CN109062532B

CN109062532B - LCD black screen processing circuit, method, device and computer readable storage medium

Info

Publication number: CN109062532B
Application number: CN201810676952.3A
Authority: CN
Inventors: 蒋权
Original assignee: Nubia Technology Co Ltd
Current assignee: Nubia Technology Co Ltd
Priority date: 2018-06-27
Filing date: 2018-06-27
Publication date: 2021-07-20
Anticipated expiration: 2038-06-27
Also published as: CN109062532A

Abstract

The invention discloses a LCD black screen processing circuit, a method, a device and a computer readable storage medium; the circuit comprises a CPU, an LCD display connector, a first power supply manager, a second power supply manager, a diode, a capacitor, a resistor and a common mode inductor; the LCD display connector comprises an MIPI module and a WLED backlight module; the second power manager comprises a backlight driving module; the method comprises the steps of monitoring the signal level of a GPIO n pin of a CPU in real time, and judging that an LCD is black when the signal level is low voltage; when the current black screen is abnormal, the power-off operation is executed on the LCD, and after the power-off operation is finished, the power-on operation is executed again; and after the electrification is finished, the LCD resumes displaying. The circuit of the invention has simple structure, low cost and easy realization; the method is simple to implement, does not need manual operation in the whole process, has high processing speed and improves user experience.

Description

LCD black screen processing circuit, method, device and computer readable storage medium

Technical Field

The present invention relates to the field of screen Display of mobile terminals, and in particular, to a black screen processing circuit, method, apparatus, and computer readable storage medium for an LCD (Liquid Crystal Display).

Background

A mobile terminal, or a mobile communication terminal, refers to a computer device that can be used in mobile, and broadly includes a mobile phone, a notebook, a tablet computer, a point of sale (POS) machine, and even a vehicle-mounted computer. But most often refer to cell phones or smart phones and tablets with multiple application functions. With the development of network technology, the mobile communication industry will move to the real mobile information age. On the other hand, with the rapid development of integrated circuit technology, the processing capability of the mobile terminal has already possessed strong processing capability, and the mobile terminal is changing from a simple conversation tool to an integrated information processing platform. This also adds more development space to mobile terminals.

The mobile terminal, especially the intelligent mobile terminal, has following characteristics.

(1) In a hardware system, a mobile terminal includes a central processing unit, a memory, an input unit, an output unit, and a display screen, that is, the mobile terminal is often a microcomputer device having a communication function. In addition, the mobile terminal may have various input means such as a keyboard, a mouse, a touch screen, a microphone, a camera, etc., and may adjust input as needed. Meanwhile, the mobile terminal often has multiple output modes, such as a receiver and a display screen, and can be adjusted according to needs.

(2) In a software system, the Mobile terminal must have an operating system, such as Windows Mobile, Symbian, Palm, Android, iOS, and the like. Meanwhile, these operating systems are increasingly open, and there are many personalized application software developed based on these open operating system platforms, such as a communication book, a calendar, a notepad, a calculator, various games, and the like, which greatly meet the requirements of personalized users.

(3) In terms of communication capacity, the mobile terminal has flexible access mode and high-bandwidth communication performance, and can automatically adjust the selected communication mode according to the selected service and the environment, thereby being convenient for users to use. The Mobile terminal may support GSM (Global System for Mobile Communication), WCDMA (Wideband Code Division Multiple Access), CDMA2000(Code Division Multiple Access), TDSCDMA (Time Division-Synchronous Code Division Multiple Access), Wi-Fi (WIreless-Fidelity), WiMAX (world Interoperability for Microwave Access), etc., thereby adapting to various types of networks, and supporting not only voice services but also various WIreless data services.

(4) In the aspect of function use, the mobile terminal focuses more on humanization, individuation and multi-functionalization. With the development of computer technology, the mobile terminal enters a human-centered mode from an equipment-centered mode, integrates embedded computing, control technology, artificial intelligence technology, biological recognition technology and the like, and fully embodies the human-oriented purpose.

