CN106713903A - Method and system for detecting screen brightness uniformity - Google Patents

Abstract

The invention relates to a method and a system for detecting screen brightness uniformity, which are used for acquiring a screen image of a pure-color picture displayed on a screen of electronic equipment, dividing the screen image into a plurality of first sub-regions, calculating the brightness difference ratio of each first sub-region, and acquiring the screen brightness uniformity according to the brightness difference ratio of each first sub-region. The process can be controlled and finished through a computer, manual operation is not needed, automatic detection is achieved, detection time is in the second level, detection efficiency is high, all batches of electronic equipment on a production line can be detected, and the overall quality of screen brightness uniformity of all batches of electronic products is guaranteed.

Description

Method and system for detecting screen brightness uniformity

technical field

The invention relates to the technical field of screen parameter detection, in particular to a method and system for detecting screen brightness uniformity.

Background technique

For an electronic device with a display screen, various indicators of the screen need to be tested before the electronic device is used, including the detection of the brightness uniformity of the screen. Taking a TV as an example, before using the TV, it is necessary to detect the brightness uniformity of its screen.

In the traditional technology, a color analyzer is used to test the brightness uniformity of the screen of an electronic device. During the test, the color analyzer needs to be connected to the electronic device, and the test process takes a long time. Taking the test of a TV in a factory as an example, most factories use the following Test the brightness uniformity of the TV screen by means of: select a part of TVs on the production line, and connect the color analyzer to the TV before testing a TV, and multiple connections are required to detect multiple TVs. The operation is cumbersome, and the detection process using a color analyzer takes a long time.

It can be seen that the traditional detection method using a color analyzer leads to low detection efficiency of the brightness uniformity of the screen of an electronic device.

Contents of the invention

Based on this, it is necessary to provide a detection method and system for screen brightness uniformity to solve the problem that the detection efficiency of electronic device screen brightness uniformity is low due to the traditional detection method using a color analyzer.

A method for detecting the brightness uniformity of a screen, comprising the following steps:

Obtain a screen image displaying a solid color picture on the screen of the electronic device;

dividing the screen image into several first sub-regions, and determining the brightness compensation coefficient of each first sub-region according to the preset brightness compensation coefficient of the screen image;

Acquiring the solid-color grayscale value of each first sub-region, and calculating the solid-color grayscale compensation value of each first sub-region according to the brightness compensation coefficient and the pure-color grayscale value of each first sub-region;

Calculate the brightness difference ratio of each first sub-area according to the pure color gray scale compensation value of each first sub-area;

The brightness uniformity of the screen is obtained according to the brightness difference ratios of the first sub-regions.

A detection system for screen brightness uniformity, comprising the following units:

An image acquisition unit, configured to acquire a screen image displaying a solid-color image on the screen of the electronic device;

A coefficient determination unit, configured to divide the screen image into several first sub-regions, and determine the brightness compensation coefficient of each first sub-region according to the preset brightness compensation coefficient of the screen image;

The compensation calculation unit is used to obtain the solid-color grayscale value of each first sub-area, and calculate the solid-color grayscale compensation value of each first sub-area according to the brightness compensation coefficient and the pure-color grayscale value of each first sub-area;

A ratio calculation unit, configured to calculate the brightness difference ratio of each first sub-area according to the solid-color grayscale compensation value of each first sub-area;

The uniformity acquisition unit is configured to acquire the brightness uniformity of the screen according to the brightness difference ratio of each first sub-region.

According to the method and system for detecting the brightness uniformity of the above screen, it is to obtain the screen image of the solid color picture displayed on the screen of the electronic device, and divide the screen image into several first sub-regions, and calculate the brightness difference ratio of each first sub-region , obtaining the brightness uniformity of the screen according to the brightness difference ratio of each first sub-region. This process can be controlled by a computer, without manual operation, to realize automatic detection, the detection time is at the second level, and the detection efficiency is high.

