3D holographic display device and method of operating the same

Abstract

A three-dimensional holographic display device includes: a light-emitting diode (LED) array including a plurality of light sources controlled to sequentially output light according to a preset pattern; a lens configured to refract light incident from the LED array; a spatial light modulator (SLM) configured to modulate light incident from the lens; and a processor configured to generate a plurality of holographic signals each including depth information adjusted according to an arrangement position of each of the plurality of light sources, and for each of the plurality of light sources, control the SLM to modulate light based on a holographic signal corresponding to the light source.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2021-0024232 filed on February 23, 2021, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to a three-dimensional holographic display device and its operating method. Background Technology

[0004] Three-dimensional holographic display devices can achieve high-quality holograms in real time by using spatial light modulators (SLMs) that can simultaneously control the amplitude and phase of light. Because three-dimensional holographic display devices do not utilize binocular parallax like stereoscopic displays, they can produce realistic three-dimensional images that do not cause visual fatigue for the user. Summary of the Invention

[0005] A three-dimensional holographic display device and its operation method are provided. The technical objectives to be achieved by this disclosure are not limited to the above-mentioned objectives, and other technical objectives can be inferred from the following example embodiments.

[0006] 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 exemplary embodiments of this disclosure.

[0007] According to one aspect of this disclosure, a three-dimensional holographic display device includes an array of light-emitting diodes (LEDs) comprising a plurality of light sources controlled to sequentially output light according to a preset pattern; a lens configured to refract light incident from the LED array; a spatial light modulator (SLM) configured to modulate light incident from the lens; and a processor configured to generate a plurality of holographic signals, each holographic signal including depth information adjusted according to the arrangement position of each of the plurality of light sources; and for each of the plurality of light sources, controlling the SLM to modulate light based on the holographic signal corresponding to the light source.

[0008] When the second light source among multiple light sources outputs light after the first light source among multiple light sources according to a preset pattern, the processor can change the holographic image pattern displayed by the SLM at the moment when the second light source starts to output light, and the changed holographic image pattern can be formed by the second holographic signal among multiple holographic signals. The second holographic signal includes second depth information adjusted according to the arrangement position of the second light source.

[0009] LED arrays can change the source of output light at a cycle of at least 1 MHz.

[0010] The three-dimensional holographic display device may also include a filter configured to remove the noise component of the light modulated by the SLM.

[0011] The processor can also be configured to drive an LED array in units of light source sets, each light source set including at least two of a plurality of light sources.

[0012] For each set of light sources, the distance between at least two light sources in the set can be set such that holographic images displayed in space by at least two light sources do not overlap each other.

[0013] For each of the light sources in the light source set, the processor can also be configured to adjust the brightness of at least some of the light sources in at least two of the light sources in the light source set to be different from the brightness of the other light sources in the light source set.

[0014] The processor can also be configured to adjust the brightness of the light sources around the defective light source to compensate for the defect when it is determined that at least two light sources in at least one light source set of the light source set include the defective light source.

[0015] The LED array may include a first region and a second region. The first region includes a light source among a plurality of light sources for displaying a first holographic image perceived by the user's left eye, and the second region includes a light source among a plurality of light sources for displaying a second holographic image perceived by the user's right eye.

[0016] The three-dimensional holographic display device may also include a driving device configured to move the LED array in at least one of a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to both the first and second directions, or to rotate the LED array about at least one of the first, second, and third directions as an axis.

[0017] According to one aspect of this disclosure, a method of operating a three-dimensional holographic display device includes: generating a plurality of holographic signals, each holographic signal including depth information adjusted according to the arrangement position of each of a plurality of light sources in a light-emitting diode (LED) array; controlling the plurality of light sources to sequentially output light according to a preset pattern; and for each of the plurality of light sources, controlling a spatial light modulator (SLM) to modulate light incident from the LED array based on the holographic signal corresponding to the light source.

[0018] The method may further include, when a second light source among a plurality of light sources outputs light after the first light source among the plurality of light sources outputs light according to a preset pattern, changing the holographic image pattern displayed by the SLM at the moment when the second light source begins to output light, wherein the changed holographic image pattern is formed by a second holographic signal among a plurality of holographic signals, the second holographic signal including second depth information adjusted according to the arrangement position of the second light source.

[0019] Control of multiple light sources can include light sources that change the output light at a period of at least 1 MHz.

[0020] The method may also include removing the noise component of the light modulated by the SLM.

[0021] When controlling multiple light sources, the LED array can be driven in units of light source sets, each light source set including at least two of the multiple light sources.

[0022] For each of the light sources in the light source set, the distance between at least two light sources in the light source set can be set such that holographic images displayed in space by at least two light sources do not overlap each other.

[0023] The method may further include, for each of the light sources in the light source set, adjusting the brightness of at least some of the light sources in at least two of the light sources in the light source set to be different from the brightness of the other light sources in the light source set.

