Takumi Matsui

Bio: Takumi Matsui is an academic researcher from Konica Minolta. The author has contributed to research in topics: Lens (optics) & Cylindrical lens. The author has an hindex of 6, co-authored 8 publications receiving 144 citations.

Image pickup lens and image pickup device

Abstract: An image pickup lens includes: a first lens which is a positive lens having a positive refractive power; a second lens which is a negative lens having a negative refractive power; a third lens which is a positive lens; a fourth lens having at least one surface with an aspherical shape, wherein the first lens, the second lens, the third lens and the fourth lens are arranged from an object side of the image pickup lens in this order and the image pickup lens is designed using a predefined condition.

Imaging lens and imaging device

Abstract: An imaging lens comprising, sequentially from an object side, a positive lens, a negative lens, a positive lens and a lens having at least one plane in an aspherical shape, whereby, by being designed to fulfill specified conditions, the imaging lens can be downsized and provided with a higher imaging performance, is suitable for a wider angle, and has good image-side telecentric characteristics; and an imaging device using it.

Small imaging lens and imaging apparatus

Abstract: An imaging lens includes sequentially, from an object side, a first lens group, a second lens group, a third lens group, and a fourth lens group The first lens group includes only a first lens having a meniscus shape with a concave surface facing the object side The second lens group has positive refracting power as a whole and includes sequentially, from the object side, a second-first lens having positive refracting power and a second-second lens cemented to or separated from the second-first lens and having negative refracting power The third lens group includes only a third lens having a meniscus shape with a concave surface facing the object side The fourth lens group includes only a fourth lens

Small imaging lens and imaging device

Abstract: A small imaging lens having aberration correction and image-side telecentric characters, comprising, sequentially from an object side, a first lens group (G1), a second lens group (G2), a third lens group (G3) and a fourth lens group (G4). The first lens group (G1) consists of only a meniscus-shaped first lens (L1) with its concave plane facing the object side, the second lens group has as a whole a positive refractive power and consists of, sequentially from an object side, a (2-1)th lens (L2a) having a positive refractive power and a (2-2)th lens (L2b) being joined to or separated from the lens (L2a) and having a negative refractive power, and the third lens group consists of only a meniscus-shaped third lens (L3) with its concave plane facing the object side, and the fourth lens group consists of only a fourth lens (L4).

Zoom lens and image capturing apparatus

Abstract: PROBLEM TO BE SOLVED: To achieve miniaturization, and also ensure a high performance of a wide angle and highly variable magnification. SOLUTION: The zoom lens includes, in order from the object side to the image side, a first lens group of negative refractive power, a second lens group of positive refractive power, and a third lens group of positive refractive power. To zoom from a wide-angle end to a tele-photo end, the first lens group is moved and the second lens group is moved to the object side so that an air interval between the first and second lens groups decreases and an air interval between the second and third lens groups increases. The first lens group has, in order from the object side to the image side: a first lens which is a negative lens having aspherical faces on both sides and a concave face on the image side; and a second lens which is a positive meniscus lens having aspherical faces on both sides and a convex face on the object side. COPYRIGHT: (C)2010,JPO&INPIT

Optical image capturing system

Abstract: A six-piece optical lens for capturing image and a six-piece optical module for capturing image are provided. In order from an object side to an image side, the optical lens along the optical axis includes a first lens with refractive power, a second lens with refractive power, a third lens with refractive power, a fourth lens with refractive power, a fifth lens with refractive power and a sixth lens with refractive power. At least one of the image-side surface and object-side surface of each of the six lens elements is aspheric. The optical lens can increase aperture value and improve the imagining quality for use in compact cameras.

Image capturing lens assembly

Abstract: This invention provides an image capturing lens assembly in order from an object side to an image side comprising: a first lens group has only one first lens element with a positive refractive power, and a second lens group in order from the object side to the image side comprising: a second lens element with a negative refractive power, a third lens element, a fourth lens element and a fifth lens element; while a distance between an imaged object and the image capturing lens assembly changes from far to near, focusing is performed by moving the first lens group along the optical axis and a distance between the first lens group and an image plane changes from near to far. By such arrangement and focusing adjustment method, good image quality is achieved and less power is consumed.

Optical image capturing lens assembly

Abstract: An optical image capturing lens assembly 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, and a sixth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region. The second lens element with negative refractive power has an object-side surface being concave in a paraxial region and an image-side surface being convex in a paraxial region. The third lens element has refractive power. The fourth lens element with refractive power has an object-side surface being convex in a paraxial region. The fifth lens element with positive refractive power has an image-side surface being convex in a paraxial region. The sixth lens element with refractive power has an image-side surface being concave in a paraxial region.

Systems and methods for minimizing aberrating effects in imaging systems

Abstract: A biometric optical recognition system includes optics, including a wavefront coding mask, for imaging a wavefront of object to be recognized to an intermediate image, and a detector for detecting the intermediate image. A modulation transfer function detected by the detector contains no zeros such that subsequent task based image processing recognizes the object. A biometric recognition system includes optics for imaging a wavefront of an object to be recognized to a first intermediate image, and a detector for detecting the first intermediate image. The optics include a phase changing element configured for modifying the wavefront such that a modulation transfer function characterizing detection of the first intermediate image contains no zeros such that subsequent task based image processing recognizes the object. In an optical imaging system that includes a solid state detector, a phase-modifying element reduces reflected power from electromagnetic energy incident upon the detector without introducing aberrations.

Optical imaging lens assembly

Abstract: This invention provides an optical imaging lens assembly comprising five lens elements with refractive power, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element with negative refractive power; a fourth lens element with negative refractive power having at least one of the object-side and image-side surfaces thereof being aspheric; and a fifth lens element having a concave image-side surface, at least one of the object-side and image-side surfaces thereof being aspheric, and made of plastic. By such arrangement, photosensitivity and total track length of the optical imaging lens assembly can be reduced, and the aberration and astigmatism of the assembly can be effectively corrected. Moreover, high image resolution can be obtained.