U.S. patent application number 15/886858 was filed with the patent office on 2018-06-07 for organic light-emitting display panel, driving method and driving device therefor.
This patent application is currently assigned to SHANGHAI TIANMA AM-OLED CO., LTD.. The applicant listed for this patent is SHANGHAI TIANMA AM-OLED CO., LTD.. Invention is credited to Zhonglan CAI, Yana GAO, Yue LI, Dongxu XIANG, Renyuan ZHU.
Application Number | 20180158398 15/886858 |
Document ID | / |
Family ID | 60600303 |
Filed Date | 2018-06-07 |
United States Patent
Application |
20180158398 |
Kind Code |
A1 |
XIANG; Dongxu ; et
al. |
June 7, 2018 |
ORGANIC LIGHT-EMITTING DISPLAY PANEL, DRIVING METHOD AND DRIVING
DEVICE THEREFOR
Abstract
Provided are an organic light-emitting display panel, a driving
method and a driving device therefor. The driving method includes:
setting a plurality of brightness levels of the organic
light-emitting display panel and a plurality of maximum gray scale
brightnesses, and the plurality of maximum gray scale brightnesses
include a first maximum gray scale brightness corresponding to a
maximum brightness level of the organic light-emitting display
panel, and an effective pulse duty cycle of a light-emitting
control signal for driving the first maximum gray scale brightness
is defined as a first effective pulse duty cycle; determining a
target brightness level of the switched picture and a target
maximum gray scale brightness corresponding to the target
brightness level; adjusting the target effective pulse duty cycle
of the light-emitting control signal for driving the switched
picture.
Inventors: |
XIANG; Dongxu; (SHANGHAI,
CN) ; LI; Yue; (SHANGHAI, CN) ; ZHU;
Renyuan; (SHANGHAI, CN) ; GAO; Yana;
(SHANGHAI, CN) ; CAI; Zhonglan; (SHANGHAI,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHANGHAI TIANMA AM-OLED CO., LTD. |
SHANGHAI |
|
CN |
|
|
Assignee: |
SHANGHAI TIANMA AM-OLED CO.,
LTD.
SHANGHAI
CN
|
Family ID: |
60600303 |
Appl. No.: |
15/886858 |
Filed: |
February 2, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09G 2300/0866 20130101;
G09G 3/22 20130101; G09G 3/3233 20130101; G09G 2300/0842 20130101;
H01L 27/3241 20130101; G09G 2320/0626 20130101; G09G 3/3266
20130101; G09G 2300/0819 20130101; G09G 2310/0262 20130101; G09G
2310/0264 20130101; G09G 2310/0286 20130101; G09G 2300/0861
20130101 |
International
Class: |
G09G 3/22 20060101
G09G003/22; H01L 27/32 20060101 H01L027/32 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 14, 2017 |
CN |
201710690526.0 |
Claims
1. A driving method for an organic light-emitting display panel,
comprising: setting a plurality of brightness levels of the organic
light-emitting display panel and a plurality of maximum gray scale
brightnesses, wherein each of the plurality of brightness levels
corresponds to a respective one of the plurality of maximum gray
scale brightnesses, the plurality of maximum gray scale
brightnesses comprise a first maximum gray scale brightness
corresponding to a maximum brightness level of the organic
light-emitting display panel, and an effective pulse duty cycle of
a light-emitting control signal for driving the first maximum gray
scale brightness is defined as a first effective pulse duty cycle;
determining, when a picture in the organic light-emitting display
panel is controlled to be switched, a target brightness level of
the switched picture and a target maximum gray scale brightness
corresponding to the target brightness level; and adjusting, based
on the target maximum gray scale brightness of the switched
picture, the first maximum gray scale brightness and the first
effective pulse duty cycle, a target effective pulse duty cycle of
the light-emitting control signal for driving the switched
picture.
2. The driving method according to claim 1, wherein an effective
pulse of the light-emitting control signal is configured to control
at least one row of corresponding sub-pixels to emit light.
3. The driving method according to claim 2, wherein the effective
pulse of the light-emitting control signal is configured to control
adjacent two rows of corresponding sub-pixels corresponding to emit
light.
4. The driving method according to claim 1, wherein an output
waveform of the light-emitting control signal comprises a plurality
of effective pulses and a plurality of ineffective pulses.
5. The driving method according to claim 4, wherein adjusting the
target effective pulse duty cycle of the light-emitting control
signal for driving the switched picture comprises: calculating a
target ratio of the target maximum gray scale brightness to the
first maximum gray scale brightness; and adjusting the target
effective pulse duty cycle of the light-emitting control signal for
driving the switched picture in such a way that the ratio of the
target effective pulse duty cycle to the first effective pulse duty
cycle is equal to the target ratio.
