JP3609874B2 - Stereoscopic endoscope - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a stereoscopic endoscope that stereoscopically observes an object in a space that cannot be directly observed from the outside.
[0002]
[Prior art]
A stereoscopic endoscope is a rigid endoscope provided with a primary optical system including an objective lens system that forms an object image and a relay system that transmits this image, as disclosed in, for example, Japanese Patent Laid-Open No. 6-194581. A pupil dividing unit that divides the image transmitted by the primary optical system into left and right so that the image can be viewed stereoscopically, and two secondary optical systems that observe or capture the two divided images, respectively.
[0003]
This type of stereoscopic rigid endoscope is used for medical purposes for observing a site in a body cavity or for industrial use for observing the inside of a machine such as an engine.
[0004]
Images taken with each secondary optical system are, for example, a method using polarized glasses, a method of displaying left and right screens in time division in synchronization with glasses with a liquid crystal shutter, and from the back using a lenticular screen. Displayed by a method of projecting with two projectors, etc., the observer can recognize the displayed image as a stereoscopic image.
[0005]
[Problems to be solved by the invention]
However, since the stereoscopic rigid endoscope described in the above-mentioned publication is provided with two secondary optical systems fixed, the positions of the two viewpoints for stereoscopic vision are fixed and rigid. The observation direction with respect to the object cannot be changed unless the entire mirror is displaced relative to the object.
[0006]
Generally, if an object can be observed from a plurality of different directions, it is possible to more accurately determine the shape of the object. However, since the observation target of an endoscope is usually in a narrow space, a rigid endoscope It is difficult to change the viewpoint by moving the whole.
[0007]
OBJECT OF THE INVENTION
The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a stereoscopic endoscope that can change a stereoscopic viewpoint for an object without moving a primary optical system. And
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the stereoscopic endoscope according to the present invention is characterized in that three or more secondary optical systems that take in light beams that have passed through different regions in the pupil of the primary optical system are provided. Each secondary optical system includes a separator lens disposed in the pupil of the primary optical system, and an imaging element disposed at a position conjugate with an image forming position by the separator lens.
[0009]
By selecting any two of the images input via the three separator lenses, stereoscopic viewing is possible, and by changing the combination of secondary optical systems to be selected, the possibility of stereoscopic viewing of the object is expected. The direction can be changed. According to this configuration, the object can be observed from a plurality of different directions without moving the primary optical system, and the properties of the object can be determined more accurately.
[0010]
In this specification, a change in the position of at least one of the two viewpoints necessary for the stereoscopic view is defined as a “change in the prospective direction of the stereoscopic view”. This includes not only a change in the direction of the line segment connecting the two viewpoints but also a change by moving the viewpoint without changing the direction of the line segment. The latter includes a case where two viewpoints are moved while keeping the viewpoint interval constant and a case where at least one of the two viewpoints is moved while changing the viewpoint interval to change the stereoscopic effect.
[0011]
In order to change the directionality of the line segment connecting the two viewpoints, it is necessary to arrange the separator lens two-dimensionally in the pupil of the primary optical system. When it is not necessary to change the directionality of the line segment, the separator lens may be arranged on a straight line in the pupil.
[0012]
When displaying a captured image by a projection device using a lenticular screen, the image is captured by each secondary optical system and projected by a projector so that the observer can change the viewpoint with respect to the screen. The observation angle can be changed. Note that when an image is taken by an imaging device, it is not only displayed in real time but also recorded and stored on a video tape or the like.
[0013]
It is sufficient that the number of secondary optical systems is three or more, and five separator lenses may be arranged on a straight line, or the same number or more separator lenses may be arranged two-dimensionally. Further, when four or more secondary optical systems are provided, at least one of them may be used for observation with the naked eye. For example, when five secondary optical systems are provided, 3 One can be used for photographing, two can be used for observation with the naked eye, and two for observation can be shared with photographing.
