Abstract: A key switch is provided which includes a key top which is pressed down by optional force and which can move in the press-down direction. The key switch also includes a spring for generating a rebound according to the optional force applied to the key top. The key switch also includes a housing having an elastic member which generates the press-down force against the rebound according to a distance by which the key top moves. The key switch realizes the press-down characteristics in which the inclination of the rebound is zero or negative.

Abstract: A keyboard includes a keyboard body, a plurality of keys arranged in rows and columns, and switching elements for turning switching elements ON and OFF in response to operations on the plurality of keys. A special key among the plurality of keys has a keytop which is at least a stroke length of the special key higher than keytops of keys arranged in a row in which the special key is located.

Abstract: A keyboard includes a keyboard body, a plurality of keys arranged in rows and columns, and switching elements for turning switching elements ON and OFF in response to operations on the plurality of keys. A special key among the plurality of keys has a keytop which is at least a stroke length of the special key higher than keytops of keys arranged in a row in which the special key is located.

Abstract: A key touch adjusting device wherein the position of a key top is detected, and a resistive force corresponding to that position is generated and applied to the key top. The numeral array for the position data and the force data is stored in a memory. To apply hysteresis to a key force profile curve, a RS flip-flop whose output is inverted by the position data is provided to generate different resistive forces in the key top depressing process and the key top returning process. Also disclosed are a method of comparing an actually obtained profile curve with a predetermined profile curve on a display device by detecting both the position of the key top and the depressing force thereof, a method of achieving hysteresis characteristics by storing a plurality of numeral arrays of the depressing force vs.

Abstract: A portable data processing apparatus such as a personal computer comprising in series a base portion, a top cover portion, a display housing portion, and a keyboard portion. These portions are pivotally connected one after another by first, second and third hinge means, respectively. The first, second and third hinge means are parallel to each other, so that the apparatus can adopt a spread position in which the keyboard portion and the display housing portion are spread to the front and a retracted position in which the keyboard portion overlaps the display housing portion. The top cover portion, the display housing portion, the keyboard portion, and the base portion are folded in a face-to-face relationship in the retracted position.

Abstract: An electronic mail processing device includes a magnetic disk with a control table. The device establishes a line between an originating terminal and a destination terminal designated by the originating terminal as a destination of electronic mail information and enters the destination into the control table provided on the magnetic disk as a wrong destination when the destination terminal performs no prescribed response operation to receive the electronic mail information. No electronic mail information is delivered to any of destinations entered into the control table. Thereby, once a destination is stored in the control table, a line is never connected to the destination terminal again, which prevents repeated wrong calls from being made to the same terminal.