A mobile device, display driving method, and driving circuit

Abstract

Embodiments of the present application provide a mobile device, a display driving method and a driving circuit. The mobile device comprises a display screen configured to display an image; a processor configured to generate a level control signal according to state information of the mobile device, the level control signal being configured to indicate that the mobile device is in a screen-on mode or an idle mode; and a display driving controller configured to generate a data signal for controlling brightness of the display image according to the level control signal, the data signal being a pulse width modulation signal when the mobile device is in the screen-on mode, and the data signal being a pulse amplitude modulation signal when the mobile device is in the idle mode. The above scheme can effectively save system power consumption of the mobile terminal in the idle state, thereby improving the endurance.

Description

Technical Field

[0001] This application relates to the field of drive control, and more particularly to a mobile device, a display driving method, and a driving circuit. Background Technology

[0002] A light-emitting diode, or LED for short, is made of compounds containing gallium (Ga), arsenic (As), phosphorus (P), and nitrogen (N). When electrons and holes recombine, they emit visible light, which is why LEDs are used to create light-emitting diodes. They are used in circuits and instruments as indicator lights or to form text or number displays. Gallium arsenide diodes emit red light, gallium phosphide diodes emit green light, silicon carbide diodes emit yellow light, and gallium nitride diodes emit blue light. Based on their chemical properties, they are further classified into organic light-emitting diodes (OLEDs) and inorganic light-emitting diodes (LEDs).

[0003] Micro LED, or micro light-emitting diode, refers to a high-density integrated array of light-emitting diodes (LEDs). The LED pixels in this array are spaced on the order of 10 micrometers, and each LED pixel is self-emissive. Micro LED miniaturizes traditional inorganic LED arrays, allowing each 10-micrometer LED pixel to be independently addressed and illuminated. Micro LED displays connect 10-micrometer-scale LED chips to a TFT driving substrate, enabling precise control of the brightness of each chip and thus achieving image display.

[0004] With the rapid development of electronic technology, mobile terminal devices have greatly changed people's lives and work, and the image display quality of their screens is also improving rapidly. For example, Micro LED displays are a representative of current display technology. Micro LED miniaturizes traditional inorganic LED arrays. Its display method involves connecting 10-micron-scale LED chips to a TFT driving substrate, thereby achieving precise control over the brightness of each chip and thus realizing image display.

[0005] To allow users to experience the convenience of mobile devices anytime, anywhere, mobile devices are often kept in standby mode for extended periods. However, even in standby mode when the user is not using the display, the display's power consumption remains relatively high. Summary of the Invention

[0006] This invention provides a pixel driving architecture and a display device, which aims to reduce the power consumption of terminal systems, especially display systems, and improve the battery life of mobile terminals to a certain extent.

[0007] The above effects are achieved through the features in the independent claims, and further implementation methods are shown in the dependent claims, the specification and the drawings.

[0008] In a first aspect, a mobile device is provided, comprising: a display screen for displaying images; a processor for generating a level control signal based on state information of the mobile device, the level control signal indicating whether the mobile device is in a screen-on mode or an idle mode; and a display driver controller for generating a data signal for controlling the brightness of the display screen based on the level control signal, wherein when the mobile device is in the screen-on mode, the data signal is a pulse width modulation signal; and when the mobile device is in the idle mode, the data signal is a pulse amplitude modulation signal.

[0009] Specifically, the display screen may include a foldable display screen or a non-foldable display screen, and the light-emitting element used may be a Micro LED or an OLED or other light-emitting diode element. The processor may be an application processor (AP) or a micro-controller unit (MCU), and the micro-processor may further integrate the mobile terminal's sensors and other components.

[0010] It should be understood that the status information can be information that enables the mobile terminal to switch between the screen-on mode and the idle mode. For example, the information detected by the sensor after the user double-clicks the screen; the status signal sent to the terminal after the user presses the power button of the mobile terminal; or the instruction information to switch to the idle mode after the screen-on mode is maintained for a preset time. The status information can take many forms. In one example, it can be a level signal or software code, or other common instructions that carry the status information of the mobile terminal.

[0011] In one example, the level control signal is a single level signal. It should be understood that the form of the level control signal is not limited to this; the level control signal can be any transmission carrier signal between the processor and the integrated unit. The processor sends information about the current screen-on or idle state to the display driver controller. The display driver controller then uses the current level control signal to control the display brightness in either the screen-on mode or the idle mode.

[0012] The display driver controller may specifically include an integrated circuit of a power integrated circuit (Power IC) and a display driver integrated circuit (DDIC), or a DDIC alone. After receiving a level control signal from a processor, the display driver controller can perform either a screen-on mode operation or an idle mode operation according to the indication of the level control signal. Specifically, in screen-on mode, it sends a pulse width modulation signal (hereinafter referred to as a PWM signal) to the display screen, or in idle mode, it sends a pulse amplitude modulation signal (hereinafter referred to as a PAM signal) to the display screen. It should be understood that the data signal is not a single signal but refers to a collection of signals sent by the display driver controller to the display screen. In one example, the data signal can be a PWM signal, a PAM signal, or a grayscale setting signal, etc.

[0013] Optionally, the pixel driving architecture within the display typically performs brightness processing on the image data, usually in two ways. The first is PWM (Pulse Width Modulation), which adjusts brightness by changing the duty cycle of the data signal. The longer the data signal controls the pixel circuit to emit light within a time frame, the higher the brightness of the display area, and vice versa. For example, assuming a time frame is 16ms long, the EM signal controls the pixel circuit to emit light for 8ms and keeps it off for the remaining 8ms. To increase brightness, the EM signal can be set to control the pixel circuit to emit light for 10ms and keep it off for the remaining 6ms. The second method of brightness modulation is PAM (Pulse-Modulated Amplitude Modulation), which adjusts brightness based on the voltage level of the data signal.

[0014] When the mobile device is in the screen-on mode, the data signal is a pulse width modulation (PWM) signal; when the mobile device is in the idle mode, the data signal is a pulse amplitude modulation (PAM) signal. Specifically, in idle mode, since the display driver controller uses a PAM signal, which is more power-efficient than PWM, the power consumption of the PWM signal in the circuit architecture is reduced, greatly improving the battery life of the mobile terminal. In screen-on mode, it can freely switch to the PWM signal, which provides more delicate and precise brightness control, ensuring a better user experience. At the same time, both methods use the same pixel driving architecture, without adding unnecessary functional components, thus improving battery life while saving internal space in the mobile terminal.

[0015] In conjunction with the first aspect, in one possible implementation, the display screen includes: a driving circuit and a light-emitting diode, the driving circuit being configured to receive the pulse amplitude modulation signal and to set the brightness of the light-emitting diode according to the pulse amplitude modulation signal.

[0016] In conjunction with the first aspect, in another possible implementation, the driving circuit includes a current control unit for generating a current control signal based on the pulse amplitude modulation signal and driving the light-emitting diode based on the voltage value of the current control signal.

[0017] Specifically, the voltage value of the current control signal is between 0 and 5V. In one example, the current control signal can set the initial current value of the LED, and simultaneously adjust the brightness of the LED according to changes in the current value.

[0018] In conjunction with the first aspect, in another possible implementation, the current control unit includes: a first transistor and a second transistor; wherein: the source of the first transistor is used to receive the pulse amplitude modulation signal, the gate of the second transistor is used to receive a first pulse signal, and the first transistor is used to generate the current control signal according to the pulse amplitude modulation signal and the first pulse signal; the voltage value of the current control signal is the voltage difference between the gate voltage of the first transistor and the voltage of the pulse amplitude modulation signal.

[0019] It should be understood that the transistor is a conventional transistor that can be used as a display driving architecture, having a gate, a source, and a drain. In one example, the first pulse signal is a line-by-line scan signal from a Gate Driver On Array (GOA) cell, which provides a gating signal for each row of pixel circuits to control the on or off state of each row of pixel circuits.

[0020] In conjunction with the first aspect, in another possible implementation, the drain of the first transistor is connected to the source of the second transistor, and the drain of the second transistor is connected to the gate of the first transistor.

[0021] In conjunction with the first aspect, in another possible implementation, the mobile device includes a driving circuit that further includes a comparator for generating a signal with a constant voltage value; and a driving loop unit for controlling the switching on and off of the light-emitting diode based on the constant voltage value signal and a second pulse signal.

[0022] Specifically, in one example, the comparator unit is also used to receive the pulse width modulation signal and to set the brightness of the light-emitting diode according to the pulse width modulation signal.

[0023] This example is performed in screen-on mode. The structure of the comparator unit remains unchanged in both modes. This reused structure greatly simplifies the circuit routing and saves materials and functional components. In one example, the saved space can be used to set more pixels, thereby increasing pixel density and improving image quality.

[0024] In conjunction with the first aspect, in another possible implementation, the drive circuit unit includes a third transistor and a fourth transistor, wherein: the third transistor is used to receive a signal of the constant voltage value, the constant voltage value signal being a first level signal; the fourth transistor is used to receive the second pulse signal, and when the second pulse signal is at the first level, the drive circuit unit controls the light-emitting diode to turn on; when the second pulse signal is at the second level, the drive circuit unit controls the light-emitting diode to turn off.

