Image display apparatus

• US 20060001977A1
• Filed: 06/28/2005
• Published: 01/05/2006
• Est. Priority Date: 07/01/2004
• Status: Active Grant

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Shimizu, Yoshie
• Granted Patent: US 7,502,153 B2
• Time in Patent Office: Days
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 27/0103 comprising holographic elements

Abstract

In an image display apparatus, two light sources emit illumination light having different wavelengths, with which a liquid crystal display device is illuminated. By modulating the illumination light, the liquid crystal display device produces a first and a second image light having different wavelengths. Two holographic optical elements respectively reflect the first and second image lights and direct them to the user'"'"'s eye so that virtual images of the images represented by the first and second image lights are formed at different positions. As the light source from which to obtain the illumination light is switched between the two, the dioptric power with which to present an image is changed.

Claims

1. An image display apparatus worn on a head of a user, comprising:

a display that operates either in a first state in which the display displays an image with a first light and a second state in which the display displays an image with a second light having a different wavelength from the first light;

a first holographic optical element that directs the first light from the display to an eye of the user so that a virtual image of the image represented by the first light is presented at a first distance from the eye of the user;

a second holographic optical element that directs the second light from the display to the eye of the user so that a virtual image of the image represented by the second light is presented at a second distance from the eye of the user; and

a controller that switches the display between the first and second states.

2. The image display apparatus of claim 1,

wherein the first and second holographic optical elements transmit light from an outside world to direct the light to the eye of the user.

3. The image display apparatus of claim 1,

wherein the first and second holographic optical elements are provided on a same surface of a same member.

4. The image display apparatus of claim 3, further comprising:

a third holographic optical element that makes a size of the virtual image presented by the second holographic optical element equal to a size of the virtual image presented by the first holographic optical element, the third holographic optical element being disposed away from the first and second holographic optical elements.

5. The image display apparatus of claim 1, further comprising:

a detector that detects a posture of the user,

wherein the controller switches the display between the first and second states according to the posture of the user detected by the detector.

6. The image display apparatus of claim 1,

wherein the first light from the display contains a plurality of lights having different wavelengths and representing different color component images of a color image;

wherein the first holographic optical element presents, superimposed on one another on a same surface, the different color component images represented by the plurality of lights contained in the first light;

wherein the second light from the display contains a plurality of lights having different wavelengths and representing different color component images of a color image; and

wherein the second holographic optical element presents, superimposed on one another on a same surface, the different color component images represented by the plurality of lights contained in the second light.