WO2013159504A1

WO2013159504A1 - Mother board of liquid crystal display device and a liquid crystal display device detection method

Info

Publication number: WO2013159504A1
Application number: PCT/CN2012/084251
Authority: WO
Inventors: 王辉; 秦锋; 李小和; 林炳仟
Original assignee: 京东方科技集团股份有限公司; 合肥京东方光电科技有限公司
Priority date: 2012-04-25
Filing date: 2012-11-07
Publication date: 2013-10-31
Also published as: CN102681224A; CN102681224B

Abstract

A mother board of a liquid crystal display device and a liquid crystal display device detection method. The mother board comprises multiple liquid crystal display devices and at least a group of signal ports. Each signal port group is used for a unit liquid crystal display device on at least one row. Each unit liquid crystal display device comprises a gate signal end (31), a common voltage signal end (32), and multiple primary voltage signal ends (33-35). At least signal port group is connected to the gate signal end (31), the common voltage signal end (32), and the multiple primary voltage signal ends (33-35) of each unit liquid crystal display device on a corresponding row. The voltage of at least one signal port group can drive the signal end of multiple unit liquid crystal display devices to simultaneously lighten multiple unit liquid crystal display devices. During the detection on the liquid crystal display devices, the mother board is detected before being cut, which improves testing efficacy of a liquid crystal cell.

Description

Mother board and liquid crystal display device detection method of liquid crystal display device

Embodiments of the present invention relate to a mother board and a liquid crystal display device detecting method of a liquid crystal display device. Background technique

Thin Film Transistor Liquid Crystal Display (TFT-LCD) has been rapidly developed in recent years due to its small size, low power consumption, and no radiation. It has gradually occupied a leading position in the current flat panel display market. At present, TFT-LCD has various sizes of large, medium and small products, covering almost all major electronic products in today's information society, such as LCD TVs, computers (desktops and notebooks), mobile phones, PDAs, GPS, car displays, camcorders, digital cameras, Calculators, electronic instruments, and unreal displays.

1 shows a general structure of a conventional TFT-LCD liquid crystal display device, which mainly includes a glass substrate 101 of a color filter (CF) substrate and a glass substrate 102 of an array substrate, and a liquid crystal 103 interposed therebetween. The color filter 104, the black matrix 105, the spacer 106, the transparent electrode 107, the alignment film 108, the wiring 109, and the like. A polarizing plate 110 is also disposed on the outer sides of the two glass substrates 101, 102. The two glass substrates 101, 102 are closed by a sealant 111 to enclose the liquid crystal 103 in a liquid crystal cell formed by the two.

At present, the TFT-LCD production line mainly includes four main working segments of the array process, the color filter process, the box forming process and the module process.

The array process includes the preparation of a TFT array substrate, that is, forming signal lines on the TFT array substrate, individual pixel units, and the like. 2 is a schematic plan view of a TFT array substrate. The signal lines mainly include a data line (or source line) 201, a gate line 202, and a common line 203 for inputting data signals (source signals), gate signals, and common signals, respectively. The data line 201 and the gate line 202 cross each other to define sub-pixel units P arranged in a matrix; each sub-pixel unit includes at least one thin film transistor (TFT) 204 and a common storage capacitor 205 (by the pixel electrode 206 and the common electrode unit 207) Together, the TFT 204 is used for switching of a pixel voltage and driving of a liquid crystal.

The color filter process mainly includes a black matrix (BM) layer on the CF substrate, and RGB. Preparation of layers (red, green and blue layers) as well as transparent conductive layers and the like.

The box-forming process includes bonding the fabricated TFT array substrate and CF substrate together with a sealant to form a complete, closed panel (liquid crystal display device), mainly including alignment film coating, alignment film orientation preparation, and liquid crystal droplets. Several steps are required to enter and seal the frame glue. After the card forming process, a large substrate (e.g., a mother board) is cut to obtain a small unit liquid crystal display device (single liquid crystal display device).

Thereafter, a cell test is performed on the cell liquid crystal display device (Cell Test). The purpose of the liquid crystal cell test is to detect various defects in the array process and the box-forming process of the liquid crystal display device, and these defects mainly include various Mura (plaque), block (block), Cell stain, bright line and the like. Detection screen liquid crystal cell used for testing include Black Raster L0, Cyan L127, low highlights _{Pattern ¾ White Raster L255, Gray Raster} L63, Gray Raster 127, Raster Red L127, Raster Green L127, Raster Blue L127, Raster Red L63, Raster Green 12 kinds of screens such as L63 and Raster Blue L63. All detected pictures are grayscale pictures or solid color pictures. For various sizes of liquid crystal display devices, special dot-screen devices are matched in the product development stage, and the display process of the dot-screen devices is the same as that of the finished liquid crystal display.