[0025] Specifically, the first level signal is a relatively low level signal, meaning its voltage value is lower than the preset turn-on voltage value of the third transistor. Therefore, the third transistor maintains a constant on state. In one example, the second pulse signal comes from the display driver controller. It is used to send the first or second level signal to the fourth transistor in this embodiment according to the timing instructions of the display driver controller. In one example, the voltage value of the first level signal can be 0V, and the voltage value of the second level signal can be 5V.

[0026] In conjunction with the first aspect, in another possible implementation, a fifth transistor and a sixth transistor are included, wherein: the fifth transistor is used to receive the second pulse signal; the sixth transistor is used to receive the pulse width modulation signal and the grayscale setting signal, and is used to generate the comparison signal based on the pulse width modulation signal, the grayscale setting signal and the second pulse signal; the voltage value of the comparison signal is the difference between the voltage value of the pulse width modulation signal and the voltage value of the grayscale setting signal.

[0027] In conjunction with the first aspect, in another possible implementation, the drive circuit unit includes a third transistor and a fourth transistor, wherein: the third transistor is used to receive the comparison signal, and the fourth transistor is used to receive the second pulse signal.

[0028] When both the second pulse signal and the comparison signal are at the first level, the driving circuit unit controls the light-emitting diode to turn on; when at least one of the second pulse signal and the comparison signal is at the second level, the driving circuit unit controls the light-emitting diode to turn off.

[0029] In conjunction with the first aspect, in another possible implementation, the display driver controller includes: a pulse width modulation module for generating a pulse width modulation signal; a grayscale setting module for generating a grayscale setting signal, the grayscale setting signal being used to set the initial voltage value of the light-emitting diode; and a current setting module for generating a constant current control signal, the constant current control signal being used to drive the light-emitting diode.

[0030] In conjunction with the first aspect, in another possible implementation, the display driver controller further includes: a pulse width modulation module for generating a pulse width modulation signal, and the current setting module for generating a constant current control signal for controlling the light-emitting diode. Specifically, this example is performed in screen-on mode. The structure of the comparator unit remains unchanged in both modes. This reused structure greatly simplifies circuit routing, saves materials and functional components. In one example, the saved space can be used to set more pixels, thereby increasing pixel density and improving image quality.

[0031] Secondly, this application provides a driving method, the driving method comprising: generating a level control signal based on state information, the level control signal being used to indicate whether the mobile device is in a screen-on mode or an idle mode; generating a data signal for controlling the brightness of the display screen based on the level control signal; when the mobile device is in the screen-on mode, the data signal is a pulse width modulation signal; when the mobile device is in the idle mode, the data signal is a pulse amplitude modulation signal.

[0032] It should be understood that the driving method of the second aspect and the mobile device of the first aspect are based on the same inventive concept. Therefore, the beneficial technical effects that the technical solution of the second aspect can achieve can be referred to the description of the first aspect, which will not be repeated here.

[0033] In conjunction with the second aspect, in another possible implementation, the driving method includes: the source of the first transistor is used to receive the pulse amplitude modulation signal, the gate of the second transistor is used to receive the first pulse signal, and the first transistor is used to generate the current control signal according to the pulse amplitude modulation signal and the first pulse signal; the voltage value of the current control signal is the voltage difference between the voltage of the gate of the first transistor and the voltage of the pulse amplitude modulation signal.

[0034] It should be understood that the transistor is a conventional transistor that can be used as a display driving architecture, having a gate, a source, and a drain. In one example, the first pulse signal is a line-by-line scan signal from a Gate Driver On Array (GOA) cell, which provides a gating signal for each row of pixel circuits to control the on or off state of each row of pixel circuits.

[0035] In conjunction with the second aspect, in another possible implementation, the driving method includes a comparator for generating a signal with a constant voltage value; and a driving loop unit for controlling the switching on and off of the light-emitting diode based on the constant voltage value signal and a second pulse signal.

[0036] Specifically, in one example, the comparator unit is also used to receive the pulse width modulation signal and to set the brightness of the light-emitting diode according to the pulse width modulation signal. This example is performed in screen-on mode, and the structure of the comparator unit remains unchanged in both modes. This reused structure greatly simplifies circuit routing, saves materials and functional components. In one example, the saved space can be used to set more pixels, thereby increasing pixel density (Pixels Per Inch, PPI) and improving image quality.

[0037] In conjunction with the second aspect, in another possible implementation, the driving method includes a third transistor and a fourth transistor, wherein: the third transistor is used to receive a signal of the constant voltage value, the signal of the constant voltage value being a first level signal; the fourth transistor is used to receive the second pulse signal, and when the second pulse signal is at the first level, the driving circuit unit controls the light-emitting diode to turn on; when the second pulse signal is at the second level, the driving circuit unit controls the light-emitting diode to turn off.

[0038] Specifically, the first level signal is a relatively low level signal, meaning its voltage value is lower than the preset turn-on voltage value of the third transistor. Therefore, the third transistor maintains a constant on state. In one example, the second pulse signal comes from the display driver controller. It is used to send the first or second level signal to the fourth transistor in this embodiment according to the timing instructions of the display driver controller.

[0039] In conjunction with the second aspect, in another possible implementation, the driving method includes a fifth transistor and a sixth transistor, wherein: the fifth transistor is configured to receive a second pulse signal; the sixth transistor is configured to receive the pulse width modulation signal and the grayscale setting signal, and to generate the comparison signal based on the pulse width modulation signal, the grayscale setting signal, and the second pulse signal; the voltage value of the comparison signal is the difference between the voltage value of the pulse width modulation signal and the voltage value of the grayscale setting signal.

[0040] In conjunction with the second aspect, in another possible implementation, the driving method includes a third transistor and a fourth transistor, wherein: the third transistor is used to receive the comparison signal, and the fourth transistor is used to receive the second pulse signal; when both the second pulse signal and the comparison signal are at a first level, the driving circuit unit controls the light-emitting diode to turn on; when at least one of the second pulse signal and the comparison signal is at a second level, the driving circuit unit controls the light-emitting diode to turn off.

[0041] In conjunction with the second aspect, in another possible implementation, the driving method includes: a pulse width modulation module for generating a pulse width modulation signal; a grayscale setting module for generating a grayscale setting signal, the grayscale setting signal being used to set the initial voltage value of the light-emitting diode; and a current setting module for generating a constant current control signal, the constant current control signal being used to drive the light-emitting diode.

[0042] In conjunction with the second aspect, in another possible implementation, the driving method further includes: a pulse width modulation module for generating a pulse width modulation signal, and the current setting module for generating a constant current control signal for controlling the light-emitting diode. Specifically, this example is performed in screen-on mode. The structure of the comparator unit remains unchanged in both modes. This reused structure greatly simplifies circuit routing, saves materials and functional components. In one example, the saved space can be used to set more pixels, thereby increasing pixel density (Pixels Per Inch, PPI) and improving image quality.

[0043] Thirdly, a driving circuit is provided, the driving circuit comprising: a first transistor, a second transistor, a third transistor, a fourth transistor, and a fifth transistor, wherein: the gate of the first transistor is connected to the drain of the second transistor as a first node.

[0044] The drain of the first transistor is connected to the source of the second transistor as a second node; the source of the first transistor is connected to the drain of the third transistor and the drain of the fourth transistor as a third node; the source of the fifth transistor is connected to the drain of the first transistor as a fourth node; the driving circuit further includes a ninth transistor, a tenth transistor, and an eleventh transistor, wherein: the drain of the tenth transistor is connected to the source of the ninth transistor as a ninth node; the ninth node is connected to the seventh node; the drain of the ninth transistor is connected to the drain of the eleventh transistor as a tenth node; the drain of the ninth transistor and the drain of the eleventh transistor are connected to one end of the second capacitor through the tenth node as an eleventh node; the drain of the ninth transistor and the drain of the eleventh transistor are connected to the gate of the tenth transistor through the eleventh node.

[0045] In conjunction with the third aspect, in one possible implementation, the driving circuit further includes a sixth transistor and a seventh transistor, wherein: the source of the fifth transistor is also connected to the source of the sixth transistor through the fourth node; the drain of the sixth transistor is connected to the source of the seventh transistor as the fifth node.

[0046] In conjunction with the third aspect, in one possible implementation, the driving circuit further includes: the driving circuit includes a first capacitor, one end of the first capacitor is connected to the source of the third transistor as a twelfth node, and the other end of the first capacitor is connected to the drain of the seventh transistor as a sixth node; the drain of the seventh transistor is connected to the second node through the sixth node.

[0047] In conjunction with the third aspect, in one possible implementation, the driving circuit further includes an eighth transistor, wherein the drain of the eighth transistor is connected to the gate of the third node as a seventh node. The source of the eighth transistor is connected to the second input terminal as an eighth node.

[0048] In conjunction with the third aspect, in one possible implementation, the source of the tenth transistor is connected to the first input terminal.

[0049] In conjunction with the third aspect, in one possible implementation, the twelfth node is connected to the third input terminal.

[0050] In conjunction with the third aspect, in one possible implementation, the first input terminal is a second-level power supply input terminal; the second input terminal is a first-level power supply input terminal; and the third input terminal is a second-level power supply input terminal.

[0051] In conjunction with the third aspect, in one possible implementation, the drain of the fifth transistor is connected to the anode of the light-emitting diode, and the cathode of the light-emitting diode is connected to the first-level power supply input terminal. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the display mode of a mobile terminal according to an embodiment of this application.

