Abstract: A real time ultrasound imaging system which includes coherent demodulation of echo signals followed by time delay and coherent summation of the demodulated signals is described. As the range from which echoes are being received increases, coherent demodulation is maintained. Demodulation and time delay accuracies are relatively easy to maintain over a large field of view and a long range. The system has high resolution and high sensitivity.

Abstract: A real time ultrasound imaging system which includes coherent demodulation of echo signals followed by time delay and coherent summation of the demodulated signals is described. As the range from which echoes are being received increases, coherent demodulation is maintained. Demodulation and time delay accuracies are relatively easy to maintain over a large field of view and a long range. The system has high resolution and high sensitivity.

Abstract: In a charge transfer transversal filter a substrate of one conductivity type semiconductor material is provided. A first plurality of electrodes insulatingly overlie the substrate, each split into a first and a second part with a small gap therebetween. A second plurality of electrodes insulatingly overlie the substrate, each spaced between the adjacent electrodes of the first plurality. A first clock line is connected to the first parts of the first plurality of electrodes and a second clock line is connected to the second parts of the first plurality of electrodes. A fixed d-c voltage is applied to the first and second clock lines. A voltage pulsating above and below the fixed d-c voltage is applied to the second plurality of electrodes. Means are provided for introducing packets of charge representing sequential samples of an analog signal into the filter.

Abstract: A charge transfer filter includes an accumulator charge storage location and means for alternately introducing charge into the accumulator charge storage location and then for removing a preselected fraction of the total charge in the accumulator charge storage location so that the total accumulated charge is known.

Abstract: A charge transfer filter includes an accumulator charge storage location and means for alternately introducing charge into the accumulator charge storage location and then for removing a preselected fraction of the total charge in the accumulator charge storage location so that the total accumulated charge is known.

Abstract: Signal processing apparatus is disclosed comprising a plurality of charge storage cells, each including first and second storage regions in a semiconductor substrate. Means are provided responsive to a scanning signal for introducing into each of the cells a respective quantity of charge, a first portion of which is contained in one of the storage regions and represents a respective analog signal sample. Means are provided for transferring each first portion of charge from one storage region to the other storage region in a respective cell in response to a respective second signal. Means are provided connected in circuit with the first electrodes for sensing the charge transferred to and from the first charge storage regions of the cells for detecting the signal samples.

Abstract: In signal detection apparatus for sensing large excursion of a time varying signal from its average value, charge transfer circuits are utilized to provide a threshold level for detection which adapts to the changing average value of the background component of the time varying signal.

Abstract: An analog multiplier for multiplying each sample of an input sequence of samples of an analog signal by a respective multiplying coefficient of a series of coefficients is provided. The multiplier includes a plurality of charge storage cells, each cell including a first and a second storage region. Means are provided for introducing into each of the charge storage cells a respective quantity of charge representing a respective sample of a signal. The quantity of charge is divided between the first and second storage regions of a cell in proportion to the ratio of the width of the first storage region to width of the second storage region thereof. Means are provided for altering the charge in each of the second storage regions of each of the cells.

Abstract: A plurality of charge storage cells, each including first and second storage regions, are provided in a semiconductor substrate. Means are provided responsive to a scanning signal for introducing into each of the first charge storage regions a respective quantity of charge proportional to a respective sample of an analog signal. Means are provided responsive to the bits of one value of a digital reference word for maintaining storage of the analog samples in the first storage regions of the cells associated with such bits of one value. Means are provided responsive to bits of the other value of the digital reference word for transferring the analog samples to the second storage regions of the cells associated with such bits of the other value.

Abstract: The output circuit includes a high gain differential amplifier having an inverting input terminal, a non-inverting input terminal and an output terminal with a feedback capacitance connected between the output terminal and the inverting input terminal. The input terminals are connected to first and second commonly phased lines of the charge transfer transversal filter. A first switchable impedance means is connected between the first line and the output terminal. A second switchable impedance means is connected between the second line and a d-c source of voltage. The lines are charged periodically to the voltage of the source by the first and second switchable impedance means prior to the transfer of charge in a cycle of operation of the filter and are then isolated from the source during the transfer of charge in the filter by the first and second switchable impedance means.

