Light emitting diode light source device and driving method thereof

Abstract

The embodiment of the invention provides a light-emitting diode light source device and a driving method thereof. The light-emitting diode light source device comprises a driving circuit which comprises N driving input ends and N driving output ends and is connected with a first power supply input end, and N is an integer larger than 1; and the N light emitting diode strings with different colors are respectively connected between the N driving output ends and the second power supply input end. The N driving input ends are used for receiving N target pulse width modulation signals respectively, so that the driving circuit drives the N different-color light emitting diode strings connected with the N driving output ends respectively to emit light for color mixing respectively based on the N target pulse width modulation signals, the duty ratio of at least one target pulse width modulation signal in the N target pulse width modulation signals is 1, and the sum of the duty ratios of the N target pulse width modulation signals is larger than 1 and smaller than N. The embodiment of the invention can effectively solve the stroboscopic problem of color temperature adjustment of the pulse width modulation signal.

Description

Technical Field

[0001] The present invention relates to the field of light source technology, and in particular to a light emitting diode light source device and a driving method for the light emitting diode light source device. Background Art

[0002] There are two existing color temperature adjustment technologies: one is dial-code color temperature adjustment, and the other is PWM (pulse-width modulation) signal color temperature adjustment. PWM signal color temperature adjustment is to adjust the color temperature by adjusting the duty cycle of the PWM signal, which usually encounters the problem of flicker. The flicker problem of light can cause eye fatigue. Long-term exposure to flickering environment can cause vision loss, visual fatigue, dry eyes and keratitis; flicker can also interfere with attention, increase anxiety, cause headaches and other diseases.

[0003] Therefore, how to avoid the flicker problem caused by PWM signal color temperature adjustment is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a light emitting diode light source device and a driving method of the light emitting diode light source device, which can effectively solve the flicker problem caused by adjusting the color temperature of a PWM signal.

[0005] Specifically, on the one hand, an embodiment of the present invention provides an LED light source device, for example, including: a driving circuit and N LED strings of different colors; the driving circuit includes N driving input terminals and N driving output terminals, and is connected to a first power input terminal, N is an integer greater than 1; the N LED strings of different colors are respectively connected between the N driving output terminals and the second power input terminal; furthermore, the N driving input terminals are used to respectively receive N target pulse width modulation signals, so that the driving circuit drives the N LED strings of different colors respectively connected to the N driving output terminals to emit light for color mixing based on the N target pulse width modulation signals, the duty cycle of at least one of the N target pulse width modulation signals is 1, and the sum of the duty cycles of the N target pulse width modulation signals is greater than 1 and less than N.

[0006] On the other hand, an embodiment of the present invention provides a driving method for an LED light source device, wherein the LED light source device includes N LED strings of different colors, where N is an integer greater than 1; the driving method includes, for example: receiving N target pulse width modulation signals, wherein the duty cycle of at least one of the N target pulse width modulation signals is 1, and the sum of the duty cycles of the N target pulse width modulation signals is greater than 1 and less than N; and, based on the N target pulse width modulation signals, driving the N LED strings of different colors to emit light for color mixing.

[0007] The above-mentioned embodiment of the present invention can have the following beneficial effects: by setting the duty cycle of at least one of the N target pulse width modulation signals used to respectively drive N light-emitting diode strings of different colors to 1, and setting the sum of the duty cycles of the N target pulse width modulation signals to be greater than 1 and less than N, in this way, within a single cycle, the N light-emitting diode strings of different colors are in the lighting state at the same time, and are not in the extinguishing state at the same time, thus solving the flicker problem of the pulse width modulation signal adjusting the color temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The specific implementation modes of the present invention will be described in detail below with reference to the accompanying drawings.

[0009] Figure 1A The figure is a schematic diagram of the component connection relationship of a light emitting diode light source device in the related art.

[0010] Figure 1B for Figure 1A Waveform diagram of multiple pulse width modulation signals used in the light emitting diode light source device.

[0011] Figure 2A A schematic diagram of the component connection relationship of a light emitting diode light source device provided by an embodiment of the present invention.

[0012] Figure 2B for Figure 2A Waveform diagram of multiple pulse width modulation signals used in the light emitting diode light source device.

[0013] Figure 3 A schematic diagram of component connection relationships of yet another light emitting diode light source device provided in an embodiment of the present invention.

[0014] Figure 4 A schematic diagram of component connection relationships of another light emitting diode light source device provided by an embodiment of the present invention.

[0015] Figure 5 A schematic diagram of component connection relationships of another light emitting diode light source device provided by an embodiment of the present invention.

[0016] Figure 6 A schematic diagram of component connection relationships of yet another LED light source device provided by an embodiment of the present invention.

[0017] Figure 7 A schematic diagram of component connection relationships of yet another light emitting diode light source device provided by an embodiment of the present invention.

[0018] Figure 8 A schematic diagram of component connection relationships of yet another LED light source device provided by an embodiment of the present invention.

[0019] Fig. 9 A schematic diagram of component connection relationships of yet another light emitting diode light source device provided by an embodiment of the present invention.

[0020] Fig.10 The present invention provides a schematic diagram of component connection relationships of yet another light emitting diode light source device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] It should also be noted that the division of multiple embodiments in the present invention is only for the convenience of description and should not constitute a special limitation. The features in various embodiments can be combined and referenced to each other without contradiction.