6. The driving method according to claim 5, wherein adjusting the
target effective pulse duty cycle of the light-emitting control
signal for driving the switched picture comprises: decreasing
gradually, when the target effective pulse duty cycle of the
light-emitting control signal for driving the switched picture is
less than the effective pulse duty cycle of the light-emitting
control signal for driving the preceding picture of the frame, the
target effective pulse duty cycle of the light-emitting control
signal until the ratio of the target effective pulse duty cycle to
the first effective pulse duty cycle is equal to the target
ratio.
7. The driving method according to claim 5, wherein adjusting the
target effective pulse duty cycle of the light-emitting control
signal for driving the switched picture comprises: increasing
gradually, when the target effective pulse duty cycle of the
light-emitting control signal for driving the switched picture is
larger than the effective pulse duty cycle of the light-emitting
control signal for driving the preceding picture of the frame, the
target effective pulse duty cycle of the light-emitting control
signal until the ratio of the target effective pulse duty cycle to
the first effective pulse duty cycle equal to the target ratio.
8. A driving device of an organic light-emitting display panel,
comprising: display brightness determining device, which is
configured for determining, when a picture in the organic
light-emitting display panel is controlled to be switched, a target
brightness level of the switched picture and a target maximum gray
scale brightness corresponding to the target brightness level;
display brightness adjusting device, which is configured for
adjusting the target effective pulse duty cycle of the
light-emitting control signal for driving the switched picture
according to the target maximum gray scale brightness of the
switched picture, the first maximum gray scale brightness and a
first effective pulse duty cycle, wherein the maximum gray scale
brightness corresponding to the maximum brightness level of the
organic light-emitting display panel is defined as a first maximum
gray scale brightness, and the effective pulse duty cycle of the
light-emitting control signal for driving the first maximum gray
scale brightness is defined as a first effective pulse duty
cycle.
9. The driving device according to claim 8, wherein an effective
pulse of the light-emitting control signal is configured to control
at least one row of corresponding sub-pixels to emit light.
10. The driving device according to claim 9, wherein the effective
pulse of the light-emitting control signal is configured to control
two adjacent rows of corresponding sub-pixels to emit light.
11. The driving device according to claim 8, wherein an output
waveform of the light-emitting control signal comprises a plurality
of effective pulses and a plurality of ineffective pulses.
12. The driving device according to claim 11, wherein the display
brightness adjusting device comprises: brightness calculating
device, which is configured to calculate the target ratio of the
target maximum gray scale brightness to the first maximum gray
scale brightness; and pulse adjusting device, which is configured
to adjust the target effective pulse duty cycle of the
light-emitting control signal for driving the switched picture in
such a way that the ratio of the target effective pulse duty cycle
to the first effective pulse duty cycle is equal to the target
ratio.
13. The driving device according to claim 12, wherein an
implementation process of the display brightness adjusting device
comprises: decreasing gradually, when the target effective pulse
duty cycle of the light-emitting control signal for driving the
switched picture is less than the effective pulse duty cycle of the
light-emitting control signal for driving the preceding picture of
the frame, the target effective pulse duty cycle of light-emitting
control signal until the ratio of the target effective pulse duty
cycle to the first effective pulse duty cycle is equal to the
target ratio.
14. The driving device according to claim 12, wherein the
implementation process of the display brightness adjusting device
comprises: increasing gradually, when the target effective pulse
duty cycle of the light-emitting control signal for driving the
switched picture is larger than the effective pulse duty cycle of
the light-emitting control signal for driving the preceding picture
of the frame, the target effective pulse duty cycle of
light-emitting control signal until the ratio of the target
effective pulse duty cycle to the first effective pulse duty cycle
is equal to the target ratio.
15. An organic light-emitting display panel, comprising: a driving
device, wherein the driving device comprises: display brightness
determining device, which is configured for determining, when a
picture in the organic light-emitting display panel is controlled
to be switched, a target brightness level of the switched picture
and a target maximum gray scale brightness corresponding to the
target brightness level; display brightness adjusting device, which
is configured for adjusting the target effective pulse duty cycle
of the light-emitting control signal for driving the switched
picture according to the target maximum gray scale brightness of
the switched picture, the first maximum gray scale brightness and a
first effective pulse duty cycle, wherein the maximum gray scale
brightness corresponding to the maximum brightness level of the
organic light-emitting display panel is defined as a first maximum
gray scale brightness, and the effective pulse duty cycle of the
light-emitting control signal for driving the first maximum gray
scale brightness is defined as a first effective pulse duty
cycle.
