Detection device
A detection device comprises a chip holder, a light source, a light-guide rod, a wavelength separation filter, and an optical sensor. Given the relationship between the angle of incidence and light intensity of fluorescence on a light reception surface of the optical sensor, the optical transmittance of the wavelength separation filter at the dominant wavelength of the rays of fluorescence incident on the light reception surface at a peak angle of incidence at which the light intensity is the highest is greater than the optical transmittance of the wavelength separation filter at the dominant wavelength of the rays of excitation light incident on the light reception surface at the peak angle of incidence and is higher than the optical transmittance of the wavelength separation filter at the dominant wavelength of the rays of fluorescence incident on the light reception surface at an angle of incidence of 0 DEG.
1. A detection device comprising:
a light source that irradiates a detection object substance labeled by a fluorescence material with excitation light;
a light sensor that detects fluorescence generated by irradiating the detection object substance with the excitation light;
a light guiding rod that guides the fluorescence to the light sensor; and
a wavelength separation filter disposed at a position between the detection object substance and the light sensor,
wherein a light transmittance of the wavelength separation filter for a light beam of a main wavelength of the fluorescence which is incident on a light reception surface of the light sensor at a predetermined peak incident angle is higher than a light transmittance of the wavelength separation filter for a light beam of a main wavelength of the excitation light which is incident on the light reception surface at the predetermined peak incident angle;
wherein the predetermined peak angle is an angle higher than 0 degrees.
2. The detection device of claim 1 ,
wherein the light transmittance of the wavelength separation filter for a light beam of a main wavelength of the fluorescence which is incident on the light reception surface of the light sensor at the predetermined peak incident angle is higher than a light transmittance of the wavelength separation filter for a light beam of a main wavelength of the fluorescence which is incident on the light reception surface of the light sensor at an incident angle of 0 degrees.
3. The detection device of claim 2 ,
wherein the light transmittance of the wavelength separation filter for the light beam of the main wavelength of the fluorescence which is incident on the light reception surface at the incident angle of 0 degrees is not higher than one-fifth of the light transmittance of the wavelength separation filter for the light beam of the main wavelength of the fluorescence which is incident on the light reception surface at the predetermined peak incident angle.
4. The detection device of claim 1 ,
wherein in a relationship between a light quantity and an incident angle of the fluorescence at the light sensor, the peak incident angle which is an incident angle at which the light quantity of the fluorescence is maximized.
5. The detection device of claim 1 ,
wherein the predetermined peak incident angle is greater than 0 degrees and less than 45 degrees.
6. The detection device of claim 1 ,
wherein the predetermined peak incident angle is between 30 degrees and 35 degrees.
7. The detection device of claim 1 ,
wherein the wavelength separation filter is integrated with the light guiding rod.
8. The detection device of claim 1 ,
wherein the light reception surface is perpendicular to an axis direction of the light guiding rod, and
wherein the wavelength separation filter is disposed along a direction perpendicular to the axis direction of the light guiding rod.
9. The detection device of claim 1 ,
wherein the light guiding rod has a columnar shape.
10. The detection device of claim 1 , further comprising a detection chip that includes a prism, and a metal film disposed on the prism, wherein:
the detection object region is at least a part of a surface of the metal film;
the light source applies, from the prism side, excitation light to a rear surface of the metal film;
the fluorescence is a fluorescence which is emitted from the fluorescence material which is excited by localized light generated by the excitation light applied to the rear surface of the metal film through the prism.