Head-mounted display device

Abstract

According to an embodiment, a head-mounted display device includes a display panel and an optical system disposed in front of the display panel. The display panel includes a light emitting device unit, three cholesteric layers disposed on a front surface of the light emitting device unit, an upper light blocking layer disposed between two cholesteric layers, a retardation plate disposed on a front surface of the cholesteric layers, and an absorption type polarizer disposed in front of the retardation plate. Each cholesteric layer has a different wavelength value according to the following formula: wavelength value = n * pitch value wherein n is the refractive index value of each cholesteric liquid crystal layer and the pitch value is the pitch value of the liquid crystal molecules of the cholesteric layer, the wavelength value being for the light having the wavelength value, and n is the refractive index value of each cholesteric liquid crystal layer. The cholesteric liquid crystal layer is capable of transmitting circularly polarized light in one direction and reflecting circularly polarized light in the opposite direction.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2023 - 0081108, filed with the Korean Intellectual Property Office on June 23, 2023, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present disclosure relates to a head - mounted display device, and more particularly, to a head - mounted display device. Background art

[0004] A light - emitting display device is a self - luminous display device that displays an image by emitting light from a light - emitting diode. Such light - emitting display devices are included in various electronic devices. To enhance a user experience with a three - dimensional effect or immersion, head - mounted display devices that directly display an image in front of a user are also widely distributed.

[0005] However, when using a polarizer, a head - mounted display device may have reduced light efficiency. Summary of the utility model

[0006] Embodiments provide a head - mounted display device.

[0007] The head - mounted display device includes a display panel and an optical system disposed in front of the display panel. The display panel includes: a light - emitting device unit; a first cholesteric liquid crystal layer, a second cholesteric liquid crystal layer, and a third cholesteric liquid crystal layer disposed on a front surface of the light - emitting device unit; an upper light - blocking layer disposed between two of the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, and the third cholesteric liquid crystal layer; a retardation plate disposed on a front surface of the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, the third cholesteric liquid crystal layer, and the upper light - blocking layer; and an absorption - type polarizer disposed in front of the retardation plate. The first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, and the third cholesteric liquid crystal layer have different wavelength values according to the following equation:

[0008] Wavelength value=n×Pitch value

[0009] where n is a refractive index value of a corresponding cholesteric liquid crystal layer among the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, and the third cholesteric liquid crystal layer, and the pitch value is a pitch value of liquid crystal molecules of the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, or the third cholesteric liquid crystal layer, and where the wavelength value refers to circularly polarized light that the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, or the third cholesteric liquid crystal layer can transmit in one direction and reflect circularly polarized light in the opposite direction for light having the wavelength value.

[0010] The head-mounted display includes a display panel and an optical system disposed in front of the display panel. The display panel includes a light-emitting device unit, a retardation plate disposed in front of the light-emitting device unit, and a reflective polarizing plate for the display device disposed in front of the retardation plate. The optical system includes a first curved lens and a second curved lens. The first curved lens includes a first retardation plate disposed on the inner surface and a beam splitter disposed on the outer surface. The second curved lens includes a second retardation plate disposed on the inner surface and a reflective polarizing plate disposed on the outer surface. The first curved lens is disposed on the display panel, and the second curved lens is disposed on the first curved lens. The light-emitting device unit emits circularly polarized light. Description of the Drawings

[0011] Figure 1 is a schematic cross-sectional view of a head-mounted display device according to an embodiment.

[0012] Figure 2 is a schematic cross-sectional view of the display panel of a head-mounted display device according to an embodiment.

[0013] Figure 3 is a diagram showing a schematic optical path of a head-mounted display device according to an embodiment.

[0014] Figure 4 is a diagram schematically showing the optical path of a head-mounted display device according to an embodiment.

[0015] Figure 5 is a diagram schematically showing the optical path of a head-mounted display device according to a comparative example.

[0016] Figures 6 to 8 is a view schematically showing the optical path of a head-mounted display device according to an embodiment.

[0017] Figure 9 and Figure 10 are schematic cross-sectional views of the display panel of a head-mounted display device according to various embodiments.

[0018] Figure 11 and Figure 12 is a diagram showing details of an example of a light-emitting layer in the display panel of a head-mounted display device according to an embodiment. Detailed Description of the Embodiments

[0019] Hereinafter, various embodiments will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present application.

[0020] The present application can be implemented in many different forms and is not necessarily limited to the embodiments set forth herein.

[0021] To clearly describe the present application, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

[0022] Although each drawing may represent one or more specific embodiments of the present disclosure and is drawn to scale so that relative lengths, thicknesses, and angles can be inferred therefrom, it should be understood that the present application is not necessarily limited to the relative lengths, thicknesses, and angles shown. These values can be changed within the spirit and scope of the present disclosure, for example, to allow for manufacturing limitations and the like.

[0023] In addition, when a part such as a layer, film, region, or plate component is referred to as being "on" or "above" another part, this is not only when it is "directly" on the other part, but also when there is another part between them.

[0024] Conversely, when a part is referred to as being "directly" on another part, this means that there are no other parts between them.

[0025] In addition, being "above" or "on" a reference part means being located above or below the reference part, and does not necessarily mean being "above" or "on" it in the opposite direction of gravity.

[0026] In addition, throughout the specification, when a component is referred to as "including", this means that it may also include other components without excluding other components, unless otherwise specified.

[0027] In addition, throughout the specification, when referring to a "planar image", this means when observing the target part from above, and when referring to a "cross-sectional image", this means when observing the cross-section of the target part vertically cut from the side. In addition, throughout the specification, when it is referred to as "on the plane" or "in the plan view", this means when observing the target part from above. Similarly, throughout the specification, when using "connected", this not only means the case where two or more components are directly connected, but also means the case where two or more components are indirectly connected, physically connected, in the case of electrical connection, and when different names are used to refer to them according to position or function, and each part that is substantially integral can be connected to each other.

[0028] In addition, throughout the specification, when a part such as a line, layer, film, region, plate, component, etc. "extends in a first direction or a second direction", this not only means a straight line extending in the corresponding direction. On the contrary, it is a structure that generally extends in the first direction or the second direction, and it includes a structure that is bent at a part, has a zigzag structure, or extends while including a curved surface structure.

[0029] In addition, an electronic device including a display device and a display panel described in the specification (e.g., a mobile phone, a TV, a monitor, a laptop computer, etc.) or a display device and a display panel manufactured by a manufacturing method described in the specification is not excluded from the scope of the present specification.

[0030] Hereinafter, a head-mounted display device according to an embodiment will be described with reference to Figure 1 FIG.

[0031] Figure 1 is a schematic cross-sectional view of a head-mounted display device according to an embodiment.

[0032] A head-mounted display device according to an embodiment includes a display panel 100 (hereinafter also referred to as the display panel of the head-mounted display device) and an optical system 200 located in front of the display panel 100.

[0033] Here, the optical system 200 is located between the display panel 100 and the user's eyes 300 so that the light emitted from the display panel 100 appears wider, thereby improving the immersion or three-dimensional effect.

[0034] The optical system 200 includes two curved lenses, namely, a first curved lens 210 and a second curved lens 220 (hereinafter referred to as a pancake lens). Each of the curved lenses 210 and 220 includes two optical films 211, 212, 221, and 222.

