| CPC G02B 13/0045 (2013.01) [G02B 9/64 (2013.01)] | 15 Claims |
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1. An optical imaging system, comprising:
a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having negative refractive power, a fifth lens having positive refractive power, a sixth lens having a concave image-side surface in a paraxial region, and a seventh lens having a negative refractive power, sequentially arranged from an object side,
wherein the optical imaging system includes a total of seven lenses,
wherein the optical imaging system satisfies f3/f>1.5 and −2.0<f2/f3<0.0, where a focal length of the second lens is f2, a focal length of the third lens is f3, and an overall focal length of the optical imaging system is f,
wherein Fno<1.9, where an F-number of the optical imaging system is Fno,
wherein v1−v3<25, where an Abbe number of the first lens is v1, and an Abbe number of the third lens is v3,
wherein TTL/(2*Img HT)<0.7, where a distance on an optical axis from an object-side surface of the first lens to an imaging plane of an image sensor is TTL, and half of a diagonal length of the imaging plane of the image sensor is Img HT, and
wherein a refractive index of the second lens is 1.66 or greater and a refractive index of the fourth lens is 1.66 or greater.
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