LED color deviation compensation correction method based on temperature

Abstract

The invention discloses a temperature-based LED color deviation compensation correction method. The method comprises the following steps: measuring LED lamp bead data by using a spectrograph and importing the data into a PC terminal; normal-temperature color coordinate values and normal-temperature luminous flux values of red, green and blue channels of the LED lamp beads collected at the normal temperature of 25 DEG C and the temperature t serve as independent variables at a PC end, data of the LED lamp beads are fitted into a multivariate high-order function through machine learning, and the multivariate high-order function is written into a program code of a controller; measuring primary color coordinate values and primary luminous flux values of red, green and blue channels of the LED lamp beads at 25 degrees once by using a spectrograph, and writing the primary color coordinate values and the primary luminous flux values into a controller; the controller obtains the current temperature value t ', and the actual color coordinate value and the actual luminous flux value of the LED lamp bead under the current temperature value t' are calculated; and calculating the target duty ratios of the red, green and blue channels of the LED lamp beads with the target color and writing the target duty ratios into an LED driver, wherein the LED driver drives the LED lamp beads to mix light with the same color as the target color. The production efficiency of the atmosphere lamp is improved, the production process is simplified, and the color cast compensation precision of the atmosphere lamp is improved.

Description

Technical Field

[0001] The invention relates to the technical field of LED lamp color calibration, and in particular to a temperature-based LED color deviation compensation correction method. Background Art

[0002] Due to the light decay characteristics of LED devices, the luminous flux will decay with the increase of temperature, and the main wavelength and color coordinates will also drift with the increase of temperature. Among them, the luminous flux decay of red light is the most obvious. Therefore, in the field of automotive ambient lights, in order to ensure that the light of the ambient light does not produce color deviation under various temperature conditions, a color deviation compensation algorithm needs to be added. The color coordinate offset curve of the red, green and blue lamp beads with temperature is pre-set, and the brightness offset curve of the red, green and blue lamp beads with temperature is pre-set. Then, at different temperatures, the color coordinate parameters and brightness parameters of the RGB channels of the LED lamp beads are obtained by looking up the table, and then the new RGB channel PWM duty cycle is calculated according to the target color, so as to ensure that the color coordinates and brightness do not have a large offset.

[0003] But the disadvantages of this approach are as follows:

[0004] 1. The color coordinate temperature curve and brightness temperature curve of each LED RGB channel are different. Therefore, it is necessary to measure the color coordinates and brightness values ​​of the LED at different temperatures in advance during production, and then write the data into the LED control system for storage. This method of measuring lamp bead parameters and presetting parameters on the production line greatly slows down the production efficiency of the production line.

[0005] 2. If the temperature of each point is measured and preset, the production efficiency of the production line will be extremely low. Therefore, most manufacturers classify LEDs into bins and pre-measure the data of bin LED parameters of each combination at different temperatures. During production, the preset data is burned according to the bin value information. The production efficiency is improved, but the LED binning link is added during production, and there are many types of LED bin value combinations, which makes the production process complicated. Due to the shared temperature curve data, the compensation accuracy will also decrease.

[0006] Disadvantages of existing technology: low production efficiency, complicated production process and reduced compensation accuracy. Summary of the invention

[0007] The present invention provides a temperature-based LED color deviation compensation correction method, which not only improves production efficiency but also ensures the accuracy of temperature color deviation compensation.

[0008] To achieve the above-mentioned purpose, the present invention provides a temperature-based LED color deviation compensation correction method, the key of which is to include a data processing step A before the atmosphere lamp leaves the factory and a software color deviation compensation step B after the atmosphere lamp leaves the factory;

[0009] The data processing step A of the atmosphere lamp before leaving the factory includes the following steps:

[0010] Step A1: Use a spectrometer to collect M groups of batch-produced LED lamp bead data, and import the collected LED lamp bead data into the PC end. The LED lamp bead data corresponds to the following color coordinate value and luminous flux value combination under the measured temperature t:

[0011] The red coordinate value (rx_t, ry_t) and red luminous flux value rY_t of the red channel of the LED lamp bead at 100% duty cycle;

[0012] The green coordinate value (gx_t, gy_t) and green luminous flux value gY_t of the green channel of the LED lamp bead at 100% duty cycle;

[0013] The blue coordinate value (bx_t, by_t) and blue light flux value by_t of the blue channel of the LED lamp bead at 100% duty cycle; where the temperature range of t is 0°~120°;

[0014] When the measured temperature t=25°, the color coordinate value and luminous flux value combination of the red, green and blue channels of the LED lamp beads collected are the normal temperature color coordinate value and normal temperature luminous flux value combination [(rx_25,ry_25), (gx_25,gy_25), (bx_25,by_25)], [rY_25,gY_25,bY_25];

[0015] Step A2: When the measured temperature t≠25°, the normal temperature color coordinate value and the normal temperature luminous flux value combination [(rx_25,ry_25), (gx_25,gy_25), (bx_25,by_25)], [rY_25,gY_25,bY_25] and the measured temperature t are used as independent variables on the PC side, and the LED lamp bead data is fitted into a multivariate high-order function using machine learning, and the obtained multivariate high-order function is written into the program code of the controller;

