Two-axis ball-based cursor control apparatus with tactile feedback

• US 20020101402A1
• Filed: 01/29/2002
• Published: 08/01/2002
• Est. Priority Date: 01/29/2001
• Status: Active Grant

• Current Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Original Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Inventors: Yu, Yat Shun
• Granted Patent: US 6,937,228 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/03549 Trackballs G06F3/03541 takes precedence

Abstract

A two-axis ball-based cursor control apparatus with tactile feeling is provided, which includes a housing; a spherical ball contained partially within the housing and having a plurality of recesses distributed about its outer surface; two pairs of spring biased sensor mechanisms each including a probe, a spring, and a transducer; and a means for processing the signals received from the sensor mechanisms. Each of the four probes is positioned so that it rests within one of the recesses on the spherical ball when the ball is stationary. As the ball is rotated, the probes are pushed up and out of the recesses by the ball, causing the corresponding springs to alternately compress and decompress, before the probes come to rest in adjacent recesses. Each transducer generates an electrical signal corresponding to the rate of compression and decompression in the corresponding spring. The signal processing means then translates the signals from each of the transducers into movement of a cursor on an electronic display screen which corresponds to the rotation of the spherical ball about each of its axes.

Claims

1. A two-axis ball-based cursor control apparatus providing for discrete, uniform displacements in each direction of rotation in order to achieve a precise alignment of a cursor and target in electronic displays while simultaneously providing tactile feedback to the user corresponding to each incremental displacement, said cursor control apparatus comprising:

a housing;

a spherical ball contained at least partially within said housing, said spherical ball capable of rotating about at least two axes, and said spherical ball further including a plurality of recesses distributed about the outer surface of said spherical ball;

a first pair of spring biased sensor mechanisms disposed within the housing, including a first sensor mechanism and a second sensor mechanism for measuring the displacement of said spherical ball about a first axis of rotation, and a second pair of spring biased sensor mechanisms disposed within the housing, including a third sensor mechanism and a fourth sensor mechanism for measuring the displacement of said spherical ball about a second axis of rotation; and

wherein each of said sensor mechanisms includes a probe configured to rest within said recesses on said spherical ball, a spring serving to bias said probe toward the surface of said spherical ball, whereby said spring compresses and decompresses as a result of the normal force exerted on said probe by the sides of said recesses as said spherical ball is rotated, and a transducer connecting with said spring for generating an electrical signal corresponding to the rate of compression and decompression of said spring; and

a means for processing the signals received from said sensor mechanisms in order to determine the direction and rate of rotation of said spherical ball about each axis of rotation based on the waveform of the signals received from each of said transducers.

2. The two-axis cursor control apparatus according to claim 1, wherein said probes associated with said first and second sensor mechanisms are of substantially identical shape and orientation, and said probes associated with said third and fourth sensor mechanisms are of substantially identical shape and orientation, so that when said spherical ball is rotated about one of its axes, both of said springs corresponding to each pair of sensor mechanisms are compressed in a like fashion, such that the waveforms generated by a pair of sensor mechanisms are identical in shape to one another, while having a different shape than the waveforms generated by the other pair of sensor mechanisms.

3. The two-axis cursor control apparatus according to claim 2, wherein said probes associated with said first and second sensor mechanisms are offset from one another relative to said recesses on said spherical ball, and said probes associated with said third and fourth sensor mechanisms are offset from one another relative to said recesses on said spherical ball, such that when said spherical ball is rotated about one axis, the electrical signals generated by at least one pair of said sensor mechanisms manifest a phase shift, thereby permitting said signal processing means to determine the direction of rotation of said spherical ball about that axis.

4. The two-axis cursor control apparatus according to claim 1, wherein said spherical ball protrudes partially from said housing such that said spherical ball is directly rotated by the user in order to generate motion of a cursor on an electronic display screen.

5. The two-axis cursor control apparatus according to claim 1, further comprising at least one switch element for allowing the user to select options corresponding to particular cursor locations on an electronic display screen.

6. The two-axis cursor control apparatus according to claim 5, wherein said at least one switch element comprises at least one button element which is manipulated directly by pressure applied thereto by the user, triggering said switch element.

7. The two-axis cursor control apparatus according to claim 5, wherein said at least one switch element is positioned so as to contact said spherical ball when pressure is applied to said spherical ball by the user, causing said spherical ball to depress said switch element, thereby triggering said switch element.