The present invention relates to display technology, more particularly, to a data driving integrated circuit, a display apparatus, and a pixel compensation method.
In organic light-emitting diode (OLED) display apparatus, a pixel-driving circuit includes a driving transistor for controlling a driving current flowing through an organic light-emitting diode. Due to instability in fabrication process, device parameter drifting, and aging of transistor, the driving current may vary from one transistor to another and drift over time, leading to non-uniformity issue across subpixels in a display apparatus. Pixel compensation may be used for compensating the voltage signal or current signal.
In an aspect, the present disclosure provides a data driving integrated circuit, comprising a digital-to-analog converter configured to receive a respective digital data signal from a timing controller and convert the respective digital data signal to a respective analog data signal, which is output to a display panel through a respective data line; an analog-to-digital converter configured to receive a respective analog sensing signal from a respective sensing line in the display panel and convert respective analog sensing signal to a respective digital sensing signal, which is output to the timing controller; a first sensing switch configured to control a connection between a first reference voltage line and the respective sensing line; a second sensing switch configured to control a connection between a second reference voltage line and the respective sensing line; and a third sensing switch configured to control the connection between the analog-to-digital converter and the respective sensing line.
In an aspect, the present disclosure provides a display apparatus, comprising the above data driving integrated circuit; a plurality of data lines respectively coupled to the data driving integrated circuit; a plurality of sensing line respectively coupled to the data driving integrated circuit; the first reference voltage line configured to provide a first reference voltage signal; and the second reference voltage line configured to provide a second reference voltage signal.
In some embodiments, the respective sensing line is coupled to a plurality of columns of pixel driving circuits.
In some embodiments, the respective sensing line is coupled to n columns of pixel driving circuits, n number of pixel driving circuits in a respective row of n columns of pixel driving circuits being respectively connected to n number of light emitting elements respectively in n number of subpixels.
In some embodiments, the respective sensing line is coupled to 2n columns of pixel driving circuits, 2n number of pixel driving circuits in a respective row of 2n columns of pixel driving circuits being respectively connected to 2n number of light emitting elements respectively in 2n number of subpixels.
In some embodiments, the display apparatus further comprises a plurality of pixel driving circuits and a plurality of light emitting diodes; a respective pixel driving circuit comprises a storage capacitor having a first capacitor electrode coupled to a first node and a second capacitor electrode coupled to a second node; a driving transistor having a first electrode coupled to a respective voltage supply line, a second electrode coupled to the second node, and a gate electrode coupled to the first node; a switching transistor having a first electrode coupled to a respective data line, a second electrode coupled to the first node, and a gate electrode coupled to a respective first gate line; and a sensing transistor having a first electrode coupled to the respective sensing line, a second electrode coupled to the second node, and a gate electrode coupled to a respective second gate line.
In an aspect, the present disclosure provides a pixel compensation method, comprising in a sensing voltage write-in stage, providing a tuning-on voltage signal to a respective first gate line to turn on a switching transistor in a respective pixel driving circuit; providing a turning-on voltage signal to a respective second gate line to turn on a sensing transistor in the respective pixel driving circuit; controlling a first sensing switch of a data driving integrated circuit in a conductive state to electrically connect a first reference voltage line to a respective sensing line while maintaining a second sensing switch and a third sensing switch of the data driving integrated circuit in a non-conductive state; providing a first reference voltage signal to the respective sensing line through the first reference voltage line; and providing a sensing voltage signal to a first electrode of the switching transistor through a respective data line, the sensing voltage signal passing through the switching transistor to a first node coupled to a gate electrode of a driving transistor, a drain electrode of the switching transistor, and a first capacitor electrode of a storage capacitor.
In some embodiments, the second sensing switch is configured to control a connection between a second reference voltage line and the respective sensing line; and the third sensing switch is configured to control a connection between an analog-to-digital converter of the data driving integrated circuit and the respective sensing line.
