CN116453474B

CN116453474B - Brightness adjusting method and device for backlight module

Info

Publication number: CN116453474B
Application number: CN202310449948.4A
Authority: CN
Inventors: 梅洪格; 冉培培; 路永全; 林荣镇; 严丞辉
Original assignee: Beijing Xianxin Technology Co ltd
Current assignee: Beijing Xianxin Technology Co ltd
Priority date: 2023-04-24
Filing date: 2023-04-24
Publication date: 2023-12-12
Anticipated expiration: 2043-04-24
Also published as: CN116453474A

Abstract

The embodiment of the disclosure discloses a brightness adjusting method and device of a backlight module, which are used for acquiring brightness data corresponding to each light-emitting area; and controlling the actual output current value corresponding to each light-emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light-emitting area. The high-precision low-flicker backlight brightness adjusting function with gray scale display capability is realized by combining and adjusting the output current and the duty ratio of the pulse width modulation signal.

Description

Brightness adjusting method and device for backlight module

Technical Field

The disclosure relates to the technical field of display, and in particular relates to a brightness adjusting method and device of a backlight module.

Background

With the development of display technology, display devices are important components of many electronic devices, for example: a liquid crystal display device (Liquid Crystal Display, LCD). The LCD is generally composed of a liquid crystal display panel and a backlight module. The backlight module is arranged below the liquid crystal display panel and is used for providing a backlight source for the liquid crystal display panel.

Disclosure of Invention

The brightness adjusting method and device of the backlight module provided by the embodiment of the disclosure are used for improving the display effect.

In a first aspect, an embodiment of the present disclosure provides a method for adjusting brightness of a backlight module, where the backlight module includes a plurality of light emitting areas;

the brightness adjustment method comprises the following steps:

acquiring brightness data corresponding to each light-emitting area; the brightness data is a signal carrying an output current value;

and controlling the actual output current value corresponding to each light-emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light-emitting area.

In some possible embodiments, the luminance data is a K-bit digital signal carrying an output current value;

the controlling the actual output current value corresponding to each light emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light emitting area comprises the following steps:

according to the brightness data and 2 corresponding to each light-emitting area ^N Sum of output current data 2 ^M The duty ratio data relationship is used for controlling the actual output current value corresponding to each light-emitting area; n, M is a positive integer, n+m=k.

In some possible embodiments, the method of 2 ^N The output current data relationships include: 2 ^N Setting level of current, 2 ^N Set current value 2 ^N One-to-one correspondence between the output voltage values of 2 ^M The individual duty cycle data relationships include: 2 ^M Setting level of duty ratio, 2 ^M Individual duty cycle current adjustment values and 2 ^M One-to-one correspondence of the set duty cycles;

the brightness data corresponding to each luminous area is 2 ^N Sum of output current data 2 ^M And controlling the actual output current value corresponding to each light-emitting area according to the duty ratio data relation, wherein the actual output current value comprises the following components:

according to the brightness data corresponding to each light-emitting area, the brightness data is 2 ^N Data relationship of the output currents and said 2 ^M Determining a target output voltage value and a target duty ratio of a pulse width modulation signal corresponding to each light emitting area according to the duty ratio data relation;

generating a pulse width modulation signal corresponding to each light emitting area according to the target output voltage value and the target duty ratio corresponding to each light emitting area, outputting the generated pulse width modulation signal to the corresponding light emitting area, and controlling the actual output current value corresponding to each light emitting area.

In some possible embodiments, the step of forming a pattern according to each of the steps Luminance data corresponding to the light emitting region, 2 ^N Data relationship of the output currents and said 2 ^M The duty cycle data relation, determining the target output voltage value and the target duty cycle of the pulse width modulation signal corresponding to each light emitting area, comprises:

determining an output current value corresponding to each light-emitting area according to the brightness data corresponding to each light-emitting area;

according to the output current value and the 2 corresponding to each light-emitting area ^N Determining the target output voltage value corresponding to each light emitting region according to the output current data relationship, and determining the target output voltage value corresponding to each light emitting region according to the output current value and the target output voltage value 2 ^M And determining the target duty ratio corresponding to each light emitting area according to the duty ratio data relation.

In some possible embodiments, the method of 2 ^N The output current data relationships include: 2 ^N Setting level of current, 2 ^N Set current value 2 ^N One-to-one correspondence between the output voltage values;

said output current value and said 2 corresponding to each of said light emitting regions ^N Determining the output voltage value corresponding to each light emitting region according to the output current data relation, including:

The following operations are performed for the output current value corresponding to any one of the light emitting regions:

upon determining that the output current value is at said 2 ^N When two adjacent set current values in the set current values are used, determining current set grades corresponding to the two adjacent set current values, and determining target output voltage values of low level and high level of the pulse width modulation signal according to the output voltage values corresponding to the two determined current set grades;

at the time of determining the output current value and 2 ^N When any of the set current values is the same, determining a current setting level corresponding to the same set current value as the output current value, and according toAnd determining the output voltage value corresponding to the determined current setting grade, and determining the target output voltage values of the low level and the high level of the pulse width modulation signal.

In some possible embodiments, the method of 2 ^N In the output current data relationship, the current setting level is increased, and the output voltage value is increased;

the determining the target output voltage values of the low level and the high level of the pulse width modulation signal according to the determined output voltage values corresponding to the two current setting levels comprises the following steps:

And determining the determined output voltage value corresponding to the higher current setting level of the two current setting levels as a high-level target output voltage value of the pulse width modulation signal, and determining the determined output voltage value corresponding to the lower current setting level of the two current setting levels as a low-level target output voltage value of the pulse width modulation signal.

In some possible embodiments, the method of 2 ^N In the output current data relationship, the current setting level is increased, and the output voltage value is reduced;

and determining the determined output voltage value corresponding to the higher current setting level of the two current setting levels as a low-level target output voltage value of the pulse width modulation signal, and determining the determined output voltage value corresponding to the lower current setting level of the two current setting levels as a high-level target output voltage value of the pulse width modulation signal.

In some possible embodiments, the output current value corresponding to each of the light emitting regions and the 2 ^N Determining the output voltage value corresponding to each light emitting region according to the output current data relation, including:

upon determining that the output current value is at said 2 ^N When the output voltage value of one level of the pulse width modulation signal is unchanged between two adjacent set current values, determining a current set grade corresponding to a set current value which is larger or smaller than the output current value in the two adjacent set current values, and determining a target output voltage value of the other level of the pulse width modulation signal according to the determined output voltage value corresponding to the current set grade;

at the time of determining the output current value and 2 ^N When any one of the set current values is the same, determining a current set level corresponding to the set current value which is the same as the output current value, and determining a target output voltage value of the low level and the high level of the pulse width modulation signal according to the determined output voltage value corresponding to the current set level.

In some possible embodiments, the fixing the output voltage value of one level of the pwm signal, determining a current setting level corresponding to a set current value greater than or less than the output current value of the two adjacent set current values, and determining the target output voltage value of the other level of the pwm signal according to the determined output voltage value corresponding to the current setting level includes:

Fixing the high-level output voltage value of the pulse width modulation signal, and determining the determined output voltage value corresponding to the current setting level as the low-level target output voltage value of the pulse width modulation signal; or,

and fixing the low-level output voltage value of the pulse width modulation signal, and determining the determined output voltage value corresponding to the current setting level as the high-level target output voltage value of the pulse width modulation signal.

In some possible embodiments, the method of 2 ^N The current setting in the output current data relationshipA step-up, the output voltage value being increased; or,

said 2 ^N In the output current data relationship, the current setting level increases and the output voltage value decreases.

