Head mount display apparatus allowing easy switching operation from electronic image to external field image

• US 5,621,424 A
• Filed: 02/16/1995
• Issued: 04/15/1997
• Est. Priority Date: 08/24/1992
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Mohri, Koh, Tokuhashi, Yuki, Konuma, Osamu, Imai, Satoshi, Shimada, Naoto, Tabata, Seiichiro, Okamura, Toshiro
• Primary Examiner(s): NGUYEN, CHANH DUY
• Application Number:
  US08/390,821
• Time in Patent Office: 789 Days
• Field of Search: 345/7, 345/8, 345/9, 359/13, 359/630, 359/631, 359/632, 359/633, 2/8, 2/15, 2/12, 2/13, 2/410, 358/88, 358/92, 348/51, 348/52, 348/53, 348/56, 348/55
• US Class Current: 345/8
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• 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 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 3/012 Head tracking input arrangements
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: H04N 13/341 using temporal multiplexing
• CPC Class Codes: H04N 13/344 with head-mounted left-right displays
• CPC Class Codes: H04N 13/346 using prisms or semi-transparent mirrors
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof

Abstract

A display apparatus, which can be mounted on the head portion of a man, includes a two-dimensional display unit for displaying an image. A projection optical system projects the image displayed on the two-dimensional display unit onto the retina of the eyeball of a user. A shutter is arranged in front of the eyeball of the user. A detector detects at least a forward inclination of motions of the head portion of the user. A control unit controls the shutter in accordance with the output from the detector to switch the shutter between a light transmission state and a light shielding state. A housing incorporates and holds the two-dimensional display unit, the projection optical system, the shutter, and the detector to be mountable on the head portion of the user.

Claims

1. A display apparatus, which can be mounted on a head portion of a person using the display apparatus, the display apparatus comprising:

first and second two-dimensional display units arranged at positions which are away from a field of vision of right and left eyeballs of a user, for displaying images corresponding to the right and left eyeballs of the user respectively;

first and second image enlargement and projection optical systems for optically enlarging the images displayed on said first and second two-dimensional display units;

a shutter unit, arranged in front of the eyeball of the user;

an inclination detector for detecting at least a forward inclination of motions of the head portion of the user;

control means for controlling said shutter unit in accordance with an output signal from said inclination detector, and for switching said shutter unit between a light transmission state when the user inclines the head portion forward, and a light-shielding state when the user does not incline the head portion forward;

first and second semi-transparent reflection units, arranged between said shutter unit and said right and left eyeballs, for overlapping in a certain region the first and second images enlarged by said image enlargement and projection optical systems and an external image transmitted through said shutter unit and for projecting said first and second images and said external images onto retinas of said right and left eyeballs; and

a housing, which encloses and holds all of said first and second two-dimensional display units, said first and second enlargement and projection optical systems, said shutter unit, said first and second semi-transparent reflection units and said inclination detector, and wherein said housing mountable on the head portion of the user and wherein said housing is arranged to prevent light other than light transmitted through said shutter means from being incident on the eyeballs of the user.

2. An apparatus according to claim 1, wherein:

light from said first and second two-dimensional display units is reflected by said first and second semi-transparent reflection units and reaches the eyeballs of the user; and

light transmitted through said shutter unit is transmitted through said first and second semi-transparent reflection units and reaches the eyeballs of the user.

3. An apparatus according to claim 1 wherein:

said first and second semi-transparent reflection units each have a shape of concave mirror; and

the light transmitted through said shutter unit is reflected by said first and second semi-transparent reflection units and reaches the eyeballs of the user.

4. A display apparatus, which can be mounted on a head portion of a person using the display apparatus, the display apparatus comprising:

first and second two-dimensional display units, arranged at positions away from a field of vision of right and left eyeballs of a user, for displaying images corresponding to the right and left eyeballs of the user, respectively;

image enlargement and projection optical systems for optically enlarging the images displayed on said first and second two-dimensional display units;

a shutter unit, arranged in front of the eyeball of the user;

an inclination detector for detecting at least a downward motion of a visual axis direction of the user;

control means for controlling said shutter unit in accordance with an output signal from said inclination detector, and for switching said shutter unit between a light transmission state when the user inclines the head portion downward, and a light-shielding state when the user does not incline the head portion downward;

first and second semi-transparent reflection units, arranged between said shutter unit and said right and left eyeballs, for overlapping in a certain region the first and second images enlarged by said image enlargement and projection optical systems and an external image transmitted through said shutter unit and for projecting said first and second images and said external images onto retinas of said right and left eyeballs; and

a housing, which encloses and holds all of said first and second two-dimensional display units, said first and second image enlargement and projection optical systems, said shutter unit, said first and second semi-transparent reflection units and said inclination detector, and wherein said housing is mountable on the head portion of the user and wherein said housing is arranged to prevent light other than light transmitted through said shutter unit from being incident on the eyeballs of the user.

