CN115297590B

CN115297590B - Color non-shift control method for dimming lamp and application thereof

Info

Publication number: CN115297590B
Application number: CN202211231112.9A
Authority: CN
Inventors: 王忠泉; 请求不公布姓名
Original assignee: Hangzhou Roledith Technology Co ltd
Current assignee: Hangzhou Roledith Technology Co ltd
Priority date: 2022-10-10
Filing date: 2022-10-10
Publication date: 2023-02-14
Anticipated expiration: 2042-10-10
Also published as: CN115297590A

Abstract

The application provides a dimming lamp color non-deviation control method and application thereof, comprising the following steps: s00, setting the PWM output of the dimming lamp to obey linear distribution, and measuring the corresponding original absolute lumen value of each primary color of the dimming lamp under each level of dimming; s10, normalizing original lumen data and dimming levels formed by collecting original absolute lumen values through linear transformation to obtain a linear locus diagram of each primary color in a two-dimensional coordinate system; the two-dimensional coordinate system takes the dimming grade as an abscissa and takes the lumen value as an ordinate; s20, calculating a correction coefficient corresponding to each primary color based on the abscissa and the ordinate of each primary color under each level of dimming; and S30, outputting the correction coefficient corresponding to each primary color multiplied by the linear distribution according to the PWM, and controlling the dimming lamp to emit light. The color offset problem that produces when this application can solve effectively to adjust luminance.

Description

Color non-shift control method for dimming lamp and application thereof

Technical Field

The application relates to the technical field of LED lamps, in particular to a control method for preventing color of a dimming lamp from being shifted and application thereof.

Background

The color is closely related to life, and different colors are adjusted by the lamp, so that different atmospheres are created for people. However, in actual dimming and toning, inevitable color drift often occurs, resulting in a large color mixing deviation. Color drift is multifactorial, one being that the current versus lumen characteristic of prior art LED light sources is non-linear (fig. 9); second, the drive circuit device responds to the input PWM and the output current is nonlinear. These two points result in different non-linearity of each primary color, so when the color is adjusted based on linear PWM, color mixing may cause color drift.

Even worse, the LEDs of different primary colors will not start to light at the same threshold current, as shown in fig. 9, and will not light below the threshold current near the origin. Referring to fig. 9, when RGB is dimmed from level 0, a black patch is not lighted during a period, and then B, G, R sequentially start to light, and the mixed light is discolored during the period, and the color shift is particularly serious.

Ideally it is based on linear PWM dimming, but the human eye does not have a simple linear relationship between the perception of brightness and the physical power, but a relationship that is a power function with an exponent of typically 2.2, called the gamma value, i.e. a power function with typically y = x ^{2 .2} （0≤x≤1）. In prior art dimming, PWM applies this gamma curve. For the reasons stated above, the color shift of the dimming color mixture perceived by the human eye is still caused after applying the gamma curve.

Therefore, a control method and an application thereof capable of solving the color shift problem during dimming are desired.

Disclosure of Invention

The embodiment of the application provides a dimming lamp color non-deviation control method and application thereof, aiming at the problems of color deviation and the like in dimming in the prior art.

The core technology of the invention is mainly to solve the problem of nonlinear color cast by linear correction, then optimize a gamma curve, solve the problem of color cast of a low brightness threshold, finally combine and apply, perform double optimization, and solve the problem of global color cast.

In a first aspect, the present application provides a method for controlling color non-shift of a dimming lamp, the method comprising the following steps:

s00, setting the PWM output of the dimming lamp to obey linear distribution, and measuring the corresponding original absolute lumen value of each primary color of the dimming lamp under each level of dimming;

s10, normalizing original lumen data and dimming levels formed by collecting original absolute lumen values through linear transformation to obtain a linear locus diagram of each primary color in a two-dimensional coordinate system;

the two-dimensional coordinate system takes the dimming grade as an abscissa and takes the lumen value as an ordinate;

s20, calculating a correction coefficient corresponding to each primary color based on the abscissa and the ordinate of each primary color under each level of dimming;

and S30, multiplying the PWM output obedience linear distribution by the correction coefficient corresponding to each primary color to control the dimming lamp to emit light.

