The invention relates to an incorporation of a current limiting/regulating circuit on a luminaire board for ensuring that the luminaire board will automatically operate at its desired current after a replacement. Since the current control at the luminaire board causes an initial mismatch between the current supply of the driver and the demand of the luminaire board, the driver output voltage will drift towards the maximum output voltage of the driver. When the maximum output voltage is reached, the driver is configured to operate in constant-voltage (CV) mode, sense the output current and reduce its output current to the same value as consumed by current-controlled luminaire board. Alternatively, the driver may gradually reduce the setpoint of the output current until it just leaves the CV mode and stay at that setpoint. In this way, the driver will automatically operate at the correct current of a newly installed luminaire board without any action from the user.

A light-emitting diode (LED) lighting device driver with improved luminous performance is provided, which includes a driving circuit and a current ripple reduction circuit. The driving circuit outputs a driving current. The current ripple reduction circuit receives the driving current and reduces the current ripple of the driving current to generate an output current in order to drive a light-emitting module. The current ripple reduction can effectively depress the current ripple of the driving current outputted from the driving circuit in order to generate the output current and then drive the light-emitting module by the output current. Thus, the luminous performance of the light-emitting module can be significantly improved with a view to achieve energy saving and conform to environmental protection requirements.

A light emitting diode device is provided and includes a first light emitting diode(LED) package emitting light to generate a first brightness. The first LED package includes a first diode being driven in response to a pulse width modulation (PWM) current to generate a first portion of the first brightness and a second diode being driven in response to a first direct current (DC) current to generate a second portion of the first brightness. In a first operation mode of the LED device, the first diode and the second diode are enabled to make the first brightness to reach a first value. In a second operation mode, different from the first operation mode, of the LED device, the second diode is disabled to reduce the brightness from the first value to a second value.

A current driving circuit configured to drive a light-emitting device is provided. The current driving circuit includes a first current generating circuit, a second current generating circuit and a driver circuit. The first current generating circuit is configured to generate a reference current. The second current generating circuit includes at least one variable resistor, and may generate a compensation current according to the at least one variable resistor. The at least one variable resistor is selected from at least one of a positive TCR resistor and a negative TCR resistor. The driver circuit is coupled to the first current generating circuit and the second current generating circuit, and configured to receive the reference current and the compensation current to serve as a driving current. The driver circuit outputs the driving current to drive the light-emitting device.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

A visible light sensor may be configured to sense environmental characteristics of a space using an image of the space. The visible light sensor may be controlled in one or more modes, including a daylight glare sensor mode, a daylighting sensor mode, a color sensor mode, and/or an occupancy/vacancy sensor mode. In the daylight glare sensor mode, the visible light sensor may be configured to decrease or eliminate glare within a space. In the daylighting sensor mode and the color sensor mode, the visible light sensor may be configured to provide a preferred amount of light and color temperature, respectively, within the space. In the occupancy/vacancy sensor mode, the visible light sensor may be configured to detect an occupancy/vacancy condition within the space and adjust one or more control devices according to the occupation or vacancy of the space. The visible light sensor may be configured to protect the privacy of users within the space via software, a removable module, and/or a special sensor.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current generator configured to generate a first current flowing through one or more light emitting diodes. The one or more light emitting diodes are configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer. Additionally, the system includes a bleeder configured to receive the rectified voltage, and a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder. The sensing voltage indicates a magnitude of the first current.

The present invention is equipped with: a substrate (10) that has a surface upon which a drive circuit containing a TFT (20) is formed; a planarization film (30) that makes the surface of the substrate planar by covering the drive circuit; and an organic light-emitting element (40) that is provided with a first electrode (41) formed upon the surface of the planarization film and connected to the drive circuit, an organic light-emitting layer (43) formed upon the first electrode, and a second electrode (44) formed upon the organic light-emitting layer. In addition, the planarization film has a two-layer structure comprising an inorganic insulating film (31) and an organic insulating film (32) that are layered upon the TFT, a conductor layer containing a titanium layer and a copper layer is embedded in the interior of a contact hole, and the first electrode is formed electrically connected to the conductor layer.

Provided are a display panel and a display device. The display panel includes a first light-emitting element, a second light-emitting element, a first driver circuit and a second driver circuit. The first driver circuit is electrically connected to the first light-emitting element and configured to provide a first drive current to the first light-emitting element to control the first light-emitting element to emit light, and the second driver circuit is electrically connected to the second light-emitting element and configured to provide a second drive current to the second light-emitting element to control the second light-emitting element to emit light. At least at a maximum grayscale, an average current value of the first drive current is greater than an average current value of the second drive current.

A driver for a Light Emitting Diode (LED) comprises a main circuit of a Ringing Choke Converter (RCC), a driving circuit of the RCC, and a first adjustment module. The main circuit of the RCC comprises: an energy input terminal, an energy output terminal, and a control terminal. The energy input terminal is configured to receive an input voltage. The energy output terminal is coupled to the LED and configured to provide an output current to the LED. The control terminal is configured to receive a driving signal. The driving circuit comprises a driving signal output terminal coupled to the control terminal, and is configured to provide the driving signal to the main circuit via the driving signal output terminal. The first adjustment module is coupled between the energy input terminal and the driving signal output terminal, and is configured to adjust the driving signal according to the input voltage.