[0025] See also Figure 1A In the related art, the light emitting diode light source device includes: a red light emitting diode string, a green light emitting diode string, a blue light emitting diode string, a driving chip U1, a voltage stabilizing diode D1, a fuse F1 and a plurality of anti-strobe circuits. Among them, the input pins DIM1, DIM2 and DIM3 of the driving chip U1 are respectively connected to the resistors R1, R2 and R3 and are respectively used to receive the pulse width modulation signals R-PWM0, G-PWM0 and B-PWM0. One of the plurality of anti-strobe circuits includes a anti-strobe chip U2 and a capacitor C1 connected to the anti-strobe chip U2, another includes a anti-strobe chip U3 and a capacitor C2 connected to the anti-strobe chip U3, and another includes a anti-strobe chip U4 and a capacitor C3 connected to the anti-strobe chip U4. The red light emitting diode string includes red light emitting diodes LED-R1, LED-R2, LED-R3, and LED-R4 connected in series, one end of which is connected to the power input terminal VIN through a fuse F1, and the other end is connected to the output pin OUT1 of the driver chip U1 through a corresponding anti-strobe circuit; the green light emitting diode string includes green light emitting diodes LED-G1, LED-G2, LED-G3, and LED-G4 connected in series, one end of which is connected to the power input terminal VIN through a fuse F1, and the other end is connected to the output pin OUT2 of the driver chip U1 through a corresponding anti-strobe circuit; the blue light emitting diode string includes blue light emitting diodes LED-B1, LED-B2, LED-B3, and LED-B4 connected in series, one end of which is connected to the power input terminal VIN through a fuse F1, and the other end is connected to the output pin OUT3 of the driver chip U1 through a corresponding anti-strobe circuit. Furthermore, the external resistor connection pin REXT of the driver chip U1 is connected to the power input terminal GND through parallel resistors R4 and R5, that is, grounded; the power terminal VDD of the driver chip U1 is connected to the power input terminal VIN, the ground terminal GND of the driver chip U1 is connected to the power input terminal GND, one end of the voltage regulator diode D1 is connected to the power input terminal GND, and the other end is connected to the power input terminal VIN through the fuse F1.

[0026] Table 1 Mapping relationship between duty cycle of pulse width modulation signal and mixed color temperature

[0027]

[0028] Based on the above, Table 1 shows the mapping relationship between the duty cycle of the pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 and the mixed color temperature. It can be seen from Table 1 that for each mixed color temperature, the sum of the duty cycles of the corresponding pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 is 1, that is, 100%.

[0029] Taking the mixed light with a color temperature of 4000K obtained by driving the red light emitting diode string, the green light emitting diode string and the blue light emitting diode string with the pulse width modulation signals R-PWM0, G-PWM0 and B-PWM0 as an example, the duty ratios of the pulse width modulation signals R-PWM0, G-PWM0 and B-PWM0 are 19.0%, 48.0% and 33.0% respectively. The waveforms of the pulse width modulation signals R-PWM0, G-PWM0 and B-PWM0 are as follows: Figure 1B shown.

[0030] from Figure 1B It can be seen that when the pulse width modulation signal R-PWM0 (or G-PWM0, or B-PWM0) is at a high level "1", the corresponding red (or green, or blue) LED string is lit, and when it is at a low level "0", the corresponding red (or green, or blue) LED string is off; in one cycle, the time when the red, green, and blue LED strings are simultaneously lit accounts for 19%, and the time when they are simultaneously off accounts for 52%; that is, the red, green, and blue LED strings are sometimes in a lit state and sometimes in an off state at the same time, which will cause a stroboscopic problem; although Figure 1A The red, green and blue LED strings of the LED light source device are respectively provided with a plurality of anti-flash circuits consisting of anti-flash chips U2, U3, U4 and capacitors C1, C2, C3, so that the flicker is reduced, but the flicker still exists, and the driving efficiency will decrease by about 2% due to the existence of the anti-flash circuit.

[0031] Therefore, in order to effectively solve the problem of flickering when adjusting the color temperature using a pulse width modulation signal, an embodiment of the present invention provides a light emitting diode light source device and a driving method thereof.

[0032] Specifically, Figure 2AAs shown, an embodiment of the present invention provides a light emitting diode light source device 10, including: a driving circuit 11, and N light emitting diode strings of different colors, such as LS1, LS2, and LS3, where N=3 is used as an illustrative example. The driving circuit 11 includes N driving input terminals, such as INPUT1, INPUT2, and INPUT3, and N driving output terminals, such as OUTPUT1, OUTPUT2, and OUTPUT3, and is connected to the power input terminal GND. The light emitting diode strings LS1, LS2, and LS3 of different colors are respectively connected between the driving output terminals OUTPUT1, OUTPUT2, and OUTPUT3 and the power input terminal VIN; specifically, the light emitting diode string LS1, for example, includes a plurality of red light emitting diodes LED-R1, LED-R2, LED-R3, and LED-R4 connected in series, one end of which is connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end of which is connected to the driving output terminal OUTPUT1; the light emitting diode string LS2, for example, includes a plurality of green light emitting diodes connected in series. The light emitting diodes LED-G1, LED-G2, LED-G3, and LED-G4 have one end connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end connected to the drive output terminal OUTPUT2; the light emitting diode string LS3, for example, includes a plurality of blue light emitting diodes LED-B1, LED-B2, LED-B3, and LED-B4 connected in series, one end connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end connected to the drive output terminal OUTPUT3. The driving input terminals INPUT1, INPUT2, and INPUT3 are used to receive target pulse width modulation signals R-PWM, G-PWM, and B-PWM respectively, so that the driving circuit 11 drives the different color light-emitting diode strings LS1, LS2, and LS3 connected to the driving output terminals OUTPUT1, OUTPUT2, and OUTPUT3 respectively to emit light and mix colors based on the target pulse width modulation signals R-PWM, G-PWM, and B-PWM, thereby obtaining mixed light with a target mixed color temperature.