The module process mainly includes attaching the fabricated unit liquid crystal display device to the polarizer and the PCB driving circuit, and then assembling the unit liquid crystal display device with the backlight to form a final display module product. So far, the fabrication process of the TFT-LCD liquid crystal display device has been basically completed.

At present, the liquid crystal cell test is usually performed on the unit panel (unit liquid crystal display device) after the large glass substrate (motherboard) cutting process is completed. However, since all processes before the liquid crystal cell test are performed for the mother board during the manufacture of the liquid crystal display device, the cause of the failure of many liquid crystal display devices is closely related to the distribution of the liquid crystal display device on the mother board. The detection of the unit liquid crystal display device in the prior art can usually only detect the bad phenomenon relatively intuitively, and further analysis and judgment are still needed for the cause of the defect.

In addition, the liquid crystal display device after cutting has a variety of different sizes, and the liquid crystal cell testing device of the liquid crystal display device of different sizes needs to be customized to purchase expensive dot-screen devices in the product development stage, and the liquid crystal display device of different sizes The cell test equipment cannot be shared at all. During the development stage, the liquid crystal cell test equipment for different size liquid crystal display devices is complicated to debug and has low work efficiency. Summary of the invention The embodiment of the invention provides a mother board of a liquid crystal display device and a liquid crystal display device detecting method, which can detect the mother board, significantly improve working efficiency, and solve the efficiency of the liquid crystal cell testing device for the unit liquid crystal display device Not a high problem.

An aspect of the invention provides a motherboard for preparing a liquid crystal display device, comprising: a plurality of unit liquid crystal display devices; at least one set of signal ports, each set of signal ports being used for at least one column of liquid crystal display devices; wherein, each The unit liquid crystal display device comprises a gate signal terminal, a common voltage signal terminal and a plurality of primary color voltage signal terminals, the at least one signal port and a gate signal terminal of each unit liquid crystal display device on the corresponding column, a common voltage signal The terminal and the plurality of primary color voltage signal terminals are connected such that voltages of the at least one set of signal ports can drive signal terminals of the plurality of unit liquid crystal display devices to simultaneously illuminate the plurality of unit liquid crystal display devices.

In the motherboard, for example, on one side of the motherboard, the glass substrate area of the opposite substrate is smaller than the glass substrate of the array substrate, and the signal line of the array substrate is exposed on the side to connect the at least one group Signal input of the signal port.

In the mother board, for example, in each unit liquid crystal display device, gate lines of each row are all connected together to form the gate signal terminal.

In the motherboard, for example, in each unit liquid crystal display device, the traces corresponding to the primary color sub-pixels in the data line are separated, and the traces of the same primary color sub-pixel are connected together to form respective primary color voltages. Signal side.

In the motherboard, for example, the primary color voltage signal terminal includes R, G, and B voltage signal terminals. In the motherboard, for example, the traces of the 1, G, and B sub-pixel units in the data line are separated, all the R sub-pixel unit traces are connected together, and all the G sub-pixel unit traces are connected together, all The B sub-pixel unit traces are connected together to form the R, G, and B voltage signal terminals, respectively.

In the motherboard, for example, the R sub-pixel unit trace is implemented by a first metal layer in the array substrate; the G sub-pixel unit trace and the signal input end of the B sub-pixel unit trace In the first metal layer formed in the array substrate, connection is achieved by a second metal layer in the array substrate.

In the motherboard, for example, in the G sub-pixel unit trace and the B sub-pixel unit trace, the first metal layer and the second metal layer are electrically connected through via holes.

In the motherboard, for example, the detection signal lines of the liquid crystal display devices of the respective units are sequentially widened in a ratio from the near to the far distance from the input end of the signal, so that all the cells on the motherboard are liquid crystal display. The resistances of the detection signal lines of the display device are substantially equal, and the voltage distribution between the unit liquid crystal display devices is uniform.

In the motherboard, for example, the primary color voltage signal terminal further includes a W voltage signal terminal or a Y voltage signal terminal.

In the motherboard, for example, all W sub-pixel unit traces are connected together or all Y sub-pixel unit traces are connected together to form the W or Y voltage signal terminals, respectively.

Another aspect of the present invention provides a liquid crystal display device detecting method, comprising: performing dot screen detection before cutting a mother board, the mother board comprising a plurality of unit liquid crystal display devices; and being disposed on the motherboard by control The voltage of at least one of the signal ports drives each of the unit liquid crystal display devices; and simultaneously illuminates all of the unit liquid crystal display devices on the motherboard.

In the method, for example, when all the liquid crystal display devices on the mother board are simultaneously illuminated, the common signals of all the unit liquid crystal display devices are input by a common signal source, and the gate signals of all the liquid crystal display devices are one by one. Gate signal source input, a plurality of primary color sub-pixel unit signals of all unit liquid crystal display devices are input by respective primary color sub-pixel unit signal sources.

