Display device

Abstract

A display device is disclosed, the display device comprising a display panel and a lens array, wherein the display panel has a central portion and a peripheral portion surrounding the central portion, the display panel comprising a plurality of pixels, the lens array being located on the display panel, wherein: the lens array comprises first lenses located on the central portion and second lenses located on the peripheral portion; a first focal length of the first lenses is less than a second focal length of the second lenses; and each of the first lenses and the second lenses overlaps at least two pixels among the plurality of pixels.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2010-0000413, filed on January 2, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Some exemplary embodiments disclosed herein relate to display devices and head-mounted display devices with improved display quality, as well as methods for manufacturing head-mounted display modules. Background Technology

[0004] Head-mounted displays are devices worn on a user's head and can be used to achieve augmented reality (AR) or virtual reality (VR). AR head-mounted displays provide virtual graphics through a semi-transparent screen. In this case, the user can simultaneously view virtual graphics and real objects. VR head-mounted displays show virtual graphics visible to the user. Users experience VR through the virtual content displayed by the device.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the background art, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0006] Some exemplary embodiments of this disclosure include display devices and head-mounted display devices with improved display quality, as well as methods for manufacturing head-mounted display modules.

[0007] According to some exemplary embodiments of the present invention, a display device includes a display panel and a lens array. The display panel has a central portion and a peripheral portion surrounding the central portion. The display panel includes a plurality of pixels. The lens array is located on the display panel, wherein the lens array includes a first lens located on the central portion and a second lens located on the peripheral portion; a first focal length of the first lens is less than a second focal length of the second lens; each of the first lens and the second lens overlaps with at least two pixels among the plurality of pixels.

[0008] According to some exemplary embodiments, the display device may also include a main body portion that houses the display panel and the lens array, wherein two opening portions may be located in a region of the main body portion facing the lens array.

[0009] According to some exemplary embodiments, the curvature of the first lens may be greater than the curvature of the second lens.

[0010] According to some example embodiments, a refractive index of the first lens and a refractive index of the second lens can be identical to each other.

[0011] According to some example embodiments, a thickness of the first lens can be greater than a thickness of the second lens.

[0012] According to some example embodiments, the display apparatus can further include a first electrode under the first lens and the second lens, and a second electrode on the first lens and the second lens, wherein each of the first lens and the second lens can include an active compound and liquid crystal molecules.

[0013] According to some example embodiments, a fixed area in which an orientation direction of the liquid crystal molecules is fixed by the active compound can be defined in the lens array, the fixed area can include a first fixed area included in the first lens and a second fixed area included in the second lens, and an area of the first fixed area and an area of the second fixed area can be different from each other.

[0014] According to some example embodiments, the area of the first fixed area can be smaller than the area of the second fixed area.

[0015] According to some example embodiments, a thickness of the first lens and a thickness of the second lens can be identical to each other.

[0016] According to some example embodiments, in a plan view, the first lens can overlap five pixels among the plurality of pixels.

[0017] According to some example embodiments, the five pixels can include a central pixel located at a center and four peripheral pixels surrounding the central pixel.

[0018] According to some example embodiments, in a plan view, a center of the first lens can overlap the central pixel.

[0019] According to some example embodiments, the central pixel can be a green pixel, two peripheral pixels among the four peripheral pixels can be red pixels, and the remaining two peripheral pixels can be blue pixels.

[0020] According to some example embodiments, the central pixel can be a red pixel or a blue pixel, and the four peripheral pixels can be green pixels.

[0021] According to some example embodiments of the inventive concept, in a method for manufacturing a head-mounted display module, the method includes: forming a display panel having a central portion and a peripheral portion surrounding the central portion, the display panel including a plurality of pixels; forming a lens array including first lenses and second lenses, the first lenses and the second lenses having different shapes from each other, wherein the first lenses are formed on the central portion, the second lenses are formed on the peripheral portion, and each of the first lenses and the second lenses overlaps at least two pixels among the plurality of pixels in a plan view.

[0022] According to some example embodiments, forming the lens array can include: forming a photoresist layer on the display panel; placing a mask on the photoresist layer; and patterning the photoresist layer to form the first lenses and the second lenses.

[0023] According to some example embodiments, the mask can define a central opening pattern overlapping the central portion in a plan view and a peripheral opening pattern overlapping the peripheral portion in the plan view, and a size of the central opening pattern and a size of the peripheral opening pattern can be different from each other.

[0024] According to some example embodiments, forming the lens array can include: forming a primary layer on the display panel, the primary layer having a reactive compound and liquid crystal molecules mixed therein; placing a mask on the primary layer; and forming a fixed region in which an orientation direction of the liquid crystal molecules is fixed, wherein the fixed region can include a first fixed region corresponding to the first lenses and a second fixed region corresponding to the second lenses, and an area of the first fixed region can be smaller than an area of the second fixed region.

[0025] According to some example embodiments, a focal length of the first lenses with respect to light incident in a first direction can be smaller than a focal length of the second lenses with respect to the light incident in the first direction.

