Automatic erasing typewriter system

Claim 2

In a system including a typewriter having means for printing visible symbols at a print point on a page, means for moving said print point to ordered print positions along a line of the page, including backspace means for moving said print point incrementally to immediately adjacent lower order print positions, a keyboard that is manipulated to control said symbol printing and print point moving means, signal output means for transmitting signals representative of tYpewriter operations, signal input means for receiving control signals for causing operations of said typewriter, and selectively operable symbol erase mechanism operable in response to ERASE command signals, the improvement comprising: a memory capable of storing a plurality of symbol information identifying bytes each corresponding with an individual print position on a line of the page and each being at least capable of identifying the symbol intended to appear in the corresponding print position, queuing means for identifying individual ones of said bytes in said memory in accordance with the order of print positions with which said bytes correspond, keystroke recording control means responsive to manipulation of said keyboard and to said queuing means for writing a byte of symbol identifying information into said memory and ordered therein in accordance with its corresponding print position, manually operable selection means including means to initiate an erase sequence erase sequence control means responsive to said erase sequence initiation for producing erase control operations and comprising: signal generating means for issuing next ERASE command signals to said typewriter, and erase sequence repeating means operating following each erase control operation to cause operation of said typewriter backspace means, and producing a further one of said erase control operations.

Claim 3

A system as defined in claim 1 having the further improvement comprising: said erase sequence control means further including erase sequence terminating means including means for detecting the completion of the erasure of all characters within a single word unit, and means responsive to said completion detecting means for inhibiting further operation of said erase sequence repeating means.

Claim 4

A system as defined in claim 1 having the further improvement comprising: said erase sequence control means further including erase sequence terminating means including means for detecting the completion of the erasure of all characters within a single line unit, and means responsive to said completion detecting means for inhibiting further operation of said erase sequence repeating means.

Claim 5

A system as defined in claim 1 wherein the improvement further comprises: said selection means including mode selecting means having a first state for defining an erase sequence of ''''character'''' length and a second state for defining an erase sequence of ''''word'''' length. said erase sequence control means further comprising erase sequence terminating means including first detecting means for detecting the completion of the erasure of a single character, second detecting means for detecting the completion of the erasure of all characters within a single word unit, and means responsive to said further mode selecting means and to said first and second detecting means for inhibiting further operation of said erase sequence repeating means upon the completion of the erasure of a single character when said further mode selecting means defines a ''''character'''' length erase sequence and upon completion of the erasure of all characters within a single word unit when said further mode selecting means defines a ''''word'''' length erase sequence.

Claim 6

A system as defined in claim 1 wherein the improvement further comprises: said selection means including mode selecting means having a first state for defining an erase sequence of ''''character'''' length and a second state for defining erase sequence of ''''word'''' length and a third state for defining an erase sequence of ''''line'''' length, said erase sequence control means further comprising erase sequence terminating means including first detecting means for detecting the completion of the erasure of a single character, second detecting means for detecting the completion of the erasure of all characters within a single word unit, third detecting means for detecting the completion of tHe erasure of all characters within a single line unit and means responsive to said mode selecting means and to said first, second and third detecting means for inhibiting further operation of said erase sequence repeating means upon the completion of the erasure of a single character when said mode selecting means defines a ''''character'''' length erase sequence, upon completion of the erasure of all characters within a single ''''word'''' unit when said mode selecting means defines a ''''word'''' length erase sequence, and upon completion of the erase of all characters within a single line unit when said mode selecting means defines a ''''line'''' length erase sequence.

Claim 7

In a system including a typewriter having means for printing visible symbols at a print point on a page, means for moving said print point to ordered print positions along a line of the page, a keyboard that is manipulatable to control said symbol printing and print point moving means, signal output means for transmitting signals representative of typewriter operations, signal input means for receiving control signals for causing operations of said typewriter, and selectively operable symbol erase mechanism operable in response to ERASE command signals, the improvement comprising: a memory capable of storing a plurality of symbol information identifying bytes, each corresponding with an individual print position on a line of the page and each being at least capable of identifying (i) whether it contains useful information, (ii) the symbol intended to appear in the corresponding print position, and (iii) whether the symbol intended to appear in the corresponding print position currently appears, queuing means for identifying individual ones of said bytes in said memory in accordance with the order of print positions with which said bytes correspond, keystroke recording control means responsive to manipulation of said keyboard and to said queuing means for writing a byte of symbol identifying information into said memory and ordered therein in accordance with its corresponding print position, manually operable selection means including means to initiate an erase sequence and mode control means settable to define either an ''''erase only'''' operation or an ''''erase and delete'''' operation of said erase sequence, and erase sequence control means responsive to said erase sequence initiation for producing erase control operations and comprising: signal generating means for issuing said ERASE command signals to said typewriter, and memory writing means responsive to said mode control means for selectively writing into the byte identified by said queuing means as corresponding with the relative print position from which said erase mechanism erases a symbol in response to issuance of said ERASE command, ''''symbol not appear'''' if said ''''erase only'''' operation has been defined or ''''no significant information'''' if said ''''erase and delet'''' operation has been defined.