[0016] Step A3: During production on the production line, use a spectrometer to measure the normal temperature measured color coordinate values ​​and normal temperature measured luminous flux values ​​of the red, green and blue three channels of the LED lamp beads at 100% duty cycle at 25°C, and write the measured normal temperature measured color coordinate values ​​and normal temperature measured luminous flux value combinations [(m_rx_25,m_ry_25),(m_gx_25,m_gy_25),(m_bx_25,m_by_25)],[m_rY_25,m_gY_25,m_bY_25] into the controller;

[0017] The software color deviation compensation step B of the atmosphere lamp after leaving the factory includes the following steps:

[0018] Step B1: construct an LED driving circuit, in which the controller uses the temperature sensor around the LED lamp bead or reads the forward bias voltage of the red, green and blue channels of the LED lamp bead to obtain the current temperature t' of the LED lamp bead. When the current temperature t' obtained by the controller changes, enter step B2; otherwise, continue to obtain the current temperature value t';

[0019] Step B2: The controller calculates the actual color coordinate value and actual luminous flux value combination [(rx,ry), (gx,gy), (bx,by)], [rY, gY, bY] of the red, green and blue channels of the LED lamp bead at the current temperature t' at 100% duty cycle according to the current temperature t and the written normal temperature measured color coordinate value and normal temperature measured luminous flux value combination [(m_rx_25,m_ry_25), (m_gx_25,m_gy_25), (m_bx_25,m_by_25)], [m_rY_25,m_gY_25,m_bY_25] and multivariate high-order functions;

[0020] Step B3: According to the target color coordinate value (Cx_t', Cy_t') and the target luminous flux value Y_t' of the given target color LED lamp bead at the current temperature t', the target duty cycle (Duty_r, Duty_g, Duty_b) of the red, green and blue channels of the target color LED lamp bead at the current temperature t' is calculated, and the controller writes the calculated target duty cycle (Duty_r, Duty_g, Duty_b) into the LED driver, which drives the LED lamp beads to mix light with the same target color.

[0021] Through the above design, the data processing step A of the atmosphere light before leaving the factory provides data support and guarantee for the subsequent software color deviation compensation step B after the atmosphere light leaves the factory; in the software color deviation compensation step B after the atmosphere light leaves the factory, the controller calculates in real time the actual color coordinate values ​​[(rx,ry), (gx,gy), (bx,by)] and actual luminous flux values ​​[rY, gY, bY] of the red, green and blue channels of the LED lamp beads at the current temperature value t' at 100% duty cycle according to the change of the current temperature t', and combines the target color coordinate values ​​(Cx_t', Cy_t') and target luminous flux value Y_t' of the LED lamp beads of the given target color at the current temperature value t' to calculate the target duty cycle (Duty_r, Duty_g, Duty_b) of the red, green and blue channels of the LED lamp beads of the target color at the current temperature value t', and the controller controls the LED driver to realize the color deviation compensation of the LED lamp beads to ensure that the LED lamp beads emit light with the same color as the target color.

[0022] Through the above design, not only the production efficiency of the atmosphere light is improved, but also the production process is simplified and the color deviation compensation accuracy of the atmosphere light is improved.

[0023] Preferably, in step A2, the multivariate high-order function includes:

[0024] Function-1: f_r_x(rx_25,ry_25,t);

[0025] Function -1 is a three-variable function of function f_r_x with respect to independent variables rx_25, ry_25 and measured temperature t, wherein function f_r_x is a function fitted by the red channel color coordinate value rx of M groups of LED lamp beads at various temperatures, and (rx_25, ry_25) is the red channel color coordinate value of the corresponding LED lamp bead at room temperature;

[0026] Function-2: f_r_y(rx_25,ry_25,t);

[0027] Function-2 is a three-variable function of function f_r_y with respect to independent variables rx_25, ry_25 and measured temperature t, wherein function f_r_y is a function fitted by the red channel color coordinate value ry of M groups of LED lamp beads at various temperatures;

[0028] Function-3: f_r_Y(rY_25,t);

[0029] Function-3 is a two-variable function of function f_r_Y with respect to independent variable rY_25 and measured temperature t, wherein function f_r_Y is a function fitted by the red channel luminous flux value rY of M groups of LED lamp beads at various temperatures, and rY_25 is the red channel luminous flux value of the corresponding LED lamp bead at room temperature;

[0030] Function-4: f_g_x(gx_25,gy_25,t);

[0031] Function-4 is a three-variable function of function f_g_x with respect to independent variables gx_25, gy_25 and measured temperature t, wherein function f_g_x is a function fitted by the green channel color coordinate values ​​gx of M groups of LED lamp beads at various temperatures, and (gx_25, gy_25) is the green channel color coordinate value of the corresponding LED lamp beads at room temperature;

