# US 11,906,442 B2 · Foreign material inspection system of display unit

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- Number: US 11,906,442 B2
- Document ID: US11906442B2
- Status: Granted
- Kind: B2
- Application number: 17/252,567
- Filed: 2019-06-21
- Published: 2021-08-19
- Granted: 2024-02-20
- Earliest claimed: 2018-06-22
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Beom Seok Lee; Chan Soo Kim; Eung Jin Jang; Sung Hyun Baek; Yu Jin Lim
- Web page: https://patentgrep.com/patent/US11906442B2

## CPC

- G01N 21/94: Investigating contamination, e.g. dust (G01N21/85 takes precedence)
- G01N 21/55: Specular reflectivity
- G01N 21/95: characterised by the material or shape of the object to be examined (G01N21/89 - G01N21/91, G01N21/94 take precedence)
- H10K 71/70: Testing, e.g. accelerated lifetime tests
- G01N 2021/9513: {Liquid crystal panels}
- G02B 5/3025: {Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence)}
- G02B 5/3083: {Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001)}
- H10K 71/00: Manufacture or treatment specially adapted for the organic devices covered by this subclass
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An exemplary embodiment of the present invention provides a foreign substance inspection system for a display unit, including: a lighting unit configured to provide incident light to a display unit having an organic light emitting display panel; and a foreign substance detecting unit configured to receive incident light that is reflected by the display unit and detect whether a foreign substance is introduced into the display unit.

## Claims

### Claim 1

A foreign substance inspection system comprising:
a light source configured to provide incident light to a display, the display having an organic light emitting display panel, a quarter-wave plate disposed on the organic light emitting display panel, and a polarizing plate disposed on the quarter-wave plate; and
a foreign substance detector configured to receive incident light that is reflected by the display, and detect whether a foreign substance is introduced into the display,
wherein the foreign substance detector determines that a foreign substance is introduced into the display when the foreign substance detector determines that the reflected light is provided.

### Claim 2 (depends on 1)

The foreign substance inspection system of claim 1, wherein the light source provides the incident light having an inclined incident angle smaller than 90° to the display.

### Claim 3 (depends on 1)

The foreign substance inspection system of claim 1, wherein the foreign substance detector includes an image capturing device configured to capture an image of the display, and a controller configured to receive the image of the display from the image capturing device and detect whether a foreign substance is introduced into the display.

### Claim 4 (depends on 1)

The foreign substance inspection system of claim 1, wherein the quarter-wave plate and the polarizing plate are configured such that when no foreign substance is present on the display, light reflected from the display is not transmitted through the polarizing plate and the reflected light is not received by the detector.