Description of drawings

Fig. 1 is a schematic flow chart of a detection method for screen brightness uniformity in one of the embodiments;

Fig. 2 is a schematic structural diagram of a detection system for screen brightness uniformity in one of the embodiments;

Fig. 3 is a schematic structural diagram of a detection system for screen brightness uniformity in one of the embodiments;

Fig. 4 is a schematic structural diagram of a detection system for screen brightness uniformity in one of the embodiments;

Fig. 5 is a schematic structural diagram of a detection system for screen brightness uniformity in one of the embodiments;

Fig. 6 is a schematic diagram of the device connection of the method for detecting the brightness uniformity of the TV screen in one of the specific embodiments;

Fig. 7 is an actual device diagram of a method for detecting brightness uniformity of a television screen in one of the specific embodiments;

Fig. 8 is a schematic flowchart of a method for detecting brightness uniformity of a television screen in one specific embodiment.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, and do not limit the protection scope of the present invention.

Referring to FIG. 1 , it is a schematic flowchart of a method for detecting brightness uniformity of a screen according to the present invention. The detection method of screen brightness uniformity in this embodiment, comprises the following steps:

Step S101: Acquiring a screen image displaying a solid-color image on the screen of the electronic device;

In this step, the solid-color picture displayed on the screen refers to a picture with only a single color, and the color can be selected according to needs;

Optionally, in order to facilitate the comparison of brightness, you can choose a pure white screen;

Step S102: Divide the screen image into several first sub-regions, and determine the brightness compensation coefficient of each first sub-region according to the preset brightness compensation coefficient of the screen image;

In this step, the preset brightness compensation coefficients of different regions of the screen image are different, and according to the distribution of the preset brightness compensation coefficients of the screen image in different regions, the brightness compensation coefficients of each first sub-region can be determined;

Step S103: Obtain the solid-color grayscale value of each first sub-region, and calculate the solid-color grayscale compensation value of each first sub-region according to the brightness compensation coefficient and the pure-color grayscale value of each first sub-region;

In this step, each sub-region has a corresponding solid-color gray value and a brightness compensation coefficient, and the pure-color gray-scale compensation value after the brightness compensation coefficient is used to compensate the pure-color gray value is the final pure-color gray value;

Step S104: Calculate the brightness difference ratio of each first sub-area according to the solid-color grayscale compensation value of each first sub-area;

In this step, each sub-region has a corresponding brightness difference ratio;

Step S105: Acquiring screen brightness uniformity according to the brightness difference ratio of each first sub-region.

In this embodiment, the screen image of the solid-color picture displayed on the screen of the electronic device is obtained, and the screen image is divided into several first sub-regions, and the brightness difference ratio of each first sub-region is calculated, and according to the The brightness difference ratio obtains the brightness uniformity of the screen. This process can be controlled by a computer, without manual operation, to realize automatic detection, the detection time is at the second level, and the detection efficiency is high.

Optionally, before obtaining a screen image displaying a solid-color image on the screen of the electronic device, the electronic device may be controlled by a remote control device to display a solid-color image, so that the electronic device displays a solid-color image only before obtaining the screen image, saving energy consumption;

Optionally, the screen display of the electronic equipment can be adjusted through the infrared emitting device. The infrared emitting device belongs to the remote control device and does not need to be connected with the electronic equipment, which simplifies the preparation steps before the detection. The remote control device can also be a wireless remote control device such as a Bluetooth remote control device or a WIFI remote control device.

In one of the embodiments, the step of obtaining the solid color gray value of each first sub-region includes the following steps:

Acquiring the solid color gray value of each pixel in each first sub-area;

The step of calculating the solid-color gray-scale compensation value of each first sub-area according to the brightness compensation coefficient and the pure-color gray-scale value of each first sub-area includes the following steps:

When calculating the pure-color grayscale compensation value of any first subregion, the product values of the solid-color grayscale values of each pixel in the first subregion and the brightness compensation coefficient of the first subregion are respectively calculated to obtain each product value The average value of is used as the pure color gray compensation value of the first sub-region.

In this embodiment, when acquiring the solid-color grayscale value of the first sub-region, the solid-color grayscale value of each pixel is obtained. When calculating the pure-color grayscale compensation value of the first sub-region, the first sub-region is calculated The product value of the pure-color gray value of each pixel in a sub-region and the brightness compensation coefficient of the first sub-region, and then calculate the average value of each product value, and use the average value as the pure-color gray-scale compensation of the first sub-region value, because in any sub-area, the solid-color gray value of each pixel may be different, so the pure-color gray-scale compensation value of each pixel is calculated first, and then the average value can reflect the sub-area to the maximum extent. Solid grayscale.

