CN106054418B

CN106054418B - LCD detection method and detection device

Info

Publication number: CN106054418B
Application number: CN201610544177.7A
Authority: CN
Inventors: 杜长运; 倪漫利; 邹少林
Original assignee: Zhejiang Huamao Photoelectric Technology Co ltd
Current assignee: Zhejiang Huamao Photoelectric Technology Co ltd
Priority date: 2016-07-11
Filing date: 2016-07-11
Publication date: 2020-05-15
Anticipated expiration: 2036-07-11
Also published as: CN106054418A

Abstract

The invention discloses a detection method and a detection device of an LCD (liquid crystal display). by utilizing the principle that the LCD cannot display pictures or display wrong pictures when an applied MIPI (mobile industry processor interface) signal is high in frequency, a display defect is converted into a picture with a bright line, and the bright line is the edge of a qualified picture displayed by the LCD when the MIPI signal with a preset frequency is applied; during detection, if the LCD displays a qualified picture below the bright line, the LCD is judged to be qualified; if the LCD does not display qualified pictures below the bright lines, the LCD is judged to be unqualified, and the frequency corresponding to the bright lines is adjustable, so that the detection effect of the display defects of the LCD can be improved, and the development of high resolution of the LCD is facilitated.

Description

LCD detection method and detection device

Technical Field

The embodiment of the invention relates to the technical field of Liquid crystal display, in particular to a detection method and a detection device of an LCD (Liquid crystal display).

Background

With the rapid development of the mobile display industry, more and more electronic products use the LCD as a human-computer interaction window, so that the electronic products are more intelligent and humanized. Along with this, the quality of LCD products is also more and more required. In the production process of the LCD, the LCD may have display defects due to the influence of factors such as process and environment. Currently, the general detection method in the industry is to drive the LCD to display a specific test picture, and check whether there are defects such as a screen defect, a noise defect, and a dark spot on the specific test picture. For example, whether there is a bright spot in a solid black picture, whether there is a dark green spot in a solid green picture, and the like are checked. However, with the continuous improvement of the resolution of the LCD, the traditional detection method has a poor detection effect on the tiny defects, and cannot meet the requirement of the modern mass production on the high resolution of the LCD.

Disclosure of Invention

In view of this, the present invention provides a method and an apparatus for detecting an LCD, which can improve the detection effect of the LCD display defect and facilitate the development of the LCD with high resolution.

The LCD detection method of one embodiment of the invention comprises the following steps: marking a bright line on an LCD to be detected in advance, wherein the bright line is the edge of a qualified picture displayed by the LCD when an MIPI signal with preset frequency is applied to the LCD; dividing an LCD into a plurality of regions arranged along a preset direction and applying MIPI signals respectively, wherein the frequency of the MIPI signals applied to each region along the preset direction is less than that of the MIPI signals applied to the next region, and applying the MIPI signals with rated frequency to the first region, wherein the rated frequency is the frequency of the MIPI signals to be applied to achieve the resolution of the LCD, and the rated frequency is less than the preset frequency; and detecting whether the LCD is qualified or not according to the picture displayed by the LCD below the bright line.

Alternatively, the preset direction includes a direction perpendicular to a scan line on direction of the LCD.

Optionally, the difference between the frequencies of the MIPI signals applied to any two adjacent regions is equal.

Optionally, each region includes a plurality of rows of pixels, and the number of rows of pixels included in each region is the same.

Optionally, the step of detecting whether the LCD is qualified according to the picture displayed by the LCD below the bright line includes: judging whether the LCD below the bright line displays a qualified picture or not; if the LCD displays qualified pictures below the bright lines, the LCD is judged to be qualified; and if the LCD does not display qualified pictures below the bright lines, judging that the LCD is unqualified.

The LCD detection device of an embodiment of the invention comprises: the identification module is used for identifying a bright line on the LCD to be detected in advance, wherein the bright line is the edge of a qualified picture displayed by the LCD when an MIPI signal with preset frequency is applied to the LCD; the driving module is used for dividing the LCD into a plurality of areas which are arranged along a preset direction and applying MIPI signals respectively, wherein the frequency of the MIPI signals applied to each area along the preset direction is smaller than that of the MIPI signals applied to the next area, the MIPI signals with rated frequency are applied to the first area, the rated frequency is the frequency of the MIPI signals to be applied to achieve the resolution of the LCD, and the rated frequency is smaller than the preset frequency; and the detection module is used for detecting whether the LCD is qualified or not according to the picture displayed by the LCD below the bright line.

