A pattern forming apparatus for inverting at least one of plural patterns according to numerical design data respectively representing the plural patterns and synthesizing thus inverted pattern with the remainder of the plural patterns, comprises first operation device for attaching a flag of a positive image to the design data of uninverted patterns, and attaching a flag of an inverted image to the design data of inverted patterns, second operation device for handling the entire area of either inverted patterns or uninverted ones among the plural patterns as a single pattern, and attaching a corresponding flag to the design data of the pattern, and image forming device for forming image data of the area according to the data of the second operation device and then forming image data of each pattern according to the data of the first operation device.

An apparatus for displaying waveform of a physiological signal such as a cardiographic signal has a waveform display control device for picking up the physiological signal and for conducting a control for displaying the waveform of the physiological signal in the form of a continuous waveform or a freeze waveform, a pattern display control device for forming a pattern signal of a back scale which is displayed simultaneously with the waveform of the physiological signal and for conducting a control to vary the brightness of the display of the back scale depending on whether the waveform of the physiological signal is displayed in the form of the continuous waveform or the freeze waveform, and a display monitor device for displaying the physiological signal waveform and the back scale on a display screen thereof. When the apparatus is used in the mode for displaying the physiological signal in the form of a continuous waveform, the brightness of display of the back scale pattern signal is lowered or reduced to zero, whereas, when the apparatus is used in a mode for displaying the physiological signal in the form of a freeze waveform, the brightness of display of the back scale pattern signal is elevated.

A data processing device for writing various kinds of rule data easily and rapidly in a pixel image memory. Rule pattern store means stores a plurality of kinds of rule patterns in the line direction and a plurality of kinds of rules in the digit direction, the line and digit directions respectively being associated with those of an image data store area of the pixel image memory. Means is provided for selecting one of the rule patterns stored in the rule pattern store means and moving it to the pixel image memory. In response to a command entered through an input device, desired one of the rule patterns is selected and only a desired length of the selected rule pattern is moved.

In a word processing system having a keyboard display for data entry and modification, and a printer with a choice of pitch, the technique is presented for displaying on less than the entire CRT screen a representation of a full page of text being processed. The full page representation is in fact visually proportional to the yet unproduced printed output. The full page representation is made possible by using a 2.times.4 character representation structure to represent an 8.times.16 normal character. Proportionality within the represented data is achieved by displaying particular character representations more than once. The interval between multiply displayed representations is a function of the output pitch with which proportionality is desired and the size of a dot on the CRT screen.

An image memory data processing control apparatus having an image memory unit divided into a plurality of block memories, for each of which each pixel register and each timing control means are disposed, whereby a high-speed data drawing may be made. When executing a bitblt processing, writing decoders and reading decoders select modules associated with the pixel registers concerned. Data are read out from the image memory unit and data obtained by a raster operation are written into the image memory unit.