1. An apparatus for measuring an inner radius of a hollow cylinder, comprising:
at least a light emitting means for providing a light source with multiple wavelength or a spectrum, the light emitting means including a light emitting component for providing the light source;
at least a light dispersing means for receiving light from the light emitting means and respectively focusing rays with different wavelengths in the light source into focal points with different intervals;
at least a reflecting component disposed in the centre of an inner circle of the hollow cylinder and within a range of the focal points, for reflecting rays within the range of the focal points to an inner wall of the hollow cylinder and reflecting rays reflected or scattered by the inner wall of the hollow cylinder;
at least a wavelength measuring means for measuring wavelengths of the rays reflected by the reflecting component, such that the inner radius of the hollow cylinder is determined from the measured wavelengths of the reflected rays; and
a modulating component provided between the wavelength measuring means and the light emitting component, for receiving the rays reflected by the reflecting component and modulating the rays into applicable light beams.
2. The apparatus of claim 1, wherein the light emitting means further comprises:
a further modulating component for receiving the light from the light emitting component and modulating the light into applicable light beams.
3. The apparatus of claim 1, further comprising a first optical signal separating component provided between the light dispersing means and the wavelength measuring means, for passing the rays reflected by the reflecting component to the wavelength measuring means.
4. The apparatus of claim 3, wherein the wavelength measuring means comprises:
a second optical signal separating component for receiving the rays from the first optical signal separating component and separating the rays into a first light beam and a second light beam;
a first filtering component for receiving the first light beam and attenuating the first light beam to a third light beam;
a first photosensor for receiving the third light beam and measuring a first light intensity of the third light beam; and
a second photosensor for receiving the second light beam and measuring a second light intensity of the second light beam, such that a primary wavelength of the rays reflected by the reflecting component is learned by comparing the first light intensity and the second light intensity.
5. The apparatus of claim 1, wherein the wavelength measuring means comprises:
a third optical signal separating component for receiving the rays from the second modulating component and separating the rays into a fourth light beam and a fifth light beam;
a second filtering component for receiving the fourth light beam and attenuating the fourth light beam to a sixth light beam;
a third photosensor for receiving the sixth light beam and measuring a third light intensity of the sixth light beam; and
a fourth photosensor for receiving the fifth light beam and measuring a fourth light intensity of the fifth light beam, such that a primary wavelength of the rays reflected or scattered by the hollow cylinder is learned by comparing the third light intensity and the fourth light intensity.
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 polarizing plate, comprising:
a polarizer; and
a retardation layer that is laminated on one side of the polarizer, and that comprises an uniaxial retardation film or a biaxial retardation film,
wherein a reflectivity of the polarizing plate is 12% or less at an inclined angle of 50 degrees.
2. The polarizing plate according to claim 1, wherein a thickness-direction retardation of the retardation layer is more than 0 nm and also not more than 300 nm.
3. The polarizing plate according to claim 1, of which a reflectivity at all radial angles measured at the inclined angle of 50 degrees is 12% or less.
4. The polarizing plate according to claim 1, wherein the retardation layer satisfies the following Formula 7;
R(450)R(550)<R(650)R(550)\u2003\u2003Formula 7
where R(450) is in-plane retardation of the retardation layer with respect to light having a wavelength of 450 nm, R(550) is in-plane retardation of the retardation layer with respect to light having a wavelength of 550 nm, and R(650) is in-plane retardation of the retardation layer with respect to light having a wavelength of 650 nm.
5. The polarizing plate according to claim 1, wherein the retardation layer comprises a positive uniaxial retardation film and a C plate.
6. The polarizing plate according to claim 5, wherein the C plate is disposed closer to the polarizer than the positive uniaxial retardation film.
7. The polarizing plate according to claim 6, wherein an angle between a slow axis of the positive uniaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
8. The polarizing plate according to claim 6, wherein a thickness-direction retardation of the C plate is from 0 nm to 200 nm.
9. The polarizing plate according to claim 5, wherein the positive uniaxial retardation film is disposed closer to the polarizer than the C plate.
10. The polarizing plate according to claim 9, wherein an angle between a slow axis of the positive uniaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
11. The polarizing plate according to claim 9, wherein a thickness-direction retardation of the C plate is from 0 nm 200 nm.
12. The polarizing plate according to claim 1, wherein the retardation layer includes a positive biaxial retardation film.
13. The polarizing plate according to claim 12, wherein an angle between a slow axis of the positive biaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
14. The polarizing plate according to claim 12, wherein a thickness-direction retardation of the positive biaxial retardation film is 160 nm or less.
15. The polarizing plate according to claim 12, wherein the retardation layer further comprises a positive uniaxial retardation film, and the positive biaxial retardation film is disposed closer to the polarizer than the positive uniaxial retardation film.
16. The polarizing plate according to claim 15, wherein the slow axis of the positive biaxial retardation film is parallel to the light absorption axis of the polarizer, and an angle between a slow axis of the positive uniaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees.
17. The polarizing plate according to claim 15, wherein a thickness-direction retardation of the positive biaxial retardation film is 220 nm or less.
18. The polarizing plate according to claim 11, wherein the retardation layer further comprises a negative biaxial retardation film, and the positive biaxial retardation film is disposed closer to the polarizer than the negative biaxial retardation film.
19. The polarizing plate according to claim 18, wherein the slow axis of the positive biaxial retardation film is parallel to the light absorption axis of the polarizer, and an angle between a slow axis of the negative biaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees.
20. The polarizing plate according to claim 18, wherein the sum of a thickness-direction retardation of the positive biaxial retardation film and a thickness-direction retardation of the negative biaxial retardation film is from 60 nm to 270 nm.
21. The polarizing plate according to claim 11, wherein the retardation layer further includes a negative biaxial retardation film, and the negative biaxial retardation film is disposed closer to the polarizer than the positive biaxial retardation film.
22. The polarizing plate according to claim 21, wherein an angle between the slow axis of the positive biaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees, and a slow axis of the negative biaxial retardation film is parallel to the light absorption axis of the polarizer.
23. The polarizing plate according to claim 21, wherein the sum of a thickness-direction retardation of the positive biaxial retardation film and a thickness-direction retardation of the negative biaxial retardation film is from 60 nm to 200 nm.
24. The polarizing plate according to claim 1, wherein the retardation layer includes a negative biaxial retardation film and a C plate.
25. The polarizing plate according to claim 24, wherein the C plate is disposed closer to the polarizer than the negative biaxial retardation film.
26. The polarizing plate according to claim 25, wherein an angle between a slow axis of the negative biaxial retardation film and a light absorption axis of the polarizer is from 40 degrees to 50 degrees.
27. The polarizing plate according to claim 25, wherein the sum of a thickness-direction retardation of the C plate and a thickness-direction retardation of the negative biaxial retardation film is from 70 nm to 250 nm.
28. The polarizing plate according to claim 24, wherein the negative biaxial retardation film is disposed closer to the polarizer than the C plate.
29. The polarizing plate according to claim 28, wherein an angle between a slow axis of the negative biaxial retardation film and the light absorption axis of the polarizer is from 40 degrees to 50 degrees.
30. The polarizing plate according to claim 28, wherein the sum of a thickness-direction retardation of the C plate and a thickness-direction retardation of the negative biaxial retardation film is from 50 nm to 250 nm.
31. A display comprising the polarizing plate of claim 1.