[0054] Figure 2 This is a block diagram of the display module architecture in a mobile terminal according to an embodiment of this application.

[0055] Figure 3 This is a schematic diagram of the pixel driving architecture in the screen-on mode according to an embodiment of this application.

[0056] Figure 4 This is a schematic diagram of a pixel driving architecture in idle mode according to an embodiment of this application.

[0057] Figure 5 This is a schematic diagram of the architecture of a display driver controller according to an embodiment of this application.

[0058] Figures 6a-6b This is an example timing diagram of a display driver controller according to an embodiment of this application.

[0059] Figure 7 This is a schematic diagram of a pixel driving circuit structure according to an embodiment of this application.

[0060] Figure 8 This is a timing diagram of the pixel driving circuit in screen-on mode according to an embodiment of this application.

[0061] Figure 9 This is a timing diagram of the pixel driving circuit in idle mode according to an embodiment of this application.

[0062] Figure 10 This is a schematic diagram of a pixel driving circuit structure according to another embodiment of this application.

[0063] Figure 11 This is a timing diagram of the pixel driving circuit in screen-on mode according to another embodiment of this application.

[0064] Figure 12This is a timing diagram of the pixel driving circuit in idle mode according to another embodiment of this application. Detailed Implementation

[0065] The embodiments of this application will be further described below with reference to the accompanying drawings, providing a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0066] It should be understood that all instances of the abbreviation "PWM" mentioned below refer to "Pulse Width Modulation", and all instances of the abbreviation "PAM" refer to "Pulse Amplitude Modulation".

[0067] First, let's introduce the terminology related to the embodiments of this application:

[0068] OLED: Organic Light Emitting Diode, also known as Organic Electroluminescence Display or Organic Light Emitting Semiconductor. OLED is a different type of product from Thin Film Transistor Liquid Crystal Display. OLED features self-illumination, wide viewing angle, high contrast, high response rate, and full color. Organic Light Emitting Diode displays can be further divided into passive matrix (PMOLED) and active matrix (AMOLED) depending on the driving method.

[0069] Micro LED: Micro Light Emitting Diode (abbreviated as MicroLED) is an array of LED pixels spaced on the order of 10 micrometers, with each LED pixel capable of self-illumination. Micro LED miniaturizes traditional inorganic LED arrays, allowing each 10-micrometer LED pixel to be independently addressed and lit. Micro LED displays connect 10-micrometer-scale LED chips to a TFT driving substrate, enabling precise control over the brightness of each chip and thus achieving image display.

[0070] Display modes: Display screens generally have two display modes: normal mode and idle mode. Normal mode refers to the display state when the user is using the screen normally; idle mode refers to the display state when the user is not using the screen.

[0071] Horizontal scanning circuit: OLED or Micro LED displays are arrays, and the image refresh process is performed by scanning line by line. The horizontal scanning circuit is the circuit module that provides the horizontal scanning signal to the display array.

[0072] Pulse amplitude modulation (PAM) is a driving method for Micro LED or OLED displays used to achieve different brightness levels. Specifically, it's a driving method that controls the magnitude of the light-emitting current of a light-emitting diode. In this embodiment, it can also be abbreviated as PAM.

[0073] Pulse Width Modulation (PWM): Pulse width modulation (PWM) is a driving method for Micro LED or OLED displays. Specifically, it is a driving method that keeps the light-emitting current of the LED constant while controlling the light-emitting time of the LED. In this embodiment, it can also be abbreviated as PWM.

[0074] Gate driver array: A gate driver array (GOA) is used to provide gating signals for each row of pixel circuits to control the on or off state of each row of pixel circuits. In the embodiments of this application, the gate driver array can also be abbreviated as gate array signal or GOA signal.

[0075] DDIC: Display Driver Integrated Circuit (abbreviated as DDIC unit), a type of display driver controller. The DDIC unit provides clock signals to control the operation of the GOA unit, and provides other signals required by the pixel circuit, such as the Vd signal to control the current of the LED light-emitting device, and the DATA signal and PWM signal together to control the grayscale brightness of the display.

[0076] Current control signal: also known as Vd signal, is used to control the current of LED light-emitting device. Specifically, after the GOA unit completes line-by-line scanning, voltage is uniformly sent to all pixels to complete the current value setting of LED light-emitting device.

[0077] PWM ramp signal: Pulse width modulation signal. For simplicity, the PWM ramp signal or PWM signal mentioned below refers to the pulse width modulation signal. It controls the duration of light emission by sending a continuously changing sweep signal during the light emission period of the LED.

[0078] Unless otherwise defined, the technical or scientific terms used in the embodiments of this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. Furthermore, the terms "first," "second," and similar terms used in the embodiments of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0079] This application provides a pixel driving architecture, a pixel driving circuit, a display driving method, and an electronic device. The pixel driving architecture and pixel driving circuit can be integrated into the electronic device. The electronic device in this application can include any electronic device with a display screen, such as a smartphone, tablet computer, or smartwatch; this application is not limited to this type.

[0080] The display screen in this application may include a foldable display screen or a non-foldable display screen, and the light-emitting element used may be a Micro LED or a light-emitting diode element such as an OLED. The following embodiments use a Micro LED non-foldable display screen on a smartwatch as an example, combined with... Figure 1 This is a schematic diagram illustrating the display mode of an electronic device according to an embodiment of this application.

[0081] like Figure 1 As shown, screen-on mode (English: normal mode) Figure 1 (Left) shows the display screen during normal user operation, i.e., the normal display state of the screen; idle mode (English: idle mode, Figure 1 (Right) This shows the display when the user is not using the screen. In idle mode, some pixels are not illuminated, or are in a black state. The display device only shows partial information; in one example, the time scale, hour hand, and minute hand are displayed in idle mode. It should be understood that... Figure 1 The display device shown is only an example. In the embodiments of this application, the appearance of the display device and the display screen can take many forms, which will not be described in detail in the embodiments of this application.

[0082] The following is based on Figure 2 The architecture of the display module of a mobile terminal in one embodiment of this application is described by way of example. Figure 2This is a block diagram of the display module architecture in a mobile terminal according to an embodiment of this application. In one example, such as... Figure 2 As shown, the display screen includes a pixel array and GOA units. The pixel array includes light-emitting diodes and driving circuits. The display screen is connected to the display driver integrated circuit (DDIC) and a flexible printed circuit (FPC) (not shown in the figure). The display driver controller can receive control signals from the processor of the mobile terminal. For example, if the mobile terminal is a smartphone or tablet, the processor of the mobile terminal can be a SoC or application processor; if the mobile terminal is a smartwatch, the processor of the mobile terminal can be a central processing unit. It should be understood that the solution of the present invention can be used in a smart terminal with a display screen. The smart terminal includes a display screen, a processor, and a display driver controller. The display screen is used to display images; the processor is used to generate a level control signal according to the status information of the mobile device, the level control signal being used to indicate whether the mobile device is in a screen-on mode or an idle mode; the display driver controller is used to generate a data signal to control the brightness of the displayed image according to the level control signal. When the mobile device is in the screen-on mode, the data signal is a pulse width modulation signal; when the mobile device is in the idle mode, the data signal is a pulse amplitude modulation signal.

[0083] The pixel array is the display area of ​​the screen, used to provide image information; the GOA unit is the pulse drive circuit area, used to provide pulse signals for line-by-line scanning of the pixel area; the DDIC is used to receive level control signals from the processor and transmit the signals to the screen according to a specific timing control; and the FPC provides a signal transmission connection path between the drive system and the screen.

[0084] The pixel driving architecture within a display screen typically performs brightness processing on image data, usually using two methods. The first is PWM (Pulse Width Modulation), which adjusts brightness by changing the duty cycle of the data signal. The longer the data signal controls the pixel circuit to emit light within a time frame, the higher the display brightness of the area, and vice versa. For example, assuming a time frame is 16ms long, the EM (Electronic Mode) signal controls the pixel circuit to emit light for 8ms and keeps it off for the remaining 8ms. To increase brightness, the data signal can be set to control the pixel circuit to emit light for 10ms and keep it off for the remaining 6ms. The second method is PAM (Pulse Amplification), which adjusts brightness based on the voltage of the data signal. This embodiment uses different brightness adjustment methods in on-screen and idle modes. In idle mode, the lower-power PAM method is used, while in on-screen mode, the more precise PWM method is used. This ensures a good user experience for the mobile terminal display while saving power and improving battery life.

[0085] Figure 3 This is a schematic diagram of a pixel driving architecture in screen-on mode provided in an embodiment of this application. Figure 3 As shown, the pixel driving architecture includes a comparator unit, a driving loop unit, a current control unit, and a light-emitting diode.

[0086] In one example, the drive circuit unit is connected to the current control unit, the comparator unit, and the light-emitting diode (LED) respectively, and is used to drive the LED to turn on and off. The following describes the process in conjunction with... Figure 3 Let me explain the specific control methods in detail.

[0087] like Figure 3 As shown, in the screen-on mode, the display driver controller can output a current control signal to the current control unit. The current control signal is used to set the drive current value of the drive circuit unit. In one example, the current control signal is a constant value.

