Holographic display device

Abstract

This application relates to a holographic display device comprising a backlight unit and a spatial light modulator, wherein the backlight unit is used to emit light. The spatial light modulator includes a plurality of pixels and a color filter layer comprising a plurality of color filter groups. The pixels are arranged in a zigzag pattern and configured to modulate at least one of the amplitude and phase of the light. Each of the color filter groups includes a first subgroup, a second subgroup, and a third subgroup, the first subgroup including a plurality of first color filters, the second subgroup including a plurality of second color filters, and the third subgroup including a plurality of third color filters, and each pixel is aligned with one of the first, second, and third color filters of the color filter layer.

Description

[0001] This application is a divisional application of application number 201910216623.5, filed on March 21, 2019, entitled "Holographic Display Device".

[0002] Cross-references to related applications

[0003] This application claims priority and benefit to Korean Patent Applications No. 10-2018-0032794 and No. 10-2018-0032787, filed with the Korean Intellectual Property Office on March 21, 2018, the entire disclosure of which is incorporated herein by reference. Technical Field

[0004] The embodiments of this disclosure relate to holographic display devices. Background Technology

[0005] With increasing user interest in display devices that express (or display) augmented reality images with three-dimensional (3D) features (e.g., display devices capable of realizing (or displaying) 3D images), display devices capable of expressing 3D images have recently been developed.

[0006] The proposed techniques for displaying 3D stereoscopic images using display devices (such as liquid crystal displays) with 2D image display screens include stereoscopic image display methods using special glasses, glasses-free stereoscopic image display methods, and holographic display methods.

[0007] Among 3D image display methods, holographic display has recently attracted much attention. In using holographic display methods, techniques for providing a satisfactory viewing angle to reproduce holographic images have been studied. Furthermore, astigmatic lenses for reproducing color holographic images have been investigated. Summary of the Invention

[0008] Embodiments of this disclosure provide a holographic display device configured to display color holograms while having a simplified configuration.

[0009] According to embodiments of this disclosure, a holographic display device includes a backlight unit and a spatial light modulator, wherein the backlight unit is used to emit light. The spatial light modulator includes a plurality of pixels and a color filter layer including a plurality of color filter groups. The pixels are arranged in a zigzag pattern and configured to modulate at least one of the amplitude and phase of the light. Each of the color filter groups includes a first subgroup, a second subgroup, and a third subgroup, the first subgroup including a plurality of first color filters, the second subgroup including a plurality of second color filters, and the third subgroup including a plurality of third color filters, and each of the pixels is aligned with one of the first, second, and third color filters of the color filter layer.

[0010] The color filter group can be arranged along a first direction and a second direction intersecting the first direction.

[0011] The first color filter can be arranged in multiple rows in the first subgroup, the second color filter can be arranged in multiple rows in the second subgroup, and the third color filter can be arranged in multiple rows in the third subgroup.

[0012] The number of first color filters in the first subgroup, the number of second color filters in the second subgroup, and the number of third color filters in the third subgroup can be the same.

[0013] The columns of the first, second, and third color filters arranged in odd-numbered rows can be located between multiple columns of the first, second, and third color filters arranged in even-numbered rows.

[0014] A pixel can be divided into multiple unit pixels, and each unit pixel can include a first sub-pixel, a second sub-pixel, and a third sub-pixel. The first sub-pixel can include a pixel aligned with a first color filter, the second sub-pixel can include a pixel aligned with a second color filter, and the third sub-pixel can include a pixel aligned with a third color filter.

[0015] The holographic display device can be configured to be selectively driven in a first mode for displaying three-dimensional images or a second mode for displaying two-dimensional images.

[0016] In the second mode, the spatial light modulator can be supplied with a data signal corresponding to the unit pixel.

[0017] Holographic display devices may also include field lenses located on spatial light modulators.

[0018] The field lens may include a plurality of first patterned regions corresponding to a first color filter and allowing light of a first color to pass through therethrough, a plurality of second patterned regions corresponding to a second color filter and allowing light of a second color to pass through therethrough, and a plurality of third patterned regions corresponding to a third color filter and allowing light of a third color to pass through therethrough.

[0019] The field lens may include multiple diffraction pattern groups, and each of the diffraction pattern groups may include a first pattern region among the first pattern regions, a second pattern region among the second pattern regions, and a third pattern region among the third pattern regions.

[0020] When viewed on a plane, the first pattern region and the first subgroup can overlap each other; when viewed on a plane, the second pattern region and the second subgroup can overlap each other; and when viewed on a plane, the third pattern region and the third subgroup can overlap each other.

