Abstract: A light-emitting device includes: a light guide that includes (i) a light-transmissive member that is light-transmissive at least in a visible light region and (ii) a light control layer that is disposed on at least a part of a surface of the light-transmissive member; and a light source that emits light toward at least one end surface of the light-transmissive member. The light control layer has reflected-wavelength selectivity that makes a wavelength of reflected light dependent on an incident angle of incident light.

Abstract: A gate drive device drives a gate of each of two semiconductor switching elements constituting upper and lower arms of a half bridge circuit. The gate drive device detects a peak value of an element voltage that is a voltage of a main terminal of one of the two semiconductor switching elements, as one semiconductor switching element, or a change rate of the element voltage during a change period in which the element voltage changes. The gate drive device determines whether an energization to the one semiconductor switching element during the change period is a forward energization in which a current flows in a forward direction or a reverse energization in which the current flows in a reverse direction.

Abstract: A gate drive device drives a gate of a semiconductor switching element constituting an upper or lower arm of a half bridge circuit which supplies an output current, which is alternating current, to a load. The gate drive device detects a peak value of an element voltage which is a voltage of a main terminal of the semiconductor switching element or a change rate of the element voltage when the semiconductor switching element is switching. The gate drive device acquires a maximum value among a plurality of peak values or a plurality of change rates during a predetermined detection period including a period in which the semiconductor switching element performs switching multiple number of times.

Abstract: A change rate control circuit computes a first drive speed, which is a gate drive speed of a gate of a drive-subject element, for controlling a change rate of an element voltage of the drive-subject element at a target change rate during a change period. A timing generating circuit acquires, in advance, a delay time caused when the gate is driven and determines a switching timing, at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-off of the drive-subject element and generates a timing signal representing the switching timing. A speed change circuit changes the gate drive speed from the first drive speed to a second drive speed at the switching timing during turn-off of the drive-subject element.

Abstract: A gate driver drives a gate of a semiconductor switching element. The gate driver includes a command signal output circuit, a pre-drive circuit and a drive circuit. The command signal output circuit outputs a current command signal that indicates a command value of a gate current as a current flowing through the gate of the semiconductor switching element. The pre-drive circuit receives the current command signal and generate a drive signal corresponding to the current command signal to output the drive signal. The drive circuit drives the gate of the semiconductor switching element based on the drive signal. The command signal output circuit switches the command value indicated by the current command signal while controlling a transient voltage at a desired target value. The drive circuit includes output circuits connected in parallel. Each of output circuits has at least one cascode circuit in which two MOSFETs are cascode-connected.

Abstract: A gate drive device drives a gate of a semiconductor switching element and controls a transient voltage corresponding to a voltage of a main terminal of the semiconductor switching element to a target value of the transient voltage at a time of switching the semiconductor switching element. The gate drive device includes a calculation circuit, a drive circuit, a detection circuit, and a learning circuit. The calculation circuit executes a predetermined calculation mode to calculate an operation amount for operating gate drive speed of the semiconductor switching element. The drive circuit drives the gate of the semiconductor switching element according to the operation amount. The detection circuit detects the transient voltage. The learning circuit executes learning processing to change the predetermined calculation mode based on the operation amount calculated by the calculation circuit and the transient voltage detected by the detection circuit.

Abstract: A gate drive device drives a gate of a semiconductor switching element and controls a transient voltage corresponding to a voltage of a main terminal of the semiconductor switching element to a target value of the transient voltage at a time of switching the semiconductor switching element. The gate drive device includes a calculation circuit, a drive circuit, a detection circuit, and a learning circuit. The calculation circuit executes a predetermined calculation mode to calculate an operation amount for operating gate drive speed of the semiconductor switching element. The drive circuit drives the gate of the semiconductor switching element according to the operation amount. The detection circuit detects the transient voltage. The learning circuit executes learning processing to change the predetermined calculation mode based on the operation amount calculated by the calculation circuit and the transient voltage detected by the detection circuit.

Abstract: A light-emitting device includes: a light guide that includes (i) a light-transmissive member that is light-transmissive at least in a visible light region and (ii) a light control layer that is disposed on at least a part of a surface of the light-transmissive member; and a light source that emits light toward at least one end surface of the light-transmissive member. The light control layer has reflected-wavelength selectivity that makes a wavelength of reflected light dependent on an incident angle of incident light.

Abstract: A change rate control circuit computes a first drive speed, which is a gate drive speed of a gate of a drive-subject element, for controlling a change rate of an element voltage of the drive-subject element at a target change rate during a change period. A timing generating circuit acquires, in advance, a delay time caused when the gate is driven and determines a switching timing, at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-off of the drive-subject element and generates a timing signal representing the switching timing. A speed change circuit changes the gate drive speed from the first drive speed to a second drive speed at the switching timing during turn-off of the drive-subject element.

Abstract: A gate drive device drives a gate of each of two semiconductor switching elements constituting upper and lower arms of a half bridge circuit. The gate drive device detects a peak value of an element voltage that is a voltage of a main terminal of one of the two semiconductor switching elements, as one semiconductor switching element, or a change rate of the element voltage during a change period in which the element voltage changes. The gate drive device determines whether an energization to the one semiconductor switching element during the change period is a forward energization in which a current flows in a forward direction or a reverse energization in which the current flows in a reverse direction.