In some possible embodiments, the method of 2 ^M The individual duty cycle data relationships include: 2 ^M Setting level of duty ratio, 2 ^M Individual duty cycle current adjustment values and 2 ^M One-to-one correspondence of the set duty cycles;

said output current value and said 2 corresponding to each of said light emitting regions ^M The determining the target duty ratio corresponding to each light emitting area according to the duty ratio data relation comprises the following steps: determining a fraction part in the output current value corresponding to each light emitting area, and executing the following operations for any one fraction part:

Upon determining that the fractional portion is at said 2 ^M When two adjacent duty cycle current regulating values are between, determining duty cycle setting grades corresponding to the duty cycle current regulating values of which the duty cycle current regulating values are smaller than or larger than the decimal part in the two adjacent duty cycle current regulating values, and determining the setting duty cycle corresponding to the duty cycle setting grades as the target duty cycle;

upon determining the fractional portion with the 2 ^M And when any one of the duty cycle current adjustment values is the same, determining a duty cycle setting level corresponding to the duty cycle current adjustment value which is the same as the decimal part, and determining the determined setting duty cycle corresponding to the duty cycle setting level as the target duty cycle.

In some possible embodiments, the 2 is established ^N A plurality of output current data relationships comprising:

determination 2 ^N Setting the current level, dividing the maximum output current value by taking the first fixed interval current value as an interval step length to form 2 from 0 to the end of the maximum output current value ^N Setting current values;

said 2 to be determined ^N A current setting level of 2 ^N Each set current value is 2 preset ^N The output voltage values are in one-to-one correspondence to establish the voltage value 2 ^N And output current data relationships.

In some possible embodiments, the 2 is established ^M A duty cycle data relationship comprising:

determination 2 ^M Setting the duty ratio to a level, dividing the first constant interval current value by taking the second constant interval current value as an interval step length to form 2 from 0 to the end of the maximum duty ratio current adjustment value ^M A duty cycle current regulation value, and, at 1/2 ^M Dividing 1 for interval step length to form 2 from 0 to maximum duty cycle ^M Setting duty cycle; the maximum duty cycle current adjustment value is the difference between the first fixed interval current value and the second fixed interval current value; the maximum duty cycle is 1-1/2 ^M ；

Said 2 to be determined ^M Duty cycle set level, 2 ^M Individual duty cycle current adjustment values and 2 ^M The set duty ratios are in one-to-one correspondence to establish the 2 ^M A duty cycle data relationship.

determination 2 ^M Setting the duty ratio, dividing the set current value which is not smaller than the output current value and closest to the output current value by taking the third fixed interval current value as an interval step length to form 2 from 0 to the end of the maximum duty ratio current adjustment value ^M A duty cycle current regulation value, and, at 1/2 ^M Dividing 1 for interval step length to form 2 from 0 to maximum duty cycle ^M Setting duty cycle; the maximum duty ratio current adjustment value is a difference value between the set current value which is not less than the output current value and is closest to the output current value and the third fixed interval current value; the maximum duty cycle is 1-1/2 ^M ；

In some possible embodiments, the output current value corresponding to each of the light emitting regions and the 2 ^M The determining the target duty ratio corresponding to each light emitting area according to the duty ratio data relation comprises the following steps:

upon determining that the output current value is at said 2 ^M When two adjacent duty cycle current regulating values are between, determining duty cycle setting grades corresponding to the duty cycle current regulating values smaller than or larger than the output current value in the two adjacent duty cycle current regulating values, and determining the setting duty cycle corresponding to the duty cycle setting grades as the target duty cycle;

At the time of determining the output current value and 2 ^M And when any one of the duty cycle current adjustment values is the same, determining a duty cycle setting level corresponding to the duty cycle current adjustment value which is the same as the output current value, and determining the determined setting duty cycle corresponding to the duty cycle setting level as the target duty cycle.

In a second aspect, a driving chip of a backlight module provided by an embodiment of the present disclosure includes a plurality of light emitting areas, where the driving chip is connected to one or more of the light emitting areas;

the driver chip is configured to: acquiring brightness data corresponding to each light-emitting area; the brightness data is a signal carrying an output current value;

In a third aspect, a display device provided in an embodiment of the present disclosure includes: a liquid crystal display panel and a backlight module arranged below the liquid crystal display panel;

the backlight module comprises: a light emitting substrate having a plurality of light emitting regions and a plurality of driving chips connected to one or more of the light emitting regions;

The driving chip is the driving chip of the backlight module.

The embodiment of the disclosure provides a brightness adjusting method and device of a backlight module, which realize high precision and low flicker by adjusting the duty ratio combination of output current and pulse width modulation (Pulse Width Modulation, PWM) signals, and simultaneously have a backlight brightness adjusting function of gray scale display capability.

Drawings

Fig. 1 is a schematic diagram of some structures of a backlight module according to an embodiment of the disclosure;

fig. 2 is a flowchart of a method for adjusting brightness of a backlight module according to an embodiment of the disclosure;

FIG. 3 is a flowchart illustrating a method for adjusting brightness of a backlight module according to an embodiment of the disclosure;

fig. 4 is a flowchart of a brightness adjustment method of a backlight module according to an embodiment of the disclosure;

FIG. 5 is a timing diagram of some signals in an embodiment of the present disclosure;

FIG. 6a is a timing diagram of yet other signals in an embodiment of the present disclosure;

FIG. 6b is a timing diagram of yet other signals in an embodiment of the present disclosure;

FIG. 7a is a timing diagram of yet other signals in an embodiment of the present disclosure;

fig. 7b is a timing diagram of yet other signals in an embodiment of the present disclosure.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. It will be apparent that the described embodiments are some, but not all, of the embodiments of the present disclosure. And embodiments of the disclosure and features of embodiments may be combined with each other without conflict. All other embodiments, which can be made by one of ordinary skill in the art without the need for inventive faculty, are within the scope of the present disclosure, based on the described embodiments of the present disclosure.

Unless defined otherwise, technical or scientific terms used in this disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

It should be noted that the dimensions and shapes of the various figures in the drawings do not reflect true proportions, and are intended to illustrate the present disclosure only. And the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

As shown in fig. 1, the backlight module is provided with a light emitting substrate having a plurality of light emitting areas 110 and a plurality of driving chips 120. The driving chip 120 may be connected to one or more light emitting regions 110 to drive the light emitting regions to emit light.

Illustratively, as shown in fig. 1, the light emitting region 110 includes one or more light emitting units including a plurality of light emitting devices sequentially connected in series. For example, the cathode of a first light emitting device of the plurality of light emitting devices connected in series is connected to the driving output pin of the driving chip, the anode of a last light emitting device is connected to the driving voltage line VE, and the remaining light emitting devices are sequentially connected in series between the anode of the first light emitting device and the cathode of the last light emitting device.

Illustratively, the driver chip may have one or more driver output pins. For example, as shown in fig. 1, the light emitting region 110 includes one light emitting unit, and the driving chip may have 4 driving output pins: OUT0, OUT1, OUT2, OUT3, the driving output pins OUT0, OUT1, OUT2, OUT3 are respectively connected with one light emitting region.

Illustratively, the driver chip also has a ground pin GND, a supply voltage pin VDD, a data input pin DI, and a data output pin DO. The power voltage pin VDD is applied with a positive voltage, the ground pin GND is applied with a ground voltage or a negative voltage, and data is received through the data input pin DI and output through the data output pin DO.

