Abstract: A drawing method for forming a reflective curved surface by pressing a metal plate fitted in a fixed die with a movable die. The fixed die is composed of a lower die and a core, and the movable die is composed of an upper die and a presser. During the drawing, the metal plate is pressed to have a compressed border portion between a non-pressed portion and a curved surface pressed portion. It is the most desirable to compress the border portion to have a thickness which is 70% of the thickness of the metal plate before drawing.

Abstract: A drawing method for forming a reflective curved surface by pressing a metal plate fitted in a fixed die with a movable die. The fixed die is composed of a lower die and a core, and the movable die is composed of an upper die and a presser. During the drawing, the metal plate is pressed to have a compressed border portion between a non-pressed portion and a curved surface pressed portion. It is the most desirable to compress the border portion to have a thickness which is 70% of the thickness of the metal plate before drawing.

Abstract: An acoustooptic device is structured by providing an interdigital transducer in which arch-shaped electrode fingers are interdigitated so that the interdigital transducer is circular or annular in shape as a whole, on an optical waveguide which is circular when viewed from the front. This acoustooptic device is used as a diffraction optical device on which light is incident from the front. When an alternating voltage of a predetermined frequency is applied to the interdigital transducer by an oscillator, a concentric acoustic compressional wave is generated on the optical waveguide. The concentric acoustic compressional wave diffracts the incident light, so that the diffraction optical device functions like a lens and converges the luminous flux.

Abstract: An acoustooptic device is structured by providing an interdigital transducer in which arch-shaped electrode fingers are interdigitated so that the interdigital transducer is circular or annular in shape as a whole, on an optical waveguide which is circular when viewed from the front. This acoustooptic device is used as a diffraction optical device on which light is incident from the front. When an alternating voltage of a predetermined frequency is applied to the interdigital transducer by an oscillator, a concentric acoustic compressional wave is generated on the optical waveguide. The concentric acoustic compressional wave diffracts the incident light, so that the diffraction optical device functions like a lens and converges the luminous flux.

Abstract: A laser beam scanning optical apparatus which images each laser beam emitted from a laser diode array via a deflector and optical elements and scans the laser beam linearly on a scanning surface at a substantially constant speed. The laser diode array has a plurality of light emitting sources arranged two-dimensionally, and more specifically, arranged in a first direction at uniform intervals of P1 and in a second direction perpendicular to the first direction at uniform intervals of P2 which is different from P1. In the laser beam scanning optical apparatus, the magnification ratio in the main scanning direction and the magnification ratio in the sub scanning direction are different from each other.

Abstract: In a multibeam scanning optical apparatus of a type where two parallel lines are simultaneously scanned by two laser beams irradiated from two semiconductor lasers, stable images are formed on the scanned surface by the two laser beams and the cost is reduced. The two laser beams irradiated from the two semiconductor lasers are directed substantially in the same direction through a beam splitter and then shaped by a condenser lens into two luminous fluxes whose optical axes are substantially parallel to each other. In another arrangement, the semiconductor lasers are directly secured to a surface of the beam splitter by use of an ultraviolet setting resin.

Abstract: A multi-beam optical scanning device capable of suppressing jitter at the image edges within allowable tolerance by satisfying the following equation: ##EQU1## Where r represents the radius of photosensitive member (mm); .alpha. represents the maximum value of the angle obtained by subtracting the angle formed by the light beam and the scanned line on the surface of the photosensitive member from 90 degrees; D represents the distance (mm) on the surface of the photosensitive member between the light beam condensing position on the furthermost upstream side and the condensing position on the furthermost downstream side in the direction of rotation of the photosensitive member.

Abstract: Provided is a laminate type multi-semiconductor laser device and a laser beam scanning optical apparatus employing the semiconductor laser device to be assembled into a laser printer or a digital copying machine for executing image printing at a high speed by means of a plurality of laser beams. The laminate type multi-semiconductor laser device is provided with a laminate wafer in which a plurality of active layers are laminated and light emitting regions which are provided in the active layers as mutually displaced in a direction perpendicular to the laminate direction in which the active layers are laminated. Assuming that an interval between the light emitting regions of adjacent active layers in the direction perpendicular to the laminate direction is p and an interval between the adjacent active layers is q, then a relational expression of q>p is satisfied.

Abstract: A light beam scanning optical apparatus in which is capable of switching over the image density. The light beam scanning optical apparatus comprises a light source unit having at least three light emitting points, a control circuit block which selects and lights the light emitting points for switching over the image density at least either between different pages or within one page, an optical deflector for deflecting light beams emitted from the light emitting points, a scanning surface, a first optical system placed between the laser diode array and the optical deflector, and a second optical system placed between the optical deflector and the scanning surface. For switching over the image density, light emitting points corresponding to a specified image density are selected and lighted by the control circuit block.

Abstract: A light beam scanning optical apparatus which writes two lines at one scan on a photosensitive member with light beams emitted from laser diodes. The light beams are combined at a beam splitter. The beam splitter is supported on a surface including a semitransparent layer by total three balls provided on a base block.

