Optical device and wearable device including the same

Abstract

An optical device according to one embodiment includes: a first region for guiding incident light; a second region for emitting light guided from the first region, where the first region includes a first pattern, the second region includes a second pattern different in size or shape from the first pattern, defining a first virtual straight line passing through a first center of the first region, defining a second virtual straight line passing through a second center of the second region and parallel to the first straight line, defining a third straight line connecting the first center and the second center, defining a fourth straight line connecting the first straight line and the second straight line, the third straight line being perpendicular to the first straight line and the second straight line, the third straight line being longer than the fourth straight line, and if a line perpendicular to the first straight line at the first center is defined as an X-axis and the first straight line is defined as a Y-axis, coordinates of the first center of the first region are (0, 0), and coordinates of the second center of the second region are (x, y), x is 30 mm to 45 mm, y is-10 mm to 5 mm, and y does not include 0.

Description

Technical Field

[0001] Embodiments relate to an optical device and a wearable device including the optical device. Background Art

[0002] Recent technological advances have led to various types of wearable devices that can be worn on the body. Among them, augmented reality (AR) devices are wearable devices in the form of glasses worn on the user's head. The augmented reality device provides visual information through a display. Therefore, the user can receive augmented reality services.

[0003] Augmented reality mixes real-world information with virtual images by inserting 3D images into the real environment.

[0004] Real world information may contain information that the user does not need. Alternatively, real world information may lack information that the user needs. However, augmented reality systems combine the real world and the virtual world. Therefore, the interaction between the real world and the virtual world occurs in real time.

[0005] Unlike virtual reality (VR) devices that block the field of view, augmented reality (AR) devices do not block the field of view when used. In addition, augmented reality (AR) devices display a wide screen level display in front of the eyes when worn like regular glasses. In addition, augmented reality (AR) devices can provide extended reality that combines reality and AR content based on the user's use of a 360° space. In addition, augmented reality (AR) devices can provide users with optimized displays while freeing their hands.

[0006] The augmented reality device includes an optical module. The optical module provides an augmented reality image to the user. For example, the augmented reality device can be configured by wearable glasses as the optical device. In addition, a projector that projects an image onto the wearable glasses can be combined.

[0007] The light emitted from the projector passes through the optical device and is incident on the user's eyes. As a result, the user sees an augmented reality display.

[0008] The light emitted from the projector is diffracted by the optical device and incident on the user's eyes. Therefore, the optical device may include a diffraction pattern. When the size of the diffraction pattern becomes larger, the size of the optical device may increase. In addition, the diffraction pattern may be visible to the user. Therefore, the visibility of the user may be reduced.

[0009] Therefore, an optical device that can solve the problem is needed. Summary of the invention

[0010] [Technical issues]

[0011] Embodiments are directed to providing an optical device having a small size and a wearable device including the optical device.

[0012] Embodiments are directed to providing an optical device having improved wearing feeling and visibility, and a wearable device including the optical device.

[0013] [Technical solution]

[0014] An optical device according to an embodiment includes: a first area configured to guide incident light; and a second area configured to emit light guided from the first area, wherein the first area includes a first pattern, the second area includes a second pattern having a size or shape different from the first pattern, a first virtual straight line passing through a first center of the first area is defined, a second virtual straight line passing through a second center of the second area and parallel to the first straight line is defined, a third straight line connecting the first center and the second center is defined, a fourth straight line connecting the first straight line and the second straight line is defined, the third straight line is perpendicular to the first straight line and the second straight line, the third straight line is longer than the fourth straight line, and when a line perpendicular to the first straight line at the first center is defined as the X-axis and the first straight line is defined as the Y-axis, the coordinates of the first center of the first area are (0, 0), the coordinates of the second center of the second area are (x, y), x is 30 mm or more and 45 mm or less, y is -10 mm or more and 5 mm or less, and y is not 0.

[0015] [Beneficial Effects]

[0016] The size of the optical device according to the embodiment is reduced. In detail, the optical device includes a second diffraction element that diffracts light in two directions. Therefore, no additional diffraction element is required to expand the angle of light.

[0017] Since the additional diffraction element is omitted, the size of the optical device is reduced. In addition, the visibility for the user is improved.

[0018] The incident area and the exit area of ​​the optical device are spaced apart in the X-axis direction. That is, the light incident to the incident area moves in the X-axis direction and is emitted to the exit area.

[0019] The light source member for emitting light to the optical device is disposed in an area adjacent to the user's temple. Therefore, the user can use the wearable device with a wearing feeling similar to that of wearing actual glasses.

[0020] The center of the first region as the incident region and the center of the second region as the exit region do not coincide with each other in the X-axis direction and the Y-axis direction.

[0021] Therefore, the second area is disposed below the first area. Therefore, the user can easily see the light including the image information emitted from the light source member.

[0022] The optical device according to the embodiment includes a first diffraction element and a second diffraction element, wherein a pattern of the first diffraction element and a pattern of the second diffraction element are inclined with respect to an X-axis direction.

[0023] Therefore, the diffraction efficiency of the first diffraction element and the second diffraction element is improved. Therefore, the area in the second area that emits light toward the user can be formed at the optimal position. Therefore, the visibility of the user is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a diagram showing a display device including an optical device according to an embodiment.

