The present disclosure relates to the field of display technologies, and particularly, to a conversion circuit, an operation method of the conversion circuit, a compensation device, and a display apparatus.
In an existing pixel circuit, a drive TFT (Thin Film Transistor) is turned on by a data voltage to generate a drive current acting on an OLED (Organic Light-Emitting Diode), thereby driving the OLED to emit light. Due to uncontrollable factors in processes and uncontrollable factors in practical manufacture, characteristics of drive TFTs are not all the same, and may even be quite different. As such, drive currents generated by drive TFTs under a same data voltage may not be the same, and may even be quite different, such that brightness of OLEDs is not uniform.
In the prior art, in order to address this problem, the data voltage is compensated, so that the drive current generated by the drive TFT can have a desired value. In the process of the compensation, a current signal needs to be converted into a voltage signal. However, effect of the compensation is affected by loss of conversion accuracy.
The present disclosure provides a conversion circuit, an operation method of the conversion circuit, a compensation device, and a display apparatus, which can at least partially address the problem of affected effect of the compensation due to loss of conversion accuracy occurring in conversion from a current signal to a voltage signal in the compensating process for pixel.
In an aspect, the present disclosure provides a conversion circuit including a conversion unit connected between an output terminal and a first voltage terminal, and an input unit connected with an input terminal and the conversion unit, respectively; the input unit is configured to receive a current signal from the input terminal and supply the current signal to the conversion unit, and the conversion unit is configured to convert the current signal supplied by the input unit into a voltage signal and output the voltage signal from the output terminal; and an equivalent resistance of the conversion unit is configured such that a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal.
Optionally, the conversion unit includes a plurality of divider resistors connected in series, each of which is connected in parallel with a switch element, and the equivalent resistance of the conversion unit is adjusted by controlling the switch elements corresponding to the plurality of divider resistors, such that the preset voltage corresponding to the standard current is output from the output terminal when the standard current is input from the input terminal.
Optionally, the input unit is a mirror current source.
Optionally, the input unit includes a first transistor, a second transistor, a third transistor, and a fourth transistor;
a gate electrode of the first transistor is connected with the input terminal, a first electrode of the first transistor is connected with the input terminal, and a second electrode of the first transistor is connected with a second electrode of the second transistor;
a gate electrode of the second transistor is connected with the input terminal, a first electrode of the second transistor is connected with a second electrode of the third transistor, and the second electrode of the second transistor is grounded;
a gate electrode of the third transistor is connected with the first electrode of the second transistor, and a first electrode of the third transistor is connected with a first electrode of the fourth transistor; and
a gate electrode of the fourth transistor is connected with the first electrode of the second transistor, and a second electrode of the fourth transistor is connected with the conversion unit.
Optionally, each of the first and second transistors is an n-type MOS transistor, and each of the third and fourth transistors is a p-type MOS transistor.
Optionally, the first voltage terminal is grounded.
Optionally, the input unit includes a fifth transistor and a sixth transistor:
a gate electrode of the fifth transistor is connected with the input terminal, a first electrode of the fifth transistor is connected with the input terminal, and a second electrode of the fifth transistor is connected with a second electrode of the sixth transistor; and
a gate electrode of the sixth transistor is connected with the input terminal, a first electrode of the sixth transistor is connected with the conversion unit, and the second electrode of the sixth transistor is grounded.
Optionally, each of the fifth and sixth transistors is an n-type MOS transistor.
Optionally, the first voltage terminal is connected with a high level input terminal.
In another aspect, the present disclosure further provides a compensation device including a compensation unit and any one of the above conversion circuits, an input terminal of the compensation unit being connected with the output terminal of the conversion circuit, and the compensation unit being configured to perform a compensation operation based on the voltage signal output from the conversion circuit.
In another aspect, the present disclosure further provides a display apparatus including a pixel unit and the compensation device described above, a drive current output terminal of the pixel unit being connected with the input terminal of the conversion circuit, the conversion circuit being configured to receive a drive current output from the pixel unit and output a voltage signal corresponding to the drive current, and the compensation unit being configured to perform a compensation operation on a data voltage supplied to the pixel unit based on the voltage signal output from the conversion circuit.
In another aspect, the present disclosure further provides an operation method of a conversion circuit, the conversion circuit including a conversion unit connected between an output terminal and a first voltage terminal, and an input unit connected with an input terminal and the conversion unit, respectively; wherein
the operation method of the conversion circuit includes:
inputting a standard current from the input terminal, supplying, by the input unit, the standard current to the conversion unit, and adjusting an equivalent resistance of the conversion unit such that a preset voltage corresponding to the standard current is output from the output terminal; and
inputting a drive current from the input terminal, supplying, by the input unit, the drive current to the conversion unit, converting, by the conversion unit, the drive current supplied by the input unit into a voltage signal, and outputting, by the conversion unit, the voltage signal from the output terminal.
