1. An integrally woven preform with stiffeners in two or more directions constructed from a woven base fabric, said base fabric comprising:
a first woven fabric;
a second woven fabric; and
a plurality of yarns interwoven between said first woven fabric and said second woven fabric, wherein said plurality of yarns are interwoven over a region between said first fabric and said second fabric, and said first fabric is folded relative to said second fabric such that a first off-axis stiffener is formed in said preform.
2. The woven preform of claim 1, wherein said first woven fabric is slit from a top surface of said second woven fabric in one or more regions.
3. The woven preform of claim 2, wherein a first portion on a first side of an interwoven region of said first woven fabric is folded together with a first portion on a second side of the interwoven region of said first woven fabric to form an off-axis stiffener rib in a first direction.
4. The woven preform of claim 1, further comprising:
a third woven fabric; and
a plurality of yarns interwoven between said second woven fabric and said third woven fabric, wherein said plurality of yarns are interwoven over a region between said second fabric and said third fabric, and said third fabric is folded relative to said second fabric such that a second off-axis stiffener is formed in said preform.
5. The woven preform of claim 4, wherein said third woven fabric is slit from a bottom surface of said second woven fabric in one or more regions.
6. The woven preform of claim 5, wherein a first portion on a first side of an interwoven region of said third woven fabric is folded together with a first portion on a second side of the interwoven region of said third woven fabric to form an off-axis stiffener rib in a second direction.
7. The woven preform of claim 1, wherein said base fabric is woven from warp and weft yarns or fibers.
8. The woven preform of claim 7, wherein the warp fiber pattern is a pattern selected from the group consisting of ply-to-ply, orthogonal, and angle interlock.
9. The woven preform of claim 7, wherein the interwoven yarns are warp yarns.
10. The woven preform of claim 7, wherein the interwoven yarns are weft yarns.
11. The woven preform of claim 7, wherein said warp and weft yarns or fibers are selected from the group of consisting of carbon, nylon, rayon, fiberglass, cotton, ceramic, aramid, and polyethylene.
12. The woven preform of claim 4, wherein said first and second off-axis stiffeners are formed at \xb160 degrees or \xb145 degrees orientation.
13. A fiber reinforced composite comprising an integrally woven preform with stiffeners in two or more directions constructed from a woven base fabric, said base fabric comprising:
a first woven fabric;
a second woven fabric; and
a plurality of yarns interwoven between said first woven fabric and said second woven fabric, wherein said plurality of yarns are interwoven over a region between said first fabric and said second fabric, and said first fabric is folded relative to said second fabric such that a first off-axis stiffener is formed in said preform.
14. The composite of claim 13, further comprising a matrix material.
15. The composite of claim 14, wherein said matrix material is a resin, and said composite is formed from a process selected from the group consisting of resin transfer molding and chemical vapor filtration.
16. The composite of claim 14, wherein said matrix material is selected from the group consisting of epoxy, polyester, bismaleimide, vinyl-ester, ceramic, and carbon.
17. The composite of claim 13, wherein said first off-axis stiffener is formed at \xb160 degrees or \xb145 degrees orientation.
18. An integrally woven preform with stiffeners in two or more directions constructed from a woven base fabric, said base fabric comprising:
a first woven fabric;
a second woven fabric; and
a plurality of yarns interwoven between said first woven fabric and said second woven fabric in a plurality of independent regions,
wherein said first fabric is folded relative to said second fabric such that a first stiffener is formed in a first direction in said preform, and a portion of said first stiffener is folded to form a second stiffener in a second direction in said preform, said second stiffener being an off-axis stiffener.
19. The woven preform of claim 18, wherein said first woven fabric is slit from a top surface of said second woven fabric in one or more regions.
20. The woven preform of claim 18, further comprising:
a third woven fabric; and
a plurality of yarns interwoven between said second woven fabric and said third woven fabric in a plurality of independent regions,
wherein said third fabric is folded relative to said second fabric such that a third stiffener is formed in a third direction in said preform, and a portion of said third stiffener is folded to form a fourth stiffener in a fourth direction in said preform, said fourth stiffener being an off-axis stiffener.
21. The woven preform of claim 20, wherein said third woven fabric is slit from a bottom surface of said second woven fabric in one or more regions.
22. The woven preform of claim 18, wherein said base fabric is woven from warp and weft yarns or fibers.
23. The woven preform of claim 22, wherein the warp fiber pattern is a pattern selected from the group consisting of ply-to-ply, orthogonal, and angle interlock.
24. The woven preform of claim 22, wherein the interwoven yarns are warp yarns.
25. The woven preform of claim 22, wherein the interwoven yarns are weft yarns.
26. The woven preform of claim 22, wherein said warp and weft yarns or fibers are selected from the group of consisting of carbon, nylon, rayon, fiberglass, cotton, ceramic, aramid, and polyethylene.
