KR20210115117A - Inspection system for inspecting defects of display device and inspection method using the same - Google Patents

Abstract

Disclosed are an inspection system for inspecting a failure of a display apparatus and an inspection method using the same. The inspection method comprises the following steps of: radiating a polarized pattern from a light radiation unit; passing the reflected polarized pattern through a polarization filter unit; extracting a regular reflection image of an inspection object by using a light field camera; generating a single image by obtaining a phase map; obtaining a three-dimensional image of the inspection object; and inspecting a failure of the inspection object. The present invention detects a failure or presence of a foreign substance inside an inner layer of the inspection object.

Description

Inspection system for inspecting defects of display device and inspection method using the same

The present invention relates to an inspection system for inspecting a defect of a display device and an inspection method using the same.

Typically, the display device is a mobile device such as a smart phone, a laptop computer, a digital camera, a camcorder, a portable information terminal, a notebook computer, a tablet personal computer, a desktop computer, a television, an outdoor billboard, an exhibition display device, an automobile instrument panel, It can be used in an electronic device such as a head up display (HUD).

A display device forms a plurality of functional layers on a substrate through various manufacturing processes. During the manufacturing process, there may be defects in the functional layer laminated on the substrate. Various inspection systems may be used to inspect these defects.

However, when a defect or a foreign material is generated in the inner layer of the object to be measured, it is not easy to detect a defect in the display device using the inspection system. In addition, when the measurement object is partially scattered, visibility is deteriorated.

SUMMARY Embodiments of the present invention provide an inspection system for inspecting a defect of a display device and an inspection method using the same.

A method of inspecting a defect of a display device according to an aspect of the present invention includes: irradiating a polarization pattern from a light irradiation unit toward a measurement object; and a first polarizing filter in which the polarization pattern reflected from the measurement object is orthogonal to each other selectively passing through a polarization filter unit having a second polarization filter; and extracting a specular reflection image of the measurement object using a light field camera; and obtaining a phase map from each captured image to obtain a single image generating; and acquiring a three-dimensional image of the measurement object; and inspecting a defect of the measurement object.

In one embodiment, the first polarization filter transmits the first polarization, and the second polarization filter passes the second polarization.

In one embodiment, in the step of extracting the specular reflection image, the light field camera includes a main lens, an optical sensor, and a microlens array between the main lens and the optical sensor, and the polarization filter unit is the main lens. It is disposed on the focal plane, receiving the filtered light from the polarization filter unit to the microlens array, and receiving the filtered light from the microlens array to the photosensor to convert an optical image into an electrical image signal; and the electrical image signal to generate an image, and extract a specular reflection image of the measurement object from the generated image.

In an embodiment, a diffuse reflection image is extracted by sampling a region that has passed through the second polarizing filter from among the entire region of the generated image, and a diffuse component and a specular component are obtained by sampling the region that has passed through the first polarizing filter. A captured sample image is generated, and the specular reflection image is extracted using a difference between the sample image and the diffuse reflection image.

In an embodiment, a phase map is obtained in a wavelength region having the least diffraction by selectively irradiating light of an ultraviolet, visible, or infrared wavelength from the light irradiator to the measurement object.

A method of inspecting a defect of a display device according to another aspect of the present invention includes: irradiating a pattern from a light irradiator toward a measurement object; obtaining an image reflected from a specific layer; and generating a single image by obtaining a phase map from each captured image; and obtaining a three-dimensional image of the measurement object; and Including; checking for defects.

In an embodiment, the light field camera includes a main lens, a photosensor, and a microlens array between the main lens and the photosensor, and generates a focused image for each layer of the measurement object.

In an exemplary embodiment, a defective area of the measurement object is detected by analyzing a difference in brightness of a focused image for each layer from the obtained image of the measurement object.

An inspection system for inspecting a defect of a display device according to another aspect of the present invention includes: a light irradiator for irradiating a pattern on a measurement object; and a main lens through which light reflected from the measurement object passes to form an optical image; a light field camera including an optical sensor that converts the optical image into an electrical image signal, and a microlens array disposed between the main lens and the optical sensor and having a plurality of microlenses; and is connected to the light field camera , a signal processing unit for processing an electrical image signal; and an inspection device connected to the signal processing unit to acquire a three-dimensional image of the measurement object and inspect the defect of the measurement object.