The specific structure of the light emitting device is not limited in the present disclosure. Illustratively, the light emitting device includes, but is not limited to,: light-Emitting Diode (LED), mini Light-Emitting Diode (Mini LED), micro Light-Emitting Diode (Micro LED).

In practical applications, the brightness of the backlight module is controlled by adjusting the driving current of the input light emitting region by combining Local Dimming (LD) technology, so as to improve the display image quality of the liquid crystal display device. Since the brightness of the backlight module needs to follow the display frame, the driving chip is required to have gray scale adjustment capability. However, the conventional driving chip has only a single or a few brightness settings, which cannot meet the requirement of high-precision brightness display, or the duty ratio of the pulse width modulation (Pulse Width Modulation, PWM) signal is adjusted purely, so that the problem of low gray scale flicker and insufficient adjustment precision exists.

Based on the above, the embodiment of the disclosure provides a brightness adjustment method of a backlight module, which realizes high precision, low flicker and a backlight brightness adjustment function with gray scale display capability by adjusting the duty ratio combination of an output current and a PWM signal.

As shown in fig. 2, an embodiment of the present disclosure provides a method for adjusting brightness of a backlight module, including:

S100, acquiring brightness data corresponding to each light-emitting area. The brightness data is a signal carrying an output current value. The luminance data may be a digital signal of K bits (bit) carrying the output current value, or may be an analog signal carrying the output current value, which is not limited herein.

The luminance data is a digital signal carrying K bits (bits) of the output current value.

S200, controlling the actual output current value corresponding to each light-emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light-emitting area, so that the light-emitting areas can emit corresponding brightness by inputting the output current corresponding to the output current value to each light-emitting area.

For example, when the luminance data is a digital signal carrying K bits of the output current value, the luminance data corresponding to each light emitting region may be 2 ^N Sum of output current data 2 ^M And controlling the actual output current value corresponding to each light-emitting area according to the duty ratio data relation. In the embodiment of the disclosure, N is an integer and N is more than or equal to 1, M is an integer and M is more than or equal to 1; n+m=k. This corresponds to an output current data relationship of N bits and a duty cycle data relationship of M bits. Therefore, the N bit current setting and the M bit PWM signal duty ratio setting can be adopted, the output current of the driving chip is controlled by the combination of the N bit current setting and the M bit PWM signal duty ratio setting, the high precision and the low flicker are realized, and the backlight brightness adjusting function with gray scale display capability is realized.

Besides, except for the traditional backlight module, the display device is mainly used for Local Dimming display of the Mini LED backlight module, matching of backlight gray scale display and display screen gray scale display is achieved, contrast ratio of the liquid crystal display device is improved, and display effect is improved.

Illustratively, the steps S100 and S200 may be performed in each display frame, so as to further improve the contrast ratio of the liquid crystal display device and improve the display effect by matching the backlight gray-scale display with the display screen gray-scale display in each display frame.

Illustratively, k=5, then n=2, m=3. Alternatively, k=16 may be set, where n=6, m=10, or n=4, m=12. Of course, the specific numerical values of N, M, K are not limited in the present disclosure, and the above requirements are satisfied in the specific implementation.

In implementations, the output current to the light emitting region may be adjusted by adjusting the PWM signal. The output current value of the input light-emitting areas can be adjusted by combining the voltage of the pulse of the PWM signal and the duty ratio, the actual output current value corresponding to each light-emitting area is controlled, high precision and low flicker are realized, and the backlight brightness adjusting function with gray scale display capability is realized.

Illustratively, as shown in FIG. 3, step S200 is performed based on the luminance data, 2, corresponding to each light-emitting region ^N Sum of output current data 2 ^M The controlling the actual output current value corresponding to each light emitting region according to the duty ratio data relationship may include:

s210, according to the brightness data corresponding to each light-emitting area, 2 ^N Sum of output current data 2 ^M And determining the target output voltage value and the target duty ratio of the pulse width modulation signal corresponding to each light emitting area according to the duty ratio data relation.

Illustratively, 2 ^N The output current data relationships include: 2 ^N Setting level of current, 2 ^N Set current value 2 ^N One-to-one correspondence between the output voltage values. I.e. a current set level, a set current value and an output voltage value corresponding to each other, may be used as an output current data relationship. For example, taking n=2 as an example, there is 2 ² And output current data relationships. The 2 ² The output current data relationships include: 2 ² Setting level of current, 2 ² Set current value 2 ² One-to-one correspondence between the output voltage values. Thus can be according to 2 ^N And determining the target output voltage value of the pulse width modulation signal corresponding to each light emitting area according to the output current data relation.

For example, as shown in Table one, 2 ² The current setting levels are respectively as follows: s1, S2, S3, S4,2 ² The set current values are respectively: i1, I2, I3, I4,2 ² The output voltage values are respectively: v1, V2, V3, V4. Wherein, S1, I1 and V1 correspond to each other as an output current data relationship, and the rest are the same, and are not described herein.

Current setting grade	Setting a current value	Output voltage value
			S1	I1	V1
S2	I2	V2
			S3	I3	V3
S4	I4	V4

List one

In some examples, the backlight module has a peak brightness (i.e. a maximum brightness), the peak brightness current value required by the backlight module when the backlight module is at the peak brightness can be determined according to the peak brightness of the backlight module, the driving chip inputs the peak brightness current value to the light-emitting area, so that the light-emitting area can present the peak brightness, and the maximum output current value output by the driving chip is not less than the peak brightness current value, thereby ensuring the backlightThe module is capable of achieving maximum peak brightness. Based on this, 2 can be established according to the maximum output current value of the driving chip ^N And output current data relationships. This allows the output current data relationship to be correlated to the maximum output current. The present disclosure does not limit specific values of the peak luminance and the maximum output current value, and may be determined according to the needs of practical applications.

Alternatively, 2 is established according to the maximum output current value ^N The process of the output current data relationship may include the steps of: first, determine 2 ^N Setting the current level, dividing the maximum output current value by taking the first fixed interval current value as an interval step length to form 2 from 0 to the end of the maximum output current value ^N The set current value. Thereafter, the determined 2 ^N Setting level of current, 2 ^N Each set current value is 2 preset ^N The output voltage values are in one-to-one correspondence to establish 2 ^N And output current data relationships. Thus dividing the maximum output current value into 2 at a first fixed interval ^N Each set current value corresponds to a current set level, namely 2 ^N A current setting level, and a current setting level corresponding to a preset 2 ^N Output voltage value of 2 ^N Setting level of current, 2 ^N Each set current value is 2 preset ^N The output voltage values are in one-to-one correspondence to form an output current data relationship of N bits.

The specific values of the first fixed interval current values are not limited in this disclosure. For example, the first fixed interval current value may be determined according to a manner of equally dividing the maximum output current value.

For example, taking the 2bit output current data relationship, n=2 as an example, the specific correspondence relationship of the output current data relationship with the first fixed interval of 1mA and 2bit is shown in table two, if the maximum output current value is3 mA.

Current setting grade	Setting a current value	Output voltage value
			S1	0mA	V1
S2	1mA	V2
			S3	2mA	V3
S4	3mA	V4

Watch II

Illustratively, 2 ^M The individual duty cycle data relationships include: 2 ^M Setting level of duty ratio, 2 ^M Individual duty cycle current adjustment values and 2 ^M One-to-one correspondence of the set duty cycles. I.e. a duty cycle set level, a duty cycle current adjustment value and a set duty cycle corresponding to each other, may be used as a duty cycle data relationship. For example, taking m=3 as an example, there is2 ³ A duty cycle data relationship. The 2 ³ The individual duty cycle data relationships include: 2 ³ Setting level of duty ratio, 2 ³ Individual duty cycle current adjustment values and 2 ³ One-to-one correspondence between the set duty cycles. Thus can be according to 2 ^M The data relation of the duty ratio is determinedThe target duty cycle of the pulse width modulated signal corresponding to each light emitting region.

