PIXEL DRIVE APPARATUS, LIGHT EMITTING APPARATUS, AND DRIVE CONTROL METHOD FOR THE LIGHT EMITTING APPARATUS
First Claim
1. A pixel drive apparatus for driving pixels each having a light emitting device and a drive transistor whose current path has one end connected to the light emitting device, the apparatus comprising:
- a power supply configured to be connectable to an other end of the current path of the drive transistor and output a supply voltage;
an offset voltage generating circuit that generates an offset voltage;
a voltage controlling circuit that generates an output voltage which is a predetermined gradation voltage added with the offset voltage; and
a current comparison circuit that compares a current value of a reference current corresponding to the gradation voltage with a current value of the current flowing in the current path of the drive transistor when the supply voltage is applied to the other end of the current path of the drive transistor and a voltage based on the output voltage is applied to a control terminal of the drive transistor,the offset voltage generating circuit setting a voltage value of the offset voltage through binary search based on a voltage value of an initial voltage, and acquiring a specific offset voltage corresponding to variation of a characteristic of the drive transistor based on a result of comparison performed by the current comparison circuit according to the offset voltage.
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Accused Products
Abstract
An offset voltage generating circuit sets an offset voltage through binary search based on a voltage value of the initial voltage, and a voltage controlling circuit generates an output voltage which is a predetermined gradation voltage added with the offset voltage, and applies a voltage based on the output voltage to a control terminal of a drive transistor. A current comparison circuit applies a supply voltage from a power supply to the other end of current path of the drive transistor. The current comparison circuit compares the current value of a reference current corresponding to the gradation voltage with a current value of the current flowing in the current path of the drive transistor at this time. The offset voltage generating circuit acquires a specific offset voltage corresponding to variation of the characteristic of the drive transistor based on a result of comparison performed by the current comparison circuit.
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Citations
19 Claims
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1. A pixel drive apparatus for driving pixels each having a light emitting device and a drive transistor whose current path has one end connected to the light emitting device, the apparatus comprising:
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a power supply configured to be connectable to an other end of the current path of the drive transistor and output a supply voltage; an offset voltage generating circuit that generates an offset voltage; a voltage controlling circuit that generates an output voltage which is a predetermined gradation voltage added with the offset voltage; and a current comparison circuit that compares a current value of a reference current corresponding to the gradation voltage with a current value of the current flowing in the current path of the drive transistor when the supply voltage is applied to the other end of the current path of the drive transistor and a voltage based on the output voltage is applied to a control terminal of the drive transistor, the offset voltage generating circuit setting a voltage value of the offset voltage through binary search based on a voltage value of an initial voltage, and acquiring a specific offset voltage corresponding to variation of a characteristic of the drive transistor based on a result of comparison performed by the current comparison circuit according to the offset voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A light emitting apparatus comprising:
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at least one pixel having a light emitting device and a drive transistor whose current path has one end connected to the light emitting device; at least one signal line connected to the pixel; a power supply configured to be connectable to an other end of the current path of the drive transistor and output a supply voltage; at least one offset voltage generating circuit provided in association with the signal line to generate an offset voltage; at least one voltage controlling circuit provided in association with the signal line to generate an output voltage which is a predetermined gradation voltage added with the offset voltage; and at least one current comparison circuit that compares a current value of a reference current corresponding to the gradation voltage with a current value of the current flowing in the current path of the drive transistor when the supply voltage is applied to the other end of the current path of the drive transistor and a voltage based on the output voltage generated is applied to a control terminal of the drive transistor, the offset voltage generating circuit setting a voltage value of the offset voltage through binary search based on a voltage value of an initial voltage, and acquiring a specific offset voltage corresponding to variation of a characteristic of the drive transistor based on a result of comparison performed by the current comparison circuit according to the offset voltage. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. A drive control method for a light emitting apparatus including at least one pixel having a light emitting device and a drive transistor whose current path has one end connected to the light emitting device, and at least one signal line connected to the pixel, the method comprising:
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a gradation voltage generating step of generating a predetermined gradation voltage; an offset voltage generating step of generating an offset voltage; an output voltage generating step of generating an output voltage which is the gradation voltage added with the offset voltage; an output voltage applying step of applying a voltage based on the output voltage to a control terminal of the drive transistor via the signal line; a current comparison step of comparing a current value of a reference current corresponding to the gradation voltage with a current value of the current flowing in the current path of the drive transistor when a supply voltage is applied to the other end of the current path of the drive transistor and the voltage based on the output voltage is applied to the control terminal of the drive transistor; and a specific offset voltage acquiring step of acquiring a specific offset voltage corresponding to variation of a characteristic of the drive transistor based on a result of comparison performed in the current comparison step, the offset voltage generating step including a binary search step of setting a voltage value of the offset voltage through a binary search based on a voltage value of an initial voltage, wherein in the specific offset voltage acquiring step including, the specific offset voltage corresponding to the variation of the characteristic of the drive transistor is acquired based on the result of comparison performed in the current comparison step according to the offset voltage set in the binary search step. - View Dependent Claims (19)
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Specification