Display device

Abstract

The present application relates to a display apparatus. The display apparatus includes a light source portion including a first light source and a second light source, a collimator collimating light incident from the light source portion, a waveguide guiding and diffracting light incident from the collimator, a spatial light modulator forming a hologram pattern for modulating light passing through the waveguide to reproduce a holographic image, a focusing optical system focusing the holographic image spatially, and a light separation plate disposed between the light source portion and the collimator, the light separation plate separating light of the first light source and light of the second light source from each other.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0117487, filed on September 14, 2020, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to display devices. Background Technology

[0004] As methods for realizing three-dimensional (3D) images, stereo methods and automatic stereo methods can be used. Stereo methods include polarization stereo methods and shutter stereo methods, while automatic stereo methods include lens methods and parallax barrier methods.

[0005] These methods utilize binocular parallax between the two eyes and may have limitations in increasing the number of viewpoints. Furthermore, the depth perception by the brain may not match the eye's focus, which can cause viewer fatigue.

[0006] Holographic display, as a 3D image display method that matches the depth perception of the brain with the focus of the eyes and can provide full parallax, is gradually becoming practical.

[0007] Holographic display methods use the principle of reproducing an image of the original object by applying and diffracting a reference light onto a holographic pattern, wherein interference fringes can be recorded by interfering the object light and the reference light reflected from the original object.

[0008] In practical holographic display methods, a computer-generated hologram (CGH) can be provided as an electrical signal to a spatial light modulator, instead of directly exposing the original object to obtain a holographic pattern. Based on the input CGH signal, the spatial light modulator can form a holographic pattern to diffract reference light, thereby producing a 3D image.

[0009] It should be understood that this background information is intended in part to provide a useful context for understanding the art. However, this background information may also include ideas, concepts, or knowledge that were not known or understood by a person skilled in the art prior to the relevant effective application date of the subject matter disclosed herein. Summary of the Invention

[0010] This disclosure provides a holographic display device that can have a small size and a wide viewing angle.

[0011] The scope of this disclosure is not limited to the foregoing aspects, and other aspects not mentioned may be clearly understood by those skilled in the art based on the following description.

[0012] Implementations of the display device may include: a light source unit, including a first light source and a second light source; a collimating lens, for calibrating light incident from the light source unit; a waveguide, for guiding and diffracting light incident from the collimating lens; a spatial light modulator, for modulating light passing through the waveguide to form a holographic pattern for reproducing a holographic image; a focusing optical system, for focusing the holographic image in space; and a light separation plate, disposed between the light source unit and the collimating lens, the light separation plate separating the light from the first light source and the light from the second light source from each other.

[0013] The height of the collimating mirror can be less than the height of the waveguide.

[0014] The waveguide may include a first surface facing the light source and a second surface opposite to the first surface. Light emitted from the collimating lens may be incident on a portion of the first surface of the waveguide.

[0015] Light incident on this portion of the first surface of the waveguide can propagate in the waveguide and can be uniformly emitted to the entire second surface of the waveguide.

[0016] The waveguide may include a first diffraction pattern region and a second diffraction pattern region. In the first diffraction pattern region, light from a first source can be diffracted, and in the second diffraction pattern region, light from a second source can be diffracted.

[0017] The spatial light modulator may include a first holographic pattern region and a second holographic pattern region. A first holographic pattern may be provided in the first holographic pattern region, and the first holographic pattern modulates light passing through the first diffraction pattern region. A second holographic pattern may be provided in the second holographic pattern region, and the second holographic pattern modulates light passing through the second diffraction pattern region.

[0018] In a waveguide, the angle of incidence of light incident on the waveguide can be the same as the angle of emission of light emitted from the waveguide.

[0019] The light separation plate can extend from the collimating lens toward the light source.

[0020] The light separation plate can extend from the optical axis of the collimating lens toward the space between the first and second light sources.

[0021] The display device may further include: an eye tracker configured to track the observer's gaze; a light source moving part that can move the light source in response to the movement of the observer's gaze; and a light separation plate rotating part that can rotate the light separation plate in response to the movement of the observer's gaze.

[0022] The light separator may include a first end facing the collimator and located on the optical axis of the collimator and a second end facing the light source, and the light separator rotating part may rotate the second end of the light separator relative to the first end of the light separator.

[0023] The rotating part of the light separation plate can rotate the second end of the light separation plate so that the second end of the light separation plate faces the space between the first light source and the second light source when the light source part moves.

[0024] The rotating part of the light separator can rotate the second end of the light separator in the opposite direction to the direction of the observer's line of sight movement.

[0025] When the light source moving part moves the light source part in a first side direction relative to the optical axis of the collimating lens, the holographic image can move in a second side direction opposite to the first side direction relative to the optical axis of the collimating lens.

