# US 7,407,305 B2 · Fixing apparatus for reducing noise of backlit unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,407,305 B2 - Document ID: US7407305B2 - Status: Granted - Kind: B2 - Application number: 11/170,757 - Filed: 2005-06-28 - Published: 2006-01-05 - Granted: 2008-08-05 - Earliest claimed: 2004-06-30 - Assignees: Chi Mei Optoelectronics Corp. - Inventors: Cheng-Hsiang Chen; Yu Suzuki - Web page: https://patentgrep.com/patent/US7407305B2 ## CPC - G02F 1/133608: {including particular frames or supporting means} - G02F 2201/503: Arrangements improving the resistance to shock - 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 A fixing apparatus, applied to a diffuser plate of a backlight unit (BLU), comprises a receiving portion and a positioning portion. The receiving portion is symmetrically formed at a first centrosymmetric line of the diffuser plate, a first pair of edges of the receiving portion set at two sides of the first centrosymmetric line. The positioning portion is located within the receiving portion, and a first distance is formed between the positioning portion and the first pair of edges. The first distance is determined according to a mechanical tolerance of the diffuser plate. Movement of the diffuser plate along a direction of a second centrosymmetric line perpendicular to the first centrosymmetric line, is constrained by the positioning portion. The receiving portion and a positioning portion may comprise a fixing hole and a positioning pin. Alternatively, the receiving portion and the positioning portion comprise a fixing groove and a positioning piece. ## Claims ### Claim 1 A fixing apparatus, applied to a diffuser plate of a backlight unit (BLU), the fixing apparatus comprising: a receiving portion, symmetrically formed at a first centrosymmetric line of a diffuser plate, and a first pair of edges of the receiving portion setting at two sides of the first centrosymmetric line; and a positioning portion located within the receiving portion such that a first distance is formed between the positioning portion and the first pair of edges of the receiving portion, the first distance determined by a mechanical tolerance of the diffuser plate, wherein movement of the diffuser plate along a direction of a second centrosymmetric line perpendicular to the first centrosymmetric line, is constrained by the positioning portion. ### Claim 2 (depends on 1) The fixing apparatus according to claim 1, wherein the receiving portion further comprises a second pair of edges intersecting the first pair of edges, a second distance formed between the positioning portion and the second pair of edges, the second distance determined according to an overall expansion coefficient of the diffuser plate. ### Claim 3 A fixing apparatus, applied to a diffuser plate of a backlight unit (BLU), the fixing apparatus comprising: a fixing hole, symmetrically formed at a centrosymmetric line of a diffuser plate, a first pair of edges setting at two sides of the centrosymmetric line, and a second pair of edges cutting across the centrosymmetric line; and a positioning pin, located within the fixing hole, and separated from the first pair of edges of the fixing hole at a first distance, and separated from the second pair of edges of the fixing hole at a second distance, wherein the first distance is smaller than the second distance. ### Claim 4 (depends on 3) The fixing apparatus according to claim 3, wherein the first distance is determined according to a mechanical tolerance of the diffuser plate. ### Claim 5 (depends on 3) The fixing apparatus according to claim 3, wherein the second distance is determined according to an overall expansion coefficient of the diffuser plate. ### Claim 6 A backlight unit (BLU) comprising: a housing comprising a frame configured to enclose a plurality of backlight components; and a fixing apparatus configured to constrain movement of a diffuser plate within the housing, the fixing apparatus comprising, a receiving portion symmetrically formed at a centrosymmetric line of the diffuser plate, a first pair of edges of the receiving portion setting at either sides of the centrosymmetric line, another edge of the receiving portion cutting across the centrosymmetric line; and a positioning portion located within the receiving portion and separated from the first pair of edges at a first distance, and separated from another edge of the receiving portion at a second distance, wherein the first distance is smaller than the second distance. ### Claim 7 (depends on 6) The backlight unit according to claim 6, wherein the receiving portion comprises a fixing hole defined on the diffuser plate, and the positioning portion comprises a positioning pin. ### Claim 8 (depends on 7) The backlight unit according to claim 7 wherein: the fixing hole has an elliptical cross section with a major axis lying over the centrosymmetric line; and the positioning pin has a circular cross section with a diameter smaller than a minor axis of the elliptical cross section. ### Claim 9 (depends on 6) The backlight unit according to claim 6 wherein: the receiving portion comprises a fixing groove defined by the frame; and the positioning portion comprises a positioning piece projecting from the diffuser plate. ### Claim 10 (depends on 9) The backlight unit according to claim 9, wherein the positioning piece is configured at a direction of the centrosymmetric line and integrated with the diffuser plate. ### Claim 11 (depends on 6) The backlight unit according to claim 6 further comprising a plurality of diffuser films in contact with the frame, the fixing apparatus also constraining movement of the diffuser films. ### Claim 12 A displaying device comprising: a backlight unit (BLU), comprising, a housing configured to enclose a plurality of backlight components of the BLU, the housing having a frame, and a diffuser plate placed on the frame and having a fixing apparatus for constraining the movement of the diffuser plate, the fixing apparatus comprising, a receiving portion symmetrically formed at a centrosymmetric line of the diffuser plate, a first pair of edges of the receiving portion setting at either sides of the centrosymmetric line, another edge of the receiving portion cutting across the centrosymmetric line; and a positioning portion located within the receiving portion and separated from the first pair of edges at a first distance, the positioning portion separated from another edge of the receiving portion at a second distance, wherein the first distance is smaller than the second distance. ### Claim 13 (depends on 12) The displaying device according to claim 12, wherein the receiving portion is a fixing hole defined on the diffuser plate, and the positioning portion is a positioning pin. ### Claim 14 (depends on 12) The displaying device according to claim 12, wherein the receiving portion is a fixing groove defined at the frame, and the positioning portion is a positioning piece projected from the diffuser plate. ### Claim 15 (depends on 14) The displaying device according to claim 14, wherein the positioning piece is configured at a direction of the centrosymmetric line and integrated with the diffuser plate.