Abstract: A door handle device for vehicles includes a handle body positioned on an outer surface of a vehicle door and lifted to be pulled back when the vehicle door is opened. The handle body is provided with a finger rest which extends to at least three directions of four directions including up, down, right and left directions.

Abstract: A door handle device for vehicles includes a handle body positioned on an outer surface of a vehicle door and lifted to be pulled back when the vehicle door is opened. The handle body is provided with a finger rest which extends to at least three directions of four directions including up, down, right and left directions.

Abstract: A plastic lens which can be positioned correctly during lens mounting. The plastic lens is used as a pickup lens on an optical head for an optical disk and it has a lens portion in the center with an annular rim formed on the periphery. The rim has two opposed surfaces, one of which provides a reference plane to effect positioning for fixing the plastic lens in a lens holder. The rim has a gate portion which remains to project from the periphery after a molten plastic material was injected through the corresponding channel during molding. The gate portion is cut off by a pair of cutting blades which are moved to come closer to each other in a direction substantially parallel to the optical axis of the lens portion. As the result of the cutting operation, a bur occurs at a distal end of the gate portion and it projects in a direction parallel to a plane orthogonal to the optical axis.

Abstract: A plastic lens which can be positioned correctly during lens mounting. The plastic lens is used as a pickup lens on an optical head for an optical disk and it has a lens portion in the center with an annular rim formed on the periphery. The rim has two opposed surfaces, one of which provides a reference plane to effect positioning for fixing the plastic lens in a lens holder. The rim has a gate portion which remains to project from the periphery after a molten plastic material was injected through the corresponding channel during molding. The gate portion is cut off by a pair of cutting blades which are moved to come closer to each other in a direction substantially parallel to the optical axis of the lens portion. As the result of the cutting operation, a bur occurs at a distal end of the gate portion and it projects in a direction parallel to a plane orthogonal to the optical axis.

Abstract: A UV image forming optical system includes a collimating lens for collimating light emitted from a UV light source, an imaging lens for forming an image of the collimated light transmitted through the collimating lens, and a beam splitting optical system positioned in an optical path of the collimated light between the collimating lens and the imaging lens. At least one of the collimated light emitted from the collimating lens and the light transmitted through the imaging lens, reflected by a reflector and transmitted again through the imaging lens is made incident upon an external viewing optical system.

Abstract: A plastic lens is molded from a suitable transparent thermoplastic resin, and has a lens body and an annular portion integrally formed around the lens body. The annular portion has an annular surface, as a first positioning surface, extending perpendicularly from a peripheral outer edge of a lens surface of the lens body with respect to an optical axis of the lens body, and a peripheral cylindrical surface, as a second positioning surface, extending perpendicularly with respect to the first positioning surface. A right-angled annular corner, defined by an intersection of a hypothetical extension of the first positioning surface and a hypothetical extension of the second positioning surface, is eliminated.

Abstract: A UV image forming optical system includes a collimating lens which collimates light emitted from a UV light source, and an imaging lens which forms an image of the collimated UV light transmitted through the collimating lens. A rear focal point of the collimating lens adjacent to the imaging lens is located closer to the imaging lens than a last lens surface of the collimating lens on the light emission side. A front focal point of the imaging lens adjacent to the collimating lens is located within the imaging lens. A lens system for UV radiation is also provided, which can be used as an imaging lens for the UV image forming optical system.

Abstract: An optical system of an optical information recording/reproducing apparatus includes a light source for emitting a generally parallel luminous flux. An objective optical system for converging the luminous flux emitted from the light source portion onto a medium is provided. The objective optical system can comprise a hologram lens or can have both surfaces formed as convex aspherical surfaces. A chromatic aberration correcting element having almost no power is adapted to correct chromatic aberration of the objective lens. A mechanism for independently actuating the objective lens at least in an optical axis direction is provided. Further, a beam splitter for splitting the luminous flux reflected by the medium from a light path directed to the light source portion and guiding the luminous flux to a light receiving system can be provided.

Abstract: An optical system of an optical information recording/reproducing apparatus including a light source, an objective lens, and a chromatic aberration correcting element is provided and also includes a mechanism for independently actuating the objective lens. A beam splitter for splitting the luminous flux reflected by a medium can also be provided. The chromatic aberration correcting element is formed of a positive lens and a negative lens cemented together and satisfies the relation .vertline.n.sub.p -n.sub.n .vertline..times.10.sup.-5 <300, wherein the refractive index in a central wavelength in use of the positive lens is represented by n.sub.p and the refractive index of the negative lens is represented by n.sub.n.