[0021] The diffraction pattern group can be arranged along a first direction and a second direction intersecting the first direction.

[0022] The grating constant of the diffraction grating located in the first pattern region can be greater than the grating constant of the diffraction grating located in the second pattern region.

[0023] The grating constant of the diffraction grating located in the second pattern region can be greater than the grating constant of the diffraction grating located in the third pattern region.

[0024] The light with the first color can be red light, the light with the second color can be green light, and the light with the third color can be blue light.

[0025] According to another embodiment of this disclosure, a holographic display device includes a backlight unit for emitting light, a spatial light modulator, and a field lens located on the spatial light modulator. The spatial light modulator includes: a plurality of pixels configured to modulate at least one of the amplitude and phase of light; and a plurality of first color filters, a plurality of second color filters, and a plurality of third color filters. The first, second, and third color filters are arranged in a zigzag pattern, and each of the pixels is aligned with one of the first, second, and third color filters. The field lens includes a plurality of first patterned regions corresponding to the first color filters and allowing light of a first color to pass through therethrough, a plurality of second patterned regions corresponding to the second color filters and allowing light of a second color to pass through therethrough, and a plurality of third patterned regions corresponding to the third color filters and allowing light of a third color to pass through therethrough.

[0026] The first, second, and third color filters can be arranged alternately along the first direction.

[0027] The first pattern area, the second pattern area, and the third pattern area can be arranged alternately along the first direction.

[0028] When viewed on a plane, the first pattern area and the first color filter can overlap each other; when viewed on a plane, the second pattern area and the second color filter can overlap each other; and when viewed on a plane, the third pattern area and the third color filter can overlap each other. Attached Figure Description

[0029] In the following description, exemplary embodiments of the present disclosure will be described more fully with reference to the accompanying drawings; however, the present disclosure may be implemented in various forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0030] In the accompanying drawings, dimensions may be exaggerated for clarity, and the same reference numerals denote the same elements throughout.

[0031] Figure 1This is a schematic diagram illustrating the configuration of a holographic display device according to an embodiment of the present disclosure.

[0032] Figure 2 yes Figure 1 The diagram shows the configuration of the display panel.

[0033] Figure 3 It is shown Figure 2 The block diagram shown illustrates the configuration of the spatial light modulator.

[0034] Figure 4 This is a diagram illustrating the relationship between pixel spacing and the viewing area.

[0035] Figure 5 This is a plan view showing a color filter layer according to an embodiment of the present disclosure.

[0036] Figure 6 It shows the arrangement in Figure 5 A plan view of the color filters in the color filter group shown.

[0037] Figure 7A This is a plan view showing the pixel structure of a holographic display device according to a comparative example.

[0038] Figure 7B This is a plan view showing the pixel structure of a holographic display device according to an embodiment of the present disclosure.

[0039] Figure 8 These are illustrations of the observation area in a holographic display device according to a comparative example and the observation area in a holographic display device according to an embodiment of the present disclosure.

[0040] Figure 9 This is an illustration of a unit pixel according to an embodiment of the present disclosure.

[0041] Figure 10 This is a view showing the focal length of light transmitted through a field lens according to a comparative example.

[0042] Figure 11 This is a plan view showing a field lens according to an embodiment of the present disclosure.

[0043] Figure 12 It is shown Figure 11 The diagram shows a plan view of the diffraction pattern group.

[0044] Figure 13 It is along Figure 12 A sectional view taken by line I-I'.

[0045] Figure 14 It is shown that... Figure 7A The pixel structure shown is a planar view of the color filter layer.

[0046] Figure 15 This is a plan view showing a field lens according to another embodiment of the present disclosure. Detailed Implementation

[0047] Aspects and features of this disclosure, as well as methods of implementing them, will become apparent from the exemplary embodiments described below in conjunction with the accompanying drawings. However, this disclosure is not limited to these exemplary embodiments, but may be implemented in various forms. These embodiments are provided for illustrative purposes and to enable those skilled in the art to fully understand the scope of this disclosure.

[0048] It should be understood that when an element or layer is referred to as being on, connected to, or coupled to another element or layer, it may be directly on, connected to, or coupled to the other element or layer, or there may be one or more intermediate elements or layers. When an element or layer is referred to as being directly on, directly connected to, or directly coupled to another element or layer, there are no intermediate elements or layers. For example, when a first element is described as being coupled to or connected to a second element, the first element may be directly coupled to or connected to the second element, or the first element may be indirectly coupled to or connected to the second element via one or more intermediate elements. It should be understood that when an element is referred to as being between two elements, it may be the only element between the two elements, or there may be one or more intermediate elements.

