KR20010108732A - Electro-optical converter and it's sensing method - Google Patents

Abstract

The present invention relates to a non-contact electro-optical device for detecting a defect state of a flat panel display device, comprising: a light source means, an electro-optic material layer, a common electrode means, for non-contact measurement of voltages of a plurality of electrodes distributed on a plane; In the non-contact electro-optical conversion device comprising a dielectric thin film means and a camera means, the common electrode means, the electro-optic material layer is attached, a plurality of horizontal length is smaller than the size of the pixel electrode and have a long shape in the longitudinal direction An incidence side medium means for inducing the incidence of light generated by the light source means to be modulated in the electro-optic material layer, and modulated in the electro-optic material layer by being irradiated from the incidence side medium means And a light emitting medium means for guiding the emitted light to the camera means,

The light generated from the light source is guided to the electro-optic material layer by the incident medium while the driving device moves on the screen on which the pixel electrodes are arranged, and the induced light is applied to the electro-optic material layer by the applied current. Modulating the light emitting device and outputting the light through a plurality of reflections in the center of the common electrode, guiding the emitted light from the output medium, capturing the light induced by the medium in the photodetector, and converting the light into an image; The inspection method of performing the inspection of the array electrodes is performed.

Description

Non-contact electro-optic converter and array electrode inspection method {Electro-optical converter and it's sensing method}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact electro-optical device for detecting a defect state of a flat panel display device, and in particular, to provide a device capable of a faster detection operation and an inspection method accordingly.

Commercialization of display devices (FPD, Flat Display Panel) such as liquid crystal display (LCD) and plasma display panel (PEP) is in full swing.

Such a flat panel display device makes an electrode in each pixel constituting the screen and controls the voltage applied to the pixel electrode to change the optical characteristics (refractive index, transmittance, light emission, polarization characteristics, etc.) of the electro-optic material on the pixel electrode. The characteristics of light passing or reflecting through the pixel electrodes are changed, and a two-dimensional image can be displayed by using the arrangement of the pixels.

In the production process of such a flat panel display device, once the assembly of the pixel electrode is arranged with the electro-optic material, once the pixel electrode is defective, regeneration is impossible. It needs to be detected.

Since the current flowing through the wire is invisible, it can be measured through contact with a voltmeter, or in the case of radio wave emission, it can be measured by a radio wave sensing device such as an antenna.

However, when the insulating layer is coated with the outside during the manufacturing of the pixel electrode, contact measurement is impossible and when the radio wave emission is difficult due to the structure of the pixel electrode, the antenna cannot be measured. In particular, in the electrical measurement, measuring multiple pixels simultaneously is not possible. Difficult to apply in high volume production processes requiring fast inspection speeds.

Therefore, in order to use an optical means such as a camera capable of simultaneously receiving a plurality of pixels at a high speed, a means for converting the voltage of the pixel electrode into an image has been devised.

As an example of such a means, an electro-optic modulator developed by Photon Dynamics, Inc. is a published technique (Domestic Patent No. 0,168,440, US Pat. No. 56,150,39). In addition, it can be implemented using various structures in the published literature.

The principle of non-contact detection of the voltage of the electrode by the electro-optic effect is described with reference to FIG.

When voltage is applied from the voltage source 2 to both ends of the electro-optic material layer 1, the refractive index or transmittance of the electro-optic material layer 1 is changed, so that the electro-optic material layer on the upper part of the pixel electrode 3 Part of (1) will show different optical properties locally.

For example, the electro-optic material layer 1 is opaque in a state where no voltage is applied, and when the voltage is applied, only the upper portion of the pixel electrode 3 is locally transparent.

When a voltage is applied, the dielectric thin film 5 is disposed between the electro-optic material layer 1 and the pixel electrode 3 so that a capacitance can be formed between the common electrode 4 and the pixel electrode 3.

Due to this basic principle, a structure that can be actually applied to the inspection of a flat array pixel electrode is known as illustrated in FIGS. 2 and 3.

2 is a structure for detecting incident light by reflecting it.

A dielectric reflecting film 6 is inserted between the electro-optic material layer 1 and the dielectric thin film 5 of FIG. 1 so that light incident from the light source 7 above the electro-optic material layer 1 is applied to the pixel electrode layer under measurement. It is a structure that is reflected before reaching to be detected by the photodetecting device (8).

