Imaging optical system and imaging device

Abstract

To provide an imaging optical system capable of scanning an object with a simple mechanism without moving the object and an imaging element.SOLUTION: An imaging optical system 10 according to the present disclosure is used for obtaining a spectral image of an object S by guiding light L for imaging the object S into an imaging element 31, the system comprising: a first diaphragm 11 positioned on an objective lens 70 side; a scanning part 12 positioned on an imaging element 31 side relative to an image forming position of the light L having passed through the first diaphragm 11; a light condensing part 13 condensing the light L having passed through the scanning part 12; a second diaphragm 14 positioned on the imaging element 31 side relative to the light condensing part 13; and a slit 15 disposed on a position at which the light L passes through the second diaphragm 14 and is condensed by the light condensing part 13. The slit 15 causes only the light L corresponding to a predetermined region of the object S out of the light L having passed through the scanning part 12 to pass. The scanning part 12 changes the predetermined region to scan the object S while keeping constant an optical path length between the image forming position and the light condensing part 13.SELECTED DRAWING: Figure 1

Claims

1. An imaging optical system used to guide light for imaging an object to an image sensor and to obtain a spectral image of the object, The first aperture is located on the objective lens side, A scanning unit located on the image sensor side of the image formation position by the light that has passed through the first aperture, A light-collecting unit that collects the light that has passed through the scanning unit, A second aperture located closer to the image sensor than the light-gathering section, A slit is positioned so that the light passes through the second aperture and is focused by the light-gathering section, Equipped with, The slit allows only the light corresponding to a predetermined area of ​​the object to pass through the scanning unit. The scanning unit scans the object by changing the predetermined area while maintaining a constant optical path length between the imaging position and the light-gathering unit. Imaging optical system.

2. The imaging optical system according to claim 1, The scanning unit has a first mirror and a second mirror that move in the same direction and by the same distance from each other along the short-side direction of the slit during scanning of the object. Imaging optical system.

3. The imaging optical system according to claim 2, The scanning unit includes a third mirror that reflects the light reflected by the first mirror back to the second mirror, and a fourth mirror that reflects the light reflected by the second mirror back to the light-gathering unit. Imaging optical system.

4. An imaging optical system according to any one of claims 1 to 3, The first aperture is positioned in an open state with an aperture value of 4 or less. Imaging optical system.

5. An imaging optical system according to any one of claims 1 to 3, The second aperture has an F-number of 11 or more and 16 or less. Imaging optical system.

6. An imaging optical system according to any one of claims 1 to 3, The width of the slit in the shorter direction of the slit is within the range of 80 μm to 120 μm. Imaging optical system.

7. An imaging optical system according to any one of claims 1 to 3, The system further comprises a spectroscopic element that spectrally separates the light that has passed through the slit into multiple wavelength regions defined by a hyperspectrum. Imaging optical system.

8. An imaging apparatus comprising the imaging optical system according to any one of claims 1 to 3, the objective lens, and the image sensor.

9. The imaging apparatus according to claim 8, The imaging device includes a rigid endoscope. Imaging device.

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