Display

• US 6,903,876 B2
• Filed: 12/04/2002
• Issued: 06/07/2005
• Est. Priority Date: 12/05/2001
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Fujitsu Limited
• Inventors: Okada, Toru, Yamaguchi, Shingo, Fujii, Masanao, Watanabe, Haruyasu, Shimoura, Seiichi
• Primary Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US10/309,575
• Publication Number:
  US 20030103169A1
• Time in Patent Office: 916 Days
• Field of Search: 359/630, 359/631, 359/633, 345 7- 9
• US Class Current: 359/633
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

A body has a configuration in which a first ellipse has a first and second focal points and a second ellipse having a third and fourth points are arranged such that the second and third focal points coincide. This body is equivalent to an optical system having an optical path in which light gathered to the first focal point passes through the first focal point, and is reflected by a first concave reflecting surface, being a part of the first ellipse, to go through the second focal point, and then reflected by a second concave reflecting surface, being a part of the second ellipse, to be gathered to the fourth focal point.

Claims

1. A display comprising as the light-guiding body, there is used a divided light-guiding body, having such a construction that a virtual elliptic light-guiding body, formed of a first ellipse having a first focal point and a second focal point and a second ellipse having a third focal point and a fourth focal point, is divided at a focal point corresponding to the second focal point, and at an end of the light-guiding body formed by the segmentation, there are formed a plane of incidence perpendicular to the optical axis of the light entering the end and a total reflecting surface which totally reflects the light entering from the plane of incidence, so that the end becomes thin, wherein the virtual elliptic light-guiding body having an arrangement such that, the second focal point and the third focal point overlap each other, and

having a construction such that a first concave reflecting surface and a second concave reflecting surface are arranged on the same side with respect to a virtual line connecting the first to the fourth focal points, and a pair of flat reflecting surfaces facing each other is formed between the first concave reflecting surface and the second concave reflecting surface, so that the light reflected by the first concave reflecting surface passes through a focal point corresponding to the second focal point, located between the pair of reflecting surfaces, towards the second concave reflecting surface, while being reflected by the pair of flat reflecting surfaces.

2. The display according to claim 1, wherein the display device is constituted of a liquid crystal display device, and a polarizer and an analyzer are respectively provided in front of and back sides of the liquid crystal display device in the optical path.

3. The display according to claim 2, wherein the liquid crystal display device is integrated with a field lens.

4. The display according to claim 1, wherein a correcting lens is provided on the optical path between the display device and the divided light-guiding body, which distorts an image entering the divided light-guiding body beforehand so as to compensate for the distortion of a visible image, in order to correct the distortion of the visible image watched by an observer which is emitted from the divided light-guiding body.

5. The display according to claim 4, wherein both surfaces of the correcting lens are formed by a concave surface which constitutes a part of a spherical surface having a different curvature.

6. The display according to claim 3, wherein the field lens is a free-form surface lens which also works as a correcting lens which distorts an image entering the divided light-guiding body beforehand so as to compensate for the distortion of a visible image, in order to correct the distortion of the visible image watched by an observer which is emitted from the divided light-guiding body.

7. The display according to claim 6, wherein the field lens is a free-form surface lens having a high light-gathering power.

8. The display according to claim 1, wherein in the divided light-guiding body, if it is assumed that the angle between the plane of incidence and the virtual plane obtained by extending a reflecting surface, of the pair of flat reflecting surfaces facing each other, on the side crossing the plane of incidence is a, and the angle between the total reflecting surface and the virtual plane obtained by extending a reflecting surface, of the pair of flat reflecting surfaces facing each other, on the side crossing the total reflecting surface is β

, α and

β

respectively satisfy 0°

<

α

<

θ and

0°

<

β

<

(θ

−

α

)/2, and 42°

<

θ

<

90°

.

9. The display according to claim 1 further comprising a head mount section mounted on an observer'"'"'s head and a controller connected to the head mount section via a wired communication unit, the head mount section includes the optical system, a display device driving circuit and a receiving circuit, and the controller includes an interface circuit for the connection with an external attachment, an image control circuit and a transmitting circuit.

10. The display according to claim 9, wherein the display device driving circuit and the receiving circuit are provided on a circuit board fitted to the rear face of the display device and having substantially the same size as that of the rear face of the display device.

11. The display according to claim 9, wherein the communication unit is a communication unit by LVDS.

12. The display according to claim 1, wherein in the divided light-guiding body, the angle between the plane of incidence and the virtual plane obtained by extending a reflecting surface, of the pair of flat reflecting surfaces facing each other, on the side crossing the plane of incidence is 20°

, and the angle between the total reflecting surface and the virtual plane obtained by extending the reflecting surface, of the pair of flat reflecting surfaces facing each other, on the side crossing the total reflecting surface is 25.25°

.

13. The display according to claim 1, wherein at least one reflector is provided on the optical path between the light emission element and the imaging device.