Abstract: A noise reduced photon detector incorporates an array (10) of semiconductor diode detector elements (12). Each element (12) has an extrinsic active layer (20) sandwiched between two layers (18, 22) of wider bandgap and mutually opposite conductivity type. These layers are in turn sandwiched between two further layers (16, 24) of wider bandgap than the active layer (20) and of higher doping than the other layers (18, 22). A mirror (34) extends round much the array (10) and isolates each element (12) from photons emitted by other elements (12). In operation the elements (12) are reverse biased and exhibit negative luminescence which reduces their photon emission. These two effects reduce unwanted photon generation and absorption, and consequently photon noise is also reduced.

Abstract: A multi-layer Auger suppressed diode having at least two exclusion interfaces and at least two extraction interfaces. A specific embodiment has two composite contacts, each consisting of a heavily doped layer (3, 4) and a buffer layer (8, 9) of lower doped, high bandgap material sandwiched between the heavily doped layer and the active region (2) of the device.

Abstract: An infrared detector comprises a thin film of photo-responsive material on transparent dielectric material with an array of planar antennae adjacent to the film surface. The antennae are separate from ohmic contacts arranged to connect the film to an external circuit. The antennae concentrate radiation in fringe fields at antenna edges and extremities interacting with the photo-responsive material. The detectors may be photovoltaic or photoconductive. The antennae may be rectangular, bow-tie, cruciform, elliptic, circular or square, and are dimensioned for resonance (preferably half-wavelength resonance) at frequencies within the photo-responsive material absorption band. Half-wavelength resonant antennae are best matched by F/0.7 optics. The detector may be a reticulated array. The dielectric material may be formed as a lens.

Abstract: A photodetector (10) of the non-equilibrium kind incorporates three successively disposed sections (14, 16, 18) of like layer construction. Each of the sections (e.g. 14) contains three layers (14A, 14B, 14C) of semiconductor materials of the Cd.sub.x Hg.sub.1-x Te alloy system (CMT). The central layer (14B) of each section (14) is of narrow bandgap CMT, i.e. x=0.19 or 0.265 for absorption at 3-5 .mu.m or 8-12 .mu.m, and has very low doping (10.sup.15 cm.sup.-3) providing intrinsic conductivity. It is 1.5 .mu.m thick, less than one third of an optical absorption length. The outer layers of each section (14A, 14B) are 10 .mu.m thick and are of wide bandgap CMT, i.e. x=0.4. They have respective n and p type dopant concentrations of 3.times.10.sup.16 cm.sup.-3 providing extrinsic conductivity. Each central layer (14B) is therefore bounded by an excluding contact (14AB) and an extracting contact (14BC), which depress its carrier concentration to an extrinsic level under the action of electrical bias.

Abstract: A detector, of photosensitive semiconductor material with input and output bias contacts. To improve both frequency response and spatial resolution, minority carriers having tendency to accumulate in the vicinity of the output bias contact are instead rapidly swept out, being driven towards this contact by a concentrated electric field. To produce a local field concentration, the output bias contact may be extended towards the input bias contact, or the detector material near this contact may be configured by slotting or tapering.

Abstract: An infra red photo detector system comprises a piece of detector material, such as Cd.sub.x Hg.sub.1-x Te, InSb, InAs, etc, carrying at least a pair of spaced electrodes. An optical arrangement directs a small spot of radiation onto the detector. The position of the small spot on the much larger detector is found by applying an electrical bias between the electrodes causing a drift of photo carriers. The bias may be of alternating polarity and the detector output measured at each polarity. Alteratively a high frequency bias may be applied and the A.C. offset from the detector used to indicate spot position. Alternatively the spot position may be modulated or swept along the detector by a mirror moving in a sawtooth scanning action.

Abstract: A detector in which a barrier region is interposed in the current path between the emitter and collector of the detector. This region is of a material having a valance band edge approximately level to that of the emitter material and an appreciably wider band gap. It thus serves to impede majority carrier current flow and as a consequence device resistance is high. When the detector is biased, the pedestal contribution to detector signal is low. The collector may be of semiconductor material of the same majority carried type as the emitter material; or may be of opposite type but dopant enriched; or it may be a Schottky metal contact. In one variant of the detector, the emitter and collector are located on opposite sides of the barrier and are of different bandgap materials. The infra red band response of this detector can be changed by reversing bias polarity. In another variant of the detector the emitter is in strip form and has a pair of bias contacts.

Abstract: The transfer apparatus comprises a transfer arm (16) and a distributor (18). The transfer arm has two axes of movement (22,26) and is non-extendable so that it moves between a take-off station and an intermediate station (I) through a fixed distance. The distributor (18) has a table (50) which receives a shoe (S) at the intermediate station (I). Furthermore, the table (50) can be positioned at any one of four stations (I,F1,F2,F3) each aligned with a channel (12) of a heat setting apparatus (14). A pneumatic control circuit causes shoes (S) fed successively to the table (50) to be transferred in a sequence to the channels (12) by operation of pusher means.The apparatus is suitable for transferring shoes from a lasting machine, a shoe support (10) of which can be positioned at the take-off station, to a heat setting apparatus (14).