[0026] The light source moving part can move linearly.

[0027] The light source moving part can move along the curve.

[0028] The center of curvature of the moving trajectory of the light source can be located on the optical axis of the collimating lens.

[0029] The light source moving part may include a moving stage and a drive motor.

[0030] The light separation plate may include at least one of light-absorbing materials and light-blocking materials.

[0031] Implementations of the display device may include: a light source unit including a pair of light sources; a light source moving unit for moving the light source unit; a light separating plate for separating the light emitted from the pair of light sources from each other; and a light separating plate rotating unit for rotating the light separating plate. Attached Figure Description

[0032] The above and other aspects and features of this disclosure will become more apparent from the detailed description of embodiments thereof with reference to the accompanying drawings, in which:

[0033] Figure 1 This is a schematic perspective view of a display device according to an embodiment;

[0034] Figure 2 yes Figure 1 A schematic cross-sectional view of a display device;

[0035] Figure 3 This is a schematic plan view of a display device with the light source section located in the first position according to an embodiment;

[0036] Figure 4 This is a schematic plan view of a display device with the light source located at a reference position according to an embodiment;

[0037] Figure 5 This is a schematic plan view of a display device with the light source located in the second position according to an embodiment;

[0038] Figure 6 This is a schematic plan view showing the viewing angle of the display device according to the embodiment;

[0039] Figures 7 to 9 This is a schematic plan view showing the light source moving part of a display device according to an embodiment; and

[0040] Figures 10 to 12 This is a schematic plan view showing the light source moving part of a display device according to another embodiment. Detailed Implementation

[0041] This disclosure will now be described more fully below with reference to the accompanying drawings, in which embodiments of the disclosure are illustrated. However, this disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided precisely so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Throughout the specification, the same reference numerals denote the same components. In the drawings, the thickness of layers and regions may be exaggerated for clarity.

[0042] It should also be understood that when a layer is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or there may be an intermediate layer. Conversely, when an element is referred to as being "directly" on another element, there may be no intermediate element.

[0043] In the specification and claims, the term "and / or" is intended to include any combination of the terms "and" and "or" for the purposes of its meaning and interpretation. For example, "A and / or B" can be understood to mean "A, B, or A and B". The terms "and" and "or" can be used in a combined or separate sense and can be understood as equivalent to "and / or".

[0044] In the specification and claims, the phrase “at least one of…” is intended to include the meaning of “at least one selected from the group consisting of…” for purposes of meaning and interpretation. For example, “at least one of A and B” can be understood to mean “A, B, or A and B”.

[0045] As used herein, “about” or “approximately” includes the value as well as the average of the value within an acceptable range of deviations from the particular value, as determined by a person skilled in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., limitations of the measurement system). For example, “about” may mean within one or more standard deviations or within ±30%, ±20%, ±10%, ±5% of the value.

[0046] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that, unless expressly defined herein, terms (such as those defined in common dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and shall not be interpreted in an idealized or overly formalized sense.

[0047] Figure 1 This is a schematic perspective view of a display device according to an embodiment. Figure 2 yes Figure 1 A schematic cross-sectional view of the display device. Figure 3 This is a schematic plan view of a display device with the light source section located in the first position according to an embodiment. Figure 4 This is a schematic plan view of a display device with the light source located at a reference position according to an embodiment. Figure 5 This is a schematic plan view of a display device with the light source located in the second position according to an embodiment.

[0048] In the following text, the first direction X, the second direction Y, and the third direction Z may intersect each other in different directions. For example, the first direction X may refer to the length direction, the second direction Y may refer to the width direction, and the third direction Z may refer to the thickness direction. The first direction X, the second direction Y, and the third direction Z may include two or more directions. For example, the third direction Z may include the upward direction facing upward in the figures and the downward direction facing downward in the figures. A surface of a member facing upward may be referred to as the upper surface, and another surface of a member facing downward may be referred to as the lower surface. However, the directions should be understood as relative directions, and this disclosure is not limited to the examples above.

[0049] The display device 1 according to an embodiment of the present disclosure can be a holographic display device. The holographic display device can reproduce an image of the original object by applying and diffracting a reference light onto a holographic pattern, wherein interference fringes obtained by interfering the object light and reference light reflected from the original object can be recorded. The holographic display device can provide a computer-generated hologram (CGH) as an electrical signal to a spatial light modulator 500, which will be described below, and the spatial light modulator 500 can form a holographic pattern to diffract the reference light, thereby generating a 3D image.

[0050] Reference Figures 1 to 3The display device 1 may include a light source unit 100, a collimating lens 200, a waveguide 300, a focusing optical system 400, a spatial light modulator 500, a light splitter 600, a light source moving part 100_M, a light splitter rotating part 600_M, an image processor 700, an eye tracker 800, and a controller 900.

