Hinges for electronic instrument and the electronic instrument using this hinges

This invention is related to a hinge for an electronic instrument and an electronic instrument using this hinges. In an electronic instrument having a first part 1 and a second part that are connected in an open/close manner, a hinge for controlling opening/closing of the first and second parts are provided, such that by pushing a pushbutton installed on the hinge portions mounted on the first and second parts, the first and second parts are locked to a closing state which may be released. By opening the pushbutton, the first and second parts may be automatically opened to an operative angle under which a single hand is required to open the electronic instrument to any angle within the full range so as to open the electronic instrument to an operative angle. The operator may use hands to randomly stop at any desired angle within the range from an open angle to a manually locking state, and the range from an automatically opening angle to a fully open angle.