[0032] Function-5: f_g_y(gx_25,gy_25,t);

[0033] Function-5 is a three-variable function of function f_g_y with respect to independent variables gx_25, gy_25 and measured temperature t, wherein function f_g_y is a function fitted by the green channel color coordinate value gy of M groups of LED lamp beads at various temperatures;

[0034] Function-6: f_g_Y(gY_25,t);

[0035] Function-6 is a two-variable function of function f_g_Y with respect to independent variable gY_25 and measured temperature t, wherein function f_g_Y is a function fitted by the green channel luminous flux value gY of group M LED lamp beads at various temperatures, and gY_25 is the green channel luminous flux value of the corresponding LED lamp bead at room temperature;

[0036] Function-7: f_b_x(bx_25,by_25,t);

[0037] Function-7 is a three-variable function of function f_b_x with respect to independent variables bx_25, by_25 and measured temperature t, wherein function f_b_x is a function fitted by the blue channel color coordinate value bx of M groups of LED lamp beads at various temperatures, and (bx_25, by_25) is the blue channel color coordinate value of the corresponding LED lamp bead at room temperature;

[0038] Function-8: f_b_y(bx_25,by_25,t);

[0039] Function-8 is a three-variable function of function f_b_y with respect to independent variables bx_25, by_25 and measured temperature t, wherein function f_b_y is a function fitted by the blue channel color coordinate value by of M groups of LED lamp beads at various temperatures;

[0040] Function-9: f_b_Y(bY_25,t);

[0041] Function-9 is a two-variable function of function f_b_Y with respect to independent variables bY_25 and measured temperature t, wherein function f_b_Y is a function fitted by the blue channel luminous flux values ​​bY of M groups of LED lamp beads at various temperatures, and bY_25 is the blue channel luminous flux value of the corresponding LED lamp beads at room temperature.

[0042] Preferably, in step B2, the calculation formula of the actual color coordinate value and actual luminous flux value combination [(rx,ry), (gx,gy), (bx,by)], [rY, gY, bY] of the red, green and blue channels of the LED lamp bead at the current temperature value t' at 100% duty cycle is as follows:

[0043] At the current temperature value t', the actual color coordinate value (rx, ry) and actual luminous flux value rY of the red channel at 100% duty cycle are calculated as follows:

[0044] rx=f_r_x(m_rx_25,m_ry_25,t′);

[0045] ry=f_r_y(m_rx_25,m_ry_25,t′);

[0046] rY=f_r_Y(m_rY_25,t′);

[0047] At the current temperature value t', the actual color coordinate value (gx, gy) and actual luminous flux value gY of the green channel at 100% duty cycle are calculated as follows:

[0048] gx=f_g_x(m_gx_25,m_gy_25,t′);

[0049] gy=f_g_y(m_gx_25,m_gy_25,t′);

[0050] gY=f_g_Y(m_gY_25,t′);

[0051] At the current temperature value t', the actual color coordinate value (bx, by) and the actual luminous flux value by of the blue channel at 100% duty cycle are calculated as follows:

[0052] bx=f_b_x(m_bx_25,m_by_25,t′);

[0053] by=f_b_y(m_bx_25,m_by_25,t′);

[0054] bY=f_b_Y(m_bY_25,t′).

[0055] Preferably, in step B3, the duty cycle of the three channels of red, green and blue of the target color LED lamp beads at the current temperature value t' is calculated as follows:

[0056]

[0057] Tar_Y=Y_t'

[0058]

[0059]

[0060] LED_R_Y=rY

[0061]

[0062]

[0063] LED_G_Y=gY

[0064]

[0065]

[0066] LED_B_Y=bY

[0067]

[0068]

[0069] Among them, (Tar_X, Tar_Y, Tar_Z) are the target tristimulus values ​​of the target color, (Cx_t', Cy_t') are the target color coordinate values, and Y_t' is the target luminous flux value; (LED_R_X, LED_R_Y, LED_R_Z) are the red tristimulus values ​​of the red channel of the LED lamp bead at 100% duty cycle at the current temperature value t', (LED_G_X, LED_G_Y, LED_G_Z) are the green tristimulus values ​​of the green channel of the LED lamp bead at 100% duty cycle at the current temperature value t', (LED_B_X, LED_B_Y, LED_B_Z) are the blue tristimulus values ​​of the blue channel of the LED lamp bead at 100% duty cycle at the current temperature value t', and (Duty_r, Duty_g, Duty_b) are the target duty cycles of the red, green and blue channels of the target color.

[0070] Preferably, the spectrometer is an integrating sphere, an imaging colorimeter, or an illuminometer. The corresponding spectrometer equipment can be selected according to actual use requirements.

[0071] Preferably, in step B1, the LED driving circuit is composed of a controller, an LED driver (IC1), an LED lamp bead D1, a diode D3, a voltage regulator diode D4, a bidirectional voltage regulator diode D5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C10 and a magnetic bead L1;

[0072] The output terminal X2 of the controller is connected to the input terminal of the LED driver IC1 via the magnetic bead L1. The output terminal X2 of the controller is also connected in series with a bidirectional voltage regulator diode D5 and then grounded. The input terminal of the LED driver (IC1) is connected in series with the capacitor C3 and then grounded.