However, images are always the most intuitive expression mode, the development of mobile terminals cannot depart from the development of display screens, and the LCD is the expression medium which is most applied at present. With the enhancement of technology, the requirements of human beings on vision are continuously increased, and the requirements on the resolution and the color of an image are also increased more and more. At present, mobile terminals basically use LCDs, and LCD large-screen mobile terminals also continuously enter our visual field; currently, there are two types of LCDs used in mobile terminals, one is an OLED (Organic Light-Emitting Diode) LCD, and the other is a TFT (thin film transistor) LCD. Since the OLED LCD has a self-luminous characteristic, and does not need to provide an additional light source, it uses a very Thin organic material coating and a glass substrate, when a current flows, these organic materials emit light, thousands of light emitting diodes capable of emitting light of three colors of red, green, and blue are mounted on the substrate of the screen in a specific arrangement, these light emitting bodies emit light of red, green, or blue when a voltage is applied, the voltage conversion needs to be driven by a Thin Film Transistor (TFT), and after the ratio of three primary colors is adjusted, various colors can be emitted, which has the advantages of low driving voltage, long service life of the light emitting component, and high brightness mode, but compared with the LCD screen, it has high cost and more complicated manufacturing process, and is difficult to control in cost; the TFT LCD cannot emit light, if the TFT LCD is to display data or images, a backlight source needs to be added, the white light backlight source in the mobile terminal generally consists of a plurality of side-emitting white LED lamps, the number of the LED lamps is determined by the size of the screen, generally 10 to 16 white light lamps are adopted, the white light passes through the light guide plate and the reflector plate, and the light passes through the liquid crystal to emit light with different colors, the brightness of the screen depends on the brightness of the white LED lamps, and the backlight of the LCD screen on the market generally reaches the brightness of 400nits at most. As a general display device, the LCD device has compact structure and simple driving device; in practical application, the brightness of the LCD is often difficult to read due to the change of ambient light, especially the STN type LCD cannot be read when the temperature difference between the indoor and outdoor in the north is large, so the display brightness of the LCD needs to be constantly adjusted; in addition, as the resolution/size increases, the backlight driving circuit of the LCD becomes more complicated; the LCD with high resolution, high display color and large size requires a large backlight system, a large TFT-LCD panel, and a driving IC with high operation speed, which all cause high power consumption, thereby causing a problem of continuous flight of the mobile terminal.

In the TFT LCD display technology, in order to reduce the power consumption of the backlight LED, a cabac (Content Adaptive Brightness Control) technology is introduced, that is, the backlight Brightness is adjusted according to the Content of the image. Namely, a content analyzer circuit is added in the TFT LCD driver IC. Suppose that when the mobile terminal processor transmits a picture data to the TFT LCD driver IC, the content analyzer calculates and counts the picture data, and then automatically increases the gray scale brightness by 30% (when the picture becomes bright) and decreases the backlight brightness by 30% (when the picture becomes dark) according to the setting and algorithm. Because we have already compensated the luminance through the circuit of the content analyzer in advance with the picture, so users can get the display effect that is comparable to the original circuit, but reduce the power consumption of the backlight by 30%; that is, CABC achieves power saving by increasing the content gray scale level while decreasing the backlight brightness.

The power consumption problem is improved, but the display problem still exists, in the existing TFT LCD display scheme, when a user causes a black screen of the LCD due to an ESD (Electro-Static discharge) problem during the use process, the user needs to manually press a power key twice to restore normal display, or the ESD check function is integrated in a software form, but the function needs to be normally opened to take effect, and the normally opened function occupies the module resource of the LCD MIPI (Mobile Industry Processor Interface), thereby causing the phenomena of LCD display blocking and the like.

Disclosure of Invention

The invention aims to provide an LCD black screen processing circuit, a method, a device and a computer readable storage medium; the problem that manual recovery is needed when the LCD is in a black screen in the prior art is solved.

