diffraction efficiency of light.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] FIG. 2 is a perspective view of an electronic device including a light guide device according to an embodiment of the present invention.

[0039] FIG. 3 is a schematic diagram of a light guide device according to an embodiment of the present invention.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] FIGS. 8A and 8B are graphs showing the height of each column of a transfer diffraction element according to the first embodiment of the present invention and the efficiency accordingly.

[0045] FIGS. 9a and 9b are graphs showing the height of each column of a transfer diffraction element according to a second embodiment of the present invention and the efficiency accordingly.

[0046] FIGS. 10a and FIGS. 10b are graphs showing the height of each column of a transfer diffraction element according to a third embodiment of the present invention and the efficiency accordingly.

[0047] FIGS. 11a and FIGS. 11b are graphs showing the height of each column of a transfer diffraction element according to the fourth embodiment of the present invention and the efficiency accordingly.

[0048] FIG. 12 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.

[0049] FIG. 13 is a perspective view showing an example of a grating pattern in the transfer diffraction element of FIG. 8a.

[0050] FIG. 14a is a diagram showing a divided region of the transfer diffraction element of FIG. 13, FIG. 14b is a side view of the grating pattern for the first column of the transfer diffraction element, and FIG. 14c is a side view of the grating pattern for the second column of the transfer diffraction element.

[0051] FIGS. 15a and 15b are graphs showing the fill factor of each column of a transfer diffraction element according to the fifth embodiment of the present invention and the efficiency accordingly.

[0052] FIGS. 16a and 16b are graphs showing the fill factor of each column of a transfer diffraction element according to the 6th embodiment of the present invention and the efficiency accordingly.

[0053] FIGS. 17a and 17b are graphs showing the fill factor of each column of a transfer diffraction element according to the seventh embodiment of the present invention and the efficiency accordingly.

[0054] FIGS. 18a and 18b are graphs showing the fill factor of each column of a transfer diffraction element according to the eighth embodiment of the present invention and the efficiency accordingly.

[0055] FIGS. 19a and 19b are graphs showing the fill factor of each column of a transfer diffraction element according to the 11th embodiment of the present invention and the efficiency accordingly.

[0056] FIGS. 20a and FIGS. 20b are graphs showing the fill factor of each column of a transfer diffraction element according to the 12th embodiment of the present invention and the efficiency accordingly.

[0057] FIGS. 21a and 21b are graphs showing the fill factor of each column of a transfer diffraction element according to the 13th embodiment of the present invention and the efficiency accordingly.

[0058] FIGS. 22a and 22b are graphs showing the fill factor of each column of a transfer diffraction element according to the 14th embodiment of the present invention and the efficiency accordingly.

[0059] FIG. 23 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.

[0060] FIG. 24 is a perspective view showing an example of a grating pattern in a transfer diffraction element according to the 5th to 14th embodiments described above.

[0061] FIG. 25a is a diagram showing a divided region of the transfer diffraction element of FIG. 24, FIG. 25b is a side view of the grating pattern for the first column of the transfer diffraction element, and FIG. 25c is a side view of the grating pattern for the second column of the transfer diffraction element.

[0062] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0063] 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.

[0064] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a meaning 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0069] 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.

[0070] 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.

[0071] 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 computer graphics (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.

[0072] 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.

[0073] 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.

[0074] Hereinafter, an electronic device providing extended 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] This wireless communication unit (11) 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.

[0079] 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.

[0080] 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. 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, 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 also utilize a combination of information detected by at least two of these sensors.

[0081] 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.

[0082] The interface section (15) serves as a passage 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. 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.

[0083] Additionally, the memory (16) can store 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 / outgoing function, message receiving / sending function).

[0084] 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.

[0085] 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) may 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.

[0086] 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).

[0087] 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).

[0088] 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.

[0089] 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).

[0090] FIG. 2 is a perspective view of an electronic device including a light guide device according to an embodiment of the present invention.

[0091] 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).

[0092] 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.

[0093] The frame (100) is supported by a head and may include 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).

[0094] 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.

[0095] 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.

[0096] In the frame (100), the length (D1) in the x direction and the length (L1) in the y direction may be the same or different.

[0097] The projection device (200) may be configured to control various electronic components provided in the electronic device. The projection device (200) may be used interchangeably with 'light output device', 'light projection device', 'light irradiation device', 'optical device', etc.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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).

[0104] 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.

[0105] 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 that overlays a virtual image onto a real image or background to display it as a single image.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] FIG. 3 is a schematic diagram of a light guide device according to an embodiment of the present invention.

[0110] 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).

[0111] 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 the input diffraction element (320), the substrate (310), the transfer diffraction element (330), and the output diffraction element (340) 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 be the Z-axis direction in the drawing. The third direction may mean the direction of incidence of the light or the opposite direction. Additionally, the third direction may mean the optical axis direction.