[0049] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Furthermore, when describing embodiments of the invention, the use of “may” refers to “one or more embodiments of the invention.” Expressions such as “at least one of” modify the entire list of elements when placed after the list of elements, but not individual elements within the list. As used herein, the terms “use,” “using,” and “used” are considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. As used herein, the terms “approximately,” “about,” and other similar terms are used as approximate terms rather than as terms of degree, and are intended to allow for inherent deviations in measurements or calculations that will be apparent to those skilled in the art.

[0050] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, first component, first region, first layer, or first segment discussed below may be referred to as a second element, second component, second region, second layer, or second segment.

[0051] For ease of description, this document uses spatial relative terms such as “below,” “under,” “lower,” “above,” and “upper” to describe the relationship between one element or feature as shown in the accompanying drawings and another element or feature. It should be understood that, in addition to the orientations depicted in the drawings, the spatial relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the drawings is flipped, the element described as “below” or “under” other elements or features will then be oriented “above” or “on” said other elements or features. Therefore, the term “below” can encompass both upper and lower orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein should be interpreted accordingly.

[0052] The terminology used herein is for the purpose of describing specific exemplary embodiments of the invention and is not intended to limit the exemplary embodiments of the invention described. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the terms “includes,” “including,” “comprises,” and “comprising,” when used in this specification, indicate the presence of the set forth features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0053] In the following description, a spatial light modulator and a holographic display device including a spatial light modulator will be described with reference to exemplary embodiments and in conjunction with the accompanying drawings.

[0054] Figure 1 This is a schematic diagram illustrating the configuration of a holographic display device according to an embodiment of the present disclosure.

[0055] Reference Figure 1 The holographic display device according to embodiments of the present disclosure may include a display panel DP and a field lens FL.

[0056] The display panel (DP) may include a light source for displaying images, multiple pixels, and a display driver for driving the pixels. The following will refer to... Figure 2 and Figure 3 Provides further details describing the functions, structure, etc. of the display panel (DP).

[0057] The field lens (FL) can adjust the optical path of light emitted from the display panel (DP) by diffracting the light emitted from the display panel (DP). The light passing through the field lens (FL) can be displayed as a holographic image (IM) in front of the field lens (FL).

[0058] A holographic display device according to embodiments of the present disclosure can display planar images (e.g., two-dimensional (2D) images) and holographic images (IM). For example, the holographic display device can be driven in a first mode for displaying three-dimensional holographic images or in a second mode for displaying two-dimensional planar images.

[0059] The holographic display device can be driven in a first mode or a second mode according to user settings (e.g., the holographic display device can be selectively driven in a first mode or a second mode). In some embodiments, the holographic display device can be driven in a first mode or a second mode according to control signals or data signals (e.g., predetermined control signals or data signals) input from an external source (e.g., from an external device).

[0060] Figure 2 yes Figure 1 The diagram shows the configuration of the display panel.

[0061] Reference Figure 2 The display panel DP may include a backlight unit 10 and a spatial light modulator (SLM) 20.

[0062] The backlight unit 10 can generate and emit light. The backlight unit 10 may include a laser source and can emit laser light. In other embodiments, the backlight unit 10 may include a light-emitting diode (LED) light source.

[0063] The spatial light modulator 20 may include a plurality of pixels for modulating at least one of the amplitude and phase of light passing through the spatial light modulator 20.

[0064] For example, each of the plurality of pixels may include a pixel electrode, a counter electrode, and a liquid crystal layer interposed between the pixel electrode and the counter electrode. The arrangement of the liquid crystals included in the liquid crystal layer may be changed according to an electric field formed between the pixel electrode and the counter electrode, and at least one of the amplitude and phase of the light passing through the liquid crystal layer may be modulated according to the arrangement of the liquid crystals.

[0065] Each of the plurality of pixels includes a color filter for determining the light passing through the liquid crystal layer. For example, the spatial light modulator 20 may include a color filter layer provided with a plurality of color filters, and the plurality of color filters may be aligned with a plurality of pixels.

[0066] Figure 3 It is shown Figure 2 The block diagram shown illustrates the configuration of the spatial light modulator.

[0067] Reference Figure 3 The spatial light modulator 20 may include multiple data lines DL1 to DLm, multiple gate lines GL1 to GLn, and multiple pixels PX. The multiple pixels PX may be arranged in a Z-shape.

[0068] Each of the multiple data lines DL1 to DLm may extend in the second direction DR2, and each of the multiple gate lines GL1 to GLn may extend in the first direction DR1 that intersects (e.g., is perpendicular to) the second direction DR2.