Abstract: A gate drive device drives a gate of a semiconductor switching element constituting an upper or lower arm of a half bridge circuit which supplies an output current, which is alternating current, to a load. The gate drive device detects a peak value of an element voltage which is a voltage of a main terminal of the semiconductor switching element or a change rate of the element voltage when the semiconductor switching element is switching. The gate drive device acquires a maximum value among a plurality of peak values or a plurality of change rates during a predetermined detection period including a period in which the semiconductor switching element performs switching multiple number of times.

Abstract: A gate drive apparatus includes a driver, a peak voltage detector and a drive capability controller. The driver drives a gate of a first switching element as one of two switching elements respectively in an upper arm and a lower arm of a half-bridge circuit. The peak voltage detector detects a peak voltage at a second switching element in a situation where the first switching element is turned on. The drive capability controller calculates a value of drive capability when the driver turns on the first switching element, in a condition that the peak voltage at the second switching element does not exceed a tolerance value of a voltage at the second switching element according to a specification of the second switching element, and modifies the drive capability when the driver turns on the first switching element, based on a calculated result of the value of the drive capability.

Abstract: A gate drive apparatus includes a driver, a peak voltage detector and a drive capability controller. The driver drives a gate of a first switching element as one of two switching elements respectively in an upper arm and a lower arm of a half-bridge circuit. The peak voltage detector detects a peak voltage at a second switching element in a situation where the first switching element is turned on. The drive capability controller calculates a value of drive capability when the driver turns on the first switching element, in a condition that the peak voltage at the second switching element does not exceed a tolerance value of a voltage at the second switching element according to a specification of the second switching element, and modifies the drive capability when the driver turns on the first switching element, based on a calculated result of the value of the drive capability.

Abstract: A semiconductor device includes a plurality of switching elements electrically connected in parallel with each other, a control unit that outputs a control signal for controlling a current supplied to each of the switching elements, and a temperature estimation unit that estimates a temperature difference between the switching elements. When an estimated temperature difference becomes equal to or higher than a predetermined threshold temperature, the control unit shifts an operation mode to a stop mode for stopping driving of a switching element having a temperature higher than the other.

Abstract: A lighting apparatus includes: a light source module; a light guide that guides light emitted from the light source module; and a light exit structure provided in the light guide, for causing the light to exit the light guide. The light guide includes: a base material that is flexible and light-transmissive; and a visible-light absorber uniformly dispersed in the base material. The visible-light absorber has a maximum absorption wavelength of at least 500 nm and at most 750 nm.

Abstract: A lighting apparatus includes: a light source module; a light guide that guides light emitted from the light source module; and a light exit structure provided in the light guide, for causing the light to exit the light guide. The light guide includes: a base material that is flexible and light-transmissive; and a visible-light absorber uniformly dispersed in the base material. The visible-light absorber has a maximum absorption wavelength of at least 500 nm and at most 750 nm.

Abstract: An illumination device is provided. The illumination device includes a substrate including a light-emitter. An instrument main body includes a substrate arrangement surface, with the substrate being on the substrate arrangement surface. A cover is attached to the instrument main body, covers the substrate, and is transparent. An antenna is on the cover and configured to receive a signal from an outside of the illumination device. A driver is on the instrument main body and configured to supply power to the light-emitter. A controller is configured to control the power supplied from the driver to the light-emitter based on the signal received by the antenna. The cover includes a diffusion factor from 40% to 90%.

Abstract: A semiconductor device includes a plurality of switching elements electrically connected in parallel with each other, a control unit that outputs a control signal for controlling a current supplied to each of the switching elements, and a temperature estimation unit that estimates a temperature difference between the switching elements. When an estimated temperature difference becomes equal to or higher than a predetermined threshold temperature, the control unit shifts an operation mode to a stop mode for stopping driving of a switching element having a temperature higher than the other.

Abstract: An illumination device is provided. The illumination device includes a substrate including a light-emitter. An instrument main body includes a substrate arrangement surface, with the substrate being on the substrate arrangement surface. A cover is attached to the instrument main body, covers the substrate, and is transparent. An antenna is on the cover and configured to receive a signal from an outside of the illumination device. A driver is on the instrument main body and configured to supply power to the light-emitter. A controller is configured to control the power supplied from the driver to the light-emitter based on the signal received by the antenna. The cover includes a diffusion factor from 40% to 90%.

Abstract: A semiconductor device has a drive unit outputting a first drive signal to a first electrode and a second drive signal to a second electrode, an instruction signal generation unit generating an instruction signal as a basis of the drive signals and a control unit outputting a first control signal as a basis of the first drive signal and a second control signal as a basis of the second drive signal, based on the instruction signal to control the drive unit. The control unit synchronizes the first control signal with the instruction signal, delays a turning-on timing of the second control signal by a predetermined time relative to the instruction signal and determines a turning-off timing of the second control signal based on a previous pulse width of the instruction signal.