Method and apparatus for mouse positioning device based on infrared light sources and detectors

• US 6,333,735 B1
• Filed: 05/24/1999
• Issued: 12/25/2001
• Est. Priority Date: 03/16/1999
• Status: Expired due to Fees

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Anvekar, Dinesh Kashinath
• Primary Examiner(s): Liang, Regina
• Application Number:
  US09/317,189
• Time in Patent Office: 946 Days
• Field of Search: 345/173, 345/175, 345/177, 345/180-183, 345/168, 345/163, 345/166, 345/158
• US Class Current: 345/175
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

Pointer positioning device based on infrared light sources and detectors that is compact, rugged and ergonomically easy to use such as can be used in laptop computers and similar devices. The pointer positioning device fits in the same area as a conventional touch-pad device in a portable computing device. It detects movement in a movement area by scanning for shadow information with infrared (IR) light sources. To increase the resolution of scanning and to avoid non-uniform beam widths, the scanning of the touchpad area may be carried out by using low power IR laser beams produced by a single IR laser source each for x and y directions and a plurality of optical fibers to transmit the laser beams in the x and y directions. Optionally, this divergency is minimized by positioning IR light sources and light detectors in an alternating pattern around the periphery of a movement area. A mouse device with an opaque plunger depressed with a finger is used as an object to create a well defined shadow in the x and y directions of a movement area.

Claims

1. A pointing device for use in computing devices comprising

means for producing scanned infrared (IR) light in first and second dimensions over a movement area;

means for detecting movement of an object in said movement area using shadow information in said first and second dimensions and generating a detector output, wherein said shadow information is produced by a mouse device, comprising;

a button assembly, wherein depressing a button on said button assembly causes a plunger to create a shadow in said movement area;

a base assembly, said base assembly moving freely in two dimensions over said movement area; and

means for connecting said button assembly to said base assembly; and

means for converting the detector output to position information associated with a pointer on a screen display area.

2. A pointing device for use in computing devices as recited in claim 1, wherein said base assembly comprises:

a base disk;

a piston;

a center stock having a first end connected to said base disk, and a second end connected to said piston.

3. A pointing device for use in computing devices as recited in claim 2, wherein said base disk is weakly magnetic and said movement area has a horizontal magnetic surface for stable positioning of said base disk on said movement area.

4. A pointing device for use in computing devices as recited in claim 2, wherein said button assembly comprises:

a button;

a plunger;

an hollow member having a first end connected to said button and a second end connected to said plunger.

5. A pointing device for use in computing devices as recited in claim 4, wherein said button assembly allows a user to grip said button easily with one or more fingers, facilitating movement of said mouse device in two dimensions over said movement area.

6. A pointing device for use in computing devices as recited in claim 5, wherein said button has a depression on its surface, resulting in a comfortable finger grip, allowing said mouse device to be moved easily with one finger.

7. A pointing device for use in computing devices as recited in claim 5, wherein said button extends upward as a stock and is easily gripped by two or more fingers.

8. A pointing device for use in computing devices as recited in claim 4, wherein said means for connecting said button assembly to said base assembly positions said base assembly interposed within said button assembly, said piston positioned within said hollow member and said center stock moving freely through a hole in said plunger when said plunger is depressed and released, wherein said plunger is in an upward position at rest and in a downward position when pressure is applied to said button, allowing said piston to move freely within said hollow member.

9. A pointing device for use in computing devices as recited in claim 8, wherein said means for connecting said button assembly to said base assembly further comprises a spring assembly located within said hollow member, acting to produce at rest pressure against both said piston and said button, said spring assembly allowing said plunger to be depressed by applying pressure from a finger to said button.

10. A pointing device for use in computing devices as recited in claim 1, wherein said means for detecting movement comprises a plurality of x-direction IR light detectors, and a plurality of y-direction IR light detectors, wherein when said plunger is depressed it creates a broad shadow of known properties which is different from a narrow shadow produced when said plunger is not depressed, said broad shadow detected by said x-direction IR light detectors or said y-direction IR light detectors, generating a detector output showing movement when said plunger is depressed and ignoring movement when said plunger is not depressed.