Accordingly, even if the base 9 supporting the pixel electrode layer is opaque, the pixel electrode 3 can be detected.

Denoted at 10 is a half mirror that functions to partially transmit light and partially reflect light.

3 is a structure of sensing the electrode voltage by transmitting light through the object under test.

Unlike the case of FIG. 2, there is no dielectric reflector 6.

In this case, the base 9 must be transparent.

In order for light to pass through the electro-optic layer, the common electrode 4 must be transparent, and the transparent electrode is manufactured by depositing indium tin oxide (ITO) or the like.

In addition, when the electro-optic modulator is close enough to the pixel electrode 3, crosstalk by the adjacent pixel electrode 3 may be reduced, and the driving voltage may be prevented from being excessively high.

Interference is also affected by the properties of the electro-optic layer 1 itself.

A representative example of the electro-optic material layer 1 is liquid crystal. Since the liquid crystal is a liquid phase, it cannot be molded while maintaining a narrow gap between the common electrode 4 and the pixel electrode 3.

Therefore, polymer dispersed liquid crystals (PDLC-Polymer Dispersed Liquid Crystal) in which liquid crystal droplets are dispersed on a polymer matrix are frequently used.

4 is a diagram when a voltage is applied between the pixel electrode 3 and the common electrode 4 to form an electric field.

The case of the electro-optic material layer 1 in which the electric field effect is represented by a difference in transmittance is illustrated. In this case, the portion of the pixel electrode 3 is transparent and the remaining portion is opaque or translucent.

This is the case where a polymer dispersed liquid crystal layer is used as an electro-optic material layer, and as shown in FIG. 5, the operation principle of the polymer dispersed liquid crystal (a) is a state in which no electric field is applied, and (b) is a state in which an electric field is applied. It was.

That is, when an electric field is applied, due to the arrangement of liquid crystal molecules, the refractive index of the liquid crystal droplets becomes similar to the refractive index of the polymer surrounding the liquid crystal, and when the electric field is removed, the light is scattered and becomes opaque.

In order to lower the electric field voltage, the distance between the common electrode and the pixel electrode should be close enough. In this case, since the thickness of the electro-optic material layer becomes thin, it may not be opaque even when no voltage is applied, which is a contrast ratio for obtaining a clear image. Contrast can be reduced, and unwanted unwanted images can be detected by the detection element, making it difficult to judge.

Therefore, it is practical to prevent light from directly reflecting on the pixel plane or the base plane through the dielectric reflector.

However, the conventional electro-optic converter (modulator) as described above is manufactured to obtain an image by using a two-dimensional solid-state imaging device.

Therefore, the lower surface of the electro-optic material layer 1 is manufactured in a two-dimensional plane, and the gap distance between the lower surface of the electro-optic material layer 1 and the pixel electrode 3 is uniform over a wide surface, so that Reliability can be obtained that the sensed image is an image obtained from an actual pixel electrode.

In other words, the characteristics of the electro-optic material layer 1 are accompanied by a change in characteristics proportional to the electric field, and an important factor for determining the strength of the electric field is the spacing between the electrodes.

If there is an abnormal partial image in the acquired image, it is determined whether the electro-optic conversion value of the portion is different and that the abnormal value is due to the irregularity of the gap gap or the defect of the arrangement of the pixel electrodes 3 during image data processing. Because it is difficult.

Therefore, in order to implement an inspection system using an electro-optic converter as in the prior art, the spacing between electrodes must be adjusted with high precision.

In the current commercial equipment, the area of the electro-optic layer is about 72 mm x 72 mm, which requires a complex mechanical alignment device to maintain a 20 μm spacing over the entire area. This is called Gapping), which takes several minutes.

In addition, when a two-dimensional camera is used, the image transmission speed is fixed, and the resolution thereof is limited.

Therefore, a method of using a one-dimensional camera (linear camera) can be considered.

One-dimensional cameras acquire and transmit images line by line. Generally, the resolution is higher than that of 2D and the transmission speed is high, so that inspection can be performed at higher speed.