The invention discloses an LCD black screen processing circuit, which is applied to a mobile terminal and comprises a CPU, an LCD display connector, a first power supply manager and a second power supply manager, wherein the LCD display connector comprises an MIPI module and a WLED backlight module; the second power manager comprises a backlight driving module; the circuit further comprises a diode, a capacitor, a resistor and a common mode inductor;

the anode of the diode is connected with a CABC pin of the LCD display connector, and the cathode of the diode is connected with one end of the capacitor, one end of the resistor and a GPIO n pin of the CPU;

the other ends of the capacitor and the resistor are grounded;

the CPU is connected with the LCD MIPI module through the common-mode inductor;

the sink1-sink4 input ends of the WLED backlight module are correspondingly connected with the sink1-sink4 output ends of the backlight driving module;

the CABC pin of the LCD display connector is simultaneously connected with the CABC pin of the backlight driving module;

the VSP pin of the LCD display connector is connected with the VDISP _ P _ OUT pin of the second power management module;

the VSM pin of the LCD display connector is connected with the VDISP _ M _ OUT pin of the second power management module;

an IO pin of the LCD display connector is connected with an LDO pin of the first power manager;

the RST pin of the LCD display connector is connected with the GPIO-6 pin of the CPU;

and the TE pin of the LCD display connector is connected with the GPIO-10 pin of the CPU.

Preferably, the diode is a low-voltage drop diode, and the forward voltage drop is less than or equal to 0.3V.

Preferably, the capacitance performance simultaneously satisfies the following condition:

when the LCD normally displays, the voltage on the LCD is more than or equal to half of the GPIO n pin high-level voltage of the CPU;

when the LCD is abnormally black, the voltage on the LCD is reduced to be below 0.2V within a preset time.

Preferably, the resistance properties simultaneously satisfy the following conditions:

when the LCD displays normally, the voltage on the capacitor is more than or equal to half of the GPIO n pin high-level voltage of the CPU;

and when the LCD is abnormally shielded, the voltage on the capacitor is reduced to be below 0.2V within a preset time.

Preferably, the preset time is 2 s.

The invention also discloses an LCD black screen processing method based on the LCD black screen processing circuit, which comprises the following steps:

monitoring the signal level of a GPIO n pin of a CPU in real time, and judging that an LCD is black when the signal level is low voltage;

judging whether the current black screen is an abnormal black screen;

if the screen is abnormal black, performing power-off operation on the LCD, and after the power-off operation is finished, performing power-on operation; and after the electrification is finished, the LCD resumes displaying.

Preferably, the method judges whether the current blank screen is an abnormal blank screen or not by the following method:

judging whether the mobile terminal system enters a dormant state or is entering the dormant state; if so, the current black screen is a normal black screen; otherwise, the current blank screen is an abnormal blank screen.

The invention further discloses an LCD black screen processing device based on the black screen processing method, the device comprises a black screen detection module, a judgment module and a control module, wherein the black screen detection module detects the black screen of the LCD, and the judgment module judges whether the black screen of the LCD is black or not according to the black screen detection result

The black screen detection module is used for monitoring the signal level of a GPIO n pin of the CPU in real time and judging that the LCD is black when the signal level is low voltage;

the judging module is used for judging whether the current black screen is an abnormal black screen;

and the abnormal black screen processing module is used for performing power-off operation on the LCD when the LCD is abnormally black, and performing power-on operation after the power-off operation is finished.

Preferably, the judging module judges whether the mobile terminal system enters the dormant state or is entering the dormant state; and judging whether the current black screen is a normal black screen or an abnormal black screen.

The invention also discloses a computer readable storage medium having stored thereon a program or instructions executable by a processor for implementing the steps of the LCD black screen processing method according to claim 6 or 7.

According to the LCD black screen processing circuit, the switching circuit mode is added on the basis of the existing mobile terminal control device, so that the abnormal black screen of the LCD can be quickly found and processed, and the circuit is simple in structure, low in cost and easy to realize; the LCD black screen processing method of the invention is based on the LCD black screen processing circuit of the invention, according to the pin level change, the black screen processing flow is automatically triggered, and then whether the black screen is detected and whether the black screen is abnormal is determined, and the LCD of the abnormal black screen is restored to display by the power-on and power-off mode, so the method is simple to realize, the whole process does not need manual operation, and the processing speed is high because the method is matched with a matched hardware circuit and automatically triggers the black screen processing; by using the mobile terminal provided by the invention, the non-inductive recovery can be achieved under the condition of abnormal black screen, and the user experience is improved.

