Optical imaging lens including six lenses of +-+-+-or +++-+-refractive powers

An optical imaging lens, sequentially comprising, from an object side to an image side along an optical axis:

• a first lens having positive refractive power;
• a second lens having refractive power;
• a third lens having refractive power;
• a fourth lens having negative refractive power, wherein an object-side surface thereof is a concave surface, while an image-side surface is a convex surface;
• a fifth lens having positive refractive power;
• and
• a sixth lens having negative refractive power, wherein an object-side surface thereof is a convex surface;
• and
• TTL is a distance from an object-side surface of the first lens to an imaging surface of the optical imaging lens on the optical axis, ImgH is a half of a diagonal length of an effective pixel region on the imaging surface of the optical imaging lens, TTL and ImgH meet:
• 4.0 mm<ImgH/(TTL/ImgH)<7.0 mm;
• an effective focal length f4 of the fourth lens, an effective focal length f6 of the sixth lens and a total effective focal length f of the optical imaging lens meet:
• 0.6<(f6−f4)/f<2.0;
• an effective focal length f1 of the first lens and an effective focal length f5 of the fifth lens meet:
• 0.7<f1/f5<1.2;
• a curvature radius R7 of the object-side surface of the fourth lens and a curvature radius R8 of the image-side surface of the fourth lens meet:
• 0.4<R7/R8<0.7;
• a maximum effective radius DT11 of the object-side surface of the first lens, a maximum effective radius DT12 of an image-side surface of the first lens and a maximum effective radius DT62 of an image-side surface of the sixth lens meet:
• 1.3<DT62/(DT11+DT12)<1.7;
• a combined focal length f123 of the first lens, the second lens and the third lens and a total effective focal length f of the optical imaging lens meet:
• 0.7<f123/f<1.0;
• 1.5<SAG62/SAG32<3.4,
• wherein SAG32 is an on-axis distance from an intersection point of an image-side surface of the third lens and the optical axis to an effective radius vertex of the image-side surface of the third lens, and SAG62 is an on-axis distance from an intersection point of an image-side surface of the sixth lens and the optical axis to an effective radius vertex of the image-side surface of the sixth lens.