Abstract: Light quantity and temperature settings are applied by a control circuit to a semiconductor laser controller and a temperature controller, respectively. A temperature actuator is controlled by the temperature controller responsive to an output signal from a temperature sensor for equalizing the temperature of a semiconductor laser to the temperature setting. The semiconductor laser is controlled by the semiconductor laser controller responsive to an output signal from a light quantity sensor so that a laser beam will be emitted from the semiconductor laser at the light quantity setting. Mode hoping noise is detected by a mode hopping noise detector or the control circuit in combination with a memory which stores mode hopping noise ranges. In response to a mode hopping noise signal, the control circuit changes at least one of the light quantity and temperature settings.

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: The speed of a motor supported on a supporting base the position of which is changed during operation of the motor is controlled by use of a detector for detecting the degree of angular acceleration of the motor supporting base in a plane normal to the shaft of the motor. The angular acceleration detector is supported on the motor supporting base, and the signal detected thereby is used as one of the speed control command signals.

Abstract: A semiconductor laser is mounted on a support by way of a semiconductor laser mount. The semiconductor laser mount is provided, in the surface to be mated with the support, with an adhesive retaining groove which substantially surrounds the mounting position of the semiconductor laser. The adhesive retaining groove is communicated with an inlet and an outlet each of which opens in a surface of the mount other than the mating surface. When bonding the semiconductor laser mount to the support, the laser mount is first located in a predetermined position relative to the support, and then adhesive is charged into the adhesive retaining groove through the inlet. The mount is secured to the support by the adhesive charged into the groove.

Abstract: In a semiconductor laser beam source apparatus, a semiconductor laser is positioned inside of a case for shielding at least a laser beam outlet face from ambient atmosphere. The case is provided with a double-layer window which is positioned at least on the optical path of a laser beam emitted by the semiconductor laser, and which comprises two laser beam-permeable plates facing each other via a space shielded from the ambient atmosphere. Or, the case is provided with a heater for heating at least the laser beam passing section of the case surface, or with a blower for feeding dry air at least to the laser beam passing section.

Abstract: A sheet carrying an image stored therein is scanned by a light beam emitted by a light source. Light which is obtained by the scanning of the sheet and which carries the image is detected by use of a photomultiplier. When the level of output current of the photomultiplier becomes higher than a predetermined standard level, the intensity of the light beam is decreased so that the level of the output current of the photomultiplier does not exceed the predetermined standard level, thereby preventing the photomultiplier from being broken by light of high intensity.

Abstract: A light beam scanning recording apparatus for recording information on a recording material by modulating a laser beam emitted by a semiconductor laser and scanning the recording material with the modulated laser beam is constituted to modulate the laser beam by combining pulse number modulation or pulse width modulation with intensity modulation. Intensity modulation of the laser beam is conducted by controlling the drive current of the semiconductor laser. A plurality of semiconductor lasers may be provided for scanning with a coalesced laser beam obtained by coalescing laser beams emitted by the semiconductor lasers, and intensity modulation may be conducted by changing the number of the laser beams which are coalesced.

Abstract: A shading elimination device comprises a memory for storing characteristics of shading in an image read-out apparatus, a sensitivity adjuster for adjusting the sensitivity of a photodetector of the image read-out apparatus or an image density adjuster for adjusting the density of an image reproduced by an image reproducing apparatus, and a control circuit. The control circuit receives a signal representing the shading characteristics from the memory, and controls the sensitivity adjuster or the image density adjuster to eliminate changes in the output of the photodetector caused by shading in the image read-out apparatus.

Abstract: A signal representing the period between adjacent positive-going edges and the period between adjacent negative-going edges of a pulse train generated by a rotary encoder coupled coaxially to a motor is compared with a reference period signal for the motor to produce a deviation signal. The rotation of the motor is controlled by the deviation signal.

Abstract: A brushless motor includes a plurality of stator armature windings having winding frames with spaces defined therein, respectively, a rotor mounted on a rotatable shaft and having field poles rotatable with respect to the armature windings, and a plurality of rotor position detectors such as Hall-effect devices disposed in the spaces, respectively, and having output terminals connected respectively to the input terminals of other armature windings, for continuously varying the currents flowing through the other armature windings dependent on signals indicative of the magnetic fluxes from the field poles as detected by the rotor position detectors.

Abstract: In a light beam scanning apparatus, two photodetectors are positioned in spaced relation by a predetermined distance within a scanning region in a main scanning direction. The start and the end of scanning in the main scanning direction are detected by the photodetectors. The scanning speed of a main scanning means is controlled so that a predetermined number of pulses of a pulse signal having a predetermined period are input within the time between the start and the end of scanning in the main scanning direction. Or, a single photodetector is positioned within the scanning region, and the scanning time from the start of scanning to the photodetector is detected by use of the photodetector. The initial position of scanning is controlled so that a predetermined number of pulses of the pulse signal having a predetermined period are input within the scanning time.

