CN110491340A - Micro display pixel arrangement, micro display device and compensation method - Google Patents

Abstract

The present invention relates to a micro-display pixel device, comprising: a light-emitting device; a display drive module, coupled to the light-emitting device, configured to receive scan signals and data signals and drive the light-emitting device, which at least includes a light-emitting device coupled to the light-emitting device A driving transistor of the device; and a feedback compensation module, which is coupled to the light emitting device and the display driving module, configured to perform feedback compensation on the driving module through capacitive coupling, and which at least includes a control electrode coupled to the driving transistor first storage capacitor. The invention also relates to a micro display device and a compensation method for the micro display pixel device.

Description

Micro-display pixel device, micro-display device and compensation method

technical field

The invention relates to a circuit, in particular to a micro display pixel circuit.

Background technique

Due to its small size and portability, microdisplay devices have become a hot issue in the field of display research. However, due to the small display area of the micro-display device, which is very close to the user's eyes, in order to achieve the same resolution as the large-screen display, the size of a single pixel in the micro-display device is very small, only a few hundred microns. Therefore, the storage capacitance in a single pixel circuit of the micro display device is also very small, generally only at the fF level. Due to the existence of the leakage current of the switch transistor in the pixel circuit, the voltage of the storage capacitor will change too much within a frame time. Since the light-emitting device emits light when the voltage of the storage capacitor changes, if the voltage on the storage capacitor changes too Otherwise, it will affect the normal display of the display panel. The traditional and commonly used method is to extract the voltage across the light-emitting device such as OLED, and compensate the change of charge in the storage capacitor through feedback, but this will make the current generated by the driving transistor of the pixel circuit be affected by the aging of the light-emitting device such as OLED to a certain extent. .

Contents of the invention

Aiming at the technical problems in the prior art, the present invention proposes a micro-display pixel device that uses capacitive coupling to compensate for changes in the charge of the storage capacitor, thereby reducing the impact of transistor leakage current on the pixel circuit.

The technical solution of the present invention is as follows: a micro-display pixel device, including: a light emitting device; a display driving module, coupled to the light emitting device, configured to receive scan signals and data signals and drive the light emitting device, which at least includes a light emitting device coupled to The first driving transistor of the light emitting device; and a feedback compensation module, at least one input terminal and an output terminal of which are coupled to the control electrode of the first driving transistor, configured to perform feedback compensation on the driving module through capacitive coupling, It includes at least a first storage capacitor coupled to the gate of the first drive transistor.

Specifically, the feedback compensation module further includes: a first feedback transistor, the first pole of which is coupled to the first common potential, and the control pole is coupled to the control pole of the first driving transistor; the first switch transistor, whose first pole is coupled To the second pole of the first feedback transistor, the second pole and the control pole thereof are coupled and grounded; the first storage capacitor is coupled between the control pole and the second pole of the first feedback transistor.

In particular, the feedback compensation module further includes a second switch transistor, the first pole of which is coupled to the first common potential, the control pole of which is configured to receive the compensation control signal, and the second pole of which is coupled to the first feedback transistor of the first feedback transistor. pole.

Specifically, the display driving module further includes: a first display switching transistor, the control pole of which is configured to receive a scan signal, and the first pole of which is configured to receive a data signal; the first pole of the driving transistor is coupled to a first common potential , the control electrode of which is coupled to the second electrode of the first display switch transistor, the second electrode of which is coupled to the anode of the light emitting device; and a second storage capacitor, which is coupled to the control electrode of the first driving transistor and the first between poles.

The present invention also relates to a micro display device, comprising: a pixel array, wherein the pixel array includes at least one or more micro display pixel devices as claimed in claims 1-4; A data driving circuit and a gate driving circuit providing scanning signals; and a sampling compensation circuit coupled to the pixel array, configured to sample the data signal provided by the data driving circuit and determine whether to start the specific data signal The compensation module in the above pixel circuit.

Specifically, the sampling compensation circuit includes: a light emitting device; a display driving module, coupled to the light emitting device, configured to receive scan signals and data signals and drive the light emitting device; an initial sampling module, coupled to the sampling The light emitting device in the compensation circuit and the display driving module in the sampling compensation circuit are configured to sample the driving voltage of the light emitting device corresponding to a certain gray scale, and compare the sampled result with a preset threshold, so as to judge whether to The gray scale is compensated; and a storage module configured to store the judgment result output by the initial sampling module.

