What is claimed is:
1. A hydraulic power steering apparatus for a vehicle comprising:
an input member interlocking with a steering wheel;
an output member connected to said input member so as to freely move relatively;
a steering mechanism steering a steered wheel in an interlocking relationship with said output member;
a main control valve having a first valve portion and a second valve portion in which a valve opening degree is controlled on the basis of a relative movement between said input member and said output member;
a power cylinder mechanism generating a steering assist force applied to said steering mechanism in correspondence to a fluid pressure in a working chamber in which a working fluid is supplied and discharged;
a first flow passage communicating a pump apparatus for discharging a fixed flow amount of working fluid with said main control valve;
a second flow passage branched from said first flow passage and communicated with a low pressure portion via an assist control valve and said main control valve;
a control unit controlling said assist control valve;
said first valve portion controlling a supply amount of the working fluid in said first flow passage to said working chamber; and
said second valve portion controlling a discharge amount of the working fluid in said second flow passage to said low pressure portion in accordance with cooperation with said assist control valve,
wherein a vehicle speed sensor for detecting a vehicle speed and a pressure sensor for detecting a fluid pressure of the working fluid in said first flow passage are provided, and said control unit controls a valve opening degree of said assist control valve to a set valve opening degree set on the basis of the vehicle speed detected by said vehicle speed sensor and the fluid pressure detected by said pressure sensor.
2. A hydraulic power steering apparatus for a vehicle as claimed in claim 1, wherein said control unit is arranged and constructed to set the valve opening degree of said assist control valve to a fully closed side at a time of a vehicle speed equal to or less than a predetermined low vehicle speed including a vehicle stop time, and is arranged and constructed to set the valve opening degree so as to be increased in accordance with an increase of the vehicle speed from the predetermined low vehicle speed, in connection with the vehicle speed detected by the vehicle speed sensor, and is arranged and constructed to set the valve opening degree so that the fluid pressure by which the steering assist force having an optimum magnitude is generated is generated in the power cylinder mechanism, with respect to the steering torque generated at a time when the driver operates the steering wheel at a certain vehicle speed, in connection with the fluid pressure detected by the pressure sensor.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A projection optical system forming an image of an object in a first plane onto a second plane comprising:
an optical element group including at least one refractive member and a plurality of reflective members; and
a plurality of lens-barrel units holding said optical element group divided into a plurality of groupings;
wherein said plurality of reflective members is all held by one lens-barrel -unit of said plurality of lens-barrels units.
2. The projection optical system according to claim 1, further comprising;
a partial optical element group forming an intermediate image on a third plane between said first plane and said second plane;
wherein said partial optical element group is integrally held by one lens-barrel unit of said plurality of lens-barrel units.
3. The projection optical system according to claim 1, wherein said optical element group is disposed along a single optical axis.
4. The projection optical system according to claim 1, wherein
said optical element group comprising:
a first partial optical element group disposed along a first optical axis;
a second partial optical element group disposed belong a second optical axis which extends in a direction that intersects said first optical axis, and is optically connected to said first partial optical element group; and
a third partial optical element group disposed along a third optical axis which extends in the same direction as said first optical axis, and is optically connected to said second partial optical element group.
5. The projection optical system according to claim 1, wherein
said second partial optical element group comprises said plurality of reflective members; and
said one lens-barrel unit of said plurality of lens-barrel units holds said second partial optical element group.
6. The projection optical system according to claim 1, wherein said plurality of lens-barrel units are independently supported each other.
7. The projection optical system according to claim 1, wherein at least one lens-barrel unit of said plurality of lens-barrel units holds with an adjustable state of a predetermined optical element that is held by said lens-barrel unit.
8. The projection optical system according to claim 1, wherein
at least one of said plurality of lens-barrel units further comprising a plurality of holding blocks holding one or a plurality of optical elements;
wherein said plurality of holding blocks have an adjustment mechanism to adjust the state of optical elements respectively held therein.
9. The projection optical system according to claim 1, wherein at least one of said plurality of lens-barrel units is detachable.
10. The projection optical system according to claim 1, wherein
said projection optical system is used with illumination light with wavelengths of 200 nm or shorter; and
a purge gas through which said illumination light passes is supplied to inside said projection optical system.
11. The projection optical system according to claim 10, wherein each of said optical element groups is held by either a frame mechanism or a frame member with an opening through which purge gas may pass.
