Display device for providing an extended viewing window

Abstract

A display device capable of providing an extended viewing window includes: a light guide plate including an input coupler and an output coupler; and an image providing device facing the input coupler to provide an image to the input coupler. The input coupler may include a plurality of sub-input couplers configured to propagate an image provided by the image providing device at different angles within the light guide plate.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0066675, filed on June 2, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Example embodiments of the present disclosure relate to a display device, and more particularly, to a display device capable of providing an expanded viewing window. Background Art

[0004] Recently, as electronic devices and display devices capable of providing virtual reality (VR) images have been developed, interest in VR has increased. As a next step regarding VR, technologies that provide augmented reality (AR) and mixed reality (MR) have been studied.

[0005] Unlike VR, which involves a completely virtual world, AR is a display technology that further enhances the effect of reality by overlaying (combining) virtual objects or information about the real-world environment. Whereas VR is limited in its applicability to fields such as gaming or virtual experiences, AR can be applied to a variety of real-world environments. In particular, AR has attracted attention as a next-generation display technology suitable for ubiquitous environments or Internet of Things (IoT) environments. AR can be an example of MR because it mixes the real world with additional information (the virtual world).

[0006] The AR display device is manufactured as a near-eye display device such as a glasses type display device, a head-mounted type display device, a goggle type display device, etc. Various optical structures have been studied to manufacture a small and light near-eye display device. Summary of the Invention

[0007] One or more example embodiments provide a display device capable of providing an expanded viewing window.

[0008] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0009] According to aspects of an embodiment, a display device includes: a light guide plate including an input coupler and an output coupler; and an image providing device facing the input coupler and configured to provide an image to the input coupler, wherein the input coupler includes a plurality of sub-input couplers configured to propagate the image provided from the image providing device at different angles in the light guide plate.

[0010] The image providing apparatus may include: a spatial light modulator including a plurality of display areas respectively corresponding to the plurality of sub-input couplers; and a light source configured to provide coherent illumination light to the spatial light modulator.

[0011] The spatial light modulator may additionally include non-display areas between the plurality of display areas.

[0012] The spatial light modulator may be configured to display the same image on each of the plurality of display areas or to display images at different viewpoints on the plurality of display areas, respectively.

[0013] The display device may further include a diffraction grating disposed between the light source and the spatial light modulator, the diffraction grating being configured to diffract the coherent illumination light incident from the light source so that a traveling direction of the coherent illumination light incident on each of a plurality of display areas of the spatial light modulator is different from a traveling direction of the coherent illumination light incident on other display areas of the plurality of display areas.

[0014] The size of the diffraction grating may be larger than the size of the spatial light modulator.

[0015] The diffraction grating may be configured to diffract the coherent illumination light into a -1 order portion, a 0 order portion, and a +1 order portion, and the plurality of display regions of the spatial light modulator may include: a first display region on which the -1 order portion of the coherent illumination light is incident; a second display region on which the 0 order portion of the coherent illumination light is incident; and a third display region on which the +1 order portion of the coherent illumination light is incident.

[0016] The multiple display areas of the spatial light modulator may include a first display area, a second display area and a third display area, and the multiple sub-input couplers may include: a first sub-input coupler on which the first image diffracted by the -1st order of the first display area is incident, a second sub-input coupler on which the second image diffracted by the 0th order of the second display area is incident, and a third sub-input coupler on which the third image diffracted by the +1st order of the third display area is incident.

[0017] The size of the first display area may be larger than that of the first sub-input coupler, the size of the second display area may be larger than that of the second sub-input coupler, and the size of the third display area may be larger than that of the third sub-input coupler.

[0018] The image providing apparatus may include: a plurality of spatial light modulators respectively corresponding to the plurality of sub-input couplers, the plurality of spatial light modulators being separated from one another; and a light source configured to provide coherent illumination light to each of the plurality of spatial light modulators.

[0019] A plurality of sub-input couplers may be two-dimensionally arranged on the surface of the light guide plate, and a plurality of spatial light modulators may be two-dimensionally arranged on the same plane as each other, and each of the plurality of spatial light modulators may face a corresponding sub-input coupler among the plurality of sub-input couplers.

[0020] The light source may include a plurality of light sources configured to provide coherent illumination light to the plurality of spatial light modulators, respectively.

[0021] Each light source of the plurality of light sources may be configured to provide a color of coherent illumination light that is different from a corresponding color of coherent illumination light of each other light source of the plurality of light sources.

[0022] The image providing device may include an image scanner configured to provide a plurality of images to the plurality of sub-input couplers sequentially or simultaneously.

[0023] The input coupler may include: a first input coupler including a plurality of sub-input couplers; and a second input coupler including a plurality of sub-input couplers, and the image providing device may include: a first image providing device including a spatial light modulator arranged to face the first input coupler and a light source configured to provide coherent illumination light to the spatial light modulator; and a second image providing device including an image scanner arranged to face the second input coupler.

[0024] The light guide plate may further include an intermediate coupler arranged in the optical path between the input coupler and the output coupler, wherein the input coupler is configured to output light in a first direction in the light guide plate, wherein the intermediate coupler is configured to output light in a second direction perpendicular to the first direction in the light guide plate, and wherein the output coupler is configured to output light outside the light guide plate in a third direction perpendicular to the first direction and the second direction.

[0025] The display device may include a virtual reality display device, an augmented reality display device, or a mixed reality display device, and may include a head-mounted device, a glasses-type device, or a goggle-type device.

[0026] According to one aspect of example embodiments, a display device includes a light guide plate including an input coupler and an output coupler; and an image providing device configured to provide a plurality of images traveling in different directions to the input coupler.

[0027] The image providing device may include: a spatial light modulator facing the input coupler and including a plurality of display areas configured to provide a plurality of images to the input coupler; a light source configured to provide coherent illumination light to the spatial light modulator; and a diffraction grating disposed between the light source and the spatial light modulator, the diffraction grating configured to diffract the coherent illumination light incident from the light source so that a traveling direction of the coherent illumination light incident on each of the plurality of display areas of the spatial light modulator is different from a traveling direction of the coherent illumination light incident on the other display areas of the plurality of display areas.

[0028] The size of the diffraction grating may be larger than the size of the spatial light modulator, and the size of the spatial light modulator may be larger than the size of the input coupler.

[0029] The diffraction grating may be configured to diffract the coherent illumination light into a -1 order portion, a 0 order portion, and a +1 order portion, and the plurality of display regions of the spatial light modulator may include: a first display region on which the -1 order portion of the coherent illumination light is incident; a second display region on which the 0 order portion of the coherent illumination light is incident; and a third display region on which the +1 order portion of the coherent illumination light is incident.

[0030] The input coupler may include: a first sub-input coupler corresponding to the first display area of ​​the spatial light modulator, a second sub-input coupler corresponding to the second display area of ​​the spatial light modulator, and a third sub-input coupler corresponding to the third display area of ​​the spatial light modulator, and the first, second and third sub-input couplers may be configured to propagate the image provided from the spatial light modulator at different angles in the light guide plate.

[0031] The size of the first display area may be larger than that of the first sub-input coupler, the size of the second display area may be larger than that of the second sub-input coupler, and the size of the third display area may be larger than that of the third sub-input coupler.

[0032] The diffraction grating may include a plurality of diffraction gratings respectively corresponding to a plurality of display regions of the spatial light modulator, the plurality of diffraction gratings being configured to diffract the coherent illumination light in different directions.

