Display apparatus and display driving method
View Patent ↗A display apparatus includes the following components. A pixel array includes matrix-arranged pixel circuits each including at least a light emitting element, a drive transistor in which a drive voltage is applied between the drain and the source to supply a current corresponding to a signal value supplied between the gate and the source to the light emitting element, and a holding capacitor which is connected between the gate and the source of the drive transistor and which holds the input signal value. A mobility correction operating unit supplies the drive voltage to the transistor while the capacitor holds a correction signal value lower than the signal value to perform mobility correction for the transistor. A light emission operating unit allows the capacitor to hold the signal value and supplies the drive voltage to the transistor after correction to perform light emission at a luminance corresponding to the signal value.
1. A display apparatus comprising:
a pixel array including pixel circuits arranged in a matrix, each pixel circuit including at least a light emitting element, a drive transistor in which a drive voltage is applied between the drain and the source to supply a current corresponding to a signal value supplied between the gate and the source to the light emitting element, and a holding capacitor which is connected between the gate and the source of the drive transistor and which holds the input signal value;
mobility correction operating means for supplying the drive voltage to the drive transistor while allowing the holding capacitor to hold a correction signal value that is a lower voltage than that of the signal value, which is to be supplied to the holding capacitor, to perform a mobility correction operation for correcting the mobility of the drive transistor; and
light emission operating means for, after the mobility correction operation, introducing the signal value to the holding capacitor and supplying the drive voltage to the drive transistor to perform a light emission operation for causing the light emitting element to emit light at a luminance corresponding to the signal value.
2. The apparatus according to claim 1 , further comprising:
a signal selector configured to supply the signal value, the correction signal value, and a potential as a reference value to signal lines arranged in columns in the pixel array;
a writing scanner configured to drive write control lines arranged in rows in the pixel array to apply the potential in the signal line to the pixel circuit; and
a driving control scanner configured to apply the drive voltage to the drive transistor of the pixel circuit using power control lines arranged in rows in the pixel array, wherein
the mobility correction operating means is realized by an operation, performed by the writing scanner, for setting the correction signal value supplied from the signal line to a gate potential of the drive transistor and an operation, performed by the driving control scanner, for supplying the drive voltage to the drive transistor, and
the light emission operating means is realized by an operation, performed by the writing scanner, for setting the signal value supplied from the signal line to the gate potential of the drive transistor and an operation, performed by the driving control scanner, for supplying the drive voltage to the drive transistor.
3. The apparatus according to claim 2 , wherein
each pixel circuit further includes a sampling transistor in addition to the light emitting element, the drive transistor, and the holding capacitor,
the gate of the sampling transistor is connected to the write control line, one of the source and the drain thereof is connected to the signal line, and the other one is connected to the gate of the drive transistor,
after the writing scanner brings the sampling transistor into conduction while a potential applied from the signal selector to the signal line is the correction signal value, the driving control scanner performs the operation for supplying the drive voltage to the drive transistor, thus performing the operation of the mobility correction operating means, and
after the writing scanner brings the sampling transistor into conduction while a potential applied from the signal selector to the signal line is the signal value, the driving control scanner performs the operation for supplying the drive voltage to the drive transistor, thus performing the operation of the light emission operating means.
4. A display driving method for a display apparatus including a pixel array including pixel circuits arranged in a matrix, each pixel circuit including at least a light emitting element, a drive transistor in which a drive voltage is applied between the drain and the source to supply a current corresponding to a signal value supplied between the gate and the source to the light emitting element, and a holding capacitor which is connected between the gate and the source of the drive transistor and which holds the input signal value, the method comprising the steps of:
supplying the drive voltage to the drive transistor while allowing the holding capacitor to hold a correction signal value that is a lower voltage than that of the signal value, which is to be supplied to the holding capacitor, to perform a mobility correction operation for correcting the mobility of the drive transistor; and after the mobility correction operation,
introducing the signal value to the holding capacitor and supplying the drive voltage to the drive transistor to perform a light emission operation for causing the light emitting element to emit light at a luminance corresponding to the signal value.
