JPH02230210A - Single objective stereoscopic microscope - Google Patents

Abstract

PURPOSE:To obtain a bright image where stereoscopic effect is properly obtained even in the cases of high and low magnifications by arranging a 1st and a 2nd polarizing plates which have mutually orthogonal vibrating directions at the pupil of an objective or in the vicinity of its conjugate position so that they move forth/back in mutually opposite directions at perpendicular to the optical axis. CONSTITUTION:Light passes through a contact lens 2 and the 1st and 2nd polarizing plates 9 and 10 in the entrance pupil 11 and is converged on a sample surface 4 by a condenser lens 3. The transmitted light is split by a beam splitter 6 into a right and a left beam. Their images are observed with the right and left eyes through 3rd and 4th polarizing plates 12 and 13, a right-angled prism 7, and an ocular 8. When the magnification is low, the polarizing plates 9 and 11 are advanced into the optical path from left and right to put the centers of gravity of visual fields viewed with the left and right eyes away from each other and emphasize the stereoscopic effect, and the presence ratio of the polarizing plates 9 and 10 is increased to make the quantity of dimming large. When the magnification is high, the polarizing plates 9 and 10 are moved away from the optical path to the left and right to suppress the stereoscopic effect and the presence ratio of the polarizing plates 9 and 10 is decreased to make the quantity of dimming small. Consequently, the bright image where stereoscopic effect is properly obtained even in the cases of the high and low magnifications is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a single-objective stereoscopic microscope for observing stereoscopic images using polarized light.

[Conventional technology]

As described in Japanese Utility Model Publication No. 47-18686, this type of conventional single-objective stereoscopic microscope has a configuration in which the left and right polarization directions are at right angles to each other at the position of the aperture stop of the condenser lens or the position of the exit pupil of the objective lens. A divided polarizing plate consisting of a segment is arranged, and a polarizing plate whose polarization direction coincides with or perpendicular to the polarization direction of the left and right parts of the split polarizing plate is arranged in each optical path of the eyepiece of the binoculars. There is a system in which a three-dimensional effect is obtained by introducing polarized light having vibration directions perpendicular to each other into the left and right optical paths to obtain independent left and right information.

However, in such a single-objective stereoscopic microscope, the amount of light is halved because polarization in one vibration direction cannot be used.
In addition, since the transmittance of the polarizing plate itself is not good, there is a problem that the image becomes dark due to insufficient amount of light.

Furthermore, since the vertical magnification is generally effective as the square of the horizontal magnification, there is a problem in that the higher the magnification, the more the three-dimensional effect is emphasized, resulting in an unrealistic image.

Therefore, to solve this problem, a single-objective stereoscopic microscope was developed, for example, as described in Japanese Patent Application Laid-Open No. 62-208019. a second linearly polarized light component whose polarization direction is orthogonal to the first linearly polarized light component, one side of which is separated by a plane containing the axis, consisting of a region that passes only the first linearly polarized light component and a region that also passes other polarized light components; A split polarizing plate consisting of a region where only the polarized light passes through and a region where the other polarized light components also pass is arranged, and a polarizing plate that passes only the first linearly polarized light component is placed in one optical system of the binocular eyepiece, and a second polarizing plate is placed in the other optical system. By arranging polarizing plates that pass only the linearly polarized light component, a portion of the split polarizing plate allows light other than the predetermined linearly polarized light component to pass through, increasing the amount of transmitted light and moderately reducing the three-dimensional effect. In some cases, as described in Japanese Patent Application Laid-open No. 63-113414, one side separated by a plane containing the optical axis is located at the pupil of the objective lens or at a position conjugate to the pupil. A split polarizing plate is arranged, which consists of a region that passes only a linearly polarized light component, and a region on the other side that passes only a second linearly polarized light component whose polarization direction is perpendicular to the first linearly polarized light component, The system includes a section wave plate that can be rotated around the optical axis and a first wave plate.
By placing a polarizing plate that passes only the linearly polarized light component in the other optical system, and an X wavelength plate that can freely rotate around the optical axis and a polarizing plate that passes only the second linearly polarized light component, it is possible to A device has been proposed in which the direction of vibration is changed by rotating the angle to change the linearly polarized light to circularly polarized light, thereby slightly losing the independence of the left and right optical paths, thereby reducing the three-dimensional effect.

