Abstract: A scanning optical system which includes a light source for emitting a beam of light, a light deflector for deflecting the beam of light in a main scanning direction, and a scanning lens which receives a beam of light deflected by the light deflector for focusing the deflected beam of light onto a scanning surface. The scanning lens includes a lens having a refractive index distribution in either the main or the sub-scanning direction.

Abstract: A laser drawing apparatus is provided including, a first beam splitting element for splitting laser light emitted from a laser source into a plurality of beams, a second beam splitting element for splitting the beams split by the first beam splitting element into a plurality of groups of drawing beams, optical modulators which provide separate ON/OFF drawing data to the respective split drawing beams split by the second splitting element, a beam combining element for combining the split drawing beams to which the ON/OFF drawing data has been provided, and a beam scanning element for scanning a drawing surface on which an image is to be formed with the combined drawing beams.

Abstract: A scanning optical system having both a reading optical system and an image forming optical system is capable of using one or more components for both systems.

Abstract: A reflection type scanning optical device comprises a rotatable polygonal mirror arranged so that a light beam deflected from the polygonal mirror is separated from the light beam incident thereto, a first curved mirror having a negative power in the main scanning direction to reflect the deflected light beam from the polygonal mirror toward the polygonal mirror, a second curved mirror having a positive power in the main scanning direction to reflect the light beam reflected from the first curved mirror toward the first curved mirror, and a toric lens having a positive power at least in the auxiliary scanning direction to converge the light beam reflected from said second curved mirror and to form a spot on a surface to be scanned.

Abstract: A scanning (f.theta.) lens includes first, second, third, and fourth lenses, respectively having negative, positive, positive, and negative power in at least the main scanning directions. The lenses are arranged in order from a polygon mirror to a drawing surface. The Abbe number of the fourth lens is less than 40. In a further refinement, the Abbe number of the fourth lens subtracted from half the difference between the Abbe numbers of the second and third lenses is greater than 20. In another refinement, the scanned surface side surface of the first lens element is a cylindrical surface having negative power only in the auxiliary scanning direction, and the scanned surface side surface of one of the second or third lens elements is a toric surface having greater positive power in the auxiliary scanning direction than in the main scanning direction.

Abstract: A reflection type scanning optical device includes a light source; a deflector for deflecting and scanning the light beam emitted from the light source; a first imaging optical system, between the light source and the deflector, that has a positive power in an auxiliary scanning direction for converging a light beam from the light source to form a linear image at the position between the deflector and the imaging surface; and a second imaging optical system that converges the light beam deflected by the deflector to form a beam spot on the imaging surface, the second imaging optical system including a curved surface mirror having a positive power mainly in a main scanning direction and an anamorphic lens having a positive power mainly in the auxiliary scanning direction, wherein the light beam from the deflector is reflected by the curved surface mirror and then passes the anamorphic lens.

Abstract: Lens arrangements for a multibeam recording device include a first lens group that forms collimated beams paired with a second lens group, allowing the second lens group to be moved for focusing. A first lens group forms non-collimated beams is paired with a second lens group, allowing one lens group to be moved for magnification change. A first lens group forms non-collimated beams between internal portions and collimated beams leading to a second lens group, allowing magnification change by moving the two portions and focus change by moving the second lens group. A first lens group having two movable portions is paired with a second lens group, both movable portions being shiftable and tiltable to correct for decentering errors. Three concrete reduction lens system examples applicable in each of the embodiments use positive anomalous dispersion glass, allowing low dispersion and the use of blue LEDs to increase the imaging resolution.

Abstract: A laser drawing apparatus including a splitting means for splitting laser light emitted from a laser source into groups of drawing beams, the drawing beams being aligned in a common plane; a lens to which said drawing beams are made incident upon; and a scanning means for scanning a drawing surface with the said drawing beams passed through the lens in a main scanning direction; wherein the laser source and the splitting means are arranged in a manner such that the drawing beams in the common plane are alinged on a meridian of the lens, and the drawing beams are made incident upon the lens as linearly polarized light having a direction of oscillation which is parallel with or normal to the meridian of the lens.

