Abstract: Provided is a polyester-based sealant film having highly excellent heat seal strength and excellent recyclability. A polyester-based sealant film of a first aspect of the present invention is a laminated film composed of at least two layers and having a sealing layer and an outermost layer, in which the sealing layer includes a copolymerized polyester formed from a copolymer of terephthalic acid as well as another dicarboxylic acid component and a diol component, the outermost layer includes homopolyethylene terephthalate as a main component, the laminated film has a lamination configuration in which a content proportion (mol %) of the other dicarboxylic acid component in each layer decreases from the sealing layer toward the outermost layer, and a heat seal strength obtainable when the sealing layers of the laminated films are sealed at 0.2 MPa for 1 second in the range of 140° C. to 220° C. is 25 N/15 mm or higher.

Abstract: A lens unit includes a first lens having positive power, an aperture stop, a meniscal second lens having negative power, a meniscal third lens having positive power, and a fourth lens including an object side surface and an image side surface, each being aspherical and including at least one inflection point. The image side surface is concave at an image side. The first lens, the aperture stop, the second lens, the third lens, and the fourth lens are arranged in order from an object side toward the image side. The first lens includes an image side surface that is convex at the image side. The second lens includes an object side surface that is convex at the object side.

Abstract: A lens unit including a first lens, a second lens, a third lens, and a fourth lens arranged in order from an object side toward an image side. The first lens is laminated with the second lens. An aperture stop is held between the first lens and the second lens.

Abstract: A lens unit including a first lens, an aperture stop, a second lens, a third lens, and a fourth lens arranged in order from an object side to an image side. The first lens is a meniscus lens having positive power. The second lens is a meniscus lens including a convex object side surface and having negative power. The third lens is a meniscus lens including a convex image side surface and having negative power. The fourth lens is aspherical, includes an image side surface and an object side surface, and has at least one inflection point on each of the image side surface and object side surface. The image side surface has a concave surface facing toward the image side.

Abstract: In an imaging lens, one compound lens and two single lenses are arranged in a lens barrel. On the light output side of the lens barrel, a filter is arranged with a distance from lens barrel. With a further distance from the filter, an imaging element is arranged. In the compound lens, a resin lens is bonded to a base member lens, having an output surface center of the resin lens displaced by a prescribed amount relative to an output surface center of the base member lens, so that a transmission decentration amount attributed to the base member lens, not including the resin lens, and the single lenses is cancelled by a transmission decentration amount by the resin lens when taken as a whole lens system. Thus, the imaging lens capable of suppressing reduction in resolving power due to transmission decentration of the lenses is obtained.

Abstract: An imaging lens unit which achieves a lower profile without adversely affecting the optical performance. The imaging lens unit includes a first lens, an aperture stop, a second lens, and a third lens arranged sequentially along the optical axis from the object side to the image side. The first lens includes a first surface located on the object side and being convex toward the object side and a second surface located on the image side and being concave toward the image side near the optical axis and convex toward the image side as the rim of the first lens becomes closer.

Abstract: An optical waveguide in which a groove is formed on the top surface of a substrate used as a lower clad and a core is formed in the groove, characterized in that the core is formed in such a way that the top face of the core within the groove is at a lower level than the top face of the substrate, and an upper clad may also be provided on the core, and the core is preferably formed from an organic-inorganic hybrid material.

Abstract: A lens unit including a first lens, an aperture stop, a second lens, a third lens, and a fourth lens arranged in order from an object side to an image side. The first lens is a meniscus lens having positive power. The second lens is a meniscus lens including a convex object side surface and having negative power. The third lens is a meniscus lens including a convex image side surface and having negative power. The fourth lens is aspherical, includes an image side surface and an object side surface, and has at least one inflection point on each of the image side surface and object side surface. The image side surface has a concave surface facing toward the image side.

Abstract: A lens unit includes a first lens having positive power, an aperture stop, a meniscal second lens having negative power, a meniscal third lens having positive power, and a fourth lens including an object side surface and an image side surface, each being aspherical and including at least one inflection point. The image side surface is concave at an image side. The first lens, the aperture stop, the second lens, the third lens, and the fourth lens are arranged in order from an object side toward the image side. The first lens includes an image side surface that is convex at the image side. The second lens includes an object side surface that is convex at the object side.

Abstract: A lens unit including a first lens, a second lens, a third lens, and a fourth lens arranged in order from an object side toward an image side. The first lens is laminated with the second lens. An aperture stop is held between the first lens and the second lens.

Abstract: A composite lens of the present invention has a resin layer made from a resin to be polymerized by ultraviolet rays provided on at least a part of a surface of a glass base material, the resin layer including a completely cured resin layer and an incompletely cured resin layer. The incompletely cured resin layer may be formed outside a lens effective diameter. Preferably, the incompletely cured resin layer has a polymerization degree of 60 to 90%.

