Abstract: A laser processing method, which uses laser beam from a laser oscillator to emit continuously light pulse having large spacial and temporal energy concentration in a pulse emission period of one picosecond or less, and projects mask pattern with a projection lens onto a work piece almost transparent to the wavelength of the laser beam for sublimation processing thereof, comprises the following steps of setting the focal point of projecting image of the mask pattern on the surface of contour boundary on the opposite side of the work piece irradiated by the laser when the processing begins, at the same time, irradiating and converging the laser beam on the focal point portion so as to make the energy concentration thereof to be more than the threshold value enabling designated ablative action to be generated, moving the work piece in the direction of laser irradiation gradually in a designated amount or at a designated speed in synchronism with the progress of ablation processing by the irradiation of the laser

Abstract: An image can be outputted with a high sharpness without deteriorating a resolution. In order to output an image of a high picture quality while suppressing the occurrence of a moire, an exposure amount is modulated in accordance with pixel density information of the image divided into pixels of a predetermined size by an exposure amount modulating unit in a light scanning unit, thereby expressing an image dark/light state. In this case, in a highlight density region in which a pixel density is equal to or less than ⅓ of the maximum image density, the density data of two adjoining pixels is modulated by one pixel and the other pixel is not recorded. In a density region in which the image density lies within a range from ⅓ to ½ of the maximum image density, a part of the density data of one of the two adjoining pixels is transposed to the other pixel.

Abstract: An exposure apparatus for exposing an object of exposure to a pattern of a mask by reduction projection with a projection lens utilizing light from a light source, comprising a mask fixed to the optical axis, means for dynamically moving the pattern and means for moving the object of exposure, wherein the exposure is moved in synchronization with the movement of the pattern displayed by the mask.

Abstract: A method for forming through holes, which has laser beam as the light source to project the laser beam to the work object using an optical system through a photomask for the formation of through holes on the work object by ablation processing, comprises the steps of increasing the concentration of the optical processing energy contributing to the process using the reflected beam created from the work object in the laser ablation processing; and forming each of through holes having the configuration enabling the narrower end to be changed to the wider end in the incident direction of laser beam. With the structure thus arranged, it becomes possible to increase the energy concentration that contributes to the process as compared with the usual ablation processing, because the reflected beam created in the ablation processing can be utilized again for the optical processing.

Abstract: An image can be outputted with a high sharpness without deteriorating a resolution. In order to output an image of a high picture quality while suppressing the occurrence of a moire, an exposure amount is modulated in accordance with pixel density information of the image divided into pixels of a predetermined size by an exposure amount modulating unit in a light scanning unit, thereby expressing an image dark/light state. In this case, in a highlight density region in which a pixel density is equal to or less than ⅓ of the maximum image density, the density data of two adjoining pixels is modulated by one pixel and the other pixel is not recorded. In a density region in which the image density lies within a range from ⅓ to ½ of the maximum image density, a part of the density data of one of the two adjoining pixels is transposed to the other pixel.

Abstract: An image can be outputted with a high sharpness without deteriorating a resolution. In order to output an image of a high picture quality while suppressing the occurrence of a moire, an exposure amount is modulated in accordance with pixel density information of the image divided into pixels of a predetermined size by an exposure amount modulating unit in a light scanning unit, thereby expressing an image dark/light state. In this case, in a highlight density region in which a pixel density is equal to or less than 1/3 of the maximum image density, the density data of two adjoining pixels is modulated by one pixel and the other pixel is not recorded. In a density region in which the image density lies within a range from 1/3 to 1/2 of the maximum image density, a part of the density data of one of the two adjoining pixels is transposed to the other pixel. In a density region in which the image density is equal to or larger than 1/2 of the maximum density, the pixel transposition is not performed.

Abstract: An image forming paper comprises at least pulp, wherein the paper has a spectral reflectance of at least 85% for light diffused-reflected therefrom in a wavelength range of from 440 nm to 640 nm, and a spectral reflectance distribution in which the difference between the maximum and minimum values of the spectral reflectance of the light in the above wavelength range is 5% or less. Therefore, since the amount of light reflected by the paper is large and the reflectance in blue to red regions is constant, color chroma of a color image on the paper is enhanced particularly in green to red regions, and a color reproduction area of the color image is enlarged.

Abstract: An image forming apparatus includes a movable photosensitive member, a slit for imagewise exposure of said photosensitive member to light in a slit exposure area having a width in a direction of movement of said photosensitive member, and a movable reflecting member for forming a non-image area on said photosensitive member by light from said reflecting member. When blank exposure is effected, the reflecting member is disposed at a first position or a second position. When the reflecting member is disposed at the first position, the light from the reflecting member is substantially condensed on or adjacent to an upstream end of the exposure area width on the photosensitive member with respect to the movement direction of the photosensitive member, and an area before an image area on the photosensitive member in which an image is formed by the slit exposure means is exposed to the light.