Drawings

Fig. 1 is a schematic diagram of a hardware structure of an optional mobile terminal for implementing various embodiments of the present invention;

fig. 2 is a diagram of a communication network system architecture according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a preferred embodiment of the LCD black screen processing circuit according to the present invention;

FIG. 4 is a flowchart illustrating a method for processing a blank screen of an LCD according to a preferred embodiment of the present invention;

FIG. 5 is a schematic block diagram of a preferred embodiment of the LCD black screen processing apparatus according to the present invention;

reference numerals:

the implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.

The terminal may be implemented in various forms. For example, the terminal described in the present invention may include a mobile terminal such as a mobile phone, a tablet computer, a notebook computer, a palmtop computer, a Personal Digital Assistant (PDA), a Portable Media Player (PMP), a navigation device, a wearable device, a smart band, a pedometer, and the like, and a fixed terminal such as a Digital TV, a desktop computer, and the like.

The following description will be given by way of example of a mobile terminal, and it will be understood by those skilled in the art that the construction according to the embodiment of the present invention can be applied to a fixed type terminal, in addition to elements particularly used for mobile purposes.

Referring to fig. 1, which is a schematic diagram of a hardware structure of a mobile terminal for implementing various embodiments of the present invention, the mobile terminal 100 may include: RF (Radio Frequency) unit 101, WiFi module 102, audio output unit 103, a/V (audio/video) input unit 104, sensor 105, display unit 106, user input unit 107, interface unit 108, memory 109, processor 110, and power supply 111. Those skilled in the art will appreciate that the mobile terminal architecture shown in fig. 1 is not intended to be limiting of mobile terminals, which may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

The following describes each component of the mobile terminal in detail with reference to fig. 1:

the radio frequency unit 101 may be configured to receive and transmit signals during information transmission and reception or during a call, and specifically, receive downlink information of a base station and then process the downlink information to the processor 110; in addition, the uplink data is transmitted to the base station. Typically, radio frequency unit 101 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency unit 101 can also communicate with a network and other devices through wireless communication. The wireless communication may use any communication standard or protocol, including but not limited to GSM (Global System for Mobile communications), GPRS (General Packet Radio Service), CDMA2000(Code Division Multiple Access 2000), WCDMA (Wideband Code Division Multiple Access), TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), FDD-LTE (Frequency Division duplex Long Term Evolution), and TDD-LTE (Time Division duplex Long Term Evolution).

WiFi belongs to short-distance wireless transmission technology, and the mobile terminal can help a user to receive and send e-mails, browse webpages, access streaming media and the like through the WiFi module 102, and provides wireless broadband internet access for the user. Although fig. 1 shows the WiFi module 102, it is understood that it does not belong to the essential constitution of the mobile terminal, and may be omitted entirely as needed within the scope not changing the essence of the invention.

The audio output unit 103 may convert audio data received by the radio frequency unit 101 or the WiFi module 102 or stored in the memory 109 into an audio signal and output as sound when the mobile terminal 100 is in a call signal reception mode, a call mode, a recording mode, a voice recognition mode, a broadcast reception mode, or the like. Also, the audio output unit 103 may also provide audio output related to a specific function performed by the mobile terminal 100 (e.g., a call signal reception sound, a message reception sound, etc.). The audio output unit 103 may include a speaker, a buzzer, and the like.

The a/V input unit 104 is used to receive audio or video signals. The a/V input Unit 104 may include a Graphics Processing Unit (GPU) 1041 and a microphone 1042, the Graphics processor 1041 Processing image data of still pictures or video obtained by an image capturing device (e.g., a camera) in a video capturing mode or an image capturing mode. The processed image frames may be displayed on the display unit 106. The image frames processed by the graphic processor 1041 may be stored in the memory 109 (or other storage medium) or transmitted via the radio frequency unit 101 or the WiFi module 102. The microphone 1042 may receive sounds (audio data) via the microphone 1042 in a phone call mode, a recording mode, a voice recognition mode, or the like, and may be capable of processing such sounds into audio data. The processed audio (voice) data may be converted into a format output transmittable to a mobile communication base station via the radio frequency unit 101 in case of a phone call mode. The microphone 1042 may implement various types of noise cancellation (or suppression) algorithms to cancel (or suppress) noise or interference generated in the course of receiving and transmitting audio signals.