For example, as shown in Table three, 2 ³ The duty cycle setting levels are respectively: x1, X2, X3, X4, X5, X6, X7, X8,2 ³ The duty cycle current adjustment values are respectively: IS1, IS2, IS3, IS4, IS5, IS6, IS7, IS8,2 ³ The set duty ratios are respectively: p1, P2, P3, P4, P5, P6, P7, P8. Wherein, X1, IS1 and P1 correspond to each other as a duty ratio data relationship, and the rest are the same, and are not described herein.

Duty cycle setting level	Duty cycle current regulation value	Setting the duty cycle
			X1	IS1	P1
X2	IS2	P2
			X3	IS3	P3
X4	IS4	P4
			X5	IS5	P5
X6	IS6	P6
			X7	IS7	P7
X8	IS8	P8

Watch III

In some examples, 2 may be established based on the first fixed interval current value ^M A duty cycle data relationship. This may relate the duty cycle data relationship to the first fixed interval current value.

Optionally, establishing 2 based on the first fixed interval current value ^M The process of the individual duty cycle data relationship may include the steps of: first, determine 2 ^M Setting the duty ratio to a level, dividing the first constant interval current value by taking the second constant interval current value as an interval step length to form 2 from 0 to the end of the maximum duty ratio current adjustment value ^M A duty cycle current regulation value, and, at 1/2 ^M Dividing 1 for interval step length to form 2 from 0 to maximum duty cycle ^M Setting duty cycle; the maximum duty cycle current adjustment value is the difference between the first fixed interval current value and the second fixed interval current value; the maximum duty cycle is 1-1/2 ^M . Thereafter, the determined 2 ^M Setting level of duty ratio, 2 ^M Individual duty cycle current adjustment values and 2 ^M The set duty ratios are in one-to-one correspondence to establish 2 ^M A duty cycle data relationship. Thus dividing the first constant interval current value into 2 according to the second constant interval current value ^M Duty cycle currentAnd each duty cycle current regulating value corresponds to one duty cycle setting grade, and each duty cycle setting grade corresponds to one set duty cycle, so that the duty cycle data relationship of M bits is formed.

The specific values of the second fixed interval current values are not limited in this disclosure. For example, the second fixed interval current value may be determined according to a manner of equally dividing the first fixed interval current value.

For example, taking the 3bit duty cycle data relationship, m=3 as an example, the first fixed interval current value is 1mA, the second fixed interval current value is 1/8mA, and the specific correspondence of the 3bit duty cycle data relationship is shown in table four.

Duty cycle setting level	Duty cycle current regulation value	Setting the duty cycle
			X1	0mA	0
X2	1/8mA	1/8
			X3	2/8mA	2/8
X4	3/8mA	3/8
			X5	4/8mA	4/8
X6	5/8mA	5/8
			X7	6/8mA	6/8
X8	7/8mA	7/8

Table four

Illustratively, as shown in FIG. 4, step S210 is performed based on the luminance data corresponding to each light-emitting region, 2 ^N Sum of output current data 2 ^M The determining the target output voltage value and the target duty cycle of the pulse width modulation signal corresponding to each light emitting region may include:

S211, determining an output current value corresponding to each light-emitting area according to the brightness data corresponding to each light-emitting area. Since the luminance data is a K-bit (bit) digital signal carrying an output current value, the K-bit (bit) luminance data corresponding to each light emitting region can be decoded to decode the output current value corresponding to each light emitting region.

S212, according to the output current value and 2 corresponding to each light-emitting area ^N Determining a target output voltage value corresponding to each light emitting region according to the output current data relationship, and determining a target output voltage value corresponding to each light emitting region according to the output current value and 2 ^M And determining a target duty cycle corresponding to each light emitting area according to the duty cycle data relation. Thus according to the decoded output currentValues and 2 above ^N And determining a target output voltage value corresponding to each light-emitting area according to the output current data relationship. And based on the decoded output current value and 2 ^M And determining a target duty ratio corresponding to each light emitting area according to the duty ratio data relation.

In some possible embodiments, the output current value corresponding to each light emitting region is equal to 2 ^N The determining the output voltage value corresponding to each light emitting region may include the following: the following operations are performed for the output current value corresponding to any one light emitting region:

Operation (1): at the moment of determining that the output current value is 2 ^N When two adjacent set current values in the set current values are used, current set grades corresponding to the two adjacent set current values are determined, and target output voltage values of low level and high level of the pulse width modulation signal are determined according to the determined output voltage values corresponding to the two current set grades. For example, taking n=2 and one light emitting region as an example, as shown in table one, if the output current value I0 of the light emitting region is between the set current values I2 and I3, the output voltage values V2 and V3 corresponding to the current set levels S2 and S3 are determined as the target output voltage values of the low level and the high level of the pulse width modulation signal. At this time, the duty ratio of the pwm signal is not equivalent to 100% or 0%, so that it is necessary to continuously determine the duty ratio thereof.

In some examples, 2 ^N In the output current data relationship, the output voltage value may be increased as the current setting level is increased. And determining target output voltage values of low level and high level of the pulse width modulation signal according to the determined output voltage values corresponding to the two current setting levels, comprising: and determining the output voltage value corresponding to the higher current setting level in the two determined current setting levels as a high-level target output voltage value of the pulse width modulation signal, and determining the output voltage value corresponding to the lower current setting level in the two determined current setting levels as a low-level target output voltage value of the pulse width modulation signal. This enables the PWM signal to be output The amplitude of the output waveform (the difference between the voltage value of the high level and the voltage value of the low level) is positively correlated with the output current value carried in the luminance data, and is positively correlated with the actual output current value.

For example, taking n=2 and one light emitting region as an example, as shown in table one and fig. 5, S1 to S4 rise sequentially, I1 to I4 rise sequentially, and V1 to V4 rise sequentially. If the output current value I0 of the light emitting region is between the set current values I1 and I2, the output voltage value V1 corresponding to the current set level S1 is determined as the target output voltage value of the low level of the pwm signal pwm1, and the output voltage value V2 corresponding to the current set level S2 is determined as the target output voltage value of the high level of the pwm signal pwm 1. If the output current value I0 of the light emitting region is between the set current values I2 and I3, the output voltage value V2 corresponding to the current set level S2 is determined as the target output voltage value of the low level of the pwm signal pwm2, and the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage value of the high level of the pwm signal pwm 2. If the output current value I0 of the light emitting region is between the set current values I3 and I4, the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage value of the low level of the pwm signal pwm3, and the output voltage value V4 corresponding to the current set level S4 is determined as the target output voltage value of the high level of the pwm signal pwm 3. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

In still other examples, 2 ^N In the output current data relationship, the current setting level increases and the output voltage value decreases. And determining target output voltage values of low level and high level of the pulse width modulation signal according to the determined output voltage values corresponding to the two current setting levels, comprising: determining the output voltage value corresponding to the higher current setting level of the two determined current setting levels as the target output voltage value of the low level of the pulse width modulation signal, and determining the output voltage value corresponding to the lower current setting level of the two determined current setting levels as the pulseThe high level of the pulse width modulated signal is the target output voltage value. This makes it possible to inversely correlate the amplitude of the output waveform of the PWM signal (the difference between the voltage value of the high level and the voltage value of the low level) with the output current value carried in the luminance data, and also inversely correlate with the actual output current value.

