Tape program location method and means

Claim 2

In a control system for a tape reader having a reading hed and having a transporting mechanism which provides transport of a tape in the forward and reverse directions and further includes a rotatable member of the kind that rotates in a forward motion when the tape is transported forwardly past said head and that rotates in the reverse direction when the tape is transported in the reverse said direction past said head and that does not rotate when the tape is not being transported past said head, the improvement which comprises: means responsive to rotation of said rotatable member in both directions for developing an algebraic count indicative of the resultant number of times that said rotatable member has revolved in one direction; means for comparing a reference count with said algebraic count and for providing a difference signal which indicates whether the counts are equal, whether the algebraic count is greater than the reference count, and whether the algebraic count is less than the reference count; and means responsive to said difference signal for causing said transporting mechanism to transport said tape until said difference signal indicates that said counts are equal.

Claim 3

The invention defined in claim 1 which further comprises: reference means for developing a reference count; and means sensitive to output signals of a given character from said head for causing said reference count means to develop a given reference count.

Claim 4

The invention defined in claim 2 in which said means sensitive to output signals of a given character from said head further comprises means for causing said transport mechanism to drive said rotatable member until the algebraic count equals said given reference count.

Claim 5

The invention defined in claim 2 in which said means sensitive to output signals of a given character from said head further comprises means for causing the algebraic count to correspond to said given reference count.

Claim 6

The invention defined in claim 1 in which said means responsive to said rotation of said rotational member for developing an algebraic count comprises a mirror carried by said rotatable member; a source of light directed towards said rotatable mirror; and a light sensor positioned to receive light from said source by reflection from said mirror when the mirror occupies a position within a given range of angular positions as an incident of rotation of said rotatable member.

Claim 7

The invention defined in claim 5 in which said means responsive to rotation of said rotatable member for developing an albegraic count further comprises a second means sensitive to light from said source after reflection from said mirror and positioned to receive reflected light when said mirror occupies a different range of angular positions as an incident to rotation of said rotatable member; said means responsive to rotation of said rotatable member for developing an algebraic count being effective to increase the count when reflected light is received first by said first light means for receiving reflected light and they by said second means for receiving reflected light; said means responsive to rotation of said rotatable member for developing an algebraic count being effective to decrease the count when reflected light is received first by said second means for receiving reflected light and thereafter by said first means for receiving said reflected light.

Claim 8

In a tape transport system which provides transport of a tape in the forward and reverse directions and further includes a member that rotates in one direction as the tape is advanced and which rotates in an opposite direction when the tape is reversed and which does not rotate when the tape is not being transported, the improvement which comprises: a mirror carried by said rotating member; light means for directing a beam of light upon said rotating member such that it impinges upon and is reflected by said mirror when the mirror moves through a given segment of rotation; first light sensing means positioned to receive light from said light means after reflection from said mirror when said mirror moves through one portion of said segment of rotation to provide a signal responsive to illumination; and a second light sensing means positioned to receive light from said light means after reflection from said mirror, when said mirror moves through a portion of said segment different from said one portion to provide a signal responsive to illumination; and direction logic means responsive to said signals from said first and second light sensing means for distinguishing whether the tape is being transported in the forward or the reverse direction.

Claim 9

In a tape transport system which provides transport of a tape in the forward and reverse directions and further includes a member that rotates in one direction as the tape is advanced and which rotates in an opposite direction when the tape is reversed and which does not rotate when the tape is not being transported, the improvement which comprises: a mirror carried by said rotating member; light means for directing a beam of light upon said rotating member such that it impinges upon and is reflected by said mirror when the mirror moves through a given segment of rotation; first light sensing means positioned to receive light from said light means after reflection from said mirror when said mirror moves through one portion of said segment of rotation to provide a signal responsive to illumination; and a second light sensing means positioned to receive light from said light means after reflection from said mirror, when said mirror moves through a portion of said segment different from said one portion to provide a signal responsive to illumination; and direction logic means responsive to said signals from said first and second light sensing means for distinguishing whether the tape is being transported in the forward or the reverse direction.

Claim 10

The invention defined in claim 7 in which said first and second light sensing means comprise first and second light sensitive cells that provide an electrical signal responsive to being illuminated, said first and second cells being disposed on opposite sides of said light means; said mirror extending over a sufficiently long distance such that light is reflected first to one cell and then to both cells and finally to said second cell during the course of rotation of said rotatable member whereby a signal is furnished by both cells simultaneously for one period and by one or the other of said cells prior to that period and by the other of said cells following said period whereby to provide a signal to said direction logic means to distinguish whether the tape is being transported in the forward or the reverse direction.