CN116312403B - Mini LED driving method - Google Patents
Mini LED driving method Download PDFInfo
- Publication number
- CN116312403B CN116312403B CN202310551899.5A CN202310551899A CN116312403B CN 116312403 B CN116312403 B CN 116312403B CN 202310551899 A CN202310551899 A CN 202310551899A CN 116312403 B CN116312403 B CN 116312403B
- Authority
- CN
- China
- Prior art keywords
- bit
- switch
- current
- shift controller
- gray
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 230000010355 oscillation Effects 0.000 claims description 2
- 239000013589 supplement Substances 0.000 claims description 2
- 230000001502 supplementing effect Effects 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 10
- 238000010586 diagram Methods 0.000 description 7
- 239000004973 liquid crystal related substance Substances 0.000 description 6
- 239000011159 matrix material Substances 0.000 description 5
- 230000000630 rising effect Effects 0.000 description 3
- 230000001668 ameliorated effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/32—Pulse-control circuits
- H05B45/325—Pulse-width modulation [PWM]
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
- H05B45/59—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits for reducing or suppressing flicker or glow effects
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0233—Improving the luminance or brightness uniformity across the screen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The invention discloses a mini LED driving method, which is characterized in that a set value and gray data are input into a comparator for comparison, and the gray data size input into a PWM generator and the constant current input into a constant current switch are adjusted according to the judging result of the gray data and the preset value, so that PWM gray control of a constant current peak value of an LED is realized by controlling the constant current switch through a PWM control signal generated by the PWM generator. Through the design, the PWM pulse frequency and the pulse width of the mini LED during low-gray display can be effectively improved, the flickering and shooting distortion problems of the mini LED during low-gray display are greatly improved, meanwhile, the uniformity of the low-gray display of the mini LED can be improved, and the display effect and the image quality of the mini LED are improved.
Description
Technical Field
The invention belongs to the technical field of LED driving, and particularly relates to a mini LED driving method.
Background
The LED has the advantages of long service life, high luminous efficiency, high brightness, quick switching, high dynamic contrast display, wide color gamut and the like, and is widely applied to the display field. Mini LED (sub-millimeter light emitting diode) display is widely applied to medium-distance watching occasions such as advertisement display screens, conference room screens and the like because the pixel point spacing is about 1 millimeter and the display has the characteristic of splice. Recently, mini LEDs have been used for matrix backlight driving of liquid crystal display, and indirectly used in close-range viewing applications, so that the requirements for driving display effects of the mini LEDs are higher. The addition of the mini LED backlight has the advantages that the liquid crystal display screen has high dynamic contrast and wider color gamut, and the standby power consumption of the liquid crystal display is greatly reduced by the technology of the mini LED matrix backlight, so that the low-cost LCD (liquid crystal display screen) has the strength of competing with the high-cost OLED (organic light emitting diode) display screen. Therefore, the liquid crystal television gradually starts to spread matrix mini LED backlight.
At present, mini LED backlight has two modes of AM (active matrix) driving and PM (passive matrix) driving, but the brightness adjustment of the main mini LED is mainly PWM (pulse width modulation) dimming mode. PWM dimming has the advantages of extremely high dimming precision and good combination with digital control technology, and high-frequency switch switching is used, so that the flickering of the lamp cannot be seen by human eyes. Currently, the mainstream LED dimming is a PWM dimming mode with a fixed peak current, that is, the driving current when the LED is turned on remains unchanged, and the average current of the LED is changed by changing the pulse width of PWM.
In order to solve the problem of LED flickering, the PWM of a frame of picture is usually split into several smaller-period PWM, as shown in fig. 1, and the PWM of a frame of picture is split into 8 smaller-period PWM, so that the brightness of the final LED is not affected when the LED is displayed with high gray, and the frequency of LED lighting is increased, that is, the refresh rate of the LED is increased, and the LED is more uniformly lighted. PWM has a minimum pulse width limitation due to the rising and falling edges of the PWM pulse. When the brightness of the LED is low, the total pulse width of the PWM is small, and when the minimum pulse width is limited to be insufficient to be split into 8 parts, as shown in fig. 2, when the gray level of the LED is low, the total pulse width of the PWM can only be split into 4 parts, and only 4 PWM periods exist, so that the refresh rate of the LED is reduced by half. When the total pulse width of the PWM can only be divided into 2 parts, only 2 PWM periods are needed, and the refresh rate of the LED is only one fourth, so that the refresh rate and the display effect of the LED are greatly affected.