For example, taking n=2 and one light emitting region as an example, as shown in table one, S1, S2, S3, S4 are sequentially increased, I1> I2> I3> I4, and V1 to V4 are sequentially decreased. If the output current value I0 of the light emitting region is between the set current values I2 and I3, the output voltage value V2 corresponding to the current set level S2 is determined as the target output voltage value of the high level of the pwm signal, and the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage value of the low level of the pwm signal. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

Operation (2): at the time of determining the output current value and 2 ^N When any one of the set current values is the same, determining a current set level corresponding to the set current value which is the same as the output current value, and determining a target output voltage value of the low level and the high level of the pulse width modulation signal according to the output voltage value corresponding to the determined current set level. For example, taking n=2 and one light emitting region as an example, as shown in table one, if the output current value I0 of the light emitting region is the same as the set current value I3, the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage values of the low level and the high level of the PWM signal, that is, the output waveform of the PWM signal is a signal with a fixed voltage value, at this time, the duty ratio of the PWM signal is equivalent to 100% or 0%, so that the duty ratio can be no longer determined, and the calculation time is saved. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

In some examples, 2 ^N In the output current data relationship, the output voltage value may be increased as the current setting level is increased. This makes the PWM signal of fixed voltage value bright The output current value carried in the degree data is positively correlated, and is positively correlated with the actual output current value. That is, the larger the actual output current value, the larger the output voltage value corresponding to the corresponding current setting level, that is, the larger the target voltage value corresponding to the output waveform of the PWM signal.

In still other examples, 2 ^N In the output current data relationship, the current setting level increases and the output voltage value decreases. This makes the PWM signal of a fixed voltage value inversely related to the output current value carried in the luminance data and inversely related to the actual output current value. That is, the larger the actual output current value, the smaller the output voltage value corresponding to the corresponding current setting level, that is, the smaller the target voltage value corresponding to the output waveform of the PWM signal.

In still other possible embodiments, the output current value corresponding to each light emitting region is equal to 2 ^N The output current data relationship, determining the output voltage value corresponding to each light emitting region, includes: the following operations are performed for the output current value corresponding to any one light emitting region:

operation (1): at the moment of determining that the output current value is 2 ^N When the output voltage value of one level of the pulse width modulation signal is fixed between two adjacent set current values, the current set level corresponding to the set current value which is larger or smaller than the output current value in the two adjacent set current values is determined, and the target output voltage value of the other level of the pulse width modulation signal is determined according to the output voltage value corresponding to the determined current set level. For example, taking n=2 and one light emitting region as an example, as shown in table one, if the output current value I0 of the light emitting region is between the set current values I2 and I3, the output voltage value of one level of the PWM signal is fixed, the current setting level corresponding to the set current value greater than or less than the output current value I0 out of the set current values I2 and I3 is determined, and the output voltage value corresponding to the determined current setting level is determined as the target output voltage value of the other level of the PWM signal. At this time, the duty ratio of the PWM signal is not equal to 100% or 0%, so It is necessary to continue to determine its duty cycle.

In some examples, 2 ^N In the output current data relationship, the current setting level increases and the output voltage value increases. And, the output voltage value of one level of the pulse width modulation signal is fixed, the current setting grade corresponding to the setting current value which is larger or smaller than the output current value in the two adjacent setting current values is determined, the target output voltage value of the other level of the pulse width modulation signal is determined according to the output voltage value corresponding to the determined current setting grade, and the method comprises the following steps: and fixing the high-level output voltage value of the pulse width modulation signal, and determining the output voltage value corresponding to the determined current setting level as the low-level target output voltage value of the pulse width modulation signal. This makes it possible to inversely correlate the amplitude of the output waveform of the PWM signal (the difference between the voltage value of the high level and the voltage value of the low level) with the output current value carried in the luminance data, and also inversely correlate with the actual output current value.

For example, taking n=2 and one light emitting region and the output voltage value corresponding to the current setting level corresponding to the setting current value larger than the output current value among the adjacent two setting current values as an example, the target output voltage value of the low level of the pwm signal is determined, in combination with table one and fig. 6a, S1, S2, S3, S4 rise in order, I1< I2< I3< I4, V1 to V4 rise in order. If the output current value I0 of the light emitting region is between the set current values I2 and I3, i.e., I2< I0< I3, the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage value of the low level of the pwm signal pwm 3. The high-level output voltage V0 of the pwm signal is fixed (for example, fixed to a voltage different from the output voltages V1 to V4). The other PWM signals PWM1, PWM2, and PWM4 are the same, so that the voltage value of the low level of the output waveform of the PWM signal corresponding to the smaller current setting level is lower, and the voltage difference between the high level and the low level is larger. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

In still other examples, 2 ^N In the output current data relationship, the current setting level increases and the output voltage value decreases. And, the output voltage value of one level of the pulse width modulation signal is fixed, the current setting grade corresponding to the setting current value which is larger or smaller than the output current value in the two adjacent setting current values is determined, the target output voltage value of the other level of the pulse width modulation signal is determined according to the output voltage value corresponding to the determined current setting grade, and the method comprises the following steps: and fixing the high-level output voltage value of the pulse width modulation signal, and determining the output voltage value corresponding to the determined current setting level as the low-level target output voltage value of the pulse width modulation signal. This makes it possible to positively correlate the amplitude of the output waveform of the PWM signal (the difference between the voltage value of the high level and the voltage value of the low level) with the output current value carried in the luminance data, and also positively correlate with the actual output current value.

For example, taking n=2 and one light emitting region and the output voltage value corresponding to the current setting level corresponding to the setting current value larger than the output current value among the adjacent two setting current values as an example, as the target output voltage value of the low level of the pwm signal, as shown in fig. 6b in combination with table one, S1, S2, S3, S4 are sequentially increased, I1> I2> I3> I4, V1 to V4 are sequentially decreased. If the output current value I0 of the light emitting region is between the set current values I2 and I3, i.e., I2> I0> I3, the output voltage value V2 corresponding to the current set level S2 is determined as the target output voltage value of the low level of the pwm signal pwm 2. The high-level output voltage V0 of the pwm signal is fixed (for example, fixed to a voltage different from the output voltages V1 to V4). The other PWM signals PWM1, PWM3, and PWM4 are the same, so that the voltage value of the low level of the output waveform of the PWM signal corresponding to the larger current setting level is lower, and the voltage difference of the high and low levels is larger. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

In some examples, 2 ^N Data relationship of output currentsIn the above, the current setting level increases, and the output voltage value increases. And, the output voltage value of one level of the pulse width modulation signal is fixed, the current setting grade corresponding to the setting current value which is larger or smaller than the output current value in the two adjacent setting current values is determined, the target output voltage value of the other level of the pulse width modulation signal is determined according to the output voltage value corresponding to the determined current setting grade, and the method comprises the following steps: and fixing the low-level output voltage value of the pulse width modulation signal, and determining the output voltage value corresponding to the determined current setting level as the high-level target output voltage value of the pulse width modulation signal. This makes it possible to positively correlate the amplitude of the output waveform of the PWM signal (the difference between the voltage value of the high level and the voltage value of the low level) with the output current value carried in the luminance data, and also positively correlate with the actual output current value.

