Auto-stereoscopic display device with a striped backlight and two lenticular lens arrays
Autostereoscopic display device comprising a backlight ( 66 ), a display panel ( 62 ) comprising rows and columns of pixels and a lenticular arrangement ( 60, 64 ), wherein the backlight ( 66 ) provides a striped output comprising stripes in the column direction or offset by an acute angle to the column direction the lenticular arrangement comprises a first lenticular lens array ( 60 ) on the side of the display panel ( 62 ) facing the display output for directing different display panel pixel outputs in different directions and a second lenticular lens array ( 64 ) on the opposite side of the display panel ( 62 ), facing the backlight ( 66 ), for providing collimation of the striped back-light output.
1. An autostereoscopic display device comprising:
a backlight;
a display panel, the display panel comprising rows and columns of pixels; and
a lenticular arrangement,
wherein the backlight provides a striped output comprising stripes in a column direction or offset by an acute angle to the column direction,
wherein the lenticular arrangement comprises:
a first lenticular lens array; and
a second lenticular lens array,
wherein the first lenticular lens array is disposed on the side of the display panel facing the display output,
wherein the first lenticular lens array comprises negative lens elements,
wherein the first lenticular lens array is arranged to direct different display panel pixel outputs in different directions,
wherein the second lenticular lens array is disposed on the opposite side of the display panel, facing the backlight,
wherein the second lenticular lens comprises positive lens elements, wherein the second lenticular lens array is arranged to provide collimation of the striped backlight output.
2. The device as claimed in claim 1 , wherein the backlight stripes are slanted with respect to the display column direction.
3. The device as claimed in claim 1 , wherein an aperture width of each backlight stripe is less than one quarter of a pitch of sub-pixels of the display panel.
4. The device of claim 1 ,
wherein a pitch of the second lenticular lens array is a factor, N, greater than a pitch of the backlight stripes, and
wherein N is an integer greater than one.
5. The device as claimed in claim 2 ,
wherein the first lenticular lens array and the second lenticular lens arrays have the lens axes slanted with respect to the display column direction,
wherein the lens axes and the backlight stripes are parallel to each other.
6. The device as claimed in claim 4 , wherein N equals two.
7. The device as claimed in claim 4 , further comprising a controller circuit;
wherein the controller circuit drives the display panel in a sequence of N subframes, and
wherein each subframe is synchronized with illumination with a respective set of backlight stripes.
8. The device as claimed in claim 4 ,
wherein
tan
α
1
=
tan
α
2
N
,
wherein α 1 is an angular spread of light from the lens elements of the first lenticular lens array, and
wherein α 2 is an angle of the viewing cone of light to the lens elements of the second lenticular lens array.
9. The device as claimed in claim 4 ,
wherein
C
w
1
p
1
=
N
w
2
p
2
.
wherein w1 is a width of a sub-pixel of the display panel,
wherein p 1 is a pitch of the first lenticular lens array,
wherein w 2 a width of each backlight stripe,
wherein p 2 is the pitch of the second lenticular lens array, and
wherein C is 1.0 or less.
10. The device as claimed in claim 8 , further comprising a controller circuit,
wherein the controller circuit drives the display panel in a sequence of N subframes; and
wherein each subframe is synchronized with illumination with a respective set of backlight stripes.
11. The device as claimed in claim 8 , wherein an aperture width of each backlight stripe is less than half of a pitch of sub-pixels of the display panel.
12. The device as claimed in claim 9 , wherein C is in the range 0.5 to 1.0.
13. The device as claimed in claim 10 , wherein a pitch of the first lenticular lens array is a factor of at least 4 greater than the pitch of the second lenticular lens array.
14. The device as claimed in claim 10 , further comprising a controller circuit,
wherein the controller circuit drives the display panel in a sequence of N subframes, and
wherein each subframe is synchronized with illumination with a respective set of backlight stripes.
15. The device as claimed in claim 10 , wherein an aperture width of each backlight stripe is less than half of a pitch of sub-pixels of the display panel.
16. The device as claimed in claim 10 , wherein an aperture width of each backlight stripe is less than one quarter of a pitch of sub-pixels of the display panel.