[0112] 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. The second direction may be the X-axis direction in the drawing.

[0113] 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.

[0114] 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.

[0115] 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) in the same way as the input diffraction element (320) and the transfer diffraction element (330). The output diffraction element (340) can receive light whose path has been changed from the transfer diffraction element (330) and emit it outward. The output diffraction element (340) can change the path of the light and emit it outward. The output diffraction element (340) can change the path of the light by diffracting the light.

[0116] 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.

[0117] The cover (350) may be placed on the substrate (310), the input diffraction element (320), the transfer diffraction element (330), and the output diffraction element (340). The cover (350) may be placed adjacent to the project device (200). Light irradiated by the project 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).

[0118] 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.

[0119] 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. 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 two adjacent protrusions. The grating period of a diffraction element can be the shortest distance between the same sides of the protrusions.

[0120] The grating vector of the diffraction element may consist of a direction and a magnitude, the direction may be the separation direction of adjacent protrusions, 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] In FIG. 4, it is explained that each diffraction element is composed of one region and has one grating pattern, but each diffraction element may be composed of multiple regions.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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. That is, it refers to the amount of light projected onto an electronic device (e.g., AR glasses) relative to the amount of light emitted from the projector. 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, FIG. 5d shows the uniformity and efficiency of the light guide device including the transfer diffraction element (540) divided into a 7x1 region. FIGS. 5a to 5d illustrate an optical guide device including a one-dimensional modulated transfer diffraction element, and it can be seen from FIGS. 5a to 5d that the efficiency does not exceed 0.0055 and the uniformity is not generally high. In other words, it can be seen that even if the number of regions of the one-dimensional modulated transfer diffraction element increases, there are limitations to the efficiency and uniformity of the optical guide device including it.

[0129] FIG. 5e shows the uniformity and efficiency of a two-dimensional modulated transfer diffraction element and an optical guide device including the same. Referring to FIG. 5e, the transfer diffraction element (550) is divided into a 6x2 area. When FIG. 5e is compared with FIG. 5a to FIG. 5d, 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.

[0130] The following describes the structure of a two-dimensional modulated transfer diffraction element for increasing the efficiency and uniformity of an optical guide device. First, Figure 6 describes in detail a plurality of regions included in the two-dimensional modulated transfer diffraction element.

[0131] 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.

[0132] 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 the description in FIG. 6 is omitted.

[0133] 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 first line (625) may be connected vertically from the center of the output diffraction element (630), and this connected line may be referred to as the second line (626).In FIG. 6, a second line (626) is shown vertically 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 the perpendicular range.

[0134] 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 into a line parallel to the second line to include a 6x2 region, but 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, and so on 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.

[0135] Figure 6 describes a method for dividing the region of a transfer diffraction element. When the transfer diffraction element is divided into a first column and a second column as shown in Figure 6, the diffraction efficiency of the first column increases, and the diffraction efficiency of the second column increases and then decreases, thereby increasing the efficiency and uniformity of the optical guide device. Before explaining the grating pattern within the transfer diffraction element to increase the efficiency and uniformity of the optical guide device, we first examine the distribution of diffraction efficiency and reflection efficiency according to the height and fill factor of the grating pattern in the transfer diffraction element.

[0136] 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.

[0137] 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.

[0138] [Mathematical Formula 1]

[0139] fill factor = width of protrusion / grid period

[0140] 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.

[0141] Referring to FIGS. 7a and 7b, it can be seen that when the height of the grating pattern is lower than 100 nm (710), the diffraction efficiency gradually increases and then decreases, and the reflection efficiency gradually decreases and then increases. When the height of the grating pattern is 100 to 150 nm, it can be seen that the change in diffraction efficiency and reflection efficiency in some range of the fill factor (720) is different from when the height of the grating pattern is lower than 100 nm.

[0142] Meanwhile, the sum of the diffraction efficiency and the reflection efficiency is approximately 1. Here, diffraction efficiency refers to the ratio of light diffracted in the desired direction among the incident light, and reflection efficiency refers to the ratio of light diffracted and reflected among the light incident on the diffraction grating.

[0143] Hereinafter, a grating pattern within a transfer diffraction element for increasing the efficiency and uniformity of an optical guide device according to various embodiments of the present invention is described. As described above, when the transfer diffraction element is divided into a first column and a second column, if the diffraction efficiency of the first column increases and the diffraction efficiency of the second column increases and then decreases, the efficiency and uniformity of the optical guide device can be increased. As confirmed in FIGS. 7a and 7b, when the fill factor range is 0.5 to 0.6 and the height of the grating pattern is 100 to 150 nm, the diffraction efficiency and reflection efficiency differ from those in other ranges of the fill factor and the height of the grating pattern. Hereinafter, a change in the height of the grating pattern that can increase the efficiency of the transfer diffraction element is described based on the diffraction efficiency and reflection efficiency when the fill factor range is 0.5 to 0.6 and the height of the grating pattern is 100 to 150 nm. For example, the grating material of the transfer diffraction element is TiO2, the lattice period is 273.8 nm, and the azimuth angle is 57.5 degrees, and the transfer diffraction element may be divided into 7x2 regions in a manner similar to that described in Fig. 6.

