Disclosed is a small wide-angle lens system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens sequentially arranged from an object, wherein the first lens has a convex object-side surface, the third lens has a negative refractive power, the fourth lens has a concave image-side surface, the sixth lens has a concave object-side surface and a concave image-side surface, the ninth lens has a negative refractive power and a concave object-side surface, all surfaces of the first to ninth lenses are aspherical surfaces, the refractive power P1 of the first lens satisfies |P1|<0.01, and Fno of the lens system satisfies Fno <1.6.

A projection lens system projects an image of a reduction side into a magnification side in an image projection device, a back glass being disposed on the reduction side. In the projection lens system, all of one or more negative lenses that satisfy, in a surface on the reduction side or a surface on the magnification side, condition |h/H|<2.0 defined by height h of a most off-axis principal ray and height H of an axial ray passing through a highest pupil position satisfy conditions Tn≥98.5% and Dn/Db≤0.05 defined by transmittance Tn, thickness Dn of the negative lens on an optical axis, and total thickness Db of the back glass.

A zoom projection lens with eleven lens elements is provided. The zoom projection lens sequentially includes a first lens group, a second lens group, a third lens group, an aperture stop, a fourth lens group and a fifth lens group along an optical axis from a screen side to an image source side. The first lens group has a negative refractive power and includes three lens elements. The second lens group has a positive refractive power and includes one lens element. The third lens group has a positive refractive power and includes one lens element. The fourth lens group has a negative refractive power and includes four lens elements. The fifth lens group has a positive refractive power and includes two lens elements. A first lens element in the first lens group is an aspheric lens made of plastic.

A zoom projection lens with eleven lens elements is provided. The zoom projection lens sequentially includes a first lens group, a second lens group, a third lens group, an aperture stop, a fourth lens group and a fifth lens group along an optical axis from a screen side to an image source side. The first lens group has a negative refractive power and includes three lens elements. The second lens group has a positive refractive power and includes one lens element. The third lens group has a positive refractive power and includes one lens element. The fourth lens group has a negative refractive power and includes four lens elements. The fifth lens group has a positive refractive power and includes two lens elements. A first lens element in the first lens group is an aspheric lens made of plastic.

Provided is an optical lens. The optical lens is provided with a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, which are sequentially arranged from an object side to an image side along an optical axis. The first lens is a spherical lens having a negative focal power, the second lens is an aspheric lens having a meniscus shape bent towards an image surface, the third lens is an aspheric lens having a meniscus shape bent towards an object surface, the fourth lens is an aspheric lens having a positive focal power, the fifth lens is an aspheric lens having a positive focal power, the sixth lens is an aspheric lens having a negative focal power, and the seventh lens is an aspheric lens having a positive focal power.

A movable carrier auxiliary system includes at least one optical image capturing system disposed on a movable carrier, at least one warning module, and at least one displaying device. The optical image capturing system includes an image capturing module and an operation module, and has at least one lens group including at least two lenses having refractive power. The image capturing module captures and produces an environmental image surrounding the movable carrier. The operation module electrically connected to the image capturing module detects at least one lane marking in the environmental image to generate a detecting signal. The warning module electrically connected to the operation module receives the detecting signal to determine whether a moving direction of the movable carrier deviates from a lane, and generate a warning signal when the moving direction deviates from the lane. The displaying device electrically connected to the warning module displays the warning signal.

Provided is a camera optical lens, which includes, from an object side to an image side: 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 negative refractive power; a fifth lens having a negative refractive power; a sixth lens having a negative refractive power; a seventh lens having a positive refractive power; and an eighth lens having a negative refractive power. The camera optical lens satisfies following conditions: 3.50≤f1/f≤6.50; f2≤0.00; and 1.55≤n5≤1.70, where f denotes a focal length of the camera optical lens; f1 denotes a focal length of the first lens; f2 denotes a focal length of the second lens; and n5 denotes a refractive index of the fifth lens. The present disclosure can achieve high optical performance while achieving ultra-thin, wide-angle lenses having a big aperture.

The present invention relates generally to a head-mounted projection display, and more particularly, but not exclusively to a polarized head-mounted projection display including a light engine and a compact, high-performance projection lens for use with reflective microdisplays.

The present invention relates generally to a head-mounted projection display, and more particularly, but not exclusively to a polarized head-mounted projection display including a light engine and a compact, high-performance projection lens for use with reflective microdisplays.

There is provided an objective optical system, an image pickup apparatus, and an endoscope that are short in overall length and simple in structure and have a focusing function. The objective optical system includes, in order from the object side to the image side, a positive front lens group and a positive rear lens group. Focusing is performed by moving the front lens group along the optical axis. The front lens group includes, in order from the object side, a negative first lens, a positive second lens, an aperture stop, and a positive third lens, as lenses having refractive power. The rear lens group includes, in order from the object side, a positive cemented fourth lens and a positive fifth lens having a convex surface facing toward the object. The objective optical system satisfies the following conditional expression (1):

0.35<FL/Ff<0.85  (1).