In one of the embodiments, after the step of obtaining the solid-color gray value of each pixel in each first sub-region, the following steps are further included:

For any first sub-area, sort the pixels in the first sub-area according to the size of the pure color gray value, filter out the preset number of pixels from the maximum pure color gray value, and filter out the preset number of pixels from the minimum pure color gray value Start to filter out the preset number of pixels;

The step of calculating the product value of the pure color gray value of each pixel point of the first sub-region and the brightness compensation coefficient of the first sub-region includes the following steps:

Calculate the product value of the pure color gray value of each filtered pixel in the first sub-area and the brightness compensation coefficient of the first sub-area respectively.

In this embodiment, since a certain amount of noise points will be generated when the screen image is acquired, these noise points will affect the detection of brightness uniformity, and noise filtering processing is required. Compared with the pure color gray value of other effective pixels, the pure color gray value of noise The gray value is high or low, so as long as all the pixels in the first sub-area are sorted according to the pure color gray value, the pixels corresponding to the preset number of larger pure color gray values and the preset number of pixels are filtered out. The pixels corresponding to the smaller pure color gray value can eliminate the influence of noise.

Optionally, the preset number can be freely set according to the amount of generated noise points, and generally can be set to 1/200 of the total pixels of the sub-region.

In one of the embodiments, the step of calculating the brightness difference ratio of each first sub-area according to the solid-color gray scale compensation value of each first sub-area includes the following steps:

Selecting the maximum compensation value from the pure-color grayscale compensation values of each first sub-region, calculating the relative deviation between the pure-color gray-scale compensation value of each first sub-region and the maximum compensation value as the brightness difference ratio of each first sub-region.

In this embodiment, the luminance difference ratio of any first sub-region is the relative deviation between the solid-color grayscale compensation value of the first sub-region and the maximum compensation value in all first sub-regions, because the difference between each sub-region The pure-color grayscale compensation value can be very close, and the relative deviation between the pure-color grayscale compensation value of the first subregion and the maximum compensation value in all first subregions can be better reflected as the brightness difference ratio of the first subregion. The difference in brightness of the various sub-regions.

The calculation process of the relative deviation between the pure-color grayscale compensation value of the first subregion and the maximum compensation value in all first subregions is as follows: first calculate the difference between the maximum compensation value and the pure-color grayscale compensation value of the first subregion , the ratio of the difference to the maximum compensation value is the relative deviation.

In one of the embodiments, the step of acquiring a screen image of a solid-color picture displayed on the screen of the electronic device includes the following steps:

The screen of the electronic device is photographed to obtain a photographed image, the region where the solid-color picture is located is located in the photographed image, and the image of the region is intercepted as a screen image.

In this embodiment, the screen image is obtained by shooting, which can avoid the connection operation with the electronic device and simplify the detection steps; since the solid-color picture may not just occupy the entire captured image during shooting, images other than the solid-color picture in the captured image The area is meaningless to the detection of the brightness uniformity of the screen, so it is necessary to locate the area where the solid-color picture is located in the captured image.

In one of the embodiments, the detection method of screen brightness uniformity further includes the following steps:

Obtain a standard solid-color picture, shoot the standard solid-color picture, and obtain a reference image;

Divide the reference image into several second sub-regions, and obtain the solid color gray value of each second sub-region;

For any second sub-region, the ratio of the solid-color gray value of the second sub-region to the maximum pure-color gray value in all second sub-regions is used as the preset brightness compensation coefficient of the second sub-region; wherein, the reference image The preset brightness compensation coefficients of all the second sub-regions are applicable to all captured images.

In this embodiment, since the device used for shooting has vignetting, the periphery of the captured image will be slightly darker than the middle, so before testing the brightness uniformity of the screen, the preset brightness compensation coefficient of the shooting picture can be adjusted. set up. The solid-color gray value everywhere on the standard solid-color picture is the same. By shooting the standard solid-color picture, the obtained reference image is divided into several second sub-regions, and the solid-color gray value of any second sub-region The ratio of the maximum pure color gray value in all second sub-regions is used as the preset brightness compensation coefficient of the second sub-region, and the preset brightness compensation coefficient is applicable to all captured images; when testing the uniformity of screen brightness, Using the preset brightness compensation coefficient can eliminate the influence of the vignetting angle of the shooting device itself, so that the detection of the brightness uniformity of the screen is more accurate.

