JP2576021B2 - Transmission confocal laser microscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission type confocal laser microscope for capturing a transmitted light image from a document.

[0002]

2. Description of the Related Art In general, a confocal laser microscope scans a document surface with a laser light spot focused to about 1 micron, receives light / dark information of each position (point) by a photoelectric conversion sensor, and electrically converts the information. The obtained brightness information is accumulated and observed on an enlarged screen of a monitor television. This is because only individual positions are always illuminated, unnecessary and harmful light is not mixed, and at the conjugate position with the data surface, it is received through a pinhole of a size similar to the data surface scanning spot light,
There is a feature that defocused light and harmful light can be excluded.
Therefore, as compared with the conventional optical microscope, high resolution and high contrast can be obtained even when the same objective lens is used.

[0003] Confocal laser microscopes are classified into a reflection type that captures a reflected light image from a material and a transmission type that captures a transmitted light image. A typical configuration of a conventional transmission type confocal laser microscope is shown in FIG. The general configuration shown in FIG. In this laser microscope, a polarized laser beam is emitted from a light source 1, its beam is thickened by an expander 2, transmitted through a polarizing beam splitter 3, and passed through a galvanometer mirror 4, 5 which is a galvanometer with a mirror. Scanning is performed in the direction (Y). Next, the relay lens 6 converges once to the position corresponding to each scanning direction at the position of the field stop 7 (corresponding to the imaging position of the objective lens),
The document 9 is scanned by the spot light through the irradiation-side objective lens 8.

Then, the laser beam transmitted through the sample 9 passes through a transmission-side objective lens 10 equivalent to the irradiation-side objective lens 8 and forms an image on the surface of the concave mirror 11. The concave mirror 11 has a reflecting surface with a spherical surface centered on the pupil position of the transmission-side objective lens 10, and a light beam irradiated to the concave mirror 11 is returned through exactly the same optical path. By providing the λλ wave plate 12 for changing the direction of polarization by 45 ° between the concave mirror 11 and the transmission side objective lens 10, the reflected laser light returned to the polarization beam splitter 3 described above is used here. Only the reflected light that has passed back and forth through the quarter-wavelength plate 12 is reflected and bent in a right angle direction, passes through the condenser lens 13 and passes through the pinhole 1.
Material information detection sensor 15 consisting of light receiving element through 4
And an electric signal is sent to the memory by photoelectric conversion.

In FIG. 1, reference numeral 16 denotes a binocular tube, 17 denotes an optical path switch for using the binocular tube, 18 denotes a light source for vertical epi-illumination, and 19 denotes a relay lens for the light source.

[0006]

In using this conventional transmission type confocal laser microscope, a preparation 21 is placed on a reference table 20 as shown in FIG. I will be scorched. At that time, in order to focus the transmission-side objective lens 10 on the focal point, a preparation 2
Since the position of the data surface is different depending on the thickness of 1, the transmission side objective lens 10 needs to be slightly shifted (ΔL) each time. Normally, when the preparation is changed,
The thickness of the glass portion has a variation of about ± 0.3 m / m.

For this reason, conventionally, as shown in FIG. 2, the optical path switch 17 is switched to the optical microscope portion on the side of the binocular tube 16 and illuminated by the light source 18 for vertical epi-illumination to focus the irradiation-side objective lens 8. At the same time, a method is adopted in which the transmission side objective lens 10 is focused by duplicating with the image formed by the reflected light from the concave mirror 11, and then the optical path switch 17 is switched to the laser beam side.

In addition to this, the transmission side objective lens 10 is
It is adjusted in advance to the position where the standard thickness slide was used, focused on the optical microscope part using the irradiation side objective lens 8, then switched to laser light, and the best resolution is obtained while observing the image on the synthetic monitor. A method of finely adjusting the transmission-side objective lens 10 so as to be adopted is adopted.

In such a conventional apparatus, there is a problem that the focusing of the transmission side objective lens is particularly troublesome, the focusing accuracy is low, and it is difficult to obtain a high resolution.

