Abstract: A beam-combining laser beam source device comprising laser beam sources; collimator optical systems positioned in optical paths of laser beams radiated from the laser beam sources. Each of the collimator optical systems is constituted of a first lens section and a second lens section. Optical path adjusting elements are positioned in the optical paths of the laser beams in order to radiate the laser beams along optical paths parallel and close to one another. A support member supports the laser beam sources, the collimator optical systems, and the optical path adjusting elements. Each laser beam source and the corresponding first lens section are combined into a laser beam source unit and mounted on the support member, the positions of the laser beam source and the first lens section having been adjusted with respect to each other.

Abstract: A beam-combining laser beam source device comprising an airtight housing and a laser beam source unit housed in the housing. The laser beam source unit comprises laser beam sources and collimator optical systems respectiely positioned in optical paths of laser beams, which are radiated from the laser beam sources, in order to collimate the laser beams. Optical path adjusting elements are respectively positioned in the optical paths of the laser beams in order to radiate the laser beams along optical paths parallel and close to one another. The laser beam sources, the collimator optical systems, and the optical path adjusting elements are supported on a single support. The housing is provided with a temperature sensor, which detects the temperature in the housing, and temperature adjusting elements which heat or chill the housing on the basis of control of the temperature sensor so that the temperature in the housing is kept constant.

Abstract: An image read-out and reproducing apparatus comprises a read-out device for obtaining an image signal by two-dimensionally scanning a recording medium, on which image information has been recorded, with reading light, and a reproducing device for reproducing an image from the image signal by two-dimensionally scanning a recording sheet with reproducing light. A monitor light detector detects positions of reading light and reproducing light on main scanning lines by detecting monitor light. Read out in each main scanning is started when the monitor light is irradiated onto a first position on the monitor light detector, and reproduction in each main scanning is started when the monitor light is irradiated onto a second position on the monitor light detector, so that a position at which read out is started in each main scanning with the reading light and a position at which reproduction is started in each main scanning with the reproducing light approximately coincide in the main scanning direction.

Abstract: An image read-out and reproducing method comprises the steps of conveying an image storage sheet, on which an image has been recorded, or a recording sheet, on which an image is to be reproduced, in a sub-scanning direction by a single sub-scanning system, and reading out the image from the image storage sheet by scanning the image storage sheet with read-out light in a main scanning direction and detecting the light emitted from the image storage sheet which is being scanned. An image is reproduced on the recording sheet by scanning the recording sheet with reproducing light modulated in accordance with the image, which has been read out, in a main scanning direction. Laser beams produced by a plurality of semiconductor lasers are combined, and the combined laser beams are utilized as the read-out light. Only one or some of a plurality of the semiconductor lasers are operated at the time of image reproduction, and the laser beams emitted thereby are modulated and utilized as the reproducing light.

Abstract: An image read-out and reproducing apparatus comprises an acousto-optic modulator, and a change-over device for guiding zero-order light and first-order light radiated by the acousto-optic modulator to a predetermined optical path. A deflector deflects a light beam to scan an image-recorded image information sheet or a recording sheet in a main scanning direction, and a sub-scanning device moves the image information sheet or the recording sheet normal to the main scanning direction. When the image information sheet is moved by the sub-scanning device, zero-order light is guided by the change-over device to the predetermined optical path and deflected to scan the image information sheet, thereby to carry out image read-out from the image information sheet.

Abstract: A semiconductor laser beam splitting device comprises a beam splitting optical system which is disposed on the optical path of light generated from a semiconductor laser and splits the light in a fixed proportion irrespective of the polarized light components contained therein.

Abstract: An optical system for a semiconductor laser beam comprises a semiconductor laser which generates light comprising both stimulated emission light and spontaneous emissions in accordance with the amount of electric current applied thereto, a convergent lens disposed in the light path of the beam emitted by the semiconductor laser, and an optical element disposed in the light path of the beam from the convergent lens which cuts more spontaneous emission than stimulated emission.

Abstract: A laser optical system comprises a laser beam source, a beam diameter adjusting member disposed in the optical path of a laser beam emitted by the laser beam source and having an aperture through which only the center portion of the laser beam is to be passed, a converging lens for converging the laser beam passing through the aperture of the beam diameter adjusting member, and a spatial filter disposed in the vicinity of a convergence position of the laser beam for restricting the passage of the laser beam in at least one-dimension and allowing passage of only a zero-order light component converged to a predetermined position. Alternatively, the laser optical system comprises a laser beam source, and a density distribution filter disposed in the optical path of the laser beam emitted by the laser beam source for allowing passage of only the center portion of the laser beam in at least one-dimensional direction and gradually decreasing the transmittance toward the peripheral portion of the laser beam.

Abstract: Mode hopping of a semiconductor laser is detected by detecting at least one of movement of a laser beam emission point of the semiconductor laser in the longitudinal direction, and movement of the laser beam emission point in transverse directions. The semiconductor laser and/or a collimator lens for collimating a laser beam emitted by the semiconductor laser is moved in the longitudinal direction or in the transverse directions to cancel the movement of the laser beam emission point on the basis of a laser beam emission point signal generated by a mode hopping detecting device for detecting the movement of the laser beam emission point.

Abstract: A synchronizing signal is generated in relation to the scanning of a recording medium with a scanning light beam emitted from a scanning light source and deflected by a light deflector. A synchronizing-signal generating laser beam is emitted from a synchronizing-signal generating laser source, and deflected by the light detector in synchronous relation to the deflection of the scanning light beam. The synchronizing-signal generating laser beam deflected by the light detector is applied back to the synchronizing-signal generating laser source at least once when the synchronizing-signal generating laser beam is deflected through a prescribed angle during one scanning cycle. A change in the output power of the synchronizing-signal generating laser source which is caused upon application of the synchronizing-signal generating laser beam back to the synchronizing-signal generating laser source, is detected for thereby generating the synchronizing signal.