1. An imaging optical system comprising:
an aperture stop;
a first lens disposed at an image side of the aperture stop, the first lens having a positive refractive power and the front surface of the first lens having a convex object-side surface;
a second lens disposed at an image side surface of the first lens, the front surface of the second lens having a concave object-side surface;
a third lens disposed at an image side surface of the second lens, the rear surface of the third lens having a concave image-side surface;
a fourth lens disposed at an image side surface of the third lens, the fourth lens having a positive refractive power and the rear surface of the fourth lens having a convex image-side surface; and
a fifth lens having a negative refractive power and the rear surface of the fifth lens having a concave image-side surface,
wherein a combined refractive power of the second and third lenses is negative.
2. The imaging optical system of claim 1, wherein the second and third lenses are cemented together or spaced apart from each other at a predetermined distance.
3. The imaging optical system of claim 2, wherein one of the fourth and fifth lenses has at least one surface formed of an aspherical surface.
4. The imaging optical system of claim 3, having a dimension in an optical axis direction satisfying following condition 1:
1.0<TLf<1.5\u2003\u2003condition 1,
where TL is a distance from the object-side surface of the first lens to an image plane and f is a total focal length of the optical system.
5. The imaging optical system of claim 3, wherein the first lens has a refractive power satisfying following condition 2-1:
0.5\u2266f1f\u22661.0\u2003\u2003condition 2-1,
where f1 is a focal length of the first lens.
6. The imaging optical system of claim 3, wherein the first, second and third lenses have a refractive power satisfying following condition 3-1:
1.1<f123f\u22661.5\u2003\u2003condition 3-1,
where f123 is a combined focal length of the first, second and third lenses.
7. The imaging optical system of claim 3, wherein the fourth lens has a shape satisfying following condition 4-1:
\u22122.5<R\u2014L4Ff<\u22121.0\u2003\u2003condition 4-1,
where R_L4F is a radius of curvature of an object-side surface of the fourth lens.
8. The imaging optical system of claim 3, wherein the second and third lenses have Abbe numbers satisfying following conditions 5-1 and 5-2, respectively:
45<V_L2<71\u2003\u2003condition 5-1
23<V_L3<40\u2003\u2003condition 5-2,
where V_L2 is an Abbe number of the second lens and V_L3 is an Abbe number of the third lens.
9. The imaging optical system of claim 3, wherein the fourth and fifth lenses have a refractive power satisfying following condition 6-1:
\u22121.4<f4f5<\u22120.8\u2003\u2003condition 6-1
where f4 is a focal length of the fourth lens and f5 is a focal length of the fifth lens.
10. The imaging optical system of claim 1, wherein the second lens has a negative refractive power and the third lens has a positive refractive power.
11. The imaging optical system of claim 10, wherein one of the fourth and fifth lenses has at least one surface formed of an aspherical surface.
12. The imaging optical system of claim 11, having a dimension in an optical axis direction satisfying following condition 1:
1.0<TLf<1.5\u2003\u2003condition 1,
where TL is a distance from the object-side surface of the first lens to an image plane and f is a total focal length of the optical system.
13. The imaging optical system of claim 11, wherein the first lens has a refractive power satisfying following condition 2-2:
0.4<f1f<0.9\u2003\u2003condition 2-2,
where f1 is a focal length of the first lens.
14. The imaging optical system of claim 11, wherein the first, second and third lenses have a refractive power satisfying following condition 3-2:
1.1<f123f<1.7\u2003\u2003condition 3-2,
f123 is a combined focal length of the first and second lenses.
15. The imaging optical system of claim 11, wherein the fourth lens has a shape satisfying following condition 4-1:
\u22123.0<R\u2014L4Ff<\u22120.0\u2003\u2003condition 4-1,
where R_L4F is a radius of curvature of an object-side surface of the fourth lens.
16. The imaging optical system of claim 11, wherein the first, second and third lenses have Abbe numbers satisfying following conditions 5-3, 5-4 and 5-5, respectively:
50<V_L1<70\u2003\u2003condition 5-3,
25<V_L2<45\u2003\u2003condition 5-4,
50\u2266V_L3<70\u2003\u2003condition 5-5,
where V_L1 is an Abbe number of the first lens, V_L2 is an Abbe number of the second lens and V_L3 is an Abbe number of the third lens.
17. The imaging optical system of claim 11, wherein the first lens and fifth lenses have a refractive power satisfying following condition 6-2:
\u22121.4<f4f5<\u22120.7\u2003\u2003condition 6-2,
where f4 is a focal length of the fourth lens and f5 is a focal length of the fifth lens.
