Abstract: The present invention suppresses unevenness of an input/output current of a full bridge circuit, which is caused due to a cross current generated by a delay operation or the like of a switching element and unevenness of a driver voltage of each switching element, and suppresses an occurrence of an erroneous operation of an amplifier of a class-D full bridge circuit. A driver device of a class-D full bridge amplifier according to the present invention sets, at the same potential in terms of DC, reference potentials on a low-voltage side of two high-side driver circuits which drive two high-side switching elements which constitute a full bridge circuit, and suppresses an occurrence of unevenness of a driver voltage of the switching elements due to a cross current which flows between the bridge circuit and the high-side driver circuits.

Abstract: In the reactor in which the wiring board with the main winding formed thereon and the wiring board with the control winding formed thereon are incorporated in layers into the planer core, the magnetic flux generated by the main winding and the magnetic flux generated by the control winding are brought into the following states in order to equalize the density of the magnetic flux generated by the control current. A main winding current of high-frequency current flowing through the main winding generates an AC magnetic fluxes, each of the fluxes having a magnetic field in a direction opposite to each other so as to cancel each other out, and a control current of direct current flowing through the control winding generates a DC magnetic flux with a uniform magnetic flux density around the pair of the inner legs of which AC magnetic fluxes are cancelled out each other.

Abstract: An excessive voltage rise of load voltage, caused by an impedance mismatching on a transmission path, is prevented, and high-frequency power is regenerated. A parallel impedance is connected to the transmission path during the voltage rise, thereby regenerating voltage caused by a standing wave and preventing excessive load voltage, together with enhancing energy usage efficiency. Establishing the parallel impedance for the load impedance, on the transmission path between the high-frequency amplifier circuit of the high-frequency power supply device and the high-frequency load, reduces impedance at the connecting position to prevent generation of excessive voltage on the transmission path, and high-frequency power is regenerated from the transmission path by the parallel impedance.

Abstract: An impedance matching device comprising a variable reactor having a main winding and control winding, wherein a generated magnet field in the core is an AC magnetic field with a magnitude exceeding a value to settle a deviation between a control target value for impedance matching and a feedback value, by changing the magnitude of the generated magnetic field by changing a control current passing through the control winding, thereby controlling inductance of the variable rector to be a predetermined value to perform impedance matching, the response delay in the impedance matching is reduced by reducing a response delay in the inductance variation of the variable reactor.

Abstract: An impedance matching device comprising a variable reactor having a main winding and control winding, wherein a generated magnet field in the core is an AC magnetic field with a magnitude exceeding a value to settle a deviation between a control target value for impedance matching and a feedback value, by changing the magnitude of the generated magnetic field by changing a control current passing through the control winding, thereby controlling inductance of the variable rector to be a predetermined value to perform impedance matching, the response delay in the impedance matching is reduced by reducing a response delay in the inductance variation of the variable reactor.

Abstract: An excessive voltage rise of load voltage, caused by an impedance mismatching on a transmission path, is prevented, and high-frequency power is regenerated. A parallel impedance is connected to the transmission path during the voltage rise, thereby regenerating voltage caused by a standing wave and preventing excessive load voltage, together with enhancing energy usage efficiency. Establishing the parallel impedance for the load impedance, on the transmission path between the high-frequency amplifier circuit of the high-frequency power supply device and the high-frequency load, reduces impedance at the connecting position to prevent generation of excessive voltage on the transmission path, and high-frequency power is regenerated from the transmission path by the parallel impedance.

Abstract: In detecting the unignited state of plasma based on a reflected wave, false detection during a normal plasma ignition time is prevented so as to detect the unignited state during plasma abnormality. When a pulse output is supplied to a plasma load by pulse driving from an RF power source, the unignited state of plasma abnormality is detected on the basis of the continuous state of the reflected wave, whereby a total reflected wave generated in the unignited state during plasma abnormality is detected in distinction from the reflected wave generated in the normal ignited state. With this configuration, in detecting the unignited state by comparing a peak value of the reflected wave with a threshold, it is possible to prevent that a reflected wave generated in the normal ignited state is erroneously detected as the total reflected wave that is generated in the abnormal unignited state.

