KR20080051599A - Apparatus for measuring optical characteristics of liquid crystal panel - Google Patents

Abstract

An apparatus for measuring optical characteristics of a liquid crystal panel is provided to easily measure black luminance by precisely rotating upper and lower polarizing plates at once. An apparatus(200) for measuring optical characteristics of a liquid crystal panel includes a panel array unit(210), a lower polarizing plate array unit(220), an upper polarizing plate array unit(230), a backlight loading unit(240), camera units(260,270), and a light detector(250). The panel array unit loads a liquid crystal panel(110) marked with an array mark. The lower and upper polarized array units are provided in a lower part and an upper part of the liquid crystal panel, respectively and array a lower polarizing plate(120) and an upper polarizing plate(130), respectively. The backlight loading unit provides light passing through the lower and upper polarizing plates, and the liquid crystal panel. The camera units acquire an array mark image of each of the liquid crystal panel, and the upper and lower liquid crystal panels. The light detector detects the light passing through the upper and lower liquid crystal panels, and the liquid crystal panel.

Description

Apparatus for measuring optical characteristics of liquid crystal panel

1 is a view schematically showing a configuration of a general liquid crystal panel.

2 is a configuration diagram of a polarization direction measuring device of a polarizing plate for a liquid crystal display according to the related art.

3 is a view for explaining a principle of measuring optical characteristics of a liquid crystal panel according to an exemplary embodiment of the present invention.

4 is a configuration diagram of an optical property measuring apparatus of a liquid crystal panel according to an exemplary embodiment of the present invention.

5 is a schematic diagram of a camera control system according to an exemplary embodiment of the present invention.

6 is a diagram illustrating a hibernating stage according to an embodiment of the present invention.

FIG. 7A is a diagram illustrating obtaining an image using a camera using an alignment mark formed on the liquid crystal panel, and FIG. 7B is a diagram illustrating the camera unit of FIG. 4.

FIG. 8 is a diagram illustrating the upper polarizer alignment unit of FIG. 4.

<Explanation of symbols on main parts of the drawings>

110: liquid crystal panel 120: lower polarizing plate

130: upper polarizing plate 140: backlight unit

150, 150 'luminance meter 160, 170: camera unit

111, 112: alignment mark 200: optical property measuring apparatus

210: panel alignment unit 220: lower polarizer alignment unit

230: upper polarizer alignment unit 240: backlight loading unit

250: hibernation stage

TECHNICAL FIELD The present invention relates to a liquid crystal display device, and more particularly, to an optical property measuring apparatus of a liquid crystal panel.

In general, a liquid crystal display (LCD) is an apparatus that expresses an image by using optical anisotropy and birefringence characteristics of liquid crystal molecules. In the liquid crystal display, two substrates on which the field generating electrodes are formed are disposed so that the surfaces on which the two electrodes are formed face each other, a liquid crystal material is injected between the two substrates, and then a voltage is applied to the two electrodes. By changing the arrangement of the liquid crystal molecules by the electric field, and by controlling the amount of light transmitted through the transparent insulating substrate, the desired image is expressed.

1 is a view schematically showing a configuration of a general liquid crystal panel.

Referring to FIG. 1, a general liquid crystal panel included in the liquid crystal display includes a first substrate 10, a second substrate 20, a liquid crystal layer 30, a first polarizing plate 50, and a second polarizing plate 60. And a backlight unit 40, and the first alignment layer 15 and the second alignment layer 25 are formed on the first substrate 10 and the second substrate 20 in a rubbing manner, respectively.

The structure of FIG. 1 is an anti-parallel oriented liquid crystal panel structure, such as an in-plane switching (IPS) liquid crystal panel or an electrically controlled liquid crystal panel (ECB) liquid crystal panel. Have In this case, the first polarizing plate 50 and the second polarizing plate 60 are arranged in a cross-nicol manner.

