JPH1156757A - Stereoscopic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to adjust the distance between objective lenses of two imaging units so that an optimal stereoscopic image is obtained by designing so that a solid imaging element and its board of one imaging unit of a pair of imaging units provided at the insertion part is placed opposite to the imaging element and its board of the other imaging unit in the vertical direction. SOLUTION: In this endoscope, two pairs of imaging units 11L and 11R provided at the insertion part are placed with facing each other in the vertical direction, and circuit boards 16L and 16R are placed opposite to each other in the vertical direction. This allows objective lenses to be placed at a desired distance, and a left eye image and a right eye image can be placed with a desired azimuth difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic endoscope in which two sets of image pickup units are provided in parallel at the distal end of an insertion section, and images for both right and left eyes are obtained from these two sets of image pickup units. It is about.

[0002]

2. Description of the Related Art An endoscope includes an illumination section for illuminating an observation target section at a distal end of an insertion section inserted into a body cavity or the like of a patient.
An observation unit for performing inspection, diagnosis, and the like under illumination light from the illumination unit is provided. The observation unit has an objective lens, and is configured such that an incident end of an image guide is arranged at an image forming position of the objective lens, or a solid-state imaging device such as a CCD is arranged. The former is called an optical endoscope, and the latter is called an electronic endoscope. The electronic endoscope picks up an electric signal obtained by imaging with a solid-state imaging device and performs photoelectric conversion, and transmits the electric signal to a video signal processing device. The video signal processing apparatus performs predetermined signal processing, and then displays a video on a monitor screen.

[0003] In recent years, stereoscopic endoscopes have been developed and put into practical use so as to obtain stereoscopically visible image information so that images of the inside of a body cavity and the like can be stereoscopically grasped. It has become to. There are various methods for obtaining a stereoscopic image, but there is a method in which a pair of left and right imaging units are provided at the end of the insertion unit, and two types of images obtained from both of the imaging units are alternately displayed on a monitor screen. General. Then, when the monitor screen is viewed by wearing spectacles equipped with a liquid crystal shutter that opens and closes in conjunction with the image alternately projected on the monitor screen, the image displayed on the monitor screen can be stereoscopically observed.

Here, the imaging unit is composed of an optical system including an objective lens and a solid-state imaging device, and the solid-state imaging device is mounted on a circuit board. The circuit board must have a certain size due to the mounting of electronic components and the like in addition to the solid-state imaging device.Such a board must be placed at the same position in the axial direction of the insertion section in the direction orthogonal to the axis. If you provide two,
The insertion section becomes thicker. For this purpose, the solid-state imaging device and the circuit board are arranged in the direction of the axis of the insertion section, and the optical path from the objective lens is bent by 90 ° using a prism before being incident on the solid-state imaging device.

[0005]

By the way, the respective objective lenses constituting the two image pickup units provided in the insertion portion need to be arranged at a certain interval on the left and right in order to have parallax. However, since the imaging unit includes not only an objective lens but also a prism, a solid-state imaging device, and its substrate, the two objective lenses are too far apart from each other due to restrictions on the width dimension of the substrate, and the left and right images are left and right. It is greatly displaced and displayed on the monitor screen,
When this monitor image is visually observed, the image cannot be recognized three-dimensionally and appears double. Therefore, when the inverted Galileo lens is arranged at a position closer to the subject than the two objective lenses and the imaging magnification is reduced, the state becomes the same as if the distance between the two objective lenses was shortened. However, depending on the size and shape of the circuit board, there may be cases where the two objective lenses cannot be placed in a positional relationship that allows accurate three-dimensional viewing.

The present invention has been made in view of the above points, and an object of the present invention is to display both objective lenses in a pair of imaging units having a solid-state imaging device and its circuit board on a monitor screen. It is an object of the present invention to provide an arrangement at an optimum interval for stereoscopic viewing when the image is displayed.