In view of such a conventional problem, the present invention makes it easy and accurate to focus the transmission-side objective lens.
The purpose of the present invention is to provide a transmission type confocal laser microscope that can be performed in a stable state.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems and achieve the intended object, the gist of the present invention is to firstly provide a laser spot light focused through an objective lens. Is irradiated from the surface side of the material and scanned, and the transmitted light of the laser spot light to the back side of the material is passed through a transmission side objective lens equivalent to the irradiation side objective lens and provided at a position where an image is formed by the lens. In a transmission type confocal laser microscope of a type in which the light is reflected by the concave mirror and travels backward, and the backward light is received by the light receiving element, the optical path is switched to a direction different from the optical path to the concave mirror behind the transmission side objective lens. An optical path switch, and a target illuminated by a light source for focusing on the transmission side objective lens at a position equivalent to the concave mirror on another optical path switched by the optical path switch. Secondly, the transmission type confocal lens microscope comprises: an objective lens section capable of moving the transmission-side objective lens in the optical axis direction; and a fixedly arranged relay lens section. The object of the present invention is to prevent the movement of the objective lens unit for focusing from causing a change in the optical path after the relay lens unit.

[0012]

In the transmission type confocal laser microscope of the present invention, the focusing of the irradiation side objective lens is performed by moving the data base (stage) while illuminating by the same optical microscope part as the conventional one. Also, for focusing of the transmission side objective lens, the optical path from the objective lens to the concave mirror is switched to the target side, illuminated by a focusing light source, and the transmission side objective lens is adjusted while looking at the optical microscope portion, and the target is adjusted. By focusing, both objective lenses can be completely confocal (claim 1).

According to the second aspect of the present invention, since the transmission side objective lens is constituted by the moving objective lens unit and the fixedly arranged relay lens unit, the focusing operation can be performed by moving only the objective lens unit. Therefore, the concave mirror, the optical path switching device, and the target after the relay lens can be built in the stable fixed block.

[0014]

FIG. 1 shows an embodiment of the present invention. The same parts as those in the above-described conventional example are denoted by the same names and the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, the optical system from the light source 1 that emits polarized laser light to the sample 9 and the optical microscope from the light source 18 for vertical epi-illumination and the binocular tube 17 to the sample 9 are composed of: This is the same as the conventional example of FIG.

In this embodiment, the transmission-side objective lens 10 provided under the data base 20 is incorporated so as to be movable in the optical axis direction with respect to the relay lens unit 10b whose position is fixed. Objective lens section 10
a. The objective lens section 10a is equivalent to the infinity barrel-length objective lens.
Reference numeral 0b denotes a lens having the same characteristics as an imaging lens similar to a telescope objective lens.
Even if the distance between Oa and the relay lens unit 10b is changed, the optical performance after the relay lens unit 10b does not change.

An optical path switch 24 is provided behind the λλ wave plate 12 in the optical path after the transmission side objective lens 10. The optical path switch 24 is composed of total reflection prisms 24a and 24b that switch the optical path in two perpendicular directions. One total reflection prism 24a bends the light path at right angles toward the concave mirror 11, and the other total reflection prism 24b bends the light path at right angles to the focusing target 25 side.

The concave mirror 11 has a concave surface at a position where the laser beam reflected by the prism 24a is imaged by the transmission-side objective lens 10, and the center of the concave surface is the pupil position of the objective lens 10.

The target 25 is provided at an image forming position by the transmission side objective lens similarly to the reflection surface of the concave mirror 11, and is constituted by, for example, a circular ring. The light is radiated from a light source 27 through a relay lens 26. The portion below the relay lens 26 is fixed in the fixed block 30. Prism 2
4a and 24b may be shared by rotating one prism.