[0026] According to some example embodiments of the inventive concept, a head-mounted display device includes a display panel having a central portion and a peripheral portion surrounding the central portion, the display panel including a plurality of pixels, and a lens array on the display panel, wherein the lens array includes first lenses on the central portion and second lenses on the peripheral portion, a first focal length of the first lenses is smaller than a second focal length of the second lenses, and each of the first lenses and the second lenses overlaps at least two pixels among the plurality of pixels. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of this specification, illustrate aspects of some example embodiments of the inventive concept and together with the description serve to explain aspects of the inventive concept. In the drawings:

[0028] Figure 1 is a perspective view of a display device according to some example embodiments of the inventive concept;

[0029] Figure 2 is a perspective view of a display device according to some example embodiments of the inventive concept;

[0030] Figure 3 is an exploded perspective view of a portion of a display device according to some example embodiments of the inventive concept;

[0031] Figure 4 is a schematic cross-sectional view of a display device according to some example embodiments of the inventive concept;

[0032] Figure 5 is a cross-sectional view of a display module according to some example embodiments of the inventive concept;

[0033] Figure 6 is Figure 3 is a magnified cross-sectional view of the area AA’ shown in

[0034] Figure 7A is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept;

[0035] Figure 7B is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept;

[0036] Figure 8A is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept;

[0037] Figure 8B is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept;

[0038] Figure 9A is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept;

[0039] Figure 9B is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept;

[0040] Figures 10A to 10D is a cross-sectional view illustrating a method for manufacturing a display module according to some example embodiments of the inventive concept; and

[0041] Figures 11A to 11D is a cross-sectional view illustrating a method for manufacturing a display module according to some example embodiments of the inventive concept. DETAILED DESCRIPTION

[0042] In the specification, it will be understood that when an element (or components) is referred to as being "on" or "connected to" or "coupled to" another element or layer, it can be directly on, connected, or coupled to the other element or layer, or intervening elements can be present.

[0043] The same reference numerals are used to represent the same elements throughout the drawings. Meanwhile, in the drawings, the thickness, proportions, and dimensions of elements are exaggerated for effective explanation of the technical content.

[0044] As used herein, the term "and / or" includes all combinations of one or more of the associated items.

[0045] It will be understood that, although the terms "first" and "second" can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application. The singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0046] In addition, terms such as "below," "under," "above," and "on" can be used to describe relationships between elements shown in the drawings. These terms have a relative concept and are described according to the orientation shown in the drawings.

[0047] Unless defined otherwise, all terms used herein, including technical terms and scientific terms, have the same meanings as those generally understood by those skilled in the art to which the present application pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0048] It will be further understood that the terms "comprises" and "has," when used in this specification, specify the presence of the stated features, integers, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, numbers, steps, operations, elements, components, or combinations thereof.

[0049] Hereinafter, embodiments of the inventive concept will be described with reference to the accompanying drawings.

[0050] Figure 1 is a perspective view of a display apparatus according to some exemplary embodiments of the inventive concept. Figure 2is a use view of a display device according to some exemplary embodiments of the inventive concept.

[0051] Referring to Figure 1 and Figure 2 , the display device HMD can be a head-mounted display device that can be worn on the head of the user US. The display device HMD can provide an image when the peripheral field of view of the user US is blocked in reality. Since the peripheral field of view of the user US wearing the display is blocked, the user US can more easily immerse in virtual reality.

[0052] The display device HMD can include a main body portion 100, a band portion 200, a cushion portion 300, and display modules DM-L and DM-R (see Figure 3 ).

[0053] The main body portion 100 can be worn on the head of the user US. One or more display modules DM-L and DM-R for displaying an image, an acceleration sensor, etc. can be accommodated inside the main body portion 100. The acceleration sensor can detect the motion of the user US and transmit a predetermined signal to the display modules DM-L and DM-R. Accordingly, the display modules DM-L and DM-R can provide an image corresponding to the change in the line of sight of the user US. Thus, the user US can experience virtual reality similar to reality.

[0054] The main body portion 100 can accommodate components having various functions. For example, an operation portion for adjusting the volume, the screen brightness, etc. can also be disposed on the outer side of the main body portion 100. The operation portion can be provided as a physical button, in the form of a touch sensor, etc. In addition, the display device HMD can also include a proximity sensor for determining whether the user US wears the display device HMD.

[0055] The band portion 200 can be coupled to the main body portion 100. The main body portion 100 can be worn on the head of the user US by means of the band portion 200. The band portion 200 can include a main band 210 and an upper band 220.

[0056] The main band 210 can be worn along the periphery of the head of the user US. The main band 210 can allow the main body portion 100 to be in close contact with the head of the user US. The upper band 220 can connect the main body portion 100 with the main band 210 along the upper portion of the head of the user US. The upper band 220 can prevent or reduce the case where the main body portion 100 slips down. In addition, the upper band 220 can distribute the weight of the main body portion 100 and also improve the wearing comfort of the user US.

[0057] Although Figure 1An exemplary structure in which the lengths of the main strap 210 and the upper strap 220 are adjustable is shown, but embodiments of the inventive concept are not limited thereto. For example, according to some exemplary embodiments, the main strap 210 and the upper strap 220 have elasticity, and the length-adjustable portions can be omitted. Also, the main strap 210 and the upper strap 220 can have an integrated shape.

[0058] When the display device HMD is fixable to the user US, the main body portion 100 and the strap portion 200 can be shaped in various shapes other than those shown in Figure 1 and Figure 2 According to some exemplary embodiments of the inventive concept, the display device HMD can be shaped in various shapes such as a helmet shape or a glasses shape.