[0088] The comparator unit can receive a grayscale setting signal and a PWM ramp signal from the display driver controller. These signals are then output as a comparison signal and sent to the drive loop unit. In one example, the comparator unit adjusts the duty cycle of the PWM ramp signal to adjust the voltage value of the comparison signal. Specifically, when the voltage of the comparison signal is lower than a first preset voltage, the drive loop unit is turned on; when the output voltage signal is higher than the first preset voltage, the drive loop unit is turned off. The first preset voltage is the turn-on voltage of the first transistor in the comparator unit. When the transistor receives a voltage signal lower than the turn-on voltage, the transistor is turned on, and the circuit containing the transistor is turned on. Based on this method, the comparison signal can be used to control the on and off of the drive loop unit, thereby controlling the on and off of the light-emitting diode (LED).

[0089] Since the slope of the PWM ramp signal is a constant value, the descent speed of the PWM ramp signal is fixed; while the grayscale setting signal Dn is a signal that varies between two different voltage values. Therefore, combining the grayscale setting signal Dn and the PWM ramp signal, the comparison signal is a linearly changing voltage signal. Thus, the brightness and illumination time of the LED are linearly related. In one example, the screen-on mode can adjust the grayscale of the LED by adjusting the illumination time of the drive circuit unit.

[0090] The GOA unit is used to send progressive scan pulse signals to the drive loop unit. In one example, this set of pulse signals is used in conjunction with the aforementioned grayscale setting signals to perform progressive scan grayscale setting, wherein the progressive scan refers to rows of a pixel-by-pixel array. It should be understood that the GOA unit can be integrated under the display screen.

[0091] Figure 4 This is a schematic diagram of another pixel driving architecture in idle mode provided in an embodiment of this application. For example... Figure 4 As shown, the pixel driving architecture includes a comparator unit, a driving loop unit, a current control unit, and a light-emitting diode (LED). In one example, the driving loop is connected to the current control unit, the comparator unit, and the LED, respectively. Figure 3The difference lies in that, in idle mode, the comparator unit does not participate in adjusting the on / off state of the drive circuit unit, and therefore does not participate in controlling the illumination and off state of the LED. The current control unit, however, controls the on / off state of the drive circuit unit. When the grayscale setting signal sent by the current control unit is greater than a second preset voltage, the drive circuit unit is off, causing the LED to not emit light; when the grayscale setting signal sent by the current control unit is less than the second preset voltage, the drive circuit unit is on, causing the LED to emit light. In idle mode, the grayscale setting signal Dx of the control drive circuit unit is higher than the grayscale setting signal Dn participating in progressive scanning. Unlike the progressive scanning grayscale setting signal Dn, the grayscale setting signal Dx is a constant value that does not change over time. Therefore, unlike the aforementioned on-screen mode, the idle mode adjusts the brightness of the LED by adjusting the voltage value of the current control signal.

[0092] In such Figure 4 In the second driving mode shown, the display driver controller does not send a PWM ramp signal (the dashed line indicates that the comparator unit does not receive the PWM ramp signal), but only controls the adjustment of the light-emitting diode by the current control signal, thereby saving the power consumption required to generate the PWM ramp signal and improving the battery life of the electronic device.

[0093] To facilitate understanding of the display driver controller scheme in this application, the circuit structure and working principle of the display driver controller in this application are described in detail below with reference to example figures. It should be noted that the following description is only an example of a display driver controller. Any schemes or variations thereof obtained by those skilled in the art based on the scheme of this application, such as modifying certain connection relationships between components or replacing certain components, without creative effort, shall fall within the protection scope of this application.

[0094] Figure 5 A schematic diagram of the display driver controller architecture according to an embodiment of this application is shown. As described above, the display driver controller is used to send corresponding data signals to the comparator unit and the drive loop unit in the pixel driving architecture. It should be noted that the display driver controller can be integrated on the TFT substrate or within the DDIC unit; its location is not limited. The following is in conjunction with... Figure 5 A detailed explanation of how the drive controller works.

[0095] like Figure 5As shown, the display driver controller includes three switch signal lines (hereinafter referred to as SW1, SW2, and SW3), three transistors, a grayscale setting generation module, a current setting generation module, and a PWM ramp generation module. Specifically, SW1 is connected to the gate of the first transistor, the source of the first transistor is connected to the grayscale generation module, and the drain of the first transistor serves as the output terminal. SW2 is connected to the gate of the second transistor, the source of the second transistor is connected to the current setting generation module, and the drain of the second transistor serves as the output terminal. SW3 is connected to the gate of the third transistor, the source of the third transistor is connected to the PWM ramp generation module, and the drain of the third transistor serves as the output terminal.

[0096] It should be understood that, Figure 5 The three output terminals Data1, Data2 and Data3 shown can each send the above data signals at different time periods. The data signals sent by the output terminals are the output signals of the display driver controller and are sent to the drive circuit under the display screen.

[0097] Figure 6a and Figure 6b It shows according to Figure 5 The example timing diagram of the display driver controller circuit shown is as follows, in which, Figure 6a This is a timing diagram of the operation in screen-on mode; Figure 6b This is the timing diagram for idle mode. The following will combine... Figure 5 To explain in detail Figure 5 The operation method of the display driver controller is shown below:

[0098] by Figure 6a Taking the first example, in the screen-on mode, the operating timing of the display driver controller includes three intervals. In the first time interval, SW1 is at the second level, and SW2 and SW3 are at the first level. At this time, the grayscale setting generation module sends a grayscale setting signal to the output. During this time interval, the scanning signal of the GOA unit also provides a line-by-line scanning pulse signal to the pixel area. In the first time interval, the pixel driving architecture completes the grayscale setting. In the second time interval, SW2 is at the second level, and SW1 and SW3 are at the first level. At this time, the current setting generation module sends a current control signal to the output. During this second time interval, the pixel driving architecture completes the setting of the driving current magnitude. In the third time interval, SW3 is at the second level, and SW1 and SW2 are at the first level. At this time, the PWM ramp generation module sends a PWM ramp signal to the output. When this module is first turned on, it abruptly changes from a low level to a high level. The purpose is to raise the potential of the first node in the driving architecture to ensure that it is higher than the first preset voltage, thereby putting the driving circuit unit in the off state first. This effectively solves the short-circuit problem of the power signal in this stage. Figure 6aAs can be seen, the PWM ramp is a ramp signal with a fixed slope that gradually decreases. The PWM ramp generation module continuously transmits the PWM ramp signal during the light-emitting process, causing the PWM ramp signal to continuously change from the first level to the second level. This causes the potential stored in the first node to continuously change from high to low. When the PWM ramp signal drops sufficiently to turn on the corresponding transistor, the drive circuit unit is turned on, and the light-emitting diode emits light. Because the PWM ramp signal changes linearly according to the time interval, the turning on and off of the drive circuit unit can be controlled by adjusting the light-emitting interval time or duty cycle of the drive circuit unit. The longer the PWM ramp signal controls the light-emitting time of the pixel drive circuit within a time frame, the higher the display brightness of the display area; conversely, the shorter the time, the lower the display brightness.

[0099] In idle mode, such as Figure 6b As shown, the operating timing of the display driver controller includes two intervals. In the first time interval, SW1 is at the second level, and SW2 and SW3 are at the first level. During this time, the grayscale setting module sends a grayscale setting signal to the output terminal. In this time interval, the scanning signal of the GOA unit also provides a line-by-line scanning pulse signal to the pixel area. In the first time interval, the pixel driving architecture completes the grayscale setting. In the second time interval, SW2 is at the second level, and SW1 and SW3 are at the first level. The current setting module sends a pulse amplitude modulation signal to the output terminal. This signal is raised from a certain grayscale potential in the previous interval to a higher potential. The purpose is to put the drive circuit unit in a closed state first, thus effectively solving the short circuit problem of the power supply signal in this stage. The pulse amplitude modulation signal is a variable constant value. In order to control the opening and closing of the drive circuit, it is necessary to adjust the potential of the pulse amplitude modulation signal. When the potential of the pulse amplitude modulation signal is adjusted to be lower than the second preset voltage, the drive circuit unit is turned on.

[0100] In idle mode, SW3 remains at the first level, so the PWM ramp generation module is always off, that is, it does not send PWM ramp signals, thereby saving the power consumption required for PWM ramp signals.

[0101] The following explains the generation principle and power consumption source of the PWM ramp signal. 2n-1 reference voltages (n being the number of bits) are generated through a resistor series R. These are then passed through a DAC switching network to output a unique voltage signal V0. Finally, a data buffer amplifies the output voltage to meet load requirements. When the digital signal input to the DAC changes, the voltage signal of the DAC switching network also changes, ultimately outputting a corresponding voltage waveform over a period of time. Taking a bit depth of n=12 as an example, the power consumption is approximately 1.1mW, accounting for about 13.75% of the total power consumption of the mobile terminal in this example.

[0102] To facilitate understanding of the pixel driving scheme of this application, the structure and working principle of the pixel driving circuit in the display screen of this application embodiment are described below with reference to example figures. It should be noted that the following description is only an example of a pixel driving circuit. Any solutions or variations thereof obtained by those skilled in the art based on the scheme of this application, such as modifying certain connection relationships between components or replacing certain components, without creative effort, fall within the protection scope of this application.

