Abstract: A light-emitting device is disclosed. The light-emitting device includes a light-emitting element, a driving circuit, and a compensation unit. The driving circuit is coupled to the light-emitting element, and is configured to receive a first data signal, drive the light-emitting element, and output a sensing signal. The compensation unit is coupled to the driving circuit, and is configured to receive the sensing signal and compensate the first data signal. The compensation unit includes a first comparator circuit and a second comparator circuit. The first comparator circuit includes a first addition terminal, a first subtraction terminal, and a first output terminal. The second comparator circuit includes a second addition terminal and a second subtraction terminal. The first subtraction terminal receives the sensing signal. The first output terminal is coupled to the second addition terminal.

Abstract: An apparatus for extending the lifetime of an LED device is provided. In some embodiments, the apparatus includes an LED printed circuit board (PCB) having two or more LED circuits thereon, where each of the two or more LED circuits includes a plurality of LED emitters. The apparatus further includes a module electrically coupled to the LED PCB that has a selector configured to move between two or more positions, each position activating one of the one or more LED circuits and a relay configured to control a movement of the selector between the two or more positions based on a received input. Additionally, the apparatus includes a power supply that is electrically coupled to the relay.

Abstract: An LED lamp (1) for use in a luminaire (2), the LED lamp (1) comprising a plurality of LEDs (14) connected in a plurality of groups (15, 16); one or more rectifier circuits (10, 10a, 10b) adapted for rectifying an electrical current received from the luminaire (2) for supply to the LEDs (14); a first control circuit (24) adapted to estimate electrical current or electrical power received by or used by the LED lamp (1), and adapted to generate an output on the basis of the estimate; and a switching circuit (20) comprising a first switch (21) for switching the plurality of groups of LEDs (15, 16) between a plurality of different circuit configurations at a switching frequency of at least 300 kHz and according to a duty cycle; wherein the switching circuit (20) is configured to adjust the duty cycle in dependence on the output of the first control circuit (24) to adjust the electrical power used by the LED lamp (1).

Abstract: An LED-filament includes first and second connectors for receiving a variable power; an at least partially light-transmissive substrate; a first LED array of serially connected first LED chips on a front face of the substrate; a second LED array of serially connected second LED chips on the front face of the substrate; a first photoluminescence layer covering the first LED array for generating a first color temperature; a second photoluminescence layer covering the second LED array for generating a second different color temperature; and at least one resistor serially connected to one of the first LED chips, where the first LED array and second LED array are connected in parallel to the first and second connectors, and where current flowing through the first LED and second LED arrays depends on the power applied to the first and second connectors and where the final color temperature of light generated by the LED-filament depends on the power applied to the first and second connectors.

Abstract: Solid-state lighting devices including light-emitting diodes (LEDs), and more particularly integrated warning structures for ultraviolet LED packages are disclosed. Integrated warning structures may include passive structures, such as lumiphoric material regions, that are arranged within LED packages to receive a portion of ultraviolet light from an LED chip within the LED package and provide a small amount of wavelength-converted light. Such wavelength-converted light may serve as indication that ultraviolet light is being emitted. Exemplary lumiphoric material regions may form one or more discrete regions within LED packages and may provide such wavelength-converted light without substantial impact on color purity of the LED packages. Accordingly, LED packages may provide integrated warning emissions that may serve to indicate the presence of ultraviolet emissions and/or reduce human exposure to such ultraviolet emissions.

Abstract: A light-emitting substrate and a display device are provided. The light-emitting substrate includes a plurality of partitions, and the partitions include a first light-emitting unit and a first dummy unit. The first light-emitting unit includes at least one light-emitting element. The first dummy unit is connected in parallel with the first light-emitting unit. The first dummy unit includes a dummy light-emitting element, and an operating voltage of the first dummy unit is greater than an operating voltage of the first light-emitting unit.

Abstract: The present application provides a backlight driving circuit and a display device. The backlight driving circuit includes a light-emitting module, a light-emitting control module, and a constant current source. Wherein the light-emitting module includes a first light-emitting unit for receiving a first power supply signal and a second light-emitting unit for receiving a second power supply signal. A first connection terminal of the light-emitting control module is electrically connected to the first light-emitting unit, and a second connection terminal is electrically connected to the second light-emitting unit to control the first light-emitting unit and the second light-emitting unit to emit light in a time-division manner.