In an embodiment, a first polarizing filter and a second polarizing filter that are orthogonal to each other are provided between the main lens and the photosensor, and a polarizing filter unit disposed on a focal plane of the main lens is further disposed.

In one embodiment, the first polarization filter transmits the first polarization, and the second polarization filter passes the second polarization.

In an embodiment, the signal processing unit generates an image by using the electrical image signal and extracts a specular reflection image of the measurement object from the generated image.

In an embodiment, a diffuse reflection image is extracted by sampling a region that has passed through the second polarization filter from among the entire generated region.

In an embodiment, a sample image is generated by sampling a region that has passed through the first polarization filter, and a specular image is extracted using a difference between the sample image and the diffuse reflection image.

In an embodiment, the light field camera generates a focused image for each layer of the measurement object.

In an exemplary embodiment, the inspection apparatus detects a defective area of the measurement object by analyzing a difference in brightness of a focused image for each layer from the obtained image of the measurement object.

In an embodiment, a phase map is obtained in a region having the least diffraction by selectively irradiating light of an ultraviolet, visible, or infrared wavelength from the light irradiator to the measurement object.

In one embodiment, the light field camera comprises a plurality of light field cameras disposed at different positions.

An inspection system for inspecting a defect of a display device and an inspection method using the same according to an aspect of the present invention can read a defect or presence or absence of a foreign object in an inner layer of a measurement object through a digital image.

In addition, by applying a phase measurement deflection method to a partially scattered measurement object to improve visibility, accurate inspection may be possible.

Of course, the effects of the present invention can be derived from the contents to be described below with reference to the drawings in addition to the above-described contents.

1 is a configuration diagram illustrating an inspection system according to an embodiment of the present invention.
FIG. 2 is a configuration diagram illustrating a deflection filter unit of FIG. 1 .
FIG. 3 is a block diagram illustrating a flow of the inspection system of FIG. 1 .
4 is a block diagram illustrating an inspection system according to another embodiment of the present invention.
5 is a block diagram illustrating a flow of the inspection system of FIG. 4 .
FIG. 6 is a modified example of FIG. 4 .
FIG. 7 is a cross-sectional view illustrating a sub-pixel of a display device inspected using the inspection system of FIG. 1 .

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and a method of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

In the following embodiments, when various components such as layers, films, regions, plates, etc. are said to be “on” other components, this is not only when they are “on” other components, but also other components in between. Including cases where In addition, in the drawings for convenience of description, the size of the components may be exaggerated or reduced. For example, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar.

In the following examples, the x-axis, the y-axis, and the z-axis are not limited to three axes on a Cartesian coordinate system, and may be interpreted in a broad sense including them. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may refer to different directions that are not orthogonal to each other.

In the following embodiments, terms such as first, second, etc. are used for the purpose of distinguishing one component from another, not in a limiting sense.

In the following examples, the singular expression includes the plural expression unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have means that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components will be added. .

In the following embodiments, a specific process sequence may be performed differently from the described sequence when an embodiment is otherwise practicable. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order opposite to the order described.

Hereinafter, an embodiment of an inspection system for inspecting a defect of a display device according to the present invention and an inspection method using the same will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same or corresponding configuration Elements are given the same reference numerals, and overlapping descriptions thereof will be omitted.

1 illustrates an inspection system 100 according to an embodiment of the present invention.

Referring to the drawings, the inspection system 100 includes a light irradiation unit 110 , a light field camera 200 , a signal processing unit 120 , and an inspection device 130 .

The light irradiator 110 may be a light source irradiating light toward the measurement object 101 . For example, the light irradiation unit 110 may irradiate any one of visible light, infrared light, and ultraviolet light to the measurement object 101 . The light irradiation unit 110 may include any one of a monitor, a backlight unit, and a flash light.

In an embodiment, the light irradiator 110 may irradiate a periodic pattern in the form of a sine wave to the measurement object 101 .

In an embodiment, the light irradiator 110 may irradiate polarized light in a horizontal or vertical direction with respect to the measurement object 101 . To this end, a polarizing filter may be installed on the front surface of the light irradiation unit 110 .