The laser microscope configured as above is
As shown in FIG. 1, as in the conventional case, a polarized laser beam is emitted from a light source 1 and connected to a document 9 through an expander 2, a polarizing beam splitter 3, galobano mirrors 4, 5, a relay lens 6, a field of view and an irradiation side objective lens 8. The surface of the material 9 is scanned with the spot light that has been imaged. The transmitted light passes through the transmission-side objective lens 10, and its optical path is bent by the reflection prism 24 a and reflected by the concave mirror 11. When the reflected light passes through the same optical path in reverse and reaches the polarization beam splitter 3, only the reflected light is reflected, the optical path is bent at a right angle, and passes through the condenser lens 13 to the material information detecting sensor 15 composed of a light receiving element. To detect.

As shown in FIG. 1, the focusing of the irradiation-side objective lens 8 is performed by moving the data base 20 up and down while viewing the data 9 using a binocular tube 17 and a light source 18 for vertical epi-illumination. To focus.

When the transmission side objective lens 10 is focused, the optical path switch 24 is switched to the optical path on the target 25 side, the light source 27 is turned on, and the binocular tube 17 is used without using the light source 18.
Is focused on the target 25 by moving only the objective lens unit 10a.

After focusing the two objective lenses 8 and 10 in this manner, the upper optical path switch 17 is switched from the optical microscope to the laser light emitting side optical path, and the lower switch 24 is connected to the concave mirror 11 side. , And the above-described fluoroscopy with the laser light is performed.

The focusing of the data on the irradiation side objective lens 8 is performed by using the light source 27 without using the light source 18 for vertical epi-illumination.
May be performed while lighting.

[0025]

As described above, in the present invention, a focusing target is placed at the same position as the concave mirror in the optical path behind the transmission-side objective lens, and the focusing is performed while looking at the optical microscope. With this configuration, focusing of the transmission-side objective lens is performed easily, quickly, and with high accuracy.

Also, the transmission-side objective lens includes an objective lens portion and a relay lens portion, and movement of only the objective lens portion does not cause a change in an optical path after the relay lens portion. In addition, the concave mirror and the optical member to reach the target can be incorporated in a common immovable fixed block. Therefore, a high-precision transmission confocal system in which the optical axes of the upper and lower sides of the data base are completely aligned. A laser microscope has been easily obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a conventional example.

FIGS. 3A and 3B are diagrams comparing the movement of an objective lens unit of a conventional transmission type confocal laser microscope. FIGS.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser light 3 polarizing beam splitter 4, 5 galvano mirror 6 relay lens 8 irradiation-side objective lens 9 document 10 transmission-side objective lens 10 a objective lens unit 10 b relay lens unit 11 concave mirror 12 wavelength plate 13 condensing lens 14 pinhole 15 document information detection Sensor 17 Binocular tube 18, 27 Light source 19 Relay lens 20 Reference table 21 Preparation 24 Optical path switch 24b, 24b Reflective prism 25 Focusing target 26 Relay lens 30 Fixed block

Claims (2)

(57) [Claims] 1. A laser spot light condensed through an objective lens is irradiated from the surface side of a material to scan, and the transmitted light of the laser spot light to the back side of the material is transmitted on the same transmission side as the irradiation side objective lens. In a transmission type confocal laser microscope of a type in which the light passes through an objective lens, is reflected by a concave mirror provided at a position where an image is formed by the lens, and travels backward, and the backward light is received by a light receiving element. An optical path switcher for switching the optical path to a direction different from the optical path to the concave mirror is provided behind the lens, and a light source for focusing the transmission-side objective lens irradiates another optical path switched by the optical path switch to the same position as the concave mirror. Transmission confocal lens microscope characterized by having a target to be mounted. 2. A transmission-side objective lens comprising an objective lens portion movable in an optical axis direction and a fixedly arranged relay lens portion, wherein the movement of the objective lens portion for focusing changes to an optical path after the relay lens portion. 2. The transmission type confocal laser microscope according to claim 1, wherein the transmission type confocal laser microscope is configured not to generate the laser beam.