In the method, for example, the primary color signal includes R, G, and B signals, and the R sub-pixel unit signals of all the unit liquid crystal display devices are input by one R pixel source, and the G sub-pixel unit signals of all the unit liquid crystal display devices are A G pixel source input, the B sub-pixel unit signals of all unit liquid crystal display devices are input by a B pixel source.

In the method, for example, the primary color signal further includes a W signal or a Y signal, and the W sub-pixel unit signals of all the unit liquid crystal display devices are input by one R pixel source, and the Y sub-pixel unit signals of all the unit liquid crystal display devices are A G pixel source input.

Embodiments of the present invention perform liquid crystal cell testing before cutting the mother board, and the corresponding mother board and method can simultaneously illuminate all the unit liquid crystal display devices on one master board, under the premise of ensuring the current liquid crystal cell testing function, The aspect realizes the function of device dependence which can intuitively judge the defective phenomenon of the liquid crystal display device, and greatly improves the parameter optimization of the equipment and process of the array process and the box-forming process, and significantly improves the efficiency of poor analysis on the production line. On the other hand, the sharing of the liquid crystal cell test equipment of different size liquid crystal display devices on the liquid crystal display device manufacturing line is realized, which greatly reduces the equipment cost. DRAWINGS In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below. It is obvious that the drawings in the following description relate only to some embodiments of the present invention, and are not intended to limit the present invention. .

1 is a schematic view showing the general structure of a conventional TFT-LCD liquid crystal display device;

2 is a schematic view showing a general planar structure of a conventional TFT array substrate;

3 is a schematic diagram showing a signal line layout of a unit liquid crystal display device in a motherboard according to an embodiment of the present invention;

4 is a schematic diagram showing a hierarchical structure of an example of a TFT array substrate on a motherboard according to an embodiment of the present invention;

5 is a schematic view showing a manner in which metal layers are connected through via holes in the TFT array substrate of FIG. 4;

6 is a schematic structural diagram of a circuit in which an RGB interface of a source terminal of a unit liquid crystal display device is realized in communication according to an embodiment of the present invention;

7 is a schematic diagram showing an exemplary circuit structure of a signal line layout of all unit liquid crystal display devices on a large glass substrate according to an embodiment of the present invention;

8 is a schematic structural view of a liquid crystal display device including two cells in a group of signal ports in FIG. 7; FIG. 9 is a schematic diagram showing an equivalent circuit structure of a common liquid crystal panel;

10 is a schematic diagram showing changes in a pixel voltage waveform of 256 gray scales when the common electrode voltage is constant in a conventional liquid crystal panel;

11 is a schematic diagram showing waveform changes of a pixel voltage of 256 gray scales when the voltage of the common electrode in the ordinary liquid crystal panel is constantly changing;

FIG. 12 is a schematic diagram showing a specific wiring of a unit liquid crystal display device in a motherboard according to an embodiment of the present invention. detailed description

The technical solutions of the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings. It is apparent that the described embodiments are part of the embodiments of the invention, rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the described embodiments of the present invention without departing from the scope of the invention are within the scope of the invention. Unless otherwise defined, technical terms or scientific terms used herein shall be of ordinary meaning as understood by those of ordinary skill in the art to which the invention pertains. The words "first", "second", and the like, as used in the specification and claims, are not intended to mean any order, quantity, or importance, but are used to distinguish different components. Similarly, the words "a" or "an" do not denote a quantity limitation, but rather mean that there is at least one. "Connected" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "Down", "Left", "Right", etc. are only used to indicate the relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship is also changed accordingly.

The embodiment of the present invention considers that the detection screens of the liquid crystal display devices of different sizes are the same when performing the liquid crystal cell test, and accordingly, a new liquid crystal display device liquid crystal cell testing device and method for the mother board are proposed. . The voltage magnitude and frequency of the signal source in the motherboard of the embodiment of the present invention can be adjusted according to the dot screen of the liquid crystal display device of different sizes, and the signal source output port can be compatible with the signal input of the liquid crystal display device of different sizes, and the corresponding motherboard The signal input port on the top is also designed to be compatible. The liquid crystal cell test method in the embodiment of the invention is simple and quick, and the work efficiency is high. The most important thing is to realize the device sharing and reduce the equipment cost.

Fig. 3 is a view showing a signal line layout of a unit liquid crystal display device on a mother board of a liquid crystal display device according to an embodiment of the present invention.