[0033] Table 2 Mapping relationship between duty cycle of pulse width modulation signal and mixed color temperature

[0034]

[0035]

[0036] Based on the above, Table 2 shows the mapping relationship between the duty cycle of the target pulse width modulation signals R-PWM, G-PWM, and B-PWM and the mixed color temperature. It can be seen from Table 2 that for each mixed color temperature, the sum of the duty cycles of the corresponding target pulse width modulation signals R-PWM, G-PWM, and B-PWM is greater than 1 and less than N (N=3), and the duty cycle of at least one target pulse width modulation signal is equal to 1 (that is, 100.0%).

[0037] Taking the N different color LED strings LS1, LS2, LS3 as an example, after being driven by the target pulse width modulation signals R-PWM, G-PWM, B-PWM, the mixed light with a mixed color temperature of 4000K is obtained, the duty ratios of the target pulse width modulation signals R-PWM, G-PWM, B-PWM are 39.6%, 100.0%, 68.8%, respectively. The waveforms of the target pulse width modulation signals R-PWM, G-PWM, B-PWM are as follows: Figure 2B As shown. Figure 2B It can be seen that in one cycle, the time when the N light-emitting diode strings LS1, LS2, and LS3 of different colors are simultaneously in the on state accounts for 39.6%, and the time when they are simultaneously in the off state accounts for 0%, that is, the N light-emitting diode strings LS1, LS2, and LS3 of different colors are sometimes in the on state, but not in the off state at the same time, thus solving the problem of stroboscopic color temperature adjustment by pulse width modulation signal. In addition, since the anti-stroboscopic circuit can be saved, the driving efficiency can be further improved.

[0038] Furthermore, by comparing the duty cycles of 19.0%, 48.0%, and 33.0% of the pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 corresponding to the mixed color temperature of 4000K in the aforementioned Table 1, it can be seen that: by converting the duty cycle of the pulse width modulation signal G-PWM0 with the largest duty cycle to 1 (that is, 100.0%), the target pulse width modulation signal G-PWM can be obtained, and its conversion ratio is 100.0% / 48.0%, and the duty cycles of other pulse width modulation signals R-PWM0 and B-PWM0 are converted in the same proportion, that is, 19.0%*(100.0% / 48.0%)≈39.6%, 33.0%*(100.0% / 48.0%)≈68.8%, and other target pulse width modulation signals R-PWM and B-PWM can be obtained. Similarly, the duty cycles of the pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 corresponding to other mixed color temperatures in Table 1 can be converted to the duty cycles of the corresponding target pulse width modulation signals R-PWM, G-PWM, and B-PWM in Table 2. In short, in this embodiment, the duty cycle of at least one of the N target pulse width modulation signals R-PWM, G-PWM, and B-PWM is 1, and the sum of the duty cycles of the N target pulse width modulation signals R-PWM, G-PWM, and B-PWM is greater than 1 and less than N, for example, when N=3, it is greater than 1 and less than 3.

[0039] Please see again Figure 2A In some embodiments, the driving circuit 11 includes, for example, a driving chip U1. The N input pins of the driving chip U1, such as DIM1, DIM2, and DIM3, are connected to the driving input terminals INPUT1, INPUT2, and INPUT3 through resistors R1, R2, and R3, respectively, for receiving the target pulse width modulation signals R-PWM, G-PWM, and B-PWM, respectively. The N output pins of the driving chip U1, such as OUT1, OUT2, and OUT3, are connected to the driving output terminals OUTPUT1, OUTPUT2, and OUTPUT3, respectively. The power pin VDD of the driving chip U1 is connected to the power input terminal VIN, for example, connected to the power input terminal VIN via a protection circuit such as a fuse F1. The ground pin GND of the driving chip U1 is connected to the power input terminal GND. The external resistor connection pin REXT of the driving chip U1 is connected to the power input terminal GND through an external resistor, such as parallel resistors R4 and R5. It can be understood that in some embodiments, the LED light source device 10 may also include other peripheral circuits, such as a voltage-stabilizing circuit such as a voltage-stabilizing diode D1, one end of the voltage-stabilizing diode D1 is connected to the power input terminal VIN, for example, through a protection circuit such as a fuse F1, and the other end is connected to the power input terminal GND.

[0040] See also Figure 3, in some embodiments, Figure 2A The light emitting diode light source device 10 shown, for example, further includes a waveform conversion circuit 13, which is used to receive N initial pulse width modulation signals such as R-PWM0, G-PWM0, and B-PWM0, convert the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 into target pulse width modulation signals R-PWM, G-PWM, and B-PWM, and output the target pulse width modulation signals R-PWM, G-PWM, and B-PWM to the driving input terminals INPUT1, INPUT2, and INPUT3 of the driving circuit 11, respectively, wherein the sum of the duty cycles of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 is equal to 1. Corresponding to different mixed color temperatures, the duty cycles of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 can be obtained from the aforementioned Table 1. For example, taking the mixed color temperature of 4000K as an example, the specific operation of [converting the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 into target pulse width modulation signals R-PWM, G-PWM, and B-PWM] can be: converting the initial pulse width modulation signal with the largest duty cycle among the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0, such as G-PWM0, into a target pulse width modulation signal with a duty cycle of 1, such as G-PWM, and obtaining a conversion ratio of 100.0% / 48.0%; and converting the remaining initial pulse width modulation signals in the initial pulse width modulation signals, such as R-PWM0 and B-PWM0, into other target pulse width modulation signals R-PWM and B-PWM in the same proportion according to the conversion ratio. In this embodiment, since a waveform conversion circuit 13 is additionally provided, the pulse width modulation signal provided to the light emitting diode light source device can be the same as the pulse width modulation signal provided to the light emitting diode light source device in the aforementioned related art, so that there is no need to redesign and / or set the front-end circuit of the light emitting diode light source device.

