1. An optical system for collimating elliptical light beams, comprising:
a light source, adapted for providing an elliptical light beam defining different diverging angles in different directions, wherein any cross-section of the elliptical light beam emitted from the light source defines a long axis and a short axis which are perpendicular to each other;
a first lens, configured for collimating the elliptical light beam into a parallel elliptical light beam;
a second lens, configured as a diverging lens in directions corresponding to the short axis, for diverging the elliptical light beam and enlarging the short axis so as to narrow a difference between the long axis and the short axis and to narrow a difference between a diverging angle corresponding to the short axis and a diverging angle corresponding to the long axis, when the elliptical light beam passes therethough; and
a third lens, configured as a converging lens in the directions corresponding to the short axis, for converging the elliptical light beam and adjusting the short axis in order to obtaining a round light beam,
wherein the optical centers of the first lens, the second lens and the third lens commonly define a common optical axis along which the elliptical light beams travels.
2. The optical system as described in claim 1, wherein the second lens is a Fresnel lens having two surfaces opposite to each other, at least one of the two surfaces being configured as a Fresnel diverging surface configured for diverging light beams incident thereon.
3. The optical system as described in claim 1, wherein the third lens is a Fresnel lens having two surfaces opposite to each other, at least one of the two surfaces being configured as a Fresnel converging surface configured for converging light beams incident thereon.
4. The optical system as described in claim 1, wherein the relative positions of the light source, the first lens, the second lens, and the third lens are adjustable along the common optical axis.
5. The optical system as described in claim 1, wherein the light source, the first lens, the second lens, and the third lens are arranged in that order.
6. The optical system as described in claim 1, wherein the light source is a side light emitting laser diode.
7. The optical system as described in claim 2, wherein the second lens is configured for enlarging the short axis of the elliptical light beam incident thereon and remaining the long axis of the elliptical light beam unchanged.
8. The optical system as described in claim 3, wherein the third lens is configured for adjusting the diverging angle corresponding to the short axis of the elliptical light beam incident thereon and remaining the diverging angle corresponding to the long axis of the elliptical light beam unchanged.
9. An optical device for readingwriting to an optical disk, comprising:
an optical system configured for outputting a round parallel light beam, the optical system comprising:
a light source, adapted for providing an elliptical light beam defining different diverging angles in different directions, wherein any cross-section of the elliptical light beam emitted from the light source defines a long axis and a short axis which are perpendicular to each other;
a first lens, configured for collimating the elliptical light beam into a parallel elliptical light beam;
a second lens, configured as a diverging lens in directions corresponding to the short axis, for diverging the elliptical light beam and enlarging the short axis so as to narrow a difference between the long axis and the short axis and to narrow a difference between a diverging angle corresponding to the short axis and a diverging angle corresponding to the long axis, when the elliptical light beam passes therethough; and
a third lens, configured as a converging lens in the directions corresponding to the short axis, for converging the elliptical light beam and adjusting the short axis in order to obtaining a round light beam,
wherein the optical centers of the first lens, the second lens and the third lens commonly define a common optical axis along which the elliptical light beams travels;
a beam splitter, allowing light beams from a first direction to pass therethrough and for reflecting light beams from a second direction, the second direction being substantially opposite to the first direction;
an object lens for focusing parallel light beams to a point on an optical disk;
a collimator for collimating light beams passed therethrough; and
an optoelectronic detector, for receiving a light beam, detecting information from the light beam, converting the information into electronic signals, and outputting the electronic signals,
wherein the optical system, the beam splitter, the object lens, the collimator, and the optoelectronic detector are configured in a light path, so as to allow the round parallel light beam outputted from the optical system passes through the beam splitter, then is focused by the object lens onto a focal plane; then the focal plane reflects the focused light beam back to the object lens; the focused light beam is reverted by the object lens and incidents to round parallel light; then the beam splitter reflects the light beam to the collimator; and the collimator collimates the light beam to the optoelectronic detector.
10. An optical device for readingwriting to an optical disk, comprising:
an optical system comprising a light source emitting an elliptical diverging light beam, and at least a Fresnel lens, wherein the optical system outputs a substantially round light beam;
a beam splitter, allowing light beams from a first direction to pass therethrough and for reflecting light beams from a second direction, the second direction being substantially perpendicular to the first direction;
an object lens for focusing parallel light beams to a point on the optical disk;
a collimator for collimating light beams passed therethrough; and
an optoelectronic detector, for receiving a light beam, detecting information from the light beam, converting the information into electronic signals, and outputting the electronic signals,
wherein the optical system, the beam splitter, the object lens, the collimator and the optoelectronic detector are set in a manner that the round light beam outputted from the optical system travels in a sequence of the beam splitter, the object lens, the object lens, the beam splitter, the collimator, and the optoelectronic detector, in which the light beam outputted from the object lens is reflected by external reflective means of the optical disk back to the object lens.
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 method of inhibiting corrosion of one or more metals in contact with an aqueous system, the method comprising adding one or more corrosion inhibitor compositions to the aqueous system, wherein the one or more corrosion inhibitor compositions comprise (1) an amino acid-based polymer and (2) a dispersible andor water soluble tin compound; wherein the amino acid-based polymer has a molecular weight according to gel-permeation chromatographic analysis of at least about 1,000.
