Abstract: A tapping detection method of an optical navigation module is disclosed. The module includes an optical sensor and a processor. The method includes steps of calculating a displacement quantity of an object contacting with the optical navigation module according to a sense image sensed by the optical sensor, and comparing the displacement quantity with a displacement threshold value. When the displacement quantity is smaller than the displacement threshold value, the method further includes steps of calculating a brightness difference value of the sense image, and comparing the brightness difference value with a brightness threshold value. When the brightness difference value is smaller than the brightness threshold value, the optical navigation module may be determined to be tapped by the object.

Abstract: A detection method of an optical navigation device is disclosed. The device is used for determining whether an object is lifted from the optical navigation device or not. The method includes steps of reading the detection image detected by the optical navigation device, calculating the image signal value thereof during non-lift status, and integrating a historical threshold value with the image signal value according to adaptive factors for generating an adjustment threshold value serving as the navigation threshold of the detection image. The historical threshold value is the navigation threshold of a former detection image of the detection image. A step of comparing the adjustment threshold with the image signal value for determining whether the image signal value passes the navigation threshold or not may also be included. If the image signal value does not pass the navigation threshold, the object is determined as in the lift status.

Abstract: In one embodiment, a surface is navigated by 1) using a first light sensor, mounted to a navigation device, to detect light reflected from a surface, and 2) using outputs of the first light sensor, over time, to determine relative movement of the navigation device with respect to the surface. While using the first light sensor, it is determined whether the outputs of the first light sensor, over time, are indicating movement of the navigation device with respect to the surface. If not, 1) a second light sensor that is mounted to the navigation device, and of a different type than the first light sensor, is used to detect light reflected from the surface, and 2) outputs of the second light sensor, over time, are used to determine relative movement of the navigation device with respect to the surface.

Abstract: A technique for relative velocity determination between a surface and a velocity determination system involves capturing a set of outputs from a first photosensor array and then comparing subsequently captured sets of outputs from a second photosensor array to the set of outputs from the first photosensor array until a satisfactory match is found between the outputs. Once a satisfactory match is found, the elapsed time between the capture of the two sets of outputs represents the time to travel the known separation distance between the two photosensor arrays. Given the known distance of travel and the elapsed time to travel the distance, the relative velocity is a simple calculation of the distance traveled divided by the time to travel the distance.

Abstract: A technique for relative velocity determination between a surface and a velocity determination system involves capturing a set of outputs from a first photosensor array and then comparing subsequently captured sets of outputs from a second photosensor array to the set of outputs from the first photosensor array until a satisfactory match is found between the outputs. Once a satisfactory match is found, the elapsed time between the capture of the two sets of outputs represents the time to travel the known separation distance between the two photosensor arrays. Given the known distance of travel and the elapsed time to travel the distance, the relative velocity is a simple calculation of the distance traveled divided by the time to travel the distance.

Abstract: In one embodiment, a surface is navigated by 1) using a first light sensor, mounted to a navigation device, to detect light reflected from a surface, and 2) using outputs of the first light sensor, over time, to determine relative movement of the navigation device with respect to the surface. While using the first light sensor, it is determined whether the outputs of the first light sensor, over time, are indicating movement of the navigation device with respect to the surface. If not, 1) a second light sensor that is mounted to the navigation device, and of a different type than the first light sensor, is used to detect light reflected from the surface, and 2) outputs of the second light sensor, over time, are used to determine relative movement of the navigation device with respect to the surface.

Abstract: An encoder for measuring the position of a rotating shaft is disclosed. The encoder includes a drum having an encoding track thereon and a detector module having a light source and a photodetector. The drum includes a cylindrical surface characterized by an axis, the drum having a surface with a normal perpendicular to the axis. The encoding track includes a plurality of alternating reflective and non-reflective stripes arranged on the cylindrical surface. The first light source illuminates the stripes at an opaque angle relative to the normal. The first photodetector is positioned to receive light from the light source that is reflected from the reflective stripes when the drum moves relative to the photodetector. In one embodiment, the drum rotates about the axis when the shaft rotates. The encoding track can be either on the inside or outside of the drum.

Abstract: An encoder for measuring the position of a rotating shaft is disclosed. The encoder includes a drum having an encoding track thereon and a detector module having a light source and a photodetector. The drum includes a cylindrical surface characterized by an axis, the drum having a surface with a normal perpendicular to the axis. The encoding track includes a plurality of alternating reflective and non-reflective stripes arranged on the cylindrical surface. The first light source illuminates the stripes at an opaque angle relative to the normal. The first photodetector is positioned to receive light from the light source that is reflected from the reflective stripes when the drum moves relative to the photodetector. In one embodiment, the drum rotates about the axis when the shaft rotates. The encoding track can be either on the inside or outside of the drum.