For example, taking n=2 and one light emitting region and the output voltage value corresponding to the current setting level corresponding to the setting current value larger than the output current value among the adjacent two setting current values as an example, the target output voltage value of the low level of the pwm signal is determined, in combination with table one and fig. 7a, S1, S2, S3, S4 rise in order, I1< I2< I3< I4, V1 to V4 rise in order. If the output current value I0 of the light emitting region is between the set current values I2 and I3, i.e., I2< I0< I3, the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage value of the high level of the pwm signal pwm 3. The low-level output voltage V0' of the pwm signal pwm3 is fixed (for example, fixed to a voltage different from the output voltages V1 to V4). The other PWM signals PWM1, PWM2, and PWM4 are the same, so that the higher the current setting level is, the higher the voltage value of the high level of the output waveform of the PWM signal is, and the larger the voltage difference between the high level and the low level is. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

In still other examples, 2 ^N In the output current data relationship, the current setting level increases and the output voltage value decreases. And is combined withAnd, the output voltage value of one level of the pulse width modulation signal is fixed, and the current setting grade corresponding to the setting current value larger or smaller than the output current value in the two adjacent setting current values is determined, and the target output voltage value of the other level of the pulse width modulation signal is determined according to the determined output voltage value corresponding to the current setting grade, which comprises the following steps: and fixing the low-level output voltage value of the pulse width modulation signal, and determining the output voltage value corresponding to the determined current setting level as the high-level target output voltage value of the pulse width modulation signal. This makes it possible to inversely correlate the amplitude of the output waveform of the PWM signal (the difference between the voltage value of the high level and the voltage value of the low level) with the output current value carried in the luminance data, and also inversely correlate with the actual output current value.

For example, taking n=2 and one light emitting region and the output voltage value corresponding to the current setting level corresponding to the setting current value larger than the output current value among the adjacent two setting current values as an example, the target output voltage value of the low level of the pwm signal is determined, and as shown in fig. 7b, in combination with table one, S1, S2, S3, S4 are sequentially increased, I1> I2> I3> I4, and V1 to V4 are sequentially decreased. If the output current value I0 of the light emitting region is between the set current values I2 and I3, i.e., I2> I0> I3, the output voltage value V2 corresponding to the current set level S2 is determined as the target output voltage value of the high level of the pwm signal pwm 2. The low-level output voltage V0' of the pwm signal is fixed (for example, fixed to a voltage different from the output voltage V1 to V4). The other PWM signals PWM1, PWM3, and PWM4 are the same, so that the voltage difference between the high level and the low level is larger as the voltage value of the high level of the output waveform of the PWM signal is higher as the current setting level is smaller. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

Operation (2): at the time of determining the output current value and 2 ^N When one of the set current values is the same, determining a current set level corresponding to the set current value which is the same as the output current value, andand determining target output voltage values of low level and high level of the pulse width modulation signal according to the determined output voltage values corresponding to the current setting level. For example, taking n=2 and one light emitting region as an example, as shown in table one, if the output current value I0 of the light emitting region is the same as the set current value I3, the output voltage value V3 corresponding to the current set level S3 is determined as the target output voltage values of the low level and the high level of the PWM signal, that is, the output waveform of the PWM signal is a signal with a fixed voltage value, at this time, the duty ratio of the PWM signal is equivalent to 100% or 0%, so that the duty ratio can be no longer determined, and the calculation time is saved. The determination process of the target output voltage values corresponding to the rest of the light emitting areas is the same, and can be analogized in sequence, and the description is omitted here.

In some examples, 2 ^N In the output current data relationship, the output voltage value may be increased as the current setting level is increased. This makes the PWM signal of a fixed voltage value positively correlated with the output current value carried in the luminance data, and also positively correlated with the actual output current value. That is, the larger the actual output current value, the larger the output voltage value corresponding to the corresponding current setting level, that is, the larger the target voltage value corresponding to the output waveform of the PWM signal.

In still other possible embodiments, the output current value corresponding to each light emitting region is equal to 2 ^M The duty cycle data relationship, determining a target duty cycle corresponding to each light emitting region, includes: determining a fraction part in the output current value corresponding to each light emitting region, and performing the following operations for any one fraction part:

operation (1): at the point of determining the decimal part to be 2 ^M And when the duty ratio current regulating value is between two adjacent duty ratio current regulating values, determining the duty ratio setting grade corresponding to the duty ratio current regulating value of the part smaller than the decimal part in the two adjacent duty ratio current regulating values, and determining the setting duty ratio corresponding to the duty ratio setting grade as the target duty ratio. For example, taking m=3 and one light emitting region as an example, as shown in table three, if the fraction IS0 of the output current value I0 of the light emitting region IS between the duty current adjustment values IS4 and IS5, the set duty ratio corresponding to the fraction smaller than the output current value I0 in the duty current adjustment values IS4 and IS5 IS determined as the target duty ratio.

In some examples, 2 ^M In the duty cycle data relationship, the duty cycle current adjustment value may be increased as the duty cycle setting level is increased, and the setting duty cycle may be increased. For example, taking m=3 and one light emitting region as an example, as shown in the combination table three, X1 to X8 rise sequentially, IS1 to IS8 rise sequentially, and the set duty ratios P1 to P8 rise sequentially. If the fraction IS0 of the output current value I0 of the light-emitting region IS between the duty-cycle current adjustment values IS4 and IS5, i.e., IS4<IS0<IS5, the set duty ratio P4 corresponding to the duty ratio set level X4 IS determined as the target duty ratio.

In still other examples, 2 ^M In the duty cycle data relationship, the duty cycle current adjustment value may be decreased as the duty cycle setting level increases, and the setting duty cycle may be decreased. For example, taking m=3 and one light emitting region as an example, as shown in the combination table three, X1 to X8 are sequentially increased, IS1 to IS8 are sequentially decreased, and the set duty ratios P1 to P8 are sequentially decreased. If the fraction IS0 of the output current value I0 of the light-emitting region IS between the duty-cycle current adjustment values IS4 and IS5, i.e., IS4>IS0>IS5, the set duty ratio P5 corresponding to the duty ratio set level X5 IS determined as the target duty ratio.

Operation (2): in determining the decimal part and 2 ^M When any one of the duty cycle current adjustment values is the same, determining a duty cycle setting level corresponding to the duty cycle current adjustment value which is the same as the fractional part, and setting the determined duty cycle setting levelThe corresponding set duty cycle is determined as the target duty cycle. Wherein 2 can be made to ^M In the duty cycle data relationship, the duty cycle current adjustment value may be increased as the duty cycle setting level is increased, and the setting duty cycle may be increased. Alternatively, it may also be 2 ^M In the duty cycle data relationship, the duty cycle current adjustment value may be decreased as the duty cycle setting level increases, and the setting duty cycle may be decreased.

For example, taking m=3 and one light emitting region as an example, as shown in table three, if the fraction part IS0 of the output current value I0 of the light emitting region IS the same as the duty current adjustment value IS5, the set duty P5 corresponding to the duty setting level X5 IS determined as the target duty.

S220, generating a pulse width modulation signal corresponding to each light-emitting area according to the determined target output voltage value and target duty ratio corresponding to each light-emitting area, outputting the generated pulse width modulation signal to the corresponding light-emitting area, and controlling the actual output current value corresponding to each light-emitting area.

As shown in fig. 5 to 7b, for example, a voltage value of a high level and a low level of the PWM may be obtained according to the determined target output voltage value, a duty cycle of the PWM may be obtained according to the determined target duty cycle, and a PWM signal capable of adjusting and controlling an actual output current value corresponding to the light emitting region may be generated according to the two data. And outputting the generated PWM signals to the corresponding light-emitting areas, and regulating and controlling the actual output current values input to the light-emitting areas, so that the brightness of the light-emitting areas is controlled.

