Dual mode optical navigation device and mode switching method thereof

Abstract

There is provided a mode switching method of a dual mode optical navigation device. The dual mode optical navigation device is configured to be operated on a working surface and has a first bottom surface and a second bottom surface having an included angle with the first bottom surface. The mode switching method includes: determining whether the first bottom surface or the second bottom surface contacts with the working surface; switching the dual mode optical navigation device to a first mode when identifying that the first bottom surface contacts with the working surface; and switching the dual mode optical navigation device to a second mode when identifying that the second bottom surface contacts with the working surface.

What is claimed is: 
     
         1 . A dual mode optical navigation device, operated in a first mode or a second mode on a working surface, the dual mode optical navigation device comprising:
 a first bottom surface;   a second bottom surface having an included angle with the first bottom surface;   a light source configured to illuminate the working surface through the first bottom surface;   an image sensor configured to capture an image frame of the working surface through the first bottom surface; and   a process unit configured to calculate an image feature of the image frame to accordingly enter the first mode or the second mode,   wherein the first bottom surface is configured to be contacted with the working surface in the first mode and the second bottom surface is configured to be contacted with the working surface in the second mode.   
     
     
         2 . The dual mode optical navigation device as claimed in  claim 1 , wherein the image feature is an intensity distribution ratio, an image brightness value or an image quality of the image frame. 
     
     
         3 . The dual mode optical navigation device as claimed in  claim 2 , wherein the first mode is entered when the intensity distribution ratio is larger than a ratio threshold, the image brightness value is larger than a brightness threshold or the image quality is larger than a quality threshold; the second mode is entered when the intensity distribution ratio is within a ratio threshold range, the image brightness value is within a brightness threshold range or the image quality is within a quality threshold range; and the ratio threshold range, the brightness threshold range and the quality threshold range are respectively smaller than the ratio threshold, the brightness threshold and the quality threshold. 
     
     
         4 . The dual mode optical navigation device as claimed in  claim 1 , wherein the first mode is configured to control a cursor movement. 
     
     
         5 . The dual mode optical navigation device as claimed in  claim 1 , wherein the second mode is configured to perform a gesture operation. 
     
     
         6 . The dual mode optical navigation device as claimed in  claim 1 , wherein the image sensor comprises a film coating configured to filter out spectrums rather than a spectrum of the light source. 
     
     
         7 . The dual mode optical navigation device as claimed in  claim 1 , wherein the second bottom surface is located at at least one of a back end, a left end or a right end of the first bottom surface under the dual mode optical navigation device. 
     
     
         8 . A dual mode optical navigation device, operated in a first mode or a second mode on a working surface, the dual mode optical navigation device comprising:
 a first bottom surface;   a second bottom surface having an included angle with the first bottom surface, wherein the first bottom surface is configured to be contacted with the working surface in the first mode and the second bottom surface is configured to be contacted with the working surface in the second mode;   an actuator configured to generate a detect signal when one of the first bottom surface and the second bottom surface in contact with the working surface changes from the first bottom surface to the second bottom surface or from the second bottom surface to the first bottom surface; and   a process unit configured to enter the first mode or the second mode according to the detect signal.   
     
     
         9 . The dual mode optical navigation device as claimed in  claim 8 , further comprising:
 a light source configured to illuminate the working surface through the first bottom surface; and   an image sensor configured to capture image frames of the working surface thought the first bottom surface for the process unit calculating a displacement.   
     
     
         10 . The dual mode optical navigation device as claimed in  claim 9 , wherein the first mode is configured to control a cursor movement according to the displacement. 
     
     
         11 . The dual mode optical navigation device as claimed in  claim 9 , wherein the second mode is configured to perform a gesture operation according to the displacement. 
     
     
         12 . The dual mode optical navigation device as claimed in  claim 8 , wherein the actuator is a gyroscope or an accelerometer. 
     
     
         13 . The dual mode optical navigation device as claimed in  claim 8 , wherein the actuator is a switching element disposed at the first bottom surface or the second bottom surface of the dual mode optical navigation device. 
     
     
         14 . The dual mode optical navigation device as claimed in  claim 8 , wherein the second bottom surface is located at at least one of a back end, a left end or a right end of the first bottom surface under the dual mode optical navigation device. 
     
     
         15 . A mode switching method of a dual mode optical navigation device, the dual mode optical navigation device being operated on a working surface and having a first bottom surface and a second bottom surface with an included angle therebetween, the mode switching method comprising:
 determining, using a process unit, whether the first bottom surface or the second bottom surface contacts with the working surface;   switching to a first mode when identifying that the first bottom surface contacts with the working surface and capturing, using an image sensor, image frames of the working surface through the first bottom surface; and   switching to a second mode when identifying that the second bottom surface contacts with the working surface and capturing, using the image sensor, image frames of the working surface through the first bottom surface.   
     
     
         16 . The mode switching method as claimed in  claim 15 , wherein the process unit determines whether the first bottom surface or the second bottom surface contacts with the working surface according to an image feature of an image frame associated with the working surface. 
     
     
         17 . The mode switching method as claimed in  claim 16 , wherein the image feature comprises an intensity distribution ratio, an image brightness value or an image quality. 
     
     
         18 . The mode switching method as claimed in  claim 17 , wherein the first mode is entered when the intensity distribution ratio is larger than a ratio threshold, the image brightness value is larger than a brightness threshold or the image quality is larger than a quality threshold; the second mode is entered when the intensity distribution ratio is within a ratio threshold range, the image brightness value is within a brightness threshold range or the image quality is within a quality threshold range; and the ratio threshold range, the brightness threshold range and the quality threshold range are respectively smaller than the ratio threshold, the brightness threshold and the quality threshold. 
     
     
         19 . The mode switching method as claimed in  claim 15 , wherein the process unit determines whether the first bottom surface or the second bottom surface contacts with the working surface according to a detect signal of a gyroscope, an accelerometer or a switching element. 
     
     
         20 . The mode switching method as claimed in  claim 15 , further comprising:
 calculating, using the process unit, a displacement according to image frames of the working surface captured by the image sensor through the first bottom surface, wherein the first mode is configured to control a cursor movement according to the displacement and the second mode is configured to perform a gesture operation according to the displacement.