Abstract: A progressive-power spectacle lens includes a distance portion having a dioptric power for distance vision, a near portion having a dioptric power for near vision, and an intermediate portion having a progressive dioptric power between the distance portion and the near portion. At least one of front and back surfaces is formed as a progressive-power surface whose dioptric power varies depending upon a position thereon. The spectacle lens has a prismatic effect including a prescribed prismatic effect and unprescribed prismatic effect. A shape of the progressive-power surface of the spectacle lens is different from a shape of a progressive-power surface of a reference lens that is defined as a lens identical to the spectacle lens except that the prescribed prismatic effect is eliminated. The progressive surface of the spectacle lens is configured to compensate for aberration that is caused if the prescribed prismatic effect is added in the reference lens.

Abstract: A design method of a spectacle lens includes step for selecting one or more lens parameters as variables among a plurality of lens parameters, step for assigning values of the same optical aberration at different evaluation points on the lens to all of evaluation functions that evaluate optical aberration and step for optimizing the selected lens parameters by setting target values of the evaluation functions to zero. The optimizing step includes repetition of step for calculating the magnitude of the evaluation function at each evaluation point on the lens and step for adjusting the values of the selected lens parameters such that the evaluation functions are closer to zero.

Abstract: According to a method of manufacturing a progressive power spectacle lens, available vertex powers are divided into a plurality of vertex power groups, one surface of a spectacle lens has been formed as a common surface for the vertex powers within each of the plurality of vertex power groups, and an opposite surface of the spectacle lens is formed as a progressive power surface in accordance with a desired vertex power.

Abstract: The manufacturing system of spectacle lenses includes a computer, an input device to input data to the computer, a display and an aspherical surface processing machine. An operator input customer's data to the computer with the input device. The computer selects and determines a substantially common shape for front surfaces of the right and left lenses among predetermined shapes according to a selecting program based on the input specifications. The selecting program selects the common shape that stands midway between shapes of the front surfaces of the right and left lenses when these lenses are independently designed. The computer calculates shape data of the back surfaces, on the basis of the specifications and the selected shape of the front surfaces. Then the operator places the semifinished lens blank whose front surface agrees with the selected common shape on the machine.

Abstract: Disclosed are a single-vision aspherical spectacle lens to correct eyesight and a processing method thereof. The spectacle lens has front and back surfaces, one of which is an aspherical surface. A framing reference point that is coincident with a pupil position of a user when the lens is installed on a frame is decentered from a geometrical center of an uncut circular lens (a semifinished lens blank or an uncut finished lens). Further, the symmetric axis of the aspherical surface passes the framing reference point. With this construction, a lens blank of small-size can be employed for manufacturing a spectacle lens for a large-size frame, and the optical performance can be kept high.

Abstract: Disclosed is an aspherical spectacle lens having a prismatic power to correct hereophoria of an eye. The spectacle lens has front and back surfaces, one of which is a rotationally-asymmetrical aspherical surface. When the back surface is rotationally-asymmetrical, curvature of an intersection line of a plane containing the normal to the rotationally-asymmetrical surface at a framing reference point and the rotationally-asymmetrical surface at the prism base side is larger than that at the apex side. The framing reference point is coincident with a pupil position of a user when the spectacle lens is installed on a frame. On the other hand, when the front surface is rotationally-asymmetrical, the curvature of the intersection line at the prism base side is smaller than that at the apex side.

Abstract: A design method for an optical curved surface, includes: dividing an optical curved surface into a plurality of rectangular areas that are divided by a lattice; defining an original lattice point on the lattice, a backbone line that crosses the original lattice point on the lattice, and standard lattice points that are the lattice points located on the backbone line except the original lattice point; applying curvatures to all of the lattice points; applying inclinations to the original lattice point and the standard lattice points; applying sag to the original lattice; calculating a sectional shape of the curved surface along the backbone line based on the sag and inclination of the original lattice point and the curvatures of the lattice points on the backbone line; calculating sags of the standard lattice points based on the calculated sectional shape; calculating sectional shapes along orthogonal lines that are orthogonal to the backbone line based on the calculated sags and the applied inclinations of th

Abstract: A progressive power lens has an effective surface including a progressive surface portion which progressively varies the power, and a peripheral rim surface portion which does not function as an effective surface and which is provided to surround the progressive surface portion. The rim surface portion is made of a curved surface. The invention is also directed to a mold which is used to produce a progressive power lens. The mold includes a progressive surface which progressively varies the power and a rim surface forming portion which forms a rim surface portion of the lens which does not function as a progressive surface. The rim surface forming portion is made of a curved surface.

