JPH0526171B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an optical configuration of a binocular stereomicroscope, and more particularly to an optical configuration of a binocular microscope with a slit lamp used in the ophthalmology field. The optical types of binocular stereomicroscopes are broadly divided into Greenough type and Galileo type. As schematically shown in FIG. 1, the Greenough type is constructed such that two optical paths intersect at a narrow angle ω at the object surface.
Each of these optical paths has an objective lens system 1.
a, 1b, erecting optical systems 2a, 2b, and eyepiece systems 3a, 3b, and is configured such that the optical axis A of incidence on the objective lens and the observation optical axis B of the eyepiece are parallel. (Similarly, in the optical path, the incident optical axis A and observation optical axis B are parallel).
Here, the narrow angle ω is selected to be a convergence angle of 10° to 16° when the examiner's eyes e ₁ and e ₂ observe the subject E at close range in a natural visual state with the naked eye without using a microscope. Therefore, in the Greenough binocular microscope, the narrow angle ω between the optical axes A and A of incidence on the objective lens (hereinafter referred to as stereo angle) and the narrow angle θ between the observation optical axes B and B of the eyepiece systems 3a and 3b ( (hereinafter referred to as observation angle)
are equal, and as described above, the stereo angle ω is configured to be equal to the convergence angle in the natural viewing state, so it has the advantage of allowing natural stereoscopic viewing.
However, since the optical paths are obliquely crossed, machining for assembling optical components is complicated.
Also, objective lens systems 1a, 1b and erecting optical system 2a,
2b, the configuration of a focusing and variable magnification optical system (not shown), which is usually arranged between the lens and the lens 2b, is also complicated. On the other hand, the Galilean type binocular microscope has optical paths and optical axes parallel to each other, as shown in FIG. The optical path includes objective lens system 4 and an intermediate image.
It is composed of an imaging lens system 7a for forming Pa, an erecting optical system 5a, and an eyepiece system 6a for observing intermediate image Pa. Further, the optical path has the objective lens system 4 as a common objective lens,
Similarly to the optical path, it is composed of an imaging lens system 7b, an erecting optical system 5b, and an eyepiece system 6b. Here, the optical axes of both imaging lens systems 7a and 7b are parallel to each other and also parallel to the optical axis 4a of the objective lens system 4. Further, the observation optical axes B and B of the eyepiece lens systems 6a and 6b are also configured to be parallel to the optical axes of the imaging lens systems 7a and 7b, respectively. The optical axis A of incidence on the objective lens system 4 is determined by the base line length l defined by the interval between the imaging lens systems 7a and 7b.
The stereo angle ω created by A is determined. Because of the parallax caused by this stereo angle ω, the object E can be viewed stereoscopically even if the observation angle θ formed by the observation optical axes B and B is 0. As mentioned above, this Galileo type binocular microscope has two optical paths,
are parallel to each other, so the configuration of the optical system is simple, and the configuration of the focusing mechanism and variable magnification mechanism is also simple.
It also had the advantage that it was relatively easy to add accessory optical paths such as a photographing optical system and a side mirror. In general, when the human eye is in a far viewing state, there is no convergence in the line of sight of both eyes, and even without adjusting the crystalline lens, the human eye is able to observe in a comfortable and fatigue-free state. The same is true for microscopic observation; a Galileo-type microscope, in which both observation optical axes B and B are parallel to each other, is less tiring during observation than a Greenough-type microscope, in which both observation optical axes are convergent, and can be used for long-term observation. It is said to be advantageous. However, a microscope is a device that magnifies and observes a small object placed at a close distance, and is comparable to a Galilean type microscope. The disadvantage was that there was prerequisite information that the user was looking at an object at a distance, which created a difference from the natural sensation. This is especially true because the parallax caused by the stereo angle ω is observed even though there is no eye rotational movement information, that is, no convergence movement information, so the viewer perceives an unnatural stereoscopic effect that is stronger than the normal stereoscopic effect. I had the disadvantage of being able to see. Furthermore, if we take the case of a binocular stereomicroscope, which is a slit lamp device used in the ophthalmology field, as an example,
