Method for diagnosing display connectivity and operability

Abstract

A method of diagnosing connectivity and operational problems between a digital parallel RGB video input device and a digital parallel RGB video display, the method comprising transmitting a control signal from the input device to the display device, executing the control signal on the display device, generating a diagnostic signal and transmitting the diagnostic signal to a diagnostic processor, and determining whether the display is operating properly.

Description

TECHNICAL FIELD

[0001] The methods and systems disclosed herein relate to digital parallel RGB video displays, and more particularly to systems and methods for diagnosing video control and data signal malfunctions. BACKGROUND

[0002] Displays are output devices that display static and dynamic video information, driven by input devices such as computers or embedded systems containing microcontrollers. Certain applications, particularly safety-critical applications, require methods to diagnose display-related problems. These problems can be loss of connection between the display and the input device, or a malfunction of the display, displaying incorrect or incomplete information from the input device.

[0003] Digital parallel RGB interfaces are video display interfaces in which data and control signals are set digitally in a parallel fashion from the input device to the display device (see Figure 1 ). RGB video interfaces contain signals for color data red, green, and blue (RGB DATA), as well as control signals for controlling the operation of the display clock (CLK), horizontal sync (HSYNC), vertical sync (VSYNC), and data enable (DE). These control signals are driven according to the characteristics of the display, particularly the resolution and frame rate of the display. The video signals are transmitted over a physical medium - for example, a cable or cable bundle. SUMMARY

[0004] The disclosed systems and methods transmit diagnostic signals from the RGB video display device to a diagnostic processor to evaluate and correct for faulty connections or operation between the video input device and the video display. For example, the video control and data signals executed by the video display can be returned from the display to the video input device and compared to the original control and data signals to determine if there is a loss of signal. Corrective action can be taken, such as transmitting the diagnostic signals to a different display, or illuminating a warning light. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 is a schematic diagram of an input device and RGB display device in which transmission of video control signals does not generate or return diagnostic signals used to analyze the connectivity and operation of the display.

[0006] Figure 2 is a schematic diagram similar to Figure 1 , in which diagnostic signals are returned from the display device to the video input device to facilitate analysis of the connectivity between the video input device and the display, and to evaluate the operation of the display.

[0007] Figure 3This is a flowchart of a diagnostic method for evaluating the connectivity and operability of a digital RGB video display.

[0008] Figure 4 This is a circuit diagram used to generate diagnostic RGB video signals. Detailed Implementation

[0009] exist Figure 2 This document presents a method for diagnosing the connectivity and operability of a digital parallel RGB video display system 10. Control signals are transmitted from a video input device 12 to a display 14 via signal conductor 16. The method involves adding additional diagnostic signals to the connection between the display 14 and the control input device 12. These diagnostic signals are transmitted from the display to a diagnostic processor 18 via a diagnostic signal conductor 20. The diagnostic signals include returning an RGB video clock signal to the input device, as well as returning a horizontal sync signal, a vertical sync signal, a display enable signal, and one or more RGB color data signals to the input device.

[0010] At the input device, diagnostic signals are connected to a microcontroller, which may or may not be the same microcontroller that drives the display using RGB data and control signals. This microcontroller monitors the diagnostic signals to ensure proper display operation. The checking of CLK, HSYNC, VSYNC, DE, and RGB color data is based on… Figure 3 The flowchart is executed by software on the monitoring microcontroller. Using this method, any errors in the control or data signals can be detected.

[0011] As an example, a loss of control signal can be detected by the loss of the corresponding return signal on the diagnostic line. If the RGB video display clock signal (CLK) is absent (due to a broken or short-circuited cable), the microcontroller monitoring the diagnostic line will detect this loss of signal (incorrect CLK) because the diagnostic clock signal itself simply returns the same clock signal to the input device.

[0012] Video display malfunctions (e.g., incorrect display resolution, incorrect frame rate) can also be detected by the monitoring microcontroller. Clock, horizontal, and vertical sync lines can be measured in software by the monitoring microcontroller to ensure correct timing performance. For example, a display driven with an incorrect horizontal or vertical display resolution will have incorrect horizontal or vertical sync cycles, which the monitoring microcontroller will detect in the diagnostic horizontal or vertical sync signals returned by its measurements. Similarly, the monitoring microcontroller will detect a display driven with an incorrect frame rate due to an incorrect number of video clock signal pulses in a given cycle.

[0013] Furthermore, sending back one or more RGB data lines can also be used for diagnostics to check the display output and verify that the correct video is being displayed. For example, suppose in an automotive application, an image of the vehicle's gear shift position, the letter "P" (representing parking), is displayed on the screen. Assume the "P" is composed of pure white color using 24-bit RGB color data. Each pixel forming the letter "P" would have a binary representation of 11111111111111111111111111b. Assume the background is composed of pure black color using 24-bit RGB color data. Each pixel in the background would have a binary representation of 000000000000000000000000b.

[0014] Suppose that P is displayed on an RGB video display of arbitrary resolution and size, and we call it r. Also assume that P has a size of n pixels, that is, it is composed of n white pixels.