Further, the method also comprises a step of optimizing the gamma curve, which specifically comprises the following steps:

s40, obtaining the dimming grade corresponding to each primary color of the dimming lamp when the primary color is in critical lightening, and recording the PWM frequency set at the moment as the test PWM frequency;

s50, calculating a raising value and an opening size of a gamma curve based on a dimming grade corresponding to each primary color during critical lightening, a dimming grade currently set by a user, a test PWM frequency, a PWM frequency set by the current user, the highest dimming grade of a dimming lamp and a current gamma value, and optimizing an original gamma curve according to the raising value and the opening size so that each primary color of the dimming lamp can be lightened from a first-level dimming grade;

wherein the opening size = 1-elevated value; each primary color does not shine at the zeroth dimming level.

Further, the method also comprises a double optimization step, which specifically comprises the following steps:

s60, adjusting the correction coefficients of the dimming grade before critical lightening in each primary color of the dimming lamp to the correction coefficients of the dimming grade during the critical lightening;

and S70, continuously increasing the rising value and the opening size of the gamma curve so that the primary colors keep uniform and shine from the first-stage dimming level.

Further, in step S00, when the dimming lamp is in steady-state operation, setting the PWM output of the dimming lamp to obey linear distribution, and measuring the original absolute lumen value corresponding to each primary color of the dimming lamp under each level of dimming.

Further, in step S10, according to the maximum lumen and the minimum lumen of each primary color in the original lumen data, the abscissa and the ordinate of each primary color in the interval of [0,1] in each dimming level are calculated, so as to obtain a linear locus diagram of each primary color in the two-dimensional coordinate system.

Further, in step S50, the optimized gamma curve G (X) is:

(ii) a Wherein x is the current dimming level set by the user and is obtained by dividing the current dimming level by the highest dimming level of the dimming lamp, b is a raising value, 1-b is the opening size, and 2.2 is a gamma value.

Further, in step S50, the elevation value b = f/f ₀ *(n ₀ /N) ^2.2 ；

Wherein, f is the PWM frequency set by the current user; f. of ₀ To test the PWM frequency; n is ₀ The corresponding dimming grade of each primary color when the primary color is in critical lightening; n is the maximum dimming level of each primary color, and 2.2 is the gamma value.

In a second aspect, the present application provides a dimming lamp color non-shift control apparatus, comprising:

the acquisition module is used for setting the PWM output of the dimming lamp to obey linear distribution and measuring the original absolute lumen value of each primary color of the dimming lamp under each level of dimming; the device is used for acquiring the corresponding dimming grade of each primary color of the dimming lamp when the primary color is in critical lightening, and recording the set PWM frequency as the test PWM frequency;

the calculation module is used for normalizing original lumen data and dimming level formed by collecting original absolute lumen values through linear transformation to obtain a linear trajectory graph of each primary color in a two-dimensional coordinate system; the two-dimensional coordinate system takes the dimming grade as an abscissa and takes the lumen value as an ordinate; the correction coefficient calculation module is used for calculating a correction coefficient corresponding to each primary color based on the abscissa and the ordinate of each primary color under each level of dimming; the method comprises the steps that a lifting numerical value and an opening size of a gamma curve are calculated based on a dimming grade corresponding to each primary color during critical lightening, a dimming grade currently set by a user, a PWM frequency tested, a PWM frequency set by the current user, the highest dimming grade of a dimming lamp and a current gamma value, and the original gamma curve is optimized according to the lifting numerical value and the opening size, so that each primary color of the dimming lamp can be lightened from a first-level dimming grade; wherein the opening size = 1-elevated value; each primary color does not shine at the zero-level dimming level;

the control module is used for outputting a correction coefficient corresponding to each primary color multiplied by the linear distribution obeyed by PWM to control the dimming lamp to emit light; the correction coefficients are used for adjusting the dimming grade before critical lightening in each primary color of the dimming lamp to the dimming grade during the critical lightening; the driver is used to continuously increase the elevation value and the opening size of the gamma curve, so that the primary colors can keep uniform from the first dimming level, i.e. lightening.

In a third aspect, the present application provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to execute the dimming lamp color non-shift control method.

In a fourth aspect, the present application provides a readable storage medium having stored therein a computer program comprising program code for controlling a process to execute a process, the process comprising the dimming lamp color non-shift control method according to the above.

