Facebook Patent | Thick backlight for RGB LED of a liquid crystal display used in a virtual reality head mounted display
Publication Number: 10175417
Publication Date: 2019-01-08
Applicants: Facebook
Abstract
A liquid crystal display (LCD) device including a backlight with vertically stacked light emitting diodes (LEDs). The LCD device includes an LCD panel and a backlight for illuminating the LCD panel. The backlight includes a plurality of LEDs and a light guide. The plurality of LEDs are stacked vertically and disposed behind the LCD panel along one or more edges of the LCD panel. The plurality of LEDs include at least a first color LED and a second color LED emitting first light and second light at a first direction, respectively, at a first wavelength and a second wavelength, respectively. The light guide is disposed behind the LCD panel and adjacent to the plurality of LEDs. The light guide is configured to combine the first light and the second light received from the plurality of LEDs into combined light to illuminate the LCD panel.
Background
Edge-lit backlights provide illumination for pixels of liquid crystal displays (LCDs) to provide images on the LCD. These backlights may include a single layer of white LEDs arranged along an edge of a light guide. The light guide receives light from the white LEDs and attempts to direct the light evenly to pixels of the LCD panel of the electronic display. The single layer of white LEDs provides light having limited color gamut and brightness, making them less desirable for use as light sources for backlights for head mounted displays (HMDs).
Summary
A liquid crystal display (LCD) device including a backlight with vertically stacked light emitting diodes (LEDs). In some embodiments, the LCD device includes an LCD panel and a backlight for illuminating the LCD panel. The backlight includes a plurality of LEDs and a light guide. The plurality of LEDs are stacked vertically and disposed behind the LCD panel along one or more edges of the LCD panel. The plurality of LEDs include at least a first color LED and a second color LED emitting first light and second light at a first direction, respectively, at a first wavelength and a second wavelength, respectively. The light guide is disposed behind the LCD panel and adjacent to the plurality of LEDs. The light guide is configured to combine the first light and the second light received from the plurality of LEDs into combined light to illuminate the LCD panel, and direct the combined light to the pixels of the LCD panel in a second direction.
Some embodiments include a head-mounted display (HMD) including an LCD device including a backlight with vertically stacked light emitting diodes (LEDs).
