Electronic Device Display With Switchable Film Structures

Patent metadata

Field	Value
Publication number	US-2016356943-A1
Application number	US-201615051047-A
Country	US
Kind code	A1
Filing date	Feb 23, 2016
Priority date	Jun 3, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

An electronic device may generate content that is to be displayed on a display. The display may have an array of liquid crystal display pixels for displaying image frames of the content. The display may be operated in at least a normal viewing mode, a privacy mode, an outdoor viewing mode, and a power saving mode. The different view modes may exhibit different viewing angles. In one configuration, the display may include a backlight unit that generates a collimated light source and that includes a switchable diffuser film for selectively scattering the collimated light source depending on the current viewing mode of the display. In another configuration, the display may include a backlight unit that generates a scattered light source that includes a switchable microarray structure such as a switchable mirror structure or a tunable microlens array for selectively collimating the scattered light source depending on the current viewing mode.

First claim

What is claimed is:

1 . An electronic device display, comprising:
display layers having thin-film transistor structures; and a backlight unit that emits light through the display layers, wherein the backlight unit is configurable in a first mode in which the electronic device display exhibits a first viewing angle and in a second mode in which the electronic device display exhibits a second viewing angle that is different than the first viewing angle.

2 . The electronic device display defined in claim 1 , wherein the display layers further include:
color filter structures; and liquid crystal material interposed between the color filter structures and the thin-film transistor structures.

3 . The electronic device display defined in claim 1 , wherein the first mode comprises a normal viewing mode that provides more than a 30° viewing angle, and wherein the second mode comprises a privacy mode that provides at most a 30° viewing angle.

4 . The electronic device display defined in claim 1 , wherein the first mode comprises a normal viewing mode that provides a nominal on-axis luminance level, wherein the second mode comprises an outdoor viewing mode that provides an elevated on-axis luminance level that is greater than the nominal on-axis luminance level, and wherein the first and second modes exhibit the same net power consumption.

5 . The electronic device display defined in claim 1 , wherein the first mode comprises a normal viewing mode that provides a nominal on-axis luminance level, and wherein the second mode comprises a power saving mode that also provides the nominal on-axis luminance while consuming less power than the normal viewing mode.

6 . The electronic device display defined in claim 1 , wherein the backlight unit includes a switchable layer that selectively alters the direction of light that is emitted from the backlight unit to the display layers.

7 . Display circuitry, comprising:
display layers that include display pixels; and a backlight unit that comprises:
a light source for generating light;
a light guide plate that receives the light from the light source and that outputs backlight towards the display layers;
a turning film for collimating the backlight output from the light guide plate; and
a switchable diffuser film that receives the collimated backlight from the turning film and that is configured to selectively alter the collimated backlight.

8 . The display circuitry defined in claim 7 , wherein the switchable diffuser film is operable in a first state that passes through the collimated backlight to the display layers and is also operable in a second state that scatters the collimated backlight.

9 . The display circuitry defined in claim 8 , wherein the switchable diffuser film is implemented using polymer dispersed liquid crystal (PDLC) material.

10 . The display circuitry defined in claim 9 , wherein the switchable diffuser film includes a first layer of PDLC material having liquid crystal droplets of a first size and a second layer of PDLC material having liquid crystal droplets of a second size that is different than the first size.

11 . The display circuitry defined in claim 9 , wherein the switchable diffuser includes a layer of PLDC material having asymmetric liquid crystal droplets.

12 . The display circuitry defined in claim 9 , wherein the switchable diffuser includes embedded microlens structures.

13 . The display circuitry defined in claim 9 , wherein the switchable diffuser comprises:
a first group of switchable liquid crystal lens structures; and a second group of switchable liquid crystal lens structures that run orthogonal to the first group of switchable liquid crystal lens structures, wherein the first and second groups of switchable liquid crystal lens structures are in a concave-up orientation.

14 . The display circuitry defined in claim 9 , wherein the switchable diffuser comprises a switchable optical fiber bundle.

15 . Display circuitry, comprising:
display layers that include display pixels; and a backlight unit that comprises:
a light source for generating light;
a light guide plate that receives the light from the light source and that outputs backlight towards the display layers; and
a switchable microarray structure that is selectively activated to collimate the backlight.

16 . The display circuitry defined in claim 15 , wherein the switchable microarray structure includes a switchable mirror structure having a plurality of gaps that is configured to convert the backlight into an array of point light sources.

17 . The display circuitry defined in claim 16 , wherein the switchable microarray structure further includes polymer material that is formed on the switchable mirror structure and that forms pyramid-shaped cavities surrounding each of the gaps.

18 . The display circuitry defined in claim 16 , wherein the switchable microarray structure further includes a plurality of microlens each of which has a center that is aligned to a respective one of the gaps.

19 . The display circuitry defined in claim 15 , wherein the switchable microarray structure comprises:
a first group of switchable liquid crystal lens structures; and a second group of switchable liquid crystal lens structures that run orthogonal to the first group of switchable liquid crystal lens structures, wherein the first and second groups of switchable liquid crystal lens structures are in a concave-down orientation.

20 . The display circuitry defined in claim 15 , wherein the switchable microarray structure are implemented using tunable lens structures selected from the group consisting of: mechanically driven microlens structures, microfluidic devices, polymer network liquid crystal (PNLC) based microlens structures, piezoelectrically driven liquid lens structures, and ultrasonic transparent gel based lens structures

Assignees

• Apple Inc

Inventors

• Choi Hyungryul J
• Ge Zhibing
• Chen Cheng
• Nemati Hossein
• Chen Wei
• Qi Jun
• Bayat Khadijeh
• Doyle David A
• Zhong John Z

Classifications

• G02F1/1323

  Arrangements for providing a switchable viewing angle · CPC title

• G02B6/005 Primary

  provided by one optical element, or plurality thereof, placed on the light output side of the light guide · CPC title

• G02F1/13439

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title

• G02F1/133528

  Polarisers · CPC title

• G02F1/133526

  Lenses, e.g. microlenses or Fresnel lenses · CPC title