DISPLAY DEVICE

• US 20070247730A1
• Filed: 06/21/2007
• Published: 10/25/2007
• Est. Priority Date: 06/13/1994
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nishimura, Takeshi, Yamazaki, Shoichi
• Granted Patent: US 7,567,385 B2
• Time in Patent Office: Days
• US Class Current: 359/858
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/0143 the two eyes not being equipped with identical nor symmetrical optical devices
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• 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 2027/0198 System for aligning or maintaining alignment of an image in a predetermined direction
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/10 with curved faces

Abstract

A display device for displaying information is provided with an optical system for guiding the light of the display device to the eye, the optical system having, in the order in the proceeding direction of the light, an entrance face for receiving the light, a curved face for totally reflecting the light and a reflecting face concave to the eye side and adapted to reflect the light toward the eye. The reflected light is transmitted by the curved face and reaches the eye. Thus there is obtained a compact display device with satisfactorily suppressed aberrations.

Claims

1. A display device comprising:

display means for forming image information; and

optical means for guiding light from said display means to an eye, said optical means including a first curved face for totally reflecting the light and a second curved face for reflecting light which is totally reflected by said first curved face,

wherein the light, in an optical path from said display means to the eye, is totally reflected by said first curved face and is transmitted by said first curved face.

2. A display device according to claim 1, wherein said optical means comprises, in order in the proceeding direction of light, an entrance face for introducing the light from said display means, said curved face, and said second curved face for reflecting the light toward the eye, and

wherein the light reflected by said second curved face is transmitted by said first curved face and reaches the eye.

3. A display device according to claim 1, wherein optical power of said first curved face varies in accordance with an azimuthal angle.

4. A display device according to claim 1, satisfying a condition |α

|≦

20°

wherein ∝

is an angle between a line tangent to a vertex of said first curved face and a line perpendicular to the optical axis of the eye.

5. A display device according to claim 1, further comprising:

illumination means for illuminating the eye; and

light-receiving means for receiving the light reflected from the eye, for detecting the visual line thereof.

6. A display device according to claim 5, further comprising:

control means for controlling the display state of said display means, according to a light receiving state of said light-receiving means.

7. A display device according to claim 2, wherein said second curved face comprises a half-transmitting face.

8. A display device according to claim 2, wherein optical power of said second curved face varies in accordance with an azimuthal angle.

9. A display device comprising:

information forming means for forming an image information;

optical means for guiding a light of said information forming means to an eye, said optical means comprising a reflecting curved face decentered and having a positive optical power;

illumination means for illuminating said eye;

converging means for converging a light of said illuminating means reflected from said eye; and

detecting means for receiving a light from said converging means to detect a state of said eye,

wherein where an imaging magnification of said converging means is β

, a following condition is satisfied,

0.02<

|β

|<

0.18.

10. A display device according to claim 9, wherein optical power of said reflecting curved face varies in accordance with an azimuthal angle.

11. A display apparatus comprising:

display means for forming image information; and

optical means for guiding light of said display means to an eye,

wherein said optical means comprises a concave mirror decentered with respect to an optical axis of the eye and having different optical powers according to an azimuth angle and another surface decentered with respect to the optical axis of the eye and having different optical powers according to an azimuth angle, and

wherein a surface of said concave mirror and said other surface have optical powers having mutually different positive or negative power on a section of a meridian of each of said surfaces.

12. An apparatus according to claim 11, wherein when a paraxial curvature radius of generatrix section of said concave mirror and a paraxial curvature radius of meridian section of said concave mirror are respectively defined by r_y and r_x, the relationship of |r_x|<

|r_y| is satisfied.

13. An apparatus according to claim 12, wherein said optical means comprises an eyepiece optical system for directly magnifying the image information from said display means.

14. An apparatus according to claim 11, further comprising:

illumination means for illuminating the eye; and

light-receiving means for receiving the light reflected from the eye, for detecting the visual line thereof.

15. A display apparatus comprising:

display means for forming image information; and

optical means for guiding light of said display means to an eye, said optical means including a concave mirror decentered with respect to an optical axis of the eye and having different optical powers according to an azimuth angle and another surface decentered with respect to the optical axis of the eye and having different optical powers according to an azimuth angle,

wherein when a paraxial curvature radius of a generatrix section of said concave mirror and a paraxial curvature radius of a meridian section of said concave mirror are respectively defined by r_y and r_x, the relationship of |r_x|<

|r_y| is satisfied.

16. An apparatus according to claim 15, wherein a surface of said concave mirror and said another surface have optical powers having mutually different positive or negative power on a section of a meridian of each said surface.

17. An apparatus according to claim 16, wherein said optical means comprises an eyepiece optical system for directly magnifying the image information from said display means.

18. An apparatus according to claim 15, further comprising:

illumination means for illuminating the eye; and

light-receiving means for receiving the light reflected from the eye to detect the visual line thereof.

19. A display apparatus comprising:

display means for forming image information; and

optical means for guiding light of said display means to an eye, said optical means including a first reflecting surface having different optical powers according to an azimuth angle, a second reflecting surface having different optical powers according to an azimuth angle, and a transmission surface having different optical powers according to an azimuth angle,

wherein the light of said display means reaches the eye by way of said first reflecting surface, said second reflecting surface, and said transmission surface.

20. An apparatus according to claim 19, wherein said first reflecting surface, said second reflecting surface, and said transmission surface are decentered with respect to an optical axis of the eye.

21. An apparatus according to claim 19, wherein said first reflecting surface and said second reflecting surface have optical powers having mutually different positive or negative power on a section of a meridian of each of said surfaces.

22. An apparatus according to claim 19, wherein when paraxial curvature radii of generatrix and meridian sections of at least one of said first surface and said second surface are respectively defined by r_y and r_x, the relationship of |r_x|<

|r_y| is satisfied.

23. An apparatus according to claim 22, wherein said optical means is an eyepiece optical system for directly magnifying the image information from said display means.

24. An apparatus according to claim 19, further comprising:

illumination means for illuminating the eye; and

light-receiving means for receiving the light reflected from the eye to detect the visual line thereof.

25. An optical element, comprising:

an entrance surface at which light enters;

a first reflecting surface having different optical powers according to an azimuth angle;

a second reflecting surface having different optical powers according to an azimuth angle; and

an exit surface from which light emerges,

wherein the light entering said entrance surface emerges from said exit surface by way of said first and second reflecting surfaces, and

wherein an optical path from said entrance surface to said exit surface is filled with a medium having a refractive power greater than 1.

26. An optical element according to claim 25, wherein said entrance and exit surfaces have different optical powers according to an azimuth angle.