JPS58105211A - Optical instrument whose depth of field is deep - Google Patents

Abstract

PURPOSE:To obtain an optical instrument whose depth of field is deep, by illuminating an object to be observed, by plural illuminating lights whose wavelength bands are different from each other, in accordance with depth of field, and making its reflected rays form an image at the same point. CONSTITUTION:A microscope optical system 1 consists of an objective lens 2, an optical split prism 3 for transmitting a light (a) of one wavelength and reflecting only a light (b) of other wavelength, an image-forming lens 4, an optical composite prism 6 and reflecting only for transmitting only the light (a) the light (b), an image-forming lens 7 and an eyepiece 8. As for the light (a), a microscope optical system consisting of the objective lens 2, the optical split prism 3, the image-forming lens 4, the optical composite prism 5 and the eyepiece 8 is constituted, and as for the light (b), a microscope optical system consisting of the objective lens 2, the optical split prism 6, the image-forming lens 7, the optical composite prism 5 and the eyepiece 8 is constituted, and against the lights (a), (b), an object to be observed, whose depth of field is in areas A, B, respectively is made to form an image by the same magnification at an image- forming point P. Accordingly, an optical instrument whose depth of field is deep can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to optical instruments such as microscopes, cameras, and endoscopes that have a deep depth of field.

For example, when observing a minute object using a microscope, the object becomes larger as the magnification increases, but at the same time the depth of field becomes shallower. For this reason, it is very inconvenient to observe a deep object or an object with many irregularities at high magnification because only a portion of the object is in focus.

In view of the above points, the present invention aims to provide optical instruments such as microscopes, cameras, and endoscopes with a deep depth of field. To explain this, 1 is the microscope optical system, 2 is the objective lens, and 3 is the property of transmitting only the first color of light a but reflecting only the second color of light different from the first color. 4 is an imaging lens; 5 is a light-synthesizing prism having the property of transmitting only light a but reflecting only light; 7 is an imaging lens; 8 is an eyepiece lens. Here, for light a, objective lens 2. Light splitting prism 3.
Imaging lens 4. A microscope optical system consisting of a photosynthesizing prism 5 and an eyepiece 8 has an objective lens 2. Light splitting prism 3. A microscope optical system is composed of a prism 6, an imaging lens 7, a photosynthesis prism 5, and an eyepiece 8, and the focal length and position of each lens are such that the depth of field is region A for light a, and the light For example, the depth of field is region B, and the microscope optical system for lights a and b focuses images of objects to be observed in regions A and BK at the imaging point P at the same magnification. Selected. Furthermore, area A is illuminated by light aK, and area B is illuminated by light.

Since this embodiment is configured as described above, even if the object to be observed spans both areas A and B,
The images of the observed object illuminated by the lights a and b, respectively, are
It can be observed that the entire image is in focus. Note that at this time, the light a does not pass through the prism 6 and the imaging lens 7, and the light does not pass through the imaging lens 4, so that no light from outside the depth of field can be observed.

FIG. 2 shows a second embodiment according to the present invention, and 9.
10 is a prism, and 11 is a light-synthesizing prism having a characteristic of reflecting only light a but transmitting only light; the other configurations and functions are the same as those of the embodiment shown in FIG.

FIG. 3 shows a third embodiment according to the present invention, with 12
13 is a filter that transmits only light a, 14 is a filter that transmits only light, and the other configurations are as follows: This is the same as the □ embodiment in FIG. In this embodiment, light a from the object to be observed in area A is transmitted through the objective lens 2. Half prism 12. Filter 13.
Prism 9. The light a that passes through the spinning lens 4 and the light combining prism 11 and reaches the imaging point P, but is reflected by the half prism 12, is blocked by the filter 14, and also passes through the area B.
The light beam from the object to be observed at is the objective lens.2. No Fuji Rhythm 12. Filter 14. The light passes through the prism 10° imaging lens 7 and the light combining prism 11 and reaches the imaging point P, but the light transmitted through the -7 prism 12 is blocked by the filter 13.

Therefore, even in the case of an object to be observed that spans both areas A and B, the images of the object illuminated by the lights a and b in areas A and B, respectively, can be observed in a state where the entire image is in focus. In addition, without using filters 13 and 14, prism 9
, 10 may be provided with color-specific reflection characteristics similar to those of the filters 13, 14.

