Transparent display device including a light guide plate having light sources at both lateral surfaces and formed with a plurality of concave patterns at the lower surface thereof

Patent metadata

Field	Value
Publication number	US-9250376-B2
Application number	US-201414458956-A
Country	US
Kind code	B2
Filing date	Aug 13, 2014
Priority date	Jul 15, 2009
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Disclosed is a transparent display device including a light guide plate formed with a plurality of concave patterns at the lower surface thereof to totally reflect polarized light entered in a lateral direction while transmitting natural light entered from a lower direction therethrough; a light source disposed in a lateral direction of the light guide plate to emit visible light including first and second polarized lights; a first polarizing plate disposed at a lateral portion of the light guide plate to transmit either one of the first and second polarized lights through the light guide plate; a liquid crystal panel for driving liquid crystals to change the phase of the polarized light; and a second polarizing plate for controlling an amount of the polarized light according to the changed phase of the polarized light.

First claim

What is claimes is:

1. A transparent display device, comprising:
a light guide plate with a plurality of concave patterns at the lower surface thereof having an inclined cross-section to totally reflect polarized light entered in both lateral directions while transmitting natural light entered from a lower direction therethrough;
a first and a second light source in both lateral directions of the light guide plate to emit visible light including a first and a second polarized light;
a first and a second polarizing plate at both lateral surfaces of the light guide plate to transmit either one of the first and second polarized lights through the light guide plate;
a liquid crystal panel arranged directly above an upper surface of the light guide plate, wherein no polarizer is located between a first substrate of the liquid crystal panel and the light guide plate, and wherein the liquid crystal panel drives liquid crystals to change the phase of the polarized light; and
a third polarizing plate on a second substrate at an upper portion of the liquid crystal panel having a first substrate and the second substrate, the third polarizing plate being arranged to control an amount of the polarized light according to the changed phase of the polarized light.

2. The transparent display device of claim 1 , wherein the first and the second light sources are any one of a lamp, a light-emitting diode array, an indoor light, and natural light.

3. The transparent display device of claim 1 , wherein the light entered in a lateral direction of the light guide plate is used to make a display, and the natural light entered from a lower direction of the light guide plate is used in a transparent state.

4. The transparent display device of claim 1 , wherein the plurality of concave patterns are formed by laser irradiation.

5. The transparent display device of claim 1 , wherein a size of the concave patterns formed in a second region of the plurality of concave patterns located at a central portion of the lower surface of the light guide plate to be away from the light sources located at both lateral sides of the light guide plate is formed smaller than that of the concave patterns formed in a first region thereof located adjacent to the light sources located at both lateral sides of the light guide plate.

6. The transparent display device of claim 5 , wherein the concave patterns formed in the first region of the plurality of concave patterns are 50-350 μm in horizontal length and 50-300 μm in vertical length, and the concave patterns formed in the second region are 100-200 μm in horizontal length and 50-150 μm in vertical length.

7. The transparent display device of claim 1 , wherein a distance (D 1 ) between the left and right concave patterns adjacent to each other in a horizontal direction (X-direction) of the plurality of concave patterns is 50-350 μm, and a distance (D 2 ) between the upper and lower concave patterns adjacent to each other in a vertical direction (Y-direction) is 50-350 μm.

8. The transparent display device of claim 1 , wherein intervals between the concave patterns formed in a second region of the plurality of concave patterns located at a central portion of the lower surface of the light guide plate to be away from the light source are formed narrower than intervals between the concave patterns formed in a first region thereof located adjacent to the light sources located at both lateral sides of the light guide plate.

9. The transparent display device of claim 1 , wherein the plurality of concave patterns have an oval-shaped structure.

10. The transparent display device of claim 1 , wherein the lower surface of the light guide plate is formed to be inclined and the depth thereof is decreased as it goes from both lateral sides of the light guide plate toward the central portion thereof.

11. The transparent display device of claim 10 , wherein an inclined angle of the central portion of the lower surface of the light guide plate is less than 180 degrees.

12. The transparent display device of claim 1 , wherein inclined-shaped light incident surfaces are located at both sides of the light guide plate.

Assignees

• Lg Display Co Ltd

Inventors

• Park Se-Hong
• Park Jong-Sin

Classifications

• G02B6/0056

  for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements · CPC title

• G02B6/0023 Primary

  provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source · CPC title

• G02F1/133615

  Edge-illuminating devices, i.e. illuminating from the side · CPC title

• G02B6/0036 Primary

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0046

  Tapered light guide, e.g. wedge-shaped light guide · CPC title