[0033] The image providing device may include: a spatial light modulator facing the input coupler and including a plurality of display areas configured to provide a plurality of images to the input coupler; a light source configured to provide coherent illumination light to the spatial light modulator; and a diffraction grating disposed between the input coupler and the spatial light modulator, wherein each of the plurality of display areas is configured to provide a corresponding image of the plurality of images to the diffraction grating, and wherein the diffraction grating is configured to diffract each provided image in a different corresponding direction to be incident on the input coupler.

[0034] The multiple display areas of the spatial light modulator may include a first display area, a second display area, and a third display area, and the diffraction grating may be configured to output a -1 order diffraction of a first image provided by the first display area to propagate the first image to the input coupler, output a 0 order diffraction of a second image provided by the second display area to propagate the second image to the input coupler, and output a +1 order diffraction of a third image provided by the third display area to propagate the third image to the input coupler.

[0035] The size of the diffraction grating may be larger than the size of the input coupler.

[0036] The image providing device may include: a spatial light modulator facing the input coupler and including a plurality of display areas configured to provide a plurality of images to the input coupler; a light source configured to provide coherent illumination light to the spatial light modulator; and a diffraction grating configured to diffract the coherent illumination light incident from the light source so that a traveling direction of the coherent illumination light incident on each of the plurality of display areas of the spatial light modulator is different from a traveling direction of the coherent illumination light incident on other display areas of the plurality of display areas, wherein a light guide plate is placed between the light source and the spatial light modulator, wherein the diffraction grating is placed between the light source and the light guide plate, and wherein the spatial light modulator includes a reflective spatial light modulator.

[0037] The image providing device may include: a plurality of spatial light modulators facing an input coupler, wherein the plurality of spatial light modulators are separated from each other and configured to provide a plurality of images to the input coupler; a light source configured to provide coherent illumination light to each of the plurality of spatial light modulators; and a diffraction grating disposed between the light source and the plurality of spatial light modulators, the diffraction grating configured to diffract the coherent illumination light incident from the light source so that a traveling direction of the coherent illumination light incident on each of the plurality of spatial light modulators is different from a traveling direction of the coherent illumination light incident on the other spatial light modulators in the plurality of spatial light modulators.

[0038] The image providing device may include: a plurality of image scanners facing the input coupler and configured to provide a plurality of images; and a diffraction grating placed between each of the plurality of image scanners and the input coupler, the diffraction grating being configured to diffract the plurality of images provided by the plurality of image scanners in different respective propagation directions to be incident on the input coupler.

[0039] The image providing device may include: a spatial light modulator facing the input coupler and including a plurality of display areas configured to provide a plurality of images to the input coupler; and a light source configured to provide coherent illumination light to the spatial light modulator, and the spatial light modulator is arranged so that each display area of ​​the plurality of display areas is configured to provide a corresponding image to the input coupler, each corresponding image being formed by a different corresponding diffraction order.

[0040] The size of the spatial light modulator may be larger than the size of the input coupler.

[0041] The multiple display areas of the spatial light modulator may include: a first display area that provides a first image formed by -1 order diffraction of coherent illumination light to the input coupler; a second display area that provides a second image formed by 0 order diffraction of coherent illumination light to the input coupler; and a third display area that provides a third image formed by +1 order diffraction of coherent illumination light to the input coupler.

[0042] The input coupler may include a first sub-input coupler corresponding to the first display area of ​​the spatial light modulator, a second sub-input coupler corresponding to the second display area of ​​the spatial light modulator, and a third sub-input coupler corresponding to the third display area of ​​the spatial light modulator.

[0043] According to one aspect of an example embodiment, an image providing device includes: a light source; a spatial light modulator, including a plurality of regions, each of the plurality of regions being configured to receive light output by the light source and output a corresponding image; and an optical element, configured to change a traveling direction of incident light so that the image providing device outputs a corresponding image of each region in a different corresponding traveling direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0045] Figure 1 is a view schematically illustrating a structure of a display device according to an example embodiment;

[0046] Figure 2 is shown in more detail Figure 1 A cross-sectional view of an input coupler and a spatial light modulator of a display device shown in FIG.

[0047] Figure 3 An example of a structure of an image providing apparatus of a display apparatus according to an example embodiment is shown;

[0048] Figure 4 An example of structures showing an input coupler and a spatial light modulator of a display device according to example embodiments is shown;

[0049] Figure 5 An example of a structure of an image providing apparatus of a display apparatus according to an example embodiment is shown;

[0050] Figure 6 An example of a structure of an image providing apparatus of a display apparatus according to an example embodiment is shown;

[0051] Figure 7 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0052] Figure 8 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0053] Figure 9 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0054] Figure 10 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments is shown;

[0055] Figure 11 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments is shown;

[0056] Figure 12 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0057] Figure 13 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments is shown;

[0058] Figure 14 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0059] Figure 15 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0060] Figure 16 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments;

[0061] Figure 17 An example of structures showing an input coupler and an image providing device of a display device according to example embodiments is shown;

[0062] Figure 18 schematically illustrates a structure of a display device according to an example embodiment; and

[0063] Figures 19 to 21 Examples of various electronic devices employing the display apparatus according to example embodiments are illustrated. DETAILED DESCRIPTION

[0064] Reference will now be made in detail to an embodiment, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals refer to the same elements throughout the text. In this respect, the present embodiment may have different forms and should not be construed as being limited to the description set forth herein. Therefore, the following merely describes example embodiments with reference to the accompanying drawings to explain various aspects. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. When an expression such as "at least one" follows a series of elements, it modifies the elements of the entire series and does not modify a single element of the series.

[0065] Hereinafter, a display device for providing an extended viewing window will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals refer to the same elements throughout, and the sizes of the components may be exaggerated for the convenience of explanation and clarity of the specification.

[0066] It will also be understood that when an element is referred to as being "on another element" or "over another element," the element may be in direct contact with the other element, or intervening elements may be present. In the following description, the singular includes the plural unless the context clearly indicates otherwise. It should be understood that when a part "includes" or "comprises" an element in the specification, other elements are not excluded from the part unless otherwise specified, and the part may further include other elements.

[0067] The use of the terms "a," "an," and "the" and similar referents in the context of describing the present disclosure (especially in the context of the appended claims) are to be construed to cover both the singular and the plural. The operations of all methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context, and the operations described above are not necessarily limited to the order described.

[0068] Also, in the specification, the term "unit" or "module" means a unit or module that processes at least one function or operation and can be implemented by hardware, software, or a combination of hardware and software.

[0069] Furthermore, the connecting lines or connectors shown in the various figures presented are intended to represent functional relationships and / or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may exist in a practical device.

[0070] The use of any and all examples, or language provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed.

[0071] Figure 1 1 is a diagram schematically illustrating a structure of a display device 100 according to an example embodiment. The display device 100 according to the embodiment may include: a light guide plate 110 including an input coupler 130 and an output coupler 140; and an image providing device (eg, Figure 1 Elements 120 and 121 shown in FIG, are positioned to face the input coupler 130 to provide an image to the input coupler 130.

