1. A light intensity ratio adjustment filter for an interferometer comprising:
a light intensity ratio adjustment film of a multi-layered film structure comprising at least one optical reflection-absorption layer and at least one dielectric anti-reflection layer laminated in that order as seen from a reference surface of a Fizeau interferometer and attached to a side of a transparent substrate opposite a sample or to a side of the transparent substrate opposite the reference surface;
wherein the light intensity ratio adjustment filter is placed so as to be freely inserted and removed between a sample and the reference surface of the Fizeau interferometer inducing interference between sample light from the sample and reference light from the reference surface, and obtaining interference wave information for the sample; and
wherein the light intensity ratio adjustment film reflects part of the incident light from the surface of the transparent substrate opposite the reference surface, and after absorbing part of the remaining light, transmits the remainder towards the sample, and absorbs part of the light returned from the sample and incident from the surface side opposite the sample while controlling reflection, and transmits the remainder in the direction of the reference surface as the sample light.
2. The light intensity ratio adjustment filter for an interferometer according to claim 1, wherein the optical reflection-absorption layer comprises a metallic layer, and the dielectric anti-reflection layer comprises a metallic oxide layer.
3. The light intensity ratio adjustment filter for an interferometer according to claim 2, wherein the metallic layer comprises nickel-chrome or bismuth, and the dielectric anti-reflection layer comprises titanium oxide or bismuth oxide.
4. The light intensity ratio adjustment filter for an interferometer according to claim 1, wherein an optical anti-reflection film is attached to the surface of the transparent substrate either opposite the reference surface or opposite the sample to which the light intensity ratio adjustment film is not attached.
5. The light intensity ratio adjustment filter for an interferometer according to claim 4, wherein the optical anti-reflection film comprises a layer of alternate films of ZnS and MgF2.
6. An interferometer comprising the light intensity ratio adjustment filter for an interferometer according to claim 1.
7. The interferometer according to claim 6, wherein the light intensity ratio of the reference light in relation to the sample light at the reference surface is within a range of 5 and \u2155.
8. The interferometer according to claim 6, wherein the light intensity ratio adjustment filter for an interferometer can be freely inserted and removed from a light path.
9. The interferometer according to claim 6, wherein the surface of the light intensity ratio adjustment filter for an interferometer is inclined towards a surface perpendicular to an optical axis of the interferometer.
10. The interferometer according to claim 6, wherein the sample forms a spherical shape.
11. A light interference measurement method for obtaining interference wave information for a sample using the interferometer according to claim 6, comprising the steps of:
placing a measurement value adjustment reference plate having a surface reflectance equivalent to the reference surface at sample position, and inserting the light intensity ratio adjustment filter for an interferometer in a light path between the reference surface and the measurement value adjustment reference plate, to obtain primary interference wave information;
placing the sample to be measured at the sample position, and inserting the light intensity ratio adjustment filter for an interferometer in the light path between the reference surface and the sample to be measured, to obtain secondary interference wave information; and
computing the difference information between the secondary interference wave information and the primary interference wave information to obtain interference wave information for the sample to be measured.
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 manufacturing method of a rare-earth permanent magnet comprising steps of:
milling magnet material into magnet powder;
preparing a mixture of the magnet powder and a binder;
obtaining a green sheet through thermally melting and forming the mixture into a sheet-like shape;
heating the green sheet and simultaneouslysubsequently applying a magnetic field to multiple layers of the heated green sheet, for magnetic field orientation; and
sintering the green sheet subjected to the magnetic field orientation.
2. The manufacturing method of a rare-earth permanent magnet according to claim 1, wherein, in the step of heating the green sheet and simultaneouslysubsequently applying a magnetic field, multiple layers of the green sheet are heated.
3. The manufacturing method of a rare-earth permanent magnet according to claim 1, wherein,
in the step of obtaining a green sheet, a base that is continuously conveyed is coated with the mixture, so as to form the green sheet on the base, and
in the step of heating the green sheet and simultaneouslysubsequently applying a magnetic field, the green sheet is continuously conveyed together with the base.
4. The manufacturing method of a rare-earth permanent magnet according to claim 3 further comprising steps of:
after the step of obtaining a green sheet, rolling up the green sheet around each of a plurality of first rolls, and drawing out the green sheet from each of the plurality of first rolls, and stacking up the drawn-out green sheet to form the multiple layers of the green sheet, so that the magnetic field is simultaneously applied to the multiple layers of the green sheet; and
separating the multiple layers of the green sheet subjected to the magnetic field orientation back into each single layer of the green sheet, and rolling up the single layer of the green sheet around each of a plurality of second rolls.
5. The manufacturing method of a rare-earth permanent magnet according to claim 3, wherein,
in the step of obtaining a green sheet, each of a plurality of bases drawn out from a plurality of third rolls is coated with the mixture, so as to form the green sheet on each of the plurality of bases, and
in the step of heating the green sheet and simultaneouslysubsequently applying a magnetic field, the green sheet on each of the plurality of bases is stacked to form multiple layers of the green sheet and the magnetic field is simultaneously applied to the multiple layers of the green sheet, and wherein
the manufacturing method further comprises a step of: separating the multiple layers of the green sheet subjected to the magnetic field orientation back into each single layer of the green sheet, and rolling up the single layer of the green sheet around each of a plurality of fourth rolls.
6. The manufacturing method of a rare-earth permanent magnet according to claim 3, wherein, in the step of heating the green sheet and simultaneouslysubsequently applying a magnetic field, the green sheet conveyed together with the base is made to pass through a solenoid charged with electric current.
7. The manufacturing method of a rare-earth permanent magnet according to claim 1, wherein,
the binder is any one of thermoplastic resin, a long-chain hydrocarbon and a fatty acid methyl ester, or any mixture thereof, and
in the step of heating the green sheet and simultaneouslysubsequently applying a magnetic field, the green sheet is heated to a temperature equal to or higher than a glass-transition point or melting point of the binder.
8. The manufacturing method of a rare-earth permanent magnet according to claim 1, wherein, before the step of sintering the green sheet, the binder is decomposed and removed from the green sheet by holding the green sheet for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere.
9. A rare-earth permanent magnet manufactured through steps of:
milling magnet material into magnet powder;
preparing a mixture of the magnet powder and a binder;
obtaining a green sheet through thermally melting and forming the mixture into a sheet-like shape;
heating the green sheet and simultaneouslysubsequently applying a magnetic field to multiple layers of the heated green sheet, for magnetic field orientation; and
sintering the green sheet subjected to the magnetic field orientation.
10. The manufacturing method of a rare-earth permanent magnet according to claim 2, wherein,
in the step of obtaining a green sheet, a base that is continuously conveyed is coated with the mixture, so as to form the green sheet on the base, and
in the step of heating the green sheet and simultaneouslysubsequently applying a magnetic field, the green sheet is continuously conveyed together with the base.