Specifically, the initial sampling module includes: a third switch transistor, the first pole of which is coupled to the first common potential, and the control pole of which is configured to receive the first initialization signal; a fourth switch transistor, whose first pole is coupled to the the anode of the light emitting device, the control electrode of which is configured to receive the first initialization signal; the fifth switch transistor, the first electrode of which is coupled to the anode of the light emitting device, and the second electrode of which is coupled to the second electrode of the third switch transistor, Its control electrode is configured to receive a second initialization signal, wherein the first and second initialization signals are complementary to each other or the effective levels do not overlap; the third storage capacitor is coupled between the ground level and the second electrode of the fourth switching transistor and a hysteresis comparator, the non-inverting terminal of the hysteresis comparator is coupled to the second pole of the fifth switching transistor, and the inverting terminal is coupled to the second pole of the fourth switching transistor, wherein the preset threshold value is the The window voltage of the hysteresis comparator is the minimum value of the difference between the driving voltages of the light-emitting devices corresponding to any two gray scales of all the display drive modules; When the voltage difference is smaller than the window voltage, the judgment result is that compensation is not required for the gray level; when the voltage difference between the inverting terminal and the non-inverting terminal of the hysteresis comparator is greater than the window voltage, the judgment result is This gray scale needs to be compensated.

Specifically, the display driving module includes: a second display switching transistor, the control electrode of which is coupled to the scan signal, and the first electrode of which is coupled to the data signal; the second driving transistor, whose first electrode is coupled to the first common potential, controls The pole is coupled to the second pole of the second field display switching transistor, and the second pole is coupled to the anode of the light emitting device; the fourth storage capacitor is coupled between the control pole and the first pole of the second driving transistor.

In particular, the sampling compensation circuit further includes a sampling feedback compensation module, the sampling feedback compensation module includes: a second feedback transistor, the first pole of which is coupled to the first common potential, and the control pole of which is coupled to the fourth switching transistor The second pole; the sixth switch transistor, the first pole of which is coupled to the second pole of the second feedback transistor, the second pole and the control pole of which are coupled and grounded; the fifth storage capacitor, which is coupled to the second feedback transistor Between the control pole and the second pole of the switching transistor.

The present invention also relates to a compensation method for a micro-display pixel device, comprising: sampling and detecting data signals corresponding to all gray scales used in the micro-display device, judging whether the data signals corresponding to each gray scale need to be compensated, and storing the detected Receive the data signal corresponding to the specific grayscale signal under the control of the scanning signal; and judge whether the current data signal needs to be compensated according to the stored detection result, and output the corresponding compensation control signal to control the micro display The compensation of each pixel in the pixel array of the device.

The pixel structure provided in the present application and the corresponding compensation circuit and compensation method provide a dynamic and targeted compensation mechanism, which can dynamically determine whether to compensate a specific pixel for different gray levels. Compared with the structure that performs uniform compensation without distinguishing between gray levels and specific conditions, the power consumption of the microdisplay device provided by the present application is lower. In addition, the design in this application utilizes the original vacant area in the pixel circuit to arrange the compensation module, so the area of the original pixel will not be increased.

Description of drawings

Below, preferred embodiment of the present invention will be described in further detail in conjunction with accompanying drawing, wherein:

FIG. 1 is a schematic diagram of a conventional OLED display pixel circuit;

Fig. 2 is a schematic diagram of a micro display pixel device according to an embodiment of the present invention;

Fig. 3 is a working sequence diagram of a micro display pixel device according to an embodiment of the present invention;

FIG. 4 is a simulation result diagram of a micro-display pixel device at a specific grayscale according to an embodiment of the present invention;

5 is a simulation result diagram of a micro-display pixel device at a specific grayscale according to another embodiment of the present invention;

6 is a schematic diagram of a sampling compensation circuit of a micro-display device according to an embodiment of the present invention;

FIG. 7 is a working timing diagram of a sampling compensation circuit of a micro-display device according to an embodiment of the present invention;

FIG. 8 is a structural diagram of a microdisplay device according to an embodiment of the present invention;

9 is a flow chart of a compensation method for a pixel circuit of a micro-display device according to an embodiment of the present invention;

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following detailed description, reference is made to the accompanying drawings which are included in the specification and which illustrate specific embodiments of the application and which are included in this application. In the drawings, like reference numerals describe substantially similar components in different views. Various specific embodiments of the present application are described in sufficient detail below, so that those of ordinary skill in the art can implement the technical solutions of the present application. It should be understood that other embodiments may also be utilized or structural, logical or electrical changes may be made to the embodiments of the present application.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following detailed description, reference is made to the accompanying drawings which are included in the specification and which illustrate specific embodiments of the application and which are included in this application. In the drawings, like reference numerals describe substantially similar components in different views. Various specific embodiments of the present application are described in sufficient detail below, so that those of ordinary skill in the art can implement the technical solutions of the present application. It should be understood that other embodiments may also be utilized or structural, logical or electrical changes may be made to the embodiments of the present application.