[0072] The light guide plate 110 may include a material that is transparent to visible light so that the light guide plate 110 can be used as a waveguide for transmitting light. For example, the light guide plate 110 may include a material such as glass, polymethyl methacrylate (PMMA), or polydimethylsiloxane (PDMS). In addition, the light guide plate 110 may have a flat and uniform plate shape. The light guide plate 110 may include a first surface 110a and a second surface 110b opposite to the first surface 110a. The input coupler 130 may be configured to guide the incident light obliquely to the inside of the light guide plate 110, and the output coupler 140 may be configured to output the light propagating obliquely in the light guide plate 110 to the outside of the light guide plate 110. The input coupler 130 and the output coupler 140 may be arranged on the first surface 110a of the light guide plate 110. For example, as Figure 1 As shown, the input coupler 130 may be disposed on one end of the first surface 110 a of the light guide plate 110 , and the output coupler 140 may be disposed on the other end of the first surface 110 a of the light guide plate 110 .

[0073] The input coupler 130 is configured such that light incident on the input coupler 130 is guided obliquely to the inside of the light guide plate 110. The light guided into the light guide plate 110 propagates along the inside of the light guide plate 110 while being repeatedly totally reflected by the first surface 110a and the second surface 110b of the light guide plate 110. The output coupler 140 is configured such that light obliquely incident on the output coupler 140 is output to the outside of the light guide plate 110. The output coupler 140 can be configured to act only on light obliquely incident on the surface of the output coupler 140 within a predetermined range of incident angles, and can be configured not to act on light perpendicularly incident on the surface of the output coupler 140. In other words, the output coupler 140 can simply act as a transparent plate for the light perpendicularly incident on the surface of the output coupler 140.

[0074] Each of the input coupler 130 and the output coupler 140 may include a diffractive optical element (DOE) or a holographic optical element (HOE). The DOE includes a plurality of periodic fine grating patterns. The grating pattern of the DOE acts as a diffraction grating that diffracts the incident light. Specifically, depending on the size, height, period, etc. of the grating pattern, light incident within a predetermined angle range may be diffracted and undergo destructive interference and constructive interference, and thus the propagation direction of the light may be changed. In addition, the HOE includes a periodic fine pattern of materials with different refractive indices rather than a grating pattern. The HOE may differ from the DOE only in structure and may have the same operating principle as the DOE. In other words, the light output by the DOE may be affected by the properties of the grating pattern, while the light output by the HOE may be affected by the refractive index of the material used.

[0075] In the structure of the light guide plate 110, light incident on the input coupler 130 leaves the light guide plate 110 through the output coupler 140. In addition, the directivity of the light incident on the input coupler 130 and output through the output coupler 140 can be maintained within the coupling angle range of the input coupler 130. Therefore, the light guide plate 110 can transmit the image provided by the image providing device to the eye E of the viewer.

[0076] The image providing device may include a spatial light modulator 121 and a light source 120 that provides coherent illumination light to the spatial light modulator 121. The spatial light modulator 121 may display a holographic pattern based on a hologram data signal, such as a computer-generated hologram (CGH) signal provided by an image processor. The coherent illumination light emitted from the light source 120 and incident on the spatial light modulator 121 may be diffracted by the holographic pattern displayed on the screen of the spatial light modulator 121, and an image may be reproduced by destructive and constructive interference of the diffracted illumination light. The image may be a general 2D image or a holographic image with a 3D effect.

[0077] Because the direction in which light is diffracted changes depending on the holographic pattern displayed on the screen of the spatial light modulator 121, the spatial light modulator 121 can be used to adjust the direction in which the reproduced image propagates. For example, the spatial light modulator 121 can provide multiple images with different viewpoints to the input coupler 130 in different directions using a time-sharing method. Then, the multiple images with different viewpoints are incident on the input coupler 130 at different incident angles, pass through the light guide plate 110, and enter the viewer's eye E at different angles through the output coupler 140. Therefore, it is not necessary to arrange a separate lens optical system to change the direction of light traveling between the spatial light modulator 121 and the input coupler 130. If the lens optical system is not present, since the spatial light modulator 121 can be placed directly in front of the input coupler 130, a display device 100 with a small size can be implemented.

[0078] The light source 120 may be a coherent light source configured to emit coherent light, so that the coherent light incident on the spatial light modulator 121 may be diffracted and undergo interference. In order to provide light with high coherence, a laser diode (LD), for example, may be used as the light source 120. In addition, the light source 120 may be a light emitting diode (LED). LEDs have lower spatial coherence than lasers, but light with only some spatial coherence can be fully diffracted and modulated by the spatial light modulator 121. In addition to LEDs, any other light source capable of emitting light with spatial coherence may be used as the light source 120.

[0079] The angular range over which the reproduced image travels may generally be limited by the diffraction angle limit of the spatial light modulator 121. In order to further extend the viewing angle of the display device 100 beyond the diffraction angle limit of the spatial light modulator 121, the input coupler 130 may include a plurality of sub-input couplers 130a, 130b, and 130c that tilt and propagate the image provided from the spatial light modulator 121 at different angles within the light guide plate 110. Although Figure 1 In the figure, three sub-input couplers 130a, 130b and 130c are exemplarily shown, but the number of sub-input couplers 130a, 130b and 130c can be appropriately selected as needed. A plurality of sub-input couplers 130a, 130b and 130c can be adjacent to each other and arranged side by side. Figure 1 , the plurality of sub-input couplers 130a, 130b, and 130c are completely separated from each other, but are not limited thereto, and adjacent sub-input couplers 130a, 130b, and 130c may be positioned to be attached to each other without a gap.

[0080] The plurality of sub-input couplers 130a, 130b, and 130c may be configured to tilt the incident light at different angles. For example, among the plurality of sub-input couplers 130a, 130b, and 130c, the first sub-input coupler 130a may tilt the direction of the image incident from the spatial light modulator 121 at a first angle to provide the image to the light guide plate 110. In addition, the second sub-input coupler 130b may tilt the direction of the image incident from the spatial light modulator 121 at a second angle different from the first angle to provide the image to the light guide plate 110, and the third sub-input coupler 130c may tilt the direction of the image incident from the spatial light modulator 121 at a third angle different from the first and second angles to provide the image to the light guide plate 110. To this end, the first to third sub-input couplers 130a, 130b, and 130c may be formed as DOEs or HOEs having different patterns.

[0081] Then, the images incident on the first to third sub-input couplers 130a, 130b, and 130c, respectively, propagate within the light guide plate 110 at different angles relative to the surface of the light guide plate 110 and are emitted at different angles through the output coupler 140. For example, image L11 incident on the first sub-input coupler 130a and emitted from the output coupler 140, image L12 incident on the second sub-input coupler 130b and emitted from the output coupler 140, and image L13 incident on the third sub-input coupler 130c and emitted from the output coupler 140 have different emission angles through the output coupler 140. Therefore, images L11, L12, and L13 can be incident on the viewer's eye E at different angles and focused on different areas E1, E2, and E3 on the retina of the viewer's eye E, and thus the viewer can view images with a wide viewing angle.

[0082] Furthermore, according to example embodiments, the width W2 of the output coupler 140 is greater than the width of the input coupler 130. For example, the width W2 of the output coupler 140 is greater than the sum of the widths W11, W12, and W13 of the first to third sub-input couplers 130a, 130b, and 130c. Thus, the width of the viewing window through which the viewer views the image can be expanded. For example, the viewer's eye E does not need to be fixed relative to a specific point on the light guide plate 110, and when the viewer's eye E is within the range of the width W2 of the output coupler 140, the viewer can fully view the image.

[0083] In addition, because the output coupler 140 acts as a diffraction grating only for light incident obliquely on the surface of the output coupler 140 and transmits light incident vertically on the surface of the output coupler 140, the display device 100 can be applied to realize augmented reality (AR) or mixed reality (MR). In this case, the display device 100 can be a near-eye AR display device. For example, the images L11, L12, and L13 reproduced by the spatial light modulator 121 can be viewed together with the external light L20 that includes the external foreground and passes vertically through the output coupler 140.

