# US 11,114,026 B2 · Display apparatus comprising color accuracy enhancement transistor or brightness boosting transistor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,114,026 B2 - Document ID: US11114026B2 - Status: Granted - Kind: B2 - Application number: 16/295,361 - Filed: 2019-03-07 - Published: 2019-09-12 - Granted: 2021-09-07 - Earliest claimed: 2018-03-09 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Gun Hee Kim; Do Hyung Kim; Hyeonsik Kim; Sangho Park; Joo-Sun Yoon; Joohee Jeon - Web page: https://patentgrep.com/patent/US11114026B2 ## CPC - G09G 3/3225: using an active matrix - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - H10K 59/1213: {the pixel elements being TFTs} - G09G 2300/043: Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor - G09G 2300/0861: with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0242: Compensation of deficiencies in the appearance of colours - G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - G09G 2320/0626: for control of overall brightness - 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) - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract A display apparatus includes a plurality of pixels, each of the pixels including an organic light emitting diode, a first transistor providing a driving current to operate the organic light emitting diode, a second transistor including a gate electrode that receives a first scan signal, a first electrode that receives a data signal, and a second electrode electrically connected to the first electrode of the first transistor, a storage capacitor including a first electrode receiving a first power voltage and a second electrode electrically connected to the gate electrode of the first transistor, and a color accuracy enhancement transistor that applies a first back bias voltage to the first transistor in response to a color accuracy enhancement signal. ## Claims ### Claim 1 A display apparatus, comprising: a plurality of pixels, each of the plurality of pixels including: an organic light emitting diode; a first transistor providing a driving current to operate the organic light emitting diode; a second transistor including a gate electrode that receives a first scan signal, a first electrode that receives a data signal, and a second electrode electrically connected to a first electrode of the first transistor; a storage capacitor including a first electrode receiving a first power voltage and a second electrode electrically connected to a gate electrode of the first transistor; and a color accuracy enhancement transistor that applies a first back bias voltage to the first transistor in response to a color accuracy enhancement signal. ### Claim 2 (depends on 1) The display apparatus as claimed in claim 1, wherein the color accuracy enhancement transistor includes a gate electrode, a first electrode, and a second electrode, and the first electrode receives a data signal or a first power voltage. ### Claim 3 (depends on 2) The display apparatus as claimed in claim 2, wherein the gate electrode of the color accuracy enhancement transistor receives the color accuracy enhancement signal, the first electrode of the color accuracy enhancement transistor is electrically connected to the first transistor, and the second electrode of the color accuracy enhancement transistor is electrically connected to a back bias electrode of the first transistor. ### Claim 4 (depends on 3) The display apparatus as claimed in claim 3, wherein the first electrode of the color accuracy enhancement transistor is electrically connected to the first electrode of the first transistor. ### Claim 5 (depends on 3) The display apparatus as claimed in claim 3, wherein each of the plurality of pixels further includes a brightness boosting transistor that applies a second back bias voltage to the first transistor in response to a brightness boosting signal. ### Claim 6 (depends on 5) The display apparatus as claimed in claim 5, wherein the brightness boosting transistor includes a gate electrode, a first electrode, and a second electrode, and the first electrode receives a gate voltage of the first transistor. ### Claim 7 (depends on 6) The display apparatus as claimed in claim 6, wherein the gate electrode of the brightness boosting transistor receives the brightness boosting signal, the first electrode of the brightness boosting transistor is electrically connected to the first transistor, and the second electrode of the brightness boosting transistor is electrically connected to the back bias electrode of the first transistor. ### Claim 8 (depends on 7) The display apparatus as claimed in claim 7, wherein the first electrode of the brightness boosting transistor is electrically connected to the gate electrode of the first transistor. ### Claim 9 (depends on 5) The display apparatus as claimed in claim 5, wherein: when the color accuracy enhancement transistor is turned on by the color accuracy enhancement signal, the brightness boosting transistor is turned off by the brightness-boosting signal, and when the brightness boosting transistor is turned on by the brightness-boosting signal, the color accuracy enhancement transistor is turned off by the color accuracy enhancement signal. ### Claim 10 A display apparatus, comprising: a plurality of pixels, each of the plurality of pixels including: an organic light emitting diode; a first transistor providing a driving current to operate the organic light emitting diode; a second transistor including a gate electrode that receives a first scan signal, a first electrode that receives a data signal, and a second electrode electrically connected to a first electrode of the first transistor; and a brightness boosting transistor that applies a second back bias voltage to the first transistor in response to a brightness boosting signal. ### Claim 11 (depends on 10) The display apparatus as claimed in claim 10, wherein the brightness boosting transistor includes a gate electrode that receives the brightness boosting signal, a first electrode electrically connected to the first transistor, and a second electrode electrically connected to a back bias electrode of the first transistor. ### Claim 12 (depends on 10) The display apparatus as claimed in claim 10, wherein a first electrode of the brightness boosting transistor receives a gate voltage of the first transistor. ### Claim 13 (depends on 10) The display apparatus as claimed in claim 10, wherein each of the plurality of pixels includes a color accuracy enhancement transistor that applies a first back bias voltage to the first transistor in response to a color accuracy enhancement signal. ### Claim 14 A display apparatus, comprising: a base substrate; a back bias electrode on the base substrate; a first transistor including a first active pattern overlapping the back bias electrode and a first gate electrode overlapping the first active pattern; a first electrode electrically connected to the first transistor; a second electrode facing the first electrode; a light emitting layer disposed between the first electrode and the second electrode; a color accuracy enhancement transistor electrically connected to the back bias electrode; and a brightness boosting transistor electrically connected to the back bias electrode. ### Claim 15 (depends on 14) The display apparatus as claimed in claim 14, wherein the back bias electrode is electrically connected to a drain electrode of the color accuracy enhancement transistor and a drain electrode of the brightness boosting transistor. ### Claim 16 (depends on 14) The display apparatus as claimed in claim 14, further comprising a buffer layer disposed between the back bias electrode and the first transistor. ### Claim 17 (depends on 14) The display apparatus as claimed in claim 14, further comprising a mode selector that provides a color accuracy enhancement signal to a gate electrode of the color accuracy enhancement transistor, and provides a brightness boosting signal to a gate electrode of the brightness boosting transistor. ### Claim 18 (depends on 17) The display apparatus as claimed in claim 17, wherein: the brightness boosting signal has an off voltage that turns off the brightness boosting transistor when the color accuracy enhancement signal has an on voltage that turns on the color accuracy enhancement transistor, and the color accuracy enhancement signal has an off voltage that turns off the color accuracy enhancement transistor when the brightness boosting signal has an on voltage to turn on the brightness boosting transistor.