Showing papers on "Depth of field published in 1970"

Simulator having an infinite-depth-of-field optical pickup

Abstract: An optical pickup having a final imaging lens with means for tilting the final lens about its rear nodal point to maintain registration of the optimum image plane resulting from varying object plane orientations. This technique increases the depth of field without affecting the f-number of the optical pickup system or introducing distortions.

Electrooptical apparatus employing a hollow beam for translating an image of an object

Abstract: A hollow beam of monochromatic light is deflected repetitively through a scanning pattern and focused upon an image plane in which is located an object desired to be scanned. A detector senses light reflected from or transmitted through the object to develop video signals that at each instant of time represent light intensity. These video signals are fed to an image reproducer that creates an image of the object in synchronization with the scanning pattern. The apparatus further includes a filter system that effects a modification of the video signals in order to restore image contrast which otherwise is seriously degraded as a consequence of utilizing a hollow light beam in order to obtain an increase in depth of field for the optical system. The disclosure also concerns using the apparatus for video recording as well as reproducing.

Ultrasonic object detector

Abstract: An ultrasonic object detector system operating on the echoranging principle and including circuit adjustments which render the object detector system responsive to objects at a preselected distance. Additional circuit adjustments provide control of the depth of field sensitivity of the object detector system relative to the selected object distance as well as providing the capability of ''''locking-in'''' the object to prevent loss of object recognition.