TRANSPARENT DISPLAY BACKLIGHT ASSEMBLY

• US 20120163021A1
• Filed: 12/23/2010
• Published: 06/28/2012
• Est. Priority Date: 12/23/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bohn, David D., Fleck, Rod G., Knee, Derek Leslie
• Granted Patent: US 8,770,813 B2
• Time in Patent Office: Days
• US Class Current: 362/608
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 6/0033 Means for improving the coupling-out of light from the light guide
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02F 1/133342 for double-sided displays
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: Y10S 977/834 Optical properties of nanomaterial, e.g. specified transparency, opacity, or index of refraction

Abstract

In embodiments of a transparent display backlight assembly, a backlight panel is operable as a transparent panel, and a light source generates light that the backlight panel directs from the light source to illuminate a display panel of a display device. Light refraction features refract and scatter the light, where the light refraction features are spaced for approximate transparency of the backlight panel and to illuminate the display panel. An active diffuser can be implemented as an additional transparent panel and operable for activation to diffuse the light from the backlight panel that illuminates the display panel.

Claims

1. A backlight assembly, comprising:

a light source configured to generate light;

a backlight panel operable as a transparent panel and configured to direct the light from the light source to illuminate a display panel of a display device; and

light refraction features configured to refract and scatter the light, the light refraction features spaced for approximate transparency of the backlight panel and to refract the light to illuminate the display panel.

2. A display device as recited in claim 1, wherein the light source comprises one or more arrays of light emitting diodes (LEDs), and the backlight panel is edge-lit by the one or more arrays of LEDs.

3. A display device as recited in claim 1, wherein the light source comprises a first array of light emitting diodes (LEDs) proximate a first edge of the backlight panel, and further comprises a second array of LEDs proximate a second edge of the backlight panel.

4. A display device as recited in claim 1, wherein the light refraction features comprise light-scattering particles embedded in the backlight panel.

5. A display device as recited in claim 1, wherein the light refraction features comprise micro extraction features formed as hemisphere divots into the backlight panel.

6. A display device as recited in claim 1, wherein the light refraction features comprise diffractive optics configured to refract designated light wavelengths, the diffractive optics molded into the backlight panel.

7. A display device as recited in claim 1, wherein the light refraction features comprise negative prisms formed into the backlight panel, the negative prisms comprising at least one of nano-prisms configured to increase transparency, or micro-prisms configured to increase display panel illumination.

8. A display device as recited in claim 1, wherein the light refraction features comprise a combination of light-scattering particles embedded in the backlight panel and at least one of:

micro extraction features formed as hemisphere divots into the backlight panel;

diffractive optics configured to refract designated light wavelengths;

or

negative prisms formed into the backlight panel.

9. A transparent display, comprising:

a light source configured to generate light;

a backlight panel operable as a transparent panel and configured to direct the light from the light source to illuminate a display panel; and

an active diffuser operable as an additional transparent panel and further operable for activation to diffuse the light from the backlight panel that illuminates the display panel.

10. A transparent display as recited in claim 9, wherein the light source comprises one or more arrays of light emitting diodes (LEDs), and the backlight panel is edge-lit by the one or more arrays of LEDs.

11. A transparent display as recited in claim 9, wherein the backlight panel includes light refraction features configured to refract and scatter the light, the light refraction features spaced for approximate transparency of the backlight panel and to refract the light to illuminate the display panel.

12. A transparent display as recited in claim 11, wherein the light refraction features comprise light-scattering particles embedded in the backlight panel.

13. A transparent display as recited in claim 11, wherein the light refraction features comprise micro extraction features formed as hemisphere divots into the backlight panel.

14. A transparent display as recited in claim 11, wherein the light refraction features comprise diffractive optics configured to refract designated light wavelengths, the diffractive optics molded into the backlight panel.

15. A transparent display as recited in claim 11, wherein the light refraction features comprise negative prisms formed into the backlight panel, the negative prisms comprising at least one of nano-prisms configured to increase transparency, or micro-prisms configured to increase display panel illumination.

16. A transparent display as recited in claim 9, further comprising a stacked backlight assembly that includes the backlight panel and at least an additional backlight panel operable as a transparent panel and configured to direct the light from the light source to illuminate a display panel.

17. A method, comprising:

generating light with a light source;

refracting the light with light refraction features spaced for approximate transparency of a backlight panel and to refract the light to illuminate a display panel of a display device; and

directing the light from the light source to illuminate the display panel of the display device.

18. A method as recited in claim 17, wherein the light is generated with one or more arrays of light emitting diodes (LEDs), and the backlight panel is edge-lit by the one or more arrays of LEDs.

19. A method as recited in claim 17, wherein the light is refracted with the light refraction features that comprise at least one of:

light-scattering particles embedded in the backlight panel;

micro extraction features formed as hemisphere divots into the backlight panel;

diffractive optics configured to refract designated light wavelengths, the diffractive optics molded into the backlight panel;

or

negative prisms formed into the backlight panel, the negative prisms comprising at least one of nano-prisms configured to increase transparency, or micro-prisms configured to increase display panel illumination.

20. A method as recited in claim 17, further comprising at least one of:

diffusing the light that illuminates the display panel when activating an active diffuser;

or

switching-off the active diffuser for transparency of the display device.