[0073] The input terminal X3 of the controller is connected to the output terminal of the LED driver (IC1), and the input terminal X3 of the controller is also connected in series with a capacitor C10 and then grounded;

[0074] The power supply terminal X1 of the controller is connected to the anode of the diode D3, the cathode of the diode D3 is connected to the power supply, the power supply terminal X1 of the controller is also connected in series with capacitors C1 and C5 in sequence and then grounded, the cathode of the diode D3 is connected in series with a voltage regulator diode D4 and then grounded, the cathode of the diode D3 is also connected in series with capacitor C4 and then grounded, and the cathode of the diode D3 is also connected in series with capacitor C2 and then grounded; the ground terminal X4 of the controller is grounded;

[0075] The three driving terminals LCO, LC1 and LC2 of the LED driver (IC1) are connected to the cathodes of the red, green and blue channels of the LED lamp bead D1 in a one-to-one correspondence, the anode of the LED lamp bead D1 is connected to a power supply, the power supply terminal of the LED driver (IC1) is connected to a power supply, and the ground terminal of the LED driver (IC1) is grounded.

[0076] Through the design of the above circuit, the power supply is effectively protected from reverse connection and the LIN line is effectively protected from reverse connection.

[0077] The beneficial effects of the present invention are: not only the production efficiency of the atmosphere lamp is improved, but also the production process is simplified and the color deviation compensation accuracy of the atmosphere lamp is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is the overall flow chart of the present invention;

[0079] Figure 2 This is a LED driving circuit diagram of the present invention. DETAILED DESCRIPTION

[0080] The present invention is further described in detail below in conjunction with the accompanying drawings and specific examples. The following examples or drawings are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0081] like Figure 1 As shown: A temperature-based LED color deviation compensation correction method, the key of which is to include a data processing step A before the atmosphere lamp leaves the factory and a software color deviation compensation step B after the atmosphere lamp leaves the factory;

[0082] The data processing step A of the atmosphere lamp before leaving the factory includes the following steps:

[0083] Step A1: Use a spectrometer to collect M groups of batch-produced LED lamp bead data, and import the collected LED lamp bead data into the PC end. The LED lamp bead data corresponds to the following color coordinate value and luminous flux value combination under the measured temperature t:

[0084] The red coordinate value (rx_t, ry_t) and red luminous flux value rY_t of the red channel of the LED lamp bead at 100% duty cycle;

[0085] The green coordinate value (gx_t, gy_t) and green luminous flux value gY_t of the green channel of the LED lamp bead at 100% duty cycle;

[0086] The blue coordinate value (bx_t, by_t) and blue light flux value by_t of the blue channel of the LED lamp bead at 100% duty cycle; where the temperature range of t is 0°~120°;

[0087] When the measured temperature t=25°, the color coordinate value and luminous flux value combination of the red, green and blue channels of the LED lamp beads collected are the normal temperature color coordinate value and normal temperature luminous flux value combination [(rx_25,ry_25), (gx_25,gy_25), (bx_25,by_25)], [rY_25,gY_25,bY_25];

[0088] Step A2: When the measured temperature t≠25°, the normal temperature color coordinate value and the normal temperature luminous flux value combination [(rx_25,ry_25), (gx_25,gy_25), (bx_25,by_25)], [rY_25,gY_25,bY_25] and the measured temperature t are used as independent variables on the PC side, and the LED lamp bead data is fitted into a multivariate high-order function using machine learning, and the obtained multivariate high-order function is written into the program code of the controller;

[0089] Step A3: During production on the production line, use a spectrometer to measure the normal temperature measured color coordinate values ​​and normal temperature measured luminous flux values ​​of the red, green and blue three channels of the LED lamp beads at 100% duty cycle at 25°C, and write the measured normal temperature measured color coordinate values ​​and normal temperature measured luminous flux value combinations [(m_rx_25,m_ry_25),(m_gx_25,m_gy_25),(m_bx_25,m_by_25)],[m_rY_25,m_gY_25,m_bY_25] into the controller;

[0090] The software color deviation compensation step B of the atmosphere lamp after leaving the factory includes the following steps:

[0091] Step B1: construct an LED driving circuit, in which the controller uses the temperature sensor around the LED lamp bead or reads the forward bias voltage of the red, green and blue channels of the LED lamp bead to obtain the current temperature t' of the LED lamp bead. When the current temperature t' obtained by the controller changes, enter step B2; otherwise, continue to obtain the current temperature value t';