2. The method of claim 1 wherein the amino acid-based polymer comprises polyaspartic acid andor a salt thereof and the tin compound comprises a water soluble tin salt.
3. The method of claim 2 wherein the weight ratio of the tin salt to the polyaspartic acid compound in the one or more corrosion inhibitor compositions is about 1:5 to 1:50.
4. The method of claim 2 wherein adding the one or more corrosion inhibitor compositions result in the addition of about 0.2 to 5 ppm of the tin salt and about 1 to 50 ppm of the polyaspartic acid andor a salt thereof to the aqueous system.
5. The method of claim 2 wherein the polyaspartic acid has a molecular weight according to gel-permeation chromatographic analysis of about 1,000 to 50,000.
6. The method of claim 2 wherein the polyaspartic acid has a molecular weight according to gel-permeation chromatographic analysis of about 1,000 to 10,000.
7. The method of claim 1 wherein the one or more metals comprise a ferrous metal.
8. The method of claim 1, wherein the one or more corrosion inhibitor compositions are substantially free of zinc, molybdate and chromate.
9. The method of claim 1, wherein the one or more corrosion inhibitor compositions comprise polyaspartic acid andor a salt thereof; stannous chloride; a polycarboxylic acid chelating agent, which includes citric acid andor polymaleic acid; and a carboxylatesulfonate functional copolymer, which includes an acrylic acidacrylamidosulfonic acid copolymer.
10. The method of claim 1, wherein the dispersible andor water soluble tin compound comprises a stannous salt; the amino acid-based polymer comprises polyaspartic acid andor a salt thereof; and the one or more corrosion inhibitor compositions further comprise a polycarboxylic acid chelating agent and a carboxylatesulfonate functional copolymer.
11. The method of claim 1, wherein the one or more corrosion inhibitor compositions further comprise an azole corrosion inhibitor.
12. The method of claim 1, wherein the one or more corrosion inhibitor compositions are substantially free of phosphate, polyphosphate materials and organophosphonate compounds.
13. A method of inhibiting corrosion of one or more metals in contact with an aqueous system, the method comprising maintaining effective amounts of (1) an amino acid-based polymer and (2) a dispersible andor water soluble tin compound in the aqueous system in contact with the one or more metals; wherein the amino acid-based polymer has a molecular weight according to gel-permeation chromatographic analysis of at least about 1,000.
14. The method of claim 13 wherein the amino acid-based polymer comprises polyaspartic acid compound; the dispersible andor water soluble tin compound comprises stannous salt; and the method comprises maintaining a concentration of about 0.1 to 10 of the stannous salt and about 1 to 50 ppm of the amino acid-based polymer in the aqueous system.
15. The method of claim 14, wherein the polyaspartic acid compound comprises polyaspartic acid andor a salt thereof.
16. The method of claim 14, wherein the stannous salt comprises stannous chloride; the polyaspartic acid compound comprises polyaspartic acid andor a salt thereof; and
the method further comprises adding a polycarboxylic acid chelating agent, which includes citric acid andor polymaleic acid, and carboxylatesulfonate functional copolymer, which includes an acrylic acidacrylamidosulfonic acid copolymer, to the aqueous system.
17. The method of claim 16, wherein the method comprises adding the stannous salt and the polyaspartic acid compound to the aqueous system in a weight ratio of about 1:5 to 1:50.
18. The method of claim 14, wherein the method comprises maintaining a concentration of about 0.2 to 5 ppm (expressed as ppm tin) of the stannous salt in the aqueous system.
19. The method of claim 14 wherein the polyaspartic acid has a molecular weight according to gel-permeation chromatographic analysis of about 1,000 to 50,000.
20. The method of claim 14 wherein the polyaspartic acid has a molecular weight according to gel-permeation chromatographic analysis of about 1,000 to 10,000.
21. The method of claim 13, further comprising adding a polycarboxylic acid chelating agent to the aqueous system.
22. The method of claim 13, wherein the tin compound comprises stannous halide, stannous sulfate andor stannous carboxylate.
23. The method of claim 13, further comprising adding an azole corrosion inhibitor to the aqueous system.
24. The method of claim 13, further comprising adding a carboxylatesulfonate functional copolymer to the aqueous system.
25. The method of claim 13, further comprising adding one or more of a (meth)acrylic polymer, an acrylicsulfonic copolymer, polymaleic acid and an acrylicmaleic copolymer to the aqueous system.
26. The method of claim 13, further comprising adding a phosphateiron dispersant copolymer to the aqueous system.
27. The method of claim 13, further comprising adding one or more of a maleic acidstyrene sulfonic acid copolymer, an acrylic acidacrylamidosulfonic acid (AMPS) copolymer, acrylic acidAMPSterbutylacrylamide copolymer, acrylic acidAMPSsodium styrenesulfonate copolymer, polymaleic acid and an acrylicmaleic copolymer to the aqueous system.