Eyepiece optical system, wide-field image display device

An eyepiece optical system disposed between an eye point of a wide-field image display device and an image display element, comprising:

• a first lens with a convex lens surface on the image display element side and positive refractive power, a second lens with a concave lens surface on the image display element side, and a third lens with a convex lens surface on the eye point side, arranged in order from the eye point side;
• a first film which is adhered to the lens surface on the eye point side of the second lens and changes the polarization state of light traveling from the image display element side to the eye point side to a first polarization state, and
• a second film which is adhered to the lens surface on the eye point side of the first lens, reflects light in the first polarization state traveling from the image display element side to the eye point side and changes said light to a second polarization state, and transmits light in the second polarization state traveling from the image display element side to the eye point side, wherein a half mirror is coated on the lens surface on the image display element side of the first lens, and the following conditional expressions are satisfied,
• 0
• .
• 8
• ×
• P
• ⁢
• 0
• <
• (
• 2
• ×
• N
• ⁢
• 1
• /
• L
• ⁢
• 1
• ⁢
• e
• )
• +
• (
• 2
• ×
• N
• ⁢
• 1
• /
• L
• ⁢
• 1
• ⁢
• r
• )
• <
• 1
• .
• 2
• ×
• P
• ⁢
• 0
• ,
• v
• ⁢
• 2
• <
• v
• ⁢
• 3
• ,
• where,
• P0:
• refractive power of the eyepiece optical system (unit:
• mm−1),
• N1:
• refractive index of the first lens for light with a wavelength of 525 nm,
• L1e:
• radius of curvature of the lens surface on the eye point side of the first lens (unit:
• mm),
• L1r:
• radius of curvature of the lens surface on the image display element side of the first lens (unit:
• mm),
• ν2:
• Abbe number for the d-line (wavelength 587.6 nm) of the second lens,
• ν3:
• Abbe number for the d-line (wavelength 587.6 nm) of the third lens.