[0025] Figure 2 and Figure 3 is a top view of a first surface of an optical device according to an embodiment.

[0026] Figure 4 yes Figure 2 Magnified view of area A.

[0027] Figure 5 and Figure 6 yes Figure 2 Magnified view of area B.

[0028] Figure 7 and Figure 8 1 is another top view of the first surface of the optical device according to the embodiment.

[0029] Fig. 9 and Fig.10 is a diagram for describing the arrangement of a diffraction element of an optical device according to an embodiment.

[0030] Fig.11 and Fig.12 It is a diagram for describing the effect when the pattern of the diffraction element of the optical device according to the embodiment has directivity.

[0031] Fig.13 and Fig.14 is a diagram for describing the period of a diffraction element of an optical device according to an embodiment.

[0032] Fig.15 2 is a diagram showing a wearable device to which an optical device according to an embodiment is applied. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the technical concept of the present invention is not limited to the technical concept of the described embodiments, but can be implemented in various forms, and one or more components in the embodiments can be selectively combined or replaced and used within the scope of the technical concept of the present invention.

[0034] In addition, unless explicitly and specifically defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention may be interpreted as having the meaning commonly understood by ordinary technicians in the technical field to which the present invention belongs, and commonly used terms such as those defined in dictionaries may be interpreted in consideration of their contextual meanings in the relevant field.

[0035] In addition, 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. In this specification, unless the context clearly stipulates otherwise, the singular may also include the plural, and when described as "at least one (or one or more) of A, B and C", it may include one or more of all possible combinations of A, B and C.

[0036] In addition, when describing components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish one component from another, and these terms are not intended to limit the nature, order or sequence of the components.

[0037] In addition, when a component is described as being “connected,” “coupled” or “linked” to another component, this may include not only a case where the component is directly connected, coupled or linked to other components, but also a case where the component is “connected,” “coupled” or “linked” via other components between the component and the other component.

[0038] In addition, when a component is described as being formed or arranged "on (above) or below (below)" another component, "on" or "below" not only includes the case where the two components are directly in contact with each other, but also includes the case where one or more other components are formed or arranged between the two components.

[0039] In addition, when expressed as "up (above) or down (below)", it can include a meaning of not only an upward direction but also a downward direction based on one component.

[0040] Hereinafter, an optical device according to an embodiment will be described with reference to the accompanying drawings.

[0041] Figure 1 is a view showing a part of a wearable device including an optical device according to an embodiment. The wearable device described below is an augmented reality (AR) device.

[0042] Reference Figure 1 , the wearable device includes an optical device 100, a light source member 200, and diffractive elements 410 and 420.

[0043] The optical device 100 has a first surface 1S and a second surface 2S opposite to the first surface 1S.

[0044] Light is incident on the first surface 1S. In addition, light is emitted from the first surface 1S. In detail, light emitted from the light source member 200 is emitted in the direction of the first surface 1S. Therefore, light is incident on the inside of the optical device 100 through the first surface 1S. The light incident on the inside of the optical device 100 is totally reflected inside the optical device 100. In addition, light is emitted to the outside of the optical device 100 through the first surface 1S. Therefore, the emitted light emitted through the first surface 1S is transmitted to the user.

[0045] The optical device 100 includes a material that transmits light. The optical device 100 has a refractive index within a set range. In detail, the optical device 100 includes a material having a refractive index of 1.82 or higher. For example, the optical device 100 includes glass having a refractive index of 1.82 to 2.

[0046] The optical device 100 may have various shapes. For example, the optical device 100 may have a circular or elliptical shape including a curved surface. Alternatively, the optical device 100 may have a polygonal shape such as a triangle or a quadrilateral.

[0047] The optical device 100 guides light. For example, the optical device 100 may be a waveguide.

[0048] The light source member 200 may include a projector. The light emitted from the light source member 200 may include image information. That is, the light incident to the optical device 100 includes the image information. Therefore, the image information emitted from the light source member 200 is transmitted to the user through the optical device 200.

[0049] The optical device 100 includes a plurality of diffraction elements. In detail, the optical device 100 includes a first diffraction element 410 and a second diffraction element 420. The first diffraction element 410 is disposed between the optical device 100 and the light source member 200. In addition, the second diffraction element 420 is disposed between the optical device 100 and a user.

[0050] In detail, the first diffraction element 410 is disposed between the optical device 100 and the light source member 200 based on the path of light. In addition, the second diffraction element 420 is disposed between the optical device 100 and the user based on the path of light.

[0051] Therefore, light emitted from the light source member 100 passes through the first diffraction element 410 and is incident to the inside of the optical device 100. In addition, light emitted from the inside of the optical device 100 passes through the second diffraction element 420 and is transmitted to the user.

[0052] Hereinafter, light moving from the light source member 200 in the direction of the first surface 1S is defined as first light L1. In addition, light passing through the first diffraction element 410 and incident into the interior of the optical device 100 is defined as second light L2. In addition, light passing through the second diffraction element 420 and emitted to the user is defined as third light L3.

[0053] Reference Figure 2 and Figure 3 , the optical device 100 includes a plurality of regions. In detail, the first side 1S of the optical device 100 includes a first region 1A and a second region 2A.

