TOUCH SCREEN SENSOR HAVING VARYING SHEET RESISTANCE

• US 20100156840A1
• Filed: 02/26/2009
• Published: 06/24/2010
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Frey, Matthew H., Robrecht, Michael J., Jambor, George F.
• Granted Patent: US 8,274,494 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/14 Aqueous compositions
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• 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 3/044 by capacitive means
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch screen sensor includes a visible light transparent substrate and an electrically conductive micropattern disposed on or in the visible light transparent substrate. The micropattern includes a first region micropattern within a touch sensing area and a second region micropattern. The first region micropattern has a first sheet resistance value in a first direction, is visible light transparent, and has at least 90% open area. The second region micropattern has a second sheet resistance value in the first direction. The first sheet resistance value is different from the second sheet resistance value.

Claims

1. A touch screen sensor, comprising:

a visible light transparent substrate;

an electrically conductive micropattern disposed on or in the visible light transparent substrate, the micropattern comprising a first region micropattern within a touch sensing area and a second region micropattern;

the first region micropattern having a first sheet resistance value in a first direction, being visible light transparent, and having at least 90% open area;

the second region micropattern having a second sheet resistance value in the first direction,

wherein, the first sheet resistance value is different from the second sheet resistance value.

2. A touch screen sensor according to claim 1, wherein the first region micropattern is electrically noncontiguous with the second region micropattern.

3. A touch screen sensor according to claim 1, wherein the first region micropattern is electrically contiguous with the second region micropattern.

4. A touch screen sensor according to claim 1, wherein the first region micropattern and second region micropattern are portions of an electrically contiguous metallic micropattern mesh that extends across the sensing area.

5. A touch screen sensor according to claim 1, wherein the first region micropattern sheet resistance value varies along at least one path within the first region micropattern.

6. A touch screen sensor according to claim 1, wherein the first region micropattern sheet resistance value is in a range from 0.1 to 1000 ohms per square.

7. A touch screen sensor according to claim 1, wherein the electrically conductive micropattern has between 95% and 99.5% open area within the touch sensing area.

8. A touch screen sensor according to claim 1, wherein the electrically conductive micropattern comprises conductive deposits within the sensing area that are electrically isolated from a drive device for the touch screen sensor.

9. A touch screen sensor according to claim 1, wherein the electrically conductive micropattern comprises linear metallic features having a width value in a range from 0.5 to 5 micrometers and a uniform thickness within the sensing area of less than 1 micrometer.

10. A touch screen sensor according to claim 1, wherein the electrically conductive micropattern comprises a two-dimensional mesh comprising conductive traces, with some traces including selectively placed breaks.

11. A touch screen sensor, comprising:

a visible light transparent substrate; and

an electrically conductive micropattern disposed on or in the visible light transparent substrate, the micropattern comprising a first region micropattern within a touch sensing area;

the first region micropattern having an anisotropic first sheet resistance, being visible light transparent, and having at least 90% open area.

12. A touch screen sensor according to claim 11, further comprising a second region micropattern within the sensing area, being electrically noncontiguous with the first region micropattern, the second region micropattern having an anisotropic second sheet resistance, being visible light transparent, and having at least 90% open area.

13. A touch screen sensor according to claim 11, further comprising a second region micropattern within the sensing area, being electrically noncontiguous with the first region micropattern, the second region micropattern having an isotropic second sheet resistance, being visible light transparent, and having at least 90% open area.

14. A touch screen sensor according to claim 11, wherein the first region micropattern has an anisotropic first sheet resistance with a difference in sheet resistance values for orthogonal directions of a factor of at least 1.5, and having between 95% and 99.5% open area.

15. A touch screen sensor according to claim 11, wherein the first region micropattern sheet resistance value in at least one direction varies along the least one direction within the first region micropattern.

16. A touch screen sensor according to claim 11, wherein the first region micropattern sheet resistance value is in a range from 0.1 to 1000 ohm per square.

17. A touch screen sensor according to claim 11, wherein the electrically conductive micropattern comprises conductive deposits that are electrically isolated from a drive device for the touch screen sensor.

18. A touch screen sensor according to claim 11, wherein the electrically conductive micropattern comprises linear metallic features having a width value in a range from 0.5 to 5 micrometers and a uniform thickness within the sensing area of less than 1 micrometer.

19. A touch screen sensor comprising;

a visible light transparent substrate;

an electrically conductive micropattern disposed on or in the visible light transparent substrate, the micropattern comprising;

a first region micropattern within a touch sensing area and a second region micropattern;

the electrically conductive micropattern comprising metallic linear electrically conductive features having a thickness of less than 500 nanometers and a width between 0.5 and 5 micrometers;

the first region micropattern having a first sheet resistance value in a first direction between 5 and 500 ohm per square, being visible light transparent, and having between 95% and 99.5% open area;

the second region micropattern having a second sheet resistance value in the first direction;

wherein, the first sheet resistance value is different from the second sheet resistance value.

20. A touch screen sensor comprising;

a visible light transparent substrate;

an electrically conductive micropattern disposed on or in the visible light transparent substrate, the micropattern comprising;

a first region micropattern within a touch sensing area;

the electrically conductive micropattern comprising metallic linear electrically conductive features having a thickness of less than 500 nanometers and a width between 0.5 and 5 micrometers;

the first region micropattern having an anisotropic first sheet resistance with a difference in sheet resistance values for orthogonal directions of a factor of at least 1.5, being visible light transparent, and having between 95% and 99.5% open area.