[0015] Because color line data is transmitted back to the display input device via a diagnostic interface, when video frames are output from the input device to the RGB display, the monitoring microcontroller (from...) Figure 2 The system will receive video frame outputs. The monitoring microcontroller will then count the number of times the RGB pixel data lines are "1" for each color in a given video frame. This count must be exactly equal to the number of white pixels in the "P" of the image output to the video display. If the counts differ, it means the displayed information is incorrect or there is a problem with the diagnostic lines themselves.

[0016] For RGB video displays of any resolution (e.g., 16-bit color, 24-bit color, etc.), this method can be employed using any number of color pixel lines (one or more). The count of pixels and pixel values ​​can be used as a checksum to verify that the image displayed on the RGB video display is correct. Alternatively, the pixel data itself can be read into the microcontroller, and the original image can be reconstructed from the returned pixel data, stored in memory, and compared with the original image (see...). Figure 2 ).

[0017] A method for generating diagnostic return signals, such as in Figure 4 As shown in the diagram, video data and control signals are connected to a buffer circuit so that a copy of the signal information can be returned to the input device without affecting the termination impedance of the display signal.

[0018] Other display diagnostic solutions do not offer the same level of diagnostic coverage as this method. One approach involves using a checksum, or CRC, to examine the image stored in memory before sending it to the display. This method does not fully verify whether the image output from the input device actually matches the image stored in memory. Another method for display diagnostics involves monitoring the voltage and current supply to the display device. However, this method cannot diagnose whether the data and control signals sent to the display are correct.

[0019] The above description is intended to be illustrative and not restrictive. The scope of the invention should be determined by referring to the appended claims and all their equivalents. It is anticipated and intended that future developments in the art, as well as the disclosed apparatus, kits, and methods, will be incorporated into such future embodiments. Therefore, the invention is capable of modifications and variations and is limited only to the following claims.

Claims

1. A method for diagnosing the connectivity and operability of a digital RGB video display, the method comprising: Transmit video control and data signals from video input devices to RGB video displays; Control and data signals are executed on the RGB video display; A diagnostic signal is generated at the RGB video display, the diagnostic signal corresponding to each executed control and data signal; The diagnostic signal is transmitted to the diagnostic processor; The diagnostic processor is used to determine whether each of the diagnostic signals indicates a correctly executed control or data signal. as well as When a diagnostic signal indicates that the RGB video display has not received or has not correctly executed the corresponding video control or data signal, corrective measures shall be taken. The video control and data signals include: red, green, and blue data signals; a clock control signal; a horizontal synchronization control signal; a vertical synchronization control signal; and a data enable control signal. One or more RGB data lines are used as diagnostic signals to check the display output, and The diagnostic processor counts the number of "1"s in the binary data lines of the received diagnostic data signal and determines whether the count is exactly equal to the number of "1"s in the corresponding binary data lines of the data signal sent to the display.

2. The method according to claim 1, wherein, The loss of control signals leads to the loss of corresponding diagnostic signals.

3. The method according to claim 1, wherein, The diagnostic clock signal is the same as the clock signal.

4. The method according to claim 1, wherein, Pixel data from the video display is read into the diagnostic processor to generate a return data image, which is then compared with the original image stored in the video input device.

5. The method according to claim 1, wherein, The video control signal is connected to a buffer circuit to facilitate the generation of diagnostic signals and the transmission of the diagnostic signals to the diagnostic processor without affecting the termination impedance of the display signal.

6. The method according to claim 1, wherein, The diagnostic processor and the video input device are the same device.

7. The method according to claim 1, wherein, The diagnostic processor and the video input device are separate devices.

8. An RGB video display system with connectivity and operational diagnostic capabilities, wherein the RGB... The video display system includes: A video input device configured to transmit RGB video control and data signals; An RGB video display, the RGB video display being adapted to receive and execute video control and data signals; A signal conductor for transmitting video control signals from the video input device to the video display; Diagnostic processor; A signal conductor for transmitting diagnostic signals from the RGB video display to the diagnostic processor; The diagnostic processor is configured to determine whether each of the diagnostic signals indicates that video control or data signals are being executed correctly. The video control and data signals include: red, green, and blue data signals; a clock control signal; a horizontal synchronization control signal; a vertical synchronization control signal; and a data enable control signal. One or more RGB data lines are used as diagnostic signals to check the display output, and The diagnostic processor counts the number of "1"s in the binary data lines of the diagnostic received signal and determines whether the count is exactly equal to the number of "1"s in the corresponding binary data lines of the data signal sent to the display.

9. The system according to claim 8, wherein, The loss of control signals will lead to the loss of corresponding diagnostic signals.

10. The system according to claim 8, wherein, The diagnostic clock signal is the same as the clock signal.

11. The system according to claim 8, wherein, Pixel data from the video display is read into the diagnostic processor to generate a return data image, which is then compared with the original image stored in the video input device.

12. The system according to claim 8, wherein, The video control signal is connected to a buffer circuit to facilitate the generation of diagnostic signals and the transmission of the diagnostic signals to the diagnostic processor without affecting the termination impedance of the display signal.

13. The system according to claim 8, wherein, The diagnostic processor and the video input device are the same device.

14. The system according to claim 8, wherein, The diagnostic processor and the video input device are separate devices.

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