Abstract: Disclosed is a manufacturing method of a spectacle lens. The entire range of available vertex power of a spectacle lens is divided into a plurality of sections, and at least one type of semifinished lens blank whose front surface is finished is prepared for each of the sections. On the basis of required specification, one type of the semifinished lens blank is selected. Further, an aspherical shape design for processing the back surface of the selected semifinished lens blank is determined according to the required specification. The aspherical shape of the back surface is optimized such that average power errors or astigmatisms of the finished lenses having different vertex powers within the same section are approximately balanced. Finally the back surface is processed based on the determined aspherical shape.

Abstract: A design method of a spectacle lens includes step for selecting one or more lens parameters as variables among a plurality of lens parameters, step for assigning values of the same optical aberration at different evaluation points on the lens to all of evaluation functions that evaluate optical aberration and step for optimizing the selected lens parameters by setting target values of the evaluation functions to zero. The optimizing step includes repetition of step for calculating the magnitude of the evaluation function at each evaluation point on the lens and step for adjusting the values of the selected lens parameters such that the evaluation functions are closer to zero.

Abstract: Variable power spectacles having a pair of visual optical systems. Each of the visual optical systems includes a variable power lens and a variable angle prism. The spectacles is further provided with a first adjusting mechanism for adjusting focal power of the variable power lens, a second adjusting mechanism for adjusting prismatic power of the variable angle prism, and a linking mechanism. The first adjusting mechanism varies the curvature of the front surface of the variable power lens to change the focal power. The second adjusting mechanism varies the inclination angle of the front surface of the variable angle prism to change the prismatic power. The linking mechanism associates the adjustment by the first adjusting mechanism with the adjustment by the second adjusting mechanism to link one of the adjustments with the other adjustment.

Abstract: The manufacturing system of spectacle lenses includes a computer an input device to input data to the computer, a display and an aspherical surface processing machine. An operator input customer's data to the computer with the input device. The computer selects and determines a substantially common shape for front surfaces of the right and left lenses among predetermined shapes according to a selecting program based on the input specifications. The selecting program selects the common shape that stands midway between shapes of the front surfaces of the right and left lenses when these lenses are independently designed. The computer calculates shape data of the back surfaces, on the basis of the specifications and the selected shape of the front surfaces. Then the operator places the semifinished lens blank whose front surface agrees with the selected common shape on the machine.

Abstract: A diffusion plate includes a plurality of superimposed basic patterns, each having a large number of microstructures. The microstructures are located in two dimensional periodic arrangements, and lattice vectors, corresponding to the periodic arrangement of the microstructures, vary in accordance with the pattern. The invention also discloses a method for manufacturing a master die for such a diffusion plate, and a focusing screen using the diffusion plate.

Abstract: A method of manufacturing progressive power spectacle lenses includes preparing individual fitting condition data for a lens-wearer such as object distances for near and distance vision, the distance from the point-of-rotation of each eyeball of a lens-wearer to each spectacle lens, the pantoscopic angle of the spectacle lenses when fitted onto said lens-wearer, and determining an amount of inset in accordance with said individual fitting condition data.

Abstract: Disclosed is a spectacle lens which includes a diffractive structure for producing diffraction to correct transverse chromatic aberration caused by a macroscopic surface shape of the spectacle lens. The diffractive structure is composed of a series of rings formed integral with the spectacle lens.

Abstract: A spectacle lens having a geometric center includes front and rear surfaces, each formed as a refractive surface. At least one of the front and rear surfaces is formed as an aspherical surface in rotational symmetry about an axis of symmetry. The axis of symmetry is separated from the geometric center.

Abstract: Binocular magnifying glasses include a pair of magnifying optical systems, one system for each of the left and right eyes. Each optical system has an objective lens having a positive power and an eyepiece having a negative power arranged in that order from the object side in. The optical center of at least one eyepiece is positioned outside of a line connecting the center of rotation of the eye and the object point.

Abstract: A diffusion plate includes a plurality of superimposed basic patterns, each having a large number of microstructures, wherein the microstructures are located in two dimensional periodic arrangements, and wherein lattice vectors, corresponding to the periodic arrangement of the microstructures, vary in accordance with the pattern. The invention also discloses a method for manufacturing a master die for such a diffusion plate, and a focusing screen using the diffusion plate.

Abstract: A progressive power lens has an effective surface including a progressive surface which progressively varies the power, and a peripheral rim surface portion which surrounds the progressive surface yet does not function as an effective surface. The rim surface is curved. The invention is also directed to a mold to produce a progressive power lens. The mold includes a portion which forms progressive surface which progressively varies the power of the lens and a curved rim surface forming portion which forms a rim surface of the lens which does not function as a progressive surface.

Abstract: A diffusion plate includes a plurality of superimposed basic patterns, each having a large number of microstructures. The microstructures are located in two dimensional periodic arrangements, and lattice vectors, corresponding to the periodic arrangement of the microstructures, vary in accordance with the pattern. The invention also discloses a method for manufacturing a master die for such a diffusion plate, and a focusing screen using the diffusion plate.