Optical imaging lens assembly, image capturing unit and electronic device

1. An optical imaging lens assembly, comprising:

a focus tunable component; and

an imaging lens system comprising, in order from an object side to an image side, a first lens group and a second lens group, wherein the first lens group comprises, in order from the object side to the image side, an object-side first lens element and an object-side second lens element, the second lens group comprises, in order from the image side to the object side, an image-side first lens element and an image-side second lens element, and each of all lens elements in the imaging lens system has an object-side surface facing toward the object side and an image-side surface facing toward the image side;

wherein at least one lens surface of at least one lens element in the imaging lens system is aspheric and has at least one inflection point, the imaging lens system has a total of at least four lens elements, the lens elements of the first lens group are closer to the object side than other lens elements in the imaging lens system, and the lens elements of the second lens group are closer to the image side than other lens elements in the imaging lens system;

wherein an axial distance between the image-side first lens element and the image-side second lens element is DLr1Lr2, a central thickness of the image-side first lens element is CTLr1, a curvature radius of the object-side surface of the image-side second lens element is RLr2f, a curvature radius of the image-side surface of the image-side second lens element is RLr2r, an f-number of the optical imaging lens assembly is Fno, a minimum value among Abbe numbers of all lens elements in the imaging lens system is Vimin, and the following conditions are satisfied:

0.70< DLr 1 Lr 2 /CTLr 5.0;

| RLr 2 f/RLr 2 r|< 4.5; and

0.80< Fno< 3.0; and

10.0 <Vimin <20.0.

2. The optical imaging lens assembly of claim 1 , wherein the axial distance between the image-side first lens element and the image-side second lens element is DLr1Lr2, the central thickness of the image-side first lens element is CTLr1, the curvature radius of the object-side surface of the image-side second lens element is RLr2f, the curvature radius of the image-side surface of the image-side second lens element is RLr2r, and the following conditions are satisfied:

0.80< DLr 1 Lr 2 /CTLr 1<3.0; and

| RLr 2 f/RLr 2 r|< 3.0

3. The optical imaging lens assembly of claim 1 , wherein the f-number of the optical imaging lens assembly is Fno, half of a maximum field of view of the optical imaging lens assembly is HFOV, and the following conditions are satisfied:

1.2< Fno< 2.0; and

35.0[deg.]< HFOV <45.0[deg.].

4. The optical imaging lens assembly of claim 1 , wherein a focal length of the optical imaging lens assembly is f, a focal length of the focus tunable component is ft, a central thickness of the focus tunable component is CTt, and the following conditions are satisfied:

| f/ft |<0.10; and

0.10[mm]< CTt <1.00[mm].

5. The optical imaging lens assembly of claim 1 , wherein the object-side first lens element has positive refractive power, the object-side surface of the object-side first lens element is convex in a paraxial region thereof, the object-side second lens element has negative refractive power, and the image-side surface of the object-side second lens element is concave in a paraxial region thereof.

6. The optical imaging lens assembly of claim 5 , wherein the image-side first lens element has negative refractive power, the image-side surface of the image-side first lens element is concave in a paraxial region thereof, a curvature radius of the image-side surface of the image-side first lens element is RLr1r, a maximum image height of the optical imaging lens assembly is ImgH, and the following condition is satisfied:

RLr 1 r/ImgH <1.0.

7. The optical imaging lens assembly of claim 5 , wherein the image-side surface of the object-side first lens element is concave in a paraxial region thereof, the image-side second lens element has positive refractive power, and at least one lens surface of the image-side second lens element has at least one critical point in an off-axis region thereof.

8. The optical imaging lens assembly of claim 1 , wherein at least one lens surface of at least one lens element of the second lens group is aspheric and has at least one inflection point, a chief ray angle at a maximum image height position of the optical imaging lens assembly is CRA, and the following condition is satisfied:

30.0[deg.]< CRA <45.0[deg.].

9. The optical imaging lens assembly of claim 1 , wherein at least one lens surface of at least one lens element in the imaging lens system has at least one critical point in an off-axis region thereof, an axial distance between an object-side surface of the focus tunable component and an image surface is TL, and the following condition is satisfied:

3.50[mm]< TL <10.00[mm].

10. The optical imaging lens assembly of claim 1 , wherein the focus tunable component is located on the object side of the imaging lens system, the optical imaging lens assembly further comprises an aperture stop, the aperture stop is disposed between the object-side first lens element and an imaged object, an axial distance between the aperture stop and the image-side surface of the image-side first lens element is SDi, an axial distance between the object-side surface of the object-side first lens element and the image-side surface of the image-side first lens element is TDi, and the following condition is satisfied:

0.80 <SDi/TDi <1.0.