1 illustrates that the respective media are actually in contact with each other, but is expressed separately for convenience. In this case, the optical characteristics of the LCD may be determined by the alignment directions of the liquid crystal alignment layers 15 and 25 and the polarization directions of the polarizers 50 and 60. to be. Since the optical properties are determined by the combination thereof, it is necessary to know the exact alignment direction and the correct polarization direction, that is, the alignment axis and the polarization axis.

In other words, since the characteristics of the liquid crystal display device vary greatly according to the polarization conditions of the first polarizing plate 50 and the second polarizing plate 60 for polarizing light, an optimum design thereof is required, and the polarizing plate 50, The exact polarization direction of 60) must be known.

The first polarizer 50 may be referred to as a polarizer, and the second polarizer 60 may be referred to as an analyzer. If the polarization directions of the polarizer 50 and the analyzer 60 are not accurately controlled, the liquid crystal layer in the liquid crystal display device cannot be accurately controlled, which seriously affects the image quality of the liquid crystal display device.

2 is a block diagram of the polarization direction measuring device of the polarizing plate for liquid crystal display according to the prior art, which shows the measurement of the polarization direction of the polarizing plate among the optical properties of the liquid crystal panel.

Referring to FIG. 2, a polarization direction measuring apparatus of a polarizing plate for a liquid crystal display according to the related art includes a light source 71, a first polarizing plate 72, a measurement sample holder 73, a measurement sample 74, and a photodetector. It consists of 75, light is provided from the light source 71, and the photodetector 75 detects the quantity of light which passed the 1st polarizing plate 72 and the measurement sample 74.

Referring to FIG. 2, in order to determine the polarization direction according to the related art, a measurement sample holder capable of accurately mounting the measurement sample 74 with respect to the first polarizing plate 72 and the reference axis that accurately knows the polarization direction ( 73) is required. That is, after passing the measurement sample 74 along the reference plane of the measurement sample holder 73 inclined by a predetermined angle with respect to the polarization direction of the first polarizing plate 72, the measurement sample 74 is rotated in the azimuth direction. . At this time, by finding the rotation angle of the minimum amount of light detected by the photodetector 75, it can be found how much the polarization direction of the measurement sample 74 is distorted from the reference plane.

However, the polarization direction measuring method according to the prior art has an advantage in that it is possible to know the exact polarization direction of the measurement sample. The reference axis of the sample holder with the cutting plane coincided is also known correctly. That is, the polarization direction of the measurement sample can be accurately measured only if both the correct polarization direction of the first polarizing plate as a reference and the reference axis, which is a reference plane of the measurement sample holder that can accurately mount the measurement sample, are known.

On the other hand, according to the prior art, by attaching the polarizing plate to the luminance meter itself probe, the luminance could be measured by the rotation of the polarizing plate. Although there was a luminance meter for measuring the luminance as described above, there is no equipment that can accurately measure the black luminance.

Further, according to the prior art, the polarizer and the liquid crystal panel could not be accurately aligned because the polarizer and the liquid crystal panel were aligned by the eye, and in particular, the deviation of the black luminance value measured by each of the measurers was large. That is, conventionally, it is difficult to verify whether the measured black luminance value is an accurate black luminance value. In addition, since the degree of rotation of the polarizer is performed by the measurer, there is a problem in that it is difficult to confirm whether the value measured by the measurer is data obtained by accurately rotating a few degrees.

An object of the present invention is to provide an optical characteristic measuring apparatus for a liquid crystal panel capable of precisely measuring the optical characteristics of the liquid crystal panel by accurately aligning the liquid crystal panel and the polarizing plate.

Another object of the present invention is to provide an apparatus for measuring optical characteristics of a liquid crystal panel capable of removing distortion of black luminance due to misalignment of a polarizing plate and a liquid crystal panel.

Another technical problem to be achieved by the present invention is to measure the luminance by rotating the upper and lower polarizers at various angles, thereby measuring the optical characteristics of the liquid crystal panel that can easily measure the black luminance of the liquid crystal, the optical axis of the liquid crystal, or the optical axis of the polarizing plate. It is for providing a device.

