# US 7,411,410 B2 · LCD test device and test process thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,411,410 B2 - Document ID: US7411410B2 - Status: Granted - Kind: B2 - Application number: 11/644,959 - Filed: 2006-12-26 - Published: 2007-12-27 - Granted: 2008-08-12 - Earliest claimed: 2006-06-09 - Assignees: LG Display Co., Ltd. - Inventors: Dong Woo Kang; Soung Yeoul Eom; Ki Soub Yang - Web page: https://patentgrep.com/patent/US7411410B2 ## CPC - G02F 1/1309: {Repairing; Testing} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract An LCD test device and a test process thereof are disclosed, in which a defect of an LCD panel is exactly identified through exact electrical connection between an LCD panel and a probe unit. The LCD test device includes a work table on which an LCD panel is mounted, a clamping unit on the work table, clamping a top surface of an edge of the LCD panel mounted on the work table, a probe unit electrically connected with a pad of the LCD panel fixed to the work table by the clamping unit, and a back light unit supplying light to the LCD panel fixed to the work table. Accordingly, since the defect of the LCD panel can be tested exactly, reliability of the test is improved, and it is possible to prevent yield and the cost from being reduced in advance. ## Claims ### Claim 1 An LCD test device comprising: a work table on which an LCD (Liquid Crystal Display) panel is mounted; a clamping unit on the work table, clamping a top surface of an edge of the LCD panel mounted on the work table, thereby preventing sagging of the middle portion of the LCD panel; a probe unit electrically connected with a pad of the LCD panel fixed to the work table by the clamping unit; and a back light unit supplying light to the LCD panel fixed to the work table. ### Claim 2 (depends on 1) The LCD test device as claimed in claim 1, wherein the clamp unit includes: a clamp directly clamping the top surface of the edge of the LCD panel; and a driver rotating the clamp to allow the clamp to clamp the top surface of the edge of the LCD panel when the LCD panel is mounted on the work table. ### Claim 3 (depends on 2) The LCD test device as claimed in claim 2, wherein the clamp has a buffering member to prevent the LCD panel from being damaged by contact. ### Claim 4 (depends on 3) The LCD test device as claimed in claim 3, wherein the buffering member is formed of an elastic material such as rubber. ### Claim 5 (depends on 1) The LCD test device as claimed in claim 1, wherein the work table has a sensor to check whether the LCD panel has been mounted thereon. ### Claim 6 (depends on 1) The LCD test device as claimed in claim 1, further comprising an image device taking images of patterns displayed on the LCD panel mounted on the work table. ### Claim 7 (depends on 6) The LCD test device as claimed in claim 6, further comprising a controller extracting defect information from the images for patterns displayed on the image device. ### Claim 8 An LCD test device comprising: a work table on which an LCD (Liquid Crystal Display) panel is mounted; a carrier loading/unloading the LCD panel onto the work table; a clamping unit on the carrier, clamping a top surface of an edge of the LCD panel mounted on the work table, thereby preventing sagging of the middle portion of the LCD panel; a probe unit electrically connected with a pad of the LCD panel fixed to the work table by the clamping unit; and a back light unit that supplies light to the LCD panel fixed to the work table. ### Claim 9 (depends on 8) The LCD test device as claimed in claim 8, wherein the clamp unit has a buffering member to prevent the LCD panel from being damaged by contact. ### Claim 10 (depends on 9) The LCD test device as claimed in claim 9, wherein the buffering member is formed of an elastic material such as rubber. ### Claim 11 (depends on 8) The LCD test device as claimed in claim 8, further comprising an image device taking images of patterns displayed on the LCD panel mounted on the work table. ### Claim 12 (depends on 11) The LCD test device as claimed in claim 11, further comprising a controller extracting defect information from the images for patterns displayed on the image device. ### Claim 13 A test process for an LCD device, comprising: preparing several LCD (Liquid Crystal Display) panels by cutting a large sized glass substrate; loading the LCD panels into an LCD test device having an image device; clamping a top surface of an edge of the LCD panels to fix the LCD panels in the LCD test device, thereby preventing sagging of the middle portion of the LCD panels; and testing whether the LCD panels have a defect, using the image device. ### Claim 14 (depends on 13) The test process as claimed in claim 13, wherein the image device is a charge coupled device (CCD) camera. ### Claim 15 (depends on 13) The test process as claimed in claim 13, further comprising: removing shorting bars formed in the LCD panels using a laser trimmer; and completely removing the remaining shorting bars, using a grinder. ### Claim 16 (depends on 15) The test process as claimed in claim 15, further comprising: cleaning the LCD panels from which the shorting bars are removed; and directly testing the cleaned LCD panels with a naked eye of a worker to finally determine whether the LCD panels have a defect. ### Claim 17 (depends on 13) The test process as claimed in claim 13, further comprising removing shorting bars formed in the LCD panels using a grinder. ### Claim 18 (depends on 17) The test process as claimed in claim 17, wherein the shorting bars include a gate shorting bar connecting gate lines of the LCD panels and a data shorting bar connecting data lines of the LCD panels, the gate shorting bar being formed of the same material as that of the data shorting bar. ### Claim 19 (depends on 18) The test process as claimed in claim 18, wherein the gate shorting bar and the data shorting bar are formed of AlNd. ### Claim 20 (depends on 17) The test process as claimed in claim 17, further comprising: cleaning the LCD panels from which the shorting bars are removed; and directly testing the cleaned LCD panels with a naked eye of a worker to finally determine whether the LCD panels have a defect. ### Claim 21 (depends on 20) The test process as claimed in claim 20, wherein only the LCD panels, which are determined to have a defect using the LCD test device, are finally tested. ### Claim 22 (depends on 20) The test process as claimed in claim 20, further comprising entering the LCD panels in a stocker and storing them therein before the LCD panels are finally tested. ### Claim 23 (depends on 13) The test process as claimed in claim 13, further comprising removing surface foreign materials by cleaning the LCD panels. ### Claim 24 (depends on 13) The test process as claimed in claim 13, further comprising entering the LCD panels in a stocker and storing them therein before the LCD panels are loaded into the LCD test device.