Abstract: A mark-erasable pen cap comprises a cap body having a containing groove. The cap body is made of an elastic erasing material and defines a first end and an opposing second end. The first end has an opening. The containing groove comprises a bottom portion, an opening portion, and a wall portion. The bottom portion neighboring to the first end has a first diameter; the opening portion located at the second end has a second diameter smaller than the first diameter; and the wall portion connecting the bottom portion and the opening portion has an inner diameter substantially tapered from the opening portion to the bottom portion.

Abstract: A key structure, which comprises a key cap, a linkage mechanism, a fixed base, a resilient assembly and a membrane circuit board, of a computer keyboard is provided, The key cap has a top and a bottom. The fixed base, formed with a receiving space, has a top and a bottom. The linkage mechanism is disposed between the key cap and the fixed base. The resilient assembly fits into the receiving space of the fixed base and connected to the bottom of the key cap. The membrane circuit board is disposed on the bottom of the fixed base and located under the resilient assembly.

Abstract: A foldable mouse is disclosed. The foldable mouse includes a mouse body, a support portion, and a pivoting portion for connecting the support portion and the mouse body. The mouse body has a hollow surface and a sensing surface neighboring the hollow surface. The sensing surface is in contact with a reflection plane, and the hollow surface forms a cavity on the mouse body. The support portion can be contained in the cavity.

Abstract: A key structure, which comprises a key cap, a linkage mechanism, a fixed base, a resilient assembly and a membrane circuit board, of a computer keyboard is provided, The key cap has a top and a bottom. The fixed base, formed with a receiving space, has a top and a bottom. The linkage mechanism is disposed between the key cap and the fixed base. The resilient assembly fits into the receiving space of the fixed base and connected to the bottom of the key cap. The membrane circuit board is disposed on the bottom of the fixed base and located under the resilient assembly.

Abstract: An illuminated keyboard with illuminated figures being formed on the top surface of the keyboard including: a top cover, a bottom cover, a plurality of keys and an electroluminescent board. The top cover accommodates the keys and is combined with the bottom cover. The electroluminescent board is installed between the top cover and the bottom cover. The electroluminescent board includes at least one figured pattern to be displayed on a top surface of the keyboard on the top cover when the electroluminescent board is electrified to give light.

Abstract: A building blocks type writing instrument having a plurality of writing units, each of which is provided with a pencil lead at its front end, and at least one coupling unit engaged insertedly axially with each other in series. The writing units is formed having the front end provided with a tubular projection for insertion of pencil lead and the rear end with an insertion hole for insertion and engagement of the tubular projection at the front end, and on the outer circumferential surface at least one engaging projection at least one coupling groove corresponding to the engaging projection for engagement side by side transversely of another writing unit by corresponding engaging groove and projection. The coupling unit has a tubular body with front end and the lower portion provided on the two back to back lateral sides each cross shape coupling unit for cross engagement of the writing units. As one with a tubular projection corresponding to that of the writing unit.