The objects of the present invention are not limited to the above-mentioned objects, and other objects which are not mentioned will be clearly understood by those skilled in the art from the following description.

As a means for achieving the above technical problem, the optical property measuring apparatus of the liquid crystal panel according to the present invention, the panel alignment unit for loading the liquid crystal panel engraved alignment mark; A lower polarizer alignment unit for aligning a lower polarizer disposed under the liquid crystal panel; An upper polarizer alignment unit for aligning an upper polarizer disposed on the liquid crystal panel; A backlight loading unit configured to provide light passing through the lower polarizer, the liquid crystal panel, and the upper polarizer; A camera unit for acquiring an alignment mark image of each of the liquid crystal panel, the upper polarizer and the lower polarizer; And a photo detector for detecting light passing through the lower polarizer, the liquid crystal panel, and the upper polarizer.

Here, the lower polarizing plate and the upper polarizing plate are each characterized in that attached to the glass substrate engraved alignment mark.

Here, in the optical property measuring apparatus of the liquid crystal panel according to the present invention, each of the panel alignment unit, the upper polarizer alignment unit, and the lower polarizer alignment unit may be the same surface for moving and rotating the liquid crystal panel, the upper polarizer, and the lower polarizer, respectively. It may further comprise a stage.

Here, the hibernate stage includes a loading jig for mounting each of the liquid crystal panel, the upper polarizer and the lower polarizer.

Here, the hibernating stage is provided with one X-axis stepping motor and two Y-axis stepping motors, characterized in that the X-axis, Y-axis and Θ axis can be corrected.

Here, the hibernation stage of the liquid crystal panel may simultaneously load the loading plate and the liquid crystal panel corresponding to the size of the liquid crystal display model.

Here, each of the panel alignment unit, the upper polarizing plate and the lower polarizing plate is characterized in that the opening is formed in consideration of the luminance measurement area, the opening is characterized in that passing through the light provided from the backlight seated in the backlight loading unit. It is done.

In this case, the panel alignment unit is characterized in that it has a structure that is avoided to the rear to secure the loading of the photodetector and the camera unit when the liquid crystal panel loading.

Here, the lower polarizing plate alignment unit is a portion on which the lower polarizing plate is mounted is disposed on the upper portion of the backlight loading unit, the portion for adjusting the position of the lower polarizing plate is characterized in that disposed under the backlight loading unit.

Here, the lower polarizer alignment unit is characterized in that for adjusting the height of the lower polarizer using an adjustment bolt (Bolt).

The lower polarizer alignment unit may rotate the lower polarizer from -10 degrees to +10 degrees, and rotate the lower polarizer by 0.01 degrees.

Here, the upper polarizing plate alignment unit is a portion on which the upper polarizing plate is mounted is disposed under the photo detector, the portion for adjusting the position of the upper polarizing plate is characterized in that disposed on the upper photo detector.

The upper polarizer alignment unit may rotate the upper polarizer from 0 degrees to 90 degrees, and rotate the upper polarizer by 0.01 degrees.

The camera may be a charge coupled device (CCD) camera or a complementary metal oxide semiconductor (CMOS) camera.

Here, the optical property measuring apparatus of the liquid crystal panel according to the present invention may further include a camera control system for controlling, analyzing and monitoring the alignment mark image obtained from the camera.

Here, the camera control system, the control unit for receiving and controlling or analyzing the alignment mark image obtained from the camera; And a monitor outputting the received image.

The photodetector may be a photo detector or a luminance meter.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various forms, and the present embodiments are merely common to those skilled in the art to which the present disclosure is completed and to which the present invention pertains. It is provided to inform those skilled in the art to the fullest extent of the invention, the invention being defined only by the scope of the claims.

Hereinafter, an optical characteristic measuring apparatus of a liquid crystal panel according to the present invention will be described in detail with reference to the accompanying drawings.

As the specification of the liquid crystal panel has recently increased, so has the requirement of the contrast ratio (CR) of the liquid crystal panel. This necessitates the need to measure and reflect black luminance.