Abstract: In a class-D amplifier, oscillation phenomenon is suppressed in a high RF range and surge voltage is reduced. An oscillation absorption circuit is connected on the power supply side of the class-D amplifier circuit, and the class-D amplifier circuit and thus connected oscillation absorption circuit equivalently configure an oscillation circuit. Resistance provided in the oscillation absorption circuit is assumed as damping resistance of the oscillation circuit, thereby suppressing the oscillation phenomenon and reducing the surge voltage. The oscillation absorption circuit is made up of the RL parallel circuit of resistance and inductance. The oscillation absorption circuit and the class-D amplifier circuit constitute the oscillation circuit, and the resistance of the oscillation absorption circuit constitutes the damping resistance of the oscillation circuit in the high RF range.

Abstract: In detecting the unignited state of plasma based on a reflected wave, false detection during a normal plasma ignition time is prevented so as to detect the unignited state during plasma abnormality. When a pulse output is supplied to a plasma load by pulse driving from an RF power source, the unignited state of plasma abnormality is detected on the basis of the continuous state of the reflected wave, whereby a total reflected wave generated in the unignited state during plasma abnormality is detected in distinction from the reflected wave generated in the normal ignited state. With this configuration, in detecting the unignited state by comparing a peak value of the reflected wave with a threshold, it is possible to prevent that a reflected wave generated in the normal ignited state is erroneously detected as the total reflected wave that is generated in the abnormal unignited state.

Abstract: A high-frequency power supply device is provided with a plasma ignition step that supplies pulse power to ignite plasma, and drive power supply step to supply drive power for maintaining the plasma being generated. In the plasma ignition step, an ignition pulse being applied in an ignition pulse output operation is configured as including a main pulse that induces ignition, and a prepulse with lower power than the power of the main pulse and being applied at a stage prior to the main pulse. Since the ignition pulse is configured as including the main pulse and the prepulse, this enables protection of a high-frequency power source against reflected wave power, as well as reliably igniting the plasma.

Abstract: A high-frequency power supply device is provided with a plasma ignition step that supplies pulse power to ignite plasma, and drive power supply step to supply drive power for maintaining the plasma being generated. In the plasma ignition step, an ignition pulse being applied in an ignition pulse output operation is configured as including a main pulse that induces ignition, and a prepulse with lower power than the power of the main pulse and being applied at a stage prior to the main pulse. Since the ignition pulse is configured as including the main pulse and the prepulse, this enables protection of a high-frequency power source against reflected wave power, as well as reliably igniting the plasma.

Abstract: In a class-D amplifier, oscillation phenomenon is suppressed in a high RF range and surge voltage is reduced. An oscillation absorption circuit is connected on the power supply side of the class-D amplifier circuit, and the class-D amplifier circuit and thus connected oscillation absorption circuit equivalently configure an oscillation circuit. Resistance provided in the oscillation absorption circuit is assumed as damping resistance of the oscillation circuit, thereby suppressing the oscillation phenomenon and reducing the surge voltage. The oscillation absorption circuit is made up of the RL parallel circuit of resistance and inductance. The oscillation absorption circuit and the class-D amplifier circuit constitute the oscillation circuit, and the resistance of the oscillation absorption circuit constitutes the damping resistance of the oscillation circuit in the high RF range.

Abstract: In an RF power supply for supplying RF power to a plasma load, reflected wave power control is performed in which the reflected wave power of an RF generator is detected and the RF generator is controlled. For a short-time variation in reflected wave power, control is performed based on a peak value variation in the detection value of reflected wave power. For a long-time variation in reflected wave power, control is performed based on a variation in a smoothed value obtained by smoothing detection values of reflected wave power. A reflected wave power control loop system includes a reflected wave power peak value dropping loop system and an arc blocking system that perform control based on a peak variation in reflected wave power and a reflected wave power amount dropping loop system that performs control based on a smoothed power amount of reflected wave power.