The main contributions and innovation points of the invention are as follows: 1. compared with the prior art, the method and the device have the advantages that the nonlinear problem is corrected through the correction coefficients corresponding one by one, so that the input and output of the correction coefficients are in positive correlation and are accurate and controllable, the technical problem of dimming and color mixing color drift of a user is solved, data acquisition can be carried out on dimming lamps of the same type, the correction coefficients and the optimized gamma curves which are suitable for all dimming lamps of the same type and the same parameter can be generated, the operation is convenient, and the cost is low;

2. compared with the prior art, the gamma curve after the correction coefficient and the optimization transformation are optimized, so that each primary color starts to shine from the first-level dimming, and the method is accurate and controllable, and therefore the technical problems that the color of the dimming color mixing of a user is lack of color and the color of the user is changed in a low-light state are solved.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the application.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a flowchart of a dimming lamp color non-shift control method according to an embodiment of the present application;

FIG. 2 is a graph plotting dimming level versus lumen for original lumen data TAB _ original _ i;

FIG. 3 is a graph of the primary colors after normalization;

FIG. 4 is a graph plotted according to the correction coefficient TAB _ coefficient _ i;

FIG. 5 is a linear plot after introducing a correction factor;

FIG. 6 is a PWM compliance gamma curve profile;

FIG. 7 is a schematic diagram of an optimized gamma curve;

FIG. 8 is a diagram illustrating a hardware configuration of an electronic device according to an embodiment of the present application;

FIG. 9 is a current versus lumen plot for a prior art LED light source.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with one or more embodiments of the present specification. Rather, they are merely examples of apparatus and methods consistent with certain aspects of one or more embodiments of the specification, as detailed in the claims which follow.

It should be noted that: in other embodiments, the steps of the corresponding methods are not necessarily performed in the order shown and described in this specification. In some other embodiments, the methods may include more or fewer steps than those described herein. Moreover, a single step described in this specification may be broken down into multiple steps in other embodiments; multiple steps described in this specification may be combined into a single step in other embodiments.

At present, color drift is influenced by multiple factors, and firstly, the relation characteristic between the current and the lumen of the LED light source in the prior art is nonlinear; second, the drive circuit device responds to the input PWM and the output current is nonlinear. These two points result in different non-linearity of each primary color, so when the color is adjusted based on linear PWM, color mixing may cause color drift.

Based on this, the present invention solves the problems of the prior art based on the way to calculate the correction coefficients and optimize the gamma curve.

Example one

The application aims to provide a dimming lamp color non-deviation control method, the non-linear problem is corrected through the correction coefficients corresponding one by one, the input and output linear positive correlation is achieved, the accuracy is controllable, and therefore the technical problem of color drift of dimming and color mixing of a user is solved. By optimizing the correction coefficient and optimizing the transformed gamma curve, each primary color starts to shine from the first-stage dimming, and is accurate and controllable, so that the technical problems of color shortage and color change of user dimming and color mixing in a low-light state are solved.

Specifically, an embodiment of the present application provides a dimming lamp color non-shift control method, specifically, with reference to fig. 1, the method includes:

when the dimming lamp works in a steady state, setting the PWM output of the dimming lamp to obey linear distribution, and measuring the corresponding original absolute lumen value of each primary color of the dimming lamp under each level of dimming;

in this embodiment, a certain 3-primary-color RGB (red, green, blue) original lamp (as one of dimming lamps, or four-primary-color or five-primary-color, etc.) is placed in a black room, aging is performed for 1 hour to keep a temperature system (a device for aging test commonly used in the art) in a steady state, so that the operating characteristics of the device are in a steady state, PWM output is set to comply with linear distribution, and then the corresponding absolute lumen value L of each primary color under 0-N-level dimming is measured, and recorded as:

TAB_original _{_i} ={L ₀ ,L ₁ ,L ₂ ,… ,L _n }；

wherein the subscript i of the full set TAB _ original indicates the ith primary (in this case, i is 1-3 for RGB, the same applies below); the subscript N of the subset is 0-N, N denoting the highest dimming level (same below), typically N =99 or 255 or 65535, preferably N =255 (same below) and 0 denoting the 0 th level, which is the off (not lit) state.

In this embodiment, as shown in fig. 2, a graph of dimming level versus lumen is plotted for the collected raw lumen data TAB _ original _ i.