Here, the contrast ratio is given by CR = (white luminance / black luminance), and the term brightness substantially refers to the amount representing the brightness of the reflector surface of a light source or light having a constant width.

The terms white luminance and black luminance used in LCDs are used as white luminance when the polarizers attached to the upper and lower parts of the liquid crystal panel emit the brightest light by backlight illumination, and black luminance when the darkest light is emitted. Typically, when the upper and lower polarizers are attached in the same direction, they are the brightest and darkest when they are 90 degrees staggered from each other.

An embodiment of the present invention is a device manufactured for precisely measuring the optical characteristics of the liquid crystal panel, for example, the black brightness of the liquid crystal, the optical axis of the liquid crystal, or the optical axis (polarization direction) of the polarizing plate, according to an embodiment of the present invention. The optical characteristic measuring apparatus of a liquid crystal panel has the precision rotation function of a polarizing plate stage, and the precision alignment function between a polarizing plate and a liquid crystal panel.

3 is a view for explaining a principle of measuring optical characteristics of a liquid crystal panel according to an exemplary embodiment of the present invention.

Referring to FIG. 3, in order to measure optical characteristics of the liquid crystal panel according to the exemplary embodiment of the present invention, the liquid crystal panel 110, the lower polarizer 120, the upper polarizer 130, the backlight unit 140, and the luminance meter ( 150, first and second CCD cameras 160 and 170 are provided.

The liquid crystal panel 110 has alignment marks formed on the left and right sides of the transparent insulating glass substrate. Here, the alignment mark is generally formed in a + character shape and is formed on the non-display portion of the liquid crystal panel 110 rather than the pixel area.

The lower polarizer 120 is disposed below the liquid crystal panel 110, and alignment marks for aligning each other are formed to correspond to the alignment marks of the liquid crystal panel 110.

The upper polarizing plate 130 is disposed above the liquid crystal panel 110, and similarly, alignment marks for aligning each other are formed to correspond to the alignment marks of the liquid crystal panel 110.

The alignment mark of the liquid crystal panel 110, the alignment mark of the lower polarizer 120, and the alignment mark of the upper polarizer 130 may be the same display, but are not limited thereto. Based on the alignment marks of the lower polarizer 120 and the upper polarizer 130, respectively.

The backlight unit 140 is a light source and provides light passing through the lower polarizer 120, the liquid crystal panel 110, and the upper polarizer 130.

The luminance meter 150 is a kind of photodetector and detects light of the backlight unit 140 via the lower polarizer 120, the liquid crystal panel 110, and the upper polarizer 130. The luminance meter 150 may include a luminance probe and a luminance main body 150 ′. In addition, a photo detector may be used instead of the luminance meter 150.

First and second charge coupled device (CCD) cameras 160 and 170 acquire an alignment mark image between the liquid crystal panel 110 and the lower and upper polarizers 120 and 130. A CMOS (Complementary Metal Oxide Semiconductor) camera may be used instead of the CCD cameras 160 and 170.

Therefore, the positions of the liquid crystal panel 110 and the lower and upper polarizers 120 and 130 are aligned according to the obtained alignment mark image.

Specifically, the images acquired by the first and second CCD cameras 160 and 170 are controlled by the camera control system. For example, the acquired alignment mark images are output on the monitor, and the measurer The liquid crystal panel 110, the lower polarizer 120, and the upper polarizer 130 are moved or rotated according to the screen on the monitor to be aligned with each other.

In an embodiment of the present invention, alignment between the polarizers 120 and 130 and the liquid crystal panel 110 is performed by using the first and second CCD cameras 160 and 170 to ensure the accuracy of the measured optical characteristic values. Can be.

4 is a configuration diagram of an optical characteristic measuring apparatus of a liquid crystal panel according to an exemplary embodiment of the present invention.

3 and 4, an optical property measuring apparatus of a liquid crystal panel according to an exemplary embodiment of the present invention includes a panel alignment unit 210, a lower polarizer alignment unit 220, an upper polarizer alignment unit 230, and backlight loading. And a unit 240, a photo detector 250, and first and second camera units 260 and 270. In addition, a camera control system for controlling, analyzing, and monitoring an image acquired through the camera units 260 and 270 having the cameras 160 and 170 may be additionally formed.