As shown in FIG. 3, in the embodiment, the liquid crystal display device for lighting one unit only needs to be the gate signal terminal 31, the common voltage signal terminal 32, and the red (R), green (G), and blue (B) voltage signal terminals 33- 35 A total of five ports can be applied with signals. The R, G, and B voltage signal terminals are examples of the primary color voltage signal terminals. These signals are output by respective signal sources including a gate signal source 301, a common signal source 302, an R signal source 303, a G signal source 304, and a signal source 305. According to the current layout of the TFT-LCD motherboard, the gate lines of the liquid crystal display device, the common line, and the source of the RGB sub-pixel unit can be completely disposed in the gap space of the liquid crystal display device of each unit on the TFT-LCD motherboard. Trace the line for the purpose of detection. The gate lines of the unit liquid crystal display device for detecting the liquid crystal cell test panel on the mother board of the embodiment, the common line, and the source trace of the RGB sub-pixel unit may pass through the mother board other than the unit liquid crystal display device. The gate layer or the data layer realizes communication, and the intersection of the lines realizes the insulation between the lines and the conduction of the lines themselves through the staggered layout and via design of the gate layer or the data layer.

Fig. 4 is a view showing a hierarchical structure of an example of a TFT array substrate in a mother board. In the indication In the example, the TFT is a bottom gate structure (ie, the TFT gate is located at the bottom of the active layer), and on one surface of the TFT glass substrate 401, a second metal layer (gate layer) 402 and a first insulating layer (gate) are sequentially formed. A pole insulating layer) 403, a first metal layer (S/D layer, that is, a source/drain layer) 404, a second insulating layer (passivation layer) 405, and a pixel electrode layer (for example, an ITO layer) 406. These layers are sequentially formed and patterned during the preparation of the array substrate, so that these layers may be removed at certain locations due to the need for patterning. Therefore, it is not the same layer structure at any position on the prepared array substrate.

Fig. 5 further shows an example of the manner in which the metal layers in the TFT array substrate are connected by via holes. The first insulating layer 403 and the second insulating layer 405 are coated in a single glass substrate; the two metal layers 402 and 404 are electrically connected to the pixel electrode layer 406 through the two vias 501, 502, respectively. The via hole etches a specific portion by exposing the insulating layer between the metal layers, and then passes through a conductive material (for example, a deposition method) filled with, for example, a metal to the portion to be etched, thereby realizing a layer between the layers. Electrically connected. Via is a process commonly used in TFT-LCD production lines to achieve conduction of metal layers in different layers. Moreover, if desired, at the intersection of the first metal layer 404 and the second metal layer 402, the two metal layers can also be directly conducted through vias.

Figure 6 shows a circuit diagram in communication with the RGB interface of the source terminal of the unit liquid crystal display device. The RGB interface of the source terminal of each unit liquid crystal display device itself is composed of a first metal layer (S/D metal layer) 404. The vertical line in Fig. 6 is the first metal layer 404, and the lateral line is the second metal layer (gate layer) 402. The ports of the R pixels are connected by the first metal layer 404 and form an R signal input port; the B pixels and the G pixels are first extracted by the first metal layer 404, and then communicated through the second metal layer 402, at the first metal layer 404 and The junction of the two metal layers 402 achieves conduction of the two metal layers by a via process. The position marked with a circle in Fig. 6 is the via conduction 601, and the broken line indicates the unit's cutting line 602. The above solution is one way of implementing RGB signal input. However, in the non-unique embodiment, for example, the second metal layer 402 can also be used to realize the connection of the source terminal R pixels, and the first metal layer 404 can realize the B pixel, the G pixel connection, and the like. . In addition, for the TFT of the top gate structure, the meaning or position of the first and second metal layers are correspondingly different, but they are input with the RGB signals as needed, without the need for creative labor.

In addition, the common electrode of each unit liquid crystal display device can be fully turned on by itself, and the design of the common port is generally distributed around the unit liquid crystal display device, and the common signal line can be extracted from any one of the surrounding ports to implement the embodiment. Input of a common signal; a unit liquid crystal display device All of the gate ports can be connected by a single gate line, and the connection can be made in the same manner as all R pixels of the source terminal described above. The liquid crystal cell test circuit designed by the embodiment of the present invention completely disappears after the mother board is cut, and has no influence on the circuit lines of the liquid crystal display devices of the respective units. As shown in FIG. 6, the cutting boundary is along the cutting line shown in FIG. 620 can be done.

Fig. 7 further shows an exemplary circuit configuration of the signal line layout of all unit liquid crystal display devices on a large glass substrate (motherboard), in which three sets of signal ports as shown in Fig. 3 are present. In Figure 7, the AB side represents the signal access side. Each group of signal ports includes a gate signal terminal 31, a common voltage signal terminal 32, and five R, G, and B voltage signal terminals 33-35 for two unit liquid crystal display devices. The three sets of signal ports ultimately illuminate all of the unit liquid crystal display devices on this motherboard. A motherboard may be provided with one or several sets of such signal ports according to the size of the liquid crystal display device and the layout of the metal traces on the TFT motherboard, and each set of signal ports is used for a column of liquid crystal display devices (specific number Can be adjusted according to the situation). The distance between the signal ports of different size unit liquid crystal display devices is different, and the external signal sources corresponding to the signal ports can be completely shared.