Doctors often need to visually observe the eye to be examined in order to adjust the irradiation position of the slit illumination light onto the eye, adjust the width and length of the slit, or perform simple surgical procedures on the eye. Naturally, the doctor's observing eye is placed in a near-sighted state. Next, he had to look through a microscope and dilate his eyes to a state of distance vision without convergence to see stereoscopically, which had the disadvantage that it was not possible to instantly achieve distance vision or stereoscopic vision. The exaggeration of the stereoscopic effect and the need for divergence movement from macroscopic to stereoscopic viewing in the Galileo type binocular stereomicroscope negates the conventionally said lack of observation fatigue, and on the contrary, compared to the Greenough type microscope. Despite having the various advantages mentioned above, the Galilean type microscope had disadvantages such as increased observation fatigue, inaccurate observation, and treatment errors due to misperception of distance. On the other hand, in the case of a Greenough-type binocular stereomicroscope,
It has the above-mentioned advantage of being able to observe the object under a microscope with the same 3D visibility as close vision with the naked eye, but when you want to know even more minute differences in height, you cannot distinguish with the 3D visibility close to natural vision. In some cases, there was a request to enhance the three-dimensional effect. The present invention has been made in order to eliminate the various drawbacks of the conventional binocular microscopes described above and to satisfy the demands. The present invention will be described below with reference to figures showing preferred embodiments. FIG. 3 shows the optical arrangement of a binocular stereomicroscope according to the present invention, taking the binocular stereomicroscope section of a slit lamp as an example. This binocular microscope has first and second intermediate images 102 and 20 of the object E.
The optical system has an objective optical system for creating the optical system 2, and an eyepiece system 105, 205, and is composed of two optical paths, a first optical path 100 and a first optical path 200. 1st
The optical path 100 includes a common single objective lens system 101, an imaging lens system 103 which is a lens for forming an intermediate image 102 and whose optical axis is parallel to the optical axis 101a of the single objective lens system 101, and an optical path polarizing means. can be,
And deformed polyprism 10 as an erecting optical system
4, and an eyepiece system 105 for observing the intermediate image 102. On the other hand, the second optical path 200 includes the single objective lens system 101 and the intermediate image 2.
02, an imaging lens 203 having its optical axis parallel to the optical axis 101a of the single objective lens system 101, a deformed Porro prism 204 serving as an optical path deflection means and an erecting optical system, and Eyepiece system 2 for observing intermediate image 202
It consists of 05. The objective optical system shown in this type has one common objective lens system 101 and an optical axis 1 of the objective lens system 101.
01a, and is composed of first and second imaging lens systems 103 and 203 for forming first and second intermediate images 102 and 202. Here, the apex angle α of each of the prisms 106 and 206 constituting the deformed polyprisms 104 and 204 is (90°−ω/4).
ω is the incident optical axis 1 of the first optical path 100 to the test object E.
This is a stereo angle formed by 00A and the incident optical axis 200A of the second optical path 200, and the size is determined by the base line length l between the two imaging lenses 103 and 203. From the above relationship between α and ω, the first optical path 10
The observation angle θ formed by the observation optical axis 100B of 0 and the observation optical axis 200B of the second optical path 200 is configured to be equal to the stereo angle ω. The following experimental results also support the fact that when the stereo angle ω and the viewing angle θ are made equal in this manner, the viewing feeling is close to the natural stereoscopic viewing feeling seen by the naked eye. The experiment was conducted using an inner diameter a = 2.0 m/m as shown in Figure 4.
A test object having a conical cylindrical hole 300 with a depth d = 2.0 m/m (depth/inner diameter ratio = 1) was first observed with the naked eye by the 10 observers shown in Table 1, and then the objects shown in Table 2 were All the observers observed the above-mentioned test object using the five types of binocular stereomicroscopes shown in FIG. Then, for each model, determine whether the ratio of the inner diameter a to the depth d of the object to be examined when observed under a microscope is larger or smaller than that observed with the naked eye.
They were asked to answer on a 5-point scale from 5 to 5. Note that 3 indicates a case where the image is comparable to that seen with the naked eye, and the three-dimensional effect becomes stronger. That is, as the depth/inner diameter ratio increased, the subjects were asked to answer 4 or 5, and conversely, when the three-dimensional effect was less, they were asked to answer smaller numbers such as 2 or 1. Table 3 shows the three-dimensional effects of five types of microscopes obtained by 10 observers.