[0069] The spatial light modulator 20 may include a timing controller TC, a data driver DD, and a gate driver GD that jointly drive multiple pixels PX.

[0070] The timing controller TC can receive multiple control signals CS and data signals DATA from outside the holographic display device. The data signal DATA may include data signals corresponding to two-dimensional planar images or data signals corresponding to three-dimensional holographic images.

[0071] The timing controller TC can convert the data signal DATA into a specification suitable for the data driver DD, and can output the converted data signal DATA′ to the data driver DD.

[0072] The timing controller TC can generate a gate control signal GCS and a data control signal DCS in response to an externally provided control signal CS.

[0073] The gate control signal GCS can be a control signal used to control the operating timing of the gate driver GD. The timing controller TC can output the gate control signal GCS to the gate driver GD.

[0074] The data control signal DCS can be a control signal used to control the operating timing of the data driver DD. The timing controller TC can output the data control signal DCS to the data driver DD.

[0075] The gate driver GD outputs a gate signal in response to the gate control signal GCS. Gate lines GL1 to GLn receive the gate signal from the gate driver GD. The gate signal is then provided to the pixel PX via the gate lines GL1 to GLn.

[0076] The data driver DD can generate a data voltage. For example, the data driver DD can convert the converted data signal DATA′ into a data voltage in response to the data control signal DCS, and can output the data voltage to the pixel PX.

[0077] Figure 4 The relationship between pixel spacing and the viewing area is shown.

[0078] Pixel pitch PP can represent the distance between pixels PX (e.g., the distance between two adjacent pixels PX). In this specification, pixel pitch PP can also represent the distance between color filters with the same color (e.g., between two adjacent color filters with the same color).

[0079] like Figure 4 As shown, the width of the observation area VZ is measured at a distance of 500 mm from the spatial light modulator 20, and the width of the observation area VZ for different pixel pitches PP is shown in Table 1.

[0080] In this specification, the observation area VZ can represent the region where an observer can observe (e.g., comfortably observe) a stereoscopic image. An observer can comfortably observe a stereoscopic image when the width of the observation area VZ is equal to, approximately equal to, or greater than the distance between the observer's eyes ER and EL.

[0081] Table 1

[0082] Pixel pitch PP (μm) Width of the observation area VZ (mm) 50 5 40 7 30 9 20 13 15 18 11.3 24 3.76 71

[0083] Referring to Table 1, it can be seen that the width of the observation area VZ increases as the pixel pitch PP decreases. For example, as the pixel pitch PP decreases, even if the distance between the holographic display device and the user is relatively small, the user can still observe a high-quality holographic image.

[0084] Typically, the average distance between human pupils is about 65 mm. Therefore, the width of the observation area VZ should be about 65 mm or greater, so that a person can comfortably observe the holographic image at a distance of about 500 mm from the holographic display device. Therefore, the holographic display device should have a pixel pitch PP of less than or equal to about 3.76 μm.

[0085] Hereinafter, a method for arranging color filters according to embodiments of the present disclosure will be described, wherein the method provides a relatively narrow pixel pitch PP.

[0086] Figure 5 This is a plan view showing a color filter layer according to an embodiment of the present disclosure, and Figure 6 It shows the arrangement in Figure 5 A plan view of the color filters in the color filter group shown.

[0087] Reference Figure 5 The color filter layer CFL may include multiple color filter groups CFG.

[0088] Multiple color filter groups (CFGs) can be arranged along the first direction DR1 and the second direction DR2.

[0089] Although Figure 5 A plurality of color filter groups CFG are shown arranged along a first direction DR1, but this disclosure is not limited thereto. In other embodiments, the number of color filter groups CFG arranged along the first direction DR1 can be varied.

[0090] Reference Figure 6 Each of the multiple color filter groups (CFGs) may include a first subgroup (CFA1), a second subgroup (CFA2), and a third subgroup (CFA3). The first subgroup (CFA1), the second subgroup (CFA2), and the third subgroup (CFA3) may be arranged along a second direction (DR2) (e.g., they may be adjacent to each other in the second direction (DR2)).

[0091] The first subgroup CFA1 may include a first color filter R. The first color filter R may be arranged along a first direction DR1 (e.g., adjacent to each other in the first direction DR1). Multiple rows, each including a first color filter R, may extend along the first direction DR1. The multiple rows may be arranged along a second direction DR2 (e.g., adjacent to each other in the second direction DR2). For example, the first color filter R may be arranged in a zigzag pattern.