[Problem to be solved by the invention]

However, such a single-objective stereoscopic microscope solves the problem of over-emphasizing the stereoscopic effect at high magnifications, but has the problem of insufficient stereoscopic effect at low magnifications. Furthermore, since the state of the polarizing plate that is always in the optical path basically does not change, there is a problem that the image becomes dark at high magnification.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a single-objective stereoscopic microscope capable of obtaining bright images with appropriate stereoscopic effect at both low and high magnifications.

[Means and effects for solving the problems] One of the single-objective stereoscopic microscopes according to the present invention has vibration directions perpendicular to each other at the pupil of the objective lens, at a position conjugate to the pupil, or in the vicinity thereof. First and second polarizing plates are arranged perpendicular to the optical axis and movable in opposite directions, and the optical path is divided into two behind the first and second polarizing plates to easily guide the left and right eyepieces. a third polarizing plate that is orthogonal to the first polarizing plate in the optical path of one of the left and right eyepieces, and a third polarizing plate that is orthogonal to the second polarizing plate in the other optical path; By arranging the fourth polarizing plate, the polarizing plates enter the optical path from the left and right when the magnification is low, moving the center of gravity of the visual field that enters the left and right eyes away, emphasizing the three-dimensional effect, and increasing the proportion of the polarizing plate. At high magnification, the polarizing plate is moved back from the optical path to the left and right to bring the center of gravity of the field of view that enters the left and right eyes closer to suppress the stereoscopic effect, and the proportion of the polarizing plate is reduced to reduce the amount of light attenuation. It is designed to make it smaller.

Another single objective stereoscopic microscope according to the present invention has the same effect as the above microscope by using a polarizing beam splitter whose vibration direction coincides with the first and second polarizing plates as the optical path splitting member in the above microscope. 3rd and 4th
This allows a brighter image to be obtained without the need for a polarizing plate.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the illustrated embodiments.

FIG. 1 shows the optical system of a transmission microscope as a first embodiment, in which 1 is a light source lamp, 2 is a collector lens, 3 is a condenser lens, 4 is a specimen surface, 5 is an objective lens, and 6 is an optical path. The beam splitter 7, 7 is a left and right right angle prism, and 8, 8 is a left and right eyepiece. 9, lO
are first and second polarizing plates arranged in the entrance pupil (aperture stop) 11 of the condenser lens 3, which is a position conjugate with the pupil of the objective lens 5, perpendicular to the optical axis O and movable in opposite directions. As shown in FIG. 2, these are polarizing parts 9a and 10a having vibration directions A and B perpendicular to each other, respectively.
and transparent parts 9b and 10b having the same optical path length as the polarizing parts 9a and 10a. 12 and 13 are third and fourth polarizing plates arranged in the optical path of the left and right eyepiece tubes, for example, between the beam splitter 6 and the left and right right angle prisms 7, 7, and one of them is used for polarizing the first polarized light. Polarizing section 9a of plate 9
and the other are perpendicular Nicols to the polarizing portion 10a of the second polarizing plate 10, respectively. Note that it is desirable that the first and second polarizing plates 9 and 10 move in conjunction with each other.

Since this embodiment is configured as described above, the light emitted from the light source lamp 1 is transmitted to the collector lens 2 and the first lens in the entrance pupil 11.
and the condenser lens 3 through the second polarizing plates 9 and 10.
The light is focused on the specimen surface 4 and illuminates the specimen, and the transmitted light passes through the objective lens 5 and is sent to the beam splitter 6.
The image is divided into left and right parts, and is observed with the left eye through the third polarizing plate 12, right-angle prism 7, and eyepiece 8, and with the right eye through the fourth polarizing plate 13, right-angle prism 7, and eyepiece 8. .