The panel alignment unit 210 is for loading the liquid crystal panel 110 with the alignment mark engraved thereon. The panel alignment unit is configured with hibernating stages moving in the X, Y, and Θ directions, and the hibernation stages of each LCD model. The loading plate plate and the liquid crystal panel 110 may be simultaneously loaded according to the size.

When the liquid crystal panel 110 is loaded, the panel alignment unit 210 has a structure of avoiding backward to secure the loading of the luminance meter 250 / camera units 260 and 270 which are photodetectors.

Substantially, the panel alignment unit 210 has an opening formed in consideration of the luminance measurement area. For example, an opening of 220 mm x 170 mm is secured. In addition, the panel alignment unit 210 has a stroke of ± 10 mm in the X and Y directions, and the rotation range has a degree of ± 1 degree.

The panel alignment unit 210 includes a panel loading jig and has a structure capable of fixing the side surface by using a magnet when the liquid crystal panel 110 rotates.

In addition, the lower polarizing plate alignment unit 220 is attached to a glass substrate having an alignment mark engraved thereon to adjust the position of the lower polarizing plate 120 disposed below the liquid crystal panel 110. In the exemplary embodiment of the present invention, the portion in which the lower polarizer 120 is mounted is disposed on the upper portion of the backlight loading unit 240, but the lower polarizer alignment unit 220 for adjusting the position of the lower polarizer 120 may be a backlight loading unit. 240 is disposed below.

The lower polarizer alignment unit 220 is composed of a stage and a DDR motor to move in the X and Y directions, similar to the upper polarizer alignment unit 230, and in accordance with the size of each LCD model, to load the loading jig in the lower structure It is. The lower polarizer alignment unit 210 has a structure that can be loaded without damaging the polarizer 120 because the polarizer 120 is attached to the lower portion of the glass.

The lower polarizer alignment unit 220 has an opening formed in consideration of the luminance measurement area. For example, an opening of 220 mm x 170 mm is secured. In addition, the lower polarizer alignment unit 220 uses an adjustment bolt (not shown) to easily adjust the height of the lower polarizer 120.

In addition, the upper polarizing plate alignment unit 230 is for adjusting the position of the upper polarizing plate 130 which is attached on the glass substrate engraved with the alignment mark and disposed on the liquid crystal panel. In the exemplary embodiment of the present invention, the portion in which the upper polarizer 130 is mounted is disposed under the photo detector 250, but the upper polarizer alignment unit 230 for adjusting the position of the upper polarizer 130 may include the photo detector 250. Is placed on top. The upper polarizing plate alignment unit 230 will be described later with reference to FIG. 8.

In an embodiment of the present invention, the upper polarizer alignment unit 230 may rotate the upper polarizer 130 to 0 to +90 degrees, and the lower polarizer alignment unit 220 rotates the lower polarizer 120 to -10 to + It can rotate up to 10 degrees, that is, the upper and lower polarizers 120 and 130 can be precisely rotated simultaneously, so that both black and white luminance can be measured. That is, after the upper polarizer 130 and the lower polarizer 120 are rotated, respectively, when the upper and lower polarizers are attached in the same direction, the white luminance may be measured and the black luminance may be measured when the upper and lower polarizers are staggered by 90 degrees. have.

In this case, since the black luminance measurement needs to be measured in a state in which the gap between the polarizing plates 120 and 130 and the liquid crystal panel 110 is minimized to within a few mm, the measuring device according to the embodiment of the present invention may use the polarizing plates 120 and 130. ) And the liquid crystal panel 110 can be minimized, and at least 0.01 degrees to 0.001 degrees of precision rotation is possible.

In addition, the backlight loading unit 240 is for loading the backlight unit 140 that provides light via the lower polarizer 120, the liquid crystal panel 110, and the upper polarizer 130.

