Electrically Non-interfering Printing for Electronic Devices Having Capacitive Touch Sensors

• US 20090046072A1
• Filed: 08/13/2007
• Published: 02/19/2009
• Est. Priority Date: 08/13/2007
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Emig, David M., Foo, Ken K.
• Granted Patent: US 8,077,154 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A capacitive sensor (200) for a touch sensitive electronic device (800) includes at least one graphic (401) visible to a user. The graphic (401) is configured so as to be non-electrically interfering with the electrode array of the capacitive sensor (200). A substrate (101), configured to transmit light, has a layer of capacitive sensor material (201) deposited thereon. The layer of capacitive sensor material (201) is electrically conductive and pellucid. A layer of selectively disposed electrically conductive material (202) is then electrically coupled to the layer of capacitive sensor material (201). The layer of selectively disposed electrically conductive material (202) is arranged as a graphic, which may be a logo, brand, or other mark. The layer of selectively disposed electrically conductive material (202) has a reflectivity that is greater than the layer of capacitive sensor material (201) so as to make the graphic (401) visible to a user.

Claims

1. A capacitive sensor for an electronic device configured to present selected graphics to a user, the capacitive sensor comprising:

a substrate configured to transmit incident light;

a layer of capacitive sensor material disposed on the substrate, the layer of capacitive sensor material being electrically conductive and pellucid; and

a layer of selectively disposed, electrically conductive material electrically coupled to the layer of capacitive sensor material;

wherein a combination of the layer of selectively disposed, electrically conductive and the layer of capacitive sensor material has a greater reflectivity than the layer of capacitive sensor material;

further wherein the layer of electrically conductive material is arranged as at least one graphic visible to the user.

2. The capacitive sensor of claim 1, wherein at least the layer of capacitive sensor material is arranged as a plurality of electrodes.

3. The capacitive sensor of claim 2, further comprising a detector coupled to the layer of capacitive sensor material, the detector being configured to detect a change in capacitance between at least two of the plurality of electrodes.

4. The capacitive sensor of claim 1, wherein the layer of selectively disposed, electrically conductive material is disposed atop the layer of capacitive sensor material.

5. The capacitive sensor of claim 1, wherein the layer of selectively disposed, electrically conductive material is interspersed with the layer of capacitive sensor material.

6. The capacitive sensor of claim 1, wherein the layer of capacitive sensor material has a characteristic impedance that is greater than a characteristic impedance of the selectively disposed, electrically conductive material.

7. The capacitive sensor of claim 6, wherein both the layer of capacitor sensor material and the layer of selectively disposed, electrically conductive material comprise indium tin oxide.

8. The capacitive sensor of claim 1, wherein the layer of selectively disposed, electrically conductive material is arranged as one of a plurality of user actuation targets, a navigation device, alphanumeric text, or symbols.

9. The capacitive sensor of claim 1, wherein the layer of selectively disposed, electrically conductive and the layer of capacitive sensor material together have a greater reflectivity than the layer of capacitive sensor material, wherein the greater reflectivity is at least twice that of the layer of capacitive sensor material.

10. A method of manufacturing a capacitive sensor having visible graphic indicia for an electronic device, the method comprising the steps of:

depositing a layer of semitransparent, electrically conductive material on a substrate; and

selectively depositing, in a form of the visible graphic indicia, second layer of electrically conductive material on the substrate;

wherein the second layer of electrically conductive material is electrically coupled to at least a portion of the layer of semitransparent, electrically conductive material;

further wherein a combined material formed by the layer of semitransparent, electrically conductive material and the second layer of electrically conductive material has a greater reflectivity than does the layer of semitransparent, electrically conductive material.

11. The method of claim 10, further comprising the step of etching at least one of the layer of semitransparent material or the second layer of electrically conductive material, thereby forming a predetermined electrode pattern.

12. The method of claim 10, wherein the step of selectively depositing, in the form of the visible graphic indicia, the second layer of electrically conductive material comprises depositing an additional layer of semitransparent, electrically conductive material such that the visible graphic indicia has a thickness greater than the layer of semitransparent, electrically conductive material.

13. The method of claim 10, wherein the step of depositing the semitransparent, electrically conductive material on the substrate comprises depositing indium tin oxide on the substrate, further wherein the step of selectively depositing, in the form of the visible graphic indicia, the second layer of electrically conductive material comprises depositing indium tin oxide on the layer of semitransparent, electrically conductive material.

14. The method of claim 10, wherein the step of depositing the semitransparent, electrically conductive material on the substrate comprises depositing indium tin oxide on the substrate, further wherein the step of selectively depositing, in the form of the visible graphic indicia, the second layer of electrically conductive material comprises depositing metal on the layer of semitransparent, electrically conductive material.

15. A electronic device comprising a user interface for receiving a touch input, the user interface comprising:

a cover layer; and

a capacitive sensor layer disposed beneath the cover layer for detecting the touch input, the capacitive sensor layer comprising at least two types of capacitor sensor material, wherein a first type of capacitor sensor material is at least semitransparent and a second type of capacitor sensor material has a greater reflectivity than the first type of capacitor sensor material, wherein the at least two types of capacitor sensor material are electrically coupled together;

further wherein the second type of capacitor sensor material is arranged as at least one graphic visible through the cover layer.

16. The electronic device of claim 15, further comprising a segmented optical shutter layer disposed beneath the capacitive sensor layer, the segmented optical shutter layer being configured to present multiple user interface configurations.

17. The electronic device of claim 15, wherein the second type of capacitor material is a thicker layer of the first type of capacitive sensor material.

18. The electronic device of claim 16, further comprising an electroluminescent device disposed beneath the segmented optical shutter layer.

19. The electronic device of claim 18, further comprising further comprising a resistance sensing layer, configured to detect contact with the user interface, disposed beneath the electroluminescent device.

20. The electronic device of claim 16, further comprising a liquid crystal display disposed beneath the segmented optical shutter layer.