Abstract: A light emitting device including a first light source including a plurality of first light emitting structures and a first wavelength converter and configured to emit a first light, a second light source including a second light emitting structure and a second wavelength converter and configured to emit a second light, and a resistor member connected to the first light source and configured to distribute current to the first light emitting structures, in which a color temperature of the first light is configured to be higher than that of the second light, and the first light and second light are configured to have different light intensity.

Abstract: Disclosed herein is a lighting device with adjustable technical effects using few extraction electrodes to keep the cost low and the device simple, the device including: at least one filament group, wherein each filament group includes at least one filament, each filament includes at least one first light emitting unit and at least one second light emitting unit, which are connected in anti-parallel, and the first light emitting unit and the second light emitting unit have different light attributes from each other; and a light attribute adjusting unit, which is connected to both ends of each filament group to adjust a light attribute of light emitted from the lighting device, wherein the light attribute of the emitted light can be different from the light attribute of any light emitting unit.

Abstract: A control circuit, a drive device, and a display. The control circuit includes: a control unit and a detection unit. The detection unit is connected with a plurality of output voltage feedback terminals of a drive chip, and the detection unit is connected with the control unit. The detection unit is configured for providing a first voltage to the control unit when a voltage of at least one output voltage feedback terminal in the plurality of output voltage feedback terminals is detected, the first voltage being greater than a second voltage received by the control unit. The control unit is configured for controlling the drive chip to restart when the first voltage is greater than the second voltage.

Abstract: A parallel sequenced LED light string includes a plurality of LED modules. The LED modules are connected in parallel through a power wire with a plurality of wire resistances. Each of the LED modules includes an impedance component capable of providing an impedance characteristic. The parallel-connected LED modules receive a supply power, and the LED modules respectively get different voltages through the wire resistances and the impedance components from the supply power so as to sequencing the LED modules.

Abstract: A method for operating an automotive lighting device including providing a first preliminary current profile, calculating a first preliminary derating time associated to the first preliminary current profile, providing a second preliminary current profile, calculating a second preliminary derating time associated to the second preliminary current profile, feeding the first light module with a first current profile which provides a total amount of current lower than the first preliminary amount of current, and feeding the second light module with a second current profile which provides a total amount of current higher than the second preliminary amount of current.

Abstract: A power voltage supply circuit for a display device including: a branch node; a voltage converter having an output terminal connected to the branch node, the voltage converter configured to convert an input voltage received from outside, and output a power voltage to the branch node; a first output node connected to the branch node and configured to output the power voltage; a second output node connected to the branch node; and a charge pump connected between the branch node and the second output node and configured to transform the power voltage with different gain values in response to a control signal.

Abstract: A circuit for sharing current between parallel LEDs or parallel strings of LEDs, and a method of use of the same, are disclosed herein. The circuit for sharing current between parallel LED pathways can include a first LED pathway, a first transistor coupled to the first set of LEDs and that can control a first current through the first set of LEDs, and a first measurement node having a first sensed voltage. The circuit can include a second LED pathway, a second transistor coupled to the second set of LEDs and that can control a second current through the second set of LEDs, and a second measurement node having a second sensed voltage. The circuit includes a first differential amplifier and a second differential amplifier, each of which can compare sensed voltage and can apply a voltage to a gate of one of the first and second transistors.

Abstract: A transparent display panel with a light-transmitting substrate, a plurality of top-emitting micro light emitting diodes, a plurality of bottom-emitting micro light emitting diodes, and a light shielding layer. The light transmissive substrate has a surface. These top-emitting micro light emitting diodes and these bottom-emitting micro light emitting diodes are disposed on the surface of the light transmissive substrate. The bottom-emitting micro light emitting diodes has an epitaxial structure and a light shielding member, the epitaxial structure has a pair of upper and lower surfaces on the opposite sides, the lower surface faces toward the light transmissive substrate, and the light shielding member is disposed on the upper surface to shield the light emitted by the bottom-emitting micro light emitting diodes towards the upper surface.

Abstract: A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

Abstract: In embodiments, a first light engine produces a first light spectrum having a first CCT. A second light engine produces a second light spectrum having a second CCT. The first light spectrum is emitted from a first region of an enclosure; a second light spectrum is emitted from a second region; and a mixture is emitted from a third region that separates the first and second regions. The second CCT is less than the first CCT; a difference between the first and second CCTs is at least 10,000K. The first light spectrum may have a first emission peak in a range of 450 to 480 nm and a second emission peak in a range of 380 to 420 nm. The second light spectrum may have a third emission peak in a range of 480 to 500 nm and a fourth emission peak in the range of 450 to 480 nm.