The backlight unit 140 is supplied with a backlight lamp in a lower cabinet (Cabinet) type, the backlight loading unit 240 is provided with a loading jig in consideration of the protrusion and height, such as the heat sink of the backlight unit 140.

In addition, the camera units 260 and 270 are equipped with the CCD cameras 160 and 170 of FIG. 3 to adjust the positions of the CCD cameras 160 and 170. The liquid crystal panel 110 and the lower polarizer 120 And an alignment mark image of each of the upper polarizers 130, which will be described later with reference to FIGS. 7A and 7B.

In addition, the photo detector 250 corresponds to the luminance meter 150 of FIG. 3 and is used to detect light passing through the lower polarizer 120, the liquid crystal panel 110, and the upper polarizer 130. .

In the optical characteristic measuring apparatus according to the exemplary embodiment of the present invention, the angle between the liquid crystal panel 110 and the polarizing plates 120 and 130 that could not be measured or accurately measured in the past is precisely between 0.01 degrees and 0.001 degrees. It can be measured while rotating. In addition, since the optical axis and the black luminance value can be measured, it is a very useful device to increase the contrast ratio (CR) by not only monitoring the existing mass-production panel but also measuring the contrast ratio (CR) of the liquid crystal panel to be developed.

As described above, the biggest feature of the mechanical part of the optical characteristic measuring apparatus according to the embodiment of the present invention is that the light emitted from the backlight unit 140 in order to measure the brightness of the lower polarizer 120-> liquid crystal panel 110 )-> Must pass through the upper polarizer 130. Accordingly, an opening is formed in each loading jig of the lower polarizer 120, the liquid crystal panel 110, and the upper polarizer 130.

In addition, in order to obtain accurate data when measuring the optical characteristics, the distance between the lower polarizer 120, the liquid crystal panel 110 and the upper polarizer 130 should be as small as possible, the structure and material of each loading jig is an important factor.

On the other hand, Figure 5 is a schematic configuration diagram of a camera control system according to an embodiment of the present invention.

Referring to FIG. 5, the camera control system according to the embodiment of the present invention constitutes a high depth and high accuracy optical system, and performs alignment of the upper polarizer 130 and the lower polarizer 120 on the liquid crystal panel 110. In this case, the luminance values according to the geometric relative angles of the liquid crystal panel 110 and the polarizers 120 and 130 in the backlight lighting state are measured, and the respective characteristics thereof are analyzed.

In other words, the optical characteristic measuring apparatus according to the embodiment of the present invention uses an optical system having a high depth and high accuracy, that is, a camera control system for the alignment of the lower polarizer 120, the liquid crystal panel 110, and the upper polarizer 130. Additionally. Here, the camera control system includes a control unit 310, a monitor 320, and the like, and the liquid crystal panel 110 and the lower polarizer plate while checking the image acquired by the cameras 160 and 170 with the eyes. 120 and the position of the upper polarizer 130 can be adjusted

First, in the case of the liquid crystal panel 110, the alignment marks formed on the liquid crystal panel itself may be aligned, and in the case of the polarizing plates 120 and 130, the alignment marks may be aligned by attaching the polarizing plate to the glass on which the alignment marks are engraved. Can be.

In order to move the measured and monitored position values in the camera control system, the hierarchical stages in which the loading jig of the lower polarizer 120, the liquid crystal panel 110 and the upper polarizer 130 are moved in the X, Y and Θ axis directions, respectively use. The hibernation stage will be described with reference to FIG. 6.

6 is a diagram illustrating a hibernating stage according to an embodiment of the present invention.

Referring to FIG. 6, the hibernating stage 250 according to an embodiment of the present invention is for aligning the upper and lower polarizers and the liquid crystal panel, and includes one X-axis stepping motor 253 and two Y's. Shaft stepping motors 254 and 255. Therefore, up to the Θ axis can be corrected with a combination of one X axis and two Y axes.