The present disclosure has beneficial effects as follow.
The present disclosure provides a conversion circuit, an operation method of the conversion circuit, a compensation device, and a display apparatus. The conversion circuit includes a conversion unit connected between an output terminal and a first voltage terminal, and an input unit connected with an input terminal and the conversion unit respectively; the input unit is configured to receive a current signal from the input terminal and supply the current signal to the conversion unit, and the conversion unit is configured to convert the current signal supplied from the input unit into a voltage signal and output the voltage signal from the output terminal; and an equivalent resistance of the conversion unit is configured such that a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal. As such, when the conversion circuit is used for converting drive currents of different drive TFTs in practical applications, every drive current can be accurately converted into a voltage signal, accuracy of voltage value of which can reflect accuracy of current value of the drive current, such that the drive current can be accurately extracted and converted into the voltage signal. Moreover, in the technical solutions of the present disclosure, by adjusting the equivalent resistance of the conversion unit, the drive current for pixel is accurately converted into the voltage signal, and in turn loss of conversion accuracy due to difference between individual devices such as resistors can be avoided. Furthermore, the voltage signal can be directly applied to the compensation circuit in subsequent stage to compensate the data voltage for the pixel unit, such that drive TFTs driven by different data voltages can generate an identical drive current, thereby achieving uniform display brightness.
To make those skilled in the art better understand technical solutions of the present disclosure, a conversion circuit and an operation method thereof, a compensation device, and a display apparatus provided in the present disclosure will be described in detail below in conjunction with the accompanying drawings.
Embodiments of the present disclosure provide a conversion circuit.
In an embodiment of the present disclosure, the input unit may be a mirror current source.
Referring to
Referring to
In the present embodiment, other logic elements, transistors and resistors may be added, if the variable range of the resistance value of the equivalent resistor of the conversion unit needs to be extended. For example, data bits D6 and D7 and corresponding resistors may be added, the resistance values of the corresponding resistors may be 8R and 16R, and if R is set to be 2K ohm, the variable range of the resistance value of the equivalent resistor of the conversion unit 101 is from 936.5K ohm to 1063.5K ohm, namely, a drift within ±6.35% of internal resistance of a chip can be covered. Needless to say, the variable range of the resistance value of the equivalent resistor of the conversion unit may be further extended. For example, data bits D6, D7, D8, D9 and D10 and corresponding resistors may be added, the resistance values of the corresponding resistors may be 8R, 16R, 32R, 64R and 128R, and if R is set to be 2K ohm, the variable range of the resistance value of the equivalent resistor of the conversion unit 101 is from 488.5K ohm to 1511.5K ohm namely, a drift within ±51.15% of internal resistance of a chip can be covered, and accuracy is 0.05%.
In the present embodiment, the current signal input from the input terminal can be supplied to the conversion unit through the mirror current source, such that a problem occurred when a resistor in the conversion unit is connected in parallel with an OLED can be avoided.
The conversion circuit in the present embodiment includes a conversion unit connected between an output terminal and a first voltage terminal, and an input unit connected with an input terminal and the conversion unit respectively; the input unit is configured to receive a current signal from the input terminal and supply the current signal to the conversion unit, and the conversion unit is configured to convert the current signal supplied by the input unit into a voltage signal and output the voltage signal from the output terminal; and an equivalent resistance of the conversion unit is configured such that a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal. As such, when the conversion circuit is used for converting drive currents of different drive TFTs in practical applications, every drive current can be accurately converted into a voltage signal, accuracy of voltage value of which can reflect accuracy of current value of the drive current, such that the drive current can be accurately extracted and converted into the voltage signal. Moreover, in the technical solution of the present embodiment, by adjusting the equivalent resistance of the conversion unit, the drive current for pixel is accurately converted into the voltage signal, and in turn loss of conversion accuracy due to difference between individual devices such as resistors can be avoided. Furthermore, the voltage signal can be directly applied to the compensation circuit in subsequent stage to compensate the data voltage for the pixel unit, such that drive TFTs driven by different data voltages can generate an identical drive current, thereby achieving uniform display brightness.
Embodiments of the present disclosure also provide a compensation device.