[0014]
The primary optical system is disposed in an insertion portion that is inserted into a space such as a body cavity, and includes an objective lens system positioned at the distal end of the insertion portion and at least one relay lens system. The image transmitted by the first relay lens system is transmitted to the observation unit connected to the proximal end side of the insertion unit by the subsequent relay lens system. In this case, the separator lens and the image sensor of the secondary optical system are arranged in the observation unit.
[0015]
In another example, a relay lens system is disposed only on the distal end side of the insertion portion, and a secondary optical system separator lens is disposed in accordance with a pupil located in the insertion portion of the relay lens system. The image formed by the separator lens is transmitted to the observation unit by the image guide fiber bundle and photographed by the image sensor in the observation unit, or is photographed by the image sensor arranged at the primary image forming position of the separator lens and the electric signal. Is transmitted to the observation unit through a signal line.
[0016]
Further, when the primary optical system and the secondary optical system are separately provided on the insertion unit side and the observation unit side, a monocular rigid mirror is used as the insertion unit, and a stereoscopic adapter is used as the observation unit. It can also be set as the structure connected. In this case, an adjusting means for changing the relative positional relationship between the primary optical system and the secondary optical system may be provided. The adjusting action may be provided in a connecting means that connects the positions of the insertion portion and the observation portion, or may be provided in a holding portion that integrally holds the separator lens and the imaging element.
[0017]
【Example】
Hereinafter, embodiments of the stereoscopic endoscope according to the present invention will be described. As shown in FIG. 1A, the stereoscopic endoscope according to the first embodiment is connected to a rigid insertion portion 1 that is inserted into a narrow space such as a body cavity, and a proximal end side of the insertion portion 1. The observation unit 2 is provided.
[0018]
Inside the insertion portion 1 are a plurality of relay lens systems composed of a three-group four-element objective lens system 11 that forms an object image and a plurality of lenses that transmit the image formed by the objective lens system 11. 12, and a pupil forming lens system 13 that forms the exit pupil of the primary optical system 10 are arranged in order from the object side, and the primary optical system 10 is configured by these lens systems.
[0019]
In the observation unit 2, a light receiving unit 30 configured by five secondary optical systems is provided so as to coincide with the pupil Ep of the primary optical system 10. As shown in FIGS. 1B and 1C, the light receiving unit 30 includes five separator lenses 37a, 37b, 37c, 37d, and 37e arranged in parallel on the diameter of the pupil Ep. Imaging elements 38a, 38b, 38c, 38d, and 38e that capture images formed by the separator lenses, and each of the separator lenses and the imaging elements constitutes one secondary optical system. doing.
[0020]
The light receiving unit 30 is integrated along the front-rear direction along the optical axis Ax1 and the left-right direction perpendicular to the optical axis (in the plane of FIG. 1) by the adjusting means 40 as shown in FIG. Can be moved to.
[0021]
The adjusting means 40 is installed on a holding frame 41 that supports the light receiving unit 30 from both the left and right sides, and an end of the holding frame 41 opposite to the light receiving unit 30, and both sides are rotatably supported by the holding frame 41. The left / right position adjustment screw 44 and a front / rear position adjustment bolt 45 that is attached to the attachment portion 2 a of the observation unit 2 so as to be movable back and forth in the direction of the optical axis Ax1 and hold the left / right position adjustment screw 44.
[0022]
A nut portion 45a that is screwed to the left and right position adjusting screw 44 is fixed to the front end of the front and rear position adjusting bolt 45, and a front and rear position adjusting knob that is screwed to the front and rear position adjusting bolt 45 inside the wall surface of the mounting portion 2a. 46 is rotatably mounted.
[0023]
According to this configuration, the left / right position of the light receiving unit 30 can be adjusted as a whole by rotating and adjusting the left / right position adjustment knob 44a fixed to the left / right position adjustment screw 44, and the front / rear position adjustment. By adjusting the knob 46, the position of the light receiving unit 30 in the front-rear direction can be adjusted as a whole.
[0024]
By these two-dimensional adjustments, the object-side surfaces of the separator lenses 37 to 37e are accurately positioned within the pupil Ep of the primary optical system 10 and are symmetric with respect to the optical axis Ax1 of the primary optical system 10. Is positioned as follows.