FIG. 4 shows a fourth embodiment according to the present invention, in which four different areas A, B% O, and D are illuminated by four different colored lights a%b%'%d. The image is focused on a single point. 20 is an objective lens, 21 is a light splitting prism that transmits only light a and b, but reflects only light C and the gate, and 22 is a light beam that transmits only light a, but reflects only light beam. Splitting prism 23 is a light splitting prism having the characteristic of reflecting only element C but transmitting only light d, 24, 25, 2
6.27 is an imaging lens, 28.29 is a prism, 30 is a light synthesizing prism that transmits only light but reflects only light C, and 31 reflects only light and C but only element d. Photosynthetic prism to transmit, 32 is light a
It is a light-synthesizing prism that only reflects light but transmits light, and only transmits light c and d. In this embodiment, the element a from the observed object in area A is the objective lens 20. Light splitting prism 21. -yt, split prism 22. Imaging lens 24.
The image forming point P passes through the prism 28 and the light combining prism 32.
, and the light beam from the object to be observed in region B passes through the objective lens 201 and the splitting prism 21. Light splitting prism 22. Imaging lens 25. Photosynthetic prism 30. photosynthesis prism 3
1 and the light combining prism 32 to reach the imaging point P, and the light C from the object to be observed in the area CK passes through the objective lens 20. Light splitting prism 21. Light splitting prism 23. Imaging lens 2
6. Photosynthetic prism 30. The light d from the observed object passing through the light combining prism 31 and the light combining prism 32 reaches the imaging point P, and passes through the objective lens 20. The light passes through a light combining prism 32 and reaches an imaging point P. Therefore, in the case of the observed object extending from area A to 4. Images of the observed object illuminated by the lights a, b, c, and d in areas A, B, O, and D, respectively, can be observed in a state where the entire image is in focus. Note that the image magnifications for each color of light do not necessarily have to be equal, since in cases where an object is divided into four layers, different magnifications may not interfere with observation. The optical system shown in FIG. 4 is an example;
Light splitting prisms 21, 22, 23 and light combining prism 3
0゜31.320 Color characteristics are not limited to this, but each party a.

6% The reflected light from the observed objects in areas A, B, C, and D by C and d reaches the imaging point P, and light from outside the depth of field does not reach the imaging point P. That's fine.

In the above description, the illumination lights a, b, and c of each color are used.

Although the case where the light beam d is incident on the observed object sideways has been described, the light beam may be incident on the object obliquely from above as shown by the chain line in FIG.

Figure 5 shows the case where the present invention is applied to a camera.
41 is a strobe that emits a line of light a; 42 is a strobe that emits a beam of light; 43 is a light splitting prism that transmits only light a but reflects only the beam of light; 44, 45 is an imaging lens; 46 and 47 are Prism 48 is a photosynthesis prism that has the characteristic of reflecting only light a but transmitting only light.
42 is a film surface. Stroze 41 illuminates objects at close range, Stroze J? 42J'' to illuminate a distant object.The object illuminated by each lens is illuminated by an imaging lens 44.
．． 45, the image is formed onto a film surface 49. In this way, a long-distance object and a short-distance object can be photographed simultaneously in focus.

Fig. 6 shows the case where the present invention is applied to the inner iIK, 50 is the tip of the inner iIK, 51 is the light a'1') illuminating a short distance object -1-, 6 is the illumination optical system, 52 is the light An illumination optical system 53 is an observation optical system configured similarly to that shown in FIG. 6. In this way, a near object and a far object can be imaged on the end face of the image guide while being in focus at the same time.

In the above explanation, the present invention has been applied to a microscope, a camera, and an endoscope, but it goes without saying that the present invention is not limited to these and can be applied to other optical instruments.

As described above, according to the present invention, an object to be observed is illuminated with a plurality of illumination lights having different wavelength bands in accordance with the depth of field, and each illumination light reflected by the object to be observed is imaged at the same point. This has the effect that optical instruments such as microscopes, cameras, and Uchiyukiharu can have a deep depth of field as a whole.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an example of a microscope optical system according to the present invention, Figs. 2 and 3 are schematic diagrams similar to Fig. 1 showing other embodiments, and Fig. 4 is a schematic diagram showing four different embodiments. The fifth factor is a schematic diagram similar to FIG. 1 showing an embodiment using colored illumination light, the fifth factor is a schematic diagram showing an embodiment of the camera according to the present invention, and FIG.
1 is a schematic diagram showing an example of an endoscope according to the present invention. 1... Microscope optical system s 2t20... Objective lens 3
゜21.22,23,43--light splitting prism, 4,
7,24゜25$26,27,44,45...Imaging lens, 5 t 11 t30.31,32,48...
・Photosynthetic prism, 6. ””9゜10.28,29,4
6,47...prism, 8.i.eyepiece, 12.
...Half Prism, 13.14...Filter, 4
1,42...Store a1y, 4g...Film surface, 5
0...Endoscope tip %51.52...Illumination optical system,
53... Observation optical system. Continued from Figure 6, page 1 0 Inventor Kinyasu Okawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd.

Claims (2)

[Claims] (1) an illumination device that emits illumination light in a first wavelength band and illumination light in a second wavelength band different from the second wavelength band;
a first optical path that images only the reflected light from the observed object illuminated with the illumination light in the first wavelength band on a predetermined device;
an imaging optical system including a second optical path that images only reflected light from the object to be observed illuminated with illumination light in the second wavelength band on the predetermined position; An optical instrument with a deep depth of field, characterized in that the depth of field is increased by illuminating with illumination light of each wavelength band corresponding to the depth of field. (2) The illumination device is further configured to emit illumination light in a wavelength band different from the first and second wavelength bands, and the imaging optical system further emits illumination light in each wavelength band. An optical instrument with a deep depth of field according to claim (1), characterized in that it includes one or more optical paths that image only reflected light from an illuminated object to be observed at a predetermined position. .