[0144] FIGS. 8A and 8B are graphs showing the height of each column of a transfer diffraction element according to the first embodiment of the present invention and the efficiency accordingly.

[0145] Specifically, the height and efficiency of each column of the transfer diffraction element according to the first embodiment of the present invention are as shown in [Table 1] and [Table 2], and FIGS. 8a and 8b are graphs thereof. The fill factor of the transfer diffraction element according to the first embodiment is 0.5, and the width is 136.9 nm.

[0146] Row 1234567 1st Column 150130120115110105100 2nd Column 150135130130130135150

[0147] (Unit: nm)

[0148] Row 1234567 1st Column 0.4203560.4661040.5000650.5168770.5318180.5436210.551205 2nd Column 0.4203560.45120.4661040.4661040.4661040.45120.420356

[0149] (unit: %)

[0150] Referring to FIG. 8a and [Table 1], the height of the first column gradually decreases as it moves away from the input diffraction element, and the height of the second column gradually decreases as it moves away from the input diffraction element, and then increases. Referring to [Table 1], the height of the first row of the first column may be the same as the height of the first row of the second column. The heights of the first row and the last row of the second column may be the same.

[0151] Referring to FIG. 8b and [Table 2], the efficiency of the first column gradually increases as it moves away from the input diffraction element, and the efficiency of the second column gradually increases as it moves away from the input diffraction element, and then decreases. Here, the efficiency in FIG. 8b and [Table 2] refers to the first-order diffraction efficiency of the transfer diffraction element.

[0152] FIGS. 9a and 9b are graphs showing the height of each column of a transfer diffraction element according to a second embodiment of the present invention and the efficiency accordingly.

[0153] Specifically, the height and efficiency of each column of the transfer diffraction element according to the second embodiment of the present invention are as shown in [Table 3] and [Table 4], and FIGS. 9a and 9b are graphs thereof. The fill factor of the transfer diffraction element according to the second embodiment is 0.5, and the width is 136.9 nm.

[0154] Row 1234567 1st Column 150130120115110105100 2nd Column 150120110105110120150

[0155] (Unit: nm)

[0156] Row 1234567 1st Column 0.4203560.4661040.5000650.5168770.5318180.5436210.551205 2nd Column 0.4203560.5000650.5318180.5436210.5318180.5000650.420356

[0157] (unit: %)

[0158] The first column of the transfer diffraction element according to the second embodiment is identical to the first column of the transfer diffraction element according to the first embodiment. However, the height change of the second column of the transfer diffraction element according to the second embodiment is different from the height change of the second column of the transfer diffraction element according to the first embodiment. The height change of the second column of the transfer diffraction element according to the second embodiment may change more rapidly than the height change of the second column of the transfer diffraction element according to the first embodiment. Referring to FIG. 9a and [Table 3], the height of the first row of the first column may be the same as the height of the first row of the second column. The first row and the last row of the second column may have the same height. The row with the lowest height in the second column may be the fourth row in the middle. Also, the height of the rows in the second column may be symmetrical with respect to the middle.

[0159] Referring to FIG. 9b and [Table 4], similar to the efficiency of the transfer diffraction element according to the first embodiment, the efficiency of the first column gradually increases as it moves away from the input diffraction element, and the efficiency of the second column gradually increases as it moves away from the input diffraction element and then decreases.

[0160] FIGS. 10a and FIGS. 10b are graphs showing the height of each column of a transfer diffraction element according to a third embodiment of the present invention and the efficiency accordingly.

[0161] Specifically, the height and efficiency of each column of the transfer diffraction element according to the third embodiment of the present invention are as shown in [Table 5] and [Table 6], and FIGS. 10a and FIGS. 10b represent this as a graph. The fill factor of the transfer diffraction element according to the third embodiment is 0.5, and the width is 136.9 nm. The fill factor and width of the transfer diffraction elements according to the first to third embodiments are the same.