In the existing PWM control with fixed peak current, the number of PWM cycles in a frame of picture is necessarily reduced when the gray is low, which results in a serious decrease in PWM frequency when the gray is low, and thus a flicker problem occurs. Meanwhile, when the gray is low, the LED is turned on for a short time, and is turned off for a long time, so that the problem of photographing distortion can also occur. Although the human eye may not find flicker, such problems of LED display distortion and flicker at low gray are easily captured by the image pickup apparatus, affecting the screen display effect. Patent 202110318505.2 proposes a solution to divide the luminance values into two processing modes, y=0 and y+.0. When Y+.0, the pulse width is divided into 1 st and 2 nd periods, and then the current amplitude is reduced in the 2 nd period. Since the current amplitude variation is handled in an analog manner, it is not an ideal square wave form variation, but there is a problem of current variation hysteresis. While the rising and falling edges of the current will also affect the true current output. The LEDs are current light emitting devices, and tiny current differences can be reflected in brightness, especially when the gray is low, the tiny current differences are more easily captured by human eyes, so that image distortion is caused, and image quality is affected.
Disclosure of Invention
The invention aims to provide a mini LED driving method which mainly solves the problem that the display effect of a liquid crystal image is poor due to the fact that low-frequency flash occurs in mini LED backlight.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a mini LED driving method comprises the following steps:
s1, inputting a set value and m bits of gray data expressed in binary into a comparator, wherein m is an integer greater than 1;
s2, comparing the gray data with a set value; wherein the number of bits of the set value is less than or equal to m;
s3, when the gray data is larger than or equal to a set value, the gray data is unchanged; otherwise it goes to step S4,
s4, shifting the gray data left by 1 bit, supplementing 0 to the lower bit, and comparing with a set value;
s5, when the gray data after left shift is larger than or equal to a set value, multiplying the input m-bit gray data by 2 to obtain output gray data; otherwise, returning to the step S4 until the left-shifted gray data is greater than or equal to a set value or the left-shifted bit number of the gray data is greater than n, wherein n is the bit number of the input current value;
s6, the output gray data are sent to a PWM generator, and PWM control signals are generated by combining oscillation signals generated by the oscillator and sent to a constant current switch;
s7, the right shift controller shifts the input n-bit current value to the right by the same bit number, supplements 0 at the high position, shifts the low position into the low n-bit current value, and sends the obtained 2 n-bit current value generated by right shift to the 2 n-bit switch respectively, and selects the corresponding current magnitude through the 2 n-bit switch to output the constant current switch;
s8, a PWM control signal generated by the PWM generator controls the constant current switch to be turned on, so that the current output by the selected 2 n-bit switch realizes PWM gray scale control of the LED constant current peak value.
Further, in the step S7, the right shift controller includes a high n-bit right shift controller and a low n-bit right shift controller, and an initial value of the high n-bit right shift controller is set by an n-bit current value; the high n-bit right-shift controller shifts 1 bit to the right, and the lowest bit data of the high n-bit right-shift controller shifts into the highest bit of the low n-bit right-shift controller, so that the low bit data is prevented from being lost.
Further, in the step S7, the 2 n-bit switch is composed of switches S1, S2..sn and S1b, S2..snb connected in parallel; the high n-bit right-shift controller and the low n-bit right-shift controller form 2 n-bit current value distribution control S1, S2..Sn, S1b and S2 b..Snb, wherein the highest bit of the high n-bit right-shift controller is connected to the switch Sn, the lowest bit of the high n-bit right-shift controller is connected to the switch S1 in sequence, and the switch S1 is controlled to be opened and closed, the highest bit of the low n-bit right-shift controller is connected to the S1b, the lowest bit of the low n-bit right-shift controller is connected to the switch Snb in sequence, and the switch Snb is controlled to be opened and closed.
