# US 2014/0152914 A1 · Low-Fe Glass for IR Touch Screen Applications

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- Number: US 2014/0152914 A1
- Document ID: US20140152914A1
- Status: Published application
- Kind: A1
- Application number: 14/090,275
- Filed: 2013-11-26
- Published: 2014-06-05
- Earliest claimed: 2012-11-30
- Assignees: Corning Incorporated
- Applicants: Corning Incorporated
- Inventors: Jeffrey Stapleton King
- Web page: https://patentgrep.com/patent/US20140152914A1

## CPC

- C03C 4/0092: {for glass with improved high visible transmittance, e.g. extra-clear glass}
- C03C 1/00: Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels
- C03C 3/00: Glass compositions
- C03C 4/10: for infrared transmitting glass
- C03C 21/002: {to perform ion-exchange between alkali ions (C03C21/005 takes precedence)}
- G02B 6/0035: {provided on the surface of the light guide or in the bulk of it}
- G02B 6/0073: {Light emitting diode [LED]}
- G06F 2203/04109: FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
- Y10T 428/24355: Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T 428/24628: Nonplanar uniform thickness material
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A high optical transmittance glass for use in electronic touch screen applications is disclosed. The glass materials are principally directed to use in frustrated total internal reflection applications. The glass compositions are composed of either low concentrations of light-absorbing compounds or have low levels of scattering centers to minimize the amount of light attenuation as the light propagates through the material.

## Claims

### Claim 1

A high optical transmittance glass comprising:
a. less than 10 imperfections per cm3, wherein
i. the imperfection comprises an inclusion or bubble; and
ii. the size of the imperfection is less than about 100 μm along the axis of the longest dimension of the imperfection; or
b. less than 200 ppm Fe2O3; and
c. the absorption coefficient of the glass is less than 2.0 m−1 at 900 nm; and
d. the absorption coefficient of the glass is less than 2.0 m−1 from about 400 to about 800 nm.

### Claim 2 (depends on 1)

The glass of claim 1, wherein the glass comprises less than 100 ppm Fe2O3.

### Claim 3 (depends on 1)

The glass of claim 1, wherein the glass comprises less than 1 imperfection per cm3.

### Claim 4 (depends on 1)

The glass of claim 1, wherein the glass comprises less than 100 ppm Fe2O3 or less than 1 imperfection per cm3.

### Claim 5 (depends on 1)

The glass of claim 1, wherein the absorption coefficient of the glass is less than 1.0 m−1 at 900 nm.

### Claim 6 (depends on 1)

The glass of claim 1, wherein the absorption coefficient of the glass is less than 1.0 m−1 from about 400 to about 800 nm.

### Claim 7 (depends on 1)

The glass of claim 1, wherein the glass has a density of 2.45 g/cm3 or greater.

### Claim 8 (depends on 1)

The glass of claim 1, wherein the glass is ion exchanged.

### Claim 9 (depends on 8)

The glass of claim 8, wherein the glass has fracture toughness of 0.7 MPa m1/2 or greater.

### Claim 10 (depends on 8)

The glass of claim 8, wherein the glass has Vickers hardness under 200 g load of 600 kgf/mm2 or greater.

### Claim 11 (depends on 8)

The glass of claim 8, wherein the glass has a shear modulus 30 GPa or greater.

### Claim 12 (depends on 8)

The glass of claim 8, wherein the glass has a compressive stress of 600 MPa or greater.

### Claim 13 (depends on 1)

The glass of claim 1, wherein the glass has a depth of layer of 10 μm or greater.

### Claim 14 (depends on 1)

The glass of claim 1, wherein the glass has a thickness of 2 mm or less.

### Claim 15 (depends on 1)

The glass of claim 1, wherein the glass has a β-OH value of from 0.2 mm−1 to 0.9 mm−1.

### Claim 16 (depends on 1)

The glass of claim 1, wherein the glass has an average surface roughness (Ra) of ≦20 Å, preferably 10 Å, wherein the glass sheet has not been polished.

### Claim 17 (depends on 1)

The glass of claim 1, wherein the glass has a thickness below 3 mm, and the glass substrate has a curvature deformation, W, less than 0.5 micrometer/cm2, as described by the equation W=D/L2, wherein D is the maximum curvature of glass substrate in mm and L is the diagonal length of glass substrate in cm.

### Claim 18 (depends on 1)

An electronic touch screen device comprising the glass of claim 1.

### Claim 19 (depends on 18)

The electronic device of claim 18, wherein the device utilizes a frustrated total internal reflection system to determine a touch event.

### Claim 20 (depends on 18)

The electronic device of claim 18, wherein the frustrated total internal reflection system is able to determine single or multiple touch positions, touch pressure, or all of the above.