12. A projection optical system comprising:
an optical element group including a first and a second optical element sub-group, and forming an image of a predetermined magnification of an object in a first plane onto a second plane;
a first lens-barrel unit holding said first optical element sub-group as a single body along a first optical axis; and
a second lens-barrel unit holding said second optical element sub-group as a single body along a second optical axis that is coaxis with said first optical axis;
wherein said first lens-barrel unit is held in a position at a plane that is orthogonal to said first optical axis and that passes through a point divides a line, along said first optical axis, between an object point and an image point relative to said first sub optical element group by 1:1 (where 1 is a real number other than zero), or in a position near said plane; and
said second lens-barrel unit is held in a position at a plane that is orthogonal to said second optical axis and that passes through a point divides a line, along said second optical axis, between an object point and an image point relative to said second sub optical element group by 1:2 (where 2 is a real number other than zero), or in a position near said plane.
13. The projection optical system according to claim 12, wherein said optical element group is disposed along one optical axis.
14. The projection optical system according to claim 12, wherein
said projection optical system is used with illumination light with wavelengths of 200 nm or shorter; and
a purge gas through which said illumination light passes is supplied to inside said projection optical system.
15. The projection optical system according to claim 14, wherein each of said optical element groups is held by either a frame mechanism or a frame member with an opening through which purge gas may pass.
16. A projection optical system which forms an image of an object in a first plane onto a second plane, comprising:
an optical element group having a plurality of aspherical surfaces; and
a plurality of holding blocks holding said optical element group in a plurality of groupings;
wherein the number of said plurality of holding blocks is equal to or greater than the number of said aspherical surfaces.
17. The projection optical system according to claim 16, wherein
said optical element group has a plurality of reflective members; and
each of said plurality of reflective members is held by each of said plurality of holding blocks different from each other.
18. The projection optical system according to claim 16, wherein said optical element group is disposed along one optical axis.
19. The projection optical system according to claim 16, wherein
said optical element group comprising:
a first partial optical element group disposed along a first optical axis;
a second partial optical element group disposed along a second optical axis which extends in a direction that intersects said first optical axis, and is optically connected to said first partial optical element group; and
a third partial optical element group disposed along a third optical axis which extends in the same direction as said first optical axis, and is optically connected to said second partial optical element group.
20. The projection optical system according to claim 16, wherein
said projection optical system is used with illumination light with wavelengths of 200 nm or shorter; and
a purge gas through which said illumination light passes is supplied to inside said projection optical system.
21. The projection optical system according to claim 20, wherein each of said optical element groups is held by either a frame mechanism or a frame member with an opening through which purge gas may pass.
22. A projection optical system which forms an image of an object in a first plane onto a second plane, comprising:
an optical element group;
a plurality of lens-barrel units, which hold said optical element group in a plurality of groupings; and
frame from which at least one lens-barrel unit of said plurality of lens-barrel units is held so as to hang down.
23. The projection optical system according to claim 22, comprising a partial optical element group, which forms an intermediate image on a third plane between said first plane and said second plane; wherein said partial optical element group is integrally held by one lens-barrel unit of said plurality of lens-barrel units.
24. The projection optical system according to claim 22, wherein said optical element group is disposed along one optical axis.
25. The projection optical system according to claim 22, wherein said plurality of lens-barrel units are each independently supported.
26. The projection optical system according to claim 22, wherein at least one of said plurality of lens-barrel units has an adjustment mechanism to adjust the state of predetermined optical elements held by said lens-barrel unit.
27. The projection optical system according to claim 22, at least one of said plurality of lens-barrel units further comprising:
a plurality of holding blocks holding one or a plurality of optical elements;
wherein said plurality of holding blocks have an adjustment mechanism to adjust the state of optical elements respectively held therein.
28. The projection optical system according to claim 22, wherein at least one of said plurality of lens-barrel units is detachable.
29. The projection optical system according to claim 22, wherein
said projection optical system is used with illumination light with wavelengths of 200 nm or shorter; and
a purge gas through which said illumination light passes is supplied to inside said projection optical system.
30. The projection optical system according to claim 29, wherein each of said optical element groups is held by either a frame mechanism or a frame member with an opening through which purge gas may pass.
