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EP-3951904-B1 - VIRTUAL REALITY DISPLAY DEVICE

EP3951904B1EP 3951904 B1EP3951904 B1EP 3951904B1EP-3951904-B1

Inventors

  • WANG, CAN
  • ZHANG, CAN
  • YUE, Han
  • YANG, MING
  • CONG, Ning
  • ZHAO, Jiao
  • XUAN, MINGHUA

Dates

Publication Date
20260506
Application Date
20200318

Claims (6)

  1. A virtual reality display device, comprising an optical waveguide assembly (100) and a display assembly (200), wherein light emitted by the display assembly (200) enters the optical waveguide assembly (100); wherein the display assembly (200) comprises an electroluminescent element (10), a packaging layer (20) and a light converging layer (30) arranged sequentially, wherein the light converging layer (30) is configured to converge light emitted by the electroluminescent element (10) and transmitted through the packaging layer (20), the electroluminescent element (10) comprises a plurality of pixels (11), the light converging layer (30) is tightly attached to the packaging layer (20), and an orthogonal projection of each pixel (11) onto a surface of the packaging layer (20) to which the light converging layer (30) is tightly attached is completely covered by the light converging layer (30); wherein the light converging layer (30) comprises a plurality of lenses (31) in one-to one correspondence with the pixels (11); wherein a first protection layer (22), a color filter substrate (23) and a second protection layer (24) are sequentially arranged on the packaging layer (20) in a direction from the electroluminescent element (10) to the light converging layer (30), wherein the display assembly (200) further comprises a third protection layer (40) arranged at a side of the second protection layer (24) away from the electroluminescent element (10), and the plurality of lenses (31) are arranged between the third protection layer (40) and the second protection layer (24) in the direction from the electroluminescent element (10) to the light converging layer (30); wherein a refractive index of the third protection layer (40), a refractive index of each lens (31) and a refractive index of the second protection layer (24) meet the following formulae: n 2 − n 3 n 1 = r f and n 2 − n 3 n 1 ≥ D 2 f , where n 1 represents the refractive index of the second protection layer (24), n 2 represents the refractive index of each lens (31), n 3 represents the refractive index of the third protection layer (40), r represents a radius of curvature of each lens, f represents a focal length of each lens (31), and D represents an aperture of each lens (31).
  2. The virtual reality display device according to claim 1, wherein the orthogonal project of each pixel (11) onto the surface of the packaging layer (20) to which the light converging layer (30) is tightly attached at least partially overlap an orthogonal projection of a corresponding lens (31) onto the surface of the packaging layer (20) to which the light converging layer (30) is tightly attached.
  3. The virtual reality display device according to claim 2, wherein a distance between a center of any pixel (11) and a main optical axis of the lens (31) corresponding to the pixel (11) is smaller than or equal to 0.5µm.
  4. The virtual reality display device according to claim 2, wherein a focal length of the lens (31) is greater than or equal to 1.7 times of an aperture of the lens (31).
  5. The virtual reality display device according to claim 1, wherein the color filter substrate (23) is provided with a plurality of color units (231) in one-to one correspondence with the pixels (11), an orthogonal projection of each color unit (231) onto the surface of the packaging layer (20) to which the light converging layer (30) is tightly attached, an orthogonal projection of a corresponding pixel (11) onto the surface of the packaging layer (20) to which the light converging layer (30) is tightly attached, and the orthogonal projection of the lens (31) corresponding to the pixel (11) at least partially overlap each other, wherein for the color unit (231) and the lens (31) corresponding to the same pixel (11), light emitted from any point at a surface of the pixel (11) facing the packaging layer (20) passes through any point at a surface of the color unit (231) facing the lens (31) and passes through a surface of the lens (31) tightly attached to the packaging layer (20).
  6. The virtual reality display device according to claim 2, wherein a thickness of the packaging layer (20) is greater than or equal to 0.8 times of a focal length of each lens (31), and smaller than or equal to 1.2 times of the focal length of each lens (31).

