Patent application number | Description | Published |
20110248647 | LIGHTING DEVICE AND LIGHT FIXTURE USING LIGHTING DEVICE - A lighting device reliably detects a status (i.e., existence or absence) of a load connection, and enables or disables power output based on the detected load connection status. The device includes a DC-DC converter having input and output terminals, and a DC current conducting element coupled across the output terminals. A load terminal is also coupled across the output terminals and configured to receive an LED unit. A load detection circuit coupled between an input terminal and the load terminal detects the connection status of an LED unit via a DC current passing through the load terminal, and controls a switching operation of the DC-DC converter based on the detected connection status. A diode coupled between the load terminal and the DC current conducting element blocks a DC current path from the input terminals to the load detection circuit through the DC current conducting element. | 10-13-2011 |
20120019714 | LED LIGHTING DEVICE WITH CHOPPER CIRCUIT AND DIMMING CONTROL METHOD - A lighting device is provided for lighting control of an LED module based on an externally provided dimming control signal. A chopper circuit includes a switch coupled across a DC input and an inductor which receives and stores energy when the switch is turned on, and discharges energy to the LED module when the switch is turned off. A control circuit determines a current value to the switch, and compares the current value to a predetermined value. During normal operation, the switch is turned off when the detected current value reaches the predetermined value and turned back on when inductor discharge has completed. During a dimming operation, the normal operation is intermittently disabled in accordance with the dimming control signal. The dimming control signal may be a low-frequency PWM signal, with the lighting output being dimmed as a result of a duty ratio of the PWM signal. | 01-26-2012 |
20120098450 | LIGHTING DEVICE AND ILLUMINATION APPARATUS USING SAME - There is provided a lighting device usable in a space together with 3D glasses having shutters which alternately block respective translucent surfaces of a pair of lenses at one of a plurality of shutter frequencies. The lighting device includes: a lighting unit which outputs a direct current to a light source; and a dimming control unit which turns on/off supply of the direct current to the light source at a predetermined PWM frequency. Further, the PWM frequency is an integer multiple of the least common multiple of the plurality of shutter frequencies. | 04-26-2012 |
20120098453 | LIGHTING DEVICE AND ILLUMINATION APPARATUS USING SAME - A lighting device includes: a lighting unit which outputs a direct current; a smoothing unit having a capacitor which smoothes the direct current outputted from the lighting unit and supplies it; and a control unit for performing an intermittent control which alternately repeats a first time period in which the direct current is supplied to the smoothing unit and a second time period in which the direct current decreases to be smaller than that in the first time period. In the lighting device, a product of a frequency (Hz) and a capacitance (μF) of the capacitor is equal to or greater than 0.05 in which one cycle of the frequency corresponds to a sum of the first time period and the second time period. | 04-26-2012 |
20120249003 | LIGHTING DEVICE FOR SEMICONDUCTOR LIGHT EMITTING ELEMENT AND ILLUMINATION APPARATUS INCLUDING SAME - A lighting device for a semiconductor light emitting element includes a series circuit of two switching elements which are alternately turned on, the series circuit being connected to a direct current (DC) input power source and a reactance circuit connected between a connection node of the two switching elements and one end of the DC input power source through a capacitor, an output of the reactance circuit being supplied to the semiconductor light emitting element through a rectifier circuit. A dimming operation of the semiconductor light emitting element is performed by varying a ratio of ON periods of the two switching elements. | 10-04-2012 |
20120262082 | SEMICONDUCTOR LIGHT-EMITING ELEMENT DRIVER CIRCUIT AND LIGHT FIXTURE USING THE SAME - A driver circuit for a semiconductor light-emitting element enables stable dimmed lighting from very low luminance output to rated luminance output by use of a switching power source operating in a discontinuous mode. The driver circuit includes a DC-DC converter, an output sensor, and a feedback controller. The DC-DC converter includes a burst dimming controller for intermittently stopping an ON/OFF operation of a power switch of the DC-DC converter, thereby reducing a current flowing to the semiconductor light-emitting element. The output sensor detects at least one of the current provided to the semiconductor light-emitting element or the voltage of the semiconductor light-emitting element. The feedback controller adjusts an ON time of the power switch during the ON/OFF operation such that a detected value of the output sensor approaches a target value. Near a dimming control lower limit, power is blocked from the feedback controller. | 10-18-2012 |