[0162] Row 1234567 1st Column 150140130125120110100 2nd Column 150145140140140145150

[0163] (Unit: nm)

[0164] Row 1234567 1st Column 0.4203560.4661040.5000650.5168770.5318180.5436210.551205 2nd Column 0.4203560.4283980.438590.438590.438590.4283980.420356

[0165] (unit: %)

[0166] Referring to FIG. 10a and [Table 5], the height of the first column gradually decreases as it moves away from the input diffraction element, and the height of the second column gradually decreases as it moves away from the input diffraction element, and then increases. Referring to [Table 5], 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 lowest value among the row heights in the first column may be smaller than the lowest value among the row heights in the second column. The heights of the first row and the last row in the second column may be the same. The heights of the rows in the second column may be symmetrical with respect to the row located in the middle.

[0167] Referring to Figure 10b and [Table 6], the efficiency of the first column gradually increases as it moves away from the input diffraction element, and the efficiency of the second column gradually increases as it moves away from the input diffraction element, and then decreases.

[0168] FIGS. 11a and FIGS. 11b are graphs showing the height of each column of a transfer diffraction element according to the fourth embodiment of the present invention and the efficiency accordingly.

[0169] Specifically, the height and efficiency of each column of the transfer diffraction element according to the fourth embodiment of the present invention are as shown in [Table 7] and [Table 8], and FIGS. 11a and FIGS. 11b are graphs thereof. The fill factor of the transfer diffraction element according to the fourth embodiment is 0.52, and the width is 142.376 nm.

[0170] Row 1234567 1st Column 130125120115110105100 2nd Column 145140130110100105140

[0171] (Unit: nm)

[0172] Row 1234567 1st Column 0.4820210.4968110.5124090.5277550.5415530.5524770.559344 2nd Column 0.4466770.4569720.4820210.5415530.5593440.5524770.456972

[0173] (unit: %)

[0174] Referring to FIG. 11a and [Table 7], the height of the first column gradually decreases as it moves away from the input diffraction element, and the height of the second column gradually decreases as it moves away from the input diffraction element, and then increases. Referring to [Table 7], the height of the first furnace in the first column may be lower than the height of the first furnace in the second column. The lowest value among the furnace heights in the first column may be equal to the lowest value among the furnace heights in the second column. Also, the height of the first furnace in the second column may be higher than the height of the last furnace.

[0175] Referring to Figure 11b and [Table 8], the efficiency of the first column gradually increases as it moves away from the input diffraction element, and the efficiency of the second column gradually increases as it moves away from the input diffraction element, and then decreases.

[0176] FIG. 12 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.

[0177] Specifically, among the diffraction elements included in the light guide device, the transfer diffraction element may be the transfer diffraction element according to the first to fourth embodiments described above. 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 including a single grating pattern, but FIG. 12 may divide the column of the transfer diffraction element into 2 and the row into 7, so that the grating pattern is different for each divided region. As previously explained, the period, width, azimuth angle, and fill factor of the grating pattern in each region within the transfer diffraction element may be constant, and only the height of the protrusion of the grating pattern may differ.

[0178] FIG. 13 is a perspective view showing an example of a grating pattern in a transfer diffraction element according to the first to fourth embodiments described above.

[0179] Referring to FIG. 13, 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 path decreases as it moves away from the input diffraction element, and in the second column, the height of the grating pattern of each path decreases as it moves away from the input diffraction element, and then increases. For better understanding, this is illustrated in more detail in FIG. 14a to 14c.

[0180] FIG. 14a is a diagram showing a divided region of the transfer diffraction element of FIG. 13, FIG. 14b is a side view of the grating pattern for the first column of the transfer diffraction element, and FIG. 14c is a side view of the grating pattern for the second column of the transfer diffraction element.

[0181] Referring to FIG. 14a, the transfer diffraction element (1400) may include a 7x2 area. As described in FIG. 6, the 7x2 area included in the transfer diffraction element (1400) 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 (1400) 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 (1400) 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 (1400) may be the first column, the second column, ..., the seventh column.

[0182] Referring to FIGS. 14b and 14c, within the same row, the grating pattern 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. 14b, which is a side view of the grating pattern for the first column, the height of the grating pattern may gradually decrease as the position of the row moves away from the input diffraction element, and in FIG. 14c, which is a side view of the grating pattern for the second column, the height of the grating pattern may gradually decrease and then increase as the position of the row moves away from the input diffraction element. The row with the highest height of the grating pattern in the first column may be the first row, and the row with the highest height of the grating pattern in the second column may be the first row and / or the seventh row, which is the last row.

[0183] Hereinafter, with reference again to FIGS. 7a and 7b, a grating pattern within a transfer diffraction element for increasing the efficiency and uniformity of an optical guide device according to various embodiments of the present invention will be described. As described above, when the transfer diffraction element is divided into a first column and a second column, the efficiency and uniformity of the optical guide device can be increased if the diffraction efficiency of the first column increases and the diffraction efficiency of the second column increases and then decreases. When the height of the grating pattern of the transfer diffraction element is fixed, the efficiency and uniformity of the optical guide device can be increased when the fill factor changes as described below in the range where the fill factor is 0.55 to 0.8. The grating material of the transfer diffraction element is TiO2, the grating period is 273.8 nm, and the azimuth angle is 57.5 degrees, and the transfer diffraction element may be divided into a 7x2 region in a manner similar to that described in FIG. 6. The height of the grating pattern of the transfer diffraction element may be constant regardless of the position within the transfer diffraction element.