[0024] The method may further include adjusting the brightness of the light sources surrounding the defective light source to compensate for the defect when it is determined that at least two light sources in at least one light source set of the light source set include the defective light source.

[0025] The method further includes moving the LED array in at least one of a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to both the first and second directions, or rotating the LED array about at least one of the first, second, and third directions as an axis.

[0026] A non-transitory computer-readable recording medium may contain a program for performing the methods described above in this disclosure.

[0027] According to one aspect of this disclosure, a holographic display device includes: a plurality of light sources configured to operate independently of each other; a spatial light modulator (SLM) for receiving light emitted by the plurality of light sources; and a processor configured to turn the plurality of light sources on and off in a repeating sequence; and to sequentially provide the SLM with a plurality of signals, each of the plurality of signals corresponding to a different step in the repeating sequence.

[0028] Holographic display devices can be configured to form holographic images at multiple viewing windows, each of which corresponds to a different step in a repeating sequence.

[0029] The position of each of the multiple viewing windows can correspond to the position of one or more light sources that are turned on during the corresponding steps in the repeating sequence. Attached Figure Description

[0030] The above and other aspects, features, and advantages of exemplary embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0031] Figure 1 This is a view of the configuration of a three-dimensional holographic display device according to an embodiment;

[0032] Figure 2 It is by Figure 1 The view formed by the viewing window of the three-dimensional holographic display device;

[0033] Figure 3 This is a view of the operation of a three-dimensional holographic display device according to an embodiment;

[0034] Figure 4 This is a view of the configuration of a three-dimensional holographic display device according to an embodiment;

[0035] Figure 5 This is a view of the process of realizing a multi-eye box using a three-dimensional holographic display device according to an embodiment;

[0036] Figure 6 This is a view of the process of expanding the eye box using a three-dimensional holographic display device according to an embodiment;

[0037] Figure 7 This is a view of the configuration of the LED array according to an embodiment; and

[0038] Figure 8 This is a flowchart of a method for operating a three-dimensional holographic display device according to an embodiment. Detailed Implementation

[0039] Reference will now be made in detail to embodiments, examples of which are shown in the accompanying drawings, wherein similar reference numerals always refer to similar elements. In this respect, embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, embodiments are described below only to explain aspects by reference to the accompanying drawings. As used herein, the term “and / or” includes any and all combinations of one or more associated items. When expressions such as “at least one of…” are used after a list of elements, the entire list of elements is modified, not the individual elements in the list.

[0040] The terms used in this disclosure have been selected from commonly used terms that are currently widely used, taking into account the functionality of the functions described herein. However, terms may vary depending on the intent of a person skilled in the art, precedent, and the emergence of new technologies. Furthermore, for particular cases, the meaning of the terms chosen by the applicant is described in detail in the descriptive section. Therefore, the terms used in this disclosure are defined based on their meaning relative to what is discussed throughout the specification, rather than on their simplistic meaning.

[0041] In this specification, when a component is "connected" or "connected" to another component, the component not only directly contacts or is connected to the other component, but also electrically contacts or is connected to the other component through at least one of the other components inserted therein. Singular expressions in this specification include plural expressions unless the context clearly states otherwise. Furthermore, when a component may "comprise" a certain component, it shall not be construed as excluding other component components, but rather as including other component components, unless otherwise stated.

[0042] Terms such as “comprising” or “including” should not be construed as necessarily including any and all of the components or steps described in the specification, but may be construed as excluding some components or steps, or including additional components or steps.

[0043] Terms such as "first" and "second" can be used to describe various components, and such components are certainly not limited to the terms mentioned above. The terms mentioned above are only used to distinguish one component from another.

[0044] The following description of the embodiments should not be construed as limiting the scope of the claims, and content that can be readily inferred by those skilled in the art should be interpreted as falling within the scope of this specification. In the following, exemplary embodiments will be described in detail with reference to the accompanying drawings.

[0045] Figure 1 This is a view of the configuration of the three-dimensional holographic display device 10 according to an embodiment.

[0046] The 3D holographic display device 10 can correspond to any electronic device capable of displaying 3D holographic images. For example, the 3D holographic display device 10 can be applied to various electronic devices, such as monitors, TVs, mobile display devices, etc.

[0047] refer to Figure 1 The three-dimensional holographic display device 10 may include a light-emitting diode (LED) array 110, a lens 120, a spatial light modulator (SLM) 130, and a processor 140. However, in Figure 1 The three-dimensional holographic display device 10 only shows components relevant to the embodiment. Therefore, it will be obvious to those skilled in the art that, in addition to [other components], [the rest of the text is missing]. Figure 1 Other general-purpose components besides the main components can also be included in the three-dimensional holographic display device 10. For example, the three-dimensional holographic display device 10 may also include a memory.

[0048] The memory is hardware used to store the various data processed by the 3D holographic display device 10. For example, the memory can store multiple data that have been processed or will be processed by the 3D holographic display device 10. Furthermore, the memory may include applications, drivers, etc., that will be driven by the 3D holographic display device 10. In this example, the memory may store holographic signals generated by the processor 140.

