A terminal trackball navigation apparatus, comprising:
- a trackball;
- four raster wheels, distributed around the trackball, wherein axes of the raster wheels are on the same horizontal plane, each raster wheel points to a center of the trackball along a radial direction, an angle between adjacent raster wheels in the horizontal plane is 90 degrees, a gap exists between each raster wheel and the trackball, and light-transmitting regions alternate with light-tight regions along a circumferential direction on an axial plane of each raster wheel;
- two light-emitting apparatuses, characterized by:
- one light-emitting apparatus is set between two adjacent raster wheels, and the other light-emitting apparatus is set between the other two adjacent raster wheels, wherein light emitted by the light-emitting apparatuses can cast onto preset positions on the axial planes of the raster wheels, and the preset position is on a rotary track shared by light-transmitting regions and light-tight regions of the raster wheel;
- four light-receiving counters, each distributed on an opposite side of a light-emitting apparatus against a raster wheel along an axis of the raster wheel, wherein a light-receiving counter is unable to receive light emitted by a light-emitting apparatus when the light-tight regions of the raster wheel turn to the preset position, and is able to receive the light emitted by the light-emitting apparatus when the light-transmitting regions of the raster wheel turn to the preset position;
- and
- a navigation chip, electrically connected to the light-receiving counters, wherein:
- when the trackball rolls, the trackball touches at least one raster wheel, the raster wheel that touches the trackball rotates with the trackball, the light-emitting apparatuses cast light onto an axial plane of the rotating raster wheel;
- at least one of the light-receiving counters receives the light emitted by the one of the light-emitting apparatuses passing through the rotating raster wheel, and converts the light into electrical pulse signals and sends the signals to the navigation chip;
- the navigation chip recognizes a displacement direction of the trackball according to a position of the light-receiving counter that sends the electrical pulse signals;
- and the navigation chip calculates a displacement speed and a distance of the trackball according to a duration and a period of the electrical pulse signals and generates navigation information.