Abstract: A hand-held optical reader for reading printed indicia on a remote target includes a light source for generating a scanning light beam and a detector for detecting the light reflected from the printed indicia. The light source and detector are housed within a housing having a window through which the light beam passes from the source to the target for reflection from the target to the detector. The housing includes parallel front and rear faces, each being generally rectangular in shape and having a lower portion and upper portion. The front and rear faces are joined by a substantially planar base face at their lower edges. The window is disposed in the front face with the reader being ergonomically configured so as be comfortably held in the hand of a user, with the user's palm adjacent the rear face to enable the user to direct the scanning light beam at a remote target.

Abstract: Data is protected in a data transmission system operating on the synchronous digital hierarchy. The data is transmitted in multiplex form between ports in the system and protection is applied between ports at different or the same aggregate bit rates. This protection is achieved by selecting between individual portions of the payload within the aggregate signals and each part of mutually protective portions has the same nominal traffic capacity. By duplexing an alternative signal path is created to ensure a continuity of traffic through the system in the event of a fault in one path.

Abstract: A bare die testing apparatus comprising a multilayer interconnection structure 10 having a testing station 11 for testing the bare die 20, testing circuits and components 12 arranged in said structure adjacent the testing station 11, said testing station 11 having a plurality of microbumps 17 of conductive material soldered onto wettable metallization pads 18 located on interconnection trace terminations of the interconnection structure, said terminations being connected through the interconnections of the multilayer structure to said testing circuits and components 12. The microbumps 17 are distributed in a pattern corresponding to the pattern of contact pads 19 on a bare die 20 to be tested.

Abstract: A loading probe for use in testing transducers includes an elongated body capable of simulating the normal acoustic impedance presented to a transducer to be tested by the medium in which the transducer is to operate. The main body of the loading probe has a tube made from a rigid material, and a rod having an elongated convergent portion extending into the interior of the tube so as to define a cavity which has a varying cross section. The cavity houses a core of material having a close match of acoustic impedance with the material of the tube and rod but a higher acoustic loss factor. The cavity is sealed. The active end of the loading probe carries a piezoelectric element having a planar form, and a protective end cap is bonded to the active end of the loading probe to enclose the piezoelectric element.

Abstract: In a process for producing a narrow groove in a layer of, for example, silicon nitride, a wide groove is first formed in the layer. A layer of a metal, for example aluminium, is evaporated on to one side of the wide groove. The remainder of the wide groove is then filled with a material such a silicon nitride. The metal layer is then etched away, leaving a narrow groove in the silicon nitride equal to the thickness of the metal layer.

Abstract: Moving side panels of a display stand toward each other causes shelf supports to automatically move individual shelves from shelf-up to shelf-down positions during erection of the stand from a collapsed to an erect state.

Abstract: A duo-binary and/or binary data slicer has a data input (10) coupled via a capacitor (C1) to a d.c. restoring circuit (A2 to Q6 and Q9 to Q13) d.c. reference level is superimposed on the data signal. A sample and hold circuit (C2, Q15 to Q22) is arranged to sample the data signal and provide a voltage related to the upper and lower peak value. A divider (R16-R19) is coupled between the d.c. reference level and the voltage related to the upper and lower peak value and provides intermediate output voltages (DU, DL, B) relating to duo-binary and/or binary level for determining the slicing levels.

Abstract: A data transmission system in which multiplex data is created in accordance with the Synchronous Digital Hierarchy standard includes an add-drop multiplex having a switch across which data streams are switched between a pair of multiplexers and each input and output for a stream has a rejustifier circuit the timing of which is extracted from a timing extract from the other side of the switch.

Abstract: This method enables two components (1, 3) to be joined by soldering using heat generated by a laser beam, without the use of flux. A layer (5) of a material which has a lower melting point than the material of one of the components (3) is formed on that component and forms a bond therewith on resolidifying after melting. Solder (7) is interposed between the layer (5) and the other component (1) to form, on resolidification after melting, bonds with the material of the layer (5) and the other component (1). A coating (11) of a further material between the layer (5) and the solder (7) is dispersed when the adjacent layer material becomes molten and is not wetted by the solder (7) when molten. On applying heat to a region (15) of the layer using a laser beam, the layer is melted in this region (15) as is the adjacent solder (7) to form, on resolidification of the solder (7) and molten layer material (15 ), bonds between the solder (7) and the two components (1, 3).

Abstract: A tracking radar system comprising an aerial arrangement having a plurality of outputs, means for deriving from the aerial outputs a sum signal representative of the sum of the aerial outputs and a difference signal representative of the direction of a target relative to the aerial, a receiver for processing said sum and difference signals to produce corresponding intermediate frequency sum and difference signals, means for comparing the intermediate frequency sum signal with the output of an oscillator in a first phase-locked loop and using the resulting signal to control the oscillator frequency so as to cause the oscillator to lock on to the frequency of the intermediate frequency sum signal, a phase-sensitive detector for comparing the intermediate frequency difference signal with the output of the oscillator to produce an output signal representative of the phase difference between the sum and difference signals, and bandwidth alteration means responsive to the sum signal to alter the bandwidth of the fi