The mobile terminal 100 also includes at least one sensor 105, such as a light sensor, a motion sensor, and other sensors. Specifically, the light sensor includes an ambient light sensor that can adjust the brightness of the display panel 1061 according to the brightness of ambient light, and a proximity sensor that can turn off the display panel 1061 and/or a backlight when the mobile terminal 100 is moved to the ear. As one of the motion sensors, the accelerometer sensor can detect the magnitude of acceleration in each direction (generally, three axes), can detect the magnitude and direction of gravity when stationary, and can be used for applications of recognizing the posture of a mobile phone (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer and tapping), and the like; as for other sensors such as a fingerprint sensor, a pressure sensor, an iris sensor, a molecular sensor, a gyroscope, a barometer, a hygrometer, a thermometer, and an infrared sensor, which can be configured on the mobile phone, further description is omitted here.

The display unit 106 is used to display information input by a user or information provided to the user. The Display unit 106 may include a Display panel 1061, and the Display panel 1061 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like.

The user input unit 107 may be used to receive input numeric or character information and generate key signal inputs related to user settings and function control of the mobile terminal. Specifically, the user input unit 107 may include a touch panel 1071 and other input devices 1072. The touch panel 1071, also referred to as a touch screen, may collect a touch operation performed by a user on or near the touch panel 1071 (e.g., an operation performed by the user on or near the touch panel 1071 using a finger, a stylus, or any other suitable object or accessory), and drive a corresponding connection device according to a predetermined program. The touch panel 1071 may include two parts of a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts the touch information into touch point coordinates, sends the touch point coordinates to the processor 110, and can receive and execute commands sent by the processor 110. In addition, the touch panel 1071 may be implemented in various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. In addition to the touch panel 1071, the user input unit 107 may include other input devices 1072. In particular, other input devices 1072 may include, but are not limited to, one or more of a physical keyboard, function keys (e.g., volume control keys, switch keys, etc.), a trackball, a mouse, a joystick, and the like, and are not limited to these specific examples.

Further, the touch panel 1071 may cover the display panel 1061, and when the touch panel 1071 detects a touch operation thereon or nearby, the touch panel 1071 transmits the touch operation to the processor 110 to determine the type of the touch event, and then the processor 110 provides a corresponding visual output on the display panel 1061 according to the type of the touch event. Although the touch panel 1071 and the display panel 1061 are shown in fig. 1 as two separate components to implement the input and output functions of the mobile terminal, in some embodiments, the touch panel 1071 and the display panel 1061 may be integrated to implement the input and output functions of the mobile terminal, and is not limited herein.

The interface unit 108 serves as an interface through which at least one external device is connected to the mobile terminal 100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device having an identification module, an audio input/output (I/O) port, a video I/O port, an earphone port, and the like. The interface unit 108 may be used to receive input (e.g., data information, power, etc.) from external devices and transmit the received input to one or more elements within the mobile terminal 100 or may be used to transmit data between the mobile terminal 100 and external devices.

The memory 109 may be used to store software programs as well as various data. The memory 109 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. Further, the memory 109 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

The processor 110 is a control center of the mobile terminal, connects various parts of the entire mobile terminal using various interfaces and lines, and performs various functions of the mobile terminal and processes data by operating or executing software programs and/or modules stored in the memory 109 and calling data stored in the memory 109, thereby performing overall monitoring of the mobile terminal. Processor 110 may include one or more processing units; preferably, the processor 110 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 110.

The mobile terminal 100 may further include a power supply 111 (e.g., a battery) for supplying power to various components, and preferably, the power supply 111 may be logically connected to the processor 110 via a power management system, so as to manage charging, discharging, and power consumption management functions via the power management system.

Although not shown in fig. 1, the mobile terminal 100 may further include a bluetooth module or the like, which is not described in detail herein.

In order to facilitate understanding of the embodiments of the present invention, a communication network system on which the mobile terminal of the present invention is based is described below.

Referring to fig. 2, fig. 2 is an architecture diagram of a communication Network system according to an embodiment of the present invention, where the communication Network system is an LTE system of a universal mobile telecommunications technology, and the LTE system includes a UE (User Equipment) 201, an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) 202, an EPC (Evolved Packet Core) 203, and an IP service 204 of an operator, which are in communication connection in sequence.

Specifically, the UE201 may be the terminal 100 described above, and is not described herein again.