Optionally, the detection module judges whether the LCD displays a qualified picture below the bright line; if the LCD displays qualified pictures below the bright lines, the LCD is judged to be qualified; and if the LCD does not display qualified pictures below the bright lines, judging that the LCD is unqualified.

Has the advantages that: the embodiment of the invention converts the display defect into a picture with a bright line by using the principle that the LCD cannot display the picture or display an error picture (namely display a unqualified picture) when the applied MIPI signal is high frequency, wherein the bright line is the edge of the qualified picture displayed by the LCD when the MIPI signal with the preset frequency is applied; during detection, if the LCD displays a qualified picture below the bright line, the LCD is judged to be qualified; if the LCD does not display qualified pictures below the bright lines, the LCD is judged to be unqualified, and the frequency corresponding to the bright lines is adjustable, so that the detection effect of the display defects of the LCD can be improved, and the development of high resolution of the LCD is facilitated.

Drawings

FIG. 1 is a schematic flow chart of an embodiment of a method for inspecting an LCD according to the present invention;

FIG. 2 is a schematic diagram of a picture with bright lines formed based on the method shown in FIG. 1;

FIG. 3 is a schematic block diagram of an LCD inspection apparatus according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a hardware structure of the detecting apparatus of the LCD shown in fig. 3.

Detailed Description

The technical solutions of the exemplary embodiments provided in the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. The various embodiments described below and the features of the embodiments can be combined with each other without conflict.

Please refer to fig. 1, which illustrates an LCD inspection method according to an embodiment of the present invention. The method for detecting the LCD may include the following steps S11 and S14.

S11: a bright line is marked on an LCD to be detected in advance, and the bright line is the edge of a qualified picture displayed by the LCD when an MIPI (Mobile Industry Processor Interface) signal with preset frequency is applied to the LCD.

The preset frequency can be regarded as the frequency of an MIPI signal applied when an LCD (liquid crystal display) established by a manufacturer displays a picture without defects, namely, the preset frequency can be regarded as a qualified judgment standard established by the manufacturer, and in the detection process, if the picture displayed by the LCD does not have defects when the MIPI signal which is lower than or equal to the preset frequency is applied to the LCD, the LCD is determined to be qualified when the LCD meets the production standard; and if the picture displayed by the LCD is defective when the MIPI signal which is lower than and equal to the preset frequency is applied to the LCD in the detection process, determining that the LCD is unqualified.

To facilitate the subsequent detection operation, the embodiment of the present invention converts the preset frequency into a bright line visually displayed on the LCD, i.e., an (upper) edge of a qualified picture displayed by the LCD when the MIPI signal having the preset frequency is applied to the LCD. Therefore, in the embodiment of the invention, a picture with a bright line is added for detecting the defects of the LCD, and in the detection process, if the LCD displays a qualified picture below the bright line, the LCD is determined to be qualified according with the production standard; and if the LCD does not display qualified pictures below the bright lines, the LCD is determined to be unqualified.

The generation method of the picture with bright lines includes, but is not limited to, the following:

the LCD is divided into a plurality of areas arranged along a preset direction, and MIPI signals are sequentially applied to the areas respectively. Wherein, a MIPI signal having a rated frequency, which is a frequency of the MIPI signal to be applied to achieve the resolution of the LCD, is applied to a first region, for example, a rated frequency of the LCD having a resolution of 720 × 1280 is 230Hz, which is less than a preset frequency corresponding to the aforementioned bright line, and a frequency of the MIPI signal applied to each region in a preset direction is less than a frequency of the MIPI signal applied to a subsequent region.