In one of the embodiments, the step of acquiring a screen image of a solid-color picture displayed on the screen of the electronic device includes the following steps:

When the brightness of the screen of the electronic device is maximum, a screen image displaying a solid color image on the screen of the electronic device is obtained.

In this embodiment, when the brightness of the screen is the maximum, the screen image of the solid-color picture displayed on the screen of the electronic device is obtained, and the accuracy of the brightness uniformity test is higher when the screen brightness is the maximum;

Optionally, the brightness of the screen of the electronic device can be adjusted through the infrared emitting device. The infrared emitting device belongs to a remote control device and does not need to be connected with the electronic device, which simplifies the preparation steps before detection.

In one embodiment, the luminance uniformity includes a maximum value and a variance value of luminance difference ratios of all first sub-regions.

In this embodiment, the maximum value and variance value of the brightness difference ratios of all the first sub-regions can be used to characterize the brightness uniformity, and the maximum value and variance value can be easily obtained according to the brightness difference ratio values of the first sub-regions. The brightness uniformity can be obtained very conveniently.

In one of the embodiments, the detection method of screen brightness uniformity further includes the following steps:

If the maximum value is less than or equal to the maximum value threshold, and the variance value is less than or equal to the variance value threshold, it is determined that the screen brightness uniformity test is passed.

In this embodiment, when the maximum value and variance value are less than or equal to the corresponding threshold value, it can be determined that the screen brightness uniformity test has passed, and the maximum value and variance value are compared with the threshold value to quickly determine the screen brightness of the electronic device Whether the uniformity meets the requirements.

In one of the embodiments, the detection method of screen brightness uniformity further includes the following steps:

If the maximum value is greater than the maximum value threshold, or the variance value is greater than the variance value threshold, it is determined that the brightness uniformity of the screen is abnormal, and an alarm is issued through the indicator light.

In this embodiment, when the maximum value is greater than the corresponding threshold value or the variance value is greater than the corresponding threshold value, it can be determined that the brightness uniformity of the screen is abnormal, and an alarm will be issued through the indicator light to prompt the staff to check the electronic equipment with abnormal detection results. deal with.

In one embodiment, the electronic device is an electronic device in a light shielding device.

In this embodiment, since the screen of the electronic device is self-illuminating, the external light source will have a certain influence on its screen display, so the electronic device can be placed in the light-shielding device, and then the screen image of the electronic device can be obtained to eliminate the influence of the external light source and improve The accuracy of screen brightness uniformity detection.

In one embodiment, the sizes of the first sub-regions are the same, and the sizes of the second sub-regions are the same.

In this embodiment, the sizes of the first sub-regions are the same, which is convenient for uniform calculation of the solid color gray value and the brightness difference ratio of each first sub-region, and the sizes of the second sub-regions are the same, which is convenient for uniformly distributing the preset brightness compensation coefficients , with better comparability among the second subregions.

Optionally, in order to determine the brightness compensation coefficients of the first sub-regions according to the preset distribution of brightness compensation coefficients of the image to be tested, the number of the first sub-regions may be an integer multiple of the second sub-regions.

According to the method for detecting the uniformity of screen brightness, the present invention also provides a detection system for uniformity of screen brightness. The embodiments of the detection system for screen brightness uniformity of the present invention will be described in detail below.

Referring to FIG. 2 , it is a schematic structural diagram of a detection system for screen brightness uniformity of the present invention. The detection system of the screen brightness uniformity in this embodiment comprises the following units:

An image acquiring unit 210, configured to acquire a screen image displaying a solid-color picture on the screen of the electronic device;

A coefficient determining unit 220, configured to divide the screen image into several first sub-regions, and determine the brightness compensation coefficient of each first sub-region according to the preset brightness compensation coefficient of the screen image;

The compensation calculation unit 230 is configured to obtain the solid-color grayscale value of each first sub-region, and calculate the solid-color grayscale compensation value of each first sub-region according to the brightness compensation coefficient and the pure-color grayscale value of each first sub-region;

A ratio calculation unit 240, configured to calculate the brightness difference ratio of each first sub-area according to the solid-color grayscale compensation value of each first sub-area;

The uniformity acquiring unit 250 is configured to acquire the brightness uniformity of the screen according to the brightness difference ratio of each first sub-region.

