Abstract: An ignition device for an internal combustion engine that uses fuels including hydrogen. The ignition device includes an ignition coil including a primary coil and a secondary coil, a power supply device, a switching element, a spark plug, and a limiting diode. The switching element performs switching between passage and interruption of a primary current. The spark plug causes discharge at a gap, based on a high voltage induced at the secondary coil. The limiting diode includes a Zener diode that is forward-biased when oriented in a direction from the one end to the other end of the secondary coil. A breakdown voltage of the limiting diode is higher than the maximum value of an ON-state voltage obtained by multiplication of a value of a direct-current voltage applied to the primary coil by a ratio of the number of turns of the secondary coil to that of the primary coil.

Abstract: An internal combustion engine ignition device includes; a transformer including a primary coil and a secondary coil that are electromagnetically coupled; an energization control unit that controls energization of the primary coil; a first spark plug electrically connected between a high-voltage terminal of the secondary coil and ground; and a second spark plug electrically connected between a low-voltage terminal of the secondary coil and the ground. The first spark plug and the second spark plug are placed in one same combustion chamber of an internal combustion engine. Thus, discharge occurs in the two spark plugs, so that a fuel can be more certainly ignited. Further, residual energy of the first spark plug and residual energy of the second spark plug offset each other, which enables rapid convergence of residual energy.

Abstract: An ignition device for an internal combustion engine that uses fuels including hydrogen. The ignition device includes an ignition coil including a primary coil and a secondary coil, a power supply device, a switching element, a spark plug, and a limiting diode. The switching element performs switching between passage and interruption of a primary current. The spark plug causes discharge at a gap, based on a high voltage induced at the secondary coil. The limiting diode includes a Zener diode that is forward-biased when oriented in a direction from the one end to the other end of the secondary coil. A breakdown voltage of the limiting diode is higher than the maximum value of an ON-state voltage obtained by multiplication of a value of a direct-current voltage applied to the primary coil by a ratio of the number of turns of the secondary coil to that of the primary coil.

Abstract: An ignition device is used in an internal combustion engine that uses a flame-retardant fuel. The ignition device includes a spark plug, a discharge circuit, and a control unit. The spark plug is placed in a cylinder of the internal combustion engine. The discharge circuit induces a high voltage in the spark plug, to thereby discharge the spark plug. The control unit controls a timing at which the spark plug is discharged by the discharge circuit. The control unit causes the discharge circuit to discharge the spark plug a plurality of times while a piston performs a reciprocating operation once in the cylinder. As a result, even when a flame-retardant fuel is used for the internal combustion engine, the ignition rate of the fuel can be enhanced.

Abstract: A fuel combustion apparatus 2 according to the present invention includes: a combustion cylinder 4; a fuel feed unit 6 that introduces a swirling flow of an air-fuel mixture into the combustion cylinder; an ignition unit 10 including an igniter 32 located in the combustion cylinder 4; an ion detection unit 12 including a detector 40 located in the combustion cylinder 4; and a control unit 14 that adjusts a mixing ratio of the fuel based on a detection result obtained by the ion detection unit 12. Preferably, the fuel is ammonia. Preferably, the detector 40 is located in the vicinity of the igniter 32.

Abstract: An optical apparatus and an image pickup apparatus capable of reducing an impact force transmitted to an inside without increasing a total length is provided. A frame member which moves forward and backward in the optical axis direction integrally with an extension lens barrel has a recess facing a protrusion of a cam barrel in a radial direction. An elastic member urges the extension lens barrel and the frame member to be away from each other in the optical axis direction. A restriction member holds the frame member with a first gap formed between the extension lens barrel and the frame member in the optical axis direction. A second gap formed between the protrusion and the recess in the optical axis direction is smaller than the first gap.

Abstract: A fuel combustion apparatus 2 according to the present invention includes: a combustion cylinder 4; a fuel feed unit 6 that introduces a swirling flow of an air-fuel mixture into the combustion cylinder; an ignition unit 10 including an igniter 32 located in the combustion cylinder 4; an ion detection unit 12 including a detector 40 located in the combustion cylinder 4; and a control unit 14 that adjusts a mixing ratio of the fuel based on a detection result obtained by the ion detection unit 12. Preferably, the fuel is ammonia. Preferably, the detector 40 is located in the vicinity of the igniter 32.

Abstract: An ammonia combustion method for combusting ammonia gas in a combustion chamber 4 includes steps of separating and producing hydrogen gas from ammonia gas, supplying the separated and produced hydrogen gas into the combustion chamber 4, combusting the hydrogen gas by performing an ignition discharge on the hydrogen gas supplied into the combustion chamber 4, and igniting the ammonia gas in the combustion chamber 4 from the combusted hydrogen gas.

Abstract: A lens barrel and an image pickup apparatus that can be downsized and have a high degree of freedom in design is provided. The lens barrel includes a fixed barrel, a guide barrel fixed to the fixed barrel, a cam barrel rotatably supported by the guide barrel, a driver that is supported by the fixed barrel and drives the cam barrel, and a deceleration mechanism that is disposed so as to connect the driver and the cam barrel and decelerates rotation from the driver to transmit the rotation to the cam barrel. The driver is disposed inside the cam barrel. At least part of the deceleration mechanism is disposed so as to overlap the cam barrel when viewed from a direction of an optical axis of an image pickup optical system.

