1. An electric power steering apparatus comprising:
an operating member which is operated by a driver to steer a vehicle;
a torque detector for detecting a torque generated by a steering system of the vehicle;
a vehicle speed detector for detecting a vehicle speed of the vehicle;
a motor for applying an assistive torque to a rotational shaft of the steering system;
a rotational angle detector for detecting a rotational angle of the steering system; and
a motor controller for controlling an electric current for energizing the motor based on the torque detected by the torque detector,
wherein the electric power steering apparatus also includes:
an abnormality detector for detecting whether the torque detector becomes abnormal or not; and
a storage unit storing, as a characteristic, a relationship between the rotational angle detected by the rotational angle detector and the electric current for energizing the motor;
wherein when the abnormality detector detects an abnormality of the torque detector, the motor controller energizes the motor based on the rotational angle detected by the rotational angle detector and the characteristic, and when the motor is energized, the motor controller starts a process of reducing an electric current for energizing the motor if the absolute value of a rotational angular velocity calculated based on the rotational angle is equal to or smaller than a prescribed value, and interrupts the process of reducing the electric current for energizing the motor if the absolute value of the rotational angular velocity continues to be equal to or smaller than the prescribed value for a prescribed time.
2. The electric power steering apparatus according to claim 1, wherein after the motor controller has interrupted the process of reducing the electric current for energizing the motor, the motor controller resumes the process of reducing the electric current for energizing the motor if the absolute value of the rotational angle at the time the process of reducing the electric current is interrupted decreases by a prescribed angle or greater.
3. An electric power steering apparatus comprising:
an operating member which is operated by a driver to steer a vehicle;
a torque detector for detecting a torque generated by a steering system of the vehicle;
a vehicle speed detector for detecting a vehicle speed of the vehicle;
a motor for applying an assistive torque to a rotational shaft of the steering system;
a rotational angle detector for detecting a rotational angle of the steering system; and
a motor controller for controlling an electric current for energizing the motor based on the torque detected by the torque detector,
wherein the electric power steering apparatus also includes:
an abnormality detector for detecting whether the torque detector becomes abnormal or not; and
a storage unit storing, as a characteristic, a relationship between the rotational angle detected by the rotational angle detector and the electric current for energizing the motor;
wherein when the abnormality detector detects an abnormality of the torque detector, the motor controller energizes the motor based on the rotational angle detected by the rotational angle detector and the characteristic, and when the motor is energized, the motor controller reduces the electric current for energizing the motor as a rotational angular velocity calculated based on the rotational angle increases; and
the motor controller corrects the rotational angular velocity detected by the rotational angle detector so as to be smaller as the vehicle speed becomes smaller than a prescribed vehicle speed, and energizes the motor based on the corrected rotational angular velocity and the characteristic.
4. (canceled)
5. An electric power steering apparatus comprising:
an operating member which is operated by a driver to steer a vehicle;
a torque detector for detecting a torque generated by a steering system of the vehicle;
a vehicle speed detector for detecting a vehicle speed of the vehicle;
a motor for applying an assistive torque to a rotational shaft of the steering system;
a rotational angle detector for detecting a rotational angle of the steering system; and
a motor controller for controlling an electric current for energizing the motor based on the torque detected by the torque detector,
wherein the electric power steering apparatus also includes:
an abnormality detector for detecting whether the torque detector becomes abnormal or not; and
a storage unit storing, as a characteristic, a relationship between the rotational angle detected by the rotational angle detector and the electric current for energizing the motor;
wherein when the abnormality detector detects an abnormality of the torque detector, the motor controller detects a returning rotational angle using, as a reference angle, the rotational angle detected by the rotational angle detector when a turning assistive electric current becomes nearly zero while a returning angle remains at a time the operating member is returned during which the steering angle of the operating member changes toward a neutral position thereof, and energizes the motor based on the returning rotational angle and the characteristic.
6. The electric power steering apparatus according to claim 5, wherein when the operating member is returned, the energization of the motor is allowed if the vehicle speed is equal to or lower than a prescribed vehicle speed.
