An optical switch comprising an electro-optical crystal having optically positive or negative birefringency, a birefringent crystal having optically negative or positive birefringency and an electric power source connected with the electro-optical crystal for turning on and off the crystal, the electro-optical crystal and the birefringent crystal being arranged in cascade in such a manner that the sign of the birefringency of the former may be opposite to that of the latter, whereby the optical ...

An optical printer consisting briefly of a frame, a camera carriage, a bellows unit, a printer head module and animation motor. The printer module includes a pair of spaced film sprockets connected to a stepping motor, a pair of film tensioning pins, a pair of film registration pins, pressure plate and aperture plate.

An optical monitor in which liquid to be analyzed flows through a light transparent cell. First means passes a light beam of selected bandwidth through the cell, the beam being attenuated to an extent dependent upon the light absorption characteristic of the liquid. A photocell device is responsive to the attenuated beam, the resistance of the device varying with the amount of attenuation. An oscillator is coupled to the device to produce an attenuating signal, the signal frequency varying with ...

An optical coupler comprises at least two movable graded index-of-refraction cylindrical segments. At least two of the segments have unequal lengths and are longitudinally butted together to form a structure having flat input and output faces. The overall length of the segments approximates a half wavelength of the period of the sinusoidal path followed by a light beam in longitudinally propagating through the segments. A relatively large lateral movement of the segments, while maintaining the b...

Visual display devices containing a matrix of areas which can be selectively illuminated to display a predetermined legend or symbol. In place of individual lamps used hitherto, the proposed visual display devices utilise bundles of optical fibres coupled to a reduced number of light sources, thus simplifying the assocated control circuitry.

An optical gauge for use in measuring the setting of grooved rolls of a rolling mill receives a light beam through a space between the rolls from a light source located on the other side of the rolls and conducts the light through a bent optical path to a ground glass display located in a convenient position for viewing. A manually movable rule mechanism cooperates with a scale on the ground glass to permit measurements of the spacing of the rolls as imaged on the display, and the movable rule m...

A light-weight optical mirror in the form of a thin glass layer baked with a carrier base made of a refractory metal having a softening temperature exceeding that of the glass layer by more than 100.degree.C and a linear thermal expansion coefficient very close to that of the glass layer. A reflecting coating is applied to the external surface of the glass layer after baking it with the carrier base.

An inspection system employing television techniques makes use of coherent optical phenomena. A comparison is made between two video signals each resulting from irradiation of a photosensitive screen with coherent light consisting of two interfering beams, the light of one beam having been scattered from a surface to be inspected and imaged on the screen. In studying deformation of a surface, the two signals are derived with the surface in different states. In comparing two similar surfaces, the...

This invention provides an optical system for displaying visual information. The system has a main plane towards which light is projected, and from which the light travels in a different direction. The system is comprised of reflecting surfaces which are provided in the region of the main plane. Each surface is orthogonal to the main plane and each of the surfaces is orthogonal to an adjacent surface. Thus incident light, by successive reflections, is directed away from the main plane in a direc...

An optical instrument wherein an optical signal is projected on to a sensor array or sensitive medium and angular deflections of the path of the optical signal about an instrument signal source as centre appear as displacements from a datum lying in the general plane of the sensor array or sensitive medium, the instrument having an optical axis passing through said source and normal to said plane, characterized in that, to correct for the tangent law error that would otherwise arise, a correctin...