A wide-angle lens includes a front group, an aperture, a rear group, and an infrared cut filter. The front group includes a first lens and a second lens arranged in order from a side closest to an object to an image side. In the wide-angle lens, an anti-reflection layer having a reflectance of 1.5% or less in a wavelength range from nm to 850 nm is provided on a lens surface of the first lens on the image side to suppress an occurrence of a ghost caused by light passing through a peripheral portion of the lens surface. Therefore, even if a film forming the anti-reflection layer is thinner than an appropriate value at the peripheral portion of the lens surface, the anti-reflection layer appropriately prevents reflection of light in a long wavelength range.

A wide-angle lens includes a front group, an aperture, a rear group, and an infrared cut filter. The front group includes a first lens and a second lens arranged in order from a side closest to an object to an image side. In the wide-angle lens, an anti-reflection layer having a reflectance of 1.5% or less in a wavelength range from nm to 850 nm is provided on a lens surface of the first lens on the image side to suppress an occurrence of a ghost caused by light passing through a peripheral portion of the lens surface. Therefore, even if a film forming the anti-reflection layer is thinner than an appropriate value at the peripheral portion of the lens surface, the anti-reflection layer appropriately prevents reflection of light in a long wavelength range.

An imaging lens includes first, second, third, fourth, fifth and six lens elements arranged in order from an object side to an image side along an optical axis. Each of the lens element has a thickness along the optical axis. Two of thicknesses of the first to the fourth lens elements along the optical axis are the thickest and the second thickest among the abovementioned six lens elements, respectively.

A variable-power optical system (ZL) is constituted by, in order from the object side and along the optical axis, the following: a first lens group (G1) that has a positive refractive power; a second lens group (G2); a third lens group (G3) that has a negative refractive power; and a rear group (GR) that includes a plurality of lens groups. When power is varied from the wide-angle end to the telephoto end, the interval between the first lens group and the second lens group increases, the interval between the second lens group and the third lens group increases, and the interval between the third lens group and a lens group in the rear group positioned closest to the object decreases, thus satisfying the following conditional equation:

0.10<D1/D2<1.80, where D1 is the length on the optical axis from the lens plane closest to the object of the first lens group to the lens plane closest to the image, and D2 is the length on the optical axis from the lens plane closest to the object of the second lens group to the lens plane closest to the image.

A variable-power optical system (ZL) is constituted by, in order from the object side and along the optical axis, the following: a first lens group (G1) that has a positive refractive power; a second lens group (G2); a third lens group (G3) that has a negative refractive power; and a rear group (GR) that includes a plurality of lens groups. When power is varied from the wide-angle end to the telephoto end, the interval between the first lens group and the second lens group increases, the interval between the second lens group and the third lens group increases, and the interval between the third lens group and a lens group in the rear group positioned closest to the object decreases, thus satisfying the following conditional equation:

0.10<D1/D2<1.80, where D1 is the length on the optical axis from the lens plane closest to the object of the first lens group to the lens plane closest to the image, and D2 is the length on the optical axis from the lens plane closest to the object of the second lens group to the lens plane closest to the image.

A method for imaging a patient's gastrointestinal tract using a capsule camera and a patient positioning system are disclosed. According to the method, the capsule camera is administered to a patient by swallowing the capsule camera through patient's mouth. For each target examination position selected from a set of examination positions: the patient positioning system is adjusted to a target positioner bed position associated with the target examination position with the patient on the positioner be. Adjusting patient positioning system comprises adjusting the positioner bed to tilt at a tilt angle, and wherein the set of examination positions comprises at least two different tilt angles; and the patient positioning system still is held at the target examination position for a pre-defined period of dwelling time to allow the capsule camera to capture stable pictures. Image data captured by the capsule camera are then collected.

A method for imaging a patient's gastrointestinal tract using a capsule camera and a patient positioning system are disclosed. According to the method, the capsule camera is administered to a patient by swallowing the capsule camera through patient's mouth. For each target examination position selected from a set of examination positions: the patient positioning system is adjusted to a target positioner bed position associated with the target examination position with the patient on the positioner be. Adjusting patient positioning system comprises adjusting the positioner bed to tilt at a tilt angle, and wherein the set of examination positions comprises at least two different tilt angles; and the patient positioning system still is held at the target examination position for a pre-defined period of dwelling time to allow the capsule camera to capture stable pictures. Image data captured by the capsule camera are then collected.

Present embodiments provide for an optical imaging lens. The optical imaging lens comprises a first lens element, a second lens element, a third lens element and a fourth lens element positioned in an order from an object side to an image side. Through controlling the convex or concave shape of the surfaces of the lens elements and designing parameters satisfying at least one inequality, the optical imaging lens shows better optical characteristics and enlarge field angle while the total length of the optical imaging lens is shortened.

The present disclosure provides an optical imaging lens assembly comprising, in order from an object side to an image side: a first lens element having negative refractive power; a second lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof; a third lens element having positive refractive power; a fourth lens element having positive refractive power; a fifth lens element having positive refractive power; and a sixth lens element; wherein the optical imaging lens assembly has a total of six lens elements. With such configuration, the optical imaging lens assembly of the present disclosure is characterized by a a wide field of view, a compact size and high image quality.

An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. At least one lens among the first to the sixth lenses has positive refractive force. The seventh lens has negative refractive force, wherein both surfaces thereof can be aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the seventh lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.