Abstract: A scanning optical system that includes a light source for emitting a beam of light, a light deflector for deflecting the beam of light in the main scanning direction, and a scanning lens system which receives a beam of light deflected by the light deflector for focusing the deflected beam of light onto a scanning surface. At least one surface of a lens in the scanning lens system is formed in such a manner so as to have the cross-sectional shape of a non-circular arc in any sub-scanning plane so as to correct the spherical aberration of the scanning lens system in sub-scanning planes each extending parallel to the sub-scanning direction.

Abstract: A scanning lens converges light deflected by a deflector onto a surface to be scanned, comprises a first lens having a negative power in both a main scanning direction and in an auxiliary scanning direction, a second lens having a positive power in both the main scanning direction and in the auxiliary scanning direction, a third lens having a positive power in both the main scanning direction and in the auxiliary scanning direction, and a fourth lens provided with a cylindrical surface having a negative power in the auxiliary scanning direction. The first, second, third and fourth lenses are arranged in this order from the deflector. The first, second and third lenses are formed so that curvature of field in the auxiliary scanning direction is reduced. A bow of an abaxial scanning line, which cannot be corrected by the first, second and third lenses, can be corrected by the cylindrical surface of the fourth lens.

Abstract: An f.theta. scanning lens arrangement, arranged from a polygonal mirror side to an imaging surface side, including a first, second, third, and fourth lens with having negative, positive, positive, and negative power, respectively, in the main scanning and subscanning directions is provided. The ratio of the focal length in the main scanning direction of the fourth lens versus the focal length in the main scanning direction of the entire f.theta. lens is selected to simultaneously minimize astigmatism, field curvature, and linearity error. Further, the ratio of the focal length in a subscanning direction of the first lens versus the focal length in the subscanning direction of the second lens is selected to minimize curving of scanning lines displaced from the optical axis.

Abstract: An image forming lens system including a positive front lens group, a diaphragm, and a rear lens group, in this order from an object to be imaged. The front lens group is made of optical glass. The rear lens group is made of a single meniscus plastic lens having opposed aspherical lens surfaces with a concave surface adjacent to the diaphragm. The lens system satisfies the following relationships:f.sub.0 .multidot..vertline.1/f.sub.R-1 +1/f.sub.R-2 .vertline.<0.3-4<f.sub.0 /r.sub.R-1 <-0.7.DELTA.X.sub.R-1 /f.sub.0 <0.DELTA.X.sub.R-2 /f.sub.0 <00.1<d.sub.R /f.sub.0.In the above, f.sub.R-1 (=r.sub.R-1 /n-1) represents the focal length of the first surface of the plastic lens, f.sub.R-2 (=r.sub.R-2 /1-n) represents the focal length of the second surface of the plastic lens, f.sub.0 represents the focal length of the whole lens system, n represents the refractive index of the plastic lens at a reference wavelength, r.sub.

Abstract: A scanning optical system including a light deflector rotating about a rotational axis perpendicular to a main scanning direction, a laser beam emitter for emitting a laser beam which scans a scanning surface along the main scanning direction and for making the laser beam incident upon the light deflector with a first angle with respect to a sub-scanning direction perpendicular to the main scanning direction, a curved mirror having a curvature at least along the main scanning direction for reflecting a laser beam deflected by the light deflector with a second angle with respect to an incident laser beam upon the curved mirror, and an anamorphic lens disposed between the curved mirror and the scanning surface. The anamorphic lens has a first surface having a first aspherical surface along the main scanning direction, and a second surface having a second aspherical surface which is not rotationally symmetrical about an optical axis of the anamorphic lens.

