VIRTUAL IMAGE DISPLAY APPARATUS

• US 20120200935A1
• Filed: 01/19/2012
• Published: 08/09/2012
• Est. Priority Date: 02/04/2011
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: MIYAO, Toshiaki, TAKAGI, Masayuki, TOTANI, Takahiro, KOMATSU, Akira, TAKEDA, Takashi
• Granted Patent: US 9,081,182 B2
• Time in Patent Office: Days
• US Class Current: 359/630
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

Abstract

A support frame includes a light transmissive portion that is combined with a light guide member to form a see-through portion. The support frame assembled with the light guide member for image light observation therefore allows see-through observation of an outside-world object through the see-through portion. Further, providing the light transmissive portion in the support frame can increase the strength of the support frame while reducing the weight of the light guide member.

Claims

1. A virtual image display apparatus comprising:

a light guide member including a light guide portion, alight incident portion through which image light is incident on the light guide portion, and a light exiting portion out of which the image light guided through the light guide portion exits, the light guide member allowing observation of the image light through the light exiting portion; and

a support frame that supports the light guide member,

wherein the support frame includes alight transmissive portion that is combined with the light guide member to form a transmissive portion.

2. The virtual image display apparatus according to claim 1,

wherein the light guide portion has a first reflection surface and a second reflection surface that are disposed in parallel to each other and allow light to be guided while totally reflected,

the light incident portion has a third reflection surface inclined to the first reflection surface by a predetermined angle,

the light exiting portion has a fourth reflection surface inclined to the first reflection surface by a predetermined angle,

the fourth reflection surface has a half-silvered mirror provided thereon, and

the light transmissive portion has a wedge-shaped member bonded to the light guide member.

3. The virtual image display apparatus according to claim 2,

wherein the light transmissive portion has a light transmissive surface glued to the fourth reflection surface via the half-silvered mirror.

4. The virtual image display apparatus according to claim 3,

wherein the light transmissive portion has a first surface disposed in parallel to the first reflection surface and a second surface disposed in parallel to the second reflection surface.

5. The virtual image display apparatus according to claim 3,

wherein the support frame includes a positioning member that positions the light guide member.

6. The virtual image display apparatus according to claim 5,

wherein the light guide member has an end surface between the first reflection surface and the fourth reflection surface, and

the support frame has a locking surface as the positioning member, the locking surface formed between the first surface and the light transmissive surface and facing the end surface.

7. The virtual image display apparatus according to claim 3,

wherein the first, second, third, and fourth reflection surfaces of the light guide member are side surfaces thereof, and the light guide member further has a top surface and a bottom surface adjacent to the first, second, third, and fourth reflection surfaces, and

the support frame holds the light guide member by sandwiching the top and bottom surfaces of the light guide member.

8. The virtual image display apparatus according to claim 3,

wherein the first reflection surface of the light guide member is so positioned to be flush with the first surface of the light transmissive portion.

9. The virtual image display apparatus according to claim 3,

wherein the second reflection surface of the light guide member is so positioned to be flush with the second surface of the light transmissive portion.

10. The virtual image display apparatus according to claim 1, further comprising:

an image display device that forms image light; and

a projection system on which the image light having exited from the image display device is incident,

wherein the number of reflection of first image light in the light guide portion that exits from a first partial area in the image display device differs from the number of reflection of second image light in the light guide portion that exits from a second partial area in the image display device that differs from the first partial area in terms of a trapping direction in which the guided light is reflected in accordance with the law of reflection.

11. The virtual image display apparatus according to claim 10,

wherein the trapping direction is parallel to a cross-sectional plane including a first optical axis passing through the projection system and a normal to the third reflection surface.

12. The virtual image display apparatus according to claim 1,

wherein the light guide member and the support frame, each of which is integrally formed in an injection molding process, are formed independent from each other.

13. The virtual image display apparatus according to claim 12,

wherein each of the light guide member and the support frame is molded by using a thermally polymerized resin material.