KR20190062072A - Bubble detection device of OLED panel - Google Patents

Abstract

The present invention relates to a bubble detection device of an OLED panel which allows a quick and accurate detection of bubbles in the OLED panel using an ultrasonic nondestructive inspection method. According to the present invention, the bubble detection device comprises: a water supply unit for supplying water to an inspection object; a bubble detection unit for transmitting ultrasonic waves to the inspection object through which the water flows and outputting a signal reflected by the density difference of the inspection object as a bubble detection signal; and an image processor for converting the bubble detection signal detected by the bubble detection unit into an image. Accordingly, it is possible to quickly and accurately detect bubbles of an OLED panel by the nondestructive inspection method.

Description

[0001] The present invention relates to a bubble detection device for an OLED panel,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus for detecting bubbles in an organic light emitting diode (OLED) panel, and more particularly to an apparatus for detecting bubbles in an OLED panel capable of quickly and accurately detecting bubbles in an OLED panel using ultrasonic nondestructive inspection.

Of the display devices, the organic light emitting display (OLED) device has a wide viewing angle, excellent contrast, and fast response speed, and is receiving attention as a next generation display device.

Various types of defects may occur in the display panel such as the organic light emitting display device. Foreign objects, smearing, surface scratches, bubbles, etc. of the display panel adversely affect the performance of the display. Should be thoroughly detected / removed.

Particularly, when a display device is manufactured using the OLED panel, it is impossible to detect beforehand the occurrence of bubbles in the OLED panel. Therefore, the OLED panel bubble is detected before the display device is manufactured It is very important to do.

The display panel inspection method generally uses a macro inspection method for detecting foreign objects with the naked eye and a micro inspection method for finely detecting a defective state using a microscope.

However, since the visual inspection is inferior in precision and the microscopic examination requires a long time for inspection, new inspection methods are required.

On the other hand, a conventional technique for a method of inspecting a display panel is disclosed in the following Patent Documents 1 to Patent Documents.

The prior art disclosed in Patent Document 1 uses a 3D sensor formed so as to face the first surface of the display panel and an image acquiring unit formed so as to face the second surface of the display panel to form a defect on the first surface and the second surface, The present invention also provides a display panel inspection apparatus and a display panel inspection method capable of simultaneously inspecting a display panel.

The conventional technique disclosed in Patent Document 2 uses a camera for photographing a foreign substance, divides the thickness of the flat panel display panel into a plurality of heights, aligns the focus of the camera on each center line of the plurality of divided heights The image of the foreign substance can be clearly photographed regardless of the thickness of the foreign substance in the vertical direction, thereby inspecting the foreign substance of the flat panel display panel.

The prior art disclosed in Patent Document 3 includes a turntable capable of holding a transparent display panel that can transmit light, a turntable rotation unit for rotating the turntable, a plurality of backlights disposed on the top surface of the turntable, and a turntable A plurality of transmissive panel inspection cameras, a plurality of transmissive panel inspection cameras for moving each of the transmissive panel inspection cameras to sequentially capture various portions of the transmissive display panel, a power supply unit for supplying power to the plurality of backlights, A transparent panel inspection camera moving unit, a plurality of transparent panel inspection cameras, analyzes the images, and controls the overall operation of the apparatus, thereby implementing the inspection apparatus of the display panel.

The present invention provides an inspection apparatus for a display panel capable of continuously and rapidly inspecting various display panels through such a configuration.

In addition, the prior art disclosed in Patent Document 4 includes a panel seating table having a plurality of panel seating portions through which light can pass, a table rotating device for rotating the panel seating table, a test for obtaining images of the panel for a light- By using a camera, various light transmissive display panels can be inspected continuously and rapidly.

