US 5,701,202 A · Head or face mounted image display apparatus

Abstract

The present invention is an optical apparatus, e.g. an image display apparatus, which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The optical apparatus has an image display device (6), and an ocular optical system (7) for leading an image of the image display device (6) to an observer's eyeball (1). The ocular optical system (7) includes, in order from the image side, a third surface (5) which forms an entrance surface, a first surface (3) which forms both a reflecting surface and an exit surface, and a second surface (4) which forms a reflecting surface. The first to third surfaces (3 to 5) are integrally formed with a medium put therebetween which has a refractive index larger than 1. A bundle of light rays emitted from the image display device (6) enters the ocular optical system (7) while being refracted by the third surface (5) and is internally reflected by the first surface (3) and reflected by the second surface (4). Then, the ray bundle is incident on the first surface (3) again and refracted thereby so as to be projected into the observer's eyeball with the observer's iris position or eyeball rolling center as the exit pupil (1).

Claims33

Dependent claims

An optical apparatus comprising:

a device for displaying an image;
and
an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observer's eyeball,
said ocular optical system comprising first, second and third surfaces, in which a space defined by said first, second and third surfaces is filled with a medium having a refractive index larger than 1,
said first, second and third surfaces including, in order from an observer's eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer's visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least three surfaces having a finite curvature radius;
wherein any one of said first, second and third surfaces is a decentered aspherical surface;
wherein any one of said first, second and third surfaces is an anamorphic surface;
wherein said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer's visual axis is defined as a YZ-plane, and a horizontal plane containing said observer's visual axis is defined as an XZ-plane:
0. 5<R.sub.y2 /R.sub.x2 <5
where R.sub.y2 is a curvature radius of said second surface in the YZ-plane, and R.sub.x2 is a curvature radius of said second surface in the XZ-plane.

7 more elements

An optical apparatus comprising:

a device for displaying an image;
and
an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer's eyeball,
said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,
said device for displaying an image being disposed at a position facing said third surface,
said first, second and third surfaces including, in order from an observer's eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer's visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,
wherein any one of said first, second and third surfaces is a decentered aspherical surface,
wherein any one of said first, second and third surfaces is an anamorphic surface, and
said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer's visual axis is defined as a YZ-plane, and a horizontal plane containing said observer's visual axis is defined as an XZ-plane:
0.5<R.sub.y2 /R.sub.x2 <5
where R.sub.y2 is a curvature radius of said second surface in said YZ-plane, and R.sub.x2 is a curvature radius of said second surface in said XZ-plane.

8 more elements

An optical apparatus comprising:

a device for displaying an image;
and
an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer's eyeball,
said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,
said device for displaying an image being disposed at a position facing said third surface,
said first, second and third surfaces including, in order from an observer's eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer's visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,
wherein internal reflection that is performed by said first surface is total reflection, wherein any one of said first, second and third surfaces is a decentered aspherical surface,
wherein any one of said first, second and third surfaces is an anamorphic surface, and
said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer's visual axis is defined as a YZ-plane, and a horizontal plane containing said observer's visual axis is defined as an XZ-plane:
0. 5<R.sub.y2 /R.sub.x2 <5
where R.sub.y2 is a curvature radius of said second surface in said YZ-plane, and R.sub.x2 is a curvature radius of said second surface in said XZ-plane.

8 more elements

An optical apparatus comprising:

a device for displaying an image;
and
an ocular optical system for projecting an image formed by said device for displaying an image and for leading said image to an observer's eyeball,
said ocular optical system comprising at least first, second and third surfaces, in which a space defined by said surfaces is filled with a medium having a refractive index larger than 1,
said device for displaying an image being disposed at a position facing said third surface,
said first, second and third surfaces including, in order from an observer's eyeball side toward said device for displaying an image, said first surface serving as both a refracting surface and an internally reflecting surface, said second surface serving as a reflecting surface of a positive power which faces said first surface and is decentered or tilted with respect to an observer's visual axis, and said third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least first, second and third surfaces having a finite curvature radius,
wherein said first surface has an internally reflecting region which has been mirror-coated, wherein any one of said first, second and third surfaces is a decentered aspherical surface,
wherein any one of said first, second and third surfaces is an anamorphic surface, and
said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer's visual axis is defined as a YZ-plane, and a horizontal plane containing said observer's visual axis is defined as an XZ-plane:
0. 5<R.sub.y2 /R.sub.x2 <5
where R.sub.y2 is a curvature radius of said second surface in said YZ-plane, and R.sub.x2 is a curvature radius of said second surface in said XZ-plane.

8 more elements

Dependencies are inferred from the claim text.

Head or face mounted image display apparatus

Life of this patent

Head or face mounted image display apparatus

Life of this patent

Abstract

Claims33