16. The organic light-emitting display panel according to claim 15,
wherein the driving device comprises: a plurality of light-emitting
control lines, wherein each of the light-emitting control lines is
configured to correspond to and is electrically connected to at
least one row of sub-pixels; a multiple cascades of shift register
devices, wherein the multiple cascades of shift register devices
correspond to and are electrically connected to the plurality of
light-emitting control lines, respectively, each of the cascades of
the multiple cascades of shift register devices is configured to
provide a light-emitting control signal to corresponding one of the
light-emitting control lines.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Chinese patent
application No. 201710690526.0 filed on Aug. 14, 2017, the
disclosure of which is incorporated herein by reference in its
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to display technologies, in
particular to an organic light-emitting display panel, a driving
method and a driving device therefor.
BACKGROUND
[0003] As the next generation display device, an organic
light-emitting display device raises the wide concerns due to its
characteristics such as self-luminance, fast response, wide viewing
angle and the preparation for a flexible screen etc. An organic
light-emitting diode (OLED) display device is a current-driven
active light-emitting display device and may be divided as a
passive-matrix organic light-emitting diode (PM-OLED) display
device and an active-matrix organic light-emitting diode (AM-OLED)
display device based on the driving manner.
[0004] At present, most of the OLED display devices employ a shift
register device to control the generation of light-emitting signals
(hereinafter, referred to as EMIT), and two rows of pixels may be
driven by a cascade of the shift registers device. The conventional
OLED display device commonly has 256-levels brightness (0-255), and
the shift register device thereof commonly employs a light-emitting
control timing with four pulses. In order to avoid the flickers, a
time period of a frame is commonly divided into quarters, in order
to enable each quarter of the time period to achieve a 256-levels
brightness variation to avoid the flickers. However, for the
conventional OLED display devices, a 256-levels brightness
variation in each quarter of the time period may not be achieved,
that is, a jumping occurs in the brightness variation of the
display device, which leads to an unsmooth brightness variation of
the display device, so that the display effect of the OLED display
device is affected.
SUMMARY
[0005] The present disclosure provides an organic light-emitting
display panel, a driving method and a driving device therefor.
[0006] In an first aspect, the present disclosure provides an
driving method for the organic light-emitting display panel, and
the driving method includes: [0007] setting a plurality of
brightness levels of the organic light-emitting display panel and a
plurality of maximum gray scale brightnesses, each of the plurality
of brightness levels corresponds to a respective one of the
plurality of maximum gray scale brightnesses, the plurality of
maximum gray scale brightnesses include a first maximum gray scale
brightness corresponding to a maximum brightness level of the
organic light-emitting display panel, and an effective pulse duty
cycle of a light-emitting control signal (EMIT) for driving the
first maximum gray scale brightness is defined as a first effective
pulse duty cycle; [0008] determining, when a picture in the organic
light-emitting display panel is controlled to be switched, a target
brightness level of the switched picture and a target maximum gray
scale brightness corresponding to the target brightness level;
[0009] adjusting, based on the target maximum gray scale brightness
of the switched picture, the first maximum gray scale brightness
and the first effective pulse duty cycle, the target effective
pulse duty cycle of the EMIT for driving the switched picture.
[0010] In a second aspect, the present disclosure provides a
driving device for the organic light-emitting display panel, and
the driving device includes: [0011] a display brightness
determining device, which is configured to determine, when
controlling the picture switching of the organic light-emitting
display panel, the target brightness level of the switched picture
and the target maximum gray scale brightness corresponding to the
target brightness level; [0012] a display brightness adjusting
device, which is configured to adjust the target effective pulse
duty cycle of the EMIT for driving the switched picture on the
basis of the target maximum gray scale brightness of the switched
picture, the first maximum gray scale brightness and a first duty
cycle, the maximum gray scale brightness corresponding to the
maximum brightness level of the organic light-emitting display
panel is defined as a first maximum gray scale brightness, and the
effective pulse duty cycle of the EMIT for driving the first
maximum gray scale brightness is defined as a first effective pulse
duty cycle.
[0013] Moreover, the present disclosure provides an organic
light-emitting display panel, and the organic light-emitting
display panel includes the above mentioned driving device.
BRIEF DESCRIPTION OF DRAWINGS
[0014] A simple description about the drawings employed in the
embodiments of the present disclosure is given as below.
[0015] FIG. 1 is a flow diagram showing a driving method for an
organic light-emitting display panel according to an embodiment of
the present disclosure;
[0016] FIG. 2 is a flow diagram showing another driving method for
an organic light-emitting display panel according to an embodiment
of the present disclosure;
[0017] FIG. 3 is a diagram showing a driving device for an organic
light-emitting display panel according to an embodiment of the
present disclosure;
[0018] FIG. 4 is a diagram showing an organic light-emitting
display panel according to an embodiment of the present
disclosure;
[0019] FIG. 5 is a diagram showing a pixel circuit according to an
embodiment of the present disclosure; and
[0020] FIG. 6A, FIG. 6B and FIG. 6C are the waveform graphs showing
the light-emitting control signal with different brightness levels
according to the embodiments of the present disclosure.