Further, in the step S7, the switch S1 controls the on and off of 1 unit current, i.e. 1I, the switch S2 controls the on and off of 2 unit currents, i.e. 2I, and the switch Sn controls 2 n-1 Per unit current, i.e. 2 n-1 * I, likewise, switch S1b controls 2 -1 The unit current, i.e. I/2, is switched on and off, switch S2b controls 2 -2 Switching in and off of unit current I/4, snb switch control 2 -n Individual unit currents I/2 n Is connected and disconnected.
Compared with the prior art, the invention has the following beneficial effects:
the invention can effectively improve the PWM pulse frequency and the pulse width of the mini LED during low-gray display, greatly improve the flickering and image capturing distortion problems easily occurring during low-gray display of the mini LED, and simultaneously improve the uniformity of the low-gray display of the mini LED and the display effect and the image quality of the mini LED.
Drawings
Fig. 1 is a schematic diagram of pulse width of a conventional mini LED PWM driving mode_high gray.
Fig. 2 is a schematic diagram of pulse width of a conventional mini LED PWM driving mode_low gray.
FIG. 3 is a schematic flow chart of the method of the present invention.
Fig. 4 is a block diagram of an application circuit of an embodiment of the present invention.
Fig. 5 is a schematic diagram of pulse width according to an embodiment of the present invention.
Fig. 6 is a schematic diagram of pulse width according to another embodiment of the present invention.
Fig. 7 is a schematic diagram of pulse width according to yet another embodiment of the present invention.
Detailed Description
The invention will be further illustrated by the following description and examples, which include but are not limited to the following examples.
As shown in FIG. 3, in the mini LED driving method disclosed by the invention, a set value and m bits of gray data expressed in binary are input into a comparator, wherein m is an integer greater than 1. The gradation data is a binary value related to the brightness of the LED, and the smaller the gradation data is, the darker the LED is driven, whereas the larger the gradation data is, the brighter the LED is driven.
And comparing the gray data with a set value, wherein when the gray data is larger than or equal to the set value, the gray data is unchanged, and the output gray data is equal to the input m-bit gray data. Meanwhile, the left shift bit number of the gray data is 0, and the current value of 2n bits is kept unchanged. When the gray data is judged to be smaller than the set value, the gray data is shifted left by 1 bit, and the low bit is complemented by 0. And then comparing the gray data after shifting 1 bit to the left with a set value, and if the gray data is larger than or equal to the set value, outputting gray data 2 which is equal to the input m-bit gray data multiplied by 2. Meanwhile, the left shift number of the gray data is 1, the right shift number of the gray data is 1 corresponding to the current value of 2n bits, and the control output current is reduced by half. If the gray data is still smaller than the set value after shifting 1 bit left, the gray data continues to shift 1 bit left, and the low bit is complemented with 0. And comparing the gray data subjected to the left shift of 2 bits with a set value, if the gray data is larger than or equal to the set value, the output gray data 2 is equal to the input m-bit gray data multiplied by 4, and meanwhile, the gray data has the left shift bit number of 2, and the 2 n-bit current value is shifted to the right by 2 bits, so that the output current is controlled to be reduced to be 1/4 of the original value. And so on. Since, when binary data is processed, a left shift of 1 bit is equal to the binary data multiplied by 2, and a right shift of 1 bit is equal to the binary data divided by 2. If the gray data size is D, the default current amplitude is k×I, and one frame of picture period is T, the gray of the LED is displayed as D×k×I/T. When the gray data is subjected to left shift 1-bit processing, the gray data is changed into 2 times of the original gray data, the current amplitude is reduced by 1/2, the gray of the LED is displayed as 2 x D x K x I/2/T=D x K x I/T, and the total brightness is kept unchanged.
