Abstract: A zoom lens includes first to fifth lens groups respectively having positive, negative, positive, positive, and negative refractive powers in that order from the object side. Zooming is performed by moving the second lens group and the fourth lens group in an optical-axis direction. The first lens group includes a front lens group having a negative refractive power, an optical member for bending an optical path, and a rear lens group having a positive refractive power in that order from the object side. The front lens group is a cemented lens in which a first lens having a negative refractive power is bonded to a second lens having a positive refractive power in that order from the object side to the image side.

Abstract: A zoom lens and an image pickup apparatus are disclosed. The zoom lens includes, in order from an object side to an image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive refractive power. The fifth lens group includes a fixed group having a negative refractive power, and a movable group having a positive refractive power and being movable in a direction substantially orthogonal to the optical axis. The image formed on an image surface is movable in a direction substantially orthogonal to the optical axis by moving the movable group of the fifth lens group in the direction substantially orthogonal to the optical axis. The fifth lens group is satisfied predetermined conditions.

Abstract: A zoom lens includes, in order from an object side, a first lens group having a positive refractive power and fixed in an optical axis direction, a second lens group having a negative refractive power and moving along an optical axis to zoom, a third lens group having a positive refractive power and fixed in the optical axis direction, and a fourth lens group having a positive refractive power and moving in a non straight line along the optical axis to compensate variations of an image formation position and compensate change of the image formation position caused by changes of an object distance.

Abstract: A zoom lens includes in order and from the side of an object, a first lens group having a positive refractive power and fixed in position, a second lens group having a negative refractive power and movable in position for providing mainly zooming, a third lens group having a positive refractive power and fixed in position, a fourth lens group having a positive refractive power and movable in position for performing a focal position correction due to the zooming and for focusing, and a fifth lens group including a single lens fixed in position. Each of the lens groups from the third lens group to the fifth lens group has at least one aspheric surface, and conditional equations (1) and (2) below are satisfied. |f4/f5|<0.12??(3) 0.9<?5<1.2??(4) where f4 is a focal length of the fourth lens group, f5 is a focal length of the fifth lens group, and ?5 is a transverse magnification of the fifth lens group.

Abstract: The present invention provides a color image forming apparatus forming an image by using a plurality of image carriers, wherein at least one lens having identical optical characteristics and forming individual scanning optical systems which scan the individual image carriers with beams is formed by use of a plurality of cavities. When dividing the cavities into a plurality of groups in response to variations in the optical characteristics caused by cavity difference of the lenses formed with the plurality of cavities so that the relative differences in an optical parameters are within an allowable range, at least one lens of each scanning optical system is selected from the cavities of one of the plurality of groups.

Abstract: A zoom lens includes, in order from an object side, a first lens group having a positive refractive power and fixed in an optical axis direction, a second lens group having a negative refractive power and moving along an optical axis to zoom, a third lens group having a positive refractive power and fixed in the optical axis direction, and a fourth lens group having a positive refractive power and moving in a non straight line along the optical axis to compensate variations of an image formation position and compensate change of the image formation position caused by changes of an object distance.

Abstract: A zoom lens includes in order and from the side of an object, a first lens group having a positive refractive power and fixed in position, a second lens group having a negative refractive power and movable in position for providing mainly zooming, a third lens group having a positive refractive power and fixed in position, a fourth lens group having a positive refractive power and movable in position for performing a focal position correction due to the zooming and for focusing, and a fifth lens group including a single lens fixed in position.

Abstract: The present invention provides a color image forming apparatus forming an image by using a plurality of image carriers, wherein at least one lens having identical optical characteristics and forming individual scanning optical systems which scan the individual image carriers with beams is formed by use of a plurality of cavities. When dividing the cavities into a plurality of groups in response to variations in the optical characteristics caused by cavity difference of the lenses formed with the plurality of cavities so that the relative differences in an optical parameters are within an allowable range, at least one lens of each scanning optical system is selected from the cavities of one of the plurality of groups.

Abstract: The present invention provides a color image forming apparatus forming an image by using a plurality of image carriers, wherein at least one lens having identical optical characteristics and forming individual scanning optical systems which scan the individual image carriers with beams is formed by use of a plurality of cavities. When dividing the cavities into a plurality of groups in response to variations in the optical characteristics caused by cavity difference of the lenses formed with the plurality of cavities so that the relative differences in an optical parameters are within an allowable range, at least one lens of each scanning optical system is selected from the cavities of one of the plurality of groups.

Abstract: Disclosed is a scanning optical apparatus which can reduce color misregistration in a sub scanning direction to thereby obtain a good color image output, and a color image forming apparatus using the same. In the scanning optical apparatus, a beam emitted from light source means 1 is deflected by deflecting means 5, and the beam deflected by the deflecting means is imaged in a spot shape on a surface 7 to be scanned by scanning optical device, and light-scans on the surface to be scanned, and a scanning line scanning on the surface to be scanned has two or more extremums within the effective range of a scanning area.

