Imaging lens system, image capturing unit and electronic device

An imaging lens system comprising six lens elements, the six lens elements being, in order from an object side to an image side:

• a first lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof;
• a second lens element with negative refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof;
• a third lens element with positive refractive power having an image-side surface being convex in a paraxial region thereof;
• a fourth lens element having positive refractive power;
• a fifth lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof;
• and
• a sixth lens element having positive refractive power;
• wherein the imaging lens system further comprises an aperture stop disposed between the third lens element and the fourth lens element, and at least one of the six lens elements of the imaging lens system has an Abbe number smaller than or equal to 22;
• wherein an axial distance between an object-side surface of the first lens element and an image surface is TL, a maximum image height of the imaging lens system is ImgH, an f-number of the imaging lens system is Fno, a central thickness of the second lens element is CT2, a central thickness of the fourth lens element is CT4, a curvature radius of an object-side surface of the third lens element is R5, a curvature radius of the image-side surface of the third lens element is R6, a refractive power of the first lens element is P1, a refractive power of the second lens element is P2, a refractive power of the third lens element is P3, a refractive power of the fourth lens element is P4, a refractive power of the fifth lens element is P5, a refractive power of the sixth lens element is P6, a refractive power of the i-th lens element is Pi, and the following conditions are satisfied:
• 1.0<TL/ImgH<5.70;
• 0.70<Fno<2.70;
• CT4/CT2<4.80;
• −1.0<(R5+R6)/(R5−R6)<1.80;
• and
• 3.0<ΣPi|, wherein i=1, 2, 3, 4, 5, 6.

An imaging lens system comprising six lens elements, the six lens elements being, in order from an object side to an image side:

• a first lens element having negative refractive power;
• a second lens element with negative refractive power having an object-side surface being concave in a paraxial region thereof;
• a third lens element;
• a fourth lens element;
• a fifth lens element;
• and
• a sixth lens element having positive refractive power;
• wherein the imaging lens system further comprises an aperture stop disposed between the third lens element and the fourth lens element, a central thickness of the first lens element is CT1, a central thickness of the third lens element is CT3, an Abbe number of the second lens element is V2, an axial distance between the aperture stop and an object-side surface of the third lens element is Dsr5, an axial distance between the aperture stop and an image-side surface of the third lens element is Dsr6, an axial distance between an object-side surface of the first lens element and an image surface is TL, a maximum image height of the imaging lens system is ImgH, and the following conditions are satisfied:
• CT1/CT3<0.80;
• 10.0<V2<25.0;
• |Dsr6/Dsr5|<1.0;
• and
• 1.0<TL/ImgH<5.70.