Multifunctional LED lamp driving system and method based on single channel

Abstract

The present invention discloses a driving system for a multifunctional light emitting diode (LED) lamp, comprising: a first light source group and a second light source group, which are classified according to lamp functions; a single LED lamp driving device, which adjusts an input voltage to a voltage required for each lamp function and applies the voltage to the first light source group and the second light source group; a switching device, which controls the on / off state of the first light source group and the second light source group; and a control device, which controls the on / off time of the switching device in time division by cooperating with the LED lamp driving device to control the light amount of the first light source group and the second light source group.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2020-0131932 filed on October 13, 2020, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a driving system and method for a multifunctional light emitting diode (hereinafter referred to as "LED") lamp based on a single channel, and more specifically, to a technology for time-division control of a multifunctional LED lamp. Background Art

[0004] Vehicles typically have various lighting systems. These lighting systems serve both illumination functions, making it easier to identify objects around the vehicle during nighttime driving, and signal functions, notifying other vehicles and road users of the vehicle's driving status. For example, among these various types of lighting, headlights and fog lights serve as illumination, while turn signals, brake lights, and position lights serve as signaling functions.

[0005] Such a vehicle lamp includes a plurality of LEDs. When the plurality of LEDs are driven simultaneously, current deviations are generated when the LEDs are driven at the same voltage due to variations in the LEDs, resulting in different brightness of the LEDs.

[0006] Therefore, when driving multiple LEDs, a constant current drive mode is used instead of a constant voltage drive mode. In particular, when fine-tuning the brightness is required, a constant current drive mode is more preferred.

[0007] FIG. 1 is a view schematically showing the configuration of a conventional power supply for driving LEDs.

[0008] 1 , a conventional driving system of a multifunctional LED lamp may include an integrated central control unit (ICU) 11 , a microcomputer 12 , an LED driver 13 , and an LED load 14 .

[0009] The ICU 11 may provide a lamp driving signal to the microcomputer 12 through an intelligent power switch (IPS), and may supply power to the LED driver 13 .

[0010] The microcomputer 12 may receive a lamp driving signal from the IPS and control a constant current through the LED driver 13 .

[0011] The LED driver 13 as a DC-DC driving semiconductor may be arranged corresponding to each lamp function. In this case, the LED load 14 may be arranged to be connected to each LED driver.

[0012] The LED driver 13 may receive power from the IPS and may receive a control signal from the microcomputer 12 to control a constant current of the LED and diagnose a fault.

[0013] In other words, the IPS in the ICU (SJB) is used to provide control signals and power to the lights while detecting disconnections and short circuits in the wiring. Furthermore, the ICU 11 can receive information about faults (open circuits or short circuits) in the low-beam and turn signal lamps from the microcomputer 12 via separate tell-tale wiring circuits for each lamp function.

[0014] In a conventional driving system of a multifunctional LED lamp, since a redundant LED driver 13 is provided for each lamp function and an expensive IPS is used, the system price increases. Summary of the Invention

[0015] The present disclosure aims to solve the above-mentioned problems existing in the prior art while maintaining the advantages achieved by the prior art.

[0016] One aspect of the present disclosure provides a single-channel, multifunctional LED lamp driving system and method thereof, capable of time-division control of multiple LED lamps to minimize increases in system cost. The technical problems to be solved by the present disclosure are not limited to the aforementioned problems. Any other technical problems not mentioned herein will be readily understood by those skilled in the art through the following description.

[0017] According to one aspect of the present disclosure, a driving system for a multifunctional light emitting diode (LED) lamp may include: a first light source group and a second light source group, which are classified according to lamp functions; a single LED lamp driving device, which adjusts the input voltage to the voltage required for each lamp function and applies it to the first light source group and the second light source group; a switching device, which controls the on / off state of the first light source group and the second light source group; and a control device, which controls the on or off time of the switching device by linking with the LED lamp driving device to control the light amount of the first light source group and the second light source group.

[0018] According to an embodiment, the first light source group and the second light source group may be connected to each other in parallel.

[0019] According to an embodiment, each of the first light source group and the second light source group may include an LED or a structure in which at least two LEDs are connected in series.