As shown in FIG. 3(a), when the polarizing parts 9a and 10a of the first and second polarizing plates 9 and IO do not exist in the entrance pupil ll and only the transparent parts 9b and 1Ob exist, the left and right Both eyes observe the entire image of the entrance pupil l1, that is, the centers of gravity of the fields of view entering the left and right eyes coincide, so no stereoscopic effect occurs. Also, the image observed at this time is the brightest.

Next, as shown in FIG. 3(b), the polarizing parts 9a and 10
When a enters the entrance pupil ti with a transparent part l4 left in the center, the polarizing part 9a of the entrance pupil 11 or the polarizing part 1
The part that does not overlap with 0a, that is, the part that is not blocked by the third polarizing plate l2 or the fourth polarizing plate l3, becomes a D-shaped part on the right and an inverted D-shaped part on the left, and the centers of gravity of the visual fields entering the left and right eyes are slightly separated, so The left and right eyes observe the image with parallax, resulting in a slightly three-dimensional appearance. Also, at this time, the part where the polarizing part 98 or the polarizing part 10a exists in the entrance pupil 11, that is, the part blocked by the third polarizing plate 12 or the fourth polarizing plate l3, is formed as a crescent-shaped part, so that the observed image It gets a little dark.

Next, as shown in FIG. 3(C), the polarizing parts 9a and 10
When a is made to occupy half of the entrance pupil 11,
The portions that are not blocked by the third polarizing plate 12 or the fourth polarizing plate l3 become semicircular portions on the left and right, respectively, and the center of gravity of the field of view entering the left and right eyes becomes further apart, resulting in a three-dimensional effect compared to the state shown in FIG. 3(b). emphasized.

Furthermore, at this time, the portion blocked by the third polarizing plate 12 or the fourth polarizing plate 13 also becomes a semicircular portion, so the observed image becomes darker than the state shown in FIG. 3 (bl).

Furthermore, as shown in FIG. 3(d), the polarizing section 9a and tO
When a is made to occupy more than half of the entrance pupil 11, the portions that are not blocked by the third polarizing plate 12 or the fourth polarizing plate l3 become left and right crescent-shaped parts, respectively, and the field of view entering the left and right eyes is Since the center of gravity is further apart, the three-dimensional effect is emphasized compared to the state of Figure 3 (Cl).In addition, at this time, the part that is blocked by the third polarizing plate l2 or the fourth polarizing plate l3 is a D-shaped part or an inverted D-shaped part. 3(e), the observed image becomes darker than the state shown in FIG. 3(e).

Therefore, by changing the state shown in Figure 3 (a) to the states shown in (b) and (Cl, (d)) from high magnification to low magnification, a bright image with suppressed stereoscopic effect can be obtained at high magnification. At low magnifications, images with an enhanced three-dimensional effect that are not too bright can be obtained.

Note that since the first and second polarizing plates 9 and 10 have transparent portions 9b and 10, respectively, there is no difference in optical path length due to the difference in the amount of overlap between both polarizing plates 9 and 10, and problems caused by the difference in optical path length do not occur. does not occur.

FIG. 4 shows an optical system of a zoom-type reflection microscope as a second embodiment, which uses an objective zoom lens 5' as an objective optical system, and has a first polarizing plate 9' and a second polarizing plate in its pupil l5.
A polarizing plate 10' is arranged perpendicular to the optical axis O and movable in opposite directions. As shown in FIG. 5, the first polarizing plate 9' and the second polarizing plate 10' have polarizing parts 9'a and 10'a in the vibration directions A and B perpendicular to each other in the center, respectively. Transparent parts 9'b and 10'b having the same optical path length as the polarizing parts 9'a and 10'a are provided on both sides, respectively. Further, a roof prism 16 is arranged after the first and second polarizing plates 9' and 10' to make the image formed by the objective zoom lens 5' an erect image, and further after that, a polarizing beam splitter 6' is arranged as an optical path splitting member. are arranged, and the vibration direction of the polarizing beam splitter 6' coincides with that of the first and second polarizing plates.

