# US 2014/0153281 A1 · Backlight unit and display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153281 A1 - Document ID: US20140153281A1 - Status: Published application - Kind: A1 - Application number: 14/097,202 - Filed: 2013-12-04 - Published: 2014-06-05 - Earliest claimed: 2012-12-04 - Applicants: Beijing Boe Chatani Electronics Co., Ltd.; Boe Technology Group Co., Ltd. - Inventors: Yang ZHAO; Zhendong Zhou - Web page: https://patentgrep.com/patent/US20140153281A1 ## CPC - G02B 6/0055: {Reflecting element, sheet or layer} - G02B 6/0031: {Reflecting element, sheet or layer} - G02B 6/0051: {Diffusing sheet or layer} - G02B 6/009: {of the light source in the package (G02B6/0021 takes precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present invention provides a backlight unit including a light source and a light guide plate, wherein the backlight unit further includes a set of reflectors, the set of reflectors includes a first reflector and a second reflector, the first reflector is arranged at a side of the light guide plate, the second reflector is arranged at the back of the light guide plate, the light source is arranged below the first reflector, the first reflector is used for reflecting light emitted from the light source into the light guide plate, and light exits from the front of the light guide plate after being scattered by the light guide plate and being reflected by the second reflector. Correspondingly, a display device including the backlight unit is provided. The backlight unit has advantages of small thickness, increased effective illumination area, and various shapes. ## Claims ### Claim 1 A backlight unit including a light source and a light guide plate, wherein the backlight unit further includes a set of reflectors, the set of reflectors includes a first reflector and a second reflector, the first reflector is arranged at a side of the light guide plate, the second reflector is arranged at the back of the light guide plate, the light source is arranged below the first reflector, the first reflector is used for reflecting light emitted from the light source into the light guide plate, and light exits from the front of the light guide plate after being scattered by the light guide plate and being reflected by the second reflector. ### Claim 2 (depends on 1) The backlight unit according to claim 1, wherein a relationship between an angle between the first reflector and the bottom surface of the light guide plate and a light-emitting angle of the light source is α ≥ ( 90 + β 2 )  /  2 , wherein α is the angle between the first reflector and the bottom surface of the light guide plate, and β is the light-emitting angle of the light source. ### Claim 3 (depends on 1) The backlight unit according to claim 1, wherein the backlight unit further includes a backplane including a recessed portion and a platform portion, the light source is arranged into the recessed portion, and the light guide plate and the second reflector are arranged on the platform portion of the backplane. ### Claim 4 (depends on 3) The backlight unit according to claim 3, wherein the light guide plate further includes a bulge which is arranged at the bottom edge of the light guide plate, the bulge extends into the recessed portion of the backplane, and the light source is arranged below the bulge. ### Claim 5 (depends on 4) The backlight unit according to claim 4, wherein a relationship among a thickness of the bulge, a width of the bulge, and a light-emitting angle of the light source is B ≤ D 2  sin ( 90 - β 2 ) , wherein B is the thickness of the bulge, D is the width of the bulge, and β is the light-emitting angle of the light source. ### Claim 6 (depends on 4) The backlight unit according to claim 4, wherein the first reflector and/or the second reflector extend(s) into the recessed portion of the backplane. ### Claim 7 (depends on 5) The backlight unit according to claim 5, wherein the first reflector and/or the second reflector extend(s) into the recessed portion of the backplane. ### Claim 8 (depends on 1) The backlight unit according to claim 1, wherein an optical film is further arranged on the light guide plate, and the optical film includes a diffuser. ### Claim 9 (depends on 8) The backlight unit according to claim 8, wherein a thickness of the backlight unit is less than 5 mm; and/or the backlight unit further includes an outer frame which is arranged at the peripheries of the light source, the light guide plate, the reflectors and the optical film to fix them together, a width of the outer frame is less than 5 mm. ### Claim 10 (depends on 1) The backlight unit according to claim 1, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 11 (depends on 2) The backlight unit according to claim 2, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 12 (depends on 3) The backlight unit according to claim 3, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 13 (depends on 4) The backlight unit according to claim 4, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 14 (depends on 5) The backlight unit according to claim 5, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 15 (depends on 6) The backlight unit according to claim 6, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 16 (depends on 7) The backlight unit according to claim 7, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 17 (depends on 8) The backlight unit according to claim 8, wherein the shape of the backplane is circular or polygonal, and the shape of the light guide plate is adaptive to that of the backplane; and/or the light source is a light emitting diode or an electroluminescent sheet. ### Claim 18 A display device including a backlight unit, wherein the backlight unit includes a light source and a light guide plate, wherein the backlight unit further includes a set of reflectors, the set of reflectors includes a first reflector and a second reflector, the first reflector is arranged at a side of the light guide plate, the second reflector is arranged at the back of the light guide plate, the light source is arranged below the first reflector, the first reflector is used for reflecting light emitted from the light source into the light guide plate, and light exits from the front of the light guide plate after being scattered by the light guide plate and being reflected by the second reflector. ### Claim 19 (depends on 18) The display device according to claim 18, wherein a relationship between an angle between the first reflector and the bottom surface of the light guide plate and a light-emitting angle of the light source is α ≥ ( 90 + β 2 )  /  2 , where α is the angle between the first reflector and the bottom surface of the light guide plate, and β is the light-emitting angle of the light source. ### Claim 20 (depends on 18) The display device according to claim 18, wherein the backlight unit further includes a backplane including a recessed portion and a platform portion, the light source is arranged into the recessed portion, and the light guide plate and the second reflector are arranged on the platform portion of the backplane.