Claim 8

In a system including a typewriter having means for printing visible symbols at a print point on a page, means for moving said print point to ordered print positions along a line of the page, a keyboard that is manipulatable to control said symbol printing and print point moving means, signal output means for transmitting signals representative of typewriter operations, signal input means for receiving control signals for causing operations of said typewriter, and selectively operable symbol erase mechanism operable in response to ERASE command signals, the improvement comprising: a memory capable of storing a plurality of symbol information identifying bytes, each corresponding with an individual print position on a line of the page and each being at least capable of identifying (i) whether it contains useful information, (ii) the symbol intended to appear in the corresponding print position, and (iii) whether the symbol intended to appear in the corresponding print position currently appears, queuing means for identifying individual ones of said bytes in said memory in accordance with the order of print positions with which said bytes correspond, keystroke recording control means responsive to manipulation of said keyboard and to said queuing means for writing a byte of symbol identifying information into said memory and ordered therein in accordance with its corresponding print position, manually operable selection means including means to initiate an erase sequence and mode control means settable to define either an ''''erase only'''' operation or an ''''erase and delete'''' operation of said erase sequence, and erase sequence control means responsive to said erase sequence initiation for producing erase control operations and comprising: signal generating means for issuing said ERASE command signals to said typewriter, and memory writing means responsive to said mode control means for selectively writing into the byte identified by said queuing means as corresponding with the relative print position from which said erase mechanism erases a symbol in response to issuance of said ERASE command, ''''symbol not appear'''' if said ''''erase only'''' operation has been defined or ''''no significant information'''' if said ''''erase and delet'''' operation has been defined.

Claim 9

A. system as defined in claim 6 further comprising backspace means for moving said print point incrementally to immediately adjacent lower order print positions, and wherein the improvement further comprises: said erase sequence control means including erase sequence repeating means operating following each erase control operation to cause operation of said typewriter backspace means and producing a further one of said erase control operations.

Claim 10

A system as defined in claim 7, having the further improvement comprising: said erase sequence control means further including erase sequence terminating means including means for detecting the completion of the erasure of all characters within a single word unit, and means responsive to said completion detecting means for inhibiting further operation of said erase sequence repeating means.

Claim 11

A system as defined in claim 7, having the further improvement comprising: said erase sequence control means further including eRase sequence terminating means including means for detecting the completion of the erasure of all characters within a single line unit, and means responsive to said completion detecting means for inhibiting further operation of said erase sequence repeating means.

Claim 12

A system as defined in claim 7 wherein the improvement further comprises: said selection means including further mode selecting means having a first state for defining an erase sequence of ''''character'''' length and a second state for defining an erase sequence of ''''word'''' length, said erase sequence control means further comprising erase sequence terminating means including first detecting means for detecting the completion of the erasure of a single character, second detecting means for detecting the completion of the erasure of all characters within a single word unit, and means responsive to said further mode selecting means and to said first and second detecting means for inhibiting further operation of said erase sequence repeating means upon the completion of the erasure of a single character when said further mode selecting means defines a ''''character'''' length erase sequence and upon completion of the erasure of all characters within a single word unit when said further mode selecting means defines a ''''word'''' length erase sequence.

Claim 13

A system as defined in claim 7 wherein the improvement further comprises: said selection means including further mode selecting means having a first state for defining an erase sequence of ''''character'''' length and a second state for defining erase sequence of ''''word'''' length and a third state for defining an erase sequence of ''''line'''' length, said erase sequence control means further comprising erase sequence terminating means including first detecting means for detecting the completion of the erasure of a single character, second detecting means for detecting the completion of the erasure of all characters within a single word unit, third detecting means for detecting the completion of the erasure of all characters within a single line unit and means responsive to said further mode selecting means and to said first, second and third detecting means for inhibiting further operation of said erase sequence repeating means upon the completion of the erasure of a single character when said further mode selecting means defines a ''''character'''' length erase sequence, upon completion of the erasure of all characters within a single word unit when said further mode selecting means defines a ''''word'''' length erase sequence, and upon completion of the erase of all characters within a single line unit when said further mode selecting means defines a ''''line'''' length erase sequence.

Claim 14

A system as defined in claim 6 wherein the improvement further comprises: manually operable retype selection means, retype sequence control means operable in response to activation of said retype selection means and to the information contained within the memory byte identified by said queuing means corresponding with the current print position for producing retype operations and comprising: means for operating said typewriter to reprint the symbol identified by said byte and advance the print point to the next higher order print position in response to detection of ''''symbol not appear'''' information within said byte, and for operating said typewriter to advance the print point to the next higher order print position in response to detection of the presence of useful information within said byte if said byte does not contain ''''symbol not appear'''' information.