Similarly, when the gray data is shifted to the left by 2 bits, the gray data is changed to 4 times, the current amplitude is reduced by 1/4, the gray of the LED is displayed as 4 x D x k I/4/t=d x k x I/T, and the total brightness is still unchanged. The PWM generator generates PWM pulse width and number according to the gray data size, and the gray data is increased by increasing the PWM pulse number and pulse width. The method provided by the invention can be found that the total brightness of the LED is unchanged, and the PWM pulse frequency is greatly improved. The increase of the pulse number and the pulse width of PWM accelerates the refresh rate of the LED, thereby greatly improving the flickering and shooting distortion problems of the LED.
As shown in FIG. 4, a schematic circuit diagram of the practical application of the method of the present invention is shown, m bits of gray data and a set value are input into a comparator, the comparator outputs gray data which is greater than or equal to the set value and is subjected to left shift operation to a gray data module, the left shift bit number is recorded and output to a high n right shift controller and a low n right shift controller, the high n right shift controller is controlled to shift right by 1 bit, the lowest bit data of the high n right shift controller is shifted into the highest bit of the low n right shift controller, the loss of low bit data is avoided, and the correctness of current is ensured. Wherein the initial value of the high n-bit right shift controller is set by the n-bit current value. High n-bit right shift controller and low n-bit right shift controllerAnd forming 2 n-bit current value distribution control S1, S2..Sn, S1b and S2 b..Snb, wherein the highest bit of the high n-bit right-shift controller is connected to the switch Sn, the highest bit of the high n-bit right-shift controller is connected in sequence bit by bit, and the lowest bit of the high n-bit right-shift controller is connected to the switch S1, so as to control the opening and closing of the high n-bit right-shift controller. And the highest bit of the low n-bit right-shift controller is connected to the S1b, the lowest bit of the low n-bit right-shift controller is connected to the switch Snb in sequence bit by bit, and the opening and the closing of the low n-bit right-shift controller are controlled. Switch S1 controls the on and off of 1 unit current, i.e. 1I, switch S2 controls the on and off of 2 unit currents, i.e. 2I, and switch Sn controls 2 n-1 Per unit current, i.e. 2 n-1 * I, likewise, switch S1b controls 2 -1 The unit current, i.e. I/2, is switched on and off, switch S2b controls 2 -2 Switching on and off of unit current i.e. I/4, switch Snb control 2 -n Individual unit currents I/2 n Is connected and disconnected. The value of the right-shift controller controls the on-off of the switch, thereby controlling the connection and disconnection of the constant current source and controlling the total output current. The gray data module stores the gray data subjected to the left shift processing, sends the gray data to the PWM generator, and converts the gray data into uniformly distributed multicycle PWM pulse output by matching with a clock cycle signal output by the oscillator. The PWM pulse controls the constant current output and closing of the constant current switch, so that the set current value controlled by the 2 n-bit right-shift controller is output to the LED lamp through the constant current switch, and PWM gray scale control of the constant current peak value of the LED is realized.
Since the gray data shift left process is an accurate multiple, the current shift right process is difficult to ensure that the current is exactly 1/2 of the original current. Because the 1I and 2I of the constant current source are difficult to ensure an absolute 2 times relation due to the process manufacturing reasons, the current I and the current I/2 cannot ensure an absolute 1/2 relation, and deviation exists. Therefore, the effect achieved by the method is affected by the high-precision current source, and the method benefits from the existing technology (application number is 202211321997.1 and patent name is a mini LED driving circuit) for guaranteeing high-precision current output, so that the method can achieve the excellent effect of improving the LED refresh rate.