[0049] The memory may include random access memory (RAM) (such as dynamic random access memory (DRAM), static random access memory (SRAM), etc.), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), CD-ROM, Blu-ray disc or other optical disc storage, hard disk drive (HDD), solid-state drive (SSD) or flash memory, and in addition, other external storage devices accessible to the 3D holographic display device 10.

[0050] LED array 110 may include multiple individually controllable (e.g., operable independently of each other) light sources. For example, LED array 110 may include multiple unit LEDs arranged in a two-dimensional array in the row and column directions. Although, as an example, Figure 1 An example of a three-dimensional holographic display device 10 including an LED array 110 is shown, but the LED array 110 can be replaced by a light source array including different types of light sources. For example, the LED array 110 can be replaced by an array of various light sources such as lasers and laser diodes (LDs).

[0051] Lens 120 may include one or more lenses for refracting incident light from LED array 110 in a specific direction. For example, lens 120 may include at least one of a collimating lens for collimating incident light from LED array 110 into parallel light and a focusing lens for focusing light at a specific point. For example, lens 120 may include only a focusing lens, or both a collimating lens and a focusing lens. The collimating lens may include a cylindrical lens or an array of cylindrical lenses, and the focusing lens may be manufactured as a diffractive optical element or a holographic optical element in which the phase of the lens is recorded on a plane. However, this disclosure is not limited thereto.

[0052] although Figure 1 The illustration shows lens 120 positioned in front of SLM 130, but this disclosure is not limited thereto. Lens 120 may be positioned behind SLM 130. Furthermore, when lens 120 comprises multiple lenses, some lenses may be positioned in front of SLM 130, while others may be positioned behind SLM 130.

[0053] SLM 130 can be a device capable of spatially converting light. SLM 130 can be transmissive or reflective. In examples, SLM 130 may include a liquid crystal on silicon (LCos) device or a liquid crystal display (LCD) device, but this disclosure is not limited thereto. SLM 130 can control at least one of the intensity (amplitude), color, or phase of light leaving SLM 130, and may include a matrix of multiple pixels that can be individually controlled.

[0054] Processor 140 can perform the overall functions of controlling the 3D holographic display device 10. For example, processor 140 can control the operation of LED array 110, lens 120, and SLM 130. Processor 140 can be implemented by an array of multiple logic gates or a combination of a general-purpose microprocessor and a memory storing programs executable by the microprocessor. Although Figure 1 An example is shown where processor 140 is provided separately from SLM 130, but processor 140 can be included in SLM 130.

[0055] Processor 140 can generate holographic signals. Holographic signals may include computer-generated holograms (CGHs). To generate CGHs, computational methods using ray tracing, lookup tables, fast Fourier transforms, etc., can be used.

[0056] A holographic image pattern corresponding to the holographic signal generated by processor 140 can be output by multiple pixels of SLM 130, and due to the diffraction of light passing through the multiple pixels of SLM 130, an interference pattern of light rays may be generated in space. The user can observe a three-dimensional holographic image from the interference pattern propagating to each of the left eye LP and right eye RP. See below. Figure 2 Describe in detail the process of a user observing a 3D holographic image.

[0057] Figure 2 It is by Figure 1 The three-dimensional holographic display device 10 forms a viewing window (VW) view.

[0058] refer to Figure 2 The process of user U observing a three-dimensional holographic image is shown when the light source 110a included in the LED array 110 outputs light.

[0059] Light emitted from a light source 110a included in the LED array 110 can be refracted in one direction by passing through a lens 120. Figure 2In the example, since lens 120 is a focusing lens, light passing through lens 120 can be focused onto a specific point in space. SLM 130 can reconfigure the holographic image in space by modulating the amplitude and / or phase of the light input through lens 120.

[0060] However, due to conditions such as the characteristics of lens 120 and the pixel size of SLM 130, the holographic image may only be observed by user U in one field of view. Thus, the field of view used to observe the holographic image for user U's pupil can be referred to as the viewing window VW.

[0061] When the user U's pupil is outside the viewing window VW, the holographic image will not be perceived by the user U, thus limiting the user U's ability to continuously observe the holographic image. According to related technologies, a method has been proposed that uses a separate sensor to continuously track the position of the user U's pupil and moves the viewing window VW to adapt to the pupil's tracking position. However, since the size of the viewing window VW is similar to the size of the pupil, approximately 3 to 8 millimeters, according to related technologies, accurate matching requires a high-precision sensor, a processor capable of performing fast calculations, and other advanced technologies.

[0062] According to the three-dimensional holographic display device disclosed herein, a technique is proposed that reduces restrictions on the movement of user U even when the pupil position of user U is not continuously tracked using a separate sensor. (See below for reference.) Figure 3 The process of operating the three-dimensional holographic display device according to this disclosure is described in detail.

