TOUCH SCREEN SENSOR AND PATTERNED SUBSTRATE HAVING OVERLAID MICROPATTERNS WITH LOW VISIBILITY

• US 20110310037A1
• Filed: 02/24/2010
• Published: 12/22/2011
• Est. Priority Date: 02/26/2009
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Moran, Cristin E., Frey, Matthew H., Linzie, Brian L., Weaver, Billy L.
• Granted Patent: US 8,970,515 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/14 Aqueous compositions
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H05K 9/0094 being light-transmitting, e.g. transparent, translucent
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

Presently described are articles such as antennas, EMI shields, and touch screen sensors as well as patterned substrates having overlaid micropatterns with low visibility. Also described are methods of determining the visibility of a patterned substrate. In one embodiment, a patterned substrate is described comprising a visible light transparent substrate; and at least two overlaid electrically conductive mesh micropatterns, wherein each mesh has a repeating cell geometry and the combination of overlaid micropatterns has a spatial contrast threshold at a distance of 30000 units of greater than −35 decibels.

Claims

1. A touch screen sensor, comprising:

a visible light transparent substrate;

a first conductive micropattern comprising linear traces defining a first open mesh of a repeating cell geometry disposed on or in the visible light transparent substrate, and

a second conductive micropattern comprising linear traces defining a second open mesh of a repeating cell geometry electrically isolated from the first conductive micropattern;

wherein the second conductive micropattern overlays the first conductive micropattern such that

i) at least a portion of the linear traces of the second conductive micropattern are non-parallel to the linear traces of first conductive micropattern;

or

ii) at least a portion of the second conductive micropattern has a different cell geometry from the cell geometry of the first conductive micropattern;

or

iii) at least a portion of the second conductive micropattern has a different cell dimension from the cell dimension of the first conductive micropattern;

or a combination thereof.

2. The touch screen sensor of claim 1 wherein at least a portion of the linear traces of the second conductive micropattern are non-parallel to the linear traces of first conductive micropattern.

4. The touch screen sensor of claim 1 wherein at least a portion of the second conductive micropattern has a different cell dimension from the cell dimension of the first conductive micropattern.

6. The touch screen sensor of claim 1 wherein at least a portion of the linear traces of the second conductive micropattern are non-parallel to the linear traces of first conductive micropattern and at least a portion of the second conductive micropattern has a different cell dimension from the cell dimension of the first conductive micropattern.

9. The touch screen sensor of claim 1 wherein the first and second conductive micropatterns have the same cell geometry.

10. The touch screen sensor of claim 1 wherein the first and second conductive micropattern each comprise a regular cell geometry.

11. The touch screen sensor of claim 1 wherein the first and second conductive micropatterns comprise a hexagonal cell geometry.

12. The touch screen sensor of claim 9 wherein the second micropattern is orientated at a bias angle ranging from about 15 degrees to about 40 degrees relative to the first micropattern.

16. The touch screen sensor of claim 1 wherein the linear traces have a line width of less than 5 microns.

17. The touch screen sensor of claim 1 wherein the cell geometry of the first and second micropatterns has an average cell width of no greater than 500 microns.

18. The touch screen sensor of claim 1 wherein the first micropattern has a regular hexagonal cell geometry and the second micropattern has a regular hexagonal cell geometry;

the ratio of the cell dimension of the first micropattern to the cell dimension of the second micropattern is between 1.2 to 3; and

the bias angle between the first micropattern and the second micropattern is between 10 and 45 degrees.

19. The touch screen sensor of claim 9 wherein at least a portion of the linear traces of the second conductive micropattern are non-parallel to the linear traces of first conductive micropattern and there is a bias angle between the first conductive micropattern and second conductive micropattern of between about 0.1 and about 0.9 times the repeat angle.

21. The touch screen sensor of claim 9 wherein the cell dimension of the first conductive micropattern is between 1.1 and 6 times the cell dimension of the second conductive micropattern, and there is a bias angle between the patterns of between 0.1 and 0.9 times the repeat angle.

3. (canceled)

5. (canceled)

7-8. -8. (canceled)

13-15. -15. (canceled)

20. (canceled)

22-24. -24. (canceled)

25. An electrically conductive article comprising:

a visible light transparent substrate;

a first conductive micropattern comprising linear traces defining a first open mesh of a repeating cell geometry disposed on or in the visible light transparent substrate, and

a second conductive micropattern comprising linear traces defining a second open mesh of a repeating cell geometry electrically isolated from the first conductive micropattern;

wherein the second conductive micropattern overlays the first conductive micropattern such that

i) at least a portion of the linear traces of the second conductive micropattern are non-parallel to the linear traces of first conductive micropattern;

or

ii) at least a portion of the second conductive micropattern has a different cell geometry than the first conductive micropattern;

iii) at least a portion of the second conductive micropattern has a different cell dimension than the first conductive micropattern;

or a combination thereof.

26. The article of claim 25 wherein the first or second micropattern functions as an antenna or EMI shield.

27. A method of determining the visibility of a patterned substrate comprising:

a) providing a digital image of a micropatterned substrate; and

b) calculating the spatial contrast threshold of the digital image by use of a mathematical model for foveal detection.

28-32. -32. (canceled)

33. A method of making a substrate comprising micropatterns having low visibility comprising:

a) digitally designing a micropattern.

b) providing a digital image of a micropattern; and

c) calculating the spatial contrast threshold of the digital image by use of a mathematical model for foveal detection; and

d) selecting a micropattern having a contrast threshold greater than −

35 decibels at the normal viewing distance of the substrate.

34. A patterned substrate comprising:

a visible light transparent substrate; and

at least two overlaid electrically conductive mesh micropatterns disposed on or in the visible light transparent substrate, wherein the combination of electrically conductive micropatterns has a contrast threshold at a distance of 30000 units of greater than −

35 decibels.

35. The patterned substrate of claim 34 wherein the micropatterns have a pattern density of less than 20%.

36. The patterned substrate of claim 34 wherein the cell geometry of the first and second micropatterns has an average cell width of no greater than 500 microns.

37. (canceled)