Abstract: A scanning optical system with a light beam deflected by an optical deflector is scanned on a scanning surface in a main scanning direction through the scanning optical system. The scanning optical system comprises an image forming lens system having a refracting power at least in a direction of the main scanning direction and an optical member having at least one deviated surface whose center of radius of paraxial curvature is deviated from a main scanning plane in a sub-scanning direction which is normal to the main scanning direction. The main scanning plane is defined by a plane that the light beam scans. A light interrupting member for interrupting a ghosting light reflected by external or internal surfaces including the deviated surface in the image forming lens system is provided. The light interrupting member is disposed between the image forming lens system and the scanning surface to prevent ghosting light from reaching to the scanning surface.

Abstract: In a scanning optical system, a light emitting device emits a beam to a deflection mirror. The beam is inclined in the direction of the auxiliary scanning, so that the optical axis of the beam incident to the deflection mirror intersects the rotational axis of the deflection mirror. The optical axis of the beam, when the beam reaches the center of a predetermined scanning angle zone, is orthogonal to a light reflection surface of the deflection mirror when seen from the auxiliary scanning direction. The deflected beam is reflected by a curved mirror and directed to an object surface through an anamorphic lens. The optical axis of the anamorphic lens is displaced with respect to the optical axis of the scanning optical system.

Abstract: A scanning optical system having an image forming optical system for emitting a scanning beam modulated in accordance with image information onto a destination surface. The scanning optical system further includes a reading optical system for receiving light reflected from an object surface to obtain image information from the object surface. Both systems make use of at least one common optical component, for example, a polygonal mirror, a cylindrical mirror, a common optical path or a toric lens.

Abstract: The improved scanning optical system comprises a gas laser 10 for generating writing beam, a semiconductor laser 50 for generating monitoring beam of a different wavelength than the writing beam, a polygonal mirror 20 for deflecting and scanning the rays of light from each of the sources, a scanning lens 30 with which the rays of light deflected by the polygonal mirror 20 are focused on an image plane 40, a dichroic mirror 60 provided between the scanning lens 30 and the image plane 40 to isolate the monitoring beam from the optical path of the writing beam, and a signal generator A that receives the isolated monitoring light to generate a monitor signal. This optical system will not lower the energy of the writing beam, will not experience any change in the quantity of the monitoring beam due to leakage, and is free from the problem of curvature in the scanning lines of the monitoring beam.

Abstract: In a scanning optical system, a light emitting device emits a beam to a deflection mirror. The beam is inclined in the direction of the auxiliary scanning, so that the optical axis of the beam incident to the deflection mirror intersects the rotational axis of the deflection mirror. The optical axis of the beam, when the beam reaches the center of a predetermined scanning angle zone, is orthogonal to a light reflection surface of the deflection mirror when seen from the auxiliary scanning direction. The deflected beam is reflected by a curved mirror and directed to an object surface through an anamorphic lens. The optical axis of the anamorphic lens is displaced with respect to the optical axis of the scanning optical system.

Abstract: An optical scanning system has an image reading scanning system for emitting a first scanning beam of light to read an image of an object, an image forming scanning system for emitting a second scanning beam of light to form an image on a light receiving surface, and a light receiving element. Each of the first and second scanning beams is incident on the light receiving element when each of the first and second scanning beams is located at an end portion of a scanning area, and the first scanning beam and the second scanning beam have different optical characteristics. The optical scanning system also has a circuit for generating a horizontal synchronous signal for the image reading optical system and the image forming optical system, respectively, in accordance with light received by the light receiving element.

Abstract: A scanning optical system has a beam of light which is deflected by a light deflector and which scans a scanning surface along a main scanning direction through a scanning lens system. The scanning lens system includes an anamorphic lens made of glass which has a positive power in both the main scanning direction and in a sub-scanning direction perpendicular to the main scanning direction. The positive power in the sub-scanning direction is larger than the positive power in the main scanning direction. Also included is a plastic lens having an aspherical surface in the main scanning direction.