[0063] Figure 3 This is a view of the operation of a three-dimensional holographic display device according to an embodiment.

[0064] refer to Figure 3 An example of an LED array including multiple light sources L1 to L9 is shown, for example... Figure 1 and 2 LED array 110. Although for ease of explanation, in Figure 3 The example shown depicts a scenario with nine light sources, but the number of light sources is not limited to the example above. The number of light sources can be more or less than nine. Figure 3 In the diagram, a light source displayed as a black circle indicates the state of outputting light, while a light source displayed as a white circle (or a blank circle) indicates the state of not outputting light.

[0065] Multiple light sources, such as L1 to L9, included in an LED array, can be controlled to output light sequentially according to a preset pattern. For example, as Figure 3As shown, after light source L1 outputs light, light source L2 can output light, and after light source L2 outputs light, light source L3 can output light. After light source L9 outputs light in the same sequence, light source L1 can output light again. However, this is just an example; light sources L1 to L9 can be controlled to output light in sequence according to different patterns. For example, light sources L1 to L9 can output light in a sequence similar to... Figure 3 The light is output in the opposite order of the pattern, or in the order of a specific or preset pattern.

[0066] processor, for example Figure 1 and Figure 2 The processor 140 can generate multiple holographic signals, each holographic signal having depth information adjusted according to the arrangement position of each of a plurality of light sources (e.g., light sources L1 to L9), and control the SLM (e.g., Figure 1 and Figure 2 The SLM 130 modulates light based on the holographic signal of the light source corresponding to the current output light in the generated holographic signal. In other words, the processor 140 can turn multiple light sources on and off in a repeating sequence, and can sequentially provide multiple signals to the SLM 130, such that each of the multiple signals corresponds to a different step in the repeating sequence.

[0067] As the position of the output light source changes, the position of the viewing window can also change, allowing the user's viewing angle of the holographic image to vary. In other words, the holographic image can be formed at multiple viewing windows, each corresponding to a different step in a repeating sequence. Furthermore, the position of each of the multiple viewing windows can correspond to the position of the light source that is turned on during the corresponding step in the repeating sequence. For example, when the output light source changes from light source L1 to light source L2, the position of the viewing window can change from viewing window VW1 to viewing window VW2, as shown below. Figure 3 As shown. In this way, the position of the viewing window can be relative to the lens (e.g., Figure 1 and 2 The center of the lens 120 changes in a direction symmetrical to the direction of movement of the light source, and can change the position and / or angle at which the user's pupil perceives the holographic image. Therefore, the depth information of the holographic signal can be appropriately adjusted so that the user can correctly observe the desired holographic image.

[0068] When the second light source outputs light after the first light source according to a preset pattern, the processor can change the holographic image pattern displayed by the SLM at the moment the second light source begins to output light. The changed holographic image pattern can be formed by a holographic signal (e.g., a second holographic signal) having depth information (e.g., second depth information) adjusted according to the arrangement position of the second light source. In the example, when light source L2 outputs light after light source L1, the processor can change the holographic image pattern output by the SLM from frame 1 to frame 2. Frame 1 can have depth information adjusted considering the position of the viewing window VW1 formed according to the position of the light source L1 outputting the light, and frame 2 can have depth information adjusted considering the position of the viewing window VW2 formed according to the position of the light source L2 outputting the light.

[0069] When light source L2 starts emitting light directly after light source L1 stops emitting light, the time when the light source starts emitting light and the time when the displayed holographic image pattern is changed by the SLM can be perfectly synchronized. However, this disclosure is not limited to this, and when light source L2 starts emitting light at a specific time interval after light source L1 stops emitting light, the time when the light source starts emitting light and the time when the holographic image pattern is changed do not need to be perfectly synchronized, and the holographic image pattern can be changed before or simultaneously with the light source starts emitting light.

[0070] In this way, as multiple light sources (e.g., light sources L1 to L9) included in the LED array can be controlled to output light according to a preset pattern (e.g., in the order of L1, L2, ... L8, L9), and the SLM can modulate the light based on the holographic signal corresponding to the light source that outputs light at a specific time, the position of the viewing window of the holographic image can be continuously changed so that the user can normally perceive it.

[0071] When the LED array and SLM are driven at a sufficiently high speed, the user can observe the holographic image even when their pupil is located at any of the multiple viewing windows (e.g., viewing windows VW1 to VW9, each corresponding to multiple light sources, such as light sources L1 to L9, at a specific time). In other words, according to Figure 3 The operation process of the three-dimensional holographic display device, and its single light source, namely light source 110a, continuously outputs light. Figure 2 Compared to the previous method, the size of the area for observing a holographic image can be expanded proportionally to the number of light sources. Therefore, even as the user's pupil moves within this expanded area, the user can continuously observe the holographic image. When the number of light sources is large enough, the user may experience virtually no restriction on movement.

