US 10,520,743 B2Granted

Backlight module, display device and method for driving the same

AssigneesBoe Technology Group Co., Ltd., Beijing Boe Optoelectronics Technology Co., Ltd.

InventorsJian Gao, Xue Dong, Xiaochuan Chen, Wenqing Zhao, Pengcheng Lu, Ming Yang, Qian Wang, Xiaochen Niu, Rui Xu, Lei Wang, Pengpeng Wang

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Abstract

A backlight module, a display device and a method for driving the same are disclosed, such that brightness of display device can be increased when rendering 3D display. The backlight module includes a light guide plate, a light-splitting structure and an edge light source, wherein the light-splitting structure includes a plurality of strip-shaped first light-splitting units and a plurality of strip-shaped second light-splitting units, the first light-splitting unit and second light-splitting unit are alternately disposed on the light output surface of the light guide plate, each of first light-splitting unit and second light-splitting unit comprises at least one grating strip, the first light-splitting unit is configured for directing light to output towards a first position external to the backlight module, and the second light-splitting unit is configured for directing light to emit towards a second position external to the backlight module. The backlight module is applied into the display device, such that the display device achieves 3D display function.

Claims19

Dependent claims

A backlight module, comprising:

a light guide plate;
an edge light source, disposed on a side surface of the light guide plate;
and
a light-splitting structure, disposed on a light output surface of the light guide plate and comprising:
a plurality of strip-shaped first light-splitting units, configured for directing light to output towards a first position external to the backlight module;
and
a plurality of strip-shaped second light-splitting units, configured for directing light to emit towards a second position external to the backlight module,
wherein the first light-splitting units and second light-splitting units are alternately disposed on the light output surface of the light guide plate, each of first light-splitting unit and second light-splitting unit comprising at least one grating strip, wherein the at least one grating strip is a blazed grating, the at least one grating strip comprises a grating surface and a groove surface, the grating surface is parallel to the light output surface of the light guide plate, the groove surface is tilted relative to the grating surface, and an inclination angle between the grating surface and the groove surface is a blazed angle γ, and
wherein the at least one grating strip comprises at least a first grating strip and a second grating strip, a blazed angle of the first grating strip is
γ
1
=
arc
⁡
(
cos
⁢
D
L
1
)
,
a blazed angle of the second grating strip is
γ
2
=
arc
⁡
(
cos
⁢
D
L
2
)
,
blazing angles γ of remaining grating strips of each of the light-splitting units are within a range from
arc
⁡
(
cos
⁢
D
L
1
)
≤
γ
≤
arc
⁡
(
cos
⁢
D
L
2
)
,
where D is a vertical distance from the external target position to the back light module, L1 is a vertical distance from a first threshold position to the groove surface of the first grating strip, L2 is a vertical distance from a second threshold position to the groove surface of the second grating strip, a distance between the first threshold position and the second threshold position is less than or equal to 100 mm.

57 more elements

A method for driving a display device, the display device comprising:

