摘要 |
Provided is an image pickup apparatus including, in order from an object side: a first lens unit; a stop; a second lens unit having a positive refractive power; and an image pickup element. The second lens unit includes a second lens sub-unit including only at least one positive lens. A refractive index (N2a) at a d-line of every lens included in the second lens sub-unit, an Abbe constant (ν2a) and a partial dispersion ratio (θ2a) of the every lens, a temperature-related relative refractive index change (dn2a/dTrelative) at the d-line, a focal length (f) of the overall system, a focal length (f2a) of the second lens sub-unit, an overall length (TD) of an image pickup lens, and a distance (BF) from an image-side surface of a lens arranged closest to an image side in the image pickup lens to an image plane of the image pickup element satisfy predetermined relationships. |
主权项 |
1. An image pickup apparatus, comprising:
an image pickup lens; and an image pickup element,
the image pickup lens comprising in order from an object side to an image side:
a first lens unit;a stop; anda second lens unit having a positive refractive power,
the second lens unit comprising a second lens sub-unit including only at least one positive lens, wherein the following conditions are satisfied:
62<ν2a; N2a<1.63;0.605−(ν2a/1000)<θ2a; anddn2a/dTrelative<−2.4×10−6, where N2a represents a refractive index at a d-line of every lens included in the second lens sub-unit, ν2a represents an Abbe constant of the every lens, θ2a represents a partial dispersion ratio of the every lens, and dn2a/dTrelative represents a temperature-related relative refractive index change at the d-line, and wherein the following conditions are satisfied:
0.20<f/f2a<0.80; and3.00<TD/BF<6.50, where f represents a focal length of the image pickup lens, f2a represents a focal length of the second lens sub-unit, TD represents an overall length of the image pickup lens, and BF represents a distance from an image-side surface of a lens arranged closest to an image side in the image pickup lens to an image plane of the image pickup element. |