Optical: systems and elements – Prism – With reflecting surface
Reexamination Certificate
1998-09-21
2003-03-18
Spyrou, Cassandra (Department: 2872)
Optical: systems and elements
Prism
With reflecting surface
C359S858000, C359S859000, C359S861000, C359S633000, C359S729000, C359S731000
Reexamination Certificate
active
06535340
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical element and a picture taking system including the optical element that is particularly suitable for a video camera, a still video camera, and a copying machine.
2. Description of the Related Art
FIG. 10
schematically illustrates a main part of an optical system disclosed in Japanese Patent Laid-Open No. 8-292371.
Referring to
FIG. 10
, there is provided an optical element
10
including a transparent body formed of glass or plastic, having a plurality of curved reflecting surfaces provided on the surface thereof.
On the surface of the optical element
10
, there are formed, in the order of passage of light from an object, a concave refracting surface (incident surface) R
2
having a negative refractive power, four reflecting surfaces of concave mirror R
3
, reflecting mirrors R
4
and R
5
, a concave mirror R
6
, and a convex refracting surface (emergent surface) R
7
having a positive refractive power. In
FIG. 10
, there are shown a diaphragm (entrance pupil) R
1
disposed on the object side of the optical element
10
, an optical correcting plate
3
, such as a quartz low-pass filter, an infrared filter, or the like, a final image forming surface R
10
on which an image pick-up surface (light receiving surface) of an image pick-up element (image pick-up medium) such as a CCD is located, and a reference axis
5
of the optical system.
Both the refracting surfaces R
2
and R
7
are rotary symmetrical spherical surfaces, and all the reflecting surfaces R
3
to R
6
are aspheric surfaces symmetrical with respect to only a YZ plane.
An image forming operation of the optical element
10
will now be described. Of the light flux
1
from an object, the amount of incident light is regulated by the diaphragm R
1
, and then enters the incident surface R
2
of the optical element
10
, is reflected by the surfaces R
3
and R
4
, temporarily forms an image near the surface R
4
, is reflected from the surfaces R
5
and R
6
, and is emitted from the emergent surface R
7
to form an image again on the final image forming surface R
10
via the optical correcting plate
3
. As described above, the light from the object temporarily forms an image near the surface R
4
, while the light of the entrance pupil R
1
temporarily forms an image between the surfaces R
5
and R
6
.
The direction of the reference axis entering the optical element
10
and that emitting therefrom are parallel to and the same as each other. In addition, all of the reference axes including the incident reference axis and emergent reference axis are given in
FIG. 10
(on the YZ plane).
The optical element
10
serves as a lens unit having a desired optical performance and a positive refractive power overall by virtue of the refractive power (&phgr;=1/f; &phgr;: power, f: focal length) of the incident and emergent surfaces R
2
and R
7
, and the refractive powers of the concave reflecting mirrors R
3
and R
6
.
In addition, the optical element
10
collects light fluxes from the object existing in one direction (left side on the plane of the drawing), and forms the image thereof on the final image forming surface R
10
.
It is convenient that pictures of an object located in another direction, for example, in a direction perpendicular to the plane of the drawing (the X direction) can be taken as in the state of
FIG. 10
without rotating the optical element
10
around an axis of rotation in the Y direction.
In addition, it is also convenient that pictures of objects located in the same direction can be easily taken by substantially one optical element with different magnification.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a convenient optical element and a picture taking system having the convenient optical element.
According to an aspect of the present invention, there is provided an optical element including a plurality of curved reflecting portions, the reflecting portions reflecting light entered into the optical element, thereby transmitting the light inside the optical element, wherein the reflecting portions include a plurality of reflecting portion groups, and the reflecting portion groups form optical paths that are different from each other.
According to another aspect of the present invention, there is provided an optical element including a plurality of curved reflecting portions, the reflecting portions reflecting light entered into the optical element from a light incident portion, thereby transmitting the light inside the optical element, wherein the reflecting portions include a plurality of reflecting portion groups, and the reflecting portion groups have different optical characteristics.
In each of the above optical elements, the reflecting portions may be provided on 2n(n=integers of 2 or more) side surfaces (inner surfaces when body is hollow) of at least one of a solid body and a hollow body having the shape of a 2n-sided prism (n=integers of 2 or more), respectively, and the reflecting portion groups may be constructed by the reflecting portions provided on each pair of opposite side surfaces (inner surfaces when the body is hollow).
In addition, in each of the above optical elements, each of the reflecting portion groups may include a light incident portion and a light emergent portion; the reflecting portion groups may include a common reflecting portion and light incident portion, and the common reflecting portion and light incident portion may be rotatable together; and the reflecting portion groups may include a common final reflecting portion and light emergent portion, and the common final reflecting portion and light emergent portion may be rotatable together.
Furthermore, in each of the above optical elements, at least one of the light incident portion and the light emergent portion may include a curved surface that forms a spherical lens or an aspheric lens.
Still furthermore, in each of the above optical elements, each of the reflecting portions may include a rotary asymmetrical aspheric reflecting surface.
According to the present invention, there is provided a picture taking optical system including any one of the above optical elements, and a picture taking apparatus including the picture taking optical system and at least one of an image pick-up element and an image pick-up medium.
Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.
REFERENCES:
patent: 5995287 (1999-11-01), Sekita
Cherry Euncha
Spyrou Cassandra
LandOfFree
Optical element and picture taking system including the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical element and picture taking system including the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical element and picture taking system including the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3071172