Fig. 5 shows an example of implementing mini LED driving by using the method of the present embodiment. Gray data d=4 (binary 00100), and the set value is equal to 8 (binary 01000). The prior art PWM driving method is shown by dotted lines, and there are 4 PWM pulses in a frame of picture time, each pulse is turned on for 1t, and the peak value of the output current is k×i when PWM is turned on. The PWM driving method of the present invention is shown in solid line. The gradation data 4 is smaller than the set value 8, so that the gradation data is left-shifted by 1-bit. The gradation data 4 (00100) shifted 1 bit to the left becomes 8 (01000), and is compared with the set value 8 to find that the set value is equal. At this time, the left-shifted gradation data 8 (01000) is output to the PWM generator, and 8 PWM pulses are uniformly distributed. And the left shift bit number 1 output controls the right shift of the current value of 2n bits. Assuming that the peak output current is k×i=7i, the number of bits of the right shift controller is 2×4=8 bits. The binary number of 7 is 0111, so the value of the high 4-bit right shift controller is 0110 and the value of the low 4-bit right shift controller is 0000. Corresponding to the switches S1, S2, S3 being closed, the remaining switches are open, and 1I, 2I and 4I currents are connected. The value 0111 of the upper 4-bit right-shift controller shifts one bit to the right to 0011, and the lowest 1 shifts into the highest bit of the lower 4-bit right-shift controller, so the value of the lower 4-bit right-shift controller is 1000. The values after shifting 1 bit to the right control the switches S1, S2 and S1b to be closed respectively, and the total access current is 3.5I and is half of the original current 7I corresponding to the access 1I, 2I and I/2 current values. The PWM driving method adopting the technology of the present invention is to output 8 PWM pulses with a unit time T, and the current value of each pulse is 3.5I. It can be seen that 8t3.5i=4t7i, the total current flowing through the LED is unchanged, the brightness of the LED is also unchanged, but the refresh rate of the LED is doubled.
Likewise, as shown in fig. 6, the gradation data continues to be reduced by half d=2 (binary 00100), and the set value is still equal to 8 (binary 01000). The dashed line shows the PWM driving method in the prior art, in which only 2 PWM pulses are turned on in one frame of picture time, each pulse is turned on for 1T, and the peak value of the output current is k×i=7i. The solid line shows the PWM driving scheme of the present invention. The gradation data 2 is smaller than the set value 8, so the gradation data is left-shifted by 1-bit. The gradation data 2 (00010) shifted 1 bit to the left becomes 4 (00100), and is found to be smaller than the set value 8 after comparison with the set value 8. The gray data is changed to 8 (01000) after being shifted left by 1 bit, and is compared with the set value 8 to find that the gray data is equal to the set value 8. At this time, the left-shifted gradation data 8 (01000) is output to the PWM generator, and 8 PWM pulses are uniformly distributed. And meanwhile, the left shift bit number is 2, and the right shift of the 8-bit current value is controlled. The 7I current corresponds to the value of 0111 for the high 4-bit right-shift controller and 0000 for the low 4-bit right-shift controller. The value of the upper 4-bit right-shift controller shifts one bit to 0011, and the lowest 1 shifts into the highest bit of the lower 4-bit right-shift controller, so the value of the lower 4-bit right-shift controller is 1000. The upper 4-bit right-shift controller still needs to shift right 1 time, the value 0011 shifts right and becomes 0001, and the lowest 1 shifts into the highest bit of the lower 4-bit right-shift controller, so the value 1100 of the lower 4-bit right-shift controller. The values after the right shift by 2 bits control the switches S1, S1b and S2b to be closed respectively, and the total access current is 1.75I and 1/4 of the original current 7I corresponding to the access current values of 1I, I/2 and I/4. It can be seen that 8t×1.75i=2t×7i, the total current flowing through the LED is unchanged, the brightness of the LED is also unchanged, but the refresh rate of the LED is improved by a factor of 4. After the technology is adopted, the LED display is more uniform, and the low-gray display effect of the LED is greatly improved.
The driving method of the invention not only can improve the refresh rate of the LED, but also can improve the pulse width of the low gray display PWM. As shown in fig. 7, when the gradation data d=11, the PWM display of the related art is shown as a broken line. After the technology of the invention is adopted, when the set value is set to be 16, the gray data 11 (binary 01011) is smaller than the set value 16 (binary 10000), the gray data needs to be shifted one bit to the left and is changed into 22 (10110), and at the moment, the gray data is larger than the set value 16, so 22 (10110) is output to a gray data module and then is sent to a PWM generator, and 8 PWM pulse periods with evenly distributed pulse width are generated, as shown by a solid line in fig. 7. The frequency of the PWM pulse does not change, but the PWM pulse width is widened by about 1 time. Similarly, when the gray data is shifted left by 1 bit, the 2n right shift controller of the current value is shifted right by 1 bit, the corresponding peak current is reduced by half, and k is reduced to k is I/2. It can be known that the narrower the PWM pulse width, the less accurate the LED current, since the PWM current output of the LED is lost at the rising and falling edges, and the problem of LED low gray display non-uniformity is also present in the prior art, which can be ameliorated by the present invention.