[0072] To prevent users from perceiving differences in light intensity based on window movement, the LED array and SLM can be driven at a sufficiently high speed. For example, the LED array can change the source of the output light at a cycle of at least approximately 1 MHz. Figure 3 As shown, when light source L1 starts emitting light at point T1 and light source L2 starts emitting light at point T2, the period T of the light source can be changed to T = T2 - T1 = (1MHz). -1 =10 -6 Seconds. However, this disclosure is not limited to this, and the LED array can change the source of the output light in cycles of hundreds to thousands of hertz or higher. The SLM can have a drive speed corresponding to the drive speed of the LED array.

[0073] although Figure 3 An example is shown where multiple viewing windows, each corresponding to a different light source, do not overlap. However, depending on the size and brightness of each light source, the distance between adjacent light sources, etc., the viewing windows may overlap. When the viewing windows overlap, in some cases, the holographic image corresponding to one viewing window may appear to overlap with the holographic image corresponding to another viewing window. Furthermore, due to the high-speed driving of the LED array and the SLM holographic image, afterimages of the holographic image can be seen. In the following description, reference is made to... Figures 4 to 6 It describes in detail various methods for users to observe normal holographic images.

[0074] Figure 4 This is a view of the configuration of a three-dimensional holographic display device according to an embodiment.

[0075] refer to Figure 4 In addition to the LED array 110, lens 120, and SLM 130, three-dimensional holographic display devices, such as Figure 1 The three-dimensional holographic display device 10 may also include a filter 410 and an additional lens 420. Since the same description as that for lens 120 is applied to the additional lens 420, its redundant description is omitted.

[0076] Filter 410 removes the noise component of the light modulated by SLM 130. As filter 410 removes the noise component, the afterimage of the holographic image generated due to the high-speed driving of LED array 110 and SLM 130 can be removed. Filter 410 can dynamically change its filtering characteristics to remove the noise component. In this example, filter 410 can change its filtering characteristics at a sufficiently high speed to remove the afterimage of the holographic image caused by the high-speed driving of LED array 110 and SLM 130.

[0077] Figure 5 This is a view of the process of realizing a multi-eye box using a three-dimensional holographic display device according to an embodiment.

[0078] exist Figure 5 In the diagram, light sources displayed as black circles indicate the state of light output, while light sources displayed as white circles indicate the state of no light output. Furthermore, in... Figure 5 In this context, it is assumed that the distance between the LED array 110 and the lens 120 is the same as the distance between the lens 120 and the observation area, and the size of the observation area is shown as a ratio approximately 1:1 relative to the LED array 110. However, those skilled in the art will readily understand that the size of the viewing window area can be varied according to the ratio of the distance between the LED array 110 and the lens 120 to the distance between the lens 120 and the observation area.

[0079] processor, for example Figure 1 and 2 The processor 140 can drive the LED array 110 in units of light source sets, each light source set including at least two light sources. For example, as Figure 5 As shown, the processor can drive the LED array 110 in units of nine light sources. In other words, the processor can control nine light sources in one light source set to output light simultaneously, and then control nine light sources in another light source set to output light simultaneously.

[0080] The size of the unit view window (UVW) corresponding to a single light source is limited by the pixel size of the SLM 130. However, when a set of nine light sources outputs light simultaneously, the view windows corresponding to each of the nine light sources can overlap. Therefore, the intersection of the sets of view windows can form a noise-free effective view window (EVW). A multi-eye box can be implemented in the area corresponding to the effective view window (EVW).

[0081] An eyebox, as the area within the viewing window that is actually occupied by the holographic image, can refer to the area containing image information from the SLM 130. When the eyebox is positioned at the user's pupil, the user can observe the holographic image. The processor can form an effective viewing window (EVW) by controlling a light source set including at least two light sources to simultaneously output light; therefore, multiple eyeboxes can be formed within the effective viewing window (EVW). In other words, the user can observe the holographic image at various positions corresponding to the eyeboxes within the effective viewing window (EVW).

[0082] although Figure 5 An example is shown in which nine eyeboxes are included in the effective viewing window (EVW), but the number of eyeboxes in the effective viewing window (EVW) can vary depending on the size of the hologram, the size and brightness of each of the multiple light sources, the distance between adjacent light sources, etc. The distance between at least two light sources included in the light source set can be set such that the holograms displayed in space by each of the at least two light sources do not overlap each other. However, this disclosure is not limited thereto.

[0083] according to Figure 5 In one embodiment, the processor drives the LED array 110 in units of light source sets (each light source set includes at least two light sources), as referenced. Figure 3 As described above, high-speed scanning of viewing windows can be performed on a per-effective viewing window (EVW) basis.

[0084] Figure 6 This is a view of the process of expanding the eye box using a three-dimensional holographic display device according to an embodiment.

