Display device, display device driving method, and electronic apparatus

• US 20080291125A1
• Filed: 04/21/2008
• Published: 11/27/2008
• Est. Priority Date: 05/21/2007
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Uchino, Katsuhide, Yamashita, Junichi
• Granted Patent: US 8,325,109 B2
• Time in Patent Office: Days
• US Class Current: 345/55
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

A display device includes a pixel array portion and a driving portion for driving the pixel array portion. The pixel array portion includes row scanning lines, column signal lines, and pixels arranged in a matrix form at intersections of the scanning lines and the signal lines. The driving portion includes a write scanner for supplying a control signal to each of the scanning lines by sequentially scanning the scanning lines in each field and a signal selector for supplying a video signal to each of the signal lines in synchronization with the sequential scanning. The pixels each includes a storage capacitor, a light-emitting element, a sampling transistor for being turned on in response to the control signal, sampling the video signal, and storing the video signal in the storage capacitor, and a drive transistor for supplying a driving current to the light-emitting element in accordance with the stored video signal.

Claims

1. A display device comprising:

a pixel array portion; and

a driving portion configured to drive the pixel array portion,

the pixel array portion including row scanning lines, column signal lines, and pixels arranged in a matrix form at intersections of the row scanning lines and the column signal lines,

the driving portion including at least a write scanner configured to supply a control signal to each of the row scanning lines by sequentially scanning the row scanning lines in each field and a signal selector configured to supply a video signal to each of the column signal lines in synchronization with the sequential row scanning,

the pixels each including a storage capacitor, a light-emitting element, a sampling transistor that has a control terminal and a pair of current terminals and is configured to be turned on in response to the control signal, sample the video signal, and store the sampled video signal in the storage capacitor, and a drive transistor that has a control terminal and a pair of current terminals and is configured to supply a driving current to the light-emitting element in accordance with the video signal stored in the storage capacitor,

the control terminal of the sampling transistor being connected to one of the row scanning lines, one of the current terminals of the sampling transistor being connected to one of the column signal lines, the other one of the current terminals of the sampling transistor being connected to the control terminal of the drive transistor, one of the current terminals of the drive transistor being connected to a power supply, the other one of the current terminals of the drive transistor being connected to the light-emitting element, the storage capacitor being connected to the control terminal of the drive transistor, and

wherein each of the pixels operates in a light-emission period and a non-light-emission period in each field and performs in the non-light-emission period processing for correcting a threshold voltage of the drive transistor, processing for storing the video signal in the storage capacitor, and processing for correcting mobility of the drive transistor,

wherein the signal selector supplies not only the video signal but also a predetermined potential to each of the column signal lines so as to turn off the light-emitting element,

wherein the write scanner supplies the control signal to each of the row scanning lines such that not only the video signal but also the predetermined potential is supplied from the column signal lines to the pixels, and

wherein the sampling transistor obtains the predetermined potential from one of the column signal lines in response to the control signal supplied from the write scanner and applies the obtained predetermined potential to the control terminal of the drive transistor so as to turn off the light-emitting element and switch from the light-emission period to the non-light emission period.

2. The display device according to claim 1,

wherein the storage capacitor is connected between the control terminal of the drive transistor and the other one of the current terminals of the drive transistor in each of the pixels, and

wherein each of the pixels performs the processing for correcting a threshold voltage of the drive transistor by passing a current to the drive transistor until the drive transistor is cut off before the video signal is sampled, obtaining a voltage between the control terminal of the drive transistor and the other one of the current terminals of the drive transistor when the drive transistor is cut off, and storing the obtained voltage in the storage capacitor.

3. The display device according to claim 1,

wherein the storage capacitor is connected between the control terminal of the drive transistor and the other one of the current terminals of the drive transistor in each of the pixels, and

wherein each of the pixels performs the processing for correcting mobility of the drive transistor by negatively feeding back the driving current flowing through the driving transistor to the storage capacitor for a predetermined correction period when the sampling transistor is turned on and the video signal is stored in the storage capacitor.

4. An electronic apparatus comprising the display device according to claim 1.

5. A driving method for a display device including a pixel array portion and a driving portion configured to drive the pixel array portion,

the pixel array portion including row scanning lines, column signal lines, and pixels arranged in a matrix form at intersections of the row scanning lines and the column signal lines,

the driving portion including at least a write scanner configured to supply a control signal to each of the row scanning lines by sequentially scanning the row scanning lines in each field and a signal selector configured to supply a video signal to each of the column signal lines in synchronization with the sequential row scanning,

the pixels each including a storage capacitor, a light-emitting element, a sampling transistor that has a control terminal and a pair of current terminals and is configured to be turned on in response to the control signal, sample the video signal, and store the sampled video signal in the storage capacitor, and a drive transistor that has a control terminal and a pair of current terminals and is configured to supply a driving current to the light-emitting element in accordance with the video signal stored in the storage capacitor,

the control terminal of the sampling transistor being connected to one of the row scanning lines, one of the current terminals of the sampling transistor being connected to one of the column signal lines, the other one of the current terminals of the sampling transistor being connected to the control terminal of the drive transistor, one of the current terminals of the drive transistor being connected to a power supply, the other one of the current terminals of the drive transistor being connected to the light-emitting element, the storage capacitor being connected to the control terminal of the drive transistor, the driving method comprising the steps of:

causing each of the pixels to operate in a light-emission period and a non-light-emission period in each field and perform in the non-light-emission period processing for correcting a threshold voltage of the drive transistor, processing for storing the video signal in the storage capacitor, and processing for correcting mobility of the drive transistor;

causing the signal selector to supply not only the video signal but also a predetermined potential to each of the column signal lines so as to turn off the light-emitting element;

causing the write scanner to supply the control signal to each of the row scanning lines such that not only the video signal but also the predetermined potential is supplied from the column signal lines to the pixels; and

causing the sampling transistor to obtain the predetermined potential from one of the column signal lines in response to the control signal supplied from the write scanner and apply the obtained predetermined potential to the control terminal of the drive transistor so as to turn off the light-emitting element and switch from the light-emission period to the non-light emission period.