TOUCH SENSITIVE DISPLAYS WITH LAYERS OF SENSOR PLATES PROVIDING CAPACITANCE BASED PROXIMITY SENSING AND RELATED TOUCH PANELS

• US 20100149125A1
• Filed: 12/15/2008
• Published: 06/17/2010
• Est. Priority Date: 12/15/2008
• Status: Active Grant

• Current Assignee: Sony Mobile Communications Incorporated (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications USA Incorporated (Sony Group Corp.)
• Inventors: Klinghult, Gunnar, Futter, Paul Leonard
• Granted Patent: US 8,669,944 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• 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
• 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

Abstract

An electronic touch panel includes a plurality of spaced apart first sensor plates that are arranged in a first direction on a first planar layer. A proximity sensor plate is spaced apart from and attached to the first planar layer. The proximity sensor plate has a greater surface area than a plurality of the first sensor plates. A position detection circuit is configured to electrically charge the first sensor plates to generate capacitive coupling to an adjacent user object and to detect therefrom a location of the user object relative to the first direction across the first planar layer. The position detection circuit is further configured to electrically charge the proximity sensor plate to generate a higher level of capacitive coupling to the user object than a plurality of the first sensor plates and to detect therefrom a proximity of the user object relative to a direction away from the first planar layer.

Claims

1. An electronic touch panel comprising:

a plurality of spaced apart first sensor plates arranged in a first direction on a first planar layer;

a proximity sensor plate that is spaced apart from and attached to the first planar layer, wherein the proximity sensor plate has a greater surface area than a plurality of the first sensor plates; and

a position detection circuit that is configured to electrically charge the first sensor plates to generate capacitive coupling to an adjacent user object and detect therefrom a location of the user object relative to the first direction across the first planar layer, and configured to electrically charge the proximity sensor plate to generate a higher level of capacitive coupling to the user object than a plurality of the first sensor plates and to detect therefrom a proximity of the user object relative to a direction away from the first planar layer.

2. The electronic touch panel of claim 1, wherein the position detection circuit comprises a comparator circuit that generates a proximity signal that identifies when a charge level of the proximity sensor plate reaches a threshold level to indicate that the user object has become proximately located to the proximity sensor plate and/or that the user object is no longer proximately located to the proximity sensor plate.

3. The electronic touch panel of claim 2, wherein the comparator circuit further generates a position signal that identifies when a charge level of a defined one or more of the first sensor plates reaches a threshold level to indicate that the user object is nearly touching the defined one or more of the first sensor plates.

4. The electronic touch panel of claim 1, further comprising:

a plurality of second sensor plates arranged in a second direction across a second planar layer, and wherein;

the first planar layer is stacked on the proximity sensor plate;

the second planar layer is stacked on the first planar layer opposite to the proximity sensor plate; and

the position detection circuit is further configured to electrically charge the second sensor plates to generate capacitive coupling to the user object and detect therefrom a location of the user object relative to the second direction across the second planar layer.

5. The electronic touch panel of claim 4, wherein:

the proximity sensor plate is spaced apart from the first planar layer by a distance that is at least twice a combined thickness of the stacked first and second sensor plates and the stacked first and second layers to increase spatial differentiation between an amount of capacitive coupling that is obtained between the user object and the first and second sensor plates and an amount of capacitive coupling that is obtained between the user object and the proximity sensor plate.

6. The electronic touch panel of claim 5, wherein the position detection circuit comprises a comparator circuit that generates a proximity signal that identifies when a charge level of the proximity sensor plate changes at least a threshold amount relative to a charge level of at least one of the first sensor plates to indicate that the user object has become proximately located to the proximity sensor plate and/or that the user object is no longer proximately located to the proximity sensor plate.

7. The electronic touch panel of claim 4, wherein:

the first sensor plates are arranged in a plurality of spaced apart columns, with each of the first sensor plates being serially connected in each column and electrically isolated from first sensor plates in other columns;

the second sensor plates are arranged in a plurality of spaced apart rows, with each of the second sensor plates being serially connected in each row and electrically isolated from second sensor plates in other rows;

the proximity sensor plate extends beneath at least a majority of the first and second sensor plates; and

the position detection circuit is further configured to detect a location of the user object relative to the columns of first sensor plates, relative to the rows of second sensor plates, and relative to the proximity sensor plate in a direction away from the columns and rows of the first and second sensor plates.

8. The electronic touch panel of claim 7, wherein:

the proximity sensor plate extends beneath all of the first and second sensor plates.