[0054] The first region 1A is a region where the first diffraction element 410 is disposed. The second region 2A is a region where the second diffraction element 420 is disposed.

[0055] The first area 1A guides light incident to the optical device 100. In detail, the first area 1A is an area where light emitted from the light source member 200 is incident. The light emitted from the light source member 200 includes image information. The first area 1A guides light emitted from the light source member 200. That is, the first area 1A guides light to the inside of the optical device 100.

[0056] In addition, the light guided in the first region 1A is emitted to the outside of the optical device 100 through the second region 2A.

[0057] Therefore, the light guided to the inside of the optical device 100 through the first area 1A is emitted to the outside of the optical device 100 through the second area 2A. Therefore, image information is transmitted to the user.

[0058] The first light L1 is diffracted in one direction by the first diffraction element 410. Therefore, the first light L1 is diffracted into the second light L2. The second light L2 is guided to the inside of the optical device 100. In addition, the second light L2 is totally reflected inside the optical device 100. The second light L2 is diffracted into the third light L3 by the second diffraction element 420. The second light L2 is diffracted in at least two directions. Therefore, the second light L2 is diffracted into the third light L3. That is, the second light L2 is diffracted in two directions by the second diffraction element 420. Therefore, the third light L3 diffracted by the first diffraction element 410 and the second diffraction element 420 is transmitted to the user. Therefore, the image information is transmitted to the user.

[0059] The second region 2A includes a plurality of regions. For example, the second region 2A includes a 2-1 region 2-1A and a 2-2 region 2-2A. The 2-1 region 2-1A is an inner region of the second region 2A. In addition, the 2-2 region 2-2A is an edge region of the second region 2A. That is, the 2-2 region 2-2A surrounds the 2-1 region 2-1A.

[0060] The 2-1 region 2-1A is defined as an effective region. That is, the 2-1 region 2-1A is a region where light is transmitted toward the user. In addition, the 2-2 region 2-2A is defined as an ineffective region. That is, the 2-2 region 2-2A is a region where light is not transmitted toward the user. That is, light emitted from the 2-2 region 2-2A is not transmitted toward the user.

[0061] 2-1 area 2-1A and 2-2 area 2-2A are areas where the angle of the second light L2 is extended. In detail, the angle of the second light L2 is extended by the second diffraction element 420. Therefore, the light emitted from the 2-2 area 2-2A is emitted at an angle exceeding the viewing angle of the display device. Therefore, the light emitted from the 2-2 area 2-2A is not transmitted to the user.

[0062] Figure 4 yes Figure 2 Magnified view of area A.

[0063] Reference Figure 4 , the first area 1A includes a first pattern P1. In detail, the first area 1A includes a plurality of first patterns P1. The first diffraction element 410 is composed of the first pattern P1. The first pattern P1 has a set size. For example, the first pattern P1 has an area and a thickness within a set range. The first pattern P1 is arranged in a strip shape. In detail, the first pattern P1 extends in one direction. For example, the first pattern P1 may be a line pattern.

[0064] The first light L1 is diffracted in one direction by the first diffraction element 410 .

[0065] Figure 5 and Figure 6 yes Figure 2 Magnified view of area B.

[0066] Reference Figure 5 and Figure 6 , the second area 2A includes a second pattern P2. In detail, the second area 2A includes a plurality of second patterns P2. The second diffractive element 420 is composed of the second pattern P2. The second pattern P2 is different from the first pattern P1. In detail, the first pattern P1 and the second pattern P2 have different sizes or shapes. For example, the first pattern P1 and the second pattern P2 may have different heights, shapes, and thicknesses.

[0067] The second pattern P2 is formed in a free-form shape. The second diffraction element 420 may include a unit pattern UNP. The unit pattern UNP includes a plurality of second patterns P2.

[0068] In detail, the second diffraction element 420 includes a plurality of unit patterns UNP. That is, in the second diffraction element 420, a plurality of unit patterns UNP are repeatedly arranged. The unit pattern UNP is formed by N rows (N is a natural number) and M columns (M is a natural number). Therefore, the second area 2A includes a second pattern consisting of N×M rows and columns. The interval between the centers of the patterns arranged in one of the N rows may be the same as the interval between the centers of the patterns arranged in another row. The rows may be in the transverse direction, and the columns may be in the longitudinal direction.

[0069] It can be assumed that the above pattern has Figure 5 The shape of the enlarged view of the pattern. When a minimum quadrilateral QU including all the outermost points of the pattern is defined, the pattern center PC can be defined as the center of the quadrilateral QU. At this time, the quadrilateral can be a square or a rectangle. The interval between the pattern centers can be defined as the interval between the centers of the pattern.

[0070] A plurality of patterns are arranged inside the unit pattern UNP. For example, a plurality of patterns having different shapes or sizes are arranged inside the unit pattern UNP. Figure 5 and Figure 6 The unit pattern UNP is shown to be formed of two rows and three columns, and includes a 2-1 pattern P2-1, a 2-2 pattern P2-2, a 2-3 pattern P2-3, a 2-4 pattern P2-4, a 2-5 pattern P2-5, and a 2-6 pattern P2-6. However, the embodiment is not limited thereto. The unit pattern may be formed by a combination of various numbers of rows and columns.

