Image display system

• US 7,336,271 B2
• Filed: 03/03/2005
• Issued: 02/26/2008
• Est. Priority Date: 09/03/2002
• Status: Active Grant

• Current Assignee: AGC, Inc.
• Original Assignee: Optrex Corporation (Kyocera Corporation)
• Inventors: Ozeki, Masao, Isshiki, Masanobu, Tahara, Shinya, Suzuki, Toshihiko
• Primary Examiner(s): DHARIA, PRABODH M
• Application Number:
  US11/070,887
• Publication Number:
  US 20050243078A1
• Time in Patent Office: 1,090 Days
• Field of Search: 345/96, 345/30, 345/48, 345/204, 345/3.1, 345/97, 345/102, 345/101, 345/63, 345/206, 349/89, 349/65, 349/57, 349/62
• US Class Current: 345/204
• 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: G02F 1/1375 using dynamic scattering
• CPC Class Codes: H04N 9/3155 for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406

Abstract

An image display system includes a screen comprising a pair of substrates with transparent electrodes provided thereon, and a liquid crystal layer sandwiched between the substrates, the liquid crystal layer containing a cured resin and being capable of exhibiting a light transmissive state and a light scattering state; and an image-projecting unit for projecting an image on the screen; wherein a frame comprising a combination of the light transmissive state and the light scattering state as a minimum repetitive satisfies a certain relationship.

Claims

1. An image display system including:

a screen comprising a pair of substrates with transparent electrodes provided thereon, and a liquid crystal layer sandwiched between the substrates, the liquid crystal layer being capable of exhibiting a light transmissive state and a light scattering state, and

an image-projecting unit for projecting an image on the screen;

wherein when a voltage is applied across confronting transparent electrodes, the liquid crystal layer exhibits the light scattering state, and when no voltage is applied across confronting transparent electrodes, the liquid crystal layer exhibits the light transmissive state;

wherein the screen is provided to face the image-projecting unit so that when the liquid crystal layer exhibits the light scattering state, an image projecting from the image-projecting unit can be focused on the screen to be visually recognized;

wherein a repetition frequency of a combination of the light transmissive state and the light scattering state as a minimum repetitive unit can be set at a value in such a range that a viewer cannot recognize flickering of the image on the screen recognized; and

wherein proportions of a time period (T₁) wherein the liquid crystal layer of the screen exhibits the light scattering state and a time period (T₂) wherein the liquid crystal layer of the screen exhibit the light transmissive state are set in one frame so that the viewer can simultaneously recognize the image on the screen and a scene behind the screen.

2. The image display system according to claim 1, wherein the screen includes a plurality of screen;

and the screens are provided so as to have display surfaces overlapped each other so that when the liquid crystal layers of the respective screens exhibit the light scattering state, different images projected from the image-projecting unit are displayed on the respective screens, whereby the images on the respective screens are made different each other.

3. The image display system according to claim 1, wherein the repetition frequency in the one frame is set at a value of 33 Hz or higher;

and wherein the proportions of T₁ and T₂ are set so as to meet a relationship of T₁/(T₁+T₂)≦

0.8.

6. The image display system according to claim 1, wherein the screen comprises a plurality of screens, and wherein a rise time required for the liquid crystal layer of a screen to change from the light transparent state into the light transmissive state and a fall time required for of the liquid crystal layer of another screen to change from the light scattering state into the light transmissive state are set so that the rise time and the fall time temporal overlap each other when the respective screens are sequentially driven.

7. The image display system according to claim 1, wherein the screen comprises a plurality of screens so that adjacent screens have a distance of 0.4 to 200 mm therebetween;

and

wherein images projected on at least two screens have different brightnesses.

8. The image display system according to claim 1, wherein the liquid crystal and a cured resin in the liquid crystal layer are formed by curing by a photopolymerization method.

9. The image display system according to claim 1, wherein the screen has an instrument, an information terminal or a mirror provided therebehind.

10. The image display system according to claim 1, wherein the screen has a main part of a peripheral portion formed so as to be transparent.

11. The image display system according to claim 10, wherein the screen is transparent except a portion to be connected with an external circuit.

12. The image display system according to claim 1, wherein the screen has a transmittance of 80% or higher when no voltage is applied.

4. An image display system including:

a screen comprising a pair of substrates with transparent electrodes provided thereon, and a liquid crystal layer sandwiched between the substrates, the liquid crystal layer being capable of exhibiting a light transmissive state and a light scattering state, and

an image-projecting unit for projecting an image on the screen;

wherein when a voltage is applied across confronting transparent electrodes, the liquid crystal layer exhibits the light scattering state, and when no voltage is applied across confronting transparent electrodes, the liquid crystal layer exhibits the light transmissive state;

wherein the screen is provided to face the image-projecting unit;

wherein the liquid crystal layer contains a liquid crystal and a cured resin having a mesogen structure, the liquid crystal layer including liquid crystal molecules having a pretilt angle of 60 deg or more with respect to a substrate surface; and

wherein when the liquid crystal layer exhibits the light scattering state, an image projected from image-projecting unit is be focused on the liquid crystal layer to be visually recognized.

5. The image display system according to claim 4, wherein the repetition frequency in the one frame is set at a value of 33 Hz or higher.