DISPLAY DEVICE AND VEHICLE REARVIEW MIRROR

• US 20190047476A1
• Filed: 08/02/2018
• Published: 02/14/2019
• Est. Priority Date: 08/09/2017
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: OHIRA, Hirofumi, YOSHIDA, Koji
• Granted Patent: US 10,682,959 B2
• Time in Patent Office: Days
• CPC Class Codes: B60R 1/04 mounted inside vehicle B60R1/025, B60R1/08 take precedence
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 11/04 Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle
• CPC Class Codes: B60R 2001/1253 with cameras, video cameras or video screens
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• 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

According to an aspect, a display device includes: a first polarization member configured to absorb light linearly polarized in a second polarization direction orthogonal to a first polarization direction; an optical sheet configured to reflect light linearly polarized in the second polarization direction and transmit light linearly polarized in the first polarization direction; a front panel disposed between the first polarization member and the optical sheet and capable of changing a polarization direction of incident light into another polarization direction in accordance with a voltage applied to the front panel; and a display panel overlapping with the front panel with a second polarization member interposed therebetween, the second polarization member configured to transmit light linearly polarized in the second polarization direction to the optical sheet.

Claims

1. A display device comprising:

a first polarization member configured to absorb light linearly polarized in a second polarization direction orthogonal to a first polarization direction;

an optical sheet configured to reflect light linearly polarized in the second polarization direction and transmit light linearly polarized in the first polarization direction;

a front panel disposed between the first polarization member and the optical sheet and capable of changing a polarization direction of incident light into another polarization direction in accordance with a voltage applied to the front panel; and

a display panel overlapping with the front panel with a second polarization member interposed therebetween, the second polarization member configured to transmit light linearly polarized in the second polarization direction to the optical sheet.

2. The display device according to claim 1, wherein

the front panel includes a liquid crystal layer, and

a retardation Δ

nd (μ

m) of the liquid crystal layer satisfies the following Expression (1);

0.3996≤

Δ

nd≤

0.4995.  

 

(1)

3. The display device according to claim 1, wherein

the front panel includes a liquid crystal layer, and

a retardation Δ

nd (μ

m) of the liquid crystal layer satisfies the following Expression (2);

0.4329≤

Δ

nd≤

0.4662.  

 

(2)

4. The display device according to claim 1, wherein

a transmission axis of the first polarization member and a transmission axis of the optical sheet are parallel to each other, and

a retardation Δ

nd (μ

m) satisfies the following Expression (3);

0.444≤

Δ

nd≤

0.4551.  

 

(3)

5. A vehicle rearview mirror capable of displaying an image both in a reflective state in which incident light is reflected and in a transmissive state in which incident light is transmitted, the vehicle rearview mirror comprising:

the display device according to claim 1; and

an image capturing device configured to capture an image of a region behind a vehicle, wherein

the display panel displays an image in the transmissive state, and

the display panel displays no image in the reflective state.

6. The vehicle rearview mirror according to claim 5, wherein

the front panel includes a liquid crystal layer, and

a retardation Δ

nd (μ

m) of the liquid crystal layer satisfies the following Expression (1);

0.3996≤

Δ

nd≤

0.4995.  

 

(1)

7. The vehicle rearview mirror according to claim 5, wherein

the front panel includes a liquid crystal layer, and

a retardation Δ

nd (μ

m) of the liquid crystal layer satisfies the following Expression (2);

0.4329≤

Δ

nd≤

0.4662.  

 

(2)

8. The vehicle rearview mirror according to claim 5, wherein

a transmission axis of the first polarization member and a transmission axis of the optical sheet are parallel to each other, and

a retardation Δ

nd (μ

m) satisfies the following Expression (3);

0.444≤

Δ

nd≤

0.4551.  

 

(3)