[0092] The second subgroup CFA2 may include a second color filter G. The second color filter G may be arranged along a first direction DR1 (e.g., adjacent to each other in the first direction DR1). Multiple rows, each including a second color filter G, may extend along the first direction DR1. Multiple rows may be arranged along a second direction DR2 (e.g., adjacent to each other in the second direction DR2). For example, the second color filter G may be arranged in a zigzag pattern.

[0093] The third subgroup CFA3 may include a third color filter B. The third color filter B may be arranged along a first direction DR1 (e.g., adjacent to each other in the first direction DR1). Multiple rows, each including a third color filter B, may extend along the first direction DR1. Multiple rows may be arranged along a second direction DR2 (e.g., adjacent to each other in the second direction DR2). For example, the third color filter B may be arranged in a zigzag pattern.

[0094] Reference Figure 6 The number of first color filters R included in the first subgroup CFA1, the number of second color filters G included in the second subgroup CFA2, and the number of third color filters B included in the third subgroup CFA3 can be the same.

[0095] Furthermore, the columns of color filters arranged in even-numbered rows can be located between the columns of color filters arranged in corresponding odd-numbered rows.

[0096] For example, the columns of the first color filter R arranged in the first row, the second color filter G arranged in the third row, and the third color filter B arranged in the fifth row can be positioned sequentially (e.g., they can be arranged alternately).

[0097] Although Figure 6 The illustration shows an embodiment in which the first subgroup CFA1 is positioned to one side (e.g., above) of the second subgroup CFA2 and the third subgroup CFA3 is positioned to the other side (e.g., below) of the second subgroup CFA2, but this disclosure is not limited thereto. For example, in other embodiments, the arrangement order of the first subgroup CFA1, the second subgroup CFA2, and the third subgroup CFA3 may be varied.

[0098] Figure 7A This is a plan view showing the pixel structure of a holographic display device according to a comparative example, and Figure 7B This is a plan view showing the pixel structure of a holographic display device according to an embodiment of the present disclosure. Figure 8 Show Figure 7A The observation area and, according to the comparative example, the holographic display device shown in the figure. Figure 7B The image shows the observation area in a holographic display device according to an embodiment of the present disclosure.

[0099] exist Figure 7A and Figure 7B In the comparative example, the components of the holographic display device are the same as those of the holographic display device according to the embodiments of the present disclosure, but the color filters are arranged differently.

[0100] like Figure 7A As shown, in the holographic display device according to the comparative example, a sub-pixel PR for emitting light of a first color (e.g., red), a sub-pixel PG for emitting light of a second color (e.g., green), and a sub-pixel PB for emitting light of a third color (e.g., blue) together constitute a pixel. Sub-pixels PR, PG, and PB are arranged side by side (e.g., adjacent to each other) along a first direction DR1.

[0101] When displaying a color holographic image, the horizontal distance (e.g., pixel pitch PP) between subpixels that emit light of the same color determines the horizontal viewing angle.

[0102] In having Figure 7AIn the pixel arrangement structure shown in the comparative example of the holographic display device, the horizontal distance between the sub-pixels PR that emit light of a first color and are positioned closest to each other in the horizontal direction can be approximately 11.28 μm. Figure 8 As shown in (a), at a distance with Figure 7A The width of the observation area VZ at a point of 500 mm for the spatial light modulator 20 of the pixel arrangement structure shown can be approximately 24 mm, and at a distance of... Figure 7A The width of the observation area VZ at a point of 700 mm for the spatial light modulator 20 of the pixel arrangement structure shown can be approximately 35 mm, and at a distance of... Figure 7A The spatial light modulator 20 of the pixel arrangement structure shown can have an observation area VZ width of approximately 47 mm at a point of 1000 mm. In other words, when the distance between the observer's eyes ER and EL is approximately 65 mm, even at a distance of... Figure 7A Even at an observation distance of approximately 1 m, the spatial light modulator 20 with the pixel arrangement structure shown may have difficulty observing a stereoscopic image.

[0103] In having such Figure 7B In the holographic display device with the pixel arrangement structure shown, the horizontal distance between the sub-pixels PG that emit light of the same color and are positioned closest to each other in the horizontal direction can be approximately 3.76 μm. This distance is greater than that in... Figure 7A The small one in the holographic display device shown. For example... Figure 8 As shown in (b), at a distance with Figure 7B The width of the observation area VZ at a point of 500mm for the spatial light modulator 20 of the pixel arrangement structure shown in the figure can be approximately 71mm, at a distance of... Figure 7B The spatial light modulator 20 of the pixel arrangement structure shown can have an observation area VZ of approximately 106 mm at a point of 700 mm, and at a distance of... Figure 7B The width of the observation area VZ at a point of 1000 mm for the spatial light modulator 20 with the pixel arrangement structure shown can be approximately 142 mm. In other words, when the distance between the observer's eyes ER and EL is approximately 65 mm, the observer can fully (or comfortably) observe the stereoscopic image even at an observation distance of approximately 500 mm from the spatial light modulator 20 with the pixel arrangement structure according to an embodiment of the present disclosure.