In some embodiments, the pixel compensation method further comprises in a charging stage, controlling the first sensing switch, the second sensing switch, and the third sensing switch of the data driving integrated circuit respectively in a non-conductive state; providing a turning-off voltage signal to the respective first gate line to turn off the switching transistor in the respective pixel driving circuit; providing a turning-on voltage signal to the respective second gate line to turn on the sensing transistor in the respective pixel driving circuit; and providing a voltage signal to a respective voltage supply line coupled to a first electrode of the driving transistor, allowing a charging current to flow through the driving transistor, thereby charging the respective sensing line.
In some embodiments, the respective sensing line is charged from a voltage level of the first reference voltage signal to a voltage level within a conversion voltage range of an analog-to-digital converter of the data driving integrated circuit.
In some embodiments, in the charging stage, the pixel compensation method further comprises discontinuing data voltage signal to any data line.
In some embodiments, the pixel compensation method further comprises in a sensing stage subsequent to a charging stage, controlling the third sensing switch of the data driving integrated circuit in a conductive state to electrically connect the respective sensing line to an analog-to-digital converter while maintaining the first sensing switch and the second sensing switch of the data driving integrated circuit in a non-conductive state.
In some embodiments, the pixel compensation method further comprises in a conversion stage, converting a respective analog sensing signal from a respective sensing line to a respective digital sensing signal; and outputting the respective digital sensing signal to a timing controller.
In some embodiments, the pixel compensation method further comprises in a data write-back stage subsequent to a charging stage and a conversion stage, controlling the second sensing switch of the data driving integrated circuit in a conductive state to electrically connect a second reference voltage line to the respective sensing line while maintaining the first sensing switch and the third sensing switch of the data driving integrated circuit in a non-conductive state; providing a second reference voltage signal to the respective sensing line through the second reference voltage line; providing the turning-on voltage signal to the respective first gate line to turn on the switching transistor in a respective pixel driving circuit; providing the turning-on voltage signal to the respective second gate line to turn on the sensing transistor in the respective pixel driving circuit; and providing a respective data signal to the first electrode of the switching transistor through the respective data line, the respective data signal passing through the switching transistor to the first node; wherein the second reference voltage signal has a voltage level higher than a voltage level of the first reference voltage signal.
In some embodiments, the pixel compensation method further comprises in an idle stage subsequent to the data write-back stage, controlling the first sensing switch, the second sensing switch, and the third sensing switch of the data driving integrated circuit respectively in the non-conductive state; providing a turning-off voltage signal to the respective first gate line to turn off the switching transistor in the respective pixel driving circuit; and providing a turning-on voltage signal to the respective second gate line to turn on the sensing transistor in the respective pixel driving circuit.
In some embodiments, the pixel compensation method further comprises in the idle stage, discontinuing data voltage signal to any data line.
In some embodiments, the pixel compensation method further comprises in an image display period subsequent to a sensing period, controlling the second sensing switch of the data driving integrated circuit in a conductive state to electrically connect a second reference voltage line to the respective sensing line while maintaining the first sensing switch and the third sensing switch of the data driving integrated circuit in a non-conductive state; providing a second reference voltage signal to the respective sensing line through the second reference voltage line; providing the turning-on voltage signal to the respective first gate line to turn on the switching transistor in a respective pixel driving circuit; providing the turning-on voltage signal to the respective second gate line to turn on the sensing transistor in the respective pixel driving circuit; and providing a respective data signal to the first electrode of the switching transistor through the respective data line, the respective data signal passing through the switching transistor to the first node; wherein the second reference voltage signal has a voltage level higher than a voltage level of the first reference voltage signal.
In some embodiments, the sensing voltage signal comprises consecutively a first low voltage level, a first high voltage level, a second high voltage level, and a second low voltage level; wherein the first high voltage level is higher than the second high voltage level; and the second high voltage level is higher than a voltage level of a threshold voltage of the driving transistor.