Abstract: A semiconductor laser beam scanning device includes a plurality of semiconductor lasers for emitting respective laser beams which are combined into a single laser beam to scan a desired surface. The amount of energy of the single laser beam is detected by a laser beam energy detector which applies a laser beam energy signal to a laser drive/control circuit. Alternatively, the laser beam energy signal is applied to a comparator which compares the laser beam energy signal with a reference signal and issues a difference signal to a control circuit connected to a laser drive circuit. The laser drive/control circuit or the control circuit is responsive to the applied signal for controllably energizing at least one of the semiconductor lasers to control the amount of energy of the laser beam emitted therefrom to thereby keep the amount of energy of the single laser beam at a constant level.

Abstract: A radiation image reader/recorder which mainly scans an optical beam (2, 22) emitted from the optical beam generation means of a laser light source (1, 21) via a light deflector (4, 25) with a frequency less than a main scanning frequency of 1 KHz, and which sub-scans at a sub-scanning density of more than 2.5 lines/mm, reading or recording a radiation image of continuous halftones. A cover (11, 29) is provided over at least at the optical passage between the means (1, 21) and the deflector (4, 25), thereby preventing the flow of air.

Abstract: A metal mount of a galvanometer is secured to a plate made of an electrically conductive material via a thin insulating layer in electrically insulated relation to the plate. The thin insulating layer has a thickness within the range of about 10 .mu.m to about 500 .mu.m. The metal mount and the thin insulating layer are cylindrical and are secured to a cylindrical through hole formed in the plate. Or, the metal mount has an L-shaped cross-section. One section of the L-shaped metal mount is secured to the plate by use of bolts, and the other section thereof is secured to the galvanometer by use of screws. In this case, an insulation sheet is positioned between the one section of the L-shaped metal mount and the plate.

Abstract: A light beam scanning apparatus includes a sweeping unit for sweeping a light beam in response to a first signal. A photodetector has a plurality of optical gratings arranged in an array in a predetermined direction in which the light beam is swept. The photodetector generates a second signal in response to a movement of the light beam along the grating array. A control circuit generates the first signal in response to the second signal. The control circuit detects a scan speed of the light beam based on the second signal, and adjusts the first signal in response to the detected scan speed to control the scan speed of the light beam such that the detected scan speed substantially coincides with a predetermined speed.

Abstract: A stimulable phosphor sheet carrying a radiation image stored therein is scanned with stimulating rays which cause the stimulable phosphor sheet to emit light in proportion to the radiation energy stored therein. The emitted light is photoelectrically detected to obtain sequential electric signals of respective picture elements of the radiation image. The interference among the electric signals of the respective picture elements which is caused by the light emission response characteristics of the stimulable phosphor to the stimulation is eliminated electrically. The correction is conducted by adding a differentiated value of the sequential electric signals of the respective picture elements to the sequential electric signal of the respective picture elements.

Abstract: In a method of reading out a radiation image stored in a stimulable phosphor sheet by scanning the stimulable phosphor sheet by stimulating rays, preliminary read-out and final read-out are conducted. The read-out line density of the stimulating rays in the final read-out is detected in advance. Image read-out conditions and/or image processing conditions adjusted on the basis of image information obtained by the preliminary read-out are corrected in accordance with the read-out line density in the final read-out so that the same final read-out image information and/or the same image signal after image processing is obtained from the stimulable phosphor sheet carrying the same image information stored therein.

Abstract: Disclosed is a method and an apparatus for detecting the leading edge of a sheet which is on the way to the scanning-and-reading station of an image read-out system. Detection is performed by exposing, just ahead of the scanning-and-reading station, the traveling sheet to the same scanning beam of light as used at the scanning-and-reading station, and by detecting the sudden change in the amount of reflection on arrival of the sheet at the station due to the difference between the reflection coefficients of the sheet and the underlying conveyer belt. Preferably, the scanning for detecting the leading edge of the sheet is at a higher frequency and smaller amplitude than the scanning for reading an image on the sheet.

Abstract: In an image scanning and read-out system wherein a sheet carrying an image recorded thereon is scanned with a light beam at an amplitude larger than the sheet width, and detecting the light from the sheet by use of a photomultiplier, the voltage applied to the photomultiplier is decreased when the output current obtained from the photomultiplier at the time the photomultiplier receives light from outside the sheet is larger than a predetermined reference level. The output current obtained when the scanning position of the light beam is at the outside of the sheet is compared with the reference level, or the period during which the output current is continuously larger than the reference level is measured to check whether it is longer than the time required for the light beam to scan the sheet width.

Abstract: A light detecting apparatus comprises an elongated plate-shaped light guide member having an end face at one long side as a light input face and an end face at the other long side as a light output face. N number of photomultipliers having elongated light receiving faces optically associated with N divisions of the light output face divided into N divisions in the length direction of the light output face of the light guide member are positioned for converting the light emitted from the divisions of the light output face into electric signals. The photomultipliers are connected to a correction circuit for electrically eliminating deterioration in sensitivity at least at adjacent photomultiplier side end portions of the photomultipliers.