7. The electric power steering apparatus according to claim 5, wherein the electric current for energizing the motor at the time the operating member is returned is multiplied by a prescribed coefficient depending on a steerability of the vehicle.
8. The electric power steering apparatus according to claim 5, wherein when the operating member is returned, the electric current for energizing the motor is reduced as the steering angle of the operating member approaches the neutral position.
9. The electric power steering apparatus according to claim 5, wherein when the operating member is returned, the returning rotational angle is reset if the steering angle of the operating member reaches the neutral position.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-10. (canceled)
11. A method of making a diffuser comprising:
coating a mixture of materials on a carrier film, the mixture of materials including at least a first material that polymerizes upon irradiation and at least a second material that phase separates from the at least a first material when the at least a first material polymerizes;
selectively irradiating the mixture of materials to polymerize a portion of the mixture of materials to form polymerized structures; and
removing that part of the mixture of materials not forming part of the structures.
12. The method of claim 11, wherein the irradiation is a UV light.
13. The method of claim 11, wherein the first material includes a photopolymer.
14. The method of claim 11, wherein the second material includes a photopolymer.
15. The method of claim 11, wherein the second material includes a thermopolymer.
16. The method of claim 11, wherein the second material includes a non-polymerizable material.
17. The method of claim 11, wherein the selectively irradiating is performed with a photomask.
18. The method of claim 11, wherein the removing that part of the mixture of materials not forming part of the structures is performed by washing the mixture of materials on the carrier film with a solvent.
19. The method of claim 11, further comprising coating the structures with a transparent material having a refractive index different than a refractive index of the structures.
20. The method of claim 19, wherein the transparent material includes glass beads or polymeric particles.
21. The method of claim 19, wherein the refractive index of the transparent material differs from the refractive index of the structures by at least 0.005 after being selectively irradiated.
22-33. (canceled)
34. The method of claim 11, wherein the mixture of materials is degassed prior to coating on the carrier film.
35. The method of claim 11, wherein the first material is selected from the group consisting of: ethoxylated (3) bisphenol diacrylate, ethoxylated (4) bisphenol diacrylate, trimethylolpropane triacrylate, propoxylated (2) neopentyl glycol diacrylate, 2(2-ethoxyethoxy) ethyl acrylate, epoxy acrylate, or urethane acrylate.
36. The method of claim 11, wherein the second material is selected from the group consisting of: polyethylene glycol (600) diacrylate, ethoxylated (6) trimethylolpropane triacrylate, metallic acrylate oligomer, or polystyrene.
37. The method of claim 15, wherein the thermopolymer is bisphenol A diglycidyl ether.
38. The method of claim 16, wherein the non-polymerizable material is selected from the group consisting of: 4\u2032-pentyl-4-biphenylcarbonitrile, phenyl salicylate, or phenyl benzoate.
39. The method of claim 11, wherein the mixture of materials includes a photoinitiator.
40. The method of claim 39, wherein the photoinitiator is selected from the group consisting of: benzyl dimethyl ketal, 4-methylbenzophenone, trimethyl benzophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-keytone, amine coinitiator, or 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide.
41. The method of claim 11, further comprising, before the step of selectively irradiating the mixture of materials, adding to the mixture of materials a dye or pigment material.
42. The method of claim 14, wherein the second material polymerizes at different rate from that of the first material.
43. The method of claim 14, wherein the second material polymerizes at the same rate as that of the first material.
44. The method of claim 19, wherein the transparent material is chosen from the group consisting of: silicone, fluorinated acrylates, fluorinated methacrylates, fluoro epoxy, fluorosilicones, polysulfone, polyphenylsulfone, or polyethersulfone.
45. A method of making a diffuser comprising:
coating a mixture of materials on a carrier film, the mixture of materials including at least a first material that polymerizes upon irradiation and at least a second material that phase separates from the at least a first material when the at least a first material polymerizes;
selectively irradiating, using a photomask, the mixture of materials to polymerize a portion of the mixture of materials to form polymerized structures;
removing that part of the mixture of materials not forming part of the structures; and
coating the structures with a transparent material having a refractive index different than a refractive index of the structures.
46. The method of claim 45, wherein the transparent material includes glass beads or polymeric particles.