Claim 15

A system as defined in claim 12 wherein said retype sequence control means further comprises retype sequence repeating means operating following each advance of the print point and for producing a further one of said retype sequence control operations, and retype terminating means for inhibiting operation of said retype sequence repeatIng means when said byte contains no useful information.

Claim 16

A system as defined in claim 6, having the further improvement comprising said erase sequence control means further comprising: memory regression sequence control means responsive to selection of an ''''erase and delete'''' operation of said erase sequence by said mode selecting means for successively regressing to a lower order, the bytes identified by said queuing means as being of a higher order than a byte into which has been written ''''no significant information.''''

Claim 17

A system as defined in claim 6 wherein said improvement further comprises: said keystroke recording control means further including memory advance sequence control means comprising means responsive to said queuing means for detecting the prior recording of information having ''''symbol not appear'''' information within the byte of said memory corresponding to the current print position of the typewriter to advance to a higher order the byte corresponding to said current print position and those bytes of higher order than said current print position.

Claim 18

In a system including a typewriter having means for printing visible symbols at a print point on a page, means for moving said print point to ordered print positions along a line of the page, a keyboard that is manipulatable to control said symbol printing and print point moving means, signal output means for transmitting signals representative of typewriter operations, signal input means for receiving control signals for causing operations of said typewriter, and selectively operable symbol erase mechanism operable in response to an ERASE command signal, the improvement comprising: a memory capable of storing a plurality of symbol information identifying bytes, each corresponding with an individual print position on a line of the page and each being at least capable of identifying (i) whether it contains useful information, and (ii) the symbol intended to appear in the corresponding print position, queuing means for identifying individual ones of said bytes in said memory in accordance with the order of print positions with which said bytes correspond, keystroke recording control means responsive to manipulation of said keyboard and to said queuing means for writing a byte of symbol identifying information into said memory and ordered therein in accordance with its corresponding print position, manually operable selection means including means to initiate an erase sequence and mode control means settable to define either an ''''erase only'''' operation or an ''''erase and delete'''' operation of said erase sequence, and erase sequence control means responsive to said erase sequence initiation for producing erase control operations and comprising: signal generating means for issuing said ERASE command signals to said typewriter, and memory writing means responsive to said mode control means defining said ''''erase and delete'''' operation for writing ''''no significant information'''' into the byte identified by said queuing means as corresponding with the relative print position from which said erase mechanism erases a symbol.

Claim 19

In a system including a typewriter having means for printing visible symbols at a print point on a page, means for moving said print point to ordered print positions along a line of the page, a keyboard that is manipulatable to control said symbol printing and print point moving means, signal output means for transmitting signals representative of typewriter operations, signal input means for receiving control signals for causing operations of said typewriter, and selectively operable symbol erase mechanism operable in response to an ERASE command signal, the improvement comprising: a memory capable of storing a plurality of symbol information identifying bytes, each corresponding with an individual print position on a line of the page and each being at least capable of identifying (i) whether it contains useful information, and (ii) the symbol intended to appear in the corresponding print position, queuing means for identifying individual ones of said bytes in said memory in accordance with the order of print positions with which said bytes correspond, keystroke recording control means responsive to manipulation of said keyboard and to said queuing means for writing a byte of symbol identifying information into said memory and ordered therein in accordance with its corresponding print position, manually operable selection means including means to initiate an erase sequence and mode control means settable to define either an ''''erase only'''' operation or an ''''erase and delete'''' operation of said erase sequence, and erase sequence control means responsive to said erase sequence initiation for producing erase control operations and comprising: signal generating means for issuing said ERASE command signals to said typewriter, and memory writing means responsive to said mode control means defining said ''''erase and delete'''' operation for writing ''''no significant information'''' into the byte identified by said queuing means as corresponding with the relative print position from which said erase mechanism erases a symbol.

Claim 20

A system as defined in claim 16 wherein the improvement further comprises: manually operable retype selection means, retype sequence control means operable in response to activation of said retype selection means and to the information contained within the memory byte identified by said queuing means corresponding with the current print position for producing retype operations and comprising: means for operating said typewriter to reprint the symbol identified by said byte and advance the print point to the next higher order print position.

Claim 21

A system as defined in claim 17 wherein said retype sequence control means further comprises retype sequence repeating means operating following each advance of the print point and for producing a further one of said retype sequence control operations, and retype terminating means for inhibiting operation of said retype sequence repeating means when said byte contains no useful information.

Claim 22

A system as defined in claim 16, having the further improvement comprising: said erase sequence signal generating means further comprising: memory regression sequence control means responsive to selection of an ''''erase and delete'''' operation of said erase sequence by said mode selecting means for successively regressing to a lower order, the bytes identified by said queuing means as being of a higher order than a byte into which has been written ''''no significant information.''''