Abstract: The main structure of a keyboard of PDA includes a case, a key set, function keys, a circuit board, and a PDA support frame. The device is characterized in that the case opens to the left and to the right and is a rectangle that contains the key set. The key set has two parts fitted at the bottom of the case and on the inner side of the cover respectively. One of the parts can slide inside the case to integrate with the other part for easy operation. They can also be folded so that the case becomes smaller and convenient for carrying.

Abstract: An external keyboard for PDAs includes first and second sections hinged together. The keyboard is adapted for electrically connected with a PDA (Personal Digital Assistant) device and then serving as an inputting device for the connected PDA. A PDA device supporting bracket is built-in the keyboard for easy install a PDA device thereon for easy operation of the PDA. The supporting bracket further includes an anchoring leg such that the supporting bracket can be firmly positioned in an inclined position. Accordingly, a screen of the PDA device can be easily read. The PDA supporting bracket can be readily stored within the keyboard when the first and second sections are folded together.

Abstract: An encoding device in which signals generated thereof can be efficiently propagated comprises a housing and a tracing ball rotatably arranged on said housing. An encoding assembly including a pair of encoding wheels is mechanically arranged adjacent to said tracing ball and driven by said tracing ball. Pairs of light emitters and receivers are arranged respectively to each encoding wheel. A gearing including first and second gears is arranged between the tracing ball and the encoding assembly. The teeth number of the first gear is smaller than the second gear, such that the rotations of the encoding wheel can be considerably increased.

Abstract: A furniture device includes two or more plates and two or more panels and one or more boards each having a number of ribs for forming a number of openings. The plates each includes four corner blocks each having a number of helical fins for engaging with fasteners and for allowing the plates and the panels to be assembled together without being damaged. The plates each has a rear side portion having one or more grooves for engaging with the board and for allowing the boards to be secured between the plates without engaging with fasteners.