[0007]

In order to achieve the above-mentioned object, the present invention provides an objective lens, a prism for bending the optical path of the objective lens by approximately 90 °, and an objective lens in the optical path bent by the prism. An imaging unit including a solid-state imaging device and its substrate arranged at an imaging position,
A stereoscopic endoscope in which two sets are arranged at a predetermined interval at a distal end of an insertion portion and an image for the left and right eyes having a predetermined parallax is obtained by the two sets of imaging units, It is characterized in that the solid-state imaging device of one of the imaging units and its substrate are arranged so as to face the opposite side in the vertical direction with respect to the solid-state imaging device and its substrate on the other side. It is assumed that.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 1 shows the entire configuration of an endoscope. In FIG. 1, reference numeral 1 denotes an endoscope, and 2 denotes a light source unit provided integrally with a light source unit and a video signal processing unit. The endoscope 1 includes an insertion section 3 inserted into a body cavity, a main body operation section 4 provided in connection with a base end of the insertion section 3, and a universal cord 5 pulled out from the main body operation section 4. Be composed. The distal end of the universal cord 5 is branched, and one of the cords 5a is provided with a light source connector 6 detachably connected to the light source unit side socket 2a of the light source unit 2. The other cord 5b is provided with an electrical connector 7 that is detachably connected to the video signal processing unit side socket 2b provided in the light source unit 2. Further, a monitor 8 is connected to the light source unit 2.

FIG. 2 shows the structure of the distal end portion 3a of the insertion portion 3. The distal end portion 3a has a housing 9. The housing 9 includes an observation section provided at a central portion, and illumination sections located on both sides of the observation section. The illumination section has a pair of right and left light guides. The emission ends 10 and 10 (see FIG. 4) face and are for irradiating the body cavity with illumination light. The light guide 10 is moved from the insertion section 3 to the main body operation section 4.
, And is extended to the universal code 5, and further guided by the code 5 a of the universal code 5, and the incident end faces the light source connector 6.

As shown in FIGS. 3 and 4, two observation units 11L and 11R are provided in the observation section between the light guides 10. As shown in FIGS. 5 and 6, the imaging units 11L and 11R respectively include an objective lens 13L and an objective lens 13R on the objective lens barrels 12L and 12R.
L, 13R, and these objective lens barrels 12L,
12R has a prism 14L for bending the optical path by 90 °,
14R is joined and fixed. In the objective optical system described above, the imaging unit 11L and the imaging unit 11R have the same configuration. The prisms 14L and 14R are provided with solid-state image pickup devices 15L and 15R as image pickup means, and these solid-state image pickup devices 15L and 15R are connected to the circuit board 16 respectively.
L, 16R.

Here, the solid-state image sensor 15L and the solid-state image sensor 15R are mounted upside down. That is, the joining direction of the solid-state imaging device 15L to the prism 14L and the joining direction of the solid-state imaging device 15R to the prism 14R are upside down. For this, the circuit board 16L
Direction of pulling out the cable 17L from the
It is opposite to the direction in which the cable 17R is pulled out from R.
The cable 17R is pulled out forward from the circuit board 16R, and the cable 17R is routed inside the insertion portion 3 so as to be folded back on the back side of the circuit board 16R. The cables 17L and 17R are routed together with the light guide 10 into the insertion section 3, the main body operation section 4 and the universal cord 5, and are connected from the cord 5b to a terminal (not shown) provided on the electric connector 7. .

Since the endoscope 3 is configured as a stereoscopic endoscope, the two sets of image pickup units 11
L and 11R are attached. As is clear from FIG. 4, the two imaging units 11L and 11R are arranged at a distance D from each other. An observation window 18 (see FIG. 2) having a large opening is formed at the position of. The inverted Galileo lens 19 which is a combination of a concave lens and a convex lens is mounted on the observation window 18.