[0092] Step B2: The controller calculates the actual color coordinate value and actual luminous flux value combination [(rx,ry), (gx,gy), (bx,by)], [rY, gY, bY] of the red, green and blue channels of the LED lamp bead at the current temperature t' at 100% duty cycle according to the current temperature t and the written normal temperature measured color coordinate value and normal temperature measured luminous flux value combination [(m_rx_25,m_ry_25), (m_gx_25,m_gy_25), (m_bx_25,m_by_25)], [m_rY_25,m_gY_25,m_bY_25] and multivariate high-order functions;

[0093] Step B3: According to the target color coordinate value (Cx_t', Cy_t') and the target luminous flux value Y_t' of the given target color LED lamp bead at the current temperature t', the target duty cycle (Duty_r, Duty_g, Duty_b) of the red, green and blue channels of the target color LED lamp bead at the current temperature t' is calculated, and the controller writes the calculated target duty cycle (Duty_r, Duty_g, Duty_b) into the LED driver IC1, which drives the LED lamp beads to mix light with the same target color.

[0094] Specifically, in step A2, the multivariate high-order function includes:

[0095] Function-1: f_r_x(rx_25,ry_25,t);

[0096] Function -1 is a three-variable function of function f_r_x with respect to independent variables rx_25, ry_25 and measured temperature t, wherein function f_r_x is a function fitted by the red channel color coordinate value rx of M groups of LED lamp beads at various temperatures, and (rx_25, ry_25) is the red channel color coordinate value of the corresponding LED lamp bead at room temperature;

[0097] Function-2: f_r_y(rx_25,ry_25,t);

[0098] Function-2 is a three-variable function of function f_r_y with respect to independent variables rx_25, ry_25 and measured temperature t, wherein function f_r_y is a function fitted by the red channel color coordinate value ry of M groups of LED lamp beads at various temperatures;

[0099] Function-3: f_r_Y(rY_25,t);

[0100] Function-3 is a two-variable function of function f_r_Y with respect to independent variable rY_25 and measured temperature t, wherein function f_r_Y is a function fitted by the red channel luminous flux value rY of M groups of LED lamp beads at various temperatures, and rY_25 is the red channel luminous flux value of the corresponding LED lamp bead at room temperature;

[0101] Function-4: f_g_x(gx_25,gy_25,t);

[0102] Function-4 is a three-variable function of function f_g_x with respect to independent variables gx_25, gy_25 and measured temperature t, wherein function f_g_x is a function fitted by the green channel color coordinate values ​​gx of M groups of LED lamp beads at various temperatures, and (gx_25, gy_25) is the green channel color coordinate value of the corresponding LED lamp beads at room temperature;

[0103] Function-5: f_g_y(gx_25,gy_25,t);

[0104] Function-5 is a three-variable function of function f_g_y with respect to independent variables gx_25, gy_25 and measured temperature t, wherein function f_g_y is a function fitted by the green channel color coordinate value gy of M groups of LED lamp beads at various temperatures;

[0105] Function-6: f_g_Y(gY_25,t);

[0106] Function-6 is a two-variable function of function f_g_Y with respect to independent variable gY_25 and measured temperature t, wherein function f_g_Y is a function fitted by the green channel luminous flux value gY of group M LED lamp beads at various temperatures, and gY_25 is the green channel luminous flux value of the corresponding LED lamp bead at room temperature;

[0107] Function-7: f_b_x(bx_25,by_25,t);

[0108] Function-7 is a three-variable function of function f_b_x with respect to independent variables bx_25, by_25 and measured temperature t, wherein function f_b_x is a function fitted by the blue channel color coordinate value bx of M groups of LED lamp beads at various temperatures, and (bx_25, by_25) is the blue channel color coordinate value of the corresponding LED lamp bead at room temperature;

[0109] Function-8: f_b_y(bx_25,by_25,t);

[0110] Function-8 is a three-variable function of function f_b_y with respect to independent variables bx_25, by_25 and measured temperature t, wherein function f_b_y is a function fitted by the blue channel color coordinate value by of M groups of LED lamp beads at various temperatures;

[0111] Function-9: f_b_Y(bY_25,t);

[0112] Function-9 is a two-variable function of function f_b_Y with respect to independent variables bY_25 and measured temperature t, wherein function f_b_Y is a function fitted by the blue channel luminous flux values ​​bY of M groups of LED lamp beads at various temperatures, and bY_25 is the blue channel luminous flux value of the corresponding LED lamp beads at room temperature.

[0113] In step B2, the calculation formula of the actual color coordinate value and actual luminous flux value combination [(rx,ry), (gx,gy), (bx,by)], [rY, gY, bY] of the red, green and blue channels of the LED lamp bead at the current temperature value t' at 100% duty cycle is as follows:

[0114] At the current temperature value t', the actual color coordinate value (rx, ry) and actual luminous flux value rY of the red channel at 100% duty cycle are calculated as follows:

[0115] rx=f_r_x(m_rx_25,m_ry_25,t′);

[0116] ry=f_r_y(m_rx_25,m_ry_25,t′);

[0117] rY=f_r_Y(m_rY_25,t′);

[0118] At the current temperature value t', the actual color coordinate value (gx, gy) and actual luminous flux value gY of the green channel at 100% duty cycle are calculated as follows:

[0119] gx=f_g_x(m_gx_25,m_gy_25,t′);

[0120] gy=f_g_y(m_gx_25,m_gy_25,t′);

[0121] gY=f_g_Y(m_gY_25,t′);

[0122] At the current temperature value t', the actual color coordinate value (bx, by) and the actual luminous flux value by of the blue channel at 100% duty cycle are calculated as follows:

[0123] bx=f_b_x(m_bx_25,m_by_25,t′);

[0124] by=f_b_y(m_bx_25,m_by_25,t′);

[0125] bY=f_b_Y(m_bY_25,t′).

