A vehicle-mounted display screen circuit

Abstract

The utility model discloses a vehicle display screen circuit, including main control chip, one end respectively with deserializer, TCON, liquid crystal display unit, the enable switch of backlight drive electricity connection makes, and the other end of enable switch is provided with latch between main control chip, and the input of latch is electrically connected with the GPIO mouth of main control chip, and the output is electrically connected with enable switch, the input of latch receives the high impedance signal of GPIO mouth output of main control chip, and keeps high level output to enable switch at the output, makes enable switch keep closing, thereby can when main control chip carries out software upgrade, control enable switch closing, makes liquid crystal display unit keep display image, promotes the experience of user.

Description

Technical Field

[0001] This utility model relates to the field of vehicle display screens, and in particular to a vehicle display screen circuit. Background Technology

[0002] The in-vehicle display circuit mainly consists of a deserializer, a TCON (timing controller), a main control chip, and a backlight driver. The deserializer receives image data from a host computer (such as a graphics processing unit, camera, etc.), and then the TCON receives the image data from the deserializer and converts the data format into a format that can be displayed on the LCD unit before transmitting it to the LCD unit. The LCD unit then displays the content, and the backlight driver controls the backlight switching and brightness adjustment of the LCD unit. The main control chip enables and controls the deserializer, TCON, LCD unit, and backlight driver. Figure 1 and Figure 2 As shown, in a traditional vehicle display circuit, under normal operating conditions, the GPIO (General Purpose Input / Output) port of the main control chip outputs a high-level signal to control the enable switch to turn off, allowing the LCD unit to display images. However, as... Figure 3 As shown, when the main control chip of the display screen is upgraded, the main control chip needs to restart and enter the Bootloader upgrade mode. During the restart of the main control chip, the GPIO port is in a high impedance state and cannot maintain control of the enable switch. When the enable switch is turned on, the LCD display unit displays a black screen, resulting in a poor user experience. Utility Model Content

[0003] The purpose of this invention is to provide a vehicle display circuit that can control the enable switch to be turned off when the main control chip is upgraded, so as to keep the liquid crystal display unit displaying images, thereby improving the user experience.

[0004] The vehicle display circuit of this utility model includes a main control chip, an enable switch whose one end is electrically connected to a deserializer, a TCON, a liquid crystal display unit, and a backlight driver, and a latch is provided between the other end of the enable switch and the main control chip. The input end of the latch is electrically connected to the GPIO port of the main control chip, and the output end is electrically connected to the enable switch. The input end of the latch receives a high-impedance signal output from the GPIO port of the main control chip, and maintains a high level output at the output end to the enable switch, so that the enable switch remains closed.

[0005] In the vehicle display circuit described in this utility model, when the main control chip is undergoing a software upgrade and restart, the GPIO port of the main control chip outputs a high-impedance signal, while the output of the latch remains at a high level and outputs to the enable switch. The enable switch remains closed, thereby enabling the enable switch to be closed when the main control chip is undergoing a software upgrade, so that the liquid crystal display unit continues to display images, thus improving the user experience.

[0006] As a preferred embodiment of this utility model, the input terminal of the latch receives a low level output from the GPIO port of the main control chip, and outputs a low level to the enable switch at the output terminal to turn on the enable switch.

[0007] In a preferred embodiment of this utility model, the input terminal of the latch receives a high level output from the GPIO port of the main control chip, and outputs a high level to the enable switch at the output terminal to turn the enable switch off.

[0008] As a preferred embodiment of this utility model, the latch is a D latch.

[0009] In a preferred embodiment of this utility model, the D input pin of the D latch is electrically connected to one GPIO port of the main control chip, the E input pin of the D latch is electrically connected to another GPIO port of the main control chip, and the Q output pin of the D latch is electrically connected to the enable switch.

[0010] As a preferred embodiment of this utility model, four enable switches are provided. One end of each enable switch is electrically connected to the deserializer, TCON, LCD display unit, and backlight driver, respectively, and the other end is electrically connected to four corresponding latches. Attached Figure Description

[0011] Figure 1 Background technology: Circuit diagram of a conventional in-vehicle display screen in a non-operating state; Figure 2 Background Technology: Circuit diagram of a conventional vehicle display screen in its working state; Figure 3 Background: Circuit diagram of an in-vehicle display screen during a software upgrade and restart of the main control chip; Figure 4 This is a schematic diagram of the D latch circuit and its truth table; Figure 5 This is a circuit diagram of the vehicle display screen in the non-working state of the present invention; Figure 6 This is a circuit diagram of the vehicle display screen under normal operating conditions. Figure 7 This is a circuit diagram of the vehicle display screen during the software upgrade and restart state of the main control chip of this utility model. Detailed Implementation

[0012] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0013] A vehicle-mounted display circuit, such as Figure 7 As shown, the device includes a main control chip, an enable switch connected at one end to a deserializer, a TCON, a liquid crystal display unit, and a backlight driver, and a latch between the other end of the enable switch and the main control chip. The input of the latch is electrically connected to the GPIO port of the main control chip, and the output is electrically connected to the enable switch. The input of the latch receives a high-impedance signal output from the GPIO port of the main control chip, and maintains a high level output at the output to the enable switch, thereby keeping the enable switch closed.