[0020] According to an embodiment, the switching device may include: a first switch connected in parallel with a first LED group of a first light source group that performs a first function to control an on / off state of the first LED group; a second switch connected in parallel with a second LED group of the first light source group that performs a second function to control an on / off state of the second LED group; and a third switch connected in parallel with a third LED group of the first light source group that performs a third function to control an on / off state of the third LED group.

[0021] According to an embodiment, the switch device may further include: a fourth switch connected to the output end of the LED lamp driving device and the input end of the first light source group; and a fifth switch connected to the output end of the LED lamp driving device and the input end of the second light source group.

[0022] According to an embodiment, the first function may include a low beam function, the second function may include a high beam function, the third function may include a sub-high beam function, and the second light source group may perform a daytime running light (DRL) function or a positioning light function.

[0023] According to an embodiment, the LED lamp driving apparatus may reduce an input voltage and apply the reduced input voltage to the second light source group when the DRL function is turned on.

[0024] According to an embodiment, the LED lamp driving apparatus may boost an input voltage and apply the boosted input voltage to the first light source group when the high beam function is turned on.

[0025] According to an embodiment, the LED lamp driving device may increase or decrease the input voltage according to a difference between the input voltage and a voltage required to perform the low beam function when the low beam function is turned on and apply the increased or decreased input voltage to the first light source group.

[0026] According to an embodiment, an LED lamp driving device may include: a first switching device and a second switching device, which are connected in series with each other between an input voltage terminal and a ground terminal; a third switching device and a fourth switching device, which are connected in series with each other between an output voltage terminal and a ground terminal; and an inductor, which is connected between a common node of the first switching device and the second switching device and a common node of the third switching device and the fourth switching device.

[0027] According to an embodiment, the control device may control the second light source group to be turned off when the first light source group is turned on; and control the first light source group to be turned off when the second light source group is turned on.

[0028] According to an embodiment, the first light source group may include a plurality of LED groups according to functions, and the control device may control the switching device so that the LED groups are sequentially lit starting from the LED group having the highest duty cycle.

[0029] According to an embodiment, the control device may set a duty cycle of lighting the first light source group to be longer than a duty cycle of lighting the second light source group.

[0030] According to an embodiment, the control device may calculate the output current value applied to the first light source group or the second light source group based on a duty ratio of lighting the first light source group or the second light source group and a maximum output current.

[0031] According to an embodiment, the system may further include: an input-end capacitor to stabilize the input current; an output-end capacitor to stabilize the output current; and a comparison capacitor to discharge the charging current.

[0032] According to an embodiment, the control device may be configured to determine that the failure of the LED load of at least one of the first light source group or the second light source group is caused by a disconnection state (open circuit) when the output current of the single LED lamp driving device is equal to or less than a specific value.

[0033] According to an embodiment, the control device can be configured to determine that the failure of the LED load of at least one of the first light source group or the second light source group is caused by a short circuit when the voltage difference applied across each of the multiple LED groups in the first light source group or the voltage difference applied across the second light source group is less than a specific value.

[0034] According to an embodiment, the control device may be configured to, when there is a failed LED group in the first light source group or the second light source group, perform a fail-safe operation to eliminate the failed LED group.

[0035] According to another aspect of the present disclosure, a driving method of a multifunctional LED lamp may include: adjusting and outputting a voltage applied to a first light source group and a second light source group classified according to the function of the lamp; and controlling the on / off state and light amount of the first light source group and the second light source group by time-divisionally controlling the on or off time of a switching device connected to the first light source group and the second light source group. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description in conjunction with the accompanying drawings:

[0037] FIG1 is a view schematically showing the configuration of a conventional power supply for driving LEDs;

[0038] Figure 2 is a block diagram illustrating a configuration of a vehicle system including a driving system for a multifunctional LED lamp based on a single channel according to an embodiment of the present disclosure;

[0039] Figure 3A It shows Figure 2 A view of the detailed configuration of the LED lamp driver;

[0040] Figure 3B Show Figure 2 Detailed circuit diagrams of each component;

[0041] Figure 4A 、 Figure 4B and Figure 4C is a view illustrating a driving mode of a driving system for a multifunctional LED lamp according to an embodiment of the present disclosure;

