HDR OLED display power control
An organic light emitting diode (OLED) display system comprises an OLED array and a power management system that includes at least one voltage generator for the OLED array. A timing microcontroller comprises a decoder/encoder configured to receive HDR pixel data and output display pixel data. A portion of the HDR pixel data is sampled and a luminance index value of the sampled portion is determined, where the luminance index value corresponds to a maximum luminance of the sampled portion. The luminance index value is used to control the at least one voltage generator to reduce power consumption of the OLED display system.
1 . An organic light emitting diode (OLED) display system configured to reproduce high dynamic range (HDR) video and reduce power consumption, the OLED display system comprising:
an OLED array of OLED pixels;
a power management system configured to provide power to the OLED pixels, the power management system comprising a plurality of voltage generators that generate OLED voltages for OLED emission in the OLED array;
a timing microcontroller comprising a decoder/encoder configured to receive HDR pixel data and output display pixel data; and
a memory storing instructions executable by the timing microcontroller to, for each sampling rate of a plurality of sampling rates of HDR pixel data:
sample a sampled portion of the HDR pixel data;
determine a luminance index value of the sampled portion of the HDR pixel data, wherein the luminance index value corresponds to a maximum luminance of the sampled portion of the HDR pixel data; and
use the luminance index value to control a portion of the plurality of voltage generators to generate different pixel DAC reference voltages for different OLED pixels in the OLED array to dynamically adjust a default maximum luminance capability of the OLED pixels to a runtime maximum luminance capability that is lower than the default maximum luminance capability.
2 . The OLED display system of claim 1 , wherein the instructions are executable to cause a luminance histogram analyzer of the decoder/encoder to (1) generate a luminance histogram of the sampled portion of the HDR pixel data and (2) determine the luminance index value from analyzing the luminance histogram.
3 . The OLED display system of claim 1 , wherein the instructions are executable to use the luminance index value to select the different pixel DAC reference voltages from a pre-set table of pixel DAC reference voltages.
4 . The OLED display system of claim 1 , wherein the instructions are executable to provide the pixel DAC reference voltages to column DACs of column drivers for the OLED array.
5 . The OLED display system of claim 4 , wherein the column DACs utilize the pixel DAC reference voltages to generate Column DAC bias voltages, and each of the Column DAC bias voltages determines an impedance of a drive transistor for a selected OLED pixel of the OLED array.
6 . The OLED display system of claim 1 , wherein the instructions are executable to use the luminance index value to control another portion of the plurality of voltage generators to generate different EL cathode bias voltages for different OLED pixels of the OLED array.
7 . The OLED display system of claim 6 , wherein the instructions are executable to use the luminance index value to select the different EL cathode bias voltages from a pre-set table of EL cathode bias voltages.
8 . The OLED display system of claim 6 , wherein the instructions are executable to provide the different EL cathode bias voltages to different cathodes of corresponding OLED pixels of the OLED array.
9 . The OLED display system of claim 1 , wherein the instructions are executable to sample the sampled portion of the HDR pixel data over a sampling rate of between one frame and 240 frames of the HDR pixel data.
10 . At an organic light emitting diode (OLED) display system configured to reproduce high dynamic range (HDR) video via an OLED array, a method for reducing power consumption of the OLED display system, the method comprising:
receiving HDR pixel data from an HDR data source; and
for each sampling rate of a plurality of sampling rates of the HDR pixel data:
sampling a sampled portion of the HDR pixel data;
determining a luminance index value of the sampled portion of the HDR pixel data, wherein the luminance index value corresponds to a maximum luminance of the sampled portion of the HDR pixel data; and
using the luminance index value to control a plurality of voltage generators to generate different EL cathode bias voltages for different OLED pixels in the OLED array to dynamically adjust a default maximum luminance capability of the OLED pixels to a runtime maximum luminance capability that is lower than the default maximum luminance capability.
11 . The method of claim 10 , further comprising causing a luminance histogram analyzer of the decoder/encoder to (1) generate a luminance histogram of the sampled portion of the HDR pixel data and (2) determine the luminance index value from analyzing the luminance histogram.
12 . The method of claim 10 , further comprising using the luminance index value to select the different EL cathode bias voltages from a pre-set table of EL cathode bias voltages.
13 . The method of claim 10 , further comprising providing the different EL cathode bias voltages to different cathodes of corresponding OLED pixels of the OLED array.
14 . The method of claim 10 , further comprising using the luminance index value to control another plurality of voltage generators to generate different pixel DAC reference voltages for different OLED pixels of the OLED array.
15 . The method of claim 14 , further comprising providing the pixel DAC reference voltages to column DACs of column drivers for the OLED array.
16 . The method of claim 15 , wherein the column DACs utilize the pixel DAC reference voltages to generate Column DAC bias voltages, and each of the Column DAC bias voltages determines an impedance of a drive transistor for a selected OLED pixel of the OLED array.
17 . The method of claim 14 , further comprising using the luminance index value to select the different pixel DAC reference voltages from a pre-set table of pixel DAC reference voltages.
18 . A computing device comprising an organic light emitting diode (OLED) display system having a default maximum luminance capability, the OLED display system configured to reproduce high dynamic range (HDR) video, the OLED display system comprising:
an OLED array of OLED pixels;
a power management system configured to provide power to the OLED pixels, the power management system comprising a plurality of voltage generators that generate OLED voltages for OLED emission in the OLED array;
a timing microcontroller comprising a decoder/encoder configured to receive HDR pixel data and output display pixel data; and
a memory storing instructions executable by the timing microcontroller to, for each sampling rate of a plurality of sampling rates of the HDR pixel data:
sample a sampled portion of the HDR pixel data;
determine a luminance index value of the sampled portion of the HDR pixel data, wherein the luminance index value corresponds to a maximum luminance of the sampled portion of the HDR pixel data; and
use the luminance index value to control a portion of the plurality of voltage generators to generate different pixel DAC reference voltages for different OLED pixels in the OLED array to dynamically adjust the default maximum luminance capability of the OLED pixels to a runtime maximum luminance capability that is lower than the default maximum luminance capability.
19 . The computing device of claim 18 , wherein the instructions are executable to provide the pixel DAC reference voltages to column DACs of column drivers for the OLED array.
20 . The computing device of claim 18 , wherein the instructions are executable to use the luminance index value to control another portion of the plurality of voltage generators to generate different EL cathode bias voltages for different OLED pixels of the OLED array.