1. An optical pickup device for irradiating a recording medium having laminated recording layers and servo layers with laser light, the optical pickup device comprising:
a first laser light source for emitting first laser light having a first wavelength;
a second laser light source for emitting second laser light having a second wavelength different from the first wavelength;
an objective lens for converting the first laser light emitted from the first laser light source, and the second laser light emitted from the second laser light source on the recording medium;
a focus position adjuster for changing a focus position of the first laser light by the objective lens in an optical axis direction,
an astigmatism element for imparting astigmatism to the first laser light and the second laser light reflected on the recording medium;
a spectral element for imparting diffraction in such a manner that at least four light fluxes of the first laser light are separated from each other, when a light flux of the first laser light and a light flux of the second laser light reflected on the recording medium are divided into four by a first straight line in parallel to a converging direction by the astigmatism element, and a second straight line perpendicular to the first straight line, and that the four light fluxes of the first laser light propagate on an outer side than the light flux of the second laser light; and
a photodetector including a first sensor group for receiving the separated four light fluxes of the first laser light to generate a reproduction signal, and a second sensor group for receiving the second laser light to generate a servo signal for use in controlling the objective lens.
2. The optical pickup device according to claim 1, wherein
the spectral element imparts diffraction in such a manner that four light fluxes of the second laser light obtained by dividing the light flux of the second laser light by the first straight line and the second straight line are separated from each other, and that the four light fluxes of the second laser light propagate on an inner side than the light fluxes of the first laser light, and
the second sensor group receives each light flux of the second laser light separated by the spectral element.
3. The optical pickup device according to claim 1, wherein
the spectral element transmits a part of the light flux of the second laser light without diffraction, and
the second sensor group receives the light flux of the second laser light transmitted through the spectral element without diffraction.
4. The optical pickup device according to claim 1, wherein
the spectral element is configured to guide each light flux after the separation to four different vertex positions of a square on a light receiving surface of the photodetector.
5. The optical pickup device according to claim 1, wherein
sensing portions constituting the first sensor group and for receiving the four light fluxes are electrically connected to each other.
6. The optical pickup device according to claim 1, further comprising
an optical system which irradiates the recording medium with the first laser light in a direction opposite to an incident direction from the objective 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.
1-34. (canceled)
35. A cylinder adapted for use in a machine that is usable for processing lengths of material, said cylinder comprising:
a non-rotatable shaft having a longitudinal shaft axis;
a casing supported for rotation on said shaft and adapted to receive a sleeve on a casing circumferential surface;
spaced bearing assemblies between an outer surface of said shaft and an inner surface of said casing;
a lubricant channel in said shaft; and
a compressed gas bore in said shaft.
36. The cylinder of claim 35 further including at least one lubricant chamber between said shaft and said casing and divided axially into lubricant chamber sections, at least one compressed gas chamber between said shaft and said casing and divided axially into compressed gas chamber sections, and compressed gas outlet openings extending from said compressed gas chamber sections to said casing circumferential surface.
37. The cylinder of claim 36 further including at least one lubricant-side sealing ring and one compressed gas-side sealing ring separating each said lubricant chamber and an adjacent compressed gas chamber.
38. The cylinder of claim 37 wherein each said sealing ring has a sealing edge and an annular sealing body extending radially between said shaft and casing inner surface, each said sealing edge facing its respective one of said lubricant chamber and said compressed gas chamber.
39. The cylinder of claim 36 wherein said at least one compressed gas chamber is supplied with a gas under pressure through said compressed gas bore.
40. The cylinder of claim 35 further including a shaft axial end with a compressed gas bore inlet at said shaft axial end.
41. The cylinder of claim 39 further including at least one radially extending compressed gas supply bore extending between said compressed gas bore and said compressed gas chamber.
42. The cylinder of claim 35 further including at least one lubricant chamber between said shaft and said casing and divided into lubricant chamber sections by one of said spaced bearing assemblies, said at least one lubricant channel extending between said lubricant chamber sections divided by said bearing assembly.
43. The cylinder of claim 42 wherein said at least one lubricant channel extends through said shaft at an angle with respect to said shaft longitudinal axis.
44. The cylinder of claim 43 further wherein said at least one lubricant channel intersects said compressed gas bore and is seated in an airtight manner with respect to said compressed gas bore.
45. The cylinder of claim 44 wherein said at least one lubricant channel is a tube in a through bore located in said shaft.
46. The cylinder of claim 36 further including at least a first oil deflector in each said lubricant chamber.
47. The cylinder of claim 46 wherein said at least first oil deflector is located adjacent an inner surface of said casing and adjacent said one of said bearings located in said lubricant chamber.
48. The cylinder of claim 47 wherein said at least first oil deflector is angled whereby oil removed from said inner surface of said casing, during rotation of said casing, is accelerated axially by said at least first oil deflector in a direction of said bearing.
49. The cylinder of claim 46 further including a second oil deflector in each said lubricant chamber.
50. The cylinder of claim 49 further including a lubricant-side sealing ring defining a portion of said lubricant chamber and wherein said second oil deflector is arranged near an inner surface of said casing and adjacent said lubricant-side sealing ring.
51. The cylinder of claim 50 wherein a first end of said lubricant channel ends in said lubricant chamber adjacent said first oil deflector and a second end of said lubricant channel ends in said lubricant chamber adjacent said second oil deflector.
52. The cylinder of claim 50 wherein said second oil deflector is between said bearing and said lubricant-side sealing ring.
53. The cylinder of claim 36 wherein said at least one lubricant chamber is located axially adjacent an end of said cylinder and said at least one compressed gas chamber is located axially centrally in said cylinder.
54. The cylinder of claim 36 wherein said bearings are roller bearings in said lubricant chamber.
55. The cylinder of claim 37 wherein said lubricant-side sealing ring is made of a first material and said compressed gas-side sealing ring is made of a second material which is different from said first material.
56. The cylinder of claim 37 wherein each said lubricant-side sealing ring is located adjacent one of said spaced bearing assemblies.
57. The cylinder of claim 37 further including a spacer ring between said lubricant-side sealing ring and said compressed gas-side sealing ring and usable to allow lubricant flow to said compressed gas-side sealing ring.
58. The cylinder of claim 36 further including an oil fill bore in said shaft and extending from an oil fill opening to said at least one lubricant chamber.
59. The cylinder of claim 58 wherein said oil fill bore extends through said shaft at an angle with respect to said longitudinal shaft axis.
60. The cylinder of claim 58 wherein said oil fill bore acts as a lubricant chamber vent opening.
61. The cylinder of claim 58 further including an oil level gauge insertable in said oil fill bore.
62. The cylinder of claim 35 wherein said cylinder is an impression cylinder of a printing machine.
63. The cylinder of claim 35 wherein said cylinder is a printing cylinder.
64. The cylinder of claim 35 wherein a sleeve positionable on said casing is a printing forme.
65. The cylinder of claim 35 wherein said cylinder is arranged in a printing press.
66. The cylinder of claim 35 wherein said cylinder is arranged in a gravure printing press.