In some embodiments, the pixel compensation method further comprises calibrating a plurality of analog-to-digital converters in one or more data driving integrated circuits in a display apparatus with respect to each other; wherein calibrating the plurality of analog-to-digital converters comprises in a first calibration stage, controlling the second sensing switch of a respective data driving integrated circuit in a conductive state to electrically connect a second reference voltage line to the respective sensing line while maintaining the first sensing switch and the third sensing switch of the respective data driving integrated circuit in a non-conductive state; and providing a second reference voltage signal to the respective sensing line through the second reference voltage line; wherein calibrating the plurality of analog-to-digital converters further comprises in a second calibration stage, controlling the third sensing switch of the respective data driving integrated circuit in a conductive state to electrically connect the respective sensing line to a respective analog-to-digital converter while maintaining the first sensing switch and the second sensing switch of the respective data driving integrated circuit in a non-conductive state; converting a respective analog sensing signal to a respective digital sensing signal by the respective analog-to-digital converter; and outputting the respective digital sensing signal to a timing controller; wherein values of a plurality of analog sensing signals respectively converted by the plurality of analog-to-digital converters are used for calibrating the plurality of analog-to-digital converters with respect to each other.
The following drawings are merely examples for illustrative purposes according to various disclosed embodiments and are not intended to limit the scope of the present invention.
The disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of some embodiments are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.
The present disclosure provides, inter alia, a data driving integrated circuit, a display apparatus, and a pixel compensation method that substantially obviate one or more of the problems due to limitations and disadvantages of the related art. In one aspect, the present disclosure provides a data driving integrated circuit. In some embodiments, the data driving integrated circuit includes a digital-to-analog converter configured to receive a respective digital data signal from a timing controller and convert the respective digital data signal to a respective analog data signal, which is output to a display panel through a respective data line; an analog-to-digital converter configured to receive a respective analog sensing signal from a respective sensing line in the display panel and convert respective analog sensing signal to a respective digital sensing signal, which is output to the timing controller; a first sensing switch configured to control a connection between a first reference voltage line and the respective sensing line; a second sensing switch configured to control a connection between a second reference voltage line and the respective sensing line; and a third sensing switch configured to control the connection between the analog-to-digital converter and the respective sensing line.
Optionally, the first reference voltage line Vref1 is configured to provide a first reference voltage signal. Optionally, the second reference voltage line Vref2 is configured to provide a second reference voltage signal. Optionally, the second reference voltage signal has a voltage level higher than a voltage level of the first reference voltage signal.
In another aspect, the present disclosure provides a display apparatus having the data driving integrated circuit described herein. In some embodiments, the display apparatus further includes a plurality of data lines respectively coupled to the data driving integrated circuit; a plurality of sensing line respectively coupled to the data driving integrated circuit; the first reference voltage line configured to provide a first reference voltage signal; and the second reference voltage line configured to provide a second reference voltage signal.
In some embodiments, the display apparatus further includes a plurality of voltage supply lines EL. In one example, the plurality of voltage supply lines EL includes one or more high voltage supply lines (e.g., a Vdd signal line configured to provide a VDD signal). In another example, the plurality of voltage supply lines EL includes one or more low voltage supply lines (e.g., a Vss signal line configured to provide a VSS signal).
In some embodiments, the display apparatus further includes a first reference voltage line Vref1 and a second reference voltage line Vref2. Optionally, the first reference voltage line Vref1 is configured to provide a first reference voltage signal. Optionally, the second reference voltage line Vref2 is configured to provide a second reference voltage signal. Optionally, the second reference voltage signal has a voltage level higher than a voltage level of the first reference voltage signal.
In some embodiments, the respective sensing line RSL is coupled to n columns of pixel driving circuits, n number of pixel driving circuits in a respective row of the n columns of pixel driving circuits being respectively connected to n number of light emitting elements respectively in n number of subpixels. Optionally, n stands of a number of subpixels of different colors in a respective pixel. In one example, the respective pixel includes a red subpixel, a green subpixel, and a blue subpixel, and n=3.
As used herein, in the context of a transistor, a first electrode in some embodiments refers to a source electrode, and a second electrode in some embodiments refers to a drain electrode.
