Abstract: In the power supply apparatus which performs voltage conversion of an input voltage (Vbat), with a predetermined set voltage as a target value, and outputs the converted voltage, a boost ratio setting unit sets a boost ratio (XCP) of the charge pump circuit based on the input voltage (Vbat) and a predetermined set voltage. A voltage adjustment unit is a regulator circuit, and adjusts voltage (Vx) so that output voltage (Vout) of the charge pump circuit approaches the set voltage. An output voltage setting unit generates a predetermined set voltage as a digital value (Dset). An A/D converter performs analog-digital conversion of the input voltage (Vbat). The boost ratio setting unit sets the boost ratio based on a result of comparing an input voltage (Ddet) that has undergone analog-digital conversion, and the set voltage (Dset).

Abstract: An LED driver 5 includes current sources (52R, 52G, 52B) for generating drive current of LED (4R, 4G, 4B); and a black insert control section (54) for generating a black insert signal (BK) for determining a black insert period in one frame from a frame synchronizing signal (such as vertical synchronizing signal VS). The current sources (52R, 52G, 52B) stop current supply to the LEDs (4R, 4G, 4B) during the black insert period according to the black insert signal (BK). With this configuration, it is possible to enhance the moving image visibility of a liquid crystal display device without increasing the load on display control means or significantly lowering the light source brightness.

Abstract: A control device has: an external terminal receiving a control signal; an output setting circuit changing an output state every time a predetermined edge appears in the control signal; an oscillator generating a clock signal; a period detector counting the number of pulses in the clock signal to detect whether or not the control signal has been kept at a predetermined logic level for a predetermined period; an initializing circuit initializing, based on the output of the period detector, the output state specified by the output setting circuit when the control signal is found to have been kept at the predetermined logic level for the predetermined period; and an oscillation control circuit permitting the operation of the oscillator only when the control signal is at the predetermined logic level and inhibiting the operation of the oscillator otherwise.

Abstract: A light emission control circuit includes a current source circuit for generating currents to be supplied to a plurality of light emitting elements, a plurality of switches disposed corresponding to the respective light emitting elements for switching between supplying or not supplying the currents generated by the current source circuit to the respective light emitting elements, and a PWM control circuit for controlling the respective switches to intermittently supply the currents generated by the current source circuit to the respective light emitting elements and to switch from a stopped state to an initiated state of current supply at different timings for each light emitting element.

Abstract: In the power supply apparatus which performs voltage conversion of an input voltage (Vbat), with a predetermined set voltage as a target value, and outputs the converted voltage, a boost ratio setting unit sets a boost ratio (XCP) of the charge pump circuit based on the input voltage (Vbat) and a predetermined set voltage. A voltage adjustment unit is a regulator circuit, and adjusts voltage (Vx) so that output voltage (Vout) of the charge pump circuit approaches the set voltage. An output voltage setting unit generates a predetermined set voltage as a digital value (Dset). An A/D converter performs analog-digital conversion of the input voltage (Vbat). The boost ratio setting unit sets the boost ratio based on a result of comparing an input voltage (Ddet) that has undergone analog-digital conversion, and the set voltage (Dset).

Abstract: An LED driver 5 includes current sources (52R, 52G, 52B) for generating drive current of LED (4R, 4G, 4B); and a black insert control section (54) for generating a black insert signal (BK) for determining a black insert period in one frame from a frame synchronizing signal (such as vertical synchronizing signal VS). The current sources (52R, 52G, 52B) stop current supply to the LEDs (4R, 4G, 4B) during the black insert period according to the black insert signal (BK). With this configuration, it is possible to enhance the moving image visibility of a liquid crystal display device without increasing the load on display control means or significantly lowering the light source brightness.

Abstract: A control device has: an external terminal receiving a control signal; an output setting circuit changing an output state every time a predetermined edge appears in the control signal; an oscillator generating a clock signal; a period detector counting the number of pulses in the clock signal to detect whether or not the control signal has been kept at a predetermined logic level for a predetermined period; an initializing circuit initializing, based on the output of the period detector, the output state specified by the output setting circuit when the control signal is found to have been kept at the predetermined logic level for the predetermined period; and an oscillation control circuit permitting the operation of the oscillator only when the control signal is at the predetermined logic level and inhibiting the operation of the oscillator otherwise.