20120326617 | ILLUMINATION APPARATUS - An illumination apparatus, for outputting a light of mixed colors in a desired color temperature by controlling light outputs from light sources, includes: a light output setting unit for outputting a set signal presenting a set value for adjusting an output of the light of mixed colors; a first filter for smoothing the set signal from the light output setting unit; a light output adjustment unit for adjusting the light outputs from the respective light sources based on the set signal smoothed by the first filter; and a plurality of second filters smoothing signals outputted from the light output adjustment unit to the light sources, respectively. Each of time constants of the second filters is lower than that of the first filter. | 12-27-2012 |
20120326631 | LIGHTING DEVICE AND ILLUMINATION APPARATUS INCLUDING SAME - A lighting device includes lighting control units respectively provided for controlling lighting of solid state light emitting element groups irradiating light of different chromaticities and a color ratio setting unit for setting a target output ratio of the solid state light emitting element groups. In an xy chromaticity diagram of an XYZ color system, a straight line connecting chromaticity coordinates of lights irradiated by a first and a second solid state light emitting element group intersects a black body locus. Further, the lighting control units include a first and a second lighting control unit for controlling lighting of the first and the second solid state light emitting element group, and the first and the second control unit perform a feedback control such that an output ratio of the second to the first solid state light emitting element group becomes equal to the target output ratio thereof. | 12-27-2012 |
20130099691 | SEMICONDUCTOR LIGHT EMITTING ELEMENT DRIVE DEVICE AND LIGHTING FIXTURE WITH THE SAME - If a dimming ratio of a light source unit is higher than a first ratio, an ON width of a first switching device is increased with a second switching device kept off when the dimming ratio is increased, and also the ON width of the first switching device is decreased with the second switching device kept off when the dimming ratio is decreased. If a dimming ratio of the light source unit is lower than the first ratio, the ON width of the second switching device is regulated with the ON width of the first switching device held at a lower limit. | 04-25-2013 |
20130141002 | LIGHTING APPARATUS AND ILLUMINATING FIXTURE WITH THE SAME - In a first control mode, a control circuit turns a switching element on and off at a predetermined oscillating frequency and an On time so that a current flows through inductor in continuous mode without a sleep interval. In a second control mode, control circuit fixes oscillating frequency of switching element and changes On time of switching element. In a third control mode, control circuit fixes On time of switching element and changes oscillating frequency of switching element. Second control mode and third control mode are allocated for at least two intervals of intervals into which a dimming range is divided. Control circuit selects first control mode to fully light a light source load, and then, if a dimming ratio is designated, control circuit selects one of second and third control modes according to the interval, to which the dimming ratio corresponds, to dim light source load. | 06-06-2013 |
20130141003 | LIGHTING APPARATUS AND ILLUMINATING FIXTURE WITH THE SAME - The lighting apparatus in accordance with the present invention includes: a switching regulator including a switching element; and a control circuit configured to adjust a switching frequency and on-duration of the switching element in accordance with a dimming ratio. The control circuit is configured to, when the dimming ratio falls within a first dimming range, adjust the switching frequency to a frequency associated with the first dimming range and adjust the on-duration to duration corresponding to the dimming ratio. The control circuit is configured to, when the dimming ratio falls within a second dimming range, adjust the on-duration to duration associated with the second dimming range and adjust the switching frequency to a frequency corresponding to the dimming ratio. | 06-06-2013 |
20130141016 | LIGHTING APPARATUS AND ILLUMINATING FIXTURE WITH THE SAME - A control circuit selects a first control mode in which a switching element is turned on/off so as to flow current in an inductor in a continuous mode by which the current flows in the inductor without a sleep period, thereby fully lighting a light source load. The control circuit selects one of a second control mode in which a turn-on time of the switching element is changed and a third control mode in which an oscillating frequency is changed according to an interval, to which the designated dimming ratio corresponds, to light the light source load. An output capacitor connected between output terminals of a step-down chopper circuit smoothes a pulsation component of an output current supplied to the light source load and has capacity set so that a ripple ratio of the output current is less than 0.5 at the full lighting of the light source load. | 06-06-2013 |