Abstract: A light beam scanning optical apparatus is provided which simultaneously converges a plurality of light beams on different locations in a scanning surface and thereby simultaneously writes a plurality of lines in one scanning operation. The light beam scanning optical apparatus comprises a light source having three or more light emitting points, and a converging lens which shapes light beams emitted from the light source, into generally parallel or convergent bundles of rays. The converging lens has a shape generally symmetrical with respect to the optical axis, and the light emitting points on the light source are disposed on a circle having its center generally on the optical axis. Alternatively, the light source comprises a first light source having one light emitting point, a second light source having a plurality of light emitting points, and a light beam coupling device for unifying the directions of travel of light beams emitted from the first and second light sources.

Abstract: A laser diode array unit for use in laser beam scanning optical apparatus and the like. The laser diode array has plural light emitting sources to be drivingly controlled independently of each other. The laser diode array is so disposed as to permit laser beams emitted from the light emitting sources to be incident to a collimator lens. On an optical axis between the laser diode array and the collimator lens is disposed a beam splitter for splitting the laser beams emitted from the light emitting sources into image light and monitor light. A magnifier lens and a photoreceptor element are arranged on the optical axis so as to allow incidence of monitor light oriented to advance in a direction perpendicular to the direction of advance of image light.

Abstract: A light beam scanning optical apparatus which writes two lines at one scan on a photosensitive member with light beams emitted from two light sources. A light source unit of the apparatus has a first movable retainer block which retains a first laser diode and a second movable retainer block which retains a second laser diode. The second movable retainer block becomes adjustable two-dimensionally on a base block by loosening screws which fit the second movable retainer block to the base block.

Abstract: A scanning optical apparatus has a convex cylindrical lens and a concave cylindrical lens between a light source for emitting a light beam and a polygon mirror. The cylindrical lenses condense the light beam in the vicinity of a deflecting surface of the polygon mirror only in the sub-scanning direction. The cylindrical lenses are held by a lens barrel to form one unit, and the lens barrel is mounted on a V groove formed in a base. The position of the unit having the cylindrical lenses is adjustable along the optical axis, and the rotational angle of the unit is adjustable about the optical axis.

Abstract: A scanning apparatus has a luminous flux deflector and a single f.theta. lens. The deflector deflects a convergent luminous flux on a scanned surface at a uniform angular velocity. The f.theta. lens is arranged between the deflector and the scanned surface. The f.theta. lens is bi-convex in a main scanning direction and is made of a material having a refractive index of at most 1.6. One surface of the f.theta. lens in a main scanning direction is so curved that a radius of curvature in the main scanning direction A decreases as an angle of view in the main scanning direction increases.

Abstract: A multi-beam emitting device which splits a light beam emitted from a light source into a plurality of beams with a beam splitter to emit a plurality of beams. As the beam splitter, an optical waveguide type acoustooptic element or the like is used. A multi-beam emitting device according to the present invention has a beam splitter which drives an acoustooptic element with a plurality of electric signals with different frequencies applied thereto so as to deflect a light beam emitted from a light source and split the light beam into a plurality of beams, a signal generator which generates the electric signals with different frequencies which are used for the drive of the acoustooptic element, a modulating circuit which turns on and off the electric signals generated by the signal generater individually based on a data signal, an intensity control circuit which controls the light source to change the intensity of the light beam emitted therefrom.

Abstract: A light source device has a semiconductor laser element, a collimator lens, a lens barrel for holding the collimator lens, first and second lens barrel support member and a laser support member. The lens barrel support members are formed of the same type of material as that of the lens barrel and engage the lens barrel at a surface parallel to the optical axis of the collimator lens. The laser support member is formed of a different type material from that of the lens barrel support members, and joins the lens barrel support members at a surface perpendicular to the optical axis of the collimator lens.

Abstract: A scanning optical apparatus for a printer and a digital copying machine has a light source, a deflector, first and second imaging units. The deflector deflects a light beam emitted from the light source to a main scanning direction. The first imaging unit makes the light beam emitted from the light source form an image in the vicinity of the deflection position of said deflector in the sub-scanning direction. The first imaging unit has a first resin lens having a negative refractive power only in a sub-scanning direction. The second imaging unit makes the light beam deflected by the deflector form an image on a scanned surface in the sub-scanning direction. The second imaging unit has a second resin lens having a positive refractive power only in the sub-scanning direction.

Abstract: A laser beam scanning apparatus used for scanning a surface of a photoreceptor in an image forming apparatus. In the laser beam scanning apparatus, the laser beam emitted from a semiconductor laser is formed into a bundle of parallel rays by an objective lens, thereafter is converged by a converging lens immediately in front of a deflector such as a polygonal mirror. The converged laser beam is deflected by the polygonal mirror, and is concentrated on a beam receiving surface by scanning lenses.

Abstract: A scanning apparatus has a luminous flux deflector and a single f.theta. lens. The deflector deflects a convergent luminous flux on a scanned surface at a uniform angular velocity. The f.theta. lens is arranged between the deflector and the scanned surface. The f.theta. lens is bi-convex in a main scanning direction and is made of a material having a refractive index of at most 1.6. One surface of the f.theta. lens in a main scanning direction is so curved that a radius of curvature in the main scanning direction decreases as an angle of view in the main scanning direction increases.