[0042] Figure 5 and Figure 6 is a view illustrating a driving control concept of a multifunctional LED lamp according to an embodiment of the present disclosure;

[0043] Figure 7 and Figure 8 is a diagram illustrating a fault determination method and a fail-safe operation of a driving system of a multifunctional LED lamp according to an embodiment of the present disclosure; and

[0044] Figure 9 is a diagram illustrating a time-division sequence of a driving system for a multifunctional LED lamp according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When adding reference numerals to the components of each figure, it should be noted that even when the same or equivalent components are shown in other figures, they are represented by the same reference numerals. In addition, in the following description of the embodiments of the present disclosure, detailed descriptions of well-known features or functions will be omitted so as not to unnecessarily obscure the main purpose of the present disclosure.

[0046] When describing the components according to the embodiments of the present disclosure, terms such as "first", "second", "A", "B", "(a)", "(b)", etc. may be used. These terms are intended only to distinguish one component from another, and these terms do not limit the nature, order or sequence of the constituent components. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those skilled in the art to which the present disclosure belongs. Terms such as those defined in general dictionaries should be interpreted as having the same meanings as in the context of the relevant technical field, and should not be interpreted as having ideal or overly formal meanings unless expressly defined as having such meanings in this application.

[0047] In the following, reference will be made to Figures 2 to 9 Embodiments of the present disclosure are described in detail.

[0048] The headlights of a vehicle include lights with multiple functions (high beam, low beam, turn, DRL, fog, etc.), specifically including low beam, high beam, daytime running light (hereinafter referred to as "DRL"), positioning lamp (or tail light; hereinafter referred to as "PSTN"), sub-high beam (hereinafter referred to as "SUB"). Low beam and high beam are to ensure the driver's forward vision. Regardless of whether the user operates the switch or not, regardless of whether the driver is driving during the day or at night, as long as the vehicle is started and in motion, the DRL will automatically light up to prevent traffic accidents by improving safety between vehicles in countries with foggy and humid climates. PSTN is an indicator light installed on the front of the vehicle.

[0049] The present invention discloses a configuration for controlling a multifunctional LED lamp applied to a vehicle headlamp by using a single LED lamp driver and controlling an on / off state and a light amount of the multifunctional LED lamp through time-division control.

[0050] Figure 2 is a block diagram showing a configuration of a vehicle system including a driving system for a multifunctional LED lamp based on a single channel according to an embodiment of the present disclosure, Figure 3A It shows Figure 2 A view of the detailed configuration of the LED lamp driver, Figure 3B It shows Figure 2 A detailed circuit view of each component.

[0051] According to an embodiment of the present disclosure, the multifunctional LED lamp driving system 100 can be implemented in a headlamp inside a vehicle. In this case, the multifunctional LED lamp driving system 100 can be integrated with the vehicle's internal control unit. Alternatively, the multifunctional LED lamp driving system 100 can be implemented separately from the vehicle's internal control unit and can be connected to the vehicle's internal control unit via a separate connection unit.

[0052] Reference Figure 2 The multifunctional LED lamp driving system 100 may include an LED lamp driving device 110 , a switching device 130 , an LED load 150 , a control device 160 , an input-end capacitor 161 , a comparison capacitor 162 , and an output-end capacitor 163 .

[0053] The LED lamp driving device 110 turns on or off a lamp having a specific function in a multi-function lamp, or when adjusting the light amount, adjusts (increases or decreases) the input voltage as the voltage of the vehicle battery to the voltage required for each function and provides the adjusted input voltage to the LED load 150.

[0054] The LED lamp driving device 110 can control multiple lamps with a single component by utilizing a high-speed switching (DC-DC) LED driving semiconductor. The LED lamp driving device 110 can increase or decrease the voltage according to the voltage required for each function of the LED lamp. For example, when the DRL function among the multi-functions is on, the LED lamp driving device 110 reduces the input voltage and provides the reduced input voltage to the lamp that performs the DRL function. When the high beam function (hereinafter referred to as "high beam") is on, the LED lamp driving device 110 increases the input voltage and provides the increased input voltage to the LED lamp that performs the high beam function. When the low beam function (hereinafter referred to as "low beam") is on, the LED lamp driving device 110 increases or decreases the input voltage according to the level of the input voltage and provides the increased or decreased input voltage to the LED lamp that performs the low beam function. The following will refer to Figures 4A to 4C The configuration and method for converting the voltage into the voltage required for each lamp function in the LED lamp driving apparatus 110 are described in more detail.

