# US 2014/0152190 A1 · Pixel unit driving circuit, pixel unit and display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152190 A1 - Document ID: US20140152190A1 - Status: Published application - Kind: A1 - Application number: 13/996,138 - Filed: 2012-12-27 - Published: 2014-06-05 - Earliest claimed: 2012-01-04 - Assignees: Boe Technology Group Co., Ltd. - Applicants: Boe Technology Group Co., Ltd. - Inventors: Wen Tan; Xiaojing Qi - Web page: https://patentgrep.com/patent/US20140152190A1 ## CPC - G09G 3/3241: the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror - H05B 45/60: Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED] - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2300/0852: being a dynamic memory with more than one capacitor - G09G 2300/0876: Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes - 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) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A pixel unit driving circuit, a pixel unit and a display device, wherein said pixel unit driving circuit of the pixel unit comprises a switching unit (201) having a first terminal connected to a high-voltage signal terminal (Vdd), a second terminal connected to a light-emitting device (OLED), a third terminal connected to a first control line (CN1), and a fourth terminal connected to a second control line (CN2); a driving transistor (T1) having a drain connected to the switching unit (201), and a source connected to a low-voltage signal terminal (Vss); and a capacitance storage unit (202) having a first terminal connected to the gate of the driving transistor (T1), a second terminal connected to the source of the driving transistor (T1), and a third terminal connected to the second control line (CN2). Amount and on-off of the driving current Ioled and data current Idata can be controlled via the switching unit (201) to make the current scaling ratio Idata/Ioled change inversely as Ioled changes, thus guaranteeing the data current Idata can quickly charge the first capacitor regardless of amount of the driving current Ioled. ## Claims ### Claim at position 1 1-10. (canceled) ### Claim 11 A pixel unit driving circuit comprises: a switching unit having a first terminal connected to a high-voltage signal terminal, a second terminal connected to a light-emitting device, a third terminal connected to a first control line, and a fourth terminal connected to a second control line; a driving transistor having a drain connected to the switching unit, and a source connected to a low-voltage signal terminal; a capacitance storage unit having a first terminal connected to the gate of the driving transistor, a second terminal connected to the source of the driving transistor, and a third terminal connected to the second control line. ### Claim 12 (depends on 11) The pixel unit driving circuit according to claim 11, said capacitance storage unit includes: a first capacitor, a second capacitor, and a fifth transistor; wherein said first capacitor having one terminal connected to the gate of said driving transistor, and another terminal connected to the source of the driving transistor; said second capacitor having one terminal connected to the gate of said driving transistor, and another terminal connected to the drain of said fifth transistor; said fifth transistor having a gate connected to said second control line, and a source connected to the source of said driving transistor. ### Claim 13 (depends on 11) The pixel unit driving circuit according to claim 11, said capacitance storage unit includes: a first capacitor, a second capacitor, and a fifth transistor; wherein said first capacitor having one terminal connected to the gate of the driving transistor, and another terminal connected to one terminal of said second capacitor; said second capacitor having another terminal connected to the source of the driving transistor; said fifth transistor having a drain connected between said first capacitor and the second capacitor, a gate connected to the second control line, and a source connected to the source of said driving transistor. ### Claim 14 (depends on 11) The pixel unit driving circuit according to claim 11, wherein said switching unit comprises: a second transistor, and a fourth transistor; said second transistor having a drain connected to the high-voltage signal terminal, a gate connected to the second control line, and a source connected to the drain of said driving transistor; said fourth transistor having a source connected to the gate of said driving transistor, a gate connected to the first control line, and a drain connected to the high-voltage signal terminal. ### Claim 15 (depends on 12) The pixel unit driving circuit according to claim 12, wherein said switching unit comprises: a second transistor, and a fourth transistor; said second transistor having a drain connected to the high-voltage signal terminal, a gate connected to the second control line, and a source connected to the drain of said driving transistor; said fourth transistor having a source connected to the gate of said driving transistor, a gate connected to the first control line, and a drain connected to the high-voltage signal terminal. ### Claim 16 (depends on 