In one of the embodiments, the compensation calculation unit 230 obtains the gray value of each solid color of each pixel in each first sub-area;

Compensation calculation unit 230 calculates the product value of the pure color gray value of each pixel in the first sub-area and the brightness compensation coefficient of the first sub-area respectively when calculating the solid-color gray scale compensation value of any first sub-area, The average value of each product value is obtained as the pure color gray compensation value of the first sub-region.

In one of the embodiments, as shown in FIG. 3 , the detection system of screen brightness uniformity further includes a filtering unit 260, and the filtering unit 260 is used for any first sub-region, according to the size of the pure color gray value. The pixels in a sub-area are sorted, and the preset number of pixels are filtered out from the maximum pure color gray value, and the preset number of pixels are filtered out from the minimum pure color gray value;

The compensation calculation unit 230 is used to calculate the product value of the gray value of each pixel in the first sub-area after filtering and the brightness compensation coefficient of the first sub-area.

In one of the embodiments, the ratio calculation unit 240 selects the maximum compensation value from the solid-color grayscale compensation values of each first subregion, and calculates the relative deviation between the solid-color grayscale compensation value of each first subregion and the maximum compensation value as The brightness difference ratio of each first sub-region.

In one embodiment, the image acquisition unit 210 captures the screen of the electronic device to obtain a captured image, locates the area where the solid-color picture is located in the captured image, and captures the image of the area as the screen image.

In one of the embodiments, as shown in FIG. 4 , the detection system of screen brightness uniformity further includes a preset unit 270, configured to acquire a standard solid-color picture, shoot the standard solid-color picture, and obtain a reference image; divide the reference image into For several second sub-regions, obtain the solid-color gray value of each second sub-region; The ratio of is used as the preset brightness compensation coefficient of the second sub-area; wherein, the preset brightness compensation coefficients of all second sub-areas of the reference image are applicable to all captured images.

In one embodiment, the image acquiring unit 210 acquires a screen image of a solid-color picture displayed on the screen of the electronic device when the brightness of the screen of the electronic device is maximum.

In one embodiment, the luminance uniformity includes a maximum value and a variance value of luminance difference ratios of all first sub-regions.

In one of the embodiments, as shown in FIG. 5 , the detection system of screen brightness uniformity further includes a judging unit 280, configured to judge when the maximum value is less than or equal to the maximum value threshold and the variance value is less than or equal to the variance value threshold. Screen brightness uniformity test passed.

In one embodiment, the electronic device is an electronic device in a light shielding device.

The detection system of the screen brightness uniformity of the present invention corresponds to the detection method of the screen brightness uniformity of the present invention one by one, and the technical features and beneficial effects described in the above-mentioned embodiment of the detection method of the screen brightness uniformity are applicable to the screen brightness Example of a detection system for uniformity.

The above method and system for detecting the uniformity of screen brightness can be applied to electronic equipment such as television sets and computers.

Taking TVs as an example, the TV production line needs to conduct tests after assembling the TVs, which includes judging whether the brightness uniformity of the screen is normal or not.

The specific device connection of the detection method of screen brightness uniformity is shown in Figure 6. When the TV to be tested enters the detection station of screen brightness uniformity, the devices that operate in sequence are as follows: computer (built-in AOI program), infrared emitting device, industrial Cameras, alarm lights.

AOI (Automatic Optic Inspection) is a necessary part of the industrial production process. It uses optical methods to obtain the surface state of products, and uses image processing to detect abnormalities or surface defects.

The real picture of the shading device is shown in Figure 7:

The alarm indicator light is placed outside the shading device and is used to display the test results of the TV.

The infrared emitting device can be placed outside or inside the shading device according to the time when the TV sets the brightness and switches the pure white screen. When the infrared emitting device sends infrared commands to the TV, the TV is still flowing on the production line, improving Operating efficiency; if the time for the TV to set the brightness and switch the pure white screen is very short, the infrared emitting device can be placed in the shading device; otherwise, the infrared emitting device can be placed in the corresponding position on the production line outside the shading device.

When the TV reaches the screen brightness uniformity testing station, the brightness has just been adjusted and switched to a pure white screen. Since the TV is in a static state during the test, all other equipment is placed in the shading device.

On the right of the shading device is a defective product discharge device.

