31results about How to "Optical performance is deteriorated" patented technology

A light-amount adjusting apparatus includes a plurality of light-amount adjusting blades that causes a size of a light-passing aperture to change by rotation thereof. Each of the light-amount adjusting blades includes a base portion on which a rotation center portion and a driven portion are formed, and a blade portion that overlaps another light-amount adjusting blade in a light-passing direction so as to form the light-passing aperture. A thickness of the blade portion is thinner than that of the base portion. When the plurality of light-amount adjusting blades is rotated to set the light-passing aperture to be smaller than a full-opened aperture, a thickness of a portion that overlaps an adjacent stop blade is thinner than that of a portion that does not overlap the adjacent stop blade in each of the light-amount adjusting blades. The blades have high dimension accuracy, and deterioration of the optical performance of the apparatus is reduced.

An imaging lens includes, in order from an object side, a first lens group having a positive power, an aperture diaphragm, and a second lens group having a positive or negative power. The first lens group includes, in order from the object side, a first lens which is a biconcave lens, a second lens that has a positive power and includes a convex image-side surface, and a third lens that has a positive power and includes a convex object-side surface. The second lens group includes, in order from the object side, a fourth lens that has a negative power and includes a concave image-side surface, and a fifth lens which is a biconvex lens. Each of the first to fifth lenses is a single spherical glass lens.

This camera system includes: a vibration compensation unit including a vibration compensation optical system and an image-capturing unit; a drive unit that drives the vibration compensation unit; a detection unit that detects vibration; a position detection unit that detects the position of the vibration compensation unit; a target position determination unit that determines a target position for the vibration compensation unit according to the vibration of the camera; a calculation unit that calculates a drive amount for the drive unit; a range of movement limitation unit that limits the position of the vibration compensation unit within a range; a range setting unit that sets a movement permitted range that is within the range in which the vibration compensation unit can be positioned; and a centering unit that controls the drive unit so that the vibration compensation unit is centered in the center of the movement permitted range.

This camera system includes: a vibration compensation unit including a vibration compensation optical system and an image-capturing unit; a drive unit that drives the vibration compensation unit; a detection unit that detects vibration; a position detection unit that detects the position of the vibration compensation unit; a target position determination unit that determines a target position for the vibration compensation unit according to the vibration of the camera; a calculation unit that calculates a drive amount for the drive unit; a range of movement limitation unit that limits the position of the vibration compensation unit within a range; a range setting unit that sets a movement permitted range that is within the range in which the vibration compensation unit can be positioned; and a centering unit that controls the drive unit so that the vibration compensation unit is centered in the center of the movement permitted range.

A light-amount adjusting apparatus includes a plurality of light-amount adjusting blades that causes a size of a light-passing aperture to change by rotation thereof. Each of the light-amount adjusting blades includes a base portion on which a rotation center portion and a driven portion are formed, and a blade portion that overlaps another light-amount adjusting blade in a light-passing direction so as to form the light-passing aperture. A thickness of the blade portion is thinner than that of the base portion. When the plurality of light-amount adjusting blades is rotated to set the light-passing aperture to be smaller than a full-opened aperture, a thickness of a portion that overlaps an adjacent stop blade is thinner than that of a portion that does not overlap the adjacent stop blade in each of the light-amount adjusting blades. The blades have high dimension accuracy, and deterioration of the optical performance of the apparatus is reduced.

There is provided an optical pick-up used for recording data to and / or reproducing data from at least three types of optical discs having at least two different thicknesses of cover layers. The optical pick-up includes light sources and an objective lens. A thickness t1 of a first optical disc, a thickness t2 of a second optical disc, and a thickness t3 of a third optical disc satisfy a relationship t1≦t2<t3. A numerical aperture NA1 for the first optical disc, a numerical aperture NA2 for the second optical disc and a numerical aperture NA3 for the third optical disc satisfy a relationship NA1≧NA2>NA3. Further, a first light beam for the first optical disc is incident on the objective lens as a converging light beam, and the second and third light beams for the second and third optical discs are incident on the objective lens as diverging light beams, respectively. Given that magnification of the objective lens is m1 when the first optical disc is used, magnification of the objective lens is m2 when the second optical disc is used, and magnification of the objective lens is m3 when the first optical disc is used, following conditions are satisfied: m1>0, m3<m2<0.

An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; and a sixth lens, arranged in this order from an object side to an image plane side. The second lens has a convex surface facing the object side near an optical axis thereof. The fifth lens has a convex surface facing the image plane side near an optical axis thereof. The sixth lens has a convex surface facing the image plane side near an optical axis thereof. The first lens is arranged so that a surface thereof on the object side is away from an image plane by a specific distance on an optical axis thereof. The second lens is arranged to be away from the third lens by a specific distance on the optical axis thereof. The third lens has a specific Abbe's number.

A laser beam output from a semiconductor laser light source 1 is transmitted through a cover glass 2 in the optical axis Z direction, is incident on a molded lens 4 in a state of divergent rays, is converted into convergent rays by the molded lens 4, and is applied onto a recording face 5 of the optical recording medium. A diaphragm 3 is arranged. An area of each lens surface onto which a luminous flux of the laser beam restricted by the diaphragm 3 is applied corresponds to an effective area. The following expression (1) is satisfied:d1−d0≧0.04 mm  (1)where d0 denotes an effective aperture of one of the lens surfaces, andd1 denotes an outer diameter of the one of the lens surfaces.

A zoom lens including, in order from the object side to the image side, a first lens group including a positive refractive power, a second lens group having a negative refractive power, an image side lens group having a positive refractive power, wherein the distance between the first lens group and the second lens group changes during zooming, and a refractive optical element A, which has a positive refractive power when its object side surface and image side surface are exposed to air, is provided in the first lens group and located closest to the object side in the first lens group, and the refractive optical element A is cemented together with an optical element B. The Abbe constant νd and the relative partial dispersion θgF of the refractive optical element A satisfies certain conditions.