Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ndLZ+(0.01425×?dLZ)<2.12, and ?dLZ<35.0, where ndLZ: a refractive index of the lens with reference to d-line, and ?dLZ: Abbe number of the lens with reference to d-line.

Abstract: A variable magnification optical system comprising, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a rear lens group; upon varying magnification, the first lens group being fixed with respect to the image plane and each distance between the neighboring lens groups being varied; the rear lens group comprising a focusing lens group which is moved upon carrying out focusing; and the predetermined conditional expressions being satisfied, whereby it is possible to suppress superbly variations in aberrations upon varying the magnification.

Abstract: A cutter blade of a lawn mower includes a blade body and flaps. The blade body includes a shape with a sweepback angle inclined in a reverse-rotation direction of the cutter blade. The flap pivotal axis is provided along a blade edge without intersecting with a blade rotational axis. A flap pivotal axis is provided at a position offset from a line perpendicular to the blade rotational axis and in parallel to the pivotal axis, in a rotation direction of the cutter blade.

Abstract: A power supply system includes: a hydrogen generation device that uses electric power to generate hydrogen; a hydrogen storage device that stores hydrogen generated by the hydrogen generation device; a fuel cell system that uses hydrogen stored in the hydrogen storage device to generate electric power; a power storage device; and a control device executing at least one of first control and second control based on an electricity expense, the first control controlling a first ratio between electric power to be supplied from a natural energy power generation device to the hydrogen generation device and electric power to be supplied from the natural energy power generation device to the power storage device, the second control controlling a second ratio between electric power to be supplied from the power storage device to a load and electric power to be supplied from the fuel cell system to the load.

Abstract: This work machine is provided with a machine body equipped with a battery storage part for accommodating a battery. The machine body has a grip part on one side in the left-right direction. The battery storage part has an opening formed in the machine body and a lid capable of opening and closing the opening. The opening and the lid are provided on the other side of the machine body in the left-right direction.

Abstract: Comprising, in order from an object side: a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power; upon varying a magnification, the first lens group being fixed with respect to the image plane, and each distance between the neighboring lens groups being varied; upon focusing, at least a portion of the fourth lens group being moved; and predetermined conditional expression(s) being satisfied, thereby variations in various aberrations upon varying magnification being superbly suppressed.

Abstract: Comprising a first lens group G1 having positive refractive power, disposed at the most object side, and an image side lens group disposed at a side closer to an image than the first lens group G1, upon zooming, at least a distance between the first lens group G1 and the image side lens group being varied, the image side lens group comprising a vibration reduction lens group GVR which is moved so as to have a component in a direction perpendicular to the optical axis and a focusing lens group GF which is moved along the optical axis upon focusing, thereby providing a variable magnification optical system which has a higher optical performance, an optical apparatus and a method for manufacturing a variable magnification optical system.

Abstract: A bridge circuit converts input direct-current voltage and outputs alternating-current voltage. A filter circuit attenuates a high-frequency component of the alternating-current voltage output from the bridge circuit. A clamping circuit is disposed between the bridge circuit and the filter circuit, and is capable of short-circuiting the output side of the bridge circuit. A control circuit has a first mode in which a switching element causes the alternating-current voltage to be output to the filter circuit at three or more voltage levels, and a second mode in which the switching element causes the alternating-current voltage to be output to the filter circuit at two voltage levels. When power conversion devices have their alternating-current side output paths connected and operate in parallel, at least one of the power conversion devices operating in parallel operates in the second mode.

Abstract: Comprising a first lens group G1 having positive refractive power, disposed at the most object side, and an image side lens group disposed at a side closer to an image than the first lens group G1, upon zooming, at least a distance between the first lens group G1 and the image side lens group being varied, the image side lens group comprising a vibration reduction lens group GVR which is moved so as to have a component in a direction perpendicular to the optical axis and a focusing lens group GF which is moved along the optical axis upon focusing, thereby providing a variable magnification optical system which has a higher optical performance, an optical apparatus and a method for manufacturing a variable magnification optical system.

Abstract: A zooming optical system comprises, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power. Upon zooming, distances between adjacent lens groups of the first to the fifth lens groups change respectively. The zooming optical system further satisfies the conditional expression 9.6<ft/(?f2)<20.0, where ft denotes a focal length of the zooming optical system in a telephoto end state, and f2 denotes a focal length of the second lens group.

Abstract: A zoom optical system includes, disposed in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power, wherein at least a part of the third lens group is arranged to be movable along an optical axis as a focusing lens group, the focusing lens group is moved toward an image when a focusing state on a long-distance object is changed to a focusing state on a short-distance object, and the following conditional expression is satisfied: 0.90<f3/fw<1.50 where f3 denotes a focal length of the third lens group, and fw denotes a focal length of the zoom optical system in a wide-angle end state.