[0051] The light source 100 can provide light. Light emitted from the light source 100 can be incident on the collimating lens 200. The light can have spatial coherence and can be diffracted and modulated by the spatial light modulator 500, which will be described below. In one embodiment, the light source 100 may include a light-emitting diode (LED). In some embodiments, the light source 100 may include a laser diode.

[0052] The light source unit 100 may include a first light source 110 for forming a holographic image in the right eye RE of observer P and a second light source 120 for forming a holographic image in the left eye LE of observer P.

[0053] The first light source 110 and the second light source 120 may be arranged to be spaced apart from each other in the second direction Y. Each of the first light source 110 and the second light source 120 may include a light-emitting diode.

[0054] The light from the first light source 110 and the light from the second light source 120 can be separated from each other by the light separation plate 600 and can pass through the collimating lens 200, the waveguide 300, the focusing optical system 400 and the spatial light modulator 500 to be provided to each of the observer P's right eye RE and left eye LE.

[0055] In the plan view, the light from the first light source 110 can be incident on a portion of the collimating lens 200 (e.g., located relative to the collimating lens 200). Figure 3 The light from the second light source 120 can be incident on another part of the collimating lens 200 (e.g., located relative to the reference line RL on the upper side), and the light from the second light source 120 can be incident on another part of the collimating lens 200 (e.g., located relative to the reference line RL on the upper side). Figure 3 The reference line RL is located on the lower part of the reference line RL. In the plan view, the reference line RL may extend in the first direction X and pass through the center of the collimating lens 200, waveguide 300, focusing optics system 400, and / or spatial light modulator 500. The reference line RL may be the optical axis of the collimating lens 200.

[0056] The light source moving part 100_M can move the light source part 100 in at least one direction. The light source moving part 100_M can move the light source part 100 along a straight line and / or a curve. The light source moving part 100_M can move the light source part 100 in response to the movement of the observer P's line of sight. Therefore, the display device 1 can provide a wide viewing angle θ (refer to...). Figure 6In one embodiment, the first light source 110 and the second light source 120 can move together via the light source moving part 100_M. In some embodiments, the light source moving part 100_M can move the first light source 110 and the second light source 120 independently. Further reference will be made below. Figure 4 and Figure 5 The operation of the light source unit 100 and the light separation plate 600 is described in terms of their movement according to the viewer P's line of sight.

[0057] A light-splitting plate 600 may be disposed between the light source section 100 and the collimating lens 200. The light-splitting plate 600 may include a plate-shaped member extending from the collimating lens 200 toward the light source section 100 in a first direction X. Specifically, the light-splitting plate 600 may extend from a point on the optical axis of the collimating lens 200 toward the space between the first light source 110 and the second light source 120. The light-splitting plate 600 may include a first end facing the collimating lens 200 and located on the optical axis of the collimating lens 200, and a second end facing the space between the first light source 110 and the second light source 120.

[0058] The light separation plate 600 can separate the light from the first light source 110 and the light from the second light source 120 to prevent interference between them. For example, when the light source section 100 includes a light-emitting diode, the light separation plate 600 can prevent interference between the radially emitting light from the first light source 110 and the second light source 120. In other words, the light separation plate 600 can separate the space through which the light from the first light source 110 passes and the space through which the light from the second light source 120 passes.

[0059] The light-blocking plate 600 may include at least one of a light-blocking material and a light-absorbing material. For example, the light-blocking plate 600 may include a black base material. As another example, the light-blocking plate 600 may include a metal film containing chromium and / or chromium oxide, or a resin containing carbon pigment, graphite, or a combination thereof.

[0060] The light-separating plate 600 can rotate about a first rotation axis RX. In one embodiment, the first rotation axis RX can extend in a third direction Z and intersect with the optical axis of the collimating lens 200 extending in a first direction X. The light-separating plate 600 can be rotated by the light-separating plate rotating part 600_M.

[0061] The light-separating plate rotating part 600_M can rotate the light-separating plate 600 in response to the movement of the observer P's line of sight. In an embodiment, a first rotation axis RX can be provided at a first end of the light-separating plate 600, and a second end of the light-separating plate 600 can rotate relative to the first end. Figure 3As shown, the light separation plate 600 can be rotated by the light separation plate rotating part 600_M, and therefore the light separation plate 600 can be set on the optical axis of the collimating lens 200 to be parallel to the optical axis, or it can be set to be tilted to the optical axis of the collimating lens 200.

[0062] A collimating lens 200 can be disposed between the light splitter 600 and the waveguide 300. The collimating lens 200 can be aligned parallel to the direction of light emitted radially from the light source 100 and emit light towards the waveguide 300. The light source 100 can be disposed within the focal length of the collimating lens 200. In some embodiments, the focal point of the collimating lens 200 can be disposed on the light source 100.