In this application, a transistor may refer to a transistor of any structure, such as a field effect transistor (FET) or a bipolar junction transistor (BJT). When the transistor is a field effect transistor, its control pole refers to the gate of the field effect transistor, the first pole can be the drain or source of the field effect transistor, and the corresponding second pole can be the source or drain of the field effect transistor When the transistor is a bipolar transistor, its control pole refers to the base of the bipolar transistor, the first pole can be the collector or emitter of the bipolar transistor, and the corresponding second pole can be bipolar The emitter or collector of a transistor. The hysteretic comparator can be a non-inverting hysteretic comparator or an inverting hysteretic comparator. The light emitting device may be an organic light emitting diode (OLED), a quantum dot light emitting diode (QLED), an inorganic light emitting diode (LED), or the like.

FIG. 1 is a schematic diagram of a traditional display pixel circuit.

As shown, the circuit includes a drive transistor 111 , a display switch transistor 112 , a storage capacitor 113 and a light emitting device 114 . The scan control signal on the scan control signal line SCAN is used to control the display switch transistor 112 to receive the data voltage information on the data signal line DATA and store it in the storage capacitor 113 . When the transistor 112 is turned off, the voltage on the storage capacitor 113 will be used to drive the driving transistor 111 to make the light emitting device 114 emit light. However, due to the leakage current of the switching transistor 112 , it will affect the voltage of the storage capacitor 113 , thereby affecting the luminous intensity of the light emitting device 114 .

In view of the above problems, the present invention proposes a pixel circuit with a feedback compensation mechanism. Hereinafter, the present application will be described in detail by taking the transistor as a P-type field effect transistor and the light-emitting device as an organic light-emitting diode (OLED) as an example. It can be understood that, in other embodiments, the transistor may also be a bipolar transistor, and the light emitting device may also be a quantum dot light emitting diode, or other light emitting devices.

FIG. 2 is a schematic diagram of a micro display pixel device according to an embodiment of the present invention. The circuit includes a display driving module 21 , a feedback compensation module 22 and a light emitting device 23 coupled to each other. Wherein, the feedback compensation module 22 can be configured to perform corresponding compensation according to the leakage current of the transistor in the display driving module 21 .

According to an embodiment, the display driving module 21 may include a driving transistor 211 , a display switching transistor 212 , and a first storage capacitor 213 .

The first pole of the driving transistor 211 is coupled to receive the first potential signal VCC, the second pole is coupled to the anode of the light emitting device 23 , and the control pole is coupled to the second pole of the display switch transistor 212 . The first electrode of the display switch transistor 212 is coupled to the data signal line to receive the data voltage Vdata, and the control electrode of the display switch transistor 212 is coupled to the scan signal line to receive the scan voltage Vscan. The storage capacitor 213 is coupled between the control electrode and the first electrode of the driving transistor 211 . The cathode of the light emitting device 23 is coupled to the second electrode Vcom. According to an embodiment, the Vcom is a low potential that can be changed according to the requirements of the light-emitting display and the conditions of the light-emitting device, wherein Vcom<VCC.

According to an embodiment, the feedback compensation module 22 may include a switch transistor 221 , a feedback transistor 222 , a switch transistor 223 and a capacitor 224 .

The first pole of the switch transistor 221 is configured to receive the high potential signal VCC, the second pole is coupled to the first pole of the feedback transistor 222 , and the control pole is configured to receive the compensation control signal Vctrl. According to an embodiment, when the driving module 21 needs to be compensated, Vctrl can be adjusted by the system to a level that can turn on the switching transistor 221 , otherwise it can be kept at a level that can turn off the transistor 221 . The control electrode of the feedback transistor 222 is coupled to the control electrode of the driving transistor 211 and the node A, and the second electrode is coupled to the first electrode of the second switching transistor 223 and the node B. The second electrode of the switch transistor 223 is coupled to the control electrode and grounded, which is configured to be equivalent to a diode, and forms a charging and discharging circuit with the capacitor 224 . Capacitor 224 is coupled between node A and node B.

According to another embodiment, optionally, the switch transistor 223 can also be replaced with a constant current source to form a charging and discharging circuit with the capacitor 224, which can also achieve the above purpose.

FIG. 3 is a working sequence diagram of a micro-display pixel device according to an embodiment of the present invention. The working principle of the first embodiment of the present invention will be described in detail below in conjunction with FIG. 2 and FIG. 3 . Here, the transistor is a PMOS transistor as an example for description. Of course, as known to those skilled in the art, the transistor in this embodiment may also be an NMOS transistor.

As shown in FIG. 3 , according to one embodiment, in the data writing phase, when Vscan is at a low level, the switch transistor 212 is turned on, and the data signal Vdata with display grayscale information is stored in the capacitor 213 .

Subsequently, in the light-emitting phase, Vscan jumps to a high level, the switching transistor 212 is turned off, the capacitor 213 is discharged, the driving transistor 211 is turned on, and the light-emitting device 23 emits light.

According to one embodiment, as shown in FIG. 3 , if the system considers that the driving module 21 does not need to be compensated under the current gray scale, Vctrl can be set to a high level, the switching transistor 221 is turned off, and the feedback compensation module 22 is not activated. Work.

