# US 11,308,883 B2 · Temperature based OLED sub-pixel luminosity correction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,883 B2 - Document ID: US11308883B2 - Status: Granted - Kind: B2 - Application number: 17/048,692 - Filed: 2018-09-26 - Published: 2021-08-05 - Granted: 2022-04-19 - Earliest claimed: 2018-09-26 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Hsing-Hung Hsieh; Cheng-Hua Yu; Ann Alejandro Villegas - Web page: https://patentgrep.com/patent/US11308883B2 ## CPC - G09G 3/3225: using an active matrix - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - G01K 1/026: {arrangements for monitoring a plurality of temperatures, e.g. by multiplexing} - G01K 13/00: Thermometers specially adapted for specific purposes - G09G 2320/041: Temperature compensation - G09G 2320/048: using evaluation of the usage time - G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data - 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) - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) ## Abstract In an example implementation according to aspects of the present disclosure, a system including a controller to receive a temperature value, from a temperature sensor corresponding to a sub-pixel in an organic light emitting display. The controller calculates a luminous value of the sub-pixel based on the temperature value and a function corresponding to a degradation of luminosity over time and temperature. The controller determines, based on the luminous value, a corrected luminous value corresponding to a target luminous value. The controller retrieves a voltage value from a second database, wherein the second database comprises a luminous-voltage relationship. The controller applies the voltage value to the sub-pixel. ## Claims ### Claim 1 A system comprising: an organic light emitting diode (OLED) display, wherein the display is an array of sub-pixels; a plurality of temperature sensors disposed within the array of sub-pixels to measure a respective temperature value corresponding to each sub-pixel of the array of sub-pixels; a controller communicatively coupled to the plurality of temperature sensors, the controller to: receive the respective temperature value corresponding to each sub-pixel of the array of sub-pixels; determine a present luminous value of each sub-pixel of the array of sub-pixels, wherein a present luminous value of a sub-pixel of the array of sub-pixels is determined by extracting the present luminous value from a first database correlating a plurality of historical laboratory measured temperatures and a plurality of corresponding historical laboratory measured luminosity values of an OLED sub-pixel over time; determine a corrected luminous value of each sub-pixel of the array of sub-pixels, wherein a corrected luminous value of the sub-pixel of the array of sub-pixels is determined by determining a difference between the determined present luminous value of the sub-pixel and a targeted luminous value for the sub-pixel; determine a voltage value to apply to each sub-pixel of the array of sub-pixels to cause each sub-pixel of the array of sub-pixels to reach a corresponding targeted luminous value, wherein a voltage value of the sub-pixel of the array of sub-pixels is determined by extracting a targeted applied voltage value to produce the corrected luminous value from a second database correlating historical laboratory measured luminosity values and a plurality of corresponding applied voltage values of the OLED sub-pixel and determining a difference between a presently applied voltage producing the present luminous value and the targeted applied voltage value to produce the corrected luminous value; and apply the determined voltage value to the sub-pixel. ### Claim 2 (depends on 1) The system of claim 1, wherein the plurality of temperature sensors include a temperature sensor disposed at an edge of the display and a received temperature value of the sub-pixel is based on an interpolation between a first temperature value from the temperature sensor and a second temperature value from a second temperature sensor disposed on the display. ### Claim 3 (depends on 2) The system of claim 2, wherein the second temperature sensor is disposed on an opposite edge of the display from the temperature sensor. ### Claim 4 (depends on 2) The system of claim 2, wherein wherein the interpolation is a linear interpolation to determine an approximate temperature for the sub-pixel based on a distance between the first temperature sensor, the second temperature sensor, and the sub-pixel. ### Claim 5 (depends on 1) The system of claim 1, wherein the database comprises functional extrapolated values of luminosity over time and temperature, wherein the functionally extrapolated values correspond to sub-pixel decay over time under a variety of temperature conditions. ### Claim 6 (depends on 1) The system of claim 1, wherein the second database resides remotely from the system and wherein the second database periodically receives updated luminosity and voltage values comprises a luminous-voltage relationship. ### Claim 7 A method comprising: receiving a temperature value, from a temperature sensor corresponding to a sub-pixel in an organic light emitting display comprising an array of sub-pixels; calculating a present luminous value of the sub-pixel by extracting the present luminous value from a first database correlating a plurality of historical laboratory measured temperature values and a plurality of corresponding historical laboratory measured luminosity values of an OLED sub-pixel over time; determining a corrected luminous value of the sub-pixel by determining a difference between the determined present luminous value of the sub-pixel and a targeted luminous value for the sub-pixel; determining a voltage value by extracting a targeted applied voltage value to produce the corrected luminous value from a second database correlating historical laboratory measured luminosity values and a plurality of corresponding applied voltage values of the OLED sub-pixel and determining a difference between a presently applied voltage producing the present luminous value and the targeted applied voltage value to produce the corrected luminous value and applying the determined voltage value to the sub-pixel. ### Claim 8 (depends on 7) The method of claim 7, wherein the temperature sensor is disposed at an edge of the display and the received temperature value is based on an interpolation between a first temperature value from the temperature sensor and a second temperature value from a second temperature sensor disposed on the display. ### Claim 9 (depends on 8) The method of claim 8, wherein the second temperature sensor is disposed on an opposite edge of the display from the temperature sensor. ### Claim 10 (depends on 9) The method of claim 9, wherein the temperature sensor and the second temperature sensor are disposed outside a perimeter of the display. ### Claim 11 (depends on 7) The method of claim 7, wherein the present luminous value is calculated utilizing a degradation function comprising a curve function based on the plurality of historical laboratory measured temperatures and the plurality of corresponding historical laboratory measured luminosity values over time. ### Claim 12 (depends on 7) The method of claim 7, wherein the first database comprises functional extrapolated values of luminosity over time and temperature. ### Claim 13 A computing device comprising: a controller; a memory, communicatively coupled to the controller, having instructions stored thereon that when executed cause the controller to: receive a temperature value from a temperature sensor corresponding to a sub-pixel; determine from a first database a present luminous value of the sub-pixel based on the received temperature value by extracting the present luminous value from the first database correlating a plurality of historical laboratory measured temperature values and a plurality of corresponding historical laboratory measured luminosity values of an OLED sub-pixel over time; determine a corrected luminous value of the sub-pixel by determining a difference between the determined present luminous value of the sub-pixel and a targeted luminous value for the sub-pixel; determine a voltage value by extracting a targeted applied voltage value to produce the corrected luminous value from a second database correlating historical laboratory measured luminosity values and a plurality of corresponding applied voltage values of the OLED sub-pixel and determining a difference between a presently applied voltage producing the present luminous value and the targeted applied voltage value to produce the corrected luminous value; and apply the determined voltage value to the sub-pixel. ### Claim 14 (depends on 13) The computing device of claim 13, wherein the temperature sensor is disposed at an interior to an edge of a display comprising an array of sub-pixels including the sub-pixel and the received temperature value is based on an interpolation between a first temperature value from the temperature sensor and a second temperature value from a second temperature sensor disposed on the display. ### Claim 15 (depends on 13) The computing device of claim 13, wherein the second temperature sensor is disposed on interior to an edge of the display from the temperature sensor.