JPS5863906A - Focused position detector for microscope - Google Patents

Abstract

PURPOSE:To ensure the accurate detection for the focused position, by providing an invisible light reflecting film on the lower surface of a cover glass on a sample and detecting the deflection of the reflected light given from the reflecting film. CONSTITUTION:An infrared light reflecting film 9 is provided on the lower surface of a cover glass 6. The light given from an infrared light source 1' is made incident to a photodetecting element 4 via pinhole diaphragm 10, a sample 6 and an infrared light pass filter 11. The sample 6 is irradiated from the lower part by the observing light 12. As a result, the infrared light that is sent from a pinhole P of the diaphragm 10 is formed into an image P' on the film 9 through an image forming lens 2 when an objective lens 5 is at the focused position. The infrared light sent from the image P', i.e. the infrared light reflected from the film 9 is formed into an image P'' on the element 4 through an image forming lens 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inexpensive focusing position detection device for a microscope.

Conventionally, there are focus position detection devices for microscopes that capture an image of a specimen with a light-receiving element or the like and utilize its contrast or frequency, but these devices have complicated configurations and are expensive. In addition, as an inexpensive method, as shown in FIG. 1, for example, a light source 1, an imaging lens 2 that makes the light emitted from the light source 1 obliquely incident on the specimen surface A and forms a light source image, It consists of an imaging lens 3 that re-images the light reflected by the specimen surface A as a light source image, and a light receiving element 4 arranged so that its light receiving surface coincides with the imaging surface of the imaging lens 3. can be moved together with the objective lens 5 of the microscope optical system.

If the specimen surface A is in the in-focus position, the reflected light will enter the light receiving element 4 as shown by the solid line; on the other hand, if the specimen surface A moves to the out-of-focus position, the reflected light will be received as shown by the broken line. There is a well-known device in which the in-focus position can be detected by detecting changes in the output of the light-receiving element because the light falls off from the element 4, and furthermore, it is possible to detect the direction out of focus by using an array of light-receiving elements. There is. However, when this device is applied to a specimen with a canopy glass, as shown in FIG. A plurality of reflected lights Bl'rB'2 are reflected from the upper surface E of the slide P glass 8.
'+B'3/, it becomes impossible to distinguish the light reflected by the lower surface D of the canopy glass 6, and as a result, there is a problem in that the in-focus position cannot be detected.

Incidentally, since the thickness of the cuckoo glass 6 varies more than the depth of focus of the objective lens, it is impossible to detect the correct in-focus position using the method using reflected light from the upper surface of the cuckoo glass 6.

In view of the above problems, the present invention provides an invisible light reflecting film on the lower surface of the cuckoo glass on the specimen, allows invisible light to be incident obliquely from above the cuckoo glass, and reduces the deviation of the reflected light on the invisible light reflecting film. The purpose is to provide a focus position detection device for a microscope that detects the focus position by detecting the focus position.Hereinafter, based on an embodiment shown in FIG. 9 is an infrared light reflecting film provided on the lower surface of the cuckoo glass 6, 11 is an infrared light source, and 10 is placed immediately after the infrared light source ll for focusing. At times, a pinhole aperture, l, is configured such that an image P' of the pinhole P is formed on an infrared light reflecting film 9 by an imaging lens 2.
1 is an infrared light transmitting filter disposed in front of the light receiving element 4, and 12 is visible light observation light that is irradiated onto the specimen 6 from below.

Since the focus position detection device according to the present invention is constructed as described above, the objective lens/I? 5 is in the focused position, the infrared light emitted from the pinhole P of the pinhole diaphragm 10 is focused by the imaging lens 2 on the infrared light reflecting film α' as an image P'. The emitted infrared light, that is, the infrared light reflected by the infrared light reflecting film 9, is focused by the imaging lens 3 on the light receiving element 4 as an image P. Furthermore, when the objective lens 5 moves to the out-of-focus position, that is, when the specimen 7 moves upward or downward, 1, the infrared light reflecting film 9 also moves upward or downward. The image P〃 moves on the light receiving element 4. Therefore, by detecting this and noting the vertical movement of the microscope optical system including the objective lens 5, automatic alignment becomes possible. In this case, although there is some reflection of the infrared light on surfaces other than the infrared light reflective film 9, the light reflected by the infrared light reflective film 9 is much stronger than the light reflected by other surfaces. If a certain level is set for detection of the reflected light intensity, it becomes possible to discriminate the reflected light by the infrared light opposing film 9. Therefore, the in-focus position on the lower surface of the cuckoo glass 6, that is, the upper surface of the specimen 7 can be detected. Furthermore, since the infrared light transmitting filter 11 is placed in front of the light receiving element 4, the influence of external light is removed and detection sensitivity is improved.

