Imaging lens system, image capturing device and electronic device

An imaging lens system, comprising, in order from an object side to an image side:

• a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof;
• a second lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof;
• a third lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, an object-side surface and the image-side surface thereof being aspheric, the image-side surface having at least one inflection point in an off-axis region thereof;
• a fourth lens element with positive refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, the object-side surface and the image-side surface thereof being aspheric;
• and
• a fifth 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, the object-side surface and the image-side surface thereof being aspheric, the image-side surface having at least one convex shape in an off-axis region thereof;
• wherein the imaging lens system has a total of five lens element with refractive power and an air gap is arranged between every two adjacent lens elements with refractive power;
• wherein an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, a curvature radius of the object-side surface of the second lens element is R3, a focal length of the imaging lens system is f, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, a central thickness of the fourth lens element is CT4, and the following conditions are satisfied:
• |V2−V3|<10;
• |R3|/f<4.0;
• and
• 0.85<(T34+T45)/CT4.