Cursor positioning device operable over various degrees of elevation

Abstract

The present invention relates to cursor control devices for computers, and particularly relates to cursor control devices for personal computers which involve the use of a ball rotatable by the fingers for controlling cursor movement.

What is claimed is: 
     
       1. A trackball comprising a lower housing member,   a ball suitable for rotational manipulation by the fingers and generally accessible through the upper surface of the trackball,   a skeleton member having ball receiving means therein for receiving the ball,   a plurality of optomechanical encoders having the mechanical components thereof mounted on the skeleton member and urged into mechanical engagement with the ball, the mechanical components supporting the ball,   an upper housing member having ball retaining means and capable of being fixedly mounted to the lower housing member and thereby fixedly locating at least the skeleton member therebetween.   
     
     
       2. The trackball of claim 1 wherein the skeleton member further includes pressure roller means for rotatably supporting the ball. 
     
     
       3. The trackball of claim 1 wherein the encoders are urged into mechanical engagement with the ball by coil springs. 
     
     
       4. The trackball of claim 1 wherein the optomechanical encoders include a mask and an encoding wheel for generating quadrature signals. 
     
     
       5. The trackball of claim 1 wherein the ball retaining means of the upper member cooperates with the ball receiving means of the skeleton member to maintain the ball in contact with the optomechanical encoders at all elevational angles. 
     
     
       6. A trackball comprising a ball suitable for rotational manipulation by the fingers and generally accessible through the upper surface of the trackball,   a lower member having mounted thereon a plurality of photosources and photodetectors,   a skeleton member having mounted thereon a plurality of shafts, each shaft having mounted thereon an optical encoding wheel and a ball engagement wheel, each optical encoding wheel being disposed to be located between the photosource and the photodetector, the plurality of shafts providing at least partial support for the ball,   an upper housing adapted to be fixedly mounted to the lower member and for fixedly locating therebetween the skeleton member, the uppoer housing having therein an opening for passing the ball therethrough, and   ball retaining means capable of being fixedly mounted to the upper housing for maintaining the ball in contact with the ball engagement wheels regardless of elevational angles.   
     
     
       7. The trackball of claim 6 wherein the lower member includes printed circuit means. .Iadd. 
     
     
       8.  A cursor control device comprising: a lower housing member;   a ball suitable for rotation through an opening defined by said lower housing member;   a skeleton member having ball receiving means therein for receiving the ball;   a plurality of encoders having mechanical components thereof mounted on said skeleton member, said mechanical components engaged with said ball for detecting rotational motion of said ball;   an upper housing member having ball retaining means and capable of being fixedly mounted to the lower housing member and thereby fixedly locating at least the skeleton member therebetween, wherein a centerpoint of said ball remains equidistant from said lower housing member when said cursor control device is inverted. .Iaddend. .Iadd.   
     
     
       9.  The cursor control device as recited in claim 8 wherein said mechanical components are urged into mechanical engagement with said ball by an urging means. .Iaddend. .Iadd.10. The cursor control device as recited in claim 9 wherein said urging means is a spring. .Iaddend. .Iadd.11. The cursor control device as recited in claim 10 wherein said skeleton member further includes pressure roller means for rotatably supporting said ball. .Iaddend. .Iadd.12. The cursor control device as recited in claim 11 wherein said plurality of encoders are optomechanical encoders. .Iaddend. .Iadd.13. A cursor control device for entering commands into a computer, comprising: a housing;   a rotatable ball within said housing;   a first ball retainer in contact with said ball at a point on a first side of a centerline of said ball, said first ball retainer including a plurality of encoding means contacting said ball for generating an electrical signal corresponding to rotational movement of said ball; and   a second ball retainer positioned for contact with said ball at a point on a second side of said centerline of said ball and holding said ball in contact with said encoding means regardless of the elevational orientation of said housing. .Iaddend. .Iadd.14. The cursor control device as recited in claim 13 wherein said housing is comprised of an upper member and a lower member and said second ball retainer is removably coupled to said upper member. .Iaddend. .Iadd.15. The cursor control device as recited in claim 14 wherein said first ball retainer is further comprised of a plurality of pressure rollers for rotatably supporting said ball. .Iaddend. .Iadd.16. A cursor control device comprising:   a ball suitable for rotational manipulation;   a lower assembly having ball receiving means therein for receiving and supporting said ball, said lower assembly further having mounted thereon encoding means for detecting rotational motion of said ball and translating said rotational motion into cursor control signals;   an upper housing coupled to said lower assembly, said upper housing having therein an opening for passing said ball therethrough; and   ball retaining means coupled to said upper housing, said ball retaining means for maintaining said ball in contact with said encoding means regardless of elevational angle. .Iaddend. .Iadd.17. The cursor control device as recited in claim 16 wherein said lower assembly is comprised of a skeleton member and a printed circuit assembly. .Iaddend. .Iadd.18. The cursor control device as recited in claim 17 wherein said skeleton member further includes pressure roller means for rotatably supporting said ball.   
     