[0025]
Each image pickup device captures an image obtained by viewing an object from a different angle according to the position occupied by each separator lens in the pupil Ep. That is, images having parallax are captured in the five secondary optical systems, respectively, and by displaying any two of these images using a known stereoscopic image display method, the observer can view the object in a stereoscopic manner. Can be observed.
[0026]
In addition, by changing the selected secondary optical system, it is possible to change the prospective direction of stereoscopic vision for the object. For example, when the displayed stereoscopic image is switched from an image photographed via the separator lenses 37a and 37e at both ends to an image photographed via the inner separator lenses 37b and 37d, the parallax is reduced. The three-dimensional effect is reduced. Further, when the image photographed through the adjacent separator lenses 37a and 37b on one side is switched to the image photographed through the adjacent separator lenses 37d and 37e on the other end side, the stereoscopic effect does not change. However, the observation direction with respect to the object changes, and the observation direction with respect to the object can be changed without mechanical movement.
[0027]
Further, when an image is displayed by the projection device 200 using a lenticular screen, as shown in FIG. 2, 5 images captured by each secondary optical system are provided in parallel in the horizontal direction. It is possible to project simultaneously from the two projectors 210 to 214 toward the back of the lenticular screen 220.
[0028]
The lenticular screen 220 is formed by assembling a large number of cylindrical lenses having generatrix lines in a direction perpendicular to the paper surface, and the direction of an image projected from each projector through the lenticular screen 220 is projected to each cylindrical lens. It is limited to a predetermined direction according to the incident angle. Accordingly, when the observer's viewpoint changes in the horizontal direction, the photographer observes images from different projectors accordingly, and the observation direction for the object can be changed by changing the viewpoint.
[0029]
For example, if the photographer's head H is at the position indicated by the solid line, the image of the second projector 211 is mainly incident on the right eye and the image of the third projector 212 is mainly incident on the left eye. On the other hand, when the photographer's head H moves to the position indicated by the broken line in the horizontal direction, the image of the fourth projector 213 is mainly incident on the right eye and the image of the fifth projector 214 is mainly incident on the left eye. To do.
[0030]
The stereoscopic endoscope according to the second embodiment illustrated in FIG. 3 is configured as a monocular endoscope only by the insertion unit 1 provided with the primary optical system 10, and the secondary optical system is included in the endoscope. The observation unit 2 provided with is attached as a binocular adapter. The optical configuration and the configuration of the adjusting means 40 are the same as those of the first embodiment shown in FIG.
[0031]
On the proximal end side of the insertion portion 1, a brim-shaped hood 14 that comes into contact with the periphery of the observer's eyes and blocks ambient light during observation with a single eye is attached. The observation unit 2 is fixed to the insertion unit 1 via an attachment 50 attached to the hood 14.
[0032]
The attachment 50 is attached to the hood 14 from the observation unit 2 side and surrounds the hood 14 from the outside. The fixing bolt 53 is configured to fix the 52 to the mounting ring 51.
[0033]
The attachment ring 51 includes a disc part 51 a having an opening formed in the center that contacts the hood 14, and a cylindrical part 51 b that rises from the peripheral part of the disc part 51 a toward the object side and surrounds the outer periphery of the hood 14. And a flange portion 51c formed from the object-side tip of the cylindrical portion toward the inner periphery. The abutting piece 52 is a small piece having an L-shaped cross section, and the hood 14 is abutted against the attachment ring 51 at at least three places in the circumferential direction.
[0034]
Further, adjustment bolts 54 that protrude toward the observation unit 2 side are fixed to three portions in the circumferential direction on the outer peripheral portion of the surface of the attachment ring 51 on the observation unit 2 side. The observation portion 2 is formed with an outer flange 2b in the peripheral portion on the insertion portion 1 side, and a through hole 2c through which the adjustment bolt 54 is inserted is formed in the outer flange 2b. The adjustment bolt 54 is fixed to the outer flange 2b by nuts 55 and 56 located on both sides of the outer flange 2b in a state of being inserted into the through hole 2c, and the insertion portion 1 attached to the attachment 50 is attached to the observation portion 2. Fix against.