Abstract: An image forming paper comprises at least pulp, wherein the paper has a spectral reflectance of at least 85% for light diffused-reflected therefrom in a wavelength range of from 440 nm to 640 nm, and a spectral reflectance distribution in which the difference between the maximum and minimum values of the spectral reflectance of the light in the above wavelength range is 5% or less. Therefore, since the amount of light reflected by the paper is large and the reflectance in blue to red regions is constant, color chroma of a color image on the paper is enhanced particularly in green to red regions, and a color reproduction area of the color image is enlarged.

Abstract: A plurality of elongated beams are generated by dividing a laser beam, said plurality of beams being respectively applied to corresponding lens elements of a flyeye lens array. The structure is arranged in such a manner that the diameter of the plurality of the beams in the shorter direction is made smaller than that of each of the lens elements, so that the plurality of beams are further divided into a plurality of elongated secondary beams by the flyeye lens. The plurality of the secondary beams are bundled on a diaphragm in such a manner that their lengthwise directions substantially coincide with each other so that a beam pattern is formed. A row of openings arranged in the lengthwise direction of the beam pattern and formed in the diaphragm member are uniformly and efficiently irradiated with the thus-formed beam pattern. Then, the image of the row of openings is projected onto a plastic plate or the like so that a multiplicity of holes are formed in the plate.

Abstract: In an optical scanning apparatus, a light beam emitted from a light source is collimated and is incident on a reflecting surface of a deflector via stop member. The deflector deflectively reflects the light beam to be directed to a surface to be scanned. The light beam deflectively reflected by the deflector is converged on the surface to be scanned by an optical system. The stop member has an aperture which is constructed such that a circular shape aperture and a slit-like shape aperture are combined. The width of the slit-like shape aperture is arranged in a sub-scanning direction while the circular portion of the circular shape aperture is arranged in a main scanning direction.

Abstract: An achromatic-type scanning optical arrangement includes a laser source, a first optical system for converging a beam of light emanating from the laser source, a deflecting device for deflecting the beam of light converged by the first optical system and a second optical system for focusing the beam of light deflected by the deflecting device onto a predetermined position. The entire optical system including the first optical system and the second optical system is corrected for chromatic aberration, as a whole, to eliminate the adverse influence of wavelength variations in the laser source upon variations in the focus position of the aforesaid beam of light.

Abstract: A plurality of elongated beams are generated by dividing a laser beam, said plurality of beams being respectively applied to corresponding lens elements of a flyeye lens array. The structure is arranged in such a manner that the diameter of the plurality of the beams in the shorter direction is made smaller than that of each of the lens elements, so that the plurality of beams are further divided into a plurality of elongated secondary beams by the flyeye lens. The plurality of the secondary beams are bundled on a diaphragm in such a manner that their lengthwise directions substantially coincide with each other so that a beam pattern is formed. A row of openings arranged in the lengthwise direction of the beam pattern and formed in the diaphragm member are uniformly and efficiently irradiated with the thus-formed beam pattern. Then, the image of the row of openings is projected onto a plastic plate or the like so that a multiplicity of holes are formed in the plate.

Abstract: An optical scanning apparatus for effecting the scanning with plural light beams, without aberrations among the obtained scanning lines and without curvature in the scanning lines. For this purpose plural light beams emitted from plural light sources are deflected by a single deflector, composed for example of a rotary polygon mirror, and guided to respective scanned planes through a scanning condenser lens system, having the f-.theta. characteristics in the scanning direction and also having plural optical axes in the sub scanning direction.

Abstract: A light scanning apparatus comprises a light source having a plurality of light emitting unit, a deflector for deflecting a plurality of light beams emanated from the light source, a first optical system which is for focusing the plural light beams deflected by the deflector and which is afocal in a refractive power in a sub-scan direction and has an f-.theta. characteristic in a refractive power in a scan direction, and a second optical system which is for directing the light beams from the first optical system to a predetermined plane and is provided for each of the light beams.

Abstract: An image forming apparatus includes an image carrier, an LED (light emitting diode) array having a plurality of light-emitting units arranged in correspondence with the longer direction of the image carrier, the width of the LED array being smaller than an image carrying width of the image carrier, and a projection unit for projecting and magnifying the light from the LED array upon the image carrier.

Abstract: A variable magnification image forming apparatus includes a photosensitive member, a light source, projecting device for forming and projecting on the photosensitive member an image of the original illuminated by the light source, the projecting device including lens system movable in accordance with a magnification of projection selected, a first limiting member for limiting light rays disposed with a fixed positional relation with respect to the lens system, and a second limiting member for limiting light rays in the lens system, the second limiting member being displaceable in a direction different from a direction of an optical axis of the lens system in accordance with magnification change to change the positional relation with respect to the first limiting member.