[0059] The cushion portion 300 can be disposed on one surface of the main body portion 100. The one surface can be a surface facing the user US when the user US uses the display device HMD. The cushion portion 300 can include a material that can have a freely variable shape or a flexible shape. The cushion portion 300 can include a polymeric resin. For example, the cushion portion 300 can include polyurethane, polycarbonate, polypropylene, or polyethylene, or a sponge foamed by using a rubber liquid, a urethane-based material, or an acrylic-based material. However, the material constituting the cushion portion 300 is not limited to the above examples.

[0060] The cushion portion 300 can improve the wearing comfort of the display device HMD. The cushion portion 300 is removable from the main body portion 100. According to some exemplary embodiments of the inventive concept, the cushion portion 300 can also be omitted.

[0061] Figure 3 is an exploded perspective view of a portion of a display device according to some exemplary embodiments of the inventive concept.

[0062] Referring to Figure 3 , the display modules DM-L and DM-R can include a left-eye display module DM-L and a right-eye display module DM-R. Although Figure 3 An example in which the display device HMD includes two display modules DM-L and DM-R is shown, but exemplary embodiments of the inventive concept are not limited thereto. For example, according to some exemplary embodiments of the inventive concept, the display device HMD can also include only one display module. That is, the left-eye display module DM-L and the right-eye display module DM-R can be integrally disposed.

[0063] Two openings OP-L and OP-R can be provided in one region of the main body part 100. The openings OP-L and OP-R can be divided into a left-eye opening OP-L and a right-eye opening OP-R. A user US (see Figure 2 ) can view an image provided from the left-eye display module DM-L through the left-eye opening OP-L and an image provided from the right-eye display module DM-R through the right-eye opening OP-R.

[0064] Figure 4 is a schematic cross-sectional view of a display device according to some example embodiments of the inventive concept. Figure 5 is a cross-sectional view of a display module according to some example embodiments of the inventive concept.

[0065] Referring to Figure 4 and Figure 5 , the left-eye display module DM-L and the right-eye display module DM-R (see Figure 3 ) can have substantially the same structure. Accordingly, the left-eye display module DM-L will be described, and the description of the right-eye display module DM-R will be omitted.

[0066] The left-eye display module DM-L can include a display panel DP and a lens array LA.

[0067] The display panel DP can generate an image corresponding to input image data. The display panel DP can include various embodiments. For example, the display panel DP can include an organic light emitting diode display panel, a liquid crystal display panel, a micro LED display panel, a plasma display panel, an electrophoretic display panel, or an electro wetting display panel. Although the display panel DP can be an organic light emitting diode display panel according to some example embodiments, embodiments of the inventive concept are not limited thereto.

[0068] The display panel DP can include a base layer BL, a circuit layer ML, a light emitting element layer EL, and a thin film encapsulation layer TFE.

[0069] The circuit layer ML can include transistors TR and a plurality of layers L1, L2, L3, L4, and L5.

[0070] The first layer L1 is located on the base layer BL, and the transistors TR can be located on the first layer L1. The transistors TR can each include a semiconductor layer ACL, a control electrode GED, a first electrode ED1, and a second electrode ED2.

[0071] The semiconductor layer ACL can be located on the first layer L1. The first layer L1 can be a buffer layer that provides an improved surface on the semiconductor layer ACL. In this case, the semiconductor layer ACL can have a higher adhesion degree to the first layer L1 than to the base layer BL. Further, the first layer L1 can be a barrier layer that protects a lower surface of the semiconductor layer ACL. In this case, the first layer L1 can prevent or reduce a case in which moisture or contaminants of the base layer BL itself or moisture or contaminants introduced through the base layer BL penetrate into the semiconductor layer ACL. Alternatively, the first layer L1 can be a light shielding layer that prevents or reduces external light incident through the base layer BL from being incident on the semiconductor layer ACL. In this case, the first layer L1 can further include a light shielding material.

[0072] The semiconductor layer ACL can include polysilicon or amorphous silicon. Further, the semiconductor layer ACL can include a metal oxide semiconductor. The semiconductor layer ACL can include a first ion-doped region and a second ion-doped region and a channel region serving as a path through which electrons or holes are movable, in which the first ion-doped region and the second ion-doped region are positioned such that the channel region is located therebetween.

[0073] The second insulating layer L2 is located on the first layer L1 and can cover the semiconductor layer ACL. The second insulating layer L2 can include an inorganic material. The inorganic material can include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide.

[0074] The control electrode GED can be located on the second insulating layer L2. The third insulating layer L3 is located on the second insulating layer L2 and can cover the control electrode GED. The third insulating layer L3 can include an inorganic material.

[0075] The fourth insulating layer L4 can be located on the third insulating layer L3. The first electrode ED1 and the second electrode ED2 can be located on the fourth insulating layer L4. The first electrode ED1 and the second electrode ED2 can be connected to the semiconductor layer ACL via a via hole passing through the second insulating layer L2, the third insulating layer L3, and the fourth insulating layer L4.