18. The imaging optical system of claim 1, having a dimension in an optical axis direction satisfying following condition 1, and wherein the first lens has a refractive power satisfying following condition 2-1:
1.0<TLf<1.5\u2003\u2003condition 1,
0.5<f1f<1.0\u2003\u2003condition 2-1,
where TL is a distance from the object-side surface of the first lens to an image plane, f is a total focal length of the optical system and f1 is a focal length of the first lens.
19. The imaging optical system of claim 18, wherein the first, second and third lenses have a refractive power satisfying following condition 3-1:
1.1<f123f<1.5\u2003\u2003condition 3-1,
where f123 is a combined focal length of the first, second and third lenses.
20. The imaging optical system of claim 1, having a dimension in an optical axis direction satisfying following condition 1, and wherein the first lens has a refractive power satisfying following condition 2-2:
1.0TLf<1.5\u2003\u2003condition 1,
0.4<f1f<0.9\u2003\u2003condition 2-2,
where TL is a distance from the object-side surface of the first lens to an image plane, f is a total focal length of the optical system and f1 is a focal length of the first lens.
21. The imaging optical system of claim 20, wherein the first, second and third lenses have a refractive power satisfying following condition 3-2:
1.1<f123f<1.7\u2003\u2003condition 3-2,
where f123 is a combined focal length of the first, second and third lenses.
22. An imaging optical system comprising:
an aperture stop;
a first lens disposed at an image side of the aperture stop, the first lens having a positive refractive power and the front surface of the first lens having a convex object-side surface;
a second lens disposed at an image side surface of the first lens;
a third lens disposed at an image side surface of the second lens;
a fourth lens having a positive refractive power and the rear surface of the fourth lens having a convex image-side surface; and
a fifth lens having a negative refractive power and the rear surface of the fifth lens having a concave image-side surface,
wherein a combined refractive power of the second and third lenses is negative and the second lens has a positive refractive power and the third lens has a negative refractive power.
23. An imaging optical system comprising:
an aperture stop;
a first lens disposed at an image side of the aperture stop, the first lens having a positive refractive power and having both convex surfaces;
a second lens disposed at an image-side surface of the first lens, the front surface of the second lens having a concave object-side surface;
a third lens disposed at an image-side surface of the second lens, the third lens cemented to the second lens or spaced apart from the second lens at a predetermined distance, the rear surface of the third lens having a concave image-side surface;
a fourth lens disposed at an image side surface of the third lens, the fourth lens having a positive refractive power and having a convex image-side surface; and
a fifth lens having a negative refractive power and having a concave image-side surface, the fifth lens having at least one surface formed of an aspherical surface,
wherein a combined refractive power of the second and third lenses is negative.
24. The imaging optical system of claim 23, having a dimension in an optical axis direction satisfying following condition 1:
1.0<TLf<1.5\u2003\u2003condition 1,
where TL is a distance from an object-side surface of the first lens to an image plane and f is a total focal length of the optical system.
25. The imaging optical system of claim 24, wherein the second lens has a positive refractive power and the third lens has a negative refractive power.
26. The imaging optical system of claim 24, wherein the second lens has a negative refractive power and the third lens has a positive refractive power.
27. The imaging optical system of claim 24, wherein the fifth lens has a point of inflection formed on the image-side surface thereof.
28. The imaging optical system of claim 23, wherein the fourth lens has at least one surface formed of an aspherical surface.
29. The imaging optical system of claim 28, wherein the second lens has a positive refractive power and the third lens has a negative refractive power.
30. The imaging optical system of claim 28, wherein the second lens has a negative refractive power and the third lens has a positive refractive power.
31. The imaging optical system of claim 28, wherein the fifth lens has the image-side surface convexed toward an object side near an optical axis and convexed toward an image plane at peripheral portions.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A reflection detection type measurement apparatus for skin fluorescence, the apparatus comprising:
a first light source irradiating excitation light on a measurement target;
a second light source irradiating light of a wavelength different from that of light from the first light source on the measurement target;
a first optical detector detecting a reflected light generated from the measurement target due to the excitation light of the first light source; and
a second optical detector detecting a skin fluorescence generated from the measurement target due to the excitation light of the first light source, and detecting a reflected light generated from the measurement target due to the excitation light of the second light source;
wherein the first optical detector is disposed in an area other than a total reflection area to which the excitation light of the first light source is reflected after irradiating to the measurement target, and the second optical detector is disposed in an area other than a total reflection area to which the excitation light of the first light source and the light of the second light source are reflected after irradiating to the measurement target.
2. The reflection detection type measurement apparatus of claim 1, wherein the first light source and the second light source irradiate light to the same area of the measurement target, and the first optical detector and the second optical detector are disposed to detect light generated from the same area of the measurement target.