[0035] The detailed form of the optical system 200 is as follows.

[0036] The first curved lens 210 (hereinafter referred to as the first pancake lens) is positioned relative to the display panel 100 in the third direction DR3 (also referred to as inside). The first curved lens 210 includes a first retardation plate 211 (hereinafter also referred to as the first optical system retardation plate) and a beam splitter 212. For example, the first retardation plate 211 is placed on the outer side (inner surface) of the first curved lens 210 opposite to the third direction DR3 with respect to the first curved lens 210. The beam splitter 212 is located on the outer side (outer surface) of the first curved lens 210 facing the third direction DR3 with respect to the first curved lens 210.

[0037] The first retardation plate 211 is also referred to as a λ / 4 plate and can change linearly polarized light to circularly polarized light or circularly polarized light to linearly polarized light by providing a retardation of λ / 4 with respect to the retardation axis.

[0038] The beam splitter 212 can transmit half of the incident light and reflect the other half of the incident light regardless of the polarization characteristics of the light.

[0039] The second aspherical lens 220 (also referred to as the second pancake lens) positioned adjacent to the user's eye 300 includes a second retardation plate 221 (also referred to as the second optical system retardation plate) and a reflective polarizer 222 (also referred to as the optical system reflective polarizer), wherein the second retardation plate 221 is formed on the outer side (inner surface) of the second aspherical lens 220 in the opposite direction to the second aspherical lens 220 in the third direction DR3, and the reflective polarizer 222 is formed on the outer side (outer surface) of the second aspherical lens 220 facing the third direction DR3 with respect to the second aspherical lens 220.

[0040] The second retardation plate 221 is also referred to as a λ / 4 plate and can change linearly polarized light to circularly polarized light or circularly polarized light to linearly polarized light by providing a retardation of λ / 4 with respect to the retardation axis.

[0041] The reflective polarizer 222 includes a reflection axis and reflects linearly polarized light along this axis while transmitting linearly polarized light perpendicular to the reflection axis.

[0042] The reflective polarizer 222 may have a wire grid structure including a plurality of metal lines with a fine width arranged in one direction. The wire grid structure can reflect light parallel to the orientation of the metal lines and transmit light perpendicular to the orientation of the metal lines.

[0043] In this case, the interval between the plurality of metal lines may be narrower than the wavelength of visible light.

[0044] The first aspherical lens 210 and the second aspherical lens 220 included in the optical system 200 may include optically isotropic materials such as glass or polymethyl methacrylate (PMMA).

[0045] In addition, the curved surfaces of the first aspherical lens 210 and the second aspherical lens 220 may be spherical or aspherical.

[0046] Hereinafter, reference will be made to Figure 2 describe the display panel of the head-mounted display device according to the embodiment.

[0047] Figure 2 is a schematic cross-sectional view of the display panel of the head-mounted display device according to the embodiment.

[0048] The display panel 100 used in the head-mounted display device according to the embodiment may be a self-emitting display panel that emits light by itself. For example, the self-emitting display panel may include micro light-emitting diodes (LEDs), organic light-emitting diodes OLED (for example, see Figure 9 ) and / or inorganic light-emitting diodes.

[0049] In Figure 2In [reference], a schematic representation of a light-emitting device unit 150 included in a display panel 100 is shown. The light-emitting device unit 150 may include a plurality of layers of the display panel 100 in which an organic light-emitting diode (OLED) (for example, see Figure 9 ) is formed and a transistor connected to the organic light-emitting diode (OLED) (for example, see Figure 9 ).

[0050] In some embodiments, a color filter (see 230r, 230g, and 230b in Figure 4 ) or a color conversion layer may be located on the front surface (in the third direction DR3) of the organic light-emitting diode (OLED) (for example, see Figure 9 ).

[0051] In Figure 2 , only the cathode of the organic light-emitting diode (OLED) (for example, see Figure 9 ) is shown at the top of the light-emitting device unit 150, and a detailed cross-sectional structure will be described in Figure 9 and the like.

[0052] Cholesteric liquid crystal layers 140r, 140g, 140b (also referred to as circularly polarized light reflection and transmission layers) and an absorption type polarizer 110 (hereinafter also referred to as an absorption type for a display panel) are provided on the front surface (in the third direction DR3) of the light-emitting device unit 150. In addition, a type polarizing plate and a retardation plate 130 (hereinafter also referred to as a retardation plate for a display panel) are formed on the front surface of the light-emitting device unit 150. For example, when observed in a cross-sectional view, the cholesteric liquid crystal layers 140r, 140g, and 140b, the absorption type polarizer 110, and the type polarizing plate and the retardation plate 130 are all provided on the light-emitting device unit 150.

[0053] The absorption type polarizer 110 is located on the outermost side (in the third direction DR3) of the light-emitting device unit 150, and the retardation plate 130 is provided inside the absorption type polarizer 110, followed by the cholesteric liquid crystal layers 140r, 140g, and 140b.

[0054] The absorption type polarizer 110 includes an absorption axis. The absorption type polarizer 110 may absorb linearly polarized light along the absorption axis and may transmit linearly polarized light perpendicular to the absorption axis.

[0055] In this document, the direction perpendicular to the absorption axis corresponds to the transmission axis.

[0056] In the embodiments of Figure 2 , the absorption axis of the absorption type polarizer 110 may be set at an angle of 90 degrees, and the absorption type polarizer 110 may have a film form including tri-acetyl cellulose (TAC).

[0057] The retardation plate 130 is also referred to as a λ / 4 plate and can change linearly polarized light into circularly polarized light or change circularly polarized light into linearly polarized light by providing a retardation of λ / 4 with respect to the retardation axis.

[0058] Here, the retardation axis of the retardation plate 130 may have an angle of 45 degrees with respect to the absorption axis or the transmission axis of the absorption-type polarizer 110.

[0059] The cholesteric liquid crystal layers 140r, 140g, and 140b can be formed by coating chiral liquid crystal molecules having a twisted structure. Additionally, the cholesteric liquid crystal layers 140r, 140g, and 140b can be formed by coating the inner surface of the retardation plate 130 or the light-emitting device unit 150, or formed on the top surface.

[0060] The cholesteric liquid crystal layers 140r, 140g, and 140b have a pitch value based on the degree of twist of the liquid crystal molecules. The cholesteric liquid crystal layers 140r, 140g, and 140b can modulate the transmission of light based on the pitch value, and can adjust the wavelength of light, or allow light to be transmitted or reflected.

[0061] That is, for light with a wavelength of λ, the cholesteric liquid crystal layers 140r, 140g, and 140b can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction, where the wavelength λ is defined by Equation 1 provided below.

[0062] [Equation 1]

[0063] Wavelength (λ) = n × pitch value

[0064] Here, the wavelength λ represents the wavelength of the light reflected or transmitted by the cholesteric liquid crystal layers 140r, 140g, and 140b. The variable n represents the refractive index value of the corresponding cholesteric liquid crystal layer 140r, 140, or 140b, and the pitch value of the corresponding cholesteric liquid crystal layers 140r, 140g, and 140b represents the pitch value of the liquid crystal molecules.

[0065] In Equation 1, the refractive index value n can be the average refractive index value of the corresponding cholesteric liquid crystal layers 140r, 140g, and 140b.