     
        .Iaddend. .Iadd.19.  A keyboard for providing input to a computer system, said keyboard comprising: a first portion having a plurality of alpha-numeric keys for providing alpha numeric input to said computer system;   a second portion having a trackball for controlling a cursor on a display coupled to said computer system, said second portion comprised of:   a ball suitable for rotational manipulation;   a lower assembly having ball receiving means therein for receiving and supporting said ball, said lower assembly further having mounted thereon encoding means for detecting rotational motion of said ball and translating said rotational motion into cursor control signals;   an upper housing coupled to said lower assembly, said upper housing having therein an opening for passing said ball therethrough; and   ball retaining means coupled to said upper housing, said ball retaining means for maintaining said ball in contact with said encoding means regardless of elevational angle. .Iaddend. .Iadd.20. A computer command apparatus for entering commands into a computer, comprising:   a housing;   a rotatable ball within said housing;   a first ball retaining member in abutting contact with said ball below a horizontal centerline of said ball;   a pair of encoder shafts within said housing and in frictional contact with said ball such that rotation of said ball causes said encoder shafts to rotate;   a second ball retaining member positioned above the horizontal centerline of said ball, said second ball retaining member being adapted to retain said ball within said housing and in frictional contact with said pair of encoder shafts throughout a 360° elevational rotation of said housing; and   a spring member assembly within said housing, said spring member assembly being positioned to retain said encoder shafts in frictional contact with   
     
     
        said ball. .Iaddend. .Iadd.21.  A computer system having: a process for processing information;   storage means for storing data;   a display device for displaying data; and   a keyboard comprising: a first key portion having a plurality of alpha-numeric keys for providing alpha numeric input to said computer system;   a second portion having a trackball for controlling a cursor on said display, said second portion comprised of:   a ball suitable for rotational manipulation;   a lower assembly having ball receiving means therein for receiving and supporting said ball, said lower assembly further having mounted thereon encoding means for detecting rotational motion of said ball and translating said rotational motion into cursor control signals;   an upper housing coupled to said lower assembly, said upper housing having therein an opening for passing said ball therethrough; and   ball retaining means coupled to said upper housing, said ball retaining means for maintaining said ball in contact with said encoding means regardless of elevational angle. .Iaddend. .Iadd.22. A laptop computer having:     a process for processing information;   a keyboard for input of information to said processor; and   a cursor control device for producing signals to control cursor movement, said cursor control device mounted into said keyboard and being electrically connected to said laptop computer, said cursor control device having:   a ball suitable for rotational manipulation;   a lower assembly having all receiving means therein for receiving and supporting said ball, said lower assembly further having mounted thereon encoding means for detecting rotational motion of said ball and translating said rotational motion into cursor control signals;   an upper housing coupled to said lower assembly, said upper housing having therein an opening for passing said ball therethrough; and   ball retaining means coupled to said upper housing, said ball retaining means for maintaining said ball in contact with said encoding means regardless of elevational angle. .Iaddend.