Here, the stepping motor is also called a step motor or a pulse motor, and it is used for accurate angle control by circulating a predetermined step angle. The characteristic of the stepping motor is that it rotates in response to the pulse power, the rotation angle is displaced in proportion to the number of input pulses, and the rotation speed is converted in proportion to the input frequency, thereby controlling the operation of the motor without feedback.

The structure of the hibernation stage 250 may have the same structure in the panel alignment unit 210, the lower polarizer alignment unit 220, and the upper polarizer alignment unit 230, and may be applied only to the panel alignment unit 210, and is hibernated. The above-described loading jig is provided on the stage 250, and reference numeral 251 denotes an opening formed in consideration of the luminance measurement area as described above, and is a portion through which light provided from the backlight unit 140, which is a light source, passes. . In addition, reference numeral 252 denotes an open area for acquiring an alignment mark image in the cameras 160 and 170, and in the embodiment of the present invention, four are formed.

7A is a diagram illustrating photographing an alignment mark formed on the liquid crystal panel using a camera, and FIG. 7B is a diagram illustrating the camera unit of FIG. 4.

Referring to FIG. 4 again, the camera units 260 and 270 according to the embodiment of the present invention may be configured to position the upper polarizer 130, the liquid crystal panel 110, and the lower polarizer 120. As an apparatus for acquiring an image for determination using (160, 170), an embodiment of the present invention uses two cameras, as shown in Figure 7a. In this case, the liquid crystal panel 110 determines X, Y, and Θ positions based on the alignment marks 111 and 112 of the liquid crystal panel 110, and the alignment criteria of the polarizers 120 and 130 are the polarization plates 120 and 130. It can be an alignment mark on the attached glass.

The driving of the cameras 160 and 170 may be operated by a servo motor and an LM guide on each of the X, Y, and Z axes, but is not limited thereto.

In addition, the camera units 260 and 270 are typically composed of two-axis robots moving in the X-axis and Y-axis, where the Z-axis uses the manual stage 161, as shown in FIG. It may have a structure that can correct the fine distance between the liver.

8 is a diagram illustrating the upper polarizer alignment unit of FIG. 4.

Referring to FIG. 8, the upper polarizer alignment unit 230 includes a stage movable in X and Y axes, a connection part 231, and a DDR motor 232, in which the upper polarizer 130 is the DDR motor. (232) is designed to rotate the rotation angle from 0 degrees to 90 degrees. Here, reference numeral 131 denotes a loading jig for loading the upper polarizer 130. That is, there is a loading jig for positioning the upper polarizer 120 of the liquid crystal panel 110.

In addition, the upper polarizing plate alignment unit 230 may operate the entire upper polarizing plate alignment unit 130 as a servo motor to smoothly supply the backlight unit 140, the lower polarizing plate 120, and the liquid crystal panel 110. Motor) and LM guide are combined to have a structure that can move backward.

Meanwhile, the upper and lower polarizers 120 and 130 measure the optical axes of the polarizers 120 and 130 in advance while rotating by mounting only the polarizers in advance, and the optical axes of the polarizers 120 and 130 are measured during the black luminance measurement. By compensating for the distortion, the black luminance may be measured by inserting the liquid crystal panel based on the actual optical axes of the polarizing plates 120 and 130.

On the other hand, since the actual backlight unit of the LCD model is used as the light source, the influence of the reflective sheet or the diffusion sheet in the backlight unit can be reflected.

According to an embodiment of the present invention, the upper and lower polarizers and the liquid crystal panel may be aligned using a CCD camera which is a vision system, and the upper and lower polarizers 120 and 130 may be rotated at various angles. Therefore, not only the black luminance but also the twisted angle of the liquid crystal LC injected into the liquid crystal panel 110 or the absorption and transmission axes of the upper and lower polarizers 120 and 130 may be measured.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive.

According to the present invention, the upper and lower polarizers and the liquid crystal panel can be accurately aligned, and the black luminance can be easily measured by precisely rotating the upper and lower polarizers simultaneously. As a result, the distortion of the black luminance can be removed. In addition, by measuring the luminance by rotating the upper and lower polarizers at various angles, the distorted angle (LC optical axis) of the liquid crystal in the liquid crystal panel and the optical axes of the upper and lower polarizers can be easily measured.