According to another embodiment, if the system considers that the driving module 21 needs to be compensated in the current gray scale, Vctrl can be set to a low level, the switching transistor 221 is turned on, and the feedback compensation module 22 works. Due to the leakage of the switching transistor 212, when the voltage of the node A increases, the voltage of the control electrode of the feedback transistor 222 increases, so the current flowing through the feedback transistor 222 decreases, so that the voltage of the node B decreases, and the node B and the lower pole of the capacitor 224 A voltage difference is generated between the plates, so the excess charge stored in the capacitor 224 flows out through the switching transistor 223, so that the voltage of the lower plate of the capacitor 224 decreases. Furthermore, through the capacitive coupling between the capacitor 224 and the capacitor 213 , the voltage at point A drops.

FIG. 4 is a simulation result diagram of a micro-display pixel device at a specific grayscale according to an embodiment of the present invention, that is, a simulation result diagram of the gate voltage of the driving transistor 211 and the current flowing through the driving transistor 211 . Wherein, the data voltage of the current frame (that is, the charge stored in the capacitor 213) corresponds to the lowest gray scale, the switching transistor 212 is turned off, and the data signal of the next frame (that is, the voltage to be written received on the Vdata data line) corresponds to the highest gray scale. In this way, the influence of transistor leakage current on the pixel circuit can be reflected to the greatest extent.

FIG. 4 shows the gate voltage of the driving transistor 211 and the frequency of the pixel circuit flowing through the driving transistor 211 after being compensated by the feedback compensation module 22 in the circuit shown in FIG. 2 and without feedback compensation according to an embodiment of the present application. Changes within a frame of 60HZ images. In FIG. 4 , the curve 401 represents the variation of the gate voltage of the driving transistor 211 with time when the feedback compensation module 22 is not started in the circuit shown in FIG. 2 , and the curve 402 represents the situation when the feedback compensation module 22 is started in the circuit shown in FIG. The gate voltage of the driving transistor 211 below changes with time, and the curve 404 represents the change of the current flowing through the light-emitting device 23 with time when the feedback compensation module 22 is not activated in the circuit shown in FIG. The circuit changes with time the current flowing through the light emitting device 23 when the feedback compensation module 22 is activated.

According to experiments, when the feedback compensation module 22 is not activated, the gate voltage of the driving transistor increases by 256.815mV, and the driving current increases by 5989pA before and after the leakage of the switching transistor 212 occurs. When the feedback compensation module 22 is activated, the gate voltage of the driving transistor increases by 18.834 mV, and the driving current increases by 497.2 pA before and after the leakage of the switching transistor 212 occurs. Much lower than without the compensation module activated.

FIG. 5 is a simulation result diagram of a micro-display pixel device at a specific grayscale according to another embodiment of the present invention, that is, a simulation result diagram of the gate voltage of the driving transistor 211 and the current flowing through the driving transistor 211 . Wherein, the data voltage of the current frame (that is, the charge stored in the capacitor 213) corresponds to the highest gray scale, the switching transistor 212 is turned off, and the data signal of the next frame (that is, the voltage to be written received on the Vdata data line) corresponds to the lowest gray scale. In this way, the influence of transistor leakage current on the pixel circuit can also be reflected to the greatest extent.

FIG. 5 shows the gate voltage of the driving transistor 211 and the frequency of the pixel circuit flowing through the driving transistor 211 after being compensated by the feedback compensation module 22 in the circuit shown in FIG. 2 and without feedback compensation according to an embodiment of the present application. Changes within a frame of 60HZ images. In FIG. 5 , the curve 501 represents the variation of the gate voltage of the driving transistor 211 with time under the condition that the feedback compensation module 22 is not started in the circuit shown in FIG. 2 , and the curve 502 represents the situation in which the circuit shown in FIG. The gate voltage of the driving transistor 211 below changes with time, and the curve 504 represents the change of the current flowing through the light-emitting device 23 with time when the feedback compensation module 22 is not started in the circuit shown in FIG. The circuit changes with time the current flowing through the light emitting device 23 when the feedback compensation module 22 is activated.

According to the experimental measurement, in the uncompensated state, the gate voltage of the driving transistor 211 increases by 174.714mV, and the driving current increases by 87.49pA. In the compensated state, the gate voltage of the driving transistor increases by 35.599mV, and the driving current increases by 54.66pA.

It can be seen from FIG. 4, FIG. 5 and simulation data that, in the pixel circuit according to one embodiment of the present application, for example, using PMOS, when the transistor leakage current generated in the circuit shown in FIG. When the current flowing through the driving transistor 211 is continuously decreasing, when the feedback compensation module 22 is activated, the variation range of the gate voltage of the driving transistor 211 and the current flowing through the driving transistor 211 is much smaller than that when the feedback compensation module 22 is not activated.