The connection method of each component: A. The computer and the industrial camera are connected through a network cable for control and transmission of photo data, and the two communicate bidirectionally; B. The computer and the infrared transmitter are connected through a serial port, and a specific serial port protocol is used to control the infrared transmitter to emit corresponding signals. Infrared waveform, two-way communication between the two; C. The computer and the alarm indicator light are connected through a serial port, and the alarm indicator light is controlled through a specific serial port protocol, and the two two-way communication; D. The infrared emitting device remotely controls the TV by emitting infrared waveforms, and the two are single One-way communication; E. The camera obtains the TV screen by taking pictures, and the two communicate one-way.

The process flow of the method is shown in FIG. 8 . The detection work of the screen brightness uniformity detection station is fully automatic and does not require judgment by workers.

Step 1. Preparation before testing

In this method, the original detection method of manually using a color analyzer is changed to a method of automatically detecting images of a TV set obtained by a camera. Since the screen of the TV is self-illuminating, external light sources will affect the screen (for example, light up), so the entire test process is tested in a shading device. Place A. computer at the corresponding position (inside or outside) of the shading device: used to control the infrared emitting device, control the industrial camera, and run the AOI program; B. infrared emitting device: used to remotely control the TV to adjust to the maximum brightness and display pure white Screen; C. Industrial camera: used to collect TV screen; D. Alarm indicator light: used to notify workers to deal with defective products.

Since the camera lens itself has vignetting (the four corners of the captured photo will be darker than the middle), before starting the inspection, it is necessary to correct the brightness compensation coefficient of the vignetting of the industrial camera lens. The calibration process is as follows:

Obtain a standard solid-color picture, shoot the standard solid-color picture, and obtain a reference image;

Divide the reference image into several second sub-regions, and obtain the solid color gray value of each second sub-region;

For any second sub-region, the ratio of the solid-color gray value of the second sub-region to the maximum pure-color gray value in all second sub-regions is used as the preset brightness compensation coefficient of the second sub-region; wherein, all the second sub-regions The preset brightness compensation coefficients of the second sub-area are applicable to all captured images.

In practical applications, if there is no standard solid-color picture, the screen picture of the TV can also be used directly. The specific method is as follows: Divide the picture taken by the camera into M×N equal parts (for example, 5×5=25 equal parts, from left to right) , numbered from top to bottom, the upper left corner is area 1, the middle is area 13, ...), set the brightness of the TV to the maximum and display a pure white screen, let the camera take M×N photos respectively, in which the TV is The middle areas are located in M×N different areas, and the white gray value of the middle area of the TV in the M×N photos is calculated, so as to determine the brightness coefficient of the camera in these M×N areas, such as the middle area of the TV The white grayscale value in area 1 is 209, and the white grayscale value in area 13 in the middle of the TV set is the maximum value of 250, then the brightness compensation coefficient of area 13 is 250÷250=1, the brightness compensation coefficient of area 1 It is 250÷209=1.1962,....

Step 2. The TV arrives at the screen brightness uniformity detection station

After the preparations before the test are done, the test can be started. When the TV reaches the screen brightness uniformity test station, the computer (built-in AOI program) can remotely set the TV brightness to the maximum through the infrared emitting device and display a pure white screen. The computer controls the industrial The camera takes pictures of the TV, and the industrial camera sends the pictures back to the computer for AOI program processing.

Step 3. Locate the TV screen and divide the TV

The AOI program calculates the coordinates of the four corners on the side of the TV screen through the classic corner point algorithm on the captured photos, and these four corner points can locate the TV screen. The AOI program divides the TV screen into I×J equal parts according to the coordinates of the four corners, for example, 10×10=100 equal parts. In extreme cases, you can directly treat each pixel as an area without dividing the area. However, since industrial cameras will generate a certain amount of noise after taking pictures, according to the way each pixel is treated as an area, these noises will affect the judgment result.

Step 4. Calculate the mean value of the white gray value compensation value of each area of the TV screen in combination with the brightness compensation coefficient of the camera lens

After the TV screen is divided into I×J equal parts, each area is numbered (such as 1, 2, 3, represented by q), and after numbering, the calculation process is performed separately, and the processing method is as follows:

Calculate the white gray value of all points, filter out the part of the noise with the highest white gray value and the part of the noise with the lowest white gray value (the ratio can be set freely according to the number of noise points captured by the camera, and the number of noise points in the area can be set by default The ratio to all pixels in the area is 1/200)

Determine the lens area to which each normal point belongs after filtering out the noise, determine the brightness compensation coefficient of each normal point, and set the brightness compensation coefficient to B

Calculate the white gray value compensation value of each normal point: white gray value compensation value X _i =white gray value W _i ×brightness compensation coefficient B (wherein i is the subscript of the pixel point)

Calculating the mean value of the final white gray value compensation value in this area: Suppose: the number of normal points is m, then the mean value of the white gray value compensation value is W _q =∑X _i ÷m, i is an integer from 1 to m.