[0066] The cholesteric liquid crystal layers 140r, 140g, and 140b include a first-color cholesteric liquid crystal layer 140r (hereinafter referred to as the first cholesteric liquid crystal layer), a second-color cholesteric liquid crystal layer 140g (hereinafter referred to as the second cholesteric liquid crystal layer), and a third-color cholesteric liquid crystal layer 140b (hereinafter referred to as the third cholesteric liquid crystal layer).

[0067] For light having a wavelength range corresponding to a first color, the first-color cholesteric liquid crystal layer 140r can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction.

[0068] For example, the first color may be red, i.e., one of the primary colors of light, and the wavelength value of Formula 1 of the first-color cholesteric liquid crystal layer 140r may have a wavelength of 600 nm to 700 nm corresponding to the first color.

[0069] In the case of light having a wavelength range corresponding to a second color, the second-color cholesteric liquid crystal layer 140g can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction.

[0070] For example, the second color may be green, i.e., one of the primary colors of light, and the wavelength value of Formula 1 of the second-color cholesteric liquid crystal layer 140g may have a wavelength of 500 nm or greater and less than 600 nm corresponding to the second color.

[0071] In the case of light having a wavelength range corresponding to a third color, the third-color cholesteric liquid crystal layer 140b can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction.

[0072] For example, the third color may be blue, i.e., one of the primary colors of light, and the wavelength value of Formula 1 of the third-color cholesteric liquid crystal layer 140b may have a wavelength of 400 nm or greater and less than 500 nm corresponding to the third color.

[0073] The optical path in the head-mounted display device having the above structure can be as Figure 3 shown.

[0074] Figure 3 is a diagram showing a schematic optical path of a head-mounted display device according to an embodiment.

[0075] Figure 3 Schematically shows the optical path of light emitted from the display panel 100 of the head-mounted display device passing through the optical system 200 and being transmitted to the user's eyes 300.

[0076] The light emitted from the display panel 100 of the head-mounted display device can pass through the first curved lens 210 and the second curved lens 220 before reaching the user's eyes 300.

[0077] In addition, the light emitted from the display panel 100 can reach the user's eyes 300 from the beam splitter 212 of the first curved lens 210 after being reflected by the reflective polarizer 222 of the second curved lens 220. Before reaching the user's eyes 300, multiple reflections occur from the reflective polarizer 222 and the beam splitter 212.

[0078] Referring Figure 3 , since the user's eyes 300 can recognize the light bent by the first curved lens 210 and the second curved lens 220, the size of the display panel 100 of the head-mounted display device can be larger than the size of the display panel 100.

[0079] Therefore, the user can experience an enhanced level of immersion in the image, thereby enhancing the perceived three-dimensional display effect during display.

[0080] In addition, when two curved lenses 210 and 220 are used as Figure 3 shown, the optical path becomes longer. Therefore, even in the case of a thin head-mounted display device, the user can perceive the image as if it is presented from a greater distance.

[0081] The light characteristics and transmittance of the head-mounted display device according to the present embodiment will be described in detail below with reference to Figure 4 .

[0082] Figure 4 FIG. is a diagram schematically showing the optical path of the head-mounted display device according to an embodiment.

[0083] The optical system 200 has a curved surface.

[0084] In Figure 4 , the transmittance, path, and polarization characteristics of light in the display panel 100 of the head-mounted display are as follows.

[0085] Referring Figure 4 , in the display panel 100 of the head-mounted display device, only the color filters 230r, 230g, and 230b are shown on the uppermost side of the light-emitting device unit 150, and the color filters 230r, 230g, and 230b, the cholesteric liquid crystal layers 140r, 140g, and 140b, the retardation plate 130, and the absorption-type polarizer 110 are sequentially located on the upper side in the third direction DR3. For example, the absorption-type polarizer 110 can be disposed farthest from the light-emitting device unit 150. In addition, the cholesteric liquid crystal layers 140r, 140g, and 140b are disposed between the retardation plate 130 and the light-emitting device unit 150.

[0086] In an embodiment, the absorptive polarizer 110 is arranged at an angle of 90 degrees with respect to the absorption axis and at an angle of 0 degrees with respect to the transmission axis. The retardation axis of the retardation plate 130 may be arranged at an angle of 45 degrees with respect to the absorption axis or the transmission axis of the absorptive polarizer 110.

[0087] The light emitting device unit 150 may further include a light emitting diode OLED, which is disposed below the color filters 230r, 230g, and 230b and emits light corresponding to each of the color filters 230r, 230g, and 230b.

[0088] For example, the light emitted from the light emitting diode OLED may display white color, and when the light passes through the corresponding color filters 230r, 230g, and 230b, it may display a color corresponding to one of the primary colors of light.

[0089] The red color filter 230r (hereinafter referred to as the first color filter) may be positioned to overlap with the first color cholesteric liquid crystal layer 140r in a plane, the green color filter 230g (hereinafter referred to as the second color filter) may be positioned to overlap with the second color cholesteric liquid crystal layer 140g in a plane, and the blue color filter 230b (hereinafter referred to as the third color filter) is for the third color cholesteric liquid crystal layer 140b and may be positioned to overlap with the third color cholesteric liquid crystal layer 140b in a plane.

[0090] Refer to Figure 4 , the red color filter 230r, the green color filter 230g, and the blue color filter 230b are used, but the colors are not necessarily limited thereto. For example, other primary colors of light may be used.

[0091] In some embodiments, a color conversion layer may be included instead of the color filters 230r, 230g, and 230b. The color conversion layer may change light of a specific wavelength into light of a wavelength corresponding to one of the primary colors of light.

[0092] In some embodiments, the light emitting device unit 150 may not include separate color filters 230r, 230g, and 230b or a color conversion layer. Instead, each light emitting diode OLED may emit light corresponding to the primary colors of light.

[0093] In some embodiments, a light blocking layer (see Figure 9 BM) may be located between any two of the color filters including the red color filter 230r, the green color filter 230g, and the blue color filter 230b.

[0094] The light-emitting diode OLED may include an anode, a light-emitting layer, and a cathode. According to an embodiment, the cathode of the light-emitting diode OLED may be formed to have a semi-transmissive and semi-reflective property, transmitting 50% of the light and reflecting the remaining 50% of the light. However, the reflectivity of the cathode is not necessarily limited thereto, and the percentage of the reflected light may vary.

[0095] On the other hand, the anode of the light-emitting diode OLED has a reflective property and may reflect all incident light.

[0096] The light emitted from the light-emitting diode OLED of the light-emitting device unit 150 passes through the color filters 230r, 230g, and 230b and is provided to the cholesteric liquid crystal layers 140r, 140g, and 140b.

[0097] The light of each color transmitted through the color filters 230r, 230g, and 230b is incident on the cholesteric liquid crystal layers 140r, 140g, and 140b corresponding to each color.

[0098] The wavelength of the light TL1 and TL2 transmitted through the cholesteric liquid crystal layers 140r, 140g, and 140b or the light RL1 reflected by the cholesteric liquid crystal layers 140r, 140g, and 140b corresponds to the wavelength of the light passing through the color filters 230r, 230g, and 230b. Therefore, the transmitted light TL1, which is circularly polarized light in a specific direction (hereinafter referred to as the first circularly polarized light), passes through the cholesteric liquid crystal layers 140r, 140g, and 140b, while the reflected light RL1, which is circularly polarized light in the opposite direction (hereinafter referred to as the second circularly polarized light), is reflected.