Therefore, according to an embodiment of the present invention, through the feedback compensation of the driving transistor 211 , the influence of transistor leakage current on the light emitting device 23 in the pixel circuit can be effectively reduced, so that the operation of the pixel circuit is more stable. Moreover, the feedback compensation circuit directly acts on the storage capacitor 213, and will not be affected by the aging of the light emitting device.

As mentioned above, in the pixel circuit shown in FIG. 2 , the feedback compensation module of the pixel circuit is controlled to be turned on or off by the compensation control signal Vctrl. There are many ways to implement the compensation control signal Vctrl, and one of the implementation methods and circuit structure will be described in detail below.

The present invention also proposes a sampling compensation circuit for providing a compensation control signal of a corresponding compensation module for a pixel array inside the micro-display device. The general working principle of the sampling compensation circuit is that, during the initialization stage of the micro-display device, it is possible to record the conditions that the pixel circuit as an example needs to perform compensation under each display gray scale, and when the micro-display device is officially working, according to the above-mentioned records. The feedback compensation module in the pixel circuit performs corresponding control.

Hereinafter, the present application will be described in detail by taking the transistor as a P-type field effect transistor and the light-emitting device as an organic light-emitting diode as an example. It can be understood that, in other embodiments, the transistor may also be a bipolar transistor, and the light emitting device may also be a quantum dot light emitting diode, or other light emitting devices.

In a display device that uses the pixel circuit provided by the embodiment of the present application to form a pixel array, a sampling compensation circuit as described above may be included. According to an embodiment, the sampling circuit may include a display driving module 61 , an initial sampling module 62 , a storage control module 63 and a light emitting device 65 coupled to each other.

According to an embodiment, the display driving module 61 may include a driving transistor 611 , a display switching transistor 612 , and a storage capacitor 613 .

As shown in FIG. 6 , the first pole of the driving transistor 611 is configured to receive the high-level signal VCC, the second pole thereof is coupled to the anode of the light emitting device 65 , and the control pole thereof is coupled to the second pole of the display switching transistor 612 . The first electrode of the display switch transistor 612 is coupled to the data signal line to receive the data electric signal Vdata, and the control electrode thereof is coupled to the scan signal line to receive the scan signal Vscan. The storage capacitor 613 is coupled between the control electrode and the first electrode of the driving transistor 211 . The cathode of the light emitting device 65 is configured to receive the common potential signal Vcom. According to an embodiment, the Vcom is a low potential that can be changed according to the requirements of the light-emitting display and the conditions of the light-emitting device.

According to an embodiment, the initial sampling module 62 may include a switch transistor 621 , a switch transistor 622 , a switch transistor 623 , a hysteresis comparator 624 and a storage capacitor 625 . The so-called hysteresis comparator keeps its output unchanged when the difference between the positive and negative inputs is within the threshold difference or the range of the window voltage Vw, otherwise the output is reversed. The use of a hysteresis comparator can avoid turning on the compensation function due to slight voltage fluctuations, and can ensure that the compensation function is turned on only when the leakage current of the transistor does occur. Therefore, a hysteretic comparator with a corresponding window voltage can be selected according to user's needs.

As shown in FIG. 6 , the first pole of the switching transistor 621 is configured to receive the high potential signal VCC, the second pole thereof is coupled to the non-inverting node C of the hysteresis comparator 624 , and the control pole thereof is configured to receive the initialization signal voltage ViniA. The first pole of the switch transistor 622 is coupled to the second pole of the driving transistor 611 , the second pole is coupled to the inverting terminal node D of the hysteresis comparator 624 , and its control pole is configured to receive the initialization signal voltage ViniA. The first pole of the switching transistor 623 is coupled to the second pole of the driving transistor 611 , the second pole is coupled to the non-inverting node C of the hysteresis comparator 624 , and its control pole is configured to receive the initialization signal voltage ViniB.

According to one embodiment, as shown in FIG. 6 , the output terminal of the hysteresis comparator 624 is coupled to the input terminal of the storage control module 63 . The storage capacitor 625 can be coupled between the ground level and the inverting terminal node D of the hysteresis comparator 624 , and the inverting terminal node D of the hysteresis comparator 624 can also be coupled to the input terminal of the feedback compensation module 64 .

According to one embodiment, the storage control module 63 may include a register 631 . As shown in FIG. 6 , the input of register 631 may be coupled to the output of hysteretic comparator 624 . According to one embodiment, the output terminal of the register 631 may be coupled to a feedback compensation module of a pixel circuit in a pixel array of a micro display device. (not shown in Figure 6)

According to one embodiment, the window voltage value Vw of the hysteresis comparator 624 is defined as the minimum gradient difference of the gray scale, and this voltage difference is the two gray scales with the smallest difference among all the gray scales to be displayed. The potential difference of the anode of the light-emitting device corresponding to the transistor leakage current or the condition that the transistor leakage current has no influence. In the process of sampling light emission, the potential difference between the positive and negative input terminals of the delay comparator is the difference between the anode potential of the light emitting device in an ideal state and in the presence of transistor leakage current when a specific gray scale is present.

