Transparent screen and image display system

• US 10,642,145 B2
• Filed: 11/01/2018
• Issued: 05/05/2020
• Est. Priority Date: 05/02/2016
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Yanai, Yujiro, Nagai, Michio, Yamamoto, Akira
• Primary Examiner(s): LaBalle, Clayton E.
• Assistant Examiner(s): Butler, Kevin C
• Application Number:
  US16/178,165
• Publication Number:
  US 20190079380A1
• Time in Patent Office: 551 Days
• Field of Search: 359443
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 5/0294 adapted to provide an additional optical effect, e.g. anti-reflection or filter
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G03B 21/604 Polarised screens
• CPC Class Codes: G03B 21/62 Translucent screens

Abstract

Provided are a transparent screen having high transparency in which a hot spot caused by transmitted light can be reduced; and an image display system in which visibility of a screen is excellent and a hot spot is reduced by using the transparent screen. The transparent screen includes, in this order: a first λ/4 plate; a reflecting layer that has a structure obtained by immobilizing a cholesteric liquid crystalline phase and reflects a part of incidence light; and a polarizing film that has an absorption axis in a thickness direction.

Claims

1. A transparent screen comprising, in this order:

a first λ

/4 plate;

a reflecting layer that has a structure obtained by immobilizing a cholesteric liquid crystalline phase and reflects a part of incidence light; and

a polarizing film that has an absorption axis in a thickness direction,

wherein the absorption axis of the polarizing film is aligned at an angle of 80°

to 90°

with respect to a surface of the polarizing film.

2. The transparent screen according to claim 1, further comprising:

a second λ

/4 plate that is provided between the reflecting layer and the polarizing film.

3. The transparent screen according to claim 2,

wherein a slow axis of the first λ

/4 plate and a slow axis of the second λ

/4 plate are perpendicular to each other.

4. The transparent screen according to claim 3,

wherein the reflecting layer has a structure in which reflecting dots obtained by immobilizing a cholesteric liquid crystalline phase are two-dimensionally arranged, and

the reflecting dots are convex on the first λ

/4 plate side.

5. The transparent screen according to claim 4,

wherein the polarizing film has a structure in which a dichromatic colorant is homeotropically aligned.

6. An image display system comprising:

the transparent screen according to claim 5; and

a short focal length projector that projects light from the first λ

/4 plate side to the transparent screen,

wherein light emitted from the short focal length projector is linearly polarized light.

7. The transparent screen according to claim 1,

wherein the reflecting layer has a structure in which reflecting dots obtained by immobilizing a cholesteric liquid crystalline phase are two-dimensionally arranged, and

the reflecting dots are convex on the first λ

/4 plate side.

8. The transparent screen according to claim 1,

wherein the polarizing film has a structure in which a dichromatic colorant is homeotropically aligned.

9. An image display system comprising:

the transparent screen according to claim 1; and

a short focal length projector that projects light from the first λ

/4 plate side to the transparent screen,

wherein light emitted from the short focal length projector is linearly polarized light.

10. The transparent screen according to claim 1,

wherein the absorption axis of the polarizing film is aligned perpendicular to a surface of the polarizing film.