PEN STYLUS ENABLED CAPACITIVE TOUCH SYSTEM AND METHOD

• US 20090256825A1
• Filed: 04/11/2008
• Published: 10/15/2009
• Est. Priority Date: 04/11/2008
• Status: Abandoned Application

• Current Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: Klinghult, Gunnar, Futter, Paul
• Application Number:
  US12/101,506
• Publication Number:
  US 20090256825A1
• Time in Patent Office: Days
• US Class Current: 345/179
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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

Abstract

Described is a capacitive touch screen apparatus. An indium tin oxide (ITO) ground screen covers and protects an optical display. One or more support structures are secured atop the ground screen layer. A first capacitance sensing patterned ITO trace layer is secured atop the support structures such that an air gap exists between the layers. A second capacitance sensing patterned ITO trace layer can be secured atop the first patterned ITO trace layer. A pointed object brought into contact with the outermost patterned ITO trace layer will deform the surface and penetrate a portion of the air gap sufficiently to register a change in capacitance at the point of contact. A protective transparent film layer covering the outermost patterned ITO trace layer can be utilized to protect the surface of the ITO layer from damage. The ITO layers are electronically coupled with a controller capable of sensing changes in capacitance.

Claims

1. A capacitive touch screen apparatus comprising:

an indium tin oxide (ITO) ground screen layer bonded to a clear plastic substrate;

one or more support structures secured atop the ground screen layer; and

a first patterned ITO trace layer bonded to a clear plastic substrate and electronically coupled with a controller capable of sensing a change in capacitance, the first patterned ITO trace layer bonded to a clear plastic substrate secured atop the one or more support structures such that an air gap exists between the first patterned ITO trace layer bonded to a clear plastic substrate and the ground screen layer bonded to a clear plastic substrate wherein the first patterned ITO trace layer bonded to a clear plastic substrate substantially covers the ground screen layer bonded to a clear plastic substrate,

such that a pointed object brought into contact with the first patterned ITO trace layer bonded to a clear plastic substrate will deform the surface and penetrate a portion of the air gap sufficiently to register a change in capacitance at the point of contact.

2. The capacitive touch screen apparatus of claim 1 further comprising:

a second patterned ITO trace layer bonded to a clear plastic substrate electronically coupled with a controller capable of sensing a change in capacitance, the second patterned ITO trace layer bonded to a clear plastic substrate secured atop and substantially covering the first patterned ITO trace layer bonded to a clear plastic substrate.

3. The capacitive touch screen apparatus of claim 1 further comprising a protective transparent film layer substantially covering the first patterned ITO trace layer bonded to a clear plastic substrate.

4. The capacitive touch screen apparatus of claim 2 further comprising a protective transparent film layer substantially covering the second patterned ITO trace layer bonded to a clear plastic substrate.

5. The capacitive touch screen apparatus wherein the one or more support structures are insulating dots.

6. A capacitive touch screen apparatus comprising:

an indium tin oxide (ITO) ground screen layer bonded to a clear plastic substrate;

a transparent flexible layer secured to and substantially covering the ground screen layer; and

a first patterned ITO trace layer bonded to a clear plastic substrate and electronically coupled with a controller capable of sensing a change in capacitance, the first patterned ITO trace layer bonded to a clear plastic substrate secured atop the transparent flexible layer,

such that a pointed object brought into contact with the first patterned ITO trace layer bonded to a clear plastic substrate will deform the surface and penetrate a portion of the transparent flexible layer sufficiently to register a change in capacitance at the point of contact.

7. The capacitive touch screen apparatus of claim 6 further comprising:

a second patterned ITO trace layer bonded to a clear plastic substrate electronically coupled with a controller capable of sensing a change in capacitance, the second patterned ITO trace layer bonded to a clear plastic substrate secured atop and substantially covering the first patterned ITO trace layer bonded to a clear plastic substrate.

8. The capacitive touch screen apparatus of claim 6 further comprising a protective transparent film layer substantially covering the first patterned ITO trace layer bonded to a clear plastic substrate.

9. The capacitive touch screen apparatus of claim 7 further comprising a protective transparent film layer substantially covering the second patterned ITO trace layer bonded to a clear plastic substrate.

10. A method of constructing a capacitive touch screen apparatus comprising:

securing one or more support structures atop an indium tin oxide (ITO) ground screen layer bonded to a clear plastic substrate; and

securing a first patterned ITO trace layer bonded to a clear plastic substrate atop the one or more support structures such that an air gap exists between the first patterned ITO trace layer bonded to a clear plastic substrate and the ground screen layer bonded to a clear plastic substrate wherein the first patterned ITO trace layer bonded to a clear plastic substrate substantially covers the ground screen layer bonded to a clear plastic substrate.

11. The method of claim 10 further comprising:

securing a second patterned ITO trace layer bonded to a clear plastic substrate atop and substantially covering the firs t patterned ITO trace layer bonded to a clear plastic substrate.

12. The method of claim 10 further comprising substantially covering the first patterned ITO trace layer bonded to a clear plastic substrate with a protective transparent film layer.

13. The method of claim 11 further comprising substantially covering the second patterned ITO trace layer bonded to a clear plastic substrate with a protective transparent film layer.

14. The method of claim 10 wherein the one or more support structures are insulating dots.

15. A method of constructing a capacitive touch screen apparatus comprising:

securing a transparent flexible layer substantially atop an indium tin oxide (ITO) ground screen layer bonded to a clear plastic substrate; and

securing a first patterned ITO trace layer bonded to a clear plastic substrate atop the transparent flexible layer wherein the first patterned ITO trace layer bonded to a clear plastic substrate substantially covers the ground screen layer bonded to a clear plastic substrate.

16. The method of claim 15 further comprising:

securing a second patterned ITO trace layer bonded to a clear plastic substrate atop and substantially covering the firs t patterned ITO trace layer bonded to a clear plastic substrate.

17. The method of claim 15 further comprising substantially covering the first patterned ITO trace layer bonded to a clear plastic substrate with a protective transparent film layer.

18. The method of claim 16 further comprising substantially covering the second patterned ITO trace layer bonded to a clear plastic substrate with a protective transparent film layer.

19. A method of interpreting capacitive touch screen contacts wherein the capacitive touch screen includes a deformable space between at least one capacitive sensing ITO layer and an ITO ground screen layer, the method comprising:

sensing a first capacitance change resulting from an initial contact to the at least one ITO layer that results in a slight deformation in the space between the at least one ITO layer and the ITO ground screen layer wherein the first sensed capacitance change triggers a function;

sensing a second capacitance change resulting from a stronger sustained contact to the at least one ITO layer that results in a greater deformation in the space between the at least one ITO layer and the ITO ground screen layer wherein the second sensed capacitance change affects how the function is carried out.

20. The method of claim 19 wherein the deformable space is an air gap.

21. The method of claim 19 wherein the deformable space is comprised of a deformable flexible transparent plastic material.