Abstract: An optical device receives light from an adjustable light source, focuses part of the light into an optical waveguide, and directs another part of the light toward a control unit as monitor light for feedback control of the light source. The optical device is an optical plate with a computer-generated hologram formed on at least one surface to focus light into the optical waveguide. The monitor light may be reflected at this surface or another surface of the optical plate. The monitor light may be focused by the same or another computer-generated hologram.

Abstract: An optical device for use in optical communication optical network units, having an aptitude for efficient production, manufacturing cost reduction and size reduction, comprising: a first CGH element 21 for converting a multiplexed light from the first input terminal 11 into a parallel light beam; a wavelength splitting filter 23 for deflecting a light having passed through the CGH elements according to wavelengths; a second CGH element 22 for directing a first wavelength component separated by the wavelength splitting filter to the first output terminal 12; an optical path splitting means 22 for guiding a second wavelength component separated by the wavelength splitting filter to a desired optical path; a third CGH element 24 for directing a beam of a second wavelength component having passed through one optical path 27 to a second output terminal 18; and a fourth CGH element 26 guiding a beam of the second wavelength component from the second input terminal 17 to the optical path splitting means 24 so as to

Abstract: To provide a microoptical system for free-space optical interconnection capable of relaxing the arrangement accuracy of a light source and a photodetector. A point light source and a photodetector are interconnected each other by first and second imaging lenses and focused Gaussian beams. In this case, the point light source, first imaging lens, second imaging lens, and photodetector are positioned so that the effective beam radius .omega..sub.2 of a focused Gaussian beam on the first interconnecting lens is larger than the effective beam radius .omega..sub.4 of a focused Gaussian beam on the second imaging lens.

Abstract: A non-diffracting beam generator converts coherent light from a semiconductor laser into a small, intense, non-diffracting beam, which is directed into a non-linear optical element. The non-linear optical element converts this beam to light of a different wavelength. The non-linear optical element is a bulk element, not having an internal waveguide, and not requiring precise alignment of the non-diffracting beam. The non-diffracting beam preferably has a length matching the thickness of the non-linear optical element.

Abstract: A wavelength conversion device employs an axicon lens to form Bessel beams of signal light and pump light, which are directed into an anisotropic nonlinear optical crystal. The signal light and pump light are both polarized parallel to the uniquely determined Z-axis of the anisotropic nonlinear optical crystal, the Z-axis being oriented perpendicular to the beam axis. The axicon lens is configured to refract the signal light and pump light at angles such that a phase matching condition is satisfied in the anisotropic nonlinear optical crystal, and converted light, also polarized parallel to the Z-axis and having a new wavelength, is generated.

Abstract: A tension reducer used in a webbing retractor is provided with a weak coil spring, a strong coil spring, and a connecting member all connected in series, the rotation of the connecting member in the webbing winding direction being stopped at a predetermined time after the webbing has been pulled out from the winding shaft when a passenger puts on the webbing. The inner end of the weak coil spring is connected to the connecting member so that, after the rotation of the connecting member has stopped, the urging force of the spring is released as the spring unwinds from its outer end.

Abstract: A hydraulic variable damping device for installation in the frame of a structure to control vibrations while evaluating the damping property of the structure during seismic disturbances. Control means for this device include a command value judging circuit for comparing the plus or minus sign of a differential pressure value between hydraulic chambers within the device with that of a generated damping force command value to output a valve opening command value for fully opening a flow regulating valve when the signs of the command value and the differential pressure value are different from each other. A pressure controller is provided for making a correction based on the feedback of the pressure valve when the signs of the damping force command value and the differential pressure value are the same to generate a valve opening command value.

Abstract: Disclosed herein is a tension reducer suitable for use in a webbing retractor, which comprises a weak resilient spiral spring whose one end is connected to a webbing take-up spindle of the webbing retractor and which exerts an urging force in a webbing winding direction, a connecting member connected to the other end of the weak resilient spiral spring and disposed rotatably about the take-up spindle, a strong resilient spiral spring whose one end is connected to the connecting member and which exerts an urging force in the webbing winding direction greater than the urging force of the weak resilient spiral spring, a device for stopping the rotation of the connecting member in the webbing winding direction so as to avoid the exertion of the urging force of the strong resilient spiral spring on a webbing at the time that the webbing is pulled out of the take-up spindle to be fastened to an occupant, and a device disposed about the take-up spindle for controlling the degree of tightening of the windings of the

Abstract: A webbing retractor for taking up an occupant-restraining webbing used in a seat belt apparatus for a vehicle has a takeup shaft held by a frame, and the webbing is wound around the takeup shaft. The takeup shaft is pivotally held at a substantially intermediate portion of each of a pair of arms. One end of each arm is pivotally supported by a support shaft, and the arms are adapted to rotate about the support shaft.

Abstract: A tension reducer for use in a webbing retractor having a webbing take-up spindle for winding a webbing thereon having two types of flat spiral springs, one with strong and the other with weak resilient characteristics connected in series to each other through a gear wheel is urged in a webbing winding direction. The gear wheel is locked to avoid the urging force of the strong flat spiral spring on an occupant. The tension reducer comprises inertial mass bodies movable when the gear wheel is unlocked and a C-shaped friction spring whose diameter is enlarged by the movement of the inertial mass bodies for avoiding an abrupt rotation of the gear wheel relative to the take-up spindle. Thus, the abrupt tension of the strong flat spiral spring is prevented so that the occurrence of an improper sound is reduced.

Abstract: An elevator valve apparatus for controlling the hydraulic supply flow to the hydraulic actuator and the hydraulic discharge flow from the actuator, comprises a solenoid proportional control valve device for ascending, a solenoid proportional control valve device for descending, and a valve control unit for controlling both of the control valve devices with a predetermined acceleration characteristic and a predetermined deceleration characteristic by an open loop control system.Furthermore, if preferable, the valve control unit carries out oil temperature compensating control, pressure compensating control, pre-start pressure raising compensation control, and feedback control of the supply flow in the low speed ascending.

Abstract: In a support construction of securing member for securing an occupant restraining webbing applied to a vehicle and adapted for supporting the securing member to a vehicle body through an extension member, an intermediate portion of the extension member is connected to the securing member through connecting means, therewith a forward end portion of the extension member formed in a portal shape is received in a support hole formed on the securing member, and the back portion of the portal shape portion is caused to abut on a peripheral portion of the support hole and a pair of receiving portions are formed on both sides of the portal shape portion.Accordingly, the receiving portions are latched to a peripheral portion of the support hole and a large tension load acting between the securing member and the extension member can surely be sustained in an emergency situation of the vehicle.