The light field camera 200 may obtain 4D information about the light reflected from the measurement object 101 . The light field camera 200 includes a main lens 210 , an optical sensor 220 , and a micro lens array 230 disposed between the main lens 210 and the photosensor 220 . include

The main lens 210 may condense the light incident from the measurement object 101 . The photosensor 220 may detect light and generate an electrical image signal corresponding to the sensed optical image. The optical image formed by the main lens 210 may be converted into an electrical image signal by the optical sensor 220 . In an embodiment, the photosensor 220 may be a charge coupled device (CCD).

The microlens array 230 includes a plurality of microlenses 231 . One microlens 231 in the microlens array 230 may correspond to a plurality of pixels of the photosensor 220 . Accordingly, images of different viewpoints may be obtained from a plurality of pixels corresponding to one microlens 231 . The microlens array 230 may focus the focal plane fp of the main lens 210 .

The light field camera 200 may be connected to the signal processing unit 120 . The signal processing unit 120 may extract a specular component and a diffuse component of the measurement object 101 from the image generated by the microlens array 230 . The signal processing unit 120 may analyze a plurality of images generated by the microlens array 230 and generate one image using software.

The inspection apparatus 130 may evaluate whether there is a defect by using the image obtained from the measurement object 101 . The inspection apparatus 130 may be a computer capable of receiving the image obtained from the light field camera 200 and generating 3D information of the measurement object 101 according to a predefined algorithm. The inspection device 130 may be configured by a combination of hardware and software according to the purpose of inspecting whether the surface or interior of the measurement object 101 is defective using phase measuring deflectometry (PMD). have.

The measurement object 101 to be inspected using the inspection system 100 may include a plurality of functional layers. Specifically, the measurement object 101 may correspond to the organic light emitting display device 700 of FIG. 7 which will be described later. The organic light emitting display device 700 may have a structure in which a plurality of layers are stacked. When the plurality of layers are formed in this way, a diffuse reflection component may be generated due to inter-reflection between the plurality of layers. For example, diffuse reflection may occur at the interface of each of the window cover 715 , the second adhesive 716 , and the polarizing layer 713 continuously arranged from the uppermost layer to the lower portion of the display device 700 .

When diffuse reflection occurs, visibility of the optical system to which the phase measurement deflection method is applied may decrease. If only the specular component is selectively extracted and inspected using the light field camera 200 according to the present embodiment, a decrease in visibility of the phase measurement deflection method can be prevented. For example, when a defect exists in the polarization layer 413 or the window cover 415, a specular reflection image and a diffuse reflection image are extracted, and a decrease in visibility is prevented by using the specular reflection image from the display apparatus 400. defects can be detected.

Meanwhile, in the light reflected from the measurement object 101, a specular component and a diffuse component may be mixed. A polarization filter unit 240 may be installed on the focal plane fp of the main lens 210 in order to extract the specular component and the diffuse component. The light polarized horizontally or vertically from the light irradiation unit 110 may pass through the polarization filter unit 240 .

As shown in FIG. 2 , the polarization filter unit 240 includes a first polarization filter 240V and a second polarization filter 240H. The first polarization filter 240V and the second polarization filter 240H may have polarization regions orthogonal to each other. The first polarization filter 240V may pass the first polarized light from the light irradiation unit 110 , and the second polarization filter 240H may pass the second polarized light in a direction perpendicular thereto. For example, the first polarization passing through the first polarization filter 240V may be vertical polarization, and the second polarization passing through the second polarization filter 240H may be horizontal polarization.

In an embodiment, the polarization filter unit 240 may have a circular shape. The first polarization filter 240V may be an upper semicircle, and the second polarization filter 240H may be a lower semicircle. Alternatively, on the contrary, the first polarization filter 240V and the second polarization filter 240H may be disposed. The polarized light irradiated from the light irradiation unit 110 may be selectively passed by the polarization filter unit 240 .

A method of inspecting the defect of the measurement object 101 using the inspection system 100 will be described with reference to FIGS. 1 to 3 .

Light is irradiated from the light irradiation unit 110 toward the measurement object 101. (S10) In an embodiment, the light irradiation unit 110 may be a monitor. The light irradiation unit 110 may generate at least one sine wave pattern and irradiate it to the measurement object 101 . The at least one sinusoidal pattern may change phase.

