Abstract: A controller to control a driving-torque distribution to a front wheel and a rear wheel comprises an obtainment portion to obtain a vehicle's lateral acceleration, an engine's output torque, and a vehicle's turning radius during turning of a vehicle, a determination portion to determine a rear-wheel driving-torque distribution rate denoting a rate of the driving torque to be transmitted to the rear wheel relative to the driving torque corresponding to the engine's output torque based on the obtained vehicle's lateral acceleration, engine's output torque, and vehicle's turning radius, and a control-signal output portion to output a control signal to a driving-torque transmission device to adjust the driving torque transmitted to the rear wheel such that the driving torque to be distributed to the rear wheel is controlled according to the determined rear-wheel driving-torque distribution rate.

Abstract: A controller to control a driving-torque distribution to a front wheel and a rear wheel comprises an obtainment portion to obtain a vehicle's lateral acceleration, an engine's output torque, and a vehicle's turning radius during turning of a vehicle, a determination portion to determine a rear-wheel driving-torque distribution rate denoting a rate of the driving torque to be transmitted to the rear wheel relative to the driving torque corresponding to the engine's output torque based on the obtained vehicle's lateral acceleration, engine's output torque, and vehicle's turning radius, and a control-signal output portion to output a control signal to a driving-torque transmission device to adjust the driving torque transmitted to the rear wheel such that the driving torque to be distributed to the rear wheel is controlled according to the determined rear-wheel driving-torque distribution rate.

Abstract: A light amount adjuster for adjusting a size of a diaphragm aperture on an optical axis of an optical system, includes: a pair of straight moving diaphragm blades so provided at a portion to which the diaphragm aperture is opposed as to slide along a plane orthogonal to the optical axis in a direction of getting close to or separated from the optical axis; a pair of swing diaphragm blades so provided at a portion to which the diaphragm aperture is opposed as to swing about a center axis in parallel to the optical axis in a direction of getting close to or separated from the optical axis; and a drive mechanism for adjusting the size of the diaphragm aperture by sliding the pair of straight moving diaphragm blades and by allowing the pair of swing diaphragm blades to swing.

Abstract: A light amount adjuster for adjusting a size of a diaphragm aperture on an optical axis of an optical system, includes: a pair of straight moving diaphragm blades so provided at a portion to which the diaphragm aperture is opposed as to slide along a plane orthogonal to the optical axis in a direction of getting close to or separated from the optical axis; a pair of swing diaphragm blades so provided at a portion to which the diaphragm aperture is opposed as to swing about a center axis in parallel to the optical axis in a direction of getting close to or separated from the optical axis; and a drive mechanism for adjusting the size of the diaphragm aperture by sliding the pair of straight moving diaphragm blades and by allowing the pair of swing diaphragm blades to swing.