DETAILED DESCRIPTION
[0021] Referring to FIG. 1, FIG. 1 is a flow diagram showing a
driving method for an organic light-emitting display panel
according to an embodiment of the present disclosure. The driving
method for the organic light-emitting display panel includes: Step
110, setting a plurality of brightness levels of the organic
light-emitting display panel and a plurality of maximum gray scale
brightnesses, wherein each of the plurality of brightness levels
corresponds to a respective one of the plurality of maximum gray
scale brightnesses, the plurality of maximum gray scale
brightnesses include a first maximum gray scale brightness
corresponding to a maximum brightness level of the organic
light-emitting display panel, and an effective pulse duty cycle of
a light-emitting control signal (hereinafter, referred to as EMIT)
for driving the first maximum gray scale brightness is defined as a
first effective pulse duty cycle.
[0022] In this embodiment, the brightness level of the organic
light-emitting display panel and the maximum gray scale brightness
corresponding to the brightness level may need be set before the
organic light-emitting display panels leave the factory. Since the
light-emitting organic display panels in the prior art generally
employ an 8-bits shift register to control the pixels to emit
light, the light-emitting organic display panel of this embodiment
may have a 256-levels brightness (0-255), and each brightness level
is configured to have a minimum gray scale brightness and a maximum
gray scale brightness. The minimum gray scale brightness of each
brightness level is zero, and different brightness levels have
different maximum gray brightness thereof, so that the higher the
brightness level is, the higher the maximum gray scale brightness
corresponding to the brightness level is. Apparently, the maximum
gray scale brightness corresponding to the maximum brightness level
of the organic light-emitting display panel has a maximum
brightness of the organic light-emitting display panel, Therefore,
the maximum gray scale brightness corresponding to the maximum
brightness level of the organic light-emitting display panel is
defined as a first maximum gray scale brightness.
[0023] The brightness of each brightness level of the organic
light-emitting display panel in this embodiment may be divided into
a 256-levels gray scale (0-255). Therefore, for any of brightness
levels of the organic light-emitting display panel, the
255-th-level gray scale brightness corresponding to the brightness
level has the maximum gray scale brightness of the brightness
level. For example, the maximum gray scale brightness corresponding
to the 240-th-level brightness is 350 nit, and the maximum gray
scale brightness corresponding to the 255-th-level brightness is
400 nit.
[0024] In this embodiment, a plurality of brightness levels of the
organic light-emitting display panel and the maximum gray scale
brightness corresponding to each of the brightness levels are set
before the organic light-emitting display panels leaves the
factory. It should be noted that, the inputted voltage potential of
a gate electrode of a thin film transistor (TFT) for driving an
organic light-emitting diode (OLED) may be adjusted by adjusting
the data signal voltage, so that the gate-source voltage of the TFT
is changed, thereby controlling the magnitude of the current
flowing through the OLED, which in turn changes the luminous
intensity of the OLED. Thereby, the data signal voltage
corresponding to a gray scale level of the brightness level may be
determined, that is, when the brightness level of the organic
light-emitting display panel is determined, the desired gray level
of each pixel may be achieved by adjusting the data signal
voltage.
[0025] In this embodiment, the effective pulse of the EMIT is
configured to control the at least one row of corresponding
sub-pixels to emit light, wherein the organic light-emitting
display panel includes a plurality of light-emitting control lines,
a light-emitting control line corresponds to and is electrically
connected to at least one row of the corresponding sub-pixels, and
hence the EMIT outputted by the light-emitting control line
controls at least one row of corresponding sub-pixels to emit
light.
[0026] In one embodiment, the EMIT is configured to control the
turning on and off of each light-emitting control transistor for
driving the OLED in the at least a row of pixel circuits
corresponding thereto. When the EMIT turns on the light-emitting
transistor, the OLED emits light. When the EMIT turns off the
light-emitting transistor, the OLED does not emit light. Therefore,
the EMIT can control the light-emitting time period of the OLED,
the longer of the light-emitting time period is, the higher
brightness of the OLED is.
[0027] Apparently, the EMIT may change the brightness level of the
OLED by adjusting the length of the light-emitting time period. The
pulse of the EMIT for controlling the turning on of the
light-emitting control transistor is defined as an effective pulse.
On the contrary, the pulse of the EMIT for controlling the turning
off of the light-emitting control transistor is defined as an
ineffective pulse. The ratio of the effective pulse duration of a
light-emitting control cycle to the light-emitting control cycle is
defined as an effective pulse duty cycle. In this embodiment, the
effective pulse duty cycle of the EMIT for driving the first
maximum gray scale brightness is defined as a first effective pulse
duty cycle. The effective pulse duty cycle of the EMIT for driving
other gray scale brightness is certainly less than the first
effective pulse duty cycle.