[0071] The second light L2 is diffracted in multiple directions by the second diffraction element 420. The second light L2 is diffracted in a first direction in which the second light is extended and in a second direction different from the first direction. In detail, the first direction is a direction in which the second light L2 is extended by the second diffraction element 420 to 60° or 90°.

[0072] The second light L2 is diffracted in multiple directions by the second diffraction element 420. Therefore, the number of diffraction elements of the optical device 100 is reduced. Conventionally, the third diffraction element is arranged between the first diffraction element 410 and the second diffraction element 420. The light passing through the first diffraction element, the second diffraction element and the third diffraction element is diffracted in one direction. However, as the viewing angle of the optical device becomes larger, the size of the third diffraction element increases. Therefore, the size of the optical device increases. Alternatively, the diffraction element is visible to the user.

[0073] However, in the optical device, since the second diffraction element 420 diffracts light in multiple directions, this problem can be solved.

[0074] Reference Figure 2 and Figure 3 In the first area 1A and the second area 2A, the center of each area is defined. For example, in the first area 1A, a first center C1 is defined. In the second area 2A, a second center C2 is defined.

[0075] Furthermore, a plurality of virtual straight lines passing through the first center C1 and the second center C2 are defined.

[0076] For example, a virtual first straight line VL1 passing through the first center C1 is defined. In addition, a virtual second straight line VL2 passing through the second center C2 and parallel to the first straight line VL1 is defined. In addition, a virtual third straight line VL3 connecting the first center C1 and the second center C2 is defined. In addition, a virtual fourth straight line VL4 perpendicular to the first straight line VL1 and the second straight line VL2 and connecting the first straight line VL1 and the second straight line VL2 is defined. In detail, the fourth straight line VL4 may be a straight line connecting the first straight line VL1 and the second straight line VL2 at the shortest distance.

[0077] The third straight line VL3 and the fourth straight line VL4 may have different lengths. In detail, the length of the third straight line VL3 may be longer than the length of the fourth straight line VL4.

[0078] A line perpendicular to the first straight line VL1 is defined as an X axis. In addition, the first straight line VL1 is defined as a Y axis. Thus, the coordinates of each of the first center C1 and the second center C2 are set.

[0079] Specifically, the first coordinate of the first center C1 is set to (0, 0). In addition, the second coordinate of the second center C2 is set to (x, y).

[0080] x and y have set dimensions. x can be 30 mm or more to 45 mm or less. In addition, y can be -10 mm or more to 5 mm or less (y≠0).

[0081] Therefore, the first center C1 and the second center C2 are spaced apart from each other by a first interval d1. The first interval d1 may be 30 mm to 45 mm in the X-axis direction.

[0082] In addition, y has a positive value or a negative value. That is, the second center C2 is disposed below or above the first center C1 in the Y-axis direction.

[0083] Reference Figure 2, the second center C2 is arranged below the first center C1 in the Y-axis direction. y may be between -10 mm and less than 0. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a set range in the Y-axis direction. In detail, the first center C1 and the second center C2 are spaced apart from each other by -10 mm to less than 0 mm in the Y-axis direction. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a second interval d2. The second interval d2 may be less than -10 mm to less than 0 mm in the Y-axis direction.

[0084] Therefore, the second area 2A is disposed below the first area 1A. Therefore, the user can easily see the third light emitted from the second area 2A. Typically, users wearing AR glasses use the lower part of the glasses lens more than the upper part of the glasses lens. The light source member 200 can be disposed on the user's temple. That is, when the light source member 200 is disposed on the frame of the AR glasses, the light emitted from the light source member 200 is incident on the upper part of the glasses lens. The second area from which light is emitted is disposed below the first area. Therefore, the user can easily see the image information transmitted by the optical device.

[0085] Reference Figure 3 , the second center C2 is arranged above the first center C1 in the Y-axis direction. y may be greater than 0 mm to less than or equal to 5 mm. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a set range in the Y-axis direction. In detail, the first center C1 and the second center C2 are spaced apart from each other by a set range in the Y-axis direction. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a second interval d2. The second interval d2 may be greater than 0 mm and less than or equal to 5 mm in the Y-axis direction.

[0086] Therefore, the second area 2A is disposed above the first area 1A. Therefore, even if the 2-1 area 2-1A emitting light to the user is disposed significantly tilted to the lower portion of the second area 2A in the Y-axis direction, the user can easily see the image information transmitted by the optical device.

[0087] At the same time, refer to Figure 7 and Figure 8 , the first center C1 and the second center C2 may be defined differently.

[0088] First, the optical arrangement has defined X and Y axes.

[0089] In addition, a plurality of virtual straight lines passing through the first center C1 and the second center C2 are defined.

[0090] For example, a fifth virtual straight line VL5 passing through the first center C1 and parallel to the X-axis is defined. In addition, a sixth virtual straight line VL6 passing through the first center C1 and parallel to the Y-axis is defined. In addition, a seventh virtual straight line VL7 passing through the second center C2 and parallel to the X-axis is defined. In addition, an eighth virtual straight line VL8 passing through the second center C2 and parallel to the Y-axis is defined.

[0091] Therefore, the first center C1 is defined as the point where the fifth straight line VL5 and the sixth straight line VL6 intersect. In addition, the second center C2 is defined as the area where the seventh straight line VL7 and the eighth straight line VL8 intersect.