[0035]
In this embodiment, the positional relationship between the attachment 50 and the observation unit 2 can be adjusted three-dimensionally by adjusting the positions of the nuts 55 and 56 that are screwed into the three adjustment bolts 54. it can.
[0036]
4 to 7 show Embodiments 3 to 6 of the present invention. In these embodiments, the relay lens system 12 and the pupil forming lens system 13 are disposed only on the distal end side of the insertion unit 1, and the secondary optical system separator lens is aligned with the pupil of the primary optical system located in the insertion unit 1. 37a to 37e are arranged. Accordingly, the distal end portion 1a in which the lenses 11 to 13 of the insertion portion 1 are arranged is rigid as in the first embodiment. However, the intermediate portion 1b connecting the distal end portion 1a and the observation portion 2 has a soft tube. Can also be used.
[0037]
In Example 3 shown in FIG. 4, the image sensor is arranged at the primary image formation position of the separator lens, and the light receiving unit 30 similar to that in FIG. 1 is configured. The image signal from each image sensor is a signal line as an electric signal. 30a is transmitted to the observation part 2 through the intermediate part 1b.
[0038]
In Example 4 shown in FIG. 5, the image guide fiber bundles 39a to 39e are arranged so that the incident end faces coincide with the primary imaging positions of the separator lenses 37a to 37e, and the images transmitted to the observation unit 2 are thereby combined. The images are formed on the image pickup devices 38 a to 38 e fixed in the observation unit 2 through the image lenses 32 a to 32 e.
[0039]
In the fifth embodiment illustrated in FIG. 6, the image captured by the separator lens is transmitted to the observation unit 2 side using the image guide fiber bundles 39 a to 39 e in substantially the same manner as the fourth embodiment. However, in this example, the secondary optical system includes two eyepiece optical systems capable of observation with the naked eye in addition to the three including the imaging elements 38a to 38c. That is, the images transmitted by the image guide fiber bundles 39a, 39c, and 39e are imaged on the image sensors 38a, 38b, and 38c by the imaging lenses 32a, 32b, and 32c, respectively. On the other hand, the images transmitted by the image guide fiber bundles 39b and 39d are transmitted to the outside of the observation unit 2 through the eyepieces 33a and 33b, and can be observed with the naked eye.
[0040]
In Example 6 shown in FIG. 7A and a partially enlarged view of FIG. 7B, the same configuration as in Example 5 is adopted, and an image used for observation with the naked eye is also used for photographing. doing. The configuration of the three secondary optical systems at the center for directly forming the images from the image guide fiber bundles 39a, 39c, and 39e is the same as that of the fifth embodiment.
[0041]
Part of the light beam transmitted by the image guide fiber bundles 39b and 39d and transmitted through the imaging lenses 32d and 32e is reflected by the half mirrors 60a and 60b as optical path dividing means, and passes through the re-imaging lenses 32f and 32g. An image is formed on the image sensors 38d and 38e. The light flux that has passed through the half mirrors 60a and 60b is subjected to observation with the naked eye via the eyepieces 33a and 33b.
[0042]
In each of the above embodiments, each has five secondary optical systems, and five separator lenses are provided in parallel on the diameter on the pupil of the primary optical system. The number of secondary optical systems is as shown in FIG. As shown in Example 7 shown in FIG.
[0043]
In the example of FIG. 8, the primary optical system 10 is disposed in the rigid insertion portion 1 in the same manner as in the first embodiment, and is disposed in the observation portion 2 at the respective imaging positions with the three separator lenses 37a, 37b, and 37c. A secondary optical system including the image sensors 38a, 38b, and 38c is provided.
[0044]
In this example, the central separator lens 37c and the image sensor 38c are integrally fixed to the observation unit 2, and the separator lenses 37a and 37b and the image sensors 38a and 38b on both sides are integrally formed as support members 47a and 47a, respectively. 47b is movably supported.
