# US 10,502,394 B2 · Display device and method for manufacturing display board

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- Number: US 10,502,394 B2
- Document ID: US10502394B2
- Status: Granted
- Kind: B2
- Application number: 16/089,018
- Filed: 2017-03-31
- Published: 2019-05-02
- Granted: 2019-12-10
- Earliest claimed: 2016-04-21
- Assignees: Kabushiki Kaisha Tokai Rika Denki Seisakusho
- Applicants: Kabushiki Kaisha Tokai Rika Denki Seisakusho
- Inventors: Hiroshi Yoshida
- Web page: https://patentgrep.com/patent/US10502394B2

## CPC

- F21V 9/14: for producing polarised light
- G02F 1/133528: {Polarisers}
- F21V 11/16: using sheets without apertures, e.g. fixed
- G02B 5/30: Polarising elements (light-modulating devices with active elements G02F1/00)
- G02B 5/3058: {comprising electrically conductive elements, e.g. wire grids, conductive particles}
- G02B 30/25: using polarisation techniques
- G02F 1/133512: {Light shielding layers, e.g. black matrix (G02F1/136209 takes precedence)}
- G02F 1/133538: {with spatial distribution of the polarisation direction}
- G02F 1/133548: {Wire-grid polarisers}
- G02F 1/133562: {on the viewer side}
- G09F 13/04: Signs, boards or panels, illuminated from behind the insignia
- F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS

## Abstract

A display device includes board with a display region, and a light source that emits an illumination light having a polarization direction along a direction of a first absorption axis or a direction of a second absorption axis perpendicular to the first absorption axis. The display region includes a first region including a region polarization-microfabricated in the direction of the first absorption axis, a second absorption axis, and a third region that transmits the light. Only the first region and the third region are displayed on the display board by emitting the light having a polarization direction along the direction of the second absorption axis. Only the second region and the third region are displayed on the display board by the emitting the light having a polarization direction along the direction of the first absorption axis.

## Claims

### Claim 1

A display device, comprising:
a display board comprising a display region that comprises a plurality of regions each having a different polarization direction due to a difference in absorption axis direction; and
a light source that emits an illumination light having a polarization direction along a direction of a first absorption axis or along a direction of a second absorption axis perpendicular to the first absorption axis,
wherein the display region comprises a first region comprising a region polarization-microfabricated in the direction of the first absorption axis, a second region comprising a region polarization-microfabricated in the direction of the second absorption axis, and a third region that transmits the illumination light,
wherein only the first region and the third region are displayed on the display board by emitting the illumination light having a polarization direction along the direction of the second absorption axis,
wherein only the second region and the third region are displayed on the display board by emitting the illumination light having a polarization direction along the direction of the first absorption axis, and
wherein the display board comprises a single substrate on a surface of which the first to third regions are directly formed.

### Claim 2 (depends on 1)

The display device according to claim 1, wherein display produced by the first and third region and display produced by the second and third regions overlap in the third region on the display board.

### Claim 3 (depends on 1)

The display device according to claim 1, wherein a region other than the first to third regions comprises a light shielding portion that does not transmit the illumination light.

### Claim 4 (depends on 1)

The display device according to claim 1, wherein the light source comprises a first light source with a polarization direction parallel to the direction of the second absorption axis, and a second light source with a polarization direction parallel to the direction of the first absorption axis.

### Claim 5 (depends on 2)

The display device according to claim 2, wherein a region other than the first to third regions comprises a light shielding portion that does not transmit the illumination light.

### Claim 6

A method for manufacturing a display board, comprising:
preparing a single substrate; and
polarization-microfabricating a first region of the substrate to provide a polarizing function in a direction of a first absorption axis and for polarization-microfabricating a second region of the substrate to provide the polarization function in a direction of a second absorption axis perpendicular to the first absorption axis,
wherein the first and second regions are directly formed on a surface of the single substrate.

### Claim 7 (depends on 1)

The display device according to claim 1, wherein the display board comprises a glass substrate and a metal layer formed on the glass substrate, and the metal layer is polarization-microfabricated in a thickness direction thereof.

### Claim 8 (depends on 6)

The method according to claim 6, wherein the polarization microfabricating comprises fabricating a third region where no blade for an absorption axis is formed.

### Claim 9 (depends on 8)

The method according to claim 8, wherein the third region is fabricated as an overlap of the first and second regions.