System for reading coded information from punched cards with automatic error detection and correction

Claim 2

In a system for reading a medium having coded information punched therein and detecting and correcting errors thereof, the combination comprising: a first and a second reading means for producing a first type of signal when said reading means senses a hole in the medium and a second type of signal when said reading means senses an absence of a hole; a signal timing means coupled to said first and second reading means for producing a third signal for a predetermined time upon receiving said first type of signal; a first signal controlling means coupled to said signal timing means and to said first reading means for generating a fourth signal upon the concurrence of said first signal and said third signal; a second signal controlling means coupled to said signal timing means and to said second reading means for generating a fifth signal upon the concurrence of said first signal and said third signal; bistable means coupled to said first signal controlling means for producing a set and reset signal representative of said fourth signal; and means for comparing the state of said bistable means and said fifth signal for detecting and correcting errors in the reading of coded information punched in said medium.

Claim 3

A system as described in claim 1 wherein said means coupled to said signal controlling means for periodically providing a fourth signal comprises a timing generator for generating said fourth signal.

Claim 4

A system as described in claim 1 wherein said signal timing means comprises a monostable multivibrator.

Claim 5

In a system for reading a medium having coded information punched therein and employing reading means for sequentially twice sensing the presence and absence of holes in said medium and for delivering a first type of signal when said sensing means reads a hole and a second type of signal when said sensing means reads the absence of a hole, the combination comprising: a pair of storage means each coupled to receive said first type of signal for assuming a first state, one of said storage means receiving signals representative of the information first sensed by said reading means and the other of said storage means sequenTially receiving signals representative of the information sensed the second time by said reading means, a pair of signal timing means, a first one of said timing means being coupled to receive the signals representative of the information first sensed by said reading means and the second one of said timing means being coupled to receive the signals representative of the information sensed by the second reading of said information, each of said timing means upon receipt of said first type of signal delivering a third signal for a predetermined time, and a pair of signal controlling means, one of said signal controlling means being coupled to receive said first type of signal from said reading means representative of the first reading of said information and the other of said signal controlling means being coupled to receive said first type of signal representative of the second reading of said information, said one of said signal controlling means upon the concurrence of said first type of signal from said reading means and said third signal from either of said timing means causing said one of said storage means to assume said first state.

Claim 6

In a system for reading a medium having coded information punched therein and employing reading means for sequentially twice sensing the presence and absence of holes in said medium and for delivering a first type of signal when said sensing means reads a hole and a second type of signal when said sensing means reads the absence of a hole, the combination comprising: a pair of storage means each coupled to receive said first type of signal for assuming a first state, one of said storage means receiving signals representative of the information first sensed by said reading means and the other of said storage means sequenTially receiving signals representative of the information sensed the second time by said reading means, a pair of signal timing means, a first one of said timing means being coupled to receive the signals representative of the information first sensed by said reading means and the second one of said timing means being coupled to receive the signals representative of the information sensed by the second reading of said information, each of said timing means upon receipt of said first type of signal delivering a third signal for a predetermined time, and a pair of signal controlling means, one of said signal controlling means being coupled to receive said first type of signal from said reading means representative of the first reading of said information and the other of said signal controlling means being coupled to receive said first type of signal representative of the second reading of said information, said one of said signal controlling means upon the concurrence of said first type of signal from said reading means and said third signal from either of said timing means causing said one of said storage means to assume said first state.

Claim 7

A system as described in claim 4 wherein each of said signal timing means comprises a monostable multivibrator.

Claim 8

In a system for reading a medium having coded information punched therein and employing reading means for sequentially twice sensing the presence and absence of holes in said medium and for delivering a first type of signal when said reading means senses a hole and a second type of signal when said reading means senses the absence of a hole, the combination comprising: a pair of storage means each coupled to receive said first type of signal for assuming a first state, one of said storage means receiving signals representative of the information first sensed by said reading means and the other of said storage means sequentially receiving signals representative of the information sensed the second time by said reading means, pair of signal timing means, a first one of said timing means being coupled to receive the signals representative of the information first sensed by said reading means and the second one of said timing means being coupled to receive the signals representative of the information sensed by the second reading of said information, each of said timing means upon receipt of said first type of signal delivering a third signal for a predetermined time, and a pair of signal controlling means, one of said signal controlling means being coupled to receive said first type of signal from said reading means representative of the first reading of said information and the other of said signal controlling means being coupled to receive said first type of signal representative of the second reading of said information, each of said signal controlling means upon the receipt and concurrence of said first type of signal from said reading means and said third signal from either of said timing means causing a different one of said storage means to assume said first state.