[0099] The transmitted light TL1 and the reflected light RL1 passing through the cholesteric liquid crystal layers 140r, 140g, and 140b may account for 50% of the total light.

[0100] The reflected circularly polarized light is reflected from the cathode or the anode of the light-emitting diode OLED and is provided in the third direction DR3. Then, the light TL2, which is changed to the first circularly polarized light due to reflection, passes through the cholesteric liquid crystal layers 140r, 140g, and 140b. The re-transmission allows the use of more than 50% of the total light, enhancing the light efficiency.

[0101] For example, in Figure 4 the embodiment, the transmitted light TL1 of red having circular polarization in the clockwise direction passes through the first-color cholesteric liquid crystal layer 140r. The light having the opposite circular polarization (i.e., circular polarization in the counterclockwise direction) is reflected as the reflected light RL1.

[0102] Reflected light RL1 with circular polarization in the counterclockwise direction is reflected from the cathode or anode in the third direction DR3. For example, the reflected light RL1 moves away from the light-emitting device unit 150. Then, the light TL2 that has been changed to clockwise circularly polarized light due to reflection passes through the first cholesteric liquid crystal layer 140r and is re-transmitted.

[0103] In Figure 4 the embodiment of, the transmitted light TL1 of green with circular polarization in the clockwise direction passes through the second cholesteric liquid crystal layer 140g. The light with the opposite circular polarization (i.e., circular polarization in the counterclockwise direction) is reflected as the reflected light RL1.

[0104] Reflected light RL1 with circular polarization in the counterclockwise direction is reflected from the cathode or anode in the third direction DR3. Then, the light TL2 that has been changed to clockwise circularly polarized light due to reflection passes through the second cholesteric liquid crystal layer 140r and is re-transmitted.

[0105] In Figure 4 the embodiment of, the transmitted light TL1 of blue with circular polarization in the clockwise direction passes through the third cholesteric liquid crystal layer 140b. Then, the light with the opposite circular polarization (i.e., circular polarization in the counterclockwise direction) is reflected as the reflected light RL1.

[0106] Reflected light RL1 with circular polarization in the counterclockwise direction is reflected from the cathode or anode in the third direction DR3. Then, the light TL2 that has been changed to clockwise circularly polarized light due to reflection passes through the third cholesteric liquid crystal layer 140b and is re-transmitted.

[0107] As described above, the counterclockwise circularly polarized light is transmitted and re-transmitted to the retarder 130 for each color through the cholesteric liquid crystal layers 140r, 140g, and 140b.

[0108] Since the retarder 130 provides a retardation of λ / 4 along the retardation axis, the retarder 130 can change the counterclockwise circularly polarized light to 0-degree linearly polarized light.

[0109] The linearly polarized light thus changed is incident on the absorption-type polarizer 110. However, this light is transmitted from the display panel 100 of the head-mounted display device to the optical system 200. This transmission is aligned with the transmission axis of the absorption-type polarizer 110.

[0110] In Figure 4 the optical system 200 of the head-mounted display device of, the reflection axis of the reflective polarizer 222 can be set at an angle of 90 degrees with respect to the reflective polarizer 222, and the transmission axis of the reflective polarizer 222 can be set at an angle of 0 degrees with respect to the reflective polarizer 222. For example, the transmission axis of the reflective polarizer 222 can be parallel to the reflective polarizer 222.

[0111] The retardation axes of the first retarder plate 211 and the second retarder plate 221 can be set at an angle of 45 degrees with respect to the reflection axis of the reflective polarizer 222 and the absorption axis of the absorption-type polarizer 110.

[0112] When the linearly polarized light at 0 degrees transmitted through the optical system 200 passes through the first retarder plate 211, it is changed into circularly polarized light. Subsequently, it is transmitted through the beam splitter 212.

[0113] The beam splitter 212 transmits half of the incident light and reflects the remaining half downward.

[0114] The light reflected by the beam splitter 212 can be transmitted through the absorption-type polarizer 110 and absorbed by the absorption-type polarizer 110.

[0115] When the circularly polarized light transmitted through the beam splitter 212 passes through the second retarder plate 221, it can be changed into linearly polarized light at 90 degrees. Subsequently, this light is reflected to be aligned with the reflection axis of the reflective polarizer 222.

[0116] When the light reflected from the reflective polarizer 222 passes through the second retarder plate 221, it is changed into circularly polarized light. This light is reflected by the beam splitter 212 again and advances toward the second retarder plate 221 in the third direction DR3. Subsequently, the light is changed into linearly polarized light at 0 degrees and can be transmitted through the reflective polarizer 222.

[0117] The trajectories discussed above eliminate the need for the user's eyes to be positioned away from the optical system 200. Therefore, the thickness of the head-mounted device can be minimized, providing a wider and more extensive image view for the user's eyes.

[0118] Generally, due to the absorption-type polarizer 110, a head-mounted display including a polarizer has reduced light efficiency. However, the cholesteric liquid crystal layers 140r, 140g, and 140b that reflect circularly polarized light in one direction increase the amount of light circulation from the display panel 100 of the head-mounted display device transmitted through the optical system 200.

[0119] Hereinafter, it will be compared and reviewed with Figure 5 through a comparative example of Figure 4 the differences from the embodiments of

[0120] Figure 5 is a diagram schematically showing the optical path of a head-mounted display device according to the comparative example.

[0121] Figure 5 The comparative example of Figure 4The structure is the same as that of the embodiment, but the display panel 100 of the head-mounted display device only includes an absorptive polarizer 110, and does not include cholesteric liquid crystal layers 140r, 140g, and 140b and retardation plates 130.

[0122] Therefore, in Figure 5 the path of light in the optical system 200 in the comparative example of Figure 4 can be different from the path of light in the example of

[0123] In Figure 5 the light transmitted from the display panel 100 of the head-mounted display device to the optical system 200 is linearly polarized light aligned with the transmission axis of the absorptive polarizer 110. Different from the Figure 4 embodiment, only the light TL1 is transmitted.

[0124] That is, since the absorptive polarizer 110 transmits 50% of the total light and absorbs the remaining 50%, the amount of light transmitted to the optical system 200 cannot exceed 50% of the total light.

[0125] In contrast, in the Figure 4 embodiment, 50% of the light TL1 reflected from the cholesteric liquid crystal layers 140r, 140g, and 140b is re-reflected, and the cholesteric liquid crystal layers 140r, 140g, and 140b can transmit the light TL2, allowing for a potential utilization of up to 100% of the light.

[0126] Hereinafter, some improved structures of the Figure 4 embodiment will be described in detail.

[0127] Figures 6 to 8 is a view schematically showing the optical path of a head-mounted display device according to another embodiment.

[0128] In Figure 6 an improved structure of the display panel 100 of the head-mounted display including cholesteric liquid crystal layers 140r, 140g, and 140b as in the Figure 4 embodiment will be described.

[0129] Figure 6 It further includes an upper light-blocking layer BM2 capable of blocking light interference between the cholesteric liquid crystal layers 140r, 140g, and 140b.

