Source: https://patents.justia.com/patent/8159675
Timestamp: 2019-08-20 03:23:59
Document Index: 260678095

Matched Legal Cases: ['Application No. 2007', 'art 21', 'art 21', 'art 21', 'art 8', 'art 21', 'art 21', 'art 8', 'Application No. 08720479']

US Patent for Observation device and wavelength limiting filter Patent (Patent # 8,159,675 issued April 17, 2012) - Justia Patents Search
Justia Patents With Color Transmitting FilterUS Patent for Observation device and wavelength limiting filter Patent (Patent # 8,159,675)
Observation device and wavelength limiting filter
Jul 29, 2009 - Nikon
An observation device observing a sample cultured in a culture vessel includes an illuminating unit including an illumination optical system and illuminating the sample, an image-capturing unit including an imaging sensor and generating an image by capturing an image of the sample illuminated by the illuminating unit, and a wavelength limiting filter being placed on an optical axis of the illumination optical system and between the illuminating unit and the image-capturing unit, and limiting a part of wavelengths of an illumination light from the illumination optical system in accordance with optical absorption properties of an additive contained in a culture medium used for culturing the sample. Accordingly, it is possible to suppress a change of the image resulting from the additive and to enable to generate an appropriate image in an automatic observation.
This application is a continuation application of International Application PCT/JP2008/000593, filed Mar. 14, 2008, designating the U.S., and claims the benefit of priority from Japanese Patent Application No. 2007-071099, filed on Mar. 19, 2007, the entire contents of which are incorporated herein by reference.
An observation device of the present embodiment observing a sample cultured in a culture vessel includes an illuminating unit including an illumination optical system and illuminating the sample, an image-capturing unit including an imaging sensor and generating an image by capturing an image of the sample illuminated by the illuminating unit, and a wavelength limiting filter being placed on an optical axis of the illumination optical system and between the illuminating unit and the image-capturing unit, and limiting a part of wavelengths of an illumination light from the illumination optical system in accordance with optical absorption properties of an additive contained in a culture medium used for culturing the sample.
FIG. 1 is a block diagram illustrating a configuration of a microscope of the present embodiment.
Hereinafter, embodiments of the present invention are described with reference to the drawings. Incidentally, in the present embodiments, it is described while using a phase-contrast microscope as an example of an observation device of the present invention.
Next, the optical absorption property of phenol red is described. FIG. 3 is a view illustrating the optical absorption property of phenol red. As illustrated in FIG. 3, there is a characteristic absorption band in a vicinity of 500 nm to 600 nm in phenol red. This absorption band is known to change in accordance with a change of a pH value of the culture medium, thickness of the culture medium in the optical axis direction (hereinafter, it is called as “optical path length of culture medium”), and a concentration change of phenol red in the culture medium. Incidentally, the optical path length of the culture medium and the concentration change of phenol red in the culture medium are factors relating to the concentration of the culture medium.
Iin(λ)=Io(λ)×τ1(λ)×τ2(λ)×A (expression 1)
Incidentally, in the expression 1, “Io(λ)” represents an output of the illumination source part 21, “τ1(λ)” represents an influence of the wavelength limiting filter 24, “τ2(λ)” represents an influence of the culture medium (phenol red added to the culture medium), and “A” represents the optical absorption property resulting from surrounding media of the sample represented by the following expression 2.
A=α(λ)×L×C (expression 2)
Incidentally, “α(λ)” represents an absorption constant, “L” represents the optical path length of the culture medium, and “C” represents the concentration of phenol red in the culture medium, in the expression 2.
Besides, “Res(λ)” at the imaging sensor 8A in FIG. 6 represents a response function of the imaging sensor SA. This response function is a function determined in accordance with a spectral sensitivity characteristic of the imaging sensor 8A. The spectral sensitivity characteristic of the imaging sensor 8A is illustrated in FIG. 7.
O ⁡ ( Io ) = ∫ λ ⁢ min λ max ⁢ Iin ⁡ ( λ ) · Res ⁡ ( λ ) ⁢ ⅆ λ ( expression ⁢ ⁢ 3 )
As it is obvious from the expression 3, it is preferable that the wavelength limiting filter 24 is made up by considering a sensitivity characteristic of the imaging sensor 8A in addition to the optical absorption property of phenol red.
Accordingly, output characteristics when the sensitivity characteristic of the imaging sensor 8A is added to the optical absorption properties described in FIG. 4 when the optical path length of the culture medium and the concentration of phenol red in the culture medium are fixed and the pH value of the culture medium is changed are illustrated in FIG. 8. A vertical axis in FIG. 8 represents a change of a value in which the incident light Iin(λ) incident on the imaging sensor 8A and the response function Res(λ) of the imaging sensor 8A are multiplied and normalized into “0” (zero) to “1”. As illustrated in FIG. 8, the output characteristics change largely within a range of 500 nm to 600 nm, and become stable within a range of 600 nm to 650 nm.
Besides, output characteristics when the sensitivity characteristic of the imaging sensor 8A is added to the optical absorption properties described in FIG. 5 when the pH value of the culture medium and the concentration of phenol red in the culture medium are fixed and the optical path length of the culture medium is changed are illustrated in FIG. 9. A vertical axis in FIG. 9 represents a change of a value in which the incident light Iin(λ) incident on the imaging sensor 8A and the response function Res(λ) of the imaging sensor 8A are multiplied and normalized into “0” (zero) to “1” as same as in FIG. 8. As illustrated in FIG. 9, the output characteristics change largely within a range of 500 nm to 600 nm, and becomes stable within a range of 600 nm to 650 nm.
In the present embodiment, an example is illustrated in which the wavelength limiting filter 24 is placed between the illumination source part 21 and the ring aperture 22, but it may be placed at any position as long as it is between the illumination source part 21 and the image-capturing part 8 and on the optical axis of the illumination source part 21. A disposed position of the wavelength limiting filter 24 may be determined in accordance with the wavelengths limited by the wavelength limiting filter 24 and the constitution of the microscope 1. A flowchart until the light irradiated from the illumination source part 21 reaches the imaging sensor 8A and the image is generated when the wavelength limiting filter 24 is placed between the stage 5 and the image-capturing part 8 is illustrated in FIG. 12. As illustrated in FIG. 12, the incident light Iin(λ) is similar to the case in FIG. 6 even though the position placing the wavelength limiting filter 24 is changed.
the wavelength limiting filter is placed on an optical axis of the illumination optical system and between the illuminating unit and the image-capturing unit, and limits a part of wavelengths of light entering the image-capturing unit by cutting off the part of wavelengths in accordance with optical absorption properties of an additive contained in a culture medium used for culturing the sample.
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European Search Report issued in corresponding European Patent Application No. 08720479.8, mailed May 21, 2010.
Patent number: 8159675
Patent Publication Number: 20090296208
Inventor: Yasujiro Kiyota (Tokyo)
Application Number: 12/461,013
Current U.S. Class: With Color Transmitting Filter (356/416); Including Optical Measuring Or Testing Means (435/288.7); Optical Sensing Apparatus (435/808)
International Classification: G01J 3/51 (20060101); G02B 21/00 (20060101);