Imaging lens having four lens elements, and electronic apparatus having the same

An imaging lens comprising a first lens element, a second lens element, a third lens element, and a fourth lens element arranged from an object side to an image side in the given order, each of the first, second, third, and fourth lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

• the image-side surface of the first lens element comprises a concave portion in a vicinity of an optical axis of the imaging lens;
• the second lens element has negative refractive power;
• the object-side surface of the third lens element comprises a concave portion in a vicinity of the optical axis;
• the object-side surface of the fourth lens element comprises a convex portion in a vicinity of the optical axis;
• and
• the imaging lens does not include any lens element with refractive power other than the first, second, third, and fourth lens elements,
• wherein the imaging lens satisfies 1.900≤ALT/(G34+T4)≤2.614, where ALT represents a sum of thicknesses of all four lens elements along the optical axis, G34 represents a distance between the image-side surface of the third lens element and the object-side surface of the fourth lens element at the optical axis, and T4 represents a distance between the object-side surface and the image-side surface of the fourth lens element at the optical axis.

An imaging lens comprising a first lens element, a second lens element, a third lens element, and a fourth lens element arranged from an object side to an image side in the given order, each of the first, second, third, and fourth lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein:

• the image-side surface of the first lens element comprises a concave portion in a vicinity of an optical axis of the imaging lens;
• the object-side surface of the third lens element comprises a concave portion in a vicinity of the optical axis;
• the fourth lens element has positive refractive power;
• the object-side surface of the fourth lens element comprises a convex portion in a vicinity of the optical axis;
• and
• the imaging lens does not include any lens element with refractive power other than the first, second, third, and fourth lens elements, wherein the imaging lens satisfies 1.900≤ALT/(G34+T4)≤2.614, where ALT represents a sum of thicknesses of all four lens elements along the optical axis, G34 represents a distance between the image-side surface of the third lens element and the object-side surface of the fourth lens element at the optical axis, and T4 represents a distance between the object-side surface and the image-side surface of the fourth lens element at the optical axis.