[0130] Each of the cholesteric liquid crystal layers 140r, 140g, and 140b has wavelengths for reflection and transmission based on Formula 1. Therefore, when different colors of light are applied, the light disappears without being transmitted or reflected, reducing the light efficiency.

[0131] To prevent this, Figure 6The embodiment also includes an upper light blocking layer BM2 between the cholesteric liquid crystal layers 140r, 140g, and 140b.

[0132] The display panel 100 of the head-mounted display device includes a light-emitting device unit 150 and cholesteric liquid crystal layers 140r, 140g, and 140b located on the front surface of the light-emitting device unit 150.

[0133] The upper light blocking layer BM2 located between two of the cholesteric liquid crystal layers 140r, 140g, and 140b, the retardation plate 130 located in front of the cholesteric liquid crystal layers 140r, 140g, and 140b, the upper light blocking layer BM2, the absorption type polarizer 110 located on the front surface of the retardation plate 130, and the cholesteric liquid crystal layers 140r, 140g, and 140b each have different wavelength values according to the above formula 1.

[0134] The first-color cholesteric liquid crystal layer 140r can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction within the wavelength range corresponding to the first color.

[0135] For example, the first color can be red, which is one of the primary colors of light. The wavelength value of formula 1 for the first-color cholesteric liquid crystal layer 140r is the wavelength band corresponding to the first color, which is 600 nm or greater and 700 nm or less.

[0136] The second-color cholesteric liquid crystal layer 140g can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction within the wavelength range corresponding to the second color.

[0137] For example, the second color can be green, which is one of the primary colors of light. The wavelength value of formula 1 for the second-color cholesteric liquid crystal layer 140g is the wavelength band corresponding to the second color, and is 500 nm or greater and less than 600 nm.

[0138] The third-color cholesteric liquid crystal layer 140b transmits circularly polarized light in one direction and reflects circularly polarized light in the opposite direction within the wavelength range corresponding to the third color.

[0139] For example, the third color can be blue, which is one of the primary colors of light. The wavelength value of formula 1 for the third-color cholesteric liquid crystal layer 140b is the wavelength band corresponding to the third color, and is 400 nm or greater and less than 500 nm.

[0140] In accordance with Figure 6In the display panel 100 of the head-mounted display device according to the embodiment, the upper light-blocking layer BM2 is located between the cholesteric liquid crystal layers 140r, 140g, and 140b. For example, the upper light-blocking layer BM2 covers the red color filter 230r, so that the transmitted light is transmitted only to the first-color cholesteric liquid crystal layer 140r. The upper light-blocking layer BM2 covering the green color filter 230g allows the light passing through the green color filter 230g to be transmitted only to the second-color cholesteric liquid crystal layer 140g. The upper light-blocking layer BM2 covering the blue color filter 230b allows the blue color filter light passing through the blue color filter 230b to be transmitted only to the third-color cholesteric liquid crystal layer 140b.

[0141] As a result, in Figure 6 the embodiment, the clockwise circularly polarized light is transmitted through the first-color cholesteric liquid crystal layer 140r, and the light in the opposite direction (i.e., the counterclockwise direction) is re-transmitted.

[0142] The reflected light RL1 circularly polarized in the counterclockwise direction is reflected from the cathode or anode in the third direction DR3. Then, the light TL2 changed to clockwise circularly polarized light due to reflection passes through the first-color cholesteric liquid crystal layer 140r and is re-transmitted.

[0143] In Figure 6 the embodiment, the transmitted light TL1 of green with circular polarization in the clockwise direction passes through the second-color cholesteric liquid crystal layer 140b. The light RL1 with the opposite circular polarization (i.e., circular polarization in the counterclockwise direction) is reflected.

[0144] The reflected light RL1 circularly polarized in the counterclockwise direction is reflected from the cathode or anode in the third direction DR3. Then, the light TL2 changed to clockwise circularly polarized light due to reflection passes through the second-color cholesteric liquid crystal layer 140r and is re-transmitted.

[0145] In Figure 6 the embodiment, the transmitted light TL1 of blue with circular polarization in the clockwise direction passes through the third-color cholesteric liquid crystal layer 140b. The light RL1 with the opposite circular polarization (i.e., circular polarization in the counterclockwise direction) is reflected RL1.

[0146] The reflected light RL1 circularly polarized in the counterclockwise direction is reflected from the cathode or anode in the third direction DR3. Then, the light TL2 changed to clockwise circularly polarized light due to reflection passes through the third-color cholesteric liquid crystal layer 140b and is re-transmitted, thereby improving the light efficiency.

[0147] Compared with Figure 4 the embodiment, Figure 6 the embodiment has the advantage of maintaining the light efficiency because the light of a specific color will only reach the corresponding cholesteric liquid crystal layers 140r, 140g, and 140b.

[0148] In some embodiments, the display panel 100 of the head-mounted display device may not include the cholesteric liquid crystal layers 140r, 140g, and 140b, which will be described by Figure 7 and Figure 8 The display panel 100 of the head-mounted display device in

[0149] Figure 7 and Figure 8 does not include the absorptive polarizer 110. Instead, the embodiment includes a reflective polarizer (also referred to as a reflective polarizer for a display device) that reflects some of the linearly polarized light and transmits some of the linearly polarized light.

[0150] Figure 7 shows an embodiment in which the brightness enhancement film 111 (e.g., a double brightness enhancement film (DBEF)) is used as the reflective polarizer, and in Figure 8 a wire grid is arranged in one direction as a reflective polarizer (also referred to as a wire grid reflective polarizer) 112.

[0151] Referring to Figure 7 the brightness enhancement film 111 includes two layers with different refractive indices that are repeatedly stacked. At the boundary between the two layers, due to the difference in refractive indices, some light is reflected. However, multiple boundaries cause all the light reflected in a specific direction to be transmitted while the light perpendicular to that direction is transmitted.

[0152] Referring to Figure 8 the wire grid reflective polarizer 112 includes multiple metal lines with a fine width arranged in one direction. The wire grid reflective polarizer 112 can reflect light parallel to the arrangement direction of the metal lines and transmit light perpendicular to the arrangement direction of the metal lines.

[0153] The interval between the multiple metal lines of the wire grid reflective polarizer 112 can be narrower than the wavelength of visible light.

[0154] The reflection axes of the brightness enhancement film 111 and the wire grid reflective polarizer 112 can have the same angle as the reflection axis of the reflective polarizer 222.

[0155] In the embodiments of Figure 7 and Figure 8 the retardation plate 130 and the light emitting device unit 150 can be located below the brightness enhancement film 111 and the wire grid reflective polarizer 112. The term "below" used herein can mean that the retardation plate 130 is located on the side opposite to the third direction DR3.

[0156] In this text, the light-emitting device unit 150 can emit circularly polarized light from the organic light-emitting diode (OLED). The light-emitting layer of the organic light-emitting diode (OLED) can be as shown in Figure 11 and Figure 12 .

[0157] This will be described later with reference to Figure 11 and Figure 12 .

[0158] The circularly polarized light emitted from the light-emitting device unit 150 passes through the retarder 130 and is changed into linearly polarized light. When the changed linearly polarized light is aligned with the transmission axes of the brightness enhancement film 111 and the reflective polarizer 112, it is transmitted.