Also, the reason why infrared light is used as detection light is observation light 1? Since this is visible light, if the reflective film 9 is designed to transmit visible light and reflect infrared light, the observation light 12
This is because the impact on - can be prevented. Further, even if the detection light is reflected and scattered by the upper and lower surfaces of the cuckoo glass 6 and the specimen 7, the contrast of the observed image will not be reduced. Incidentally, instead of the infrared light and infrared light reflecting film, an ultraviolet light and ultraviolet light reflecting film can also be used.

It is also possible to provide a reflective film on the lower surface of the specimen 7, that is, on the upper surface of the slide glass 8, but this is not preferred since scattering occurs when the detection light passes through the specimen 7, making it unusable.
It's not right.

FIG. 4 shows another embodiment, and 13 is a pinhole P.
j4 is a mirror for reflecting the infrared light that has emitted and passed through the imaging lens 2 and passing it into the outer edge of the objective lens 5; A mirror for reflecting infrared light that has passed through the outer edge portion of the objective lens 5, emitted from the image P' formed at the axial focal position) and making it enter the imaging lens 3, The light emitted from the pinhole P is focused on the axis of the objective lens 5!
The focal length of the imaging lens 2 and the objective lens 5 formed by the mirror 14 are set so that the light emitted from the image P' at the time of focusing is formed on the light receiving element 4 as an image PI. The angle of incidence of the light beam, that is, the inclination of the mirror 13, the inclination of the mirror 14, and the focal length of the imaging lens 3 are selected. Therefore, in the case of this embodiment, since the incident light for detection and the reflected light are made to pass through the objective lens 5, the focal length of the objective lens 5 may vary when the objective lens 5 is replaced. Even if it were, there is no need to adjust the positional relationship with the objective lens 5.

As mentioned above, the focusing position detection device for a microscope according to the present invention can accurately detect the focusing position for a specimen with a Camo glass, and has an excellent advantage in that it is simple in structure and inexpensive. have.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the optical system of a conventional focusing position detection device for a microscope, Fig. 2 is a diagram showing a state in which the above conventional example is applied to a specimen with a cut glass, and Fig. 3 is a diagram showing a microscope according to the present invention. FIG. 4 is a diagram showing an optical system of one embodiment of the focusing position detection device for use in a vehicle, and FIG. 4 is a diagram showing an optical system of another embodiment. 1'... Infrared light source, 2, 3... Imaging lens, 4...
- Light receiving element, 5... Objective lens, 6... Cummer glass, 7... Specimen, 8... Sly P glass, 9...
・Infrared light reflective film, 10... Pinhole aperture, 11...
・Infrared light transmission filter, 12...Light for observation, 13
．． 14...Mirror. 11 Figures 1-2 Procedural Amendment (Voluntary) February 5, 1980 Director General of the Japan Patent Office 1. Indication of the case Japanese Patent Application No. 163725/1982 Publication No. 2 Title of Invention Correction of focus position detection device for microscope Patent applicant 2-43-2 Hatagaya, Shibuya-ku, Tokyo (037) Shigeru Kitamura, Representative Director Olin Shuko Kogyo Co., Ltd. 4, Agent Address: tOS 5-19 Shinbashi, Minato-ku, Tokyo Telephone Tokyo (432) ) 4 576 jin; ↑t(65
82) Yasushi Shinohara, patent attorney Correct it to ``location''.

Claims (1)

[Claims] An invisible light reflecting film is provided on the lower surface of the cummer glass on the specimen, and invisible light is made obliquely incident from above the cummer glass, and the focal position is detected by detecting the deviation of the reflected light on the invisible light reflecting film. A focusing position detection device for a microscope is constructed as follows.