Imaging optical system, imaging apparatus and electronic device

An imaging optical system, comprising three lens elements, the three lens elements, in order from an object side to an image side, being:

• a first lens element having an object-side surface toward the object side and an image-side surface toward the image side;
• a second lens element having an object-side surface toward the object side and an image-side surface toward the image side;
• and
• a third lens element having an object-side surface toward the object side and an image-side surface toward the image side;
• wherein the third lens element has positive refractive power, the imaging optical system has a total of three lens elements, 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, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is TD, a maximum image height of the imaging optical system is ImgH, a focal length of the imaging optical system is f, an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, a half of the maximal field of view is HFOV, and the following conditions are satisfied:
• 1.2<(CT1+CT2+CT3)/(T12+T23);
• 1.6<TD/ImgH<4.5;
• 3.6<f/TD<25;
• 40.0<V1+V2+V3<140.0;
• 3.59≤T23/T12<200;
• and
• 3.2 degrees<HFOV<7.0 degrees.

An imaging optical system, comprising three lens elements, the three lens elements, in order from an object side to an image side, being:

• a first lens element having an object-side surface toward the object side and an image-side surface toward the image side;
• a second lens element having an object-side surface toward the object side and an image-side surface toward the image side;
• and
• a third lens element having an object-side surface toward the object side and an image-side surface toward the image side;
• wherein the second lens element has negative refractive power, the imaging optical system has a total of three lens elements, 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, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is TD, a maximum image height of the imaging optical system is ImgH, a focal length of the imaging optical system is f, an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, a minimum among Abbe numbers of the first lens element, the second lens element and the third lens element is V min, and the following conditions are satisfied:
• 1.2<(CT1+CT2+CT3)/(T12+T23)<4.0;
• 1.0<TD/ImgH<4.5;
• 3.6<f/TD<45;
• 50.0<V1+V2+V3<130.0;
• and
• 10.0<V min<30.0.