Abstract: An optical apparatus and an image pickup apparatus capable of reducing an impact force transmitted to an inside without increasing a total length is provided. A frame member which moves forward and backward in the optical axis direction integrally with an extension lens barrel has a recess facing a protrusion of a cam barrel in a radial direction. An elastic member urges the extension lens barrel and the frame member to be away from each other in the optical axis direction. A restriction member holds the frame member with a first gap formed between the extension lens barrel and the frame member in the optical axis direction. A second gap formed between the protrusion and the recess in the optical axis direction is smaller than the first gap.

Abstract: An apparatus includes a lens, a cam barrel configured to rotate around an optical axis, an actuator disposed on an inner peripheral side of the cam barrel, a movement unit disposed on the inner peripheral side of the cam barrel and configured to move the lens in an optical-axis direction, and an adjustment unit disposed on the inner peripheral side of the cam barrel and configured to adjust a position of the lens. The movement unit, the adjustment unit, and the actuator are arranged at different phases from one another in a circumferential direction of the cam barrel. Widths of the movement unit, the adjustment unit, and the actuator in the optical-axis direction overlap one another.

Abstract: Interchangeable lenses 100A, B, C, and D include a focusing lens unit FLU that is to be moved in an optical axis direction to focus, a focus operation ring 103 that moves the focusing lens unit FLU in the optical axis direction, and a custom operation ring 104 that realizes one of a function among a first function and a second function different from the focusing, and a surface of the focus operation ring 103 has a first structure and a surface of the custom operation ring 104 has a second structure different from the first structure.

Abstract: A lens driving apparatus that enables to improve responsiveness. The lens driving apparatus drives a lens in an optical axis direction. A holding member holds the lens and is movable in the optical axis direction. A first detection unit detects a position of the holding member in the optical axis direction as a current position. A second detection unit detects information about deformation of the holding member. A control unit controls movement of the holding member based on the current position and the information about deformation.

Abstract: An image stabilization apparatus includes a first optical element configured to move in a direction different from an optical axis, a first driver including a first magnet magnetized in a first magnetized direction and a first coil and configured to drive the first optical element by an electromagnetic action, a second optical element configured to move in a direction different from the optical axis, and a second driver including a second magnet magnetized in a second magnetized direction and a second coil and configured to drive the second optical element by an electromagnetic action. The first magnet is disposed outside a second area onto which the second magnet is projected in the second magnetized direction and the second magnet is disposed outside a first area onto which the first magnet is projected in the first magnetized direction.

Abstract: A driving device that is capable of suppressing enlargement of diameter when a movable amount of a moving part increases. The driving device drives a moving part that is movably supported by a fixing part in a predetermined direction. A drive unit has first and second actuators each of which includes a coil arranged in one of the fixing part and moving part and a magnet arranged in the other part so as to face the coil, and gives a thrust to drive the moving part. A control unit controls the drive unit by controlling electric currents supplied to the coils of the first and second actuators in response to results obtained by multiplying first and second coefficients that vary in response to the position of the moving part to first and second control values obtained from first and second functions based on the position of the moving part, respectively.

Abstract: According to an aspect of the invention, an imaging apparatus includes: an imaging unit capable of continuously acquiring first images and second images for which a time from start of accumulation to end thereof is longer than that of the first image; a computing unit configured to calculate a motion vector from the plurality of first images; and an image processing unit configured to perform image processing on a moving image generated from the second images using the motion vector.

Abstract: An image stabilization apparatus includes a first optical element configured to move in a direction different from an optical axis, a first driver including a first magnet magnetized in a first magnetized direction and a first coil and configured to drive the first optical element by an electromagnetic action, a second optical element configured to move in a direction different from the optical axis, and a second driver including a second magnet magnetized in a second magnetized direction and a second coil and configured to drive the second optical element by an electromagnetic action. The first magnet is disposed outside a second area onto which the second magnet is projected in the second magnetized direction and the second magnet is disposed outside a first area onto which the second magnet is projected in the first magnetized direction.

Abstract: An image stabilization apparatus which reduces variations in performance with surface accuracy of a rolling surface for rolling members. A movable unit holds an optical element and is rotatable about a first rotational axis perpendicular to an optical axis of the optical element and a second rotational axis perpendicular to the optical axis and the first formational axis through rolling of the rolling members. With the second rotational axis coinciding with a center of the rolling surface, a first ratio of the first moving range of the rolling members to the first rotational range of the movable unit is smaller than a second ratio of the second moving range of the rolling members to the second rotational range of the movable unit.

Abstract: A lens driving apparatus that enables to improve responsiveness. The lens driving apparatus drives a lens in an optical axis direction. A holding member holds the lens and is movable in the optical axis direction. A first detection unit detects a position of the holding member in the optical axis direction as a current position. A second detection unit detects information about deformation of the holding member. A control unit controls movement of the holding member based on the current position and the information about deformation.

Abstract: A driving device that is capable of suppressing enlargement of diameter when a movable amount of a moving part increases. The driving device drives a moving part that is movably supported by a fixing part in a predetermined direction. A drive unit has first and second actuators each of which includes a coil arranged in one of the fixing part and moving part and a magnet arranged in the other part so as to face the coil, and gives a thrust to drive the moving part. A control unit controls the drive unit by controlling electric currents supplied to the coils of the first and second actuators in response to results obtained by multiplying first and second coefficients that vary in response to the position of the moving part to first and second control values obtained from first and second functions based on the position of the moving part, respectively.