The purpose of setting the window voltage Vw as the minimum gray scale gradient difference is to prevent gray scale display errors caused by transistor leakage current. When the difference between the voltage at the non-inverting terminal and the voltage at the inverting terminal of the hysteresis comparator 624 is less than the window voltage Vw of the hysteresis comparator 624, that is, when |V _D -V _C | The output value _Cout =1 of the device ₆₂₄ is given to the storage module 63 to store the corresponding relationship between the grayscale and its corresponding Cout value; When the voltage is Vw, that is, when |V _D -V _C |≥Vw, the output of the hysteresis comparator 624 is reversed to, for example, a low level, and the output value Cout=0 of the hysteresis comparator 624 is given to the storage module 63 to store the gray level and its corresponding Correspondence of Cout value.

According to an embodiment, optionally, as shown in FIG. 6 , the sampling compensation circuit may further include a feedback compensation module 64 for compensating the capacitor 625 to avoid wrong sampling. According to an embodiment, the feedback compensation module 64 may have a circuit structure similar to that of the feedback compensation module in the pixel circuit. For example, the feedback compensation module 64 may include a feedback transistor 641 , a switching transistor 642 and a capacitor 643 .

The control electrode of the feedback transistor 641 is used as the input terminal of the feedback control module 64 and is coupled to the inverting input node D of the hysteresis comparator 624 and the upper plate of the capacitor 625, the first electrode of which is configured to receive the high potential signal VCC, and the second electrode of which The pole is coupled to the first pole of the switching transistor 642. The second electrode and the control electrode of the switch transistor 642 are coupled to each other and are commonly grounded, which can be configured to be equivalent to a diode and form a discharge circuit with the capacitor 643 . The capacitor 643 is coupled between the control electrode and the second electrode of the feedback transistor 641 . According to an embodiment, the switch transistor 643 can also be replaced by a constant current source, forming a discharge circuit with the capacitor 644, which can also achieve the above purpose.

FIG. 7 is an exemplary working timing diagram of the circuit shown in FIG. 6 . V _C is the non-inverting terminal voltage of the hysteresis comparator, V _D is the inverting terminal voltage of the hysteresis comparator, Vw is the window voltage of the hysteresis comparator, and Cout is the output value of the hysteresis comparator. The initialization process of the display device according to an embodiment of the present application will be described in detail below with reference to FIG. 6 and FIG. 7 .

The working sequence in FIG. 7 can be divided into a pre-jump phase P1 and a sampling working phase P2.

(1) Pre-jump stage P1

At this stage, Vscan is at a low level, indicating that the switching transistor 612 is in an on state. The data signal Vdata corresponding to a specific gray scale is written, and the driving transistor 611 is turned on. The initialization signal ViniA is at low level, and ViniB is at high level. At this time, the switch transistor 621 and the switch transistor 622 are in the on state, and the switch transistor 623 is in the off state. At this time, the non-inverting terminal of the hysteresis comparator 624 is configured to receive the high-level signal VCC.

Since the driving transistor 611 is turned on shortly at this time, the influence of the leakage current of the transistor can be ignored, so the voltage V _D of the inverting terminal of the hysteresis comparator 624 can be considered as the anode voltage of the light emitting device corresponding to the specific gray scale in an ideal state. At this stage, the voltage difference between the two input terminals of the hysteresis comparator 624 (substantially equal to the threshold voltage of the transistor 611) is smaller than the window voltage of the hysteresis comparator 624, ie |V _C −V _D |<Vw. Therefore, the hysteresis comparator 624 can be configured, for example, to output a high level, ie output value Cout=1.

The purpose of setting the pre-jump stage is to precharge the two input terminals of the hysteresis comparator 624, charge the inverting terminal to the anode voltage of the light-emitting device in an ideal state and maintain it, and use it for comparison in the adopting stage; charge the non-inverting input terminal to a high level to ensure the possibility of the hysteresis comparator 624 flipping in time during the sampling phase. Otherwise, the non-inverting terminal of the hysteresis comparator 624 will experience a period of voltage rising from 0V to the actual anode voltage of the light emitting device. In most of the time before the voltage of the non-inverting terminal climbs to the actual anode voltage of the light-emitting device, the output value of the hysteresis comparator may be 0, that is, no matter whether the influence of the leakage current of the transistor is large enough to be compensated, the result of the output of the hysteresis comparator is required. compensate. This can lead to incorrect settings of the compensation control signal, wasting unnecessary power consumption. Charging the non-inverting terminal of the hysteresis comparator to a high level in the pre-jump stage can make the non-inverting terminal of the hysteresis comparator reach the actual voltage of the anode of the light emitting device faster.