5. The display driving method according to claim 4 , further comprising:
supplying, by a signal selector, the signal value, the correction signal value, and a potential as a reference value to signal lines arranged in columns in the pixel array;
driving, by a writing scanner, write control lines arranged in rows in the pixel array to apply the potential in the signal line to the pixel circuit; and
applying, by a driving control scanner, the drive voltage to the drive transistor of the pixel circuit using power control lines arranged in rows in the pixel array,
wherein the mobility correction operating means is realized by an operation, performed by the writing scanner, for setting the correction signal value supplied from the signal line to a gate potential of the drive transistor and an operation, performed by the driving control scanner, for supplying the drive voltage to the drive transistor, and
wherein the light emission operating means is realized by an operation, performed by the writing scanner, for setting the signal value supplied from the signal line to the gate potential of the drive transistor and an operation, performed by the driving control scanner, for supplying the drive voltage to the drive transistor.
6. The display driving method according to claim 5 , wherein
each pixel circuit further includes a sampling transistor in addition to the light emitting element, the drive transistor, and the holding capacitor,
the gate of the sampling transistor is connected to the write control line, one of the source and the drain thereof is connected to the signal line, and the other one is connected to the gate of the drive transistor,
after the writing scanner brings the sampling transistor into conduction while a potential applied from the signal selector to the signal line is the correction signal value, the driving control scanner performs the operation for supplying the drive voltage to the drive transistor, thus performing the operation of the mobility correction operating means, and
after the writing scanner brings the sampling transistor into conduction while a potential applied from the signal selector to the signal line is the signal value, the driving control scanner performs the operation for supplying the drive voltage to the drive transistor, thus performing the operation of the light emission operating means.
7. A display apparatus comprising:
a pixel array including pixel circuits arranged in a matrix, each pixel circuit including at least a light emitting element, a drive transistor in which a drive voltage is applied between the drain and the source to supply a current corresponding to a signal value supplied between the gate and the source to the light emitting element, and a holding capacitor which is connected between the gate and the source of the drive transistor and which holds the input signal value;
a mobility correction operating unit configured to supply the drive voltage to the drive transistor while allowing the holding capacitor to hold a correction signal value that is a lower voltage than that of the signal value, which is to be supplied to the holding capacitor, to perform a mobility correction operation for correcting the mobility of the drive transistor; and
light emission operating unit configured to introduce, after the mobility correction operation, the signal value to the holding capacitor and supply the drive voltage to the drive transistor to perform a light emission operation for causing the light emitting element to emit light at a luminance corresponding to the signal value.
8. The display apparatus according to claim 7 , further comprising:
a signal selector configured to supply the signal value, the correction signal value, and a potential as a reference value to signal lines arranged in columns in the pixel array;
a writing scanner configured to drive write control lines arranged in rows in the pixel array to apply the potential in the signal line to the pixel circuit; and
a driving control scanner configured to apply the drive voltage to the drive transistor of the pixel circuit using power control lines arranged in rows in the pixel array, wherein
the mobility correction operating unit is realized by an operation, performed by the writing scanner, for setting the correction signal value supplied from the signal line to a gate potential of the drive transistor and an operation, performed by the driving control scanner, for supplying the drive voltage to the drive transistor, and
the light emission operating unit is realized by an operation, performed by the writing scanner, for setting the signal value supplied from the signal line to the gate potential of the drive transistor and an operation, performed by the driving control scanner, for supplying the drive voltage to the drive transistor.
9. The display apparatus according to claim 8 , wherein
each pixel circuit further includes a sampling transistor in addition to the light emitting element, the drive transistor, and the holding capacitor,
the gate of the sampling transistor is connected to the write control line, one of the source and the drain thereof is connected to the signal line, and the other one is connected to the gate of the drive transistor,
after the writing scanner brings the sampling transistor into conduction while a potential applied from the signal selector to the signal line is the correction signal value, the driving control scanner performs the operation for supplying the drive voltage to the drive transistor, thus performing the operation of the mobility correction operating unit, and
after the writing scanner brings the sampling transistor into conduction while a potential applied from the signal selector to the signal line is the signal value, the driving control scanner performs the operation for supplying the drive voltage to the drive transistor, thus performing the operation of the light emission operating unit.