DISPLAY THAT EMITS CIRCULARLY-POLARIZED LIGHT

• US 20110124260A1
• Filed: 01/31/2011
• Published: 05/26/2011
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Gettemy, Shawn R., Chen, Cheng, Zhong, John Z., Chen, Wei, Yin, Victor H. E.
• Granted Patent: US 8,115,892 B2
• Time in Patent Office: Days
• US Class Current: 445/24
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 2413/03 Number of plates being 3
• CPC Class Codes: G02F 2413/06 Two plates on one side of the LC cell

Abstract

One embodiment of the present invention provides a display that emits circularly-polarized light. This display includes a display mechanism that emits linearly-polarized light and a layer placed in the path of the linearly-polarized light. The layer receives the linearly-polarized light on one surface, converts the linearly-polarized light to circularly-polarized light, and then emits the circularly-polarized light from another surface. By emitting circularly-polarized light, the display reduces the perceived distortion found at some angles when the display is viewed through a linearly-polarizing filter.

Claims

1. A method for manufacturing a display that emits circularly-polarized light, comprising:

forming a display mechanism that emits linearly-polarized light;

forming a layer that circularly polarizes light in the path of the linearly-polarized light, so that the layer converts the linearly-polarized light to circularly-polarized light; and

forming one or more a-plates coupled to the layer that circularly polarizes light;

wherein the display reduces perceived distortion when the display is viewed through a linearly-polarizing filter.

2. The method of claim 9, wherein forming the layer that circularly-polarizes light comprises:

forming a retardation film;

wherein the retardation film has a higher refractive index in a first direction than in a second direction perpendicular to the first direction.

3. The method of claim 10, where forming the retardation film further involves aligning the first direction in the retardation film 45 degrees with respect to the plane of the linearly-polarized light emitted by the display mechanism.

4. The method of claim 10, wherein forming the retardation film further involves tuning the thickness of the retardation film to convert linearly-polarized light to circularly-polarized light.

5. The method of claim 9, wherein forming the layer that circularly-polarizes light further involves:

laminating the layer on top of the display mechanism;

forming a film in front of the display mechanism; and

/or

incorporating the layer into a display cover which can be attached to the display mechanism.