Patent ID: 7417655

Claim:
A printer in which a print head records a one-frame image one line by one line while a recording paper is moved by a feed roller to which driving force of a motor is transmitted via a reducer, said printer comprising: a rotary encoder for generating a pulse whenever said feed roller rotates by a unit angle; a counter for counting said pulse, a pulse number counted by said counter being equivalent to an actual feed amount of said recording paper; a feed-error detector for comparing said actual feed amount with a predetermined reference feed amount to detect a difference between these amounts as a feed error whenever recording of the line is performed by a predetermined number; and a printing-length controller for adjusting a printing length of said one-frame image to a predetermined target printing length, said printing-length controller changing a printing cycle of said print head to control a recording width of each line such that the detected feed error is eliminated while recording of the succeeding line is performed by the predetermined number.