One-dimensional camera is not a technology that has receded more than a two-dimensional camera, but a two-dimensional camera can acquire a certain area at a time, whereas one line can be acquired continuously so that the camera or a subject under test can be specially manufactured to acquire an image. Will be.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and to provide a non-contact electro-optical device for detecting a defect state of a flat panel display more quickly.

Electro-optical conversion device of the present invention for achieving this purpose,

In a non-contact electro-optical converter comprising a light source means, an electro-optic material layer, a common electrode means, a dielectric thin film means, and a camera means to measure the voltage of a plurality of electrodes distributed on a plane in a non-contact manner,

The common electrode means,

The electro-optic material layer is attached to the lower part and is divided into a plurality of parts so that the horizontal length is smaller than the size of the pixel electrode and has a long shape in the vertical direction.

An incidence side medium means for inducing the incidence of light generated by the light source means to be modulated in the electro-optic material layer;

And an emission-side medium means for guiding the light emitted from the incident-side medium means and emitted after being modulated in the electro-optic material layer to the camera means.

Another feature of the present invention is to guide the light generated from the light source to the electro-optic material layer by the incident medium while the driving device is moving on the screen on which the pixel electrode is arranged;

The induced light is modulated by an electric field in the electro-optic material layer by an applied current and emitted through a plurality of reflections at the center of the common electrode;

Inducing the emitted light from the output medium and capturing the light induced by the medium in a photodetector to convert the light into an image;

Characterized in that the step of performing the inspection of the array electrode.

1 is a view showing a principle of non-contact detection of the voltage of a conventional electrode.

2 is a detection diagram applied to inspection of a conventional flat panel array pixel electrode;

3 is a detection diagram applied to inspection of a conventional flat panel array pixel electrode;

4 is a diagram of an electric field formed by applying a voltage between a conventional pixel electrode and a common electrode;

5 is a view showing the operation principle of a conventional polymer dispersed liquid crystal.

6 is a block diagram of the present invention.

7 is a perspective view of the electro-optical sensor of the present invention.

8 is a view showing the operation of the present invention.

9 is a view showing a case in which the optical fiber is used as a medium in the present invention.

10 is a view showing the operation when the light is incident from the side in the present invention.

11 is a view showing a change of light in an opaque state of one end of the electro-optic material in another embodiment of the present invention.

12 is a view showing a path of light for each position on a pixel electrode when scanning on the pixel electrode according to the present invention;

13 is a perspective view of a driving device of an electro-optical sensor including the common electrode according to the present invention.

*** Explanation of symbols of main part of drawing ***

101: light source 102: electro-optic material

103,103 ': incident medium 104: exit medium

105: pixel electrode 106: common electrode

107: dielectric reflective thin film 108: camera

109: basis

The non-contact electro-optic converter and inspection method of the present invention will be described with reference to FIGS. 6 to 13.

In the apparatus for measuring the voltage of a plurality of electrodes distributed on a plane in a non-contact,

The light source 101 as a means for generating light, the incident medium 103 and 103 'as a means for guiding the light generated by the light source 101 to the electro-optic material layer 102, and the medium 103 and 103'. An electro-optic material layer 102, which is a means for modulating the light irradiated through the electric field, and an emission-side medium 104, which is a means for inducing light emitted by being modulated from the electro-optic material layer 102; In addition, the electro-optic material applied to the electro-optic material layer 102 acts as a conductive layer to work with the pixel electrode 105 to change the electric field of the electro-optic material layer 102 so as to produce an optical effect. The middle part is reflective and opaque and both sides are transparent common electrode 106, or two parts are transparent on one side and the other is reflective, or one part is transparent or opaque The common electrode 106 and the incident light It consists of a dielectric reflective thin film 107 located on the lower surface of the electro-optic material layer 102 so as to totally reflect before reaching the positive electrode, and a camera 108 which is a means for condensing and converting light into an image.

In addition, the common electrode 106 has a shape in which the horizontal length is smaller than the size of the pixel electrode 105 and is long in the vertical direction, as shown in FIG. 6, and in three parts in the horizontal direction as in the enlarged portion. When light is incident, the medium side (a) and the exiting medium side (b) become transparent to allow the light to pass through, and the middle portion (c) is an opaque conductor having excellent reflection characteristics.

