Emissive display with photo-switchable polarization

• US 9,825,260 B2
• Filed: 08/10/2016
• Issued: 11/21/2017
• Est. Priority Date: 11/26/2014
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Kwong, Raymond
• Primary Examiner(s): Everhart, Caridad
• Assistant Examiner(s): SINGAL, ANKUSH K
• Application Number:
  US15/232,994
• Publication Number:
  US 20160351857A1
• Time in Patent Office: 468 Days
• CPC Class Codes: C07C 245/08 with the two nitrogen atoms of azo groups bound to carbon atoms of six-membered aromatic rings, e.g. azobenzene
• CPC Class Codes: G02B 1/08 made of polarising materials
• CPC Class Codes: G02F 1/0126 Opto-optical modulation, i.e. control of one light beam by another light beam, not otherwise provided for in this subclass
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 50/868 Arrangements for polarized light emission H10K50/86 takes precedence
• CPC Class Codes: H10K 59/10 OLED displays
• CPC Class Codes: H10K 59/50 OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements
• CPC Class Codes: H10K 59/60 OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 85/141 comprising aliphatic or olefinic chains, e.g. poly N-vinylcarbazol, PVC or PTFE
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence

Abstract

A novel emissive display assembly incorporates a photo-switchable polarizer that is switchable between an active, polarizing, state and an inactive, non-polarizing, state depending on the predetermined level of intensity of UV light in the ambient light and enhance the viewable quality of the emissive display by minimizing or eliminating UV light reflection on the emissive display.

Claims

1. An emissive display assembly comprising:

an emissive display panel having a viewing surface; and

a photo-switchable polarizer located in front of the viewing surface, wherein the photo-switchable polarizer is switchable between an active state and an inactive state depending on a level of intensity of UV light in ambient light of the emissive display assembly.

2. The emissive display assembly of claim 1, wherein the photo-switchable polarizer is configured to be in the active state when the level of intensity of the UV light in the ambient light is greater than or equal to a predetermined level and the photo-switchable polarizer is configured to be in the inactive state when the level of intensity of the UV light in the ambient light is less than the predetermined level.

3. The emissive display assembly of claim 1, wherein the photo-switchable polarizer is a circular polarizer.

4. The emissive display assembly of claim 3, wherein the photo-switchable polarizer is configured to be in the active state when the level of intensity of the UV light in the ambient light is greater than or equal to a predetermined level and the photo-switchable polarizer is configured to be in the inactive state when the level of intensity of the UV light in the ambient light is less than the predetermined level.

5. The emissive display assembly of claim 1, wherein the photo-switchable polarizer is a linear polarizer, the emissive display assembly further comprising a quarter wave plate located between the photo-switchable polarizer and the emissive display panel.

6. The emissive display assembly of claim 5, wherein the photo-switchable polarizer is configured to be in the active state when the level of intensity of the UV light in the ambient light is greater than or equal to a predetermined level and the photo-switchable polarizer is configured to be in the inactive state when the level of intensity of the UV light in the ambient light is less than the predetermined level.

7. The emissive display assembly of claim 1, wherein the photo-switchable polarizer comprises one or more azobenzene compounds doped in a polymer material selected from poly-methylmethacrylate or poly-vinyl polymer.

8. The emissive display assembly of claim 7, wherein the azobenzene compound has a structure according to Formula 1:

9. The emissive display assembly of claim 1, wherein the photo-switchable polarizer comprises one or more polymer compounds with azobenzene derivative pendant groups, the one or more polymer compounds having a structure according to Formula 2:

10. The emissive display assembly of claim 1, further comprising a sensor that detects the level of intensity of UV light in the ambient light and adjusts the emissive display panel'"'"'s brightness depending on whether the level of intensity of UV light in the ambient light is greater than or equal to a predetermined level or less than the predetermined level.

11. The emissive display assembly of claim 1, wherein the emissive display panel includes an array of OLED light emissive elements.