In an embodiment, it is assumed that the light irradiator 110 irradiates the measurement object 101 with a vertically polarized pattern that can pass through the first polarization filter 240V of the polarization filter unit 240 . do. To this end, a polarizing filter may be provided on the front surface of the light irradiation unit 110 .

The polarization pattern in the vertical direction reflected from the measurement object 101 selectively passes through the polarization filter unit 240. (S20) Specifically, the polarization pattern irradiated to the upper portion of the polarization filter unit 240 is It passes through the first polarization filter 240V and reaches the photosensor 220 via the microlens array 230 . On the other hand, the polarization pattern irradiated to the lower portion of the polarization filter unit 240 is blocked by the second polarization filter 240H.

The filtered light may be received from the polarization filter unit 240 to the microlens array 230 . By receiving light from the microlens array 230 to the photosensor 220 , the optical image formed by the main lens 210 is converted into an electrical image signal. Each image is generated for each pattern having different phases using the electrical image signal, and a specular reflection image of the measurement object 101 is extracted from the generated image. (S30)

The polarization pattern in the vertical direction irradiated from the light irradiation unit 110 may be reflected by mixing a specular component and a diffuse reflection component on the surface of the measurement object 101 . In this case, the specular component may maintain a polarization state, but the diffuse component loses polarization properties. Accordingly, the diffuse component may pass through both the first polarization filter 240V and the second polarization filter 240H, but the specular component may pass only through the first polarization filter 240H.

On the other hand, due to refraction by the main lens 210, the polarization pattern passing through the second polarization filter 240H relatively reaches the upper region of the photosensor 220 and closes the first polarization filter 240V. The passed polarization pattern relatively reaches the lower region of the photosensor 220 .

When one specific microlens 231 is viewed, the upper semicircle is an image formed by the light passing through the second polarizing filter 240H, and the lower semicircle is the light passing through the first polarizing filter 240V. The image formed by Looking at the micro-image, the lower portion includes a specular component and a diffuse component, and the upper portion includes only the diffuse component.

The signal processing unit 120 samples a region that has passed through the second polarization filter 240H to extract a diffuse reflection image. That is, only the uppermost pixels in each microimage are sampled. The diffuse reflection image refers to an image in which the specular component is removed and only the diffuse component is captured. Subsequently, the signal processing unit 120 generates a sample image by sampling the region that has passed through the first polarization filter 240V. That is, pixels at the bottom of each micro-image are sampled. The sample image refers to an image in which both the diffuse component and the specular component are captured. Next, the signal processing unit 120 extracts the specular reflection image by using the difference between the sample image and the diffuse reflection image. The specular image refers to an image in which the diffuse component is removed and only the specular component is captured.

As such, an image is generated using an electrical image signal, and a specular image and a diffuse image having different reflection characteristics of the specific object 101 are extracted from the generated image. Among them, the specular reflection component of the measurement object 101 is extracted and used.

Next, a phase map is implemented from each captured image. Specifically, the phase measurement bias algorithm is processed to obtain a phase map, and a single image is generated from the captured image (S40).

Subsequently, a three-dimensional image of the measurement object 101 is acquired. (S50) Methods for implementing the three-dimensional image of the measurement object 101 include a path integration method and a least-squares method. For example, by measuring the surface slope of the measurement object 101 at a specific position based on the reflection angle reflected from the surface of the measurement object 101 and integrating it, the surface shape of the measurement object 101 can be measured. can

It is possible to evaluate the defect of the measurement object 101 from the obtained image of the measurement object 101. (S60) Specifically, it is possible to detect surface defects such as pressing, protrusion, denting, etc. of the measurement object 101 have. Even on the partially reflective surface of the measurement object 101 in which the diffuse reflection and the specular reflection are mixed, the visibility due to the diffuse reflection on the surface of the measurement object 101 decreases, so that the visibility of the phase measurement deflector decreases. As such, when only the specular component of each image is selectively imaged using the polarization filter unit 240 , a decrease in visibility of the phase measurement deflection method can be prevented.

On the other hand, even when there is a periodic pattern inside the measurement object 101, the visibility of the phase measurement deflection method is reduced due to diffraction. For example, when diffuse reflection occurs due to the bending of the light emitting element 703 in the organic light emitting display device 700 of FIG. 7 , the light of the ultraviolet, visible, and infrared wavelengths is selectively transmitted from the light irradiator 110 to the measurement object 101 . ) to obtain a phase map in the wavelength region where diffraction occurs the least.

