Displays for information obtained by vector scanning

A method of converting data present in a plurality of A-scan signals obtained from a vector scanning arrangement for the eventual display on a matrix type display comprising the steps of:

• converting the r, .theta. coordinate data into x, y coordinate data,
• quantising the signal data corresponding to the converted r, .theta. coordinate data, and
• selectively manipulating and storing the quantised signal data according to its corresponding x, y coordinate for eventual display if, and only if, the number of previous manipulations for the x, y coordinate is less than a number required to give a representation of the signal data.

A system for converting A-scan signal information in r, .theta. coordinates into display data for x, y coordinate display locations comprising means for contributing the signal information in each A-scan signal to the display data only when the r coordinate of said A-scan signal is greater than a predetermined value, and means for establishing different predetermined values of r for different A-scans.

A system for displaying on a matrix-type display, data obtained from A-scan signals of a vector scanning arrangement, comprising means for displaying data, means for deriving the data to be displayed from the A-scans of more than one B-scan, and means for storing the data to be displayed by said means for displaying data such as to provide persistence in the display.

A system for converting A-scan signals in r, .theta. coordinates into display data for x, y coordinate display locations, comprising means for generating a plurality of A-scan signals whose .theta. coordinates are so closely similar that each of the A-scan signals in said plurality includes an A-scan signal value having the same x, y coordinate display location, and means operable to generate the display data for said x, y coordinate display location from only a limited plurality of said A-scan signal values which have the same x, y coordinate display location.

A system for converting data present in a plurality of A-scan signals obtained from a vector scanning arrangement for eventual display on a matrix type display comprising:

• means for converting the r, .theta. coordinate data into x, y coordinate data,
• means for quantising the signal data corresponding to the converted r, .theta. coordinate data, and
• means for selectively manipulating and storing the quantised signal data according to its corresponding x, y coordinate for eventual display if, and only if, the number of previous manipulations for the x, y coordinate is less than a number required to give a representation of the signal data.