Controlling polarization for liquid crystal displays

• US 20070008471A1
• Filed: 05/23/2006
• Published: 01/11/2007
• Est. Priority Date: 05/23/2005
• Status: Abandoned Application

• Current Assignee: Min-Shine Wang, Ran-Hong Wang
• Original Assignee: Min-Shine Wang, Ran-Hong Wang
• Inventors: Wang, Ran-Hong, Wang, Min-Shine
• Application Number:
  US11/438,905
• Publication Number:
  US 20070008471A1
• Time in Patent Office: Days
• US Class Current: 349/117
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• CPC Class Codes: G02F 1/133541 Circular polarisers
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: G02F 2413/03 Number of plates being 3
• CPC Class Codes: G02F 2413/07 All plates on one side of the LC cell

Abstract

Certain embodiments of liquid crystal display protection panels and liquid crystal display protection panel integrals have low reflection for outdoor applications. Various embodiments also have the advantage of being able to provide increased contrast and brightness for certain convenient viewing directions for outdoor viewers wearing polarized sunglasses.

Claims

1. A polarizing liquid crystal display protection panel having a protection panel rear surface and a protection panel front surface through which light from a display module may pass and exit to a viewer, said protection panel comprising:

a retarder layer RB having a front surface, a rear surface, a slow axis RBX, and a retardance of about (2m+1)λ

/4, where m is an integer and λ

is between about 400 nm to 700 nm;

a linear polarizer PB forward said retarder layer RB and closer to the viewer, said linear polarizer PB having a linear polarization axis PBX that forms an angle θ

₂ of about 45°

or −

45°

to said slow axis RBX of said retarder layer RB; and

a transparent supportive panel, said transparent supportive panel comprises a sheet of glass substrate, a sheet of plastic substrate, or a touch input device,

wherein at least one of said panel front and rear surfaces comprises an anti-reflection treatment.

2. The protection panel of claim 1, wherein said transparent supportive panel is positioned forward said linear polarizer PB.

3. The protection panel of claim 1, wherein said transparent supportive panel is positioned between said linear polarizer PB and said retarder layer RB.

4. The protection panel of claim 1, wherein said transparent supportive panel is positioned rearward said retarder layer RB.

5. The protection panel of claim 1 further comprising a retarder layer RC, said retarder layer RC comprising one or more retarders oriented such that display module light exits as elliptical or circular polarized light.

6. A polarizing protection panel liquid crystal display integral comprising:

a liquid crystal display module having a module front surface that selectively outputs linearly polarized light oriented along a linear polarization axis PAX, said liquid crystal display module comprising a backlight module and a liquid crystal cell having a liquid crystal layer sandwiched between two transparent substrates;

a polarizing protection panel forward said liquid crystal display module, said polarizing protection panel has a protection panel rear surface and a protection panel front surface and comprises a transparent supportive panel and a linear polarizer PB with a linear polarization axis PBX that is positioned either forward or rearward said transparent supportive panel; and

a display front surface through which light from said backlight module exits,

wherein said transparent supportive panel of said protection panel comprises a sheet of glass substrate, a sheet of plastic substrate, or a touch input device and at least one of said display front surface, said protection panel rear surface, and said module front surface comprises an anti-reflection treatment.

7. The display integral of claim 6, wherein said transparent supportive panel comprises a linear polarizer forward said liquid crystal cell.

8. The display integral of claim 6, wherein said protection panel further comprising a retarder layer RB having a front surface, a rear surface, and a slow axis RBX with a retardance of about (2m+1)λ

/4, where m is an integer and λ

is between about 400 nm to 700 nm, said retarder RB being positioned at the rear side of said linear polarizer PB such that said linear polarization axis PBX forms an angle θ

₂ of about ±

45°

to said slow axis RBX and said transparent supportive panel being in one of the following positions;

forward said linear polarizer PB, rearward said retarder layer RB, or between said linear polarizer PB and retarder layer RB.

9. The display integral of claim 8, further comprising a reflective functional part rearward said retarder layer RB, said reflective functional part having a rear surface and comprising at least one of an EMI shield, an infrared filter, and an LCD heater which is formed by conductive film coating on the rear surface of said retarder RB or by conductive film coating on a separate substrate.

10. The display integral of claim 8 further comprising a retarder layer RA rearward said protection panel and forward said display module, said retarder layer RA having a front surface, a rear surface, a retardance of about (2n+1)λ

/4, and a slow axis RAX, which forms an angle θ

₁ to said linear polarization axis PAX, where n is an integer and λ

is between about 400 nm to 700 nm.

11. The display integral of claim 10, where in said θ

₁ is between about +25°

to about +65° and

θ

₂ is about +45°

, or θ

₁ is between about −

25°

to about −

65° and

θ

₂ is about −

45°

when (m+n) is zero or an even integer.

12. The display of claim 10, wherein θ

₁ is between about +25°

to about +65° and

θ

₂ is about −

45°

, or θ

₁ is between about −

25°

to about −

65° and

θ

₂ is about +45°

when (m+n) is an odd integer.

