Grayscale-based field-sequential display for low power operation

摘要

A field-sequential display is operated in one of a color mode or a grayscale mode. In the color mode, a video source provides image content in the form of multiple-color image data having a frame rate of X Hz and a display controller uses the multiple-color image data to drive the field-sequential display so as provide multiple-color image content at the field-sequential display. In the grayscale mode, the display controller generates grayscale image data from the multiple-color image data and the display controller then drives the field-sequential display with the grayscale image data at a lower frame rate of Y Hz. While in the grayscale mode, the display controller can take advantage of the enhanced contrast provided by the grayscale image content to reduce or disable backlighting at the field-sequential display. The reduced timing requirements afforded by the lower frame rate, as well as the reduction or elimination of backlighting, can reduce power consumption compared to the color mode.

主权项

1. A method comprising:
operating a field-sequential display in a first mode in response to an ambient light intensity being less than a threshold value and in a second mode in response to the ambient light intensity being greater than the threshold value; in the first mode:
receiving N-color image data, where N is a number of image color elements;driving the field-sequential display with the N-color image data at a first frame rate of 180 Hz, which can also be calculated as N*F, where F is a virtual frame rate; andenabling a backlight of the field-sequential display; and in the second mode:
receiving the N-color image data;converting the N-color image data to grayscale image data;driving the field-sequential display with the grayscale image data at a second frame rate of 60 Hz, the second frame rate less than the virtual frame rate; anddisabling the backlight of the field-sequential display via a pulse-width modulation controller to provide a duty cycle to the backlight.