S10, normalizing original lumen data and dimming levels formed by collecting original absolute lumen values through linear transformation to obtain a linear trajectory diagram of each primary color in a two-dimensional coordinate system, as shown in FIG. 3;

calculating the abscissa and the ordinate of each dimming grade of each primary color in a [0,1] interval according to the maximum lumen and the minimum lumen of each primary color in the original lumen data to obtain a linear locus diagram of each primary color in a two-dimensional coordinate system; the two-dimensional coordinate system takes the dimming grade as an abscissa and takes the lumen value as an ordinate;

in this embodiment, the original lumen data TAB _ original is processed _{_i} And the dimming level n is subjected to a normalization process, so that the result falls to [0,1]Intervals, written as: TAB _ normalization _{_i} ={ L' ₀ ,L' ₁ ,L' ₂ ,…,L' _n The ordinate conversion function is as follows:

wherein max is the maximum value of the sample data (the original lumen data collected in step S00), and min is the minimum value of the sample data;

the normalized abscissa transfer function is as follows:

as can be seen in fig. 3, the 3 primary colors have poor linearity and are inconsistent. If PWM is input according to linear color matching, the output color mixing is necessarily different from the target, which causes color drift, and therefore, a correction coefficient needs to be calculated.

in the present embodiment, the correction coefficient is denoted as TAB _ coeffient _{_i} ={C ₀ ,C ₁ ,C ₂ ,…,C _n The calculation method is as follows:

the graph plotted by the correction coefficient is shown in fig. 4, and it can be seen that the linearity of the device is poor and sawtooth fluctuation occurs at low brightness.

S30, outputting a correction coefficient corresponding to each primary color multiplied by the linear distribution according to PWM, and controlling the dimming lamp to emit light, namely PWM = TAB _ coefficient multiplied by G (x);

in this embodiment, the correction coefficient TAB _ coefficient _ i is sent to and stored in the dimming lamp, and when the correction coefficient TAB _ coefficient _ i is applied, the original nonlinear characteristic can be corrected to be linear by multiplying the output linear PWM by the corresponding correction coefficient. The effect of fig. 2 at this time becomes the effect of fig. 5. It can be seen that the response of the 3 primary colors to the dimming level is now linear. At this time, the output lumens can be responded linearly by linearly adjusting the dimming level at the input end, so that the color mixing is accurate and the color drift does not occur any more.

The LEDs of different primary colors will not start to light at the same threshold current, as shown in fig. 2, and will not light near the origin below the threshold current. As shown in fig. 2, when RGB is dimmed from level 0, the black paint is not emitted during a period, and then B, G, R sequentially start emitting light, and the mixed light is discolored during the period, and the color shift is particularly serious. Ideally it is based on linear PWM dimming, but the human eye does not have a simple linear relationship between the perception of brightness and the physical power, but a relationship that is a power function with an exponent of typically 2.2, called the gamma value, i.e. a power function with typically y = x ^{2 .2} (x is more than or equal to 0 and less than or equal to 1). In prior art dimming, PWM applies this raw gamma curve.

At present, when a user inputs a dimming level n, the control module outputs a corresponding PWM to the light source driving module, so as to output a corresponding current to the light source and emit light of a corresponding lumen. The present PWM follows a gamma curve profile, as shown in FIG. 6. It can be seen that since in step S00, a linear PWM output is used when data is collected, the curve of fig. 2 is obtained, and no light is emitted below the threshold current. As shown in fig. 6, when the PWM output used follows a gamma curve profile, the PWM output will be lower at low light, resulting in a longer segment of low light adjustment that will not shine, resulting in problems of color loss and discoloration at low light conditions.

In order to solve the technical problem that the dimming and color mixing of the user generates color shortage and color change in a low-brightness state, the method further comprises the following steps:

in this embodiment, the color-adjustable lamp is placed in a black room, the dimming level of each primary color is adjusted from 0, and the dimming level corresponding to the critical lightening time is recorded as n _{0_i} E.g. measuring n _{0_R} =23，n _{0_G} =16，n _{0_B} =13. And records the PWM frequency f set during the test ₀ E.g. is f ₀ =2.4k Hz。

wherein the opening size = 1-elevated value; each primary color does not shine at the zero-level dimming level;

as shown in fig. 2, in N =255 levels of dimming, the red light needs to be adjusted to about 23 levels (N =255 levels of dimming) _{0_R} = 23) is lit. To solve this technical problem, the technical solution used is to transform the gamma curve so that it reaches the threshold current at the first stage and starts to light.

Since the prior art gamma curve is typically y = x ^{2 .2} (x is 0. Ltoreq. X.ltoreq.1) and the index may be 2.0, 2.2, 2.4.