[0055] like Figure 3A As shown, the LED lamp driving device 110 may include a communication unit 111 , a storage unit 112 , a control unit 113 , a voltage conversion switch unit 114 and a measurement unit 115 .

[0056] The communication unit 111 may allow the LED lamp driving device 110 to perform internal control communication with the control device 160 based on a vehicle network communication technology such as a serial peripheral interface (SPI).

[0057] For example, the communication unit 111 can communicate with the control device 160 and can transmit the voltage value or output current value of the LED load 150 measured by the measurement unit 115 to the control device 160. Therefore, the control device 160 can use the voltage value or current value of the LED load 150 received through the communication unit 111 to determine whether the LED load 150 has failed. In addition, the communication unit 111 can receive the output value of the target voltage or target current from the control device 160. Figure 7 and Figure 8 Describe the fault diagnosis in more detail.

[0058] The storage unit 112 may store data and / or algorithms executed by the control unit 113. In addition, the storage unit 112 may include at least one type of storage medium among the following types of memories: a flash memory type, a hard disk type, a micro, a card type (e.g., a secure digital (SD) card or an extreme digital card), a random access memory (RAM), a static RAM (SRAM), a read-only memory (ROM), a programmable ROM (PROM), an electrically erasable programmable ROM (EEPROM), a magnetic RAM (MRAM), a magnetic disk type memory, or an optical disk type memory.

[0059] The control unit 113 can control the operation of each component, can be electrically connected to the communication unit 111, the storage unit 112, the voltage conversion switch unit 114, and the measurement unit 115, and can electrically control each component. In addition, the control unit 113 can be a circuit that executes software commands. Therefore, the control unit 113 can process and calculate various data described below.

[0060] The voltage conversion switch portion 114 may step down or step up the input voltage VIN according to a driving mode of the head lamp, and may output the input voltage VIN to the LED load 150 .

[0061] For this reason, Figures 4A to 4C As shown, the voltage conversion switch section 114 includes transistors M1, M2, M3, M4, an inductor L1, and a resistor R1. Figures 4A to 4C is a view illustrating a driving mode of a driving system of a multifunctional LED lamp according to an embodiment of the present disclosure.

[0062] like Figure 4A As shown, when the headlight driving mode is DRL mode, the voltage conversion switch section 114 can reduce the voltage (buck) and output the reduced voltage to the LED device 152. For example, when the input voltage is in the range of 9V to 16V (vehicle battery voltage), the voltage conversion switch section 114 can reduce the voltage to 6V for lighting the DRL and output it. To this end, when the clock cycle starts with transistor M4 always on and transistor M3 kept off, transistor M2 turns on, and the current of inductor L1 decreases. During the remaining clock cycle, transistor M2 turns off, transistor M1 turns on again, and inductor L1 charges.

[0063] In addition, if Figure 4B As shown, when the driving mode of the headlights is the high-beam mode, the voltage conversion switch portion 114 may increase the voltage (Boost) and may output the increased voltage to the LED group 154 ​​performing the high-beam function.

[0064] For example, when the input voltage is between 9V and 16V, i.e., the vehicle battery voltage, the voltage conversion switch section 114 can boost the input voltage to a total of 28V and output the boosted voltage to the LED load 150, thereby illuminating the LED groups 153, 154, and 155. To this end, when a clock cycle begins with transistor M1 always on and transistor M2 always off, transistor M3 turns on, causing the input current to flow into inductor L1. Then, during the remaining clock cycle, when transistor M3 turns off and transistor M4 turns on, the current flowing into inductor L1 decreases.

[0065] In addition, if Figure 4C As shown, when the driving mode of the headlight is the low beam mode, the voltage conversion switch unit 114 can increase or decrease (Buck-Boost) the input voltage according to the level of the input voltage, and can output the increased or decreased input voltage to the LED group 153 that performs the low beam function.