[0104] When the width of the observation area VZ (i.e., the area in which the observer of the holographic display device can observe the stereoscopic image) is equal to or approximately equal to or greater than the distance between the observer's eyes ER and EL, the observer can comfortably observe the stereoscopic image.

[0105] When displaying a color holographic image, the horizontal distance between pixels that emit light of the same color determines the horizontal viewing angle, and the width of the viewing area VZ can increase as the horizontal viewing angle increases.

[0106] When pixels emitting light of the same color are arranged side by side along the first direction DR1, the horizontal distance between pixels emitting light of the same color can be reduced compared to an example where pixels emitting light of different colors are arranged side by side along the first direction DR1.

[0107] Figure 9 This is a view of a unit pixel according to an embodiment of the present disclosure.

[0108] As described above, the holographic display device according to embodiments of the present disclosure can be driven in a first mode for displaying three-dimensional holographic images and / or a second mode for displaying two-dimensional planar images.

[0109] When the holographic display device is driven in the second mode, the timing controller TC of the spatial light modulator 20 can provide the data driver DD with a data signal corresponding to the two-dimensional image.

[0110] The data signal corresponding to a two-dimensional image may include data signals corresponding to multiple unit pixels (e.g., RGB stripe data signals).

[0111] Reference Figure 9 Multiple pixels PX can be divided into multiple unit pixels UPX to emit light by being supplied with data signals corresponding to a two-dimensional image.

[0112] Each unit pixel UPX may be configured with (for example, may include) a first sub-pixel SPX1 that emits light of a first color, a second sub-pixel SPX2 that emits light of a second color, and a third sub-pixel SPX3 that emits light of a third color.

[0113] The first sub-pixel SPX1 may include a plurality of pixels PX containing a first color filter R, the second sub-pixel SPX2 may include a plurality of pixels PX containing a second color filter G, and the third sub-pixel SPX3 may include a plurality of pixels PX containing a third color filter B. The plurality of pixels PX may constitute each of sub-pixels SPX1, SPX2, and SPX3.

[0114] When multiple pixel PXs are configured to have a resolution of 2250 ppi (pixels per inch) and at such a... Figure 7B When the distances shown are arranged adjacent to each other, and when each of the first to third sub-pixels SPX1, SPX2, and SPX3 comprises nine pixels PX, the unit pixel UPX can have a size of approximately 33.84 μm and a resolution of approximately 750 ppi. Therefore, a high-resolution two-dimensional image can be represented in the second mode.

[0115] Although the number of pixels PX including the first color filter R in the first sub-pixel SPX1, the number of pixels PX including the second color filter G in the second sub-pixel SPX2, and the number of pixels PX including the third color filter B in the third sub-pixel SPX3 are... Figure 9 The same is shown in the figure, but this disclosure is not limited thereto.

[0116] In the following text, reference will be made to Figures 10 to 15 The field lens FLC according to the comparative example and the field lenses FL and FL′ according to embodiments of the present disclosure are described in detail.

[0117] Figure 10 The focal length of light transmitted through the field lens according to the comparative example is shown.

[0118] exist Figure 10 In the example, the first focal point (e.g., the first focal point or the first focal length) FLR is the focal point of light of the first color passing through the field lens FLC according to the comparative example, the second focal point (e.g., the second focal point or the second focal length) FLG is the focal point of light of the second color passing through the field lens FLC according to the comparative example, and the third focal point (e.g., the third focal point or the third focal length) FLB is the focal point of light of the third color passing through the field lens FLC according to the comparative example.

[0119] The first color can be red, the second color can be green, and the third color can be blue.

[0120] Reference Figure 10 The focal points of light having the first to third colors can be different from each other. For example, the first focal point FLR can be located at a point approximately 1110 mm from the field lens FLC, the second focal point FLG can be located at a point approximately 1050 mm from the field lens FLC, and the third focal point FLB can be located at a point approximately 930 mm from the field lens FLC.

[0121] To display a high-resolution color holographic image, the light having the first to third colors should be focused at the same or substantially the same point (e.g., at the same or substantially the same distance from the holographic display device). Therefore, it is desirable to have a field lens that focuses the light having the first to third colors to the same or substantially the same point.

[0122] Figure 11 This is a plan view of a field lens according to an embodiment of the present disclosure, and Figure 12 yes Figure 11 The diagram shows a plan view of the diffraction pattern group.