13) The pixel unit driving circuit according to claim 13, wherein said switching unit comprises: a second transistor, and a fourth transistor; said second transistor having a drain connected to the high-voltage signal terminal, a gate connected to the second control line, and a source connected to the drain of said driving transistor; said fourth transistor having a source connected to the gate of said driving transistor, a gate connected to the first control line, and a drain connected to the high-voltage signal terminal. ### Claim 17 (depends on 14) The pixel unit driving circuit according to claim 14, said switching unit further comprises: a third transistor having a source connected to the drain of said driving transistor, a drain connected to the high-voltage signal terminal, and a gate connected to the first control line. ### Claim 18 (depends on 17) The pixel unit driving circuit according to claim 17, the driving transistor, the second transistor, the third transistor, the fourth transistor, and the fifth transistor are n-type thin film transistors. ### Claim 19 A pixel unit includes an OLED, and a pixel unit driving circuit, said pixel unit driving circuit being connected to the cathode of said OLED, the anode of said OLED being connected to the high-voltage signal terminal, wherein said pixel unit driving circuit comprises: a switching unit having a first terminal connected to a high-voltage signal terminal, a second terminal connected to a light-emitting device, a third terminal connected to a first control line, and a fourth terminal connected to a second control line; a driving transistor having a drain connected to the switching unit, and a source connected to a low-voltage signal terminal; a capacitance storage unit having a first terminal connected to the gate of the driving transistor, a second terminal connected to the source of the driving transistor, and a third terminal connected to the second control line. ### Claim 20 (depends on 19) The pixel unit according to claim 19, said capacitance storage unit includes: a first capacitor, a second capacitor, and a fifth transistor; wherein said first capacitor having one terminal connected to the gate of said driving transistor, and another terminal connected to the source of the driving transistor; said second capacitor having one terminal connected to the gate of said driving transistor, and another terminal connected to the drain of said fifth transistor; said fifth transistor having a gate connected to said second control line, and a source connected to the source of said driving transistor. ### Claim 21 (depends on 19) The pixel unit according to claim 19, said capacitance storage unit includes: a first capacitor, a second capacitor, and a fifth transistor; wherein said first capacitor having one terminal connected to the gate of the driving transistor, and another terminal connected to one terminal of said second capacitor; said second capacitor having another terminal connected to the source of the driving transistor; said fifth transistor having a drain connected between said first capacitor and the second capacitor, a gate connected to the second control line, and a source connected to the source of said driving transistor. ### Claim 22 (depends on 19) The pixel unit according to claim 19, wherein said switching unit comprises: a second transistor, and a fourth transistor; said second transistor having a drain connected to the high-voltage signal terminal, a gate connected to the second control line, and a source connected to the drain of said driving transistor; said fourth transistor having a source connected to the gate of said driving transistor, a gate connected to the first control line, and a drain connected to the high-voltage signal terminal. ### Claim 23 (depends on 22) The pixel unit according to claim 22, said switching unit further comprises: a third transistor having a source connected to the drain of said driving transistor, a drain connected to the high-voltage signal terminal, and a gate connected to the first control line. ### Claim 24 (depends on 23) The pixel unit driving circuit according to claim 23, the driving transistor, the second transistor, the third transistor, the fourth transistor, and the fifth transistor are n-type thin film transistors. ### Claim 25 A display device comprises plurality of pixel units, the pixel unit includes an OLED, and a pixel unit driving circuit, said pixel unit driving circuit being connected to the cathode of said OLED, the anode of said OLED being connected to the high-voltage signal terminal, wherein said pixel unit driving circuit comprises: a switching unit having a first terminal connected to a high-voltage signal terminal, a second terminal connected to a light-emitting device, a third terminal connected to a first control line, and a fourth terminal connected to a second control line; a driving transistor having a drain connected to the switching unit, and a source connected to a low-voltage signal terminal; a capacitance storage unit having a first terminal connected to the gate of the driving transistor, a second terminal connected to the source of the driving transistor, and a third terminal connected to the second control line.