[0063] The collimating lens 200 can have a smaller size than the waveguide 300. Specifically, the collimating lens 200 can have a width in the second direction Y that is the same as or similar to the width of the waveguide 300, and a height in the third direction Z that is smaller than the height of the waveguide 300. For example, the height of the collimating lens 200 can be about 1 / 10 or less of the height of the waveguide 300.

[0064] In some embodiments, the collimating lens 200 may be disposed on the light source section 100 and / or on a region of the waveguide 300 facing the first surface of the collimating lens 200. Light aligned parallel to the collimating lens 200 can be incident only on a region of the first surface of the waveguide 300. Figure 2 As shown in the illustration, in an embodiment, the area on the first surface on which light can be incident may be the lower end of the first surface.

[0065] Waveguide 300 can guide and diffract light incident through collimating lens 200. Specifically, as... Figure 2 As shown, in waveguide 300, light incident from the lower end of the first surface can propagate within waveguide 300 to be uniformly emitted across the entire second surface of waveguide 300, which may be opposite the first surface. Waveguide 300 can diffract the incident light such that the angle of incidence of the incident light incident on the region of the first surface of waveguide 300 can be equal to the emission angle of the emitted light emitted from the second surface of waveguide 300. The second surface of waveguide 300 may be a surface facing the focusing optical system 400 and / or the spatial light modulator 500. Waveguide 300 may include diffractive optical elements to which a diffraction pattern may be rasterized. In the display device 1 according to the embodiment, since waveguide 300 can be used, general lens elements for holographic display can be omitted, and thus the size of the device can be reduced.

[0066] like Figure 3As shown, waveguide 300 may include a first diffraction pattern region 310 and a second diffraction pattern region 320. Light from the first light source 110 passes through the first diffraction pattern region 310, and light from the second light source 120 passes through the second diffraction pattern region 320. The first diffraction pattern region 310 and the second diffraction pattern region 320 may be respectively disposed in the optical paths of the first light source 110 and the second light source 120. For example, in a planar view, the first diffraction pattern region 310 may be disposed in... Figure 3 The second diffraction pattern region 320 can be set on the upper side relative to the reference line RL. Figure 3 The first diffraction pattern region 310 and the second diffraction pattern region 320 can respectively guide and diffract the light from the first light source 110 and the light from the second light source 120.

[0067] The focusing optical system 400 can focus light passing through the waveguide 300 onto space. The reconstructed light can be focused onto space by the focusing optical system 400, enabling the formation of a holographic image in that space. The reconstructed light can refer to light modulated by the spatial light modulator 500. In one embodiment, the focusing optical system 400 can focus light emitted from the first light source 110 onto the right eye RE of the observer P, and light emitted from the second light source 120 onto the left eye LE of the observer P. In one embodiment, the focusing optical system 400 can be positioned between the spatial light modulator 500 and the waveguide 300, but this disclosure is not limited thereto. In some embodiments, the positions of the focusing optical system 400 and the spatial light modulator 500 can be interchanged. In some embodiments, the focusing optical system 400 can include a fixed-focal-length optical system with a fixed focal length and a variable-focal-length optical system with a variable focal length that can be changed by electrical control. The variable-focal-length optical system can change its focal length in response to changes in the distance between the observer P and the display device 1.

[0068] Spatial light modulator 500 can form a holographic pattern for diffraction and modulation of light passing through waveguide 300 and / or focusing optics 400 based on a holographic signal (e.g., a CGH data signal) provided from image processor 700. Spatial light modulator 500 may include a phase modulator capable of performing only phase modulation, an amplitude modulator capable of performing only amplitude modulation, and a composite modulator capable of performing both phase and amplitude modulation. Spatial light modulator 500 may include a transmission modulator (e.g., a semiconductor modulator based on a compound semiconductor such as GaAs), a liquid crystal device (LCD), or a reflection modulator (e.g., a digital micromirror device (DMD), a liquid crystal on silicon (LCoS), and a semiconductor modulator).

[0069] like Figure 3As shown, the spatial light modulator 500 may include a first holographic pattern region 510 and a second holographic pattern region 520. The first holographic pattern region 510 may provide a first holographic pattern for modulating light passing through the first diffraction pattern region 310, and the second holographic pattern region 520 may provide a second holographic pattern for modulating light passing through the second diffraction pattern region 320. The first holographic pattern region 510 and the second holographic pattern region 520 may be respectively disposed in the optical paths of the first light source 110 and the second light source 120. For example, in a planar view, the first holographic pattern region 510 may be disposed in... Figure 3 The second holographic pattern area 520 can be set on the upper side relative to the reference line RL. Figure 3 It is on the lower side of the reference line RL.

