Abstract: The present invention allows image recording with plural light beams while eliminating alignment changes of light spots on the inner face of a drum. A light beam output unit 212 combines two circularly polarized light beams having opposite handedness to each other to produce a composite light beam CB. A polarization beam splitter 203 and mirrors 205 and 207 change the course of the light beam towards the inner face of a drum 120. A quarter-wave plate 202 is included, and the polarization beam splitter 203 splits the composite light beam to two separate light beams as a function of the handedness of the circularly polarized light. The optical elements 202, 203, 205, and 207 are integrally rotated around the axis of the drum 120 by a main scanning motor 230, thus scanning a photosensitive material 110 held on the inner face of the drum 120 with the light beams.

Abstract: A drum scanning type image reading apparatus includes an illumination optical system and an imaging optical system. The illumination optical system is an optical system for irradiating light upon an original. A variable aperture stop is disposed at a conjugate position with the original. In the imaging optical system, a pick-up lens focuses an image of an image reading region of the original on an image focusing surface, and photomultiplier tubes read light passing through one of holes which are formed in a main aperture plate which is disposed on the image focusing surface. To change an image reading resolution in the image reading apparatus, the image reading region and an illumination region are changed by changing the aperture size of the main aperture plate and the size of the variable aperture stop.

Abstract: The present invention allows image recording with plural light beams while eliminating alignment changes of light spots on the inner face of a drum. A light beam output unit 212 combines two circularly polarized light beams having opposite handedness to each other to produce a composite light beam CB. A polarization beam splitter 203 and mirrors 205 and 207 change the course of the light beam towards the inner face of a drum 120. A quarter-wave plate 202 and the polarization beam splitter 203 splits the composite light beam to two separate light beams as a function of the handedness of the circularly polarized light. The optical elements 202, 203, 205, and 207 are integrally rotated around the axis of the drum 120 by a main scanning motor 230, thus scanning a photosensitive material 110 held on the inner face of the drum 120 with the light beams.

Abstract: An afocal optical system is formed by a paraboroid mirror and an optical element having a stereographic projection characteristics which is defined by the following equation:hi'=2.multidot.f.multidot.tan (.theta.i/2)where hi' is a height of a light beam, leaving the optical element, taken from the optical axis or a heigh of an image taken from the optical axis, f is a focal length of the optical element and .theta.i is an angle of incidence with respect to the optical element. The focal point of the optical element coincide with that of the first paraboroid mirror. Thus, a compact afocal optical system which satisfies hi'=m.multidot.hi is manufactured at low costs.

Abstract: An afocal optical system is formed by a paraboroid mirror and an optical element having a stereographic projection characteristics which is defined by the following equation:hi'=2.multidot.f.multidot.tan(.theta.i/2)where hi' is a height of a light beam, leaving the optical element, taken from the optical axis or a heigh of an image taken from the optical axis, f is a focal length of the optical element and .theta.i is an angle of incidence with respect to the optical element. The focal point of the optical element coincide with that of the first paraboroid mirror. Thus, a compact afocal optical system which satisfies hi'=m.multidot.hi is manufactured at low costs.

Abstract: An apparatus for recording an image with a plurality of laser beams on a recording surface comprises a plurality of laser source units each generating a laser beam and a first lens for directing the laser beam from each one of the plurality of laser source units to the recording surface. In the apparatus, the laser source units are each disposed on a holding member in such a manner that the principal ray of the laser beam therefrom passes through a front focal point of the first lens. Thus, the apparatus is advantageous in that it is not necessary to employ an enlarged lens despite increase in the number of the laser source units, or the channel numbers.

Abstract: Laser beams corresponding to an image are directed through an afocal optical system such that chief rays of the laser beams outgoing from the system are substantially perpendicular to a recording surface and such that beam waists of the laser beams are approximately located at the recording surface. Thus, the image can be recorded on the recording surface with high picture quality.

Abstract: An uncomplicated system for exposing a recording medium by scanning the medium with laser light to form a clear, uniformly dense recording pattern without interference.

Abstract: A photosensitive film is scanned with nine laser beams for recording an image on the same. The subscanning pitch .DELTA.X.sub.1 is so determined as to be 4.5 P, where P is an alignment pitch of photospots formed by the laser beams. Scanning lines which belong to a "front line group" and are scanned in a main scanning are spatialy alternated with other scanning lines which belong to a "rear line group" and are scanned in the next main scanning.

Abstract: A laser exposure system for use in scanning and recording images, the system comprising subdividing the laser beam from the laser source into several parallel traces of laser beams; modulating the laser beams individually in response to the image signals be means of a multi-channel optical modulator; directing the modulated laser beams through a first mirror and a second mirror so as to enable the laser beams from the second mirror to be in parallel with the reference plane with respect to the sub-scanning direction; varying the distance between the modulator and the first mirror; and adjusting the angles of the first and second mirrors to the reference plane so that a possible decline of the laser beams in the sub-scanning direction is compensated.

Abstract: A laser exposure system for use in scanning and recording images, the system comprising subdividing the laser beam from the laser source into several parallel traces of laser beams; modulating the laser beams individually in response to the image signals by means of a multi-channel optical modulator; directing the modulated laser beams through a first mirror and a second mirror so as to enable the laser beams from the second mirror to be in parallel with the reference plane with respect to the sub-scanning direction; varying the distance between the modulator and the first mirror; and adjusting the angles of the first and second mirrors to the reference plane so that a possible decline of the laser beams in the subscanning direction is compensated.