Step 5. Determine whether the brightness uniformity test of the TV screen passes

According to step 4, calculate the mean value of the white gray value compensation value for each area, and obtain I×J W values, which are respectively W ₁ , W ₂ . . . W _I×J . Take the largest W value and set it as W _max , and calculate the brightness difference ratio of each region: P _q =(W _max -W _q )÷W _max , where q is an integer from 1 to I×J.

The conditions for judging whether the screen brightness uniformity detection passes through the brightness difference ratio of each area are as follows. If the following two conditions are met at the same time, it will be judged as passed, otherwise, it will be judged as failed.

Condition 1: Compare P _q , find out P _Max , compare P _max with the preset P' _max (maximum difference ratio allowable value), if P _max >P' _max , it is determined that the screen brightness uniformity detection is abnormal, and vice versa , then judge condition 2;

Condition 2: Calculate the variance S ₂ of all P _q values, compare S ₂ with the preset S' ₂ (maximum variance allowable value), if S ₂ >S' ₂ , it is determined that the screen brightness uniformity test fails, and vice versa , then it is determined that the screen brightness uniformity test has passed.

Step 6, pass the test/fail the test

During the inspection process, if there are TVs that fail the inspection items, the computer controls the alarm indicator light to alarm and inform the production line PLC (programmable logic device), the production line will discharge the TVs from the defective product discharge device, and the workers will paste Label the "defective product" and remove the TV from the defective product discharge device; if the brightness uniformity test of the TV screen passes, the computer will notify the production line PLC of the test status, and the production line will control the flow of the TV to the next work bit for testing other testing items.

In the automatic TV production line, the assembly and testing of the TV are all on the same production line, and each process on the production line must be completed within a certain period of time, otherwise the workers need to press the stop button, and the entire production line Wait for an operation to complete before proceeding. This production line requires a relatively high level of overall layout and automation procedures to minimize human operations and avoid possible unstable factors.

After the TV is assembled from the assembly station, it is necessary to test the uniformity of the screen brightness of the TV (previously, due to the long testing time, it did not meet the production rhythm of the production line, so the testing items can only be put into OQC (Outgoing Quality Control/shipping) Quality control) sampling link, the device automatically detects the uniformity of screen brightness of the TV. After the test of brightness uniformity of the screen passes, the TV enters the next detection link and finally enters the packing station. After the TV is packed, it enters the If the screen brightness uniformity test fails, the alarm at the station on the production line will sound, and the production line will discharge the TV from the discharge device, and the workers will put the defective product label on the TV and move the TV Walk.

The traditional technical solution adopts the method of manual detection, the detection efficiency is low, and the detection effect may not meet the requirements; while the technical solution of the present invention adopts the method of automatic detection, and the detection efficiency is high (generally, only a detection time within 1 second is required. ).

In addition, the traditional technical solution adopts OQC random inspection method to test the brightness uniformity of TV screens, which can only randomly detect a certain proportion (such as 5%) of TVs in the whole batch of TVs. For the whole batch of TVs, there are The possibility of missed inspection cannot guarantee the overall quality of batch product shipments; and the technical solution of the present invention adopts the method of automatic detection, which greatly shortens the detection time, so this detection item can be placed on the assembly line for all Assembled TVs can be tested for screen brightness uniformity, and the missed detection rate is reduced, ensuring the overall quality of screen brightness uniformity of all batches of electronic products.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. a kind of detection method of the screen intensity uniformity, it is characterised in that comprise the following steps：

The screen picture of pure color picture is shown on the screen for obtaining electronic equipment；

The screen picture is divided into several the first subregions, the predetermined luminance penalty coefficient according to the screen picture is true The luminance compensation coefficient of fixed each first subregion；

The pure color gray value of each first subregion is obtained, according to the luminance compensation coefficient and pure color of each first subregion Gray value calculates the pure color grey level compensation value of each first subregion respectively；

Pure color grey level compensation value according to each first subregion calculates the luminance difference ratio of each first subregion respectively；

Luminance difference ratio according to each first subregion obtains the screen intensity uniformity.