In the compensation device provided in the present embodiment, the conversion unit is connected between the output terminal and the first voltage terminal, and the input unit is respectively connected with the input terminal and the conversion unit; the input unit is configured to receive a current signal from the input terminal and supply the current signal to the conversion unit, and the conversion unit is configured to convert the current signal supplied by the input unit into a voltage signal and output the voltage signal from the output terminal; and an equivalent resistance of the conversion unit is configured such that a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal. As such, when the conversion circuit is used for converting drive currents of different drive TFTs in practical applications, every drive current can be accurately converted into a voltage signal, accuracy of voltage value of which can reflect accuracy of current value of the drive current, such that the drive current can be accurately extracted and converted into the voltage signal. Moreover, in the technical solution of the present embodiment, by adjusting the equivalent resistance of the conversion unit, the drive current for pixel is accurately converted into the voltage signal, and in turn loss of conversion accuracy due to difference between individual devices such as resistors can be avoided. Furthermore, the voltage signal can be directly applied to the compensation circuit in subsequent stage to compensate the data voltage for the pixel unit, such that drive TFTs driven by different data voltages can generate an identical drive current, thereby achieving uniform display brightness.
Embodiments of the present disclosure also provide a display apparatus.
In the display apparatus provided in the present embodiment, the conversion circuit includes the conversion unit and the input unit; the conversion unit is connected between the output terminal and the first voltage terminal, and the input unit is respectively connected with the input terminal and the conversion unit; the input unit is configured to receive a current signal from the input terminal and supply the current signal to the conversion unit, and the conversion unit is configured to convert the current signal supplied by the input unit into a voltage signal and output the voltage signal from the output terminal; and an equivalent resistance of the conversion unit is configured such that a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal. As such, when the conversion circuit is used for converting drive currents of different drive IFTs in practical applications, every drive current can be accurately converted into a voltage signal, accuracy of voltage value of which can reflect accuracy of current value of the drive current, such that the drive current can be accurately extracted and converted into the voltage signal. Moreover, in the technical solution of the present embodiment, by adjusting the equivalent resistance of the conversion unit, the drive current for pixel is accurately converted into the voltage signal, and in turn loss of conversion accuracy due to difference between individual devices such as resistors can be avoided. Furthermore, the voltage signal can be directly applied to the compensation circuit in subsequent stage to compensate the data voltage for the pixel unit, such that drive TFTs driven by different data voltages can generate an identical drive current, thereby achieving uniform display brightness.
Embodiments of the present disclosure also provide an operation method of a conversion circuit.
Step 1001 includes: inputting a standard current from the input terminal, supplying, by the input unit, the standard current to the conversion unit, and adjusting an equivalent resistance of the conversion unit such that a preset voltage corresponding to the standard current is output from the output terminal.
Step 1002 includes: inputting a drive current from the input terminal, supplying, by the input unit, the drive current to the conversion unit, converting, by the conversion unit, the drive current supplied by the input unit into a voltage signal, and outputting, by the conversion unit, the voltage signal from the output terminal.
In the present embodiment, by adjusting the equivalent resistance of the conversion unit, a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal. Specifically, a standard current is input from the input terminal, a voltage value at the output terminal is measured at this time, and an equivalent resistance of the conversion unit is continuously adjusted based on the measured voltage value and a preset voltage value until the measured voltage value reaches the preset voltage value. As such, when the conversion circuit is used for converting drive currents of different drive TFTs in practical applications, every drive current can be accurately converted into a voltage signal, accuracy of voltage value of which can reflect accuracy of current value of the drive current, such that the drive current can be accurately extracted and converted into the voltage signal.
In the operation method of the conversion circuit according to the present embodiment, the equivalent resistance of the conversion unit is adjusted such that a preset voltage corresponding to a standard current is output from the output terminal when the standard current is input from the input terminal. As such, when the conversion circuit is used for converting drive currents of different drive TFI's in practical applications, every drive current can be accurately converted into a voltage signal, accuracy of voltage value of which can reflect accuracy of current value of the drive current, such that the drive current can be accurately extracted and converted into the voltage signal. Moreover, in the technical solution of the present disclosure, by adjusting the equivalent resistance of the conversion unit, the drive current for pixel is accurately converted into the voltage signal, and in turn loss of conversion accuracy due to difference between individual devices such as resistors can be avoided. Furthermore, the voltage signal can be directly applied to the compensation circuit in subsequent stage to compensate the data voltage for the pixel unit, such that drive TFTs driven by different data voltages can generate an identical drive current, thereby achieving uniform. display brightness.
It should be understood that the above implementations are merely exemplary implementations adopted for explaining the principle of the present disclosure, but the present disclosure is not limited thereto. For those skilled in the art, various modifications and improvements may he made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also considered to be within the protection scope of the present disclosure.
Number | Date | Country | Kind |
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201610575644.2 | Jul 2016 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2017/083201 | 5/5/2017 | WO | 00 |