4 illustrates an inspection system 400 according to another embodiment of the present invention.

Referring to the drawings, the inspection system 400 includes a light irradiation unit 110 , a light field camera 500 , a signal processing unit 120 , and an inspection device 130 . The light field camera 400 includes a main lens 510 , an optical sensor 520 , and a microlens array 530 disposed between the main lens 510 and the optical sensor 520 . The microlens array 530 includes a plurality of microlenses 531 . Unlike the inspection system 400 of FIG. 1 , the inspection system 400 of the present embodiment may not include the polarization filter unit 240 of FIG. 1 .

The light irradiation unit 110 may irradiate any one of visible light, infrared light, and ultraviolet light to the measurement object 101 . The light irradiator 110 may irradiate a periodic pattern of a sinusoidal waveform to the measurement object 101 . The light irradiator 110 may irradiate at least one sine wave pattern to the measurement object 101 .

The light field camera 500 may obtain 4D information about the light reflected from the measurement object 101 through the microlens array 530 . The light field camera 500 may generate an image focused on an arbitrary focal plane fp through the microlens array 530 .

The light field camera 500 may be connected to the signal processing unit 120 . The signal processing unit 120 may generate one image by analyzing a plurality of images generated by the microlens array 530 .

The inspection apparatus 130 may acquire a three-dimensional image from the measurement object 101 and evaluate whether it is defective. The inspection apparatus 130 may be configured by a combination of hardware and software in order to inspect the internal defect of the measurement object 101 using a phase measurement deflection method.

A method of inspecting the defect of the measurement object 101 using the inspection system 400 will be described with reference to FIGS. 4 and 5 .

First, a pattern is irradiated from the light irradiation unit 110 toward the measurement object 501. (T10) In an embodiment, the light irradiation unit 110 may be a monitor. The light irradiator 110 may irradiate a pattern in which the distribution of brightness is different in one dimension or two dimensions, or a pattern in which the brightness is changed as a whole. The light irradiation unit 110 may irradiate at least one pattern to the measurement object 501 . The light irradiation unit 110 may change the phase of at least one sine wave pattern to capture an image.

An image reflected from a specific layer of the measurement object 101 may be acquired from the pattern reflected from the measurement object 101 by using the light field camera 500 (T20).

Specifically, the light field camera 500 may generate an image focused on an arbitrary focal plane fp. Since the measurement object 101 is composed of a plurality of layers, there may be a defect in a specific layer. When the pattern is reflected from the measurement object 101, the light field camera 500, for example, the window 715 continuously from the top layer of the display device 700 to the bottom thereof, the second adhesive ( 716 ), a focused image for each polarization layer 713 may be generated.

Next, a phase map is implemented from the captured image. Specifically, the phase measurement deflection algorithm is processed to obtain a phase map, and a single image is generated from a plurality of captured images. Due to this, a change occurs in the pattern image, which is indicated by a change in the brightness value in the phase map.

Then, a three-dimensional image of the measurement object 101, for example, a height, or a curve, is obtained. (T40) A method of implementing a three-dimensional image of the measurement object 101 with the measured slope is There are path integration method and least squares method.

The defect of the measurement object 101 may be evaluated from the obtained image of the measurement object 101. (T50) Specifically, the difference in brightness of the focused image for each layer is analyzed. If there is a defect or foreign material in a specific layer of the measurement object 101, the area with the coupling shows a relative difference in the distribution of pixel brightness values compared to the normal area in the phase map. Accordingly, a pixel area representing such a difference is detected as a defective area.

When there is a defect or a foreign material in a specific layer of the measurement object 101, the light field camera 500 can amplify a difference in brightness compared to a normal area, so that it is easy to detect a defect. In this way, the inspection system 400 may detect a bond and a foreign material occurring in a specific inner layer of the measurement object 101 .

Meanwhile, as shown in the inspection system 600 of FIG. 6 , a plurality of light field cameras, for example, a first light field camera 610 and a second light field camera 620 may be provided. The inspection system 100 of FIG. 1 or the inspection system 400 of FIG. 4 uses one light field camera 100 and 500, respectively, but in this embodiment, a plurality of light field cameras 610 and 620 are used. ) can be used simultaneously.

