Display apparatus, driving method thereof, and electronic system

• US 20080198102A1
• Filed: 02/19/2008
• Published: 08/21/2008
• Est. Priority Date: 02/21/2007
• 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 7,764,251 B2
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A display apparatus includes: a pixel array section including a row of scanning lines, a column of signal lines, and pixels in a matrix, with each of the pixels disposed at an intersection of both of the lines; and a drive section. The drive section performs line progressive scanning on the pixels. The pixel includes a light emitting device, a sampling transistor, a driving transistor, a switching transistor, and a holding capacitor. The sampling transistor samples a video signal in the holding capacitor, the driving transistor changes the device to a luminous state, the switching transistor becomes ON in advance of the sampling of the video signal to change the light emitting device to a non-luminous state, and the sampling transistor takes in the OFF voltage from the signal line to the driving transistor, thereby preventing a penetration current from flowing from the power source toward the fixed potential.

Claims

1. A display apparatus comprising:

a pixel array section; and

a drive section driving the pixel array section,

wherein the pixel array section includes a row of first scanning lines and second scanning lines, a column of signal lines, and pixels in a matrix, each of the pixels disposed at an intersection of each of the first scanning lines and each of the signal lines,

the drive section outputs control signals to the row of first scanning lines and second scanning lines, respectively, to perform line progressive scanning on the pixels for each row, and supplies a signal potential and a predetermined off potential to a column of signal lines in synchronism with the line progressive scanning,

the pixel includes a light emitting device, a sampling transistor, a driving transistor, a switching transistor, and a holding capacitor,

the sampling transistor has a control terminal connected to the first scanning line and a pair of current terminals, one of the current terminals is connected to the signal line, and the other of the current terminals is connected to a control terminal of the driving transistor,

the driving transistor has a pair of current terminals, one of the current terminals is connected to a power source, and the other current terminals is connected to the light emitting device,

the switching transistor has a control terminal connected to the second scanning line and a pair of current terminals, one of the current terminals is connected to a fixed potential, and the other of the current terminals is connected to the other current terminals of the driving transistor, and

the holding capacitor has one terminal connected to the control terminal of the driving transistor and the other terminal connected to the other of the current terminals of the switching transistor; and

wherein the sampling transistor passes a current in accordance with the control signal supplied from the first scanning line, and samples a signal potential of a video signal supplied from the signal line to hold the signal potential in the holding capacitor,

the driving transistor allows a drive current to flow through the light emitting device to change the device to a luminous state in accordance with the held signal potential supplied by the current from the power source,

the switching transistor becomes ON in accordance with the control signal supplied from the second scanning signal in advance of the sampling of the video signal to connect the other terminal of the holding capacitor to a fixed potential to change the light emitting device to a non-luminous state, and

the sampling transistor becomes ON in accordance with the other control signal supplied from the first scanning line when the switching transistor becomes ON, and takes in the OFF voltage from the signal line to apply the voltage to the control terminal of the driving transistor, thereby preventing a penetration current from flowing from the power source toward the fixed potential.

2. The display apparatus according to claim 1,

wherein the sampling transistor becomes ON in accordance with the control signal supplied from the first scanning line at the time of the signal line being a predetermined reference potential after turning OFF the driving transistor, writes the reference potential to the control terminal of the driving transistor, thereby setting a potential difference between both ends of the holding capacitor to a higher value than a threshold voltage of the driving transistor, and

the sampling transistor turns OFF the switching transistor next, charges the holding capacitor until the driving transistor is cutoff, thereby holding a voltage corresponding to the threshold voltage in the holding capacitor.

3. The display apparatus according to claim 1,

wherein the driving transistor negatively feeds back the drive current flowing through the driving transistor to the holding capacitor for a predetermined correction time period in a state of the signal voltage being applied to the control terminal thereof, thereby applying a correction in accordance with a mobility of the driving transistor to the signal potential held by the holding capacitor.

5. An electronic system including the display apparatus according to claim 1.

4. A method of driving a display apparatus, the display apparatus including:

a pixel array section, and

a drive section driving the pixel array section,

wherein the pixel array section includes a row of first scanning lines and second scanning lines, a column of signal lines, and pixels in a matrix, each of the pixels disposed at an intersection of each of the first scanning lines and each of the signal lines,

the drive section outputs control signals to the row of first scanning lines and second scanning lines, respectively, to perform line progressive scanning on the pixels for each row, and supplies a signal potential and a predetermined off potential to a column of signal lines in synchronism with the line progressive scanning,

the pixel includes a light emitting device, a sampling transistor, a driving transistor, a switching transistor, and a holding capacitor,

the sampling transistor has a control terminal connected to the first scanning line and a pair of current terminals, one of the current terminals is connected to the signal line, and the other current terminals is connected to a control terminal of the driving transistor,

the driving transistor has a pair of current terminals, one of the current terminals is connected to a power source, the other current terminals is connected to the light-emitting device,

the switching transistor has a control terminal connected to the second scanning line and a pair of current terminals, one of the current terminals is connected to a fixed potential, and the other of the current terminals is connected to the other current terminals of the driving transistor,

the holding capacitor has one terminal connected to the control terminal of the driving transistor and the other terminal connected to the other of the current terminals of the switching transistor, and

wherein the method comprising the steps of

the sampling transistor passing a current in accordance with the control signal supplied from the first scanning line, and sampling a signal potential of a video signal supplied from the signal line to hold the signal potential in the holding capacitor,

the driving transistor allowing a drive current to flow through the light emitting device to change the device to a luminous state in accordance with the held signal potential supplied by the current from the power source,

the switching transistor becoming ON in accordance with the control signal supplied from the second scanning signal in advance of the sampling of the video signal to connect the other terminal of the holding capacitor to a fixed potential to change the light emitting device to a non-luminous state, and

the sampling transistor becoming ON in accordance with the other control signal supplied from the first scanning line when the switching transistor becomes ON, and taking in the OFF voltage from the signal line to apply the voltage to the control terminal of the driving transistor, thereby preventing a penetration current from flowing from the power source toward the fixed potential.