[0123] Reference Figure 11According to embodiments of the present disclosure, the field lens FL may include a plurality of diffraction pattern groups DPG.

[0124] Multiple diffraction pattern groups DPG can be arranged side by side along the first direction DR1 and the second direction DR2.

[0125] Reference Figure 12 Each of the multiple diffraction pattern groups DPG may include a first pattern region FLA1, a second pattern region FLA2, and a third pattern region FLA3. The first pattern region FLA1, the second pattern region FLA2, and the third pattern region FLA3 may be arranged along the second direction DR2 (e.g., they may be adjacent to each other).

[0126] The first pattern region FLA1 can correspond to the first subgroup CFA1. Therefore, light of the first color can pass through the first pattern region FLA1. Therefore, when viewed on a plane, the first subgroup CFA1 and the first pattern region FLA1 can overlap each other.

[0127] The second patterned region FLA2 corresponds to the second subgroup CFA2. Therefore, light of the second color can pass through the second patterned region FLA2. Thus, when viewed on a plane, the second subgroup CFA2 and the second patterned region FLA2 can overlap each other.

[0128] The third pattern region FLA3 corresponds to the third subgroup CFA3. Therefore, light of the third color can pass through the third pattern region FLA3. Thus, when viewed on a plane, the third subgroup CFA3 and the third pattern region FLA3 can overlap each other.

[0129] Figure 13 It is along Figure 12 The sectional view taken from line II′.

[0130] Reference Figure 13 A diffraction grating pattern can be formed in a field lens (FL). For example, the diffraction grating pattern can have multiple sawtooth patterns formed at a certain distance from each other.

[0131] Although Figure 13 The diffraction grating pattern shown is only an example of the diffraction grating pattern located in the first pattern region FLA1, but serrated diffraction grating patterns can also be formed in the second pattern region FLA2 and the third pattern region FLA3.

[0132] To compensate for color difference, the grating constants d (e.g., the distance between adjacent grating patterns in a sawtooth grating pattern) of the diffraction grating patterns located in the first pattern region to the third pattern regions FLA1, FLA2 and FLA3 can be different from each other.

[0133] For example, the grating constant d of the diffraction grating pattern located in the first pattern region FLA1 can be greater than the grating constant d of the diffraction grating pattern located in the second pattern region FLA2, and the grating constant d of the diffraction grating pattern located in the second pattern region FLA2 can be greater than the grating constant d of the diffraction grating pattern located in the third pattern region FLA3.

[0134] The holographic display device according to the comparative example typically includes a microlens. The microlens refracts light and includes a curved surface different from that of the field lens FL according to embodiments of the present disclosure. When using a microlens, a separate process is required to form a planarization layer covering the curved surface. However, when using the field lens FL according to embodiments of the present disclosure, the separate planarization process can be omitted.

[0135] Furthermore, when using microlenses, the distance between the focal points of each pixel needs to be taken into account when the microlenses are arranged on each pixel. For example, a compensation value corresponding to the distance between the focal point and the pixel is calculated, and the microlenses are arranged such that the difference between the distance between the center of the microlens and the center of the pixel corresponds to the compensation value. However, when using a field lens FL according to an embodiment of this disclosure, it is not necessary to consider the distance between the focal points of each pixel.

[0136] Furthermore, when using microlenses, multiple processes are performed, such as designing microlenses corresponding to each color, calculating the aforementioned compensation values, manufacturing imprints or molds for arranging the microlenses based on the compensation values, and arranging the microlenses manufactured using the imprints or molds onto the pixels. However, when using a field lens FL according to an embodiment of this disclosure, the processes of calculating compensation values ​​and / or manufacturing separate imprints or molds for the microlenses can be omitted. Furthermore, the field lens FL according to an embodiment of this disclosure can be manufactured to have dimensions equal to the dimensions of the panel on which the pixels are formed. Therefore, the field lens FL is easier to arrange than arranging microlenses on each pixel.

[0137] Furthermore, the fill factor of the field lens (FL) can be greater than that of the microlens.

[0138] Furthermore, field lenses (FLs) can be relatively thinner compared to microlenses. For example, while microlenses are manufactured in bulk with a thickness of about 3 μm to about 10 μm, field lenses (FLs) are manufactured with a thickness of about 1 μm.

[0139] Figure 14 Is with Figure 7A The diagram shows a planar view of the color filter layer corresponding to the pixel structure. The main description will focus on... Figure 14 The color filter layer CFL′ shown in the figure is compared with the reference. Figure 6 The described implementation methods differ in aspects, components, and configurations, and references may be omitted. Figure 6The description of aspects, components, and configurations of the described implementations overlaps (e.g., is the same or substantially similar). The arrangement of the color filters will be described primarily below.