[0084] Figure 2 is shown in more detail Figure 1 FIG. 1 is a cross-sectional view of the structure of the input coupler 130 and the spatial light modulator 121 of the display device 100 shown in FIG. Figure 2 , the spatial light modulator 121 may include a plurality of display areas 121a, 121b, and 121c corresponding to the plurality of sub-input couplers 130a, 130b, and 130c, respectively. The plurality of display areas 121a, 121b, and 121c of the spatial light modulator 121 may correspond one-to-one to the plurality of sub-input couplers 130a, 130b, and 130c, respectively. For example, the spatial light modulator 121 may include a first display area 121a corresponding to the first sub-input coupler 130a, a second display area 121b corresponding to the second sub-input coupler 130b, and a third display area 121c corresponding to the third sub-input coupler 130c.

[0085] The spatial light modulator 121 includes a plurality of pixels arranged two-dimensionally. One spatial light modulator 121 can be logically divided into a plurality of regions, such as first to third display regions 121a, 121b, and 121c. Each of the first to third display regions 121a, 121b, and 121c includes a plurality of pixels arranged two-dimensionally and can independently display a holographic pattern. For example, under the control of an image processor, the spatial light modulator 121 can independently display a holographic pattern on each of the first to third display regions 121a, 121b, and 121c.

[0086] The first to third display regions 121a, 121b, and 121c are positioned to face the first to third sub-input couplers 130a, 130b, and 130c, respectively. Furthermore, the first to third display regions 121a, 121b, and 121c may have widths equal to or slightly smaller than the widths W11, W12, and W13 of the first to third sub-input couplers 130a, 130b, and 130c. The widths W11, W12, and W13 of the first to third sub-input couplers 130a, 130b, and 130c may be the same as each other, but are not limited thereto and may be designed differently as needed.

[0087] The first display area 121a may correspond to the first input coupler 130a, the second display area 121b may correspond to the second input coupler 130b, and the third display area 121c may correspond to the third input coupler 130c. Thus, the image reproduced by the first display area 121a may be incident on the first input coupler 130a and then guided into the interior of the light guide plate 110. Similarly, the image reproduced by the second display area 121b may be incident on the second input coupler 130b and then guided into the interior of the light guide plate 110, and the image reproduced by the third display area 121c may be incident on the third input coupler 130c and then guided into the interior of the light guide plate 110. Thereafter, the images reproduced by the first to third display areas 121a, 121b, and 121c may be emitted from the output coupler 140 at different angles and may be focused on different areas E1, E2, and E3 on the retina of the viewer's eye E, respectively. The images reproduced by the first to third display areas 121a, 121b, and 121c may be different images, or may be the same image with different viewpoints. For example, under the control of the image processor, the spatial light modulator 121 may operate to reproduce the same image or images with different viewpoints in each of the first to third display areas 121a, 121b, and 121c.

[0088] When gaps exist between adjacent sub-input couplers 130a, 130b, and 130c, gaps may also exist between adjacent display areas 121a, 121b, and 121c of the spatial light modulator 121. For example, the spatial light modulator 121 may further include non-display areas 121d disposed between the first display area 121a and the second display area 121b, and between the second display area 121b and the third display area 121c. Each of the non-display areas 121d may include a plurality of pixels of the spatial light modulator 121. Under the control of the image processor, the pixels of the spatial light modulator 121 assigned to the non-display areas 121d may be operated so as not to display a hologram.

[0089] exist Figure 2 In the embodiment, a spatial light modulator 121 is logically divided into a plurality of display areas 121a, 121b, and 121c, but the present invention is not necessarily limited thereto. For example, a plurality of physically separate spatial light modulators corresponding to the plurality of sub-input couplers 130a, 130b, and 130c, respectively, may be used. In addition, a plurality of physically separate light sources may also be used in addition to the spatial light modulator.

[0090] For example, Figure 3 An example of a structure of an image providing device of a display device according to an exemplary embodiment is shown. Figure 3 , the image providing device may include a plurality of spatial light modulators 121R, 121G, and 121B separated from each other and corresponding to the plurality of sub-input couplers 130a, 130b, and 130c, respectively. The image providing device may also include a plurality of light sources 120R, 120G, and 120B that provide coherent illumination light to the plurality of spatial light modulators 121R, 121G, and 121B, respectively. The plurality of light sources 120R, 120G, and 120B may provide illumination light of different colors. For example, the first light source 120R may provide red light to the first spatial light modulator 121R corresponding thereto, the second light source 120G may provide green light to the second spatial light modulator 121G corresponding thereto, and the third light source 120B may provide blue light to the third spatial light modulator 121B corresponding thereto. Then, the display device can provide a full-color image to the viewer.

[0091] A plurality of light sources 120R, 120G, and 120B providing illumination lights of different colors may also be applied. Figure 2 For example, the first light source 120R may be positioned to provide red light to the first display area 121a of the spatial light modulator 121. Furthermore, the second light source 120G may be positioned to provide green light to the second display area 121b of the spatial light modulator 121, and the third light source 120B may be positioned to provide blue light to the third display area 121c of the spatial light modulator 121.

[0092] exist Figure 1 、 Figure 2 and Figure 3 , the three sub-input couplers 130a, 130b, and 130c are arranged one-dimensionally, but are not necessarily limited thereto. For example, Figure 4 1 shows an example of the structure of the input coupler 130 and the spatial light modulator 121 of the display device according to the example embodiment. Figure 4 As shown, the input coupler 130 may include a plurality of sub-input couplers arranged two-dimensionally on the surface of the light guide plate 110. In addition, the spatial light modulator 121 may include a plurality of independent spatial light modulators arranged two-dimensionally on the same plane as each other, facing the plurality of sub-input couplers. Conversely, a single spatial light modulator 121 may be logically divided into a plurality of display areas arranged two-dimensionally. Figure 4 , the diagram shows an example of a 3×3 arrangement of sub-input couplers and spatial light modulators, but the present invention is not necessarily limited thereto. Various arrangements such as 2×2, 2×3, 4×4, etc. can be selected when necessary. Although multiple sub-input couplers can couple incident light into the light guide plate 110 at different angles, some sub-input couplers can be designed to couple incident light into the light guide plate 110 at the same angle.

[0093] The spatial light modulator 121 described above is a transmissive spatial light modulator that modulates the illumination light while transmitting it, but the spatial light modulator may not be transmissive. For example, Figure 5 An example of a structure of an image providing device of a display device according to an exemplary embodiment is shown. Figure 5 The image providing device may include a beam splitter 125 disposed facing the input coupler 130, a light source 120 disposed on one side of the beam splitter 125, and a spatial light modulator 123 disposed on the other side of the beam splitter 125. The spatial light modulator 123 is a reflective spatial light modulator that reflects and modulates illumination light.

[0094] The beam splitter 125 is configured to reflect light incident from the light source 120 toward the spatial light modulator 123 and transmit light incident from the spatial light modulator 123 toward the input coupler 130. The beam splitter 125 may be, for example, a half-mirror that simply reflects half of the incident light and transmits the other half. Alternatively, the beam splitter 125 may be a polarization beam splitter having polarization selectivity. For example, the beam splitter 125 may be configured to reflect light having a first linear polarization component and transmit light having a second linear polarization component, the second linear polarization component being orthogonal to the first linear polarization component.

