Mirror with built-in display

• US 7,362,505 B2
• Filed: 11/16/2004
• Issued: 04/22/2008
• Est. Priority Date: 11/24/2003
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Hikmet, Rifat Ata Mustafa, Horsten, Jan Baptist Adrianus Maria
• Primary Examiner(s): Allen; Stephone B.
• Assistant Examiner(s): Chapel; Derek S.
• Application Number:
  US10/579,932
• Publication Number:
  US 20070064321A1
• Time in Patent Office: 1,253 Days
• Field of Search: None
• US Class Current: 359/485.07
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence

Abstract

A mirror display device which may be simultaneously used for display purposes, based on a display, wherein the display device during use provides light of a first (circular) polarization, with a switchable polarizing mirror placed in front of it. The reflectivity of such a mirror display device may be enhanced by providing a second switchable (circular) polarizer between the display device and the polarizing mirror.

Claims

1. A polarizing mirror for viewing purposes having a first plane reflecting light of a first kind of polarization to a viewing side, the polarizing mirror passing light of a second kind of polarization and being provided with a display device at its non-viewing side, which display device during use provides light of the second kind of polarization, the polarizing mirror being switchable between a state passing light of the second kind of polarization and reflecting light of the first kind of polarization and a state passing light of both kinds of polarizing, wherein a switchable polarizer is located between the polarizing mirror and a ¼

λ

foil.

2. The polarizing mirror as claimed in claim 1, wherein the switchable polarizer is switchable between a state passing light of the first kind of polarization and reflecting light of the second kind of polarization and a state passing light of both kinds of polarization.

3. The polarizing mirror as claimed in claim 1, wherein the switchable polarizer is switchable between a state passing light of the second kind of polarization and reflecting light of the first kind of polarization and a state passing light of both kinds of polarization, the polarizing mirror comprising a retarding layer being provided between the polarizing mirror and the switchable polarizer, wherein the retarding layer is configured to change the polarization of light from the first kind of polarization into the second kind of polarization or change the polarization of light from the second kind of polarization into the first kind of polarization.

4. The polarizing mirror as claimed in claim 3, the retarding layer comprising a ½

λ

foil, λ

having a value of 500-600 nm.

5. The polarizing mirror as claimed in claim 4, the retarding layer having a double layer comprising a retarder with a negative birefringence.

6. The polarizing mirror as claimed in claim 1, the polarizing mirror and switchable polarizers being cholesteric polarizers.

7. The polarizing mirror as claimed in claim 6, the display device comprising a partial display emitting polarized light having at the emitting side, the ¼

λ

foil, λ

having a value of 500-600 nm.

8. The polarizing mirror as claimed in claim 6, the display device comprising a partial display emitting non-polarized light having at the emitting side, a ½

λ

foil, λ

having a value of 500-600 nm.

9. The polarizing mirror as claimed in claim 1 having a bandwidth of at least 50 nm.

10. The polarizing mirror as claimed in claim 1 reflecting in the visible range of the spectrum.

11. The polarizing mirror as claimed in claim 1, further comprising an LCD device positioned next to the ¼

λ

foil.

13. The polarizing mirror as claimed in claim 1, wherein an area of the display unit is smaller than an area of the first plane.

14. The polarizing mirror as claimed in claim 1, wherein the polarizing mirror is switchable between a state passing light of the second kind of polarization and reflecting light of the first kind of polarization and a state passing light of both kinds of polarization, and the polarizing mirror is immediately next to the switchable polarizer.

15. The polarizing mirror as claimed in claim 1, wherein λ

has a value of 500-600 nm.

12. A polarizing mirror for viewing purposes having a first plane reflecting light of a first kind of polarization to a viewing side, the polarizing mirror passing light of a second kind of polarization and being provided with a display device at its non-viewing side, which display device during use provides light of the second kind of polarization, the polarizing mirror being switchable between a state passing light of the second kind of polarization and reflecting light of the first kind of polarization and a state passing light of both kinds of polarization, the polarizing mirror having at the non-viewing side, a switchable polarizer between the display device and the polarizing mirror, wherein the switchable polarizer is positioned between a ¼

λ

foil and a ½

λ

foil.