Optimizing according to the existing gamma curve, wherein the optimized gamma curve G (X) is as follows:

(ii) a Wherein x is the current dimming level set by the user divided by the highest dimming level of the dimming lamp (x = N/N, N is the current dimming level set by the user, N is the highest dimming level of the lamp), b is the elevation value, 1-b is the opening size (i.e. the opening size is converted to 1-b times of the original size), and 2.2 is the gamma value (in the prior art, 2.0,2.4, etc.);

obviously, the optimized gamma curve and the original gamma curve both constantly pass through a point (0,0) and a point (1,1).

Wherein the elevation value b = f/f ₀ *(n ₀ /N) ^2.2 ；

Wherein f is the PWM frequency set by the current user, and is 24k Hz; f. of ₀ For testing the PWM frequency, 2.4k Hz is taken; n is ₀ Respectively taking n for the corresponding dimming grade of each primary color during critical lightening _{0_R} =23，n _{0_G} =16，n _{0_B} =13; n is the maximum dimming level of each primary color, and is 255;2.2 is gamma value (prior art, 2.0,2.4, etc.);

thus, b can be calculated _{_R} =0.0519；b _{_G} =0.0227；b _{_B} =0.0134; thus, the optimized gamma curve effect is shown in FIG. 7. As can be seen in fig. 7, the dashed line is the prior art gamma curve (original gamma curve), and the solid line is the optimized gamma curve of the present application. Obviously, the gamma curve of this application, the terminal point is unchangeable, and the starting point is raised to the threshold value of shining accurately for just shine from first level dimming.

Based on steps S00-S50, the red light R starts emitting light at the 23 rd level, i.e. the 1 st to 22 nd levels do not emit light, see FIG. 2, i.e. the lumen value L ₁ To L ₂₂ 0 to calculate the correction coefficient C of the red light R ₁ To C ₂₂ Also 0, see fig. 4. A correction factor of 0 results in a PWM output of 0 for stages 1 to 22, the dimming lamp not being lit. Therefore, the current problems of non-lightening and non-synchronization of the primary colors in low brightness still exist, and the problem of global color cast cannot be solved.

In order to solve the global color cast problem, the method further comprises the following steps:

in this embodiment, in order to make C ₂₂ To C ₂₃ Smooth transition, correcting the coefficient C ₁ To C ₂₂ Assigned a value of C ₂₃ 。

For correction coefficient TAB _ coefficient _{_i} ={C ₀ ,C ₁ ,C ₂ ,…,C _n And (5) further optimizing, wherein the general formula is as follows:

wherein n is ₀ Is the dimming level at critical lightening of each primary color, L' _n Normalized lumen data for the nth order obtained in step S10. The remaining parameters are in accordance with the parameter meanings of the preceding formula.

After the correction coefficient TAB _ coeffient is optimized, it can be known from PWM = TAB _ coeffient × G (x) that the optimized elevated gamma curve G (x) is further multiplied by a coefficient TAB _ coeffient smaller than 1, resulting in the output PWM being depressed again. I.e. coefficient C of e.g. red light R ₁ =C ₂₃ <1, coefficient C ₁ Multiplying by the gamma curve G (x) will lower the boost value b as in step S50, resulting in dimming that is not illuminated at the first level.

Therefore, the solution to this problem is to continue to raise the threshold b such that b' = b/C ₂₃ And is free from the influence of the correction coefficient.

And S70, continuously increasing the rising value and the opening size of the gamma curve so as to enable the primary colors to keep uniform dimming level from the first level, namely, to shine.

In this embodiment, the further optimization of the gamma curve results in the following formula:

wherein b' is obtained by optimizing the elevation threshold b, and the optimization formula is as follows:

wherein, C _n0 Indicating the correction factor when each primary color is critically illuminated.

In the above example, to get the red coefficient from C ₂₂ To C ₂₃ Smooth transition, correcting the coefficient C ₁ To C ₂₂ Assigned a value of C ₂₃ . I.e. C _n0 It can also be understood as a correction coefficient at level 1, i.e., b' = b/C ₁ . In general terms, level 0 is now not bright, raising level 1 (and later) so as not to be covered by the factor C ₁ And (5) pressing down.

Therefore, the gamma curve and the correction coefficient after further optimization are written into the dimming lamp, so that when a user dims each primary color from 0 to 255 levels, the 0 th level is that the lamp is turned off, the 1 st level is that 3 primary colors RGB start to be lightened, the 255 th level primary colors reach the lightest level, and the middle change process is in linear transition, so that the technical effect that color drift cannot be generated by dimming and color mixing is achieved.