[0028] In this embodiment, the effective pulse of the EMIT is
configured to control the adjacent two rows of sub-pixels to emit
light. That is, the organic light-emitting display panel includes a
plurality of light-emitting control lines, and each of the
light-emitting control lines is electrically connected to adjacent
two rows of sub-pixels. In other embodiments, the effective pulse
of the EMIT is also configured to control the adjacent four rows of
sub-pixels to emit light.
[0029] In one embodiment, an output waveform of the EMIT includes a
plurality of effective pulses and ineffective pulses. By employing
the effective pulse and ineffective pulse to alternately control
turning on and off of the light-emitting control transistor of the
OLED for driving the pixel circuit, the power consumption of the
organic light-emitting display panel is reduced.
[0030] In one embodiment, different organic light-emitting display
panels may have different light-emitting control circuits, so that
the number of brightness levels for different organic
light-emitting display panels may be different. The number of
brightness levels of the organic light-emitting display panel is
not limited in the present disclosure.
[0031] Step 120, when a picture in the organic light-emitting
display panel is controlled to be switched, a target brightness
level of the switched picture and a target maximum gray scale
brightness corresponding to the target brightness level are
determined.
[0032] In this embodiment, when a picture in the organic
light-emitting display panel is to be switched, a target brightness
level of the switched picture may need be determined by the organic
light-emitting display panel. It should be noted that, if the user
does not adjust the brightness level of the organic light-emitting
display panel, the target brightness level of the switched picture
conforms with brightness level of the picture of current frame; if
the user adjusts the brightness level of the organic light-emitting
display panel, the adjusted brightness level is the target
brightness level of the switched picture. When the maximum
brightness level of organic light-emitting display panel
corresponding to each of the brightness levels and the target
brightness level of the switched picture are given, the target
maximum gray scale brightness of the switched picture may be
determined.
[0033] Step 130, based on the target maximum gray scale brightness
of the switched picture, the first maximum gray scale brightness
and the first effective pulse duty cycle, the target effective
pulse duty cycle of the EMIT for driving the switched picture is
adjusted.
[0034] In this embodiment, since the EMIT may change the brightness
level of the OLED by adjusting the length of the light-emitting
time period of the OLED, and the first maximum gray scale
brightness and the first effective pulse duty cycle are given, when
the picture of the organic light-emitting display panel is
switched, the target effective pulse duty cycle of the EMIT for
driving the switched picture may be adjusted based on the
determined target maximum gray scale brightness of the switched
picture, thereby enabling the switch picture to reach a target
maximum gray scale brightness. In one embodiment, the duty cycle
ratio of the target effective pulse duty cycle to first effective
pulse duty cycle is determined as the brightness ratio of the
target maximum gray scale brightness to the first maximum gray
scale brightness, thereby computing the target effective pulse duty
cycle. As a driving timing of the EMIT for driving the switched
picture is adjusted by the organic light-emitting display panel in
order to conform to the driving timing of the target effective
pulse duty cycle, the display brightness of the switched picture is
just the target maximum gray scale brightness.
[0035] It should be noted that, the gray scales of different
sub-pixels for the picture of a frame may be different. As target
gray scale of display picture and target maximum gray scale
brightness are determined, the data signal voltage outputted to
each sub-pixel may be adjusted for the organic light-emitting
display panel, thereby enabling each sub-pixel of the picture of a
frame to display the corresponding gray scale. The organic
light-emitting display panel provided in present disclosure may
achieve a smooth adjustment of 0-255 gray scales within a
brightness level by adjusting the data signal voltage.
[0036] In this embodiment, it is preset in the organic
light-emitting display panel a plurality of brightness levels, the
maximum gray scale brightness corresponding to each of the
brightness level, the first maximum gray scale brightness
corresponding to the maximum brightness level and the first
effective pulse duty cycle of the EMIT for driving the first
maximum gray scale brightness. By adjusting the target effective
pulse duty cycle of the EMIT for driving the switched picture, a
target brightness level is enabled to be adjusted in the organic
light-emitting display panel. In this embodiment, the display time
period of the organic light-emitting display panel can be adjusted
by adjusting the effective pulse duty cycle of the organic
light-emitting display panel, thereby adjusting the total
brightness of the organic light-emitting display panel.
Furthermore, the driving method for the organic light-emitting
display panel may also achieve the smooth adjustment of the
brightness of the organic light-emitting display panel and improve
the display effect of the organic light-emitting display panel.
[0037] In one embodiment, as shown in FIG. 2, adjusting the target
effective pulse duty cycle of the EMIT for driving the switched
picture in above mentioned step 130 includes: Step 131, calculating
a target ratio of the target maximum gray scale brightness to the
first maximum gray scale brightness; and Step 132, adjusting the
target effective pulse duty cycle of the EMIT for driving the
switched picture, so that the ratio of the target effective pulse
duty cycle to the first effective pulse duty cycle is equal to the
target ratio.