Abstract: In a charge transfer transversal filter a semiconductor substrate is provided with main and parallel portions. A group of serially arranged electrodes insulatingly overlie and are uniformly spaced from the channel portions. The electrodes form with the substrate a plurality of stages of first and second charge transfer shift register over the main and parallel channel portions of the substrate, respectively. One electrode of each of the stages of the shift registers has a split along the length dimension thereof over the main channel portion dividing each of the one electrodes over the main channel portion into a first part and a second part with a third part overlying the parallel channel portion. The first parts of the one electrodes are connected to a first conductive line and the second and third parts of the one electrodes are connected to a second conductive line. The area of the first parts of the one electrodes being equal to the sum of the areas of the second and third parts of the one electrode.

Abstract: Methods for storing and transferring electrical charges between adjacently spaced storage regions in semiconductor substrate are disclosed. In one embodiment, a plurality of adjacently spaced conductor members are insulatingly disposed over a major surface of a semiconductor substrate. Each storage region is separated from each other storage region by an electrical barrier region underlying the spacing between the adjacent conductor members. These barrier regions are controllably lowered by an electrode interposed between adjacent conductor members. Electrical charges stored in one storage region are transferred to an adjacent storage region by applying a voltage signal to the interposed electrode to lower the barrier region between the adjacent storage regions. Direction of charge transfer is controlled by the relative surface potentials of the adjacent storage regions and the magnitude of transfer is controlled by the height of the barrier region when lowered.

Abstract: In optical imaging apparatus a semiconductor substrate in which a pattern of charge is produced in a plurality of charge storage sites therein in accordance with a spatial pattern of radiation, output means are provided for deriving an output comprising signals proportional to the algebraic sums of selected combinations of the charge in the plurality of charge storage sites.

Abstract: In a charge transfer transversal filter a substrate of one conductivity type semiconductor material is provided. A plurality of electrodes insulatingly overlie the substrate and form therewith a plurality of stages of a charge transfer shift register. One electrode of each of the stages is split into a first and a second part with a small gap therebetween. A region of opposite conductivity type is provided in the substrate underlying each of the gaps to electrically couple the pair of storage regions underlying each of the one electrodes. A first clock line is connected to the first parts of the one electrodes. A second clock line is connected to the second parts of the one electrodes. Means are provided for applying phase related voltage to each of the stages of the shift register to effect transfer of charge from stage to stage. The same voltage is applied to the first and second clock lines.

Abstract: The output circuit includes a high gain differential amplifier having an inverting input terminal, a non-inverting input terminal and an output terminal with a feedback capacitance connected between the output terminal and the inverting input terminal. The input terminals are connected to first and second commonly phased lines of the charge transfer transversal filter. First and second charging and isolating means are connected between a source of operating voltage and the first and second commonly phased lines, respectively. The lines are charged periodically to the voltage of the source by the first and second charging and isolating means prior to the transfer of charge in a cycle of operation of the filter and are then isolated from the source during the transfer of charge in the filter by the first and second charging and isolating means.

Abstract: Apparatus and methods for regenerating electrical charges to predetermined levels are disclosed. In one embodiment, electrical charges are regenerated in response to a changed voltage condition on an electrically isolated diffused region adapted to receive such charges. The regenerated charges are of predetermined magnitudes substantially independent of the magnitude of the received charge except for whether or not the received charges are above or below a threshold value. Means for regenerating a level of charge substantially less than 100 per cent of a normalized charge are also disclosed.

Abstract: In a charge transfer device electrode operating voltage is applied through a high-gain differential amplifier having an inverting and a non-inverting input terminal with capacitive feedback from the output terminal to the inverting terminal. The inverting terminal is connected to the charge transfer device electrode. The non-inverting terminal is connected to a source of operating voltage. During the transfer of charge the voltage on the electrode is maintained substantially constant and a voltage change is produced at the output of the amplifier which is approximately equal to the induced charge divided by the feedback capacitance.