【table】

【table】

[Table] As can be seen from the results in Table 3, the viewer's three-dimensional impression is closely related to the viewing angle θ, and for both the Galileo type and the Greenough type, the smaller the viewing angle θ, the greater the three-dimensional effect. Become. Furthermore, it has been proven that in both types, when the stereo angle ω and the observation angle θ are equal, a natural three-dimensional effect similar to that seen with the naked eye can be obtained. As explained above, according to this embodiment, since the optical axes of the imaging lenses 103 and 203 remain parallel to each other, the variable magnification optical system and the focusing optical system ( (In some cases, the imaging lens also serves as this function) and the drive mechanism for these is simpler than that of the Greenough type, and it is also easier to incorporate attached optical systems such as the imaging optical system in the Galileo type binocular stereo microscope. It is possible to obtain a new Galileo-type binocular stereomicroscope that combines the advantages of the Greenough type, which allows observation under a microscope with the same natural three-dimensional effect as when observed with the naked eye. In the first embodiment, the configuration is fixed so that the stereo angle ω and the observation angle θ are equal, but by making the observation angle θ variable, both Greenough type and Galileo type can be used for observation under a microscope. Making the three-dimensional effect of time larger than that seen with the naked eye,
It may be desirable to be able to make it smaller or change it. FIG. 5 shows an embodiment of a configuration equipped with an observation angle adjusting means for this purpose, which is both types of optical path polarizing means shown in FIG. 1 or FIG. 2, and a modification of the erecting optical system. shows only an erect optical system with one optical path. The erecting optical system 400, which is an optical path deflection means, includes two doped prisms 401 and 40.
2, the second doped prism 402
The reflective surface 402a of the first doped prism 401
The two doped prisms constitute an erecting optical system such that an inverted image is observed as an erect image. Then, the second doped prism 402 is
3 as the rotation axis, the observation optical axis 4
04 within a horizontal plane, and is configured so that the three-dimensional effect can be changed by changing the viewing angle θ. FIG. 6 is a diagram showing another embodiment for changing the three-dimensional effect. An erecting optical system 410 which is an optical path deflection means for one optical path includes a first right angle prism 41
1, a rotating mirror 412, and a first right angle prism 4
The rotating mirror 412 and the second right angle prism 413 are integrated with the eyepiece 500 and rotate about the rotation axis 412a. The camera is constructed with observation angle adjustment means that allows the user to adjust the observation angle. This allows the viewing angle θ to be changed, thereby making it possible to change the three-dimensional effect. FIG. 7 is a diagram showing still another embodiment for making the three-dimensional effect variable, in which an erecting optical system 420 that is an optical path deflection means for one optical path includes a roof rectangular prism 421 having a roof surface 421a, This second right-angle prism 422 has a rotation axis 4 within its reflecting surface 422a.
The viewing angle adjustment means is configured to be able to rotate integrally with the eyepiece lens 500 about 22b. This allows the viewing angle θ to be changed and the three-dimensional effect to be changed. Further, the distance D between the second right angle prism 422 and the roof right angle prism 421 is
The optical system is configured so that the observation optical system can be adjusted to the interpupillary distance of the observer. Incidentally, the provision of such an observation angle adjusting means is applicable not only to the example shown in FIG. 3 but also to the Greenough type shown in FIG. 1 and the Galileo type shown in FIG. 2. In this case, in the Greenough type, the objective lens type and the imaging lens system are used in common, and the objective optical system uses the first objective lens system 1a for forming the first intermediate image and the second intermediate image. The first and second objective lens systems 1a and 1b intersect each other's optical axes so as to form a stereo angle ω. As explained above, if a binocular stereomicroscope with the observation angle adjusting means shown in FIGS. 5 to 7 is used,
You can freely select the stereoscopic effect when observing under a microscope, making it extremely convenient for stereoscopic observation. Further, although each of the above embodiments uses a reflective surface to obtain the observation angle θ, the present application is not limited to this, and the refraction effect of a prism may also be used. FIG. 8 shows an example of this, in which a deflection prism 50 is used to form an observation angle θ between the objective lens 101 and the imaging lens 103 in the first optical path 100.
