# US 8,542,166 B2 · Electroluminescence display apparatus with video signal rewriting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,166 B2 - Document ID: US8542166B2 - Status: Granted - Kind: B2 - Application number: 11/959,663 - Filed: 2007-12-19 - Published: 2008-12-11 - Granted: 2013-09-24 - Earliest claimed: 2006-12-22 - Assignees: Sanyo Semiconductor Co., Ltd.; Semiconductor Components Industries, LLC - Applicants: Tsutomu Murata; Takashi Ogawa - Inventors: Tsutomu Murata; Takashi Ogawa - Web page: https://patentgrep.com/patent/US8542166B2 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/3275: Details of drivers for data electrodes - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0285: using tables for spatial correction of display data - G09G 2330/12: Test circuits or failure detection circuits included in a display system, as permanent part thereof - 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 In performing a display in accordance with a video signal, a display signal for inspection is supplied to a pixel within a predetermined inspected row to operate an EL element therein and to thereby detect a current that flows through the EL element. The current detection data is stored in a volatile primary memory. In accordance with data obtained in this manner, a variation correcting section sequentially corrects data signals to be supplied to the respective pixel. At the time of turning on power, the variation correcting section performs the correction using the current detection data saved in a secondary memory. With this arrangement, it is possible to execute display variation correction from immediately after turning on power, and it is also possible to execute real-time correction. ## Claims ### Claim 1 An electroluminescence display apparatus, comprising: a display section having a plurality of pixels arranged in a matrix, a variation detecting section which detects an inspection result of a display variation in each pixel, and a correcting section which corrects the display variation, wherein each of the plurality of pixels in the display section comprises an electroluminescence element having a diode structure, and an element driving transistor which is connected to the electroluminescence element and controls a current that flows through the electro luminescence element; wherein the variation detecting section comprises: an inspection signal generator which generates an inspection signal to be supplied to a pixel in a row to be inspected and supplies the inspection signal to the pixel in the inspected row at a predetermined timing during execution of a display in accordance with a video signal; a current detector which detects a current that flows through the electroluminescence element in response to the inspection signal; a memory section which stores a data corresponding to the current detected by the current detector; wherein the memory section includes a volatile primary memory which stores the data corresponding to the current supplied from the current detector, a non-volatile secondary memory which stores and maintains therein the data stored in the primary memory during when the apparatus power supply is turned off, and a selector which selectively supplies the data stored in the secondary memory to the primary memory when the apparatus power supply is turned on; wherein the correcting section executes a correction with respect to the video signal for each pixel in accordance with the data read out from the primary memory of the memory section; wherein during a blanking period, the inspection signal generator supplies, as the inspection signal to the pixel in the inspected row, an inspection ON signal and also an inspection OFF signal that sets the electroluminescence element to a non-emission level; a current detection amplifier detects an ON current obtained during application of the inspection ON signal and an OFF current obtained during application of the inspection OFF signal; and the memory section stores a data corresponding to a current difference between the detected ON current and OFF current; wherein the electroluminescence elements in the plurality of pixels have a common cathode; wherein the current detector detects cathode current at the common cathode; and wherein after inspection, the video signal that was previously supplied and used for driving the electroluminescence element is again supplied to the pixel that was inspected. ### Claim 2 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein the correcting section executes the correction with respect to the video signal for each pixel using a correction data corresponding to a characteristic variation amount of the element driving transistor created by a correction data creating section based on the data read out from the primary memory. ### Claim 3 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein the data corresponding to the current supplied from the current detector to the memory section is a correction data created by a correction data creating section based on the current detected by the current detector and in accordance with a characteristic variation amount of the element driving transistor. ### Claim 4 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein the blanking period is a horizontal blanking period; and during a predetermined horizontal blanking period, the current difference between the ON current and the OFF current is detected sequentially for the pixels in the inspected row and is sequentially stored in the memory section. ### Claim 5 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein the blanking period is a vertical blanking period; and during the vertical blanking period, the current difference between the ON current and the OFF current is detected sequentially for the pixels in the inspected row and is sequentially stored in the memory section. ### Claim 6 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein in the memory section, a data save controller operates to save the data stored in the primary memory into the secondary memory at a predetermined timing. ### Claim 7 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein the current that flows through the electroluminescence element is a cathode current. ### Claim 8 An electroluminescence display panel driving apparatus, comprising: a variation detecting section which detects an inspection result of a display variation in each pixel of an electroluminescence display panel provided with a display section having a plurality of pixels arranged in a matrix, each of the plurality of pixels including an electroluminescence element having a diode structure and an element driving transistor which is connected to the electroluminescence element and controls a current that flows through the electroluminescence element; and a correcting section which corrects the display variation; wherein the variation detecting section comprises: an inspection signal generator which generates an inspection signal to be supplied to a pixel in a row to be inspected and supplies the inspection signal to the pixel in the inspected row at a predetermined timing during execution of a display in accordance with a video signal; a current detector which detects a current that flows through the electroluminescence element in response to the inspection signal; a volatile primary memory which stores a data corresponding to the current supplied from the current detector, a selector which selectively supplies to the primary memory a data read out from a non-volatile secondary memory which stores and maintains therein the data stored in the primary memory during when an apparatus power supply is turned off; and wherein the correcting section executes a correction with respect to the video signal for each pixel in accordance with the data read out from the primary memory of a memory section; wherein during a blanking period, the inspection signal generator supplies, as the inspection signal to the pixel in the inspected row, an inspection ON signal and also an inspection OFF signal that sets the electroluminescence element to a non-emission level; a current detection amplifier detects an ON current obtained during application of the inspection ON signal and an OFF current obtained during application of the inspection OFF signal; and the memory section stores a data corresponding to a current difference between the detected ON current and OFF current; wherein the electroluminescence elements in the plurality of pixels have a common cathode; wherein the current detector detects cathode current at the common cathode; and wherein after inspection, the video signal that was previously supplied and used for driving the electroluminescence element is again supplied to the pixel that was inspected. ### Claim 9 (depends on 8) The electroluminescence display panel driving apparatus as defined in claim 8, wherein the current that flows through the electroluminescence element is a cathode current. ### Claim 10 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein the data corresponding to a current is written into the primary memory during a horizontal blanking period or a vertical blanking period. ### Claim 11 (depends on 1) The electroluminescence display apparatus as defined in claim 1, wherein data stored in the primary memory is transferred to the secondary memory before the power supply is turned off. ### Claim 12 (depends on 8) The electroluminescence display panel driving apparatus as defined in claim 8, wherein the data corresponding to a current is written into the primary memory during a horizontal blanking period or a vertical blanking period. ### Claim 13 (depends on 8) The electroluminescence display panel driving apparatus as defined in claim 8, wherein data stored in the primary memory is transferred to the secondary memory before the power supply is turned off.