[0076] The fifth insulating layer L5 is located on the fourth insulating layer L4 and can cover the first electrode ED1 and the second electrode ED2. The fifth insulating layer L5 can include a single layer or a plurality of layers. For example, the single layer can include an organic layer. The plurality of layers can be provided by layering an organic layer and an inorganic layer. The fifth insulating layer L5 can be a planarization layer that provides a planar surface thereon.

[0077] The light emitting element layer EL and the definition pattern PDP can be located on the fifth insulating layer L5.

[0078] The light emitting element layer EL can include a first electrode E1, a light emitting layer EM, and a second electrode E2. The first electrode E1 can be located on the fifth insulating layer L5 and electrically connected to the second electrode E2 via a via hole passing through the fifth insulating layer L5.

[0079] The definition pattern PDP can be located on the circuit layer ML and define the pixel PXA. The definition pattern PDP can cover at least a portion of the first electrode E1 and be located on the fifth insulating layer L5. A portion of the first electrode E1 can not be covered by the definition pattern PDP and the portion can correspond to the pixel PXA. Accordingly, the definition pattern PDP can also be referred to as a pixel definition pattern or a pixel definition film.

[0080] The light emitting layer EM can be located between the first electrode E1 and the second electrode E2. The light emitting layer EM can have a single layer structure including a single material, a single layer structure including a plurality of materials different from each other, or a multi-layer structure including a plurality of layers including a plurality of materials different from each other.

[0081] The light emitting layer EM can include an organic material. The organic material is not particularly limited. For example, the light emitting layer EM can include any appropriate material emitting red light, green light, or blue light, and can also include a fluorescent material or a phosphorescent material.

[0082] The second electrode E2 can be located on the light emitting layer EM and the definition pattern PDP. The second electrode E2 can receive a common voltage.

[0083] The thin film encapsulation layer TFE is located on the second electrode E2. The thin film encapsulation layer TFE can directly cover the second electrode E2. According to some example embodiments of the inventive concept, a cap layer covering the second electrode E2 can also be positioned between the thin film encapsulation layer TFE and the second electrode E2. In this case, the thin film encapsulation layer TFE can directly cover the cap layer.

[0084] The thin film encapsulation layer TFE can include a first inorganic layer ECL1, an organic layer ECL2, and a second inorganic layer ECL3. The organic layer ECL2 can be located between the first inorganic layer ECL1 and the second inorganic layer ECL3. The first inorganic layer ECL1 and the second inorganic layer ECL3 can be formed by depositing an inorganic material, and the organic layer ECL2 can be formed by depositing, printing, or coating an organic material.

[0085] The first inorganic layer ECL1 and the second inorganic layer ECL3 protect the light emitting element layer EL from moisture and oxygen, and the organic layer ECL2 protects the light emitting element layer EL from foreign substances such as dust particles. The first inorganic layer ECL1 and the second inorganic layer ECL3 can include at least any one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide. The organic layer ECL2 can include a polymer such as an acrylic organic layer. However, this is merely an example, and embodiments of the inventive concept are not limited thereto.

[0086] Although Figure 5 An example in which the thin film encapsulation layer TFE includes two inorganic layers and one organic layer is shown, but embodiments of the inventive concept are not limited thereto. For example, the thin film encapsulation layer TFE can include three inorganic layers and two organic layers, and in this case, the inorganic layers and the organic layers can have an alternating layer-stacked structure.

[0087] Referring to Figure 4 , a central portion C-A and a peripheral portion P-A surrounding the central portion C-A are defined in the display panel DP. The central portion C-A can be an area including a center of the display panel DP when viewed in a plan view. The center can mean a position at which a center of the display panel DP in the first direction DR1 overlaps with a center of the display panel DP in the second direction DR2. Although Figure 4 An example in which the peripheral portion P-A is spaced apart from the central portion C-A is shown, but the peripheral portion P-A can also be adjacent to the central portion C-A.

[0088] The lens array LA can be located on a surface of the display panel DP displaying an image. The display panel DP can provide an image in a direction toward the thin film encapsulation layer TFE, and in this case, the lens array LA can be located on the thin film encapsulation layer TFE. According to some exemplary embodiments of the inventive concept, the lens array LA can also be located below the base layer BL when the display panel DP provides or displays an image in a direction toward the base layer BL.

[0089] According to some exemplary embodiments of the inventive concept, because the lens array LA is disposed on the display panel DP, an optical lens that has been located between the display panel DP and the user's eye US-E can be omitted. Accordingly, the weight of the display device HMD (see Figure 1 ) can be reduced. Furthermore, because a space for placing the optical lens can not have to be secured inside the main body portion 100 (see Figure 1 ), the thickness of the main body portion 100 (see ) can be reduced. According to some exemplary embodiments of the inventive concept, the optical lens can not be located between the display panel DP and the user's eye US-E. Accordingly, the distance in the first direction DT1 can be no greater than about 50 mm.

[0090] The lens array LA can be used to magnify an image provided from the pixel PXA and project the magnified image on a virtual surface. The user US (see Figure 2 ) can view the virtual image magnified by the lens array LA. The lens array LA can include the optical distance adjustment layer OLL and a plurality of lenses LS.

[0091] The optical distance adjustment layer OLL can be a light transmissive layer. The display panel DP and the plurality of lenses LS can be spaced apart from each other by a predetermined distance through the optical distance adjustment layer OLL.

