# US 10,121,399 B2 · LCD source driver feedback system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,399 B2 - Document ID: US10121399B2 - Status: Granted - Kind: B2 - Application number: 14/227,578 - Filed: 2014-03-27 - Published: 2014-10-23 - Granted: 2018-11-06 - Earliest claimed: 2013-03-27 - Applicants: American Panel Corporation - Inventors: Charles Lemons; David Williams; Gary Baek; Steve Preston - Web page: https://patentgrep.com/patent/US10121399B2 ## CPC - G09G 3/006: {Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309)} - G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} - G09G 3/3275: Details of drivers for data electrodes - G09G 3/3685: {Details of drivers for data electrodes} - G09G 2310/0275: Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current - G09G 2330/12: Test circuits or failure detection circuits included in a display system, as permanent part thereof - G09G 2380/12: Avionics applications - 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 An electrical assembly and method for detecting failures in an LCD source driver is disclosed herein. A plurality of active channels are placed on the source driver which communicate electronically with an LCD. At least one dummy channel may be placed on the source driver which is driven with an original signal. A microprocessor may then receive the dummy channel and compare the received dummy channel signal to the original signal. An error message may be transmitted when the received dummy channel signal does not match the original signal. Alternatively, the source driver may be provided with a split active channel which is provided with an original signal that is split into an active split channel and a dummy split channel. While the active split channel is sent to the LCD, the dummy split channel is sent to the microprocessor for comparison with the original signal. ## Claims ### Claim 1 A method for detecting a failure in an LCD source driver comprising the steps of: providing at least one dummy channel in addition to the active channels on the source driver; driving the dummy channel and all of the active channels to be used, with original signals; receiving said dummy channel original signal at a microprocessor; and comparing said dummy channel original signal with at least one active channel original signal at the microprocessor. ### Claim 2 (depends on 1) The method of claim 1 further comprising the steps of: converting the received dummy channel signal from analog to digital before comparing with the original signal. ### Claim 3 (depends on 1) The method of claim 1 further comprising the step of: alerting upstream logic that a failure has occurred when the received dummy channel signal does not match the original signal. ### Claim 4 (depends on 1) The method of claim 1 further comprising the step of: splitting an active channel so as to produce a resulting active channel signal and dummy channel signal based on the same original signal. ### Claim 5 (depends on 4) The method of claim 4 further comprising the steps of: receiving the dummy channel signal and comparing it with the original signal; and receiving the active channel signal at the LCD. ### Claim 6 An electrical assembly for detecting failures in an LCD source driver comprising: a plurality of active channels on the source driver which communicate electronically with an LCD; a dummy channel on the source driver which is driven with an original signal; and a microprocessor which receives the dummy channel and compares the received dummy channel signal to the original signal; wherein the dummy channel is configured to bypass the LCD. ### Claim 7 (depends on 6) The electrical assembly of claim 6 further comprising: an analog to digital converter which digitizes the received dummy channel signal before comparing it to the original signal. ### Claim 8 (depends on 6) The electrical assembly of claim 6 wherein: the microprocessor is located on a display interface board. ### Claim 9 (depends on 6) The electrical assembly of claim 6 further comprising: a second dummy channel on the source driver which is driven with a second original signal; and wherein the microprocessor additionally receives the second dummy channel and compares the received second dummy channel to the second original signal. ### Claim 10 (depends on 9) The electrical assembly of claim 9 wherein: the microprocessor is adapted to transmit an error message when either (1) the received dummy channel signal does not match the original signal or (2) the received second dummy channel signal does not match the second original signal. ### Claim 11 (depends on 6) The electrical assembly of claim 6 wherein: the microprocessor is adapted to transmit an error message when the received dummy channel signal does not match the original signal.