[0092] The coordinates of each of the first center C1 and the second center C2 are set.

[0093] Specifically, the first coordinate of the first center C1 is set to (0, 0). In addition, the second coordinate of the second center C2 is set to (x, y).

[0094] x and y may have set sizes. x may be 30 mm or more to 45 mm or less. In addition, y may be -10 mm or more to 5 mm or less (y≠0).

[0095] x has a positive value. That is, the second center C2 is set to the right of the first center C1 in the X-axis direction. x has a set range. In detail, x can be 30 mm or more. x can be 45 mm or less. x can be 30 mm to 45 mm. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a set range in the X-axis direction. In detail, the first center C1 and the second center C2 are spaced apart from each other by 30 mm to 45 mm in the X-axis direction. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a first interval d1. The first interval d1 can be 30 mm to 45 mm in the X-axis direction.

[0096] y has a positive value or a negative value. That is, the second center C2 is disposed below or above the first center C1 in the Y-axis direction.

[0097] Reference Figure 7 , the second center C2 is arranged below the first center C1 in the Y-axis direction. y has a set range. In detail, y may be -10 mm or more. y may be less than 0. y may be between -10 mm and less than 0. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a set range in the Y-axis direction. In detail, the first center C1 and the second center C2 are spaced apart from each other by -10 mm to less than 0 mm in the Y-axis direction. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a second interval d2. The second interval d2 may be -10 mm to less than 0 mm in the Y-axis direction.

[0098] Therefore, the second area 2A is disposed below the first area 1A. Therefore, the user can easily see the third light emitted from the second area 2A. Typically, users wearing AR glasses use the lower part of the glasses lens more than the upper part of the glasses lens. The light source member 200 can be disposed on the user's temple. That is, when the light source member 200 is disposed on the frame of the AR glasses, the light emitted from the light source member 200 is incident on the upper part of the glasses lens. The second area from which light is emitted is disposed below the first area. Therefore, the user can easily see the image information transmitted by the optical device.

[0099] Reference Figure 8 , the second center C2 is arranged above the first center C1 relative to the Y-axis direction. y has a set range. In detail, y may be greater than 0. y may be 5 mm or less. y may be greater than 0 to less than or equal to 5 mm. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a set range in the Y-axis direction. In detail, the first center C1 and the second center C2 are spaced apart from each other by a greater than 0 mm to less than or equal to 5 mm in the Y-axis direction. Therefore, the first center C1 and the second center C2 are spaced apart from each other by a second interval d2. The second interval d2 may be greater than 0 mm to less than or equal to 5 mm in the Y-axis direction.

[0100] Therefore, the second area 2A is disposed above the first area 1A. Therefore, even if the 2-1 area 2-1A emitting light to the user is disposed significantly tilted to the lower portion of the second area 2A in the Y-axis direction, the user can easily see the image information transmitted by the optical device.

[0101] That is, y is -10 mm to less than 0 or greater than 0 to less than or equal to 5 mm. Therefore, the first center C1 and the second center C2 are spaced apart from each other in the Y-axis direction by -10 mm to less than 0 mm or greater than 0 mm to less than or equal to 5 mm.

[0102] Therefore, the first center C1 and the second center C2 are spaced apart from each other by a first interval d1 of 30 mm to 45 mm in the X-axis direction, and spaced apart from each other by a second interval d2 of -10 mm to less than 0 mm or greater than 0 mm to less than or equal to 5 mm in the Y-axis direction.

[0103] In addition, a ninth straight line VL5 connecting the first center C1 and the second center C2 is defined. The ninth straight line VL9 is not parallel to the fifth straight line VL5. In addition, the ninth straight line VL9 is not parallel to the seventh straight line VL7. That is, the ninth straight line VL9 is not parallel to the X-axis direction.

[0104] Therefore, the first center C1 and the second center C2 do not coincide with each other in both the X-axis direction and the Y-axis direction.

[0105] The first region 1A and the second region 2A are spaced apart from each other by a first interval d1 in the X-axis direction, and are spaced apart from each other by a second interval d2 in the Y-axis direction. At this time, the first interval d1 is greater than the second interval d2.

[0106] Therefore, the incident area and the exit area of ​​the optical device 100 are spaced apart from each other in the X-axis direction. That is, the light incident to the first area 1A is guided in the X-axis direction and emitted from the second area 2A.

[0107] Therefore, the user can use the display device with the same feeling as if he or she wears actual glasses. That is, the light source member 200 is not disposed on the user's eyes, but is disposed at a position adjacent to the user's temple. Therefore, the user can use the display device as a portable glasses-type display device.

[0108] Meanwhile, the pattern of the first diffractive element 410 and the pattern of the second diffractive element 420 may have a set directivity.

[0109] Reference Fig. 9 In the first pattern P1 of the first diffraction element 410, a tenth straight line VL10 perpendicular to the length direction of the pattern is defined. In detail, the first pattern P1 is a line pattern. In addition, the tenth straight line VL10 is a line passing through the center C of the line pattern.

[0110] The tenth straight line VL10 is not parallel to the fourth straight line VL4. That is, the tenth straight line VL10 is inclined at an acute first angle θ1 relative to the fourth straight line VL4 or the fifth straight line VL5. That is, a line passing through the center C of the line pattern forms an acute first angle with the fourth straight line. The center C of the line pattern may be defined as an area having the same interval as the outermost lines of the line pattern.

