OPTICAL MEMBER AND VIRTUAL IMAGE DISPLAY APPARATUS

• US 20140139403A1
• Filed: 11/08/2013
• Published: 05/22/2014
• Est. Priority Date: 11/16/2012
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Hiraide, Noriaki
• Granted Patent: US 9,746,674 B2
• Time in Patent Office: Days
• US Class Current: 345/8
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features

Abstract

According to a light guide device that is an optical member, since a protruding rib extending along a sideways end portion is provided, first and second surfaces including a first surface and other free-form surfaces can be aligned with another member that forms, for example, a virtual image display apparatus with high precision when the light guide device is assembled to the other member by using part of the protruding rib, which is provided separately from the first and second surfaces, as a reference, whereby an optical function of the light guide device in the virtual image display apparatus or any other apparatus can be ensured. Further, an optical main body provided with the first and second surfaces has a shape similar to that of glasses and hence has a good external appearance.

Claims

1. An optical member comprising:

a first surface and a second surface which face each other and each of which is formed of a free-form surface that directs light from a video image device toward a viewer'"'"'s eye to allow the viewer to visually recognize an image;

a sideways end portion provided between the first surface and the second surface; and

a protruding rib provided along at least part of the sideways end portion.

2. The optical member according to claim 1,

wherein the first and second surfaces reflect video images from the video image device and guide the video images to the viewer'"'"'s eye.

3. The optical member according to claim 2,

wherein each of the first and second surfaces is formed as a surface of a prism-shaped member and guides video image light from a video image display device that is the video image device to the viewer'"'"'s eye while reflecting the video image light in the prism-shaped member.

4. The optical member according to claim 1,

wherein the rib has an attachment portion that allows the first and second surfaces to be attached to a support frame that is a first another member with the first and second surfaces positioned relative to the support frame.

5. The optical member according to claim 4,

wherein the attachment portion has a flat surface portion that comes into contact with a stopper surface provided on the frame when the first and second surfaces are attached to the frame and hence serves as a reference for fixing a relative attitude of the first and second surfaces.

6. The optical member according to claim 5,

wherein the attachment portion is disposed outside an eye cover including one of the free-form surfaces, having an oval contour, and disposed in front of the eye.

7. The optical member according to claim 1,

wherein the rib, which is attached to the frame, limits displacement of the first and second surfaces relative to the other member.

8. The optical member according to claim 1,

wherein the optical member is produced by bonding a light guide prism to an auxiliary prism,

the light guide prism is a main body that guides video image light and allows outside light to be recognized in see-through observation, and

the auxiliary prism is bonded and integrally fixed to the light guide prism and assists the see-through observation capability of the light guide prism.

9. The optical member according to claim 8,

wherein a half-silvered mirror layer is provided along the boundary between the light guide prism and the auxiliary prism.

10. The optical member according to claim 8,

wherein the light guide prism has a first bonding rib as part of the rib,

the auxiliary prism has a second bonding rib as part of the rib, and

the light guide prism and the auxiliary prism are bonded to each other by using the first bonding rib and the second bonding rib as a reference.

11. The optical member according to claim 8,

wherein the light guide prism is formed in an injection molding process.

12. The optical member according to claim 11,

wherein the rib has a flat plate section extending along the sideways end portion, and the flat plate section is formed along a parting line of a molding die used in the injection molding process.

13. The optical member according to claim 12,

wherein the rib has a gate portion associated with the flat plate section and corresponding to a port through which a resin used in the injection molding process flows in.

14. The optical member according to claim 12, further comprising

a connecting surface disposed between the first surface and the flat plate section and inclined to a plane perpendicular to the flat plate section.

15. The optical member according to claim 1,

an inclined side surface that is adjacent to the rear-side second surface close to the wearer'"'"'s face and forms an obtuse angle with respect to the second surface is provided.

16. The optical member according to claim 15,

a tapered surface that includes the inclined side surface and extends along the face of the wearer who wears the optical member is provided between the first surface and the second surface.

17. The optical member according to claim 16,

wherein the tapered surface has three flat surface portions corresponding to an upper edge of the eye socket, the cheek, and the nose.

18. The optical member according to claim 1,

wherein a connecting portion is provided to connect the optical member to an image formation main body portion that is second another member provided on the side where the video image light is incident, and the connecting portion allows relative alignment of the first and second surfaces with the second another member.

19. The optical member according to claim 18,

wherein the connecting portion is a fitting portion that fits into the image formation main body portion to allow alignment of the attitude of the optical member with the image formation main body portion.

22. A virtual image display apparatus comprising:

a video image device that produces video image light; and

the optical member according to claim 1, which directs the video image light from the video image device toward a viewer'"'"'s eye to allow the viewer to visually recognize an image.

23. The virtual image display apparatus according to claim 22, further comprising

a frame that supports the video image device and the optical member in such a way that the optical member is disposed in front of the viewer'"'"'s eye.

20. An optical member comprising

a first surface and a second surface which face each other and each of which is formed of a free-form surface that directs light from a video image device toward a viewer'"'"'s eye to allow the viewer to visually recognize an image,

wherein each of the first and second surfaces is formed of a curved surface having an oval contour.

21. The optical member according to claim 20,

wherein an eye cover including one of the curved surfaces having an oval contour and disposed in front of the eye has a drop-shaped external appearance.