Imaging device, display system, and imaging system
An imaging device includes an image sensor and an optical system. An imaging surface of the image sensor includes a first region including an intersection with an optical axis and a second region different from the first region. The optical system forms a subject image on the imaging surface so as to cause resolution of the first region to be higher than resolution of the second region. A relationship between a vertical view angle and resolution is different from a relationship between a horizontal view angle and resolution in the subject image.
1. An imaging device comprising:
an image sensor that includes an imaging surface on which a plurality of pixels are two-dimensionally arranged at equal intervals and that generates image data from a subject image formed on the imaging surface; and
an optical system that images a subject on the imaging surface, the subject being in a predetermined range of a vertical view angle and in a predetermined range of a horizontal view angle, wherein:
a number of pixels used for capturing the subject image included in a unit view angle is defined as resolution,
the imaging surface includes a first region including an intersection with an optical axis and a second region different from the first region,
the optical system forms the subject image on the imaging surface so as to cause resolution of the first region to be higher than resolution of the second region, and
a relationship between a vertical view angle and resolution is different from a relationship between a horizontal view angle and resolution in the subject image.
2. The imaging device according to claim 1 , wherein the optical system includes a free-form lens.
3. The imaging device according to claim 1 , wherein in a first subject image of the subject image an average of vertical resolution is higher than an average of horizontal resolution, the first subject being formed in the first region.
4. The imaging device according to claim 1 being mounted to rear of a moving body to capture the subject behind the moving body.
5. The imaging device according to claim 4 , wherein the moving body is an automobile, a railway vehicle, a vessel, an airplane, a robot, a robot arm, a drone, an agricultural machine, or a construction machine.
6. The imaging device according to claim 1 , wherein in the optical system, a ratio of the vertical view angle to the horizontal view angle does not correspond to an aspect ratio of the imaging surface.
7. A display system comprising:
the imaging device according to claim 1 ; and
a display that displays an image based on the image data generated by the imaging device.
8. An imaging system comprising:
the imaging device according to claim 1 ; and
a control device that analyzes the image data generated by the imaging device.
9. The imaging device according to claim 1 , wherein
the optical system is configured to form the subject image on the imaging surface so that, (1) when compared with a second optical system having a predetermined vertical view angle with a uniform magnification in the vertical direction and (2) when the optical system maintains the predetermined vertical view angle:
the resolution of the first region in the optical system is larger than in the second optical system; and
the resolution of the second area located at the upper and lower portions of the first area in the optical system is lower than in the second optical system.