[0184] FIGS. 15a and 15b are graphs showing the fill factor of each column of a transfer diffraction element according to the fifth embodiment of the present invention and the efficiency accordingly.

[0185] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the fifth embodiment of the present invention are as shown in [Table 9] and [Table 10], and FIGS. 15a and FIGS. 15b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the fifth embodiment is 30 nm.

[0186] Row 1234567 1st Column 0.80.720.640.560.540.620.8 2nd Column 0.80.780.780.760.780.780.8

[0187] Row 1234567 1st Column 7.9311.4714.2715.7815.9214.807.93 2nd Column 7.938.838.839.728.838.837.93

[0188] (unit: %)

[0189] Referring to FIG. 15a and [Table 9], the fill factor of the first column and the second column gradually decreases and then increases as they move further away from the input diffraction element. Referring to [Table 9], the fill factor of the first row of the first column may be the same as the fill factor of the first row of the second column. Also, the fill factor of the last row of the first column may be the same as the fill factor of the last row of the second column. The fill factors of the first row and the last row of the first and second columns may all have the same value. The row with the smallest fill factor of the first column may be the fifth row, which is a region located further than the middle relative to the input transfer element. The row with the smallest fill factor of the second column may be the fourth row, which is the middle region of the transfer diffraction element. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column. In the same row, the fill factor of the first column may be less than or equal to the fill factor of the second column.

[0190] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 9], the efficiency may be as shown in [Table 10]. Referring to [Table 10] and Fig. 15b, the efficiency of the first and second columns gradually increases and then decreases as they move away from the input diffraction element. Here, the efficiency in Fig. 15b and [Table 10] refers to the first-order diffraction efficiency of the transfer diffraction element.

[0191] The efficiency of the optical guide device including the transfer diffraction element according to the fifth embodiment may be 1.16% and the uniformity may be 31.70%.

[0192] FIGS. 16a and 16b are graphs showing the fill factor of each column of a transfer diffraction element according to the 6th embodiment of the present invention and the efficiency accordingly.

[0193] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 6th embodiment of the present invention are as shown in [Table 11] and [Table 12], and FIGS. 16a and FIGS. 16b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 6th embodiment is 30 nm.

[0194] Row 1234567 1st Column 0.80.660.60.560.580.60.64 2nd Column 0.80.780.760.740.720.740.8

[0195] Row 1234567 1st Column 7.9313.6615.2315.7815.5615.2314.27 2nd Column 7.938.839.7210.6011.4710.607.93

[0196] (unit: %)

[0197] The fill factor of the first column and the second column of the transfer diffraction element according to the sixth embodiment also gradually decreases and then increases as it moves away from the input diffraction element. Additionally, similar to the fill factor of the first column and the second column of the transfer diffraction element according to the first embodiment, the fill factor of the first row may be the same. The fill factor of the first row and the last row of the second column may have the same value. The row with the smallest fill factor of the first column may be the fourth row, which may be the middle region of the transfer diffraction element. The row with the smallest fill factor of the second column may be the fifth row, which may be a region located further than the middle relative to the input transfer element. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column. In the same row, the fill factor of the first column may be less than or equal to the fill factor of the second column.

[0198] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 11], the efficiency may be as shown in [Table 12]. Referring to Fig. 16b and [Table 12], the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0199] The efficiency of the optical guide device including the transfer diffraction element according to the 6th embodiment may be 1.15% and the uniformity may be 30.15%.

[0200] FIGS. 17a and 17b are graphs showing the fill factor of each column of a transfer diffraction element according to the seventh embodiment of the present invention and the efficiency accordingly.

[0201] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 7th embodiment of the present invention are as shown in [Table 13] and [Table 14], and FIGS. 17a and FIGS. 17b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 7th embodiment is 30 nm.

[0202] Row 1234567 1st Column 0.80.640.560.540.560.580.6 2nd Column 0.80.780.760.740.720.740.8

[0203] Row 1234567 1st Column 7.9314.27 15.78 15.92 15.78 15.56 15.23 2nd Column 7.938.8 39.72 10.60 11.47 10.60 7.93

[0204] (unit: %)

[0205] The fill factor of the first column and the second column of the transfer diffraction element according to the seventh embodiment also gradually decreases and then increases as it moves away from the input diffraction element. The fill factor of the second column of the transfer diffraction element according to the second embodiment and the fill factor of the second column of the transfer diffraction element according to the seventh embodiment may be the same. Only the fill factor of the first column of the transfer diffraction element may differ. Compared to the sixth embodiment, the change in the fill factor of the first column of the transfer diffraction element in the seventh embodiment may be greater. The path where the fill factor of the first column is smallest may be the fourth path, which may be the middle region of the transfer diffraction element. The path where the fill factor of the second column is smallest may be the fifth path, which may be a region located further than the middle relative to the input transfer element. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column. In the same path, the fill factor in the first column may be less than or equal to the fill factor in the second column.