Claims (21)

A panel alignment unit for loading a liquid crystal panel engraved with an alignment mark; A lower polarizer alignment unit for aligning a lower polarizer disposed under the liquid crystal panel; An upper polarizer alignment unit for aligning an upper polarizer disposed on the liquid crystal panel; A backlight loading unit configured to provide light passing through the lower polarizer, the liquid crystal panel, and the upper polarizer; A camera unit for acquiring an alignment mark image of each of the liquid crystal panel, the upper polarizer and the lower polarizer; And A photo detector for detecting light passing through the lower polarizer, the liquid crystal panel, and the upper polarizer Optical property measuring apparatus of the liquid crystal panel comprising a. The method of claim 1 The lower polarizing plate and the upper polarizing plate are each attached to the glass substrate engraved alignment mark, characterized in that the optical properties of the liquid crystal panel. The method of claim 1, Each of the panel alignment unit, the upper polarizer alignment unit, and the lower polarizer alignment unit is a hibernating stage for moving and rotating the liquid crystal panel, the upper polarizer, and the lower polarizer, respectively. Optical characteristic measuring device of the liquid crystal panel further comprising. The method of claim 3, And said hibernation stage comprises a loading jig for mounting each of said liquid crystal panel, said upper polarizing plate and said lower polarizing plate. The method of claim 3, The hibernating stage is provided with one X-axis stepping motor and two Y-axis stepping motors, and the optical characteristic measuring apparatus of the liquid crystal panel, characterized in that the X-axis, Y-axis and Θ-axis can be corrected. The method of claim 3, The hibernation stage of the liquid crystal panel is configured to simultaneously load the loading plate and the liquid crystal panel corresponding to the size of the liquid crystal display model. The method of claim 1, And an opening is formed in each of the panel alignment unit, the upper polarizer, and the lower polarizer in consideration of a luminance measurement area. The method of claim 7, wherein And the opening passes the light provided from the backlight seated in the backlight loading unit. The method of claim 1, And the panel alignment unit has a structure which is avoided backward to secure the loading of the photodetector and the camera unit when the liquid crystal panel is loaded. The method of claim 1, In the lower polarizer alignment unit, a portion on which the lower polarizer is mounted is disposed above the backlight loading unit, and a portion for adjusting the position of the lower polarizer is disposed below the backlight loading unit. Characteristic measuring device. The method of claim 1, And the lower polarizer alignment unit adjusts the height of the lower polarizer using an adjustment bolt. The method of claim 1, And the lower polarizer alignment unit rotates the lower polarizer from -10 degrees to +10 degrees. The method of claim 12, And the lower polarizing plate alignment unit rotates the lower polarizing plate by 0.01 degrees. The method of claim 1, Wherein the upper polarizing plate alignment unit, the portion on which the upper polarizing plate is mounted is disposed below the photo detector, but the portion for adjusting the position of the upper polarizing plate is disposed above the photo detector. . The method of claim 1, And the upper polarizing plate alignment unit rotates the upper polarizing plate from 0 degrees to 90 degrees. The method of claim 15, The upper polarizing plate alignment unit rotates the upper polarizing plate by 0.01 degrees. The method of claim 1, The camera unit is moved in the X-axis and Y-axis, the Z-axis is characterized in that the manually adjusted device of the liquid crystal panel. The method of claim 1, The camera may be a charge coupled device (CCD) camera or a complementary metal oxide semiconductor (CMOS) camera. The method of claim 1, And a camera control system for controlling, analyzing, and monitoring the alignment mark image obtained from the camera. The method of claim 19, wherein the camera control system, A control unit for receiving and controlling or analyzing the alignment mark image obtained from the camera; And A monitor for outputting the received image Optical characteristic measurement apparatus of the liquid crystal panel comprising a. The method of claim 1, The optical detector is a photo detector (photo detector) or a luminance meter, characterized in that the optical properties of the liquid crystal panel.

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