Note that it is desirable that the first and second polarizing plates 9' and 10' move in conjunction with each other.

Since this embodiment is configured as described above, the light from the specimen surface 4 illuminated by the illumination system (not shown) is transmitted through the objective zoom lens 5', the first and second polarizing plates 9' in the pupil 15, and the
0', the beam is converted into an erect image by the roof prism 16, split into left and right by the polarizing beam splitter 6', and observed by the left and right eyes through the right-angle prisms 7 and eyepieces 8, respectively. Basically, based on the same principle as the first embodiment,
In the case of Fig. 6(a), there is no stereoscopic effect and the image is the brightest, and in the order of Fig. 6(bl, (CL) (d), the stereoscopic effect becomes stronger and the image becomes darker, and Fig. 6(e) ),Ge),(
In the order of the height, the high part of the specimen appears to be depressed, the three-dimensional effect decreases and the image becomes brighter, and in Figure 6 (h), the three-dimensional effect becomes absent again and the image becomes the brightest. Observation of fake bodies is
This is very convenient because it looks normal when viewing a copy.

In addition, in this embodiment, since the polarized light can be separated by the polarizing beam splitter 6', the third and fourth polarizing plates l
2 and l3 can be omitted. Furthermore, since the polarizing beam splitter 6' can separate polarized light with almost no loss of light quantity, it has the advantage that a brighter image can be observed than when using a normal polarizing plate with low transmittance.

〔Effect of the invention〕

As described above, the single-objective stereoscopic microscope according to the present invention has the practically important advantage of being able to obtain bright images with appropriate stereoscopic effect at both low and high magnifications.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the optical system of the first embodiment, Figures 2 and 3 are diagrams showing the optical system of the first embodiment.
The figures show the first and second polarizing plates and their operating states in the first embodiment, Figure 4 shows the optical system in the second embodiment, and Figure 5 shows the optical system in the second embodiment.
FIG. 6 is a diagram showing the first and second polarizing plates of the second embodiment and their operating states. 1... Light source lamp, 2... Collector lens, 3
...Condenser lens, 4...Specimen surface, 5.
...Objective lens, 5'...Objective zoom lens, 6
... Beam splitter, 6'... Polarizing beam splitter, 7... Right angle prism, 8... Eyepiece, 9, 9'... First polarizing plate, 10.10'・・・
...Second polarizing plate, 11...Entrance pupil, l2...Third polarizing plate, 13...Fourth polarizing plate, 14...Transparent part, 15...Pupil, l6...Dach prism. =0 17( spear 4 figure yuj4

Claims (2)

[Claims] (1) first and second polarizing plates having vibration directions perpendicular to each other are disposed in the pupil of the objective lens or at a position conjugate with the pupil or in the vicinity thereof so as to be movable in directions perpendicular to the optical axis and opposite to each other; An optical path dividing member is disposed behind the first and second polarizing plates to divide the optical path into two and guide the optical path to the left and right eyepiece tubes, and the optical path of one of the left and right eyepiece tubes is perpendicular to the first polarizing plate. A single-objective stereoscopic microscope comprising a third polarizing plate having a Nicol polarization and a fourth polarizing plate having a Nicol orthogonal to the second polarizing plate disposed in the other optical path. (2) first and second polarizing plates having vibration directions perpendicular to each other are disposed in the pupil of the objective lens or in a position conjugate with the pupil or in the vicinity thereof so as to be movable in directions perpendicular to the optical axis and opposite to each other; A single-objective stereoscopic microscope comprising a polarizing beam splitter arranged behind the first and second polarizing plates, whose vibration direction matches the polarizing plates, and which splits the optical path into two and guides the optical path to the left and right eyepiece tubes.