In another aspect, the present disclosure further provides a pixel compensation method. In some embodiments, the pixel compensation method includes, in a sensing voltage write-in stage, providing a turning-on voltage signal to a respective first gate line to turn on a switching transistor in a respective pixel driving circuit; providing a turning-on voltage signal to a respective second gate line to turn on a sensing transistor in the respective pixel driving circuit; controlling a first sensing switch of a data driving integrated circuit in a conductive state to electrically connect a first reference voltage line to a respective sensing line while maintaining a second sensing switch and a third sensing switch of the data driving integrated circuit in a non-conductive state; providing a first reference voltage signal to the respective sensing line through the first reference voltage line; and providing a sensing voltage signal to a first electrode of the switching transistor through a respective data line, the sensing voltage signal passing through the switching transistor to a first node coupled to a gate electrode of a driving transistor, a drain electrode of the switching transistor, and a first capacitor electrode of a storage capacitor.
In the image display period P1, referring to
In the image display period P1, the second sensing switch SW2 of the data driving integrated circuit is controlled in a conductive state to electrically connect a second reference voltage line Vref2 to the respective sensing line RSL while the first sensing switch SW1 and the third sensing switch SW3 of the data driving integrated circuit are maintained in a non-conductive state. A second reference voltage signal (e.g., 1 V) is provided to the respective sensing line RSL through the second reference voltage line Vref2, and then transferred to the second capacitor electrode of the respective storage capacitor RCst. The second reference voltage signal is a relatively high voltage signal (as compared to the first reference voltage signal). The voltage level at the anode of the respective light emitting element RLE is reset by the sensing line SL (e.g., to the voltage level of the second reference voltage signal).
Subsequently in the image display period P1, a turning-off voltage signal is provided to the respective first gate line RGL1 (e.g., row-by-row) to turn off the switching transistor T2 in a respective pixel driving circuit RPDC; a turning-off voltage signal is provided to the respective second gate line RGL2 to turn off the sensing transistor T3 in the respective pixel driving circuit RPDC. The driving transistor T1 is turned on by the data driving voltage, and working in a saturation area. A voltage supply signal (e.g., a VDD signal) is provided to the first electrode of the driving transistor T1, the driving transistor T1 generates a driving current. The driving current flows through the respective light emitting element RLE, driving the respective light emitting element RLE to emit light.
Referring to
Referring to
Similarly, in the next adjacent frame of image F(n+1), the sensing is performed in a green subpixel in the next adjacent frame of image F(n+1), the sensing voltage signal (e.g., DL_G_Sense) having a relatively high voltage level is provided to the first electrode of the switching transistor T2 in the green subpixel through a respective data line (e.g., DL_G), whereas a low voltage signal (e.g., 0 V) is provided to first electrodes of the switching transistor T2 in subpixels of other colors (e.g., red subpixels and blue subpixel) respectively through other respective data lines (e.g., DL_R and DL_B). This ensures that a charging current in a subsequent charging stage would not flow through the driving transistors in the red subpixels and green subpixels. Interference among adjacent subpixels may be avoided.
Referring to
As discussed in the context of the sensing voltage write-in stage S1, in the sensing voltage write-in stage S1 in the present frame of image Fn, the sensing voltage signal (e.g., DL_R_Sense) having a relatively high voltage level is provided to the first electrode of the switching transistor T2 in the red subpixel through a respective data line (e.g., DL_R), whereas a low voltage signal (e.g., 0 V) is provided to first electrodes of the switching transistor T2 in subpixels of other colors (e.g., blue subpixels and green subpixels) respectively through other respective data lines (e.g., DL_G and DL_B). In the charging stage S2 in the present frame of image Fn, a charging current flows through the driving transistor T1 in the red subpixel, whereas a charging current would not flow through the driving transistors in the blue subpixels and green subpixels. Interference among adjacent subpixels may be avoided.