[0103] This application provides a pixel driving circuit. Figure 7 This is a circuit diagram of a pixel driving circuit according to an embodiment of this application. Figure 7 As shown, the pixel driving circuit includes 11 transistors. For simplicity, the first transistor will be referred to as T1, the second transistor as T2, and so on, corresponding one-to-one with the component labels in the accompanying drawings. The pixel driving circuit also includes two capacitors, such as... Figure 7 As shown, C1 and C2 are respectively. And a light-emitting diode; in addition, the pixel driving circuit also includes three nodes, such as... Figure 7 As shown, the first node is the in node, the second node is the out node, and the third node is the G node. The nodes are used to store the voltage values ​​of the signal input.

[0104] It should be noted that the aforementioned light-emitting diode can be an organic light-emitting diode (OLED). In this case, the display screen of the electronic device is an OLED display. Alternatively, the light-emitting diode can be a micro light-emitting diode (Micro LED), in which case the display screen of the electronic device is a Micro LED display. For ease of description, the following examples will use Micro LED as an example.

[0105] The following description Figure 7 Definitions of terms related to other signals:

[0106] Gn and Em are two different GOA units sending line-by-line scan signals, where n and m represent the nth and mth rows, respectively. In one embodiment of this application, Gn is also called the first scan signal and Em is also called the second scan signal.

[0107] Data refers to data signals from the display driver controller, including the grayscale setting signal Dn, the current control signal Vd, and the PWM ramp signal.

[0108] RST, RST2, S0, and WT are pulse signals provided by the display driver controller. In one example of this application, RST2 is also called the first pulse signal, S0 is also called the second pulse signal, RST is also called the third pulse signal, and WT is also called the fourth pulse signal. For the sake of brevity, the following descriptions will use abbreviations that correspond one-to-one with the figures.

[0109] VSS, Va, VDD1, and VDD2 are power signals, which in one example can be provided by a Power IC unit integrated in the display driver controller. In one example of this application, VDD1 is also called the first power signal, VDD2 is also called the second power signal, Va is also called the third power signal, and VSS is also called the fourth power signal. For brevity, the following descriptions use abbreviations that correspond one-to-one with the illustrations. It should be noted that in one example, VDD1 and VDD2 are higher levels; Va and VSS are lower levels. The terms "higher" and "lower" are relative concepts based on the embodiments of this application. In one embodiment of this application, when the same signal undergoes a potential change, the higher level of the signal is also called the first level, and the lower level is also called the second level. "First level" in this application refers to a low level, and "second level" in this application refers to a high level. The low level is a level lower than other level signals in the driving circuit, and the high level is a level higher than other level signals in the driving circuit. In one example, the high level can be 5V, and the low level can be 0V.

[0110] It is important to note that, in order to prevent short circuits, the difference between Va and VSS must be less than the turn-on voltage of the LED, and the difference between VDD1 and VDD2 must be greater than the turn-on voltage of the fourth transistor T4.

[0111] like Figure 7 As shown, the comparator unit includes a ninth transistor T9, a tenth transistor T10, and an eleventh transistor T11. Specifically, the gate of the tenth transistor T10 is connected to the first node (hereinafter referred to as the in node), the source of the tenth transistor T10 is connected to the first power supply signal terminal (hereinafter referred to as VDD1), and the drain of the tenth transistor T10 is connected to the second node (hereinafter referred to as the out node). The gate of the ninth transistor T9 is connected to the first scan signal terminal (hereinafter referred to as Gn), and the source of the ninth transistor T9 is connected to the drain of the tenth transistor T10. The gate of the eleventh transistor T11 is connected to the third pulse signal (hereinafter referred to as RST), the source of the eleventh transistor T11 is connected to the third power supply signal terminal (hereinafter referred to as Va), and the drain of the eleventh transistor T11 is connected to the second node (hereinafter referred to as the out node).

[0112] The comparator unit adjusts the switching on and off of the tenth transistor T10 by comparing VDD1 with the voltage value at the in node. The ninth transistor T9 is used to compensate for the threshold voltage Vth of the tenth transistor T10 to prevent threshold voltage offset issues, thereby improving the accuracy of the comparator unit. The operating states of the comparator unit in two driving modes are described in detail below:

[0113] In the bright screen mode, the in node receives the power signal from VDD1, the grayscale setting signal from the display drive controller Data, the PWM ramp signal, and the threshold voltage Vth(T10) of the tenth transistor T10. Specifically, VDD1 transmits the power signal to the in node through the T10-T9 line until the voltage of the in node differs from the voltage of VDD1 by a threshold voltage Vth, i.e., Vin = VDD1 + Vth(T10). Additionally, Data also transmits a signal to the second capacitor C2, which is adjusted according to the timing diagram of this embodiment. The voltage drop across C2 is maintained at ΔV = VDD1 + Vth(T10) - Vdata. When the comparator enters the grayscale setting time interval, Data inputs the grayscale setting signal voltage Dn. At this time, ΔV = VDD1 + Vth(T10) - Dn. Since Vin = VDD1 + Vth(T10), we can obtain:

[0114] The expression for Vin within the grayscale voltage setting range is: Vin = VDD1 + Vth(T10) - Dn. When the comparator unit enters the PWM ramp setting stage, the PWM ramp signal will generate a ramp signal Dx that first raises Dn and then decreases at a constant speed. At this time, Vin = VDD1 + Vth(T10) - Dn + Dx. The voltage signal of Vin at this time is called the comparison signal.

[0115] The screen-on mode adjusts the voltage value of Vin (i.e., the comparison signal) by adjusting the time of the grayscale setting signal Dn and the PWM ramp signal Dx. When Vin drops to VDD1+Vth(T10), the tenth transistor T10 turns on. VDD1+Vth(T10) is called the first preset voltage.

[0116] In idle mode, the in node receives the second-level voltage signal from Va, therefore the tenth transistor remains on, thus Vout maintains the first level of VDD1, the fourth transistor remains off, and the comparator unit does not participate in adjusting the level change of Vout in this mode. Therefore, combined with Figure 5As shown in Figure 6, the circuit structure and timing diagram of the display driver controller indicate that the PWM ramp signal generation module can be disabled in this mode, thereby saving the power consumption required for the PWM ramp signal and improving the battery life and service life of the electronic device.

[0117] The drive circuit unit includes a fourth transistor T4, a third transistor T3, and a sixth transistor T6. The gate of the fourth transistor T4 is connected to the out node, the source of the fourth transistor T4 is connected to the second power supply signal terminal VDD2, and the drain of the fourth transistor T4 is connected to the source of the third transistor T3. The fourth transistor T4 is switched on or off according to the voltage signal of the out node. The gate of the third transistor T3 is connected to a third node (hereinafter referred to as the G node), the source of the third transistor T3 is connected to the drain of the fourth transistor T4, and the drain of the third transistor T3 is connected to the source of the sixth transistor T6. The third transistor T3 is switched on or off according to the voltage signal of the G node. The gate of the sixth transistor T6 is connected to a fourth pulse signal terminal (hereinafter referred to as WT), the source of the sixth transistor T6 is connected to the drain of the third transistor T3, and the drain of the sixth transistor T6 is connected to the light-emitting diode.

[0118] Based on the circuit description of the comparator unit above, when the tenth transistor T10 is turned on, the out node receives a higher level signal of VDD1, that is, Vout = VDD1. This will cause the gate level of the fourth transistor T4 to be the first level, so the fourth transistor is in the off state. The power supply signal of VDD2 cannot be sent to the fourth transistor, and the drive circuit unit is turned off.

[0119] The current control unit includes a fifth transistor T5, a third transistor T3, and a second transistor T2. The gate of the fifth transistor T5 is connected to the second scan signal terminal (hereinafter referred to as Em), the source of the fifth transistor T5 is connected to the display driver controller, and the drain of the fifth transistor T5 is connected to the drain of the fourth transistor T4 and the source of the third transistor T3. The gate of the third transistor T3 is connected to the G node, the source of the third transistor T3 is connected to the drain of the fifth transistor T5, and the drain of the third transistor T3 is connected to the source of the second transistor T2. The gate of the second transistor T2 is connected to Em, the source of the second transistor T2 is connected to the drain of the third transistor T3, and the drain of the second transistor T2 is connected to the G node.

[0120] In screen-on mode, the output of the display driver controller sends a current control signal to node G through the current control unit, specifically through T5-T3-T2, until the voltage at node G differs from the voltage of the current control signal by the threshold voltage Vth of the third transistor T3. Ultimately, VG = Vd + Vth(T3). This stage completes the current setting of the drive circuit unit. In one example, the threshold voltage of the third transistor T3 is also referred to as the second threshold voltage. When the third transistor T3 is turned on, Vd + Vth(T3) is the power supply for its activation, also referred to as the second preset voltage in one example. Since Vd is a constant value, the voltage at node G is also constant, and the third transistor remains on, not participating in regulating the activation and deactivation of the drive circuit unit.

[0121] In idle mode, the output of the display driver controller sends a grayscale setting voltage Dn to node G via the current control unit. Dn is assigned a different voltage value according to the grayscale of different pixels, i.e., VG = Dn + Vth(T3). In one example, the voltage signal of node G is also called the second current signal. In this driving mode, the voltage difference between the source and drain of the third transistor T3 is V = Dn + Vth(T3) - VDD2. By adjusting the grayscale setting voltage, V is made to be less than or greater than the turn-on voltage of the third transistor, thereby achieving switching control of the third transistor. As mentioned above, in idle mode, the fourth transistor remains off, such as... Figure 7 As shown, when RST is at the second level, the eleventh transistor T11 is turned on, and Vout receives the second-level voltage of Va at this time, thereby turning on the fourth transistor. The switching control of the drive circuit unit is achieved by controlling the third transistor T3 through the aforementioned grayscale setting voltage Dn.