When the measurement object 101 is imaged at different positions using the first light field camera 610 and the second light field camera 620 , the angle of view can be widened. In addition, it is easy to measure the three-dimensional shape and depth value of the measurement object 101 by stereo vision, which may be more advantageous in determining whether the size of a defect exceeds an allowable standard.

7 is a cross-sectional view illustrating one sub-pixel of the display device 700 inspected using the inspection system according to the present embodiment.

In this embodiment, the display device 700 is an organic light emitting display device (OLED) as an example, but a display device that implements an image when a predetermined power is applied, for example, a liquid crystal display It is not limited to any one device, such as a liquid crystal display device (LCD), a field emission display device (FED), or an electronic paper display device (EPD).

Referring to the drawings, the display device 700 includes a substrate 701 . The substrate 701 may be a glass substrate, a polymer substrate, or a flexible film. A thin film transistor 702 and a light emitting device 703 electrically connected to the thin film transistor 702 may be disposed on the substrate 701 . Although not shown, the thin film transistor 702 includes elements such as a semiconductor layer, a gate, an electrode, a source electrode, and a drain electrode. Insulating layers may be disposed between the devices to insulate them.

A passivation layer 704 may be disposed on the thin film transistor 702 . The passivation layer 704 may cover the thin film transistor 702 . The passivation film 704 includes either a passivation film or a planarization film. The passivation layer 704 may be a single layer layer or a multilayer layer.

The light emitting device 703 may be an organic light emitting device (OLED) having a pixel electrode 705 , a counter electrode 707 , and an intermediate layer 706 interposed between the pixel electrode 705 and the counter electrode 707 . have. The pixel electrode 705 may be electrically connected to the thin film transistor 702 . A pixel defining layer 708 may be disposed on the opposite electrode 705 . The pixel defining layer 708 exposes a partial region of the pixel electrode 707 , and an intermediate layer 706 including an emission layer may be positioned on the exposed partial region. The light emitting layer provided on the intermediate layer 706 includes a low molecular weight organic material or a high molecular weight organic material.

A thin film encapsulation (TFE) 709 may be disposed on the substrate 701 . The thin film encapsulation layer 709 may encapsulate a display area in which a plurality of sub-pixels are disposed.

A touch sensing unit 710 may be disposed on the thin film encapsulation layer 709 . The touch sensing unit 710 may be an on-cell touch screen panel in which a touch screen pattern is disposed on the thin film encapsulation layer 709 . The touch sensing unit 710 may be an electrostatic capacitive type touch sensing unit, but is not limited thereto.

A black matrix 711 may be disposed on the touch sensing unit 710 . The black matrix 711 may be disposed around the sub-pixels. The black matrix 711 may be covered by an overcoat layer 712 .

A polarization layer 713 may be disposed on the overcoat layer 712 . The polarization layer 713 prevents external light from being reflected from the inside of the panel. When the polarizing layer 713 is in the form of a film, a first adhesive 714 for adhering them may be interposed between the polarizing layer 713 and the overcoating layer 712 .

A window cover 715 may be disposed on the polarization layer 713 to protect the display device 700 . A second adhesive 716 for adhering them may be interposed between the polarizing layer 713 and the window cover 715 .

In the case of inspection using the inspection system of the present embodiment, the presence or absence of defects or foreign substances that may exist on the surface of the display device 700 or on a plurality of layers, for example, the window 715 and the polarization layer 713 , is checked. It can be easily inspected through digital images.

