Display color measurement method, device and terminal equipment

Abstract

The invention discloses a display screen chromaticity measurement method, device and terminal equipment. The measurement method includes: acquiring multi-channel image data of the display screen to be tested captured by an image detector, and the image plane of the image detector is divided into A plurality of identical imaging arrays, each of which has a plurality of spectral response channels with different spectral transmittances, and each spectral response channel corresponds to receiving an incident light signal of a band; from the multi-channel image data Respectively extract and calibrate the response values ​​of multiple spectral response channels in each imaging array to obtain the tristimulus value of each pixel in the display screen to be tested; Obtaining the sample information of multiple spectral response channels of the display screen at the same time is conducive to eliminating the spectral deviation of the display screen caused by the slight difference in the manufacturing process, and improving the measurement accuracy and the robustness of the measurement results.

Description

technical field [0001] The invention belongs to the technical field of machine vision, and more specifically relates to a display chromaticity measurement method, device and terminal equipment, which are suitable for chromaticity measurement of LCD and OLED display screens. Background technique [0002] In the display industry, the chromaticity coordinates of the light emitted by the display screen are very important information. It can not only reflect the intensity and color of the light emitted by the screen simply and intuitively, but also can be used to analyze the color shift phenomenon of the screen body and assist in the screen inspection. Body color cast calibration. Therefore, it is of great significance to realize fast and accurate chromaticity measurement of the entire screen body. [0003] The screens in the display industry are mainly used for viewing by the human eye. The human eye is not a very precise instrument, and can only distinguish the three primary c...

AI Technical Summary

Problems solved by technology

However, to analyze the color shift of the display body, it is necessary to measure the entire surface of the screen body. If a single-point measuring instrument is used to measure points one by one, the measurement efficiency is very low, which cannot meet the needs of assembly line production testing, and the practicability is poor.

[0006] (2) Imaging spectrometers, including line-scan imaging spectrometers and liquid crystal imaging spectrometers; among them, the core components of liquid crystal imaging spectrometers include optical lenses, liquid crystal tunable filters (Liquid Crystal Tunable Filters, LCTF), CCD detectors and control systems , the LCTF is placed between the optical lens and the CCD photosensitive element. Its working principle is: the light reflected by the item to be measured enters the optical lens and is tuned and filtered by the LCTF (tuned by selecting the transmission wavelength through the liquid crystal retarder), and the CCD detector Imaging; in the working state, every time the camera is exposed, the system records the two-dimensional image data of a single wavelength, and the selection of the observation center wavelength is controlled by the computer. The computer determines the next center wavelength and obtains the image data by sending instructions, and so on until Complete the imaging tasks of all wavelengths; although they can also measure the chromaticity of the area array, the line-scan imaging spectrometer uses a line-scanning line-by-line measurement method, and the liquid crystal imaging spectrometer realizes different spectral measurements by changing the liquid crystal film, and the system structure is complex , although the measurement efficiency is slightly higher than that of single-point measuring instruments, it cannot meet the needs of assembly line production testing, and its practicability is poor;

However, this method has extremely high requirements on the manufacturing process of the XYZ filter, and in the actual filter production, the XYZ filter cannot fully comply with the standard CIE1931 XYZ tristimulus value curve

At the same time, the spectral difference in the screen body has a great impact on the measurement accuracy

Figure 5 For the simulation results of chromaticity measurement using the actual XYZ filter, R-Lv in the figure represents the influence of the R spectral shift on the R picture Lv; the abscissa is the spectral shift, and the ordinate is the error amount; from Figure 5 It can be seen from the figure that when considering the spectral shift of the actual screen body, there is still a lot of room for improvement in the measurement accuracy of the XYZ filter; in addition, the XYZ filter + camera method also has the following disadvantages: First, it needs to be taken when taking pictures. Rotate the filter wheel in turn to switch filters for shooting. Using the XYZ filter requires three channel switching to complete the image capture process. If the filter wheel with more channels is used, more channel switching is required to capture the image. The time is long; the second is that for each batch of screens made of different processes, it is necessary to calibrate once with a standard measuring instrument, which is a bit complicated to use

[0008] All in all, the current chromaticity measuring instruments have the defect of not being able to take into account the measurement accuracy and measurement speed, and the practicability is not strong, so it cannot be applied to the screen body test of the display industry

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