Abstract: A lighting device includes a first light source composed of first LEDs each configured to emit light with a first color temperature, a second light source composed of second LEDs each configured to emit light with a second color temperature lower than the first color temperature, a lighting circuit, and a control circuit. The number of second LEDs is less than that of the first LEDs. The lighting circuit is configured to cause the first and second light sources to light on by supplying first and second drive currents to the first and second light sources, respectively. The control circuit is configured to control lighting conditions of the first and second light sources so that: total light intensity of the first light source varies in response to a dimming signal; and total light intensity of the second light source is kept constant independently of the dimming signal.

Abstract: A lighting device includes a first light source composed of first LEDs each configured to emit light with a first color temperature, a second light source composed of second LEDs each configured to emit light with a second color temperature lower than the first color temperature, a lighting circuit, and a control circuit. The number of second LEDs is less than that of the first LEDs. The lighting circuit is configured to cause the first and second light sources to light on by supplying first and second drive currents to the first and second light sources, respectively. The control circuit is configured to control lighting conditions of the first and second light sources so that: total light intensity of the first light source varies in response to a dimming signal; and total light intensity of the second light source is kept constant independently of the dimming signal.

Abstract: An illumination light communication device includes a power supply unit controlling a load current in a light source unit to be maintained constant based on a dimming signal; an impedance unit series connected to the light source unit; a switch element parallel connected to the impedance unit to connect/disconnect the impedance unit with the light source unit; and a control unit controlling on/off of the switch element to modulate a light intensity of the light source unit such that a binary communication signal is superimposed on illumination light therefrom. The control unit controls the impedance of the impedance unit such that a difference between magnitudes of the load currents respectively when the pulse of the communication signal is superimposed and is not superimposed is maintained constant regardless of a dimming rate of the dimming signal in a range of a dimming rate equal to or greater than a predetermined level.

Abstract: An illumination light communication device includes a light source unit including light emitting elements; a power supply unit controlling a load current flowing through the light source unit to be maintained at a constant; a switch element connected in series to the light source unit; and a control unit configured to control on/off of the switch element to modulate a light intensity of illumination light from the light source unit such that a binary communication signal is superimposed on the illumination light. The control unit has a switching circuit to open/close a path between the light source unit and the power supply unit, controls on/off of the switching circuit based on a dimming signal to perform a dimming control on the light source unit by a PWM control, and allows the communication signal to be superimposed on the illumination light in synchronization with an ON time of the switching circuit.

Abstract: A light emitting device includes: a plurality of light emitting elements configured to emit light when a direct current is supplied thereto; and a direct current power supply circuit configured to supply an electric current of a given level or more to the light emitting elements. The light emitting device further includes: a light emitting element voltage detection circuit configured to detect a voltage applied to the light emitting elements; and a forward/reverse inverting circuit configured, when the light emitting element voltage detection circuit detects an abnormality in a light emitting element, to apply a reverse voltage to the light emitting element in which the abnormality is detected.

Abstract: A planar light-emitting module lighting circuit uses a lamp comprising an organic electroluminescence layer and electrodes sandwiching the organic electroluminescence layer as a load, and applies a current to the load so as to cause the organic electroluminescence layer to emit light. In the planer light-emitting module lighting circuit, a current at a lighting start time of the lamp is made small as compared with a current at a stationary lighting time at which a predetermined time period has passed since a lighting start.

Abstract: An OLED driver for driving at least one organic electroluminescence element, lighting apparatus equipped with the driver and an adjustment method of the apparatus. The driver has a square-wave voltage source and a controller. The source generates square-wave voltage and applies the voltage to the element. The controller controls the source so as to change the frequency of the voltage to change and adjust light output of the element.

Abstract: An LED driving circuit includes a dimming control value detection circuit adapted to detect a dimming control value which indicates a ratio of the actual current to be supplied from a current source to the driving circuit during a predetermined time period with respect to a rated current. A control circuit is adapted to regulate the amount of current supplied to one or more LEDs during the predetermined time period to either of the dimming control value squared or the dimming control value cubed times the rated current. The characteristic of light output to the amount of current supplied from the current source during a predetermined time period is therefore made approximate to that of an incandescent bulb.

Abstract: A light control apparatus and a lighting appliance using the same enable increased luminous efficiency in light control and elongated operative life of a light source. The lighting appliance includes a light source and a light control apparatus. The light control apparatus comprises an electric current output circuit that outputs a constant electric current for lighting to a light source configured of an organic electroluminescence device, and a light control circuit that performs light control of the light source by intermittently supplying the constant electric current outputted from the electric current output circuit. The light control apparatus also comprises an electric discharge prevention circuit (diode) that prevents electric discharge of an electric charge charged in a capacitive component of the organic electroluminescence device.

Abstract: An illumination light communication device includes a light source unit including light emitting elements; a power supply unit controlling a load current flowing through the light source unit to be maintained at a constant; a switch element connected in series to the light source unit; and a control unit configured to control on/off of the switch element to modulate a light intensity of illumination light from the light source unit such that a binary communication signal is superimposed on the illumination light. The control unit has a switching circuit to open/close a path between the light source unit and the power supply unit, controls on/off of the switching circuit based on a dimming signal to perform a dimming control on the light source unit by a PWM control, and allows the communication signal to be superimposed on the illumination light in synchronization with an ON time of the switching circuit.

