Display element, image display system, and method of controlling display element

• US 9,013,526 B2
• Filed: 02/09/2012
• Issued: 04/21/2015
• Est. Priority Date: 02/21/2011
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Yamauchi, Taisuke
• Primary Examiner(s): Wang-Hurst, Kathy
• Assistant Examiner(s): Shen, Peijie
• Application Number:
  US13/369,866
• Publication Number:
  US 20120212523A1
• Time in Patent Office: 1,167 Days
• Field of Search: 349/5, 349/15, 349/62, 345/690, 345/173, 353/94, 353/79
• US Class Current: 345/697
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13476 in which at least one liquid crystal cell or layer assumes a scattering state
• CPC Class Codes: G03B 21/60 characterised by the nature of the surface
• CPC Class Codes: G03H 1/0256 having specific functional layer
• CPC Class Codes: G03H 2250/42 Reflective layer G03H2250/36 takes precedence
• CPC Class Codes: G03H 2260/12 Photopolymer
• CPC Class Codes: G03H 2260/33 Having dispersed compound
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 3/3473 based on light coupled out of a light guide, e.g. due to scattering, by contracting the light guide with external means
• CPC Class Codes: G09G 3/38 using electrochromic devices
• CPC Class Codes: H04N 9/3197 using light modulating optical valves

Abstract

A display element includes a transmission/diffusion switching layer switched between a diffusion state of diffusing visible light and a transmission state of transmitting visible light by electrical switching, and a transmission/reflection switching layer switched between a reflection state of reflecting visible light and a transmission state of transmitting visible light by electrical switching, and the transmission/diffusion switching layer and the transmission/reflection switching layer overlap each other.

Claims

1. An image display device comprising:

a projector adapted to emit visible light forming a picture; and

a screen on which the picture is projected, the screen having a display element, wherein

the projector is spaced apart from the screen,

the display element includes;

a transmission/diffusion switching layer switched between a diffusion state of diffusing the visible light and a transmission state of transmitting the visible light by electrical switching, the transmission/diffusion switching layer including a first electrode and a second electrode; and

a transmission/reflection switching layer switched between a reflection state of reflecting the visible light and a transmission state of transmitting the visible light by electrical switching, the transmission/reflection switching layer including the second electrode and a third electrode, wherein

the transmission/diffusion switching layer and the transmission/reflection switching layer overlap each other, and

the second electrode is a single common electrode of the transmission/diffusion switching layer and the transmission/reflection switching layer.

2. The image display device according to claim 1, wherein

the transmission/diffusion switching layer includes

a polymer-dispersed liquid crystal layer disposed between the pair of first and second electrodes, and

the transmission/reflection switching layer includes a light control mirror layer having an electrochromic material.

3. The image display device according to claim 2, wherein

the light control mirror layer and the polymer-dispersed liquid crystal layer are stacked via a protective layer.

4. The image display device according to claim 3, wherein

the second electrode is the light control mirror layer.

5. The image display device according to claim 4, wherein

the light control mirror layer is grounded.

6. The image display device according to claim 2, wherein

the polymer-dispersed liquid crystal layer is in a reverse mode in which the transmission state can be obtained with no voltage applied.

7. The image display device according to claim 2, wherein

the polymer-dispersed liquid crystal layer is a hologram structure including polymer sections having a birefringent property and liquid crystal sections disposed alternately in a stacked manner, and is capable of electrically switching between transmission and diffusion of visible light passing through the hologram structure.

8. A method of controlling the image display device according to claim 1, the method comprising:

controlling the display element such that, when the display element is set to the diffusion state,

the transmission/diffusion switching layer is set to the diffusion state; and

the transmission/reflection switching layer is set to the reflection state.

9. A method of controlling the image display device according to claim 1, the method comprising:

controlling the display element such that, when the display element is set to the transmission state,

the transmission/diffusion switching layer is set to the transmission state; and

the transmission/reflection switching layer is set to the transmission state.