Position indicator

• US 8,674,967 B2
• Filed: 01/23/2008
• Issued: 03/18/2014
• Est. Priority Date: 01/26/2007
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Fukushima, Yasuyuki, Fujitsuka, Hiroyuki
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): LAM, VINH TANG
• Application Number:
  US12/018,512
• Publication Number:
  US 20080180092A1
• Time in Patent Office: 2,246 Days
• Field of Search: 345173-183, 178 1801- 1905
• US Class Current: 345/179
• CPC Class Codes: G01D 5/208 using polyphase currents
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01D 5/2417 by varying separation
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/046 by electromagnetic means
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 17/045 with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 3/08 made from powder powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36
• CPC Class Codes: H01G 5/16 using variation of distance between electrodes

Abstract

A position indicator for use with a digitizer is provided. The position indicator generates a response to an alternating field received from the digitizer. The position indicator includes a core formed of a composition including a soft magnetic metal powder mixed with a resin binder, and at least one coil provided around the core configured to generate the response to the alternating field based on the alternating field received from the digitizer.

Claims

1. A digitizer device, comprising:

a position indicator, including;

a housing;

an elongated magnetic core disposed in said housing, said magnetic core having an elongated hole extending therethrough, and said magnetic core comprising a composition of soft magnetic metal powder mixed with a binder resin;

a core stem extending through said elongated hole, said core stem having a pen tip extending from said magnetic core at a first end and a conductive elastic member extending from said magnetic core at a second end opposite to said first end, and said core stem being movable with respect to said housing;

a resonant coil wound around said magnetic core for electromagnetic communication; and

a variable capacitance operably associated with said conductive elastic member, said variable capacitance comprising a dielectric element, a first electrode disposed on a first surface of said dielectric element, and a second electrode disposed on a second surface of said dielectric element opposite to said first electrode,

wherein said elastic conductive member changes an area of the variable capacitance when forced into contact with said dielectric element.

2. A digitizer device according to claim 1, further comprising:

a digitizer tablet comprising a plurality of sensor coils arranged in an array, said sensor coils transmitting and receiving signals to and from said resonant coil of said position indicator.

3. A digitizer device according to claim 1, further comprising:

an air interface extending continuously between an outer surface of the magnetic core and an inner surface of the outer housing.

4. A digitizer device according to claim 1, further comprising:

a control circuit for controlling internal components of said position indicator; and

a storage battery being charged when an electric current is induced on said resonant coil by an external magnetic field, said storage battery driving said control circuit and said internal components thereby operating said position indicator wirelessly and without an external power supply.

5. A digitizer device, comprising:

a position indicator, including;

a housing;

an elongated magnetic core disposed in said housing, said magnetic core having an elongated hole extending therethrough, and said magnetic core comprising a composition of soft magnetic metal powder mixed with a binder resin;

a core stem extending through said elongated hole, said core stem having a pen tip extending from said magnetic core at a first end and a conductive elastic member extending from said magnetic core at a second end opposite to said first end, and said core stem being movable with respect to said housing;

a resonant coil wound around said magnetic core for electromagnetic communication; and

a variable capacitance operably associated with said conductive elastic member, said variable capacitance comprising a dielectric element, a first electrode disposed on a first surface of said dielectric element, and a second electrode extending along a side of said dielectric element toward a circuit board and being in electrically connected to said elastic conductive member when a force is applied to said pen tip,

wherein said elastic conductive member changes an area of the variable capacitance when forced into contact with said dielectric element.

6. A digitizer device according to claim 5, further comprising:

a digitizer tablet comprising a plurality of sensor coils arranged in an array, said sensor coils transmitting and receiving signals to and from said resonant coil of said position indicator.

7. A digitizer device according to claim 5, further comprising:

an air interface extending continuously between an outer surface of the magnetic core

and an inner surface of the outer housing.

8. A digitizer device according to claim 5, further comprising:

a control circuit for controlling internal components of said position indicator; and

a storage battery being charged when an electric current is induced on said resonant coil by an external magnetic field, said storage battery driving said control circuit and said internal components thereby operating said position indicator wirelessly and without an external power supply.