CN113920928B - Display panel driver and display device - Google Patents

Display panel driver and display device Download PDF

Info

Publication number
CN113920928B
CN113920928B CN202111274952.9A CN202111274952A CN113920928B CN 113920928 B CN113920928 B CN 113920928B CN 202111274952 A CN202111274952 A CN 202111274952A CN 113920928 B CN113920928 B CN 113920928B
Authority
CN
China
Prior art keywords
light emitting
display panel
switch
driving
switches
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
Application number
CN202111274952.9A
Other languages
Chinese (zh)
Other versions
CN113920928A (en
Inventor
周满城
熊志
袁海江
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HKC Co Ltd
Chongqing HKC Optoelectronics Technology Co Ltd
Original Assignee
HKC Co Ltd
Chongqing HKC Optoelectronics Technology Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by HKC Co Ltd, Chongqing HKC Optoelectronics Technology Co Ltd filed Critical HKC Co Ltd
Priority to CN202111274952.9A priority Critical patent/CN113920928B/en
Publication of CN113920928A publication Critical patent/CN113920928A/en
Application granted granted Critical
Publication of CN113920928B publication Critical patent/CN113920928B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • G09G3/22—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 using controlled light sources
    • G09G3/30—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 using controlled light sources using electroluminescent panels
    • G09G3/32—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • 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
    • G09G3/22—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 using controlled light sources
    • G09G3/30—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 using controlled light sources using electroluminescent panels
    • G09G3/32—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]

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)
  • Control Of El Displays (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

The application discloses display panel driver and display device belongs to and shows technical field. The display panel driver includes a timing controller and a plurality of first switches. Each first switch is connected between one driving wire and a preset signal end, and the control end of each first switch is connected with the time schedule controller. When any one of the plurality of scanning lines outputs a scanning signal and the timing controller controls any one of the plurality of first switches to be turned on, the light emitting unit connected to the scanning line outputting the scanning signal and to the driving line connected to the turned-on first switch emits light. When the display panel driver works, along with the reduction of the luminous brightness of each luminous unit, the display panel driven by the display panel driver does not have the color cast phenomenon.