Similarly, as discussed in the context of the sensing voltage write-in stage S1, in the sensing voltage write-in stage S1 in the next adjacent frame of image F(n+1), the sensing is performed in a green subpixel in the next adjacent frame of image F(n+1), the sensing voltage signal (e.g., DL_G_Sense) having a relatively high voltage level is provided to the first electrode of the switching transistor T2 in the green subpixel through a respective data line (e.g., DL_G), whereas a low voltage signal (e.g., 0 V) is provided to first electrodes of the switching transistor T2 in subpixels of other colors (e.g., red subpixels and blue subpixel) respectively through other respective data lines (e.g., DL_R and DL_B). In the charging stage S2 in the present frame of image Fn a charging current flows through the driving transistor T1 in the green subpixel, whereas a charging current would not flow through the driving transistors in the red subpixels and blue subpixels. Interference among adjacent subpixels may be avoided.
The descriptions of the operation in the sensing voltage write-in stage S1 and the charging stage S2 generally also apply to the operation of a display apparatus having a format depicted in
In some embodiments, the respective sensing line RSL is charged from a voltage level of the first reference voltage signal to a voltage level within a conversion voltage range of an analog-to-digital converter of the data driving integrated circuit. In one example, the conversion voltage range of the analog-to-digital converter is, for example, 1 V to 4V. In another example, the respective sensing line RSL is charged from a voltage level of the first reference voltage signal to, e.g., 1 V (as shown in
Optionally, the respective sensing line RSL is charged from a voltage level of the first reference voltage signal to a medium voltage level of the conversion voltage range of the analog-to-digital converter (e.g., 2.5 V). In another example, the respective sensing line RSL is charged from a voltage level of the first reference voltage signal to, e.g., 2.5 V (as shown in
In some embodiments, in the charging stage S2, the pixel compensation method further includes discontinuing data voltage signal to any data line (e.g., DL_R, DL_G, DL_B in
Referring to
In some embodiments, in the sensing stage S3, the pixel compensation method further includes discontinuing data voltage signal to any data line (e.g., DL_R, DL_G, DL_B in
Referring to
In some embodiments, in the conversion stage S4, the pixel compensation method further includes discontinuing data voltage signal to any data line (e.g., DL_R, DL_G, DL_B in
Referring to
In the charging stage S2, the sensing stage S3, and the conversion stage S4, the data lines (e.g., DL_R, DL_G, DL_B in
Referring to
In some embodiments, in the idle stage S6, the pixel compensation method further includes discontinuing data voltage signal to any data line (e.g., DL_R, DL_G, DL_B in
Referring to
As discussed above, in some embodiments, in the sensing voltage write-in stage S1, a sensing voltage signal (e.g., DL_R_Sense and DL_G_Sense as depicted in
In some embodiments, the display apparatus may include one or more data driving integrated circuits, and a respective data driving integrated circuit may include one or more analog-to-digital converters. The plurality of analog-to-digital converters in the display apparatus may output digital signals having different values, upon receiving a same analog signal. Thus, it is desirable to calibrate the plurality of analog-to-digital converters in the display apparatus.
In some embodiments, calibrating the plurality of analog-to-digital converters further includes in a second calibration stage CP2, controlling the third sensing switch SW3 of the respective data driving integrated circuit in a conductive state to electrically connect the respective sensing line RSL to the respective analog-to-digital converter ADC while maintaining the first sensing switch SW1 and the second sensing switch SW2 of the respective data driving integrated circuit in a non-conductive state; converting a respective analog sensing signal to a respective digital sensing signal by the respective analog-to-digital converter; and outputting the respective digital sensing signal to a timing controller. Values of a plurality of analog sensing signals respectively converted by the plurality of analog-to-digital converters are used for calibrating the plurality of analog-to-digital converters with respect to each other.
The foregoing description of the embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. Moreover, these claims may refer to use “first”, “second”, etc. following with noun or element. Such terms should be understood as a nomenclature and should not be construed as giving the limitation on the member of the elements modified by such nomenclature unless specific number has been given. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2021/096006 | 5/26/2021 | WO |