[0092] A portion of the plurality of lenses LS can have a first focal length, and another portion of the plurality of lenses LS can have a second focal length different from the first focal length. The first focal length and the second focal length can be focal lengths with respect to light incident at the same angle. For example, the focal length of a lens located on the central portion C-A of the display panel DP can be smaller than the focal length of a lens located on the peripheral portion P-A of the display panel DP.

[0093] A first direction DT1 between the central portion C-A of the display panel DP and the user's eye US-E and a second direction DT2 between the peripheral portion P-A of the display panel DP and the user's eye US-E can be different from each other. The first direction DT1 can be a direction perpendicular to the display panel DP, and the second direction DT2 can be a direction inclined with respect to the display panel DP.

[0094] A single lens can have different focal lengths according to the direction of light incident thereto. The different directions of light can mean different angles between light incident to the lens and an optical axis of the lens. The focal length with respect to light perpendicularly incident to the lens can be greater than the focal length with respect to light obliquely incident to the lens. The perpendicularly incident light can be light incident in a direction parallel to the optical axis. The obliquely incident light can be light incident in a direction inclined with respect to the optical axis. That is, when the plurality of lenses LS of the lens array LA have the same focal length with respect to light incident in the same direction, the focal length of light incident to a lens placed at the central portion C-A can be greater than the focal length of light incident to a lens placed at the peripheral portion P-A.

[0095] According to some exemplary embodiments of the inventive concept, the focal length of a lens placed on the peripheral portion P-A can be designed to be longer than the focal length of a lens placed on the central portion C-A. Accordingly, the difference in the focal length of obliquely incident light to a lens placed on the peripheral portion P-A and the focal length of light incident to a lens placed on the central portion C-A can be reduced. That is, the deviation between the focal lengths of the image viewed by the user US can be reduced. Accordingly, the user US can view a video of a clear image. Furthermore, the image of the peripheral portion P-A of the display panel DP can also be viewed clearly, and thus, the viewing angle of the user US can be increased. That is, the display device HMD (seeFigure 1 ) can be improved.

[0096] Figure 6 is Figure 3 is an enlarged sectional view of the region AA' shown in

[0097] Referring to Figure 5 and Figure 6 , the display panel DP can include a plurality of pixels PXA. For example, the plurality of pixels PXA can include first pixels PXA-1, PXA-1a, and PXA-1b that display a first color, second pixels PXA-2 and PXA-2a that display a second color, and third pixels PXA-3 and PXA-3a that display a third color. The first color, the second color, and the third color can be different colors from each other. For example, the first color can be green, the second color can be red, and the third color can be blue.

[0098] The area of the first pixels PXA-1, PXA-1a, and PXA-1b can be smaller than the area of the second pixels PXA-2 and PXA-2a and the area of the third pixels PXA-3 and PXA-3a. The area of the third pixels PXA-3 and PXA-3a can be larger than the area of the first pixels PXA-1, PXA-1a, and PXA-1b and the area of the second pixels PXA-2 and PXA-2a.

[0099] The lens array LA can include a plurality of lenses LSa, LSb, and LSc. Each of the plurality of lenses LSa, LSb, and LSc can overlap at least two pixels PXA. The at least two pixels PXA can include pixels having different colors from each other. Figure 6 The plurality of lenses LSa, LSb, and LSc shown in Figure 4 ) can be lenses located on a central portion C-A (see

[0100] When viewed in a plan view, the first lens LSa can overlap five pixels PXA-1, PXA-2a, and PXA-3a. The five pixels PXA-1, PXA-2a, and PXA-3a can be divided into a single central pixel PXA-1 located at the center and four peripheral pixels PXA-2a and PXA-3a positioned at a periphery of the central pixel PXA-1. The central pixel PXA-1 can be positioned to overlap the center of the first lens LSa at the same time. The central pixel PXA-1 can be a first pixel of green. Two of the peripheral pixels PXA-2a among the peripheral pixels PXA-2a and PXA-3a can be second pixels of red, and the remaining two peripheral pixels PXA-3a can be third pixels of blue.

[0101] The second lens LSb can overlap five pixels PXA-3 and PXA-la. A central pixel PXA-3 among the five pixels PXA-3 and PXA-la can be a blue third pixel, and four peripheral pixels PXA-la can be green first pixels. The third lens LSc can overlap five pixels PXA-2 and PXA-lb. A central pixel PXA-2 among the five pixels PXA-2 and PXA-lb can be a red second pixel, and four peripheral pixels PXA-lb can be green first pixels.

[0102] According to some exemplary embodiments of the inventive concept, when a central pixel overlapping a single lens is a green pixel, two peripheral pixels among four peripheral pixels can be red pixels, and the remaining two peripheral pixels can be blue pixels. Also, when the central pixel overlapping the single lens is a red pixel or a blue pixel, the four peripheral pixels can be green pixels.

[0103] According to some exemplary embodiments of the inventive concept, a single lens can overlap at least two pixels. That is, a single lens can provide a multi-viewpoint to a user, and the user can watch a three-dimensional image.

[0104] Figure 7A is a magnified sectional view of a portion of a display module according to some exemplary embodiments of the inventive concept, and Figure 7B is a magnified sectional view of a portion of a display module according to some exemplary embodiments of the inventive concept.