Abstract: In the optical waveguide which comprises a core layer to be an optical transmission region and an upper clad layer and a lower clad layer covering the surrounding of the core layer and of which the upper clad layer is formed while being shrunk in the volume, a stress moderating layer formed a material with a smaller storage modulus than that of the upper clad layer is formed between the upper clad layer and the lower clad layer in at least a portion of a region where the upper clad layer and the lower clad layer are brought into contact with each other.

Abstract: In a photographing lens unit, an aperture diaphragm, a first lens having positive refractive power, a second lens having negative refractive power, a third lens of a positive meniscus lens with a concave surface on the object side, an ND filter, a fourth lens of a negative meniscus lens with a convex surface on the object side, an IR cut filter, and an imaging element are disposed in order from the object side to the imaging element side. In the third lens, a surface shape on the object side changes from concave to convex as it is away from an optical axis, and a surface shape on the image side changes from convex to concave as it is away from the optical axis. In the fourth lens, a surface shape on the object side changes from convex to concave as it is away from the optical axis.

Abstract: Disclosed herein is an optical waveguide comprising a core layer to be an optical waveguide region, an upper clad layer covering the core layer and a lower clad layer, characterized in that an ultraviolet control region for preventing ultraviolet light from entering is provided at any one location of under the lower clad layer, on an interface of the lower clad layer and the upper clad layer, and on the upper clad layer. And a method of fabricating this optical waveguide is also disclosed.

Abstract: An imaging lens unit which achieves a lower profile without adversely affecting the optical performance. The imaging lens unit includes a first lens, an aperture stop, a second lens, and a third lens arranged sequentially along the optical axis from the object side to the image side. The first lens includes a first surface located on the object side and being convex toward the object side and a second surface located on the image side and being concave toward the image side near the optical axis and convex toward the image side as the rim of the first lens becomes closer.

Abstract: A composite lens that prevents insufficient hardening of an ultraviolet curable resin near the periphery of an optically effective portion. The composite lens includes a plastic lens and a resin layer. The plastic lens includes the optically effective portion and a flange surrounding the optically effective portion. The resin layer is formed from an ultraviolet curable resin and arranged in contact with the optically effective portion. The flange includes a diffusion portion which diffuses ultraviolet light irradiating the plastic lens toward the resin layer through the plastic lens.

Abstract: Disclosed herein is an optical waveguide comprising a core layer to be an optical transmission region, an upper clad layer and a lower clad layer covering the core layer, in which the core layer, the upper clad layer and the lower clad layer are formed from resin materials, characterized in that a microlens made of a material having a higher refractive index than that of a material constituting said core layer is disposed in the vicinity of an end face of said core layer.

Abstract: An optical lens includes a lens effective portion, an inclined portion and a flange portion. The lens effective portion has, on a first side, a lens face with a small radius of curvature and also has, on a second side, a lens face with a large radius of curvature. The inclined portion has, on the first side, an inclined face inclined outwardly from the first side to the second side. The flange portion has, on the second side, a reference face protruding longer than the lens face with the large radius of curvature on the second side. Thus, it is possible to obtain an optical lens which is less susceptible to deformation or chipping and suppresses transmission eccentricity, a compound lens and a method for producing the same, as well as a cemented lens and a method for producing the same.

Abstract: In an imaging lens, one compound lens and two single lenses are arranged in a lens barrel. On the light output side of the lens barrel, a filter is arranged with a distance from lens barrel. With a further distance from the filter, an imaging element is arranged. In the compound lens, a resin lens is bonded to a base member lens, having an output surface center of the resin lens displaced by a prescribed amount relative to an output surface center of the base member lens, so that a transmission decentration amount attributed to the base member lens, not including the resin lens, and the single lenses is cancelled by a transmission decentration amount by the resin lens when taken as a whole lens system. Thus, the imaging lens capable of suppressing reduction in resolving power due to transmission decentration of the lenses is obtained.

Abstract: In a photographing lens unit, an aperture diaphragm, a first lens having positive refractive power, a second lens having negative refractive power, a third lens of a positive meniscus lens with a concave surface on the object side, an ND filter, a fourth lens of a negative meniscus lens with a convex surface on the object side, an IR cut filter, and an imaging element are disposed in order from the object side to the imaging element side. In the third lens, a surface shape on the object side changes from concave to convex as it is away from an optical axis, and a surface shape on the image side changes from convex to concave as it is away from the optical axis. In the fourth lens, a surface shape on the object side changes from convex to concave as it is away from the optical axis.