TOUCH AND HOVER SWITCHING

• US 20120050180A1
• Filed: 09/30/2010
• Published: 03/01/2012
• Est. Priority Date: 08/27/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: KING, Brian Michael, LEUNG, Omar, BERNSTEIN, Jeffrey Traer, AMM, David T., KERR, Duncan Robert, PUSKARICH, Paul G., MUCIGNAT, Andrea, CIEPLINSKI, Avi E., CHOUDRY, Muhammad U., SUBRAMANI, Praveen R., PICHE, Marc J.
• Granted Patent: US 9,268,431 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• 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 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• 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

Touch and hover switching is disclosed. A touch and hover sensing device can switch between a touch mode and a hover mode. During a touch mode, the device can be switched to sense one or more objects touching the device. During a hover mode, the device can be switched to sense one or more objects hovering over the device. The device can include a panel having multiple sensors for sensing a touching object and/or a hovering object and a touch and hover control system for switching the device between the touch and hover modes. The device'"'"'s touch and hover control system can include a touch sensing circuit for coupling to the sensors to measure a capacitance indicative of a touching object during the touch mode, a hover sensing circuit for coupling to the sensors to measure a capacitance indicative of a hovering object during the hover mode, and a switching mechanism for switching the sensors to couple to either the touch sensing circuit or the hover sensing circuit. The device can switch modes based on a condition of the device, such as an expiration of a timer or a relative distance of an object from the panel.

Claims

1. A touch and hover sensing device comprising:

at least one sensor configured to detect a touch or a hover thereat; and

a touch and hover control system configured to control switching between a touch mode to measure the detected touch and a hover mode to measure the detected hover,

wherein the control system comprises

a touch sensing circuit configured to measure capacitance caused by the detected touch,

a hover sensing circuit configured to measure capacitance caused by the detected hover, and

a switching mechanism configured to switch between the touch sensing circuit and the hover sensing circuit responsive to a condition at the device, the switching mechanism switching to the touch sensing circuit during the touch mode and to the hover sensing circuit during the hover mode.

2. The device of claim 1, wherein the switching mechanism is a switch configured to couple the sensor to the touch sensing circuit during the touch mode and to the hover sensing circuit during the hover mode.

3. The device of claim 1, wherein the control system further comprises a controller configured to control the switching mechanism, the controller sending a control signal to the switching mechanism to actuate the switching mechanism.

4. The device of claim 1, wherein the hover sensing circuit comprises a gain amplifier for sensing the detected hover, the gain amplifier coupling to the sensor through a first connection to receive the capacitance measurement caused by the detected hover and to a reference voltage source through a second connection to receive a reference signal, the gain amplifier subtracting the reference signal from the hover capacitance measurement so as to output a hover signal compensated for parasitic capacitance at the switching mechanism.

5. The device of claim 1, wherein the control system further comprises a capacitor disposed between the sensor and the switching mechanism so as to compensate the capacitance measurement caused by the detected hover for parasitic capacitance at the switching mechanism.

6. The device of claim 1, wherein the switching mechanism is a controller configured to send control signals to the touch sensing circuit and the hover sensing circuit to switch between the sensing circuits.

7. The device of claim 6, wherein, during the touch mode, the controller sends an enable signal to the touch sensing circuit and a disable signal to the hover sensing circuit and, during the hover mode, the controller sends a disable signal to the touch sensing circuit and an enable signal to the hover sensing circuit.

8. The device of claim 1, wherein the condition at the device comprises at least one of an expiration of a timer or a relative distance from the device of an object causing the detected touch or hover.

9. The device of claim 1, wherein the control system measures self capacitance at the sensor during the hover mode.

10. The device of claim 1, wherein the control system measures mutual capacitance at the sensor during the touch mode.

11. A method of switching between a first sensing mode and a second sensing mode of a sensing device, the method comprising:

measuring capacitance at the sensing device, the capacitance being indicative of an object proximate to the device;

determining a relative distance of the object from the device based on the measurement; and

switching between the first and second sensing modes based on the determined relative distance.

12. The method of claim 11, wherein switching between the first and second sensing modes comprises:

if the determined relative distance of the object exceeds a first threshold, switching the device to the first sensing mode; and

if the determined relative distance of the object is less than a second threshold, switching the device to the second sensing mode.

13. The method of claim 12, wherein the first threshold is higher than the second threshold.

14. The method of claim 11, wherein the first sensing mode is a touch mode to detect the object touching the device.

15. The method of claim 11, wherein the second sensing mode is a hover mode to detect the object hovering over the device.

16. A method of switching between multiple sensing modes of a sensing device, the method comprising:

operating in one of the sensing modes during a predetermined time period to obtain a set of capacitance measurements indicative of an object proximate to the sensing device;

after the predetermined time period expires, switching to an other of the sensing modes and resetting the period; and

operating in the other of the sensing modes during the reset predetermined time period to obtain an other set of capacitance measurements indicative of the proximate object.

17. The method of claim 16, wherein the sensing modes includes a hover mode to detect the object hovering over the device and a touch mode to detect the object touching the device.

18. The method of claim 17, wherein the device operates in the touch mode for the predetermined time period, switches to the hover mode after the predetermined time period expires, operates in the hover mode for the reset predetermined time period, and then repeats.

19. A touch and hover sensing device comprising:

a touch and hover control circuit configured to switchably select a touch mode or a hover mode of the device, the control circuit comprising;

a touch sensing circuit configured to measure capacitance indicative of a touch event at the device,

a hover sensing circuit configured to measure capacitance indicative of a hover event at the device,

a switching mechanism configured to switchably select the touch sensing circuit during the touch mode and the hover sensing circuit during the hover mode, and

a compensating element configured to compensate for parasitic capacitance from the switching mechanism.

20. The device of claim 19, wherein the switching mechanism switchably selects the touch mode or the hover mode based on a relative distance of an object from the device or based on a predetermined time period.

21. The device of claim 19, wherein the compensating element comprises at least one of a capacitor or an amplifier.

22. A touch and hover sensing device comprising:

a touch and hover sensing panel having multiple sensors configured to detect one or more objects proximate to the panel, wherein the objects touch the panel to cause a touch event, hover over the panel to cause a hover event, or touch and hover concurrently to cause touch and hover events; and

a touch and hover control system configured to measure capacitance associated with the proximate objects and to switch the sensors between a touch detection mode and a hover detection mode according to the touch and hover events.

23. The device of claim 22, wherein the control system switches a portion of the sensors to the touch detection mode and another portion of the sensors to the hover detection mode so as to partition the panel to concurrently detect touch and hover events.

24. The device of claim 22, further comprising a display configured to display graphical information to select in response to the touch and hover events.

25. The device of claim 22 incorporated into at least one of a mobile phone, a digital media player, or a computer.