[0041] More specifically, the waveform conversion circuit 13 includes, for example, a waveform conversion chip U0, which may be a microcontroller chip (MCU) or other chip with processing capabilities. The input pins of the waveform conversion chip U0, such as IN1, IN2, and IN3, are respectively used to receive initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0, and the input pin IN4 is vacant. Its output pins, such as OUT1, OUT2, and OUT3, are respectively used to output target pulse width modulation signals R-PWM, G-PWM, and B-PWM to the drive circuit 11, and the output pin OUT4 is vacant. Its power pin VDD is connected to the power supply voltage VCC, and its ground pin GND is connected to the power input terminal GND, that is, grounded.

[0042] See also Figure 4, in some embodiments, Figure 3 The light emitting diode light source device shown, for example, further includes an information processing circuit 15, the information processing circuit 15 is used to receive / acquire color control information (such as color temperature control information, and / or color control information, etc.) wirelessly or in other ways (such as wired or key-triggered), process the color control information to obtain initial pulse width modulation signals R-PWM0, G-PWM0, B-PWM0, and output the initial pulse width modulation signals R-PWM0, G-PWM0, B-PWM0 to the waveform conversion circuit 13. For example, the specific operation of [processing the color control information to obtain initial pulse width modulation signals R-PWM0, G-PWM0, B-PWM0] can be: according to the color control information and the mapping relationship table between the duty cycle of the pulse width modulation signal and the mixed color temperature, the initial pulse width modulation signals R-PWM0, G-PWM0, B-PWM0 are obtained, wherein the mapping relationship table between the duty cycle of the pulse width modulation signal and the mixed color temperature adopts the aforementioned Table 1, that is, the information processing circuit 15 stores Table 1. For example, when the color control information indicates that the mixed color temperature is 4000K, the information processing circuit 15 accordingly searches Table 1 to find out that the duty ratios of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 corresponding to the mixed color temperature of 4000K are 19.0%, 48.0%, and 33.0% respectively; or, when the color control information indicates that the mixed color temperature is 2700K, the information processing circuit 15 accordingly searches Table 1 to find out that the duty ratios of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 corresponding to the mixed color temperature of 2700K are 19.0%, 48.0%, and 33.0% respectively. The duty ratios of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 are 45.3%, 48.0%, and 6.7% respectively; or, when the color control information indicates that the mixed color temperature is 6500K, the information processing circuit 15 accordingly searches Table 1 to find that the duty ratios of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 corresponding to the mixed color temperature of 6500K are 14.7%, 5.3%, and 80.0% respectively; and so on. In this embodiment, since the information processing circuit 15 is additionally provided, it can realize remote control of the mixed color temperature of the light emitting diode light source device, thereby improving the convenience of use of the light emitting diode light source device.

[0043] More specifically, the information processing circuit 15 includes, for example, an intelligent control chip U10, which is configured with a WiFi module, a Bluetooth module or other wireless communication modules; thus, the intelligent control chip U10 can wirelessly communicate with a control terminal such as a smart phone through wireless methods such as WiFi and Bluetooth to receive color control information, and then generate initial pulse width modulation signals R-PWM0, G-PWM0, B-PWM0 based on a mapping relationship table of the duty cycle of the pulse width modulation signal and the mixed color temperature and the received color control information, and output them to the waveform conversion circuit 13 via output pins PWM1, PWM2, and PWM3 respectively.

[0044] See also Figure 5 , in some embodiments, Figure 2A The light emitting diode light source device shown, for example, also includes an information processing circuit 15, the information processing circuit 15 is used to receive / acquire color control information in a wireless manner or other manner (for example, a wired manner or a key triggering manner, etc.), process the color control information to obtain target pulse width modulation signals R-PWM, G-PWM, B-PWM, and output the target pulse width modulation signals R-PWM, G-PWM, B-PWM to the driving input terminals INPUT1, INPUT2, and INPUT3 of the driving circuit 11. For example, the specific operation of [processing the color control information to obtain the target pulse width modulation signals R-PWM, G-PWM, and B-PWM] can be: according to the color control information and the mapping relationship table between the duty cycle of the pulse width modulation signal and the mixed color temperature, the target pulse width modulation signals R-PWM, G-PWM, and B-PWM are obtained, wherein the mapping relationship table between the duty cycle of the pulse width modulation signal and the mixed color temperature adopts the aforementioned Table 2, that is, the information processing circuit 15 stores Table 2. For example, when the color control information indicates that the mixed color temperature is 4000K, the information processing circuit 15 accordingly searches Table 2 to find out that the duty ratios of the target pulse width modulation signals R-PWM, G-PWM, and B-PWM corresponding to the mixed color temperature of 4000K are 39.6%, 100.0%, and 68.8% respectively; or, when the color control information indicates that the mixed color temperature is 2700K, the information processing circuit 15 accordingly searches Table 2 to find out that the duty ratios of the target pulse width modulation signals R-PWM, G-PWM, and B-PWM corresponding to the mixed color temperature of 2700K are 39.6%, 100.0%, and 68.8% respectively. The duty ratios of the target pulse width modulation signals R-PWM, G-PWM, and B-PWM are 94.4%, 100.0%, and 14.0% respectively; or, when the color control information indicates that the mixed color temperature is 6500K, the information processing circuit 15 accordingly searches Table 2 to find that the duty ratios of the target pulse width modulation signals R-PWM, G-PWM, and B-PWM corresponding to the mixed color temperature of 6500K are 18.4%, 6.6%, and 100.0% respectively; and so on. In this embodiment, since the information processing circuit 15 is additionally provided, it can realize remote control of the mixed color temperature of the light emitting diode light source device, thereby improving the convenience of use of the light emitting diode light source device.