[0085] exist Figure 6 In the diagram, light sources displayed as black circles indicate the state of light output, while light sources displayed as white circles indicate the state of no light output. Furthermore, in... Figure 6 At the bottom, the light source displayed as a circle containing a pattern indicates a state where the light output brightness is lower than that of the light source displayed as a black circle. Figure 6 In this context, it is assumed that the distance between the LED array 110 and the lens 120 is the same as the distance between the lens 120 and the observation area, and the size of the observation area is shown as a ratio approximately 1:1 relative to the LED array 110. However, those skilled in the art will readily understand that the size of the viewing window area can be varied according to the ratio of the distance between the LED array 110 and the lens 120 to the distance between the lens 120 and the observation area.

[0086] processor, for example Figure 1 and 2 The processor 140 can drive the LED array 110 in units of light source sets, each light source set including at least two light sources. Furthermore, the processor can adjust the brightness of at least some of the at least two light sources included in a light source set to a brightness different from that of the other light sources. For example, as... Figure 6 As shown, in addition to Figure 5 In addition to the nine controlled light sources shown, the processor can control four more light sources to output additional light. The brightness of these four light sources can be controlled to be lower than the brightness of the nine light sources.

[0087] When the size of the unit light source is too small, as the size of the eyebox formed at the viewing position decreases to less than the size of the user's pupil, the user may have difficulty properly observing the holographic image. In this case, the processor controls additional light sources, such as... Figure 6 Four light sources of medium to medium brightness are used to output light simultaneously, thus expanding the size of the eye box itself. For example, when Figure 6 When the existing eyebox (EYE BOX1) is smaller than the size of the user's pupil, the new eyebox (EYE BOX2) can be increased to be larger than the size of the user's pupil by controlling four additional light sources.

[0088] Furthermore, the holographic image can be calibrated by the processor appropriately adjusting the brightness of each of the multiple light sources. For example, a high-resolution holographic image can be provided to the user when the processor maximizes the brightness of the main light source while appropriately adjusting the brightness of the light sources located around it. Additionally, when it is determined that at least two light sources in the light source set include a defective light source, the processor can adjust the brightness of the light sources surrounding the defective light source to compensate for the defect.

[0089] Figure 7 This is a view of the configuration of the LED array according to an embodiment.

[0090] refer to Figure 7 The LED array 110 may include a first region 710 corresponding to a light source for displaying a holographic image (e.g., a first holographic image) perceived by the user's left eye and a second region 720 corresponding to a light source for displaying a holographic image (e.g., a second holographic image) perceived by the user's right eye. Each of the first region 710 and the second region 720 may be driven based on various operating methods of the 3D holographic display device described above.

[0091] When the LED array 110 and the lens (e.g., Figure 1 When the distance between the lenses 120 is the same as the distance between the lens and the user's viewing position, the distance ES between the first region 710 and the second region 720 can be approximately 65 mm, which is the average interpupillary distance of the user. However, this disclosure is not limited thereto, and the distance ES between the first region 710 and the second region 720 can be appropriately set according to the focal length of the lens, etc. Processor, for example Figure 1 and Figure 2 The processor 140 can assign at least some of the light sources included in the LED array 110 to the first region 710 and assign other light sources to the second region 720, so the distance ES between the first region 710 and the second region 720 can be easily adjusted.

[0092] Return to reference Figure 1 The three-dimensional holographic display device 10 may further include a driving device that moves the LED array 110 in at least one of a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to both the first and second directions, or rotates the LED array 110 about at least one of the first, second, and third directions as an axis. For example, from a viewpoint facing the LED array 110 from the front, the driving device may move the LED array 110 in at least one of the vertical, horizontal, and depth directions, or rotate the LED array 110 about at least one of the vertical, horizontal, and depth directions as an axis.

[0093] As per the above reference Figure 3 As described above, even when the viewing area is expanded by high-speed driving of the LED array 110 and SLM 130, the 3D holographic display device 10 can change the position of the LED array 110 by using the driving device when the user is outside the expanded viewing area. Therefore, the viewing area can be further expanded. For example, fine-tuning of the viewing area can be achieved by controlling the light sources included in the LED array 110, and large-scale tuning can be achieved by controlling the driving device. Furthermore, when the LED array 110 includes a defective light source, the driving device can replace the defective light source with another light source by moving the LED array 110.

[0094] Figure 8 This is a flowchart of a method for operating a three-dimensional holographic display device according to an embodiment.

[0095] refer to Figure 8 The method of operating a three-dimensional holographic display device may include: Figure 1 The operations in the three-dimensional holographic display device 10 are processed in a time sequence. Therefore, it can be seen that the reference... Figures 1 to 7 Although the above description is omitted below, it can be applied to... Figure 8 Methods for operating three-dimensional holographic display devices.

[0096] In operation 810, the three-dimensional holographic display device can generate a holographic signal having depth information adjusted according to the arrangement position of each of a plurality of light sources included in the LED array. The holographic signal may include a CGH.

