Mirror with built-in display

• US 20070064321A1
• Filed: 11/09/2004
• Published: 03/22/2007
• Est. Priority Date: 11/24/2003
• Status: Active Grant

• 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, Horsten, Jan Baptist Adrianus
• Granted Patent: US 7,362,505 B2
• Time in Patent Office: Days
• US Class Current: 359/838
• 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 (1) which can be simultaneously used for display purposes, based on a display (5), which display device during use provides light of a first (circular) polarization, with a switchable polarizing mirror (2) placed in front of it. The reflectivity of such a mirror display device is enhanced by providing between the display device and the polarizing mirror a second switchable (circular) polarizer (11).

Claims

1. A polarizing mirror (1) for viewing purposes having a first plane (2) reflecting light of a first kind of polarization (20′

) to a viewing side, the mirror passing light of a second kind of polarization (20″

) and being provided with a display device (5) 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 between the display device and the polarizing mirror a switchable polarizer (11).

2. A polarizing mirror as claimed in claim 1, having at the non viewing side between the display device and the polarizing mirror a switchable polarizer being 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. A polarizing mirror as claimed in claim 1, having at the non viewing side between the display device and the polarizing mirror a switchable polarizer 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, a retarding layer (12) being provided between the polarizing mirror and the switchable polarizer changing the kind of polarization from the first kind of polarization into the second kind of polarization or vice versa.

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

λ

foil, λ

having a value of 500-600 nm

5. A polarizing mirror as claimed in claim 1, the polarizing mirror and switchable polarizers being cholesteric polarizers.

6. A polarizing mirror as claimed in claim 5, the display device comprising a partial display emitting polarized light having at the emitting side a ¼

λ

foil, λ

having a value of 500-600 nm.

7. A polarizing mirror as claimed in claim 5, 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.

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

9. A polarizing mirror as claimed in claim 1 having a band width of at least 50 nm.

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