[0045] More specifically, the information processing circuit 15 includes, for example, an intelligent control chip U10, which is configured with a WiFi module, a Bluetooth module or other wireless communication modules; thereby, the intelligent control chip U10 can wirelessly communicate with a control terminal such as a smart phone through wireless methods such as WiFi and Bluetooth to receive color control information, and then generate target pulse width modulation signals R-PWM, G-PWM, B-PWM based on a mapping relationship table of a pulse width modulation signal's duty cycle and mixed color temperature and the received color control information, and output them to the drive circuit 11 via output pins PWM1, PWM2, and PWM3, respectively.

[0046] See also Figure 6 In some embodiments, the driving circuit 11 of the light-emitting diode light source device in the aforementioned embodiments is replaced by, for example, three (corresponding to N=3) three-terminal devices, wherein each control terminal of the three three-terminal devices is connected to three driving input terminals of the driving circuit 11, such as INPUT1, INPUT2, and INPUT3, through resistors such as R1, R2, and R3, respectively, so as to receive three target pulse width modulation signals, such as R-PWM, G-PWM, and B-PWM, respectively, each first current path terminal of the three three-terminal devices is connected to three driving output terminals of the driving circuit 11, such as OUTPUT1, OUTPUT2, and OUTPUT3, respectively, and each second current path terminal of the three three-terminal devices is connected to the power input terminal GND through resistors such as R6, R7, and R8, respectively. As an example, the three three-terminal devices are, for example, three field effect transistors Q1, Q2, and Q3, the control terminal is, for example, the gate of the field effect transistors Q1, Q2, and Q3, the first current path terminal is, for example, the drain of the field effect transistors Q1, Q2, and Q3, and the second current path terminal is, for example, the source of the field effect transistors Q1, Q2, and Q3. In addition, it is worth mentioning that the three three-terminal devices are not limited to field effect transistors, and they can also be other three-terminal devices such as triodes and thyristors. In some embodiments, resistors R6, R7, and R8 can also be replaced by wires of specific resistors.

[0047] like Figure 7As shown, in some embodiments, the number of N light-emitting diode strings of different colors in the light-emitting diode light source device of the embodiment of the present invention is not limited to N=3, and it can also be N=4, such as four light-emitting diode strings LS1, LS2, LS3, and LS4. For example, the light-emitting diode string LS1 includes a plurality of red light-emitting diodes LED-R1, LED-R2, LED-R3, and LED-R4 connected in series, one end of which is connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end of which is connected to the drive output terminal OUTPUT1; the light-emitting diode string LS2 includes a plurality of green light-emitting diodes LED-G1, LED-G2, LED-G3, and LED-G4 connected in series, one end of which is connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end of which is connected to the drive output terminal OUTPU T2; the light-emitting diode string LS3, for example, includes a plurality of blue light-emitting diodes LED-B1, LED-B2, LED-B3, and LED-B4 connected in series, one end of which is connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end of which is connected to the drive output terminal OUTPUT3; the light-emitting diode string LS4, for example, includes a plurality of white light-emitting diodes LED-W1, LED-W2, LED-W3, and LED-W4 connected in series, one end of which is connected to the power input terminal VIN, for example, connected to the power input terminal VIN through a protection circuit such as a fuse F1, and the other end of which is connected to the drive output terminal OUTPUT4.

[0048] In addition, for Figure 7In the case where a single driver chip such as U11 and U12 in the driver circuit 11 has only three input pins DIM1, DIM2, DIM3 and three output pins OUT1, OUT2, OUT3, two driver chips U11 and U12 can be used to jointly drive four light-emitting diode strings LS1, LS2, LS3, and LS4. More specifically, the input pins DIM1 and DIM2 of the driver chip U11 are respectively connected to the resistors R1 and R2 and are used to receive the target pulse width modulation signals R-PWM and G-PWM, the input pin DIM3 is vacant, its output pins OUT1 and OUT2 are respectively connected to the driving output terminals OUTPUT1 and OUTPUT2 of the driver circuit 11, the output pin OUT3 is vacant, the power pin VDD is connected to the power input terminal VIN, the ground pin GND is connected to the power input terminal GND, and the external resistor connection pin REXT is connected to the power input terminal GND through an external resistor such as parallel resistors R4 and R5. The input pins DIM1 and DIM2 of the driving chip U12 are respectively connected to the resistors R3 and R9 and are used to receive the target pulse width modulation signals B-PWM and W-PWM, the input pin DIM3 is vacant, and its output pins OUT1 and OUT2 are respectively connected to the driving output terminals OUTPUT3 and OUTPUT4 of the driving circuit 11, the output pin OUT3 is vacant, the power pin VDD is connected to the power input terminal VIN, the ground pin GND is connected to the power input terminal GND, and the external resistor connection pin REXT is connected to the power input terminal GND through an external resistor, such as parallel resistors R10 and R11.

