The endoscope objective optical system includes in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. A lens surface positioned nearest to an image side in the second lens group is a concave surface which is directed toward the image side. The second lens group moves along an optical axis.

The objective lens unit includes, a front lens group having a negative refractive power, a diaphragm, and a rear lens group having a positive refractive power, in order from an object side. The front lens group includes a negative lens having a concave surface facing an image surface side, and a positive lens having a convex surface facing the object side, and the rear lens group includes a positive lens having a convex surface facing the image surface side and a cemented lens in which a positive lens and a negative lens are cemented. The endoscope objective lens unit satisfies −1.6<f.sub.F/f.sub.R<−1.2 and −1.3<f.sub.3/f.sub.F<−0.7. Note that f.sub.F and f.sub.R are focal lengths of the entire system of the front lens group and the rear lens group, and f.sub.3 is a focal length of a positive lens, in the rear lens group.

The objective lens unit includes, a front lens group having a negative refractive power, a diaphragm, and a rear lens group having a positive refractive power, in order from an object side. The front lens group includes a negative lens having a concave surface facing an image surface side, and a positive lens having a convex surface facing the object side, and the rear lens group includes a positive lens having a convex surface facing the image surface side and a cemented lens in which a positive lens and a negative lens are cemented. The endoscope objective lens unit satisfies −1.6<f.sub.F/f.sub.R<−1.2 and −1.3<f.sub.3/f.sub.F<−0.7. Note that f.sub.F and f.sub.R are focal lengths of the entire system of the front lens group and the rear lens group, and f.sub.3 is a focal length of a positive lens, in the rear lens group.

An imaging lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens disposed in order from an object side. In the imaging lens system, the first lens has positive refractive power and an object-side surface of the first lens is concave. A field of view of the imaging lens system is 100 degrees or more. In the imaging lens system, a distance TTL from the object-side surface of the first lens to an imaging plane and a height ImgH of the imaging plane satisfy TTL/ImgH<1.5.

This application generally describes an imaging system, such as a multi-camera imaging system. The imaging system can include a plurality of channels and individual of the channels can include an objective lens and a relay optical system. The object lens images received light on a first image plane, as a first image, and the relay optical system images the first image on a second image plane, as a second, magnified image. In examples, the object lens and the relay optical system make up an optically coherent system.

An optical imaging lens assembly, which is applied for an endoscopic optical device, from an object side to an image side aligned in order includes a first lens element, a second lens element and a third lens element. The first lens element has negative refracting power, and further has a first convex object-side surface and a first image-side surface. The second lens element has positive refracting power, and further has a second convex object-side surface and a second concave image-side surface. The third lens element has positive refracting power, and further has a third convex image-side surface and a third object-side surface.

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 positive refractive power, a fourth lens having a refractive power, a fifth lens having a refractive power, a sixth lens having a refractive power, a seventh lens having a positive refractive power, and an eighth lens having a negative refractive power. The camera optical lens satisfies the following conditions: 0.85≤f1/f≤1.10, 1.00≤d6/d8≤3.00, 3.00≤(R11+R12)/(R11−R12)≤20.00, and d15 max/d15 min≤2.20. The camera optical lens according to the present invention has excellent optical characteristics, such as large aperture, wide angle, and ultra-thin.

Provided is an optical system, sequentially comprising, from an object side to an image side, a first lens having negative refractive power, an object side face of the first lens being convex, and an image side face being concave; a second lens having negative refractive power, an image side face of the second lens being concave; a third lens having positive refractive power, an object side face and an image side face of the third lens each being convex; a fourth lens having positive refractive power, an object side face and an image side face of the fourth lens each being convex; a lens unit having refractive power; and a stop arranged on an object side of the fourth lens. The optical system satisfies the condition of FOV/CRA>10.

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 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.