2. the detection method of the screen intensity uniformity according to claim 1, it is characterised in that the acquisition each described The step of pure color gray value of one subregion, comprises the following steps：

Obtain the pure color gray value of each pixel in each first subregion；

The luminance compensation coefficient and pure color gray value according to each first subregion calculates each first sub-district respectively The step of pure color grey level compensation value in domain, comprises the following steps：

When the pure color grey level compensation value of any one the first subregion is calculated, each pixel of first subregion is calculated respectively The pure color gray value of point and the product value of the luminance compensation coefficient of first subregion, obtain the average value conduct of each product value The pure color grey level compensation value of first subregion.

3. the detection method of the screen intensity uniformity according to claim 2, it is characterised in that obtaining each described first In subregion the step of the pure color gray value of each pixel after it is further comprising the steps of：

For any one the first subregion, the pixel in first subregion is arranged according to pure color gray value size Sequence, filters the pixel of predetermined number since full colour gray value, is filtered since minimum pure color gray value described default The pixel of number；

The pure color gray value of each pixel for calculating first subregion respectively and the luminance compensation of first subregion The step of product value of coefficient, comprises the following steps：

The pure color gray value of each pixel after filtering in first subregion and the brightness of first subregion are calculated respectively The product value of penalty coefficient.

4. the detection method of the screen intensity uniformity according to claim 1, it is characterised in that described according to each described The step of pure color grey level compensation value of one subregion calculates the luminance difference ratio of each first subregion respectively includes following step Suddenly：

Maximum offset is chosen from the pure color grey level compensation value of each first subregion, each first sub-district is calculated respectively The relative deviation of the pure color grey level compensation value in domain and the maximum offset as each first subregion luminance difference ratio.

5. the detection method of the screen intensity uniformity according to claim 1, it is characterised in that the acquisition electronic equipment Screen on comprise the following steps the step of show the screen picture of pure color picture：

Screen to the electronic equipment shoots, and obtains shooting image, the pure color is positioned in the shooting image and is drawn Region where face, intercepts the image in the region as the screen picture.

6. the detection method of the screen intensity uniformity according to claim 5, it is characterised in that further comprising the steps of：

Acquisition standard pure color picture, shoots to the standard pure color picture, obtains reference picture；

Reference picture is divided into several the second subregions, the pure color gray value of each second subregion is obtained；

It is maximum pure in the pure color gray value of second subregion and all second subregions for any one the second subregion The ratio of color shade value as second subregion predetermined luminance penalty coefficient；Wherein, all the second of the reference picture The predetermined luminance penalty coefficient of subregion is applied to the image of all shootings.

7. the detection method of the screen intensity uniformity according to claim 1, it is characterised in that the acquisition electronic equipment Screen on comprise the following steps the step of show the screen picture of pure color picture：

When the screen intensity of electronic equipment is maximum, the screen picture of pure color picture is shown on the screen for obtaining electronic equipment.

8. the detection method of the screen intensity uniformity according to claim 1, it is characterised in that the luminance uniformity bag Include the maximum and variance yields of the luminance difference ratio of all first subregions；

The detection method is further comprising the steps of：

If the maximum is less than or equal to maximum threshold, and the variance yields is less than or equal to variance yields threshold value, then judge screen Luminance uniformity detection passes through.

9. the detection method of the screen intensity uniformity as claimed in any of claims 1 to 8, it is characterised in that institute It is the electronic equipment in shade to state electronic equipment.

10. a kind of detecting system of the screen intensity uniformity, it is characterised in that including with lower unit：

Image acquisition unit, the screen picture for showing pure color picture on the screen for obtaining electronic equipment；

Factor determination unit, for the screen picture to be divided into several the first subregions, according to the screen picture Predetermined luminance penalty coefficient determines the luminance compensation coefficient of each first subregion；

Compensation calculation unit, the pure color gray value for obtaining each first subregion, according to each first subregion Luminance compensation coefficient and pure color gray value calculate the pure color grey level compensation value of each first subregion respectively；

Ratio calculation unit, for calculating each first son respectively according to the pure color grey level compensation value of each first subregion The luminance difference ratio in region；

Uniformity acquiring unit is uniform for obtaining the screen intensity according to the luminance difference ratio of each first subregion Degree.