A system for localizing a region of a display incorporates a plurality of resettable counters for defining the position and extent of a cursor in two dimensions. Data is set into the counters periodically at the beginning of each frame, or at the beginning of each scanning line, so that the size and shape of the cursor is selectable, as well as its position on the display. When the data is modified during successive time periods, the cursor can be made to progressively reduce its size so as to indicate a point, and/or to progressively change its location.
A method is disclosed for creating simultaneously viewable coarse and fine resolution displays, respectively presenting an "entire image" with coarse resolution of detail and a selected portion of that image in an enlarged view with fine resolution of detail. The method also provides for creation of cursor and crosshair images overlying the portion of the coarse display selected for enlarged viewing, and creation of an enlarged crosshair image overlying the enlarged display. The cursor image is in the form of a rectangle outlining the portion selected for "magnified" viewing in the fine display segment. The crosshairs provide relatively scaled position references on the coarse and fine views for enabling operators to accurately locate points within fine segments for specification to a computer system.
There is provided a picture-forming device which is capable of easily drawing an arrow having a desired shape on a display screen of a display device, such as a CRT. The picture-forming device is capable of setting a basic shape of an arrow to be used in picture-forming. The basic shape of the arrow set is stored. When arrow display conditions indicative of a position, a direction, and a length of the arrow are entered via the display screen, data of the basic shape of the arrow and data of the arrow display conditions are synthesized, to display an image data thus synthesized, on the display screen.
A test signal generator applies a test pattern to a device under test. The output of the device under test is displayed on a video picture monitor. The test signal generator inserts a cursor into the test pattern, the position of the cursor within the test pattern being variable. From the cursor the test signal generator also generates a trigger signal. The trigger signal may be used to trigger the horizontal sweep of a waveform display device to which the output of the device under device is input. By observing the picture monitor an operator may adjust the cursor to a position just prior to an anomaly in the displayed test pattern so that only that portion of the output waveform of the device under test in the vicinity of the cursor is displayed on the waveform display device.
A display controller which can display a cursor on either of a CRT display or a liquid crystal type display device is described. The liquid crystal type display device is a type that has an upper and lower display blocks which are scanned substantially in parallel. This display controller allows the display position of the cursor to be designated in the same manner, independent of the type of display device used. The display controller operates in a time sharing manner, alternately on the upper and lower display blocks of the liquid crystal device. Two groups of data corresponding to these upper and lower blocks are formed and are supplied to the liquid crystal display device substantially in parallel. X and Y coordinate positions of the cursor position are also stored. The cursor pattern signal for the liquid crystal display device is also stored in a time shared manner.
In a cathode ray tube display system in which objects to be displayed are represented by digital signals, a technique is employed to reduce distortion caused by aliasing. The objects to be displayed are represented in a memory by transition specifications which represent the object to be displayed by defining the character of the edges of the object to be displayed. From the transition specifications, a video signal is generated and applied to the cathode ray tube display device to display the object represented by the stored transition specifications. The circuitry generating the video signal causes the video to change in steps across the width of a transition from the brightness prior to the edge to the final brightness of the other side of the edge with the width of the transition varying in accordance with the slope that the edge makes with the raster scan line.