[0122] based on Figure 7 The schematic diagram of the pixel driving circuit shown in this application illustrates a pixel driving method, which includes... Figure 8 The six stages shown, and including those in idle mode Figure 9 The diagram illustrates the four stages. The following section, with illustrations, details the pixel driving methods under two driving modes in an example:

[0123] In screen-on mode, such as Figure 8 As shown:

[0124] Phase 1①, such as Figure 8As shown in ①, RST2 is set to the second level, and other signals are at the first level. At this time, T8 is turned on, Va sends a second-level signal to the in node to achieve a reset, thus turning on T10. Simultaneously, the first-level signal VDD1 resets the out node, and T4 is turned off. During this time period, Vin = Va; Vout = VDD1.

[0125] Phase 2, such as Figure 8 As shown in ②, Gn outputs the second level line by line, while other signals are at the first level. At this time, T9 and T10 are turned on, and VDD1 transmits the signal to the in node through T10-T9 until the in node differs from VDD1 by a Vth, that is, Vin = VDD1 + Vth(T10).

[0126] In one example, while VDD1 sends a signal to the in node, the output of the display driver controller also sends a signal to the other end of capacitor C2 connected to the in node, making the potential of the out node Vout = VDD1, and the potential of the output of the display driver controller VDATA = Dn. Dn is given a different voltage value according to the gray level of different pixels. This stage completes the Vth compensation and gray level voltage setting of T10, that is, maintaining the voltage drop across C2 at ΔV = Vin - Dn. Since Vin = VDD1 + Vth, substituting into the above formula, we get: ΔV = VDD1 + Vth - Dn.

[0127] Phase 3③, such as Figure 8 As shown in ③, S0 and WT are at the second level, while other signals are at the first level. At this time, T1, T6, and T7 are turned on, and Va sends signals to nodes G and anode, making VG = Vanode = Va, thus completing the reset action. At this time, the out node is in a floating state, maintaining the second-stage potential, i.e., Vout = VDD1. Since the out node remains at the VDD1 level, T4 remains off, and the drive circuit does not work. Additionally, due to coupling with C2, the in node's potential at this time is Vin = VDD1 + Vth – Dn + Dp, where Dp is the potential of the display drive controller's output at this moment.

[0128] Phase 4, such as Figure 8As shown in section ④, Em is at the second level, while other signals are at the first level. At this time, T2, T3, and T5 are turned on, and the output of the display drive controller transmits the Vd potential to node G through T5-T3-T2 until the potential at point G differs from the Vd potential by a Vth, i.e., VG = Vd + Vth. This stage completes the setting of the current value for the drive circuit and also completes the Vth compensation for T3. In section ④, the GOA unit simultaneously sets the output signals of all rows to the second level. Additionally, the out node and anode node are in a floating state, maintaining the potential from the previous stage, i.e., Vout = VDD1, Vanode = Va. The in node is affected by the coupling effect of the signal Vd from the output of the display drive controller, with a potential Vin = VDD1 + Vth – Dn + Vd.

[0129] Fifth stage (5), such as Figure 8 -⑤ As shown, RST is at the second level, and other signals are at the first level. At this time, T11 is turned on. Va sends a signal to the out node, making Vout = Va, and thus T4 is turned on. Points G and anode remain at the potential of the previous stage, i.e., VG = Vd + Vth, Vanode = Va. T3 is turned on. Since WT is at the first level, T6 is not turned on, so the Micro LED device does not emit light. In one example, the signal at the output of the display driver controller in the fifth stage changes abruptly from a lower level to a higher level. Through the coupling of C2, the potential of the in node increases, achieving the effect of turning off T10. This effectively solves the short circuit problem between VDD1 and Va signals in the fifth stage. At this time, the potential of the in node is Vin = VDD1 + Vth – Dn + Dx, where Dx is the voltage value at which the output of the display driver controller changes to a high level. This stage is the preparatory stage for Micro LED light emission.

[0130] Stage 6, such as Figure 8As shown in Figure 6, WT is at the second level, and other signals are at the first level. At this time, T6 is on. Since the out node and G node remain in a floating state, they maintain the potentials of the previous stage, i.e., Vout = Va, VG = Vd + Vth. Therefore, T3 and T4 are also on, forming a loop VDD2-T4-T3-T6-VSS, and the Micro LED emits light. During the switching process, the output of the display driver controller continuously transmits a PWM ramp signal. This ramp signal continuously changes from the first level to the second level, and through the coupling effect of C2, it causes the potential of the in node to also continuously change from the first level to the second level. When the PWM ramp signal decreases to Dn, Vin decreases to VDD1 + Vth, T10 is turned on again, and VDD1 again transmits potential to the out node, making Vout = VDD1, and T4 turns off again. After T4 turns off, the drive loop is disconnected, and the Micro LED does not emit light. Since the voltage drop rate of the PWM ramp signal is fixed, when Dn takes different values, the time it takes for the PWM to drop to the Dn potential and cause the Micro LED to stop emitting light will also be different, thus realizing the display of different brightness by adjusting the light emission time.

[0131] It's important to note that the "stages" mentioned above refer to time concepts. Each stage can include multiple time frames, with the display scanning one frame of image within each time frame. In one example, the pixel driving method described above processes the display data for brightness, using a technique called Pulse Width Modulation (PWM). This means adjusting the brightness by changing the switching time, or duty cycle, of the PWM ramp signal. The longer the PWM ramp signal controls the pixel driving circuit to emit light within a time frame, the higher the display brightness of the area, and vice versa. For example, if a time frame is 10ms long, the PWM ramp signal controls the pixel driving circuit to emit light for 5ms and keeps it off for the remaining 5ms. To increase brightness, the PWM ramp signal can be set to control the pixel driving circuit to emit light for 8ms and keep it off for 2ms.

[0132] The following is combined with Figure 9 This paper introduces the pixel driving circuit structure in the idle mode, i.e., the pixel driving method in the idle mode, according to the embodiments of this application.

[0133] Phase 1, such as Figure 9As shown in ①, S0, WT, and RST2 are at the second level, while other signals are at the first level. At this time, T1, T6, T7, and T8 are turned on, and Va transmits signals to nodes G, anode, and in, making VG = Vanode = Vin = Va, thus completing the reset action. By adjusting the Va potential, Va - VSS is made less than the LED's turn-on voltage, ensuring that the LED does not emit light at this time. Additionally, since Vin = Va, T10 is turned on, VDD1 transmits potential to node out, Vout = VDD1, and T4 is turned off.

[0134] The second stage, such as Figure 9 As shown in ②, Em outputs a second-level signal line by line, RST2 is at the second level, and other signals are at the first level. At this time, T2, T5, and T8 are on. Because VG = Va in the previous moment, T3 is on. The output of the display drive controller transmits the grayscale setting voltage Dn to the G node through T5-T3-T2. Dn is given different voltage values ​​according to the grayscale of different pixels. When the potential of point G reaches VG = Dn + Vth(T3), T3 is off, and the output of the display drive controller stops transmitting signals to the G node. Since RST2 is still on, the in and out nodes maintain the first-stage potential, i.e., Vin = Va, Vout = VDD1, and T4 is off. Additionally, the anode node floats, maintaining the previous-stage potential, i.e., Vanode = Va. This stage completes the pixel grayscale setting and T3's Vth compensation.

[0135] The third stage, such as Figure 9 As shown in ③, RST2 and the display driver controller change from the second level to the first level. It should be understood that the pulse change of RST2 occurs before the pulse amplitude modulation signal is generated at the output of the display driver controller. In the third stage, other signals are at the first level. At this time, T8 is off, the in node remains at the Va potential, T10 remains on, and Vout = VDD1. When the output of the display driver controller changes from the second level to the first level (i.e., from a certain gray level potential Dn to a higher potential Dx), since in is in a floating state, after coupling through C2, the potential of the in node changes to Vin = Va + Dx - Dn. The potential of Dx can be adjusted to ensure that Va + Dx – Dn – VDD1 is greater than the turn-on voltage of T10, which is sufficient to turn off T10. The out node remains at the VDD1 potential, and T4 remains off. In addition, the G node and the anode node are in a floating state at this moment, so VG = Dn + Vth (T3), Vanode = Va.

[0136] The fourth stage, such as Figure 9As shown in section ④, RST and WT are at the second level, while other signals are at the first level. At this time, T6 and T11 are on, and Va transmits potential to out through T11, making Vout = Va. T4 is then on, and VDD2 transmits a signal to the S node, making VS = VDD2. Since the G-point potential is maintained at Dn + Vth(T3) in the third stage, the voltage difference between the gate and source of T3, VGS = Dn + Vth(T3) - VDD2. By adjusting the Dn potential in the second stage, VGS can be made less than the turn-on voltage of T3, causing T3 to conduct. This forms a loop: VDD2-T4-T3-T6-LED-VSS, and the LED light-emitting device operates. When WT changes to the first level, T6 is turned off, and the LED device does not emit light.