[0126] In step B3, the calculation process of the duty cycle of the three channels of red, green and blue of the target color LED lamp beads at the current temperature value t' is as follows:

[0127]

[0128] Tar_Y=Y_t'

[0129]

[0130]

[0131] LED_R_Y=rY

[0132]

[0133]

[0134] LED_G_Y=gY

[0135]

[0136]

[0137] LED_B_Y=bY

[0138]

[0139]

[0140] Among them, (Tar_X, Tar_Y, Tar_Z) are the target tristimulus values ​​of the target color, (Cx_t', Cy_t') are the target color coordinate values, and Y_t' is the target luminous flux value; (LED_R_X, LED_R_Y, LED_R_Z) are the red tristimulus values ​​of the red channel of the LED lamp bead at 100% duty cycle at the current temperature value t', (LED_G_X, LED_G_Y, LED_G_Z) are the green tristimulus values ​​of the green channel of the LED lamp bead at 100% duty cycle at the current temperature value t', (LED_B_X, LED_B_Y, LED_B_Z) are the blue tristimulus values ​​of the blue channel of the LED lamp bead at 100% duty cycle at the current temperature value t', and (Duty_r, Duty_g, Duty_b) are the target duty cycles of the red, green and blue channels of the target color.

[0141] like Figure 2 As shown: the LED driving circuit is composed of a controller, an LED driver IC1, an LED lamp bead D1, a diode D3, a voltage regulator diode D4, a bidirectional voltage regulator diode D5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C10 and a magnetic bead L1;

[0142] The output terminal X2 of the controller is connected to the input terminal of the LED driver IC1 via the magnetic bead L1. The output terminal X2 of the controller is also connected in series with a bidirectional voltage regulator diode D5 and then grounded. The input terminal of the LED driver IC1 is connected in series with the capacitor C3 and then grounded.

[0143] The input terminal X3 of the controller is connected to the output terminal of the LED driver IC1, and the input terminal X3 of the controller is also connected in series with a capacitor C10 and then grounded;

[0144] The power supply terminal X1 of the controller is connected to the anode of the diode D3, the cathode of the diode D3 is connected to the power supply, the power supply terminal X1 of the controller is also connected in series with capacitors C1 and C5 in sequence and then grounded, the cathode of the diode D3 is connected in series with a voltage regulator diode D4 and then grounded, the cathode of the diode D3 is also connected in series with capacitor C4 and then grounded, and the cathode of the diode D3 is also connected in series with capacitor C2 and then grounded; the ground terminal X4 of the controller is grounded;

[0145] The three driving terminals LCO, LC1 and LC2 of the LED driver IC1 are connected one by one to the cathodes of the red, green and blue channels of the LED lamp bead D1, the anode of the LED lamp bead D1 is connected to the power supply, the power terminal of the LED driver IC1 is connected to the power supply, and the ground terminal of the LED driver IC1 is grounded.

[0146] Through the design of the above circuit, the power supply is effectively protected from reverse connection and the LIN line is effectively protected from reverse connection.