5. A display apparatus according to claim 4, wherein:

said inclination detector projects light onto the eyeballs of the user, and detects at least one of a visual axis direction of the eyeballs of the user and a blink of the eyes of the user upon reception of light reflected by the eyeballs of the user; and

said display apparatus further comprises optical path synthesizing means for synthesizing an optical path of said image enlargement and projection optical systems, and an optical path of light projected form said inclination detector onto the eyeballs of the user.

6. An apparatus according to claim 5 wherein:

said optical path synthesizing comprises a half mirror arranged in front of the eyeballs of the user;

said first and second semi-transparent reflection units have a shape of a concave mirror;

light from said first and second two-dimensional display units is reflected by said half mirror, is reflected by said semi-transparent reflection means having a shape of concave mirror, is transmitted through said half mirror, and reaches the eyeballs of the user; and

light projected from said inclination detector is reflected by said half mirror and reaches the eyeballs of the user.

7. An apparatus according to claim 6, wherein:

the light projected from said inclination detector onto the eyeballs of the user includes infrared light; and

said optical path synthesizing means includes a dichroic mirror.

8. An apparatus according to claim 6, wherein:

the light projected from said inclination detector onto the eyeballs of the user includes infrared light; and

the apparatus further comprises a filter for transmitting the infrared light and for shielding visible light, said filter being arranged in an optical path between said inclination detector and said optical path synthesizing means.

9. A display apparatus according to claim 5, wherein:

said optical path synthesizing means includes a half mirror arranged in front of the eyeballs of the user;

said display apparatus further comprises a concave mirror arranged above or below said optical path synthesizing means;

light from said two-dimensional display units is transmitted through said half mirror, is reflected by said concave mirror, is reflected by said half mirror, and reaches the eyeballs of the user; and

light projected from said inclination detector is transmitted through said half mirror, and reaches the eyeballs of the user.

10. An apparatus according to claim 9, wherein:

the light projected from said inclination detector onto the eyeballs of the user includes infrared light; and

said optical path synthesizing means includes a dichroic mirror.

11. An apparatus according to claim 9, wherein:

the light projected from said inclination detector onto the eyeballs of the user includes infrared light; and

the apparatus further comprises a filter for transmitting the infrared light and for shielding visible light, said filter being arranged in an optical path between said inclination detector and said optical path synthesizing means.

12. An apparatus according to claim 5, wherein:

the light projected from said inclination detector onto the eyeballs of the user includes infrared light; and

said optical path synthesizing means includes a dichroic mirror.

13. An apparatus according to claim 5, wherein:

the light projected from said inclination detector onto the eyeballs of the user includes infrared light; and

the apparatus further comprises a filter for transmitting the infrared light and for shielding visible light, said filter being arranged in an optical path between said inclination detector and said optical path synchronizing means.

14. An apparatus according to claim 4 wherein:

said first and second semi-transparent reflection units each have a shape of concave mirror; and

the light transmitted through said shutter unit is reflected by said first and second semi-transparent reflection units and reaches the eyeballs of the user.

15. A display apparatus, which can be mounted on a head portion of a person using the display apparatus, the display apparatus comprising:

a two-dimensional display unit for displaying an image;

a projection optical system for projecting the image displayed on said two-dimensional display unit onto a retina of an eyeball of a user;

a shutter unit, arranged in front of the eyeball of the user, for switching an arbitrary region between a light-transmission state and a light-shielding state;

an inclination detector for detecting at least a forward inclination of motions of the head portion of the user and for outputting a detection signal;

image signal control means for delaying a scan start line number of an image signal supplied to said two-dimensional display unit, in proportion to the detection signal which is outputted from said inclination detector;

shutter control means, operating in synchronism with the image signal control means, for controlling said shutter unit to be in said light-shielding sate during a time period between a scan start time and a scan end time of said image signal control means, and in said light-transmission state during other time periods; and

a housing, which encloses and holds all of said two-dimensional display unit, said projection optical system, said shutter unit, and said inclination detector, and wherein said housing is mountable on the head portion of the user.

16. An apparatus according to claim 15, wherein said shutter unit comprises a liquid-crystal shutter.

17. An apparatus according to claim 15, wherein said projection optical system comprises a concave mirror.