Pointing device for use in a computer system

A pointing device for controlling cursor movement on a computer display by entering positional information into the computer, comprising:

• a housing having an upper opening and a lower inside base directly facing said upper opening;
• a cylindrical bar with a tube mount part of a given length adjacent to each end mounted on said lower inside base so as to rotate around and slide along its central axis in said upper opening;
• a first marking tube mounted on the tube mount part at one end of said cylindrical bar and having a plurality of first marking lines disposed around its periphery, said first marking lines being in parallel with said central axis a constant interval between the adjacent marking lines;
• a second marking tube mounted on said tube mount part at another end of said cylindrical bar and having a plurality of second marking lines disposed around its periphery, said second marking lines being perpendicular to said first marking lines and having a constant interval between the adjacent marking lines;
• a detection circuit for respectively measuring the rotational and sliding movements of said cylindrical bar by sensing the movements of said first and second marking lines;
• and
• a microcomputer for analyzing the detection signal produced by said detection circuit to obtain said positional information.

A computer system including a main housing for mounting a microcomputer, a first opening formed in the upper surface of said main housing, a display, and a pointing device for controlling cursor movement on said display screen by entering positional information into the computer, said pointing device comprising:

• a panel having a second opening and a lower inside base directly facing said second opening, said panel being mounted in the inside of said main housing with the upper surface exposed through said first opening;
• a cylindrical bar mounted on said lower inside base so as to rotate around and slide along its central axis in said second opening and being exposed in said second opening;
• a detection circuit for detecting the rotational and sliding movements of said cylindrical bar;
• and
• a controller for analyzing the detection signal produced by said detection circuit to obtain said positional information.

A computer system including a main housing for mounting a microcomputer, a first opening formed in the upper surface of said main housing, a display, and a pointing device for controlling cursor movement on said display screen by entering positional information into the computer, said pointing device comprising:

• a panel having a second opening and a lower inside base directly facing said second opening, said panel being mounted in the inside of said main housing with the upper surface exposed through said first opening;
• a cylindrical bar mounted on said lower inside base so as to rotate around and slide along its central axis in said second opening and being exposed in said second opening;
• a detection circuit for detecting the rotational and sliding movements of said cylindrical bar;
• and
• a controller for analyzing the detection signal produced by said detection circuit to obtain said positional information, said cylindrical bar further comprising;
• a plurality of first marking lines disposed around a part of the periphery adjacent to one end thereof, said first marking lines being in parallel with said central axis and having a constant interval between adjacent marking lines, and said first marking lines being extended to a given length from said one end;
• and
• a plurality of second marking lines disposed around another part of the periphery adjacent to another end thereof, said second marking lines being perpendicular to said first marking lines and having a constant interval between adjacent marking lines, and said second marking lines being extended to a given length from said another end;
• and
• said detection circuit respectively measuring the rotational and sliding movements of said cylindrical bar by sensing the movements of said first and second marking lines.

A computer system including a main housing for mounting a microcomputer, a first opening formed in the upper surface of said main housing, a display, and a pointing device for controlling cursor movement on said display screen by entering positional information into the computer, said pointing device comprising:

• a panel having a second opening and a lower inside base directly facing said second opening, said panel being mounted in the inside of said main housing with the upper surface exposed through said first opening;
• a cylindrical bar mounted on said lower inside base so as to rotate around and slide along its central axis in said second opening and being exposed in said second opening;
• a detection circuit for detecting the rotational and sliding movements of said cylindrical bar;
• and
• a controller for analyzing the detection signal produced by said detection circuit to obtain said positional information, said cylindrical bar comprising:
• a tube mount part of a given length provided adjacent to each end thereof;
• a first marking tube mounted on the tube mount part at one end of said cylindrical bar and having a plurality of first marking lines disposed around its periphery, said first marking lines being in parallel with said central axis and having a constant interval between adjacent marking lines;
• and
• a second marking tube mounted on the tube mount part at another end of said cylindrical bar and having a plurality of second marking lines disposed around its periphery, said second marking lines being perpendicular to said first marking lines and having a constant interval between adjacent marking lines;
• and
• said detection circuit respectively measuring the rotational and sliding movements of said cylindrical bar by sensing the movements of said first and second marking lines.

A method of controlling cursor movement on the display of a computer system by entering positional information into the computer, comprising the steps of:

• sending one of first and second light beams to a cylindrical bar;
• sensing the light beam reflected by said cylindrical bar through a pair of optical fibers;
• converting the two light beams received by said pair of optical fibers into two respective electrical signals;
• analyzing said two electrical signals to obtain the measurement of said cursor movement in one of the X and Y directions in a Cartesian coordinate system;
• sending the other light beams to a cylindrical bar;
• sensing the light beam reflected by said cylindrical bar through another pair of optical fibers;
• converting the two light beams received by said another pair of optical fibers into two other respective electrical signals;
• analyzing said two other electrical signals to obtain the measurement of said cursor movement in the other direction in the cartesian coordinate system;
• transferring the measurement information to said computer system;
• and
• moving the cursor on said display in the X and Y directions according to said measurement information.