Interlaced liquid crystal display panel and backlight used in a head mounted display

Patent metadata

Field	Value
Publication number	US-10170060-B2
Application number	US-201615391034-A
Country	US
Kind code	B2
Filing date	Dec 27, 2016
Priority date	Dec 27, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A liquid crystal display (LCD) device is driven in interlaced scan to accommodate for liquid crystal (LC) setting times without sacrificing brightness. The LCD device includes an LCD panel including a first group of (e.g., even) pixel lines and a second group (e.g., odd) pixel lines, a backlight disposed behind the LCD panel to emit light toward the even and odd pixel lines, a shift grating disposed between the LCD and the backlight, the shift grating configured to block the light from the backlight from reaching either the first group of pixel lines or the second group of pixel lines, and a controller. The controller drives the LCD panel using an interlaced scan, coordinates the activation of the backlight (e.g., a strobed backlight), and changes the state of the shift grating to block the light from the backlight from reaching either the first group of pixel lines or the second group of pixel lines.

First claim

What is claimed is:

1. A display device, comprising:
a liquid crystal display (LCD) panel including at least a first group of pixel lines and a second group of pixel lines;
a backlight disposed behind the LCD panel to emit light toward the first and second groups of pixel lines;
a shift grating disposed between the LCD and the backlight, the shift grating configured to block the light from the backlight from reaching either the first group of pixel lines or the second group of pixel lines; and
a controller configured to:
while the shift grating is blocking the light from the backlight from reaching the first group of pixel lines, set the first group of pixel lines with first group line data for a video frame;
control the backlight and the shift grating such that the light from the backlight illuminates the first group of pixel lines when the first group of pixel lines are set with the first group line data;
while the backlight is illuminating the first group of pixel lines, the first group line data is set on the first group of pixel lines, and the shift grating is blocking the light from reaching the second group of pixels lines, set the second group of pixel lines with second group line data for the video frame; and
control the backlight and the shift grating such that the light from the backlight illuminates the second group of pixel lines and the shift grating blocks the light from reaching the first group of pixel lines when the second group of pixel lines are set with the second group line data.

2. The display device of claim 1 , wherein the first group of pixel lines are even pixel lines and the second group of pixel lines are odd pixel lines.

3. The display device of claim 1 , wherein the backlight is a strobed backlight, and the controller configured to control the backlight includes the controller being configured to flash the strobe backlight on and off according to a periodic signal.

4. The display device of claim 1 , wherein:
the controller configured to control the shift grating includes the controller being configured to provide a shift grating control signal that transitions the shift grating between a first state and a second state according to a periodic signal;
the shift grating blocks the light from the backlight from reaching the second group of pixel lines in the first state;
the shift grating blocks the light from the backlight from reaching the first group of pixel lines in the first state.

5. The display of claim 1 , wherein the controller is further configured to:
while the backlight is illuminating the second group of pixel lines and the second group line data is set on the second group of pixel lines, set the first group of pixel lines with second first group line data for a second video frame; and
control the back light and the shift grating that the light from the backlight illuminates the first group of pixel lines when the first group of pixel lines are set with the second first group line data.

6. The display device of claim 1 , wherein the controller is further configured:
set the first group of pixel lines with the first group line data using a first progressive scan of the first group of pixel lines; and
set the second group of pixel lines with the second group line data using a second progressive scan of the second group of pixel lines.

7. A display device, comprising:
a liquid crystal display (LCD) panel including at least a first group of pixel lines and a second group of pixel lines;
a backlight disposed behind the LCD panel to emit light toward the first and second groups of pixel lines;
a shift grating disposed between the LCD and the backlight, the shift grating configured to block the light from the backlight from reaching either the first group of pixel lines or the second group of pixel lines; and
a controller configured to:
set the first group of pixel lines with first group line data for a video frame;
control the backlight and the shift grating such that the light from the backlight illuminates the first group of pixel lines when the first group of pixel lines are set with the first group line data;
while the backlight is illuminating the first group of pixel lines and the first group line data is set on the first group of pixel lines, set the second group of pixel lines with second group line data for the video frame; and
control the backlight and the shift grating such that the light from the backlight illuminates the second group of pixel lines when the second group of pixel lines are set with the second group line data; and

wherein:
the first group of pixel lines and the second group of pixel lines include pixel line pairs, each pixel line pair including a first pixel line and an adjacent second pixel line; and
the display device further includes micro-optic elements disposed in front of the LCD panel, the micro-optics elements configured to, for each pixel line pair, spread light from the first pixel line and the adjacent second pixel line across a pixel space of the pixel line pair.

8. The display device of claim 7 , wherein each micro-optics element includes a prism and a negative cylindrical lens.

9. A display device, comprising:
a liquid crystal display (LCD) panel including at least a first group of pixel lines and a second group of pixel lines;
a backlight disposed behind the LCD panel to emit light toward the first and second groups of pixel lines;
a shift grating disposed between the LCD and the backlight, the shift grating configured to block the light from the backlight from reaching either the first group of pixel lines or the second group of pixel lines; and
a controller configured to:
set the first group of pixel lines with first group line data for a video frame;
control the backlight and the shift grating such that the light from the backlight illuminates the first group of pixel lines when the first group of pixel lines are set with the first group line data;
while the backlight is illuminating the first group of pixel lines and the first group line data is set on the first group of pixel lines, set the second group of pixel lines with second group line data for the video frame; and
control the backlight and the shift grating such that the light from the backlight illuminates the second group of pixel lines when the second group of pixel lines are set with the second group line data; and

wherein:
the first group of pixel lines and the second group of pixel lines include pixel line pairs, each pixel line pair including a first pixel line and an adjacent second pixel line; and
the controller is further configured to generate the first group line data and the second group line data from the video frame such that the first group line data and second group line data are the same for each pixel line pair.

10. A display device, comprising:
a liquid crystal display (LCD) panel including at least a first group of pixel lines and a second group of pixel lines;
a backlight disposed behind the LCD panel to emit light toward the first and second groups of pixel lines;
a shift grating disposed between the LCD and the backlight, the shift grating configured to block the light from the backlight from reaching either the first group of pixel lines or the second group of pixel lines; and
a controller configured to:
set the first group of pixel lines with first group line data for a video frame;
control the backlight and the shift grating such that the light from the backlight illuminates the first group of pixel lines when the first group of pixel lines are set with the first group line data;
while the backlight is illuminating the first group of pixel lines and the first group line data is set on the firs

Assignees

• Facebook Tech Llc

Inventors

• Tseng Shie Ping Jeffrey
• Richards Evan M
• Shi Jianru
• Shi Yue

Classifications

• G06F3/013

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G02F2201/30

  grating · CPC title

• G09G3/3413 Primary

  Details of control of colour illumination sources · CPC title

• G02F1/1336

  Illuminating devices · CPC title

• G09G2310/0224

  Details of interlacing · CPC title