[0038] In this embodiment, since the EMIT may change the brightness
level of the OLED by adjusting the time period of data signal
voltage inputted to the OLED, and the first maximum gray scale
brightness and the corresponding first effective pulse duty cycle
are given, when controlling the switching of pictures of the
organic light-emitting display panel, the target effective pulse
duty cycle of the EMIT may be adjusted for driving the switched
picture based on the determined target maximum gray scale
brightness of the switched picture, thereby enabling the switch
picture to reach a target maximum gray scale brightness.
[0039] In one embodiment, a target ratio is obtained by calculating
a brightness ratio of the target maximum gray scale brightness to
the first maximum gray scale brightness, and then the target
effective pulse duty cycle of the EMIT for driving the switched
picture is adjusted, thereby enabling the ratio of the target
effective pulse duty cycle to the first effective pulse duty cycle
to be equal to a target ratio. The driving for the organic
light-emitting display panel is controlled according to the
adjusted EMIT, and thus the display brightness of the switched
picture is just the target maximum gray scale brightness.
[0040] In one embodiment, adjusting the target effective pulse duty
cycle of the EMIT for driving the switched picture in step 130
includes: decreasing gradually, when the target effective pulse
duty cycle of the EMIT for driving the switched picture is less
than the target effective pulse duty cycle of the EMIT for driving
the preceding picture of the frame, the target effective pulse duty
cycle until the ratio of the target effective pulse duty cycle to
the first effective pulse duty cycle is equal to the target
ratio.
[0041] If the target effective pulse duty cycle of the EMIT after
switched is less than that of the EMIT before switched, it
indicates that the brightness of the switched picture is lower than
that of the picture before switched. Based on the case that the
brightness becomes lower before and after the picture switching,
the target effective pulse duty cycle of the EMIT for driving the
switched picture is decreased. That is, the width of each
ineffective pulse is adjusted individually until the ratio of the
target effective pulse duty cycle of the EMIT for driving the
switched picture to the first effective pulse duty cycle is equal
to the target ratio. Therefore, the display time period of the
organic light-emitting display panel is reduced, so that the
brightness is decreased.
[0042] In one embodiment, an output waveform of the EMIT includes a
plurality of effective pulses and a plurality of ineffective
pulses. If the effective pulse duty cycles of the EMIT before and
after picture switching are almost same, the target effective pulse
duty cycle may be adjusted individually so as to achieve the
fine-tuning on the brightness of the organic light-emitting display
panel. If the effective pulse duty cycles of the EMIT before and
after picture switching are largely different, the width of a
plurality of ineffective pulse may be adjusted so as to achieve the
fast-tuning on the brightness of the organic light-emitting display
panel.
[0043] In one embodiment, adjusting the target effective pulse duty
cycle of the EMIT for driving the switched picture in step 130
includes: increasing gradually, when the target effective pulse
duty cycle of the EMIT for driving the switched picture is larger
than the target effective pulse duty cycle of the EMIT for driving
the preceding picture of the frame, the target effective pulse duty
cycle until the ratio of the target effective pulse duty cycle to
the first effective pulse duty cycle is equal to the target
ratio.
[0044] If the target effective pulse duty cycle of the EMIT after
switched is larger than that of the EMIT before switched, it
indicates that the brightness of the switched picture is higher
than that of the picture before switched. In the case that the
brightness becomes higher before and after the picture switching,
the target effective pulse duty cycle of the EMIT for driving the
switched picture is increased. That is, the width of each
ineffective pulse is adjusted individually until the ratio of the
target effective pulse duty cycle of the EMIT for driving the
switched picture to the first effective pulse duty cycle is equal
to the target ratio. Therefore, the display time period of the
organic light-emitting display panel is increased and the
brightness is improved. In one embodiment, the target effective
pulse duty cycle may be adjusted so as to achieve the adjustment to
the brightness of the organic light-emitting display panel.
[0045] Based on the same inventive concept, the present disclosure
further provides a driving device of the organic light-emitting
display panel. Since the principle of the driving device for
solving the problems is similar to that of the driving method of
the organic light-emitting display panel, the operations of the
driving device may refer to that of the driving method and do not
discuss again here.
[0046] As shown in FIG. 3, a driving device of the organic
light-emitting display panel is provided in this embodiment, the
driving device includes: a display brightness determining device
210 and a display brightness adjusting device 220.