[0095] Figure 5 The spatial light modulator 123 shown in FIG. 1 may also include a Figure 2 Instead, as shown in Figure 3 As shown in FIG, a plurality of independent spatial light modulators 123 may be arranged on the same surface of the beam splitter 125. In addition, a plurality of light sources 120 providing illumination lights of different colors may be arranged on the same surface of the beam splitter 125.

[0096] Figure 6 An example of the structure of an image providing device of a display device according to an example embodiment is shown. The image providing device is described as including a light source and a spatial light modulator, but is not necessarily limited thereto. For example, the image providing device may include an image scanner 150. The image scanner 150 may be configured to provide images to multiple sub-input couplers 130a, 130b, and 130c sequentially or simultaneously. For example, the image scanner 150 may include a display panel, a beam scanning unit, and a projector. The image scanner 150 may directly generate a 2D color image according to a time-sharing method and sequentially scan the 2D color image to multiple sub-input couplers 130a, 130b, and 130c. Alternatively, the image scanner 150 may provide multiple images to multiple sub-input couplers 130a, 130b, and 130c simultaneously.

[0097] Figure 71 and 2. The input coupler 130 and the image providing device (eg, Figure 7 120, 121 and 122). Figure 7 , the image providing device may be configured to provide a plurality of images traveling in different directions to the input coupler 130. In addition, the input coupler 130 may be formed as a single DOE or a single HOE. Then, a plurality of images may be incident on the single input coupler 130 at different incident angles. The propagation angle of the image coupled by the input coupler 130 and propagating in the light guide plate 110 may be changed according to the incident angle of the image with respect to the input coupler 130. Therefore, a plurality of images incident on the input coupler 130 at different incident angles may propagate in the light guide plate 110 at different angles and then be emitted from the output coupler 140 at different angles.

[0098] The image providing device may include: a spatial light modulator 121, which is positioned facing the input coupler 130 and includes a plurality of display areas 121a, 121b, and 121c that provide a plurality of images; a light source 120 that provides coherent illumination light to the spatial light modulator 121; and a diffraction grating 122, which is positioned between the light source 120 and the spatial light modulator 121. The diffraction grating 122 may be configured to cause the illumination light incident on the plurality of display areas 121a, 121b, and 121c of the spatial light modulator 121 to travel in different directions. To this end, the diffraction grating 122 may include a periodic diffraction pattern that diffracts the incident light in the 0th order and higher orders so that the incident light travels in different directions.

[0099] For example, among the illumination light emitted from the light source 120, the light diffracted by the 0th order of the diffraction grating 122 may be vertically incident on the second display area 121b located at the center of the spatial light modulator 121. In addition, among the illumination light, the light diffracted by the -1st order (i.e., the first negative order) of the diffraction grating 122 may be incident on the first display area 121a of the spatial light modulator 121 slightly obliquely toward the right direction, as shown in FIG. Figure 7 In addition, among the illumination light, light diffracted by the diffraction grating 122 in the +1st order (ie, the first positive order) may be incident on the third display region 121c of the spatial light modulator 121 at a slight inclination toward the left direction.

[0100] Thereafter, the image reproduced by the first display area 121a of the spatial light modulator 121 may be incident on the input coupler 130 at a slight angle toward the right, the image reproduced by the second display area 121b may be incident perpendicularly to the input coupler 130, and the image reproduced by the third display area 121c may be incident on the input coupler 130 at a slight angle toward the left. Therefore, the plurality of images respectively reproduced in the first to third display areas 121a, 121b, and 121c of the spatial light modulator 121 may be incident on the input coupler 130 at different angles.

[0101] In order to implement the above operations, Figure 7 As shown in , the size of the diffraction grating 122 is larger than the size of the spatial light modulator 121. In addition, the size of the spatial light modulator 121 is larger than the size of the input coupler 130. Specifically, the width of the input coupler 130 can be smaller than the distance between the center of the first display area 121a and the center of the third display area 121c of the spatial light modulator 121. In addition, the beam width of the illumination light emitted from the light source 120 is equal to or slightly smaller than the size of the diffraction grating 122. Specifically, the beam width of the illumination light emitted from the light source 120 is larger than the size of the spatial light modulator 121. In addition, the input coupler 130, the spatial light modulator 121, the diffraction grating 122, and the light source 120 can be arranged so that the center of the input coupler 130, the center of the spatial light modulator 121, the center of the diffraction grating 122, and the center of the illumination light are collinear.

[0102] In this structure, a portion of the illumination light diffracted by the 0th order diffraction grating 122 may be incident on the first display area 121a or the third display area 121c of the spatial light modulator 121. However, as a result of the relative widths of the elements, the illumination light diffracted by the 0th order diffraction grating 122 and transmitted through the first display area 121a or the third display area 121c is not incident on the input coupler 130. Similarly, the illumination light diffracted by the -1st order diffraction grating 122 and transmitted through the second display area 121b or the third display area 121c is not incident on the input coupler 130, and the light diffracted by the +1st order diffraction grating 122 and transmitted through the first display area 121a or the second display area 121b is not incident on the input coupler 130. Therefore, among the illumination light diffracted by the 0th order of the diffraction grating 122, only the illumination light that is transmitted through the second display area 121b can reach the viewer's eye E through the input coupler 130 and the light guide plate 110, among the illumination light diffracted by the -1st order of the diffraction grating 122, only the illumination light that is transmitted through the first display area 121a can reach the viewer's eye E through the input coupler 130 and the light guide plate 110, and among the illumination light diffracted by the +1st order of the diffraction grating 122, only the illumination light that is transmitted through the third display area 121c can reach the viewer's eye E through the input coupler 130 and the light guide plate 110.

[0103] Figure 8 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 8 , the input coupler 130 may include a plurality of sub-input couplers 130a, 130b, and 130c, which couple incident light to the light guide plate 110 at different angles. For example, the input coupler 130 may include a first sub-input coupler 130a corresponding to the first display area 121a of the spatial light modulator 121, a second sub-input coupler 130b corresponding to the second display area 121b, and a third sub-input coupler 130c corresponding to the third display area 121c. The size of the first display area 121a of the spatial light modulator 121 may be larger than the size of the first sub-input coupler 130a, the size of the second display area 121b may be larger than the size of the second sub-input coupler 130b, and the size of the third display area 121c may be larger than the size of the third sub-input coupler 130c. Figure 8 The structure of the image providing device (e.g., elements 120, 121, and 122) shown in FIG. Figure 7 The image providing devices shown in the figure have the same structure.

[0104] The illumination light diffracted by the -1 order of the diffraction grating 122 and transmitted through the first display area 121a can be coupled into the light guide plate 110 through the first sub-input coupler 130a. In addition, the illumination light diffracted by the 0 order of the diffraction grating 122 and transmitted through the second display area 121b can be coupled into the light guide plate 110 through the second sub-input coupler 130b, and the illumination light diffracted by the +1 order of the diffraction grating 122 and transmitted through the third display area 121c can be coupled into the light guide plate 110 through the third sub-input coupler 130c.

[0105] Figure 9 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 9 , the image providing device may include a plurality of physically separated independent spatial light modulators 121 rather than a single spatial light modulator having multiple display areas. Figure 9 The input coupler 130 and the rest of the image providing device shown in FIG. Figure 7 Same as described in .