Korean Registered Patent No. 10-1584767 (Announcement of Jan. 12, 2016) (Display panel inspection apparatus and display panel inspection method) Korean Registered Patent No. 10-1789651 (Announcement of October 25, 2017) (Foreign matter Inspection Method for Flat Panel Display Panel) Korean Registered Patent No. 10-1146721 (Announcement of May 17, 2012) (Inspection Apparatus for Display Panel) Korean Registered Patent No. 10-1146722 (Announcement on May 17, 2012) (Inspection Apparatus for Display Panel)

However, the above-mentioned related arts are a method of inspecting a display panel using a vision device such as a camera, and it is possible to inspect an OLED panel from the outside with a vision camera, but there is a limitation in inspecting a bubble inside.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a bubble detection apparatus for an OLED panel capable of quickly and accurately detecting bubbles in an OLED panel using ultrasonic nondestructive inspection The purpose is to do.

According to an aspect of the present invention, there is provided an apparatus for detecting bubbles in an OLED panel, including: a water supply unit for supplying water to an object to be inspected; A bubble detecting unit that emits ultrasonic waves to the inspection object through which the water flows and outputs a signal reflected by the density difference of the inspection object as a bubble detection signal; And an image processor for converting the bubble detection signal detected by the bubble detector into an image.

The inspection target may be a liquid crystal display panel or an organic light emitting diode (OLED) panel.

The bubble detection unit includes a pulse / receiver for generating ultrasonic pulses and converting the reflected ultrasonic signals into electric signals; A probe for transmitting an ultrasonic wave generated in the pulse / receiver to an object to be inspected, a signal reflected from the object to be inspected, and transmitting the signal to the pulse / receiver; And an analog-to-digital converter for converting the electric signal received by the pulse / receiver into a digital signal and transmitting the digital signal to the image processor.

The probe may be a transducer that transmits ultrasonic waves generated by the probe to the object to be inspected, receives a signal reflected from the object, and converts the reflected signal into an electric signal.

The image processor includes an image converter for converting the bubble detection signal detected by the bubble detector into an image; And a display unit for displaying the image signal converted by the image converter on the screen to display bubble generation information.

The image processor may further include a bubble determination unit for determining whether bubble detection is performed by analyzing pixel color information of the unit image image converted by the image converter; And a bubble detection alarm unit for alerting the bubble when the bubble determination unit determines that the bubble is detected.

According to the present invention, bubbles of an OLED panel are detected using an ultrasonic nondestructive inspection, so that bubbles can be detected quickly and accurately.

Further, according to the present invention, by utilizing the ultrasonic nondestructive inspection apparatus for bubble detection of an OLED panel, it is possible to realize bubble detection equipment of an OLED panel at a low cost, and it is advantageous for general use.

Further, according to the present invention, by using the ultrasonic nondestructive testing apparatus as a bubble detecting apparatus of an OLED panel, tact time can be reduced and visibility can be secured compared to a system using a conventional line scanner, a laser vision system, and a camera .

1 is a configuration diagram of an apparatus for detecting bubbles of an OLED panel according to the present invention,
FIG. 2 is a block diagram of an embodiment of the image processor of FIG. 1,
3 is a diagram illustrating a process of detecting bubbles of an OLED panel using ultrasound in the present invention.
FIGS. 4A and 4B illustrate an image in which bubbles of an OLED panel are detected using ultrasonic waves. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for detecting bubbles of an OLED panel according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of an apparatus for detecting bubbles in an OLED panel according to a preferred embodiment of the present invention. Referring to FIG. 1, A bubble detection unit 30 that emits ultrasonic waves to the inspected object 10 to be inspected and outputs a signal reflected by the density difference of the inspected object 10 as a bubble detection signal and a bubble detection unit 30 that detects the bubble detected by the bubble detection unit 30 And an image processor 40 for converting a signal into an image.

Here, the inspection target 10 may be a liquid crystal display panel or an organic light emitting diode (OLED) panel.

The water supply unit 20 includes a water inlet 21 for supplying water for inspection to an object to be inspected and a water jetting unit 22 for discharging water supplied from the water inlet 21 to the object 10 .

