Directional backlight, 3d image display apparatus having the same, and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2017176669-A1
Application number	US-201615171523-A
Country	US
Kind code	A1
Filing date	Jun 2, 2016
Priority date	Dec 18, 2015
Publication date	Jun 22, 2017
Grant date	—

Abstract

A directional backlight and a 3D image display apparatus including the directional backlight are provided. The directional backlight includes a light guide plate guiding light emitted from a light source; a diffractive device configured to adjust the direction of light exiting the light guide plate; and an aperture adjusting layer including a plurality of apertures. The aperture adjusting layer may adjust the optical output efficiency of the diffractive device.

First claim

What is claimed is:

1 . A directional backlight comprising:
a light source; a light guide plate comprising an entrance surface receiving light emitted from the light source, the light guide plate guiding the light emitted from the light source; a diffractive device comprising a plurality of grating units configured to adjust a direction of light exiting the light guide plate; and an aperture adjusting layer arranged on the diffractive device and comprising a plurality of apertures.

2 . The directional backlight of claim 1 , wherein each of the grating units comprises a plurality of sub-grating units, wherein the sub-grating units are dependent on different wavelength bands of light, and the apertures of the aperture adjusting layer respectively correspond to the sub-grating units.

3 . The directional backlight of claim 2 , wherein the apertures of the aperture adjusting layer have different sizes so as to adjust aperture ratios of the corresponding sub-grating units.

4 . The directional backlight of claim 1 , wherein the light source comprises a light source configured to emit light of a plurality of colors in different directions, the aperture adjusting layer comprises aperture units corresponding to the grating units, and each of the aperture units comprises a plurality of sub-apertures transmitting the light of the colors.

5 . The directional backlight of claim 4 , wherein sizes of the sub-apertures increase in the directions in which the light of the colors propagates.

6 . The directional backlight of claim 1 , wherein each of the grating units comprises a plurality of sub-grating units, wherein the sub-grating units are dependent on different wavelength bands of light, the aperture adjusting layer comprises aperture units corresponding to the grating units, and each of the aperture units comprises a plurality of sub-apertures respectively corresponding to the sub-grating units.

7 . The directional backlight of claim 6 , wherein the sub-apertures have different size ratios in different aperture units.

8 . The directional backlight of claim 6 , wherein the aperture adjusting layer is divided into a plurality of sections, and the sub-apertures of the aperture units have different size ratios in different sections.

9 . A directional backlight comprising:
a light source emitting light of a plurality of colors; a light guide plate comprising an entrance surface receiving the light emitted from the light source, the light guide plate guiding the light emitted from the light source; and a diffractive device comprising a plurality of grating units configured to adjust a direction of the light of the colors when the light exits the light guide plate, wherein each of the grating units comprises a plurality of sub-grating units corresponding to the light of the colors, and the sub-grating units have different refractive indexes such that output efficiency of the light of the colors increases in a direction away from the entrance surface of the light guide plate.

10 . The directional backlight of claim 9 , wherein the diffractive device is divided into a plurality of sections, and refractive indexes of sub-grating units of grating units included in a section relatively distant from the entrance surface of the light guide plate are greater than refractive indexes of sub-grating units of grating units included in a section relatively close to the entrance surface of the light guide plate.

11 . A three-dimensional (3D) image display apparatus comprising:
a directional backlight; and a display panel forming images using light output from the directional backlight, wherein the directional backlight comprises:
a light source;
a light guide plate comprising an entrance surface receiving light emitted from the light source, the light guide plate guiding the light emitted from the light source;
a diffractive device comprising a plurality of grating units configured to adjust a direction of light exiting the light guide plate; and
an aperture adjusting layer arranged on the diffractive device and comprising a plurality of apertures.

12 . A method of manufacturing a directional backlight, the method comprising:
forming grating units, each grating unit comprising a plurality of sub-grating units on a substrate, the sub-grating units comprising different diffraction patterns; preparing a mask comprising an aperture array corresponding to the sub-grating units; and etching the sub-grating units formed on the substrate using the mask such that the sub-grating units have different sizes.

13 . The method of claim 12 , wherein the mask comprises mask aperture units corresponding to the grating units, and the mask aperture units comprise mask sub-apertures respectively corresponding to the sub-grating units.

14 . The method of claim 12 , wherein the diffraction patterns have nano-sizes, and the aperture array has a micro-size.

15 . The method of claim 12 , further comprising attaching a light guide plate to the substrate.

16 . A method of manufacturing a directional backlight, the method comprising:
printing a first material pattern having a first refractive index on a substrate by an inkjet printing method; printing a second material pattern having a second refractive index on the substrate by an inkjet printing method; and forming diffraction patterns on the first and second material patterns by a nanoimprinting method.

17 . The method of claim 16 , further comprising printing a third material pattern having a third refractive index on the substrate by an inkjet printing method.

18 . The method of claim 16 , further comprising attaching a light guide plate to the substrate.

19 . The method of claim 18 , wherein the first and second material patterns are configured to adjust output efficiency of light guided via the light guide plate.

20 . The method of claim 19 , wherein the first and second material patterns are configured such that output efficiency of light guided via the light guide plate increases in a direction away from an entrance surface of the light guide plate.

21 . The method of claim 16 , wherein the first and second material patterns comprise a plurality of grating units, and each of the grating units comprises a plurality of sub-grating units selectively diffracting light of different colors.

22 . A directional backlight comprising:
a first light source emitting light in a first direction; a second light source emitting light in a second direction; a light guide plate comprising a first entrance surface receiving light emitted from the first light source and a second entrance surface receiving light emitted from the second light source; and a diffractive device provided on a surface of the light guide plate that is orthogonal to the first entrance surface and the second entrance surface, the diffractive device comprising a plurality of grating units configured to adjust a direction of light exiting the light guide plate, wherein the grating units are configured such that a grating unit relatively far away from the first entrance surface emits more light from the first light source than a grating unit relatively closer to the first entrance surface, and such that a grating unit relatively far away from the second entrance surface emits more light from the second light source than a grating unit relatively closer to the second entrance surface.

23 . The directional backlight of claim 22 , wherei

Assignees

• Samsung Electronics Co Ltd

Inventors

• Chung Jaeseung
• Lee Sunghoon
• Bae Jihyun
• Park Joonyong
• Song Hoon
• Lee Hongseok
• Kim Dongouk
• Kim Hyunjoon
• Shin Bongsu
• Shim Dongsik
• Hong Seogwoo

Classifications

• G02B6/0061 Primary

  to provide homogeneous light output intensity · CPC title

• G02B5/1842

  Gratings for image generation (G02B5/1847 takes precedence) · CPC title

• G02B6/0068

  Arrangements of plural sources, e.g. multi-colour light sources · CPC title

• G02B5/1819

  Plural gratings positioned on the same surface, e.g. array of gratings (plural diffractive elements positioned sequentially along the optical path G02B27/4272) · CPC title

• G02B5/1857

  using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams · CPC title