[0159] Meanwhile, when the linearly polarized light is aligned with the reflection axes of the brightness enhancement film 111 and the wire-grid reflective polarizer 112, it is reflected, and then is changed back into circularly polarized light at the retarder 130 and is reflected in the third direction DR3 at the cathode or the anode.

[0160] When the light is converted into linearly polarized light in the retarder 130, the light is aligned with the transmission axes of the brightness enhancement film 111 and the wire-grid reflective polarizer 112 and is transmitted.

[0161] Therefore, the amount of light used in the head-mounted display device is increased, thereby increasing the light efficiency.

[0162] In the above text, the structure of the light-emitting device unit 150 of the display panel 100 of the head-mounted display device has been schematically reviewed.

[0163] In the following text, the detailed cross-sectional structure of the light-emitting device unit 150 of the display panel 100 of the head-mounted display device will be described in detail through Figure 9 and Figure 10 .

[0164] In Figure 9 and Figure 10 , the cholesteric liquid crystal layers 140r, 140g, and 140b, the absorptive polarizer 110, the retarder 130, the upper light-blocking layer BM2, and / or the brightness enhancement film 111 and the wire-grid reflective polarizer 112 located above the light-emitting device unit 150 used in the head-mounted display device are omitted and can be additionally attached according to each embodiment.

[0165] Figure 9 and Figure 10 are schematic cross-sectional views of the display panel of the head-mounted display device according to various embodiments.

[0166] First, the structure of the display panel 100 of the head-mounted display device according to an embodiment will be described through Figure 9 .

[0167] According to Figure 9 An embodiment of a display panel 100 used in a head-mounted display device shows an organic light-emitting display panel including an organic light-emitting diode OLED.

[0168] The organic light-emitting diode OLED may include an encapsulation substrate Encap1, a color filter 230, and a light-blocking layer BM.

[0169] The organic light-emitting display panel further includes a substrate SUB. The substrate SUB includes an inorganic insulating material such as glass or an organic insulating material such as plastic or polyimide (PI). In some embodiments, the substrate SUB may include a silicon substrate.

[0170] The substrate SUB may include at least one base layer including a polymer resin and at least one inorganic layer. The base layer and the inorganic layer are stacked in sequence and alternately.

[0171] The substrate SUB may have different degrees of flexibility.

[0172] The substrate SUB may be a rigid substrate or a flexible substrate capable of being bent, folded, or rolled up.

[0173] A semiconductor layer is located on the substrate SUB.

[0174] The semiconductor layer may include polysilicon or an oxide semiconductor.

[0175] The semiconductor layer includes a channel region C, a first region S, and a second region D.

[0176] The first region S and the second region D are disposed on both sides of the channel region C. For example, the channel region C is disposed between the first region S and the second region D and is in direct contact with the first region S and the second region D. The channel region C, the first region S, and the second region D are aligned at the same level.

[0177] Compared with the first region S and the second region D, the channel region C is a semiconductor region doped with fewer impurities or not doped with impurities. Compared with the channel region C, the first region S and the second region D are semiconductor regions doped with a larger amount of impurities.

[0178] A first inorganic insulating layer In1 is located on the semiconductor layer.

[0179] The first inorganic insulating layer In1 may have a single-layer or multi-layer structure including silicon oxide (SiO x ), silicon nitride (SiN x ), and / or silicon oxynitride (SiO x N y ).

[0180] A first gate conductive layer including a gate electrode GAT is located on the first inorganic insulating layer In1.

[0181] The first gate conductive layer may be a single layer including a laminated metal film, and the laminated metal film includes copper (Cu), copper alloy, aluminum (Al), aluminum alloy, molybdenum (Mo), molybdenum alloy, titanium (Ti), and / or titanium alloy. In some embodiments, the first gate conductive layer may be a multilayer film.

[0182] The gate electrode GAT may overlap with the channel region C of the planar semiconductor layer. For example, the gate electrode GAT may be disposed on the channel region C.

[0183] The semiconductor layer including the channel region C, the first region S, and the second region D and the gate electrode GAT overlapping with the channel region C may form a transistor TFT.

[0184] The second inorganic insulating layer In2 is located on the first gate conductive layer and the first inorganic insulating layer In1.

[0185] The second inorganic insulating layer In2 may be a single layer or a multilayer including silicon oxide (SiO x ), silicon nitride (SiN x ), and / or silicon oxynitride (SiO x N y ).

[0186] The first data conductive layer including electrodes (source and drain) is connected to the first region S and the second region D of the semiconductor layer and the signal lines SL1 and SL2 on the second inorganic insulating layer In2.

[0187] The source and the drain may be electrically connected to the first region S and the second region D of the semiconductor layer respectively through contact holes formed in the second inorganic insulating layer In2.

[0188] In some embodiments, the semiconductor layer may directly extend and be electrically connected to adjacent pixels without source and drain.

[0189] The first data conductive layer includes aluminum (Al), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and / or copper (Cu), etc., and may include a single layer or a multilayer structure including aluminum (Al), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and / or copper (Cu), etc.

[0190] In some embodiments, the second gate conductive layer and an additional inorganic insulating layer may also be included on the second inorganic insulating layer In2 and between the first data conductive layers.

[0191] The second gate conductive layer may include a storage electrode overlapping with the gate electrode GAT of the first gate conductive layer and form a storage capacitor with the gate electrode GAT.

[0192] An additional inorganic insulating layer covers the second gate conductive layer and insulates the gate conductive layer from the first data conductive layer.

[0193] The third organic insulating layer In3 is located on the first data conductive layer.

[0194] The third organic insulating layer In3 may include a general polymer (such as polymethyl methacrylate (PMMA) or polystyrene (PS)), a polymer derivative having a phenolic group, an acrylic polymer, an imide polymer, a polyimide, a silicone polymer, etc. It may also include an organic insulating material.

[0195] An opening may be located in the third organic insulating layer In3, and the electrodes of the transistor TFT are electrically connected to the anode.

[0196] The anode is located on the third organic insulating layer In3.

[0197] The anode is electrically connected to the transistor TFT through the opening in the third organic insulating layer In3.

[0198] The anode may include metals such as silver (Ag), lithium (Li), calcium (Ca), aluminum (Al), magnesium (Mg), gold (Au), indium tin oxide (ITO), or indium. The anode may also include a transparent conductive oxide (TCO) such as indium zinc oxide (IZO).

[0199] The anode may be formed of a single layer including a metal material or a transparent conductive oxide. In some embodiments, the anode may be a multi-layer including a metal material or a transparent conductive oxide.

[0200] The pixel defining layer PDL is located on the third organic insulating layer In3 and the anode.

[0201] The pixel defining layer PDL has an opening overlapping with at least a part of the anode and defining an emission region.

[0202] The opening may have a planar shape substantially similar to the planar shape of the anode.

[0203] For example, the opening may have a rhombus shape or an octagon shape similar to a rhombus in a plane, but is not necessarily limited thereto, and may have any shape such as a rectangle, a polygon, a circle, an ellipse, etc.

[0204] The pixel defining layer PDL is an organic insulating material, for example, a general polymer (polymethyl methacrylate (PMMA) or polystyrene (PS)), a polymer derivative having a phenolic group, an acrylic polymer, an imide polymer, a polyimide, or a silicone polymer.