[0105] Referring to Figure 4 , Figure 7A and Figure 7B , the lens array LA can include a first lens LS1 and a second lens LS2 having different focal lengths. The first lens LS1 can be located on a central portion C-A of the display panel DP, and the second lens LS2 can be located on a peripheral portion P-A of the display panel DP.

[0106] According to some exemplary embodiments of the inventive concept, in consideration of the fact that a focal length of an image displayed on the peripheral portion P-A is smaller than a focal length of an image displayed on the central portion C-A, the focal length of the second lens LS2 can be designed to be longer than the focal length of the first lens LS1. Accordingly, a deviation between the focal length of the image displayed on the central portion C-A and the focal length of the image displayed on the peripheral portion P-A can be reduced. Accordingly, a display quality of the display device HMD (see Figure 1 ) can be improved, and the user US can watch a video of a relatively clearer image.

[0107] The first lens LS1 and the second lens LS2 can have the same material as each other and the same refractive index as each other. The curvature of the first lens LS1 can be greater than the curvature of the second lens LS2. The curvature can mean the reciprocal of the radius of curvature. The maximum thickness TK1 of the first lens LS1 can be greater than the maximum thickness TK2 of the second lens LS2.

[0108] The width WT1 of the first lens LS1 can be the same as the width WT2 of the second lens LS2. Accordingly, as shown in FIG. 1A, when viewed in a plan view, the first lens LS1 can overlap one central pixel and four peripheral pixels. However, embodiments of the inventive concept are not limited thereto. For example, according to some exemplary embodiments of the inventive concept, the width WT1 of the first lens LS1 can also be greater than or less than the width WT2 of the second lens LS2. Figure 6

[0109] According to some exemplary embodiments of the inventive concept, the shape of the first lens LS1 and the shape of the second lens LS2 are different from each other. Accordingly, when light having the same direction is incident to each of the first lens LS1 and the second lens LS2, the focal length of the first lens LS1 and the focal length of the second lens LS2 can be different. Although Figure 7A Figure 7B An exemplary method in which the focal length of the first lens LS1 and the focal length of the second lens LS2 are made different from each other in order to make the focal length of the first lens LS1 and the focal length of the second lens LS2 different from each other is shown, but embodiments of the inventive concept are not limited thereto.

[0110] According to some exemplary embodiments of the inventive concept, the lens array LA can further include a third lens located between the central portion C-A and the peripheral portion P-A, and the third lens has a curvature between the curvature of the first lens LS1 and the curvature of the second lens LS2.

[0111] According to some exemplary embodiments of the inventive concept, the lens array LA is divided into a plurality of regions, and the plurality of lenses located in a single region can all have the same curvature. In this case, the curvature of the lens located on a region overlapping the center can be the greatest. Further, according to some exemplary embodiments of the inventive concept, the lens array LA can include lenses each of which has a smaller curvature as it is farther from the center.

[0112] Figure 8A is a magnified sectional view of a portion of a display module according to some exemplary embodiments of the inventive concept, Figure 8B is a magnified sectional view of a portion of a display module according to some exemplary embodiments of the inventive concept.

[0113] Referring to Figure 8A and​​Figure 8B The display module DM-1 can include a display panel DP, a lens array LA-1, a first electrode LE1, and a second electrode LE2.

[0114] The first electrode LE1 can be located on the display panel DP, the lens array LA-1 can be located on the first electrode LE1, and the second electrode LE2 can be located on the lens array LA-1.

[0115] The lens array LA-1 can include a reactive compound RM and liquid crystal molecules LCL. When a voltage is applied to the first electrode LE1 and the second electrode LE2, an orientation state of the liquid crystal molecules LCL changes, and a refractive index of the lens array LA-1 can change according to the orientation state of the liquid crystal molecules LCL.

[0116] Figure 9A is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept, Figure 9B is a magnified cross-sectional view of a portion of a display module according to some example embodiments of the inventive concept.

[0117] Figure 9A shows a state in which a voltage is applied to the first electrode LE1 and the second electrode LE2 of Figure 8A and an orientation state of a portion of the liquid crystal molecules LCL changes. Figure 9B shows a state in which a voltage is applied to the first electrode LE1 and the second electrode LE2 of Figure 8B and an orientation state of a portion of the liquid crystal molecules LCL changes.

[0118] Fixed areas FA1 and FA2 can be defined in the lens array LA-1. The fixed areas FA1 and FA2 can include a first fixed area FA1 and a second fixed area FA2. The first fixed area FA1 can be defined on a central portion C-A of the display panel DP (see Figure 4 ), and the second fixed area FA2 can be defined on a peripheral portion P-A of the display panel DP. An area of the first fixed area FA1 can be smaller than an area of the second fixed area FA2. For example, referring to Figure 9A and 9B , a width of the first fixed area FA1 in the second direction DR2 can be smaller than a width of the second fixed area FA2 in the second direction DR2.

