1. A lighting system comprising:
a first light source for analyzing a sample of interest, light from the first light source defining a first optical path that is incident on the sample of interest; and
a second light source operating with the first light source for determining a position of the first optical path relative to the sample of interest.
2. The system of claim 1, wherein the angle of incidence of said first optical path with respect to the sample causes total internal reflection at the sample of light produced by said first light source.
3. The system of claim 2, further comprising a microscope having a total internal reflection objective positioned so as to observe the sample.
4. The system of claim 1, wherein said first light source is a fluorescent light source.
5. The system of claim 1, wherein the first light source and the second light source operate simultaneously.
6. The system of claim 1, wherein light from the second light source defines a second optical path at least partially coaxial with the first optical path.
7. The system of claim 1, wherein light from the second light source is directed to a position sensor for sensing an angle of incidence of the first optical path relative to the sample of interest.
8. The system of claim 7, wherein the position of the first optical path is adjusted to vary the angle of incidence at the sample of interest in response to a signal from the position sensor.
9. The system of claim 8, wherein the position of the first optical path is adjusted to obtain substantially total internal reflection of light from the first light source incident at the sample of interest.
10. The system of claim 1, wherein the first light source comprises a wavelength from about 390 nm to about 1550 nm.
11. The system of claim 1, wherein the second light source comprises infrared light.
12. The system of claim 1, wherein at least one of the first light source and the second light source is selected from the group consisting of a laser, a light emitting diode, and a lamp.
13. The system of claim 1, further comprising an imaging device for imaging the sample of interest.
14. The system of claim 1, further comprising a third light source for analyzing the sample of interest, light from the third light source defining a third optical path at least partially coaxial with the first optical path.
15. The system of claim 14, wherein the first light source and the third light source are operated simultaneously.
16. The system of claim 1, wherein the second light source continuously monitors the position of the first optical path.
17. The system of claim 1, adapted for use to detect a single molecule fluorescent event.
18. A method of substantially maintaining the relative orientation or a light source and sample of interest in a light-based microscope, the method comprising the steps of:
providing a first beam of light for intersecting with the sample of interest;
providing a second beam of light for determining a position of the first beam of light on the sample of interest;
directing the second beam of light onto a position sensor;
adjusting the relative orientation of the first beam of light and the sample of interest in response to a signal from the position sensor to vary an angle of incidence of the first beam of light with respect to the sample of interest to substantially maintain total internal reflection.
19. The method of claim 18, wherein the first beam of light is at least partially coaxial with the second beam of light.
20. The method of claim 18, further comprising the steps of continuously monitoring the orientation of the first beam of light and adjusting the relative angle of the first beam of light and the sample of interest in response thereto to substantially maintain total internal reflection
21. The method of claim 18, wherein the first beam detects a position of a molecule of interest.
22. The method of claim 18, wherein the first light source comprises a wavelength from about 390 nm to about 1550 nm.
23. The method of claim 18, wherein the second light source comprises an infrared light source.
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 vehicle steering apparatus comprising:
a driving state detecting device for detecting a driving state of the vehicle;
a wheel adjusting device for adjusting separately the wheel angles of left and right wheels;
a judgment portion for determineing whether vehicle braking is to be permitted or not based on the driving state of the vehicle; and
a control portion controlling the wheel adjusting device,
wherein, in the case that vehicle braking is permitted by the judgment portion, the control portion sets the wheel angles of the left and right wheels to be in opposite phase and adjusts the wheel angles in accordance with the braking force to be applied to the left and right wheels.
2. The vehicle steering apparatus according to claim 1, wherein the control portion sets the wheel angles to be larger than the current value if the current braking force to be applied is larger than the previous braking force, and sets the wheel angles to be smaller than the current value if the current braking force to be applied is smaller than the previous braking force.
3. The vehicle steering apparatus according to claim 1, further comprising:
a detecting portion which detects the deceleration of the vehicle,
wherein the control portion estimates the braking force based on the deceleration of the vehicle.
4. The vehicle steering apparatus according to claim 1, further comprising:
a detecting portion which directly detects the longitudinal force and lateral force acting on the wheels,
wherein the control portion estimates the braking force based on the size of the circle of friction of the wheels calculated from the longitudinal force and lateral force.
5. The vehicle steering apparatus according to claim, further comprising:
a detecting portion which directly detects the longitudinal force and lateral force acting on the wheels,
wherein the control portion estimates the braking force based on the longitudinal force, lateral force and angle of wheels.
6. The vehicle steering apparatus according to any one of claim 1, wherein the control portion defines the angle of wheels so that the left and right wheels are in a toe-in orientation.
7. A vehicle steering method comprising:
a first step of determining whether vehicle braking is to be permitted or not based on a driving state of the vehicle; and
a second step of controlling the wheel angles of left and right wheels,
wherein, in the case that the vehicle braking is permitted, the second step sets the wheel angles of the left and right wheels to be in opposite phase and adjusts the wheel angles in accordance with the braking force to be applied to the left and right wheels.
8. The vehicle steering method according to claim 7, wherein the second step sets the wheel angles to be larger than the current angles if the current braking force to be applied is larger than the previous braking force and sets the wheel angles to be smaller than the current value if the current braking force to be applied is smaller than the previous braking force.