Imaging optical system, projection type display device, and imaging apparatus

An imaging optical system in which a magnification side imaging surface and a reduction side imaging surface are conjugate,

• wherein the imaging optical system forms a first intermediate image at a position conjugate to the magnification side imaging surface and a second intermediate image at a position closer to a reduction side than the first intermediate image on an optical path and conjugate to the first intermediate image,
• wherein the imaging optical system is configured to be telecentric on the reduction side,
• wherein the imaging optical system consists of a first optical system, a second optical system, and a third optical system in order from a magnification side to the reduction side along the optical path,
• wherein magnification side surfaces of all lenses of the first optical system are located on the optical path to be closer to the magnification side than the first intermediate image,
• wherein magnification side surfaces of all lenses of the second optical system are located on the optical path to be closer to the reduction side than the first intermediate image and to be closer to the magnification side than the second intermediate image,
• wherein magnification side surfaces of all lenses of the third optical system are located on the optical path to be closer to the reduction side than the second intermediate image,
• wherein in a case where a maximum image height on the reduction side imaging surface is Ymax and a ray is incident from the reduction side imaging surface to the imaging optical system at a height of Ymax from the optical axis in parallel with an optical axis, assuming that
• an air gap in which the first intermediate image is located is a first air gap in a case where the first intermediate image is located inside the air gap, and an air gap which is adjacent to the magnification side of a lens in which the first intermediate image is located is the first air gap in a case where the first intermediate image is located inside the lens,
• an angle formed between a first extension line obtained by extending the ray in the first air gap and the optical axis is θ, and
• a sign of θ is negative in a case where a first intersection point, which is an intersection point between the first extension line and the optical axis, is located to be closer to the magnification side than the first intermediate image, and the sign of θ is positive in a case where the first intersection point is located to be closer to the reduction side than the first intermediate image, where a unit of θ is degrees,
• Conditional Expression (1) is satisfied, which is represented by
• −15<θ<13 (1), and
• wherein assuming that a focal length of the imaging optical system is f, Conditional Expression (2) is satisfied, which is represented by
• 2.15<|Y max/f|<5 (2).