This application claims priority to Chinese Patent Application No. 202211561378.X, filed on Dec. 7, 2022, the disclosure of which is incorporated herein by reference in its entirety.
The present disclosure relates to display technologies, and in particular, to luminance compensation circuits, drive backplanes, and luminance compensation methods.
Mini/Micro Light Emitting Diode (MLED) has become one hot spot in future display technology due to its fast response, high color gamut, high pixel density, low energy consumption, etc. MLED display is considered as the next generation display solution, which has a display effect significantly better than LED display. However, production yield and reliability of MLED may limit development of MLED. For example, poor luminance uniformity and stability of the MLED may result in poor production yield and product reliability of an array substrate based MLED.
In order to cope with temporal and spatial unevenness of the MLED display luminance, the MLED may be designed with a compensation function to improve the luminance uniformity and stability thereof.
One or more embodiments of the present disclosure provide a luminance compensation circuit, including:
One or more embodiments of the present disclosure provide a drive backplane including the luminance compensation circuit as described above.
One or more embodiments of the present disclosure provide a luminance compensation method for a drive backplane. The drive backplane includes the luminance compensation circuit as described above. The luminance compensation method includes:
Some embodiments of the present disclosure will be described in detail below in connection with the accompanying drawings. The embodiments are described for illustrative purposes only and are not intended to limit the present disclosure.
In addition, the terms “first”, “second”, etc. in the description and claims of this disclosure are used to distinguish different objects, rather than describing a specific sequence. The terms “include” and “have” and any variations thereof are intended to cover non-exclusive inclusion. Since a source and a drain of the transistor used in this disclosure are symmetrical, the source and drain are interchangeable. According to a shape in the attached figure, a middle terminal of the transistor is a gate, a signal input terminal is the source, and an output terminal is the drain.
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The light-emitting circuit 10 is configured to receive a data signal data and emit light under the action of the data signal data.
The luminance detector 20 is electrically connected to a first power terminal V1, a second power terminal V2, and a first node P, respectively. That is, the luminance detector 20 is connected in series in a loop formed by the first power terminal V1 and the second power terminal V2. The luminance detector 20 is used to control and store a magnitude of a voltage output from the first power terminal V1 to the first node P based on luminance of the light-emitting circuit 10.
It is worth mentioning that voltage signals provided by the first power terminal V1 and the second power terminal V2 are different. That is, when the first power terminal V1 provides a high-voltage power signal, the second power terminal V2 may provide a low-voltage power signal; or when the first power terminal V1 provides a low-voltage power signal, the second power terminal V2 may provide a high-voltage power signal.
The reading device 30 is electrically connected to the first node P and the timing controller 40. The reading device 30 is used to read the magnitude of the voltage at the first node P and output the read magnitude of the voltage to the timing controller 40.
The timing controller 40 is electrically connected to the light-emitting circuit 10 and is used to compensate for the data signal data provided to the light-emitting circuit 10 based on the magnitude of the voltage (i.e., the voltage at the first node P) provided by the reading device 30.
In the luminance compensation circuit 100 provided in some embodiments, the luminance detector 20 is set to convert luminous intensity of the light-emitting circuit 10 into the corresponding voltage value of the first node P, and the timing controller 40 compensates the data signal data of the light-emitting circuit 10 based on the voltage of the first node P, thereby improving display uniformity of the light-emitting circuit 10.
In some embodiments of the present disclosure, please refer to
The photosensitive device 21 is electrically connected to the first power terminal V1 and the first node P, respectively. The photosensitive device 21 is used to control the voltage output from the first power terminal V1 to the first node P based on the luminance of the light-emitting circuit 10.
The storage device 22 is electrically connected to the first node P and the second power terminal V2, respectively. The storage device 22 is used to store the voltage of the first node P for reading by the reading device 30.
In some embodiments of the present disclosure, please refer to
A gate of the photosensitive transistor T1 is electrically connected to a first control terminal S1, one of a source and a drain of the photosensitive transistor T1 is electrically connected to the first power terminal V1, and an other one of the source and the drain of the photosensitive transistor T1 is electrically connected to the first node P.
