Image pickup system
An image pickup system includes an image pickup apparatus mounted on a movable body. The image pickup apparatus includes an optical system and an image sensor configured to image an object via the optical system. An imaging surface of the image sensor has a first area for imaging an object included in a first angle of view, and a second area for imaging an object included in a second angle of view larger than the first angle of view. The number of pixels per unit angle of view in the second area is larger than the number of pixels per unit angle of view in the first area. In a case where the movable body moves in a horizontal direction, the image pickup apparatus is installed so that an optical axis of the optical system is nonparallel to the horizontal direction. Predetermined inequalities are satisfied.
1. An image pickup system comprising an image pickup apparatus mounted on a movable body,
wherein the image pickup apparatus includes an optical system and an image sensor configured to image an object via the optical system,
wherein an imaging surface of the image sensor has a first area for imaging an object included in a first angle of view, and a second area for imaging an object included in a second angle of view larger than the first angle of view,
wherein the number of pixels per unit angle of view in the second area is larger than the number of pixels per unit angle of view in the first area,
wherein in a case where the movable body moves in a horizontal direction, the image pickup apparatus is installed so that an optical axis of the optical system is nonparallel to the horizontal direction, and
wherein the optical system satisfies the following inequalities:
55°≤θmax
20%<| d θmax|
where θmax is a maximum half angle of view, and dθmax is a distortion amount at a position corresponding to a maximum image height of the optical system.
2. The image pickup system according to claim 1 , wherein in a case where the movable body moves in the horizontal direction, the image pickup apparatus is installed so that the optical axis is parallel to a vertical direction when viewed from the moving direction of the movable body.
3. The image pickup system according to claim 1 , wherein in a case where the movable body moves in the horizontal direction, the image pickup apparatus is installed so that the optical axis is tilted toward a side away from the movable body relative to a vertical direction when viewed from the moving direction of the movable body.
4. The image pickup system according to claim 1 , wherein in a case where the movable body moves in the horizontal direction, the image pickup apparatus is installed so as to image an object on a lower side in a vertical direction relative to the optical system.
5. The image pickup system according to claim 1 , wherein when viewed from the horizontal direction as a first direction, the optical system satisfies the following inequality:
0°≤θ L≤ 20°
where θL is an angle between the optical axis and a vertical direction as a second direction.
6. The image pickup system according to claim 1 , wherein the optical system is disposed so that the optical axis is shifted toward a side away from the movable body in a third direction orthogonal to the first and second directions with respect to a center of the imaging surface.
7. The image pickup system according to claim 6 , wherein the optical system satisfies the following inequality:
0.3 Ls≤La≤ 0.5 Ls
where La is a shift amount of the optical axis from the center of the imaging surface, and Ls is a length of a side of the imaging surface extending in a direction from the center of the imaging surface toward the optical axis.
8. The image pickup system according to claim 6 , wherein in a case where the movable body moves in the horizontal direction, when viewed from a moving direction of the movable body, the optical system satisfies the following inequality:
0.3 Ls≤La+yα≤ 0.5 Ls
where α is an angle between the optical axis and a first straight line connecting an intersection of a surface closest to an object of the optical system and the optical axis, and an endpoint of the movable body in a vertical direction, yα is a distance from an intersection of the first straight line and the imaging surface to the optical axis, La is a shift amount of the optical axis from the center of the imaging surface, and Ls is a length of a side of the imaging surface extending in a direction from the center of the imaging surface toward the optical axis.
9. The image pickup system according to claim 1 , wherein in a case where the movable body moves in the horizontal direction, when viewed from a direction orthogonal to a moving direction of the movable body and a vertical direction, the optical system satisfies the following inequality:
θmax<θ f≤ 1.3θmax
where θf is an angle formed between the optical axis and a straight line connecting an intersection of a surface closest to an object of the optical system and the optical axis, and an endpoint of a front wheel of the movable body in the moving direction in the second angle of view.
10. The image pickup system according to claim 1 , wherein in a case where the movable body moves in the horizontal direction, when viewed from a third direction orthogonal to a moving direction of the movable body and a vertical direction, the optical system satisfies the following inequality:
0.5 Lh<Lf≤ 0.65 Lh
where Lf is a distance between an image point at an endpoint image point of a front wheel of the movable body in the moving direction at the second angle of view and a center of the imaging surface, and Lh is a length of a side of the imaging surface extending in a direction from the center of the imaging surface toward the image point.
11. The image pickup system according to claim 1 , further comprising a display unit configured to display image data generated using an output from the image sensor.
12. The image pickup system according to claim 1 , further comprising a processing unit configured to process image information acquired by the image pickup apparatus.
13. The image pickup system according to claim 12 , further comprising a determining unit configured to determine whether a dangerous event is likely based on distance information to the object acquired by the image pickup apparatus.
14. The image pickup system according to claim 13 , further comprising a control apparatus configured to control the movable body in a case where it is determined that the dangerous event is likely.
15. The image pickup system according to claim 13 , further comprising a warning apparatus configured to issue a warning to a user of the movable body in a case where it is determined that the dangerous event is likely.
16. The image pickup system according to claim 13 , further comprising a notifying apparatus configured to notify outside of information about the dangerous event.
17. A movable body comprising the image pickup system according to claim 1 .