The bubble detecting unit 30 includes a pulse / receiver 32 for generating an ultrasonic pulse and converting the reflected ultrasonic signal into an electric signal, an ultrasonic wave generated from the pulse / A probe 31 for receiving a signal reflected from the object to be inspected 10 and delivering the signal to the pulse / receiver 32, an electric signal received from the pulse / receiver 32 into a digital signal, And an analog-to-digital converter (33) for transferring the image data to the image processor (40).

Here, the probe 31 may be implemented by various devices for transmitting ultrasound waves and receiving reflected ultrasound signals. In the present invention, ultrasound waves are transmitted to the object 10 to be inspected, A transducer for converting the received signal into an electric signal will be described as an example.

2, the image processor 40 includes an image converter 41 for converting the bubble detection signal detected by the bubble detector 30 into an image, an image converted by the image converter 41, A bubble determining unit 43 for determining whether bubbles are detected by analyzing pixel color information of the unit image image converted by the image converter 41, And a bubble detection alarm unit (44) for alarming the bubble detected by the bubble detection unit (43).

The operation of the apparatus for detecting bubbles of the OLED panel according to the present invention will now be described in detail.

1, the object to be inspected 10 is placed on the inspection target 10 while the OLED panel is placed in the inspection position, while the water is supplied to the object 10 through the water supply unit 20, A pulse corresponding to a high frequency ultrasonic wave is generated and transmitted to the probe 31. The probe 31 uses a device such as a transducer to transmit the transmitted high-frequency ultrasonic wave to the object 10 to be inspected. Thereafter, the ultrasonic wave reflected from the object 10 to be inspected is received by the probe 31 and transmitted to the pulse / receiver 32.

In the present invention, ultrasonic waves, which is a non-destructive inspection method, are used to measure bubbles or defects to be inspected in the form of images. As the inspection method using ultrasonic waves, there are a water immersion method, a waterfall method, and a water flume method.

In the water immersion type method, both the object to be inspected and the probe are placed in the water and the reflected wave signal of the object to be inspected is inspected by the ultrasonic method. In the waterflume method, the object to be inspected is positioned at the upper part, And then inspected by ultrasound method.

In addition, the waterfall method is a method of inspecting an object to be inspected in such a manner that an object to be inspected is located at the lower part, ultrasonic waves are transmitted to the object while the water is flowed to the object using a water guide, and a reflection signal is received.

Since the water erosion method is not suitable due to the nature of OLED which is vulnerable to moisture and water infiltration can be minimized by adopting the waterfall method, water may be introduced into the OLED.

A process of detecting bubbles to be inspected will be described in detail as follows.

As shown in FIG. 3, in the first step, the probe 31 transmits the high-frequency ultrasonic wave to the OLED panel as the inspection target 10, and receives ultrasonic signals reflected from the inspection target 10 in the next step. In this case, the OLED panel has a lower FSM and an FSA or FSP on it, and a TFT & OLED is placed on the FSA or FSP. Bubbles are generated in the unstable FSC material in the process of bonding the FSM and the FSA or FSP. At this time, ultrasonic waves are reflected or transmitted through each region by the density difference of the material, and ultrasonic waves are reflected in a region where bubbles are generated. The ultrasonic waves reflected from the bubbles are received by the probe 31 in the next step. In the next step, the probe 31 converts the reflected ultrasonic waves into electrical signals and transmits them to the pulse / receiver 32. In the next step, the analog-to-digital converter 33 converts the analog electric signal transmitted through the pulse / receiver 32 into a corresponding digital signal. The converted digital signal becomes a bubble detection signal. The thus converted bubble detection signal is transmitted to the image processor 40 in the next step.

2, the image processor 40 collects the bubble detection signal detected by the bubble detector 30 in the image converter 41, converts the bubble detection signal collected by the image processing algorithm into an image do. Then, the video converter 41 displays the converted video signal on the screen through the display device 42. [

The inspector looks at the inspection image displayed on the screen of the display 42 and visually confirms whether bubbles have occurred or not.

