Apparatuses, systems, and methods for microLED (mLED) backplane architectures
Methods, apparatuses, and systems to control current through a sub-pixel micro-LED (mLED) of a mLED display using a dynamic current mirror are taught. A dynamic current mirror is shifted to phase zero. Phase zero includes establishing a first voltage for a sub-pixel mLED control transistor. The first voltage is produced using a predetermined reference current. An energy storage device used in the sub-pixel mLED is charged to the first voltage during phase zero. The dynamic current mirror is shifted to phase one. In phase one, the first voltage is used with the sub-pixel mLED control transistor to pass an illumination current through the sub-pixel mLED.
1 . A method to control current through a sub-pixel micro-LED (mLED) of a mLED display using a dynamic current mirror, comprising:
shifting the dynamic current mirror to phase zero, phase zero comprising:
establishing a first voltage for a sub-pixel mLED control transistor, the first voltage produced using a predetermined reference current, wherein the establishing includes a threshold voltage for the sub-pixel mLED control transistor;
charging an energy storage device used in the sub-pixel mLED to the first voltage during phase zero; and
shifting the dynamic current mirror to phase one, phase one comprising:
utilizing the first voltage with the sub-pixel mLED control transistor to pass an illumination current through the sub-pixel mLED.
2 . The method of claim 1 , wherein the predetermined reference current is created by a digital signal and a digital-to-analog (DA) converter is used to create an analog signal from the digital signal, the analog signal is used during the establishing.
3 . The method of claim 1 , wherein the energy storage device is a capacitor and during the phase zero a voltage on the capacitor is applied to a gate terminal and a source terminal of the sub-pixel mLED control transistor.
4 . A computer-readable storage medium storing program code for causing a data processing system to perform the steps comprising:
shifting a dynamic current mirror to phase zero, phase zero comprising:
establishing a first voltage for a sub-pixel mLED control transistor, the first voltage produced using a predetermined reference current, wherein the establishing includes a threshold voltage for the sub-pixel mLED control transistor;
charging an energy storage device used in the sub-pixel mLED to the first voltage during phase zero; and
shifting the dynamic current mirror to phase one, phase one comprising:
utilizing the first voltage with the sub-pixel mLED control transistor to pass an illumination current through the sub-pixel mLED.
5 . The computer-readable storage medium of claim 4 , wherein the predetermined reference current is created by a digital signal and a digital-to-analog (DA) converter is used to create an analog signal from the digital signal, the analog signal is used during the establishing.
6 . The computer-readable storage medium of claim 4 , wherein the energy storage device is a capacitor and during the phase zero a voltage on the capacitor is applied to a gate terminal and a source terminal of the sub-pixel mLED control transistor.
7 . A sub-pixel micro-LED (mLED) drive circuit to control current through a sub-pixel micro-LED (mLED) of a mLED display using a dynamic current mirror, comprising:
a sub-pixel mLED control transistor;
a sub-pixel energy storage device; and
two switches, the two switches are operable in two phases as follows:
1. in phase 0 operation, the two switches are configured to charge the sub-pixel energy storage device to a first voltage from a reference current source, and the first voltage includes a threshold voltage for the sub-pixel mLED control transistor;
2. in phase 1 operation, the two switches are configured to disconnect from the reference current source and to use the first voltage with the sub-pixel mLED control transistor to pass an illumination current through the sub-pixel mLED.