[0147] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A temperature-based LED color deviation compensation correction method, characterized in that: It includes a data processing step A before the ambient light leaves the factory and a software color deviation compensation step B after the ambient light leaves the factory; The data processing step A of the atmosphere lamp before leaving the factory includes the following steps: Step A1: Use a spectrometer to collect M groups of batch-produced LED lamp bead data, and import the collected LED lamp bead data into the PC end. The LED lamp bead data corresponds to the following color coordinate value and luminous flux value combination under the measured temperature t: The red coordinate value (rx_t, ry_t) and red luminous flux value rY_t of the red channel of the LED lamp bead at 100% duty cycle; The green coordinate value (gx_t, gy_t) and green luminous flux value gY_t of the green channel of the LED lamp bead at 100% duty cycle; The blue coordinate value (bx_t, by_t) and blue light flux value by_t of the blue channel of the LED lamp bead at 100% duty cycle; where the temperature range of t is 0°~120°; When the measured temperature t=25°, the color coordinate value and luminous flux value combination of the red, green and blue channels of the LED lamp beads collected are the normal temperature color coordinate value and normal temperature luminous flux value combination [(rx_25,ry_25), (gx_25,gy_25), (bx_25,by_25)], [rY_25,gY_25,bY_25]; Step A2: When the measured temperature t≠25°, the normal temperature color coordinate value and the normal temperature luminous flux value combination [(rx_25,ry_25), (gx_25,gy_25), (bx_25,by_25)], [rY_25,gY_25,bY_25] and the measured temperature t are used as independent variables on the PC side, and the LED lamp bead data is fitted into a multivariate high-order function using machine learning, and the obtained multivariate high-order function is written into the program code of the controller; Step A3: During production on the production line, use a spectrometer to measure the normal temperature measured color coordinate values ​​and normal temperature measured luminous flux values ​​of the red, green and blue three channels of the LED lamp beads at 100% duty cycle at 25°C, and write the measured normal temperature measured color coordinate values ​​and normal temperature measured luminous flux value combinations [(m_rx_25,m_ry_25),(m_gx_25,m_gy_25),(m_bx_25,m_by_25)],[m_rY_25,m_gY_25,m_bY_25] into the controller; The software color deviation compensation step B of the atmosphere lamp after leaving the factory includes the following steps: Step B1: construct an LED driving circuit, in which the controller uses the temperature sensor around the LED lamp bead or reads the forward bias voltage of the red, green and blue channels of the LED lamp bead to obtain the current temperature t' of the LED lamp bead. When the current temperature t' obtained by the controller changes, enter step B2; otherwise, continue to obtain the current temperature value t'; Step B2: The controller calculates the actual color coordinate value and actual luminous flux value combination [(rx,ry), (gx,gy), (bx,by)], [rY, gY, bY] of the red, green and blue channels of the LED lamp bead at the current temperature t' at 100% duty cycle according to the current temperature t and the written normal temperature measured color coordinate value and normal temperature measured luminous flux value combination [(m_rx_25,m_ry_25), (m_gx_25,m_gy_25), (m_bx_25,m_by_25)], [m_rY_25,m_gY_25,m_bY_25] and multivariate high-order functions; Step B3: According to the target color coordinate value (Cx_t', Cy_t') and the target luminous flux value Y_t' of the given target color LED lamp bead at the current temperature t', the target duty ratio (Duty_r, Duty_g, Duty_b) of the red, green and blue channels of the target color LED lamp bead at the current temperature t' is calculated, and the controller writes the calculated target duty ratio (Duty_r, Duty_g, Duty_b) into the LED driver (IC1), and the LED driver (IC1) drives the LED lamp beads to mix light with the same target color.

2. The temperature-based LED color deviation compensation correction method according to claim 1, characterized in that: In step A2, the multivariate high-order function includes: Function-1: f_r_x(rx_25,ry_25,t); Function -1 is a three-variable function of function f_r_x with respect to independent variables rx_25, ry_25 and measured temperature t, wherein function f_r_x is a function fitted by the red channel color coordinate value rx of M groups of LED lamp beads at various temperatures, and (rx_25, ry_25) is the red channel color coordinate value of the corresponding LED lamp bead at room temperature; Function-2: f_r_y(rx_25,ry_25,t); Function-2 is a three-variable function of function f_r_y with respect to independent variables rx_25, ry_25 and measured temperature t, wherein function f_r_y is a function fitted by the red channel color coordinate value ry of M groups of LED lamp beads at various temperatures; Function-3: f_r_Y(rY_25,t); Function-3 is a two-variable function of function f_r_Y with respect to independent variable rY_25 and measured temperature t, wherein function f_r_Y is a function fitted by the red channel luminous flux value rY of M groups of LED lamp beads at various temperatures, and rY_25 is the red channel luminous flux value of the corresponding LED lamp bead at room temperature; Function-4: f_g_x(gx_25,gy_25,t); Function-4 is a three-variable function of function f_g_x with respect to independent variables gx_25, gy_25 and measured temperature t, wherein function f_g_x is a function fitted by the green channel color coordinate values ​​gx of M groups of LED lamp beads at various temperatures, and (gx_25, gy_25) is the green channel color coordinate value of the corresponding LED lamp beads at room temperature; Function-5: f_g_y(gx_25,gy_25,t); Function-5 is a three-variable function of function f_g_y with respect to independent variables gx_25, gy_25 and measured temperature t, wherein function f_g_y is a function fitted by the green channel color coordinate value gy of M groups of LED lamp beads at various temperatures; Function-6: f_g_Y(gY_25,t); Function-6 is a two-variable function of function f_g_Y with respect to independent variable gY_25 and measured temperature t, wherein function f_g_Y is a function fitted by the green channel luminous flux value gY of group M LED lamp beads at various temperatures, and gY_25 is the green channel luminous flux value of the corresponding LED lamp bead at room temperature; Function-7: f_b_x(bx_25,by_25,t); Function-7 is a three-variable function of function f_b_x with respect to independent variables bx_25, by_25 and measured temperature t, wherein function f_b_x is a function fitted by the blue channel color coordinate value bx of M groups of LED lamp beads at various temperatures, and (bx_25, by_25) is the blue channel color coordinate value of the corresponding LED lamp bead at room temperature; Function-8: f_b_y(bx_25,by_25,t); Function-8 is a three-variable function of function f_b_y with respect to independent variables bx_25, by_25 and measured temperature t, wherein function f_b_y is a function fitted by the blue channel color coordinate value by of M groups of LED lamp beads at various temperatures; Function-9: f_b_Y(bY_25,t); Function-9 is a two-variable function of function f_b_Y with respect to independent variables bY_25 and measured temperature t, wherein function f_b_Y is a function fitted by the blue channel luminous flux values ​​bY of M groups of LED lamp beads at various temperatures, and bY_25 is the blue channel luminous flux value of the corresponding LED lamp beads at room temperature.