Claim 9

In a system for reading a medium having coded information punched therein and employing reading means for sequentially twice sensing the presence and absence of holes in said medium and for delivering a first type of signal when said reading means senses a hole and a second type of signal when said reading means senses the absence of a hole, the combination comprising: a pair of storage means each coupled to receive said first type of signal for assuming a first state, one of said storage means receiving signals representative of the information first sensed by said reading means and the other of said storage means sequentially receiving signals representative of the information sensed the second time by said reading means, pair of signal timing means, a first one of said timing means being coupled to receive the signals representative of the information first sensed by said reading means and the second one of said timing means being coupled to receive the signals representative of the information sensed by the second reading of said information, each of said timing means upon receipt of said first type of signal delivering a third signal for a predetermined time, and a pair of signal controlling means, one of said signal controlling means being coupled to receive said first type of signal from said reading means representative of the first reading of said information and the other of said signal controlling means being coupled to receive said first type of signal representative of the second reading of said information, each of said signal controlling means upon the receipt and concurrence of said first type of signal from said reading means and said third signal from either of said timing means causing a different one of said storage means to assume said first state.

Claim 10

A system as described in claim 6 wherein each of said signal timing means comprises a monostable multivibrator.

Claim 11

A system as described in claim 6, in further combination with error detection means coupled to said pair of storage means for indicating the storage status of the dual reading of the information.

Claim 12

In a system for reading a medium having coded information punched therein and employing reading means for sequentially twice sensing the presence and absence of holes in said medium and for delivering a first type of signal when said reading means senses a hole and a second type of signal when said reading means senses the absence of a hole, the combination comprising: a pair of storage means each coupled to receive said first type of signal for assuming a first state, one of said storage means receiving signals representative of the information first sensed by said reading means and the other of said storage means sequentially receIving signals representative of the information sensed the second time by said reading means, a pair of signal timing means, a first one of said timing means being coupled to receive the signals representative of the information first sensed by said reading means and the second one of said timing means being coupled to receive the signals representative of the information sensed by the second reading of said information, each of said timing means upon receipt of said first type of signal delivering a third signal for a predetermined time, a pair of signal controlling means, one of said signal controlling means being coupled to receive said first type of signal from said reading means representative of the first reading of said information and the other of said signal controlling means being coupled to receive said first type of signal representative of the second reading of said information, each of said signal controlling means upon the receipt and concurrence of said first type of signal from said reading means and said third signal from either of said timing means causing a different one of said storage means to assume said first state, a third storage means coupled to said first storage means for periodically assuming the storage condition of said first storage means, and error detection means coupled to said second and third storage means for producing an error signal when the storage conditions of said second and third storage means are different.

Claim 13

In a system for reading a medium having coded information punched therein and employing reading means for sequentially twice sensing the presence and absence of holes in said medium and for delivering a first type of signal when said reading means senses a hole and a second type of signal when said reading means senses the absence of a hole, the combination comprising: a pair of storage means each coupled to receive said first type of signal for assuming a first state, one of said storage means receiving signals representative of the information first sensed by said reading means and the other of said storage means sequentially receIving signals representative of the information sensed the second time by said reading means, a pair of signal timing means, a first one of said timing means being coupled to receive the signals representative of the information first sensed by said reading means and the second one of said timing means being coupled to receive the signals representative of the information sensed by the second reading of said information, each of said timing means upon receipt of said first type of signal delivering a third signal for a predetermined time, a pair of signal controlling means, one of said signal controlling means being coupled to receive said first type of signal from said reading means representative of the first reading of said information and the other of said signal controlling means being coupled to receive said first type of signal representative of the second reading of said information, each of said signal controlling means upon the receipt and concurrence of said first type of signal from said reading means and said third signal from either of said timing means causing a different one of said storage means to assume said first state, a third storage means coupled to said first storage means for periodically assuming the storage condition of said first storage means, and error detection means coupled to said second and third storage means for producing an error signal when the storage conditions of said second and third storage means are different.