20130141017 | LIGHTING APPARATUS AND ILLUMINATING FIXTURE WITH THE SAME - A control circuit selects a first control mode in which a switching element is turned on and off so that a current flows through an inductor in a critical or discontinuous mode, thereby fully lighting a light source load. The control circuit selects one of a second control mode in which On time of the switching element is changed and a third control mode in which an oscillating frequency is changed according to an interval, to which a designated dimming ratio corresponds, to dim the light source load. An output capacitor connected between output terminals of a step-down chopper circuit smoothes pulsation component of an output current supplied to the light source load and has capacity set so that a ripple ratio of the output current is less than 0.5 at full lighting of the light source load. | 06-06-2013 |
20130207571 | SEMICONDUCTOR LIGHT EMITTING ELEMENT DRIVE DEVICE AND LIGHTING FIXTURE WITH THE SAME - A semiconductor light emitting element drive device includes: a converter circuit configured to supply a light source unit with a load current from a first-primary winding; and a current regulation circuit. The converter circuit further includes a second-secondary winding. The current regulation circuit includes a switching device (second switching device) connected in series with the second-secondary winding. In a dimming ratio of the light source unit is lower than a first ratio, the second switching device is controlled to ON and OFF so as to decrease the load current through the light source unit by a shunt of a part of the energy stored in the primary winding. | 08-15-2013 |
20140232268 | LIGHTING DEVICE AND LIGHTING FIXTURE - The lighting device according to the present invention includes a power supply circuit, a temperature detection circuit, and a temperature control circuit. The power supply circuit supplies operation power to a light source including a solid state light emitting device. The temperature detection circuit measures a surrounding temperature of the light source and outputs the measured surrounding temperature as a detection temperature. The temperature control circuit determines whether an increase rate of the surrounding temperature exceeds a predetermined criterion value. When determining that the increase rate exceeds the criterion value, the temperature control circuit performs a process of decreasing a temperature of the light source. | 08-21-2014 |
20150042228 | ELECTRONIC BALLAST AND LUMINAIRE WITH THE SAME - An electronic ballast includes an AC-DC converter, a DC-DC converter, a cooling device and a power supply. The cooling device is configured to cool the light source. The power supply includes a first power supply configured to generate a first operating voltage from a first voltage obtained from a chopper circuit included in the AC-DC converter to supply the first operating voltage to at least one of the AC-DC converter and the DC-DC converter. The power supply further includes a second power supply configured to generate a second operating voltage from a second voltage obtained from the chopper circuit to supply the second operating voltage to at least the cooling device of the AC-DC converter, the DC-DC converter and the cooling device. | 02-12-2015 |
20150054419 | LIGHTING DEVICE AND ILLUMINATION APPARATUS USING THE SAME - In first mode, controller is configured, when receiving a dimming instruction signal, to control voltage-adjusting part to provide a DC voltage with a magnitude corresponding to a luminous level, across output ends of DC power supply, and apply a control voltage with a magnitude kept constant to a control terminal of switching element. In second mode, controller is configured, when receiving the dimming instruction signal, to apply the control voltage with a magnitude corresponding to luminous level to the control terminal of switching element, and control voltage-adjusting part to provide the DC voltage with a magnitude kept constant, across the output ends of DC power supply. Controller is configured to operate in one of first and second modes when luminous level is predetermined level or more, and in the other of first and second modes when luminous level is less than predetermined level. | 02-26-2015 |
20150054420 | LIGHTING DEVICE AND ILLUMINATION APPARATUS USING THE SAME - A controller has a first mode and a second mode. First mode is of generating a PWM signal that has a duty ratio to be changed according to a luminous level for a light emitting element and has a constant amplitude. Second mode is of generating a PAM signal that has a constant duty ratio and has an amplitude to be changed according to the luminous level for the light emitting element. Controller is configured to apply one of PWM signal in first mode and PAM signal in second mode to a control terminal of a switching element, when the luminous level is a predetermined level or more. Controller is configured to apply the other of PWM signal in first mode and PAM signal in second mode to the control terminal of the switching element, when the luminous level is less than the predetermined level. | 02-26-2015 |