Imaging optical lens system, image capturing unit and electronic device

An imaging optical lens system comprising seven lens elements, the seven lens elements being, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element;

• each of the seven lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side, the image-side surface of the second lens element being convex in a paraxial region thereof, the third lens element having negative refractive power, the object-side surface of the fifth lens element being concave in a paraxial region thereof, and the object-side surface of the seventh lens element being convex in a paraxial region thereof;
• wherein at least one surface among the object-side surfaces and the image-side surfaces of the seven lens elements has at least one critical point in an off-axis region thereof, an Abbe number of the first lens element is V1, an Abbe number of the fourth lens element is V4, a focal length of the third lens element is f3, a focal length of the fifth lens element is f5, and the following conditions are satisfied:
• 1.10<V1/V4<6.50;
• and
• |f5/f3|<0.80.

An imaging optical lens system comprising seven lens elements, the seven lens elements being, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element;

• each of the seven lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side, the image-side surface of the second lens element being convex in a paraxial region thereof, the object-side surface of the fifth lens element being concave in a paraxial region thereof, and the object-side surface of the seventh lens element being convex in a paraxial region thereof;
• wherein at least one surface among the object-side surfaces and the image-side surfaces of the seven lens elements has at least one critical point in an off-axis region thereof, a curvature radius of the object-side surface of the second lens element is R3, a curvature radius of the image-side surface of the second lens element is R4, a curvature radius of the object-side surface of the fifth lens element is R9, a curvature radius of the image-side surface of the fifth lens element is R10, and the following conditions are satisfied:
• −0.50<(R3+R4)/(R3−R4);
• and
• 1.85<|R9/R10|.