An encoder for a wheel comprises a linear Hall-effect sensor and magnet mounted on a non-ferrous metal shaft. A ferrous metal ring having a toothed structure extending inward such that each tooth ends at a point on a spiral curve is molded into the printwheel encircling the shaft. The Hall-effect sensor output provides a determined output when each tooth is positioned over the sensor to enable an absolute position determination while the signal drop off between the teeth as the wheel is moved al...

A photoelastic effect measuring device comprising a single white light source, a prism dispersing light emitted by said white light source and a variable slit device, which selects an arbitrary spectrum of light thus dispersed is disclosed, in which for a photoelastic effect measurement using white light, the slit width is opened totally so that all the light spectrum pass therethrough so as to pass through a sample to be measured and for a photoelastic effect measurement using a specified monoc...

A circuit for processing television signals to produce special effects includes a special effects circuit and a key signal generating circuit. Instead of generating the key signal separately and tailoring it for the desired special effects by using complicated circuits, the key signal is superimposed onto a video signal to produce a composite video signal which signal is processed to conform to the desired special effects. After the processing, the key signal is separated from the composite vide...

The mobility of carriers in the channel region of a field effect transistor can be increased by providing a layered structure wherein electrons are separated from impurities. The channel is made up of external layers of wide bandgap material and internal layers with a narrower bandgap where the bottom of the conduction band of one layer is below the top of the valence band of the adjacent layer. A structure is shown with a layered channel having AlSb external layers and at least one or both of I...

A method for accumulating component video signals non-additively adds the luminance components to produce an accumulated luminance component, and additively adds the chrominance components to produce an accumulated chrominance component. The accumulated chrominance component may be clipped to limit chrominance values in an overlap area to legal color values. The intentional overlap of the component video signals produces an accumulation special effect in the overlap area.

The gate of a gallium indium arsenide FET grown on an indium phosphide substrate comprises a top layer of GaInAsP (band gap 1.2 eV) a middle layer of GaInAs and a bottom layer of InP. This can be etched to produce an overhanging top layer which allows self-aligned gate contact metallization avoiding the registration problems of a further masking stage.

A system and method for generating indicia of registration error between respective, separately adjustable printing units of a printing press, the printing units cooperating to print an image on a moving web, the system being of the type comprising a photo-optical control, having a field of view and depth-of-field, for generating output signals indicative of a predetermined relative disposition of marks on a web passing through the field of view within the depth-of-field of the photo-optical con...

A proximity switch with a noncontact effect which includes a plug-in adapter having a plug-in socket for the sensor part equipped with a plug-in cable, a ac/dc converter with a core coil connected in front thereof being arranged in the adapter. The adapter is associated with a dc/ac converter located in the basic housing of the main part and includes a core coil connected thereafter. The core coil lie in each case behind the mounting sides of the basic housing and plug-in adapter and transmit by...

A two-terminal field effect transistor device which is capable of operation as an oscillator including a field effect transistor connected in a two-terminal manner. The transistor has the usual drain source and gate electrodes and oscillating instability is provided by means of an inductance means of value so as to provide this circuit instability to enable circuit oscillations. The two-terminal arrangement is enabled by means of essentially interconnecting the gate and drain electrodes by way o...

A field effect semiconductor device having a compound semiconductor substrate e.g. GaAs, GaAlAs and the like, having an active region, and a gate electrode of one or more silicides of one or more refractory metals varying the composition or compositions thereof along the height of the gate electrode, resultantly varying the etching rate thereof along the height of the gate electrode. The gate electrode having a shorter length of the portion contacting the active region than of the portion remote...