[0045]
The base end portions of the support members 47 a and 47 b are screwed into a distance adjusting screw 42 that is rotatably supported on the distal end side that is the primary optical system 10 side of the holding frame 41, and in the center of the distance adjusting screw 42. The interval adjusting knob 43 is fixed integrally. Since the attachment structure of the holding frame 41 to the attachment portion 2a is the same as that of the first embodiment, description thereof is omitted.
[0046]
The interval adjusting screw 42 is formed with a screw groove in which the spiral direction is reversed with respect to the interval adjusting knob 43 as a boundary. By rotating the interval adjusting knob 43, the support members 47a and 47b are moved, As a result, the separator lenses 37a and 37b and the image sensors 38a and 38b move away from each other so as to be symmetric about the optical axis Ax1 of the primary optical system 10 or move closer to each other.
[0047]
According to the configuration of the seventh embodiment, as shown in FIGS. 9A and 9B, the interval between the separator lenses 37a and 37b on both sides can be changed with the central separator lens 37c as a boundary, and the observation field of view can be changed. It is possible to change the stereoscopic effect continuously.
[0048]
When the number of secondary optical systems is three, if the separator lenses 37a to 37c are arranged without gaps in the pupil Ep as shown in FIG. 9C, the separator lenses cannot be moved. The maximum amount of light taken into each secondary optical system can be ensured.
[0049]
Further, from the viewpoint of changing the observation direction, the three separator lenses provided in the observation section are arranged so as to circumscribe each other as shown in FIG. 9D, and correspond to each of these three separator lenses. The range of the light beam captured by each of the secondary optical systems is changed within the pupil Ep without changing the relative relationship of the three secondary optical systems. It is also possible.
[0050]
Further, the separator lenses are arranged not only in a straight line as shown in FIG. 1C and FIG. 9, but also in three or more separator lenses as shown in FIG. You may arrange in a dimension. In the arrangements of FIGS. 1C and 9, the prospective direction of stereoscopic vision for the objects of the two selected secondary optical systems can be changed only in one direction that is the arrangement direction of the separator lenses.
[0051]
Therefore, when this is a horizontal direction, it is necessary to rotate the entire endoscope in order to obtain a stereoscopic image observed from another direction, for example, the vertical direction. There is a time difference in the obtained timing. The internal organs and the internal mechanisms of the machine, which are the observation targets of the endoscope, are often accompanied by movement, and it is not preferable that a time difference occurs in switching of images.
[0052]
When the separator lens is two-dimensionally arranged as shown in FIG. 10, the directionality of the line segment connecting the two viewpoints can be changed only by changing the selection of the secondary optical system.
[0053]
For example, in the example of FIG. 10A, by changing the combination of the separator lenses (secondary optical systems) to be selected, the directionality of the line segment connecting the viewpoints is changed to directions different from each other by d1, d2, and d3 by 60 °. can do. Further, according to the arrangement of FIG. 10B, the directionality of the line segment connecting the two viewpoints can be switched between the horizontal direction dh and the vertical direction dv by selecting the separator lens.
[0054]
FIGS. 10C and 10D show examples in which more separator lenses are arranged in the pupil Ep of the primary optical system. According to these examples, the degree of freedom of selection becomes higher, and the prospective direction of stereoscopic vision with respect to the object can be changed without moving the primary optical system.
[0055]
【The invention's effect】
As described above, according to the present invention, any two images input through at least three separator lenses can be obtained by providing three or more secondary optical systems each including a separator lens and an image sensor. By selecting, stereoscopic viewing is possible, and by changing the combination of secondary optical systems to be selected, the prospective direction of stereoscopic viewing for the object is changed, and the object is observed in more detail from multiple directions Can do.
[Brief description of the drawings]
1A and 1B show a first embodiment of a stereoscopic endoscope according to the present invention, in which FIG. 1A is an overall cross-sectional view, FIG. 1B is an enlarged view of a light receiving unit, and FIG. 1C is an arrangement of separator lenses on a pupil; FIG.