Example two

Based on the same conception, the application also provides a dimming lamp color non-deviation control device, which comprises:

the acquisition module is used for setting the PWM output of the dimming lamp to obey linear distribution and measuring the corresponding original absolute lumen value of each primary color of the dimming lamp under each level of dimming; the device is used for acquiring the corresponding dimming grade of each primary color of the dimming lamp when the primary color shines in a critical manner, and recording the set PWM frequency at the moment as the test PWM frequency;

the control module is used for outputting a correction coefficient corresponding to each primary color multiplied by the linear distribution obeyed by the PWM to control the dimming lamp to emit light; the correction coefficients are used for adjusting the dimming grade before critical lightening in each primary color of the dimming lamp to the dimming grade during the critical lightening; the method is used for continuously increasing the rising value and the opening size of the gamma curve so that the primary colors keep uniform and shine from the first dimming level.

EXAMPLE III

The present embodiment also provides an electronic device, referring to fig. 8, comprising a memory 404 and a processor 402, wherein the memory 404 stores a computer program, and the processor 402 is configured to execute the computer program to perform the steps in any of the above method embodiments.

Specifically, the processor 402 may include a Central Processing Unit (CPU), or A Specific Integrated Circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

Memory 404 may include, among other things, mass storage 404 for data or instructions. By way of example, and not limitation, memory 404 may include a hard disk drive (hard disk drive, HDD for short), a floppy disk drive, a solid state drive (SSD for short), flash memory, an optical disk, a magneto-optical disk, tape, or a Universal Serial Bus (USB) drive or a combination of two or more of these. Memory 404 may include removable or non-removable (or fixed) media, where appropriate. The memory 404 may be internal or external to the data processing apparatus, where appropriate. In a particular embodiment, the memory 404 is a Non-Volatile (Non-Volatile) memory. In particular embodiments, memory 404 includes Read-only memory (ROM) and Random Access Memory (RAM). The ROM may be mask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), electrically rewritable ROM (EAROM), or FLASH memory (FLASH), or a combination of two or more of these, where appropriate. The RAM may be a static random-access memory (SRAM) or a dynamic random-access memory (DRAM), where the DRAM may be a fast page mode dynamic random-access memory 404 (FPMDRAM), an extended data output dynamic random-access memory (EDODRAM), a synchronous dynamic random-access memory (SDRAM), or the like.

Memory 404 may be used to store or cache various data files needed for processing and/or communication purposes, as well as possibly computer program instructions executed by processor 402.

The processor 402 reads and executes the computer program instructions stored in the memory 404 to implement any one of the dimming lamp color non-shift control methods in the above-described embodiments.

Optionally, the electronic apparatus may further include a transmission device 406 and an input/output device 408, where the transmission device 406 is connected to the processor 402, and the input/output device 408 is connected to the processor 402.

The transmitting device 406 may be used to receive or transmit data via a network. Specific examples of the network described above may include wired or wireless networks provided by communication providers of the electronic devices. In one example, the transmission device includes a Network adapter (NIC) that can be connected to other Network devices through a base station to communicate with the internet. In one example, the transmitting device 406 may be a Radio Frequency (RF) module, which is used to communicate with the internet in a wireless manner.

The input-output device 408 is used to input or output information. In the present embodiment, the input information may be a dimming level, a PWM frequency is set, and the like, and the output information may be a corresponding color, and the like.

Example four

The present embodiment also provides a readable storage medium having stored therein a computer program including program code for controlling a process to execute a process including the dimming lamp color non-shift control method according to the first embodiment.

It should be noted that, for specific examples in this embodiment, reference may be made to examples described in the foregoing embodiments and optional implementations, and details of this embodiment are not described herein again.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

Embodiments of the invention may be implemented by computer software executable by a data processor of the mobile device, such as in a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets and/or macros can be stored in any device-readable data storage medium and they include program instructions for performing particular tasks. The computer program product may include one or more computer-executable components configured to perform embodiments when the program is run. The one or more computer-executable components may be at least one software code or a portion thereof. Further in this regard it should be noted that any block of the logic flow as in the figures may represent a program step, or an interconnected logic circuit, block and function, or a combination of a program step and a logic circuit, block and function. The software may be stored on physical media such as memory chips or memory blocks implemented within the processor, magnetic media such as hard or floppy disks, and optical media such as, for example, DVDs and data variants thereof, CDs. The physical medium is a non-transitory medium.

