Abstract: Disclosed is a laser optical system including a multiline laser source that emits a laser beam having a plurality of peak wavelengths, a wavelength separating optical system that separates the laser beam emitted from the laser source into two monochromatic beams, a pair of modulating optical systems that modulate intensities of the monochromatic beams, a beam combining optical system that combines the laser beams modulated by the modulating optical systems, a deflector for deflecting a plurality of laser beam combined by the beam combining optical system, and a converging optical system that converges the laser beams deflected by the deflector to form beam spots on an object surface to be exposed. The modulating optical systems, which include diffractive beam-dividing elements, are optimized for the respective monochromatic beams to form the beam spots at the identical pitches on the object surface.

Abstract: Provided is a game screen display controlling method comprising the steps of displaying a first game screen obtained from a first projection of a virtual 3-D space; comparing the priority of the first projection with the priority of a second projection correlated with a predetermined area when there is a predetermined positional relationship between a character who moves in the virtual 3-D space and the predetermined area set within the virtual 3-D space; and displaying a second game screen obtained from the second projection of the virtual 3-D space when the priority of the second projection is higher than the priority of the first projection. Thereby, the invention allows game pictures for effectively rendering the virtual 3-D space to be presented corresponding to the situation of the game.

Abstract: A scanning optical system is provided with a laser diode, a polygonal mirror and a scanning lens system. The scanning lens system has positive power. Further, the scanning lens system has a plurality of lens surfaces, one of which is formed with a diffractive lens structure for compensating for aberration in a main scanning direction caused by characteristics of a refractive lens structure of the scanning optical system. The diffractive lens structure is arranged such that an axis that connects a front focal point and a rear focal point of the diffractive lens structure is shifted in an auxiliary scanning direction with respect to an optical axis of the refractive lens structure of the scanning lens system.

Abstract: A multi-beam optical system has a beam-dividing element that divides a light beam emitted by a light source into a plurality of light beams, which are emerged therefrom at different angles, respectively. A propagation optical system, through which the divided light beams propagate, includes a plurality of curved surface mirrors, and an image-forming optical system that forms a plurality of beam spots on an objective surface by converging the light beams propagated through the propagation optical system. In such an optical system, the curved mirrors are arranged such that the affection of the mirrors on the alignment of the beam spots is accumulatively cancelled.

Abstract: Disclosed is a diffractive optical element which includes a diffractive grating pattern on a base plate. The diffractive grating pattern includes a plurality of phase gratings arranged in parallel lines extending along a predetermined direction to cause diffraction of an incident beam. Each of the plurality of phase gratings has an asymmetrical phase pattern. There is a phase gap, &Dgr;P, representing a phase difference (in radians) between an end point and a beginning point of each phase pattern. The phase gap, &Dgr;P, is substantially equal for each of the plurality of phase gratings and satisfies the relationship. 0.7&pgr;<|&Dgr;P|<1.2&pgr;.

Abstract: Provided is a game screen display controlling method comprising the steps of displaying a first game screen obtained from a first projection of a virtual 3-D space; comparing the priority of the first projection with the priority of a second projection correlated with a predetermined area when there is a predetermined positional relationship between a character who moves in the virtual 3-D space and the predetermined area set within the virtual 3-D space; and displaying a second game screen obtained from the second projection of the virtual 3-D space when the priority of the second projection is higher than the priority of the first projection. Thereby, the invention allows game pictures for effectively rendering the virtual 3-D space to be presented corresponding to the situation of the game.

Abstract: A scanning optical element made of light transmitting material has alight transmissive first surface, and a reflective second surface. The first and second surfaces have first and second intersection points with first and second reference planes, respectively. The first and second reference planes are perpendicular to a predetermined single axis, on which the first and second intersection points are located. The first surface is tangent to the first reference plane at the first intersection point. The second surface is expressed by a SAG amount defined by a two-dimensional polynomial having variables which are two-dimensional coordinates, in the main scanning direction and in the auxiliary scanning direction, on the second reference plane. Coefficients for the two-dimensional polynomial defining the second surface are configured such that a coefficient for a term having only a first order component with respect to the coordinates in the auxiliary scanning direction is not zero.