[0119] The liquid crystal molecules LCL disposed on the first fixed area FA1 and the second fixed area FA2 can have an orientation direction fixed by the active compound RM. Accordingly, even when a voltage is applied to the first electrode LE1 and the second electrode LE2, the orientation direction of the liquid crystal molecules LCL disposed in the first fixed area FA1 and the second fixed area FA2 can not change. The liquid crystal molecules LCL disposed in the periphery of the first fixed area FA1 and the second fixed area FA2 can have an orientation direction that changes according to an electric field generated between the first electrode LE1 and the second electrode LE2. As the orientation direction of the liquid crystal molecules LCL changes, a first lens LS1-1 including the first fixed area FA1 and a second lens LS2-1 including the second fixed area FA2 can be defined. The first lens LS1-1 and the second lens LS2-1 are depicted by dotted lines.

[0120] A first thickness TK1a of the first lens LS1-1 and a second thickness TK2a of the second lens LS2-1 can be identical to each other. The first thickness TK1a and the second thickness TK2a can correspond to a distance between the first electrode LE1 and the second electrode LE2.

[0121] A first width WT1-1 of the first lens LS1-1 and a second width WT2-1 of the second lens LS2-1 can be different from each other. The first width WT1-1 can be smaller than the second width WT2-1. Accordingly, a curvature of the first lens LS1-1 can be greater than a curvature of the second lens LS2-1. Further, because the first width WT1-1 is smaller than the second width WT2-1, a pitch between the first lenses LS1-1 and LS1-2 located on the central portion C-A can be smaller than a pitch between the second lenses LS2-1 located on the peripheral portion P-A.

[0122] An area of the first fixed area FA1 included in the first lens LS1-1 and an area of the second fixed area FA2 included in the second lens LS2-1 are different from each other. Accordingly, when light having the same direction is incident to each of the first lens LS1-1 and the second lens LS2-1, a focal length of the first lens LS1-1 and a focal length of the second lens LS2-1 can be different.

[0123] Figures 10A to 10D is a cross-sectional view illustrating a method for manufacturing a display module according to some exemplary embodiments of the inventive concept.

[0124] Reference Figure 10A A display panel DP is formed. In the display panel DP, a central portion C-A and a peripheral portion P-A surrounding the central portion C-A can be defined.

[0125] An optical distance adjusting layer OLL is formed on the display panel DP. The optical distance adjusting layer OLL can include a light-transmitting material.

[0126] Referring to Figure 10B A photoresist layer PR is formed on the optical distance adjustment layer OLL. The photoresist layer PR can include a positive photoresist material or a negative photoresist material.

[0127] Referring to Figure 10C A mask MK is positioned on the photoresist layer PR. The mask MK can be a binary mask including a light-transmissive portion and a light-blocking portion. The mask MK can include a central region overlapping the central portion C-A when viewed in a plan view and a peripheral region overlapping the peripheral portion P-A when viewed in a plan view. The light-transmissive portion can include a central opening pattern C-OP defined in the central region and a peripheral opening pattern P-OP defined in the peripheral region. The central opening pattern C-OP can be located on the central portion C-A of the display panel DP, and the peripheral opening pattern P-OP can be located on the peripheral portion P-A of the display panel DP.

[0128] The transmittance of light passing through the mask MK can be adjusted by adjusting the size of the mask MK. For example, the size of the central opening pattern C-OP and the size of the peripheral opening pattern P-OP can be different from each other. When the photoresist layer PR includes a negative photoresist material, the width of the central opening pattern C-OP in the second direction DR2 can be greater than the width of the peripheral opening pattern P-OP in the second direction DR2. Also, when the photoresist layer PR includes a positive photoresist material, the width of the central opening pattern C-OP in the second direction DR2 can be less than the width of the peripheral opening pattern P-OP in the second direction DR2.

[0129] Also, according to some example embodiments of the inventive concept, the size of the central opening pattern C-OP and the size of the peripheral opening pattern P-OP can also be the same. In this case, the time during which light is emitted to the central opening pattern C-OP and the time during which light is emitted to the peripheral opening pattern P-OP can be different from each other.

[0130] The lenses LSI and LS2 can be formed by patterning the photoresist layer PR (see Figure 7A and Figure 7B ). The patterning can include an exposure process and a development process.

[0131] Referring to Figure 10D , the region XX’ of the magnified version of the lens array LA located on the central portion C-A can correspond to the first lens LSI of Figure 7A . The region YY’ of the magnified version of the lens array LA located on the peripheral portion P-A can correspond to the second lens LS2 of Figure 7Bcorresponding to the second lens LS2. The lens located on the area between the central portion C-A and the peripheral portion P-A can have a curvature between the curvature of the first lens LS1 and the curvature of the second lens LS2. Further, according to some exemplary embodiments of the inventive concept, the lens can have a shape in which the closer to the peripheral portion P-A, the smaller the curvature.

[0132] Figures 11A to 11D is a sectional view illustrating a method for manufacturing a display module according to some exemplary embodiments of the inventive concept.

[0133] Referring to Figure 11A A first electrode LE1 is formed on the display panel DP. The first electrode LE1 can include a light-transmissive material. For example, the first electrode LE1 can include at least any one among indium zinc oxide (IZO), indium tin oxide (ITO), indium gallium oxide (IGO), indium zinc gallium oxide (IGZO), and mixtures / compounds thereof. However, embodiments of the inventive concept are not limited thereto.

[0134] Referring to Figure 11B A primary layer PLL is formed on the first electrode LE1. The primary layer PLL can be a layer in which an active compound RM and liquid crystal molecules LC are mixed. The active compound RM can be a photosensitive compound. For example, the active compound RM can be cured by reacting with ultraviolet rays. In this case, a portion of the liquid crystal molecules LC included in the primary layer PLL can be fixed in an initial orientation direction as the active compound RM is cured.