4A is a bubble detection screen of the OLED FSA sample, and FIG. 4B is a bubble detection screen of the OLED FSP sample. In FIGS. 4A and 4B, a portion indicated by a red circle is a bubble image, and a portion indicated by a yellow circle is an example of a bubble size. Illustratively, the bubble size is 80 탆 or more.

In the above-described method, the bubble image detected by the OLED panel is displayed on the display device 42 as an image, and the inspector visually confirms whether the bubble image is defective or not.

Such a method may inconvenience the inspectors to continuously view the screen when they are inspected.

Therefore, in order to solve the inconvenience of the manual determination method, the present invention analyzes color information per pixel of the unit image converted by the image converter 41 in the bubble determination unit 43 to automatically determine whether or not bubbles are detected do. For example, as shown in Figs. 4A and 4B, in the inspection image obtained by inspecting the inspection object by the ultrasonic method, the color of the portion where bubbles are detected and the portion without bubbles are different. Therefore, the presence or absence of bubbles can be determined by analyzing the color color information of such pixels. In addition, by setting only the reference value in advance by experiment, it is possible to detect the presence of bubbles as well as the amount of bubbles. Based on the analysis information, the bubble detection is made, and if bubbles are generated to the extent that the determination result is defective, the bubble detection alarm unit 44 is notified.

If the bubble detection unit 44 determines that the bubble is detected as a result of the determination by the bubble determination unit 43, the bubble detection alarm unit 44 generates an alarm for bubble detection through the audiovisual.

The alarm system for detecting bubbles can be used to indicate the presence or absence of defective or defective products to be inspected or the presence or absence of bubbles by using the red LED and the blue LED and can alert the occurrence of bubbles to be inspected using a buzzer .

When such an automatic method is used, it is possible to conveniently check whether bubbles have occurred or not, by only knowing that an alarm is generated while performing other tasks without inconvenience of continuously viewing the screen by the inspector.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It is obvious to those who have.

The present invention is applied to a technique for detecting bubbles of an OLED panel in a non-destructive inspection manner.

10: Object to be inspected (OLED panel)
20: water supply part
21:
22:
30: bubble detector
31: Probe
32: Pulse / Receive
33: Analog-to-digital converter
40: image processor
41: Video Converter
42: display device
43: bubble determination unit
44: bubble detection alarm unit

Claims (6)

An apparatus for detecting bubbles of a display panel by a nondestructive inspection method,
A water supply unit for supplying water to the object to be inspected;
A bubble detecting unit that emits ultrasonic waves to the inspection object through which the water flows and outputs a signal reflected by the density difference of the inspection object as a bubble detection signal; And
And an image processor for converting the bubble detection signal detected by the bubble detector into an image.
The apparatus of claim 1, wherein the inspection object is a liquid crystal display panel or an organic light emitting diode (OLED) panel.
The bubble detector may include a pulse / receiver for generating an ultrasonic pulse and converting the reflected ultrasonic signal into an electric signal; A probe for transmitting an ultrasonic wave generated in the pulse / receiver to an object to be inspected, a signal reflected from the object to be inspected, and transmitting the signal to the pulse / receiver; And an analog / digital converter for converting the electric signal received by the pulse / receiver into a digital signal and transmitting the digital signal to the image processor.
The apparatus for detecting bubbles in an OLED panel according to claim 3, wherein the probe uses a transducer that transmits generated ultrasonic waves to the object to be inspected and receives a signal reflected from the object to be inspected and converts the signal into an electric signal.
The image processor according to claim 1, wherein the image processor comprises: an image converter for converting the bubble detection signal detected by the bubble detector into an image; And a display unit for displaying the image signal converted by the image converter on a screen to display bubble generation information.
The image processor may further include a bubble determining unit for determining whether bubble detection is performed by analyzing pixel color information of the unit image image converted by the image converter; Further comprising a bubble detection alarm unit for alarming the bubble when the bubble determination unit determines that the bubble is detected.

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