Single-focal lens system, imaging device having single-focal lens system, and moving body having imaging device

An imaging device capable of outputting an optical image of an object as an electrical image signal, the imaging device consisting of:

• a single-focal lens system that forms the optical image of the object;
• and
• an imaging element that converts the optical image formed by the single-focal lens system into the electrical image signal,
• wherein the single-focal lens system consists of, in order from an object side to an image side,
• a first lens group having positive power,
• an aperture diaphragm, and
• a second lens group having positive power,
• the first lens group consists of
• a first lens element having negative power,
• a second lens element having negative power, and
• a third lens element having positive power,
• the second lens group consists of
• a fourth lens element having power, and
• a fifth lens element having positive power, and
• a condition (1), a condition (3c) and a condition (6) shown below are satisfied,
• 0.5<fG1/fG2<3.0 (1)
• 11.5<|f4/f| (3c)
• 60<w (6)
• when fG1 is a focal length of the first lens group at a d-line, fG2 is a focal length of the second lens group at the d-line, f4 is a focal length of the fourth lens element at the d-line, f is a focal length of an entire system at the d-line, and w is a half angle of view.

A moving body that converts an optical image of an object into an electrical image signal and performs at least one of display and record of the electrical image signal being converted, the moving body consisting of:

• a single-focal lens system that forms the optical image of the object;
• an imaging element that converts the optical image formed by the single-focal lens system into the electrical image signal;
• and
• a controller that controls the imaging element,
• wherein the single-focal lens system consists of, in order from an object side to an image side,
• a first lens group having positive power,
• an aperture diaphragm, and
• a second lens group having positive power,
• the first lens group consists of
• a first lens element having negative power,
• a second lens element having negative power, and
• a third lens element having positive power,
• the second lens group consists of
• a fourth lens element having power, and
• a fifth lens element having positive power, and
• a condition (1), a condition (3c) and a condition (6) shown below are satisfied,
• 0.5<fG1/fG2<3.0 (1)
• 11.5<|f4/f| (3c)
• 60<w (6)
• when fG1 is a focal length of the first lens group at a d-line, fG2 is a focal length of the second lens group at the d-line, f4 is a focal length of the fourth lens element at the d-line, f is a focal length of an entire system at the d-line, and w is a half angle of view.