Optical sheet for reducing scintillation effects in touch panels and display panels

Patent metadata

Field	Value
Publication number	US-9535194-B2
Application number	US-201514643550-A
Country	US
Kind code	B2
Filing date	Mar 10, 2015
Priority date	Mar 11, 2014
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

An optical sheet used as a component for a touch panel or a display element of a display device is capable of imparting a variety of characteristics such as anti-glare properties and preventing the scintillation of image light in ultrahigh-definition display elements having a pixel density of 300 ppi or more. The optical sheet has an uneven shape on a surface, and the uneven shape satisfies at least one of three disclosed conditions relating to the inclination angles of the uneven portions of the sheet and the distribution curves of the inclination angles.

First claim

The invention claimed is:

1. In a touch panel, the improvement comprising an optical sheet as a component of the touch panel, the optical sheet having an uneven shape on a surface, the uneven shape satisfying at least one condition selected from the following (A) to (C), and the touch panel being used for a front surface of a display element having a pixel density of 300 ppi or more,
Condition (A); a gap between inclination angles indicating a half value of a peak value of an inclination angle distribution curve of the uneven shape is in a range of 5 degrees to 15 degrees,
Condition (B); an inclination angle indicating an inflection point on a positive direction side of the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 4 degrees to 15 degrees, and a difference between the inclination angle indicating the inflection point on the positive direction side and the inclination angle indicating the peak value of the inclination angle distribution curve is in a range of 2.2 degrees to 10 degrees, and
Condition (C); the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 2 degrees to 8 degrees, skewness of the inclination angle distribution curve of the uneven shape is in a range of 0 degrees to 1.5 degrees, and/or kurtosis of the inclination angle distribution curve of the uneven shape is in a range of 1.5 to 6.

2. The touch panel according to claim 1 ,
wherein the optical sheet further satisfies Additional Condition (1) described below,
Additional Condition (1); a proportion of inclination angles in a range of 0 degrees to 1.25 degrees in inclination angles of the uneven shape is 20% or less in terms of cumulative percentage.

3. The touch panel according to claim 1 ,
wherein the optical sheet further satisfies Additional Condition (2) described below,
Additional Condition (2); a proportion of inclination angles of 15 degrees or more in the inclination angles of the uneven shape is 3% or less in terms of cumulative percentage.

4. In a display device, the improvement in which the display device comprises a display element having a pixel density of 300 ppi or more and an optical sheet on a front surface of the display element, wherein the optical sheet has an uneven shape on a surface, and the uneven shape satisfies at least one condition selected from the following (A) to (C),
Condition (A); a gap between inclination angles indicating a half value of a peak value of an inclination angle distribution curve of the uneven shape is in a range of 5 degrees to 15 degrees,
Condition (B); an inclination angle indicating an inflection point on a positive direction side of the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 4 degrees to 15 degrees, and a difference between the inclination angle indicating the inflection point on the positive direction side and the inclination angle indicating the peak value of the inclination angle distribution curve is in a range of 2.2 degrees to 10 degrees, and
Condition (C); the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 2 degrees to 8 degrees, skewness of the inclination angle distribution curve of the uneven shape is in a range of 0 degrees to 1.5 degrees, and/or kurtosis of the inclination angle distribution curve of the uneven shape is in a range of 1.5 to 6.

5. An optical sheet having an uneven shape on a surface,
wherein the uneven shape satisfies at least one condition selected from the following (A) to (C), and the optical sheet is useful for a front surface of a display element having a pixel density of 300 ppi or more,
Condition (A); a gap between inclination angles indicating a half value of a peak value of an inclination angle distribution curve of the uneven shape is in a range of 5 degrees to 15 degrees,
Condition (B); an inclination angle indicating an inflection point on a positive direction side of the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 4 degrees to 15 degrees, and a difference between the inclination angle indicating the inflection point on the positive direction side and the inclination angle indicating the peak value of the inclination angle distribution curve is in a range of 2.2 degrees to 10 degrees, and
Condition (C); the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 2 degrees to 8 degrees, skewness of the inclination angle distribution curve of the uneven shape is in a range of 0 degrees to 1.5 degrees, and/or kurtosis of the inclination angle distribution curve of the uneven shape is in a range of 1.5 to 6.

6. The optical sheet according to claim 5 ,
wherein the optical sheet further satisfies Additional Condition (1) described below,
Additional Condition (1); a proportion of inclination angles in a range of 0 degrees to 1.25 degrees in inclination angles of the uneven shape is 20% or less in terms of cumulative percentage.

7. The optical sheet according to claim 5 ,
wherein the optical sheet further satisfies Additional Condition (2) described below,
Additional Condition (2); a proportion of inclination angles of 15 degrees or more in the inclination angles of the uneven shape is 3% or less in terms of cumulative percentage.

8. A method for manufacturing an optical sheet having an uneven shape on a surface and being useful for a front surface of a display element having a pixel density of 300 ppi or more, the method comprising:
applying to a transparent base material a coating fluid for forming an uneven layer having the uneven shape on the surface, the coating fluid comprising a resin component and transmissive particles,
wherein the uneven shape is manufactured so as to satisfy at least one condition selected from the following (A) to (C),
Condition (A); a gap between inclination angles indicating a half value of a peak value of an inclination angle distribution curve of the uneven shape is in a range of 5 degrees to 15 degrees,
Condition (B); an inclination angle indicating an inflection point on a positive direction side of the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 4 degrees to 15 degrees, and a difference between the inclination angle indicating the inflection point on the positive direction side and the inclination angle indicating the peak value of the inclination angle distribution curve is in a range of 2.2 degrees to 10 degrees, and
Condition (C); the inclination angle indicating the peak value of the inclination angle distribution curve of the uneven shape is in a range of 2 degrees to 8 degrees, skewness of the inclination angle distribution curve of the uneven shape is in a range of 0 degrees to 1.5 degrees, and/or kurtosis of the inclination angle distribution curve of the uneven shape is in a range of 1.5 to 6.

Assignees

• Dainippon Printing Co Ltd

Inventors

• Furui Gen
• Tsujimoto Jun
• NAITOU Aya

Classifications

• G02F2001/133507

  Physics · mapped topic

• G02B5/0221 Primary

  the surface having an irregular structure (G02B5/0226 takes precedence) · CPC title

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title

• B05D5/06

  to obtain multicolour or other optical effects (B05D5/02 takes precedence) · CPC title

• G02B5/0268

  characterized by the fabrication or manufacturing method · CPC title