Displays with Adaptive Spectral Characteristics

• US 20150348468A1
• Filed: 09/29/2014
• Published: 12/03/2015
• Est. Priority Date: 06/02/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chen, Cheng, Teoman, Deniz, Wu, Jiaying, Zhong, John Z., Jiang, Jun
• Granted Patent: US 10,475,363 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/08 Arrangements within a display terminal for setting, manually or automatically, display parameters of the display terminal
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

An electronic device may include a display having an array of display pixels and having display control circuitry that controls the operation of the display. The display control circuitry may adaptively adjust the spectral characteristics of display light emitted from the display to achieve a desired effect on the human circadian system. For example, the display control circuitry may adjust the spectral characteristics of blue light emitted from the display based on the time of day such that a user'"'"'s exposure to the display light may result in a circadian response similar to that which would be experienced in natural light. The spectral characteristics of blue light emitted from the display may be adjusted by adjusting the relative maximum power levels provided to blue pixels in the display or by shifting the peak wavelength associated with blue light emitted from the display.

Claims

1. A method for displaying images on an array of display pixels in a display, comprising:

with display control circuitry, gathering time of day information from a time source; and

adjusting spectral characteristics of display light emitted from the display based on the time of day information.

2. The method defined in claim 1 wherein adjusting the spectral characteristics of the display light comprises adjusting the spectral characteristics of blue light emitted from the display based on the time of day information.

3. The method defined in claim 2 further comprising:

determining a daylight level based on the time of day information; and

adjusting the spectral characteristics of blue light emitted from the display based on the daylight level.

4. The method defined in claim 3 wherein adjusting the spectral characteristics of the blue light emitted from the display comprises attenuating the blue light emitted from the display based on the time of day information.

5. The method defined in claim 4 wherein the display pixels include blue display pixels and wherein adjusting the spectral characteristics of the display light comprises adjusting the relative maximum power levels delivered to the blue display pixels based on the time of day information.

6. The method defined in claim 3 wherein adjusting the spectral characteristics of the blue light emitted from the display comprises shifting a peak wavelength of the blue light emitted from the display based on the time of day information.

7. The method defined in claim 6 wherein the display comprises a switchable filter and wherein adjusting the spectral characteristics of the display light comprises adjusting the switchable filter.

8. The method defined in claim 6 wherein the display comprises first and second light sources that provide backlight for the display, wherein the first light source emits blue light associated with a first peak wavelength, wherein the second light source emits blue light associated with a second peak wavelength, and wherein adjusting the spectral characteristics of the blue light emitted from the display comprises switching between the first and second light sources.

9. The method defined in claim 1 wherein adjusting the spectral characteristics of the display light based on the time of day information comprises:

determining whether the time of day information is associated with daylight hours or nighttime hours; and

in response to determining that the time of day information is associated with nighttime hours, setting a maximum luminance for blue light at a level that is lower than that used during daylight hours.

10. A method for displaying images on an array of display pixels in a display, comprising:

with location detection circuitry, gathering geographic location information;

with a light sensor, gathering ambient lighting information; and

adjusting spectral characteristics of display light emitted from the display based on the geographic location information and the ambient lighting information.

11. The method defined in claim 10 wherein adjusting the spectral characteristics of the display light comprises adjusting spectral characteristics of blue light emitted from the display based on the geographic location information and the ambient lighting information.

12. The method defined in claim 11 further comprising:

determining a daylight level based on the geographic location information and the ambient lighting information; and

adjusting the spectral characteristics of the blue light emitted from the display based on the daylight level.

13. The method defined in claim 12 wherein adjusting the spectral characteristics of the blue light emitted from the display comprises attenuating the blue light emitted from the display based on the daylight level.

14. The method defined in claim 13 wherein the display pixels include blue display pixels and wherein adjusting the spectral characteristics of the display light comprises adjusting relative maximum power levels delivered to the blue display pixels based on the daylight level.

15. The method defined in claim 12 wherein adjusting the spectral characteristics of the blue light emitted from the display comprises shifting a peak wavelength of the blue light emitted from the display based on the daylight level.

16. A method for displaying images on an array of display pixels in a display, comprising:

with control circuitry, determining a daylight level; and

adjusting spectral characteristics of blue light emitted from the display based on the daylight level.

17. The method defined in claim 16 wherein the display pixels include blue display pixels and wherein adjusting the spectral characteristics of the blue light emitted from the display comprises adjusting relative maximum power levels delivered to the blue display pixels based on the daylight level.

18. The method defined in claim 16 wherein adjusting the spectral characteristics of the blue light emitted from the display comprises shifting a peak wavelength of the blue light emitted from the display based on the daylight level.

19. The method defined in claim 16 wherein determining the daylight level comprises:

gathering ambient lighting information from a light sensor; and

determining the daylight level based on the ambient lighting information.

20. The method defined in claim 16 wherein determining the daylight level comprises:

gathering time of day information from a time source;

gathering geographic location information from location detection circuitry; and

determining the daylight level based on the time of day information and the geographic location information.