27. The woven preform of claim 20, wherein said second stiffener and fourth stiffener are formed at \xb160 degrees or \xb145 degrees orientation.
28. A fiber reinforced composite comprising an integrally woven preform with stiffeners in two or more directions constructed from a woven base fabric, said base fabric comprising:
a first woven fabric;
a second woven fabric; and
a plurality of yarns interwoven between said first woven fabric and said second woven fabric in a plurality of independent regions,
wherein said first fabric is folded relative to said second fabric such that a first stiffener is formed in a first direction in said preform, and a portion of said first stiffener is folded to form a second stiffener in a second direction in said preform, said second stiffener being an off-axis stiffener.
29. The composite of claim 28, further comprising a matrix material.
30. The composite of claim 29, wherein said matrix material is a resin, and said composite is formed from a process selected from the group consisting of resin transfer molding and chemical vapor filtration.
31. The composite of claim 29, wherein said matrix material is selected from the group consisting of epoxy, polyester, bismaleimide, vinyl-ester, ceramic, and carbon.
32. The composite of claim 28, wherein said second stiffener is formed at \xb160 degrees or \xb145 degrees orientation.
33. A method of forming an integrally woven preform comprising the steps of:
providing two or more woven fabrics;
interweaving a plurality of yarns from a first woven fabric with a plurality of yarns from a second woven fabric, said first woven fabric being foldable in relation to said second woven fabric;
slitting a portion of said first woven fabric from a top surface of said second woven fabric; and
folding said portion of said first fabric relative to said second woven fabric to form a first off-axis stiffener in said preform.
34. The method of claim 33, further comprising the step of:
folding a first portion on a first side of an interwoven region of said first woven fabric together with a first portion on a second side of the interwoven region of said first woven fabric to form an off-axis stiffener rib in a first direction.
35. The method of claim 33, further comprising the step of:
interweaving a plurality of yarns from a third woven fabric with a plurality of yarns from a second woven fabric, said third woven fabric being foldable in relation to said second woven fabric;
slitting a portion of said third woven fabric from a bottom surface of said second woven fabric; and
folding said portion of said third fabric relative to said second woven fabric to form a second off-axis stiffener in said preform.
36. The method of claim 35, further comprising the step of
folding a first portion on a first side of an interwoven region of said third woven fabric together with a first portion on a second side of the interwoven region of said third woven fabric to form an off-axis stiffener rib in a second direction.
37. The method of claim 33, wherein said two or more fabrics are woven from warp and weft yarns or fibers.
38. The method of claim 37, wherein the warp fiber pattern is a pattern selected from the group consisting of ply-to-ply, orthogonal, and angle interlock.
39. The method of claim 37, wherein the interwoven yarns are warp yarns.
40. The method of claim 37, wherein the interwoven yarns are weft yarns.
41. The method of claim 37, wherein said warp and weft yarns or fibers are selected from the group of consisting of carbon, nylon, rayon, fiberglass, cotton, ceramic, aramid, and polyethylene.
42. The method of claim 35, wherein said first and second off-axis stiffeners are formed at \xb160 degrees or \xb145 degrees orientation.
43. A method of forming a fiber reinforced composite comprising the steps of:
forming an integrally woven preform by providing two or more woven fabrics;
interweaving a plurality of yarns from a first woven fabric with a plurality of yarns from a second woven fabric, said first woven fabric being foldable in relation to said second woven fabric;
slitting a portion of said first woven fabric from a top surface of said second woven fabric; and
folding said portion of said first fabric relative to said second woven fabric to form a first off-axis stiffener in said preform.
44. The method of claim 43, further comprising the step of:
impregnating said preform in a matrix material.
45. The method of claim 44, wherein said matrix material is a resin, and said composite is formed from a process selected from the group consisting of resin transfer molding and chemical vapor filtration.
46. The method of claim 44, wherein said matrix material is selected from the group consisting of epoxy, polyester, bismaleimide, vinyl-ester, ceramic, and carbon.
47. The method of claim 43, wherein said first off-axis stiffener is formed at \xb160 degrees or \xb145 degrees orientation.
48. A method of forming an integrally woven preform comprising the steps of:
providing two or more woven fabrics;
interweaving a plurality of yarns from a first woven fabric with a plurality of yarns from a second woven fabric in a plurality of independent regions, said first woven fabric being foldable in relation to said second woven fabric;
slitting a portion of said first woven fabric from a top surface of said second woven fabric; and
folding said portion of said first fabric relative to said second woven fabric such that a first stiffener is formed in a first direction in said preform, and a portion of said first stiffener is folded to form a second stiffener in a second direction in said preform, said second stiffener being an off-axis stiffener.