In an embodiment of the present invention, the liquid crystal cell test is performed before the mother board is cut, and the gap space of each unit liquid crystal display device on the TFT-LCD mother board is performed by using the gate layer or the data layer trace to all the liquid crystal display devices of the unit. The five signal inputs are connected and pulled out from one side of the motherboard, as shown by the AB side in Figure 7. In order to enable the signal of the liquid crystal cell test to be applied to the mother board, the CF glass substrate in the mother board is shorter on the AB side than the AB side of the TFT glass substrate, so that the signal line of the AB side of the mother board of the TFT-LCD is exposed to the liquid crystal. The signal input terminals (Pads) used by the box test equipment, the size of these signal input terminals is subject to the actual situation that the liquid crystal cell test equipment can complete the voltage signal applied to the TFT glass substrate. The motherboard shown in Figure 7 has three sets of signal input ports 31-35, and the two unit liquid crystal display devices in the same column share a set of signal input ports. As shown in FIG. 8, a set of signal ports (including the gate signal terminal 31, the common voltage signal terminal 32, and the R, G, and B voltage signal terminals 33-35, five ports) in FIG. 7 are used to arrange two columns in one column. The case of a unit liquid crystal display device. According to the actual wiring condition on the TFT-LCD motherboard, more unit liquid crystal display devices, even one unit liquid crystal display device on one motherboard can share a set of signal input ports.

As described above, in order to minimize the wire load on the TFT-LCD motherboard, one motherboard can be provided with one or several sets of signal input ports. According to the actual situation of the TFT-LCD motherboard design, the unit liquid crystal display devices of one motherboard can be divided into several groups, and the liquid crystal display devices of each group share one. The group signal input port is used to minimize the influence of the signal line load for the liquid crystal cell test. According to the principle that the signal line loss is as equal as possible, the liquid crystal cell test signal line of the unit liquid crystal display device far from the signal input end is wider than the liquid crystal cell test signal line of the unit liquid crystal display device which is closer to the signal input end, so that The resistance of the signal lines for the cell test of the liquid crystal display devices of all the cells on the entire mother board is as equal as possible, so that the voltage distribution between the liquid crystal display devices of the cells is uniform.

Fig. 9 is a schematic diagram showing an equivalent circuit of a conventional liquid crystal panel. The plurality of gate traces 902 and the plurality of source traces 902 cross each other to define a plurality of sub-pixel units 901, each of the sub-pixel units 901 including a TFT as a switching element and a pixel electrode, a common electrode, a pixel electrode, a common electrode, and The liquid crystal layer is formed with Clc (liquid crystal capacitor) for display. In addition, each pixel unit may further include a capacitor in which Cs (storage capacitor) is connected in parallel with Clc. One sub-pixel unit 901 represents a point of the displayed image; a basic display unit (ie Pixel), for example, three points are displayed such that they represent three colors of red, green and blue (RGB), respectively, or four such Points, which represent red, blue, white and white (RGBW), etc. A 1024x768 resolution TFT-LCD unit panel requires a total of 1024x768x3 such points. The operation of the entire unit panel is as follows. The signal of the gate terminal of 768 rows is input by an external gate terminal signal source (gate driver, gate drive), and the gate terminal signal source sequentially turns on the TFT of each row of sub-pixel unit 901, so that the source terminal of the entire row is completed. The source (source driver, ie the data signal) simultaneously charges an entire line of display points to their respective required voltages and displays different gray levels. When a row of charging is completed, the gate driver turns off the driving voltage applied to the row; then, the gate driver of the next row turns the row of sub-pixel units on, and then the same row of source drivers goes to the next row. Display points for charging and discharging. This is continued until the charging of the display point of the last line is completed, thereby completing the scanning of one frame of the picture. After that, a new scan of one frame is started again, that is, charging is resumed from the first line until the last line of charging is completed. In a 1024x768 resolution liquid crystal display, there are a total of 768 rows of gate traces 902, while the source traces 903 require a total of 1024x3 = 3072. A typical liquid crystal display is usually an update frequency of 60 Hz, so each screen display time is about l/60 = 16.67 ms. Since there are 768 rows of gate traces for the display screen, the switching time assigned to each gate trace is about 16.67 ms / 768 = 21.7 s. Then, the signal waveform sent by the gate driver is a rectangular wave (also called a square wave) having a width of 21.7 μ _δ , and the sub-pixel units of each row are sequentially turned on. The source driver charges and discharges the pixel electrode to the required voltage via the source trace during the 21.7 μ _δ time, thereby displaying the corresponding gray scale. The functions of the gate driver and the source driver described above are mainly to control the switching and size of the applied pixel electrode voltage. At present, the display principle of the TFT-LCD liquid crystal display device is that the liquid crystal in each sub-pixel unit is flipped under the action of the pixel electrode and the common electrode, so that the light transmitted through the liquid crystal is polarized, thereby realizing display of various screens of the display.