5, similarly, the objective lens 100 of the second optical path 200
The observation angle θ is obtained by disposing deflection prisms 506 for forming the observation angle θ between the image forming lens 203 and the imaging lens 203, respectively. In this embodiment, the deflection prism 505 is further constituted by a rotary prism consisting of small achromatic prisms 501 and 502, and these rotary prisms rotate by the same amount in opposite directions about a shaft 505a. ing. Similarly, the deflection prism 506 is also constituted by a rotary prism consisting of small achromatic prisms 503 and 504. By operating the rotary prism serving as the viewing angle adjustment means, the viewing angle θ can be changed. Note that the left and right eyepiece systems after the imaging lenses 103 and 203 are also configured to change their crossing angles in conjunction with the operation of the rotary prism, so as to follow changes in the observation angle θ so as not to cause axis misalignment. ing. As explained above, the present invention maintains the condition that the light rays traveling along the optical axis of each erecting optical system travel along the optical axis of each eyepiece, and Since the observation angle adjusting means for changing the observation angle θ formed by the observation optical axis of the second eyepiece is provided between the objective lens and the eyepiece, the advantages of both the Greenough type stereo microscope and the Galileo type stereo microscope are achieved. In addition, it is possible to freely select the stereoscopic effect during observation under the microscope without deteriorating the observed image, and it is possible to provide a binocular stereomicroscope that is extremely convenient for stereoscopic observation. . Further, a pair of optical paths defined between each eyepiece lens system and the objective lens along an optical axis parallel to the optical axis of the objective optical system is deflected outward from each other to form an observation angle. By providing a deflecting prism, the examiner's visual axis is aligned with the optical axis passing through the optical center of each eyepiece, so when adjusting interpupillary distance, the eyepiece system can be moved in the direction toward or away from each other. Even if the deflection prism is rotated, the deflection prism will not rotate with the rotation of the eyepiece lens system for adjusting the interpupillary distance. This has the effect that there is no need to rotate it.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the optical arrangement of a conventional Greenough type binocular stereo microscope, Fig. 2 is a diagram showing the optical arrangement of a conventional Galileo type binocular stereo microscope, and Fig. 3 is an optical arrangement showing the first embodiment of the present application. 4 is a perspective view showing the object to be tested used for the stereoscopic effect test, FIG. The figure shows the third embodiment of the present invention with only the erecting optical system part of one optical path, and FIG. 7 shows the fourth embodiment of the present invention with only the erecting optical system part of one optical path. FIG. 8 is an optical layout diagram showing a fifth embodiment of the present invention. 100B, 200B...Observation optical axis, 1a, 1
b, 101... Objective lens system, 102, 202...
...Intermediate image, 103,203...Imaging lens system, 1
04,204,400,410,420...Optical path deflection means, 105,205...Eyepiece system, ω
...stereo angle, θ...observation angle, E...test object.

Claims (1)

[Scope of Claims] 1. An objective optical system for forming first and second intermediate images of a subject, and first and second optical systems for observing the first and second intermediate images, respectively. a binocular stereomicroscope, the binocular stereomicroscope has an eyepiece system, and has first and second erecting optical systems disposed in front of the first and second eyepieces, respectively, so that the intermediate image can be observed as an erect image. The observation angle θ formed by the first and second eyepiece systems is
The first and second erecting optical systems are used as viewing angle adjusting means for changing the three-dimensional effect of the viewing angle by changing the angle of view, and the viewing angle adjusting means is arranged along the optical axis on the optical axis. A binocular stereomicroscope characterized in that the condition is maintained that the traveling light ray travels along the optical axis of each eyepiece. 2. A patent characterized in that the objective optical system has one common objective lens system and an optical axis parallel to the optical axis of the objective lens system, and is composed of a first and a second imaging lens system. A binocular stereomicroscope according to claim 1. 3. The objective optical system consists of a first objective lens system for forming a first intermediate image and a second objective lens system for forming a second intermediate image, and 2. The binocular stereomicroscope according to claim 1, wherein the objective lens systems have their optical axes intersecting each other so as to have a stereo angle ω. 4 has one objective lens and the first and second
an objective optical system for creating an intermediate image, the first and second eyepiece systems, and first and second erecting optical systems provided between each of the eyepiece systems and each of the objective lenses. a pair of optical paths defined between each erecting optical system and the objective lens along an optical axis parallel to an optical axis passing through the optical center of the objective lens; Binoculars characterized in that the binoculars are configured such that the visual axis of the examiner coincides with the optical axis passing through the optical center of each eyepiece by providing deflecting prisms that deflect the lenses outward from each other to form an observation angle. Stereo microscope.