Hand held pen-size calculator

Claim 1

A hand held calculator comprising: an elongated hollow body; an elongated support extending lengthwise and resiliently mounted in the body, said support having a writing head mounted at one end thereof and an indicating means at its other end; an elongated barrel slidably mounted about said support, said barrel being pivotably fixed to said body at two opposite points for defining a pivot axis such that the barrel is capable of pivotal movement about said pivot axis; a character transducer located in the body for detecting the sense of movement of the writing head across the writing surface as a character is being written on said writing surface and for generating a sequence of signals representing said character, said transducer comprising first detecting means mounted on the body in axial alignment with the support so as to cooperate with said indicating means on the support for generating a first signal in response to the support being moved axially with respect to the body, second and third detecting means mounted on the body along a transverse axis perpendicular to said pivot axis for detecting the pivotal movement of said barrel about the pivot axis, said second detecting means being operative to generate a second signal indicating the pivotal movement in a first sense, and said third detecting means being operative to generate a third signal indicating the pivotal movement in the opposite sense; logic means responsive to said first, second and third signals to generate a fourth signal representing the combination of distinct states of said first, second and third signals, buffer store means for temporarily storing said fourth signal, reference store means for storing signals each representing a distinct written character, comparator means connected to accept the content of said buffer means, compare it to each signal from the reference store means and generate a distinct identification signal when the signal from the buffer means is identical to a signal from the reference store means; and a calculating unit mounted on the body, said calculating unit having a display area.