(2) Sampling working stage P2

During this phase, Vscan is high, indicating the switching transistor 612 is off. The initialization signal ViniA jumps to a high level, and ViniB jumps to a low level. At this time, the switch transistor 621 and the switch transistor 622 are in the cut-off state, and the switch transistor 623 is turned on.

According to an embodiment, since the switching transistor 622 is in the cut-off state, the voltage V _D at the inverting terminal of the hysteresis comparator 624 is provided by the capacitor 625 at this time, that is, the anode voltage of the current gray-scale light-emitting device in an ideal state, and V _D is in feedback compensation It remains stable under the action of module 64. The voltage V _C of the non-inverting terminal of the hysteresis comparator 624 is the actual anode voltage of the current grayscale light-emitting device under the condition that the leakage current of the transistor is sufficiently affected. Due to the existence of transistor leakage current, V _C will be lower than V _D at this time.

If |V _D −V _C |<Vw, the output of the hysteresis comparator 624 is high level, that is, Cout=1, which means that compensation is not needed for the current gray scale. If |V _D -V _C |≥Vw, the output of the hysteresis comparator 624 is low level, that is, Cout=0, which means that the current gray scale needs to be compensated.

After sampling the current gray scale, the sampling circuit receives the data signal corresponding to the next gray scale, and executes P1 and P2 again until the register 631 stores the Cout values corresponding to all gray scales.

After the initialization phase is completed, the display device can enter the working phase. The control module of the display device will search the corresponding Cout value stored in the storage device 63 according to the current gray scale, and use this value as the compensation control signal Vctrl in FIG. 1, do not start the compensation module; Cout=Vctrl=0, start the compensation module).

The invention also provides a micro display device. FIG. 8 is a structural diagram of a micro display device according to an embodiment of the present invention. As shown in FIG. 8 , the micro display device may include a data driving circuit 801 , a gate driving circuit 802 , a sampling compensation circuit 803 and a pixel array 804 .

The pixel array 804 includes a plurality of display pixel circuits arranged in rows and columns, and each pixel array includes a pixel circuit provided according to an embodiment of the present application. The data driving circuit 801 provides data voltage information to the pixel array 804 via a plurality of data lines, and the gate driving circuit 802 provides switching signals to the pixel array 804 via a plurality of scanning lines, so that the pixel array 804 can be controlled by the control circuit 802 based on Data voltage information to emit light of corresponding intensity.

The sampling compensation circuit 803 works in the initialization stage of the micro-display device, samples all the grayscale signals, judges which of the data signals corresponding to these grayscales need to be compensated or not, and outputs the judgment result to the storage device. After the initialization phase is over, the micro display device enters the working phase, and the control signal Vctrl of the pixel circuit compensation module is determined according to the value corresponding to the current gray scale in the storage device.

The micro display device with the above structure can effectively reduce the influence of the transistor leakage current on the pixel circuit, and the process of reducing the influence of the transistor leakage current is not affected by the aging of the light-emitting device. The sampling compensation circuit in the microdisplay device can control whether the feedback compensation module in the pixel circuit is turned on, and can effectively reduce circuit power consumption.

The present invention also proposes a compensation method for the pixel circuit of the micro-display device introduced by the embodiment of the present application. Fig. 9 is a schematic flowchart of the method.

Step 901: Sampling and detecting the data signals corresponding to all the gray scales used in the micro-display device, judging whether the data signals corresponding to each gray scale need to be compensated, and storing the detection results.

Step 902: Receive a data signal corresponding to a specific gray scale signal under the control of the scan signal.

Step 903 judges whether compensation is required for the current data signal according to the stored detection results, and outputs a corresponding compensation control signal to control the compensation of each pixel in the pixel array in the microdisplay device.

The pixel structure provided in the present application and the corresponding compensation circuit and compensation method provide a dynamic and targeted compensation mechanism, which can dynamically determine whether to compensate a specific pixel for different gray levels. Compared with the structure that performs uniform compensation without distinguishing between gray levels and specific conditions, the power consumption of the microdisplay device provided by the present application is lower. In addition, the design in this application utilizes the original vacant area in the pixel circuit to arrange the compensation module, so the area of the original pixel will not be increased.

The above-described embodiments are only for illustrating the present invention, rather than limiting the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the scope of the present invention. Therefore, all Equivalent technical solutions should also belong to the scope of the disclosure of the present invention.

Claims (10)

1. a kind of micro display pixel arrangement, comprising:

Luminescent device；

Driver module is coupled to the luminescent device, is configured to receive scanning signal and data-signal and driving institute Luminescent device is stated, the first driving transistor for being coupled to the luminescent device is included at least；And

Feedback compensation module, at least one input terminal and output end are all coupled to the control electrode of the first driving transistor, It is configured to carry out feedback compensation to the drive module by capacitive coupling, includes at least and be coupled to the first driving crystal First storage capacitance of pipe control electrode.