3. The reflection detection type measurement apparatus of claim 1, wherein the light of the second light source is light with a wavelength range of skin fluorescence generated from the measurement target due to the excitation light of the first light source.
4. The reflection detection type measurement apparatus of claim 1, wherein the first light source irradiates light with a wavelength of 370\xb120 nm.
5. The reflection detection type measurement apparatus of claim 1, wherein the second light source irradiates light with a wavelength of 440\xb120 nm.
6. The reflection detection type measurement apparatus of claim 1, wherein the first light source and the light of the second light source irradiate light to the measurement target in a different time.
7. A reflection detection type measurement apparatus for skin fluorescence, the apparatus comprising:
a first light source;
a second light source irradiating light of a wavelength different from that of light from the first light source;
a first optical detector detecting a reflected light generated after the light from the first light source is irradiated on a measurement target;
a second optical detector detecting a skin fluorescence generated after the light from the first light source is irradiated on the measurement target, and detecting a reflected light generated from the measurement target due to the light of the second light source; and
a holder to which the first light source, the second light source, the first optical detector, and the second optical detector are inserted to be disposed to face the same area of the measurement target.
8. The reflection detection type measurement apparatus of claim 7, wherein the holder comprises an inclination part having a through-hole to accept the first light source, the second light source, the first optical detector, and the second optical detector and a bottom part extended to the inclination part to have an opening.
9. The reflection detection type measurement apparatus of claim 8, wherein a stepped part to store optical component is formed in the inside of the through-hole of the inclination part.
10. The reflection detection type measurement apparatus of claim 8, wherein the holder has a pyramidal shape.
11. The reflection detection type measurement apparatus of claim 7, further comprising a holder to which the first light source, the second light source, the first optical detector, and the second optical detector are inserted,
wherein the first light source and the second light source are disposed to face each other based on a center axis of the holder, and the first optical detector and the second optical detector are disposed to face each other based on the center axis of the holder.
12. A reflection detection type measurement apparatus for skin fluorescence, the apparatus comprising:
a first light source irradiating excitation light on a measurement target;
a second light source irradiating light of a wavelength different from that of light from the first light source on the measurement target;
a first optical detector detecting a reflected light generated from the measurement target due to the excitation light of the first light source; and
a second optical detector detecting a skin fluorescence generated from the measurement target due to the excitation light of the first light source, and detecting a reflected light generated from the measurement target due to the excitation light of the second light source;
a light source switching controller controlling a turned onoff of the first light source and the second light source; and
a calculation unit calculating a skin fluorescence signal by correcting a skin fluorescence detected from the first optical detector and the second optical detector and a signal according to a reflected light.
13. The reflection detection type measurement apparatus of claim 12, wherein the light source switching controller controlling a switching of the first light source and the second light source so that the first light source and the second light source are maintained to be turned on in a different time.
14. The reflection detection type measurement apparatus of claim 12, wherein the first optical detector is turned on to detect reflected light for light irradiated from the first light source for a first time, and the second optical detector is turned on to detect a reflected light for light irradiated from the second light source for a second time after the first time and a skin fluorescence due to the light irradiated from the first light source for the first time.
15. The reflection detection type measurement apparatus of claim 12, further comprising an optical prism to transmit the light irradiated from the first light source and the second light source to the measurement target, and transmit the skin fluorescence and the reflected light to an optical detector unit,
wherein the optical prism comprises a bottom part connected to the measurement target and an upper part in which the first light source, the second light source, the first optical detector, and the second optical detector are mounted.
16. The reflection detection type measurement apparatus of claim 15, wherein the upper part has a first inclination surface and a second inclination surface, and the first inclination surface and the second inclination surface are symmetrical to each other base on a center axis of the optical prism.
17. The reflection detection type measurement apparatus of claim 15, wherein the first light source or the second light source is mounted on a first inclination surface of the optical prism, and the first optical detector or the second optical detector is mounted on a second inclination surface of the optical prism.
18. The reflection detection type measurement apparatus of claim 17, wherein the first light source and the first optical detector, and the second light source and the second optical detector are all obliquely disposed at an angle of 45 degrees based on a center axis of the optical prism.
19. The reflection detection type measurement apparatus of claim 12, further comprising a holder to which the first light source, the second light source, the first optical detector, and the second optical detector are inserted,
wherein the holder comprises an inclination part having a through-hole to accept the first light source, the second light source, the first optical detector, and the second optical detector and a bottom part extended to the inclination part to have an opening.
20. The reflection detection type measurement apparatus of claim 19, wherein the first light source, the second light source, the first optical detector, and the second optical detector are disposed in the holder to face the same area of the measurement target.