[0070] Image processor 700 can generate a holographic signal based on the holographic image to be provided to observer P, and then provide the generated holographic signal to spatial light modulator 500. Image processor 700 can control the operation of light sources. For example, image processor 700 can control the opening or closing of first light source 110 and second light source 120. Image processor 700 may include software or a semiconductor chip, and the semiconductor chip may embed software functionality.

[0071] The eye tracker 800 can acquire an image of the observer P via a camera or the like, and detect the pupil of the observer P in the image to analyze the position of the pupil. The eye tracker 800 can track changes in the position of the observer P's pupil in real time and provide the tracking results to the image processor 700. The image processor 700 can generate a holographic signal in response to the information about the position of the observer P's pupil provided by the eye tracker 800. For example, the image processor 700 can generate a holographic signal based on changes in the viewpoint according to changes in the position of the observer P's pupil, and provide the generated holographic signal to the spatial light modulator 500. The image processor 700 can control the light source movement unit 100_M to direct light toward the observer P's pupil and change the positions of the first light source 110 and the second light source 120.

[0072] The controller 900 can control at least one of the light source moving unit 100_M, the light separator rotating unit 600_M, the image processor 700, and the eye tracker 800. Specific operations of the light source moving unit 100_M, the light separator rotating unit 600_M, the image processor 700, and the eye tracker 800 can be controlled by the controller 900. For example, the controller 900 can control the light source moving unit 100_M such that the light source unit 100 can move in response to information provided from the eye tracker 800 regarding the position of the observer P's pupil. As another example, the controller 900 can control the light separator rotating unit 600_M such that the light separator 600 can rotate in response to information provided from the eye tracker 800 regarding the position of the observer P's pupil.

[0073] In the following text, reference will be made to Figures 3 to 5 The operation of the light source unit 100 and the light separation plate 600, which move according to the observer P's line of sight, is described in detail. Figures 3 to 5 In the middle, the left and right sides can be the upper and lower sides relative to the reference line RL, respectively.

[0074] Reference Figure 3 When the observer P is located at the center of the display device 1, the light splitter plate 600 and the light source unit 100 can be located on the reference line RL. The situation where the observer P can be located at the center of the display device 1 can be such that the observer P's left eye LE and right eye RE are approximately located on the reference line RL, and specifically, the observer P's left eye LE and right eye RE can be positioned such that the reference line RL is interposed between them. The light splitter plate 600 can be located on the reference line RL in the first direction X, parallel to the reference line RL, and the first light source 110 and the second light source 120 can be symmetrically positioned such that the reference line RL is interposed between them.

[0075] Reference Figure 4 and Figure 5 When the observer P moves in the first lateral direction, the light source 100 can move in the second lateral direction opposite to the first lateral direction, and the second end of the light-separating plate 600 can rotate in the second lateral direction relative to the first end of the light-separating plate 600 adjacent to the collimating lens 200. The position of the second end of the light-separating plate 600 can be maintained in the space between the first light source 110 and the second light source 120 facing the light source 100. Therefore, despite the movement of the light source 100, the light from the first light source 110 and the light from the second light source 120 can still be separated by the rotation of the light-separating plate 600.

[0076] Reference Figure 4When the observer P moves to the left, the light source 100 can move to the right. Therefore, the focal point of the light from the first light source 110 and the second light source 120, as well as the holographic image visually recognized by the observer P, can move to the left. The light separation plate 600 can rotate to the right about a first rotation axis RX in the third direction Z. Specifically, the second end of the light separation plate 600 adjacent to the light source 100 can rotate clockwise relative to the first end of the light separation plate 600 on which the first rotation axis RX is located.

[0077] Reference Figure 5 When the observer P moves to the right, the light source 100 can move to the left. Therefore, the focal point of the light from the first light source 110 and the second light source 120, as well as the holographic image visually recognized by the observer P, can move to the right. The light separation plate 600 can rotate to the left about the first rotation axis RX. Specifically, the second end of the light separation plate 600 can rotate counterclockwise relative to the first end of the light separation plate 600 on which the first rotation axis RX is located.

[0078] Figure 6 This is a schematic plan view showing the perspective of a display device according to an embodiment.

[0079] exist Figure 6 For ease of description, only the right eye RE of observer P is shown, but the following description can also be applied to the left eye LE of observer P.

[0080] Reference Figures 1 to 6 The light source unit 100 can move in response to changes in the position of the observer P (specifically, changes in the position of the observer P's pupil), and thus can increase the viewing angle θ of the display device 1.