[0137] It is important to note that the "stages" mentioned above are time-related concepts, and each stage can include multiple time frames, with the display scanning one frame of image in each time frame. In one example, the method for adjusting the display brightness in idle mode is based on voltage and current adjustment, that is, adjusting the brightness according to the grayscale setting voltage of the display driver controller. In one example, the grayscale setting signal can be based on different brightness parameters.

[0138] Another embodiment of the present invention provides another pixel driving method, such as Figure 10 As shown, the pixel driving circuit on which this driving method is based is similar to... Figure 7 The pixel driving circuit shown has the same structure, the difference being that the gate input signal of the eighth transistor T8 is changed by... Figure 7 The RST2 shown is replaced with S0, allowing the eighth transistor T8, the first transistor T1, and the seventh transistor T7 to share the same signal line S0. This further reduces the signal line bundle required by the DDIC, optimizes wiring space, and thus increases the pixel PPI (pixels per inch). Additionally, reducing the number of pulse signals from four to three further reduces the power consumption of the RST2 section.

[0139] Figure 10 This is a schematic diagram of a pixel circuit structure according to another embodiment of this application. The pixel circuit provided in this embodiment can realize the functions of a bright mode and an idle mode of a Micro LED pixel circuit.

[0140] based on Figure 10 The diagram shown is a schematic of the pixel circuit structure. Figure 11 This is a timing diagram of the pixel circuit in the screen-on mode according to another embodiment of this application, as shown below. Figure 11 As shown, the timing sequence is divided into five stages.

[0141] The following is combined with Figure 11 This paper details the working principle of the pixel driving circuit structure of another embodiment of this application in the screen-on mode.

[0142] Phase 1, such as Figure 11 As shown in ①, S0 and WT are at the second level, while other signals are at the first level. At this time, T1, T7, T6, and T8 are turned on. Va transmits signals to the anode, G, and in nodes respectively, i.e., Vanode = VG = Vin = Va, completing the reset action. Additionally, since Vin = Va, T10 is turned on, and the out node is reset to the VDD1 potential, i.e., Vout = VDD1. At this time, T4 is turned off.

[0143] The second stage, such as Figure 11 As shown in ②, Gn outputs the second level line by line, while other signals are at the first level. At this time, T9 is turned on. Since Vin maintains the first-stage potential Va, T10 is turned on. VDD1 transmits signals to the in node through T10-T9 until Vin = VDD1 + Vth(T10). At this time, Vout = VDD1. Due to floating, the G node and the anode node maintain the first-stage potential, i.e., VG = Vanode = Va. In addition, while VDD1 transmits signals to the in node, the output terminal of the display driver controller also transmits signals to the other end of the capacitor C2 connected to the in node, so that the potential VDATA = Dn of the output node of the display driver controller is given by different voltage values ​​according to the grayscale of different pixels. This stage completes the Vth compensation of T10 and the setting of grayscale voltage, that is, maintaining the voltage drop across C2 at ΔV = VDD1 + Vth(T10) - Dn.

[0144] The third stage, such as Figure 11 As shown in ③, Em is at the second level, while other signals are at the first level. At this time, T2, T3, and T5 are turned on, and the output of the display drive controller transmits the Vd potential to node G through T5-T3-T2 until the potential at point G differs from the Vd potential by a Vth, i.e., the final VG = Vd + Vth (T3). This stage completes the setting of the current value of the drive circuit and also completes the Vth compensation for T3. The Em and Gn signals are similar, being output signals from another set of GOA units. This set of GOA units simultaneously sets the output signals of all rows to the second level during this stage. Additionally, the out and anode nodes are in a floating state, maintaining the second-stage potential, i.e., Vout = VDD1, Vanode = Va; the in node is affected by the coupling effect of the signal Vd from the output of the display drive controller, with a potential Vin = VDD1 + Vth (T10) - Dn + Vd.

[0145] The fourth stage, such as Figure 11As shown in ④, RST is at the second level, and other signals are at the first level. At this time, T11 is turned on. Va sends a signal to the out node, making Vout = Va, and then T4 is turned on, while G and anode remain at the potential of the third stage, i.e., VG = Vd + Vth(T3), Vanode = Va; T3 is turned on, but since WT is at the first level, T6 is not turned on, so the LED is still not lit; in addition, the signal at the output of the display driver controller changes abruptly from a level lower than the second level to a higher level in order to raise the potential of the in node through the coupling of C2, thereby turning off T10. This can effectively solve the short circuit problem between VDD1 and Va signals in this stage. At this time, the potential of the in node is Vin = VDD1 + Vth(T10) - Dn + Dx (Dx is the voltage value of the pulse amplitude modulation signal at the output of the display driver controller that changes abruptly to the first level). This stage is the LED lighting preparation stage.

[0146] The fifth stage, such as Figure 11 -⑤ As shown, WT is at the second level, and other signals are at the first level. At this time, T6 is turned on. Because the out node and G node are floating, they still maintain the potential of the previous stage, that is, Vout = Va, VG = Vd + Vth (T3). Therefore, T3 and T4 are also turned on, and VDD2-T4-T3-T6-VSS form a loop, and the LED lights up. During the lighting process, the output of the display driver controller continuously transmits a PWM ramp signal. This ramp signal changes continuously from the first level to the second level, and then through the coupling effect of C2, it causes the potential of the in node to change continuously from the first level to the second level. When the PWM ramp signal drops to Dn, Vin drops to VDD1 + Vth (T10), T10 turns on again, and VDD1 transmits potential to the out node again, making Vout = VDD1, and T4 turns off again. After T4 turns off, the drive circuit is disconnected, and the LED does not light up. Since the voltage drop rate of the PWM ramp signal is fixed, when Dn takes different values, the time the LED does not light up when the PWM drops to the Dn potential will also be different, that is, the light-up time will be different. Thus, different brightness levels can be achieved by adjusting the light-up time.

[0147] The following is combined with Figure 12 This application describes the working principle of a pixel driving circuit structure in idle mode according to another embodiment of the present application.

[0148] Phase 1, such as Figure 12As shown in ①, S0 and WT are at the second level, while other signals are at the first level. At this time, T1, T6, T7, and T8 are turned on. Va transmits signals to the anode, G, and in nodes respectively, i.e., V - anode = VG = Vin = Va, completing the reset action. In one example, since Vin = Va, T10 is turned on, and the out node is reset to the VDD1 potential, i.e., Vout = VDD1. At this time, T4 is turned off.

[0149] The second stage, such as Figure 12 As shown in ②, the Em signal is output at the second level line by line, while other signals are at the first level. At this time, T2, T3, and T5 are turned on. The output of the display driver controller transmits the Dn potential to node G through T5-T3-T2 until the potential of point G differs from the potential of Dn by a Vth, i.e., the final VG = Dn + Vth(T3). This stage completes the setting of the current magnitude of the drive circuit and also completes the Vth compensation for T3. In addition, the out node and anode node are in floating mode, maintaining the potential of the previous stage, i.e., Vout = VDD1, Vanode = Va; the in node is affected by the coupling effect of the signal Dn from the output of the display driver controller, and the potential Vin = Va + Dn.

[0150] The third stage, such as Figure 12 As shown in ③, RST and WT are at the second level, while other signals are at the first level. At this time, T11 and T6 are on. Va sends a signal to the out node, i.e., Vout = Va, therefore T4 is on. Since the G node is floating, the VG potential remains at VG = Dn + Vth(T3), therefore T3 is also on. At this time, VDD2-T4-T3-T6-VSS form a loop, and the LED emits light. As the WT level changes from the second level to the first level, T6 is off, and the LED stops emitting light again. In one example, before RST and WT change to the second level, the pulse amplitude modulation signal at the output of the display driver controller abruptly changes from a lower potential to a higher potential. This is to couple the in node potential to a higher potential, keeping T10 off and preventing a short circuit between VDD1 and Va.

[0151] According to another embodiment of the present invention, in idle mode, the PWM generation module of the display driver controller is turned off, which can save 10%-20% of the total power consumption of the display screen and improve the battery life of the mobile terminal. Furthermore, by replacing the RST2 signal with the S0 signal, and making the S0 signals of T1 and T7 control T8, the signal lines required by the DDIC can be saved, thereby further saving the power consumption of the display screen. At the same time, due to the saving of the RST2 signal line, the number of pixels per inch (PPI) can be further increased.

[0152] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A mobile device, characterized in that, The mobile device includes: A display screen used to display images; A processor is configured to generate a level control signal based on the status information of the mobile device, the level control signal being used to indicate whether the mobile device is in a screen-on mode or an idle mode. The display driver controller is configured to generate a data signal for controlling the brightness of the displayed image based on the level control signal. When the mobile device is in the screen-on mode, the data signal is a pulse width modulation signal; When the mobile device is in the idle mode, the data signal is a pulse amplitude modulation signal.

2. The mobile device according to claim 1, characterized in that, The display screen includes: The driving circuit and the light-emitting diode are provided. The driving circuit is used to receive the pulse amplitude modulation signal and to set the brightness of the light-emitting diode according to the pulse amplitude modulation signal.

3. The mobile device according to claim 2, characterized in that, The driving circuit includes a current control unit, which is used to generate a current control signal according to the pulse amplitude modulation signal and drive the light-emitting diode according to the voltage value of the current control signal.