Through the design, the PWM pulse frequency and the pulse width of the mini LED during low-gray display can be effectively improved, the flickering and shooting distortion problems of the mini LED during low-gray display are greatly improved, meanwhile, the uniformity of the low-gray display of the mini LED can be improved, and the display effect and the image quality of the mini LED are improved. Thus, the present invention provides a significant and substantial advance over the prior art.
The above embodiment is only one of the preferred embodiments of the present invention, and should not be used to limit the scope of the present invention, but all the insubstantial modifications or color changes made in the main design concept and spirit of the present invention are still consistent with the present invention, and all the technical problems to be solved are included in the scope of the present invention.
Claims (4)
1. The mini LED driving method is characterized by comprising the following steps of:
s1, inputting a set value and m bits of gray data expressed in binary into a comparator, wherein m is an integer greater than 1;
s2, comparing the gray data with a set value; wherein the number of bits of the set value is less than or equal to m;
s3, when the gray data is larger than or equal to a set value, the gray data is unchanged; otherwise it goes to step S4,
s4, shifting the gray data left by 1 bit, supplementing 0 to the lower bit, and comparing with a set value;
s5, when the gray data after left shift is larger than or equal to a set value, multiplying the input m-bit gray data by 2 to obtain output gray data; otherwise, returning to the step S4 until the left-shifted gray data is greater than or equal to a set value or the left-shifted bit number of the gray data is greater than n, wherein n is the bit number of the input current value;
s6, the output gray data are sent to a PWM generator, and PWM control signals are generated by combining oscillation signals generated by the oscillator and sent to a constant current switch;
s7, the right shift controller shifts the input n-bit current value to the right by the same bit number, supplements 0 at the high position, shifts the low position into the low n-bit current value, and sends the obtained 2 n-bit current value generated by right shift to the 2 n-bit switch respectively, and selects the corresponding current magnitude through the 2 n-bit switch to output the constant current switch;
s8, a PWM control signal generated by the PWM generator controls the constant current switch to be turned on, so that the current output by the selected 2 n-bit switch realizes PWM gray scale control of the LED constant current peak value.
2. The mini LED driving method according to claim 1, wherein in the step S7, the right shift controller includes a high n-bit right shift controller and a low n-bit right shift controller, and an initial value of the high n-bit right shift controller is set by an n-bit current value; the high n-bit right-shift controller shifts 1 bit to the right, and the lowest bit data of the high n-bit right-shift controller shifts into the highest bit of the low n-bit right-shift controller, so that the low bit data is prevented from being lost.
3. The mini LED driving method according to claim 2, wherein in the step S7, the 2 n-bit switch is composed of switches S1, S2..sn and S1b, S2 b..snb connected in parallel; the high n-bit right-shift controller and the low n-bit right-shift controller form 2 n-bit current value distribution control S1, S2..Sn, S1b and S2 b..Snb, wherein the highest bit of the high n-bit right-shift controller is connected to the switch Sn, the lowest bit of the high n-bit right-shift controller is connected to the switch S1 in sequence, and the switch S1 is controlled to be opened and closed, the highest bit of the low n-bit right-shift controller is connected to the S1b, the lowest bit of the low n-bit right-shift controller is connected to the switch Snb in sequence, and the switch Snb is controlled to be opened and closed.