13. The display integral of claim 10, further comprising a reflective functional part rearward the retarder layer RB, said reflective functional part having a front surface and a rear surface and comprising at least one of an EMI shield, an infrared filter, and an LCD heater which comprises a conductive film coating on said retarder RB rear surface or said retarder RA front surface or a conductive film coating on a separate substrate.

14. The display integral of claim 10, wherein at least one of said display front surface, said protection panel rear surface, said RA retarder layer front and rear surfaces, and said module front surface comprises an anti-reflection treatment.

15. A polarizing protection panel transflective liquid crystal display integral comprising:

a transflective liquid crystal display module having a module front surface that selectively outputs linearly polarized light oriented along a linear polarization axis PAX, said transflective liquid crystal display module comprising a liquid crystal cell having a liquid crystal layer sandwiched between two transparent substrates, a partial reflector comprising a reflective electrode or reflective sheet member, and a backlight module;

a retarder layer RA forward said transflective liquid crystal display module, said retarder layer RA having a front surface, a rear surface, a retardance of about (2n+1)λ

/4, and a first slow axis, which forms an angle θ

₁ to said linear polarization axis PAX, where n is an integer and λ

is between about 400 nm to 700 nm;

a polarizing protection panel forward said liquid crystal display module, said protection panel having a protection panel rear surface and a protection panel front surface and comprising a transparent supportive panel, a retarder layer RB having a slow axis RBX with a retardance of about (2m+1)λ

/4, where m is an integer and λ

is between about 400 nm to 700 nm, and a linear polarizer PB having a linear polarization axis PBX, which forms an angle θ

₂ to said slow axis RBX; and

a display front surface through which light from said backlight module exits,

wherein said linear polarizer PB of said protection panel is disposed at the front side of said retarder layer RB of said protection panel and said transparent supportive panel of said protection panel comprises a sheet of glass substrate, a sheet of plastic substrate, or a touch input device and is positioned forward said linear polarizer PB, rearward said retarder layer RB, or between said linear polarizer PB and said retarder layer RB.

16. The display integral of claim 15, wherein said partial reflector comprises a reflective polarizer and a diffusing element, said diffusing element being a layer of adhesive or a corrugated diffusing surface.

17. The display integral of claim 15, further comprising a reflective functional part rearward said retarder layer RB, said reflective functional part having a rear surface and comprising at least one of an EMI shield, an infrared filter, and an LCD heater which is formed by a conductive film coated on the rear surface of said retarder RB or by a conductive film coated on a separate substrate.

18. The display integral of claim 15, wherein at least one of said display front surface, said protection panel front and rear surfaces, said RA retarder layer front and rear surfaces, and said module front surface comprises an anti-reflection treatment.

19. The display integral of claim 17, wherein at least one of said display front surface, said protection panel front and rear surfaces, said RA retarder layer front and rear surfaces, and said module front surface comprises an anti-reflection treatment.

20. A polarizing protection panel transflective liquid crystal display integral comprising:

a transflective liquid crystal display module having a module front surface, said transflective liquid crystal display module comprising, from front to rear, a linear polarizer PA having a linear polarization axis PAX, a liquid crystal cell having a liquid crystal layer sandwiched between two transparent substrates, a partial reflector comprising reflective electrode or reflective sheet members, and a backlight module;

a retarder layer RA forward said transflective liquid crystal display module, said retarder layer RA having a front surface, a rear surface, a retardance of about (2n+1)λ

/4, and a first slow axis, which forms an angle θ

₁ to said linear polarization axis PAX, where n is an integer and λ

is between about 400 nm to 700 nm;

a polarizing protection panel forward said liquid crystal display module, said protection panel having a protection panel rear surface and a protection panel front surface and comprising a transparent supportive panel, a retarder layer RB having a slow axis RBX with a retardance of about (2m+1)λ

/4, where m is an integer and λ

is between about 400 nm to 700 nm, and a linear polarizer PB having a linear polarization axis PBX, which forms an angle θ

₂ to said slow axis RBX; and

a display front surface through which light from said backlight module exits,

wherein said linear polarizer PB of said protection panel is at the front side of said retarder layer RB of said protection panel and said transparent supportive panel of said protection panel comprises a sheet of glass substrate, a sheet of plastic substrate, or a type of touch input device and is positioned forward said linear polarizer PB, rearward said retarder layer RB, or between said linear polarizer PB and said retarder layer RB.

21. The display integral of claim 20, wherein said partial reflector comprises a reflective polarizer and a diffusing element, said diffusing element being a layer of adhesive or a corrugated diffusing surface.

22. The display integral of claim 20, further comprising a reflective functional part rearward said retarder layer RB, said reflective functional part having a rear surface and comprising at least one of an EMI shield, an infrared filter, and an LCD heater which is formed by a conductive film coating on the rear surface of said retarder RB or by conductive film coating on a separate substrate.

23. The display integral of claim 20, wherein at least one of said display front surface, said protection panel front and rear surfaces, said RA retarder layer front and rear surfaces, and said module front surface comprises an anti-reflection treatment.

24. The display integral of claim 22, wherein at least one of said display front surface, said protection panel front and rear surfaces, said RA retarder layer front and rear surfaces, and said module front surface comprises an anti-reflection treatment.