Abstract: In a power converter including: a first DC-DC converter, an inverter, and a control circuit, a second DC-DC converter that controls an input and an output of a power storage unit is connectable to a DC bus. The control circuit deactivates a reverse power flow suppression function for suppressing a reverse power flow from the inverter to a power system when the second DC-DC converter is not connected to the DC bus and activates the reverse power flow suppression function when the second DC-DC converter is connected to the DC bus.

Abstract: A power supply system includes: a hydrogen generation device that uses electric power to generate hydrogen; a hydrogen storage device that stores hydrogen generated by the hydrogen generation device; a fuel cell system that uses hydrogen stored in the hydrogen storage device to generate electric power; a power storage device; and a control device executing at least one of first control and second control based on an electricity expense, the first control controlling a first ratio between electric power to be supplied from a natural energy power generation device to the hydrogen generation device and electric power to be supplied from the natural energy power generation device to the power storage device, the second control controlling a second ratio between electric power to be supplied from the power storage device to a load and electric power to be supplied from the fuel cell system to the load.

Abstract: A zoom optical system (ZL) comprises: a first lens group (G1) disposed closest to an object and having a positive refractive power; an aperture stop (S) disposed closer to an image than the first lens group (G1); a positive lens component disposed so as to oppose the image side of the aperture stop (S); and a lens group (G3) having the positive lens component, wherein a distance between the first lens group (G1) and the lens group (G3) having the positive lens component changes during zooming, at least one lens surface of the positive lens component has an aspherical surface, and the following conditional expression, 0.40<fp/fGp<3.60 is satisfied, where fp: a focal length of the positive lens component, and fGp: a focal length of the lens group (G3) having the positive lens component.

Abstract: A lawn mower includes a cutter blade having flaps and a flap drive mechanism. The flap drive mechanism includes a flap drive source and an intermediate power transmission unit. The intermediate power transmission unit is provided on a power transmission path between the flap drive source and the flaps and provided coaxially with a blade rotation axis. An output axis of a motor is provided coaxially with a blade rotation axis and the intermediate power transmission unit.

Abstract: A zoom optical system includes, disposed in order from an object, a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, and a third lens group (G3) having positive refractive power, wherein at least a part of the second lens group (G2) or at least a part of the third lens group (G3) is configured to be movable, as a vibration-proofing lens group for correcting an image blur, so as to have a movement component in a direction perpendicular to an optical axis, and the following conditional expression is satisfied: 4.40<f1/(?f2)<8.00 where f1 denotes a focal length of the first lens group (G1), and f2 denotes a focal length of the second lens group (G2).

Abstract: A zooming optical system is provided, which is constituted by, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having negative refractive power; and a fifth lens group having positive refractive power. In the zooming optical system, the first lens group is moved along the optical axis upon zooming, at least a part of the second lens group to the fifth lens group being moved so as to include a component orthogonal to the optical axis, and the following conditional expressions are satisfied: 4.41<f1/(?f2)<5.33 and 2.15<f1/f3<4.95, where f1 denotes a focal length of the first lens group, f2 denotes a focal length of the second lens group, and f3 denotes a focal length of the third lens group.

Abstract: A power system includes: a storage battery; a water electrolyzer; a fuel cell that generates electricity using hydrogen supplied from a hydrogen reservoir that stores hydrogen generated by the water electrolyzer; a detector that detects whether there is a person in a building; and a controller that performs at least one of first control and second control. The first control determines a priority between the storage battery and the water electrolyzer, to which electric power is supplied from a power generation device using renewable energy, based on information detected by the detector. The second control determines a priority between the storage battery and the fuel cell, from which electric power is supplied to a power load provided in the building, based on the information detected by the detector.

Abstract: In a power converter, a DC bus is supplied with a DC power from a voltage conversion circuit for regulating a voltage of a power output from a DC power supply, a voltage of the DC power being regulated by the voltage conversion circuit. An inverter converts a DC power on the DC bus into an AC power and supplies the AC power as converted to a power system. A controller controls the inverter. When it is necessary to suppress an output, the controller suppresses the AC power supplied by the inverter to increase a voltage on the DC bus.

Abstract: A zoom optical system (ZL) comprises a first negative lens group (G2) having a negative refractive power; and a second negative lens group (G4) disposed closer to an image than the first negative lens group (G2), wherein a distance between the first negative lens group (G2) and the second negative lens group (G4) changes during zooming, at least part of the first negative lens group (G2) is movable so as to have a displacement component in a direction perpendicular to an optical axis, at least part of the second negative lens group (G4) is movable along the optical axis during focusing, and the following conditional expression, 0.50<fGb/fGa<2.60 is satisfied, where, fGa: a focal length of the first negative lens group (G2), and fGb: a focal length of the second negative lens group (G4).