Pressure sensitive stylus for a digitizer

• US 9,513,721 B2
• Filed: 08/05/2014
• Issued: 12/06/2016
• Est. Priority Date: 09/12/2013
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Stern, Yuval
• Primary Examiner(s): ABDIN, SHAHEDA A
• Application Number:
  US14/451,448
• Publication Number:
  US 20150070330A1
• Time in Patent Office: 854 Days
• US Class Current: 1/1
• 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 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser

Abstract

A pressure sensitive stylus for operation with a digitizer sensor includes a housing, a writing tip that is movable in response to contact pressure applied on the writing tip, an extremity that is movable together with the writing tip, a switch and an elastomer element positioned around the extremity and in physical contact with at least one of the housing or an element that is fixed to the housing. The switch includes a first element that is fixedly positioned around the extremity and a second element that is fixed to the housing, wherein physical contact between the first element and the second element closes the switch. The writing tip is operable to move in response to the elastomer element compressing against the housing or an element that is fixed to the housing and the switch is operative to toggle at a pre-defined compressed state of the elastomer element.

Claims

1. A pressure sensitive stylus for operation with a digitizer sensor comprising:

a housing;

a writing tip that is movable and recedes toward the housing of the stylus in response to contact pressure applied on the writing tip;

an extremity that is movable together with the writing tip;

a switch comprising;

a first element that is fixed to the extremity;

a second element that is fixed to the housing, wherein the first element and second element are conductive and physical contact between the first element and the second element initiates electrical communication and toggles the switch;

a third element that is fixed to the housing;

a controller configured to detect the electrical communication; and

an elastomer element positioned around the extremity, the elastomer element including a base surface and at least one protruding surface extending from the base surface, wherein the at least one protruding surface maintains physical contact with the third element during toggling of the switch, and wherein the base surface is configured to move with respect to the third element during the toggling,

wherein the elastomer element is configured to compress against the third element based on the contact pressure applied on the writing tip; and

wherein the switch is configured to toggle at a pre-defined compressed state of the elastomer element.

2. The pressure sensitive stylus of claim 1, wherein toggling of the switch defines a transition between a hover operational state and a touch operational state of the stylus.

3. The pressure sensitive stylus of claim 1, wherein toggling, of the switch defines a transition between a sleep mode and an active mode of the stylus.

4. The pressure sensitive stylus of claim 1, wherein the switch is operable to alter at least one of a repetition rate, a duty cycle and a power state of the stylus.

5. The pressure sensitive stylus of claim 1, comprising:

a transmitting unit for transmitting the operational state of the stylus to a digitizer sensor that is operated together with the stylus.

6. The pressure sensitive stylus of claim 1, wherein the second element includes two terminals and wherein contact between the first element and the second element shorts the two terminals.

7. The pressure sensitive stylus of claim 1, wherein the first element or the second element is formed from a conductive material that is pliable.

8. The pressure sensitive stylus of claim 7, wherein the first element or the second element is formed from conductive particles embedded in at least one of silicon, rubber, thermoplastic polyurethane and polyoxymethylene.

9. The pressure sensitive stylus of claim 1, wherein the elastomer element is integral to the first element or the second element.

10. The pressure sensitive stylus of claim 1, wherein the switch is operative to toggle in response to the at least one protruding element resiliently collapsing due to the elastomer element compressing against the third element.

11. The pressure sensitive stylus of claim 1, wherein the switch is a normally closed switch, and wherein the first and second element of the switch is separated responsive to the writing tip receding toward the housing of the stylus.

12. The pressure sensitive stylus of claim 1, wherein the switch is a normally open switch, and wherein the first and second element of the switch is brought into contact responsive to the writing tip receding toward the housing of the stylus.

13. The pressure sensitive stylus of claim 12, wherein the first element includes a plurality of through going holes matching the plurality of protruding elements, and wherein the first element is fitted on the elastomer element so that the plurality of protruding elements protrude through the plurality of through going holes.

14. The pressure sensitive stylus of claim 13, wherein the second element and the third element are a common element and wherein the plurality of protruding elements are positioned to physically contact the second element of the switch and are sized to separate the first element of the switch from the second element of the switch over a pre-defined displacement of the writing tip associated with a hover operational state of the stylus.

15. The pressure sensitive stylus of claim 1, wherein the first element comprises a first conductive layer and the second element comprises a second conductive layer such that the first and second conductive layers face each other, wherein a first conductive layer is laminated with a non-conductive layer having a defined dielectric coefficient, and wherein during an open state of the switch a dielectric coefficient of an air gap that forms between the non-conductive layer and the second conductive layer dominates a combined dielectric coefficient of the air gap and non-conductive layer.

16. The pressure sensitive stylus of claim 15, wherein the controller is configured to detect changes in capacitance in the switch responsive to movement of the writing tip.

17. The pressure sensitive stylus of claim 1, comprising:

a displacement monitor operative to monitor displacements of the writing tip over a range of displacements;

a controller operative to sample output from the displacement monitor; and

a transmitting unit operative to transmit information associated with the output sampled to a digitizer sensor operated together with the stylus.

18. The pressure sensitive stylus of claim 17, wherein the range of displacements is a range corresponding to a touch operational mode of the stylus.

19. The pressure sensitive stylus of claim 17, wherein at least one of sampling output from the displacement monitor and transmitting information associated with the output sampled is responsive toggle state of the switch.

20. The pressure sensitive stylus of claim 17, wherein the displacement monitor is an optical detector for optically sensing the displacement of the tip and for providing output in response to the sensing.

21. The pressure sensitive stylus of claim 20, comprising a measuring rod movable with the writing tip, wherein the measuring rod includes an aperture through which an optical signal of the optical detector is detected and wherein the output of the optical detector is altered based on an overlap area between the aperture and an optical transmission and detecting area of the optical detector.

22. The pressure sensitive stylus of claim 1, wherein the base surface of the elastomer element is shaped as a flat ring.

23. The pressure sensitive stylus of claim 1, comprising:

a sleeve element movable between two partitions formed as part of the housing, wherein the extremity is fitted through the sleeve element and fixedly connect to the sleeve element so that tip movement is confined by movement of the sleeve element.

24. A pressure sensitive stylus for operation with a digitizer sensor comprising:

a housing;

a writing tip that is movable and recedes toward the housing of the stylus in response to contact pressure applied on the writing tip;

an extremity that is movable together with the writing tip;

a switch comprising;

a first conductive layer fixedly positioned on an element positioned around the extremity; and

a second conductive layer facing the first conductive layer, wherein the second conductive layer is fixed to the housing;

wherein one of the first conductive layer and the second conductive layer is laminated with a non-conductive material; and

an elastomer element including a base surface and one or more protruding surfaces extending from the base surface;

wherein one of the first conductive layer and the second conductive layer is integrated with the base surface and wherein the one or more protruding surfaces extend from the base surface and toward the other one of the first conductive layer and the second conductive layer and is in physical contact with the other one of the first conductive layer and the second conductive layer while the switch is open and closed; and

a controller configured to detect electrical communication between the first conductive layer and the second conductive layer; and

wherein physical contact between the first conductive layer and the second layer responsive to compression of the elastomer element closes the switch, wherein the physical contact is detected by the controller as a change in capacitance due to an absence of an air gap between the first and second layer.