Abstract: In one embodiment, a lighting device includes an LED lighting circuit and an LED load constituted by a plurality of parallel circuits formed by connecting a plurality of LED elements in parallel, and a series circuit formed by connecting the parallel circuits. The series circuit is connected with an output terminal of the lighting device. In case one LED element becomes open fault mode in one of the parallel circuit, the other LED elements continue lighting. In case two or more LED elements become the open fault mode, the other LED elements also become the open fault mode, and all the LED elements turn off.

Abstract: According to one embodiment of the invention, there is provided a switching power supply device including a rectifying circuit and a switching operation conversion circuit. The rectifying circuit receives a phase-controlled alternating voltage to rectify to a direct voltage. The switching operation conversion circuit starts up by being applied with the direct voltage, and includes a normally on type switching element and an off driving circuit. The normally on type switching element passes an input current, and the off driving circuit turns off the switching element when the input current reaches a prescribed value. The switching operation conversion circuit converts the direct voltage to an output voltage different from the direct voltage by repeating a switching operation of turning on and off the switching element.

Abstract: A DC power source unit 37 is provided which boosts source voltage from a power source portion 36. A lighting circuit 38 is provided which supplies DC voltage to loads, the DC voltage being obtained by stepping down output current of the DC power source circuit 37. A control circuit 39 is provided which controls the lighting circuit 38 in accordance with at least either voltage or current of LEDs 25 and controls the DC power source unit 37 so that a ratio of output voltage to voltage of the LEDs 25 becomes a preset fixed ratio.

Abstract: According to an embodiment of the invention, there is provided a switching power supply device including an integrated body and a plurality of external terminals. In the integrated body, a first switching element, a constant current element, and a diode are connected in series. The plurality of external terminals include a first external terminal connected to a main terminal of an element disposed on one end side of the integrated body and a second external terminal connected to a main terminal of an element disposed on another end side of the integrated body.

Abstract: The inverter circuit is feedback-controlled by a substantial current flowing into the discharge lamp, which is detected by the current detecting means. A high starting voltage is supplied to the discharge lamp with the operation frequency lowered by the control circuit after the end of a preheating action. The inverter circuit is controlled so that the current of the discharge lamp becomes a desired current value as soon as the current detecting means detects the current substantially flowing into the discharge lamp. The discharge lamp can be prevented from being instantaneously brightly lit without separately providing any structure for detecting lighting of the discharge lamp.

Abstract: The present invention provides a lighting device capable of controlling finely modulated light control without stopping other processing regardless of an operation clock. The light modulation signal generating portion calculates a cycle of a PWM signal based on the lighting state of lamp, which is detected by state detecting portion and a predetermined operation clock. A PWM signal of the cycle calculated by the state detecting portion is generated by the light modulation signal generating portion capable of generating the PWM signal corresponding to the cycle of a non-integral number of times of the operation clock, wherein the cycle of the PWM signal can be continuously and finely varied without stopping other processing regardless of operation clocks, and fine modulated light control is enabled.

Abstract: A fluorescent lamp lighting apparatus according to the present invention comprises an initial illuminance correction control circuit which sets a fluorescent lamp to an initial illuminance correction control lighting mode, a switching portion which changes the fluorescent lamp from the initial illuminance correction control lighting mode to an external control dimming mode when a predetermined external dimming signal is detected, and a control portion which gradually dimming so as to achieve a dimming level of a switched mode when switching the initial illuminance correction control lighting mode and the external control dimming mode, and control so as to achieve a dimming level corresponding to a cumulative lighting time of the fluorescent lamp when the changed mode is the initial illuminance correction control lighting mode.

Abstract: A fluorescent lamp lighting apparatus according to the present invention comprises an initial illuminance correction control circuit which sets a fluorescent lamp to an initial illuminance correction control lighting mode, a switching portion which changes the fluorescent lamp from the initial illuminance correction control lighting mode to an external control dimming mode when a predetermined external dimming signal is detected, and a control portion which gradually dimming so as to achieve a dimming level of a switched mode when switching the initial illuminance correction control lighting mode and the external control dimming mode, and control so as to achieve a dimming level corresponding to a cumulative lighting time of the fluorescent lamp when the changed mode is the initial illuminance correction control lighting mode.