Fuji Photo Film Company, Limited

Takenori Tomita

Takashi Shoji

Yasunori Ohta

Tsutomu Kimura

Kazuo Horikawa

Masaaki Konno

Toru Itakura

Shumpeita Torii

Yoshiaki Ishino

Hideo Watanabe

Hisao Seto

A laser beam recording method and apparatus are constituted for recording an image by obtaining a laser beam whose optical intensity is modulated by controlling a drive current for a semiconductor laser on the basis of a light emission level instructing signal corresponding to an image signal, and scanning the laser beam on a photosensitive material. The optical output is stabilized by detecting the optical intensity of the laser beam and feeding back a feedback signal corresponding to the detected optical intensity to the light emission level instructing signal. A filter circuit formed so that the gain gradually increases from near to a cutoff frequency of a circuit for the optical output stabilization toward a higher frequency side is disposed in a stage prior to the circuit for the optical output stabilization. Or, a bias current of a value smaller than the value of the drive current that produces the laser beam of the minimum optical intensity capable of exciting the photosensitive material is always fed to the semiconductor laser.

Laser beam recording method and apparatus

A sheet feed mechanism in a light scanning apparatus includes two pairs of rollers for gripping and feeding a sheet-like medium such as a stimulable phosphor sheet or a photographic film in a subscanning direction. The two pairs of rollers are spaced a distance smaller than the length of the sheet-like medium in the subscanning direction. While the sheet-like medium is being fed by the sheet feed mechanism in the subscanning direction, the sheet-like medium is scanned by a light beam deflected in a main scanning direction substantially normal to the subscanning direction, for thereby two-dimensionally scanning the sheet-like medium.

Sheet feed mechanism and method of controlling the same in light beam

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.

Motor control method

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.

Brushless motor with a rotor pole position detector associated with each

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Kanagawa, Japan

Takenori Tomita