RELATED APPLICATIONS

This application claims priority to Taiwan Application 108132276, filed on Sep. 6, 2019, which is incorporated by reference herein in its entirety.

BACKGROUND

Technical Field

The present disclosure relates to a photographing optical lens system, an image capturing unit and an electronic device, more particularly to a photographing optical lens system and an image capturing unit applicable to an electronic device.

Description of Related Art

With the development of semiconductor manufacturing technology, the performance of image sensors has been improved, and the pixel size thereof has been scaled down. Therefore, featuring high image quality becomes one of the indispensable features of an optical system nowadays.

Furthermore, due to the rapid changes in technology, electronic devices equipped with optical systems are trending towards multi-functionality for various applications, and therefore the functionality requirements for the optical systems have been increasing. However, it is difficult for a conventional optical system to obtain a balance among the requirements such as high image quality, low sensitivity, a proper aperture size, miniaturization and a desirable field of view.

SUMMARY

According to one aspect of the present disclosure, a photographing optical lens system includes six lens elements. The six lens elements are, 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 and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side.

The first lens element has positive refractive power. The second lens element has negative refractive power. The image-side surface of the fifth lens element is concave in a paraxial region thereof. The sixth lens element has negative refractive power. At least one lens surface of at least one lens element of the photographing optical lens system has at least one critical point in an off-axis region thereof.

When an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fifth lens element is CT5, a central thickness of the sixth lens element is CT6, an axial distance between the second lens element and the third lens element is T23, an axial distance between the fifth lens element and the sixth lens element is T56, and half of a maximum field of view of the photographing optical lens system is HFOV, the following conditions are satisfied:
30.0<V2+V3+V4<90.0;
1.00<CT1/(CT2+T23+CT3);
30.0 [deg.]<HFOV; and
(CT5+CT6)/T56<10.0.

According to another aspect of the present disclosure, a photographing optical lens system includes six lens elements. The six lens elements are, 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 and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side.

The first lens element has positive refractive power, and the image-side surface of the first lens element is convex in a paraxial region thereof. The second lens element has negative refractive power. The sixth lens element has negative refractive power. At least one lens surface of at least one lens element of the photographing optical lens system has at least one critical point in an off-axis region thereof.

When an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, an axial distance between the second lens element and the third lens element is T23, and half of a maximum field of view of the photographing optical lens system is HFOV, the following conditions are satisfied:
30.0<V2+V3+V4<90.0;
1.00<CT1/(CT2+T23+CT3);
30.0 [deg.]<HFOV; and
CT5/CT4<1.80.

According to another aspect of the present disclosure, a photographing optical lens system includes six lens elements. The six lens elements are, 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 and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side.

The first lens element has positive refractive power. The second lens element has negative refractive power. The sixth lens element has negative refractive power. At least one lens surface of at least one lens element of the photographing optical lens system has at least one critical point in an off-axis region thereof.

When an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, an axial distance between the second lens element and the third lens element is T23, and half of a maximum field of view of the photographing optical lens system is HFOV, the following conditions are satisfied:
30.0<V2+V3+V4<90.0;
1.00<CT1/(CT2+T23+CT3);
35.0 [deg.]<HFOV; and
CT5/CT4<1.35.

According to another aspect of the present disclosure, an image capturing unit includes one of the aforementioned photographing optical lens systems and an image sensor, wherein the image sensor is disposed on an image surface of the photographing optical lens system.

According to another aspect of the present disclosure, an electronic device includes the aforementioned image capturing unit.