Abstract: A positional relationship of a plurality of beam spots for a multi-beam imaging apparatus is detected. The imaging apparatus including a light source, a beam splitter that divides a received beam into a plurality of beams, a deflecting system that deflects the beams to scan, and an imaging optical system that forms a plurality of scanning beam spots on a surface. According to the method, a phase filter is provided between the light source and the beam splitter. The filter is configured to divide a cross section of the beam into a plurality of areas, light fluxes passed through adjoining two areas having an optical path difference of half a wavelength. Dark lines are formed, in each beam spot, due to the phase difference of the adjoining two areas. By detecting the dark lines of respective beam spots, a positional relationship between the plurality of beam spots can be determined.

Abstract: A scanning optical system for scanning a light beam on an object surface in a main scanning direction is provided. The scanning optical system includes a light source, a polygonal mirror, and an optical system for focusing the light beam deflected by the polygonal mirror on the object surface. The rotation axis of the polygonal mirror is inclined with respect to an auxiliary scanning direction, which is perpendicular to the main scanning direction, to displace the beam spot in the auxiliary scanning direction. The light beam incident on the reflecting surface is also inclined with respect to a main scanning plane, which is parallel to the main scanning direction and includes an optical axis of the optical system, to displace the beam spot in the same auxiliary scanning direction that the beam spot is displaced due to the inclination of the rotation axis.

Abstract: A laser imaging apparatus for forming an image on a surface of a substrate is provided with a laser source that emits a laser beam, a table mounting the substrate, the table being movable in a first direction within a predetermined plane, a scanning optical system which receives and deflects the laser beam emitted by the laser source to form a scanning beam spot on the substrate, the scanning beam spot scanning in a second direction that is perpendicular to the first direction, and a mechanism that moves the scanning optical system in the second direction.

Abstract: An image projecting device is provided with a light source, a modulating device that modulates the light emitted by the light source in accordance with an image to be projected, and a projecting lens that receives the light emitted by the light source and modulated by the modulating device, and projects the modulated light on a screen to form an image. The image projecting device is further provided with a relay lens system which is provided between the modulating device and the projecting lens. The relay lens system is made movable in at least one direction perpendicular to an optical axis of the projecting lens to shift the image on the screen.

Abstract: Disclosed is a scanning optical system that includes a semiconductor laser; a polygon mirror that deflects and scans a light beam emitted from the laser; and an imaging optical system that forms a beam spot on a photoconductive drum. The imaging optical system consists of a curved surface mirror having a positive power mainly in the main scanning direction and an anamorphic lens having a positive power mainly in the auxiliary scanning direction. The anamorphic lens having an anamorphic surface whose optical axis is decentered from a reference ray that reaches the center of the scanning range. The sectional shape of the anamorphic surface in an auxiliary scanning direction being a non-circular curved line to correct coma in the auxiliary scanning direction. The anamorphic surface is a rotationally asymmetrical surface that is defined by a two dimensional polynomial expression.

Abstract: Disclosed is a laser modulating optical system, which includes an argon laser that emits at a plurality of peak wavelengths, an acoustooptic modulator (AOM) that changes a direction of an emergent light by diffraction caused by input ultrasonic wave to take out a diffracted beam as a modulated beam, and a correction optical system. The correction optical system includes one pair of wedge prisms located in a parallel laser beam at the incident side of the AOM. The wedge prisms are arranged with a predetermined space therebetween. The apex of one prism is opposite in direction to the apex of the other prism to have the opposite chromatic dispersions to each other. The wedge prisms are designed to coincide the optical paths of two peak wavelengths that are deviated to each other due to a variation of the diffraction angle of the AOM.

