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A mouse is a device for determining distance coordinates for a computer system, where the coordinates represent the position of a cursor on the screen of a display unit of the computer system. A computer mouse is a handheld device that a user slides over a suitable surface causing the cursor on a computer screen to move in a direction determined by the motion of the device. The use of a hand operated pointing device for use with a computer and its display has become almost universal. To a personal computer user, the mouse is one of the basic devices utilized to input data into the PC, the other being the keyboard. Computer mice are often referred to as cursor positioning devices or cursor control devices, although mice are utilized to perform many other functions, such as to launch applications, re-size and move windows, drag, open and drop documents, select icons, text, menu items in a pull-down menu, and others. In a mechanical mouse, forward and backward and lateral motion of a roller ball over a pad having sufficient friction to assure rotation of the ball is converted by a mechanical mechanism into x and y equivalent mechanical translations. The mechanical translations are then converted into proportional x and y electrical signals which are fed by a cable to the display unit to serve as cursor-positioning input signals for the display. A conventional mechanical mouse generally employs a rolling ball and at least two encoder wheels for x- and y-axis. Centrally located within the bottom surface of the mouse is a hole through which a portion of the underside of a rubber-surfaced steel ball extends. The encoder wheels are driven by the roll ball when a user moves the mouse along a flat surface such as a mouse pad. The encoder wheels will intermittently block a light propagation in the mouse and associated electronic signal is generated to control cursor movement on a computer display. The mouse pad is typically a closed cell foam rubber pad covered with a suitable fabric. The rubber ball rolls over the fabric as the mouse is moved. The user moves the mouse as necessary to get the displayed pointer to a desired location or position. The track ball is rotated when the mouse moves on the fixture surface. The rotation of the track ball is converted into electrical signal that is transmitted through an electrical cable soldered to the circuit board to a host computer. However, the performance of the mechanical mouse is degraded after a long time use due to ball abrasion and dust inleakage. Mechanical mouse devices incorporate moving parts that can wear out. The roller ball mechanism also requires periodic cleaning to remove accumulated dirt and to prevent internal malfunctioning. To overcome those drawbacks, an optical mouse is provided and has a light transmitter such as light emitting diode (LED), light receiver such as a photo diode and associated components.An optical mouse is designed to detect movement of an image carried in light reflected from a mouse pad having the image thereon and received therein, thereby causing a cursor on an associated display screen to be moved in accordance with the movement of the mouse, and to enable several functional signals to be inputted to a computer system by clicking of buttons equipped thereon. An optical mouse is adapted to cause a cursor on a display screen to be moved, by optically detecting its own motion, converting the detected value to an electrical signal, and sending the signal to a computer. An optical mouse provides precise detection of a movement of user's hand and its smooth movement, compared with a conventional ball mouse, thus its use increasing more and more. Since such an optical mouse has advantages of the accuracy of its motion detection, and smoothness in its motion, as compared with the conventional ball-type mouse, its use is gradually increasing. An optical mouse has an image sensor for sensing an image of a motion and outputting the resulting image signal, a light source for illuminating a surface, a lens for focusing light reflected from the surface onto the optical sensor, an A/D converter for converting the image signal from the image sensor into digital data, an image processor for performing a signal processing operation for the digital data from the A/D converter to detect the motion therefrom, and a controller for providing data corresponding to the detected motion to a computer. The optical mouse comprises a bottom casing and a top cover attached to the bottom casing with a circuit board fixed between the casing and the cover. An illuminating element, such as a light emitting diode (LED), is mounted to the circuit board for projecting a light beam through an opening defined in the bottom casing. The optical mouse is operated by reflecting light emitted from the main body of the optical mouse from a touching object (for example, a mouse pad), thus, enabling the movement of the mouse on the pad to be detected and enabling a cursor on a computer monitor to be moved. As the optical mouse is moved relative to the surface, it acquires a series of images of the surface. The optical mouse determines its own position relative to the surface by comparing the differences between consecutive images. Such an optical mouse optically recognizes its movement on the touching object, converts the recognized value to an electric signal, transmits the electric signal to the computer, and thereby the position of the cursor on the monitor can be recognized. |
Electronics Information 