Description

Display panel driver and display device
Technical Field
The present disclosure relates to display technologies, and particularly to a display panel driver and a display device.
Background
The display device includes a display panel driver and a display panel. The display panel driver is used for outputting a driving signal. The display panel includes a plurality of scan lines, a plurality of driving lines, and a plurality of light emitting units. The plurality of scanning lines are used for outputting scanning signals one by one, and the time for which each scanning line continuously outputs the scanning signals is one scanning period. The driving lines are connected with the display panel driver to receive and output driving signals. Each of the plurality of light emitting units is connected to one of the plurality of scanning lines and one of the plurality of driving lines, and the driving lines to which the plurality of light emitting units connected to the same scanning line are connected are different. When the display panel works, if one scanning line outputs a scanning signal and one driving line outputs a driving signal, the light-emitting units connected with the scanning line and the driving line emit light.
However, as the light emission luminance of each light emitting unit decreases, a color cast phenomenon occurs in an image displayed by the display device.
Disclosure of Invention
The application provides a display panel driver and a display device, which can avoid the problem that the image displayed by the display device has color cast phenomenon. The technical scheme is as follows:
a display panel driver is used for driving a display panel, the display panel comprises a plurality of scanning lines, a plurality of driving lines and a plurality of light-emitting units, each light-emitting unit in the plurality of light-emitting units is respectively connected with one scanning line in the plurality of scanning lines and one driving line in the plurality of driving lines, and the driving lines connected with the plurality of light-emitting units connected to the same scanning line are different;
the display panel driver includes: a timing controller and a plurality of first switches;
a first end of each of the plurality of first switches is connected to one end of one of the plurality of driving lines, a second end of each of the plurality of first switches is connected to a preset signal end, and a control end of each of the plurality of first switches is connected to the timing controller; when any one of the plurality of scanning lines outputs a scanning signal and the timing controller controls any one of the plurality of first switches to be turned on, the light emitting unit connected to the scanning line outputting the scanning signal and connected to the driving line connected to the turned-on first switch emits light.
In the present application, a display panel driver includes a timing controller and a plurality of first switches. Each first switch is connected between one driving wire and a preset signal end, and the control end of each first switch is connected with the time schedule controller. When the display panel driver works, if the time schedule controller controls a certain first switch to be conducted, the light-emitting unit connected with the driving wire connected with the first switch and the parasitic capacitor of the driving wire connected with the first switch output current to a preset signal end. If the time schedule controller controls the first switch to be turned off, the parasitic capacitance of the light-emitting unit connected with the driving wire connected with the first switch and the parasitic capacitance of the driving wire connected with the first switch can not output current to a preset signal end. In this case, when the on-time of the first switch is controlled to control the light emitting brightness of the light emitting unit connected to the driving line connected to the first switch, the current amount ratio of the light emitting unit does not change with the change of the light emitting brightness, and thus, with the decrease of the light emitting brightness of each light emitting unit, the color cast phenomenon of the display panel driven by the display panel driver does not occur.
Optionally, the display panel driver further includes the preset signal terminal, and the preset signal terminal is a current source.
Optionally, the current source is connected with the timing controller;
the time schedule controller is used for: acquiring image data of an image to be displayed, wherein the image data comprises a plurality of target gray scale values, and the plurality of target gray scale values are the target gray scale values of the plurality of light-emitting units one by one; if each target gray scale value in the plurality of target gray scale values is smaller than or equal to a preset gray scale value, controlling the current source to output a first preset current; and if at least one target gray scale value in the target gray scale values is larger than a preset gray scale value, controlling the current source to output a second preset current, wherein the second preset current is smaller than the first preset current.
Optionally, the preset signal terminal is a ground line.
Optionally, the display panel driver further includes: a resistance;
a first terminal of the resistor is connected to a second terminal of each of the plurality of first switches, and a second terminal of the resistor is connected to the ground.
Optionally, the number of the light emitting units is N × M, the light emitting units are arranged in N rows and M columns, the number of the scanning lines is N, the number of the driving lines and the number of the first switches are M, a p-th light emitting unit in an i-th row is connected with an i-th scanning line in the N scanning lines and a p-th driving line in the M driving lines, N and M are positive integers, i is an integer greater than or equal to 1 and less than or equal to N, and p is an integer greater than or equal to 1 and less than or equal to M;
the display panel driver further includes: a scanning unit and N second switches;
the scanning unit is configured to output a scanning signal, a first end of each of the N second switches is connected to an output end of the scanning unit, and a second end of each of the N second switches is connected to one end of one of the N scanning lines, so that when any one of the N second switches is turned on, the scanning line connected to the turned-on second switch outputs the scanning signal;
the control end of each of the N second switches is connected to the timing controller, and the timing controller is configured to: controlling the ith second switch of the N second switches to be conducted in a first time period; controlling the ith second switch to be switched off within a second time period; and controlling the (i + 1) th second switch in the N second switches to be conducted in a third time length.
Optionally, the timing controller is further configured to: acquiring image data of an image to be displayed, wherein the image data comprises N × M target gray scale values, and the N × M target gray scale values are the target gray scale values of the N × M light-emitting units one by one; according to the target gray-scale value of the p-th light-emitting unit on the ith row, the first conducting time length of the p-th first switch in the M first switches in the first time length and the second conducting time length of the p-th first switch in the second time length are obtained, and the p-th first switch is conducted in the first conducting time length and the second conducting time length.
Optionally, the timing controller stores a first corresponding relationship, where the first corresponding relationship is a corresponding relationship between a target gray-scale value and a driving duration;
the time schedule controller is used for: and acquiring corresponding driving time length from the first corresponding relation according to the target gray-scale value of the p-th light-emitting unit in the ith row to be used as the first conduction time length of the p-th first switch in the first time length.
Optionally, the timing controller stores a second corresponding relationship, where the second corresponding relationship is a corresponding relationship between a target gray-scale value and a charge bleeding time;
the time schedule controller is used for: and acquiring corresponding charge drainage time length from a second corresponding relation according to the target gray-scale value of the p-th light-emitting unit in the ith row to serve as second conduction time length of the p-th first switch in the second time length.
In a second aspect, there is provided a display device comprising a display panel and the display panel driver according to any one of the first aspect;
the display panel includes a plurality of scan lines, a plurality of driving lines, and a plurality of light emitting units, each of the plurality of light emitting units is connected to one of the plurality of scan lines and one of the plurality of driving lines, respectively, and the driving lines connected to the plurality of light emitting units connected to the same scan line are different.
It is understood that the beneficial effects of the second aspect can be referred to the related description of the first aspect, and are not described herein again.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic circuit structure diagram of a first display device according to an embodiment of the present disclosure;
fig. 2 is a schematic circuit structure diagram of a second display device according to an embodiment of the present disclosure;
fig. 3 is a timing diagram illustrating an operation of a display device according to an embodiment of the present application;
fig. 4 is a schematic equivalent circuit diagram of a display device according to an embodiment of the present application;
fig. 5 is a schematic circuit diagram of a display device according to a second embodiment of the present application;
fig. 6 is a schematic circuit diagram of a first display device according to a third embodiment of the present application;
fig. 7 is a schematic circuit structure diagram of a second display device according to a third embodiment of the present application;
fig. 8 is an operation timing diagram of a display device according to a third embodiment of the present application.
Wherein, the meanings represented by the reference numerals are as follows:
10. a display panel;
110. scanning a line;
120. a drive line;
130. a light emitting unit;
20. a display panel driver;
210. a first switch;
220. a time schedule controller;
230. presetting a signal end;
232. a current source;
240. a scanning unit;
250. a second switch;
30. a display device.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
It should be understood that reference to "a plurality" in this application means two or more. In the description of the present application, "/" means "or" unless otherwise stated, for example, a/B may mean a or B; "and/or" herein is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, for the convenience of clearly describing the technical solutions of the present application, the terms "first", "second", and the like are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.
Before explaining the embodiments of the present application in detail, an application scenario of the embodiments of the present application will be described.
The display device includes a display panel driver and a display panel. The display panel driver is used for outputting a driving signal. The display panel includes a plurality of scan lines, a plurality of driving lines, and a plurality of light emitting units. The plurality of scanning lines are used for outputting scanning signals one by one, and the time for which each scanning line continuously outputs the scanning signals is one scanning period. The driving lines are connected with the display panel driver to receive and output driving signals. Each of the plurality of light emitting units is connected to one of the plurality of scanning lines and one of the plurality of driving lines, and the driving lines to which the plurality of light emitting units connected to the same scanning line are connected are different. When the display panel works, if one scanning line outputs a scanning signal and one driving line outputs a driving signal, the light-emitting units connected with the scanning line and the driving line emit light.