100...Inspection system 101...Measured object
110...Light irradiation unit 120...Signal processing unit
130...Inspection unit 200...Light field camera
210...Main lens 220...Light sensor
230...microlens array 231...microlens
240...polarizing filter unit 240V...first polarizing filter
240H...second polarizing filter

Claims (18)

irradiating a polarization pattern from the light irradiator toward the measurement object;
selectively passing through a polarization filter unit having a first polarization filter and a second polarization filter that are orthogonal to each other in the polarization pattern reflected from the measurement object;
extracting a specular reflection image of the measurement object using a light field camera;
generating a single image by obtaining a phase map from each captured image;
acquiring a three-dimensional image of the measurement object; and
A method of inspecting a defect of a display device comprising a; inspecting the defect of the measurement object. The method of claim 1,
A method of inspecting a defect in a display device, wherein the first polarization filter passes the first polarization filter and the second polarization filter allows the second polarization filter to pass therethrough. The method of claim 1,
In the step of extracting the specular reflection image,
The light field camera includes a main lens, an optical sensor, and a microlens array between the main lens and the optical sensor, and the polarization filter unit is disposed on a focal plane of the main lens,
converting an optical image into an electrical image signal by receiving filtered light from the polarization filter unit to a microlens array, and receiving the filtered light from the microlens array to the photosensor; and
A method of generating an image by using the electrical image signal and inspecting a defect in a display device for extracting a specular reflection image of the measurement object from the generated image. 4. The method of claim 3,
extracting a diffuse reflection image by sampling a region that has passed through the second polarization filter from among the entire region of the generated image;
generating a sample image in which diffuse reflection components and specular reflection components are captured by sampling the area that has passed through the first polarization filter;
A method of inspecting a defect in a display device for extracting the specular image using a difference between the sample image and the diffuse reflection image. The method of claim 1,
A method of inspecting a defect in a display device in which a phase map is obtained in a wavelength region having the least diffraction by selectively irradiating light of an ultraviolet, visible light, or infrared wavelength from the light irradiator to the measurement object. irradiating the pattern toward the measurement object from the light irradiation unit;
obtaining an image reflected from a specific layer of the measurement object from a pattern reflected from the measurement object using a light field camera;
generating a single image by obtaining a phase map from each captured image;
acquiring a three-dimensional image of the measurement object; and
A method of inspecting a defect of a display device comprising a; inspecting the defect of the measurement object. 7. The method of claim 6,
The light field camera includes a main lens, an optical sensor, and a microlens array between the main lens and the optical sensor, and a method for inspecting a defect in a display device that generates a focused image for each layer of the measurement object. 8. The method of claim 7,
A method of inspecting a defect in a display device that detects a defective area of the measurement object by analyzing the difference in brightness of the focused image for each layer from the obtained image of the measurement object. a light irradiator for irradiating a pattern on the measurement object;
A main lens through which light reflected from the measurement object passes to form an optical image, an optical sensor for converting the optical image into an electrical image signal, is disposed between the main lens and the optical sensor and includes a plurality of microlenses a light field camera with a microlens array;
a signal processing unit connected to the light field camera and processing an electrical image signal; and
and an inspection device connected to the signal processing unit and configured to acquire a three-dimensional image of the measurement object and inspect the failure of the measurement object. 10. The method of claim 9,
A first polarizing filter and a second polarizing filter that are orthogonal to each other are provided between the main lens and the optical sensor, and a polarizing filter unit disposed on a focal plane of the main lens is further disposed. 11. The method of claim 10,
and the first polarization filter passes the first polarization filter and the second polarization filter passes the second polarization filter. 11. The method of claim 10,
The signal processing unit generates an image by using the electrical image signal, and inspects a defect of a display device that extracts a specular reflection image of the measurement object from the generated image. 13. The method of claim 12,
An inspection system for inspecting defects of a display device that extracts a diffuse reflection image by sampling a region that has passed through a second polarization filter from among the generated entire region. 14. The method of claim 13,
An inspection system for inspecting a defect in a display device that generates a sample image by sampling a region that has passed through the first polarization filter, and extracts a specular image using a difference between the sample image and the diffuse reflection image. 10. The method of claim 9,
The light field camera is an inspection system for inspecting a defect in a display device that generates a focused image for each layer of the measurement object. 16. The method of claim 15,
The inspection apparatus is an inspection system for inspecting a defect of a display device that detects a defective area of the measurement object by analyzing the difference in brightness of the focused image for each layer from the obtained image of the measurement object. 10. The method of claim 9,
An inspection system for inspecting a defect of a display device that selectively irradiates light of wavelengths of ultraviolet, visible, and infrared from the light irradiator to the measurement object to obtain a phase map in a region having the least diffraction. 10. The method of claim 9,
The light field camera is an inspection system for inspecting a defect of a display device including a plurality of light field cameras disposed at different positions.

Images