Abstract: The present invention provides a color image forming apparatus forming an image by using a plurality of image carriers, wherein at least one lens having identical optical characteristics and forming individual scanning optical systems which scan the individual image carriers with beams is formed by use of a plurality of cavities. When dividing the cavities into a plurality of groups in response to variations in the optical characteristics caused by cavity difference of the lenses formed with the plurality of cavities so that the relative differences in an optical parameters are within an allowable range, at least one lens of each scanning optical system is selected from the cavities of one of the plurality of groups.

Abstract: Disclosed is a scanning optical apparatus which can reduce color misregistration in a sub scanning direction to thereby obtain a good color image output, and a color image forming apparatus using the same. In the scanning optical apparatus, a beam emitted from light source means 1 is deflected by deflecting means 5, and the beam deflected by the deflecting means is imaged in a spot shape on a surface 7 to be scanned by scanning optical device, and light-scans on the surface to be scanned, and a scanning line scanning on the surface to be scanned has two or more extremums within the effective range of a scanning area.

Abstract: An optical scanner comprises a light source for emitting a light beam, an optical deflector for deflecting the light beam and a scanning optical system for focusing the deflected light beam on a surface to be scanned. The scanning optical system has a diffracting section and a refracting section and may optionally have a reflector mirror or an optical filter. The illuminance distribution of the light beam is maintained to be substantially uniform on the surface to be scanned by offsetting the changes in the diffraction efficiency of the diffracting section, the transmittance of the refracting section, the reflectance of the reflector mirror and the transmittance of the optical mirror, due to the angle of view of the scanning optical system.

Abstract: An optical scanner comprises a light source for emitting a light beam, an optical deflector for deflecting the light beam and a scanning optical system for focusing the deflected light beam on a surface to be scanned. The scanning optical system has a diffracting section and a refracting section and may optionally have a reflector mirror or an optical filter. The illuminance distribution of the light beam is maintained to be substantially uniform on the surface to be scanned by offsetting the changes in the diffraction efficiency of the diffracting section, the transmittance of the refracting section, the reflectance of the reflector mirror and the transmittance of the optical mirror, due to the angle of view of the scanning optical system.

Abstract: A scanning optical device used for a laser beam printer, a digital copying apparatus or the like, includes a light source for emitting light beam, deflector for deflecting light beam emitted from the light source toward a surface to be scanned, and a scanning optical system for forming a spot of the light beam deflected by the deflector on the surface to be scanned. The scanning optical system has a plurality of optical elements. A diffraction optical element is formed on a curved surface of at least one of the plurality of optical elements.

Abstract: In a scanning optical device, a light beam emitted from a light source is deflected by a deflector to reach as a light spot a surface to be scanned through a scanning optical system. At least one of the optical surfaces of optical elements constituting the scanning optical system is provided with a diffraction grating having a power based on a change in pitch. The power of the diffraction grating asymmetrically changes within a plane of the optical element surface, on which the diffraction grating is formed, without any symmetrical axis, in at least one of a main scanning direction and sub-scanning direction.

Abstract: The method for producing nonionic detergent granules includes the steps of (I) blending the following (i) to (iii): (i) at least one of a nonionic surfactant and an aqueous nonionic surfactant solution; (ii) an acid precursor of an anionic surfactant capable of having a lamellar orientation; (iii) at least one of an alkali builder and an alkali, porous oil-absorbing carrier, to give a mixture of detergent starting materials containing the nonionic surfactant as a main surfactant component; and (II) heating the mixture obtained in step (I) at least up to a temperature capable of neutralizing the acid precursor of the anionic surfactant in an agitating mixer, and granulating while tumbling the agitating mixer thereby increasing a bulk density, to give nonionic detergent granules having a bulk density of from 0.6 to 1.2 g/ml.

Abstract: A scanning optical apparatus includes a light source unit, a deflector for deflectively scanning a light beam from the light source unit, an optical box in which the deflector is accommodated and an optical system for focusing the light beam deflectively scanned by the deflector on a predetermined surface. The optical system is supported by the optical box and having upside-down prevention mechanism which interferes with a predetermined portion of the optical box to prevent upside-down mounting of the optical system.

Abstract: The method for producing detergent particles having a high bulk density, the method being characterized by mixing granulated detergent particles having a bulk density of from 500 to 1,000 g/liter, while applying a shearing force to particles caused by a contact of the particles with each other in a mixer. According to the production method using a drum mixer of the present invention, it is possible to increase the bulk density of the detergent particles by 50 to 200 g/liter, wherein the granulated detergent particles or that of the granulated detergent particles subjected to a treatment of increasing bulk density by conventional methods have a bulk density of from 500 to 1,000 g/liter.

Abstract: The method for producing nonionic detergent granules includes the steps of (I) blending the following (i) to (iii): (i) at least one of a nonionic surfactant and an aqueous nonionic surfactant solution; (ii) an acid precursor of an anionic surfactant capable of having a lamellar orientation; (iii) at least one of an alkali builder and an alkali, porous oil-absorbing carrier, to give a mixture of detergent starting materials containing the nonionic surfactant as a main surfactant component; and (II) heating the mixture obtained in step (I) at least up to a temperature capable of neutralizing the acid precursor of the anionic surfactant in an agitating mixer, and granulating while tumbling the agitating mixer thereby increasing a bulk density, to give nonionic detergent granules having a bulk density of from 0.6 to 1.2 g/ml.