The present disclosure is described in detail below with reference to specific embodiments. It should be noted that, in this embodiment, the disclosure is better explained, but the disclosure is not limited thereto. The brightness adjustment method provided by the embodiment of the disclosure may include the following:

taking the output current data relationship of 2 bits, n=2 as an example, for example, the maximum output current value is 3mA, the first fixed interval is 1mA, and 2 from 0 to 3mA is formed ² Setting current value to 2 ² Setting level of current, 2 ² Each set current value and presetFixed 2 ² The output voltage values are in one-to-one correspondence, a 2bit output current data relationship is established, and the specific correspondence is shown in a table II.

The output current value is 1.5mA according to the brightness data, the output current value is 1.5mA and the output voltage value is S1 to S4 are sequentially increased, the output voltage value V3 corresponding to the current setting level S3 is taken as a high-level target voltage value of the PWM signal, and the output voltage value V2 corresponding to the current setting level S2 is taken as a low-level target voltage value of the PWM signal when the output current value is 1.5mA and the output current value is S1 to S4 are sequentially increased, and the output voltage value V1 to V4 are sequentially increased.

Taking the data relationship of 3bit duty cycle, and taking M=3 as an example for explanation, the first fixed interval current value is 1mA, the second fixed interval current value is 1/8mA, and 2 from 0 to 7/8mA is formed ³ A duty cycle current adjustment value and form 2 from 0 to 7/8 ³ Setting duty ratio to 2 ³ Setting level of duty ratio, 2 ³ Individual duty cycle current adjustment values and 2 ³ The set duty ratios are in one-to-one correspondence, a 3bit duty ratio data relationship is established, and the specific corresponding relationship is shown in a table IV.

The output current value was 1.5mA based on the luminance data, and the fractional part thereof was 0.5mA, i.e., 4/8mA. According to the fractional part 1/8mA and table four, X1 to X8 rise in order, the set duty ratio 4/8 corresponding to X5 can be determined as the target duty ratio of the PWM signal.

According to the determined low-level target voltage value V2 of the PWM signal, the high-level target voltage value V3 of the PWM signal and the target duty ratio of 4/8, a PWM signal PWM2 can be generated, the generated PWM signal PWM2 is output to a corresponding light-emitting area, and the actual output current value input to the light-emitting area is regulated and controlled, so that the brightness of the light-emitting area is controlled.

Embodiments of the present disclosure also provide for establishing the 2 ^M A process of duty cycle data relationship. In still other examples, 2 may also be established based on a set current value that is not less than and closest to the output current value ^M A duty cycle data relationship. This allows the duty cycle data relationship to be related to a set value determined from the output current valueThe flow values are correlated.

Optionally, 2 is established according to a set current value which is not smaller than and closest to the output current value ^M The process of the individual duty cycle data relationship may include the steps of: first, determine 2 ^M Setting the duty ratio, dividing the set current value which is not smaller than the output current value and is closest to the output current value by taking the third fixed interval current value as an interval step length to form 2 from 0 to the end of the maximum duty ratio current regulating value ^M A duty cycle current regulation value, and, at 1/2 ^M Dividing 1 for interval step length to form 2 from 0 to maximum duty cycle ^M Setting duty cycle; the maximum duty ratio current regulating value is the difference value between the set current value which is not less than the output current value and is closest to the output current value and the third fixed interval current value; the maximum duty cycle is 1-1/2 ^M . Thereafter, the determined 2 ^M Setting level of duty ratio, 2 ^M Individual duty cycle current adjustment values and 2 ^M The set duty ratios are in one-to-one correspondence to establish 2 ^M A duty cycle data relationship. Dividing the set current value determined based on the output current value into 2 according to the third fixed interval current value ^M And each duty cycle current regulating value corresponds to one duty cycle setting grade, and each duty cycle setting grade corresponds to one setting duty cycle, so that the duty cycle data relationship of M bits is formed.

The specific values of the third fixed interval current value are not limited in this disclosure. For example, the third fixed interval current value may be determined in such a manner that the set current value that is not smaller than the output current value and closest to the output current value is equally divided.

For example, taking a 3bit duty cycle data relationship, m=3 as an example, the set current value determined according to the output current value is 2mA, the third fixed interval current value is 2/8mA, and the specific correspondence relationship of the 3bit duty cycle data relationship is shown in table five.

TABLE five

For example, taking a 3bit duty cycle data relationship, m=3 as an example, the set current value determined according to the output current value is 3mA, the third fixed interval current value is 3/8mA, and the specific correspondence relationship of the 3bit duty cycle data relationship is shown in table six.

Duty cycle setting level	Duty cycle current regulation value	Setting the duty cycle
			X1	0mA	0
X2	3/8mA	1/8
			X3	6/8mA	2/8
X4	9/8mA	3/8
			X5	12/8mA	4/8
X6	15/8mA	5/8
			X7	18/8mA	6/8
X8	21/8mA	7/8

TABLE six

In still other possible embodiments, the output current value corresponding to each light emitting region is equal to 2 ^M The duty cycle data relationship, determining a target duty cycle corresponding to each light emitting region, includes: the following operations are performed for the output current value corresponding to any one of the light emitting regions:

operation (1): upon determining that the output current value is at said 2 ^M And when the duty ratio current regulating values are between two adjacent duty ratio current regulating values, determining the duty ratio setting grade corresponding to the duty ratio current regulating value smaller or larger than the output current value in the two adjacent duty ratio current regulating values, and determining the setting duty ratio corresponding to the duty ratio setting grade as the target duty ratio.

For example, taking m=3 and one light emitting region as an example, as shown in table five, if the output current value I0 of the light emitting region is between the duty current adjustment value 10/8mA and 12/8mA, the set duty ratio 6/8 corresponding to the duty current adjustment value 12/8mA is determined as the target duty ratio.

Operation (2): at the time of determining the output current value and 2 ^M Determining and comparing the current regulation value of any one of the duty cycle current regulation values when the current regulation value of any one of the duty cycle current regulation values is the sameAnd the duty cycle setting grade corresponding to the duty cycle current adjusting value with the same output current value is used for determining the determined setting duty cycle corresponding to the duty cycle setting grade as the target duty cycle.

For example, taking m=3 and one light emitting region as an example, as shown in table five, if the output current value I0 of the light emitting region is the same as the duty current adjustment value 12/8mA, the set duty ratio 6/8 corresponding to the duty current adjustment value 12/8mA is determined as the target duty ratio.

The present disclosure is described in detail below with reference to specific embodiments. It should be noted that, in this embodiment, the disclosure is better explained, but the disclosure is not limited thereto. Another embodiment of the present disclosure provides a brightness adjustment method, which may include:

taking the output current data relationship of 2 bits, n=2 as an example, for example, the maximum output current value is 3mA, the first fixed interval is 1mA, and 2 from 0 to 3mA is formed ² Setting current value to 2 ² Setting level of current, 2 ² Each set current value is 2 preset ² The output voltage values are in one-to-one correspondence, a 2bit output current data relationship is established, and the specific correspondence is shown in a table II.

The output current value is 1.5mA according to the brightness data, the output current value is 1.5mA, S1 to S4 are sequentially increased according to the output current value and the second table, and V1 to V4 are sequentially increased, so that the voltage value of the low level of the PWM signal is fixed to V0' when 1.5mA is between 1mA and 2mA, and the output voltage value V3 corresponding to the current setting level S3 is taken as the target voltage value of the high level of the PWM signal.

