Abstract: A method of forming a matrix image used in various devices with an image processing function.In the image forming method, each image segment constituted by an m.times.n dot matrix is divided into at least one element, and each element is defined by a parallelogram on a basic matrix. The image segment is encoded according to characteristic features of the parallelogram. Data signals representing each image segment are stored in a set of at least one coded element in a memory. The dot patterns of the entire image are formed according to image segment display data. Even a complicated pattern can be smoothly and clearly formed. In addition, processing for obtaining an enlarged image or a rotated image can be simplified and performed with a small-capacity memory.

Abstract: A bit pattern conversion apparatus has bit vertical/horizontal conversion means for converting data at the same bit positions of n-bit data into n-bit data, double expansion conversion means for converting 1-bit data into 2-bit data and producing the 2-bit data, bit number conversion means for converting 8-bit data into 6-bit data, and MSB/LSB conversion means for performing MSB/LSB conversion. The bit pattern of data stored in the memory means by the decoder means is converted by each conversion means.

Abstract: A printing timing correction device in a shuttle type dot line printer wherein a shuttle is reciprocated in directions perpendicularly intersecting a direction of feeding printing paper, printing needles regularly arranged on the shuttle are projected to recording paper to thereby conduct desirable printing operations and the shuttle performs non-constant velocity motion for which the rotation of a driving motor is transmitted by a crank mechanism.The printing timings are varied against the printing needles performing non-constant velocity motion in accordance with the speed of the printing needles, whereby the printings are performed at equal interval positions on the printing paper. This correction is performed by varying the delay time periods of signals fed to the printing needle driving device.