[0049] See also Figure 8 , in some embodiments, Figure 7The driving circuit 11 of the light-emitting diode light source device is replaced by, for example, four (corresponding to N=4) three-terminal devices, wherein each control terminal of the four three-terminal devices is connected to four driving input terminals of the driving circuit 11, such as INPUT1, INPUT2, INPUT3, and INPUT4, through resistors such as R1, R2, R3, and R9, respectively, so as to receive four target pulse width modulation signals, such as R-PWM, G-PWM, B-PWM, and W-PWM, respectively, each first current path terminal of the four three-terminal devices is connected to four driving output terminals of the driving circuit 11, such as OUTPUT1, OUTPUT2, OUTPUT3, and OUTPUT4, respectively, and each second current path terminal of the four three-terminal devices is connected to the power input terminal GND through resistors such as R6, R7, R8, and R12, respectively. As an example, the four three-terminal devices are, for example, four field effect transistors Q1, Q2, Q3, and Q4, the control terminal is, for example, the gate of the field effect transistors Q1, Q2, Q3, and Q4, the first current path terminal is, for example, the drain of the field effect transistors Q1, Q2, Q3, and Q4, and the second current path terminal is, for example, the source of the field effect transistors Q1, Q2, Q3, and Q4. In addition, it is worth mentioning that the four three-terminal devices are not limited to field effect transistors, and they can also be other three-terminal devices such as triodes and thyristors. In some embodiments, resistors R6, R7, R8, and R12 can also be replaced by wires of specific resistors.

[0050] like Fig. 9 As shown, in some embodiments, the number of N different color LED strings in the LED light source device of the embodiment of the present invention is not limited to N=3, and it can also be N=2, such as two different color LED strings LS1 and LS2. For example, the LED string LS1 includes a plurality of warm white light LEDs 2700K-1, 2700K-2, 2700K-3, and 2700K-4 connected in series, one end of which is connected to the power input terminal VIN, for example, through a protection circuit such as a fuse F1, and the other end of which is connected to the drive output terminal OUTPUT1; the LED string LS2 includes a plurality of cold white light LEDs 6500K-1, 6500K-2, 6500K-3, and 6500K-4 connected in series, one end of which is connected to the power input terminal VIN, for example, through a protection circuit such as a fuse F1, and the other end of which is connected to the drive output terminal OUTPUT2.

[0051] In addition, for Fig. 9In the case where a single driving chip in the driving circuit 11, for example, U1, has three input pins DIM1, DIM2, DIM3 and three output pins OUT1, OUT2, OUT3, the input pins DIM1 and DIM2 of the driving chip U11 are respectively connected to resistors R1 and R2 and are used to receive target pulse width modulation signals 2700K-PWM and 6500K-PWM, the input pin DIM3 is vacant, and its output pins OUT1 and OUT2 are respectively connected to the driving output terminals OUTPUT1 and OUTPUT2 of the driving circuit 11, the output pin OUT3 is vacant, the power pin VDD is connected to the power input terminal VIN, the ground pin GND is connected to the power input terminal GND, and the external resistor connection pin REXT is connected to the power input terminal GND through an external resistor, such as parallel resistors R4 and R5.

[0052] See also Fig.10 , in some embodiments, Fig. 9 The driving circuit 11 of the light emitting diode light source device is replaced by, for example, two (corresponding to N=2) three-terminal devices, each control terminal of the two three-terminal devices is connected to two driving input terminals of the driving circuit 11, such as INPUT1 and INPUT2, through resistors such as R1 and R2, respectively, so as to receive two target pulse width modulation signals, such as 2700K-PWM and 6500K-PWM, respectively, each first current path terminal of the two three-terminal devices is connected to two driving output terminals of the driving circuit 11, such as OUTPUT1 and OUTPUT2, respectively, and each second current path terminal of the two three-terminal devices is connected to the power input terminal GND through resistors such as R6 and R7. As an example, the two three-terminal devices are, for example, two field effect transistors Q1 and Q2, the control terminal is, for example, the gate of the field effect transistors Q1 and Q2, the first current path terminal is, for example, the drain of the field effect transistors Q1 and Q2, and the second current path terminal is, for example, the source of the field effect transistors Q1 and Q2. In addition, it is worth mentioning that the two three-terminal devices are not limited to field effect transistors, and may also be other three-terminal devices such as triodes, thyristors, etc. In some embodiments, the resistors R6 and R7 may also be replaced by wires of specific resistances.

[0053] It is worth mentioning that the number of N different color LED strings in the LED light source device provided in the embodiment of the present invention is not limited to the aforementioned N=2, N=3, N=4, but may also be more different color LED strings, such as N=5 or N=6; accordingly, the target pulse width modulation signal is not limited to the aforementioned two, three and four, but may also be more, such as five or six.

[0054] It is also worth mentioning that a single color LED string may include one LED, or may include multiple LEDs of the same color connected in series, or may include multiple LED sub-strings of the same color connected in parallel and connected to the same driving output terminal of the driving circuit 11, and a single LED sub-string may include one LED, or may include multiple LEDs of the same color connected in series.

[0055] In addition, a driving method of a light emitting diode light source device provided in an embodiment of the present invention is applicable to a light emitting diode light source device including N (N is an integer greater than 1) light emitting diode strings of different colors. Specifically, the driving method provided in an embodiment of the present invention includes the following steps:

[0056] (i) receiving N target pulse width modulation signals, wherein the duty cycle of at least one of the N target pulse width modulation signals is 1, and the sum of the duty cycles of the N target pulse width modulation signals is greater than 1 and less than N; and

[0057] (ii) Based on the N target pulse width modulation signals, the N light emitting diode strings of different colors are driven to emit light to perform color mixing.