31. A projection optical system forming an image of an object in a first plane onto a second plane by using light with wavelengths of 200 nm or shorter, comprising:
at least two refractive members disposed in the optical path of said light;
at least two lens-barrel units aligning said at least two refractive members;
a pipeline being connected to at least one lens-barrel unit of said at least two lens-barrel units and supplying purge gas through which said light can pass within the space between said at least two refractive members; and
at least two holding units being included in each of said at least two lens-barrel units and holding each of said at least two refractive members;
wherein said at least two holding units having openings to allow said purge gas to pass through.
32. The projection optical system according to claim 31, wherein said light has wavelengths of 160 nm or shorter.
33. A projection optical system provided in a projection exposure apparatus, comprising:
an imaging optical system including all of a plurality of reflective members which are structural components of said projection optical system;
another imaging optical system including at least one refractive member which is a structural component of said projection optical system and not including a reflective member which is a structural component of said projection optical system;
a lens-barrel unit holding said imaging optical system; and
another lens-barrel unit holding said another imaging optical system.
34. The projection optical system according to claim 33, wherein
said lens-barrel unit is structured with a plurality of divided lens-barrels, which include a mechanism for adjusting the state of said imaging optical system; and
said another lens-barrel unit is structured with a plurality of divided lens-barrels, which include a mechanism for adjusting the state of said another imaging optical system.
35. The projection optical system according to claim 34, wherein each of said plurality of reflective members is held by each of divided lens-barrel different from each other in said plurality of divided lens-barrels forming said lens-barrel unit.
36. The projection optical system according to claim 33, wherein
said projection optical system is used with illumination light with wavelengths of 200 nm or shorter; and
a purge gas through which said illumination light passes is supplied to inside said projection optical system.
37. A method of manufacturing a projection optical system which comprises an optical element group having at least one refractive member and a plurality of reflective members, and a plurality of lens-barrel units holding said optical element group as a plurality of groupings;
said method of manufacturing a projection optical system comprising the step of:
a first step of pre-setting a predetermined lens-barrel unit of said plurality of lens-barrel units to be detachable, putting together a lens-barrel unit to be adjusted at the position of said predetermined lens-barrel unit of a first projection optical system that is already completed as said projection optical system, and performing adjustment on said lens-barrel unit to be adjusted while measuring optical characteristics of said first projection optical system; and
a second step of building up a second projection optical system by an adjusted lens-barrel unit on which adjustment is performed in said first step and lens-barrel units other than this, and performing adjustment of said second projection optical system using said adjusted lens-barrel unit as a standard.
38. A projection optical system, which is manufactured in accordance with the method of manufacturing according to claim 37.
39. A method of manufacturing a projection optical system which comprises an optical element group including at least one refractive member and at least one reflective member, a plurality of lens-barrel units holding said optical element group as a plurality of groupings, a holding block being a component of at least one lens-barrel unit of said plurality of lens-barrel units and holding at least one optical element, wherein said holding block is adjustable in at least one of relative orientation and relative position to said lens-barrel unit including said holding block as structural component, and at least one entire lens-barrel unit of said plurality of lens-barrel units is adjustable;
said method comprising the step of:
a first step of adjusting said plurality of lens-barrel units relative to each other; and
a second step of adjusting said at least one of said relative orientation and said relative position of said holding block, so as to adjust residual aberrations, after said first step.
40. A projection optical system, which is manufactured in accordance with the method of manufacturing according to claim 39.
41. A projection exposure apparatus, which comprises the projection optical system according to claim 1, and which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system.
42. A projection exposure apparatus, which comprises the projection optical system according to claim 12, and which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system.
43. A projection exposure apparatus, which comprises the projection optical system according to claim 16, and which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system.
44. A projection exposure apparatus, which comprises the projection optical system according to claim 22, and which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system.
45. A projection exposure apparatus, which comprises the projection optical system according to claim 31, and which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system.
46. A projection exposure apparatus, which comprises the projection optical system according to claim 33, and which projects an image of a projection original disposed on a first plane onto a workpiece, with said projection optical system.
47. A projection exposure method, which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system according to claim 1.
48. A projection exposure method, which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system according to claim 12.
49. A projection exposure method, which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system according to claim 16.
50. A projection exposure method, which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system according to claim 22.
51. A projection exposure method, which projects an image of a projection original disposed on said first plane onto a workpiece, with said projection optical system according to claim 31.
52. A projection exposure method, which projects an image of a projection original disposed on a first plane onto a workpiece, with said projection optical system according to claim 33.