Dot-matrix printer

Claim 2

A dot-matrix printer for printing dot characters in accordance with dot character patterns input through an external unit (11), characterized by comprising: buffer memory means (13) for storing printing data containing a dot character pattern input through the external unit (11) and a character code corresponding to the dot character pattern; pattern-checking means (17) for determining whether any two adjacent dots of the pattern which are arranged in the printing direction contact; and error-indicating means (14) for indicating that the dot character pattern has an error, which said pattern-checking means (17) determines that any two adjacent dots of the pattern which are arranged in the printing direction contact.

Claim 3

A dot-matrix printer for printing dot characters in accordance with dot character patterns input through an external unit (11), characterized by comprising: buffer memory means (13) for storing printing data containing a dot character pattern input through the external unit (11) and a character code corresponding to the dot character pattern; pattern-checking means (17) for determining whether any two adjacent dots of the pattern which are arranged in the printing direction contact; pattern-correcting means (17) for erasing either of any adjacent dots if they are found to contact, thereby correcting the dot character pattern; memory means (18) for registering the dot character pattern corrected by the pattern-connecting means (17) or input through the external device at the address corresponding to the character code; and printing means (20) for printing a dot character of the pattern read from the memory means (18), in accordance with the printing data input through the external unit (11).

Claim 4

A dot-matrix printer for printing dot characters in accordance with dot character patterns input through an external unit (11), characterized by comprising: buffer memory means (13) for storing printing data containing a dot character pattern input through the external unit (11) and a character code corresponding to the dot character pattern; pattern-checking means (17) for determining whether any two adjacent dots of the pattern which are arranged in the printing direction contact; pattern-correcting means (17) for erasing either of any adjacent dots if they are found to contact, thereby correcting the dot character pattern; memory means (18) for registering the dot character pattern corrected by the pattern-connecting means (17) or input through the external device at the address corresponding to the character code; and printing means (20) for printing a dot character of the pattern read from the memory means (18), in accordance with the printing data input through the external unit (11).

Claim 5

A dot-matrix printer according to claim 2, characterized in that said pattern-correcting means (17) comprises an AND gate circuit (73a-73h) for receiving data representing a first pattern and data obtained by inverting data representing a second pattern adjacent to the first pattern in printing direction and for producing a corrected pattern data, a register (72) for storing the corrected data produced by the AND gate circuit (73a-73h).

Claim 6

A dot-matrix printer according to claim 3, characterized in that said pattern-checking means (17) comprises comparator means (74a-74h) for comparing the data stored in said register (72) with the data representing said first or second pattern, and check signal generating means (75) for generating, when the data stored in said register is different from the data representing said first or second pattern, a check signal showing that any two adjacent dots of the pattern which are arranged in the printing direction contact.

Claim 7

A dot-matrix printer according to claim 4, characterized by further comprising a microprocessor (14) for detecting, upon receipt of a check signal from said pattern-checking means (17), that any two adjacent dots of the pattern which are arranged in the printing direction contact, and then causing said pattern-correcting means (17) to transfer the data from said register to said memory means (18).

Claim 8

A dot-matrix printer according to claim 2, characterized in that said pattern-checking means (17) and pattern-correcting means (17) are comprised of a microprocessor (14) in which a program is loaded and which operates in accordance with this program.