For example, as shown in fig. 2, for the LCD to be tested, the number of pixel rows on the long side is V, the number of pixel rows on the short side is H, that is, the number of pixels in the vertical direction is V, the number of pixels in the horizontal direction is H, the bottom of the LCD is the first row of pixels, and the top of the LCD is the last row of pixels, and the LCD applies MIPI signals line by line from the first row of pixels to the last row of pixels. Then, corresponding to the foregoing, each of said regions comprises a plurality of rows of pixels, preferably the number of rows of pixels comprised by the respective region is the same; the preset direction is a direction from the first row of pixels to the last row of pixels; in addition, in combination with the turn-on principle of a TFT (Thin film transistor) of the LCD, the predetermined direction may also be regarded as a direction perpendicular to the turn-on direction of the scan line of the LCD.

In the process of applying the MIPI signal to the LCD to display the picture, the rated frequency of the MIPI signal of the LCD is increased by 10% every V/10 lines, and the increased MIPI signal is applied to the LCD. Preferably, the difference between the frequencies of the MIPI signals applied to any two adjacent regions is equal. If the manufacturer requires that the LCD not be allowed to have display defects such as noise at a frequency below 280Hz, a bright line L may be displayed on the LCD when the nominal frequency (230Hz) is increased to a preset frequency (280 Hz). The bright line L may be formed by a line drawing function, and the like, which is not limited in this embodiment of the present invention.

S12: the method includes dividing an LCD into a plurality of regions arranged in a preset direction and applying MIPI signals respectively, wherein the frequency of the MIPI signals applied to each region in the preset direction is less than that of the MIPI signals applied to the next region, and applying the MIPI signals with a rated frequency to the first region, wherein the rated frequency is the frequency of the MIPI signals to be applied to achieve the resolution of the LCD, and the rated frequency is less than the preset frequency.

This step S12 may be regarded as a formal inspection of the LCD. The process of applying the MIPI signal to the LCD can refer to the manner of generating the picture shown in fig. 2, and is not described herein again.

S13: and judging whether the LCD displays qualified pictures below the bright lines.

The LCD is connected to a CPU (Central Processing Unit) for applying MIPI signals through an FPC (Flexible Printed Circuit), and the FPC is connected to the LCD through an ACF (anisotropic conductive Film), and since the ACF has impedance, the FPC has connection (bonding) impedance between the CPU and the LCD, thereby reflecting data transmitted to the LCD by the CPU and affecting transmission of MIPI signals. And, the larger the frequency of the MIPI signal is, the stronger the reflection is, and the LCD will not receive correct data when the frequency of the MIPI signal reaches a certain degree. That is, when a certain high frequency MIPI signal is applied to the LCD, the LCD may not normally display a picture or display an erroneous picture.

Based on the principle, if the LCD does not display qualified pictures below the bright line, the LCD is unqualified, and then step S14 is executed; if the LCD displays a qualified picture below the bright line, the LCD is qualified, and step S15 is executed.

It should be noted that, the steps S13 to S15 can be regarded as detecting whether the LCD is qualified according to the picture displayed on the LCD below the bright line. Steps S13 to S15 may be performed by direct manual observation or by using an AOI (automated optical inspection) device.

S14: and judging that the LCD is unqualified.

S15: and judging that the LCD is qualified.

As can be seen from the above description, the present embodiment utilizes the principle that the LCD cannot display a picture or display an incorrect picture (i.e., display a defective picture) when the applied MIPI signal is at a high frequency, so as to convert the display defect into a picture with a bright line, where the bright line is the edge of the acceptable picture displayed by the LCD when the MIPI signal with the preset frequency is applied. During detection, if the LCD displays a qualified picture below the bright line, the LCD is judged to be qualified; if the LCD does not display qualified pictures below the bright lines, the LCD is judged to be unqualified, and the preset frequency corresponding to the bright lines is adjustable, so that the detection effect of the display defects of the LCD can be improved, and the development of high resolution of the LCD is facilitated.

Please refer to fig. 3, which illustrates an LCD inspection apparatus according to an embodiment of the present invention. The detection apparatus 30 of the LCD includes an identification module 31, a driving module 32, and a detection module 33. Wherein:

the marking module 31 is configured to mark a bright line on the LCD to be detected in advance, where the bright line is an edge of a qualified picture displayed when an MIPI signal having a preset frequency is applied to the LCD.

The driving module 32 is configured to divide the LCD into a plurality of regions arranged in a preset direction and apply the MIPI signals respectively, where a frequency of the MIPI signal applied to each of the regions in the preset direction is smaller than a frequency of the MIPI signal applied to a subsequent region, and apply the MIPI signal having a rated frequency to a first region, where the rated frequency is a frequency of the MIPI signal to be applied to achieve a resolution of the LCD, and the rated frequency is smaller than the preset frequency.

