Ocular optical system

An ocular optical system, for imaging of imaging rays entering an eye of an observer via the ocular optical system from a display screen, a side facing towards the eye being an eye-side, a side facing towards the display screen being a display-side, the ocular optical system comprising a first lens element and a second lens element from the eye-side to the display-side in order along an optical axis, the first lens element and the second lens element each comprising an eye-side surface and a display-side surface;

• the eye-side surface of the second lens element having a convex portion in a vicinity of a periphery of the second lens element, and the display-side surface of the second lens element having a concave portion in a vicinity of the optical axis;
• and
• lens elements of the ocular optical system are only the first lens element and the second lens element;
• wherein the ocular optical system satisfies:
• G2D/T2≤16.000;
• and
• 1.500≤|f2/f1|,
• wherein G2D is a distance from the second lens element to the display screen along the optical axis, T2 is a thickness of the second lens element along the optical axis, f2 is a focal length of the second lens element, and f1 is a focal length of the first lens element.

An ocular optical system, for imaging of imaging rays entering an eye of an observer via the ocular optical system from a display screen, a side facing towards the eye being an eye-side, a side facing towards the display screen being a display-side, the ocular optical system comprising a first lens element and a second lens element from the eye-side to the display-side in order along an optical axis, the first lens element and the second lens element each comprising an eye-side surface and a display-side surface;

• the eye-side surface of the first lens element having a convex portion in a vicinity of the optical axis;
• the eye-side surface of the second lens element having a convex portion in a vicinity of a periphery of the second lens element, and the display-side surface of the second lens element having a concave portion in a vicinity of the optical axis;
• and
• lens elements of the ocular optical system are only the first lens element and the second lens element;
• wherein the ocular optical system satisfies:
• G2D/T2≤16.000;
• 2.000≤T2/G12;
• and
• ER/T2≤8.000,
• wherein G2D is a distance from the second lens element to the display screen along the optical axis, T2 is a thickness of the second lens element along the optical axis, G12 is an air gap from the first lens element to the second lens element along the optical axis, and ER is a distance from a pupil of the eye of the observer to the first lens element along the optical axis.