The E-UTRAN202 includes eNodeB2021 and other eNodeBs 2022, among others. Among them, the eNodeB2021 may be connected with other eNodeB2022 through backhaul (e.g., X2 interface), the eNodeB2021 is connected to the EPC203, and the eNodeB2021 may provide the UE201 access to the EPC 203.

The EPC203 may include an MME (Mobility Management Entity) 2031, an HSS (Home Subscriber Server) 2032, other MMEs 2033, an SGW (Serving gateway) 2034, a PGW (PDN gateway) 2035, and a PCRF (Policy and Charging Rules Function) 2036, and the like. The MME2031 is a control node that handles signaling between the UE201 and the EPC203, and provides bearer and connection management. HSS2032 is used to provide registers to manage functions such as home location register (not shown) and holds subscriber specific information about service characteristics, data rates, etc. All user data may be sent through SGW2034, PGW2035 may provide IP address assignment for UE201 and other functions, and PCRF2036 is a policy and charging control policy decision point for traffic data flow and IP bearer resources, which selects and provides available policy and charging control decisions for a policy and charging enforcement function (not shown).

The IP services 204 may include the internet, intranets, IMS (IP Multimedia Subsystem), or other IP services, among others.

Although the LTE system is described as an example, it should be understood by those skilled in the art that the present invention is not limited to the LTE system, but may also be applied to other wireless communication systems, such as GSM, CDMA2000, WCDMA, TD-SCDMA, and future new network systems.

Based on the above mobile terminal hardware structure and communication network system, the present invention provides various embodiments of the method.

As shown in fig. 3, which is a schematic diagram of a preferred embodiment of the LCD black screen processing circuit according to the present invention, the LCD black screen processing circuit according to the present invention includes a CPU10, an LCD display connector 20, a first power manager 30, a second power manager 40, a diode D, a capacitor C, a resistor R, and a common mode inductor F; the LCD display connector 20 comprises a MIPI module 21 and a WLED backlight module 22; the second power manager 40 includes a backlight driving module 41; the connection mode between them is as follows:

the anode of the diode D is connected with the CABC pin of the LCD display connector 20, and the cathode of the diode D is connected with one end of the capacitor C, one end of the resistor R and the GPIO n pin of the CPU 10; the other ends of the capacitor C and the resistor R are grounded; pins of the MIPI module 21 (MIPI _ DSI0_ CLK _ CONN _ P/M, MIPI _ DSI M, MIPI _ LANE M, MIPI _ CONN _ P/M, MIPI _ DSI M, MIPI _ LANE M, MIPI _ CONN _ P/M, MIPI _ DSI M, MIPI _ LANE M, MIPI _ CONN _ P/M, MIPI _ DSI M, MIPI _ LANE M, MIPI _ CONN _ P/M, MIPI _ DSI M, MIPI _ CLK _ CONN _ P/M, MIPI _ DSI M, MIPI _ LANE M, MIPI _ CONN _ P/M, MIPI _ DSI M, MIPI _ LANE M, MIPI _ P/M, MIPI _ DSI M, MIPI _ LAP/M, MIPI _ DSI _ M, MIPI _ CONN _ P/M, MIPI _ LAP/M, MIPI _ DSI _ 36LANE M, MIPI _ 36LANE _ M, MIPI _ DSI _ 36LANE _ M, MIPI _ DSI _ 36LANE _ M, MIPI _ 36LANE _ 36LANP/M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36363672 _ M, MIPI _ 36LANE _ 363636363636363672 _ M, MIPI _ 36363636LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI _ 36LANE _ M, MIPI, MIPI _ DSI1_ LANE2_ P/N, MIPI _ DSI1_ LANE3_ P/N) are connected through the common mode inductor F; the sink1-sink4 pins of the WLED backlight module 22 are correspondingly connected with the sink1-sink4 pins of the backlight driving module 41; the CABC pin of the LCD display connector 20 is simultaneously connected with the CABC pin of the backlight driving module 22; the VSP pin of the LCD display connector 20 is connected with the VDISP _ P _ OUT pin of the second power management module 40; the VSM pin of the LCD display connector 20 is connected to the VDISP _ M _ OUT pin of the second power management module 40; the IO pin of the LCD display connector 20 is connected with the LDO pin of the first power manager 30; the RST pin of the LCD display connector 20 is connected with the GPIO-6 pin of the CPU 10; the TE pin of the LCD display connector 20 is connected with the GPIO _10 pin of the CPU 10.