[0097] In operation 820, the three-dimensional holographic display device can control the light source to output light sequentially according to a preset pattern. In the example, the three-dimensional holographic display device can change the light source of the output light at a period of at least 1 MHz. However, this disclosure is not limited thereto.

[0098] In operation 830, the 3D holographic display device can control the SLM to modulate light based on the holographic signal corresponding to the light source of the current output light in the generated holographic signal. As the position of the light source changes, the position of the viewing window can change, and the viewing angle of the holographic image can change. Therefore, the depth information of the holographic signal is appropriately adjusted so that the user can properly observe the expected holographic image.

[0099] Therefore, when the second light source outputs light after the first light source outputs light according to a preset pattern, the three-dimensional holographic display device can change the holographic image pattern displayed by the SLM at the moment the second light source begins to output light. The changed holographic image pattern can be formed by a holographic signal having depth information adjusted according to the arrangement position of the second light source.

[0100] Figure 8 The operations are not necessarily executed in the order described. For example, operation 810 may be executed before operations 820 and 830, and may be executed substantially simultaneously with operations 820 and 830. Although operations 820 and 830 correspond to operations executed together, the specific start times of the individual operations may not match exactly. Furthermore, operation 810 may be executed only once at the beginning, and only operations 820 and 830 may be repeated. However, this disclosure is not limited to this, and all operations may be executed repeatedly.

[0101] Three-dimensional holographic display devices can remove noise components from light modulated by SLMs. For example, because three-dimensional holographic display devices include an additional noise filter behind the SLM, noise components from the SLM-modulated light can be removed.

[0102] A three-dimensional holographic display device can drive an LED array in units of light source sets, each light source set including at least two light sources. In an example, the distance between the at least two light sources included in a light source set can be set such that holographic images displayed in space by the at least two light sources respectively do not overlap each other. However, this disclosure is not limited thereto.

[0103] In the example, the 3D holographic display device can adjust the brightness of at least some of the light sources in at least two of the light sources in a light source set to a brightness different from that of the other light sources. When the size of a unit light source is too small, the size of the eyebox formed at the viewing position decreases to less than the size of the user's pupil, so the user may have difficulty viewing the holographic image properly. In this case, as the 3D holographic display device maximizes the brightness of the main light source while appropriately adjusting the brightness of the light sources located around the main light source, the size of the eyebox can be expanded.

[0104] Furthermore, when it is determined that at least two light sources included in the light source set include a defective light source, the 3D holographic display device can adjust the brightness of the light sources around the defective light source to compensate for the defect.

[0105] According to an embodiment, the three-dimensional holographic display device can move the LED array in at least one of a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to both the first and second directions, or rotate the LED array about at least one of the first, second, and third directions as an axis.

[0106] The method for operating the three-dimensional holographic display device described above can be recorded on a computer-readable recording medium, on which one or more programs are recorded, the programs including instructions for performing the method. Examples of computer-readable recording media include magnetic media, such as hard disks, floppy disks, and magnetic tapes; optical media, such as optical disc read-only memory (CD-ROM) and digital versatile discs (DVDs); magneto-optical media, such as floppy disks; and hardware devices configured to store and execute program instructions, such as programming modules, such as read-only memory (ROM), random access memory (RAM), and flash memory. Furthermore, the program instructions can include not only machine code created by a compiler, but also high-level programming languages ​​that can be executed by a computer using an interpreter.

[0107] The following description of the embodiments should not be construed as limiting the scope of the claims, and the contents that can be readily inferred by those skilled in the art should be construed as falling within the scope of this specification.

[0108] It should be understood that the embodiments described herein should be considered descriptive only and not for limiting purposes. The description of features or aspects in each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the appended claims and their equivalents.

Claims

1. A three-dimensional holographic display device, comprising: A light-emitting diode (LED) array includes multiple light sources, among which... The plurality of light sources includes a plurality of light source sets, and each of the plurality of light source sets includes at least two light sources from the plurality of light sources; A lens is configured to refract light incident from the LED array; A spatial light modulator (SLM) is configured to modulate light incident from a lens; and The processor is configured as follows: Using a set of light sources as a unit, control the multiple sets of light sources to output light sequentially according to a preset repeating pattern; Multiple holographic signals are generated, each holographic signal including depth information adjusted according to the arrangement position of each of the multiple light source sets in the LED array; and For each of the plurality of light source sets, the SLM is controlled to modulate light based on a holographic signal corresponding to the light source set in the plurality of light source sets. The three-dimensional holographic display device is configured to form holographic images at multiple viewing windows, each of which is located at a position corresponding to one or more light sources in the multiple light source set that sequentially output light according to the preset repeating pattern.

2. The three-dimensional holographic display device according to claim 1, wherein, When the second light source set in the plurality of light sources outputs light after the first light source set in the plurality of light sources outputs light according to the preset repeating pattern, the processor changes the holographic image pattern formed by the first holographic signal among the plurality of holographic signals and displayed by the SLM at the moment when the second light source set begins to output light, and The altered holographic image pattern is formed by a second holographic signal among multiple holographic signals, the second holographic signal including depth information adjusted according to the arrangement position of the second light source set in the LED array.