In the related art, when the display device displays a frame of image, the scanning periods of the scanning lines are all equal. In each scanning period, the display panel driver controls the light emitting brightness of each light emitting unit to which the scanning signal is input in the scanning period by controlling the duration of the driving signal output to each driving line. The longer the duration of the driving signal output by the display panel driver to any one driving line, the higher the light emission luminance of the light emitting unit connected to the driving line.
However, the driving lines of the display panel may have parasitic capacitance. In one scanning period, for any one driving line, the amount of current output by the driving line to the display panel driver is equal to the sum of the amount of current output by the light-emitting unit to the display panel driver and the amount of current output by the parasitic capacitor to the display panel driver. When the light emitting brightness of the light emitting unit is reduced, since the duration of the driving signal output to the light emitting unit by the display panel driver through the driving line is shortened, the amount of current output to the display panel driver by the light emitting unit is reduced, while the amount of current output to the display panel driver by the parasitic capacitance is not changed, which causes the duty ratio of the amount of current of the light emitting unit to be reduced. Generally, the light emitting unit includes a red light emitting unit, a green light emitting unit, and a blue light emitting unit. When the ratio of the current amount to the light emitting cells is small, the light emitting cells of different colors are affected differently. For example, when the red light emitting unit is less affected, the color of the display image of the display device is generally reddish. That is, as the light emission luminance of each light emitting unit decreases, a color cast phenomenon occurs in an image displayed by the display device.
Therefore, the embodiments of the present application provide a display panel driver and a display device, which can solve the problem in the related art that the color cast phenomenon occurs in the image displayed by the display device along with the reduction of the light emitting brightness of each light emitting unit.
The first embodiment is as follows:
fig. 1 is a schematic circuit diagram of a display device 30 according to an embodiment of the present disclosure. As shown in fig. 1, the display device 30 includes a display panel 10 and a display panel driver 20.
The display panel 10 includes a plurality of scan lines 110, a plurality of driving lines 120, and a plurality of light emitting units 130. The scan lines 110 and the driving lines 120 are conductive lines. Each scan line 110 is for outputting a scan signal, and each driving line 120 is for outputting a driving signal. The Light Emitting unit 130 is an electroluminescent device, for example, the Light Emitting unit 130 may be a Light-Emitting Diode (LED), an Organic Light-Emitting Diode (OLED), a micro-LED (micro LED), or the like. Each of the plurality of light emitting units 130 is connected to one of the plurality of scanning lines 110 and to one of the plurality of driving lines 120, and 130 is connected to one of the plurality of scanning lines 110. Meanwhile, the driving lines 120 to which the plurality of light emitting units 130 connected to the same scanning line 110 are connected are different.
For example, in the embodiment shown in fig. 1, the plurality of scan lines 110 includes G1, G2, G3, and G4, and the plurality of drive lines 120 includes S1, S2, S3, and S4. Each of the light emitting units 130 is connected to one of G1, G2, G3, and G4, and to one of S1, S2, S3, and S4. As such, when G1 outputs a scan signal and S1 outputs a driving signal, the light emitting unit 130 connected to G1 and S1 emits electroluminescence. When G1 outputs a scan signal and S2 outputs a driving signal, the light emitting unit 130 connected to G1 and S2 emits light electrically.
The display panel driver 20 includes a timing controller 220 and a plurality of first switches 210. Each first switch 210 is a three terminal device. That is, each of the first switches 210 has a first terminal, a second terminal, and a control terminal. For any first switch 210, the control terminal of the first switch 210 is used to control the on and off between the first terminal and the second terminal of the first switch. A first terminal of each first switch 210 is connected to one terminal of one driving line 120, respectively. A second terminal of each of the first switches 210 is connected to a preset signal terminal 230. The control terminal of each first switch 210 is connected to the timing controller 220, so that the timing controller 220 can control on and off of each first switch 210, i.e., control on and off between the first terminal and the second terminal of each first switch 210.
For example, in the embodiment shown in fig. 1, the plurality of first switches 210 includes K1, K2, K3, and K4. The first end of K1 is connected to the lower end of S1 in the paper plane direction; a first end of K2 is connected to the lower end of S2 in the paper surface direction; a first end of K3 is connected to the lower end of S3 in the paper surface direction; the first end of K4 is connected to the lower end of S4 in the paper surface direction. In other embodiments, the first ends of K1, K2, K3, and K4 may also be connected to the upper ends of S1, S2, S3, and S4 along the paper, respectively, and will not be described again. Second terminals of K1, K2, K3 and K4 are all connected to the preset signal terminal 230, and on and off of K1, K2, K3 and K4 are all controlled by the timing controller 220. When the timing controller 220 controls the switch K1 to be turned on, S1 outputs a driving signal; when the timing controller 220 controls the switch K3 to be turned on, S3 outputs a driving signal. In some embodiments, as shown in fig. 2, the first switch 210 may be a metal-oxide-semiconductor (MOS) field-effect transistor. In other embodiments, not shown, the first switch 210 may also be a triac or other three-terminal switching device.
When any one of the scan lines 110 outputs a scan signal and the timing controller 220 controls any one of the first switches 210 to be turned on, the light emitting unit 130 connected to the scan line 110 outputting the scan signal and connected to the driving line 120 connected to the turned-on first switch 210 emits light. For example, in the embodiment shown in fig. 1, when G2 outputs a scan signal and K2 is turned on, the light emitting unit 130 connected to G2 and S2 emits light. When G3 outputs a scan signal and K4 is turned on, the light emitting unit 130 connected to G3 and S4 emits light. Fig. 3 is a timing diagram of an operation of the display device 30 according to the first embodiment of the present disclosure, and fig. 4 is a schematic diagram of an equivalent circuit of the display device 30 according to the first embodiment of the present disclosure. The parasitic capacitance of each drive line 120 is identified in fig. 4, where C1 is the parasitic capacitance of S1, C2 is the parasitic capacitance of S2, C3 is the parasitic capacitance of S3, and C4 is the parasitic capacitance of S4. The operation of the display device 30 will be described with reference to fig. 1, 3 and 4:
in operation of the display device 30, the plurality of scan lines 110 are used for sequentially outputting scan signals, and each of the plurality of driving lines 120 is used for outputting a driving signal when any one of the scan lines 110 outputs a scan signal. In the embodiment shown in fig. 3, the high levels of G1, G2, G3, and G4 indicate that G1, G2, G3, and G4 output scan signals. The low levels of S1, S2, S3, and S4 indicate that S1, S2, S3, and S4 output drive signals. That is to say: during the t1 period, G1 outputs a scan signal. In this period, if the driving signal is output at S1, the light emitting unit 130 connected to G1 and S1 emits light. The longer the time for which the S1 outputs the driving signal, the higher the luminance of the light emitting unit 130 connected to G1 and S1. Likewise, if the S2 outputs the driving signal during the t1 period, the light emitting unit 130 connected to G1 and S2 emits light. The longer the time for which the S2 outputs the driving signal, the higher the luminance of the light emitting unit 130 connected to G1 and S2. In the t2 period, none of G1, G2, G3, and G4 outputs a scan signal, that is, the t2 period is a line blank period in which no light emitting unit 130 emits light. During the t3 period, G2 outputs a scan signal. In the embodiment shown in fig. 3, the t3 period includes a t31 period and a t32 period. During the t31 period, the S2 outputs the driving signal, that is, during the t31 period, the light emitting unit 130 connected to G2 and S2 emits light. During the t32 period, the S1 and S3 output driving signals, that is, during the t32 period, the light emitting units 130 connected to G2 and S1 emit light, and the light emitting units 130 connected to G2 and S3 emit light. The S4 continues to output the driving signal for the entire t3 period, that is, the light emitting unit 130 connected to G2 and S4 emits light for the t3 period. It can be known that, in the period t3, the luminance of the light emitting unit 130 connected to G2 and S4 is the highest, and the luminance of the light emitting unit 130 connected to G2 and S2 is the lowest. The subsequent periods of t4, t5, t6, and t7 are not described in detail. When the period from t1 to t7 is completed, the display panel 10 in the display device 30 shown in fig. 1 or 4 displays one frame of image.
In this process, taking the light emitting process of the time period t3 as an example, that is, taking the light emitting process of the light emitting unit 130 connected to G2 as an example, in the time period t3, the amount of current output from S1 to the display panel driver 20 is:
Il＝ILl·t32+IC·t32＝(IL1+IC)t32
wherein, I1Amount of current, I, output to the display panel driver 20 for S1L1Is the current magnitude of the light emitting cell 130 connected to G2 and S1, ICThe magnitude of the current output by the parasitic capacitor C1 of S1, t32The length of time of the t32 period. From this, it can be seen that, of the amounts of current output from S1 to the display panel driver 20, the ratio of the amounts of current output from the light-emitting unit 130 connected to G2 and S1 to the display panel driver 20 is:
Figure BDA0003329123340000091
similarly, in the period t3, of the current amount output to the display panel driver 20 from S2, the ratio of the current amounts output to the display panel driver 20 from the light emitting units 130 connected with G2 and S2 is:
Figure BDA0003329123340000092
wherein，IL2Is the current magnitude of the light emitting cell 130 connected to G2 and S2, IC2The magnitude of the current output by the parasitic capacitor C2 of S2.
Therefore, for the light emitting process of any one light emitting unit 130, under the condition that the current magnitude of the light emitting unit 130 and the current magnitude of the parasitic capacitance of the driving line 120 connected to the light emitting unit 130 are not changed, when the on-time of the first switch 210 connected to the light emitting unit 130 is controlled to control the light emitting brightness of the light emitting unit 130, the current occupation ratio of the light emitting unit 130 does not change along with the change of the light emitting brightness. In other words, when any one of the light emitting units 130 stops emitting light and does not output current to the display panel driver 20 by the control of each first switch 210, the parasitic capacitance of the driving line 120 connected to the light emitting unit 130 does not output current to the display panel driver 20, so that the ratio of the amount of current output from the light emitting unit 130 to the display panel driver 20 does not change with the change of the light emitting time.
In the embodiment of the present application, the display panel driver 20 includes a timing controller 220 and a plurality of first switches 210. Each of the first switches 210 is connected between one of the driving lines 120 and a preset signal terminal 230, and a control terminal of each of the first switches 210 is connected to the timing controller 220. When the display panel driver 20 is in operation, if the timing controller 220 controls a first switch 210 to be turned on, the parasitic capacitances of the light emitting unit 130 connected to the driving line 120 connected to the first switch 210 and the driving line 120 connected to the first switch 210 output current to the predetermined signal terminal 230. If the timing controller 220 controls the first switch 210 to be turned off, the parasitic capacitance of the light emitting unit 130 connected to the driving line 120 connected to the first switch 210 and the parasitic capacitance of the driving line 120 connected to the first switch 210 cannot output current to the predetermined signal terminal 230. In this case, when the on-time of the first switch 210 is controlled to control the light emitting brightness of the light emitting unit 130 connected to the driving line 120 connected to the first switch 210, the current amount ratio of the light emitting unit 130 does not change with the change of the light emitting brightness, so that the color cast phenomenon does not occur in the display panel 10 driven by the display panel driver 20 with the decrease of the light emitting brightness of each light emitting unit 130.
It is understood that, in the above embodiments, the preset signal terminal 230 is introduced to describe the connection manner of the first switches 210 and the operation process of the display panel driver 20 for facilitating understanding, however, this does not represent that the display device 30 and the display panel driver 20 provided in the embodiments of the present application include the preset signal terminal 230. In other words, the default signal terminal 230 may exist as an environmental element in the embodiment of the present application. The display panel driver 20 provided in the embodiment of the present application may include the preset signal terminal 230, or may not include the preset signal terminal 230.
Example two:
fig. 5 is a schematic circuit diagram of a display device 30 according to a second embodiment of the present application. As shown in fig. 5, in some embodiments, the display panel driver 20 may further include a preset signal terminal 230, where the preset signal terminal 230 may be a current source 232. In the embodiment shown in fig. 5, the first switch 210 is a mosfet. In some embodiments, the current source 232 may be connected to the timing controller 220, such that the timing controller 220 controls the magnitude of the current output by the current source 232.
Specifically, the timing controller 220 is operative to implement the following steps S110 to S130:
s110, obtaining image data of an image to be displayed, where the image data includes a plurality of target gray scale values, and the plurality of target gray scale values are target gray scale values of the plurality of light emitting units 130 one by one.
When the display device 30 is applied to a Personal Computer (PC) or a notebook Computer, image data of an image to be displayed may be transmitted from a main board or a video card of the PC or the notebook Computer. When the display device 30 is applied to a mobile terminal such as a mobile phone or a tablet computer, the image data of the image to be displayed may be sent by a Central Processing Unit (CPU) of the mobile phone or the tablet computer. The image to be displayed here refers to one frame image. The image data of the image to be displayed includes a plurality of target gray scale values. In general, the number of target gray scale values in the image data may be equal to the number of light emitting units 130 in the display panel 10. The plurality of target gray-scale values are target gray-scale values of the plurality of light emitting units 130. For example, for the embodiment shown in fig. 5, the display panel 10 includes 16 light emitting units 130. The image data of the image to be displayed may also include 16 target gray-scale values, each target gray-scale value corresponding to one light-emitting unit 130, so that the image to be displayed is displayed on the display panel 10 after the display panel driver 20 drives the 16 light-emitting units 130 of the display panel 10 to emit light.
S120, if each of the plurality of target gray-scale values is less than or equal to the preset gray-scale value, the current source 232 is controlled to output a first preset current.
S130, if at least one of the target gray-scale values is greater than the preset gray-scale value, the current source 232 is controlled to output a second preset current, and the second preset current is smaller than the first preset current.
The preset gray scale value here may be 32 gray scales. The gray scale is an expression of brightness, and for any one of the light emitting units 130, when the display panel driver 20 drives the display panel 10 according to the image data of the image to be displayed, if the target gray scale value of a certain light emitting unit 130 is higher, the larger the amount of current flowing through the light emitting unit 130 (i.e. the amount of current output by the light emitting unit 130 to the display panel driver 20) is, the higher the brightness of the light emitting unit 130 is. As can be seen from the description of the first embodiment, in the embodiment of the present application, when any one of the light emitting units 130 stops emitting light and does not output current to the display panel driver 20 through the control of each first switch 210, the parasitic capacitance of the driving line 120 connected to the light emitting unit 130 does not output current to the display panel driver 20. Thus, in the driving time period of each scan line 110 outputting the scan signal, the total current amount output from the scan line 110 to the display panel driver 20 by the light-emitting unit 130 with smaller luminance is smaller, which results in the decrease of the luminance of the light-emitting unit 130, i.e. the actual gray-scale value of the light-emitting unit 130 (the gray-scale value of the light-emitting unit 130 during light emission) is smaller than the target gray-scale value. For this reason, in the embodiment of the present application, the magnitude of the output current of the current source 232 may also be controlled by the timing controller 220 according to the magnitudes of the plurality of target gray-scale values. When each of the plurality of target gray scale values is less than or equal to the predetermined gray scale value, it indicates that the display device 30 operates in the low gray scale mode, and the power-on time of each of the light emitting units 130 is short. In this case, to prevent the luminance of the display panel 10 from being low, i.e. to prevent the actual gray-scale value of each light-emitting unit 130 from being smaller than the target gray-scale value, the current source 232 may be controlled to output a larger first predetermined current. When at least one of the target gray scale values is greater than the preset gray scale value, it indicates that the display device 30 may not be operated in the low gray scale mode. In this case, the current source 232 can be controlled to output a smaller second predetermined current, so as to prevent the light emitting brightness of the display panel 10 from being too high when the display panel operates in the high gray-scale mode. Generally, the second predetermined current is equal to the current outputted by the driver of the display panel 10 in the related art.
In the above embodiment, the timing controller 220 is configured to control the magnitude of the output current of the current source 232 according to a plurality of target gray-scale values. In other embodiments, the timing controller 220 can also control the current magnitude outputted from the current source 232 to each driving line 120 according to each target gray-scale value. For example, for the display device 30 shown in fig. 5, if the target gray-scale values of the light-emitting units 130 connected to G1 in the image data of the image to be displayed along the left-to-right direction of the paper are 12, 32, 64, and 130, respectively, and the preset gray-scale value is 32, the timing controller 220 may control the four output terminals of the current source 232 along the left-to-right direction of the paper to output the first preset current, the second preset current, and the second preset current, respectively. That is, in this case, after the timing controller 220 acquires image data of an image to be displayed, the magnitude of current input in each light emitting unit 130 is controlled according to the target gray scale value of each light emitting unit 130. Thus, when the target gray-scale value of a certain light-emitting unit 130 is smaller than the preset gray-scale value and the target gray-scale values of other light-emitting units 130 are larger than the preset gray-scale value, the light-emitting unit 130 can be prevented from emitting light with a low brightness, that is, the actual gray-scale value of the light-emitting unit 130 is prevented from being smaller than the target gray-scale value, so that the brightness uniformity of the display device 30 displaying images can be improved.
In some embodiments, the timing controller 220 further stores a first corresponding relationship between the target gray-scale value and the driving time length. For example, the first correspondence may be as shown in table 1 below:
TABLE 1
Target gray scale value g000 g001 g002 g003 g004 g005 g006 g007
Duration of driving t001 t002 t003 t004 t005 t006 t007 t008
Target gray scale value g008 g009 g010 g011 g012 g013 g014 g015
Duration of driving t009 t010 t011 t012 t013 t014 t015 t016
Target gray scale value g016 g017 g018 …… g252 g253 g254 g255
Duration of driving t017 t018 t019 …… t253 t254 t255 t256
As can be seen from table 1, when the target gray scale value of the light emitting unit 130 connected to G1 and S1 is G000, the driving time period corresponding to the light emitting unit 130 connected to G1 and S1 is t 001. That is, when G1 outputs the scan signal, the timing controller 220 controls a time period during which the first switch 210 connected to S1 is turned on t 001. When the target gray scale value of the light emitting unit 130 connected to G1 and S1 is G011, the driving time period corresponding to the light emitting unit 130 connected to G1 and S1 is t 012. That is, when G1 outputs the scan signal, the timing controller 220 controls a duration for which the first switch 210 connected to S1 is turned on t 012.
Example three:
fig. 6 is a schematic circuit structure diagram of a display device 30 according to a third embodiment of the present application. As shown in fig. 6, in some embodiments, the predetermined signal terminal 230 is the ground GND. At this time, the display panel driver 20 may further include a resistor R. A first terminal of the resistor R is connected to a second terminal of each of the plurality of first switches 210. The second end of the resistor R is connected to ground GND. That is, the resistor R is connected between the ground GND and the plurality of first switches 210. In the embodiment shown in fig. 6, the first switch 210 is a mosfet.
In some embodiments, the number of the light emitting units 130 is N × M, and the light emitting units 130 are arranged in N rows and M columns. The number of the plurality of scan lines 110 is N. The number of the plurality of driving lines 120 and the plurality of first switches 210 is M. The p-th light emitting unit 130 in the i-th row is connected to the i-th scan line 110 of the N scan lines 110 and the p-th driving line 120 of the M driving lines 120. N and M are both positive integers. i is an integer greater than or equal to 1 and less than or equal to N, and p is an integer greater than or equal to 1 and less than or equal to M. For example, fig. 7 is a schematic circuit structure diagram of another display device 30 provided in the third embodiment of the present application, and in the embodiment shown in fig. 7, N and M are both 4. The 4 scan lines 110 include G1, G2, G3, and G4, the 4 drive lines 120 include S1, S2, S3, and S4, and the 4 first switches 210 include K1, K2, K3, and K4. All the light emitting cells 130 in the 1 st row are connected to G1, all the light emitting cells 130 in the 2 nd row are connected to G2, all the light emitting cells 130 in the 3 rd row are connected to G3, and all the light emitting cells 130 in the 4 th row are connected to G4. All the light emitting cells 130 located at the 1 st column are connected to S1, all the light emitting cells 130 located at the 2 nd column are connected to S2, all the light emitting cells 130 located at the 3 rd column are connected to S3, and all the light emitting cells 130 located at the 4 th column are connected to S4.
As shown in fig. 7, the display panel driver 20 further includes: a scan unit 240, and N second switches 250. The scan unit 240 is used for outputting a scan signal. Each second switch 250 is a three terminal device. That is, each of the second switches 250 has a first terminal, a second terminal, and a control terminal. For any one of the second switches 250, the control terminal of the second switch 250 is used for controlling the on and off between the first terminal and the second terminal thereof. A first terminal of each second switch 250 is connected to an output terminal of the scan unit 240. A second terminal of each of the second switches 250 is connected to one terminal of one of the scan lines 110, respectively. The control terminal of each second switch 250 is connected to the timing controller 220 (connection relation is not shown in the figure), so that the timing controller 220 can control on and off of each second switch 250, i.e. control on and off between the first terminal and the second terminal of each second switch 250. When one second switch 250 is turned on, the scan line 110 connected to the turned-on second switch 250 outputs a scan signal.
For example, in the embodiment shown in fig. 7, the plurality of second switches 250 includes K11, K12, K13, and K14. The second end of K11 is connected with the left end of G1 along the paper surface; the second end of K12 is connected with the left end of G2 along the paper surface; the second end of K13 is connected with the left end of G3 along the paper surface; the second end of K14 is connected to the left end of G4 in the direction of the page. In other embodiments, the second ends of K11, K12, K13, and K14 may also be connected to the right ends of G1, G2, G3, and G4 in the paper direction, respectively, and will not be described in detail. First terminals of K11, K12, K13 and K14 are all connected to an output terminal of the scan unit 240, and on and off of K11, K12, K13 and K14 are all controlled by the timing controller 220. When the timing controller 220 controls the switch K11 to be turned on, G1 outputs a scan signal; when the timing controller 220 controls the switch K12 to be turned on, G2 outputs a scan signal. In some embodiments, the second switch 250 may be a MOS field effect transistor. In other embodiments, the second switch 250 may also be a triac or other three-terminal switching device.
In order to sequentially output the scan signals from the plurality of scan lines 110 when the display device 30 is in operation, the timing controller 220 is configured to perform the following steps S210 to S230:
s210, in the first time period, controlling the ith second switch 250 of the N second switches 250 to be turned on.
And S220, controlling the ith second switch 250 to be switched off in the second time period.
And S230, controlling the (i + 1) th second switch 250 in the N second switches 250 to be conducted in a third time period.
The first time length, the second time length and the third time length are three time periods which are adjacent in sequence and are not overlapped with each other. Each second switch 250 is in an off state when it does not receive a control signal. Taking i equal to 1 as an example, i is: in the first time period, the 1 st second switch 250 (i.e., K11) is controlled to be turned on, so that the G1 outputs a scan signal; in the second time period, controlling the 1 st second switch 250 (namely, K11) to be turned off, so that none of G1, G2, G3 and G4 outputs a scan signal; in the third period, the 2 nd second switch 250 (i.e., K12) is controlled to be turned on, so that the G2 outputs the scan signal. Thus, the sequential output of the scanning signals of G1 and G2 can be realized. In this process, the first time period may be the time period t1 in the embodiment shown in fig. 3, the second time period may be the time period t2 in the embodiment shown in fig. 3, and the third time period may be the time period t3 in the embodiment shown in fig. 3.
Taking i equal to 2 as an example, namely: in the first time period, the 2 nd second switch 250 (namely, K12) is controlled to be turned on, so that the G2 outputs a scan signal; in the second time period, the 2 nd second switch 250 (namely, K12) is controlled to be turned off, so that no scanning signal is output by G1, G2, G3 or G4; in the third time period, the 3 rd second switch 250 (i.e., K13) is controlled to be turned on, so that the G3 outputs the scan signal. Thus, the sequential output of the scanning signals of G2 and G3 can be realized. In this process, the first time period may be the time period t3 in the embodiment shown in fig. 3, the second time period may be the time period t4 in the embodiment shown in fig. 3, and the third time period may be the time period t5 in the embodiment shown in fig. 3.
When i traverses from 1 to N-1, that is, the value of i is sequentially equal to 1, 2, and 3 … … N-1, N scan lines 110 can sequentially output scan signals. Meanwhile, as can be seen from the above description, the second time period is a line blank time period, and in the second time period, no scan signal is output from each scan line 110, so that the amount of charge in each drive line 120 can be reduced. In this way, the amount of current output by the parasitic capacitor to the display panel driver 20 can be reduced, thereby improving the problem that the image displayed by the display device 30 may have a color cast phenomenon as the light emitting brightness of each light emitting unit 130 decreases.
In some embodiments, the timing controller 220 is further configured to implement the following steps S310 to S330, and the steps S310 to S330 may precede the step S210.
S310, acquiring image data of an image to be displayed, where the image data includes N × M target gray scale values, and the N × M target gray scale values are target gray scale values of the N × M light emitting units 130 one by one.
Step S310 is substantially the same as step S110 in the second embodiment, and is not repeated.
S320, according to the target gray-scale value of the p-th light-emitting unit 130 in the ith row, a first conduction time length of the p-th first switch 210 in the M first switches 210 within the first time length is obtained, and the p-th first switch 210 is conducted within the first conduction time length.
As is known from the above description, in the embodiment of the present application, for any one of the light emitting units 130, the light emitting brightness of the light emitting unit 130 is controlled by controlling the on-time of the first switch 210 connected to the driving line 120 connected to the light emitting unit 130, that is, the light emitting brightness of the light emitting unit 130 is controlled by controlling the light emitting time of the light emitting unit 130. Therefore, for any one of the light emitting units 130, after acquiring the target gray-scale value of the light emitting unit 130, the timing controller 220 may acquire the light emitting duration of the light emitting unit 130, that is, the on duration of the first switch 210 connected to the driving line 120 connected to the light emitting unit 130, according to the target gray-scale value of the light emitting unit 130. Thus, when the scan line 110 connected to the light emitting unit 130 outputs the scan signal, the timing controller 220 controls the first switch 210 connected to the driving line 120 connected to the light emitting unit 130 to be turned on within the obtained on-duration, so that the actual gray scale value of the light emitting unit 130 is equal to the target gray scale value.
Specifically, for the embodiment shown in FIG. 7, when i equals 1 and p equals 2, there are: a first on-period of K2 within the first period is obtained according to the target gray-scale value of the 2 nd light-emitting unit 130 of row 1. As such, when the timing controller 220 executes step S210, it may: during the first time period, the control K11 is conducted, and the conduction time period of the control K2 is the first conduction time period. Thus, the actual gray-scale value of the 2 nd light-emitting unit 130 in the 1 st row is equal to the target gray-scale value. Similarly, when i equals 3 and p equals 1, there are: a first on-period of K1 within the first period is obtained according to the target gray-scale value of the 1 st light-emitting unit 130 of row 3. As such, when the timing controller 220 executes step S210, it may: during the first time period, the control K13 is conducted, and the conduction time period of the control K1 is the first conduction time period. Thus, the actual gray-scale value of the 1 st light-emitting unit 130 in the 3 rd row is equal to the target gray-scale value.
In some embodiments, the timing controller 220 may also store the first corresponding relationship, which is the corresponding relationship between the target gray-scale value and the driving time length. The first corresponding relationship may be specifically shown in table 1 in embodiment two, and is not described again. Thus, when the timing controller 220 is operating, it can: according to the target gray-scale value of the p-th light emitting unit 130 in the ith row, the corresponding driving time length is obtained from the first corresponding relation and is used as the first conducting time length of the p-th first switch 210 in the first time length.
S330, according to the target gray-scale value of the p-th light-emitting unit 130 in the ith row, a second conduction time of the p-th first switch 210 in the M first switches 210 within a second time is obtained, and the p-th first switch 210 is conducted within the second conduction time.
As is known from the foregoing description, the second period is a line blank period, and in the second period, the amount of charge in each driving line 120 is reduced, so that the problem of color cast of the image displayed by the display device 30 along with the reduction of the light emitting brightness of each light emitting unit 130 can be improved. Here, in the case that the second end of each first switch 210 is connected to the ground GND through the resistor R, the timing controller 220 may further control each first switch 210 to be turned on for the second time period to release the charges in each driving line 120 to the ground GND, so as to further reduce the amount of charges in the driving lines 120 and improve the color cast problem of the display device 30.
When one scan line 110 outputs a scan signal, for a plurality of light emitting units 130 connected to the scan line 110, since the target gray scale value of each light emitting unit 130 may be different, that is, the driving lines 120 connected to each light emitting unit 130 output different driving signals for different time periods, the amount of charges in the different driving lines 120 is different when the scan line 110 stops outputting the scan signal. Therefore, for any one of the driving lines 120 connected to the light emitting unit 130, after acquiring the target gray-scale value of the light emitting unit 130, the timing controller 220 may acquire the charge draining time length required by the driving line 120 connected to the light emitting unit 130 according to the target gray-scale value of the light emitting unit 130. Thus, in the line blank period after the light emitting unit 130 emits light, the timing controller 220 controls the first switch 210 connected to the driving line 120 connected to the light emitting unit 130 to be turned on in the acquired charge draining period, so as to completely drain the charge in the driving line 120 connected to the light emitting unit 130.
Specifically, for the embodiment shown in FIG. 7, when i equals 1 and p equals 2, there are: the second on-period of K2 within the second period is obtained according to the target gray-scale value of the 2 nd light-emitting unit 130 of the 1 st row. Thus, when the timing controller 220 executes step S220, it may: during the second period, K11 is controlled to be OFF and the ON period of K2 is controlled to be the second ON period. In this way, after the 2 nd light-emitting cell 130 in the 1 st row is caused to emit light, the entire amount of charge in S2 is discharged to the ground GND. Similarly, when i equals 3 and p equals 1, there are: the second on-period of K1 within the second period is obtained according to the target gray-scale value of the 1 st light-emitting unit 130 of the 3 rd row. Thus, when the timing controller 220 executes step S220, it may: during the second period, the K13 is controlled to be off, and the K1 is controlled to be on for the second period. In this way, after the 1 st light-emitting cell 130 in the 3 rd row emits light, the entire amount of charge in S1 is discharged to the ground GND. In this embodiment, the operation timing chart of the display device may be as shown in fig. 8. At this time, during the line blank period (including the period t2, the period t4 and the period t 6) after each scan line 120 outputs the scan signal, the first switches 210 are all turned on to discharge the charges.
In some embodiments, a second corresponding relationship between the target gray-scale value and the charge draining time period may be stored in the timing controller 220. For example, the second correspondence relationship may be as shown in table 2 below:
TABLE 2
Target gray scale value g000 g001 g002 g003 g004 g005 g006 g007
Duration of charge bleed-off ta001 ta002 ta003 ta004 ta005 ta006 ta007 ta008
Target gray scale value g008 g009 g010 g011 g012 g013 g014 g015
Duration of charge bleed-off ta009 ta010 ta011 ta012 ta013 ta014 ta015 ta016
Target gray scale value g016 g017 g018 …… g252 g253 g254 g255
Duration of charge bleed-off ta017 ta018 ta019 …… ta253 ta254 ta255 ta256
As can be seen from table 2, when the target gray scale value of the light emitting cell 130 connected to G1 and S1 is G000, the corresponding charge draining time period of S1 after the light emitting cell 130 emits light is ta 001. That is, the timing controller 220 controls the time period for which K1 is turned on ta001 during the line blank time period after G1 outputs the scan signal. When the target gray scale value of the light emitting unit 130 connected with G1 and S1 is G011, the corresponding charge draining time length of S1 after the light emitting unit 130 emits light is ta 012. That is, the timing controller 220 controls the time period for which K1 is turned on ta001 during the line blank time period after G1 outputs the scan signal.
In other embodiments, the timing controller 220 may also control each of the first switches 210 to continuously maintain the on state in each line blanking period, so as to achieve the purpose of discharging charges to the driving line 120 and improve the color cast problem of the display device 30.
Example four:
in some embodiments, the number of the light emitting units 130 is N × M, and the light emitting units 130 are arranged in N rows and M columns. The number of the plurality of scan lines 110 is N. The number of the plurality of driving lines 120 and the plurality of first switches 210 is M. The p-th light emitting unit 130 in the i-th row is connected to the i-th scan line 110 of the N scan lines 110 and the p-th driving line 120 of the M driving lines 120. N and M are both positive integers.
In the above-described second and third embodiments, for the p-th light emitting unit 130 located in the i-th row, the driving time period of the light emitting unit 130 is related only to the target gray-scale value of the light emitting unit 130, i.e., the first corresponding relationship. In other embodiments, since the amount of charge remaining in the p-th driving line 120 is related to the target gray-scale value of the p-th light emitting unit 130 of the i-1 th row when the p-th light emitting unit 130 of the i-th row emits light, the timing controller 220 may also obtain the corresponding driving time period as the first on-time period of the p-th first switch 210 in the first time period according to the following third corresponding relationship. The third correspondence may be as shown in table 3 below:
TABLE 3
Figure BDA0003329123340000181
Where a denotes a target gray-scale value of the p-th light emitting cell 130 of the i-1 th row, C denotes a target gray-scale value of the p-th light emitting cell 130 of the i-th row, and B denotes a driving time period. The third correspondence relationship may be prestored in the timing controller 220.
The third corresponding relationship is suitable for obtaining the driving time of the light emitting units 130 in the 2 nd to nth rows in the display panel 10. For the light emitting units 130 in the row 1, the driving duration can still be obtained by using the first corresponding relationship, that is, the driving duration of the light emitting unit 130 is obtained according to the target gray-scale value of each light emitting unit 130 in the row 1, and the obtained driving duration is used as the conducting duration of each first switch 210 when the scanning signal is output by the 1 st scanning line 110.
As can be seen from table 3, when the target gray scale value of the light emitting unit 130 connected to G1 and S1 is G255 and the target gray scale value of the light emitting unit 130 connected to G2 and S1 is G001, the corresponding driving time period is t 001255. That is, when G2 outputs the scan signal, the timing controller 220 controls a time period during which the first switch 210 connected to S1 is turned on t 001255. When the target gray scale value of the light emitting unit 130 connected to G1 and S1 is G002 and the target gray scale value of the light emitting unit 130 connected to G2 and S1 is G254, the corresponding driving time period is t 254002. That is, when G2 outputs the scan signal, the timing controller 220 controls a time period during which the first switch 210 connected to S1 is turned on t 254002.
Example five:
in some embodiments, the number of the light emitting units 130 is N × M, and the light emitting units 130 are arranged in N rows and M columns. The number of the plurality of scan lines 110 is N. The number of the plurality of driving lines 120 and the plurality of first switches 210 is M. The p-th light emitting unit 130 in the i-th row is connected to the i-th scan line 110 of the N scan lines 110 and the p-th driving line 120 of the M driving lines 120. N and M are both positive integers.
In the third embodiment, for the p-th light emitting unit 130 in the ith row, the charge draining time of the driving line 120 connected to the light emitting unit 130 is only related to the target gray scale value of the light emitting unit 130. In other embodiments, the timing controller 220 may also obtain a corresponding charge draining time period as the on-time period of the pth first switch 210 in the second time period according to the following fourth corresponding relationship. The fourth correspondence may be as shown in table 4 below:
TABLE 4
Figure BDA0003329123340000191
Figure BDA0003329123340000201
Where a denotes a target gray-scale value of the p-th light emitting cell 130 of the i-th row, C denotes a target gray-scale value of the p-th light emitting cell 130 of the i + 1-th row, and B denotes a charge draining period. The fourth correspondence may be prestored in the timing controller 220.
The fourth corresponding relationship is suitable for obtaining the charge draining time of the driving line 120 connected with the light emitting units 130 in the 1 st to the N-1 st rows in the display panel 10. For the nth row of light emitting units 130, the charge draining time period can still be obtained by using the second corresponding relationship, that is, the charge draining time period of the driving line 120 connected to the light emitting unit 130 is obtained according to the target gray-scale value of each light emitting unit 130 in the nth row, and is used as the conducting time period of the first switch 210 connected to the driving line 120 connected to the light emitting unit 130 in the second time period.
As can be seen from table 4, when the target gray scale value of the light emitting cell 130 connected to G1 and S1 is G000 and the target gray scale value of the light emitting cell 130 connected to G2 and S1 is G255, the corresponding charge draining time period of the light emitting cell 130 connected to G1 and S1 after light emission is ta 255000. That is, the timing controller 220 controls the time period for which K1 is turned on to ta255000 during the blank time period after G1 outputs the scan signal. When the target gray scale value of the light emitting unit 130 connected to G1 and S1 is G254 and the target gray scale value of the light emitting unit 130 connected to G2 and S1 is G002, the corresponding charge draining time length of the light emitting unit 130 connected to G1 and S1 after light emission is ta 002254. That is, the timing controller 220 controls the time period for which K1 is turned on ta002254 during the blank time period after G1 outputs the scan signal.
In the embodiment of the present application, the display panel driver 20 includes a timing controller 220 and a plurality of first switches 210. Each of the first switches 210 is connected between one of the driving lines 120 and a preset signal terminal 230, and a control terminal of each of the first switches 210 is connected to the timing controller 220. When the display panel driver 20 is in operation, if the timing controller 220 controls a first switch 210 to be turned on, the parasitic capacitances of the light emitting unit 130 connected to the driving line 120 connected to the first switch 210 and the driving line 120 connected to the first switch 210 output current to the predetermined signal terminal 230. If the timing controller 220 controls the first switch 210 to be turned off, the parasitic capacitance of the light emitting unit 130 connected to the driving line 120 connected to the first switch 210 and the parasitic capacitance of the driving line 120 connected to the first switch 210 cannot output current to the predetermined signal terminal 230. In this case, when the on-time of the first switch 210 is controlled to control the light emitting brightness of the light emitting unit 130 connected to the driving line 120 connected to the first switch 210, the current amount ratio of the light emitting unit 130 does not change with the change of the light emitting brightness, so that the color cast phenomenon does not occur in the display panel 10 driven by the display panel driver 20 with the decrease of the light emitting brightness of each light emitting unit 130.
If each of the plurality of target gray scale values is less than or equal to the preset gray scale value, the timing controller 220 controls the current source 232 to output a first preset current; if at least one of the target gray scale values is greater than the preset gray scale value, the timing controller 220 controls the current source 232 to output a second preset current, which is less than the first preset current. In this way, it is possible to avoid the low light emitting luminance of the display panel 10 when the display device 30 operates in the low gray scale mode, and avoid the too high light emitting luminance of the display panel 10 when the display device 30 operates in the high gray scale mode. The predetermined signal terminal 230 may be a ground GND, and may control all the first switches 210 to be turned on during each line blanking period, so as to release the charges remaining in the driving line 120 to the ground GND, thereby further reducing the amount of charges in the driving line 120 and improving the color cast of the display device 30.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (7)

1. A display panel driver is used for driving a display panel, the display panel comprises a plurality of scanning lines, a plurality of driving lines and a plurality of light-emitting units, the plurality of light-emitting units are arranged in N rows and M columns, each light-emitting unit in the plurality of light-emitting units is respectively connected with one scanning line in the plurality of scanning lines and one driving line in the plurality of driving lines, and the driving lines connected with the plurality of light-emitting units connected to the same scanning line are different;
wherein the display panel driver includes: a timing controller and a plurality of first switches;
a first end of each of the plurality of first switches is connected to one end of one of the plurality of driving lines, a second end of each of the plurality of first switches is connected to a ground line, and a control end of each of the plurality of first switches is connected to the timing controller; when any one of the plurality of scanning lines outputs a scanning signal and the timing controller controls any one of the plurality of first switches to be turned on, the light emitting unit connected to the scanning line outputting the scanning signal and connected to the driving line connected to the turned-on first switch emits light;
the plurality of light emitting units emit light line by line, and the timing controller is configured to: after the plurality of light emitting units in the ith row emit light and before the plurality of light emitting units in the (i + 1) th row emit light, controlling the plurality of first switches to be conducted according to target gray-scale values of the plurality of light emitting units in the ith row, wherein i is an integer greater than or equal to 1 and less than or equal to N-1.
2. The display panel driver of claim 1, wherein the display panel driver further comprises: a resistance;
a first terminal of the resistor is connected to a second terminal of each of the plurality of first switches, and a second terminal of the resistor is connected to the ground.
3. The display panel driver according to claim 1 or 2, wherein the plurality of scanning lines is N in number, the plurality of driving lines and the plurality of first switches are M in number, a p-th light emitting unit located in an i-th row is connected to an i-th scanning line of the N scanning lines and a p-th driving line of the M driving lines, N and M are positive integers, p is an integer greater than or equal to 1 and less than or equal to M;
the display panel driver further includes: a scanning unit and N second switches;
the scanning unit is configured to output a scanning signal, a first end of each of the N second switches is connected to an output end of the scanning unit, and a second end of each of the N second switches is connected to one end of one of the N scanning lines, so that when any one of the N second switches is turned on, the scanning line connected to the turned-on second switch outputs the scanning signal;
the control end of each of the N second switches is connected to the timing controller, and the timing controller is configured to: controlling the ith second switch of the N second switches to be conducted in a first time period; controlling the ith second switch to be switched off in a second time length; and controlling the (i + 1) th second switch in the N second switches to be conducted in a third time length.
4. The display panel driver of claim 3, wherein the timing controller is further configured to: acquiring image data of an image to be displayed, wherein the image data comprises N × M target gray scale values, and the N × M target gray scale values are target gray scale values of the N × M light-emitting units one by one; according to the target gray-scale value of the p-th light-emitting unit on the ith row, the first conducting time length of the p-th first switch in the M first switches in the first time length and the second conducting time length of the p-th first switch in the second time length are obtained, and the p-th first switch is conducted in the first conducting time length and the second conducting time length.
5. The display panel driver according to claim 4, wherein the timing controller stores a first correspondence relationship between a target gray-scale value and a driving time period;
the time schedule controller is used for: and acquiring corresponding driving time length from the first corresponding relation according to the target gray-scale value of the p-th light-emitting unit in the ith row to be used as the first conduction time length of the p-th first switch in the first time length.
6. The display panel driver according to claim 4, wherein the timing controller stores a second correspondence relationship between a target gray-scale value and a charge bleeding time;
the time schedule controller is used for: and acquiring corresponding charge drainage time length from a second corresponding relation according to the target gray-scale value of the p-th light-emitting unit in the ith row to serve as second conduction time length of the p-th first switch in the second time length.
7. A display device comprising a display panel and the display panel driver according to any one of claims 1 to 6;
the display panel includes a plurality of scan lines, a plurality of driving lines, and a plurality of light emitting units, each of the plurality of light emitting units is connected to one of the plurality of scan lines and one of the plurality of driving lines, respectively, and the driving lines connected to the plurality of light emitting units connected to the same scan line are different.
CN202111274952.9A 2021-10-29 2021-10-29 Display panel driver and display device Active CN113920928B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111274952.9A CN113920928B (en) 2021-10-29 2021-10-29 Display panel driver and display device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111274952.9A CN113920928B (en) 2021-10-29 2021-10-29 Display panel driver and display device

Publications (2)

Publication Number Publication Date
CN113920928A CN113920928A (en) 2022-01-11
CN113920928B true CN113920928B (en) 2022-07-12

Family

ID=79243935

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111274952.9A Active CN113920928B (en) 2021-10-29 2021-10-29 Display panel driver and display device

Country Status (1)

Country Link
CN (1) CN113920928B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114420060B (en) * 2022-01-20 2023-06-30 上海龙旗科技股份有限公司 MiniLED backlight display device and method

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1471071A (en) * 2002-07-24 2004-01-28 胜园科技股份有限公司 Method for making organic LED display device present multi grey scales
CN1573880A (en) * 2003-06-11 2005-02-02 东北先锋电子股份有限公司 Drive device and drive method for light emitting display panel
CN1797520A (en) * 2004-12-28 2006-07-05 东北先锋电子股份有限公司 Method and apparatus for driving light-emitting display panel
JP2008096651A (en) * 2006-10-11 2008-04-24 Fuji Electric Holdings Co Ltd Precharging device and display including the same
CN101191923A (en) * 2006-12-01 2008-06-04 统宝光电股份有限公司 Liquid crystal display system and relevant driving process capable of improving display quality
JP2008170842A (en) * 2007-01-15 2008-07-24 Epson Imaging Devices Corp Electrooptical device, driving circuit, and electronic equipment
CN106548751A (en) * 2017-01-13 2017-03-29 北京小米移动软件有限公司 The display packing and device of display floater
CN112967664A (en) * 2020-12-31 2021-06-15 重庆康佳光电技术研究院有限公司 Drive circuit, display panel, drive method, and storage medium
CN113450704A (en) * 2020-10-13 2021-09-28 重庆康佳光电技术研究院有限公司 LED driving method, driving unit, display device and readable storage medium
CN113450701A (en) * 2020-07-22 2021-09-28 重庆康佳光电技术研究院有限公司 Data line control method and device, data line driving device and display device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105938703B (en) * 2016-06-14 2018-11-02 深圳君略科技有限公司 The driving chip, driving circuit and driving method of LED ghosts can be eliminated
CN107561752B (en) * 2017-09-28 2020-04-10 上海天马微电子有限公司 Array substrate, driving method thereof and display panel

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1471071A (en) * 2002-07-24 2004-01-28 胜园科技股份有限公司 Method for making organic LED display device present multi grey scales
CN1573880A (en) * 2003-06-11 2005-02-02 东北先锋电子股份有限公司 Drive device and drive method for light emitting display panel
CN1797520A (en) * 2004-12-28 2006-07-05 东北先锋电子股份有限公司 Method and apparatus for driving light-emitting display panel
JP2008096651A (en) * 2006-10-11 2008-04-24 Fuji Electric Holdings Co Ltd Precharging device and display including the same
CN101191923A (en) * 2006-12-01 2008-06-04 统宝光电股份有限公司 Liquid crystal display system and relevant driving process capable of improving display quality
JP2008170842A (en) * 2007-01-15 2008-07-24 Epson Imaging Devices Corp Electrooptical device, driving circuit, and electronic equipment
CN106548751A (en) * 2017-01-13 2017-03-29 北京小米移动软件有限公司 The display packing and device of display floater
CN113450701A (en) * 2020-07-22 2021-09-28 重庆康佳光电技术研究院有限公司 Data line control method and device, data line driving device and display device
CN113450704A (en) * 2020-10-13 2021-09-28 重庆康佳光电技术研究院有限公司 LED driving method, driving unit, display device and readable storage medium
CN112967664A (en) * 2020-12-31 2021-06-15 重庆康佳光电技术研究院有限公司 Drive circuit, display panel, drive method, and storage medium

Also Published As

Publication number Publication date
CN113920928A (en) 2022-01-11

Similar Documents

Publication Publication Date Title
EP1538594B1 (en) Pixel driving circuit for a display device and a driving method thereof
CN108417149B (en) Display panel, driving method thereof and display device
KR100450761B1 (en) Active matrix organic light emission diode display panel circuit
CN112700749B (en) Display panel driving method and driving device thereof, and display device
KR100565390B1 (en) Display device
KR102122179B1 (en) Display device and driving method thereof
US20180053460A1 (en) Light-emitting device (led) and led displaying circuit
KR20130123218A (en) Organic light-emitting diode display, circuit and method for driving thereof
US20040104870A1 (en) Display device and method of driving the same
KR20060114476A (en) Driving method of organic electro luminescence display device
US20230282175A1 (en) Method for controlling switching of multiplexer of display panel according to image content and display driver circuit thereof
CN113920928B (en) Display panel driver and display device
CN110400542B (en) Pixel driving circuit, display panel and display device
JP2004126056A (en) Display device and driving method therefor
CN110534054B (en) Display driving method and device, display device, storage medium and chip
EP1614092B1 (en) Display device having a sparkling effect and method for driving the same
KR20140022345A (en) Dsiplay device, electronic device, driving circuit, and driving method thereof
JP2003345307A (en) Display device and its driving method
CN111316345B (en) Sub-pixel circuit, active type electroluminescent display and driving method thereof
US10997915B2 (en) Pixel circuit, method for driving, and display device
CN113707081B (en) Display panel driver and display device
TWI834387B (en) Driving circuit for led panel and led panel thereof
US20100309099A1 (en) Display device and driving method thereof
US20220406240A1 (en) Display panel driving circuit and display panel
US20220415964A1 (en) Micro-led display device

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