[0081] like Figure 6 As shown, the viewing angle θ of the display device 1 can be determined by a first distance D1 between the light source unit 100 and the collimating lens 200 in the first direction X, a second distance D2 between the spatial light modulator 500 and the observer P in the first direction X, a third distance D3 which can be considered as the movable distance of the light source unit 100 in the second direction Y, and a fourth distance D4 which can be considered as the movable distance of the observer P in the second direction Y. The third distance D3 and the fourth distance D4 can be distances measured relative to the reference line RL. The third distance D3 and the fourth distance D4 can be distances measured relative to the reference line RL in the leftward direction (…). Figure 6 The distance on the upper side and in the right direction ( Figure 6 The distance on the lower side.

[0082] The viewing angle θ, the first distance D1, the second distance D2, the third distance D3, and the fourth distance D4 of the display device 1 can satisfy the following expression.

[0083] (Expression 1)

[0084]

[0085] (Expression 2)

[0086]

[0087] For example, if the light source 100 moves a third distance D3 relative to the reference line RL, the position of the focal point focused on the pupil of the observer P can be moved a fourth distance D4, so that the viewing angle θ can be ensured.

[0088] The first distance D1, the second distance D2, the third distance D3, and the fourth distance D4 can be adjusted according to the desired viewing angle θ. For example, by adjusting the first distance D1 to be relatively smaller than the second distance D2, a viewing angle θ wider than the movable distance of the light source unit 100 can be ensured.

[0089] Figures 7 to 9 This is a schematic plan view showing the light source moving part of a display device according to an embodiment.

[0090] Reference Figures 7 to 9 As described above, the light source moving part 100_M can move the light source part 100 in at least one direction. In an embodiment, the light source moving part 100_M can move the light source part 100 linearly in the second direction Y.

[0091] The light source moving part 100_M may include a moving stage 100_ST and a drive motor 100_LM.

[0092] The moving stage 100_ST can provide a movement path for the light source unit 100. The moving stage 100_ST can extend linearly in the second direction Y. The first light source 110 and the second light source 120 of the light source unit 100 can be mounted on the moving stage 100_ST to be movable in the second direction Y. A first moving member 110_MM and a second moving member 120_MM can be provided on the moving stage 100_ST to allow the first light source 110 and the second light source 120 to be slidably connected to the moving stage 100_ST, respectively. In some embodiments, the first light source 110 and the second light source 120 can be mounted on one of the first moving member 110_MM and the second moving member 120_MM.

[0093] The drive motor 100_LM can move the first moving member 110_MM and the second moving member 120_MM in the second direction Y. The operation of the drive motor 100_LM can be controlled by the controller 900. The drive motor 100_LM can be a linear motor. In some embodiments, the drive motor 100_LM can be mounted on the moving stage 100_ST. In some embodiments, two linear motors can be mounted on the first moving member 110_MM and the second moving member 120_MM, respectively. In one embodiment, the first moving member 110_MM and the second moving member 120_MM can move at the same speed. In some embodiments, the first moving member 110_MM and the second moving member 120_MM can move at different speeds to correspond to, for example, the distance between the observer P and the display device 1.

[0094] Reference Figure 3 and Figure 7 With the observer P located at the center of the display device 1, the first light source 110 and the second light source 120 can be located between the moving stage 100_ST. The first light source 110 and the second light source 120 can be positioned symmetrically, and a reference line RL is interposed between them.

[0095] When the observer P is located at the center of the display device 1, the distance between the light source 100 and the focal point F of the collimating lens 200 can be minimized. The focal point F of the collimating lens 200 can be located on a reference line RL passing through the centers of the first light source 110 and the second light source 120. As described above, the reference line RL can be the optical axis of the collimating lens 200. The distance between the light source 100 and the focal point F of the collimating lens 200 can be the average of the distance between the first light source 110 and the focal point F and the distance between the second light source 120 and the focal point F. In some embodiments, the collimating lens 200 can include an optical system having multiple focal points F, and each focal point F can be located on one of the first light source 110 and the second light source 120.

[0096] When the observer P is located at the center of the display device 1, the light from the first light source 110 and the light from the second light source 120 can be aligned parallel to each other in the first direction X by the collimating lens 200 and incident on the waveguide 300. The light incident on the waveguide 300 can be emitted parallel to each other in the first direction X to the focusing optical system 400.

[0097] Reference Figure 4 and Figure 8 When the observer P moves to the left side of the display device 1, the light source moving part 100_M can linearly move the first light source 110 and the second light source 120 to the right. The distance between the light source part 100 and the focal point F of the collimating lens 200 can be increased.

[0098] When the observer P is located to the left of the display device 1, the light from the first light source 110 and the light from the second light source 120 can be incident on the collimating lens 200 at an angle, compared to the case where the observer P can be located in front of the display device 1. The parallel light emitted from the collimating lens 200 can be emitted at an angle relative to the reference line RL and incident on the waveguide 300.