[0106] Figure 10 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 10 , the image providing device may include, rather than a single diffraction grating, a plurality of diffraction gratings 122a, 122b, and 122c corresponding to the plurality of display areas 121a, 121b, and 121c of the spatial light modulator 121, respectively. For example, the image providing device may include a first diffraction grating 122a corresponding to the first display area 121a of the spatial light modulator 121, a second diffraction grating 122b corresponding to the second display area 121b, and a third diffraction grating 122c corresponding to the third display area 121c. Figure 10 The input coupler 130 and the rest of the image providing device shown in FIG. Figure 7 Same as described in .

[0107] The first to third diffraction gratings 122a, 122b, and 122c may be configured to diffract the illumination light in different directions. For example, the first diffraction grating 122a may diffract most of the illumination light slightly obliquely to the right to be incident on the first display area 121a. Figure 10 As shown. Furthermore, the second diffraction grating 122b can diffract most of the illumination light forward to be incident on the second display area 121b, and the third diffraction grating 122c can diffract most of the illumination light slightly obliquely to the left to be incident on the third display area 121c. To this end, the first to third diffraction gratings 122a, 122b, and 122c can include different periodic diffraction patterns from one another.

[0108] Figure 11 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 11 The image providing device may include: a spatial light modulator 121, including multiple display areas 121a, 121b and 121c providing multiple images; a light source 120, providing coherent illumination light to the spatial light modulator 121; and a diffraction grating 122, arranged between the input coupler 130 and the spatial light modulator 121.

[0109] The size of the diffraction grating 122 is larger than that of the input coupler 130. The size of the spatial light modulator 121 may be equal to or slightly smaller than that of the diffraction grating 122. Then, among the images reproduced in the spatial light modulator 121, the image reproduced in the first display area 121a and diffracted by the diffraction grating 122-1 order may be incident on the input coupler 130 slightly tilted toward the right direction, as shown in FIG. Figure 11 In addition, the image reproduced in the second display area 121b and diffracted by the 0th order of the diffraction grating 122 can be vertically incident on the input coupler 130, and the image reproduced in the third display area 121c and diffracted by the +1st order of the diffraction grating 122 can be incident on the input coupler 130 slightly tilted toward the left direction. Therefore, the propagation directions of the multiple images incident on the input coupler 130 from the multiple display areas 121a, 121b, and 121c of the spatial light modulator 121 can be different from each other. Figure 11 The remaining structure of the display device shown in FIG is the same as that in Figure 7 The structures of the display devices shown in the figure are the same as those of the display devices shown in the figure.

[0110] Figure 12 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 12 The image providing apparatus may include: a spatial light modulator 121 including a plurality of display areas 121a, 121b, and 121c each providing a plurality of images; a light source 120 providing coherent illumination light to the spatial light modulator 121; and a plurality of diffraction gratings 122a, 122b, and 122c disposed between an input coupler 130 and the spatial light modulator 121 and respectively corresponding to the plurality of display areas 121a, 121b, and 121c of the spatial light modulator 121. For example, the image providing apparatus may include a first diffraction grating 122a corresponding to the first display area 121a of the spatial light modulator 121, a second diffraction grating 122b corresponding to the second display area 121b, and a third diffraction grating 122c corresponding to the third display area 121c.

[0111] The first to third diffraction gratings 122a, 122b, and 122c may be configured to diffract incident light in different directions. For example, the first diffraction grating 122a may diffract the image reproduced in the first display region 121a of the spatial light modulator 121 slightly obliquely to the right to be incident on the input coupler 130, as shown in FIG. Figure 12 In addition, the second diffraction grating 122b can diffract the image reproduced in the second display area 121b forward to be incident on the input coupler 130, and the third diffraction grating 122c can diffract the image reproduced in the third display area 121c slightly obliquely to the left to be incident on the input coupler 130. To this end, the first to third diffraction gratings 122a, 122b and 122c may include periodic diffraction patterns different from each other. Figure 12 The remaining structure of the display device shown in FIG can be Figure 11 The structures of the display devices shown in FIG are the same as those shown in FIG.

[0112] Figure 13 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 13 The image providing device may include: a plurality of image scanners 150a, 150b, and 150c disposed to face the input coupler 130 and provide a plurality of images; and a diffraction grating 122 disposed between the plurality of image scanners 150a, 150b, and 150c and the input coupler 130 so that directions of images incident on the input coupler 130 from the plurality of image scanners 150a, 150b, and 150c are different from each other. The plurality of image scanners 150a, 150b, and 150c may include a first image scanner 150a, a second image scanner 150b, and a third image scanner 150c.

[0113] The image generated by the first image scanner 150a and diffracted by the diffraction grating 122-1 order may be incident on the input coupler 130 slightly tilted toward the right direction, as shown in FIG. Figure 13 In addition, the image generated by the second image scanner 150b and diffracted by the 0th order of the diffraction grating 122 may be vertically incident on the input coupler 130, and the image generated by the third image scanner 150c and diffracted by the +1st order of the diffraction grating 122 may be incident on the input coupler 130 slightly tilted toward the left direction. Therefore, the propagation directions of the multiple images incident on the input coupler 130 from the multiple image scanners 150a, 150b, and 150c may be different from each other.

[0114] Alternatively, you can use Figure 12 The multiple diffraction gratings 122a, 122b and 122c shown in FIG. Figure 13In other words, the single diffraction grating 122 shown in FIG. Figure 13 The plurality of image scanners 150a, 150b and 150c shown in FIG are used to replace Figure 12 In this case, the first image scanner 150a may be positioned to face the first diffraction grating 122a, the second image scanner 150b may be positioned to face the second diffraction grating 122b, and the third image scanner 150c may be positioned to face the third diffraction grating 122c.

[0115] Figure 14 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 14 The image providing device may include: a spatial light modulator 123, positioned facing the input coupler 130 and having a plurality of display areas 123a, 123b, and 123c; a light source 120, providing coherent illumination light to the spatial light modulator 123; and a diffraction grating 122, which makes the illumination light incident on each of the plurality of display areas 123a, 123b, and 123c of the spatial light modulator 123 travel in different directions. A light guide plate 110 is positioned between the light source 120 and the spatial light modulator 123, and the diffraction grating 122 is positioned between the light source 120 and the light guide plate 110. The spatial light modulator 123 is a reflective spatial light modulator that reflects and modulates the illumination light.

[0116] The illumination light diffracted by the diffraction grating 122-1 order may be reflected from the first display area 123a of the spatial light modulator 123 so as to be incident on the input coupler 130 slightly tilted to the right, as shown in FIG. Figure 14 As shown. Illumination light diffracted by the 0th order of the diffraction grating 122 may pass through the input coupler 130 and be reflected from the second display area 123b of the spatial light modulator 123 to be vertically incident on the input coupler 130. The input coupler 130 may be configured to couple only incident light traveling in the direction from the spatial light modulator 123 and transmit incident light traveling in the direction from the diffraction grating 122. Illumination light diffracted by the +1st order of the diffraction grating 122 may be reflected from the third display area 123c of the spatial light modulator 123 to be incident on the input coupler 130 slightly obliquely to the left.

[0117] Figure 15 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 15The image providing apparatus may include: a spatial light modulator 121 disposed to face the input coupler 130 and including a plurality of display areas 121 a , 121 b , and 121 c ; and a light source 120 providing coherent illumination light to the spatial light modulator 121 .

