Electronic devices with temperature-compensated displays

Patent metadata

Field	Value
Publication number	US-10467982-B2
Application number	US-201715658312-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Mar 31, 2017
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

An electronic device has a display with a pixel array overlapping an array of temperature sensors. Control circuitry in the device may gather temperature measurements from the temperature sensor array. The control circuitry may apply a global offset to the temperature measurements and may apply a damping factor to the globally offset measurements to produce a two-dimensional temperature profile for the display. A look-up table or other data structure may be used to store information on pixel color correction gain values as a function of temperature. This temperature-gain information and temperature information from the two-dimensional temperature profile may be used by display circuitry in the device to display color-corrected images on the display.

First claim

What is claimed is:

1. An electronic device, comprising:
a display;
a temperature sensor array overlapped by the display, wherein the temperature sensor array comprises a plurality of temperature sensors and wherein each temperature sensor of the plurality of temperature sensors is configured to measure the temperature of a respective portion of the display, wherein the temperature sensor array is formed in a pattern overlapping the display, wherein the pattern is selected from the group consisting of: an I-shaped pattern of temperature sensors and a T-shaped pattern of temperature sensors;
control circuitry configured to produce a two-dimensional temperature profile of the display from the temperature measurements taken with the plurality of temperature sensors; and
display circuitry configured to display images on the display that are color-corrected using the two-dimensional temperature profile and temperature-gain look-up table information.

2. The electronic device defined in claim 1 wherein the control circuitry is configured to produce the two-dimensional temperature profile at least partly by applying a global offset to the temperature measurements and compressing the globally offset temperature measurements using a damping factor.

3. The electronic device defined in claim 2 wherein the display circuitry is configured to display the images by determining, for each of the respective portions of the display, a pixel color correction gain value for that location based on a temperature at that location determined from the two-dimensional temperature profile.

4. The electronic device defined in claim 3 wherein the respective portions of the display correspond to grid locations on a non-uniform grid overlapping the display.

5. The electronic device defined in claim 4 further comprising:
a rectangular housing in which the display is mounted;
a light source along a given edge of the rectangular housing; and
at least one display driver integrated circuit for the display circuitry that is located along the given edge.

6. The electronic device defined in claim 5 wherein the rectangular housing has first and second opposing ends, wherein the first end includes the given edge, and wherein the non-uniform grid has a greater density of the grid locations at the first end than at the second end.

7. The electronic device defined in claim 6 wherein the light source comprises light-emitting diodes along the given edge, wherein the display includes a backlight unit with a light guide that receives light from the light-emitting diodes, and wherein the temperature sensor array includes a first group of temperature sensors that run parallel to the given edge.

8. The electronic device defined in claim 7 wherein the temperature sensor array further includes a second group of temperature sensors that run along a dimension perpendicular to the light-emitting diodes along the given edge.

9. The electronic device defined in claim 1 wherein the control circuitry is configured to produce the two-dimensional temperature profile at least partly by applying a global offset to the temperature measurements.

10. The electronic device defined in claim 1 wherein the control circuitry is configured to produce the two-dimensional temperature profile at least partly using a damping factor to compress the temperature measurements.

11. The electronic device defined in claim 1 wherein the temperature-gain look-up table information comprises pixel color correction gain values for a plurality of temperatures and wherein the display circuitry is configured to determine pixel color correction gain values for the respective portions of the display by looking up the pixel color correction gain values in look-up tables using temperatures from the two-dimensional temperature profile.

12. The electronic device defined in claim 11 wherein the look-up tables include non-temperature-dependent pixel color correction gain values determined during display characterization measurements.

13. The electronic device defined in claim 1 wherein the temperature measurements include a center temperature measurement and wherein the control circuitry is configured to produce the two-dimensional temperature profile of the display from the center temperature measurement and predetermined hot and cold offset values.

14. An electronic device, comprising:
a housing;
a display in the housing;
a temperature sensor array overlapped by the display that is configured to make temperature measurements;
control circuitry configured to produce a two-dimensional temperature profile from the temperature measurements at least partly by applying a global offset to the two-dimensional temperature profile and compressing the globally offset two-dimensional temperature profile, wherein the global offset is based on a difference between the temperature measurements of the two-dimensional temperature profile and a threshold temperature and wherein the threshold temperature is a temperature limit; and
display circuitry configured to display images on the display that are color-corrected using the two-dimensional temperature profile and temperature-dependent pixel color correction gain values.

15. The electronic device defined in claim 14 wherein the temperature-dependent pixel color correction gain values comprise temperature-gain look-up table information.

16. The electronic device defined in claim 15 wherein the display circuitry is configured to display the images by determining, for each of multiple locations on the display, a pixel color correction gain value for that location based on a temperature at that location determined from the two-dimensional temperature profile and based on the temperature-gain look-up table information.

17. The electronic device defined in claim 16 wherein the multiple locations correspond to grid locations on a non-uniform grid overlapping the display, wherein the housing has first and second opposing ends, and wherein the non-uniform grid has a greater density of the grid locations at the first end than at the second end.

18. The electronic device defined in claim 17 wherein the display comprises a backlight unit having light-emitting diodes located at the first end.

19. An electronic device, comprising:
a housing having opposing first and second ends;
a display in the housing that has a pixel array supplied with backlight illumination from a backlight unit having light-emitting diodes at the first end;
a temperature sensor array overlapped by the display;
control circuitry configured to produce a two-dimensional temperature profile from temperature measurements taken with the temperature sensor array at least partly by applying a global offset to the temperature measurements of the two-dimensional temperature profile and compressing the globally offset temperature measurements of the two-dimensional temperature profile using a damping factor that is based on a difference between the globally offset temperature measurements of two-dimensional temperature profile and a predetermined temperature, wherein the predetermined temperature is used to set a range of temperatures for the two-dimensional temperature profile; and
display circuitry configured to display images on the display that are color-corrected using the two-dimensional temperature profile and temperature-dependent pixel color correction gain values, wherein the display circuitry includes at least one display driver integrated circuit at the first end.

20. The electronic device defined

Assignees

• Apple Inc

Inventors

• Mohammadi Mahnaz
• Herranz Adria Fores
• Albrecht Marc
• Yu Alexander P
• Thompson Ross
• Xu Daming
• Gorkhali Suraj P
• Suh Heesang
• Son Mookyung
• Yin Victor H
• Segura Judith C
• Li Mingkun
• Khandhar Jay Mayur

Classifications

• G09G2320/0666

  for control of colour parameters, e.g. colour temperature · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• G09G2320/0693

  Calibration of display systems · CPC title

• G09G2320/0242

  Compensation of deficiencies in the appearance of colours · CPC title

• G09G2320/041

  Temperature compensation · CPC title