Abstract: The present disclosure provides a smart window and a driving method thereof and a smart window system. The smart window includes a glass module, a first controller, at least one light bar group and a light bar monitoring circuit. The glass module is coupled to the first controller; the at least one light bar group is coupled to the first controller; and the light bar monitoring circuit includes at least one light bar monitoring sub-circuit. The at least one light bar monitoring sub-circuit is coupled to the first controller and is coupled in a one-to-one correspondence to the at least one light bar group.

Abstract: The present application provides a mini light-emitting diode (mini-LED) backlight module and a display device. The mini-LED backlight module includes a plurality of separate backlight regions. Each of the separate backlight regions is provided with at least two LEDs. Each branch of the LEDs is connected to a protective circuit. The protective circuit includes a rectifier module connected in series with the LED, and a control module connected to the rectifier module and an output end of the LED.

Abstract: An LED drive circuit includes a power supply terminal, an LED, a first switch, and a first resistor are connected in series. The power supply terminal, a third resistor, and a second switch are connected in series. A connection point between the third resistor and the second switch, and a control terminal of the first switch are connected. A second resistor is connected between a connection point between the first switch and the first resistor, and a control terminal of the second switch. A first PTC thermistor is connected to a connection point between the control terminal of the second switch and the second resistor.

Abstract: A linkable LED lighting system designed with an on line free setting method for adjusting operating parameters of at least one LED security light is disclosed. The linkable LED lighting system comprises at least one LED security light working in conjunction with a mobile phone loaded with an APP (software application) for controlling and setting at least one lighting characteristic of the at least one LED security light including time length settings, light intensity settings, color temperature settings, detection range settings, or signal frequency range or signal format settings for screening, accepting, and processing said wireless instruction signal(s) characterized with the same signal frequency range or the same signal format.

Abstract: A multi-channel power supply system includes a power supply circuit configured to generate a drive signal for powering a plurality of color channels based on an input power signal, a first current control circuit coupled to a first color channel of the plurality of color channels and configured to adjust a first channel current of the first color channel based on the drive signal and a first reference signal, and to generate a feedback signal to control the drive signal of the power supply circuit, and a channel controller configured generate the first reference signal based on a color temperature according to a black body curve.

Abstract: A light emitting device includes a Chip Scale Packaged (CSP) LED, the CSP LED including an LED chip that generates blue excitation light; and a photoluminescence layer that covers a light emitting face of the LED chip, wherein the photoluminescence layer comprises from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the layer. The device/CSP LED can further include a further photoluminescence layer that covers the first photoluminescence and that includes a photoluminescence material that generates light with a peak emission wavelength from 500 nm to 650 nm.

Abstract: A light emitting device includes one or more light emitting elements and a plurality of fluorescent materials, and emits a first light, a second light, and a third light, wherein the first light has a correlated color temperature between 1,500 K and 3,500 K and a color rendering index R9 of 50 or more, the second light has a correlated color temperature between 3,500 K and 5,500 K and a color rendering index R9 of 50 or more, the third light has values of X and Y coordinates in the chromaticity diagram of the CIE1931 color system smaller than the values of X and Y coordinates at a color temperature of 5,500 K on the black body radiation locus, and a light having a correlated color temperature of 6,500 K has a color rendering index R9 of 50 or more and a melanopic ratio of 1.0 or more.

Abstract: A display device includes: a pixel unit including a target pixel and peripheral pixels in a unit area set based on the target pixel; a converter configured to adjust a voltage level of a data voltage of the target pixel, based on light emission statuses of the peripheral pixels, and to determine a voltage level of a black voltage of at least one peripheral pixel which does not emit light among the peripheral pixels, based on the light emission statuses of the peripheral pixels; and a data driver configured to apply the data voltage to the target pixel, and to apply the black voltage to the at least one peripheral pixel which does not emit light.

Abstract: Lighting controller including control system having first control facility and second control facility. First and second control facilities respectively are for controlling first and second visible-light sources including first and second pluralities of semiconductor light-emitting devices spaced apart from and along longitudinal axis. First and second visible-light sources respectively are positioned for directing first and second beams of first and second visible-light emissions from first and second pluralities of semiconductor light-emitting devices in first and second beam directions. First and second control facilities respectively are programmed for controlling first and second intensities of first and second beams of first and second visible-light emissions.

