# US 12,008,958 B2 · HDR OLED display power control

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- Number: US 12,008,958 B2
- Document ID: US12008958B2
- Status: Granted
- Kind: B2
- Application number: 17/815,480
- Filed: 2022-07-27
- Published: 2024-02-01
- Granted: 2024-06-11
- Earliest claimed: 2022-07-27
- Assignees: Microsoft Technology Licensing, LLC
- Applicants: Microsoft Technology Licensing, LLC
- Inventors: Nobuyuki Suzuki; Baek Woon Lee; Ying Zheng; Samu Matias Kallio; Kari Jussi Ropo
- Web page: https://patentgrep.com/patent/US12008958B2

## CPC

- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 5/10: Intensity circuits
- G09G 2300/0828: forming a digital to analog [D/A] conversion circuit
- G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor
- G09G 2310/0286: Details of a shift registers arranged for use in a driving circuit
- G09G 2310/0289: Details of voltage level shifters arranged for use in a driving circuit
- G09G 2310/0294: Details of sampling or holding circuits arranged for use in a driver for data electrodes
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- G09G 2320/0626: for control of overall brightness
- G09G 2320/0673: for control of gamma adjustment, e.g. selecting another gamma curve
- G09G 2330/021: Power management, e.g. power saving
- G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD
- G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

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.

## Claims

### Claim 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 at least one voltage generator that generates OLED voltages for OLED emission in the OLED array, the at least one voltage generator comprising a pixel digital-to-analog converter (DAC) reference voltage generator that generates a pixel DAC reference voltage and an electroluminescent (EL) cathode bias voltage generator that generates an EL cathode bias voltage;
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:
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 the pixel DAC reference voltage generator and the electroluminescent (EL) cathode bias voltage generator.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

The OLED display system of claim 1, wherein the pixel DAC reference voltage generator uses the luminance index value to generate the pixel DAC reference voltage.

### Claim 4 (depends on 3)

The OLED display system of claim 3, wherein the instructions are executable to use the luminance index value to select the pixel DAC reference voltage from a pre-set table of pixel DAC reference voltages.

### Claim 5 (depends on 3)

The OLED display system of claim 3, wherein the instructions are executable to provide the pixel DAC reference voltage to a column DAC of a column driver for the OLED array.

### Claim 6 (depends on 5)

The OLED display system of claim 5, wherein the column DAC utilizes the pixel DAC reference voltage to generate a Column DAC bias voltage, and the Column DAC bias voltage determines an impedance of a drive transistor for a selected OLED pixel of the OLED array.

### Claim 7 (depends on 1)

The OLED display system of claim 1, wherein the instructions are executable to use the luminance index value to select the EL cathode bias voltage from a pre-set table of EL cathode bias voltages.

### Claim 8 (depends on 1)

The OLED display system of claim 1, further comprising providing the EL cathode bias voltage to a cathode of a selected OLED pixel of the OLED array.

### Claim 9 (depends on 1)

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 window of between one frame and 240 frames of the HDR pixel data.

### Claim 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;
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 at least one voltage generator that generates OLED voltages for OLED emission in the OLED array, the at least one voltage generator comprising a pixel digital-to-analog converter (DAC) reference voltage generator that generates a pixel DAC reference voltage and an electroluminescent (EL) cathode bias voltage generator that generates an EL cathode bias voltage.

### Claim 11 (depends on 10)

The method of claim 10, further comprising using the luminance index value to select the pixel DAC reference voltage from a pre-set table of pixel DAC reference voltages.

### Claim 12 (depends on 10)

The method of claim 10, further comprising providing the pixel DAC reference voltage to a column DAC of a column driver for the OLED array.

### Claim 13 (depends on 12)

The method of claim 12, wherein the column DAC utilizes the pixel DAC reference voltage to generate a Column DAC bias voltage that determines an impedance of a drive transistor for a selected OLED pixel of the OLED array.

### Claim 14 (depends on 10)

The method of claim 10, further comprising using the luminance index value to select the EL cathode bias voltage from a pre-set table of EL cathode bias voltages.

### Claim 15

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 at least one voltage generator that generates OLED voltages for OLED emission in the OLED array, the at least one voltage generator comprising a pixel digital-to-analog converter (DAC) reference voltage generator that generates a pixel DAC reference voltage and an electroluminescent (EL) cathode bias voltage generator that generates an EL cathode bias voltage;
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:
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 the pixel DAC reference voltage generator and the electroluminescent (EL) cathode bias voltage generator in a manner that dynamically adjusts the default maximum luminance capability to a runtime maximum luminance capability that is lower than the default maximum luminance capability.

### Claim 16 (depends on 10)

The method of claim 10, wherein the HDR pixel data is received by a timing microcontroller comprising a decoder/encoder, the method 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.

### Claim 17 (depends on 10)

The method of claim 10, wherein the pixel DAC reference voltage generator uses the luminance index value to generate the pixel DAC reference voltage.

### Claim 18 (depends on 10)

The method of claim 10, further comprising providing the EL cathode bias voltage to a cathode of a selected OLED pixel of the OLED array.

### Claim 19 (depends on 10)

The method of claim 10, further comprising sampling the sampled portion of the HDR pixel data over a sampling window of between one frame and 240 frames of the HDR pixel data.

### Claim 20 (depends on 15)

The computing device of claim 15, wherein the pixel DAC reference voltage generator uses the luminance index value to generate the pixel DAC reference voltage.