[0099] As described above, the incident angle of the light incident on the waveguide 300 from the collimating lens 200 and the emission angle of the light emitted from the waveguide 300 can be the same. Therefore, the light emitted from the waveguide 300 can also be emitted at an angle relative to the reference line RL. For example, the light emitted from the waveguide 300 can be directed towards... Figure 7 Launched from the upper left side.

[0100] Reference Figure 5 and Figure 9 When the observer P moves to the right side of the display device 1, the light source moving unit 100_M can linearly move the first light source 110 and the second light source 120 to the left. Figure 4 and Figure 8 Similarly, the distance between the focal point F of the light source 100 and the collimating lens 200 can be increased.

[0101] When the observer P is located to the right of the display device 1, compared to the case where the observer P can be located at the center of the display device 1, the light from the first light source 110 and the light from the second light source 120 can be incident obliquely on the collimating lens 200, and the light emitted from the waveguide 300 can also be emitted obliquely relative to the reference line RL. For example, the light emitted from the waveguide 300 can be directed towards... Figure 7 It was launched from the lower left side.

[0102] In some embodiments, when the light source unit 100 moves according to the movement of the observer P, the light source moving unit 100_M can move the first light source 110 and the second light source 120 at different speeds, so that the interval between the first light source 110 and the second light source 120 can be changed based on the distance between the observer P and the display device 1. For example, when the observer P moves to the left side of the display device 1 and the distance between the display device 1 and the observer P decreases, the light source moving unit 100_M can move the first light source 110 and / or the second light source 120 individually, so that the interval between the first light source 110 and the second light source 120 can increase. The first light source 110 and the second light source 120 can move to the right, but the moving speed of the second light source 120 can be higher than the moving speed of the first light source 110. As another example, when the observer P moves to the right side of the display device 1 and the distance between the display device 1 and the observer P increases, the light source moving unit 100_M can move the first light source 110 and / or the second light source 120 individually, so that the interval between the first light source 110 and the second light source 120 can decrease. The first light source 110 and the second light source 120 can move to the left, but the moving speed of the second light source 120 can be higher than that of the first light source 110. In some embodiments, the distance between the display device 1 and the observer P can be calculated based on the distance between the left eye LE and the right eye RE of the observer P measured by the eye tracker 800.

[0103] Figures 10 to 12 This is a schematic plan view showing the light source moving part of a display device according to another embodiment.

[0104] Figures 10 to 12 Implementation methods and Figures 7 to 9 The difference in the implementation method is that the light source 100 can move along a curve.

[0105] Reference Figures 10 to 12 The light source moving part 100_Ma may include a moving stage 100_STa and a drive motor 100_LM.

[0106] The mobile station 100_STa can be configured to have a specific curvature. For example... Figures 10 to 12 As shown, the moving stage 100_STa can be configured to have an arcuate shape. In the plan view, the side of the arcuate shape facing the collimating mirror 200 (or the light separation plate 600) can be concave, and the opposite side can be convex. The center of curvature of a specific curvature can be located on the reference line RL. In one embodiment, the center of curvature of a specific curvature can be located at the first rotation axis RX, but this disclosure is not limited thereto. The first light source 110 and the second light source 120 can be movably connected to the moving stage 100_STa via the first moving member 110_MM and the second moving member 120_MM, respectively.

[0107] The drive motor 100_LM can move the first moving member 110_MM and the second moving member 120_MM according to the curvature of the moving stage 100_STa. The operation of the drive motor 100_LM can be controlled by the controller 900. The drive motor 100_LM can move the first moving member 110_MM and the second moving member 120_MM at the same speed or at different speeds.

[0108] Reference Figure 10 With the observer P located at the center of the display device 1a, the first light source 110 and the second light source 120 can be symmetrically positioned on the central portion of the moving stage 100_STa, and the reference line RL is interposed between them. The distance between the light source section 100 and the focal point F of the collimating lens 200 can be minimized.

[0109] Reference Figure 11 When the observer P moves to the left of the display device 1a, the light source moving part 100_Ma can move the first light source 110 and the second light source 120 to the right along the curve. For example, the first light source 110 and the second light source 120 can move along the curve so that their distance from the first rotation axis RX can be kept constant. The distance between the light source part 100 and the reference line RL in the second direction Y can be increased, but the distance between the collimating lens 200 and the light source part 100 in the first direction X can be decreased. The distance between the light source part 100 and the reference line RL and the distance between the light source part 100 and the collimating lens 200 can be the average of the distances measured by the first light source 110 and the second light source 120 (e.g., the distance measured based on the midpoint between the first light source 110 and the second light source 120).

[0110] Reference Figure 12 When the observer P moves to the right side of the display device 1a, the light source moving part 100_Ma can move the first light source 110 and the second light source 120 to the left along the curve. Figure 11 Similarly, the first light source 110 and the second light source 120 can be moved so that their distance from the first rotation axis RX can be kept constant, and thus the distance between the light source 100 and the reference line RL in the second direction Y can be increased, but the distance between the collimating lens 200 and the light source 100 in the first direction X can be decreased.