When the gate of the photosensitive transistor T1 is connected to a first control signal provided by the first control terminal S1, and one of the source and drain of the photosensitive transistor T1 is connected to a first power signal provided by the first power terminal V1, the photosensitive transistor T1 is turned off. The photosensitive transistor T1 may generate photo-generated carriers under the action of light due to its light sensing function, which generates a photo-generated current flowing from one of the source and drain of the photosensitive transistor T1 to the other one of the source and drain of the photosensitive transistor T1, thereby providing the current to the first node P. Different luminance results in different numbers of photo-generated carriers and different photo-generated currents. Therefore, when the luminous intensity of the light-emitting circuit 10 is different, the voltages at the first node P is different.
In some embodiments, the photosensitive transistor T1 may be manufactured at the same time as other transistors in the luminance detection circuit, which can simplify a manufacturing process of the luminance detection circuit and reduce a manufacturing cost.
In some embodiments of the present disclosure, please refer to
A first terminal of the photodiode D1 is electrically connected to the first power terminal V1, and a second terminal of the photodiode D1 is electrically connected to one of a source and a drain of the third switching transistor T4.
A gate of the third switching transistor T4 is electrically connected to the first control terminal S1, and an other one of the source and the drain of the third switching transistor T4 is electrically connected to the first node P.
In some embodiments, the photodiode D1 has a light sensing function. The photodiode D1 generates a photo-generated current after receiving light from the light-emitting circuit 10. The gate of the third switching transistor T4 is turned on under a control of the first control signal provided by the first control terminal S1, and providing the photo-generated current provided by the photodiode D1 to the first node P. Therefore, when the luminous intensity of the light-emitting circuit 10 is different, the voltages at the first node P are different.
In order to prevent the photodiode D1 from operating unnecessarily and providing the photo-generated current to the first node P, in some embodiments, the third switching transistor T4 is set to control whether the photo-generated current is provided to the first node P.
In some embodiments of the present disclosure, please refer to
A first terminal of the first storage capacitor C1 is electrically connected to the first node P, and a second terminal of the first storage capacitor C1 is electrically connected to the second power terminal V2. The first storage capacitor C1 is used to store the photo-generated current provided to the first node P.
In some embodiments of the present disclosure, please refer to
A gate of the first switching transistor T2 is electrically connected to the second control terminal S2, one of a source and a drain of the first switching transistor T2 is electrically connected to the first node P, and an other one of the source and the drain of the first switching transistor 72 is electrically connected to the timing controller 40.
In some embodiments, the reading device 30 may also be other structures that make an input voltage and an output voltage in a same phase, such as a voltage follower. However, compared with a voltage follower or other structures with the same function, a function of the reading device 30 is implemented by a transistor with a switching function, which is conducive to manufacturing the reading device 30 with other components in the luminance compensation circuit 100 simultaneously thus simplifying a manufacturing process of the luminance detection circuit and reduce a manufacturing cost.
In some embodiments of the present disclosure, please refer to
A gate of the drive transistor DT is electrically connected to a second node Q, and one of a source and a drain of the drive transistor DT is electrically connected to the first power terminal V1.
A gate of the second switching transistor T3 is electrically connected to a third control signal terminal WR, one of a source and a drain of the second switching transistor T3 is electrically connected to the second node Q, an other one of the source and the drain of the second switching transistor T3 is electrically connected to the data signal data and is electrically connected to the timing controller 40.
A first terminal of the second storage capacitor C2 is electrically connected to the second node Q, and a second terminal of the second storage capacitor C2 is electrically connected to the other one of the source and drain of the drive transistor DT.
A first terminal of the light-emitting device L is electrically connected to the other one of the source and drain of the drive transistor DT, and a second terminal of the light-emitting device L is electrically connected to the second power terminal V2. The light-emitting device L may include a Mini light-emitting diode (Mini-LED) or a Micro-LED. The light-emitting device L may include a plurality of Mini-LEDs connected in series or in parallel. The light-emitting device L may include a plurality of Mini-LEDs connected in series or in parallel.
It is worth mentioning that in some embodiments, the light-emitting circuit 10 and the luminance detector 20 are arranged in series in the loop formed by the first power terminal V1 and the second power terminal V2, that is, the light-emitting circuit 10 and the luminance detector 20 use a same high voltage power terminal and a same low voltage power terminal. Such arrangement is beneficial to reducing power terminals and reducing wiring space of the luminance compensation circuit 100. Of course, in some other embodiments provided in the present disclosure, the light-emitting circuit 10 is arranged in series in a loop formed by the third power terminal and the fourth power terminal. That is, one of the source and the drain of the drive transistor is connected to the third power terminal, the first terminal of the light-emitting device is electrically connected to the other one of the source and the drain of the drive transistor, and the second terminal of the light-emitting device is electrically connected to the fourth power terminal.