Abstract: An illumination light communication device includes a power supply unit controlling a load current in a light source unit to be maintained constant based on a dimming signal; an impedance unit series connected to the light source unit; a switch element parallel connected to the impedance unit to connect/disconnect the impedance unit with the light source unit; and a control unit controlling on/off of the switch element to modulate a light intensity of the light source unit such that a binary communication signal is superimposed on illumination light therefrom. The control unit controls the impedance of the impedance unit such that a difference between magnitudes of the load currents respectively when the pulse of the communication signal is superimposed and is not superimposed is maintained constant regardless of a dimming rate of the dimming signal in a range of a dimming rate equal to or greater than a predetermined level.

Abstract: It is an object to provide a light control apparatus and a lighting appliance using the same which enables to increase luminous efficiency in the light control. The lighting appliance includes a light source and a light control apparatus. The light control apparatus includes an electric current output circuit which outputs a constant electric current for lighting to a light source configured of an organic electroluminescence device, an electric current control circuit which controls an intensity of a driving electric current outputted from the electric current output circuit, and the electric current control circuit biases a direct current component so as to vary the driving electric current periodically between a predetermined maximum value and a predetermined minimum value and flows in the same direction at all times in the light control of the light source.

Abstract: An illumination device is provided for controlling a color temperature of light irradiated from a light source having a plurality of light-emitting elements of different light colors. A control setting module provides a control signal associated with a desired color temperature for the irradiated light. A light quantity determination circuit determines light quantities for each of the light-emitting elements based on a relationship between the control signal from the control setting module and an inverse color temperature. A plurality of driver circuits provide driver signals to the light-emitting elements corresponding to the determined light quantities. In this manner the color temperature for light irradiated from the light source coincides with the desired color temperature.

Abstract: Provision of a light emitting device having functionality for restoring to normal even if a low-voltage error occurs, by temporarily applying a reverse current to a low-voltage error light emitting element using a direction inverting circuit, and repairing portions in which impedance has fallen by applying the current.

Abstract: A planar light-emitting module lighting circuit uses a lamp comprising an organic electroluminescence layer and electrodes sandwiching the organic electroluminescence layer as a load, and applies a current to the load so as to cause the organic electroluminescence layer to emit light. In the planer light-emitting module lighting circuit, a current at a lighting start time of the lamp is made small as compared with a current at a stationary lighting time at which a predetermined time period has passed since a lighting start.

Abstract: A light emitting device includes: a plurality of light emitting elements configured to emit light when a direct current is supplied thereto; and a direct current power supply circuit configured to supply an electric current of a given level or more to the light emitting elements. The light emitting device further includes: a light emitting element voltage detection circuit configured to detect a voltage applied to the light emitting elements; and a forward/reverse inverting circuit configured, when the light emitting element voltage detection circuit detects an abnormality in a light emitting element, to apply a reverse voltage to the light emitting element in which the abnormality is detected.

Abstract: An LED driving circuit includes a dimming control value detection circuit adapted to detect a dimming control value which indicates a ratio of the actual current to be supplied from a current source to the driving circuit during a predetermined time period with respect to a rated current. A control circuit is adapted to regulate the amount of current supplied to one or more LEDs during the predetermined time period to either of the dimming control value squared or the dimming control value cubed times the rated current. The characteristic of light output to the amount of current supplied from the current source during a predetermined time period is therefore made approximate to that of an incandescent bulb.

Abstract: It is objected to provide a light control apparatus and a lighting appliance using the same which enable to increase luminous efficiency in the light control and to elongate operative life of a light source. The lighting appliance comprises a light source 1 and a light control apparatus 2. The light control apparatus 2 comprises an electric current output circuit 5 which outputs a constant electric current for lighting to a light source configured of an organic electroluminescence device, a light control circuit 6 which performs light control of the light source 1 by intermittently supplying the constant electric current outputted from the electric current output circuit, and an electric discharge prevention circuit (diode) 70 which prevents electric discharge of an electric charge charged in capacitive component of the organic electroluminescence device.

Abstract: An illumination device is provided for controlling a color temperature of light irradiated from a light source having a plurality of light-emitting elements of different light colors. A control setting module provides a control signal associated with a desired color temperature for the irradiated light. A light quantity determination circuit determines light quantities for each of the light-emitting elements based on a relationship between the control signal from the control setting module and an inverse color temperature. A plurality of driver circuits provide driver signals to the light-emitting elements corresponding to the determined light quantities. In this manner the color temperature for light irradiated from the light source coincides with the desired color temperature.

Abstract: It is an object to provide a light control apparatus and a lighting appliance using the same which enable to increase luminous efficiency in the light control. The lighting appliance includes a light source and a light control apparatus. The light control apparatus includes an electric current output circuit which outputs a constant electric current for lighting to a light source configured of an organic electroluminescence device, an electric current control circuit which controls an intensity of a driving electric current outputted from the electric current output circuit, and the electric current control circuit biases a direct current component so as to vary the driving electric current periodically between a predetermined maximum value and a predetermined minimum value and flows in the same direction at all times in the light control of the light source.