Abstract: Lighting apparatuses include an enclosure around first and second light engines. The enclosure has a diffuser over first, second and third regions. The first and second regions are separated by the third region; a first light spectrum is emitted from the first region; a second light spectrum is emitted from the second region; and a mixture of the spectrums is emitted from the third region. In some embodiments, the first spectrum has a CCT?7000K; the second spectrum has a CCT?6500K. In some embodiments, the first spectrum has a first CCT?3500K; the second spectrum has a second CCT?6500K; the second CCT<first CCT and the difference between the CCTs is at least 1000K. In some embodiments, the first spectrum has a color bounded by a first set of chromaticity coordinates, and the second spectrum has a color bounded by a second set.

Abstract: A light-emitting diode (LED) light string control system with carrier identification function includes a control module, a power capacitor, and an LED light string. The control module converts a DC voltage to carry signals on the DC voltage through a power switch according to a lighting command. The power capacitor performs a capacitive charge-discharge operation to the signals on the DC voltage to generate capacitive charge-discharge signals. The LED light string includes at least one LED module, and the at least one LED module identifies that a charge-discharge characteristic is a first logic, a second logic, or a latch indication, and to generate a drive command corresponding to the signals on the DC voltage according to one of the first logic, the second logic, and the latch identification to control lighting behavior of the LED light string.

Abstract: A display panel includes a plurality of pixels arranged in a matrix, the plurality of pixels respectively including a plurality of sub pixels. The plurality of sub pixels respectively includes a light emitting element, and a PWM pixel circuit configured to control a light emitting duration of the light emitting element, based on a pulse width modulation (PWM) data voltage and a sweep voltage. A plurality of PWM pixel circuits included in the display panel are driven, for each of row lines of the plurality of pixels, in an order of a data setting period for setting the PWM data voltage and then a light emitting period in which the light emitting element emits light during a duration corresponding to the set PWM data voltage according to a change of the sweep voltage.

Abstract: A power converter circuit may include a control circuit configured to generate a drive signal for rendering a semiconductor switch conductive and non-conductive to generate a bus voltage across a bus capacitor. The control circuit may adjust a minimum operating period of the drive signal to a first value when an output power of the power converter circuit is greater than a first threshold and to a second value when the output power is less than a second threshold. The control circuit may comprise a comparator that generates the drive signal in response to a sense voltage and a threshold voltage. When operating in a standby mode, the control circuit may adjust a magnitude of the threshold voltage based on an instantaneous magnitude of an alternating-current line voltage received by the power converter circuit, such that an input current drawn by the power converter circuit is sinusoidal.

Abstract: An RF device may include RF circuitry having a PIN diode configured to switch an RF signal, and a biasing circuit. The biasing circuit may include a controllable power supply having a control input and an current output coupled to the PIN diode to selectively bias the PIN diode into an ON state, and a feedback circuit coupled between the current output and the control input of the controllable power supply to set a current delivered to the PIN diode in the ON state.

Abstract: A lighting device includes a substrate having a plurality of flat portions and a non-flat portion disposed between the flat portions, a plurality of light emitting sources disposed on the substrate, a fluorescent substrate layer covering one or more light emitting sources and converting a wavelength of a light from the light emitting source, and a connection line disposed on the substrate and electrically connecting the light emitting sources adjacent to each other between the adjacent light emitting sources. The substrate has a first end and a second end are arranged at different distance from a central axis.

Abstract: A circuit arrangement for connecting a plurality of LED modules in parallel comprises a positive pole terminal and a negative pole terminal for connecting a driver, a positive pole terminal line for electrically connecting the positive pole terminal to the modules, a negative pole terminal line for electrically connecting the negative pole terminal to the modules, a plurality of positive pole terminal contacts for electrically connecting the positive pole terminal line to anode terminal contacts of the modules, and a plurality of negative pole terminal contacts for electrically connecting the negative pole terminal line to cathode terminal contacts of the modules.

Abstract: This disclosure includes systems, methods, and techniques for detecting one or more short connections in a plurality of light-emitting diode (LED) channels. For example, a circuit includes processing circuitry configured to control a plurality of driving devices in order to cause a pair of LED channels of the plurality of LED channels to operate in a first state during a first period of time and operate in a second state during a second period of time. Additionally, the processing circuitry is configured to compare a first electrical signal corresponding to the first state of the pair of LED channels and a second electrical signal corresponding to the second state of the pair of LED channels and determine, based on the comparison of the first electrical signal and the second electrical signal, if a short connection exists between the pair of LED channels.

