Tactile sensors and the gripping challenge

In a holographic image formation apparatus and method it has been known that the vertical components of image may be spread to achieve a wide vertical angle of observation without destroying the image nor impairing the three dimensional effect obtainable with a pair of eyes arranged horizontally with respect to each other. This has been done by the employment of a horizontally disposed cylindrical lens plate, usually near the plane of the recorded image, but optionally arranged elsewhere. Overlapping and loss of image clarity and contrast occurs in such a system due to the fact that the zero order of diffracted images and the first, or higher, orders partially superimpose one upon the other. In this invention a special mask is arranged beyond the lens plate which may be adjacent the recorded image to be reconstructed, in which the mask has opaque zones which correspond to the spacing of the individual cylindrical lens elements comprising a lens plate used for the vertical dispersion of the lines of images along the recorded image. According to this invention narrow opaque strips are disposed parallel to these cylindrical lens elements at a distance therefrom such that the elumination beam passing linearly through the recorded image tends to focus on the opaque strips whereas the first and higher order diffraction beams pass between such opaque strips, whether illuminated by monochromatic light or a series of color bands.