[0047] The display brightness determining device 210 is configured
to determine, when controlling the picture switching of the organic
light-emitting display panel, the target brightness level of the
switched picture and the target maximum gray scale brightness
corresponding to the target brightness level. The display
brightness adjusting device 220 is configured to adjust the target
effective pulse duty cycle of the EMIT for driving the switched
picture on the basis of the target maximum gray scale brightness of
the switched picture, the first maximum gray scale brightness and a
first effective pulse duty cycle. The maximum gray scale brightness
corresponding to the maximum brightness level of the organic
light-emitting display panel is defined as a first maximum gray
scale brightness, and the effective pulse duty cycle of the EMIT
for driving the first maximum gray scale brightness is defined as a
first effective pulse duty cycle.
[0048] In one embodiment, the effective pulse of the EMIT is
configured to control at least one row of sub-pixels to emit
light.
[0049] In one embodiment, the effective pulse of the EMIT is
configured to control the adjacent four rows of sub-pixels to emit
light.
[0050] In one embodiment, an output waveform of the EMIT includes a
plurality of effective pulses and ineffective pulses.
[0051] In one embodiment, the display brightness adjusting device
220 includes: a brightness calculating device 221 and a pulse
adjusting device 222.
[0052] The brightness calculating device 221 is configured to
calculate a target ratio of the target maximum gray scale
brightness to the first maximum gray scale brightness; the pulse
adjusting device 222 is configured to adjust the target effective
pulse duty cycle of the EMIT for driving the switched picture,
thereby enabling the ratio of the target effective pulse duty cycle
to the first effective pulse duty cycle to be equal to a target
ratio.
[0053] In one embodiment, the implementation process for the
display brightness adjusting device 220 includes: decreasing
gradually, when the target effective pulse duty cycle of the EMIT
for driving the switched picture is less than the target effective
pulse duty cycle of the EMIT for driving the preceding picture of
the frame, the target effective pulse duty cycle of the EMIT until
the ratio of the target effective pulse duty cycle to the first
effective pulse duty cycle is equal to the target ratio.
[0054] In one embodiment, the implementation process for the
display brightness adjusting device 220 includes: increasing
gradually, when the target effective pulse duty cycle of the EMIT
for driving the switched picture is larger than the target
effective pulse duty cycle of the EMIT for driving the preceding
picture of the frame, the target effective pulse duty cycle of the
EMIT until the ratio of the target effective pulse duty cycle to
the first effective pulse duty cycle equal to the target ratio.
[0055] In this embodiment, the display time period of the organic
light-emitting display panel is adjusted by adjusting the effective
pulse duty cycle of the organic light-emitting display panel,
thereby adjusting the total brightness of the organic
light-emitting display panel. Furthermore, the driving method for
the organic light-emitting display panel may also achieve the
smooth adjustment of the brightness of the organic light-emitting
display panel and improve the display effect of the organic
light-emitting display panel.
[0056] Based on the same inventive concept, the present disclosure
further provides a driving device of the organic light-emitting
display panel and the driving device according to any above
mentioned embodiments is integrated into the organic light-emitting
display panel. The driving device is configured to solve the
driving method according to any above mentioned embodiments and no
repetitions here.
[0057] In this embodiment, the organic light-emitting display panel
shown in FIG. 4 includes the driving device according to above
embodiments. In one embodiment, the driving device includes: a
plurality of light-emitting control lines 310, and a light-emitting
control line 310 is correspond to and is electrically connected to
at least a row of sub-pixels (not shown in drawings); multiple
cascades of shift register devices 320, and the multiple cascaded
of shift register devices 320 correspond to and are electrically
connected to the plurality of light-emitting control lines,
respectively, a cascade of the shift register devices 320 is
configured to provide a EMIT to a corresponding light-emitting
control line 310.
[0058] In this embodiment, the organic light-emitting display panel
includes a display region AA, and sub-pixels with array
distribution are disposed in the display region AA. The organic
light-emitting display panel further includes a non-display region
surround the display region AA, and a driving device is provided in
the non-display region. Each sub-pixel is controlled by a
corresponding pixel circuit, as shown in FIG. 5, the pixel circuit
includes a light-emitting control transistor M1 and a
light-emitting control transistor M7 for driving the OLED. A
light-emitting control line 310 is configured to correspond to and
is electrically connected to at least a row of sub-pixels, which
indicates that a light-emitting control line 310 is connected to
the gate electrode of the light-emitting control transistor in the
pixel circuit of at least a row of sub-pixels, and an EMIT is
transmitted to the gate electrode of the light-emitting control
transistor via the light-emitting control line 310.
[0059] In this embodiment, the driving device further includes:
multiple cascades of shift register devices 320, the multiple
cascades of shift register devices 320 are configured to be
correspond to and electrically connected to the plurality of
light-emitting control lines 310. each of the cascades of the
multiple cascades of shift register devices 320 is configured to
provide a EMIT to a corresponding light-emitting control line 310.