a backlight module, comprising:
a light guide plate;
an edge light source, disposed on a side surface of the light guide plate;
and
a light-splitting structure, disposed on a light output surface of the light guide plate and comprising:
a plurality of strip-shaped first light-splitting units, configured for directing light to output towards a first position external to the backlight module;
and
a plurality of strip-shaped second light-splitting units, configured for directing light to emit towards a second position external to the backlight module,
wherein the first light-splitting units and second light-splitting units are alternately disposed on the light output surface of the light guide plate, each of first light-splitting unit and second light-splitting unit comprising at least one grating strip,
wherein the at least one grating strip is a blazed grating, the at least one grating strip comprises a grating surface and a groove surface, the grating surface is parallel to the light output surface of the light guide plate, the groove surface is tilted relative to the grating surface, and an inclination angle between the grating surface and the groove surface is a blazed angle γ,
wherein the at least one grating strip comprises at least a first grating strip and a second grating strip, a blazed angle of the first grating strip
γ
1
=
arc
⁡
(
cos
⁢
D
L
1
)
,
a blazed angle of the second grating strip is
γ
2
=
arc
⁡
(
cos
⁢
D
L
2
)
,
blazing angles γ of remaining grating strips of each of the light-splitting units are within a range from
arc
⁡
(
cos
⁢
D
L
1
)
≤
γ
≤
arc
⁡
(
cos
⁢
D
L
2
)
,
where D is a vertical distance from the external target position to the back light module, L1 is a vertical distance from a first threshold position to the groove surface of the first grating strip, L2 is a vertical distance from a second threshold position to the groove surface of the second grating strip, a distance between the first threshold position and the second threshold position is less than or equal to 100 mm;
and
a display panel, superimposed on the backlight module and comprising a plurality of pixels arranged as an array, a width of each of the first light-splitting unit and the second light-splitting unit of the backlight module being equal to that of the pixels of the display panel, and the first light-splitting unit and the second light-splitting unit being in one-to-one correspondence with pixel columns, among pixels of the display device, pixels corresponding to the first light-splitting units of the display device are first pixels, and pixels corresponding to the second light-splitting units of the display device are second pixels;
the method comprises:
driving the display device to render 3D display, wherein image signals for the left eye are transmitted to the first pixels, and image signals for the right eye are transmitted to the second pixels at the same time.

63 more elements

A backlight module, comprising:

a light guide plate;
an edge light source, disposed on a side surface of the light guide plate;
and
a light-splitting structure, disposed on a light output surface of the light guide plate and comprising:
a plurality of strip-shaped first light-splitting units, configured for directing light to output towards a first position external to the backlight module, and
a plurality of strip-shaped second light-splitting units, configured for directing light to emit towards a second position external to the backlight module,
wherein the first light-splitting units and second light-splitting units are alternately disposed on the light output surface of the light guide plate, each of first light-splitting unit and second light-splitting unit comprising at least one grating strip,
wherein the at least one grating strip is a blazed grating, the at least one grating strip comprises a grating surface and a groove surface, the grating surface is parallel to the light output surface of the light guide plate, the groove surface is tilted relative to the grating surface, and an inclination angle between the grating surface and the groove surface is a blazed angle γ,
wherein the blazed angle γ of the at least one grating strip is equal to an angle between a vertical line from an external target position to the groove surface of the at least one grating strip having the blazed angle γ and a vertical line from the external target position to the light output surface of the light guide plate,
wherein a width of the at least one grating strip is
d
=
λ
2
⁢
sin
⁢
⁢
γ
,
where λ is a wavelength of light output from the groove surface of the at least one grating strip, and
wherein each of the first light-splitting unit and second light-splitting unit comprises at least a first grating strip and a second grating strip, a blazed angle of the first grating strip is γ1=
arc
⁡
(
cos
⁢
D
L
1
)
,
a blazed angle of the second grating strip is
γ
2
=
arc
⁡
(
cos
⁢
D
L
2
)
,
blazing angles γ of remaining grating strips of each of the light-splitting units are within a range from
arc
⁡
(
cos
⁢
D
L
1
)
≤
γ
≤
arc
⁡
(
cos
⁢
D
L
2
)
,
where D is a vertical distance from the external target position to the back light module, L1 is a vertical distance from a first threshold position to the groove surface of the first grating strip, L2 is a vertical distance from a second threshold position to the groove surface of the second grating strip, a distance between the first threshold position and the second threshold position is less than or equal to 100 mm.

67 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/509,358Filed 29 Jul 2016
Priority: CN 2016 1 00121158 Jan 2016
Published: US 2018/0143447 A124 May 2018
Granted: 31 Dec 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

G02B 30/33
Of the autostereoscopic type: involving directional light or back-light sources
G02B 6/0016
Provided on the surface of the light guide or in the bulk of it: grooves, prisms, gratings, scattering particles or rough surfaces
G02B 6/0053
Provided by one optical element, or plurality thereof, placed on the light output side of the light guide: prismatic sheet or layer; Brightness…
G02B 30/27
Of the autostereoscopic type: involving lenticular arrays