[0206] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 13], the efficiency may be as shown in [Table 14]. Referring to [Table 14] and Fig. 17b, the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0207] The efficiency of the optical guide device including the transfer diffraction element according to the 7th embodiment may be 1.16% and the uniformity may be 29.67%.

[0208] FIGS. 18a and 18b are graphs showing the fill factor of each column of a transfer diffraction element according to the eighth embodiment of the present invention and the efficiency accordingly.

[0209] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 8th embodiment of the present invention are as shown in [Table 15] and [Table 16], and FIGS. 18a and FIGS. 18b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 8th embodiment is 30 nm.

[0210] Row 1234567 1st Column 0.80.640.580.540.580.620.7 2nd Column 0.80.780.760.740.720.740.77

[0211] Row 1234567 1st Column 7.9314.27 15.56 15.92 15.56 14.80 12.28 2nd Column 7.938.839.72 10.60 11.47 10.60 8.83

[0212] (unit: %)

[0213] Referring to Fig. 18a and [Table 15], the fill factor of the first column and the second column gradually decreases and then increases as they move away from the input diffraction element. Referring to [Table 15], the fill factor of the first row of the first column may be the same as the fill factor of the first row of the second column. The fill factor of the last row may be smaller than the value of the first column. Also, the fill factor of the first column may be smallest in the central part, and the fill factor of the second column may be smallest behind the center. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column. In the same row, the fill factor of the first column may be smaller than or equal to the fill factor of the second column.

[0214] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 15], the efficiency may be as shown in [Table 16]. Referring to [Table 16] and Fig. 18b, the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0215] The efficiency of the optical guide device including the transfer diffraction element according to the 8th embodiment may be 1.14% and the uniformity may be 29.63%.

[0216] The transfer diffraction element according to the ninth embodiment of the present invention may be composed of a single region without distinction between a column and a furnace. The fill factor of the transfer diffraction element is 0.65, and the height of the grating pattern is 30 nm. In this case, the efficiency of the optical guide device including the transfer diffraction element according to the ninth embodiment may be 0.91%, and the uniformity may be 26.99%.

[0217] When comparing the 5th to 8th embodiments with the 9th embodiment, it can be confirmed that the efficiency and uniformity of the optical guide device including the transfer diffraction element are high when the transfer diffraction element is divided into multiple regions and the fill factor is varied according to the region.

[0218] Below, we examine the efficiency and uniformity of an optical guide device including a transfer diffraction element when the height of the grating pattern of the transfer diffraction element is changed to 50 nm.

[0219] Similar to the transfer diffraction element according to the ninth embodiment, the transfer diffraction element according to the tenth embodiment of the present invention may also be composed of a single region without distinction between a column and a furnace. The fill factor of the transfer diffraction element is 0.65, and the height of the grating pattern is 50 nm. In this case, the efficiency of the optical guide device including the transfer diffraction element according to the tenth embodiment may be 0.46%, and the uniformity may be 13.93%.

[0220] When comparing the 9th embodiment and the 10th embodiment, it can be confirmed that the efficiency and uniformity of the optical guide device including the transfer diffraction element are high when the height of the grating pattern of the transfer diffraction element is low.

[0221] FIGS. 19a and 19b are graphs showing the fill factor of each column of a transfer diffraction element according to the 11th embodiment of the present invention and the efficiency accordingly.

[0222] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 11th embodiment of the present invention are as shown in [Table 17] and [Table 18], and FIGS. 19a and 19b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 11th embodiment is 50 nm.

[0223] Row 1234567 1st Column 0.780.780.70.60.560.560.76 2nd Column 0.80.780.780.760.760.760.8

[0224] Row 1234567 1st Column 19.53 19.5326.49 32.31 33.36 33.36 21.32 2nd Column 17.67 19.53 19.53 21.32 21.32 21.32 17.67

[0225] (unit: %)

[0226] Referring to Fig. 19a and [Table 9], the fill factor of the first and second columns gradually decreases and then increases as they move away from the input diffraction element. Referring to [Table 17], the fill factor of the first row of the second column may be the same as the fill factor of the last row of the second column. The row with the smallest fill factor of the first column may be the fifth or sixth row, which is a region located further than the midpoint relative to the input transfer element. Also, the row with the smallest fill factor of the second column may be the fourth, fifth, or sixth row, which is a region located further than the midpoint relative to the input transfer element. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column. In the same row, the fill factor of the first column may be less than or equal to the fill factor of the second column.