Reference numeral 109 is the basis, 201 is the rangefinder, 202 is the hinge, and 203 is the linear servo actuator.

Features of the present invention configured as described above will be described below.

7 is a schematic perspective view of an electro-optic sensor composed of an electro-optic material layer 102, a dielectric reflector thin film 107, etc., including a common electrode 106 corresponding to the core portion of the present invention. It is characterized by a long longitudinal structure in comparison.

FIG. 8 shows the operation diagram of the present invention, when the electric field is acting, the electro-optic material layer 102 becomes transparent and the light incident through the incidence side medium 103, 103 'is shown in FIG. 8 (b). As described above, the intermediate portion c of the common electrode 106, which also serves as a reflecting plate, passes through the electro-optic material layer 102 and is reflected toward the exit side medium 104 through a plurality of reflections.

When the electric field does not work, as shown in FIG. 8B, the electro-optic material layer 102 under the common electrode 106 is opaque, and thus no image is detected by the camera 108 which detects light because there is no light emitted. .

The medium used to guide the entrance and exit of light may be optical fibers (d, d ').

The implementation diagram when the optical fibers d and d 'are used as a medium is illustrated in FIG.

In this case, a transparent medium (e) such as a transparent epoxy may be inserted between the light guide medium and the transparent electrode layer to support the transparent electrode layer.

In addition, when the electro-optic material layer 102 whose refractive index is changed by an electric field as shown in FIG. 10 is configured as in the structure of the present invention, light may be incident from the side by the phototransmitter.

In this case, the transparent electrode layers a and b of the common electrode do not need to be present.

The structure of the existing invention can not be carried out using an electro-optic material layer using side light, but in the present invention, such a structure can be implemented.

In another embodiment of the present invention, for example, as shown in FIG. 11, one end of the electro-optic material layer 102 is an opaque reflective layer, and the incident light is returned to the incident side medium again.

By collecting this light and directing it to the camera 108, an image of an electrode array displayed in one dimension can be viewed.

In the present invention, since the shape of the common electrode 106 is thin and long, the resistance value may be high when the electrode is formed of a thin film.

However, when there is no abnormality in causing the electric field effect of the electro-optic material, it is also possible to produce a thin film on the side of the incident medium (a), which is the reflecting portion, and (b), which is the transmission portion, which is emitted.

In this case, the middle portion c, which is a partition wall separating the incident light and the outgoing light, may be any opaque material.

The common electrode 106 is generally coated very thin when deposited, although it may be assumed that the conductor is directly below the reflecting surface, even if the reflecting surface of the common electrode 106 is not a conductor.

The device described in the present invention can be manufactured in various ways, for example, sandwiched aluminum or copper between two thin glass rods of a 1 / 4-cylindrical cylinder shape and polished the bottom surface after bonding, and the transparent electrode on the polished surface. Deposit.

Since the thickness of the electrode is small enough for the wavelength of light, leakage of light through the transparent electrode layer is negligible.

The production is completed by covering the polymer liquid crystal film polymerized on the dielectric reflective thin film on the electrode surface.

The inspection apparatus using the present invention measures while moving (scan) on the arranged pixel electrode surface.

FIG. 12 shows a path of light for each position on the pixel electrode 105 when the present invention scans on the pixel electrode 105. FIG.

Accordingly, a defect of the pixel electrode 105 can be detected by acquiring and analyzing an image image of the output light of the entire longitudinal region in which the present invention spans at a point where the entire horizontal common electrode surface is located directly above the pixel electrode 105. have.

In general, liquid crystals have optical anisotropy so that they have the maximum transmittance in the direction of the electric field, but in the case of polymer dispersed liquid crystals, the liquid crystals have sufficient transmittance for detection even when the light is inclined.

Therefore, the direction in which the incident direction or the exit direction of light gives the detection force is not large.

When the electro-optic material 102 is a polymer dispersed liquid crystal, the transmittance decreases as time passes after the electric field is applied, and thus the electric field must be alternated.

When using a 1-dimensional line camera, the common electrode voltage is alternated from + to-and-to + for each line scan.

At this time, the voltage of the pixel electrode may be alternately synchronized with the alternating of the common voltage.