[0135] Referring to Figure 11C A mask MKa can be positioned on the primary layer PLL. The mask MKa can be a binary mask including a light-transmissive portion and a light-blocking portion. The light-transmissive portion can include a central opening pattern C-OPa and a peripheral opening pattern P-OPa. The central opening pattern C-OPa can be located on the central portion C-A of the display panel DP, and the peripheral opening pattern P-OPa can be located on the peripheral portion P-A of the display panel DP.

[0136] The size of the central opening pattern C-OPa and the size of the peripheral opening pattern P-OPa can be different from each other. For example, the width of the central opening pattern C-OPa in the second direction DR2 can be smaller than the width of the peripheral opening pattern P-OPa in the second direction DR2.

[0137] The difference in the size of the central opening pattern C-OPa and the size of the peripheral opening pattern P-OPa can correspond to the difference in the size of the first fixed area FA1 (see Figure 9A ) and the size of the second fixed area FA2 (see Figure 9B ).

[0138] The light is emitted through the mask MKa, and the active compound RM of the curable primary layer PLL.

[0139] Referring to Figure 11D , the lens array LA-1 can be formed by forming a first fixed area FA1 (see Figure 9A ) and a second fixed area FA2 (see Figure 9B ) on the primary layer PLL. The second electrode LE2 can be formed on the lens array LA-1. The second electrode LE2 can include at least any one among indium zinc oxide (IZO), indium tin oxide (ITO), indium gallium oxide (IGO), indium zinc gallium oxide (IGZO), and mixtures / compounds thereof. However, embodiments of the present inventive concept are not limited thereto.

[0140] One area ZZ' of the magnified version of the lens array LA-1 located on the central portion C-A can correspond to the first lens LS1-1 of Figure 9A . One area WW' of the magnified version of the lens array LA-1 located on the peripheral portion P-A can correspond to the second lens LS2-1 of Figure 9B .

[0141] According to some exemplary embodiments, the method for manufacturing a display module can further include forming an optical distance adjustment layer. The optical distance adjustment layer can be formed between the display panel DP and the first electrode LE1 or between the first electrode LE1 and the lens array LA-1.

[0142] According to some exemplary embodiments of the present inventive concept, the lens array located on the display panel can have at least two focal lengths. Because of the deviation of the focal length according to the position inside the display panel, the user can watch a video of a clear image. In addition, the image of the peripheral portion of the display panel can be clearly watched, and thus, the viewing angle of the user can be increased. That is, the display quality of the display apparatus can be improved.

[0143] It will be apparent to those skilled in the art that various modifications and changes can be made in the present application without departing from the scope thereof. It is therefore intended that the present application cover all such modifications and changes as fall within the scope of the appended claims and their equivalents. Accordingly, the actual scope of the present application should be determined by the technical scope of the following claims, and their equivalents.

Claims

1. A head-mounted display device, comprising: a display panel having a central portion and a peripheral portion surrounding the central portion, the display panel including a plurality of pixels; and a lens array on the display panel, wherein: the lens array includes a first lens on the central portion and a second lens on the peripheral portion; a first focal length of the first lens is smaller than a second focal length of the second lens; and each of the first lens and the second lens overlaps at least two pixels among the plurality of pixels, wherein, in a plan view, the first lens overlaps only five pixels among the plurality of pixels, and wherein the five pixels include a central pixel at a center and four peripheral pixels surrounding the central pixel, and each of the four peripheral pixels overlaps an edge of the first lens. two open portions are provided in a region of the main body portion facing the lens array.

2. The head-mounted display device of claim 1, further comprising a body portion housing the display panel and the lens array, wherein, a curvature of the first lens is greater than a curvature of the second lens.

3. The head-mounted display device of claim 1, wherein, a refractive index of the first lens is equal to a refractive index of the second lens.

4. The head-mounted display device of claim 1, wherein, a thickness of the first lens is greater than a thickness of the second lens.

5. The head-mounted display device of claim 1, wherein, 6.The head-mounted display device according to claim 1, further comprising: a first electrode below the first lens and the second lens; and a second electrode on the first lens and the second lens, wherein each of the first lens and the second lens includes an active compound and liquid crystal molecules. 7.The head-mounted display device according to claim 6, wherein: a fixed region is defined in the lens array in which an orientation direction of the liquid crystal molecules is fixed by the active compound; the fixed region includes a first fixed region and a second fixed region, wherein the first fixed region is included in the first lens and the second fixed region is included in the second lens; and an area of the first fixed region and an area of the second fixed region are different from each other. the area of the first fixed region is smaller than the area of the second fixed region. a thickness of the first lens is equal to a thickness of the second lens.

8. The head-mounted display device of claim 7, wherein, the central pixel is a green pixel, two peripheral pixels among the four peripheral pixels are red pixels and the remaining two peripheral pixels are blue pixels.

9. The head-mounted display device of claim 6, wherein, the central pixel is a red pixel or a blue pixel, and the four peripheral pixels are green pixels.

10. The head-mounted display device of claim 1, wherein, ​ 11. The head-mounted display device of claim 1, wherein, ​

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