It should be noted that, the driving device of the organic
light-emitting display panel further includes a light-emitting
driving chip 330, the light-emitting driving chip 330 is configured
to apply a shift trigger signal (IN) to the first cascade of shift
register devices 320, and the light-emitting driving chip 330 is
also configured to apply a clock signal to each of the cascades of
shift register devices 320. The waveform of the IN outputted by the
light-emitting driving chip 330 is same with that of the EMIT, with
the merely difference in phases. The shift registers device 320
outputs the EMIT on basis of the shift trigger signal IN outputted
by the driving chip 330. The brightness level of the organic
light-emitting display panel may adjusted by adjusting the waveform
of the shift trigger signal IN by the light-emitting driving chip
330.
[0060] When driving device controls the picture switching, the
light-emitting driving chip 330 of the driving device may determine
the brightness level of the switched picture and maximum gray scale
brightness. Since the maximum brightness level, the first maximum
gray scale brightness corresponding to the maximum brightness level
and the first effective pulse duty cycle are known to the
light-emitting driving chip 330, the effective pulse duty cycle of
the EMIT of driving the switched picture may be calculated by the
light-emitting driving chip 330, and the adjusted EMIT is outputted
by adjusting the IN of the EMIT and the multiple cascades of shift
register devices 320 based on the calculated effective pulse duty
cycle of the EMIT of driving the switched picture.
[0061] The organic light-emitting display panel provided by this
embodiment has a dimming mode and provides a driving timing for
changing the brightness of the organic light-emitting display panel
under the dimming mode, and the dimming mode may improve the
problems of defective display in the organic light-emitting display
panel. Under the dimming mode, the display time period of the
organic light-emitting display panel can be adjusted by adjusting
the width of the effective pulse duty cycle of the EMIT outputted
by the shift registers device 320, thereby adjusting the brightness
of the organic light-emitting display panel.
[0062] It should be noted that, the driving device may achieve a
desired effective pulse duty cycle by adjusting the width of each
pulse of the EMIT, in order to achieve the adjustment for the
picture of a frame; and the driving device may also achieve the
adjustment of the gray scales for different sub-pixels in the
picture of a frame by adjusting the data signal voltage.
[0063] In order to describe the driving timing of the organic
light-emitting display panel in detail, the driving timing for
pictures of multiple frames is taken as an example to give
descriptions here. It should be noted that, a display stage of the
organic light-emitting display panel includes an initial stage, a
data-writing stage and a light emission stage. In one embodiment,
the operating timings of the initial stage and the data-writing
stage in the organic light-emitting display panel are similar to
the related technologies and no repetitions here.
[0064] In FIG. 6A, FIG. 6B and FIG. 6C, it should be noted that,
the EMIT of the organic light-emitting display panel in the light
emission stage includes two pulses; S1 is an initial control line,
and the organic light-emitting display panel is in the initial
stage when S1 outputs the low level pulses; S2 is a data-writing
control line, and the organic light-emitting display panel is in
the data-writing stage when S2 outputs the low level pulses. E[1]
is the a first light-emitting control line, S1[1] is a first
initial control line, and S2[1] is a first data-writing control
line and the like.
[0065] FIG. 6A shows a waveform of the maximum gray scale
brightness corresponding to the 255-th-level brightness of the
organic light-emitting display panel, and a high level pulse is the
ineffective pulse, and a low level pulse is the effective
pulse.
[0066] As shown in FIG. 6B, when the brightness level of the
organic light-emitting display panel may need to be decreased, the
driving device of the organic light-emitting display panel may
decrease the brightness level of the organic light-emitting display
panel by decreasing the target effective pulse duty cycle of the
EMIT. For example, if the brightness level of the organic
light-emitting display panel may need to be decreased to the
254-th-level brightness, the brightness level of the organic
light-emitting display panel may be decreased by increasing the
width of the second ineffective pulse of the EMIT. The specific
increased time period may be determined and adjusted according to
the maximum gray scale brightness corresponding to the 254-th-level
brightness.
[0067] As shown in FIG. 6C, when the brightness level of the
organic light-emitting display panel may need to be further
decreased, the driving device of the organic light-emitting display
panel may decrease the brightness level of the organic
light-emitting display panel by decreasing the target effective
pulse duty cycle of the EMIT. For example, if the brightness level
of the organic light-emitting display panel may need to be
decreased to the 253-th-level brightness, the brightness level of
the organic light-emitting display panel may be decreased by
increasing the width of the second ineffective pulse of the EMIT.
The specific increased time period may be determined and adjusted
according to the maximum gray scale brightness corresponding to the
253-th-level brightness.
[0068] The driving device according to this embodiment provides a
novel driving timing in the light emission stage of the organic
light-emitting display panel, so that the adjustment to the display
time period of the organic light-emitting display panel is
achieved, and hence adjusting the display brightness of the organic
light-emitting display panel.
* * * * *