[0205] The intermediate layer EL is located on the pixel defining layer PDL and the anode.

[0206] The intermediate layer EL may include a light-emitting layer and a functional layer.

[0207] The light-emitting layer of the intermediate layer EL generates light of a predetermined color, so that the organic light-emitting diode OLED can display one of the three primary colors of light.

[0208] In some embodiments, the organic light-emitting diode OLED can similarly display white light or light in a specific wavelength band.

[0209] In this case, a color filter or a color conversion layer may also be included on the upper side of the organic light-emitting diode OLED, so that when the light emitted from each organic light-emitting diode OLED is converted into one of the three primary colors of light, an image can be displayed.

[0210] The intermediate layer EL may include a structure in which a plurality of light-emitting layers and a plurality of functional layers are stacked (referred to as a tandem structure herein). When the organic light-emitting diode OLED generates white light, the light emitted by the light-emitting layer and the functional layer is combined, resulting in the generation of white light.

[0211] The light-emitting layer may include an organic material and / or an inorganic material.

[0212] The light-emitting layer of the present embodiment may be formed only in the opening of the pixel defining layer PDL.

[0213] The functional layer of the intermediate layer EL may include a hole injection layer, a hole transport layer, an electron transport layer, and / or an electron injection layer.

[0214] The functional layer may be divided into a first functional layer and a second functional layer. The first functional layer is located between the anode and the light-emitting layer. The second functional layer is located between the light-emitting layer and the cathode.

[0215] The functional layer may have a shape that at least overlaps with the surface of the substrate SUB.

[0216] The functional layer may be provided over a plurality of pixels.

[0217] The cathode is located on the intermediate layer EL.

[0218] The cathode may include calcium (Ca), barium (Ba), magnesium (Mg), aluminum (Al), silver (Ag), platinum (Pt), palladium (Pd), gold (Au), and / or nickel (Ni), a reflective metal including neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), and / or calcium (Ca), or a transparent conductive oxide (TCO) such as indium tin oxide (ITO). The cathode may also include indium zinc oxide (IZO).

[0219] The cathode may have a semi-transmissive and semi-reflective property.

[0220] The organic light-emitting diode OLED may include an anode, an intermediate layer EL, and a cathode.

[0221] However, this embodiment is not necessarily limited thereto, and according to the driving method of the light-emitting display panel, the upper and lower positions of the cathode and the anode may be interchanged.

[0222] Holes and electrons are respectively injected from the anode and the cathode into the intermediate layer EL, and light is emitted when excitons coupled with the injected holes and electrons drop from the excited state to the ground state.

[0223] The encapsulation substrate Encap1 is located on the cathode, and a space vc may be located between the cathode and the encapsulation substrate Encap1.

[0224] In the space vc, an inert gas such as nitrogen may be filled, or another optically transparent filler may be positioned.

[0225] In addition, according to an embodiment, an optically transparent planarization film or an adhesive for attaching the encapsulation substrate Encap1 may be positioned in the space vc.

[0226] In some embodiments, the encapsulation substrate Encap1 may be attached by a sealant located around the display area of the displayed image.

[0227] The encapsulation substrate Encap1 may be formed of optically isotropic glass or polymethyl methacrylate (PMMA).

[0228] Since the organic light-emitting device may be vulnerable to moisture and oxygen, the encapsulation substrate Encap1 seals the organic light-emitting diode OLED and blocks the inflow of external moisture and oxygen.

[0229] Spacers may also be formed on the pixel defining layer PDL to maintain a distance from the encapsulation substrate Encap1. The spacers may be formed under the cathode.

[0230] Each pixel may include more than one transistor. For example, there may be two or more transistors in each pixel.

[0231] In some embodiments, as an alternative to the encapsulation substrate Encap1, an encapsulation layer may be formed by stacking insulating films, which will be described by Figure 10 herein.

[0232] Unlike Figure 9 , in Figure 10 , the encapsulation layer Encap2 includes three insulating layers on the cathode, rather than the encapsulation substrate Encap1.

[0233] The encapsulation layer Encap2 is a layer for blocking the inflow of moisture and oxygen into the organic light-emitting diode OLED. The encapsulation layer Encap2 may have a structure including a plurality of insulating layers and have a composite film including both an inorganic layer and an organic layer.

[0234] Figure 10 The encapsulation layer Encap2 is shown. The encapsulation layer Encap2 includes three layers stacked in sequence: a first encapsulation inorganic layer Encap2-1, an encapsulation organic layer Encap2-2, and a second encapsulation inorganic layer Encap2-3.

[0235] The first encapsulation inorganic layer Encap2-1 covers the cathode and may include silicon nitride, silicon oxide, or an inorganic compound in which silicon nitride and silicon oxide are combined.

[0236] The encapsulation organic layer Encap2-2 is disposed on the first encapsulation inorganic layer Encap2-1 and may contact the first encapsulation inorganic layer Encap2-1.

[0237] The encapsulation organic layer Encap2-2 may cover the curvature formed on the upper surface of the first encapsulation inorganic layer Encap2-1 or particles present on the first encapsulation inorganic layer Encap2-1. The encapsulation organic layer Encap2-2 may have the effect of providing a flat surface.

[0238] The second encapsulation inorganic layer Encap2-3 is disposed on the encapsulation organic layer Encap2-2 and covers the encapsulation organic layer Encap2-2.

[0239] The second encapsulation inorganic layer Encap2-3 may include silicon nitride, silicon oxide, or an inorganic compound in which silicon nitride and silicon oxide are combined.

[0240] Meanwhile, in the embodiments of Figure 9 and Figure 10 , the light-emitting diode OLED may emit circularly polarized light and may include a light-emitting layer as shown in Figure 11 and Figure 12 .

[0241] Figure 11 and Figure 12It is a diagram showing details of an example of a light-emitting layer in a display panel of a head-mounted display device according to an embodiment.

[0242] Referring to Figure 11 , the light-emitting layer can emit circularly polarized light by using materials included in a chiral light emitter.

[0243] Figure 12 Examples of five light-emitting layers are shown.

[0244] Figure 12 (A) of briefly shows that a light-emitting layer material can be formed by including a fluorophore without a chiral structure in a nanotemplate having a chiral structure.

[0245] Figure 12 (B) of shows a method of combining a circularly polarized light emitter with a DNA structure, Figure 12 (C) of shows a method of combining AIEgens (biomaterials) to form chiral nanotubes to form circularly polarized light (CPL).

[0246] Figure 12 (D) of shows a method in which light is transmitted through a material formed by stacking multiple layers at a certain interval, thereby causing circular polarization. Figure 12 (E) of demonstrates a method of emitting circularly polarized light (CPL) using ultraviolet (UV) light by combining polyvinyl alcohol (PVA), cellulose nanocrystals (CNC), and carbon dots (CD).

[0247] Figure 12 The methods shown in are examples of various methods, and this application is not necessarily limited thereto.

[0248] As described above, as Figure 1 shown, the optical system 200 includes two aspherical lenses 210 and 220, and optical films 211, 212, 221, and 222 are formed on two surfaces of each aspherical lens, respectively.