The LCD black screen processing circuit of the invention has the following performance requirements on components:

the diode D is preferably a low-voltage-drop diode, and the forward voltage drop is less than or equal to 0.3V; the forward voltage drop refers to the forward voltage drop of the diode under the specified forward current, and is the lowest forward voltage at which the diode can be conducted; the low-voltage drop diode is adopted, so that on one hand, the energy consumption is reduced; on the other hand, the switching speed is high, and the processing speed of abnormal black screen is improved.

The value of the capacitor C simultaneously meets the following conditions: when the LCD displays normally, the upper voltage of the LCD is more than or equal to half of the GPIO n pin high level voltage of the CPU; namely: if the high level of GPIO n is 1.8V, the voltage of the capacitor C is more than or equal to 0.9V when the LCD displays normally; when the LCD is abnormally blacked, the voltage on the LCD is reduced to be below 0.2V within a preset time; the preset time can be defined by a user, and the default value is 2 s;

the value of the resistor R simultaneously meets the following conditions: when the LCD displays normally, the voltage on the capacitor C is larger than or equal to half of the GPIO n pin high-level voltage of the CPU; when the LCD is abnormally blacked, the voltage on the capacitor C is reduced to be below 0.2V within a preset time; the preset time can be defined by a user, and the default value is 2 s.

A common-mode inductor F is used for filtering out common-mode signal interference, and is connected in series with a cable between the CPU10 and the MIPI module; thereby suppressing the influence of the electromagnetic wave generated by the signal line on other devices.

The working principle of the LCD black screen processing circuit in this embodiment is as follows: when the LCD displays normally, the CABC pin of the LCD display connector 20 outputs a PWM (Pulse Width Modulation) waveform of 16.67ms according to the content (at this time, the LCD display screen-brushing rate is 60 HZ); when the CABC pin outputs a high level, the diode D is conducted to charge the capacitor C, when the CABC pin outputs a low level, the diode D is cut off, and the capacitor C keeps voltage because of the existence of the charge, so that when the LCD normally displays, the PWM signal is still in the high level after passing through the diode D and the capacitor C which are conducted in a one-way mode; then the signal at GPIO n pin of the CPU10 also remains high at all times; when the LCD is abnormally blacked, the CABC pin output of the LCD display connector 20 changes to low level, the diode D is turned off, the capacitor C holds the voltage due to the existence of the electric charge, but the energy stored in the capacitor C is slowly released through the resistor R as time goes up, and after the release, the signal of the GPIO n pin of the CPU10 also changes to low level. That is, the signal of the GPIO n pin of the CPU10 is high level when the LCD is normally displaying, and the signal of the GPIO n pin of the CPU10 becomes low level when the LCD is abnormally blank.

According to the working principle of the LCD black screen processing circuit shown in fig. 3, the present invention further provides an LCD black screen processing method.

FIG. 4 is a flow chart of a preferred embodiment of the LCD black screen processing method according to the present invention; the embodiment specifically comprises the following steps:

step S101: monitoring the signal level of a GPIO n pin of the CPU10 in real time;

step S102: judging whether the current level is a low level, if so, executing the step S103; otherwise, continuing to execute the step;

voltage of GPIO n pin of CPU 10: when the LCD normally displays, the CABC pin of the LCD display connector 20 is still at a high level after passing through the unidirectional conducting diode D and the capacitor C according to the PWM signal output by the content; the signal of GPIO n pin of the CPU is always kept at high level; when the LCD is abnormally blacked, the CABC pin output of the LCD display connector 20 changes to a low level, at this time, the diode D is cut off, the energy stored in the capacitor C is slowly released through the resistor R as time increases, and a signal of the GPIO n pin of the CPU10 also changes to a low level; the invention utilizes the level change to trigger the mobile terminal to enter the LCD black screen processing flow;

step S103: LCD black screen;

step S104: judging whether the current black screen is abnormal black screen movement or not, and if the current black screen is abnormal black screen movement, executing the step S105; if the screen is normally black, no processing is performed, and the current black screen processing flow is ended;

judging whether the current black screen is an abnormal black screen or not by judging whether the mobile terminal system enters a dormant state or is entering the dormant state; namely: if the system enters a dormant state or is entering the dormant state, the current black screen is a normal black screen; otherwise, the screen is abnormal black.

