TABLE 89.1 List of Input Devices Category Operation Mode Keyboard Alphanumeric Electromechanical Electromechanical Pen tablet Tablet pointing Coordinates Coordinates Curson Verbal Conversion Data Ep, Eb 网日 圖圖圖圖 FIGURE 89.1 (a)Generalized display-system block diagram. Source: After S Sherr, Electronic Displays, New York: John wiley Sons, 1979. with permission. ) (b) Alphanumeric keyboard. Courtesy of Key tronic. TABLE 89. 2 board Parameter values Parameter Snap Switch Elastomer Foam pad 3.2m 8 mm 10 million cycles 10 million cycles on cycles Feedback Audio mechanical Audio electric e 2000 by CRC Press LLC© 2000 by CRC Press LLC TABLE 89.1 List of Input Devices Category Designation Operation Mode Keyboard Alphanumeric Electromechanical Keyboard Function Electromechanical Pointing Light pen Screen pointing Pointing Touchscreen Screen pointing Pointing Pen tablet Tablet pointing Coordinates Digitizer X-Y conversion Coordinates Data tablet X-Y location Cursor Mouse Movement Cursor Trackball Movement Cursor Joystick Movement Image Scanner Conversion Verbal Voice Conversion FIGURE 89.1 (a) Generalized display-system block diagram. (Source: After S. Sherr, Electronic Displays, New York: John Wiley & Sons, 1979.With permission.) (b) Alphanumeric keyboard. (Courtesy of Key tronic.) TABLE 89.2 Keyboard Parameter Values Parameter Snap Switch Elastomer Foam Pad Key travel 3.8 mm 3.2 mm 3.8 mm Force >60 gm >50 gm >30 gm Life 10 million cycles 10 million cycles 10 million cycles Feedback Audio mechanical Audio electric Tactile