9. The electronic touch panel of claim 7, further comprising:

a liquid crystal display including an image rendering layer that is configured to control light transmissivity through pixel locations therein responsive to a display control signal and including a metallic reflector layer that is configured to direct light through the image rendering layer,

wherein the metallic reflector layer comprises the proximity sensor plate.

10. The electronic touch panel of claim 7, further comprising:

a liquid crystal display including an image rendering layer that is configured to control light transmissivity through pixel locations therein responsive to a display control signal, wherein the first and second sensor plates and the proximity sensor plate extend parallel to a plane of the liquid crystal display,

where the position detection circuit is further configured to generate a position signal that indicates a location of the user object relative to the plane of the image rendering layer and relative to a direction away from the plane of the image rendering layer.

11. The electronic touch panel of claim 7, further comprising:

a controller that includes a user application that is configured to determine from the position signal a three dimensional location of the user object relative to an image that is displayed by the image rendering layer.

12. The electronic touch panel of claim 4, further comprising:

a liquid crystal display including an image rendering layer that is configured to control light transmissivity through pixel locations therein responsive to a display control signal and including a metallic reflector layer that is configured to direct light through the image rendering layer,

wherein the metallic reflector layer comprises the proximity sensor plate.

13. The electronic touch panel of claim 4, further comprising:

a liquid crystal display including an image rendering layer that is configured to control light transmissivity through pixel locations therein responsive to a display control signal, wherein the first and second sensor plates and the proximity sensor plate extend parallel to a plane of the liquid crystal display,

wherein the position detection circuit is further configured to generate a position signal that indicates a location of the user object relative to the plane of the image rendering layer and relative to a direction away from the plane of the image rendering layer.

14. The electronic touch panel of claim 4, further comprising:

a liquid crystal display including an image rendering layer that is configured to control light transmissivity through pixel locations therein responsive to a display control signal and including a metal layer along at least some edge regions of the image rendering layer to provide structural support for the image rendering layer,

wherein the metal layer comprises the proximity sensor plate.

15. The electronic touch panel of claim 14, wherein the proximity sensor plate extends along at least a majority of the edge regions of the image rendering layer.

16. The electronic touch panel of claim 1, further comprising a controller circuit that is configured to turn on backlighting for a display device in response to the position detection circuit detecting through the proximity sensor plate that the user object has become proximately located thereto.

17. The electronic touch panel of claim 1, further comprising a controller circuit that is configured to trigger a wireless terminal to answer an incoming phone call in response to the position detection circuit detecting through the proximity sensor plate that the user object has become proximately located thereto.

18. The electronic touch panel of claim 1, further comprising a controller circuit that is configured to selectively connect an ear speaker to an audio channel and to disconnect a loudspeaker from the audio channel in response to the position detection circuit detecting through the proximity sensor plate that the user object has become proximately located thereto, and to disconnect the car speaker from the audio channel and to connect the loudspeaker to the audio channel in response to the position detection circuit detecting through the proximity sensor plate that the user object has become not proximately located thereto.

19. A touch sensitive display comprising:

an image rendering layer that is configured to control light transmissivity through pixel locations therein responsive to a display control signal;

a metallic reflector layer that is configured to direct light through the image rendering layer;

a plurality of first sensor plates that are arranged in a plurality of spaced apart columns on a first layer between the image rendering layer and the metallic reflector layer, wherein each of the first sensor plates are spaced apart and serially connected in each column and are electrically isolated from first sensor plates in other columns;

a plurality of second sensor plates that are arranged in a plurality of spaced apart rows on a second layer between the first layer and the metallic reflector layer, wherein each of the second sensor plates are spaced apart and serially connected in each row and are electrically isolated from the second sensor plates in other rows,

wherein the metallic reflector layer extends beneath at least a majority of the first and second sensor plates; and

a position detection circuit that is configured to electrically charge the first sensor plates, the second sensor plates, and the metallic reflector layer to generate capacitive coupling to an adjacent user object and detect therefrom a location of the user object relative to the columns of first sensor plates, relative to the rows of second sensor plates, and relative to the metallic reflector layer in a direction away from the columns and rows of the first and second sensor plates.

20. The touch sensitive display of claim 19, wherein the position detection circuit comprises a comparator circuit that generates a proximity signal that identifies when a charge level of the proximity sensor plate reaches a threshold level and/or when a charge level of the proximity sensor plate changes at least a threshold amount relative to a charge level of at least one of the first sensor plates to indicate that the user object has become proximately located to the proximity sensor plate.