Abstract: In an optical pick-up apparatus for recording to or reproducing from an optical information recording medium, the optical pick-up apparatus includes: a light source for emitting light flux; a light converging optical system having an aperture and an objective lens and converging the light flux emitted from the light source on the optical information recording medium; a photodetector for detecting light reflected from the optical information recording medium; and a driving section for driving the objective lens and the aperture in association with the objective lens.

Abstract: An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted

Abstract: The invention provides a washing method for a charging member by removing the deposited substance on the surface, thus making the charging member reusable. The washing method, for an electrophotographic charging member to be pressed to the surface of a member to be charged thereby charging the member to be charged, has a step of washing the surface of the charging member at least once with an acidic aqueous solution.

Abstract: An objective lens for use in an optical pickup apparatus for conducting recording and/or reproducing information for an optical information recording medium, has a lens section shaped in an approximate circle and including a flange section; and a projecting section integrally provided to the lens section.

Abstract: An objective optical element to be used for an optical pickup device for performing reproducing and/or recording of information to a first optical information recording medium and a second optical information recording medium by converging a light beam having a wavelength &lgr;1 (640 nm≦&lgr;1≦670 nm) on the first optical information recording medium having a protective substrate thickness t1, and by converging a light beam having a wavelength &lgr;2 (400 nm≦&lgr;2≦415 nm) on the second optical information recording medium having a protective substrate thickness t2; wherein an optical system magnification m1 satisfies a relation of |m1|<0.01, and wherein an optical system magnification m2 satisfies a relation of |m2|<0.01.

Abstract: In an optical pickup device for conducting reproducing and/or recording of information in at least two kinds of optical information recording media, an optical element divides a light flux into k(k≧4) pieces of ring-shaped light flux. When reproducing or recording is conduced for a first optical information recording medium, the first light flux and the k-th light flux are converged on the first information recording surface and at least two pieces of light flux of the second light flux to the (k-1)th light flux form an apparent best image plane at a position different from the position of the best image plane formed by the first light flux and the k-th light flux. A wave front aberration of each light flux passing in a required numerical aperture for the first optical information recording medium is made approximately mi&lgr;1.

Abstract: An objective lens for use in an optical pickup apparatus for conducting recording and/or reproducing information for an optical information recording medium, has a lens section shaped in an approximate circle and including a flange section; and a connecting section integrally provided to the lens section. The objective lens satisfies the following conditional formulas: 0.5≦A≦2.0, 0.3A≦B≦1.7A where A is a diameter of the lens section when the lens section is viewed from an direction of an optical axis, and B is a width of the connecting section when the connecting section is viewed from the direction of the optical axis.

Abstract: An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted

Abstract: The present invention provides a recycle developer bearing body which is an effective recycle of a used developer bearing body, which helps effective utilization of resources, and which has no fear of image quality degradation such as developer concentration unevenness. In the recycle developer bearing body, even when scars or other defects are developed on a developer bearing surface of the developer bearing body from previous use, a surface roughness Ra of the developer bearing surface having the scars or other defects of the developer bearing body is 0.8 &mgr;m or more.

Abstract: An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted

Abstract: An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted

Abstract: An objective optical element of an optical pickup apparatus has a magnification m1 satisfying the following formula for a light flux of the wavelength &lgr;1: −1/7≦m1≦−1/25 and |m1|<|M1, M1, where M1 is an optical system magnification from the first light source to the first optical information recording medium for a light flux of the wavelength &lgr;1. The objective optical element comprises a common region and an exclusive region. The exclusive region includes an exclusive diffractive structure having a function to suppress an increase of spherical aberration due to a raise of atmospheric temperature. A light flux of a wavelength &lgr;2 having passed through the exclusive diffractive structure intersects with the optical axis at a position different from the position of the converged light spot formed on the information recording plane of the second optical information recording medium.

Abstract: An objective lens for use in an optical pickup apparatus for conducting recording and/or reproducing information for an optical information recording medium, has a lens section shaped in an approximate circle and including a flange section;.and a connecting section integrally provided to the lens section.

Abstract: An objective lens for use in an optical pickup apparatus for conducting recording and/or reproducing information for an optical information recording medium, has a lens section shaped in an approximate circle and including a flange section; and a connecting section integrally provided to the lens section.

Abstract: A method for regenerating a charging member for an electrophotographic system that is pressed against a surface of a body to charge the body, a charging member and a device for regenerating a charging member are provided. The method includes a step of applying heat treatment to the charging member. A used charging member, whose resistance is not decreased enough to recover a required chargeability by cleaning the surface thereof, can easily be regenerated and reused.

Abstract: A recycling method of a part for an image forming apparatus, the part being used in the image forming apparatus and provided with a thermoplastic resin member at least in a part thereof is provided which includes: recovering the part for the image forming apparatus; disassembling the recovered part for the image forming apparatus; retrieving the thermoplastic resin member from the disassembled part for the image forming apparatus; and performing heat processing to the retrieved thermoplastic resin member to recycle the member.

Abstract: An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted

Abstract: The invention provides a washing method for a charging member by removing the deposited substance on the surface, thus making the charging member reusable. The washing method, for an electrophotographic charging member to be pressed to the surface of a member to be charged thereby charging the member to be charged, has a step of washing the surface of the charging member at least once with an acidic aqueous solution.

Abstract: An optical pickup apparatus for first and second optical information recording medium, comprises first and second light sources to emit first and second light flux; a single objective lens made and a diaphragm having an aperture. The pitch of a plurality of ring-shaped diffractive zones provided on the objective lens, becomes gradually small from the optical axis to a point h and the pitch increases at the point h. At the time of conducting recording or reproducing information of the second optical information recording medium, the second light flux has a spherical aberration discontinuous portion at the point h where a spherical aberration-stepped amount is 7 &mgr;m to 40 &mgr;m, and a spherical aberration of a light ray of the second light flux having passed through the outermost portion of the aperture of the diaphragm is 7 &mgr;m to 40 &mgr;m.

Abstract: An objective optical element for use in an optical pickup apparatus, includes an objective lens to converge the light flux emitted from the first and second light sources; and an optical functional surface including a common region and an exclusive region. When a first optical information medium is used, a sine condition unsatisfied-amount whose value is maximum exists on the common region.