Abstract: An optical system of an optical information recording/reproducing apparatus includes an objective lens for converging a generally parallel luminous flux. A chromatic aberration correction element for correcting chromatic aberration of the objective lens is provided and has substantially no power. The chromatic aberration correcting element comprises a positive lens and a negative lens positioned in the generally parallel luminous flux. The positive and negative lenses of the chromatic aberration correcting element have substantially the same refractive index and different Abbe's number.

Abstract: An objective optical system of an optical information recording/reproducing apparatus includes a light source for emitting a generally parallel luminous flux, an objective optical system for converging the luminous flux emitted from the light source portion onto a medium and a chromatic aberration correcting element for correcting a chromatic aberration of the objective lens. The chromatic aberration correcting element is formed of three lens cemented together. A first lens and a third lens of the chromatic aberration correcting element have a same polarity power while a second lens has a different power from that of the first and third lenses. Incident and outgoing end faces of the chromatic aberration correcting element are formed as generally plane surfaces. A mechanism for independently actuating the objective lens at least in an optical axis direction is provided.

Abstract: An objective lens is corrected for spherical aberration at both an operating wavelength and a measurement wavelength, such that the amount of spherical aberration to develop at the operating wavelength is substantially equal to the amount of spherical aberration to develop at a measuring wavelength. The method of lens performance measurement then uses a light source emitting at a wavelength different from the operating wavelength.

Abstract: A collimating lens system comprises a chromatic aberration correction element and a converging lens which has both surfaces formed of a convex aspherical surface. The converging lens has no aberrations except chromatic aberration. The chromatic aberration correction element has small refractive power adapted to correct a chromatic aberration of the converging lens, and the element is constructed of positive and negative lenses cemented to each other. The positive lens and the negative lens have almost the same refractive index, and have different dispersion.

Abstract: An optical system of an optical information recording/reproducing apparatus including a light source for emitting a generally parallel luminous flux; an objective optical system for converging the luminous flux emitted from said light source portion a medium; a beam splitter for splitting the luminous flux reflected by said medium from a light path directed to the light source portion and guiding the same to a light receiving system; a chromatic aberration correcting element having almost no power disposed between said objective lens and said beam splitter and adapted to correct a chromatic aberration of said objective lens; and means for independently actuating said objective lens at least in an optical axis direction thereof.

Abstract: A method and apparatus for lens measurement that provide for a small error of measurement where a light source used for measurement emits a beam of light at a wavelength different from an operating wavelength of a lens to be measured. The spherical aberration of the lens being measured, which occurs at the nonoperating wavelength, is identified and measured. An auxiliary lens is then placed in the path of the light source emitting the beam of light with the nonoperating wavelength to suppress the spherical aberration. This method allows for performance measurements of the lens to be obtained at the nonoperating wavelength without the adverse effects of the spherical aberration which occurred at the nonoperating wavelength.

Abstract: An optical system of an optical information recording/reproducing apparatus including a light source for emitting a generally parallel luminous flux; an objective optical system for converging the luminous flux emitted from the light source onto a medium; a beam splitter for splitting the luminous flux reflected by the medium from a light path directed to the light source and guiding the same to a light receiving system; a chromatic aberration correcting element having almost no power disposed between the objective lens and the beam splitter and adapted to correct a chromatic aberration of the objective lens; and means for independently actuating the objective lens at least in an optical axis direction thereof.

Abstract: An object lens system consists of a converging lens which has both surfaces formed of a convex aspherical surface and having a radius of curvature which is increased as it goes toward the periphery from the center thereof, and a chromatic aberration correcting element having almost no power disposed towards said light source side of said converging lens and adapted to correct a chromatic aberration of said converging lens.

Abstract: An optical disk apparatus comprises an optical pickup having an optical pickup body carrying a laser and a photodetector responsive to light emitted from the laser and reflected by the optical disk for producing tracking error signals mounted on the optical pickup body for reciprocal movement in a tracking direction responsive to operation of an actuator, and supports an objective for focusing the beam on the disk. A position sensor produces position signals in response to displacement of the movable portion in the tracking direction. Finally a servo tracking circuit outputs driving signals to the actuator on the basis of tracking error signals produced either in response to tracking error signals produced from outputs of the photodetector and position signals produced from output signals of the position sensor, in response only to the latter.