[0111] Reference Fig.10 In the second diffraction element 420, an eleventh straight line VL11 extending in the row direction is defined. The eleventh straight line VL11 is not parallel to the fourth straight line VL4. That is, the eleventh straight line VL11 is inclined at an acute second angle θ2 relative to the fourth straight line VL4 or the seventh straight line VL7.

[0112] In detail, the second angle θ2 is related to the first interval d1 and the second interval d2. In detail, the second angle θ2 satisfies the following formula.

[0113] [Mode]

[0114] 1 / 2×arctan(d2 / d1)<second angle (θ2)<2 / 3×arctan(d2 / d1)

[0115] Since the second angle θ2 satisfies the above formula, the position of the second area 2A is optimized. That is, the 2-1 area 2-1A can be prevented from being greatly deflected in one direction relative to the entire second area 2A. That is, the 2-1 area 2-1A emitting light to the user can be prevented from being greatly deflected in the X-axis or Y-axis direction.

[0116] Fig.11 and Fig.12 4 is a diagram for describing the effect when the first pattern of the first diffraction element 410 and the second pattern of the second diffraction element 420 have set directivities. Fig.11 4 is a diagram when the second light L2 is expanded to 60° by the second diffraction element 410. Fig.12 This is a diagram when the second light L2 is expanded to 90° by the second diffraction element 410.

[0117] Fig.11 and Fig.12 (a) shows a case where the first pattern of the first diffraction element 410 and the second pattern of the second diffraction element 420 have set directivities. Fig. 9 and Fig.10 (b) shows a case where the first pattern of the first diffraction element 410 and the second pattern of the second diffraction element 420 have no directionality.

[0118] Reference Fig. 9 and Fig.10 When the first pattern and the second pattern have set directivity, the 2-2 region 2-2A will not be biased to one side in the second region 2A. Therefore, the area of ​​the 2-2 region 2-2A where the user sees the image information increases. Therefore, the user's visibility is improved.

[0119] On the other hand, when the first pattern and the second pattern do not have set directivity, the 2-2 region 2-2A is very biased to one side in the second region 2A. Therefore, the area of ​​the 2-2 region 2-2A where the user sees the image information is reduced. Therefore, the visibility of the user is reduced.

[0120] According to an embodiment, the size of the optical device is reduced. In detail, the optical device includes a second diffraction element that diffracts light in two directions. Therefore, no additional diffraction element is required to expand the angle of light.

[0121] Since the additional diffraction element is omitted, the size of the optical device is reduced. In addition, the visibility for the user is improved.

[0122] The incident area and the exit area of ​​the optical device are spaced apart from each other in the X-axis direction. That is, the light incident to the incident area moves in the X-axis direction and is emitted to the exit area.

[0123] The light source member that emits light to the optical device is disposed in an area adjacent to the user's temple. Therefore, the user can use the wearable device with a wearing feeling similar to that of wearing actual glasses.

[0124] The center of the first region as the incident region and the center of the second region as the exit region do not coincide with each other in the X-axis direction and the Y-axis direction.

[0125] Therefore, the second area is disposed below the first area. Therefore, the user can easily see the light including the image information emitted from the light source member.

[0126] The optical device according to the embodiment includes a first diffraction element and a second diffraction element, wherein a pattern of the first diffraction element and a pattern of the second diffraction element are inclined with respect to an X-axis direction.

[0127] Therefore, the diffraction efficiency of the first diffraction element and the second diffraction element is improved. Therefore, the area in the second area that emits light toward the user can be formed at the optimal position. Therefore, the visibility of the user is improved.

[0128] Meanwhile, the first pattern P1 and the second pattern P2 may have a period. The period of the pattern is defined as a distance at which the first pattern P1 and the second pattern P2 are repeated.

[0129] Reference Fig.13 , the first pattern P1 may have a set first period PE1. The first period PE1 is a distance between the first patterns P1. In detail, the first patterns P1 are spaced apart from each other by the distance of the first period PE1. The first patterns P1 are spaced apart from each other in a direction perpendicular to the length direction of the first pattern P1.

[0130] The first period PE1 satisfies at least one of the following Expressions 1 to 4.

[0131] [Formula 1]

[0132] λ / 1.75<first period<λ / 1.37

[0133] (In Formula 1, λ is the wavelength of light (nm)).

[0134] [Formula 2]

[0135] λ / 1.75<first period<λ / 1.37

[0136] (In Formula 2, λ satisfies 450nm≤λ≤490nm).

[0137] [Formula 3]

[0138] λ / 1.75<first period<λ / 1.37

[0139] (In Formula 3, λ satisfies 490nm<λ≤570nm).

[0140] [Formula 4]

[0141] λ / 1.75<first period<λ / 1.37

[0142] (In Formula 4, λ satisfies 620nm≤λ≤780nm).

[0143] The first period PE1 may vary according to the wavelength of light emitted from the light source member 200 , as shown in Formula 1. For example, the first period PE1 may be proportional to the wavelength of light.

[0144] Equation 2 is for the case where blue light is emitted from the light source member 200. Equation 3 is for the case where green light is emitted from the light source member 200. Equation 4 is for the case where red light is emitted from the light source member 200.