FIG. 2 is an explanatory diagram illustrating the principle of a stereoscopic image display device using a lenticular screen.
FIG. 3 is an enlarged view of an observation unit showing a stereoscopic endoscope according to a second embodiment.
4 is an overall cross-sectional view showing a stereoscopic endoscope according to Embodiment 3. FIG.
FIG. 5 is an overall cross-sectional view showing a stereoscopic endoscope according to a fourth embodiment.
FIG. 6 is an overall cross-sectional view showing a stereoscopic endoscope according to a fifth embodiment.
7 is an overall cross-sectional view showing a stereoscopic endoscope according to Embodiment 6. FIG.
8 is an overall cross-sectional view showing a stereoscopic endoscope according to Embodiment 7. FIG.
FIG. 9 is a plan view showing a modified example of the arrangement of the separator lenses on the pupil.
FIG. 10 is a plan view showing another modified example of the arrangement of the separator lens on the pupil.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insertion part 2 Observation part 10 Primary optical system 11 Objective lens system 12 Relay lens system 13 Pupil formation lens system 14 Hood 200 Projection device 210-214 Projector 220 Lenticular screen 30 Light-receiving unit 30a Signal line 32a-32e Imaging lens 32f, 32g Re-imaging lens 33a, 33b Eyepiece lens 37a-37e Separator lens 38a-38e Image sensor 39a-39e Image guide fiber bundle 40 Adjustment means 50 Attachment 51 Attachment ring 52 Attaching piece 53 Fixing bolt 54 Adjustment bolt 55, 56 Nut 60a, 60b half mirror

Claims (10)

In a stereoscopic endoscope having a primary optical system having an objective lens system and a relay lens system, and a plurality of secondary optical systems that capture light beams that have passed through different regions in the pupil of the primary optical system,
Each of the secondary optical systems includes a separator lens disposed in the pupil of the primary optical system, and an imaging element disposed at a position conjugate with an image forming position by the separator lens. A stereoscopic endoscope characterized in that at least three or more are provided. The stereoscopic endoscope according to claim 1, wherein the imaging element is disposed at a primary image formation position of the separator lens. Each of the secondary optical systems has an image guide fiber bundle provided with an incident end face positioned at a primary image formation position of the separator lens, and the image pickup device transmits an image transmitted by the image guide fiber bundle. The stereoscopic endoscope according to claim 1, wherein the stereoscopic endoscope is disposed at a secondary imaging position for receiving the image. The separator lens is arranged in the pupil of the primary optical system so that the prospective direction of stereoscopic vision with respect to the object to be observed can be changed in one direction within the field of view by selecting any two of the secondary optical systems. The stereoscopic endoscope according to claim 1, wherein the stereoscopic endoscope is arranged in a straight line. The separator lens is arranged in the pupil of the primary optical system so that the prospective direction of stereoscopic vision with respect to the object to be observed can be changed in a plurality of directions within the field of view by selecting any two of the secondary optical systems. The stereoscopic endoscope according to claim 1, wherein the stereoscopic endoscope is arranged two-dimensionally. The stereoscopic endoscope according to claim 5, wherein at least three of the separator lenses are arranged so that their centers coincide with the vertices of a triangle. The stereoscopic endoscope according to claim 4, wherein the separator lens is relatively movable away from and close to the separator lens. The secondary optical system includes at least three provided with the imaging element, two separator lenses disposed at the pupil position of the primary optical system, and an eyepiece system for observing an image captured by the separator lens. The stereoscopic endoscope according to claim 1, comprising two eyepiece optical systems configured by: 9. The eyepiece optical system includes an optical path splitting unit between the separator lens and the eyepiece lens system, and an image pickup device that receives one light beam split by the optical path splitting unit. The stereoscopic endoscope described in 1. A display device for a stereoscopic endoscope according to claim 1,
A display device comprising: a lenticular screen; and a plurality of projectors that project image signals from the plurality of imaging elements toward the lenticular screen, respectively.

Images