“CVROS” is an acronym for “Compact Video Rate Optical Scanner”, a high speed optical scanner conceived and developed for serial scan thermal imaging systems.
High speed line scan and compactness derive from the CVROS thin, small diameter rotating disc in which a circular array of focusing mirrors are embedded. Each Scan Disc Mirror performs a point-by-point scan of a horizontal line in a scene.
A line image from the scene is formed by an objective mirror on an arc centered on the mirror’s center of curvature. The arc image is coincident with a “Strip Mirror”, a thin slice from a right circular reflective cone whose axis is co-linear with the scan disc axis.
The focused light from the Objective Mirror is reflected 90 degrees upwards from the Strip Mirror and then intercepted by the Scan Disc Mirror. The Scan Disc Mirror is located at a distance from the Strip Mirror equal to its focal length. Therefore, it collimates the incident cone of light rays and redirects the resultant parallel bundle of light rays downward toward the Collection Mirror.
The Collection Mirror focuses to a single point the incident collimated light from the Scan Disc Mirror throughout its travel across the arc image. A detector located at the focus outputs a signal proportional to the light intensity of successive points in the scanned scene line image.
Scan of a two-dimensional area is performed by the addition of a Framing Mirror, an oscillating flat mirror located at the center of curvature of the Objective Mirror.
The Collection Mirror axis is laterally displaced to allow passage of light from the scan area to the Framing Mirror. The Collection Mirror function is unaltered, focusing the collimated light from the moving Scan Disc Mirror onto a detector. Horizontal lines of the scan area are scanned sequentially by the Scan Disc Mirrors by rotational advancement of the Framing Mirror for each new line.
Further details can be found at “CVROS Concept and Characteristics”.