Head-mounted display with a polarization-dependent mirror

• US 6,710,928 B2
• Filed: 03/29/2001
• Issued: 03/23/2004
• Est. Priority Date: 03/31/2000
• 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: Roest, Wouter
• Primary Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US09/821,133
• Publication Number:
  US 20010028332A1
• Time in Patent Office: 1,090 Days
• Field of Search: 359/630, 359/631, 359/633, 345/7, 345/8, 345/9
• US Class Current: 359/633
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

The invention relates to a head-mounted display provided with an image display device and an optical system. The optical system comprises a first λ/4 plate, a lens element, a semi-transmissive mirror, a second λ/4 plate and a polarization-dependent mirror, arranged, in this order, from the incident side for projecting an image to be formed by the image display device on a user'"'"'s retina.

Claims

1. A head-mounted display provided with

an image display device and

an optical system comprising a semi-transmissive mirror, a lens element, a λ

/4 plate and a polarizing optical element for combining light beams so as to project an image to be formed by the image display device on a user'"'"'s retina, characterized in that the optical system comprises a second λ

/4 plate and the polarizing optical element comprises a polarization-dependent mirror, in which, viewed from the image display device, the first λ

/4 plate, the lens element, the semi-transmissive mirror, the second λ

/4 plate and the polarization-dependent mirror are arranged one behind the other.

2. A head-mounted display as claimed in claim 1, characterized in that an optical axis of the first λ

/4 plate is transverse to an optical axis of the second λ

/4 plate.

3. A head-mounted display as claimed in claim 1, characterized in that the polarization-dependent mirror is transmissive to a first direction of polarization of a linearly polarized light beam and is reflective to a second direction of polarization of the linearly polarized light beam, which direction of polarization is perpendicular to the first direction of polarization.

4. A head-mounted display as claimed in claim 1, characterized in that the lens element comprises a plano-concave lens element.

5. A head-mounted display as claimed in claim 4, characterized in that the concave surface of the plano-concave lens element is directed towards the second λ

/4 plate.

6. A head-mounted display as claimed in claim 1, characterized in that the head-mounted display comprises an integrated optical element comprising the first λ

/4 plate, the lens element and the semi-transmissive mirror.

7. A head-mounted display as claimed in claim 1, characterized in that the second λ

/4 plate and the polarization-dependent mirror are integrated.

8. A head-mounted display as claimed in claim 1, characterized in that the head-mounted display comprises at least an optical element which has an aspherical surface.

9. A head-mounted display as claimed in claim 1, characterized in that the first and the second λ

/4 plate are achromatic.

10. A head-mounted display as claimed in claim 1, characterized in that the second λ

/4 plate and the polarization-dependent mirror have curved surfaces.