49. The method of claim 48, further comprising:
interweaving a plurality of yarns from a third woven fabric with a plurality of yarns from a second woven fabric in a plurality of independent regions, said third woven fabric being foldable in relation to said second woven fabric;
slitting a portion of said third woven fabric from a top surface of said second woven fabric; and
folding said portion of said third fabric relative to said second woven fabric such that a third stiffener is formed in a third direction in said preform, and a portion of said third stiffener is folded to form a fourth stiffener in a fourth direction in said preform, said fourth stiffener being an off-axis stiffener.
50. The method of claim 48, wherein said two or more fabrics are woven from warp and weft yarns or fibers.
51. The method of claim 50, wherein the warp fiber pattern is a pattern selected from the group consisting of ply-to-ply, orthogonal, and angle interlock.
52. The method of claim 50, wherein the interwoven yarns are warp yarns.
53. The method of claim 50, wherein the interwoven yarns are weft yarns.
54. The method of claim 50, wherein said warp and weft yarns or fibers are selected from the group of consisting of carbon, nylon, rayon, fiberglass, cotton, ceramic, aramid, and polyethylene.
55. The method of claim 49, wherein said second stiffener and fourth stiffener are formed at \xb160 degrees or \xb145 degrees orientation.
56. A method of forming a fiber reinforced composite comprising the steps of:
forming an integrally woven preform by providing two or more woven fabrics;
interweaving a plurality of yarns from a first woven fabric with a plurality of yarns from a second woven fabric in a plurality of independent regions, said first woven fabric being foldable in relation to said second woven fabric;
slitting a portion of said first woven fabric from a top surface of said second woven fabric; and
folding said portion of said first fabric relative to said second woven fabric such that a first stiffener is formed in a first direction in said preform, and a portion of said first stiffener is folded to form a second stiffener in a second direction in said preform, said second stiffener being an off-axis stiffener.
57. The method of claim 56, further comprising the step of:
impregnating said preform in a matrix material.
58. The method of claim 57, wherein said matrix material is a resin, and said composite is formed from a process selected from the group consisting of resin transfer molding and chemical vapor filtration.
59. The method of claim 57, wherein said matrix material is selected from the group consisting of epoxy, polyester, bismaleimide, vinyl-ester, ceramic, and carbon.
60. The method of claim 56, wherein said first off-axis stiffener is formed at +\u221260 degrees or \xb145 degrees orientation.
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 scan type exposure apparatus for exposing a substrate, placed on an exposure plane, to a pattern of a mask with light from a light source, said apparatus comprising:
a stop member for restricting an exposure range on the exposure plane;
measuring means for measuring an illuminance distribution which is produced on a predetermined plane displaced from the exposure plane in an optical axis direction and by a predetermined amount and which is provided by light passed through an opening of said stop member and projected or to be projected at a predetermined position on the exposure plane; and
calculating means for calculating an angular characteristic of light projected or to be projected on the exposure plane, on the basis of integrating illuminance distributions which are defined by lights incident at plural positions along a scan direction upon the exposure plane and which are measured by said measuring means.
2. An apparatus according to claim 1, wherein said measuring means is adapted to measure the illuminance distributions, defined by the lights incident on the plural positions, independently of each other.
3. An apparatus according to claim 1, wherein the opening of said stop member has a variable shape, and wherein, for the measurement with said measuring means, the shape of the opening is made into a hole-like shape.
4. An apparatus according to claim 1, wherein the opening of said stop member has a slit-like shape being elongated in the scan direction.
5. An apparatus according to claim 1, wherein the opening of said stop member has a variable shape, and wherein, for the measurement with said measuring means, the shape of the opening is made into a slit-like shape being elongated in the scan direction.
6. An apparatus according to claim 1, wherein said measuring means includes a detector for detecting intensity of light, and wherein said detector is movable in a direction perpendicular to an optical axis to measure the illuminance distribution.
7. An apparatus according to claim 1, wherein said measuring means includes a sensor array which is movable in a direction perpendicular to an optical axis to measure the illuminance distribution.
8. An apparatus according to claim 1, wherein said measuring means includes a two-dimensional sensor array.
9. A scan type exposure apparatus for exposing a substrate, placed on an exposure plane, to a pattern of a mask with light from a light source, said apparatus comprising:
a stop member having a slit-like opening elongated in a scan direction, for restricting an exposure range on the exposure plane;
a two-dimensional sensor array disposed at a position corresponding to a Fourier transform plane with respect to the exposure plane; and
a detector for detecting an intensity distribution, on the Fourier transform plane, of light passed through the slit-like opening of said stop member.
10. A device manufacturing method, comprising the steps of: exposing a substrate by use of an exposure apparatus as recited in claim 1; and developing the exposed substrate.
11. A device manufacturing method, comprising the steps of: exposing a substrate by use of an exposure apparatus as recited in claim 9; and developing the exposed substrate.
12. An apparatus according to claim 9, wherein the opening of said stop member has a variable shape, and wherein, for the detection with said detector, the shape of the opening is made into the slit-like shape.