[0066] For example, when the input voltage is within a range of 9 V to 16 V, the voltage conversion switch section 114 may increase or decrease the input voltage to a voltage of 12 V for low beam mode driving. To this end, all switches of the transistors M1 to M4 may operate to match the switching frequency.

[0067] The voltage conversion switch section 114 may include an H-bridge capable of lowering or raising an output voltage according to an on / off state of an LED of each function, and the H-bridge may be a synchronous drive H-bridge.

[0068] like Figure 3B As shown, output ends of switches Q4 and Q5 connected in parallel to each other may be connected to the first light source group 151 and the second light source group 152 , respectively.

[0069] Switch Q5 can adjust the amount of light emitted by second light source group 152 by changing its duty cycle. In this case, when first light source group 151 is on, second light source group 152 is off. When second light source group 152 is on, first light source group 151 is off. Measuring unit 115 can measure the voltage applied to LED load 150. In other words, measuring unit 115 can measure the voltage across each functional LED device in LED load 150. In this case, measuring unit 115 can employ a typical voltmeter or ammeter configuration.

[0070] The switching device 130 includes a plurality of switches Q1, Q2, Q3, Q4, and Q5 that are turned on and off by the control device 160. Figure 9 The operation of switches Q1, Q2, Q3, Q4, and Q5 of the switching device 130 is described.

[0071] The LED load 150 may include a plurality of LED strings that receive DC power from the LED lamp driving device 110 and emit light. Figure 2 The LED load 150 may include Figure 3B As shown, a first light source group 151 and a second light source group 152 are connected in parallel to each other.

[0072] The first light source group 151 may include LED groups 155, 154, and 153 that operate in sub-high beam (SUB), high beam (HIGH), and low beam (LOW) functions. The second light source group 152 may have a structure in which a plurality of LED devices that operate in a DRL / PSTN function are connected in series. In this case, each of the LED groups 155, 154, and 153 may include an LED device or have at least one LED device connected in series, the first light source group 151 includes LED groups 155, 154, and 153 that are connected in series and light up or turn off according to the on / off control of the switch module 130, and the second light source group 152 may include a plurality of LED devices that perform the "DRL / PSTN" function and are connected in series.

[0073] First light source group 151 and second light source group 152 cannot be lit at the same time. Therefore, control device 160 controls switches Q1 to Q5 in switch module 130 in a time-division manner to control the LEDs in first light source group 151 and second light source group 152 that need to be controlled simultaneously, thereby creating the effect of simultaneously lighting first light source group 151 and second light source group 152. In this case, LED groups 153, 154, and 155 in first light source group 151 can be lit sequentially, starting with the LED device with the highest duty cycle.

[0074] Table 1 below shows examples of LED voltage levels and switching operations for each headlamp function. Figure 9 is a diagram illustrating a time-division sequence of a driving system for a multifunctional LED lamp according to an embodiment of the present disclosure.

[0075] Table 1

[0076]

[0077] Refer to Table 1 and Figure 9Multiple switches Q1, Q2, and Q3 are functional switches connected in series. Switches Q1, Q2, and Q3 control the application of current to LED groups 153, 154, and 155 with sub-high beam (SUB), high beam (HIGH), and low beam (LOW) functions, respectively. Switches Q1, Q2, and Q3 are connected in parallel with LED groups 153, 154, and 155 to perform a bypass function. Furthermore, switches Q1, Q2, and Q3 can control the amount of light from LED groups 153, 154, and 155 by varying their duty cycle. When all switches Q1, Q2, and Q3 are closed, i.e., turned on, current flows through switches Q1, Q2, and Q3 to ground, and no current is applied to first light source group 151. Consequently, LED groups 153, 154, and 155 are turned off.

[0078] At the same time, since switches Q4 and Q5 are enable switches, switches Q4 and Q5 cannot be turned on at the same time. In other words, the first light source group 151 and the second light source group 152 cannot be turned on at the same time.

[0079] Therefore, when switch Q5 is off and switch Q4 is on, switch Q1 is off, and switches Q2 and Q3 are on, current flows to LED group 153, thereby illuminating LED group 153 with a low-beam function. Furthermore, when switch Q5 is off and switch Q4 is on, switch Q2 is off, and the remaining switches Q1 and Q3 are on, current flows to LED group 154, thereby illuminating LED group 154 ​​with a high-beam function.

[0080] Accordingly, when the switch Q5 is off and the switch Q4 is on, the switch Q3 is off and the switches Q1 and Q2 are on, current flows to the LED group 155 , and thus the LED group 155 with the SUB function is lit.

[0081] like Figure 3B As shown, output ends of switches Q4 and Q5 connected in parallel to each other may be connected to the first light source group 151 and the second light source group 152 , respectively.

[0082] Switch Q5 can adjust the light output of second light source group 152 by changing its duty cycle. In this case, when first light source group 151 is on, second light source group 152 is off. When second light source group 152 is on, first light source group 151 is off. Control device 160 processes signals transmitted between components of multi-function LED lamp drive system 100. Control device 160 can be, for example, an electronic control unit (ECU), microcontroller unit (MCU), or other sub-controller installed in a vehicle.

[0083] The control device 160 may control the on / off state of the switch device 130 in a time-division manner to control the LED load 150. The control device 160 may perform a control operation by dividing one cycle of the output PWM signal by a specific duty ratio (Duty). Figure 5 and Figure 6 1 is a view illustrating a driving control concept of a multifunctional LED lamp according to an embodiment of the present disclosure. Figure 5 and Figure 6 , it can be known that the control operation is performed by setting one cycle to 5ms.

[0084] The control device 160 may control the second light source group 152 to be off when the first light source group 151 is on, and the first light source group 151 to be off when the second light source group 152 is on. The control device 160 may control current not to flow to the second light source group 152 when the first light source group 151 is selected.

[0085] Since the first light source group 151 includes multifunctional LED groups, the control device 160 can control the switch device 130 to light up the LED groups in sequence starting from the LED group with the highest duty cycle.

[0086] The control device 160 can set the duty cycle of lighting the first light source group 151 to be longer than the duty cycle of lighting the second light source group 152. In other words, the duty cycle of lighting the first light source group 151 is different from the duty cycle of lighting the second light source group 152. Because the high beam function or the low beam function of the first light source group 151 requires a higher current value than the current value of the DRL / PSTN function, the duty cycle of lighting the first light source group 151 is set to be longer than the duty cycle of lighting the second light source group 152 to provide the required current.

[0087] The control device 160 may calculate an output current value applied to the first light source group 151 or the second light source group 152 based on a duty ratio of lighting the first light source group 151 or the second light source group 152 and a maximum output current.

[0088] Reference Figure 9 , the control device 160 can turn on or off the switches Q1, Q2, Q3, Q4 and Q5 through time-division control operation.

[0089] In other words, when switch Q5 is on and the remaining switches Q1 to Q4 are off, the LED lamp driver 110 applies the DRL / PSTN voltage (e.g., 6V) to the second light source group 152 to illuminate the second light source group 152. Thereafter, when switch Q4 is on, switch Q5 is off, switch Q1 is off, and the remaining switches Q2 and Q3 are on, the second light source group 152 is turned off and the first LED group 153 is illuminated to perform the low-beam function. In this case, the LED lamp driver 110 outputs a 12V output voltage to illuminate the first LED group 153.

[0090] When switch Q4 remains on and switch Q5 remains off while first LED group 153 is on, and when switch Q2 is off and only switch Q3 is on while switch Q1 is off, second LED group 154 ​​is on while first LED group 153 is on, thereby enabling simultaneous high-beam and low-beam functions. In this case, LED lamp driver 110 outputs a 22V output voltage to light both first and second LED groups 153 and 154.

[0091] Thereafter, when the first LED group 153 and the second LED group 154 ​​are lit, the switch Q4 remains on and the switch Q5 remains off, and when the switches Q1, Q2, and Q3 are all off, the first LED group 153, the second LED group 154, and the third LED group 155 are all lit, thereby simultaneously performing the low beam function, the high beam function, and the sub-high beam function. In this case, the LED lamp driving device 110 outputs an output voltage of 28V to light the first LED group 153, the second LED group 154, and the third LED group 155.

[0092] Finally, as the first LED group 153 is first lit, the second LED group 154 ​​is secondly lit, and the third LED group 155 is finally lit, the switches Q1, Q2, and Q3 in the switching device 130 are sequentially turned off. Therefore, although the switches Q1, Q2, and Q3 are turned off at different time points, the switches Q1, Q2, and Q3 are turned on at the same time point.

[0093] The first and second light source groups 151 and 152 have different duty ratios, and output currents applied to the first and second light source groups 151 and 152 may be calculated according to the duty ratios, as shown in Equation 1.

[0094] Equation 1

[0095] LED current = maximum string output current × duty cycle

[0096] In this case, the control device 160 controls the switches Q4 and Q5 provided on the upper portions of the first and second light source groups 151 and 152 to prevent the first and second light source groups 151 and 152 from being simultaneously lit.

[0097] In addition, the control device 160 may communicate with the LED lamp driving device 110 to control current and determine a fault and perform a fail-safe operation based on the determined fault.

[0098] When the output current value of the single LED lamp driving device 110 is equal to or less than 50% of the target current value, the control device 160 can determine that the LED load 150 is in an open state (open circuit). For example, when the LED group 153 performing the low beam function is disconnected, as shown in FIG. Figure 7 As shown, since the output voltage of the LED lamp driving device 110 increases significantly and the output current of the LED lamp driving device 110 decreases, the disconnection state can be determined based on whether there is current output. Figure 7 and Figure 8 is a view illustrating a fault determination method and a fail-safe operation of the driving system 100 of the multifunctional LED lamp according to an embodiment of the present disclosure.

[0099] The control device 160 can determine whether a short circuit occurs by identifying a voltage difference applied across each of the LED groups 153, 154, and 155 for each function. For example, when the voltage difference between the voltages V_TAP1 and V_TAP2 across the LED group 154 ​​performing the high beam function is less than a preset voltage (e.g., 2V), the control device 160 can determine that the LED group 154 ​​is short-circuited.

[0100] When the failure of the LED load 150 is determined as described above, the control device 160 can perform a bypass function by operating the remaining LED devices except the LED device that cannot be operated due to the failure. Figure 8 As shown, when the LED group 153 performing the low beam function fails, the control device 160 can operate the remaining LED groups 154 and 155 except the LED group 153.

[0101] In addition, when the state of the switches Q1 to Q3 is switched, the off duration can be set, and the control device 160 controls the switch with the next function after the current in the output capacitor 163 and the comparison capacitor 162 is fully discharged, thereby preventing current overshoot or undershot.

[0102] The input terminal capacitor 161 is provided between a fuse box (not shown) and the LED lamp driving device 110 to stabilize the input current.

[0103] The comparison capacitor 162 may be provided between the LED lamp driving device 110 and the ground terminal, particularly between the control unit 113 and the ground terminal, so as to quickly perform a comparison operation.

[0104] The output terminal capacitor 163 may be provided between the voltage conversion switch section 114 and the LED load 150 to perform an operation for stabilizing the output current of the LED lamp driving device 110 .

[0105] As described above, according to the present disclosure, a multifunctional LED can be driven using a single channel, ie, a single LED lamp driving device, and the switch module 130 is time-division controlled to control the on / off states of the plurality of LEDs.

[0106] Although the present disclosure has been described above with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and changed by those skilled in the art without departing from the spirit and scope of the present disclosure as claimed in the appended claims.

[0107] Therefore, the exemplary embodiments of the present disclosure are provided to explain the concept and scope of the present disclosure, rather than to limit them, so that the concept and scope of the present disclosure are not limited by these embodiments. The scope of protection of the present invention should be interpreted based on the appended claims, and all technical ideas within the scope equivalent to the claims should be included in the scope of the present disclosure.

[0108] As described above, according to the present disclosure, a plurality of LED lamps are time-division controlled based on a single channel, thereby minimizing an increase in system price.

[0109] Furthermore, various effects directly or indirectly understood through the present disclosure can be provided.

[0110] Although the present disclosure has been described above with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and changed by those skilled in the art without departing from the spirit and scope of the present disclosure as claimed in the appended claims.

