An electro-optical display for the display of dark symbols against a bright background, wherein except for fine separation lines the front and rear cell plates are almost entirely covered with isolated electrode elements. The regions of overlap between these various front and rear electrode elements define the areas of the selectable display segments. The display employs an electro-optic media requiring no polarizers, for example, cholesteric liquid crystals to which has been added pleochroic dy...

A motor vehicle headlamp lens has two zones A1 and B containing ribs of different width to produce different amounts of lateral spreading of the headlamp beam. Between these zones a transition zone A2 is provided where a gradual change in the width of the ribs occurs. In the transition zone there are provided novel separating surfaces between the ribs having one surface at an angle to the general plane of the lens which act as a prism to deflect light passing therethrough in a downward direction...

In a method of geophysical prospection a transmitter dipole and a receiver dipole which is sensitive to an electromagnetic field are positioned in cooperation with the subsoil. An impulsive excitation current is applied repeatedly to the transmitter dipole, the excitation current comprising a group of pulses of alternate polarity, each followed by zero current. The transient signal, which is produced thereby at the output of the receiver dipole, is repeatedly detected, and the transient signals ...

In a lighting apparatus which illuminates light ray from an illumination light source through a light distribution lens onto an illuminated surface, an inner surface of the light distribution lens is formed as continuous surface to receive incident ray in the perpendicular direction, and an outer surface of the lens for refracting outgoing ray is formed based on the equations which are made in consideration of the illuminance on the illuminated surface, thereby uniform illuminance is obtained on...

A test administration system comprises a central computer and associated database containing a plurality of tests that may be distributed to a test taker. The central computer provides a website to be accessed by the test administrator and the test taker at remote personal computers when using the test administration system. The website includes an administrator workspace for use by the test administrator and a testing workspace for use by the test taker. The administrator workspace provides the...

A white light generating portion is comprised of a gas discharge light source and a rotated cylindrical lens. A red light generating portion is comprised of a plurality of light emitting diodes.

In radiological apparatus, edge values derived by monitoring the radiation passed through a body along many co-planar paths are subjected to a transformation process, such as a convolution integral or Fourier transform process, in order to evaluate the absorption or transmission coefficients of the elements of a matrix of elements notionally delineated, in the plane of the paths, in the body. The values are inversely transformed to synthesize further edge values, and corresponding ones of the fi...

A lighting lens having a multiplicity of lenticules is disclosed, and in particular the use of aspherical lenticules is disclosed. The lenticules are of two or more standard types, each type being defined be a different cross sectional curvature. The different lenticle types are distributed across one side of the lens in an intermixed pattern. By selecting two standard lenticule types, and determining a weighted ratio, a lens for a desired lighting pattern may be made without having to specifica...

A lighting lens having a multiplicity of lenticules is disclosed, and in particular the use of aspherical lenticules is disclosed. The lenticules are of two or more standard types, each type being defined be a different cross sectional curvature. The different lenticle types are distributed across one side of the lens in an intermixed pattern. By selecting two standard lenticule types, and determining a weighted ratio, a lens for a desired lighting pattern may be made without having to specifica...

A process for the preparation of polyvinylpyrrolidone-iodine, wherein a polyvinylpyrrolidone which has been subjected to hydrogenation is reacted with iodine in a conventional manner. The novel process is particularly suitable for use with low molecular weight polyvinylpyrrolidone, having a K value of from 10 to 20.