[0145] Referring to Formulas 1 to 4, the first period PE1 when red light is emitted from the light source member 200 may be greater than the first period PE1 when green and blue light are emitted from the light source member 200. In addition, the first period PE1 when green light is emitted from the light source member 200 may be greater than the first period PE1 when blue light is emitted from the light source member 200.

[0146] Since the first period PE1 satisfies at least one of equations 1 to 4, the diffraction efficiency of the incident light incident on the optical device 100 is improved. That is, the diffraction efficiency of the light diffracted by the first diffraction element 410 can be improved. Therefore, the light lost to the outside of the optical device 100 is reduced. In addition, the internal total reflection efficiency of the optical device 100 is improved.

[0147] Reference Fig.14 , the second pattern P2 has a set second period. The second period is the distance between the unit patterns of the second diffraction element 420. In detail, the second period is the distance between the centers of the unit patterns.

[0148] The unit patterns are spaced apart from each other by a distance of a second period.For example, the unit pattern may include a first unit pattern UNP1, a second unit pattern UNP2, and a third unit pattern UNP3.

[0149] The first unit pattern UNP1 and the second unit pattern UNP2 face each other in the row direction. In addition, the first unit pattern UNP1 and the third unit pattern UNP3 face each other in the column direction. In addition, the second unit pattern UNP2 and the third unit pattern UNP3 face each other in a direction between the row direction and the column direction.

[0150] Therefore, each of the first unit pattern UNP1 , the second unit pattern UNP2 , and the third unit pattern UNP3 has a period according to a direction.

[0151] The second period may include a 2-1 period PE2-1 of the first and second unit patterns UNP1 and UNP2, a 2-2 period PE2-2 of the first and third unit patterns UNP1 and UNP3, and a 2-3 period PE2-3 of the second and third unit patterns UNP2 and UNP3.

[0152] The 2-1 period PE2-1 is a period in the row direction. The 2-2 period PE2-2 is a period in the column direction. The 2-3 period PE2-3 is a period between the row direction and the column direction. That is, the 2-3 period PE2-3 is a period of unit patterns facing each other in the diagonal direction.

[0153] The 2-1 period PE2-1, the 2-2 period PE2-2, and the 2-3 period PE2-3 may satisfy at least one of the following Equations 5 to 7.

[0154] [Formula 5]

[0155] 0.9 < 2-1 cycle / 1st cycle < 1.1, and

[0156] 0.9<2-2 cycle / first cycle<1.1

[0157] [Formula 6]

[0158] 0.9<2-1 cycle / first cycle<1.1,

[0159] 0.9 < 2-2 cycle / first cycle < 1.1, and

[0160] 0.9<2-3 cycles / 1st cycle<1.1

[0161] [Formula 7]

[0162] 1.8<2-1 cycle / first cycle<2.2

[0163]

[0164] The second period varies according to the degree to which the second light L2 is expanded by the second diffraction pattern.

[0165] When the second light L2 is expanded to 90° by the second diffraction element 420, the second period may satisfy Formula 5 or Formula 6. That is, the 2-1 period PE2-1 and the 2-2 period PE2-2 may be the same. Alternatively, the 2-1 period PE2-1, the 2-2 period PE2-2 and the 2-3 period PE2-3 may be the same.

[0166] Alternatively, when the second light L2 is expanded to 60° by the second diffraction element 420, the second period PE2 may satisfy Equation 7. That is, the 2-1 period PE2-1 and the 2-2 period PE2-2 may be different.

[0167] In addition, the second period may vary according to the wavelength of light emitted from the light source member 200. That is, the second period is inversely proportional to the first period. Therefore, the second period may be inversely proportional to the wavelength of light.

[0168] Therefore, the second period of emitting blue light from the light source member 200 may be greater than the second period of emitting green and blue light from the light source member 200. In addition, the second period when emitting green light from the light source member 200 may be greater than the second period when emitting red light from the light source member 200.

[0169] Since the second period satisfies at least one of Formula 5 and Formula 6, the diffraction efficiency of the light emitted from the optical device 100 is improved. That is, the diffraction efficiency of the light diffracted by the second diffraction element 420 is improved. Therefore, the diffraction efficiency of the light emitted to the outside of the optical device 100 is improved. Therefore, the user can receive image information with improved brightness.

[0170] The size of the optical device according to the present embodiment can be reduced.

[0171] In detail, since the optical device includes the second diffraction element that diffracts light in two directions, no additional diffraction element is required to expand the angle of light.

[0172] Therefore, since an additional diffraction element is omitted, the size of the optical device can be reduced and the visibility for the user can be improved.

[0173] In the optical device according to the embodiment, the incident area and the exit area of ​​the optical device are spaced apart from each other in the X-axis direction. That is, light incident to the incident area of ​​the optical device moves in the X-axis direction and is emitted to the exit area.

[0174] That is, since the light source element that emits light to the optical device is provided in an area adjacent to the user's temple, the user can use the wearable device with a wearing feeling similar to that of wearing actual glasses.

[0175] In the optical device according to the embodiment, the center of the first region as the incident region and the center of the second region as the exit region do not coincide with each other in the X-axis direction and the Y-axis direction.