4. The mobile device according to claim 3, characterized in that, The current control unit includes: First transistor and second transistor; wherein: The source of the first transistor is used to receive the pulse amplitude modulation signal. The gate of the second transistor is used to receive the first pulse signal. The first transistor is used to generate the current control signal based on the pulse amplitude modulation signal and the first pulse signal; The voltage value of the current control signal is the difference between the gate voltage of the first transistor and the voltage of the pulse amplitude modulation signal.

5. The mobile device according to claim 4, characterized in that, The drain of the first transistor is connected to the source of the second transistor, and the drain of the second transistor is connected to the gate of the first transistor.

6. The mobile device according to claim 3, characterized in that, The driving circuit also includes: The comparator unit is used to generate a signal with a constant voltage value; The drive circuit unit is used to control the light-emitting diode to turn on and off according to the constant voltage value signal and the second pulse signal.

7. The mobile device according to claim 6, characterized in that, The drive circuit unit includes a third transistor and a fourth transistor, wherein: The third transistor is used to receive the signal of the constant voltage value, and the signal of the constant voltage value is a first level signal; The fourth transistor is used to receive the second pulse signal. When the second pulse signal is at the first level, the driving circuit unit controls the light-emitting diode to turn on; When the second pulse signal is at the second level, the driving circuit unit controls the light-emitting diode to turn off.

8. The mobile device according to claim 7, characterized in that, The source of the fourth transistor is connected to the drain of the first transistor in the current control unit. The drain of the fourth transistor is connected to the light-emitting diode.

9. The mobile device according to any one of claims 2-8, characterized in that, The display driver controller includes a grayscale setting module and a current setting module, wherein: The grayscale setting module is used to generate a grayscale setting signal, which is used to set the initial voltage value of the light-emitting diode. The current setting module is used to generate the pulse amplitude modulation signal.

10. The mobile device according to claim 1, characterized in that, The display screen includes a driving circuit and a light-emitting diode. The driving circuit is used to receive the pulse width modulation signal and to set the brightness of the light-emitting diode according to the pulse width modulation signal.

11. The mobile device according to any one of claims 6-8, characterized in that, The comparator unit is also used to receive the pulse width modulation signal and to set the brightness of the light-emitting diode according to the pulse width modulation signal.

12. The mobile device according to claim 11, characterized in that, The comparator unit is specifically used to generate a comparison signal based on the pulse width modulation signal, and to set the LED to be turned on or off based on the voltage value of the comparison signal.

13. The mobile device according to claim 12, characterized in that, The comparator unit includes a fifth transistor and a sixth transistor, wherein: The fifth transistor is used to receive the third pulse signal; The sixth transistor is used to receive the pulse width modulation signal and the grayscale setting signal, and to generate the comparison signal based on the pulse width modulation signal, the grayscale setting signal and the third pulse signal; The voltage value of the comparison signal is the difference between the voltage value of the pulse width modulation signal and the voltage value of the grayscale setting signal.

14. The mobile device according to claim 12, characterized in that, The drive circuit unit includes a third transistor and a fourth transistor, wherein: The third transistor is used to receive the comparison signal. The fourth transistor is used to receive the second pulse signal. When both the second pulse signal and the comparison signal are at the first level, the driving circuit unit controls the light-emitting diode to turn on; When at least one of the second pulse signal and the comparison signal is at the second level, the driving circuit unit controls the light-emitting diode to turn off.

15. The mobile device according to any one of claims 2-8, 10, and 12-14, characterized in that, The display driver controller includes: The pulse width modulation module is used to generate pulse width modulation signals. A grayscale setting module is used to generate a grayscale setting signal, which is used to set the initial voltage value of the light-emitting diode. A current setting module is used to generate a constant current control signal, which is used to drive the light-emitting diode.

16. The mobile device according to claim 9, characterized in that, The display driver controller also includes: The pulse width modulation module is used to generate pulse width modulation signals. The current setting module is also used to generate a constant current control signal, which is used to control the light-emitting diode.

17. A driving method, characterized in that, Applied to a mobile device, the mobile device including a display screen, a processor, and a display driver controller; the method includes: The processor generates a level control signal based on the status information. The level control signal is used to indicate whether the mobile device is in screen-on mode or idle mode. The display driver controller generates a data signal to control the brightness of the display screen based on the level control signal; When the mobile device is in the screen-on mode, the data signal is a pulse width modulation signal; When the mobile device is in the idle mode, the data signal is a pulse amplitude modulation signal.

18. The driving method according to claim 17, characterized in that, The driving circuit of the display screen receives the pulse amplitude modulation signal and sets the brightness of the light-emitting diodes in the display screen according to the pulse amplitude modulation signal.

19. The driving method according to claim 18, characterized in that, The current control unit of the driving circuit generates a current control signal according to the pulse amplitude modulation signal, and drives the light-emitting diode according to the voltage value of the current control signal.

20. The driving method according to claim 19, characterized in that, The current control unit receives a first pulse signal; The current control unit includes a first transistor, which generates the current control signal based on the pulse amplitude modulation signal and the first pulse signal. The voltage value of the current control signal is the difference between the gate voltage of the first transistor and the voltage of the pulse amplitude modulation signal.

21. The driving method according to claim 18, characterized in that, The comparator unit of the driving circuit generates a signal with a constant voltage value; The drive circuit unit of the drive circuit controls the light-emitting diode to turn on and off according to the constant voltage signal and the second pulse signal.

22. The driving method according to claim 21, characterized in that, The drive circuit unit receives the signal of the constant voltage value. The signal with the constant voltage value is a first-level signal; The drive circuit unit receives the second pulse signal. When the second pulse signal is at the first level, the driving circuit unit controls the light-emitting diode to turn on; When the second pulse signal is at the second level, the driving circuit unit controls the light-emitting diode to turn off.

23. The driving method according to any one of claims 18-22, characterized in that, The display driver controller generates a grayscale setting signal, which is used to set the initial voltage value of the light-emitting diode; The display driver controller generates a pulse amplitude modulation signal.

24. The driving method according to claim 17, characterized in that, The driving circuit of the display screen receives the pulse width modulation signal and sets the brightness of the light-emitting diodes of the display screen according to the pulse width modulation signal.

25. The driving method according to claim 21, characterized in that, The comparator unit of the driving circuit also receives the pulse width modulation signal and sets the brightness of the light-emitting diode according to the pulse width modulation signal.

26. The driving method according to claim 25, characterized in that, The comparator unit of the driving circuit generates a comparison signal based on the pulse width modulation signal, and sets the LED to be turned on or off based on the voltage value of the comparison signal.

27. The driving method according to claim 26, characterized in that, The comparator unit receives the third pulse signal; The comparator unit receives the pulse width modulation signal and the grayscale setting signal. The comparator unit generates the comparison signal based on the pulse width modulation signal, the grayscale setting signal, and the third pulse signal. The voltage value of the comparison signal is the difference between the voltage value of the pulse width modulation signal and the voltage value of the grayscale setting signal.

28. The driving method according to claim 27, characterized in that, When both the second pulse signal and the comparison signal are at the first level, the driving circuit unit controls the light-emitting diode to turn on; When at least one of the second pulse signal and the comparison signal is at the second level, the driving circuit unit controls the light-emitting diode to turn off.

29. The driving method according to any one of claims 18-22 and 24-28, characterized in that, The display driver controller generates a pulse width modulation signal; The display driver controller generates a grayscale setting signal, which is used to set the initial voltage value of the light-emitting diode; The display driver controller generates a constant current control signal, which is used to drive the light-emitting diode.

30. The driving method according to claim 23, characterized in that, The display driver controller also generates a pulse width modulation signal. The display driver controller also generates a constant current control signal, which is used to control the light-emitting diode.

31. A display module, characterized in that, The display module includes: Pixel unit, the pixel unit including a light-emitting diode; The display driver controller is used to receive a level control signal and generate a data signal to control the brightness of the light-emitting diode according to the level control signal, wherein the level control signal is used to indicate that the display module is in a bright screen mode or an idle mode; A driving circuit is provided, which receives the data signal and sends a control signal to the light-emitting diode according to the data signal. If the control signal indicates the screen-on mode, the data signal is a pulse width modulation signal. If the data signal indicates the idle mode, the data signal is a pulse amplitude modulation signal.

32. The display module according to claim 31, characterized in that, The driving circuit is used to receive the pulse amplitude modulation signal and to set the brightness of the light-emitting diode according to the pulse amplitude modulation signal.

33. The display module according to claim 32, characterized in that, The driving circuit includes a current control unit, which is used to generate a current control signal according to the pulse amplitude modulation signal and drive the light-emitting diode according to the voltage value of the current control signal.

34. The display module according to claim 32 or 33, characterized in that, The driving circuit also includes a comparator for generating a signal with a constant voltage value; The drive circuit unit is used to control the light-emitting diode to turn on and off according to the constant voltage value signal and the second pulse signal.

35. The display module according to claim 31, characterized in that, The driving circuit is used to receive the pulse width modulation signal and to set the brightness of the light-emitting diode according to the pulse width modulation signal.

36. The display module according to claim 35, characterized in that, The driving circuit includes a comparator for generating a comparison signal based on the pulse width modulation signal, and setting the LED to be turned on or off based on the voltage value of the comparison signal.

37. The display module according to claim 34, characterized in that, The comparator is also used to generate a comparison signal based on the pulse width modulation signal, and to set the LED to be turned on or off based on the voltage value of the comparison signal.

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