[0118] Due to the physical pixel structure therein, the spatial light modulator 121 can also act as a periodic diffraction grating. Therefore, due to the physical pixel structure inside the spatial light modulator 121, the image reproduced in each of the multiple display areas 121a, 121b and 121c may include an image formed by diffracted light diffracted by the 0th order and an image formed by diffracted light diffracted by the ±1st order or higher order. The spatial light modulator 121 can be arranged so that the images formed by the diffracted light of different orders in the multiple display areas 121a, 121b and 121c are incident on the input coupler 130. For example, the spatial light modulator 121 can be arranged so that: among the images reproduced in the first display area 121a of the spatial light modulator 121, the image diffracted by the -1st order may be incident on the input coupler 130 slightly tilted to the right, as shown in FIG. Figure 15 As shown in FIG1 , among the images reproduced in the second display area 121 b, the image diffracted by the 0th order may be vertically incident on the input coupler 130; and among the images reproduced in the third display area 121 c, the image diffracted by the +1st order may be incident on the input coupler 130 slightly tilted to the left. To this end, the size of the spatial light modulator 121 is larger than that of the input coupler 130. Furthermore, the spatial light modulator 121 may be arranged so that the center of the second display area 121 b is collinear with the center of the input coupler 130 and has a normal line that directly extends from the center of the second display area 121 b and the center of the input coupler 130.

[0119] Figure 16 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 16 The input coupler 130 may include a plurality of sub-input couplers 130a, 130b, and 130c, which couple incident light into the light guide plate 110 at different angles. For example, the input coupler 130 may include a first sub-input coupler 130a corresponding to the first display area 121a of the spatial light modulator 121, a second sub-input coupler 130b corresponding to the second display area 121b, and a third sub-input coupler 130c corresponding to the third display area 121c. Figure 16 The structure of the image providing device shown in FIG can be Figure 15 The structure of the image providing device shown in FIG is the same.

[0120] Of the images reproduced in first display area 121a of spatial light modulator 121, the image diffracted by the -1st order can be incident on first input coupler 130a. Furthermore, of the images reproduced in second display area 121b, the image diffracted by the 0th order can be incident on second input coupler 130b. Furthermore, of the images reproduced in third display area 121c, the image diffracted by the +1st order can be coupled into light guide plate 110 via third input coupler 130c. To this end, the size of first display area 121a can be larger than the size of first input coupler 130a, the size of second display area 121b can be larger than the size of second input coupler 130b, and the size of third display area 121c can be larger than the size of third input coupler 130c.

[0121] Figure 17 1 shows an example of the structure of the input coupler 130 and the image providing device of the display device according to the exemplary embodiment. Figure 17 , the image providing device may include a plurality of image scanners 150a, 150b, and 150c disposed to face the input coupler 130 and each providing a plurality of images. The plurality of image scanners 150a, 150b, and 150c may be arranged to produce images incident on the input coupler 130 at different angles. For example, among the plurality of image scanners 150a, 150b, and 150c, the first image scanner 150a may be arranged to produce an image incident on the input coupler 130 slightly tilted to the right, the second image scanner 150b may be arranged to produce an image incident on the input coupler 130 perpendicularly, and the third image scanner 150c may be arranged to produce an image incident on the input coupler 130 slightly tilted to the left.

[0122] Figure 18 Schematically illustrates the structure of a display device 200 according to an example embodiment. Figure 18 , the display device 200 may include a light guide plate 210, a first image providing device 250, and a second image providing device 260. The light guide plate 210 may include a first input coupler 230 corresponding to the first image providing device 250, a second input coupler 232 corresponding to the second image providing device 260, a first intermediate coupler 231, a second intermediate coupler 233, and an output coupler 240. The first image providing device 250 may be positioned to face the first input coupler 230, and the second image providing device 260 may be positioned to face the second input coupler 232. The first and second input couplers 230 and 232 may have a structure of an input coupler according to any one or more of the example embodiments described above.

[0123] The first intermediate coupler 231 is positioned in the optical path between the first input coupler 230 and the output coupler 240, and the second intermediate coupler 233 is positioned in the optical path between the second input coupler 232 and the output coupler 240. The first input coupler 230 can be configured so that an image incident thereon propagates in the -y direction toward the first intermediate coupler 231 in the light guide plate 210. The first intermediate coupler 231 can be configured so that an image from the first input coupler 230 propagates in the +x direction, which is perpendicular to the -y direction, toward the output coupler 240 in the light guide plate 210. The output coupler 240 is configured to output the image from the first intermediate coupler 231 to the outside of the light guide plate 210 in the +z direction, which is perpendicular to both the -y direction and the +x direction. Furthermore, the second input coupler 232 can be configured so that an image incident thereon propagates in the -y direction toward the second intermediate coupler 233 in the light guide plate 210. The second intermediate coupler 233 is configured to allow the image from the second input coupler 232 to propagate in the -x direction perpendicular to the -y direction in the light guide plate 210 toward the output coupler 240. In addition, the output coupler 240 is configured to output the image from the second intermediate coupler 233 to the outside of the light guide plate 210 along the +z direction perpendicular to both the -y direction and the +x direction.

[0124] The first and second intermediate couplers 231 and 233 are used to expand the viewing window along the y-direction. To this end, the lengths of the first and second intermediate couplers 231 and 233 along the y-direction can be greater than the lengths of the first and second input couplers 230 and 232 along the y-direction. The lengths of the first and second intermediate couplers 231 and 233 along the x-direction are the same as the lengths of the first and second input couplers 230 and 232 along the x-direction. The output coupler 240 is used to expand the viewing window along the x-direction. To this end, the length of the output coupler 240 along the x-direction is greater than the lengths of the first and second intermediate couplers 231 and 233 along the x-direction. The length of the output coupler 240 along the y-direction is the same as the lengths of the first and second intermediate couplers 231 and 233 along the y-direction. Therefore, the viewing window can be expanded in two directions perpendicular to each other by the first and second intermediate couplers 231 and 233 and the output coupler 240.

[0125] The first image providing device 250 may include a spatial light modulator 121 positioned facing the first input coupler 230 and a light source 120 providing coherent illumination light to the spatial light modulator 121. The first image providing device 250 may further include a diffraction grating 122. The first image providing device 250 may be, for example, Figures 1 to 5 、 Figures 7 to 12 ,as well as Figures 14 to 16The second image providing device 260 may include an image scanner 150 positioned to face the second input coupler 232. The second image providing device 220 may be, for example, an image scanner 150 positioned to face the second input coupler 232. Figure 6 、 Figure 13 and Figure 17 One of the image providing devices shown in the figure.

[0126] As described above, the display device can be used to implement AR and MR. For example, Figures 19 to 21 The figures show examples of various electronic devices using the display device according to the above-described exemplary embodiments. Figures 19 to 21 As shown in FIG, the display device may constitute a wearable device. In other words, the display device may be applied to a wearable device. For example, the display device may be applied to a head-mounted display (i.e., a head-mounted device). In addition, the display device may be applied to a glasses-type display (i.e., a glasses device), a goggle-type display (i.e., a goggle device), and the like. Figures 19 to 21 The wearable electronic device shown in FIG can be operated in conjunction with a smartphone. The display device can be a VR display device, an AR display device, or an MR display device of a head-mounted type or a glasses or goggles type capable of providing virtual reality or providing a virtual image together with an external real image.

[0127] Although a display device for providing an extended viewing window has been described with reference to the accompanying drawings according to example embodiments, it should be understood that the example embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered applicable to other similar features or aspects in other embodiments. It should be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope as defined in the appended claims.