[0176] Therefore, the second area may be disposed below the first area. Therefore, the user can easily see the light including the image information emitted from the light source member.

[0177] In the optical device according to the embodiment, the pattern of each of the first diffraction element and the second diffraction element has a period within a set range.

[0178] Therefore, since the diffraction efficiency of the first diffraction element and the second diffraction element is improved, an area in the second area that emits light toward the user can be formed at an optimal position, and since the light including image information can have improved brightness, the visibility of the user can be improved.

[0179] In addition, the patterns of the first diffraction element and the second diffraction element have a period within a set range.

[0180] Therefore, the diffraction efficiency of the first diffraction element and the second diffraction element is improved. Therefore, the area in the second area that emits light toward the user can be formed at the optimal position. In addition, the light including the image information has improved brightness. Therefore, the visibility of the user is improved.

[0181] In the following, reference is made to Fig.15 , an example of a display device including the optical device according to the embodiment will be described.

[0182] Reference Fig.15 , the optical device can be applied to a wearable display device. In detail, the optical device can be applied to a wearable display device worn on the head or ear of a human body.

[0183] For example, the display device 2000 may be an augmented reality device.

[0184] The display device 2000 includes a wear unit 2100 and a display unit 2200 .

[0185] The wearable unit 2100 extends in one direction. The wearable unit 2100 is worn on the user's body. For example, the wearable unit 2100 is worn on the user's head or ear. Therefore, the display device 2000 is fixed to the user's body. For example, the wearable portion 2100 can be a glasses frame of the wearable display device.

[0186] The light source member 200 is provided on the wearable unit 2100. The light source member 200 emits light in the direction of the display unit 2200. In detail, the light source member 200 emits light including image information in the direction of the display unit 2200. In detail, the light source member 200 may be a projector.

[0187] The display unit 2200 may be the above-mentioned optical device. Alternatively, the display unit 2200 may be AR glasses including the optical device.

[0188] Therefore, the user may receive light including image information emitted from the light source member 200 through the display unit 2200. Therefore, the user may see augmented reality and virtual reality of real reality through the optical device.

[0189] The features, structures, effects, etc. described in the above embodiments are all included in at least one embodiment of the present invention, and are not necessarily limited to one embodiment. In addition, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified by a person skilled in the art to which the embodiment belongs and implemented in other embodiments. Therefore, the contents related to these combinations and modifications should be interpreted as included in the scope of the present invention.

[0190] In addition, although the above description has been focused on the embodiments, they are merely examples and do not limit the present invention, and those skilled in the art to which the present invention belongs will recognize that various modifications and applications not shown above can be made without departing from the essential features of the embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention as defined in the appended claims.

Claims

1. An optical device, comprising: a first region configured to direct incident light; as well as a second region configured to emit light directed from the first region, wherein the first area includes a first pattern, The second region includes a second pattern having a size or shape different from the first pattern, defining a first virtual straight line passing through a first center of the first area, A second virtual straight line passing through a second center of the second area and parallel to the first straight line is defined, defining a third straight line connecting the first center and the second center, A fourth straight line connecting the first straight line and the second straight line is defined, The third straight line is perpendicular to the first straight line and the second straight line, The third straight line is longer than the fourth straight line, and When a line perpendicular to the first straight line at the first center is defined as an X-axis, and the first straight line is defined as a Y-axis, The coordinates of the first center of the first area are (0, 0), The coordinates of the second center of the second area are (x, y), x is 30 mm or more and 45 mm or less, y is -10 mm or more and 5 mm or less, and y is not 0.

2. The optical device according to claim 1, wherein: The first pattern comprises a line pattern, and A line passing through the center of the line pattern forms an acute first angle with the fourth straight line.

3. The optical device according to claim 1, wherein: The second pattern includes at least two patterns having different shapes.

4. The optical device according to claim 1, wherein: The first pattern diffracts light in one direction, and The second pattern diffracts light in two directions.

5. The optical device according to claim 1, wherein: The second region includes a 2-1 region disposed inside the second region and a 2-2 region disposed at an edge of the second region, and Light is emitted toward a user through the 2-1 region.

6. An optical device comprising: a first region configured to direct incident light; as well as a second region configured to emit light directed from the first region, wherein the first area includes a first pattern, The second region includes a second pattern having a size or shape different from the first pattern, defining a first virtual straight line passing through a first center of the first area, A second virtual straight line passing through a second center of the second area and parallel to the first straight line is defined, defining a third straight line connecting the first center and the second center, A fourth straight line is defined that connects the first straight line and the second straight line with the shortest distance, The third straight line is longer than the fourth straight line, The second area includes a second pattern consisting of N×M rows and columns, and The fourth straight line forms a second acute angle with the N row.

7. The optical device according to claim 6, wherein: In the N×M rows and columns, an interval between centers of patterns arranged in one of the N rows is the same as an interval between centers of patterns arranged in another of the N rows.

8. The optical device according to claim 6, wherein: The first pattern comprises a line pattern, and The line pattern forms an acute first angle with the fourth straight line.

9. The optical device according to claim 6, wherein: The second pattern includes at least two patterns having different shapes.

10. The optical device according to claim 6, wherein: The second pattern includes a plurality of unit patterns consisting of n rows (n is a natural number) and m columns (m is a natural number).

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