An imaging optical system according to the present disclosure includes: an aperture stop; an image-forming optical system that causes an image to be formed toward an imaging plane of an image sensor; and an optical phase modulator that includes a substance having a birefringence index, and gives two pupil functions to the image-forming optical system. The following conditional expressions are satisfied:

1≤(2×L×tan(w)+D)/D<1.4   (1)

λ/4*0.75<Re<λ/4*1.1   (2), where L: a distance between the aperture stop and the optical phase modulator; D: an aperture diameter (diameter) of the aperture stop; w: a maximum angle of incidence of a principal light ray that enters the aperture stop; λ: a wavelength of light; and Re: phase retardation caused by birefringence of the optical phase modulator.

An imaging optical system according to the present disclosure includes: an aperture stop; an image-forming optical system that causes an image to be formed toward an imaging plane of an image sensor; and an optical phase modulator that includes a substance having a birefringence index, and gives two pupil functions to the image-forming optical system. The following conditional expressions are satisfied:

1≤(2×L×tan(w)+D)/D<1.4   (1)

λ/4*0.75<Re<λ/4*1.1   (2), where L: a distance between the aperture stop and the optical phase modulator; D: an aperture diameter (diameter) of the aperture stop; w: a maximum angle of incidence of a principal light ray that enters the aperture stop; λ: a wavelength of light; and Re: phase retardation caused by birefringence of the optical phase modulator.

Embodiments of this application provide a lens group, a camera module, and a terminal device. The lens group includes a first group, a second group, a third group, and a fourth group that are sequentially disposed from an object side to an image side along an optical axis of the lens group. The second group includes a doublet formed by gluing a second lens and a third lens together. The optical power of a lens in each group is designed to match the optical power of the doublet so that a compact high-quality long-focus lens group can be implemented and chromatic aberration may be eliminated.

The present invention discloses a camera optical lens including, from an object side to an image side in sequence, a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, and a fifth lens having a refractive power. The camera optical lens satisfies the following conditions: 8.00≤f, 0.90≤f/TTL, 0.40≤f1/f≤0.85, −1.10≤f3/f4≤−0.40, and 0.30≤d2/d4≤2.00. The camera optical lens has large aperture, long focal length and small distortion

An image lens assembly system includes, 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, a sixth lens element and a seventh lens element. The first lens element with negative refractive power has a convex object-side surface. The second lens element has positive refractive power. The third lens element has refractive power. The fourth lens element has refractive power. The fifth lens element has refractive power. The sixth lens element with refractive power is made of plastic material, wherein at least one surface of the sixth lens element is aspheric. The seventh lens element with refractive power made of plastic material has a concave image-side surface changing from concave in a paraxial region to convex in a peripheral region, and at least one surface thereof is aspheric.

An internal focus large-aperture telephoto lens including, sequentially from an object side to an image side, a first lens assembly with positive focal power, a second lens assembly with negative focal power, an aperture stop, a third lens assembly with positive focal power, and a fourth lens assembly with negative focal power; the first lens assembly, the second lens assembly, the third lens assembly and the fourth lens assembly are all spherical lenses; when focusing from infinity to proximity, the second lens assembly moves along an optical axis towards the image side, the third lens assembly moves along the optical axis towards the object side, the first lens assembly and the fourth lens assembly remain static in position in relation to the image side. The present invention utilizes internal double lens movement to focus, thereby achieving high magnification and high resolution and increasing focusing speed.

An internal focus large-aperture telephoto lens including, sequentially from an object side to an image side, a first lens assembly with positive focal power, a second lens assembly with negative focal power, an aperture stop, a third lens assembly with positive focal power, and a fourth lens assembly with negative focal power; the first lens assembly, the second lens assembly, the third lens assembly and the fourth lens assembly are all spherical lenses; when focusing from infinity to proximity, the second lens assembly moves along an optical axis towards the image side, the third lens assembly moves along the optical axis towards the object side, the first lens assembly and the fourth lens assembly remain static in position in relation to the image side. The present invention utilizes internal double lens movement to focus, thereby achieving high magnification and high resolution and increasing focusing speed.

The present invention provides an optical imaging lens. The optical imaging lens comprises five lens elements positioned in an order from an object side to an image side, each of which has an object-side surface facing the object side and an image-side surface facing the image side. Counting from the object side to the image side, the five lens are labeled as a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, all of which have refracting power. Through controlling a variable air gap formed between two adjacent lens elements and parameters to meet an inequality, adjustment distance required for focusing the optical imaging lens will be shortened.

The present invention provides an optical imaging lens. The optical imaging lens comprises five lens elements positioned in an order from an object side to an image side, each of which has an object-side surface facing the object side and an image-side surface facing the image side. Counting from the object side to the image side, the five lens are labeled as a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, all of which have refracting power. Through controlling a variable air gap formed between two adjacent lens elements and parameters to meet an inequality, adjustment distance required for focusing the optical imaging lens will be shortened.

A fixed-focus lens includes an anti-radiation first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in order in a direction. An aperture stop is disposed between the first lens and the fourth lens. A ratio of a lens diameter of the first lens to an overall length is within a range of 0.4 to 0.5, where the overall length is an axial distance between an outer surface of the first lens and an outer surface of the seventh lens. Each of the first lens to the seventh lens is a spherical glass lens.