The voltage on the common electrode is input by a common signal source. There are two types of voltage driving methods for the common electrode, for example. The first way is that the common electrode voltage is fixed, and the voltage of the pixel electrode is constantly changing up and down according to the gray scale. For example, Figure 10 is a pixel voltage waveform change of 256 gray levels. In Fig. 10, the circle portion 1001 refers to the pixel electrode voltage of each of the different gray scales, and the broken line indicates the common electrode voltage 1002, and the upper side of the broken line is positive polarity and the lower side is negative polarity. In the gray scale of V0, if the gray scale of V0 is to be displayed on the panel, the voltage of the pixel electrode must be high once, but the other is very low.

Another way is to keep the common voltage constantly changing, and also to make the absolute value of the differential pressure across the liquid crystal constant, so that the gray scale does not change. The waveform change of this method is shown in Figure 11. In Fig. 11, the circle portion 1101 indicates the pixel electrode voltages of the respective different gray scales, and the broken line indicates the common electrode voltage 1102, and the positive polarity and the negative polarity change with the frame number period. This method only makes a large, small change in the common voltage cycle; the reason for this change is to keep the liquid crystal molecules from staying in the same direction. Liquid crystal molecules are usually not fixed at a certain voltage all the time. If such a state lasts for a long time, even if the voltage across the liquid crystal is canceled, the liquid crystal molecules will be destroyed due to their characteristics, and the corresponding electric field cannot be changed. And lose the role of the light switch.

At present, the display voltage in the liquid crystal display is divided into two types, one is positive polarity and the other is negative polarity. When the voltage of the pixel electrode is higher than the voltage of the common electrode, it is called positive polarity, and when the voltage of the pixel electrode is lower than the voltage of the common electrode, it is called negative polarity. Whether it is positive or negative, there will be a set of gray levels of the same brightness. Therefore, whether the pixel voltage is high or the common electrode voltage is high, the gray scale is exactly the same; however, in these two cases, the liquid crystal molecules are turned completely opposite, and the above-mentioned liquid crystal molecules can be avoided. The characteristic damage caused when it is fixed in one direction. That is to say, when the display screen remains motionless, the positive and negative polarities can be alternately alternated to achieve the result that the display screen is not moving and the characteristics of the liquid crystal molecules are not broken.

Also taking a 1024x768 resolution TFT-LCD as an example, in an embodiment of the present invention The signal input port of one unit liquid crystal display device is set to five, as shown in FIG. 12, which are a gate signal input terminal 31, a common signal input terminal 32, and R, G, and B voltage input terminals 33-35, respectively. On the one hand, 768 rows of gate traces are connected (parallel) together, and a specific turn-on voltage is implemented according to the specific conditions of liquid crystal display devices of different sizes, so that the turn-on voltage of the gate terminals of 768 rows will be turned on or off at the same time; In one aspect, the traces of the three sub-pixel units of the RGB in the source trace are separated, and the source traces of the three sub-pixel units of the RGB are connected together, and finally the source terminals of the liquid crystal display device of one unit form R, G, and B. Input ports. By setting the grayscale voltage values of V0 to V255 at the three input terminals of R, G, and B, it is possible to display all the detected monochrome images of the current liquid crystal cell test by applying different gray scale voltages to the RGB source walking lines.

The signal source of the gate terminal in the embodiment of the present invention is a DC voltage input device, and the voltage level thereof can be adjusted. At present, the gate terminal voltage of a TFT-LCD liquid crystal display device generally ranges from -8V to 27V. In the embodiment of the present invention, all of the gate terminals are connected in parallel, and the resistance of the metal lines may cause some voltage loss, but is negligible with respect to the magnitude of the input gate voltage. The polarity change mode of the LCD panel is Frame inversion. Fixed source extremes RGB V0 to V255 for each grayscale voltage, by changing the size of the common voltage, frame inversion can be achieved. For example, if the average refresh rate of the liquid crystal panel is 60 Hz, then we can set the frequency of the common voltage to 60 Hz. A periodic square wave voltage input source can be used to input common signal voltages. The source voltage is typically between 2V and 30V (same as a typical LCD device). In the embodiment of the present invention, the display of the monochrome picture can be realized by a DC voltage signal, and the signal source of the RGB port can be connected to the DC voltage source.

