Abstract: Provided is an optical scanning device that can be downsized and improve the reading rate of a laser-type image reading system. This is an optical scanning device that includes a torsion beam, and a variable focus mirror that is supported by the torsion beam. Furthermore, the variable focus mirror is supported at two symmetrical positions with respect to the axis of rotation of the torsion beam.

Abstract: A work hardening treatment which decreases the Young's modulus, and an age hardening treatment which recovers or increases the Young's modulus decreased by the work hardening treatment are performed to form a vibrating portion, thereby attaining a vibrating element advantageous in downsizing while ensuring desired fatigue characteristics and vibration characteristics. This downsizes, for example, an actuator device, an optical scanning device, a video projection apparatus, and an image forming apparatus.

Abstract: The oscillation element according to the present invention includes a torsion bar mounted on a base, and an oscillating member having a light reflection surface for reflecting light from a light source, which is fixed on the torsion bar protruding from the base. The oscillating member oscillates about a longitudinal axis of the torsion bar with an elastic deformation of the torsion bar, thereby deflecting the light that reflects at the light reflection surface in a direction intersecting the longitudinal axis. The oscillating member has two plates that are joined together so as to sandwich the torsion bar. On joining surfaces of the plates are provided with grooves for receiving the torsion bar, respectively. The plates have a symmetrical shape that the longitudinal axis serves as the axis of symmetry.

Abstract: The oscillation element according to the present invention includes a torsion bar mounted on a base, and an oscillating member having a light reflection surface for reflecting light from a light source, which is fixed on the torsion bar protruding from the base. The oscillating member oscillates about a longitudinal axis of the torsion bar with an elastic deformation of the torsion bar, thereby deflecting the light that reflects at the light reflection surface in a direction intersecting the longitudinal axis. The oscillating member has two plates that are joined together so as to sandwich the torsion bar. On joining surfaces of the plates are provided with grooves for receiving the torsion bar, respectively. The plates have a symmetrical shape that the longitudinal axis serves as the axis of symmetry.

Abstract: Provided is an optical scanning device that can be downsized and improve the reading rate of a laser-type image reading system. This is an optical scanning device that includes a torsion beam, and a variable focus mirror that is supported by the torsion beam. Furthermore, the variable focus mirror is supported at two symmetrical positions with respect to the axis of rotation of the torsion beam.

Abstract: The oscillation element according to the present invention includes a torsion bar mounted on a base, and an oscillating member having a light reflection surface for reflecting light from a light source, which is fixed on the torsion bar protruding from the base. The oscillating member oscillates about a longitudinal axis of the torsion bar with an elastic deformation of the torsion bar, thereby deflecting the light that reflects at the light reflection surface in a direction intersecting the longitudinal axis. The oscillating member has two plates that are joined together so as to sandwich the torsion bar. On joining surfaces of the plates are provided with grooves for receiving the torsion bar, respectively. The plates have a symmetrical shape that the longitudinal axis serves as the axis of symmetry.

Abstract: A work hardening treatment which decreases the Young's modulus, and an age hardening treatment which recovers or increases the Young's modulus decreased by the work hardening treatment are performed to form a vibrating portion, thereby attaining a vibrating element (30) advantageous in downsizing while ensuring desired fatigue characteristics and vibration characteristics. This downsizes, for example, an actuator device (1), an optical scanning device, a video projection apparatus, and an image forming apparatus.

Abstract: The present invention aims at providing a magnetic substance detection sensor: which permits a high sensitivity magnetic field detection element to be effectively operative even in the vicinity of a magnet; which permits quantitative detection without depending upon the magnetic characteristic of a medium, e.g., soft magnetic material, etc.; which is compact and permits realization of reduced space; and which has high productivity. In addition, the present invention aims at providing a compact and high performance magnetic substance detecting apparatus.

Abstract: A magnetic sensor for detecting magnetic fields deriving from a magnetic body to detect any magnetic body on a non-magnetic body by moving relative to the non-magnetic body in prescribed relative moving directions along the surface of the non-magnetic body includes a magnetizing magnet in which a line connecting the N and S poles thereof is a direction substantially orthogonal to, and of which one pole is arranged either in contact with or in proximity to, the surface of the non-magnetic body; and a magnetism detecting element having two magnetic detectors arranged along a magnetic field detecting direction, the magnetic field detecting direction being orthogonal to the relative moving directions in a surface parallel to the surface of the non-magnetic body, wherein the magnetic body is magnetized by the magnetizing magnet along with the movement relative to the non-magnetic body, and magnetic fields according to the quantity of the magnetized part of the magnetic body are differentially detected by the two m