Touch screens

• US 8,363,025 B2
• Filed: 11/10/2010
• Issued: 01/29/2013
• Est. Priority Date: 01/30/2004
• Status: Expired due to Fees

• Current Assignee: Jaguar Cars Limited (TATA Motors Limited)
• Original Assignee: Jaguar Cars Limited (TATA Motors Limited)
• Inventors: Parkinson, Richard Dean, Pickering, Carl Anthony, Thorp, Ian Richard, Wilson, Colin John, Thomas, Peter Robert
• Primary Examiner(s): Lefkowitz, Sumati
• Assistant Examiner(s): Hicks, Charles V
• Application Number:
  US12/943,168
• Publication Number:
  US 20110141041A1
• Time in Patent Office: 811 Days
• Field of Search: 345/173
• US Class Current: 345/173
• CPC Class Codes: B60K 2360/143 Touch sensitive instrument input devices
• CPC Class Codes: B60K 2360/1438 Touch screens
• CPC Class Codes: B60K 2370/143 Touch sensitive input devices
• CPC Class Codes: B60K 2370/1438 Touch screens
• CPC Class Codes: B60K 35/00 Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
• CPC Class Codes: B60K 35/10 Input arrangements, i.e. from user to vehicle, associated with vehicle functions or specially adapted therefor
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch screen control system comprising a touch screen having first and second conductive layers arranged to be brought together by touching of the screen. A detection system is arranged to detect a contact position at which the screen is touched by monitoring electrical signals from at least one of the layers. The system further comprises an antenna, and the detection system includes a proximity sensing signal generator arranged to generate a proximity sensing signal to be transmitted between the antenna and the first layer via a user of the system. The detection system is further arranged to receive the transmitted proximity sensing signal and determine therefrom the distance between a part of the user and the touch screen.

Claims

1. A detection system for use with a touch screen having first and second conductive layers operable to be brought together by touching of a user, the system comprising:

a proximity sensing controller operable to determine a distance between a part of the user and the touch screen prior to the part touching the first conductive layer based on a strength of a proximity signal emanating from the part of the user and received by the first conductive layer; and

a touch screen controller operable to detect a contact position where the part touches the first conductive layer as a function of a first electrical potential occurring prior to the part touching the first conductive layer and at least one of a second and a third electrical potential occurring after the part touches the first conductive layer with enough force to press the first conductive layer against the second conductive layer.

2. The system of claim 1 wherein the touch screen controller determines an x-coordinate of the contact position based on the second electrical potential as measured across the second conductive layer.

3. The system of claim 2 wherein, while determining the x-coordinate, one side of the first conductive layer is connected to a positive power supply and an opposite side of the first conductive layer is connected to ground, and one edge of the second conductive layer is disconnected from the positive power supply and an opposite edge of the second conductive layer is disconnected from ground.

4. The system of claim 1 wherein the touch screen controller determines a y-coordinate of the contact position based on the third electrical potential as measured across the first conductive layer.

5. The system of claim 4 wherein, while determining the y-coordinate, one side of the first conductive layer is disconnected from a positive power supply and an opposite side of the first conductive layer is disconnected from ground, and one edge of the second conductive layer is connected to the positive power supply and an opposite edge of the second conductive layer is connected to ground.

6. The system of claim 1 wherein the proximity sensing controller receives the proximity signal from the first conductive layer while the part presses the first conductive layer against the second conductive layer.

7. The system of claim 6 wherein a top edge of the second conductive layer is connected to a positive power source and a bottom edge of the second conductive layer is connected to ground for at least a substantial portion of a period of time during which the touch screen controller determines the contact position.

8. The system of claim 7 wherein the top edge is disconnected from the positive power source and the bottom edge is disconnected from ground during substantially all of a period of time during which the proximity sensing controller determines the distance.

9. The system of claim 1 wherein the proximity sensing signal passes from an antenna located within a seat occupied by the user and through a body of the user to the part prior to receipt by the first conductive layer.

10. The system of claim 1 wherein at least one of the at least one of the second and third electrical potentials varies depending on a contact point where the part presses the first and second layers together such that no contact point is at the same electrical potential as another contact point.

11. The system of claim 1 wherein the proximity sensing controller facilitates display of a first plurality of buttons within a heads-up display (HUD) when the distance is less than a threshold and facilitates removal of the HUD when the distance is greater than a threshold.

12. The system of claim 11 wherein the touch screen controller facilitates display of a second plurality of buttons within the HUD after determining selection one of the first plurality of buttons, the selection of the one of the first plurality of buttons being based on the contact positioned determined after the first conductive layers is pressed against the second conductive layer.

13. The system of claim 12 wherein the touch screen controller determines selection of one of the second plurality of buttons after the force causing the first conductive layer to press against the second conductive layer is removed and replaced with force sufficient to cause the first conductive layer to again press against the first conductive layer.

14. The system of claim 12 wherein the HUD is shown on a windshield positioned above the touch screen.

15. A touch screen comprising:

first and second layers operable to be brought together by touching of a user;

a first switch operable to connected and disconnect one edge of the first layer to a power source;

a second switch operable to connected and disconnect one edge of the first layer to ground;

a third switch operable to connected and disconnect one edge of the second layer to a power source;

a fourth switch operable to connected and disconnect one edge of the second layer to ground;

a touch screen controller operable to measure electrical potential between each of the first, second, third, and fourth edges and the corresponding one of the first, second, third, and fourth switches; and

wherein the touch screen controller determines a contact position where the first and second layers are brought together as a function of the measured electrical potentials.

16. The system of claim 15 wherein the touch screen controller determines an x-coordinate of the contact position based on electrical potentials measured while the first and second switches respectively connect the first layer to the power source and ground and the third and fourth switches respectively disconnect the second layer from the power source and ground.

17. The system of claim 15 wherein the touch screen controller determines an y-coordinate of the contact position based on electrical potentials measured while the first and second switches respectively disconnect the first layer from the power source and ground and the third and fourth switches respectively connect the second layer to the power source and ground.

18. The system of claim 15 further comprising a proximity sensing controller operable to determine a distance between a part of the user and the touch screen based on a strength of a proximity signal measured at the first layer, the proximity signaling being passed through the part of the user from an antenna included within a seat occupied by the user while the third and fourth switches respectively disconnect the second conductive layer from the power source and ground.

19. A method of controlling a heads-up display (HUD) where information displayed within the HUD is controlled according to user interaction with a touch screen having spaced apart first and second conductive layers, the method comprising:

operating in a proximity sensing mode where a distance of a part of the user to the touch screen is determined based on a signal transmitted from the part to the first conductive layer;

operating in a touch screen mode wherein a contact point at which the part presses the first conductive layer against the second conductive layer is determined, the contact point defined according to an x-coordinate and a y-coordinate, the x-coordinate being determine based on a first electrical potential at one of the first and the second conductive layers and the y-coordinate being determined based on a second electrical potential at the other one of the first and second conductive layers;

selectively alternating between the proximity sensing mode and the touch screen mode while the part is within the distance to the touch screen; and

operating exclusively according to the proximity sensing mode while the part is beyond the distance to the touch screen.

20. The method of claim 19 further comprising:

instructing display of a heads-up display (HUD) when the part is within the distance to the touch screen; and

instructing removal of the HUD when the part is beyond the distance to the touch screen.