All test pictures used in the cell phone test are usually grayscale pictures or solid color pictures. One point (ie, one pixel) seen by the human eye on the screen of the liquid crystal display device is composed of three sub-pixel units of red, green, and blue (RGB). For example, each sub-pixel unit can exhibit different brightness levels. The grayscale represents the level of hierarchy of brightness from the darkest picture to the brightest picture. The more intermediate levels, the more delicate the picture will be. Taking a general 8-bit (bit) liquid crystal display device as an example, it can represent 2 to the 8th power, which is equal to 256 brightness levels, that is, there are 256 transition pictures between the blackest and brightest pictures, which is called 256 gray levels (0~255). 0 grayscale picture to 255 grayscale picture is generally represented by L0, LI, L2... L255. The color change of each point on the screen of the liquid crystal display device is actually caused by the gray scale change of the three RGB sub-pixels constituting this point. The liquid crystal display device displays a gray scale screen when the RGB sub-pixels change with the same gray scale voltage (Black Raster LO, Cyan L127, RPattern, White Raster L255, Gray Raster L63, Gray Raster 127); When the grayscale voltages of RGB sub-pixels are not equal, various solid colors are displayed (Raster Red L127, Raster) Green L127, Raster Blue L127, Raster Red L63, Raster Green L63, Raster Blue L63). The solid color picture itself also has a gray level distinction, such as a pure green picture with L0 green picture, L255 green picture, and so on.

In the embodiment of the present invention, if the white L63 gray-scale picture needs to be displayed when detecting, and the turn-on voltage is applied to the gate terminal, and the common voltage changes at a certain frequency, the respective gray scales of the R, G, and B ports of the source terminal are used. When the voltage is adjusted to the corresponding 63 gray scale voltage value, the display of the L63 gray scale picture can be realized. At present, the detection time of each screen in the test of the liquid crystal cell on the production line is about 2 minutes. If the next detection picture of the L63 grayscale picture is the Raster Red L127 picture (solid color picture), only the source extreme is needed. The R port voltage is adjusted from the 63 grayscale voltage to the grayscale voltage corresponding to 127 grayscale, and the voltage of the G and B ports of the source terminal is turned off to display the Raster Red L127 screen. By changing the voltage switch state and size of the R, G, and B ports of the source terminal, you can display the Black Raster LO, Cyan L127, Bright Point, White Raster L255, Gray Raster L63, Gray Raster 127, Raster Red. L127, Raster Green LI 27, Raster Blue LI 27, Raster Red L63, Raster Green L63, Raster Blue L63 and other 12 grayscale pictures or solid color pictures. In summary, the mother board of the liquid crystal display device of the embodiment of the present invention can illuminate liquid crystal display devices of different sizes by adjusting the voltage and frequency of the signal sources of the five input terminals.

Further, the mother board and method of the liquid crystal display device of the embodiment of the present invention are also applicable to a non-RGB type liquid crystal display device such as an RGBW or RGBY type liquid crystal display device. These liquid crystal display devices are only required to add corresponding signal terminals to the corresponding sub-pixel units in the mother board with respect to the above-described RGB type liquid crystal display device. For example, for the RGBW type, each liquid crystal cell screen in the motherboard further includes a white sub-pixel unit (W) voltage signal terminal; for the RGBY type, each liquid crystal cell screen in the motherboard further includes a yellow sub-pixel unit (Y) Voltage signal terminal. At the time of detection, each signal terminal of each unit liquid crystal display device is driven by controlling the voltage of each group of signal ports (at this time, each group has six ports) to simultaneously illuminate all of the unit liquid crystal display devices on the entire mother board.

In the embodiment of the present invention, if a color film structure is formed on the array substrate of the liquid crystal display device, the opposite substrate facing the array substrate in the liquid crystal display device may not be a color filter substrate, but is, for example, a general cap substrate. According to the motherboard and the method of the liquid crystal display device of the embodiment of the invention, the defects caused by different devices during the preparation process of the motherboard can be clearly presented on the display screen. The relative position of the poor analysis on the liquid crystal display device of each unit of the mother board can accurately determine the fault of each device in the place where the bad position corresponds. Since the unit liquid crystal display device is in the original design position on the mother board, the design positions of the liquid crystal display devices of the respective units are fixed, so that various process conditions and design parameters can be comprehensively considered when analyzing a specific defect. Through this new liquid crystal cell test method, various defects can be analyzed intuitively and quickly, and the analysis of bad phenomena is efficient. For example, according to the shape of the defective Mura on the mother board, it can be quickly determined whether the defective Mura is caused by a rubbing process; further analysis can accurately determine the type and cause of the rubbing Mura according to the direction of the bad Mura. By the same judgment method, it is possible to judge the specific causes of various defects such as poor printing of particles of polyimide (PI), poor adhesion of ODF, and poor coating of the sealant. On the other hand, the liquid crystal cell testing method proposed by the embodiment of the present invention can realize the sharing of the liquid crystal cell testing equipment of different size liquid crystal display devices on the TFT-LCD production line, which greatly reduces the equipment cost.