Abstract: A system for driving a multi-functional light emitting diode (LED) lamp includes a first light source group and a second light source group classified depending on lamp functions, a single LED lamp driving device to regulate an input voltage to a voltage necessary for each lamp function and to apply the voltage to the first light source group and the second light source group, a switching device to control an On/Off state of the first light source group and the second light source group, and a control device to time-division control a time to turn on/off the switching device by internetworking with the LED lamp driving device and to control a light quantity of the first light source group and the second light source group.

Abstract: An omnidirectional LED light wire and a packaging method thereof, a light source and a lamp, and in particular, to the technical field of LED lighting. The omnidirectional LED light wire includes one or more than one flip chip and two or more than two conductive components. The one or more than one flip chip is connected through the conductive components to realize an electrical connection relationship, in single, in series, parallel or a combination of series and parallel, of the one or more than one flip chip. In view of technical problems of low efficacy, low temperature resistance and poor heat dissipation of the existing FPC substrate, the disclosure breaks bottlenecks of temperature resistance and dissipation of the FPC substrate.

Abstract: A method of creating a light script for a video is disclosed. The light script comprises lighting control instructions for controlling one or more light sources when the video is being displayed.

Abstract: A transceiver is disclosed including a transmitter designed to output a first signal according to a physical communication protocol, and to output a second signal comprising at least one cryptographic datum. The first and the second signal may be overlaid onto one another as an overlay signal at the output of the transceiver, and may comply with the physical communication protocol. The overlay signal may be received and processed by a receiver.

Abstract: The present disclosure provides lighting systems suitable for generating white light. The lighting systems can have a first lighting channel configured to produce a first white light having a first color point and a first spectral power distribution, a second lighting channel configured to produce a second white light having a second color point and a second spectral power distribution, and a control system configured to independently change the intensity of each of the first lighting channel and the second lighting channel. The first lighting channels can have LEDs having an emission with a first peak wavelength of between about 440 nm and about 510 nm. The second lighting channels can have LEDs having an emission with a second peak wavelength of between about 380 nm and about 420 nm. The disclosure provides methods of generating white light using the lighting systems described.

Abstract: The present invention relates to a secondary battery. The secondary battery according to the present invention comprises an electrode stack in which an electrode and a separator are combined with each other and a ground part grounding the electrode stack to the outside, wherein the ground part comprises a ground member disposed at one side of the separator to allow abnormal current flowing from the electrode to the one side of the separator to be introduced therein.

Abstract: A linear luminance adjusting circuit includes a rectifying circuit, a constant voltage circuit, a control module, a linear constant current circuit and a hybrid luminance circuit. The rectifying circuit rectifies power from the AC power source to generated a rectified voltage. The constant voltage circuit transforms the rectified voltage into a constant voltage. The control module is electrically coupled to the constant voltage circuit. The control module generates a control signal using the constant voltage. The linear constant current circuit is electrically coupled to the rectifying circuit and the control module. The linear constant current circuit is powered up using the rectifying voltage. And the linear constant current circuit generates a linear current using the control signal. The hybrid luminance circuit is electrically coupled to the rectifying circuit and the linear constant current circuit. The hybrid luminance circuit illuminates using the linear current.

Abstract: An LED package set including a substrate, a first LED package disposed on the substrate and including at least one first LED chip, a second LED package disposed on the substrate and including at least one second LED chip, and a resistor disposed on the substrate, connected to the first LED package in series, and connected to the second LED package in parallel, in which the second LED package is connected in parallel to the first LED package and the resistor, and the first LED package and the second LED package are configured to emit light having different color temperatures.

Abstract: The present disclosure provides lighting systems, which may be semiconductor light emitting devices, with two or more of blue, red, short-blue-pumped cyan, long-blue-pumped cyan, yellow, and violet channels. The lighting systems can have a plurality of operational modes that provide different biological effects while having good color rendering capability. The yellow and violet channels can include violet LEDs and be used in operational modes that provide white light with lower EML values relative to operational modes using three or more of the blue, red, short-blue-pumped cyan, and long-blue-pumped cyan color channels. The yellow, red, and violet channels can be used in an operational mode to provide low EML values while providing white light between about 1800K and about 3500K CCT.