Thus, the two imaging units 11L, 11
After transmitting the image signal acquired by R to the video signal processing unit in the light source unit 2 and performing predetermined signal processing, the left and right images are alternately displayed on the monitor 8. The observer wears glasses with a liquid crystal shutter, and
By opening and closing the liquid crystal shutter in conjunction with the switching of the image in, the image projected on the monitor 8 can be recognized three-dimensionally. Here, the objective lenses 13L, 13R constituting the imaging units 11L, 11R
If the interval is too wide, the parallax becomes unnecessarily large and stereoscopic viewing becomes impossible, resulting in a substantial double image. Therefore, the objective lenses 13L and 13R must be arranged at appropriate intervals to provide binocular parallax. The imaging units 11L and 11R are solid-state imaging devices 15L and 15R.
The circuit boards 16L and 16R on which R is mounted are the largest and widest members.
The arrangement interval of 11R is restricted by the external dimensions of the circuit boards 16L and 16R.

As described above, the image pickup unit 11R and the image pickup unit 11L are arranged so as to be turned upside down. That is, as shown in FIGS. 3 and 4, the circuit board 16R of the imaging unit 11R is located on the upper side, and the circuit board 16L of the imaging unit 11L is located on the lower side. As a result, the circuit boards 16L and 16R of the two imaging units 11L and 11R do not interfere with each other, and can be disposed even when the objective lens barrels 12L and 12R are in close contact. Therefore, the distance D between the two objective lenses 13L and 13R can be arbitrarily adjusted, and the two objective lenses 13L and 13R can be adjusted.
Can be arranged such that the left-eye image and the right-eye image have a positional relationship that enables accurate stereoscopic viewing.

Since the light receiving surfaces of the image pickup unit 11R face each other above the image pickup unit 11L, the respective solid state image pickup devices 15
In L and 15R, the object S is imaged as shown in FIG. Here, when the image obtained by the solid-state imaging device 15R is inverted around the axis A, the surface becomes the same as that of the solid-state imaging device 15L, and in this state, the upper, lower, left, and right positional relationships are the same. From the above, the imaging unit 11L and the imaging unit 11R have the same configuration except that the solid-state imaging device and its circuit board are arranged to be inverted along an axis parallel to the horizontal scanning line, and the rest is the same. As a result, a left-eye image is obtained by the solid-state imaging device 15L, and a right-eye image having a predetermined parallax with respect to the left-eye image is obtained by the solid-state imaging device 15R. However, the transfer unit 15RT of the solid-state imaging device 15R is the same as the transfer unit 15LT of the solid-state imaging device 15L.
Must be located on the opposite side of the As shown in FIG. 5, on the imaging unit 11L side, the cable 17L extends in the proximal direction of the insertion section 3, that is, in the direction opposite to the objective lens barrel 12L.
On the other hand, as shown in FIG. 6, on the imaging unit 11R side, the cable 17R is connected in the direction of the distal end of the insertion section 3, that is, in the direction of the objective lens 12R, and the cable 17R is folded.

The two images having binocular parallax obtained as described above are subjected to signal processing by a video signal processing circuit as shown in FIG. As is apparent from this figure, the solid-state image pickup device 15L of the image pickup unit 11L and the solid-state image pickup device 15R of the image pickup unit 11R are driven, and the electric charge accumulated in each of the solid-state image pickup devices 15L and 15R is read. The image signals read from the solid-state imaging devices 15L and 15R are subjected to blanking, γ correction, contour correction, aperture correction, and white balance necessary for generating predetermined image signals in the image signal processing circuits 20L and 20R. A / D converters 21L and 2L after various signal processing such as
After being converted into a digital signal by 1R, it is recorded in the image memories 22L and 22R.

When one field of image data is taken into the image memories 22L and 22R, the image data is read out, converted into analog signals by the D / A converters 23L and 23R, and output. Then, the image signal from the image memory 22L and the image signal from the image memory 22R are alternately taken into the monitor 8 by the changeover switch 24, and the left-eye image and the right-eye image are alternately displayed on the monitor 8.

