Helical bar printer logic circuitry

Claim 2

In a printer having a bar formed in the shape of a helix, means to rotate said bar about the axis of said helix, at least one hammer having a blade positioned to strike against said bar to print a dot when said hammer is actuated, means to receive a plurality of coded characters representing an alphanumeric character to be printed, and logic means responsive to said coded characters to actuate said hammer to print patterns of dots to compose the alphanumeric character represented by said coded characters, the improvement wherein said logic means comprises a shift Register having an output stage for storing and simultaneously retaining in storage a set of binary signals representing a pattern of dots to be printed in a row by said hammer, dot pattern composing means responsive to coded characters to transmit to said register sets of binary signals representing patterns of dots to be printed in rows to compose the alphanumeric character represented by such coded characters, and hammer firing means coupled to said output stage to actuate said hammer to print a pattern of dots in a row in response to the output of said register, said dot composing means transmitting each entire set of binary signals to said register during a single interval between successive actuations of said hammer, and means responsive to the rotation of said helix to successively shift binary signals in said register serially to said output stage.

Claim 3

A printer as recited in claim 1 wherein said dot pattern composing means transmits the binary signals of each set to said register in parallel.

Claim 4

A printer as recited in claim 1 wherein said register comprises a shift register, and wherein said hammer firing means shifts said binary signals out of said shift register serially and responds to each binary signal of one predetermined value as it is shifted out of said shift register to actuate said hammer.

Claim 5

A printer as recited in claim 1 wherein said dot pattern composing means transmits each of said sets of binary signals to said register during the time that the intersection of said bar and said blade is passing by the space between the positions of adjacent alphanumeric characters being printed by said printer.

Claim 6

A printer as recited in claim 4 wherein said register is a shift register and wherein said hammer firing means shifts the binary signals stored in said register serially out of said register and responds to each binary signal of one predetermined binary value as such signal is shifted out of said register to actuate said hammer to print a dot.

Claim 7

A printer as recited in claim 5 wherein said dot pattern composing means transmits the binary signals of each set in parallel to said register.

Claim 8

A printer as recited in claim 1 wherein said dot pattern composing means comprises a memory having a multiplicity of address locations and storing at each address location a set of binary signals representing a pattern of dots to be printed in a row, the sets of binary signals stored at different address locations in said memory being selected so that the patterns represented thereby can be combined to compose different alphanumeric characters, and means reponsive to each of said coded characters to select addresses in said memory to compose a corresponding alphanumeric character and to transmit the sets of binary signals stored at the selected addresses to said register.

Claim 9

In a printer comprising a bar shaped in the form of a helix having a plurality of convolutions, means to rotate said bar about the axis of said helix, a plurality of hammers each having a blade positioned adjacent to said bar, the blade of each said hammer spanning a different convolution of said helix, each of said hammers striking its blade against said bar to print a dot when such hammer is actuated, means to receive a plurality of coded characters each comprising a set of signals, said coded characters each representing an alphanumeric character to be printed, and logic means responsive to each of said coded characters to actuate one of said hammers to print a pattern of dots to compose the corresponding alphanumeric character, the improvement wherein said logic means comprises a shift register having an output stage for each of said hammers for storing and simultaneously retaining in storage a set of binary signals to represent a pattern of dots to be printed in a row, dot composing means responsive to each of said coded characters to transmit to the register sets of binary signals representing patterns of dots to be printed in rows to compose the alphanumeric character represented by such coded character, and hammer firing means coupled to said output stage to actuate the corresponding hammer to print the corresponding pattern of dots in a row, said dot composing means transmitting each entire set of binary signals to said registers during a single interval between successive actuations of said hammer and means responsive to the rotation of said helix to successively shift binary signals in said register to said output stage serially.

Claim 10

In a printer comprising a bar shaped in the form of a helix having a plurality of convolutions, means to rotate said bar about the axis of said helix, a plurality of hammers each having a blade positioned adjacent to said bar, the blade of each said hammer spanning a different convolution of said helix, each of said hammers striking its blade against said bar to print a dot when such hammer is actuated, means to receive a plurality of coded characters each comprising a set of signals, said coded characters each representing an alphanumeric character to be printed, and logic means responsive to each of said coded characters to actuate one of said hammers to print a pattern of dots to compose the corresponding alphanumeric character, the improvement wherein said logic means comprises a shift register having an output stage for each of said hammers for storing and simultaneously retaining in storage a set of binary signals to represent a pattern of dots to be printed in a row, dot composing means responsive to each of said coded characters to transmit to the register sets of binary signals representing patterns of dots to be printed in rows to compose the alphanumeric character represented by such coded character, and hammer firing means coupled to said output stage to actuate the corresponding hammer to print the corresponding pattern of dots in a row, said dot composing means transmitting each entire set of binary signals to said registers during a single interval between successive actuations of said hammer and means responsive to the rotation of said helix to successively shift binary signals in said register to said output stage serially.