Taking a 3bit duty cycle data relationship, m=3 as an example for explanation, the set current value determined according to the output current value of 1.5mA is 2mA, the third fixed interval current value is 2/8mA, and 2 from 0 to 14/8mA is formed ³ A duty cycle current adjustment value and form 2 from 0 to 7/8 ³ Setting duty ratio to 2 ³ Setting level of duty ratio, 2 ³ Individual duty cycle current adjustment values and 2 ³ The set duty ratios are in one-to-one correspondence to establish 3bit duty ratio dataThe specific correspondence is shown in table five.

The output current value was found to be 1.5mA, i.e., 12/8mA, based on the luminance data. According to 12/8mA and Table five, X1 to X8 rise in order, the set duty ratio 6/8 corresponding to X7 can be determined as the target duty ratio of the PWM signal.

According to the determined high-level target voltage value V3 and target duty ratio 6/8 of the PWM signal, a PWM signal PWM3 can be generated, the generated PWM signal PWM3 is output to a corresponding light-emitting area, and the actual output current value input to the light-emitting area is regulated and controlled, so that the brightness of the light-emitting area is controlled.

Based on the same disclosure concept, the embodiment of the disclosure also provides a driving chip of the backlight module, wherein the backlight module comprises a plurality of light-emitting areas, and the driving chip is connected with one or more light-emitting areas; the driver chip is configured to: acquiring brightness data corresponding to each light-emitting area; the brightness data is a signal carrying an output current value; and controlling the actual output current value corresponding to each light-emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light-emitting area.

It should be noted that, the working principle and the specific implementation manner of the driving chip are the same as those of the brightness adjustment method in the above embodiment, so the working method of the driving chip may be implemented with reference to the specific implementation manner of the brightness adjustment method in the above embodiment, which is not described herein again.

Based on the same disclosure concept, the embodiment of the disclosure also provides a display device, which comprises a liquid crystal display panel and a backlight module arranged below the liquid crystal display panel; the backlight module is the backlight module provided by the embodiment of the disclosure. The backlight module comprises: a light-emitting substrate having a plurality of light-emitting regions and a plurality of driving chips, the driving chips being connected to one or more of the light-emitting regions; the driving chip is the driving chip of the backlight module.

The principle of the display device for solving the problems is similar to that of the backlight module, so that the implementation of the display device can be referred to the implementation of the backlight module, and the repetition is omitted herein.

In specific implementation, in the embodiment of the disclosure, the display device may be: any product or component with display function such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like. Other essential components of the display device are those of ordinary skill in the art and will not be described in detail herein, nor should they be considered as limiting the present disclosure.

While the preferred embodiments of the present disclosure have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the disclosure.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the spirit and scope of the disclosed embodiments. Thus, given that such modifications and variations of the disclosed embodiments fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to encompass such modifications and variations.

Claims

1. A brightness adjusting method of a backlight module is characterized in that the backlight module comprises a plurality of luminous areas;

the brightness adjustment method comprises the following steps:

controlling the actual output current value corresponding to each light-emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light-emitting area;

the brightness data is a digital signal carrying K bits of an output current value; the controlling the actual output current value corresponding to each light emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light emitting area comprises the following steps: according to each ofLuminance data, 2 corresponding to one of the light emitting regions ^N Sum of output current data 2 ^M The duty ratio data relationship is used for controlling the actual output current value corresponding to each light-emitting area; n, M is a positive integer, n+m=k;

said 2 ^N The output current data relationships include: 2 one-to-one corresponding to each other ^N Setting level of current, 2 ^N Each set current value is 2 preset ^N A value of the output voltage, and 2 ^N The set current values are determined based on the maximum output current values;

said 2 ^M The individual duty cycle data relationships include: 2 one-to-one corresponding to each other ^M Setting level of duty ratio, 2 ^M Individual duty cycle current adjustment values and 2 ^M A set duty cycle, and the 2 ^M The duty current adjustment value is determined based on the first fixed interval current value or a set current value that is not less than the output current value and closest to the output current value.

2. The brightness adjustment method according to claim 1, wherein the brightness data corresponding to each of the light emitting areas is 2 ^N Sum of output current data 2 ^M And controlling the actual output current value corresponding to each light-emitting area according to the duty ratio data relation, wherein the actual output current value comprises the following components:

3. The brightness adjustment method according to claim 2, wherein said step of adjusting said brightness is performed based on brightness data corresponding to each of said light emitting areas, said 2 ^N Data relationship of the output currents and said 2 ^M The duty cycle data relation, determining the target output voltage value and the target duty cycle of the pulse width modulation signal corresponding to each light emitting area, comprises:

4. A brightness adjustment method according to claim 3, wherein said output current value and said 2 are based on each of said light emitting areas ^N Determining the output voltage value corresponding to each light emitting region according to the output current data relation, including:

at the time of determining the output current value and 2 ^N When any one of the set current values is the same, determining a current setting level corresponding to the same set current value as the output current value, and according to the determined output corresponding to the current setting levelAnd determining target output voltage values of a low level and a high level of the pulse width modulation signal.

5. The brightness adjustment method according to claim 4, wherein said 2 ^N In the output current data relationship, the current setting level is increased, and the output voltage value is increased;

6. The brightness adjustment method according to claim 4, wherein said 2 ^N In the output current data relationship, the current setting level is increased, and the output voltage value is reduced;

7. A brightness adjustment method according to claim 3, wherein said output current value and said 2 are based on each of said light emitting areas ^N Determining the output voltage value corresponding to each light emitting region according to the output current data relation, including:

8. The brightness adjustment method according to claim 7, wherein the step of fixing the output voltage value of one level of the pwm signal, determining a current setting level corresponding to a set current value greater than or less than the output current value among the two adjacent set current values, and determining a target output voltage value of the other level of the pwm signal according to the determined output voltage value corresponding to the current setting level, comprises:

9. The brightness adjustment method according to claim 8, wherein said 2 ^N In the output current data relationship, the current setting level is increased, and the output voltage value is increased; or,

10. A brightness adjustment method according to claim 3, wherein said output current value and said 2 are based on each of said light emitting areas ^M The determining the target duty ratio corresponding to each light emitting area according to the duty ratio data relation comprises the following steps: determining a fraction part in the output current value corresponding to each light emitting area, and executing the following operations for any one fraction part:

11. The brightness adjustment method according to any one of claims 1-10, characterized in that the 2 is established ^N A plurality of output current data relationships comprising:

12. The brightness adjustment method according to any one of claims 1-10, characterized in that the 2 is established ^M A duty cycle data relationship comprising:

13. A brightness adjustment method according to any one of claims 4-9, characterized in that the 2 is established ^M A duty cycle data relationship comprising:

14. The brightness adjustment method according to claim 13, wherein said output current value and said 2 corresponding to each of said light emitting areas ^M The determining the target duty ratio corresponding to each light emitting area according to the duty ratio data relation comprises the following steps:

15. The driving chip of the backlight module is characterized by comprising a plurality of light-emitting areas, wherein the driving chip is connected with one or more light-emitting areas;

wherein, the brightness data is a digital signal carrying K bits of an output current value; the controlling the actual output current value corresponding to each light emitting area according to the brightness data, the output current data relation and the duty ratio data relation corresponding to each light emitting area comprises the following steps: according to the brightness data and 2 corresponding to each light-emitting area ^N Sum of output current data 2 ^M The duty ratio data relationship is used for controlling the actual output current value corresponding to each light-emitting area; n, M is a positive integer, n+m=k;

16. A display device, comprising: a liquid crystal display panel and a backlight module arranged below the liquid crystal display panel;

the driving chip is the driving chip of the backlight module according to claim 15.