[0111] Reference Figure 11 and 12 When observer P moves to the left or right side of display device 1a, with Figure 9 and Figure 10Compared to the previous case, the distance between the focal point F of the collimating lens 200 and the light source 100 can be kept relatively small. Therefore, the lens aberrations and / or chromatic aberrations that occur as the light source 100 moves away from the focal point F of the collimating lens 200 can be reduced.

[0112] Furthermore, the light source 100 can be moved so that the distance between it and the first rotation axis RX can be maintained constant, and thus the distance between the second end of the light separation plate 600 and the light source 100 and / or the moving stage 100_STa can be maintained constant. Therefore, even if the light source 100 moves, the light emitted radially from the first light source 110 and the light from the second light source 120 can be stably separated so as not to interfere with each other.

[0113] The display device according to the embodiments can have a small size and a wide viewing angle.

[0114] The effects of the embodiments according to this disclosure are not limited to the content disclosed above, and the specification includes many more different effects.

[0115] In concluding this detailed description, those skilled in the art will understand that many variations and modifications can be made to the embodiments without substantially departing from the principles of this disclosure. Therefore, the disclosed embodiments are used in a general and descriptive sense only and not for limiting purposes.

Claims

1. A display device, including: The light source section includes a first light source and a second light source; A collimating lens is used to calibrate the light incident from the light source. A waveguide that guides and diffracts light incident from the collimating mirror; A spatial light modulator modulates light passing through the waveguide to form a holographic pattern for reproducing a holographic image; A focusing optical system focuses the holographic image in space; as well as A light-separating plate is disposed between the light source and the collimating lens, the light-separating plate separating the light from the first light source and the light from the second light source. The waveguide includes: A first diffraction pattern region, in which light from the first light source is diffracted; and The second diffraction pattern region, in which the light from the second light source is diffracted, and The first diffraction pattern region and the second diffraction pattern region are separated from each other by a reference line that serves as the optical axis of the collimating lens.

2. The display device according to claim 1, wherein, The height of the collimating mirror is less than the height of the waveguide, and The waveguide includes a first surface facing the light source and a second surface opposite to the first surface, and The light emitted from the collimating mirror is incident on a portion of the first surface of the waveguide, and Light incident on a portion of the first surface of the waveguide propagates in the waveguide and is uniformly emitted onto the entire second surface of the waveguide.

3. The display device according to claim 1, in, The spatial light modulator includes: A first holographic pattern region, wherein a first holographic pattern is provided in the first holographic pattern region, and the first holographic pattern modulates light passing through the first diffraction pattern region; and A second holographic pattern region is provided in the second holographic pattern region, wherein the second holographic pattern modulates light passing through the second diffraction pattern region.

4. The display device according to claim 1, wherein, The light-separating plate extends from the collimating lens toward the light source, and The light separation plate extends from the optical axis of the collimating lens toward the space between the first light source and the second light source.

5. The display device according to claim 1, further comprising: An eye tracker, configured to track the observer's gaze; The light source moving part moves in response to the movement of the observer's line of sight; as well as The light-separating plate rotating part rotates in response to the movement of the observer's line of sight.

6. The display device according to claim 5, wherein, The light separation plate includes: The first end faces the collimating lens and is located on the optical axis of the collimating lens; and The second end faces the light source unit, and The rotating part of the light separator rotates the second end of the light separator relative to the first end of the light separator.

7. The display device according to claim 6, wherein, The rotating part of the light-separating plate rotates the second end of the light-separating plate so that, when the light source part moves, the second end of the light-separating plate faces the space between the first light source and the second light source. The light-separating plate rotating part rotates the second end of the light-separating plate in a direction opposite to the direction of the observer's line of sight movement.

8. The display device according to claim 5, wherein, When the light source moving part moves the light source part in a first side direction relative to the optical axis of the collimating lens, the holographic image moves in a second side direction opposite to the first side direction relative to the optical axis of the collimating lens.

9. The display device according to claim 1, wherein, The light-separating plate includes at least one of a light-absorbing material and a light-blocking material.

10. A display device, including: The light source section includes a pair of light sources; A collimating lens is used to calibrate the light incident from the light source. A waveguide that guides and diffracts light incident from the collimating mirror; The light source moving part moves the light source part; A light-separating plate separates the light emitted from the pair of light sources into a first light and a second light; as well as The light-separating plate rotating part rotates the light-separating plate. The waveguide includes: A first diffraction pattern region, in which the first light is diffracted; and The second diffraction pattern region, in which the second light is diffracted, and The first diffraction pattern region and the second diffraction pattern region are separated from each other by a reference line that serves as the optical axis of the collimating lens.

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