In some embodiments of the present disclosure, please refer to
In some embodiments, the signal line that provides the data signal to the light-emitting circuit 10 and the signal line that transmits the voltage of the first node P provided by the reading device 30 share the same read signal line DL1. The wiring space of the luminance compensation circuit 100 may be reduced.
Of course, in some other embodiments provided in the present disclosure, the luminance compensation circuit further includes the read signal line and the data signal line. The read signal line is electrically connected to the reading device, and is used to read the voltage of the first node P. The data signal line is electrically connected to the light-emitting circuit and is used to provide the data signal to the light-emitting circuit.
In addition, some embodiments of the present disclosure further provide a drive backplane. The drive backplane provided by the present disclosure includes any of the luminance compensation circuits described above.
In the drive backplane provided in the embodiments, by integrating the luminance compensation circuit provided in those embodiments on the drive backplane, the luminance detector converts the luminous intensity of the light-emitting circuit into a corresponding voltage and the timing controller compensates the light-emitting circuit based on the corresponding voltage, so as to improve the luminance uniformity within the drive backplane.
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The light-emitting circuit 10 includes a drive transistor DT, a second switching transistor T3, a second storage capacitor C2, and a light-emitting device L. The luminance detector 20 includes a photosensitive device 21 and a storage device 22. The photosensitive device 21 includes a photosensitive transistor T1, the storage device 22 includes a first storage capacitor C1. The reading device 30 includes a second switching transistor T3.
Specifically, a gate of the drive transistor DT is electrically connected to a second node Q, one of a source and a drain of the drive transistor DT is electrically connected to a first power terminal V1, and an other one of the source and the drain of the drive transistor DT is electrically connected to a first terminal of the light-emitting device L. A first terminal of the second storage capacitor C2 is electrically connected to the second node Q, and a second terminal of the second storage capacitor C2 is electrically connected to the other one of the source and the drain of the drive transistor DT. A gate of the second switching transistor T3 is electrically connected to a third control signal terminal S3, and one of a source and a drain of the second switching transistor T3 is electrically connected to the second node Q, and an other one of the source and the drain of the second switching transistor T3 is connected to the data signal data. A second terminal of the light-emitting device L is electrically connected to a second power terminal V2.
Specifically, a gate of the photosensitive transistor T1 is electrically connected to the first control terminal S1, one of a source and a drain of the photosensitive transistor T1 is electrically connected to the first power terminal V1, and an other one of the source and the drain of the photosensitive transistor T1 is electrically connected to the first node P. A first terminal of the first storage capacitor C1 is electrically connected to the first node P, and a second terminal of the first storage capacitor C1 is electrically connected to the second power terminal V2.
Specifically, a gate of the first switching transistor T2 is electrically connected to a second control terminal S2, and one of a source and a drain of the first switching transistor T2 is electrically connected to the first node P, and an other one of the source and the drain of the first switching transistor 72 is electrically connected to the timing controller 40.
It should be understood that, for illustration, the photosensitive transistor T1, the first switching transistor T2, and the second switching transistor T3 shown in
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In the data signal writing phase t0, the first control terminal S1 and the second control terminal S2 provide a low-level signal, and the third control terminal WR provides a high-level signal.
In the light-emitting stage t1, the first control terminal S1 provides a high-potential signal, the second control terminal S2 and the third control terminal WR provide a low-potential signal, and the data signal data is a low-potential signal.
In the luminance detection stage t2, the second control terminal S2 provides a high-potential signal, the first control terminal S1 and the third control terminal WR provide low-potential signals, and the data signal data is a high-potential signal.
The first power terminal V1 provides a constant-voltage and high potential signal, and the second power terminal V2 provides a constant-voltage and low potential signal.
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The luminance compensation methods of the drive backplanes provided by the present disclosure converts the luminous intensity of the light-emitting circuit into a corresponding voltage by controlling the luminance detector and controls the timing controller to compensate the light-emitting circuit based on the corresponding voltage, thereby improving the luminance uniformity within the drive backplane.
Some embodiments of the present disclosure have been described in detail above. The description of the above embodiments merely aims to help to understand the present disclosure. Many modifications or equivalent substitutions with respect to the embodiments may occur to those of ordinary skill in the art based on the present disclosure. Thus, these modifications or equivalent substitutions shall fall within the scope of the present disclosure.
Number | Date | Country | Kind |
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202211561378.X | Dec 2022 | CN | national |