# US 7,609,241 B2 · Double-faced light emitting diode display > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,241 B2 - Document ID: US7609241B2 - Status: Granted - Kind: B2 - Application number: 11/168,221 - Filed: 2005-06-28 - Published: 2006-01-05 - Granted: 2009-10-27 - Earliest claimed: 2004-07-02 - Assignees: Tsinghua University; Hon Hai Precision Industry Co., Ltd. - Inventors: Pi-Jin Chen; Peng Liu; Li Qian; Yang Wei; Lei-Mei Sheng; You-Hua Lei; Liang Liu; Shou-Shan Fan - Web page: https://patentgrep.com/patent/US7609241B2 ## CPC - G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED] - G09G 2300/02: Composition of display devices - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A double-faced light emitting diode display includes a pair of parallel shield panels (20, 20′), and a light emitting module (30) located between the shield panels. Each shield panel includes a video contrast enhancement assembly. The light emitting module includes an opaque insulative substrate (31) with a pair of pixel matrixes symmetrically formed on opposite surfaces (310, 310′) thereof and a circuit driving system formed at at least one of the surfaces. Each pixel matrix includes a plurality of pixel units (320, 320′). Symmetrically opposite pairs of pixel units are electrically interconnected so that the shield panels can simultaneously display same images. The double-faced light emitting diode display has a simple structure, a small size, low cost and full color display capability, and can be advantageously applied in traffic signal boards, large-scale display boards, surround cinemas and so on. ## Claims ### Claim 1 A double-faced light emitting diode display comprising: a pair of shield panels, each shield panel comprising a video contrast enhancement assembly; and a light emitting module located between the shield panels, the light emitting module comprising an opaque insulative substrate with a pair of pixel matrixes provided at two main surfaces thereof and a circuit driving system provided on at least one of the main surfaces, each pixel matrix corresponding to a respective opposite video contrast enhancement assembly and comprising a plurality of pixel units, wherein each of pairs of pixel units is defined as one pixel unit in a row of one of the pixel matrixes and another pixel unit in a same row of the other pixel matrix, and symmetrically opposite pairs of pixel units are electrically interconnected and are electrically connected with the circuit driving system, wherein each pixel unit comprises three light emitting diodes having optical primary colors R (red), G (green) and B (blue) respectively, a common anode electrically connected with each of the three light emitting diodes, and three cathodes electrically connected with the three light emitting diodes respectively; wherein the circuit driving system comprises a row driver and a column driver located at two sides of the at least one of the main surfaces; wherein the row driver is electrically connected with the common anodes of the pixel units in parallel, and the column driver is electrically connected with the cathodes of the pixel units in parallel; wherein the common anodes of each symmetrically opposite pair of pixel units are electrically interconnected; wherein the six cathodes of each symmetrically opposite pair of pixel units are electrically interconnected in three corresponding one-to-one relationships. ### Claim 2 (depends on 1) The double-faced light emitting diode display as claimed in claim 1, wherein the row driver and the column driver are field effect transistors. ### Claim 3 (depends on 1) The double-faced light emitting diode display as claimed in claim 1, wherein each video contrast enhancement assembly comprises a plurality of video contrast enhancement units. ### Claim 4 (depends on 3) The double-faced light emitting diode display as claimed in claim 3, wherein each video contrast enhancement unit corresponds to a respective pixel unit. ### Claim 5 (depends on 4) The double-faced light emitting diode display as claimed in claim 4, wherein each video contrast enhancement unit comprises a white reflecting portion surrounding a through hole and a dark portion around the white reflecting portion. ### Claim 6 (depends on 5) The double-faced light emitting diode display as claimed in claim 5, wherein a corresponding pixel unit is received in the through hole. ### Claim 7 (depends on 1) The double-faced light emitting diode display as claimed in claim 1, wherein at least one of the shield panels defines at least one recess for receiving the circuit driving system. ### Claim 8 (depends on 1) The double-faced light emitting diode display as claimed in claim 1, wherein each of the shield panels further comprises two separate recesses defined therein and configured for receiving the row driver and the column driver.