Image display apparatus

• US 8,317,330 B2
• Filed: 10/30/2009
• Issued: 11/27/2012
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamazaki, Shoichi, Inoguchi, Kazutaka, Saito, Kenichi, Tsuyuki, Motomi, Tohara, Masakazu
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): Cruz, Magda
• Application Number:
  US12/609,878
• Publication Number:
  US 20100109977A1
• Time in Patent Office: 1,124 Days
• Field of Search: 353/30, 353/81, 353/94, 353/33, 359/625, 359/638, 359/640
• US Class Current: 353/30
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

The image display apparatus forms first and second images in mutually different viewing angle areas to display a combined (joined) image. The apparatus includes first and second image-forming elements respectively forming first and second original images, a first optical system reflecting a first light flux from the first image-forming element at least twice to introduce the first light flux to an exit pupil, and a second optical system reflecting a second light flux from the second image-forming element at least twice to introduce the second light flux to the first optical system. The first optical system introduces the first light flux and the second light flux from the second optical system to the exit pupil such that the first and second images respectively corresponding to the first and second original images are formed in the mutually different viewing angle areas in a first cross section.

Claims

1. An image display apparatus that forms a first image and a second image of mutually different viewing angle areas of a display viewing angle to display a combined image of the first and second images joined to each other, the apparatus comprising:

a first image-forming element configured to form a first original image;

a second image-forming element configured to form a second original image;

a first optical system configured to reflect a first light flux from the first image-forming element at least twice prior to introducing the first light flux to an exit pupil of the first optical system; and

a second optical system configured to reflect a second light flux from the second image-forming element at least twice prior to introducing the second light flux to the first optical system,

wherein, when a cross section where the first and second light fluxes are folded by reflection through the first and second optical systems is defined as a first cross section, the first optical system introduces the first light flux and the second light flux from the second optical system to the exit pupil such that first and second images, respectively corresponding to the first and second original images of the mutually different viewing angle areas, are formed in the first cross section.

2. An image display apparatus according to claim 1,

wherein, the first optical system includes a first optical surface including a first effective area which reflects the first light flux and through which the second light flux from the second optical system enters the first optical system, and the second optical system includes a second optical surface including a second effective area which reflects the second light flux and through which the second light flux exits from the second optical system toward the first optical surface, the first and second optical systems being arranged such that, in the first cross section, the first effective area in the first optical surface and the second effective area in the second optical surface are displaced with respect to each other in a direction along the first and second optical surfaces.

3. An image display apparatus according to claim 2,

wherein the first and second optical systems are arranged in the first cross section so as to be displaced with respect to each other in a direction in which the first effective area in the first optical surface recedes from the second image-forming element and the second effective area in the second optical surface recedes from the first image-forming element.

4. An image display apparatus according to claim 2,

wherein the first and second optical systems are arranged in the first cross section so as to be displaced with respect to each other in a direction in which the first effective area in the first optical surface approaches the second image-forming element and the second effective area in the second optical surface approaches the first image-forming element.

5. An image display apparatus according to claim 1,

wherein each of the first and second optical systems is formed by a prism element containing with a medium having a refractive index greater than 1.

6. An image display apparatus according to claim 5,

wherein an air layer is disposed between the first and second optical surfaces.

7. An image display apparatus according to claim 1,

wherein each of the first and second optical systems has three optical surfaces including two reflective surfaces.

8. An image display apparatus according to claim 1,

wherein, when a cross section orthogonal to the first cross section is defined as a second cross section, and a focal length in the second cross section of an entire optical system constituted by the first and second optical systems is shorter than a focal length in the first cross section of the entire optical system.