It should be understood by those skilled in the art that various features of the above embodiments can be combined arbitrarily, and for the sake of brevity, all possible combinations of the features in the above embodiments are not described, but should be considered as within the scope of the present disclosure as long as there is no contradiction between the combinations of the features.

The above examples are merely illustrative of several embodiments of the present application, and the description is more specific and detailed, but not to be construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for controlling color non-shift of a dimming lamp is characterized by comprising the following steps:

s00, setting the PWM output of a dimming lamp to obey linear distribution, and measuring the corresponding original absolute lumen value of each primary color of the dimming lamp under each level of dimming;

s10, normalizing original lumen data and dimming levels formed by collecting the original absolute lumen values through linear transformation to obtain a linear trajectory graph of each primary color in a two-dimensional coordinate system;

and S30, multiplying the output linear PWM by a correction coefficient corresponding to each primary color so as to control the dimming lamp to emit light.

2. The method for controlling color shift of a dimming lamp as defined in claim 1, further comprising the step of optimizing a gamma curve, specifically:

s50, calculating a raising value and an opening size of a gamma curve based on a dimming grade corresponding to each primary color during critical lightening, a dimming grade currently set by a user, a test PWM frequency, a PWM frequency set by the current user, the highest dimming grade of the dimming lamp and a current gamma value, and optimizing an original gamma curve according to the raising value and the opening size to ensure that each primary color of the dimming lamp is lightened from a first-level dimming grade;

3. The method for controlling color shift of a dimming lamp as claimed in claim 2, further comprising a double optimization step, specifically:

s60, adjusting the correction coefficients of the dimming grade of the dimming lamp before critical lightening in each primary color to the correction coefficients of the dimming grade during critical lightening;

4. The method as claimed in claim 1, wherein in step S00, when the dimming lamp is in steady operation, the PWM output of the dimming lamp is set to follow a linear distribution, and the original absolute lumen value of each primary color of the dimming lamp is measured under each level of dimming.

5. The method as claimed in claim 1, wherein in step S10, according to the maximum lumen and the minimum lumen of each primary color in the original lumen data, the abscissa and the ordinate of each primary color in the interval of [0,1] for each dimming level are calculated to obtain the linear locus diagram of each primary color in the two-dimensional coordinate system.

6. The method as claimed in claim 2, wherein in step S50, the optimized gamma curve G (X) is:

(ii) a Wherein x is the current dimming level set by the user divided by the highest dimming level of the dimming lamp, b is a raising value, 1-b is the opening size, and 2.2 is a gamma value.

7. The method as claimed in claim 6, wherein in step S50, the raising value b = f/f ₀ *(n ₀ /N) ^2.2 ；

8. A dimming lamp color non-deviation control device is characterized by comprising:

the calculation module is used for normalizing original lumen data and dimming grade formed by collecting original absolute lumen values through linear transformation to obtain a linear locus diagram of each primary color in a two-dimensional coordinate system; the two-dimensional coordinate system takes the dimming grade as an abscissa and takes the lumen value as an ordinate; the correction coefficient calculation module is used for calculating a correction coefficient corresponding to each primary color based on the abscissa and the ordinate of each primary color under each level of dimming; the method comprises the steps that a lifting numerical value and an opening size of a gamma curve are calculated based on a dimming grade corresponding to each primary color during critical lightening, a dimming grade currently set by a user, a PWM frequency tested, a PWM frequency set by the current user, the highest dimming grade of a dimming lamp and a current gamma value, and the original gamma curve is optimized according to the lifting numerical value and the opening size, so that each primary color of the dimming lamp can be lightened from a first-level dimming grade; wherein the opening size = 1-elevated value; each primary color does not shine at the zero-level dimming level;

the control module is used for multiplying the output linear PWM by the correction coefficient corresponding to each primary color so as to control the dimming lamp to emit light; the correction coefficients are used for adjusting the dimming grade before critical lightening in each primary color of the dimming lamp to the dimming grade during the critical lightening; the method is used for continuously increasing the rising value and the opening size of the gamma curve so that the primary colors keep uniform and shine from the first dimming level.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to perform the dimming lamp color shift prevention control method according to any one of claims 1 to 7.

10. A readable storage medium, characterized in that a computer program is stored therein, the computer program comprising program code for controlling a process to execute a process, the process comprising the dimming lamp color shift-free control method according to any one of claims 1 to 7.