CAPACITIVE SENSORS FOR GRIP SENSING AND FINGER TRACKING

• US 20160026216A1
• Filed: 07/23/2014
• Published: 01/28/2016
• Est. Priority Date: 07/23/2014
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Novet, Isaac Chase
• Granted Patent: US 10,139,869 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/169 the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus

Abstract

Mobile devices are increasing aware of the environment surrounding the mobile devices. In many applications, it is useful for the mobile device to be able to sense different types of hand grips and/or where fingers are positioned with respect to the mobile device. The present disclosure describes a capacitive sensing apparatus particularly suitable for sensing hand grips and/or finger tracking along edges of a mobile device. The capacitive sensing apparatus comprises strips arranged along two lines, and the respective lengths and spacing are designed to allow optimal response behavior for sensing hand grips and/or tracking fingers.

Claims

1. A capacitive sensing apparatus usable with an electronic device for grip sensing and/or finger tracking, wherein the capacitive sensing apparatus comprises:

first capacitive sensors comprising first strips spatially arranged substantially along a first line, the first strips having respective lengths and spacing(s) between the first strips; and

second capacitive sensors comprising second strips spatially arranged substantially along a second line substantially parallel to the first line, the second strips having respective lengths and spacing(s) between the second strips.

2. The capacitive sensing apparatus of claim 1, wherein:

each of the first strips is configured to generate a respective response from an object positioned near the first line; and

the respective response generated by each of the first strips is saturated when the object is positioned along the length of the respective first strip; and

the respective response tapers off as the object moves away from the ends of each of the first strips.

3. The capacitive sensing apparatus of claim 1, wherein:

respective lengths of the first strips and spacing(s) between the first strips are provided such that, over the span of the first strips along the first line, at least one of the first strips is configured to generate a tapering or increasing response when an object moves along the first line;

or

respective lengths of the first strips and spacing(s) between the first strips are provided such that, over the span of the first strips along the first line, at least one of the first strips is configured to not generate a saturated response as an object moves along the first line.

4. The capacitive sensing apparatus of claim 1, wherein:

the first strips comprises two strips.

5. The capacitive sensing apparatus of claim 4, wherein:

at least one of the two strips is in an L-shape.

6. The capacitive sensing apparatus of claim 1, wherein:

the first strips comprises a first end strip, a second end strip, and one or more middle strips arranged between the first end strip and the second end strip.

7. The capacitive sensing apparatus of claim 6, wherein:

the first end strip and/or the second end strip is configured to generate a tapering or increasing response, when an object moves along the length of any one of the one or more middle strips.

8. The capacitive sensing apparatus of claim 6, wherein:

one or more ones of the one or more middle strips is configured to generate a tapering or increasing response, when an object moves along the length of the first end strip or the second end strip.

9. The capacitive sensing apparatus of claim 6, wherein:

two of the first strips are each configured to generate a tapering or increasing response, when an object moves along the length of the spacing between the two strips.

10. The capacitive sensing apparatus of claim 6, wherein:

one or more ones of the middle strips is configured to generate a tapering or increasing response, when an object moves over the span of the first strips along the first line.

11. The capacitive sensing apparatus of claim 6, wherein:

the one or more middle strips are shorter in length than the first end strip and/or the second end strip.

12. The capacitive sensing apparatus of claim 1, wherein:

the spatial arrangement of the first capacitive sensors is substantially symmetric to the spatial arrangement of the second capacitive sensors with respect to an axis parallel to the first line.

13. The capacitive sensing apparatus of claim 1, wherein:

the spatial arrangement of the first capacitive sensors is asymmetric to the spatial arrangement of the second capacitive sensors with respect to an axis parallel to the first line.

14. The capacitive sensing apparatus of claim 1, further comprising:

differential tracing for one of the first capacitive sensors, wherein the differential tracing comprises;

a first trace connectable to a first input terminal of a capacitive sensing controller and connected to the one of the first capacitive sensors; and

a second trace connectable a second terminal of the capacitive sensing controller and not connected to the one of the first capacitive sensors.

15. The capacitive sensing apparatus of claim 1, wherein:

one of the first strips comprises a hollow portion.

16. The capacitive sensing apparatus of claim 1, wherein:

one of the first strips comprises one or more rounded corners.

17. The capacitive sensing apparatus of claim 1, further comprising:

an outer shell usable for enclosing an electronic device, said outer shell comprising contacts for connecting the first capacitive sensors and the second capacitive sensors to a component in the electronic device;

wherein at least part of the capacitive sensing apparatus is provided in the outer shell or on a surface of the outer shell configured to face towards the mobile device.

18. An electronic device comprising:

an inner chassis housing for enclosing electronics associated with the electronic device;

a capacitive sensing apparatus connectable to one or more of the electronics of the inner chassis for grip sensing and/or finger tracking, wherein the capacitive sensing apparatus comprises;

first capacitive sensors comprising first strips spatially arranged substantially along a first line, the first strips having respective lengths and spacing(s) between the first strips; and

second capacitive sensors comprising second strips spatially arranged substantially along a second line substantially parallel to the first line, the second strips having respective lengths and spacing(s) between the second strips.

19. The electronic device of claim 18, wherein:

at least part of the capacitive sensing apparatus is positioned in one or more cavities of the inner chassis.

20. The electronic device of claim 18, wherein:

at least part of the capacitive sensing apparatus is attached to one or more surfaces of the inner chassis.