Claims

1. A display device, comprising: a light guide plate, comprising an input coupler and an output coupler; as well as an image providing device facing the input coupler and configured to provide an image to the input coupler, wherein the input coupler comprises a plurality of sub-input couplers, and the plurality of sub-input couplers are configured to propagate the image provided by the image providing device at different angles in the light guide plate; The image providing device includes: a spatial light modulator comprising a plurality of display areas corresponding to the plurality of sub-input couplers, respectively; and a light source configured to provide coherent illumination light to the spatial light modulator; and The plurality of display areas of the spatial light modulator include a first display area, a second display area, and a third display area, and Among them, the first display area is configured to provide a first image formed by -1 order diffraction of coherent illumination light to the corresponding input sub-coupler; the second display area is configured to provide a second image formed by 0 order diffraction of coherent illumination light to the corresponding input sub-coupler; and the third display area is configured to provide a third image formed by +1 order diffraction of coherent illumination light to the corresponding input sub-coupler.

2. The display device according to claim 1, wherein The spatial light modulator further includes a plurality of non-display areas between the plurality of display areas.

3. The display device according to claim 1, wherein The spatial light modulator is configured to display the same image on each of the plurality of display areas or to display images at different viewpoints on the plurality of display areas, respectively.

4. The display device according to claim 1, further comprising: A diffraction grating is disposed between the light source and the spatial light modulator, the diffraction grating being configured to diffract the coherent illumination light incident from the light source so that a corresponding traveling direction of the coherent illumination light incident on each of a plurality of display areas of the spatial light modulator is different from a corresponding traveling direction of the coherent illumination light incident on the other display areas of the plurality of display areas.

5. The display device according to claim 4, wherein The size of the diffraction grating is larger than that of the spatial light modulator.

6. The display device according to claim 4, in, The diffraction grating is configured to diffract coherent illumination light into a -1st order portion, a 0th order portion, and a +1st order portion and provide the -1st order portion, the 0th order portion, and the +1st order portion to the first display area, the second display area, and the third display area, respectively.

7. The display device according to claim 1, wherein The multiple sub-input couplers include a first sub-input coupler corresponding to the first display area, a second sub-input coupler corresponding to the second display area, and a third sub-input coupler corresponding to the third display area, and wherein the size of the first display area is larger than the size of the first sub-input coupler, the size of the second display area is larger than the size of the second sub-input coupler, and the size of the third display area is larger than the size of the third sub-input coupler.

8. The display device according to claim 1, wherein The image providing device includes an image scanner configured to provide a plurality of images to the plurality of sub-input couplers sequentially or simultaneously.

9. The display device according to claim 1, in, Input couplers include: a first input coupler comprising a plurality of first sub-input couplers; and a second input coupler comprising a plurality of second sub-input couplers, and The image providing device includes: a first image providing device comprising a spatial light modulator positioned facing the first input coupler and a light source configured to provide coherent illumination light to the spatial light modulator; and The second image providing device includes an image scanner positioned to face the second input coupler.

10. The display device according to claim 1, wherein The light guide plate further includes an intermediate coupler disposed in the optical path between the input coupler and the output coupler, wherein the input coupler is configured to output light in a first direction in the light guide plate, wherein the intermediate coupler is configured to output light in a second direction perpendicular to the first direction in the light guide plate, and The output coupler is configured to output light toward the outside of the light guide plate in a third direction perpendicular to the first direction and the second direction.

11. The display device according to claim 1, wherein The display device includes a virtual reality display device, an augmented reality display device, or a mixed reality display device, and includes a head-mounted device, a glasses-type device, or a goggle-type device.

12. A display device comprising: a light guide plate, comprising an input coupler and an output coupler; as well as an image providing device configured to provide a plurality of images traveling in different directions to the input coupler; The image providing device includes: a spatial light modulator facing the input coupler and including a plurality of display areas configured to provide a plurality of images to the input coupler; and a light source configured to provide coherent illumination light to the spatial light modulator, and wherein the spatial light modulator is arranged such that each of the plurality of display areas is configured to provide a respective image to the input coupler, each respective image being formed by a different respective diffraction order; The multiple display areas of the spatial light modulator include: a first display area, configured to provide a first image formed by -1 order diffraction of coherent illumination light to the input coupler; a second display area, configured to provide a second image formed by 0 order diffraction of coherent illumination light to the input coupler; and a third display area, configured to provide a third image formed by +1 order diffraction of coherent illumination light to the input coupler.

13. The display device according to claim 12, wherein: The image providing device includes: A diffraction grating is disposed between the light source and the spatial light modulator, the diffraction grating being configured to diffract coherent illumination light incident from the light source so that a traveling direction of the coherent illumination light incident on each of a plurality of display areas of the spatial light modulator is different from a traveling direction of the coherent illumination light incident on the other display areas of the plurality of display areas.

14. The display device according to claim 13, wherein: The size of the diffraction grating is larger than the size of the spatial light modulator, and the size of the spatial light modulator is larger than the size of the input coupler.

15. The display device according to claim 13, wherein The diffraction grating is configured to diffract coherent illumination light into a -1st order portion, a 0th order portion, and a +1st order portion and provide the 1st order portion, the 0th order portion, and the +1st order portion to the first display area, the second display area, and the third display area, respectively.

16. The display device according to claim 15, wherein The input coupler includes: a first sub-input coupler corresponding to the first display area of ​​the spatial light modulator; a second sub-input coupler corresponding to the second display area of ​​the spatial light modulator; and a third sub-input coupler corresponding to the third display area of ​​the spatial light modulator, and The first sub-input coupler, the second sub-input coupler, and the third sub-input coupler are configured to propagate an image provided from the spatial light modulator at different angles in the light guide plate.

17. The display device according to claim 16, wherein: The size of the first display area is larger than that of the first sub-input coupler, the size of the second display area is larger than that of the second sub-input coupler, and the size of the third display area is larger than that of the third sub-input coupler.

18. The display device according to claim 13, wherein The diffraction grating includes a plurality of diffraction gratings respectively corresponding to the plurality of display areas of the spatial light modulator, and the plurality of diffraction gratings are configured to diffract the coherent illumination light in different directions.

19. The display device according to claim 12, wherein: The image providing device includes: The diffraction grating is placed between the input coupler and the spatial light modulator. wherein each of the plurality of display areas is configured to provide a corresponding image of the plurality of images to the diffraction grating, and Therein, the diffraction grating is configured to diffract each image in a different respective direction to be incident on the input coupler.

20. The display device according to claim 19, wherein The diffraction grating is configured to: output -1 order diffraction of the first image provided by the first display area to propagate the first image to the input coupler; output 0 order diffraction of the second image provided by the second display area to propagate the second image to the input coupler; and output +1 order diffraction of the third image provided by the third display area to propagate the third image to the input coupler.

21. The display device according to claim 19, wherein The size of the diffraction grating is larger than that of the input coupler.

22. The display device according to claim 12, wherein: The image providing device includes: a diffraction grating configured to diffract coherent illumination light incident from a light source so that a traveling direction of the coherent illumination light incident on each of a plurality of display areas of the spatial light modulator is different from a traveling direction of the coherent illumination light incident on the other display areas of the plurality of display areas, Among them, the light guide plate is placed between the light source and the spatial light modulator. The diffraction grating is placed between the light source and the light guide plate.

23. The display device according to claim 12, wherein: The size of the spatial light modulator is larger than that of the input coupler.

24. The display device according to claim 12, wherein The input coupler includes: a first sub-input coupler corresponding to the first display area of ​​the spatial light modulator; a second sub-input coupler corresponding to the second display area of ​​the spatial light modulator; and a third sub-input coupler corresponding to the third display area of ​​the spatial light modulator.

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