The above embodiments are only intended to illustrate the invention, and are not intended to limit the invention, and the scope of the invention should be defined by the appended claims.

Claims

Claim

1. A motherboard for preparing a liquid crystal display device, comprising:

a plurality of unit liquid crystal display devices;

At least one set of signal ports, each set of signal ports being used for at least one column of liquid crystal display devices; wherein each of the unit liquid crystal display devices includes a gate signal terminal, a common voltage signal terminal, and a plurality of primary color voltage signal terminals, the at least a set of signal ports are connected to a gate signal terminal, a common voltage signal terminal, and a plurality of primary color voltage signal terminals of each unit liquid crystal display device on the corresponding column, such that voltages of the at least one group of signal ports can drive the plurality of The signal terminal of the unit liquid crystal display device simultaneously illuminates the plurality of unit liquid crystal display devices.

The mother board according to claim 1, wherein, on one side of the mother board, a glass substrate area of the opposite substrate is smaller than a glass substrate of the array substrate, and a signal line of the array substrate is exposed at the side Connecting a signal input of the at least one set of signal ports.

The mother board according to claim 1 or 2, wherein, in each of the unit liquid crystal display devices, the gate lines of each row are all connected together to form the gate signal terminal.

4. The motherboard according to any one of claims 1 to 3, wherein, in each of the unit liquid crystal display devices, the traces corresponding to the respective primary color sub-pixels in the data line are separated, and the same primary color sub-pixel is taken away. The wires are connected together to form respective primary color voltage signal terminals.

The motherboard according to any one of claims 1 to 4, wherein the primary color voltage signal terminal comprises R, G, B voltage signal terminals.

The mother board according to claim 5, wherein the traces of the 1, G, and B sub-pixel units in the data line are separated, and all the R sub-pixel unit traces are connected together, and all the G sub-pixel units are taken away. The wires are connected together, and all the B sub-pixel unit wires are connected together to form the R, G, and B voltage signal terminals, respectively.

The motherboard according to claim 6, wherein the R sub-pixel unit traces are implemented by a first metal layer in the array substrate; the G sub-pixel unit traces and the B sub-pixel unit A signal input end of the trace is formed in the first metal layer in the array substrate, and the connection is achieved through the second metal layer in the array substrate.

The motherboard according to claim 7, wherein, in the G sub-pixel unit trace and the B sub-pixel unit trace, the first metal layer and the second metal layer pass through a via guide through.

The motherboard according to any one of claims 1 to 8, wherein the detection signal lines of the liquid crystal display devices of the respective units are sequentially widened in a ratio from a near to a far distance from the signal input end, so that the mother The resistances of the detection signal lines of all the unit liquid crystal display devices on the board are substantially equal, and the voltage distribution between the unit liquid crystal display devices is uniform.

The motherboard according to claim 5, wherein the primary color voltage signal terminal further comprises a W voltage signal terminal or a Y voltage signal terminal.

11. The motherboard of claim 10, wherein all W sub-pixel unit traces are connected together or all Y sub-pixel unit traces are connected together to form the W or Y voltage signal terminals, respectively.

12. A method of detecting a liquid crystal display device, comprising:

Performing dot screen detection before cutting the mother board, the mother board comprising a plurality of unit liquid crystal display devices;

Driving each unit liquid crystal display device by controlling voltages of at least one set of signal ports disposed on the motherboard;

At the same time, all the unit liquid crystal display devices on the motherboard are lit.

13. The method according to claim 12, wherein when all of the unit liquid crystal display devices on the mother board are simultaneously illuminated, common signals of all unit liquid crystal display devices are input by a common signal source, and all of the unit liquid crystal display devices The gate signal is input by a gate signal source, and the plurality of primary color sub-pixel unit signals of all the unit liquid crystal display devices are input by the respective primary color sub-pixel unit signal sources.

14. The method according to claim 12 or 13, wherein the primary color signal comprises R,

G, B signal, and the R sub-pixel unit signals of all the unit liquid crystal display devices are input by one R pixel source, and the G sub-pixel unit signals of all the unit liquid crystal display devices are input by one G pixel source, and the B sub-units of all the unit liquid crystal display devices The pixel unit signal is input by a B pixel source.

The method according to claim 14, wherein the primary color signal further comprises a W signal or a Y signal, and the W sub-pixel unit signals of all the unit liquid crystal display devices are input by one R pixel source, and all of the unit liquid crystal display devices The Y sub-pixel unit signal is input by a G pixel source.