Canon Kabushiki Kaisha

Hiroaki Maegawa

Chikara Aoshima

Michio Hirohata

Takayuki Tsuboi

Makoto Miyawaki

Minoru Tanabe

A motor provided with a rotor magnet circumferentially divided into n section which are alternately magnetized to different poles, a coil disposed axially of the rotor magnet, outer magnetic poles and inner magnetic poles excited by the coil being opposed to the outer peripheral surface and inner peripheral surface, respectively, of the rotor, and a holder for holding the rotor magnet at a position at which the centers of the poles of the magnet deviate from a line linking the centers of the outer magnetic poles and the center of rotation of the magnet together when the outer magnetic poles and the inner magnetic poles are not excited, whereby the motor is made into a one-phase motor to thereby stabilize the initial positioning of the rotor and also, the motor is made high in output and super-compact.

Motor

A single-phase motor which includes a rotor magnet alternately magnetized to different poles by dividing it along a circumferential direction and in which a coil is disposed in an axial direction of said rotor magnet. Outer magnetized portions of an outer yoke magnetized by the coil and inner magnetized portions of an inner yoke magnetized by the coil are opposed to outer and inner peripheral surfaces of the rotor, respectively. There is also provided a holder for holding the rotor magnet at a position where centers of magnetic poles of the magnet are deviated from a straight line connecting centers of the outer magnetized portions and a rotational center of the magnet when the outer and inner magnetized portions are not magnetized. The inner yoke has a small diameter portion, and, only by reducing the diameter of the small diameter portion, the space within which the coil is wound can be widened so that the coil can be wound around the small diameter portion greatly, thereby providing a single-phase motor having high output.

A motor of an increased output is provided by forming a rotor, composed of a permanent magnet circumferentially divided into equal sections and alternately magnetized in different magnetic poles, in a cylindrical shape, positioning a first coil, the rotor and a second coil along the axial direction of the rotor, providing a first outer magnetic pole and a first inner magnetic pole, magnetized by the first coil, in opposed relationship, respectively, to the external and internal peripheries of the rotor, also providing a second outer magnetic pole and a second inner magnetic pole, magnetized by the second coil, in opposed relationship respectively to the external and internal peripheries of the rotor and positioning the first outer magnetic pole and the second outer magnetic pole in an axially opposed relationship with a mutual displacement by a predetermined phase angle, or forming the ends of the first and second outer magnetic poles in a tapered shape, thereby decreasing the leaking magnetic flux.

In a motor, a rotor made of a permanent magnet which is equally divided in the circumferential direction to be alternately magnetized to different poles is formed into a cylindrical shape. The first coil, the rotor, and the second coil are sequentially arranged in the axial direction of the rotor. The first outer and inner magnetic poles excited by the first coil are set to oppose the outer and inner circumferential surfaces, respectively, of the rotor, and the second outer and inner magnetic poles excited by the second coil are set to oppose the outer and inner circumferential surfaces, respectively, of the rotor. An electric element is arranged at a position to oppose, across a predetermined gap, the circumferential surface of the permanent magnet not covered with the first or second outer magnetic pole. Alternatively, an electric element and a circuit pattern are formed on a connection member that connects the first and second outer magnetic poles to each other.

In a drop-in loading type camera, in which a film is loaded by dropping a film cartridge in a cartridge chamber from the axial direction of the cartridge, it has holding means which obliquely holds the film cartridge until the film leader is dropped in at a position beyond the aperture so that the film leader is dropped in later than the cartridge proper when dropping the film cartridge into the cartridge chamber.

Growing community of inventors

Machida, Japan

Hiroaki Maegawa