Description

TECHNICAL FIELD The present disclosure relates to the field of display technology, specifically to the field of silicon-based Organic Light-Emitting Diode (OLED), in particular to a virtual reality display device. BACKGROUND Recently, Augmented Reality (AR) has developed rapidly, and a high-end product is treated using an optical waveguide technique to acquire a thinner and lighter product. However, a relatively large optical loss occurs for an optical waveguide, so it is necessary to provide an element with relatively large brightness. A silicon-based OLED has such advantages as self-luminescence and being light and thin, so it is able to meet the requirement on portable of an AR product. However, the silicon-based OLED has relatively small brightness, and it is impossible to meet the requirement on high brightness of the AR product. There is an urgent need to increase the brightness of the silicon-based OLED, so as to apply it in an AR field. US 2012/0217521 A1 discloses a display panel apparatus and a manufacturing method for the display panel device. US 2018/0180888 A1 discloses a display module and an HMD device including the same. CN 106129260 B discloses a display panel and a display device. US 2012/0199859 A1 discloses an electroluminescent display apparatus. CN 108919493 A discloses an AR display device, a control method thereof and wearable equipment. SUMMARY An object of the present disclosure is to provide a virtual reality display device, as defined in the appended set of claims, so as to increase brightness of a silicon-based OLED. BRIEF DESCRIPTION OF THE DRAWINGS Through reading the detailed description about non-restrictive embodiments given with reference to the following drawings, the other features, objects and advantages of the present disclosure will become more apparent. Fig.1 is a schematic view showing a display assembly according to one embodiment of the present disclosure;Fig.2 is a schematic view showing a virtual reality display device according to one embodiment of the present disclosure; andFig.3 is a curve diagram showing brightness of light before and after a lens of the display assembly according to one embodiment of the present disclosure. DETAILED DESCRIPTION The present disclosure will be described hereinafter in details in conjunction with the drawings and embodiments. It should be appreciated that, the embodiments are for illustrative purposes only, but shall not be construed as limiting the present disclosure. It should be further appreciated that, for ease of description, merely components associated with the present disclosure are shown in the drawings. It should be appreciated that, in the case of no conflict, the embodiments and the features in the embodiments may be combined. The present disclosure will be described hereinafter in conjunction with the drawings and embodiments. Considering the drawbacks in the related art, an object of the present disclosure is to provide a display assembly and a virtual reality display device, so as to increase brightness of a silicon-based OLED. As shown in Fig.1, the present disclosure provides in some embodiments a display assembly, including an electroluminescent element 10, a packaging layer 20 and a light converging layer 30 arranged sequentially. The light converging layer 30 is configured to converge light emitted by the electroluminescent element 10 and transmitted through the packaging layer 20. The electroluminescent element 10 includes a plurality of pixels 11, the light converging layer 30 is tightly attached to the packaging layer 20, and an orthogonal projection of each pixel 11 onto a surface of the packaging layer 20 to which the light converging layer 30 is tightly attached is completely covered by the light converging layer 30. In the claimed invention, the electroluminescent element may be of a commonly-used structure, packaged through the packaging layer, so as to prolong a service life of the electroluminescent element and improve the reliability of the display assembly. The light converging layer is formed at a side of the packaging layer away from the electroluminescent element. The light may be emitted by the electroluminescent element and transmitted through the packaging layer toward the light converging layer. The light converging layer is configured to converge the light, so as to increase brightness of the light exiting the light converging layer in an approximately central viewing angle of the light converging layer. The light converging layer includes lenses. As shown in Fig.3, a curve without dots represents the brightness of the light from the display assembly without any light converging layer, and a curve with dots represents the brightness of the light from the display assembly with the light converging layer. The brightness of the light may be increased within ±9° of the central viewing angle of the light converging layer. For a virtual reality display device using an optical waveguide techni