3. The temperature-based LED color deviation compensation correction method according to claim 1, characterized in that: In step B2, the calculation formula of the actual color coordinate value and actual luminous flux value combination [(rx,ry), (gx,gy), (bx,by)], [rY, gY, bY] of the red, green and blue channels of the LED lamp bead at the current temperature value t' at 100% duty cycle is as follows: At the current temperature value t', the actual color coordinate value (rx, ry) and actual luminous flux value rY of the red channel at 100% duty cycle are calculated as follows: rx=f_r_x(m_rx_25,m_ry_25,t′); ry=f_r_y(m_rx_25,m_ry_25,t′); rY=f_r_Y(m_rY_25,t′); At the current temperature value t', the actual color coordinate value (gx, gy) and actual luminous flux value gY of the green channel at 100% duty cycle are calculated as follows: gx=f_g_x(m_gx_25,m_gy_25,t′); gy=f_g_y(m_gx_25,m_gy_25,t′); gY=f_g_Y(m_gY_25,t′); At the current temperature value t', the actual color coordinate value (bx, by) and the actual luminous flux value by of the blue channel at 100% duty cycle are calculated as follows: bx=f_b_x(m_bx_25,m_by_25,t′); by=f_b_y(m_bx_25,m_by_25,t′); bY=f_b_Y(m_bY_25,t′).

4. The temperature-based LED color deviation compensation correction method according to claim 1, characterized in that: In step B3, the calculation process of the duty cycle of the three channels of red, green and blue of the target color LED lamp beads at the current temperature value t' is as follows: Tar_Y=Y_t' LED_R_Y=rY LED_G_Y=gY LED_B_Y=bY Among them, (Tar_X, Tar_Y, Tar_Z) are the target tristimulus values ​​of the target color, (Cx_t', Cy_t') are the target color coordinate values, and Y_t' is the target luminous flux value; (LED_R_X, LED_R_Y, LED_R_Z) are the red tristimulus values ​​of the red channel of the LED lamp bead at 100% duty cycle at the current temperature value t', (LED_G_X, LED_G_Y, LED_G_Z) are the green tristimulus values ​​of the green channel of the LED lamp bead at 100% duty cycle at the current temperature value t', (LED_B_X, LED_B_Y, LED_B_Z) are the blue tristimulus values ​​of the blue channel of the LED lamp bead at 100% duty cycle at the current temperature value t', and (Duty_r, Duty_g, Duty_b) are the target duty cycles of the red, green and blue channels of the target color.

5. The temperature-based LED color deviation compensation correction method according to claim 1, characterized in that: The spectrometer is either an integrating sphere; or an imaging colorimeter; or an illuminometer.

6. The temperature-based LED color deviation compensation correction method according to claim 1, characterized in that: In step B1, the LED driving circuit is composed of a controller, an LED driver (IC1), an LED lamp bead D1, a diode D3, a voltage regulator diode D4, a bidirectional voltage regulator diode D5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C10 and a magnetic bead L1; The output terminal X2 of the controller is connected to the input terminal of the LED driver IC1 via the magnetic bead L1. The output terminal X2 of the controller is also connected in series with a bidirectional voltage regulator diode D5 and then grounded. The input terminal of the LED driver (IC1) is connected in series with the capacitor C3 and then grounded. The input terminal X3 of the controller is connected to the output terminal of the LED driver (IC1), and the input terminal X3 of the controller is also connected in series with a capacitor C10 and then grounded; The power supply terminal X1 of the controller is connected to the anode of the diode D3, the cathode of the diode D3 is connected to the power supply, the power supply terminal X1 of the controller is also connected in series with capacitors C1 and C5 in sequence and then grounded, the cathode of the diode D3 is connected in series with a voltage regulator diode D4 and then grounded, the cathode of the diode D3 is also connected in series with capacitor C4 and then grounded, and the cathode of the diode D3 is also connected in series with capacitor C2 and then grounded; the ground terminal X4 of the controller is grounded; The three driving terminals LCO, LC1 and LC2 of the LED driver (IC1) are connected to the cathodes of the red, green and blue channels of the LED lamp bead D1 in a one-to-one correspondence, the anode of the LED lamp bead D1 is connected to a power supply, the power supply terminal of the LED driver (IC1) is connected to a power supply, and the ground terminal of the LED driver (IC1) is grounded.

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