Television – Stereoscopic – Endoscope
Reexamination Certificate
1996-07-25
2003-08-12
Philippe, Gims S. (Department: 2613)
Television
Stereoscopic
Endoscope
C600S160000, C600S166000
Reexamination Certificate
active
06606113
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a stereoscopic endoscope system and a TV imaging system for an endoscope which are used to observe an object three-dimensionally.
BACKGROUND TECHNOLOGY
In recent years, endoscopes each having an elongated insertion unit thereof inserted in a body cavity for observation of an organ in the body cavity and making it possible to use if necessary a treatment appliance inserted in a treatment appliance channel to conduct various curative procedures have been adopted widely. Moreover, industrial endoscopes have been widely utilized for observation, inspection, or the like of flaws, corrosion, or the like inside a pipe in a boiler, gas turbine, engine, chemical plant, or the like or inside a body of an automobile engine.
The endoscopes include a flexible endoscope whose insertion unit is flexible and inserted in a curved body cavity through a mouth or the like in order to observe or diagnose a lesion in the body cavity, and a rigid endoscope whose insertion unit is rigid and inserted linearly to an intended region.
In case the flexible endoscope is of an optical type, a flexible image guide fiber is used as an image conveying means. The rigid endoscope has an excellent target-finding ability owing to its rigid insertion unit, wherein a relay optical system is usually used as an image conveying means to produce an optical image.
The endoscopes including the rigid endoscope fall into a type in which an optical image is observed directly by naked eyes and a type in which an optical image picked up by a solid-state imaging device such as a charge-coupled device (CCD) serving as an imaging means is displayed in a monitor screen for observation.
With advancements in surgical procedures, endoscopic surgery, in which a small orifice is created in the abdomen in order to observe the abdominal cavity or conduct an operation thereon using an endoscope, is prevailing as a substitute for conventionally-adopted laparotomy. Almost all the foregoing endoscopes are designed to visualize a body cavity as a planar image that cannot give depth perception.
As far as the known endoscopes for viewing a planar image are concerned, it is hard to observe minute irregularity on the surface of, for example, an inner wall of a body cavity which is a very important diagnostic indication. In an effort to overcome this drawback, a stereoscopic endoscope in which optical systems are arranged in an endoscope, which is designed for producing a planar image for observation, in such a manner that three-dimensional observation is enabled has been proposed.
The optical systems for an endoscope enabling stereoscopy fall into three types described below.
First, a stereoscopic endoscope
10
of, as shown in
FIG. 1
, a dual-objective dual-relay optical system type has been disclosed in Japanese Patent Laid-Open No. 6-160731. The stereoscopic endoscope
10
is configured by juxtaposing two identical optical systems.
In the stereoscopic endoscope
10
, as shown in
FIG. 1
, images
13
a
and
13
b
formed by objective optical systems
12
a
and
12
b
incorporated in a scope unit
11
are transmitted by a given distance by conveying optical systems
14
a
and
14
b
formed with systems of relay lenses. The images are then recomposed into parallel rays by lenses
15
a
and
15
b
and transmitted to a TV camera unit
16
.
The images transmitted to the TV camera unit
16
are formed on imaging planes of two imaging devices
18
a
and
18
b
by way of image formation lenses
17
a
and
17
b
, whereby optical images are produced. Reference numeral d
1
denotes a spacing between two optical axes that is comparable to a parallax.
Secondly, as shown in
FIG. 2
, a stereoscopic endoscope
20
of a single-objective single-relay optical system type is described in Japanese Patent Laid-Open No. 6-167658. In the stereoscopic endoscope
20
, a system of relay lenses serving as an objective optical system and conveying optical system is formed with a single optical system that is axially symmetric.
In the stereoscopic endoscope
20
, as shown in
FIG. 2
, a pair of right and left aperture stops
23
a
and
23
b
and image formation lenses
24
a
and
24
b
are located at a position
22
of image formation at the back end of the system of relay lenses
21
so that the aperture stops will have a spacing corresponding to a parallax d
2
between them. An image is therefore spatially split into two portions. Thus, a pair of right and left images having a parallax between them are formed on two imaging devices
25
a
and
25
b
, whereby optical images are produced.
Thirdly, the present applicant has disclosed a stereoscopic endoscope
30
of a dual-objective single-relay optical system type as shown in
FIG. 3
in Japanese Patent Laid-Open No. 7-261099.
In the stereoscopic endoscope
30
, as shown in
FIG. 3
, a pair of right and left systems of lenses are used as first groups of lenses
32
a
and
32
b
of an objective optical system
31
and placed so that aperture stops of the systems will have a spacing d
3
between them. A second group
33
of lenses of the objective optical system
31
, and systems of relay lenses
34
a
,
34
b
, and
34
c
serving as a conveying optical system are each formed with a single optical system that is axially symmetric. An image passing through entrance pupil formation lenses
35
located at the back end of these systems of relay lenses
34
a
,
34
b
, and
34
c
is spatially split by aperture stops
36
a
and
36
b
. Resultant right and left images are formed on two imaging devices
38
a
and
38
b
by a pair of right and left image formation lenses
37
a
and
37
b
, whereby optical images are produced.
One of the advantages of the stereoscopic endoscope
10
of a dual-objective dual-relay optical system type shown in
FIG. 1
is that a three-dimensional image can be produced merely by juxtaposing normal optical systems designed for an endoscope. For optimizing three-dimensionality, the spacing dl between the optical axes of objective optical systems should merely be varied. In this case, the optimization can be achieved irrespective of specifications including an angle of view. The stereoscopic endoscope of this type can be designed more easily than the stereoscopic endoscope
20
of a single-objective single-relay optical system type shown in FIG.
2
.
By contrast, one of the drawbacks of the stereoscopic endoscope
10
lies in that since the right and left optical systems are constructed independently, the number of parts is large. Consequently, assembling is complex. Moreover, a difference in magnification between right and left images occurs deriving from an error of each part, and a shift of a focal point are large, and fine adjustment is required for normal stereoscopy.
One of the advantages of the stereoscopic endoscope
20
of a single-objective single-relay optical system type shown in
FIG. 2
is that the structures of an objective optical system and system of relay lenses are identical to those of normal optical systems designed for an endoscope. Therefore, while right and left images are sharing the same optical path, a change of an image deriving from errors caused during manufacturing occurs in the right and left images in the same manner. A difference in magnification between the right and left images and a shift of a focal point are therefore small. Moreover, since the number of parts is small, assembling efficiency is good. When as described in Japanese Patent Laid-Open No. 6-59199, a system of relay lenses is integrated into a scope unit and image formation lenses and imaging devices are integrated into a TV camera unit, the orientations of images can be corrected by turning the units relative to each other.
On the other hand, one of the drawbacks of the stereoscopic endoscope
20
is that three-dimensionality cannot be determined irrespective of specifications including an angle of view. The spacing between right and left entrance pupils of aperture stops that determines three-dimensionality is determined by an angle of view of an objective op
Armstrong Westerman & Hattori, LLP.
Olympus Optical Co,. Ltd.
Philippe Gims S.
LandOfFree
Stereoscopic endocsope system and TV imaging system for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stereoscopic endocsope system and TV imaging system for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stereoscopic endocsope system and TV imaging system for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3079114