4. A mini LED driving method according to claim 3, wherein in said step S7, the switch S1 controls 1 unit current, i.e. 1I, on and off, the switch S2 controls 2 unit currents, i.e. 2I, on and off, and the switch Sn controls 2 n-1 Per unit current, i.e. 2 n-1 * I, likewise, switch S1b controls 2 -1 The unit current, i.e. I/2, is switched on and off, switch S2b controls 2 -2 The switching-in and switching-off of unit current, i.e. I/4, snb switch-onOff control 2 -n Individual unit currents I/2 n Is connected and disconnected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310551899.5A CN116312403B (en) | 2023-05-17 | 2023-05-17 | Mini LED driving method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310551899.5A CN116312403B (en) | 2023-05-17 | 2023-05-17 | Mini LED driving method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116312403A CN116312403A (en) | 2023-06-23 |
| CN116312403B true CN116312403B (en) | 2023-08-25 |
Family
ID=86826151
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310551899.5A Active CN116312403B (en) | 2023-05-17 | 2023-05-17 | Mini LED driving method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116312403B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116997051B (en) * | 2023-09-27 | 2023-12-08 | 中科(深圳)无线半导体有限公司 | LED dimming method and device |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07306659A (en) * | 1994-05-10 | 1995-11-21 | Nichia Chem Ind Ltd | Multicolor led display unit |
| JP2001109421A (en) * | 1999-10-04 | 2001-04-20 | Matsushita Electric Ind Co Ltd | Method and device for driving gradations of display panel |
| CN1553419A (en) * | 2000-12-27 | 2004-12-08 | ���µ�����ҵ��ʽ���� | Matrix-type display device and driving method thereof |
| JP2007114692A (en) * | 2005-10-24 | 2007-05-10 | Victor Co Of Japan Ltd | Light emitting display element driving device |
| CN104768275A (en) * | 2014-01-06 | 2015-07-08 | 聚积科技股份有限公司 | Binary distribution control method of multi-channel light-emitting diode driving system |
| CN107507557A (en) * | 2016-06-14 | 2017-12-22 | 深圳市富满电子集团股份有限公司 | A kind of LED driving pulses width dividing method and system |
| CN110191539A (en) * | 2019-06-10 | 2019-08-30 | 酷矽半导体科技(上海)有限公司 | Driving circuit, driving chip and display system, display methods |
| CN111489685A (en) * | 2020-01-22 | 2020-08-04 | 南京浣轩半导体有限公司 | Multi-line scanning L ED gray scale switching display method and system |
| CN111524489A (en) * | 2020-04-23 | 2020-08-11 | 中国科学院上海技术物理研究所 | Ultrahigh frame frequency simulation method based on composite coding |
| CN112037710A (en) * | 2020-09-09 | 2020-12-04 | 中科芯集成电路有限公司 | PWM algorithm for opening channels of multi-channel LED driving chip in time-sharing manner |
| CN115346475A (en) * | 2022-07-29 | 2022-11-15 | 西安诺瓦星云科技股份有限公司 | LED display control method, control device, electronic device and storage medium |
| CN115641809A (en) * | 2022-10-09 | 2023-01-24 | 中科芯集成电路有限公司 | LED driving chip algorithm for optimizing coupling influence among channels |
| CN115938287A (en) * | 2022-12-08 | 2023-04-07 | 南京浣轩半导体有限公司 | High-refresh-rate display method and system for LED (light emitting diode) at low gray level |
| TWI799241B (en) * | 2022-04-25 | 2023-04-11 | 大陸商集璞（上海）科技有限公司 | Gray-scale current dimming method, LED driver chip, display device and information processing device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060164345A1 (en) * | 2005-01-26 | 2006-07-27 | Honeywell International Inc. | Active matrix organic light emitting diode display |
-
2023
- 2023-05-17 CN CN202310551899.5A patent/CN116312403B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07306659A (en) * | 1994-05-10 | 1995-11-21 | Nichia Chem Ind Ltd | Multicolor led display unit |
| JP2001109421A (en) * | 1999-10-04 | 2001-04-20 | Matsushita Electric Ind Co Ltd | Method and device for driving gradations of display panel |
| CN1553419A (en) * | 2000-12-27 | 2004-12-08 | ���µ�����ҵ��ʽ���� | Matrix-type display device and driving method thereof |
| JP2007114692A (en) * | 2005-10-24 | 2007-05-10 | Victor Co Of Japan Ltd | Light emitting display element driving device |