[0058] For example, the N target PWM signals may be Figure 2A , Figure 3 , Figure 4 , Figure 5 or Figure 6 The three target pulse width modulation signals R-PWM, G-PWM, B-PWM received by the driving circuit 11 in the embodiment of the present invention are as follows: Figure 7 or Figure 8 The four target pulse width modulation signals R-PWM, G-PWM, B-PWM, W-PWM received by the driving circuit 11 in the embodiment of the present invention are as follows: Fig. 9 or Fig.10 The driving circuit 11 receives two target pulse width modulation signals 2700K-PWM and 6500K-PWM, or more target pulse width modulation signals; accordingly, the driving circuit 11 can drive N light-emitting diode strings of different colors based on the received N target pulse width modulation signals, for example, respectively drive Figure 2A , Figure 3 , Figure 4 , Figure 5 or Figure 6 The three different color LED strings LS1, LS2, LS3 in the Figure 7 or Figure 8 The four different color LED strings LS1, LS2, LS3, LS4 in the Fig. 9 or Fig.10By driving two different color LED strings LS1 and LS2, or driving more different color LED strings to mix light, mixed light with a target mixed color temperature can be obtained.

[0059] In some embodiments, the driving method may further include the steps of: receiving N initial pulse width modulation signals, wherein the sum of the duty cycles of the N initial pulse width modulation signals is equal to 1; and converting the N initial pulse width modulation signals into the N target pulse width modulation signals. For example, the N initial pulse width modulation signals may be Figure 3 or Figure 4 The waveform conversion circuit 13 receives three initial pulse width modulation signals R-PWM0, G-PWM0, B-PWM0, or other numbers of initial pulse width modulation signals such as two, four or more initial pulse width modulation signals; furthermore, the waveform conversion circuit 13 can convert the received N initial pulse width modulation signals such as R-PWM0, G-PWM0, B-PWM0 into corresponding N target pulse width modulation signals such as R-PWM, G-PWM, B-PWM.

[0060] In some embodiments, the aforementioned [converting the N initial pulse width modulation signals into the N target pulse width modulation signals] may specifically include: converting the initial pulse width modulation signal with the largest duty cycle among the N initial pulse width modulation signals into a target pulse width modulation signal with a duty cycle of 1, and obtaining a conversion ratio; and converting the remaining initial pulse width modulation signals among the N initial pulse width modulation signals into other target pulse width modulation signals among the N target pulse width modulation signals according to the conversion ratio. For example, taking the mixed color temperature of 4000K as an example, corresponding to the situation of three (N=3) light-emitting diode strings LS1, LS2, and LS3 of different colors, it can be seen from the aforementioned Table 1 that the duty cycles of the initial PWM signals R-PWM0, G-PWM0, and B-PWM0 are 19.0%, 48.0%, and 33.0%, respectively. The initial PWM signal G-PWM0 with a maximum duty cycle of 48.0% is converted into a target PWM signal G-PWM with a duty cycle of 1, and a conversion ratio of 100.0% / 48.0% is obtained. The duty cycles of the other initial PWM signals R-PWM0 and B-PWM0 are converted in the same proportion, that is, 19.0%*(100.0% / 48.0%)≈39.6%, and 33.0%*(100.0% / 48.0%)≈68.8%, and other target PWM signals R-PWM and B-PWM can be obtained. Similarly, the duty cycles of the initial pulse width modulation signals R-PWM0, G-PWM0, and B-PWM0 corresponding to other mixed color temperatures in Table 1 can be converted to the duty cycles of the corresponding target pulse width modulation signals R-PWM, G-PWM, and B-PWM in Table 2.

[0061] In some embodiments, the aforementioned driving method may further include the steps of: receiving color control information; and processing the color control information to obtain the N initial pulse width modulation signals. Figure 4 The information processing circuit 15 receives color control information wirelessly, such as WiFi, Bluetooth, etc., where the color control information includes, for example, information representing the mixed color temperature value; the information processing circuit 15 then processes the received color control information to obtain N initial pulse width modulation signals, such as R-PWM0, G-PWM0, and B-PWM0.

[0062] In some embodiments, the aforementioned [processing the color control information to obtain the N initial pulse width modulation signals] may specifically include: obtaining the N initial pulse width modulation signals according to the color control information and a first mapping relationship table, wherein the first mapping relationship table includes at least one mixed color temperature and the duty cycle of each of the N pulse width modulation signals corresponding to each of the mixed color temperatures, and the sum of the duty cycles of the N pulse width modulation signals is equal to 1. For example, the first mapping relationship table here may be stored in Figure 4 The mapping relationship table between the duty cycle of the initial pulse width modulation signal and the mixed color temperature of the information processing circuit 15, for an LED light source device including three (N=3) LED strings of different colors, the mapping relationship table between the duty cycle of the initial pulse width modulation signal and the mixed color temperature can adopt the aforementioned Table 1, but the embodiments of the present invention are not limited thereto.

[0063] In some embodiments, the aforementioned driving method may further include the steps of: receiving color control information; and processing the color control information to obtain the N target pulse width modulation signals. Figure 5 The information processing circuit 15 receives color control information wirelessly, such as WiFi, Bluetooth, etc., where the color control information includes, for example, information representing the mixed color temperature value; the information processing circuit 15 then processes the received color control information to obtain N target pulse width modulation signals, such as R-PWM, G-PWM, and B-PWM.

[0064] In some embodiments, the aforementioned [processing the color control information to obtain the N initial pulse width modulation signals] may specifically include: obtaining the N target pulse width modulation signals according to the color control information and a second mapping relationship table, wherein the second mapping relationship table includes at least one mixed color temperature and the duty cycle of each of the N pulse width modulation signals corresponding to each of the mixed color temperatures, the sum of the duty cycles of the N pulse width modulation signals is greater than 1, and the duty cycle of at least one of the N pulse width modulation signals is equal to 1. For example, the second mapping relationship table here may be stored in Figure 5 The mapping relationship table between the duty cycle of the target pulse width modulation signal and the mixed color temperature of the information processing circuit 15 in the embodiment of the present invention can adopt the aforementioned Table 2 for an LED light source device including three (N=3) LED strings of different colors, but the embodiments of the present invention are not limited thereto.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A light emitting diode light source device, It is characterized in that include: A driving circuit, comprising N driving input terminals and N driving output terminals, and connected to the first power input terminal, where N is an integer greater than 1; as well as N light-emitting diode strings of different colors are respectively connected between the N driving output terminals and the second power input terminal; Among them, the N driving input terminals are used to respectively receive N target pulse width modulation signals, so that the driving circuit drives the N light-emitting diode strings of different colors respectively connected to the N driving output terminals to emit light for color mixing based on the N target pulse width modulation signals, and the duty cycle of at least one of the N target pulse width modulation signals is 1, and the sum of the duty cycles of the N target pulse width modulation signals is greater than 1 and less than N.

2. The light emitting diode light source device according to claim 1, It is characterized in that It also includes a waveform conversion circuit, which is used to receive N initial pulse width modulation signals, convert the N initial pulse width modulation signals into N target pulse width modulation signals, and output the N target pulse width modulation signals to the N driving input terminals of the driving circuit respectively, wherein the sum of the duty cycles of the N initial pulse width modulation signals is equal to 1.

3. The light emitting diode light source device according to claim 2, It is characterized in that It also includes an information processing circuit, which is used for receiving color control information, processing the color control information to obtain the N initial pulse width modulation signals, and outputting the N initial pulse width modulation signals to the waveform conversion circuit.

4. The light emitting diode light source device according to claim 1, It is characterized in that It also includes an information processing circuit, which is used to receive color control information, process the color control information to obtain the N target pulse width modulation signals, and output the N target pulse width modulation signals to the N driving input terminals of the driving circuit respectively.

5. The light emitting diode light source device according to any one of claims 1 to 4, It is characterized in that The driving circuit includes a driving chip, N input pins of the driving chip are respectively connected to the N driving input terminals through resistors for respectively receiving the N target pulse width modulation signals, N output pins of the driving chip are respectively connected to the N driving output terminals, a power pin of the driving chip is connected to the second power input terminal, a ground pin of the driving chip is connected to the first power input terminal, and an external resistor connection pin of the driving chip is connected to the first power input terminal through an external resistor.

6. The light emitting diode light source device according to any one of claims 1 to 4, It is characterized in that The driving circuit includes N three-terminal devices, each control terminal of the N three-terminal devices is connected to the N driving input terminals via a resistor for respectively receiving the N target pulse width modulation signals, each first current path terminal of the N three-terminal devices is connected to the N driving output terminals, and each second current path terminal of the N three-terminal devices is connected to the first power input terminal via a resistor.

7. A method for driving a light emitting diode light source device, the light emitting diode light source device comprising N light emitting diode strings of different colors, where N is an integer greater than 1; the driving method include: Receiving N target pulse width modulation signals, wherein the duty cycle of at least one target pulse width modulation signal among the N target pulse width modulation signals is 1, and the sum of the duty cycles of the N target pulse width modulation signals is greater than 1 and less than N; and Based on the N target pulse width modulation signals, the N light emitting diode strings of different colors are driven to emit light to perform color mixing.

8. The driving method according to claim 7, It is characterized in that Also includes: Receiving N initial pulse width modulation signals, wherein a sum of duty cycles of the N initial pulse width modulation signals is equal to 1; as well as The N initial pulse width modulation signals are converted into the N target pulse width modulation signals.

9. The driving method according to claim 8, It is characterized in that Converting the N initial pulse width modulation signals into the N target pulse width modulation signals specifically includes: Converting the initial pulse width modulation signal with the largest duty cycle among the N initial pulse width modulation signals into a target pulse width modulation signal with a duty cycle of 1, and obtaining a conversion ratio; and The remaining initial pulse width modulation signals among the N initial pulse width modulation signals are converted into other target pulse width modulation signals among the N target pulse width modulation signals according to the conversion ratio.

10. The driving method according to claim 8 or 9, It is characterized in that Also includes: Receive color control information; as well as Processing the color control information to obtain the N initial pulse width modulation signals specifically includes: The N initial pulse width modulation signals are obtained according to the color control information and a first mapping relationship table, wherein the first mapping relationship table includes at least one mixed color temperature and the respective duty cycles of the N pulse width modulation signals corresponding to each of the mixed color temperatures, and the sum of the duty cycles of the N pulse width modulation signals is equal to 1.

11. The driving method according to claim 7, It is characterized in that Also includes: Receive color control information; as well as Processing the color control information to obtain the N target pulse width modulation signals specifically includes: The N target pulse width modulation signals are obtained according to the color control information and the second mapping relationship table, wherein the second mapping relationship table includes at least one mixed color temperature and the duty cycles of the N pulse width modulation signals corresponding to each of the mixed color temperatures, the sum of the duty cycles of the N pulse width modulation signals is greater than 1, and the duty cycle of at least one pulse width modulation signal among the N pulse width modulation signals is equal to 1.

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