Since the liquid crystal takes a long time to be rearranged by the electric field and exhibits characteristics, there is a limit to the number of alternating cycles per second.

Currently, about 1000 times per second is possible. Therefore, if the line camera input is received for one pixel column, the distance between pixels is 150 microns, so the range of 150mm per second can be inspected. It can be inspected several times faster.

In the present invention, the distance between the pixel electrode 105 and the common electrode 106 must be controlled very precisely. In the conventional invention, at least three points of support are required in the case of using the planar electrode. It is possible to maintain horizontality with only two points at both ends, and its control is also possible to measure the gap directly by using a laser rangefinder and to control in real time by using servo control.

As shown in Fig. 13, a distance measuring device 201 capable of measuring a gap is attached to both ends of the present invention, and the end of the combination is coupled with a linear servo actuator 203 using a hinge 202.

The entirety travels in a plane perpendicular to the longitudinal direction of the sensor and converts the viscous value of the arrayed pixel electrode into an image for input.

As described above, according to the present invention, an electro-optic conversion sensor having a simple shape can be manufactured by arranging a one-dimensional electro photosynthetic material, and the gap between the pixel electrode and the common electrode can be easily adjusted by only two points. In addition, it is possible to continuously scan the pixel electrode voltage in real time, so that defects of the pixel electrode can be detected more quickly.

Claims (9)

In a non-contact electro-optical converter comprising a light source means, an electro-optic material layer, a common electrode means, a dielectric thin film means, and a camera means to measure the voltage of a plurality of electrodes distributed on a plane in a non-contact manner, The common electrode means, The electro-optic material layer is attached to the lower part and is divided into a plurality of parts so that the horizontal length is smaller than the size of the pixel electrode and has a long shape in the vertical direction. An incidence side medium means for inducing the incidence of light generated by the light source means to be modulated in the electro-optic material layer; And an output side medium means for guiding the light emitted from the incident medium means to the camera means after being modulated in the electro-optic material layer. The method of claim 1, The common electrode means is divided into subdivisions in the horizontal direction so that the incident side medium means to which light is incident and the exit side medium means to emit light are transparent, A non-contact electro-optic converter characterized in that the middle portion is composed of an opaque and reflective conductor. The method of claim 1, The common electrode means is a non-contact electro-optic converter, characterized in that composed of two parts so that one side is transparent and the other side has a reflective characteristic. The method of claim 1, And said common electrode means has a one-part transparent or opaque characteristic. The method of claim 1, The common electrode means is a non-contact electro-optic converter characterized in that the incident light is reflected to the upper surface and the lower surface of the electro-optic material layer alternately to reflect. The method of claim 1, The common electrode means is a non-contact electro-optic converter, characterized in that the incident surface of the light is incident on the slopes and sides, not the upper and lower surfaces of the electro-optic material layer. The light source means, the incident side media means, the electro-optic material layer, the common electrode means, the dielectric thin film means, the exit side media means, and the camera means to measure the voltage of a plurality of electrodes distributed on the plane in a non-contact manner. In the non-contact electro-optical converter configured, In the electro-optical conversion sensor including the common electrode means, the camera and the light source and two or more linear actuators are coupled on the same structure, and the common electrode means is connected to the linear actuator through a floating structure such as a hinge. An electro-optic conversion sensor is included, and means for measuring the distance between the electro-optic sensor and the base on which the electrode to be measured is coupled to the structure or the electro-optic sensor is provided in a long direction of the electro-optic sensor. Non-contact electro-optical converter characterized in that configured to measure the voltage of the electrode on the two-dimensional base running in the vertical direction. The method of claim 7, wherein The camera is a non-contact electro-optical converter, characterized in that the linear camera. Inducing light generated from the light source while the driving device moves on the screen on which the pixel electrodes are arranged to the electro-optic material layer by the incident medium; The induced light is modulated by an electric field in the electro-optic material layer by an applied current and emitted through a plurality of reflections at the center of the common electrode; Inducing the emitted light from the output medium and capturing the light induced by the medium in a photodetector to convert the light into an image; An inspection method of an array electrode by a non-contact electro-optical device, characterized in that the step of inspecting the array electrode.