[0140] Reference Figure 14 The color filter layer CFL′ may include a first color filter R, a second color filter G, and a third color filter B.

[0141] The first color filter R, the third color filter B, and the second color filter G may be arranged successively and repeatedly along the first direction DR1. A column including one of the color filters R, G, and B arranged along the first direction DR1 (e.g., adjacent to each other in the first direction DR1) may extend along the second direction DR2.

[0142] Although Figure 14 The first color filter R, the third color filter B, and the second color filter G are arranged sequentially along the first direction DR1, but this disclosure is not limited thereto. The arrangement order of the first color filter R, the second color filter G, and the third color filter B can be changed in various appropriate ways.

[0143] Figure 15 This is a plan view of a field lens according to another embodiment of this disclosure. The main description will focus on... Figure 15 The field lens FL′ shown here differs from the embodiments described above in terms of aspects, components, and configurations, and descriptions of aspects, components, and configurations that overlap with those of the embodiments described above may be omitted. The arrangement structure of the patterned regions will be described primarily below.

[0144] Reference Figure 15 According to another embodiment of the present disclosure, the field lens FL′ may include a first patterned region FLA1, a second patterned region FLA2, and a third patterned region FLA3.

[0145] The first pattern area FLA1, the third pattern area FLA3, and the second pattern area FLA2 can be arranged successively and repeatedly along the first direction DR1 to correspond to Figure 14 The color filter layer CFL′ shown. Rows of patterned regions FLA1, FLA2 and FLA3 extending along the first direction DR1 may be arranged along the second direction DR2 (e.g., adjacent to each other in the second direction DR2).

[0146] The first pattern region FLA1 can correspond to the first color filter R. Therefore, light of the first color can pass through the first pattern region FLA1. Therefore, when viewed on a plane, the first color filter R and the first pattern region FLA1 can overlap each other.

[0147] The second patterned region FLA2 corresponds to the second color filter G. Therefore, light of the second color can pass through the second patterned region FLA2. Thus, when viewed on a plane, the second color filter G and the second patterned region FLA2 can overlap each other.

[0148] The third pattern region FLA3 corresponds to the third color filter B. Therefore, light of the third color can pass through the third pattern region FLA3. Thus, when viewed on a plane, the third color filter B and the third pattern region FLA3 can overlap each other.

[0149] According to embodiments of this disclosure, the holographic display device for realizing color holograms has a simplified configuration.

[0150] Furthermore, according to embodiments of this disclosure, the viewing angle of the holographic display device is improved.

[0151] Furthermore, according to embodiments of this disclosure, an astigmatic field lens suitable for holographic display devices is provided.

[0152] Exemplary embodiments of this disclosure have been disclosed herein, and while specific terminology has been used, it is used and interpreted in a general and descriptive sense only and is not intended to be limiting. In some examples, as will be apparent to those skilled in the art at the time of filing of this application, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made to the embodiments described herein without departing from the spirit and scope of this disclosure as set forth in the appended claims and their equivalents.

Claims

1. A holographic display device, including: The backlight unit is used to emit light; Spatial light modulator, including: Multiple pixels, configured to modulate at least one of the amplitude and phase of the light; and A plurality of first color filters, a plurality of second color filters, and a plurality of third color filters are arranged in a plurality of rows extending along one of a first direction and a second direction, the first direction intersecting the second direction. The plurality of rows are adjacent to each other in the other of the first and second directions. A row in the plurality of rows is offset from the preceding row such that the first, second, and third color filters are arranged in a zigzag pattern. Each of the plurality of pixels is aligned with one of the first, second, and third color filters. A field lens, located on the spatial light modulator, includes a plurality of first pattern regions corresponding to the first color filter and allowing light of a first color to pass through, a plurality of second pattern regions corresponding to the second color filter and allowing light of a second color to pass through, and a plurality of third pattern regions corresponding to the third color filter and allowing light of a third color to pass through.

2. The holographic display device as described in claim 1, wherein, The first color filter, the second color filter, and the third color filter are arranged alternately along a first direction.

3. The holographic display device as described in claim 2, wherein, The first pattern area, the second pattern area, and the third pattern area are arranged alternately along the first direction.

4. The holographic display device as described in claim 3, in, When viewed on a flat surface, the first patterned area and the first color filter overlap each other. When viewed on the plane, the second pattern area and the second color filter overlap each other, and When viewed on the plane, the third pattern area and the third color filter overlap each other.

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