2. micro display pixel arrangement according to claim 1, wherein the feedback compensation module further include:

First feedback transistor, the first pole are coupled to the first common potential, and control electrode is coupled to the first driving transistor Control electrode；

First switch transistor, the first pole are coupled to the second pole of first feedback transistor, the second pole and control electrode It couples and is grounded；

First storage capacitance is coupled between the control electrode and the second pole of first feedback transistor.

3. micro display pixel arrangement according to claim 2, wherein the feedback compensation module further includes second switch crystalline substance Body pipe, the first pole are coupled to the first common potential, and control electrode is configured to receive compensating control signal, and the second pole is coupled to First feedback transistor, first pole.

4. the apparatus according to claim 1, wherein the driver module further include:

First display switch transistor, control electrode are configured to receive scanning signal, and the first pole is configured to receive data-signal；

First pole of the driving transistor is coupled to the first common potential, and it is brilliant that control electrode is coupled to first display switch The second pole of body pipe, the second pole are coupled to the luminescent device anode；And

Second storage capacitance is coupled between the control electrode and the first pole of the first driving transistor.

5. a kind of micro display device, comprising:

Pixel array, wherein the pixel array includes at least one or more micro display pixel as described in claim 1-4 Device；

The data drive circuit of the offer data-signal coupled with the pixel array and the gate driving for providing scanning signal are electric Road；And

The sampling compensation circuit coupled with the pixel array, be configured to the data drive circuit provide data-signal into Row samples and judges whether start the compensating module in the pixel circuit for specific data-signal.

6. device according to claim 5, wherein the sampling compensation circuit includes:

Luminescent device；

Driver module is coupled to the luminescent device, is configured to receive scanning signal and data-signal and driving institute State luminescent device；

Initial samples module is coupled to aobvious in the luminescent device in the sampling compensation circuit and the sampling compensation circuit Show drive module, be configured to sample the corresponding luminescent device driving voltage of a certain grayscale, and by the result sampled and default threshold Value is compared, to determine whether to compensate the grayscale；And

Memory module is configured to store the judging result of the initial samples module output.

7. device according to claim 5, wherein the initial samples module includes:

Third switching transistor, the first pole are coupled to the first common potential, and control electrode is configured to receive the first initialization letter Number；

4th switching transistor, the first pole are coupled to the luminescent device anode, and control electrode is configured to receive described first Initializing signal；

5th switching transistor, the first pole are coupled to the luminescent device anode, and the second pole is coupled to the third switch The second pole of transistor, control electrode be configured to receive the second initializing signal, wherein first and second initializing signal that This complementary or significant level is not overlapped；

Third storage capacitance is coupled between ground between the second pole of level and the 4th switching transistor；And

Hysteresis comparator, the in-phase end of the hysteresis comparator are coupled to the second pole of the 5th switching transistor, reverse side coupling It is bonded to the 4th the second pole of switching transistor, wherein the preset threshold is the window voltage of the hysteresis comparator, it is all Minimum value in the difference of the corresponding luminescent device driving voltage of the driver module any two grayscale；

It is described when it is configured to when the hysteresis comparator reverse side voltage and in-phase end voltage difference are less than the window voltage Judging result is not need to compensate for the gray scale；When the hysteresis comparator reverse side and in-phase end voltage difference are greater than institute When stating window voltage, the judging result is to compensate for gray scale needs.

8. device according to claim 5, wherein the driver module includes:

Second display switch transistor, control electrode are coupled to scanning signal, and data-signal is coupled in the first pole；

Second driving transistor, the first pole are coupled to the first common potential, and control electrode is coupled to second display switch The second pole of transistor, the second pole are coupled to luminescent device anode；

4th storage capacitance is coupled between the control electrode and the first pole of the second driving transistor.

9. device according to claim 5, wherein the sampling compensation circuit further includes sampling feedback compensating module, it is described to adopt Sample feedback compensation module includes:

Second feedback transistor, the first pole are coupled to the first common potential, and control electrode is coupled to the 4th switch crystal The second pole of pipe；

6th switching transistor, the first pole are coupled to the second pole of second feedback transistor, the second pole and control electrode It couples and is grounded；

5th storage capacitance is coupled between the control electrode and the second pole of second feedback switch transistors.

10. a kind of compensation method of micro display pixel arrangement, comprising:

Sampling detecting is used for the corresponding data-signal of whole grayscale of micro display device, judges that each grayscale corresponding data signal is It is no to need to compensate, and store the detecting result；

Data-signal corresponding with specific grey-scale signal is received under the control of scanning signal；And

Whether need to compensate for current data signal according to the detecting result judgement stored, and output phase should compensate control Signal processed, to control the compensation situation to each pixel in pixel array in micro display device.