[0249] In some embodiments, the optical system 200 may include only one aspherical lens, or may include three or four aspherical lenses.

[0250] At this time, various optical films can be attached to both sides of each aspherical lens.

[0251] Although the embodiments have been described in detail above, the scope of this application is not necessarily limited thereto, and various modifications made by those skilled in the art using the basic concepts of this application defined in the following claims are also included in the scope of this application.

Claims

1. A head mounted display device, characterized in that: include: Display panel; as well as An optical system is arranged in front of the display panel. Wherein, the display panel comprises: Light emitting device unit; A first cholesteric liquid crystal layer, a second cholesteric liquid crystal layer and a third cholesteric liquid crystal layer are disposed on a front surface of the light emitting device unit; an upper light blocking layer disposed between two of the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer and the third cholesteric liquid crystal layer; a retardation plate disposed on front surfaces of the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, the third cholesteric liquid crystal layer, and the upper light blocking layer; and an absorbing polarizer, disposed in front of the retardation plate, Wherein, the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer and the third cholesteric liquid crystal layer have different wavelength values ​​according to the following formula: Wavelength value = n × spacing value wherein n is a refractive index value of a corresponding cholesteric liquid crystal layer among the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, and the third cholesteric liquid crystal layer, and the pitch value is a pitch value of liquid crystal molecules of the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer, or the third cholesteric liquid crystal layer, and The wavelength value means that for light having the wavelength value, the first cholesteric liquid crystal layer, the second cholesteric liquid crystal layer or the third cholesteric liquid crystal layer can transmit circularly polarized light in one direction and reflect circularly polarized light in the opposite direction.

2. The head mounted display device according to claim 1, wherein: The first cholesteric liquid crystal layer has a wavelength value in the range of 600 nm to 700 nm, the second cholesteric liquid crystal layer has a wavelength value of 500 nm or more and less than 600 nm, and the third cholesteric liquid crystal layer has a wavelength value of 400 nm or more and less than 500 nm, The first cholesteric liquid crystal layer transmits circularly polarized light in one direction among light having a wavelength of 600 nm to 700 nm, and reflects circularly polarized light in an opposite direction among light having a wavelength of 600 nm to 700 nm, the second cholesteric liquid crystal layer transmits circularly polarized light in one direction among light having a wavelength of 500 nm or more and less than 600 nm, and reflects circularly polarized light in the opposite direction among light having a wavelength of 500 nm or more and less than 600 nm, the third cholesteric liquid crystal layer transmits circularly polarized light in one direction among light with a wavelength in the range of 400 nm to 500 nm, and reflects circularly polarized light in the opposite direction among light with a wavelength in the range of 400 nm to 500 nm, The absorbing polarizer of the display panel has an absorption axis, absorbs polarized light aligned with the absorption axis, and transmits polarized light perpendicular to the absorption axis, and The retardation plate of the display panel has a first retardation axis, and the head-mounted display device retards light in a direction of the first retardation axis by λ / 4 to change linearly polarized light into circularly polarized light or to convert circularly polarized light into linearly polarized light.

3. The head mounted display device according to claim 2, wherein: The first retardation axis is disposed at an angle of 45 degrees relative to the absorption axis of the absorbing polarizer.

4. The head mounted display device according to claim 2, wherein: The optical system comprises: A first curved lens including a first retardation plate disposed on an inner surface and a beam splitter disposed on an outer surface; a second curved lens including a second retardation plate disposed on an inner surface and a reflective polarizing plate disposed on an outer surface, The first curved lens is disposed on the display panel, and the second curved lens is disposed on the first curved lens. The reflective polarizing plate of the second curved lens has a reflection axis, reflects polarized light aligned with the reflection axis and transmits polarized light perpendicular to the reflection axis, The first retardation plate of the first curved lens has a second retardation axis, and retards light in a direction of the second retardation axis by λ / 4 to change linearly polarized light into circularly polarized light or change circularly polarized light into linearly polarized light, and The second retardation plate of the second curved lens has a third retardation axis, and retards light in a direction of the third retardation axis by λ / 4 to change linearly polarized light into circularly polarized light or change circularly polarized light into linearly polarized light.

5. The head mounted display device according to claim 4, characterized in that: The reflection axis of the reflective polarizing plate is parallel to the absorption axis, and The second delay axis and the third delay axis are disposed at an angle of 45 degrees with respect to the absorption axis and the reflection axis.

6. The head mounted display device according to claim 4, characterized in that: The beam splitter of the first curved lens reflects half of the incident light and transmits the remaining half of the incident light.

7. The head mounted display device according to claim 1, characterized in that: The light emitting device unit includes a light emitting diode, and the light emitting diode includes an anode, an intermediate layer including a light emitting layer, and a cathode. the cathode reflects half of the light incident from the front surface of the light emitting device unit, and the anode reflects all of the light incident from the front surface of the light emitting device unit, The light emitting device unit further includes a first color filter, a second color filter and a third color filter arranged in front of the light emitting diode, The first color filter overlaps with the first cholesteric liquid crystal layer in a plane, The second color filter overlaps the second cholesteric liquid crystal layer in a plane, The third color filter overlaps with the third cholesteric liquid crystal layer in plane, The light emitting device unit further includes a light blocking layer disposed between two color filters among the first color filter, the second color filter, and the third color filter.

8. A head mounted display device, characterized in that: include: Display panel; as well as An optical system is arranged in front of the display panel. Wherein, the display panel comprises: Light emitting device unit; a retardation plate disposed in front of the light emitting device unit; and A reflective polarizing plate for a display device, arranged in front of the retardation plate, wherein the optical system comprises: a first curved lens including a first retardation plate disposed on an inner surface and a beam splitter disposed on an outer surface; and a second curved lens including a second retardation plate disposed on an inner surface and a reflective polarizing plate disposed on an outer surface, Wherein, the first curved lens is arranged on the display panel, and the second curved lens is arranged on the first curved lens, and Wherein, the light emitting device unit emits circularly polarized light.

9. The head mounted display device according to claim 8, characterized in that: The reflective polarizing plate for the display device includes a brightness enhancement film or a wire grid, The reflective polarizing plate of the second curved lens has a reflection axis, and reflects polarized light aligned with the reflection axis and transmits polarized light perpendicular to the reflection axis, The first retardation plate of the first curved lens has a second retardation axis and retards light in the direction of the second retardation axis by λ / 4 to change linearly polarized light into circularly polarized light or change circularly polarized light into linearly polarized light, The second retardation plate of the second curved lens has a third retardation axis and retards light in the direction of the third retardation axis by λ / 4 to change linear polarized light into circular polarized light or change circular polarized light into linear polarized light, The reflection axis of the reflective polarizing plate of the second curved lens is parallel to the reflection axis of the reflective polarizing plate used for the display device, The second delay axis and the third delay axis have an angle of 45 degrees with respect to the reflection axis of the reflective polarizing plate of the second curved lens, and The beam splitter of the first curved lens reflects half of the incident light and transmits the remaining half of the incident light.

10. The head mounted display device according to claim 8, characterized in that: The light emitting device unit includes a light emitting diode including an anode, an intermediate layer including a light emitting layer, and a cathode, and The cathode reflects half of light incident from a front surface of the light emitting device unit, and the anode reflects all of the light incident from the front surface.

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