The image displayed on the monitor 8 is usually 1 /
The image is switched every 60 seconds. Since the right-eye image and the left-eye image are displayed alternately, the image switching timing is 1/120 seconds. Then, when the monitor 8 is observed while wearing spectacles having a liquid crystal shutter, the image can be grasped three-dimensionally. Both objective lenses 13L, 13R
Can be arranged so as to have the most suitable positional relationship for enabling stereoscopic viewing, so that the video displayed on the monitor 8 can be faithfully stereoscopically viewed.

In the above-described embodiment, the arrangement of the solid-state imaging devices 15L and 15R is reversed so that the directions of the left-eye image and the right-eye image match, but they are arranged vertically. By performing required signal processing on image signals obtained from the two solid-state imaging devices, the directions of the two images can be matched. That is, as shown in FIG. 9, after the image signal obtained by one solid-state imaging device 15R is processed by the signal processing circuit 20R, the signal is fetched to the image rotation circuit 25, and the image rotation circuit 25 After the image obtained by the solid-state imaging device 15R is rotated by 180 °, the image is taken into the image memory 22R via the A / D converter 21R. With this configuration, one solid-state imaging device 15R
There is no need to turn back the cable 17R from the camera, and the cable 17R can be pulled out from the same direction as the solid-state imaging device 15L.

[0020]

As described above, according to the present invention, the solid-state image pickup device of the image pickup unit on one side and its substrate are arranged so as to face the other side in the vertical direction with respect to the solid-state image pickup device on the other side and its substrate. With such a configuration, there is an effect that the distance between the objective lenses in both the imaging units can be adjusted to be an optimum distance for stereoscopic viewing.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a stereoscopic endoscope showing an embodiment of the present invention.

FIG. 2 is a sectional view of a distal end portion of an insertion portion.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is an explanatory diagram showing an arrangement relationship between two imaging units.

FIG. 5 is a cross-sectional view of an imaging unit for a left-eye image.

FIG. 6 is a cross-sectional view of an imaging unit for a right eye image.

FIG. 7 is an explanatory diagram showing a horizontal and vertical positional relationship between a left-eye image and a right-eye image obtained by two sets of imaging units.

FIG. 8 is a block diagram illustrating a configuration of a video signal processing unit.

FIG. 9 is a block diagram illustrating a configuration of a video signal processing unit of a stereoscopic endoscope according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 endoscope 2 light source unit 8 monitor 11L, 11R imaging unit 12L, 12R objective lens barrel 13L, 13R objective lens 14L, 14R prism 15L, 15R solid-state imaging device 16L, 16R circuit board 18 observation window 19 reverse Galileo lens 20L, 20R video signal processing circuit 22L, 22R image memory 24 selector switch 25 image rotation circuit

Claims (4)

[Claims] An imaging unit comprising an objective lens, a prism for bending the optical path of the objective lens by approximately 90 °, a solid-state imaging device disposed at an image forming position of the objective lens in the optical path bent by the prism, and a substrate thereof. Are arranged in parallel at a predetermined interval at the distal end of the insertion portion, and a stereoscopic endoscope in which the two sets of imaging units acquire images for the left and right eyes with a predetermined parallax. ,
Among the two image pickup units, the solid-state image pickup device and the substrate of the image pickup unit on one side are arranged so as to face the opposite side in the vertical direction with respect to the solid-state image pickup device and the substrate on the other side. Stereoscopic endoscope. 2. The solid-state image pickup device of one of the two image pickup units and the solid-state image pickup device of the other image pickup unit are rotated 180 degrees around an axis including a center position thereof and parallel to a horizontal scanning line. 2. The stereoscopic endoscope according to claim 1, wherein the stereoscopic endoscope is arranged to be inverted. 3. The three-dimensional image pickup device according to claim 1, wherein an image signal from one of the solid-state image sensors constituting the two image pickup units is rotated by 180 ° by an image signal rotating means. Endoscope. 4. The stereoscopic endoscope according to claim 1, wherein an inverted Galilean lens is disposed in the insertion section at a position closer to a subject than an objective lens in each of the two imaging units.