Abstract: When RF power is supplied from an RF generator to a load via a power supply unit, (a) the internal impedance of the RF generator is made lower than the characteristic impedance of the power supply unit, and (b) the load-end voltage is increased by selecting the electrical length LE of the power supply unit, which connects between the RF generator and the load to supply RF power, so that the electrical length LE has a predetermined relation with the fundamental wavelength ? of the RF AC. More specifically, the electrical length LE of the power supply unit is selected in such a way that, when the load end, which is the input end of the load, is in an open state, the electrical length LE is (2n?1)·(?/4)?k·??LE?(2n?1)·(?/4)+k·? (n is an integer, k is {??2·cos?1(1/K)}/(4?)) with respect to the fundamental wavelength ? of the RF AC.

Abstract: When RF power is supplied from an RF generator to a load via a power supply unit, (a) the internal impedance of the RF generator is made lower than the characteristic impedance of the power supply unit, and (b) the load-end voltage is increased by selecting the electrical length LE of the power supply unit, which connects between the RF generator and the load to supply RF power, so that the electrical length LE has a predetermined relation with the fundamental wavelength ? of the RF AC. More specifically, the electrical length LE of the power supply unit is selected in such a way that, when the load end, which is the input end of the load, is in an open state, the electrical length LE is (2n?1)·(?/4)?k·??LE?(2n?1)·(?/4)+k·? (n is an integer, k is {??2·cos?1(1/K)}/(4?)) with respect to the fundamental wavelength ? of the RF AC.

Abstract: In an RF power supply for supplying RF power to a plasma load, reflected wave power control is performed in which the reflected wave power of an RF generator is detected and the RF generator is controlled. For a short-time variation in reflected wave power, control is performed based on a peak value variation in the detection value of reflected wave power. For a long-time variation in reflected wave power, control is performed based on a variation in a smoothed value obtained by smoothing detection values of reflected wave power. A reflected wave power control loop system includes a reflected wave power peak value dropping loop system and an arc blocking system that perform control based on a peak variation in reflected wave power and a reflected wave power amount dropping loop system that performs control based on a smoothed power amount of reflected wave power.

Abstract: An ophthalmic apparatus including an operation stick to adjust an optical unit, comprising: a rotary dial that is provided on a side surface of the operation stick and rotates with respect to the operation stick; a trigger arranged on a top of the operation stick while being decentered with respect to the operation stick; and a control unit adapted to control to perform one of movement and focusing of the optical unit with respect to an object in accordance with rotation of the rotary dial and perform control to cause the optical unit to start a predetermined operation in accordance with press of the trigger.

Abstract: A fundus imaging apparatus selects a focal position detection method in accordance with whether a diopter correction lens is inserted in an optical path of an imaging optical system that includes an imaging unit; and detects a focal position based on a signal from the imaging unit according to the selected focal position detection method.

Abstract: An ophthalmic apparatus including an operation stick to adjust an optical unit, comprising: a rotary dial that is provided on a side surface of the operation stick and rotates with respect to the operation stick; a trigger arranged on a top of the operation stick while being decentered with respect to the operation stick; and a control unit adapted to control to perform one of movement and focusing of the optical unit with respect to an object in accordance with rotation of the rotary dial and perform control to cause the optical unit to start a predetermined operation in accordance with press of the trigger.

Abstract: An ophthalmic apparatus including an operation stick to adjust an optical unit, comprising: a rotary dial that is provided on a side surface of the operation stick and rotates with respect to the operation stick; a trigger arranged on a top of the operation stick while being decentered with respect to the operation stick; and a control unit adapted to control to perform one of movement and focusing of the optical unit with respect to an object in accordance with rotation of the rotary dial and perform control to cause the optical unit to start a predetermined operation in accordance with press of the trigger.