3. The three-dimensional holographic display device according to claim 1, wherein, The LED array changes the set of light sources for output light at a period of at least 1 MHz.

4. The three-dimensional holographic display device according to claim 1 further includes a filter configured to remove noise components of the light modulated by the SLM.

5. The three-dimensional holographic display device according to claim 1, wherein, For each of the plurality of light source sets, the distance between at least two light sources in the light source set is set such that the holographic images displayed in space by the at least two light sources do not overlap each other.

6. The three-dimensional holographic display device according to claim 1, wherein, For each of the plurality of light source sets, the processor is further configured to adjust the brightness of at least some of the light sources in at least two of the light sources in the light source set to be different from the brightness of the other light sources in the light source set.

7. The three-dimensional holographic display device according to claim 1, wherein, The processor is also configured to adjust the brightness of light sources surrounding the defective light source to compensate for the defect when it is determined that at least two light sources in the light source set of the plurality of light source sets include a defective light source.

8. The three-dimensional holographic display device according to claim 1, wherein, The LED array includes a first region and a second region. The first region includes a light source among the plurality of light sources for displaying a first holographic image perceived by the user's left eye, and the second region includes a light source among the plurality of light sources for displaying a second holographic image perceived by the user's right eye.

9. The three-dimensional holographic display device according to claim 1 further includes a driving device, the driving device being configured to move the LED array in at least one of a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to both the first and second directions, or to rotate the LED array about at least one of the first direction, the second direction, and the third direction as an axis.

10. A method for operating a three-dimensional holographic display device, the method comprising: Multiple holographic signals are generated, each including depth information adjusted according to the arrangement position of each of the multiple light sources in the LED array, wherein... The LED array includes multiple light sources, and the multiple light sources include multiple light source sets, each of the multiple light source sets including at least two of the multiple light sources; Using a set of light sources as a unit, control all light sources in the multiple light source sets to output light sequentially according to a preset repeating pattern; and For each of the plurality of light source sets, the spatial light modulator (SLM) is controlled to modulate the light incident from the LED array based on a holographic signal corresponding to the light source set in the plurality of light source sets. The three-dimensional holographic display device is configured to form holographic images at multiple viewing windows, each of which is located at a position corresponding to one or more light sources in the multiple light source set that output light sequentially according to a preset repeating pattern.

11. The method according to claim 10, further comprising, when the second light source set in the plurality of light sources outputs light after the first light source set in the plurality of light sources outputs light according to the preset repeating pattern, changing the holographic image pattern formed by the first holographic signal among the plurality of holographic signals and displayed by the SLM at the moment when the second light source begins to output light. in, The altered holographic image pattern is formed by a second holographic signal among a plurality of holographic signals, the second holographic signal including depth information adjusted according to the arrangement position of the second light source in the LED array.

12. The method according to claim 10, wherein, Controlling the plurality of light sources includes light sources that change the output light at a period of at least 1 MHz.

13. The method of claim 10, further comprising removing the noise component of the light modulated by the SLM through a filter of the three-dimensional holographic display device.

14. The method of claim 10, wherein, For each of the plurality of light source sets, the distance between the at least two light sources in the light source set is set such that the holographic images displayed in space by the at least two light sources do not overlap each other.

15. The method of claim 10, further comprising, for each of the plurality of light source sets, adjusting the brightness of at least some of the light sources in at least two of the light sources in the light source set to be different from the brightness of the other light sources in the light source set.

16. The method of claim 10, further comprising, when it is determined that at least two light sources in the light source set of the plurality of light source sets include a defective light source, adjusting the brightness of light sources surrounding the defective light source to compensate for the defect.

17. The method of claim 10, further comprising moving the LED array in at least one of a first direction, a second direction perpendicular to the first direction, and a third direction perpendicular to both the first and second directions, or rotating the LED array about at least one of the first direction, the second direction, and the third direction as an axis.

18. A non-transitory computer-readable recording medium having a program thereon for performing the method of claim 10.

19. A holographic display device, comprising: Multiple light sources, comprising multiple sets of light sources, are configured to operate independently of each other, wherein each of the multiple sets of light sources includes at least two of the multiple light sources; A spatial light modulator (SLM) that receives light emitted by the plurality of light sources; and The processor is configured as follows: Using a set of light sources as a unit, turn all light sources in the multiple sets of light sources on and off in a preset repeating sequence; and Multiple signals are sequentially provided to the SLM, each of which corresponds to a different step in the repeating sequence and has depth information regarding the arrangement position adjustment of each of the multiple light sources in the multiple light source sets. The holographic display device is configured to form a holographic image at a plurality of viewing windows, each of the plurality of viewing windows being positioned to correspond to the position of one or more light sources that are turned on during a corresponding step in the repeating sequence.

Images