Electromagnetic pointing device using varying overlap of coils and conductive elements

• US 6,248,018 B1
• Filed: 09/15/1998
• Issued: 06/19/2001
• Est. Priority Date: 10/23/1997
• Status: Expired due to Term

• Current Assignee: Logitech Europe S A (Logitech International SA)
• Original Assignee: Logitech, Inc. (Logitech International SA)
• Inventors: Merminod, Antoine, Karaï, Dénes, Bidiville, Marc, Kehlstadt, Florian, Sommer, René
• Primary Examiner(s): Martin-Wallace, Valencia
• Assistant Examiner(s): White, Carmen D.
• Application Number:
  US09/153,567
• Time in Patent Office: 1,008 Days
• Field of Search: 273/148.B, 463/36-38, 345/161
• US Class Current: 463/38
• CPC Class Codes: G05G 2009/0474 characterised by means converting mechanical movement into electric signals
• CPC Class Codes: G05G 2009/04755 Magnetic sensor, e.g. hall generator, pick-up coil
• CPC Class Codes: G05G 9/047 the controlling member being movable by hand about orthogonal axes, e.g. joysticks for switches H01H25/04
• CPC Class Codes: H03K 17/975 using a capacitive movable element

Abstract

A micro-stick in which the movement of the micro-stick is detected inductively. The micro-stick is connected to an actuator element which varies interaction between an electromagnetic element and a number of conductive coils. In one embodiment, the coils are mounted on a printed circuit board mounted beneath the micro-stick. The micro-stick is mounted on a plate having a number of pins extending through the circuit board. On the other side of the circuit board is a flexible metal sheet which is contacted by the pins, and moved away from the coils in a direction in which the micro-stick is tilted. This increased separation of the metal sheet from the coils can then be detected.

Claims

1. An input device comprising:

a micro stick having a size that is coverable by a single finger of a user, and is actuatable by said finger;

an electromagnetic element capable of varying a quality factor of conductive coils;

at least first and second conductive coils;

an actuator element, connected to said micro stick, configured to vary an interaction between said electromagnetic element and said coils in response to movement of said micro stick by said finger, thereby varying a quality factor of said coils;

at least one capacitor coupled in parallel with at least one of said coils to form a resonant circuit; and

an impedance measuring circuit connected to said coils for measuring a change in impedance of said resonant circuit due to varied interaction of said coils and said electromagnetic element.

2. The input device of claim 1 wherein:

said coils are mounted on a printed circuit board underneath said micro stick;

said electromagnetic element is mounted below said printed circuit board; and

said actuator element extends past said printed circuit board to move a portion of said electromagnetic element away from said coils in response to movement of said micro switch.

3. The input device of claim 2 wherein said actuator element comprises a plurality of pins extending through holes in said printed circuit board.

4. The input device of claim 3 further comprising a plate, said micro stick being mounted on a top of said plate and said pins extending from a bottom of said plate.

5. The input device of claim 1 wherein said electromagnetic element comprises a metal sheet.

6. The input device of claim 1 wherein said actuator element is spring loaded to provide a resistance to movement of said micro stick by said finger.

7. The input device of claim 6 wherein said electromagnetic element is a flexible and spring loaded to provide said resistance upon deflection of said electromagnetic element by said actuator element.

8. The input device of claim 7 wherein said electromagnetic element is a metal sheet having at least four separately deformable sections.

9. The input device of claim 1 wherein each of said coils extends onto first and second sides of a printed circuit board.

10. The input device of claim 1 wherein said micro-stick is mounted on a mouse.

11. The input device of claim 1 wherein said micro-stick is mounted on a gamepad.

12. An input device comprising:

a micro stick having a size that is coverable by a single finger of a user, and is actuatable by said finger;

at least first and second conductive coil traces on a printed circuit board beneath said micro stick, each of said coil traces extending onto two sides of said printed circuit board;

a flexible metal sheet mounted below said printed circuit board;

a plurality of pins, connected to said micro stick and extending past said printed circuit board to move a portion of said flexible metal sheet away from said coil traces in response to movement of said micro switch, thereby varying a quality factor of said coil traces;

at least one capacitor coupled in parallel with at least one of said coils to form a resonant circuit; and

an impedance measuring circuit connected to said coils for measuring a change in impedance of said resonant circuit due to varied interaction of said coils and said electromagnetic element.