Claims

1. A multifunctional light emitting diode (LED) lamp driving system, comprising: a first light source group and a second light source group, wherein the first light source group and the second light source group are classified according to lamp functions; a single LED lamp driving device, regulating an input voltage to a voltage required for each lamp function and applying the voltage to the first light source group and the second light source group; a switch device for controlling the on / off state of the first light source group and the second light source group; and A control device, which controls the on or off time of the switch device by working in conjunction with the LED lamp driving device to control the light amount of the first light source group and the second light source group. Wherein, the first light source group includes a plurality of functional LED groups, and The control device controls the switch device so that the plurality of LED groups are sequentially lit starting from the LED group with the highest duty cycle.

2. The drive system according to claim 1, wherein: The first light source group and the second light source group are connected in parallel.

3. The drive system according to claim 2, wherein: Each of the first light source group and the second light source group includes an LED or a structure in which at least two LEDs are connected in series.

4. The drive system according to claim 3, wherein: The switch device comprises: a first switch connected in parallel with the first LED group of the first light source group that performs the first function, so as to control the on / off state of the first LED group; a second switch connected in parallel with the second LED group performing a second function of the first light source group to control the on / off state of the second LED group; and The third switch is connected in parallel to the third LED group of the first light source group that performs a third function, so as to control the on / off state of the third LED group.

5. The drive system according to claim 3, wherein: The switch device further comprises: a fourth switch connected to the output end of the LED lamp driving device and the input end of the first light source group; and A fifth switch is connected to the output end of the LED lamp driving device and the input end of the second light source group.

6. The drive system according to claim 4, wherein: The first function includes a low beam function, the second function includes a high beam function, the third function includes a sub-high beam function, and The second light source group performs a daytime running light function, namely a DRL function or a positioning light function.

7. The drive system according to claim 1, wherein: The LED lamp driving device reduces the input voltage and applies the reduced input voltage to the second light source group when the DRL function is turned on.

8. The drive system according to claim 1, wherein: The LED lamp driving device increases the input voltage and applies the increased input voltage to the first light source group when a high beam function is turned on.

9. The drive system according to claim 1, wherein: When a low beam function is turned on, the LED lamp driving device increases or decreases the input voltage according to a difference between the input voltage and a voltage required to perform the low beam function, and applies the increased or decreased input voltage to the first light source group.

10. The drive system according to claim 1, wherein: The LED lamp driving device comprises: A first switching device and a second switching device are connected in series between an input voltage terminal and a ground terminal; A third switching device and a fourth switching device are connected in series between the output voltage terminal and the ground terminal; and An inductor is connected between a common node of the first switching device and the second switching device and a common node of the third switching device and the fourth switching device.

11. The drive system according to claim 1, wherein: The control device is configured to: When the first light source group is turned on, the second light source group is turned off; and When the second light source group is turned on, the first light source group is turned off.

12. The drive system according to claim 1, wherein: The control device sets a duty cycle of lighting the first light source group to be longer than a duty cycle of lighting the second light source group.

13. The drive system according to claim 1, wherein: The control device calculates an output current value applied to the first light source group or the second light source group based on a duty ratio of lighting the first light source group or the second light source group and a maximum output current.

14. The drive system according to claim 1, further comprising: Input capacitor to stabilize input current; Output capacitor to stabilize the output current; as well as Comparing capacitors, discharges the charging current.

15. The drive system according to claim 1, wherein: The control device is configured to determine that the failure of the LED load of at least one of the first light source group or the second light source group is caused by an open circuit when the output current of the single LED lamp driving device is equal to or less than a specific value.

16. The drive system according to claim 1, wherein: The control device is configured to determine that the failure of the LED load of at least one of the first light source group or the second light source group is caused by a short circuit when the voltage difference applied across each of the multiple LED groups in the first light source group or the voltage difference applied across the second light source group is less than a specific value.

17. The drive system according to claim 1, wherein: The control device is configured to, when there is a failed LED group in the first light source group or the second light source group, perform a fail-safe operation to eliminate the failed LED group.

18. A method for driving a multifunctional LED lamp, comprising: adjusting and outputting voltages applied to the first light source group and the second light source group classified according to lamp functions; as well as By time-divisionally controlling the on / off time of the switch devices connected to the first light source group and the second light source group, the on / off state and light amount of the first light source group and the second light source group are controlled. Wherein, the first light source group includes a plurality of functional LED groups, and The plurality of LED groups are lit in sequence starting from the LED group with the highest duty cycle.

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