Display system utilizing ambient light and a dedicated light source

• US 6,646,636 B1
• Filed: 10/19/2000
• Issued: 11/11/2003
• Est. Priority Date: 10/29/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: DigiLens Inc
• Inventors: Smith, Ronald T., Popovich, Milan M.
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): NGUYEN, FRANCIS N
• Application Number:
  US09/693,270
• Time in Patent Office: 1,118 Days
• Field of Search: 345/204, 345/102, 345/207, 349/113, 349/177, 349/201-202, 359/13, 359/15, 359/24
• US Class Current: 345/204
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02F 1/13342 Holographic polymer dispersed liquid crystals
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133618 for ambient light
• CPC Class Codes: G02F 1/133626 providing two modes of illumination, e.g. day-night
• CPC Class Codes: G03H 2001/2228 adapted for reflection and transmission reconstruction
• CPC Class Codes: G03H 2001/2615 in physical contact, i.e. layered holograms

Abstract

A display system generally comprising a display device operable to display an image and configured for illumination by ambient light or light emitted by a dedicated light source and a light directing system. The light directing system is operable to direct one of the ambient light and the light emitted by the light source towards the display device. The light directing system comprises at least one holographic optical element which is switchable between an active state wherein light incident on the element is diffracted and a passive state wherein light incident on the element is transmitted without substantial alteration.

Claims

1. A display system comprising:

a display device operable to display an image and configured for illumination by ambient light or light emitted by a dedicated light source, wherein the display device is disposed at the rear face of the light guide; and

a light directing system operable to direct one of the ambient light and the light emitted by the light source towards the display surface and comprising at least one holographic element switchable between an active state wherein light incident on the element is diffracted and a passive state wherein light incident on the element is transmitted without alteration; and

a light guide having a front face wherein light enters and a rear face.

2. The display system of claim 1 wherein the front face of the light guide is configured to reflect light having a first polarization state and transmit light having a second polarization state.

3. A display system comprising:

a display device operable to display an image and configured for illumination by ambient light or light emitted by a dedicated light source; and

a light directing system operable to direct one of the ambient light and the light emitted by the light source towards the display surface and comprising at least one holographic element switchable between an active state wherein light incident on the element is diffracted and a passive state wherein light incident on the element is transmitted without alteration; and

a light guide having a front face wherein light enters and a rear face, wherein the rear face of the light guide has a reflective surface operable to reflect light received from the dedicated light source onto the display device.

4. The display system of claim 3 wherein the reflective surface and the light guide are configured to provide total internal reflection of the light emitted from the light source.

5. The display system of claim 3 wherein the reflective surface comprises a reflective holographic optical element.

6. A display system comprising:

a display device operable to display an image and configured for illumination by ambient light or light emitted by a dedicated light source; and

a light directing system operable to direct one of the ambient light and the light emitted by the light source towards the display surface and comprising at least one holographic element switchable between an active state wherein light incident on the element is diffracted and a passive state wherein light incident on the element is transmitted without alteration;

a light guide having a front face wherein light enters and a rear face; and

a diffuser disposed at the rear face of the light guide.

7. The display system of claim 6 wherein the diffuser is a holographic optical element.