The system dormancy is related to energy saving, along with the upgrade of hardware and software, the operating system starts to introduce advanced power management, which is used for storing all running real-time data to a storage device when the mobile terminal is idle and turning off all unnecessary hardware power supplies to reduce energy consumption; in addition, since the TFT LCD cannot emit light by itself, it can display data or images because of the backlight function; therefore, the black screen when the mobile terminal enters the sleep mode is caused by the power manager powering down the WLED backlight module 22, and therefore, in this step, it can be determined whether the mobile terminal system enters the sleep mode or is entering the sleep mode by reading the power supply condition of the backlight driving module 41 of the second power manager 40 to the WLED backlight module 22.

Step S105: performing power-off operation on the LCD;

step S106: after the power-off time sequence is finished, performing power-on operation on the LCD; and (5) ending the power-on time sequence, restoring the display of the LCD, and ending the current black screen processing flow.

That is to say, the LCD black screen processing method described in this embodiment is triggered by the GPIO n pin signal of the CPU10 becoming low level, and first determines whether the mobile terminal system enters the sleep state or is entering the sleep state, and after the condition that the normal black screen is not processed is eliminated, it is considered as an abnormal black screen, and then controls the LCD to enter the power-off timing sequence, and when the power-off timing sequence of the LCD is completed, then controls the LCD to enter the power-on timing sequence, and after the power-on timing sequence of the LCD is completed, the LCD can resume normal display.

As shown in fig. 5, which is a schematic block diagram of a preferred embodiment of the LCD black screen processing device according to the present invention, the LCD black screen processing device according to the present embodiment includes a black screen detecting module 11, a determining module 12 and an abnormal black screen processing module 13, wherein the LCD black screen processing device includes a black screen detecting module 11, a determining module 12 and an abnormal black screen processing module 13, and the above-mentioned components are described in the following

The black screen detection module 11 is used for monitoring the GPIO n pin signal level of the CPU in real time and judging that the LCD is black when the signal level is low voltage;

the judging module 12 is used for judging whether the system enters a dormant state or is entering the dormant state when the LCD is in a black screen state; if so, judging that the current black screen is a normal black screen, otherwise, judging that the current black screen is an abnormal black screen;

and the abnormal black screen processing module 13 is configured to perform a power-off operation on the LCD when the LCD is abnormally black, and perform a power-on operation after the power-off operation is finished, so that the LCD resumes displaying.

The present invention further discloses a computer readable storage medium having stored thereon a program or instructions executable by a processor for implementing the steps of the LCD black screen processing method as described in fig. 4.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An LCD black screen processing circuit is applied to a mobile terminal and comprises a CPU, an LCD display connector, a first power supply manager and a second power supply manager, wherein the LCD display connector comprises an MIPI module and a WLED backlight module; the second power manager comprises a backlight driving module; the circuit is characterized by further comprising a diode, a capacitor, a resistor and a common mode inductor;

the other ends of the capacitor and the resistor are grounded;

the CPU is connected with an MIPI module of the LCD display connector through the common-mode inductor;

the VSP pin of the LCD display connector is connected with the VDISP _ P _ OUT pin of the second power manager;

the VSM pin of the LCD display connector is connected with the VDISP _ M _ OUT pin of the second power manager;

2. The LCD black screen processing circuit of claim 1, wherein the diode is a low drop diode and the forward drop is 0.3V or less.

3. The LCD black screen processing circuit of claim 1, wherein the capacitive performance satisfies the following conditions simultaneously:

when the LCD displays normally, the voltage on the capacitor is more than or equal to half of the GPIO n pin high level voltage of the CPU;

and when the LCD is abnormally blacked, the voltage on the capacitor is reduced to be below 0.2V within a preset time.

4. The LCD black screen processing circuit of claim 1, wherein the resistance property simultaneously satisfies the following condition:

5. The LCD black screen processing circuit of claim 3 or 4, wherein the preset time is 2 s.