[0227] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 17], the efficiency may be as shown in [Table 18]. Referring to [Table 18] and Fig. 19b, the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0228] The efficiency of the optical guide device including the transfer diffraction element according to the 11th embodiment may be 0.758% and the uniformity may be 19.35%.

[0229] FIGS. 20a and FIGS. 20b are graphs showing the fill factor of each column of a transfer diffraction element according to the 12th embodiment of the present invention and the efficiency accordingly.

[0230] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 12th embodiment of the present invention are as shown in [Table 19] and [Table 20], and FIGS. 20a and FIGS. 20b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 12th embodiment is 50 nm.

[0231] Row 1234567 1st Column 0.780.760.680.60.540.580.78 2nd Column 0.80.780.780.760.760.760.8

[0232] Row 1234567 1st Column 19.53 21.3227.93 32.31 33.59 32.94 19.53 2nd Column 17.67 19.53 19.53 21.32 21.32 21.32 17.67

[0233] (unit: %)

[0234] Referring to FIG. 20a and [Table 19], the fill factor of the first column and the second column gradually decreases and then increases as they move away from the input diffraction element. Referring to [Table 19], the fill factor of the first row of the first column may be the same as the fill factor of the last row of the first column. The fill factor of the first row of the second column may also be the same as the fill factor of the last row of the second column. Additionally, the row with the smallest fill factor of the first column may be the fifth row, which is a region located further than the midpoint relative to the input transfer element. The rows with the smallest fill factor of the second column may be the fourth, fifth, and sixth rows, which are regions located further than the midpoint relative to the input transfer element. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column. In the same row, the fill factor of the first column may be less than or equal to the fill factor of the second column.

[0235] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 19], the efficiency may be as shown in [Table 20]. Referring to [Table 20] and Fig. 20b, the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0236] The efficiency of the optical guide device including the transfer diffraction element according to the 12th embodiment may be 0.74% and the uniformity may be 18.7%.

[0237] FIGS. 21a and 21b are graphs showing the fill factor of each column of a transfer diffraction element according to the 13th embodiment of the present invention and the efficiency accordingly.

[0238] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 13th embodiment of the present invention are as shown in [Table 21] and [Table 22], and FIGS. 21a and FIGS. 21b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 13th embodiment is 50 nm.

[0239] Row 1234567 1st Column 0.80.780.70.620.560.60.78 2nd Column 0.80.760.740.740.760.780.8

[0240] Row 1234567 1st Column 17.67 19.53 26.49 31.47 33.36 32.31 19.53 2nd Column 17.67 21.32 23.12 23.12 21.32 19.53 17.67

[0241] (unit: %)

[0242] Referring to Fig. 21a and [Table 21], the fill factor of the first column and the second column gradually decreases and then increases as they move further away from the input diffraction element. Referring to [Table 21], the fill factor of the first row of the first column may be greater than the fill factor of the last row of the first column, and the fill factor of the first row of the second column may be equal to the fill factor of the last row of the second column. The row with the smallest fill factor of the first column is the fifth row, which may be a region located further than the middle relative to the input transfer element. The rows with the smallest fill factor of the second column are the third and fourth rows, which may be regions closer than the middle relative to the input transfer element. The smallest value of the fill factor of the second column may be greater than the smallest value of the fill factor of the first column.

[0243] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 21], the efficiency may be as shown in [Table 22]. Referring to [Table 22] and Fig. 21b, the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0244] The efficiency of the optical guide device including the transfer diffraction element according to the 13th embodiment may be 0.725% and the uniformity may be 18.9%.

[0245] FIGS. 22a and 22b are graphs showing the fill factor of each column of a transfer diffraction element according to the 14th embodiment of the present invention and the efficiency accordingly.

[0246] Specifically, the fill factor and efficiency of each column of the transfer diffraction element according to the 14th embodiment of the present invention are as shown in [Table 23] and [Table 24], and FIGS. 22a and FIGS. 22b are graphs thereof. The height of the grating pattern of the transfer diffraction element according to the 14th embodiment is 50 nm.

