Optical: systems and elements – Single channel simultaneously to or from plural channels – By partial reflection at beam splitting or combining surface
Reexamination Certificate
2000-03-15
2001-11-06
Epps, Georgia (Department: 2873)
Optical: systems and elements
Single channel simultaneously to or from plural channels
By partial reflection at beam splitting or combining surface
C359S631000, C359S633000
Reexamination Certificate
active
06313950
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an optical system usable, for example, as an ocular optical system for a head-mounted image display apparatus or a projection optical system for a color film projection apparatus.
To display or project a color image free from uneven color by using a plurality of illuminating light sources, e.g. R (red), G (green) and B (blue), it has heretofore been necessary to combine together light from each light source provided individually by using a plurality of color filters or dichroic mirrors, resulting in a large-sized and heavy-weight arrangement undesirably. Therefore, such an arrangement is not suitable for a head-mounted image display apparatus, for example. Furthermore, because color filters and dichroic mirrors are costly, it is impossible to supply a head-mounted image display apparatus or the like at low cost.
SUMMARY OF THE INVENTION
In view of the above-described problems with the prior art, an object of the present invention is to provide an optical system for an ocular optical system or a projection optical system, in which a plurality of illuminating light sources of different colors can be placed in a side-by-side relation to each other, and which makes it possible to reduce the overall size and weight of an apparatus such as a head-mounted image display apparatus or a color film projection apparatus.
To attain the above-described object, the present invention provides an optical system having an image-forming optical system that projects a real image or virtual image of an object placed in an image plane. The image-forming optical system has an entrance pupil at a position on the side of the image plane remote from the image-forming optical system. The optical system has an exit pupil in a conjugate relation to the entrance pupil with respect to the image-forming optical system. The optical system is characterized by having a chromatic aberration producing device between the entrance pupil and the exit pupil.
According to the present invention, a chromatic aberration producing device is provided between the entrance pupil and the exit pupil. Therefore, even if a plurality of illuminating light sources of different colors are placed in a side-by-side relation to each other on the entrance pupil, rays from the different light sources can pass the exit pupil, being superimposed on one another, without chromatic aberration. Accordingly, in the case of an ocular optical system, for example, even if the observer's pupil position deviates from the exit pupil position, it is possible to observe a clear image, which is free from chromatic aberration. Thus, the present invention provides an optical system for use as an ocular optical system or a projection optical system, which makes it possible to reduce the overall size and weight of a head-mounted image display apparatus, a color film projection apparatus, etc.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
REFERENCES:
patent: 5661603 (1997-08-01), Hanano et al.
patent: 5701202 (1997-12-01), Takahashi
patent: 5706136 (1998-01-01), Okuyama et al.
patent: 5742262 (1998-04-01), Tabata et al.
patent: 5768025 (1998-06-01), Togino et al.
patent: 5790312 (1998-08-01), Togino
patent: 5917662 (1999-06-01), Sekita
patent: 5995291 (1999-11-01), Togino
patent: 6023373 (2000-02-01), Inoguchi et al.
patent: 6134051 (2000-10-01), Hayakawa et al.
patent: 6222676 (2001-04-01), Togino et al.
Hayakawa Kazuhito
Oode Hisashi
Togino Takayoshi
Epps Georgia
Olympus Optical Co,. Ltd.
Pillsbury & Winthrop LLP
Seyfari Saeed
LandOfFree
Image display apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image display apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image display apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2574059