Display apparatus to be mounted on the head or face of an individual

• US 5,726,670 A
• Filed: 10/05/1995
• Issued: 03/10/1998
• Est. Priority Date: 07/20/1992
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Iba, Yoichi, Togino, Takayoshi, Tabata, Seiichiro
• Primary Examiner(s): NGUYEN, CHANH DUY
• Application Number:
  US08/539,629
• Time in Patent Office: 887 Days
• Field of Search: 345/7, 345/8, 345/9, 359/618, 359/629, 359/630, 359/662, 353/13, 353/14
• US Class Current: 345/7
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

A display apparatus of the type that is fitted to the user'"'"'s head or face, and having a higher resolution in a first region of the display than that of the remaining area of the display, without increasing the size of the display. As an example, an image of the characters "ABC", for example, are generated or received. However, it might be desired that the center character "B", for example, be displayed at a higher resolution than that of the characters "A C". To accomplish this, the original image "ABC" is divided into an image of "A C" and an image of "B". Then, the image of "B" is electrically distorted and formed on a screen such that the image of "B" is larger in size than the image of "A C". An ocular optical system including an optical element effects a second distortion of the image to correct the electrically created distortion. This ocular optical system enlarges the image such that the image of "A C", which has been displayed relatively small, is enlarged, and projects the image of "B", which has been displayed relatively large, through a lens having a correspondingly lower magnification. Then, the image of "B" is superimposed on the image of "A C" so that the image of "A C" and "B" are displayed at the same size, but with "B" being represented by more pixels or pixels which are finer than those representing "A C".

Claims

1. A display apparatus comprising:

image producing means for providing an image by at least one of generating and receiving said image;

electrical image processing means for electrically effectuating a first distortion of said image provided by said image producing means;

an image display element for forming on a screen said image with said first distortion effectuated by said electrical image processing means;

an ocular optical system including an optical element for effectuating a second distortion of said image to correct said electrically effectuated first distortion of said image, said ocular optical system having an optical path leading said image to said observer'"'"'s eyeball; and

a support member for fitting at least said image display element and said ocular optical system to at least one of a head and a face of said observer,

wherein said first distortion is barrel distortion; and

said second distortion is pincushion distortion.

2. A display apparatus according to claim 1, wherein:

said second distortion effectuated by said ocular optical system is such that a peripheral region of said image projected toward said observer'"'"'s eyeball is magnified to a greater extent than a central region of said image projected toward said observer'"'"'s eyeball.

3. A display apparatus according to claim 1, wherein said image display element satisfies the following condition in order to improve resolution as seen by an observer'"'"'s eyeball:

space="preserve" listing-type="equation">β

.sub.1 /β

.sub.2 ≧

1.2

where β

₁ and β

₂ respectively represent maximum and minimum values of a local projection magnification.

4. A display apparatus according to claim 3, wherein:

said second distortion effectuated by said ocular optical system is such that a peripheral region of said image projected toward said observer'"'"'s eyeball is magnified to a greater extent than a central region of said image projected toward said observer'"'"'s eyeball.

5. A display apparatus according to claim 1, wherein said image producing means provides a digital image.

6. A display apparatus according to claim 1, wherein said image producing means provides an analog image.

7. A display apparatus according to claim 1, wherein said first distortion is predetermined in relation to said second distortion such that said second distortion substantially cancels said first distortion.

8. A display apparatus comprising:

an image producing means for providing an image by at least one of generating and receiving said image;

an image display element for forming said image on a flat screen, said screen of said image display element being formed by two-dimensionally arranged pixels;

an electrical image processing means for electrically effectuating a first distortion of barrel shape to image information sent from said image producing means before said image information is formed as said image on said screen of said image display element;

an ocular optical system arranged to form an optical path for leading said image formed on said flat screen to an observer'"'"'s eyeball, said ocular optical system having an optical element designed to produce a second distortion of pincushion shape to correct said barrel distortion electrically effectuated to said image; and

a support member for fitting at least said image display element and said ocular optical system to at least one of a head and a face of said observers.

9. A display apparatus according to claim 8, wherein

said second distortion effectuated by said ocular optical system is such that a peripheral region of said image projected toward said observer'"'"'s eyeball is magnified to a greater extent than a central region of said image projected toward said observer'"'"'s eyeball.

10. A display apparatus according to claim 8, wherein said image display element satisfies the following condition in order to improve resolution as seen by an observer'"'"'s eyeball:

space="preserve" listing-type="equation">β

.sub.2 /β

.sub.2 ≧

1.2

where β

₁ and β

₂ respectively represent maximum and minimum values of a local projection magnification.

11. A display apparatus according to claim 10, wherein:

said second distortion effectuated by said ocular optical system is such that a peripheral region of said image projected toward said observer'"'"'s eyeball is magnified to a greater extent than a central region of said image projected toward said observer'"'"'s eyeball.

12. A display apparatus according to claim 8, wherein said image producing means provides a digital image.

13. A display apparatus according to claim 8, wherein said image producing means provides an analog image.

14. A display apparatus according to claim 8, wherein said first distortion is predetermined in relation to said second distortion such that said second distortion substantially cancels said first distortion.