Optical lens assembly and electronic device

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

• a first lens, having a negative refractive power, an object-side surface of the first lens being a concave surface;
• a second lens, having a positive refractive power, an object-side surface of the second lens being a convex surface, and an image-side surface of the second lens being a concave surface;
• a third lens, having a positive refractive power, an object-side surface of the third lens being a convex surface, and an image-side surface of the third lens being a convex surface;
• a fourth lens, having a positive refractive power, an object-side surface of the fourth lens being a convex surface;
• a fifth lens, having a negative refractive power, an image-side surface of the fifth lens being a concave surface;
• a sixth lens, having a refractive power;
• and
• a seventh lens, having a negative refractive power,
• wherein a number of lenses having refractive powers in the optical lens assembly is seven, and the fourth lens and the fifth lens are cemented,
• wherein the optical lens assembly satisfies:
• (N6−N4)/(N5−N4)≤2, N4 is a refractive index of the fourth lens, N5 is a refractive index of the fifth lens, and N6 is a refractive index of the sixth lens.

An electronic device, comprising:

• an optical lens assembly;
• and
• an imaging element used to convert an optical image formed by the optical lens assembly into an electrical signal,
• wherein the optical lens assembly comprises, sequentially along an optical axis from an object side to an image side:
• a first lens, having a negative refractive power, an object-side surface of the first lens being a concave surface;
• a second lens, having a positive refractive power, an object-side surface of the second lens being a convex surface;
• a third lens, having a positive refractive power, an object-side surface of the third lens being a convex surface, and an image-side surface of the third lens being a convex surface;
• a fourth lens, having a positive refractive power, an object-side surface of the fourth lens being a convex surface;
• a fifth lens, having a negative refractive power, an image-side surface of the fifth lens being a concave surface;
• a sixth lens, having a refractive power;
• and
• a seventh lens, having a negative refractive power,
• wherein a number of lenses having refractive powers in the optical lens assembly is seven, and the optical lens assembly satisfies:
• (N6−N4)/(N5−N4)≤2, and
• 1≤dn/dm≤2,
• wherein N4 is a refractive index of the fourth lens, N5 is a refractive index of the fifth lens, N6 is a refractive index of the sixth lens, dn is a maximal center thickness in a center thickness of the second lens, a center thickness of the third lens, and a sum of center thicknesses of the fourth lens and the fifth lens, and dm is a minimal center thickness in the center thickness of the second lens, the center thickness of the third lens, and the sum of the center thicknesses of the fourth lens and the fifth lens.