11. A pointing device for use in computing devices which minimizes the effect of beam spreading and enables a uniform detection resolution, comprising:

an x-direction infrared (IR) source controller and a y-direction IR source controller;

a plurality of x-direction IR light sources and a plurality of y-direction IR light sources, said x and y-direction IR source controllers respectively alternately and sequentially activating the IR light sources in each of the x and y-directions;

a plurality of x-direction IR light detectors, and a plurality of y-direction IR light detectors, wherein said x-direction light sources are alternately located with said x-direction light detectors on both opposite sides of a movement area, and said y-direction light sources are alternately located with said y-direction light detectors on both opposite sides of said movement area being substantially perpendicular to said x-direction light sources and said x-direction light detectors;

a movement area of two-dimensions in x and y scanned by said IR light sources creating shadows whereby objects placed in said movement area create shadows detected by said IR light detectors; and

an x-direction signal processing circuit and a y-direction signal processing circuit respectively receiving signals from said x-direction and y-direction IR light detectors producing detector outputs in x-y directions to be sent to a pointer control circuit controlling a pointer in a screen display area,

wherein said object placed in the movement area comprises;

a button assembly, wherein depressing a button on said button assembly causes a plunger to create a shadow in said movement area;

a base assembly, said base assembly moving freely in two dimensions over said movement area; and

means for connecting said button assembly to said base assembly.

12. A pointing device for use in computing devices as recited in claim 11, wherein said base assembly comprises:

a base disk;

a piston;

a center stock having a first end connected to said base disk, and a second end connected to said piston.

13. A pointing device for use in computing devices as recited in claim 12, wherein said button assembly comprises:

a button;

a plunger;

an hollow member having a first end connected to said button and a second end connected to said plunger.

14. A pointing device for use in computing devices as recited in claim 13, wherein said means for connecting said button assembly to said base assembly positions said base assembly interposed within said button assembly, said piston positioned within said hollow member and said center stock moving freely through a hole in said plunger when said plunger is depressed and released, wherein said plunger is in an upward position at rest and in a downward position when pressure is applied to said button, allowing said piston to move freely within said hollow member.

15. A pointing device for use in computing devices as recited in claim 14, wherein said means for connecting said button assembly to said base assembly further comprises a spring assembly located within said hollow member, acting to produce at rest pressure against both said piston and said button, said spring assembly allowing said plunger to be depressed by applying pressure from a finger to said button.

16. A pointing device for use in computing devices comprising:

infrared (IR) means for producing scanned IR light in first and second dimensions over a movement area, wherein said IR means includes a low power IR laser source, a first plurality of optical fibers directing IR light beams across a movement area, and a second plurality of optical fibers located on an opposite side of said movement area capturing IR light emitted from said first plurality of optical fibers;

means connected to said second plurality of optical fibers for detecting movement of an object in said movement area using shadow information in said first and second dimensions and generating a detector output; and

means for converting the detector output to position information associated with a pointer on a screen display area

wherein all IR light beams in first said dimension are turned on or off simultaneously with alternate on and off conditions for IR light beams in said second dimension.

17. A pointing device for use in computing devices as recited comprising

infrared (IR) means for producing scanned IR light in first and second dimensions over a movement area, wherein said IR means includes a low power IR laser source, a first plurality of optical fibers directing IR light beams across a movement area, and a second plurality of optical fibers located on an opposite side of said movement area capturing IR light emitted from said first plurality of optical fibers;

means connected to said second plurality of optical fibers for detecting movement of an object in said movement area using shadow information in said first and second dimensions and generating a detector output; and

means for converting the detector output to position information associated with a pointer on a screen display area,

wherein said shadow information is produced by a mouse device comprising;

a button assembly, wherein depressing a button on said button assembly causes a plunger to create a shadow in said movement area;

a base assembly, said base assembly moving freely in two dimensions over said movement area; and

means for connecting said button assembly to said base assembly.

18. A method for detecting movement in a movement area used for positioning pointer on a screen display area comprising the steps of:

producing collimated infrared (IR) light beams in first and second dimensions over a movement area;

detecting movement of a plunger device in said movement area using shadow information in said first and second dimensions, said plunger device having a button assembly, wherein depressing a button on said button assembly causes a plunger to create a shadow in said movement area, a base assembly, said base assembly moving freely in two dimensions over said movement area, and means for connecting said button assembly to said base assembly; and

converting detected movement to position information associated with a pointer on a screen display area.

19. A method for detecting movement in a movement area used for positioning pointer on a screen display area as recited in claim 18, wherein the step of detecting movement wherein detection of rapid multiple depressing and releasing movements of said button is interpreted as a double click.

20. A method for detecting movement in a movement area used for positioning pointer on a screen display area as recited in claim 18, wherein said plunger device is moved in two dimensions in said movement area by applying pressure from one or more fingers.