Dual image and mirror display device

• US 10,288,933 B2
• Filed: 03/31/2017
• Issued: 05/14/2019
• Est. Priority Date: 03/31/2017
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsuda, Kazuhiko, Tanaka, Katsuji
• Primary Examiner(s): Liu, Shan
• Application Number:
  US15/476,258
• Publication Number:
  US 20180284506A1
• Time in Patent Office: 774 Days
• Field of Search: 349 42- 43, 349 96-103, 349113-115, 349195
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/13471 in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence

Abstract

A device capable of switching between an image display state and a mirror state is provided. The device includes an image display portion and a mirror portion. The image display portion emits image light for displaying a desired image and includes a display panel. The mirror portion is superposed on the image display portion and can switch between an image transmittance state for transmitting image light and a mirror state for reflecting outside light. The mirror portion includes a liquid crystal layer disposed between a first glass substrate and a second glass substrate and a reflective polarization layer adhered to the second glass substrate. A reflective enhancement layer separate from the reflective polarization layer is disposed between the display panel and the liquid crystal layer and has a refractive index that is different from the refractive index of the second glass substrate.

Claims

1. A device capable of switching between an image display state and a mirror state, the device comprising:

an image display portion that emits image light for displaying a desired image, wherein the image display portion includes;

a first polarization layer, and

a display panel;

a mirror portion that is superposed on the image display portion and is capable of being switched between an image transmittance state that transmits the image light and a mirror state that reflects outside light, wherein the mirror portion includes;

a second polarization layer,

a first glass substrate disposed adjacent to the second polarization layer,

a second glass substrate,

a first liquid crystal layer disposed between the first glass substrate and the second glass substrate, and

a reflective polarization layer adhered to the second glass substrate and disposed between the second glass substrate and the display panel; and

a reflective enhancement layer separated from the reflective polarization layer, wherein the reflective enhancement layer and the second glass substrate are disposed between the display panel and the first liquid crystal layer, and wherein the reflective enhancement layer has a refractive index that is different from the refractive index of the second glass substrate,

wherein the reflective enhancement layer is disposed between the second glass substrate and the reflective polarization layer, directly contacts a bottom surface of the second glass facing the reflective polarization layer and adheres to the reflective polarization layer by an optical clear adhesive layer;

the reflective enhancement layer is a transparent film made of silicon nitride and increases a reflectivity of the outside light at a boundary between the reflective enhancement layer and the second glass substrate or the optical clear adhesive layer, and

wherein a thickness of the reflective enhancement layer is bigger than 80 nm and smaller than 150 nm.

2. The device of claim 1, wherein the display panel includes:

a thin film transistor (TFT) substrate,

a color filter substrate opposed to the TFT substrate,

a second liquid crystal layer disposed between the TFT substrate and the color filter substrate, and

a third glass substrate,

wherein the TFT substrate and the color filter substrate are disposed between the first polarization layer and the third glass substrate.

3. The device of claim 1, wherein the reflective enhancement layer has a refractive index that is different from a refractive index of the second glass substrate by more than 0.2.

4. The device of claim 1, wherein the first liquid crystal layer is a twisted nematic.