Liquid crystal display having a rolling backlight

A method of controlling a backlight in a head wearable device (HWD) suitable to be worn by a user, said method comprising:

• tracking a line of sight (LOS) of the user wearing the HWD;
• displaying content to the user over on a near eye display (NED) comprising:
• a plurality of transistors groups forming a pixel array of said display;
• a plurality of backlight units, arranged in rows and columns, forming a backlight surface of said display, wherein the backlight units are independently controllable;
• periodically data at said groups of transistors, at a specified order, over time, being a predefined data refresh pattern;
• dimming the backlight units that in a predefined dimming pattern which spatially overlap one or more of the transistor groups whenever the data at said transistor groups is being refreshed;
• setting at least one of:
• a frequency and a location of the dimmed backlight units;
• and
• instructing a change at least one of:
• the frequency and the location of the dimmed backlight units, based on the LOS of the user,
• wherein at least one of:
• the tracking, the displaying, the dimming, the setting, and the instructing, is controlled by a computer processor,
• wherein the dimming is carried out independently at variable levels so that some of the backlight units are dimmed more or less than others periodically, and
• wherein the NED is a micro display integrated within the HWD, and operating in a dim-to-refresh ratio in which the specified backlight dimming rate is between 3 times to 10 times higher than the specified refresh rate,
• wherein said operating in the dim-to-refresh ratio eliminates a smearing of an image projected from the micro display over a retina of an eye of a viewer wearing the HWD, whenever a head of the viewer is moving, and
• wherein the data refresh pattern and the dimming pattern are synchronized so that the predefined dimming pattern follows the predefined data refresh pattern.

A non-transitory computer readable medium for controlling a backlight in a head wearable device (HWD) suitable to be worn by a user, the computer readable medium comprising a set of instructions that, when executed, cause at least one computer processor to:

• track a line of sight (LOS) of the user wearing the HWD;
• display content to the user over on a near eye display (NED) comprising:
• a plurality of transistors groups forming a pixel array of said display;
• a plurality of backlight units, arranged in rows and columns forming a backlight surface of said display, wherein the backlight units are independently controllable;
• said groups of transistors having data periodically refreshed, at a specified order, over time in a predefined data refresh pattern;
• dim the backlight units that spatially overlap one or more of the transistor groups whenever the data at said transistor groups is being refreshed;
• set at least one of:
• a frequency and a location of the dimmed backlight units;
• instruct a change in at least one of:
• the frequency and the location of the dimmed backlight units, based on the LOS of the user;
• dim the backlight units independently at variable levels, so that some of the backlight units are dimmed more or less than others periodically in a predefined dimming pattern,
• wherein the NED is a micro display integrated within the HWD, and operating in a dim-to-refresh ratio in which the specified backlight dimming rate is between 3 times to 10 times higher than the specified refresh rate,
• wherein said operating in the dim-to-refresh ratio eliminates a smearing of an image projected from the micro display over a retina of an eye of a viewer wearing the HWD, whenever a head of the viewer is moving;
• and
• wherein the data refresh pattern and the dimming pattern are synchronized so that the predefined dimming pattern follows the predefined data refresh pattern.