Abstract: A method of emitting light from one or more light emitting elements, the method comprising: emitting a first time period of photopic light, followed by emitting a first time period of scotopic light, followed by emitting a second time period of photopic light, and followed by emitting a second time period of scotopic light; wherein a first transition from the first time period of photopic light to the first time period of scotopic light is different compared to a second transition from the second time period of photopic light to the second time period of scotopic light, and/or wherein a third transition from the first time period of scotopic light to the second time period of photopic light is different compared to a fourth transition from the second time period of scotopic light to the first time period of photopic light or a third time period of photopic light.

Abstract: A circuit arrangement for an LED luminaire comprises a plurality of LED strings, an anode terminal line, a cathode terminal line, a plurality of first switching elements, connected in series into the anode terminal line and subdivided into individual line sections, and a plurality of second switching elements, connected in series into the cathode terminal line and subdivided into individual line sections. Each of the LED strings may be connected to the anode terminal line via a first switching element and/or the second switching elements. Each of the first switching elements may be configured to feed an operating current to an LED string, to electrically connect line sections if the current flowing through the LED string exceeds a predetermined value, and to electrically isolate line sections if the current flowing through the LED string falls below a predetermined value.

Abstract: An optoelectronic component includes a light emitter including a multiplicity of segments, wherein each segment of the light emitter includes a multiplicity of image points configured to emit light, and an optical element configured to image light emitted by the light emitter into a target region, light emitted by the individual segments of the light emitter is superimposed in the target region, the optical element is subdivided into a number of segments corresponding to a number of segments of the light emitter, each segment of the optical element is respectively arranged over a segment of the light emitter, and the segments of the optical element are respectively configured as double-sided aspherical lenses.

Abstract: A circuit includes a primary light emitting diode (LED) string, a secondary LED string, a reference line, and primary and secondary transistors. The primary string includes a voltage drop, and a node disposed between two adjacent LEDs of the primary string. The secondary string is configured in parallel with the primary string. The secondary string has a voltage drop that is less than the primary voltage drop. The reference line is coupled to the node. The primary transistor includes a drain, a gate, and a source. The drain is coupled to a primary string output terminal. The gate is coupled to the reference line, and the source is coupled to a ground. The secondary transistor includes a drain, a gate, and a source. The drain is coupled to a secondary string output terminal. The gate is coupled to the reference line, and the source is coupled to the ground.

Abstract: A light having a first set of electrically coupled solid state light sources having a first forward voltage drop and a second set of electrically coupled solid state light sources having a second forward voltage at least approximately matching the first forward voltage drop. The first set and second sets of solid state light sources are electrically coupled in parallel to a constant current source. A resistor is electrically coupled to at least one of the first and second sets of solid state light sources. Control circuitry is operably coupled to control a resistance electrically coupled in series with said at least one of the first set and the second set of solid state light sources to adjust a respective current therethrough and thereby dim said at least one of the first set and the second set of solid state light sources while maintaining the respective forward voltage drops.

Abstract: An example aspect of a backlight system of the present invention includes: a plurality of light emitting elements that operate as a light source of a backlight using bus-supplied electric power in which a voltage is changed to one of a plurality of predetermined values as a power source; a plurality of serial connection switches that connect the plurality of light emitting elements in series and disconnect connections among the plurality of light emitting elements; a plurality of parallel connection switches that connect the plurality of light emitting elements in parallel relative to the power source and disconnect the connections among the plurality of light emitting elements; and a control unit that turns on or turns off the plurality of serial connection switches and the plurality of parallel connection switches in accordance with the value of the voltage corresponding to the bus-supplied electric power.

Abstract: A liquid crystal panel driving circuit is provided. The circuit includes a pulse width modulation integrated circuit, including an input terminal, a first resistor, a second resistor, a comparator, a light-emitting diode, a latch, a RC circuit and a power supply voltage. Wherein the input terminal is connected to a ground terminal through the first resistor and the second resistor which are serially connected, a positive input terminal of the comparator is connected to a reference voltage, and a negative input terminal of the comparator is connected between the first resistor and the second resistor, an anode of the light-emitting diode is connected to an output terminal of the comparator, and a cathode of the light-emitting diode is connected to the latch, and an input terminal and an output terminal of the RC circuit are respectively connected to the power supply voltage and the latch.