Optical navigation system with lift detection
View Patent ↗An optical navigation system with a lift detection module is provided for preventing cursor movement if the optical navigation system has been lifted from the navigation surface. The optical navigation system may include an image sensor, a controller and a lift detection module. The lift detection module may be operatively coupled with the image sensor and the controller to selectively report a motion data upon determining a lift by comparing the average of the photosensitive pixel elements with a pixel element threshold value and the surface quality value with a surface quality threshold value. The lift detection module may be incorporated in a microcontroller, wherein the microcontroller may be added to a navigation system to provide an additional lift detection feature.
1. An optical navigation system, comprising:
an image sensor having photosensitive pixel elements configured to capture an image of a surface;
a controller coupled to the image sensor, the controller configured to determine an average of photosensitive pixel elements used for acquiring the image, the controller further configured to determine a surface quality value for the image;
a lift detection module configured to receive the average of the photosensitive pixel elements and the surface quality value, wherein the lift detection module is operable to selectively report motion data upon determining a lift by comparing the average of the photosensitive pixel elements with a pixel element threshold value and the surface quality value with a surface quality threshold value.
2. The system of claim 1 , wherein the lift detection module is configured to determine whether the average of the photosensitive pixel elements is lower than the pixel element threshold value.
3. The system of claim 2 , wherein the pixel element threshold value is a predetermined minimum average of photosensitive pixel elements that are integrated to successfully acquire an image.
4. The system of claim 1 , wherein the lift detection module is configured to determine whether the surface quality value is lower than the surface quality threshold value.
5. The system of claim 4 , wherein the surface quality threshold value is a predetermined minimum surface quality value for proper tracking.
6. The system of claim 1 , wherein the lift detection module is further configured to suppress the report of motion data upon determining the average of the photosensitive pixel elements is lower than the predetermined pixel element threshold value and the surface quality value is lower than the predetermined surface quality threshold value.
7. The system of claim 1 , further comprising a memory configured to receive and store the predetermined threshold value of the photosensitive pixel elements and the threshold value of the surface quality value.
8. An optical input device, comprising:
a light source;
a sensor having photosensitive pixel elements configured to capture an image of a surface;
a controller operably connected to the sensor, the controller being configured to determine an average of the photosensitive pixel elements used for acquiring the image, the controller being further configured to determine a surface quality value for the image;
a microcontroller operable to determine the operational height of the input device from the surface; and
a navigation processor configured to generate motion data and provide navigation operation;
wherein the microcontroller comprises a lift detection module configured to receive the average of the photosensitive pixel elements and the surface quality value and configured to selectively report a motion data upon determining a lift by comparing the average of the photosensitive pixel elements with a pixel element threshold value and the surface quality value with a surface quality threshold value.
9. The optical input device of claim 8 , wherein the microcontroller comprises a lift detection module configured to receive the average of the photosensitive pixel elements and the surface quality value and configured to selectively report a motion data upon determining a lift by comparing the average of the photosensitive pixel elements with a pixel element threshold value and the surface quality value with a surface quality threshold value.
10. The optical input device of claim 8 , wherein the lift detection module is configured to determine whether the average of the photosensitive pixel elements is lower than the pixel element threshold value.
11. The optical input device of claim 10 , wherein the pixel element threshold value is a predetermined minimum average of photosensitive pixel elements that are integrated to successfully acquire an image.
12. The optical input device of claim 8 , wherein the lift detection module is configured to determine whether the surface quality value is lower than the surface quality threshold value.
13. The optical input device of claim 8 , wherein the surface quality threshold value is a predetermined minimum surface quality value for proper tracking.
14. The optical input device of claim 8 , wherein the lift detection module is configured to suppress the motion data upon determining the average of the photosensitive pixel elements is lower than the predetermined pixel element threshold value and the surface quality value is lower than the predetermined surface quality threshold value.