[0247] Row 1234567 1st Column 0.80.80.720.620.540.580.76 2nd Column 0.80.740.740.740.760.780.8

[0248] Row 1234567 1st Column 17.67 17.67 24.87 31.47 33.59 32.94 21.32 2nd Column 17.67 23.12 23.12 23.12 21.32 19.53 17.67

[0249] (unit: %)

[0250] Referring to Fig. 22a and [Table 23], the fill factor of the first column and the second column gradually decreases and then increases as they move further away from the input diffraction element. Referring to [Table 23], the fill factor of the first row in the first column may be greater than the fill factor of the last row in the first column, and the fill factor of the first row in the second column may be equal to the fill factor of the last row in the second column. In the first column, the row with the lowest fill factor may be the fifth row. The fifth row may be a region further away from the input diffraction element than the center of the first column. In the second column, the row with the lowest fill factor may be multiple rows, such as the second, third, or fourth rows. The row with the lowest fill factor in the second column may be a row closer to the input diffraction element than the row with the lowest fill factor in the first column. The smallest value of the fill factor in the second column may be greater than the smallest value of the fill factor in the first column.

[0251] When the fill factor of the first and second columns of the transfer diffraction element is as shown in [Table 23], the efficiency may be as shown in [Table 24]. Referring to [Table 24] and Fig. 22b, the efficiency of the first and second columns gradually increases as they move away from the input diffraction element and then decreases.

[0252] The efficiency of the optical guide device including the transfer diffraction element according to the 14th embodiment may be 0.708% and the uniformity may be 19.5%.

[0253] FIG. 23 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.

[0254] Specifically, among the diffraction elements included in the light guide device, the transfer diffraction element may be the transfer diffraction element according to the 5th to 14th embodiments described above. 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 illustrated as including a single grating pattern, but FIG. 23 may divide the column of the transfer diffraction element into 2 and the row into 7, so that the grating pattern may be different for each divided region. As previously explained, the height and azimuth angle of the protrusion constituting the grating pattern of each region within the transfer diffraction element may be constant, and only the fill factor of the grating pattern may differ. As described above, the fill factor is determined by the width of the protruding part and the grating period. Therefore, the fill factor may be changed by changing both the width of the protruding part and the grating period, but the fill factor may also be changed by changing only one of the width of the protruding part and the grating period.

[0255] FIG. 24 is a perspective view showing an example of a grating pattern in a transfer diffraction element according to the 5th to 14th embodiments described above.

[0256] Referring to FIG. 24, the height of the grating pattern in each region included in the transfer diffraction element may be the same, and the fill factor may be different. In the first and second columns, the fill factor of each row decreases as it moves away from the input diffraction element, and then increases. For better understanding, this is illustrated in more detail in FIG. 25a to 25c.

[0257] FIG. 25a is a diagram showing a divided region of the transfer diffraction element of FIG. 24, FIG. 25b is a side view of the grating pattern for the first column of the transfer diffraction element, and FIG. 25c is a side view of the grating pattern for the second column of the transfer diffraction element.

[0258] Referring to FIG. 25a, the transfer diffraction element (2500) may include a 7x2 area. As described in FIG. 13, the 7x2 area included in the transfer diffraction element (2500) 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 (2500) 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 (2500) 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 (2500) may be the first column, the second column, ..., the seventh column.

[0259] Referring to FIGS. 25b and 25c, the grating pattern within the same furnace may be identical. That is, the height and width of the protrusions, as well as the period and azimuth of the grating pattern, may be identical. However, for different furnaces, while the height of the protrusions and the azimuth of the grating pattern may be identical, the fill factor of the grating pattern may differ from one another. In FIG. 25b, which is a side view of the grating pattern for the first column, the fill factor may gradually decrease and then increase as the position of the furnace moves further away from the input diffraction element, and in FIG. 25c, which is a side view of the grating pattern for the second column, the fill factor may also gradually decrease and then increase as the position of the furnace moves further away from the input diffraction element. As described above, the fill factor can be determined by the width of the protruding part and the grating period; FIGS. 25b and 25c illustrate, for example, an example in which the fill factor changes as the width of the protrusion is changed.

[0260] 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 gradually decreases in a direction away from the input diffraction element, and A light guide device in which the second region includes a second grating pattern, and the height of the second grating pattern also decreases and then increases in a direction away from the input diffraction element.

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 2, 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 lower than or equal to the maximum height of the second grid pattern.

5. In Paragraph 3, A light guide device in which the height of the second grid pattern is highest in the middle region among the regions in which the second region is divided into multiple regions.

6. In Paragraph 3, A light guide device in which the height of the second grid pattern is symmetrical with respect to the middle region among the regions in which the second region is divided into multiple regions.

7. In Paragraph 1, A light guide device in which the grid period, azimuth, and width of the first grid pattern and the second grid pattern are the same.

8. In Paragraph 1, A light guide device having a width / grid period of the first grid pattern and the second grid pattern of the above, which is 0.5 to 0.

6.

9. In Paragraph 1, A light guide device having a height of 100 to 150 nm for the first grating pattern and the second grating pattern.

10. In Paragraph 1, A light guide device in which the height of the first grating pattern and the height of the second grating pattern are the same in the direction closest to the input diffraction element.

Images