[0014] The latch used is a D latch. The D input pin of the D latch is electrically connected to one GPIO port of the main control chip, the E input pin is electrically connected to another GPIO port of the main control chip, and the Q output pin is electrically connected to the enable switch. The D latch circuit and truth table are as follows: Figure 4 As shown.

[0015] When the vehicle display screen is not working, such as Figure 5 As shown, when the GPIO port of the main control chip outputs a low level, the D input pin and E input pin of the D latch are 0, the output Q pin remains 0, the enable switch is turned on, and the LCD display unit displays no image.

[0016] When the vehicle display screen is working normally, such as Figure 6 As shown, the main control chip's GPIO port outputs a high level, the D input pin and E input pin of the D latch are 1, the output Q pin is 1, the enable switch is off, and the LCD display unit displays an image.

[0017] If the main control chip is in the process of software upgrade and restart, such as Figure 7 As shown, the GPIO port output of the main control chip is a high-impedance signal, the D input pin and E input pin of the D latch are 0, and the output Q pin remains 1, keeping the enable switch closed. This allows the enable switch to be closed when the main control chip is undergoing software upgrades, ensuring that the LCD display unit continues to display images and improving the user experience.

[0018] There are four enable switches. One end of each enable switch is electrically connected to the deserializer, TCON, LCD display unit, and backlight driver, respectively, and the other end is electrically connected to the four corresponding latches.

[0019] The system consists of four latches and four enable switches. The D and E input pins of the first latch are electrically connected to the GPIO port of the main control chip. The Q output pin of the first latch is electrically connected to one end of the first enable switch, and the other end of the first enable switch is electrically connected to a deserializer. The deserializer receives image data from the host computer (such as a graphics processing unit, camera, etc.), and then the TCON receives the image data from the deserializer and converts the data format to a format suitable for display on the LCD unit before transmitting it to the LCD unit for display. The D and E input pins of the second latch are electrically connected to the GPIO port of the main control chip. The Q output pin of the second latch is electrically connected to one end of the second enable switch, and the other end of the second enable switch is electrically connected to the TCON. The D and E input pins of the third latch are electrically connected to the GPIO port of the main control chip. The Q output pin of the third latch is electrically connected to one end of the third enable switch, and the other end of the third enable switch is electrically connected to the LCD unit. The D and E input pins of the fourth latch are electrically connected to the GPIO port of the main control chip. The Q output pin of the fourth latch is electrically connected to one end of the fourth enable switch. The other end of the fourth enable switch is electrically connected to the backlight driver to adjust the brightness of the liquid crystal display unit.

[0020] The above embodiments are only used to illustrate the detailed solution of this utility model. This utility model is not limited to the above detailed solution, that is, it does not mean that this utility model must rely on the above detailed solution to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions of the raw materials of this utility model product, addition of auxiliary components, selection of specific methods, etc., are all within the protection scope and disclosure scope of this utility model.

Claims

1. A vehicle-mounted display circuit, comprising a main control chip, wherein one end of which is electrically connected to a deserializer, a TCON, a liquid crystal display unit, and a backlight driver, characterized in that, A latch is provided between the other end of the enable switch and the main control chip. The input end of the latch is electrically connected to the GPIO port of the main control chip, and the output end is electrically connected to the enable switch. The input end of the latch receives the high-impedance signal output by the GPIO port of the main control chip, and maintains a high level output at the output end to the enable switch, so that the enable switch remains closed.

2. The vehicle-mounted display circuit according to claim 1, characterized in that, The input terminal of the latch receives a low level output from the GPIO port of the main control chip, and outputs a low level to the enable switch to turn on.

3. The vehicle-mounted display circuit according to claim 1, characterized in that, The input terminal of the latch receives a high level output from the GPIO port of the main control chip, and outputs a high level to the enable switch to turn it off.

4. The vehicle-mounted display circuit according to claim 1, characterized in that, The latch is a D latch.

5. The vehicle-mounted display circuit according to claim 4, characterized in that, The D input pin of the D latch is electrically connected to one GPIO port of the main control chip, the E input pin of the D latch is electrically connected to another GPIO port of the main control chip, and the Q output pin of the D latch is electrically connected to the enable switch.

6. The vehicle-mounted display circuit according to any one of claims 1-5, characterized in that, There are four enable switches. One end of each enable switch is electrically connected to the deserializer, TCON, LCD display unit, and backlight driver, respectively, and the other end is electrically connected to the four corresponding latches.

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