| CN104768275A (en) * | 2014-01-06 | 2015-07-08 | 聚积科技股份有限公司 | Binary distribution control method of multi-channel light-emitting diode driving system |
| CN107507557A (en) * | 2016-06-14 | 2017-12-22 | 深圳市富满电子集团股份有限公司 | A kind of LED driving pulses width dividing method and system |
| CN110191539A (en) * | 2019-06-10 | 2019-08-30 | 酷矽半导体科技(上海)有限公司 | Driving circuit, driving chip and display system, display methods |
| CN111489685A (en) * | 2020-01-22 | 2020-08-04 | 南京浣轩半导体有限公司 | Multi-line scanning L ED gray scale switching display method and system |
| CN111524489A (en) * | 2020-04-23 | 2020-08-11 | 中国科学院上海技术物理研究所 | Ultrahigh frame frequency simulation method based on composite coding |
| CN112037710A (en) * | 2020-09-09 | 2020-12-04 | 中科芯集成电路有限公司 | PWM algorithm for opening channels of multi-channel LED driving chip in time-sharing manner |
| TWI799241B (en) * | 2022-04-25 | 2023-04-11 | 大陸商集璞（上海）科技有限公司 | Gray-scale current dimming method, LED driver chip, display device and information processing device |
| CN115346475A (en) * | 2022-07-29 | 2022-11-15 | 西安诺瓦星云科技股份有限公司 | LED display control method, control device, electronic device and storage medium |
| CN115641809A (en) * | 2022-10-09 | 2023-01-24 | 中科芯集成电路有限公司 | LED driving chip algorithm for optimizing coupling influence among channels |
| CN115938287A (en) * | 2022-12-08 | 2023-04-07 | 南京浣轩半导体有限公司 | High-refresh-rate display method and system for LED (light emitting diode) at low gray level |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116312403A (en) | 2023-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11295657B2 (en) | Method and system for switched display of grayscale of multi-line scan led | |
| CN107591131B (en) | Backlight driving method and device | |
| US9214114B2 (en) | Method for adjusting gamma curve and gamma voltage generator and display control system therof | |
| US20080094426A1 (en) | Backlight Modulation For Display | |
| TWI408997B (en) | Control device and control method, and planar light source and control method of planar light source | |
| TWI538562B (en) | Driver and driving method for driving led backlight device | |
| KR101329967B1 (en) | Back light unit and liquid crystal display device using the same and driving method thereof | |
| KR101153219B1 (en) | PWM signal generating circuit and method for DC-DC converter using diming signal and LED driving circuit for back light having the same | |
| US9123281B2 (en) | Lighting apparatus having a plurality of light sources and control method thereof | |
| CN116312403B (en) | Mini LED driving method | |
| CN102770899A (en) | Light emitting device for image display, image display apparatus, and led driver | |
| US9135869B2 (en) | Display signal generator, display device, and method of image display | |
| CN112863427B (en) | Method for adjusting brightness of light-emitting panel, light-emitting panel and display device | |
| KR101073006B1 (en) | Display device and method for controling brightness of images in display device | |
| CN112735313B (en) | Display panel and electronic device | |
| US7746303B2 (en) | Method and apparatus for extending the color depth of displays | |
| CN102026439B (en) | Driving device and driving method for light emitting diode | |
| CN101661708B (en) | Display, driving device and driving method thereof | |
| JP5653252B2 (en) | Light emission control device, display device, and light emission control method | |
| KR100798110B1 (en) | Pwm controlling circuit, apparatus of controlling backlight comprising the same, and apparatus of driving backlight comprising the apparatus of controlling backlight | |
| KR20080022851A (en) | Apparatus and method for controlling luminance of display device | |
| KR20050111433A (en) | System for controlling light emitting diode module in electronic display board | |
| US11538425B2 (en) | Display device | |
| TWI768828B (en) | Display device and displaying method | |
| CN115731883A (en) | Dynamic self-adaptive hybrid dimming method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |