CN110930937A - Display panel and driving method - Google Patents
Display panel and driving method Download PDFInfo
- Publication number
- CN110930937A CN110930937A CN201911317548.8A CN201911317548A CN110930937A CN 110930937 A CN110930937 A CN 110930937A CN 201911317548 A CN201911317548 A CN 201911317548A CN 110930937 A CN110930937 A CN 110930937A
- Authority
- CN
- China
- Prior art keywords
- current
- light emitting
- data line
- emitting diode
- electrically connected
- 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.)
- Granted
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]
Abstract
The present invention provides a display panel including: m gate lines arranged at intervals along a first direction; the n data lines are arranged at intervals along the second direction, and the m gate lines and the n data lines are insulated and crossed to define a plurality of sub-pixels; a plurality of light emitting diodes, each light emitting diode is formed in a sub-pixel, electrically connected with a data line and a gate line, and has a reverse bias current when in a non-working state; n current sources, each current source having an output current, each current source being formed in a sub-pixel, each current source being electrically connected to a data line and a gate line, respectively, each current source being connected to a different data line; and the driver is electrically connected with the m grid lines and the n data lines, and is used for controlling the working state of each light-emitting diode and each current source and controlling the reverse bias current and the output current to drive the light-emitting diodes in the working state to emit light. The invention also provides a driving method.
Description
Technical Field
The present invention relates to the field of image display technologies, and in particular, to a display panel and a driving method applied to the display panel.
Background
In the prior art, a plurality of pixel regions arranged in an array manner are defined on a display panel of a micro light emitting diode display, each pixel region includes a plurality of sub-pixels, each sub-pixel is provided with a micro light emitting diode, a driver outputs a driving signal to each micro light emitting diode to control each micro light emitting diode to emit light or close, and the micro light emitting diode display displays different pictures through the light emitting cooperation of each micro light emitting diode. The micro light-emitting diode has the characteristic of forward conduction and reverse cut-off, namely, if the anode voltage of the micro light-emitting diode is higher than the cathode voltage and the anode-cathode voltage difference is greater than the starting voltage of the micro light-emitting diode, the micro light-emitting diode is conducted at the moment, has a conduction current and has a direct ratio of the brightness of luminance to the conduction current; if the voltage of the anode of the micro light-emitting diode is lower than the voltage of the cathode and the voltage difference between the anode and the cathode is less than the breakdown voltage of the micro light-emitting diode, the micro light-emitting diode is cut off and does not emit light at the moment, and has a reverse bias current which is extremely small and close to zero.
Although the reverse bias current is very small, the number of the micro light emitting diodes on the display panel is large, the reverse bias current directions of the micro light emitting diodes are the same, and a large reverse bias current sum can be formed through accumulation, and the reverse bias current sum can influence the picture quality of the micro light emitting diode display and cause the picture contrast to be reduced.
Disclosure of Invention
One aspect of the present invention provides a display panel including:
m gate lines arranged at intervals along a first direction, wherein m is greater than 2;
n data lines arranged at intervals along a second direction, wherein n is larger than 2, the m gate lines and the n data lines are arranged in an insulated and crossed mode, and the m gate lines and the n data lines are arranged in an insulated and crossed mode to define a plurality of sub pixels;
a plurality of light emitting diodes, each light emitting diode being formed in a sub-pixel, each light emitting diode being electrically connected to a data line and a gate line defining the sub-pixel in which the light emitting diode is located, each light emitting diode having a reverse bias current when in a non-operating state;
n current sources, each current source having an output current, each current source being formed in a sub-pixel, each current source being electrically connected to a data line and a gate line defining the sub-pixel in which the current source is located, each current source being connected to a different data line; and
and the driver is electrically connected with the m gate lines and the n data lines, and is used for controlling the working state of each light-emitting diode and each current source and controlling the reverse bias current and the output current to drive the light-emitting diodes in the working state to emit light.
Another aspect of the present invention provides a driving method applied to the display panel as described above; the driving method comprises the following steps:
acquiring a target driving current of a light emitting diode in a current working state;
acquiring initial current on each data line, wherein the initial current on each data line is the superposition sum of reverse bias current of each light-emitting diode which is electrically connected with the data line and is currently in a non-working state and output current of a current source which is electrically connected with the data line; and
and outputting a driving signal to each data line according to the target driving current and the initial current.
The display panel provided by the embodiment of the invention comprises a plurality of light emitting diodes and a plurality of current sources, wherein each light emitting diode does not emit light but has a reverse bias current when in a non-working state, each current source has an output current, the reverse bias current and the output current are controlled by a driver to drive the light emitting diode in the working state to emit light, and the reverse bias current of the light emitting diode can be utilized to display an image.
Drawings
Fig. 1 is a schematic plan view of a display panel according to an embodiment of the present invention.
Fig. 2 is another schematic view of the planar structure of the display panel in fig. 1.
Fig. 3 is a schematic circuit diagram of the switch unit in fig. 2.
Fig. 4 is a schematic plan view of a display panel according to another embodiment of the present invention.
Fig. 5 is a schematic view of a distribution of sub-pixels in the display panel of fig. 1.
Fig. 6 is a schematic waveform diagram of driving signals output to each gate line in the operation process of the display panel in fig. 1.
FIG. 7 is a diagram illustrating a V-I characteristic of a light emitting diode.
Fig. 8 is a flowchart illustrating a driving method according to an embodiment of the present invention.
Fig. 9 is a schematic partial structure diagram of the display panel in fig. 2.
Fig. 10 is a timing diagram of signals related to a light emitting diode in a display panel according to an embodiment of the invention.
FIG. 11 is a comparison graph of luminance versus driving current characteristics of LEDs emitting different colors.
Fig. 12 is a flowchart illustrating a driving method according to a second embodiment of the present invention.
Fig. 13 is a timing diagram of signals related to a light emitting diode in a display panel according to a second embodiment of the present invention.
Fig. 14 is a schematic plan view of a display panel according to an alternative embodiment of the invention.
Description of the main elements
Switch unit 1512
Gate lines GL, GL 1-GLm
Data lines SL, SL1 to SLn
Steps S1, S2, S3, S4, S5, S6
The following detailed description will further illustrate the invention in conjunction with the above-described figures.
Detailed Description
Example one
Referring to fig. 1, a display panel 10 of the present embodiment includes a substrate 11, and m gate lines (GL 1-GLm, m > 2) and n data lines (SL 1-SLn, n > 2) formed on the substrate 11, where the gate lines are arranged in parallel and at intervals, the data lines are arranged in parallel, and the m gate lines and the n data lines are insulated from each other and crossed to define a plurality of sub-pixels 12 arranged in an array, as shown in fig. 1, an X direction is defined as a row direction of the sub-pixel array, and a Y direction is defined as a column direction of the sub-pixel array.
Referring to fig. 1, the display panel 10 further includes a plurality of light emitting diodes 13 disposed on the substrate 11, and each light emitting diode 13 is located in one of the sub-pixels 12. Each light emitting diode 13 has an anode and a cathode, the anode of each light emitting diode 13 is electrically connected to the gate line GL defining the sub-pixel 12 where it is located, and the cathode of each light emitting diode 13 is electrically connected to the data line SL defining the sub-pixel 12 where it is located. The light emitting diodes 13 in the same row of the array are electrically connected to the same gate line GL, and the light emitting diodes 13 in the same column of the array are electrically connected to the same data line SL. In this embodiment, the Light emitting Diode 13 may be a Micro-Light emitting Diode (Micro-LED) with a size of less than 100 micrometers, but the size of the Light emitting Diode 13 is not limited thereto in other embodiments.
Referring to fig. 1, the display panel 10 further includes a plurality of current sources 14, and each current source 14 is formed in one of the sub-pixels 12. In this embodiment, the number of the current sources 14 is equal to the number of the data lines SL, and each current source 14 is electrically connected to one data line SL and one gate line GL of the sub-pixel 12 where it is located. In this embodiment, each current source 14 is electrically connected to the same gate line GL, that is, each current source 14 is respectively located in the sub-pixels 12 in the same row of the array. In the present embodiment, each current source 14 is electrically connected to the m-th gate line (i.e., the gate line GLm), and in the present embodiment, the m-th gate line (the gate line GLm) is the gate line closest to the driver 15. That is, on the substrate 11, a current source 14 is disposed in one-to-one correspondence in a row of the sub-pixels 12 closest to the driver 15, and a light emitting diode 13 is disposed in one-to-one correspondence in the remaining sub-pixels 12. Each current source 14 has a constant output current i when turned onpThe output current ipAnd is superposed on the data line SL electrically connected to the current source 14 for driving the light emitting diode 13 currently in operation.
The light-emitting diodes 13 are used for image display by emitting light, while the current sources 14 are used only for supplying a constant output current ipAnd does not emit light, so that the sub-pixels on the substrate 11 where the current source 14 is disposed do not participate in image display. By arranging each current source 14 to electrically connect the gate line GLm closest to the driver 15 in this embodiment, it is advantageous to improve the influence of each sub-pixel 12 arranged with the current source 14 on the image display. In other embodiments, each current source 14 may be arranged to electrically connect the gate line GL1 farthest from the driver 15.
Referring to fig. 1, the display panel 10 further includes a driver 15 disposed on the substrate 11, wherein the driver 15 is electrically connected to the m gate lines and the n data lines for controlling the operating states of each of the light emitting diodes 13 and each of the current sources 14; i.e. for controlling the light emission or the turn-off of the respective leds 13, and for controlling the turn-on and turn-off of the respective current sources 14.
Referring to fig. 2, in the present embodiment, the driver 15 includes a plurality of display driving modules 151 electrically connected to the plurality of data lines SL in a one-to-one correspondence. The display driving modules 151 are configured to output driving signals to the data lines SL to drive the light emitting diodes 13 to emit light for image display according to the initial current on the data lines SL1 to SLn. In this embodiment, the driving signal is a current driving signal, each display driving module 151 includes a current control unit 1511 and a switch unit 1512 electrically connected to each other, and the switch unit 1512 is electrically connected between the data line SL and the current control unit 1511. The circuit structure of the switch unit in this embodiment is shown in fig. 3, in which the x terminal is an input terminal and is electrically connected to the data line SL; the end f is an output end and is electrically connected with the current control unit 1511; the s terminal and the s terminal are control terminals electrically connected to the timing control port of the driver 15 according to the s terminal and the s terminal
The timing signal inputted to the terminal can control the switch unit 1512 to be turned on or off. When the switch is turned on, the electrical signal output from the output terminal f is the initial current on the data line SL electrically connected to the switch unit 1512.
Referring to fig. 2, in the present embodiment, the current control unit 1511 is a controlled source, such as a current-controlled current source or a voltage-controlled current source. The current control current source has a fixed functional relationship between the input current (the initial circuit) and the output current (the current driving signal), and the current control unit 1511 outputs a current signal to the data lines SL respectively according to the initial current on the data lines SL when the current control voltage source is current-controlled, so as to drive the light emitting diodes 13 to emit light. The voltage-controlled current source has a fixed functional relationship between an input voltage (having a fixed functional relationship with the current driving signal) and an output current (the current driving signal), determines an input voltage corresponding to the initial current according to the initial current on the data lines SL, and outputs a current signal to each data line SL according to the input voltage to drive the light emitting diodes 13 to emit light.
Referring to fig. 4, in another embodiment, the current control unit 1511 may also be a variable resistor LdThe output current (the current drive signal) is changed by a change in the resistance value.
Referring to fig. 1 again, the display panel 10 of the present embodiment includes light emitting diodes 13 emitting three colors of red light, green light, and blue light respectively, the arrangement of the light emitting diodes 13 emitting three colors of red light, green light, and blue light on the display substrate 11 is as shown in fig. 5 (for convenience of viewing, a part of the structure is omitted in fig. 5), the light emitting diodes are located in the same row of sub-pixels 12, the three sub-pixels 12 arranged adjacently are used as a display pixel, and the light emitting diodes disposed in the three sub-pixels 12 arranged adjacently emit red light (R), green light (G), and blue light (B), respectively. Each row of sub-pixels 12 includes a plurality of the above-described display pixels.
Referring to fig. 6, the axis of abscissa in fig. 6 represents time, and the axis of ordinate represents driving signals (voltage signals) on the gate lines GL1 to GLm. In this embodiment, the display panel 10 operates in a plurality of display frames, the operation process of the display panel 10 in each display frame is substantially the same, the refresh rate of the display frame is 60 hz, and each display frame lasts for 16.67 ms. Taking the display frame (n) as an example, when the driving signal output from the driver 15 to the gate line GL is at a low level, the light emitting diode electrically connected to the gate line GL is in an on state, and when the driving signal output from the driver 15 to the gate line GL is at a high level, the light emitting diode electrically connected to the gate line GL is in an off state. The driver 15 sequentially outputs low-level drive signals V in the order from the gate lines GL1 to GLmGL(including V)GL1～VGLm) As for the gate lines GL1 to GLm, the light emitting diodes 13 electrically connected to the gate lines GL1 to GLm are sequentially in an operating state, and the light emitting brightness of the light emitting diodes 13 in the operating state is controlled by the current on the data line SL electrically connected thereto. In the present embodiment, the first and second electrodes are,at the same time, each light emitting diode 13 electrically connected to only one gate line GL is in an operating state (on), and each light emitting diode 13 electrically connected to the remaining gate lines is in a non-operating state (off); that is, at the same time, only one light emitting diode 13 on each data line SL is in an active state (on), and the rest of the light emitting diodes 13 are in an inactive state (off).
Referring to fig. 7, the abscissa indicates voltage and the ordinate indicates current. According to the characteristic of the LED of 'forward on and reverse off', the voltage of the anode of the LED 13 in the working state is higher than that of the cathode, and the voltage difference between the anode and the cathode is greater than the starting voltage V of the LED 13kThe luminance of the led 13 is proportional to the current in the led 13. The voltage of the cathode of the LED 13 in the non-working state is higher than that of the anode, and the voltage difference between the anode and the cathode is less than the breakdown voltage V of the LED 13brWhen the led 13 is in the off state, there is a reverse bias current, which is very small and close to zero. And the voltage difference between the anode and the cathode of the light emitting diode 13 is less than the breakdown voltage V of the light emitting diode 13brIn this case, the magnitude of the reverse bias current hardly changes with the change in the voltage difference. In this embodiment, the reverse bias currents of the light emitting diodes 13 electrically connected to each data line SL are equal when the light emitting diodes are in the non-operating state (the magnitude of the reverse bias current depends mainly on the structural characteristics of the light emitting diodes themselves).
In this embodiment, since only the light emitting diodes 13 electrically connected to one gate line GL are in an operating state and the light emitting diodes 13 electrically connected to the other gate lines GL are all in a non-operating state at the same time, for each data line SL, only one light emitting diode 13 of the light emitting diodes 13 electrically connected to each data line is in an operating state, and the other light emitting diodes 13 are all in a non-operating state. Each of the light emitting diodes 13 in the non-operating state has a reverse bias voltage, although the reverse bias voltage is extremely small and close to zero, there are often a large number (thousands, tens of thousands) of light emitting diodes in the display panel 10, and therefore, the sum of the reverse bias currents on the data lines SL is large after the reverse bias currents of the light emitting diodes 13 in the non-operating state are superimposed. In the present embodiment, a reverse bias current generated by each light emitting diode 13 in the non-operating state is used as a drive current for driving each light emitting diode 13 in the operating state. The following is detailed:
referring to fig. 8, the present embodiment further provides a driving method applied to the display panel 10, including the following steps:
step S1, obtaining the target driving current of the LED in the working state;
step S2, acquiring initial current on each data line;
in step S3, a driving signal is output to each data line according to the target driving current and the initial current.
The present embodiment provides a display panel 10 in which the operation mode of each light emitting diode 13 in each column of sub-pixels 12 is similar, and for convenience of description, the operation process of each light emitting diode 13 in one column of sub-pixels 12, and the signal transmission on the gate line GL and the data line SL associated with the column of sub-pixels 12 will be exemplarily described below.
Referring to fig. 9, the data line SL1 is insulated from and intersects the gate lines GL1 to GLm, in the embodiment, the data line SL1 is perpendicular to and intersects the gate lines GL1 to GLm, the light emitting diodes 13 are respectively disposed in a plurality of sub-pixels 12 defined by the data line SL1 and the gate lines GL1 to GLm-1, and the current source 14 is disposed in a part of the sub-pixels 12 defined by the data line SL1 and the gate lines GLm. At this time, the light emitting diode 13 (the light emitting diode 13 in the sub-pixel 12 defined by the data line SL1 and the gate line GL 1) is in an operating state, and the remaining light emitting diodes 13 (the light emitting diodes 13 in the sub-pixels 12 defined by the data line SL1 and the gate lines GL2 to GLm-1) are in a non-operating state. The LEDs 13 in the non-operating state are cut off in the reverse direction and have a reverse bias voltage irIn the present embodiment, the reverse bias voltage i of each light emitting diode 13rEqual in magnitude and same in direction (current direction indicated by the dashed arrows in fig. 6).
Please refer toIn fig. 8, 9, and step S1, the target driving current i of the currently operating led 13 is obtainedR. In this embodiment, the target driving current i of the currently operating led 13 is obtainedRThe method specifically comprises the following steps: calculating the target brightness of the LED 13 in the working state according to the pre-stored display data, and calculating the required target driving current i according to the target brightnessR. The light emitting brightness of the light emitting diode 13 in the active state is determined by the display data, the display data is pre-stored in the driver 15, and when the display panel 10 is in operation, the driver 15 writes the pre-stored display data into the data line SL1, so as to drive the light emitting diode 13 electrically connected with the data line SL1 to emit light. The different display data are represented as different light-emitting brightness of the light-emitting diode 13, the light-emitting brightness of the light-emitting diode 13 is determined by the current for driving the light-emitting diode 13 to emit light, the light-emitting brightness of the light-emitting diode 13 determined according to the display data at present is defined as the target light-emitting brightness, and the current for driving the light-emitting diode 13 to reach the target light-emitting brightness is defined as the target driving current iRThen, according to the brightness of the LED 13 and the driving current iRThe target driving current i can be calculated from the target light-emitting brightnessR。
Referring to fig. 8 and 9, in step S2, the initial current i on the data line SL1 is obtainedSL1. Initial current iSL1The reverse bias current i of each LED 13 which is currently in the non-operation state and is electrically connected with the data line SL1rAn output current i of the current source 14 electrically connected to the data line SL1pThe sum of the superimposed currents. As can be seen from the connection of the light emitting diodes 13, the current source 14 and the data line SL1 shown in fig. 9, since the light emitting diodes 13 and the current source 14 are connected in parallel, the currents of the light emitting diodes 13 and the current source 14 are superimposed on the data line SL1 as the initial current i of the data line SL1SL1The initial current iSL1The led 13, which is in operation at this time, is flown for driving it to emit light.
Wherein the output current i of the current source 14 when being turned onpIs determined by the structure of the current source itself, and is a constant current value that does not change with the change of the signal output by the driver 15. When the current source 14 is turned on, the output current is ipAnd the current direction is opposite to the reverse bias current i of the LED 13 in the non-working staterThe same; when the current source 14 is turned off, the current i is outputpIs 0. And the reverse bias current i of each LED in non-working staterIt is not easy to directly measure, in this embodiment, the reverse bias current i of each light emitting diode in the non-operating staterThe method comprises the following steps:
all the LEDs 13 are controlled to be in the non-operating state, and the current source 14 is turned off to detect the sum I of reverse bias currents on the data line SL1r；
According to the sum I of reverse bias currents on the data line SL1rAnd the number of the light emitting diodes 13 electrically connected with the data line SL1, and calculating the reverse bias current i when the light emitting diodes 13 electrically connected with the data line SL1 are in a non-working stater。
Since the current source 14 is turned off, the sum of the reverse bias currents I on the data line SL1rFor reverse bias current i of all light emitting diodes 13rThe superimposed value and the reverse bias current i of each LED 13rEqually, the number of the light emitting diodes 13 electrically connected to the data line SL1 is known, so that the step S5 can be performed according to the total reverse bias current IrAnd calculating the reverse bias current by the quantity of the light emitting diodes: i.e. ir＝Ir/(m-1)。
In this embodiment, step S2 specifically includes: superimposing the reverse bias current i of the currently inactive led 13 electrically connected to the data line SL1rAnd an output current i of a current source 14 electrically connected to the data line SL1pTo obtain the initial current i of the data line SL1SL1：iSL1＝(m-2)ir+ip。
Initial current i on data line SL1SL1The reverse bias current i generated for each light-emitting diode 13 which is currently inactiverAnd the output current i of the current source 14pFor driving the light emitting diode 13 in the working state to emit light. But due to the reverse bias current i of the light emitting diode 13 in the inactive staterAlmost constant, the output current i of the current source 14pIs also constant, and the target driving current i required for the light emitting diode 13 in the operating state to reach the target light emitting brightnessRIs changed with the display data, so the initial current i on the data line SL1 can not be madeSL1The light emitting requirement of the light emitting diode 13 in the working state is always satisfied. Therefore, in this embodiment, the driver 15 outputs a driving signal to the data line SL1 to compensate the initial current iSL1And a target drive current iRThe difference in current between. Therefore, in this embodiment, step S3 specifically includes: according to the target driving current i of the LED 13 electrically connected with the data line SL1 in the working stateRAnd initial current i of data line SL1SL1The difference between the currents, and outputs a driving signal to the data line SL 1. In this embodiment, the driving signal output by the driver 15 is a current driving signal I0. And the current driving signal is equal to the current difference in amplitude and opposite in direction, that is: i is0＝-(iSL1-iR)，iSL1＝(m-2)ir+ip。
Referring to fig. 10, fig. 10 illustrates a signal timing sequence related to the light emitting diode 13, wherein abscissa of (a), (b), (c), and (d) represents time, ordinate of (a), (b), (c) represents current value, and ordinate of (d) represents voltage value. Referring to FIGS. 9-10, in time period I, the voltage V on the gate lines GL 1-GLm-1GLIs greater than the voltage V on the data line SL1SLAll the light emitting diodes 13 are turned off in the reverse direction and are in the non-operating state, and each light emitting diode 13 has a reverse bias current irAnd current source 14 remains activated, the value of the initial current i on data line SL1SL1＝(m-1)ir+ip. In period II, the voltage V on the gate line GL1GLIs less than the voltage V on the data line SL1SLThe voltage on the gate lines GL 2-GLm-1 is greater than that on the data line SL1, the light emitting diode 13 is turned on in the forward direction and is in an operating state, the other light emitting diodes 13 are turned off in the reverse direction and are in a non-operating state, and the light emitting diode 13 in the operating state has a target driving current iREach LED 13 in the non-operating state has a reverse bias current irAnd current source 14 remains activated, the value of the initial current i on data line SL1SL1＝(m-2)ir+ipDue to a reverse bias current irIs extremely small, close to zero, so that (m-2) ir+ip≈(m-1)ir+ipI.e. the initial current iSL1Are substantially equal in period i and period ii (the amplitude of each signal is presented only schematically in fig. 10 for convenience of distinguishing between different signals).
Referring to fig. 10, as mentioned above, in the period ii, the light emitting diode 13 is in the working state, and (a) in fig. 10 shows the initial current i on the data line SL1 when the light emitting diode 13 is in the working stateSL1Less than the target drive current i of the light emitting diode 13RIn fig. 10, (b) shows the initial current i on the data line SL1 when the light emitting diode 13 is in operationSL1Equal to the target drive current i of the light emitting diode 13RIn fig. 10, (c) shows the initial current i on the data line SL1 when the light emitting diode 13 is in operationSL1Greater than the target drive current i of the light emitting diode 13RFig. 10 (d) shows voltage waveform changes on the data line SL1 and the gate line GL 1. Initial current i as shown in (a), (b), and (c) of FIG. 10SL1And a target drive current iRWith three magnitude relationships, the current source 14 remains on all the time.
The above steps can realize the reverse bias current i generated on the light emitting diode 13 in the non-working staterAs a drive current i for driving the light emitting diode 13 in operationROn the one hand, the reverse bias current i is utilizedrThe current output of the driver 15 is reduced; on the other hand, the reverse bias current irAs a drive current i for the light emitting diode 13RIs favorable toImproving reverse bias current irThe current working light emitting diode 13 is influenced, thereby influencing the picture display quality and reducing the contrast.
As mentioned above, the steps of activating the LEDs 13 in each row of the sub-pixels 12 are substantially the same, but the signals (e.g., the target driving current i) involved in the operation of the LEDs 13 in each row of the sub-pixels 12 areRReverse bias current irEtc.) the specific values may vary.
For example, the light emitting diodes 13 in the sub-pixels 12 defined by the data lines SL1 and the gate lines GL1 are used for emitting red light, the light emitting diodes 13 in the sub-pixels 12 defined by the data lines SL2 and the gate lines GL1 are used for emitting green light, and the light emitting diodes 13 in the sub-pixels 12 defined by the data lines SL3 and the gate lines GL1 are used for emitting blue light, which may cause the difference of the electrical properties of the light emitting diodes 13 emitting different colors of light because the internal structures of the light emitting diodes are different. For example, referring to FIG. 11, curve BRCurve B, which identifies the luminous brightness of a red-emitting LED 13 as a function of its drive currentGCurve B, which identifies the functional relationship between the luminous brightness of a green-emitting LED 13 and its drive currentBThe functional relationship between the luminous brightness of the blue light-emitting leds 13 and their drive current is identified. It can be seen that the functional relationship between the luminance of the light emitting diodes 13 emitting light of different colors and the driving current thereof is different, but the overall trend is that the luminance is proportional to the driving current.
In summary, the display panel 10 and the driving method provided in the present embodiment are beneficial to saving the output current of the driver 15, improving the display effect, and increasing the contrast of the image.
Example two
The display panel provided in this embodiment has substantially the same structure as the display panel 10 in the first embodiment, and is not described again. Referring to fig. 12, the driving method according to the present embodiment is mainly different from the first embodiment in that before step S3, the method further includes:
in step S4, it is determined whether the data line SL1 is electrically connectedReverse bias current i of the operating LED 13rWhether the sum is less than the target driving current i of the light emitting diode 13 in the operating state electrically connected with the data line SL1R；
If yes, go to step S5 to control the current source 14 to turn on;
if not, step S6 is executed to control the current source 14 to turn off.
In this embodiment, the current source 14 is not continuously turned on during the operation of the display panel 10, but is turned on according to the reverse bias current i of the light emitting diode 13 in the non-operation staterSum and target drive current iRThe magnitude relationship of (a) determines whether to turn on.
As shown in fig. 9, the output current i of the current source 14pReverse bias current i with LED 13rIn the same direction, the output current i of the current source 14pReverse bias current i to each light emitting diode 13 in non-operating staterAfter superposition, the LEDs 13 in working state are driven together to emit light, and in consideration of the fact that the sum of reverse bias currents of the LEDs 13 is not enough to drive the LEDs 13 in working state, the current source 14 is additionally arranged to meet the driving current i when the LEDs 13 in working state are drivenRThe requirements of (1). However, as described above, the target drive current i of the light emitting diode 13 in the operating stateRIs constantly changing if the reverse bias current i of each LED 13 is not in operationrThe sum of the driving currents is greater than or equal to the target driving current iRThen the current source 14 does not have to be turned on; reverse bias current i only in each LED 13rThe sum is less than the target drive current iRThe current source 14 is turned on.
Referring to fig. 13, fig. 13 illustrates a signal timing sequence related to the light emitting diode 13, wherein horizontal coordinates in (a), (b), (c), and (d) represent time, vertical coordinates in (a), (b), and (c) represent current values, and vertical coordinates in (d) represent voltage values. Referring to fig. 9 and 13, in the period i, the voltage on the gate lines GL 1-GLm-1 is greater than the voltage on the data line SL1, and all the leds 13 are turned off in the opposite directionIn the non-operating state, each LED 13 has a reverse bias current irIn the period ii, the voltage on the gate line GL1 is lower than the voltage on the data line SL1, and the voltages on the gate lines GL 2-GLm-1 are higher than the voltage on the data line SL1, such that the light emitting diode 13 is turned on in the forward direction and is in the operating state, the rest of the light emitting diodes 13 are turned off in the reverse direction and are in the non-operating state, and the light emitting diode 13 in the operating state has a target driving current iREach LED 13 in the non-operating state has a reverse bias current ir。
Referring to fig. 13, in the period ii, if the step S4 determines the reverse bias current i of each light emitting diode 13 in the non-operating staterThe sum is already greater than the target drive current iRThen the control turns off the current source 14, and the value i of the initial current on the data line SL1SL1＝(m-2)irAs shown in fig. 13 (a). If it is determined in step S4 that the reverse bias current i of each light emitting diode 13 is in the inactive staterThe sum of which is already equal to the target drive current iRAlso controlling the initial current value i on the data line SL1 when the current source 14 is turned offSL1＝(m-2)irAs shown in fig. 13 (b). And step S4 is to determine the reverse bias current i of each light emitting diode 13 in the non-operation staterThe sum is less than the target drive current iRWhen the current source 14 is turned on, the initial current value i on the data line SL1SL1＝(m-2)ir+ipAs shown in fig. 13 (c). As can be seen from fig. 13, in the period i and the period ii, the current source 14 only determines the reverse bias current i of each of the light emitting diodes 13 in the non-operation state in step S4rThe sum is less than the target drive current iRAnd then is turned on.
As described above, in step S4, the reverse bias current i of each light emitting diode 13 in the non-operation state is determinedrSum and target drive current iRThe magnitude relation between the current sources determines whether the current source 14 needs to be turned on, and only the reverse bias current i of each light emitting diode 13 in the non-working state is judgedrThe sum of the driving currents is greater than or equal to the target driving current iRThe current source 14 is turned on and each is determined to be offReverse bias current i of the operating LED 13rThe sum is less than the target drive current iRThe current source 14 is turned off, which is advantageous to save the power of the display panel 10 compared to the driving method in the first embodiment.
Furthermore, in the display panel 10, the electrical connection between the light emitting diode 13 and the gate line GL and the data line SL can be changed. Specifically, the light emitting diode 13 has an anode electrically connected to a data line SL and a cathode electrically connected to a gate line GL; referring to fig. 14, in an alternative embodiment of the present invention, the light emitting diode 13 may also be electrically connected to a gate line GL through a positive electrode and a data line SL through a negative electrode.
When the anode of the led 13 is electrically connected to the gate line GL and the cathode is electrically connected to the data line SL, the signal output modes of the gate line GL and the data line SL are exactly opposite to the signal output modes described in the first to second embodiments. That is, for each light emitting diode 13, when the voltage on the gate line GL electrically connected to the light emitting diode 13 is greater than the voltage on the data line SL electrically connected to the light emitting diode 13, and the voltage difference between the gate line GL and the data line SL is greater than the threshold voltage of the light emitting diode 13, the light emitting diode 13 is in the working state; when the voltage on the gate line GL electrically connected to the light emitting diode 13 is greater than the voltage on the data line SL electrically connected to the light emitting diode, but the voltage difference between the gate line GL and the data line SL is less than the threshold voltage of the light emitting diode 13, or the voltage on the gate line GL electrically connected to the light emitting diode is less than the voltage on the data line SL electrically connected to the light emitting diode 13, the light emitting diode 13 is in the off state.
The display panel described above is also protected by the present invention.
It will be appreciated by those skilled in the art that the above embodiments are illustrative only and not intended to be limiting, and that suitable modifications and variations may be made to the above embodiments without departing from the true spirit and scope of the invention.
Claims (10)
1. A display panel, comprising:
m gate lines arranged at intervals along a first direction, wherein m is greater than 2;
n data lines arranged at intervals along a second direction, wherein n is larger than 2, the m gate lines and the n data lines are arranged in an insulated and crossed mode, and the m gate lines and the n data lines are arranged in an insulated and crossed mode to define a plurality of sub pixels;
a plurality of light emitting diodes, each light emitting diode being formed in a sub-pixel, each light emitting diode being electrically connected to a data line and a gate line defining the sub-pixel in which the light emitting diode is located, each light emitting diode having a reverse bias current when in a non-operating state;
n current sources, each current source having an output current, each current source being formed in a sub-pixel, each current source being electrically connected to a data line and a gate line defining the sub-pixel in which the current source is located, each current source being connected to a different data line; and
and the driver is electrically connected with the m gate lines and the n data lines, and is used for controlling the working state of each light-emitting diode and each current source and controlling the reverse bias current and the output current to drive the light-emitting diodes in the working state to emit light.
2. The display panel of claim 1, wherein the n current sources are connected to a same gate line.
3. The display panel of claim 1, wherein the n current sources are connected to an m-th gate line arranged in the first direction.
4. A driving method applied to the display panel according to any one of claims 1 to 3; characterized in that the driving method comprises the following steps:
acquiring a target driving current of a light emitting diode in a current working state;
acquiring initial current on each data line, wherein the initial current on each data line is the superposition sum of reverse bias current of each light-emitting diode which is electrically connected with the data line and is currently in a non-working state and output current of a current source which is electrically connected with the data line; and
and outputting a driving signal to each data line according to the target driving current and the initial current.
5. The driving method according to claim 4, wherein the step of obtaining the target driving current of the currently-operating led comprises:
and calculating the target luminous brightness of the LED in the working state at present according to the prestored display data, and calculating the required target driving current according to the target luminous brightness.
6. The driving method according to claim 4, wherein reverse bias currents of the light emitting diodes connected to the same data line, which are currently in a non-operation state, are equal, and the driving method further comprises, before the step of obtaining the initial current on each data line:
controlling all the light emitting diodes to be in a non-working state, and closing the n current sources to respectively detect the total reverse bias current on each data line;
respectively calculating the reverse bias current of the light emitting diodes electrically connected with the data lines when the light emitting diodes are in a non-working state according to the sum of the reverse bias currents on the data lines and the number of the light emitting diodes electrically connected with the data lines;
the step of obtaining the initial current on each data line specifically includes: and respectively superposing the reverse bias current of the current non-working light emitting diode electrically connected with each data line and the output current of the current source electrically connected with each data line to respectively obtain the initial current of each data line.
7. The driving method according to claim 4, wherein the step of outputting the driving signal to each data line according to the target driving current of the light emitting diode electrically connected to each data line in an operating state and the initial current of each data line comprises:
and respectively outputting a driving signal to each data line according to a current difference value between a target driving current of the light emitting diode electrically connected with each data line and in a working state and an initial current of each data line.
8. The driving method according to claim 7, wherein before the step of outputting the driving signal to each data line according to a current difference between a target driving current of the light emitting diode electrically connected to each data line in an operating state and an initial current of each data line, further comprises:
respectively judging whether the sum of reverse bias currents of the light emitting diodes in the non-working state, which are electrically connected with each data line, is less than the target driving current of the light emitting diodes in the working state, which are electrically connected with each data line;
if the judgment result is yes, controlling the n current sources to be started;
if not, controlling the n current sources to be closed.
9. The driving method according to any one of claims 5 to 8, wherein only one light emitting diode on each data line is in operation at the same time.
10. The driving method according to any one of claims 7 to 8, wherein the driving signal is a current signal, and the current signal and the current difference respectively output to each data line are equal in magnitude and opposite in direction.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911317548.8A CN110930937B (en) | 2019-12-19 | 2019-12-19 | Display panel and driving method |
| TW108147716A TWI727565B (en) | 2019-12-19 | 2019-12-26 | Display panel and driving method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911317548.8A CN110930937B (en) | 2019-12-19 | 2019-12-19 | Display panel and driving method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110930937A true CN110930937A (en) | 2020-03-27 |
| CN110930937B CN110930937B (en) | 2022-05-13 |
Family
ID=69863269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911317548.8A Active CN110930937B (en) | 2019-12-19 | 2019-12-19 | Display panel and driving method |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN110930937B (en) |
| TW (1) | TWI727565B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN113012609A (en) * | 2020-10-22 | 2021-06-22 | 重庆康佳光电技术研究院有限公司 | Display panel manufacturing method and display panel |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI792583B (en) * | 2021-09-27 | 2023-02-11 | 大陸商北京集創北方科技股份有限公司 | Driving method of self-luminous display, row driving circuit, self-luminous display device and information processing device |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1386258A (en) * | 2000-07-28 | 2002-12-18 | 日亚化学工业株式会社 | Drive circuit of display device and display device |
| US20040061670A1 (en) * | 2001-11-16 | 2004-04-01 | Junichi Muruyama | Organic el panel drive circuit |
| CN1517963A (en) * | 2003-01-09 | 2004-08-04 | �����ɷ� | Drive device of luminous display panel |
| CN1595487A (en) * | 2004-07-16 | 2005-03-16 | 贺伟 | A LED display device |
| JP2005091717A (en) * | 2003-09-17 | 2005-04-07 | Denso Corp | Display device and driving method of display panel |
| CN1818999A (en) * | 2005-02-09 | 2006-08-16 | 东北先锋电子股份有限公司 | Driving apparatus and driving method of light emitting display panel |
| CN201242591Y (en) * | 2007-05-17 | 2009-05-20 | 技领半导体(上海)有限公司 | Integrated circuit for matching sequent calibration of current source, and encapsulated integrated circuit |
| CN102034429A (en) * | 2009-09-30 | 2011-04-27 | 卡西欧计算机株式会社 | Light-emitting apparatus, drive control method thereof and electronic device |
| JP2011091017A (en) * | 2009-10-23 | 2011-05-06 | Kazumasa Noi | Balanced drive led lighting circuit |
| US20140104325A1 (en) * | 2009-11-12 | 2014-04-17 | Ignis Innovation Inc. | Stable fast programming scheme for displays |
| CN104252833A (en) * | 2013-06-28 | 2014-12-31 | 乐金显示有限公司 | Organic light emitting diode display device and method for driving same |
| US20150235595A1 (en) * | 2012-05-30 | 2015-08-20 | Sharp Kabushiki Kaisha | Display device and method for driving same |
| US20170154909A1 (en) * | 2015-11-30 | 2017-06-01 | Semiconductor Energy Laboratory Co., Ltd. | Signal processing circuit and semiconductor device including the signal processing circuit |
| CN108206684A (en) * | 2016-12-16 | 2018-06-26 | 英飞凌科技股份有限公司 | switching device and method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3498745B1 (en) * | 2002-05-17 | 2004-02-16 | 日亜化学工業株式会社 | Light emitting device and driving method thereof |
| EP1556851A2 (en) * | 2002-10-31 | 2005-07-27 | Casio Computer Co., Ltd. | Display device and method for driving display device |
| JP2007005072A (en) * | 2005-06-22 | 2007-01-11 | Toyota Industries Corp | Light-emitting device using organic electroluminescent element and display device |
| JP2007003640A (en) * | 2005-06-22 | 2007-01-11 | Tohoku Pioneer Corp | Self-luminous panel |
| TWI459351B (en) * | 2012-05-23 | 2014-11-01 | Macroblock Inc | Driving system and method thereof for driving a dot matrix led display |
-
2019
- 2019-12-19 CN CN201911317548.8A patent/CN110930937B/en active Active
- 2019-12-26 TW TW108147716A patent/TWI727565B/en active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1386258A (en) * | 2000-07-28 | 2002-12-18 | 日亚化学工业株式会社 | Drive circuit of display device and display device |
| US20040061670A1 (en) * | 2001-11-16 | 2004-04-01 | Junichi Muruyama | Organic el panel drive circuit |
| CN1517963A (en) * | 2003-01-09 | 2004-08-04 | �����ɷ� | Drive device of luminous display panel |
| JP2005091717A (en) * | 2003-09-17 | 2005-04-07 | Denso Corp | Display device and driving method of display panel |
| CN1595487A (en) * | 2004-07-16 | 2005-03-16 | 贺伟 | A LED display device |
| CN1818999A (en) * | 2005-02-09 | 2006-08-16 | 东北先锋电子股份有限公司 | Driving apparatus and driving method of light emitting display panel |
| CN201242591Y (en) * | 2007-05-17 | 2009-05-20 | 技领半导体(上海)有限公司 | Integrated circuit for matching sequent calibration of current source, and encapsulated integrated circuit |
| CN102034429A (en) * | 2009-09-30 | 2011-04-27 | 卡西欧计算机株式会社 | Light-emitting apparatus, drive control method thereof and electronic device |
| JP2011091017A (en) * | 2009-10-23 | 2011-05-06 | Kazumasa Noi | Balanced drive led lighting circuit |
| US20140104325A1 (en) * | 2009-11-12 | 2014-04-17 | Ignis Innovation Inc. | Stable fast programming scheme for displays |
| US20150235595A1 (en) * | 2012-05-30 | 2015-08-20 | Sharp Kabushiki Kaisha | Display device and method for driving same |
| CN104252833A (en) * | 2013-06-28 | 2014-12-31 | 乐金显示有限公司 | Organic light emitting diode display device and method for driving same |
| US20170154909A1 (en) * | 2015-11-30 | 2017-06-01 | Semiconductor Energy Laboratory Co., Ltd. | Signal processing circuit and semiconductor device including the signal processing circuit |
| CN108206684A (en) * | 2016-12-16 | 2018-06-26 | 英飞凌科技股份有限公司 | switching device and method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113012609A (en) * | 2020-10-22 | 2021-06-22 | 重庆康佳光电技术研究院有限公司 | Display panel manufacturing method and display panel |
| 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 |
|---|---|
| TWI727565B (en) | 2021-05-11 |
| CN110930937B (en) | 2022-05-13 |
| TW202125476A (en) | 2021-07-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10580359B2 (en) | Display device and electronic apparatus | |
| TWI820083B (en) | Display panel and method for driving the display panel | |
| JP4216246B2 (en) | Backlight drive circuit | |
| JP4602194B2 (en) | Backlight driving circuit and liquid crystal display device having the same | |
| CN110930937B (en) | Display panel and driving method | |
| US8605062B2 (en) | Display device | |
| WO2020253515A1 (en) | Pixel circuit and control method therefor, and display apparatus | |
| US20190236997A1 (en) | Display driving method and organic light-emitting display device thereof | |
| WO2020001037A1 (en) | Array substrate, driving method therefor, and display panel | |
| CN111554240B (en) | Display device driving method and display device | |
| JP2019211564A (en) | Display device and method of controlling the same | |
| CN110956922B (en) | Display panel and driving method | |
| KR102335811B1 (en) | Light emitting diode display apparatus | |
| JP2003131619A (en) | Self light emitting type display device | |
| US11783756B1 (en) | Display driving circuit and display device | |
| WO2021062785A1 (en) | Sub-pixel circuit, active electroluminescence display, and drive method thereof | |
| JP4048255B2 (en) | Drive device and drive method for organic EL display device | |
| TWI774475B (en) | Driving device for display unit and driving method thereof | |
| JP2003157050A (en) | Organic el display and driving method thereof | |
| KR100370034B1 (en) | driving circuit for display device | |
| KR20140075352A (en) | Organic Light Emitting diode display and method of driving the same | |
| TWI834387B (en) | Driving circuit for led panel and led panel thereof | |
| KR20060095132A (en) | Organic electroluminescence display device | |
| KR20080057072A (en) | Light emitting device using a pwm method and method of driving the same | |
| KR100659950B1 (en) | Driving apparatus and method for organic electro-luminescence 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 |