The detecting module 33 is used for detecting whether the LCD is qualified according to the picture displayed by the LCD below the bright line. Optionally, the detection module 33 determines whether the LCD displays a qualified picture below the bright line; if the LCD displays qualified pictures below the bright lines, the LCD is judged to be qualified; and if the LCD does not display qualified pictures below the bright lines, judging that the LCD is unqualified.

The above modules of the detection apparatus 30 for an LCD of the present embodiment correspondingly perform the methods of the above embodiments, and have the same technical effects.

It should be understood that the division of the above-described modules into one logical functional division may be implemented in other ways, for example, two modules may be integrated into another system, or some features may be omitted, or not implemented. In addition, the modules may be connected to each other through some interfaces, and may also be in an electrical or other form. The modules may be implemented in the form of software functional blocks, or in the form of hardware, for example, as shown in fig. 4.

Referring to fig. 4, the LCD detection device 30 includes at least one processor 41, at least one communication interface 42, a memory 43, and at least one communication bus 44, where the communication interface 42 is used for the processor 41 to call various data, and the memory 43 is used for storing program instructions. For convenience of explanation, the number of the processor 41, the communication interface 42, the memory 43, and the communication bus 44 is one as shown in fig. 4. Wherein the processor 41 is configured to:

and executing the program instruction to mark a bright line on the LCD to be detected in advance, wherein the bright line is the edge of a qualified picture displayed when the MIPI signal with the preset frequency is applied to the LCD.

And executing a program instruction to divide the LCD into a plurality of regions arranged along a preset direction and respectively applying the MIPI signals, wherein the frequency of the MIPI signals applied to each region along the preset direction is less than that of the MIPI signals applied to the next region, and the MIPI signals with a rated frequency are applied to the first region, the rated frequency is the frequency of the MIPI signals to be applied to achieve the resolution of the LCD, and the rated frequency is less than the preset frequency.

And executing program instructions to detect whether the LCD is qualified according to the picture displayed by the LCD below the bright line. Optionally, the processor 41 determines whether the LCD displays a qualified picture below the bright line; if the LCD displays qualified pictures below the bright lines, the LCD is judged to be qualified; and if the LCD does not display qualified pictures below the bright lines, judging that the LCD is unqualified.

It should be noted that, if the above functions of the embodiments of the present invention are implemented in the form of software functional units and sold or used as a stand-alone product, the functions may be stored in a computer readable storage medium, that is, the embodiments of the present invention may be embodied in the form of a software product, which includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present invention.

In addition, the above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures or equivalent flow transformations made by using the contents of the present specification and the drawings, such as mutual combination of technical features between various embodiments, or direct or indirect application to other related technical fields, are included in the scope of the present invention.

Claims

1. A method for inspecting an LCD, the method comprising the steps of:

step 1: marking a bright line L on the LCD to be detected in advance, specifically: dividing the LCD into a plurality of regions arranged along a preset direction, and sequentially applying MIPI signals to each region along the preset direction, wherein a first region applied with the MIPI signals is applied with MIPI signals with a rated frequency, the rated frequency is the frequency of the MIPI signals to be applied to reach the resolution of the LCD, the frequency of the MIPI signals applied to each region along the preset direction is smaller than the frequency of the MIPI signals applied to a subsequent region, the difference between the frequencies of the MIPI signals applied to any two adjacent regions is equal, when the frequency of the applied MIPI signals is increased from the rated frequency to a preset frequency, the corresponding region displays and marks the bright line, and the preset frequency meets the following conditions: the manufacturer requires that the frequency below the preset frequency does not allow the LCD to have display defects;

step 2: detecting whether the LCD is qualified, specifically comprising the following steps: applying an MIPI signal to the LCD according to the mode of applying the MIPI signal to the LCD in the step 1, and judging whether the LCD displays a qualified picture below the bright line; if the LCD displays qualified pictures below the bright lines, judging that the LCD is qualified; and if the LCD does not display qualified pictures below the bright lines, judging that the LCD is unqualified.