Abstract: A laser imaging device is provided with a laser source that emits a laser beam including a plurality of wavelength components. The wavelength components are divided by a dividing optical system, and at least two wavelength components are extracted and each of which is directed to a beam dividing element. Each wavelength component are divided into a plurality of beams, and independently modulated by the modulating optical systems. The beams having different wavelengths are directed to respective scanning optical system, and deflected thereby to scan in different areas on an objective surface.

Abstract: A multibeam optical system that employs a laser source emitting a laser beam, a diffractive beam-dividing element that diffracts the laser beam emitted from the laser source to be divided into a plurality of diffracted beams exiting at different diffraction angle, and a compensating optical system. compensating optical system, which is afocal and consists of a first group and a second group, arranged at the position where beams divided by a diffractive beam-dividing element are incident thereon. The compensating optical system has a characteristic such that the angular magnification thereof is inversely proportional to the wavelength of the incident beam. The angular difference among the diffracted beam caused by the wavelength dependence of the diffractive beam-dividing element can be reduced when the beams transmit the compensating optical system.

Abstract: A reflection type projector includes a light source, a micro mirror device having many micromirrors two-dimensionally arranged, a separation prism and a projection lens. The separation prism is disposed between the light source and the micro mirror device. The separation prism is provided with a first surface on which the illumination light is incident, a second surface whose half part faces to the micro mirror device and the remaining half part is directed to the projection lens, and a third surface. The illumination light passes through the first and second surface to be incident on the micro mirror device. The reflected light from the micro mirror device is incident on the second surface. The separation prism is disposed so that the reflected light by the micromirrors at the ON position totally reflected by the first and third surface and the reflected light by the micromirrors at the OFF position is not totally reflected by the third surfaces.

Abstract: A multi-beam optical system has a beam-dividing element that divides a light beam emitted by a light source into a plurality of light beams, which are emerged therefrom at different angles, respectively. A propagation optical system, through which the divided light beams propagate, includes a plurality of curved surface mirrors, and an image-forming optical system that forms a plurality of beam spots on an objective surface by converging the light beams propagated through the propagation optical system. In such an optical system, the curved mirrors are arranged such that the affection of the mirrors on the alignment of the beam spots is accumulatively cancelled.

Abstract: A beam shape compensation optical system includes a first anamorphic beam expander which expands a cross section of a parallel beam incident along a predetermined direction at a first magnification ratio M1 at least in a first direction which is perpendicular to the predetermined direction, and a second anamorphic beam expander which expands a cross section of a parallel beam incident along the predetermined direction at a second magnification ratio M2 at least in a second direction which is perpendicular to the predetermined direction. The first and second anamorphic beam expander are rotatable so that an angle between the first direction and the second direction on a plane perpendicular to the predetermined direction is changeable.

Abstract: Disclosed is a diffractive optical element which includes a diffractive grating pattern ion a base plate. The diffractive grating pattern includes a plurality of phase gratings arranged in parallel lines extending along a predetermined direction to cause diffraction of an incident beam. Each of the plurality of phase gratings has an asymmetrical phase pattern. There is a phase gap, &Dgr;P, representing a phase difference (in radians) between an end point and a beginning point of each phase pattern. The phase gap, &Dgr;P, is substantially equal for each of the plurality of phase gratings and satisfies the relationship. 0.7&pgr;<|&Dgr;P|<1.2&pgr;.

Abstract: A scanning optical system includes a light deflector and a light emitter which emits a beam of light which scans a scanning surface along a main scanning direction. The beam of light emitted by the emitter is incident onto the light deflector as a non-convergent beam of light in the main scanning direction. Further, an optical element which has a reflecting surface is utilized as an f.theta. element. The optical element includes a first surface onto which light from the light deflector is incident, and from which light transmitted through the optical element is emitted and a second surface which is provided with a reflective surface thereon. Further, at least the second surface of the optical element is shaped so as to have no rotational axis and to not be rotationally symmetrical about an optical axis. Additionally, at least one surface of the optical element is tilted with respect to an axis perpendicular to the beam of light incident thereon.