Abstract: An infra red photo detector system comprises a piece of detector material, such as Cd.sub.x Hg.sub.1-x Te, InSb, InAs, etc, carrying at least a pair of spaced electrodes. An optical arrangement directs a small spot of radiation onto the detector. The position of the small spot on the much larger detector is found by applying an electrical bias between the electrodes causing a drift of photo carriers. The bias may be of alternating polarity and the detector output measured at each polarity. Alternatively a high frequency bias may be applied and the A.C. offset from the detector used to indicate spot position. Alternatively the spot position may be modulated or swept along the detector by a mirror moving in a sawtooth scanning action.

Abstract: An alternating bias is applied to a modified photoconductive detector and photosignal extracted from each detector element. This extraction may be performed using an integrator to produce a dc signal output, or alternatively by using a high-pass filter or phase-sensitive detector to extract a photosignal at an harmonic of the bias frequency. The detector used is provided with elements that have a responsivity that is a different function of bias amplitude for each polarity. The detector element may be shaped with variation in width or depth, to produce this differential responsivity. Alternatively element bias contacts may be of different width to produce field gradient and differential responsivity. It is advantageous to obscure a part of each element area by including an opaque mask.

Abstract: It is a problem extracting the photosignal component from detector output, to the exclusion of pedestal bias response. To overcome this, a time varying bias signal is applied to each element of the detector. The duration of the time varying bias signal, or if a periodic signal, the signal period, is chosen as long compared to photocarrier lifetime and the signal amplitude is large enough to range over a non-linear portion of the responsivity characteristic of each element. The bias signal contains a d.c. component so that the bias signal ranges about a point of operation--a point of asymmetry lying on the responsivity characteristic. The photosignal component of the output signal may be removed by time averaging or by harmonic separation. Alternatively the bias signal may be modulated, and the photosignal component extracted by detection of demodulated signal.

Abstract: A photo diode formed by a substrate of Cd.sub.x Hg.sub.1-x Te covered with a layer of CdTe forming a p-n junction. The substrate may be p-type in which case the layer is n-type or vice versa. An array of photo diodes may be formed by covering the substrate with semi-insulating CdTe and forming islets of In on the CdTe. Heating causes In to diffuse into the CdTe doping it n-type. This results in regions of n-type CdTe surrounded by semi-insulating CdTe each region forming, with the substrate, a photo diode. The heating also causes diffusion between the Cd.sub.x Hg.sub.1-x Te and CdTe to give a graded heterostructure. Electrical connections are made to the substrate, and each n-type region. The n-type CdTe region may alternatively be formed by molecular beam epitaxial growth techniques using a beam of In dopant.

Abstract: The heat setting machine comprises a channel along which a lasted shoe upper is conveyed to be subjected to heat. The apparatus comprises a resiliently deformable member extending along and secured to one side of the channel. The resiliently deformable member, which may be in the form of an inflated bag, is arranged to extend across the channel to engage a cooperating member secured to the other side of the channel and thereby close the top of the channel. By deformation of the resiliently deformable member, the leg portion of the lasted upper of high-legged boot can be inserted between the members to be supported thereby as it is conveyed along the channel.

Abstract: A single-station combined toe and side lasting machine comprises pulling over instrumentalities 20, 22 for tensioning an upper over its last, toe lasting instrumentalities, including toe wipers 38, toe pad 48 and toe band 50, a heel support 56, two adhesive applying nozzles 28 and side lasting instrumentalities 114 constituted by two lasting rollers 176. In operation, with the upper tensioned, first the shoe is clamped by the toe lasting instrumentalities and heel support to allow adhesive to be applied progressively along opposite side portions from the toe to heel breast. Then the lasting rollers operate progressively from the ball region to the heel breast, and, when the rollers have cleared the ball region, the inwiping movement of the toe wipers is completed. The nozzles and side lasting rollers are mounted on a common carriage 26 which moved rectilinearly, supports 116 for the rollers being mounted for movement thereon about three perpendicular axes 82, 122, 140.

Abstract: The machine comprises a plurality of substantially enclosed channels in which a lasted shoe upper is subjected to hot air blown from both sides of the channel. Conveyors carry the uppers along the channels past inlets located at a distance of from 6 to 20 cms from the center-line of the lasted upper as it passes longitudinally along the channel. This arrangement enables air to be blown on to the uppers at high velocity. Moistening means may be provided to introduce moisture into the air before it is blown on to the uppers.

Abstract: Waxy, normally solid hydrocarbons are alkylated to form liquid hydrocarbons boiling in the lube oil range by contacting the wax and a low molecular weight olefin, such as ethylene, with a catalyst comprising a C.sub.3 -C.sub.5 carbon atom secondary alcohol at elevated temperature and pressure. This process is useful for making relatively high VI lube oils from wax, for decreasing the pour point of jet fuels and for dewaxing lube oil feedstocks.

Abstract: The thermal decomposition of N-methyl-2-pyrrolidone is minimized by the addition of minor amounts of water thereto prior to its being heated to temperatures in excess of 500.degree. F. This is of particular importance in processes using N-methyl-2-pyrrolidone as an extraction solvent to remove aromatics from mixtures of aromatic and non-aromatic hydrocarbons and wherein the N-methyl-2-pyrrolidone is recovered from the extracted fractions by thermal means such as flash evaporation and distillation.

Abstract: A multi-layer Auger suppressed diode having at least two exclusion interfaces and at least two extraction interfaces. A specific embodiment has two composite contacts, each consisting of a heavily doped layer (3, 4) and a buffer layer (8, 9) of lower doped, high bandgap material sandwiched between the heavily doped layer and the active region (2) of the device.