Abstract: The apparatus and method of the present invention operates upon the problem of contouring that is encountered in the digital image processing field. The preferred apparatus embodiment of the invention forms quantizing steps that vary in size during the processing of signals in order to minimize contouring effects. The embodiment includes a transforming function block for receiving digital input signals each representing a magnitude value requiring quantization, the transforming function block provides an output gain value that is a function of the magnitude of the value of each received digital input signal. A quantizer is provided for receiving the digital input signals and for performing quantizing steps on the digital input signals to provide a multibit quantized digital signal. A first randomizer is used to randomize the least significant bits of the multibit quantized digital signal when the output gain value is less than or equal to threshold value.

Abstract: An integrating analog-to-digital converter system in which alternating and different combinations of signals are integrated, and which are selected for such integration both periodically and through an integrating result reaching a reference value in the periods. A digit count is provided as a system output indicating the time duration of integration of a selected signal combination in each period.

Abstract: A method and device for acquiring signals by amplifying, sampling and digitizing for permanently controlling the stability of the gain at each successive sampling cycle carried out on the signals as disclosed. A first digitizing of a non amplified signal sample and at least a second digitizing of an amplified signal sample is performed at each cycle. Each gain is measured by establishing a ratio between the values respectively obtained at the end of each second digitizing and of the first digitizing, and the amplifier gain is corrected if the gain of each gain actually applied to the acquired signal has deviated from a nominal value. The invention has an application to the digitizing of seismic signals.

Abstract: A recording method includes converting an original sound signal into a digital sound signal in a selected conversion range, selecting the conversion range in accordance with the amplitude information of the original sound signal, and storing and recording the digital sound signal. The apparatus includes a first selecting arrangement for selecting a conversion range which corresponds to amplitude information of an original sound signal, a converting arrangement for converting the original sound signal into a digital sound signal in the conversion range selected by the selecting arrangement, and a first memory for storing the digital sound signal converted by the first converting arrangement.

Abstract: A method for analog-to-digital conversion includes the steps of applying a first transfer function to the input signal and amplifying the input signal by a defined gain factor to obtain an edited signal, subject chronologically successive samples of both the input signal and the edited signal to analog-to-digital conversion and thereby obtaining digital data having a defined number of bits corresponding to the input signal and digital data having a defined number of bits corresponding to the edited signal, multiplying the digital data corresponding to the input signal by a defined factor equal to the gain factor, applying a second transfer function to the digital data corresponding to the input signal by digital filtering, and undertaking calculations on the signals obtained in this manner to obtain a final analog-to-digital conversion result. An apparatus operating according to this method is also disclosed.

Abstract: An apparatus for effecting echo suppression facilitating communications between an analog device and a digital device comprising a transmit circuit for processing outgoing signals, a receive circuit for processing incoming signals, and a control circuit for controlling the transmit circuit and the receive circuit. The transmit circuit includes transmit attenuators for attenuating the outgoing signals as they pass through the transmit circuit, and an analog-to-digital conversion circuit for converting analog signals to digital signals. The receive circuit includes receive attenuators for attenuating the incoming signals as they pass through the receive circuit and a digital-to-analog conversion circuit for converting digital signals to analog signals. Each of the transmit attenuators and the receive attenuators is digitally adjustable by the control circuit.

Abstract: A method for analog-to-digital conversion of a chronologically changing, analog input signal includes the steps of forming an edited signal from an input signal by subjecting the input signal to a first transfer function and amplifying the result by a defined gain factor, sampling the input signal and the edited signal and subjecting the sampled signals to analog-to-digital conversion to obtain first and second digital data respectively corresponding to the edited signal and the input signal. The number of bits in each of the first and second digital data determines the dynamic range of the analog-to-digital conversion. The first digital data, corresponding to the input signal, are multiplied by a defined factor equal to the defined gain factor. If a transgression of the dynamic range in the analog-to-digital conversion has not occurred, the final analog-to-digital conversion result is calculated making use of the second digital data corresponding to the edited signal.

Abstract: A floating point analog to digital converter having an exponent converter which divides the input signal successively one-half until the divided signal is within the range of a mantissa linear analog to digital converter. The exponent converter also generate a digital exponent representative of the division factor. The resulting divided signal is then digitized by the mantissa analog to digital converter. An output is thereby provided composed of a digital exponent and a digital mantissa. In one embodiment, the floating point converter is a charge mode converter suitable for direct interface to a charge mode device such as a CCD image sensor.

Abstract: An adaptive dual range analog to digital converter particularly adaptive for use with film scanners employs a set-up parameter input arrangement for receiving externally generated control signals for adjusting the digital quantization step size of the analog to digital converter to compensate for quantization errors. According to a further embodiment of the present invention, the adaptive dual range analog to digital converter further includes an input signal range selection device for selecting a segment of the input analog signal to be converted to digital form using fine resolution quantization.

Abstract: A signal processing device comprises a comparator, a first reference signal generating unit, a second reference signal generating unit and reference signal controller and switch which is switched when the data head data of the input signal is detected by the controller. In the case when the content of the input signal is a clock producing data, the reference signal generated in a rapid process of the first reference signal generating unit is entered in the comparator, and in the case when the content of the input signal is a reproduction data, the reference signal generated in a slow process of the second reference signal generating unit is entered in the comparator so as to be compared with the input signal.

Abstract: An analog-to-digital converting unit comprises an analog level varying circuit having a plurality of gains and varying a magnitude of an analog input signal for producing a plurality of analog output signals different in magnitude from one another with the respective gains, a plurality of analog-to-digital converting circuits respectively supplied with the analog output signals and producing a plurality of digital code signals, respectively, a controlling circuit supplied with two of the digital code signals and calculating a difference therebetween for producing a first control signal indicative of varying one of the digital code signals in value so as to be equal in value to the other digital code signal, a calculating circuit responsive to the first control signal and causing one of the digital code signals to be varied in value for producing a candidate of a digital output signal, and an output circuit coupled to one of the analog-to-digital converting circuits and to the calculating circuit and supplying

Abstract: An automatic gain control system for controlling a gain of an A/D converter automatically by controlling reference voltages of said A/D converter at the time of analog-to-digital conversion of a signal which signal being clamped by a clamp circuit to a clamp level which is set to a center level before entering said A/D converter, comprising a clamp level control circuit for detecting the clamp level from an output of said A/D converter to control the clamp level; a first A/D converter for digital-to-analog converting an output of said clamp level control circuit; an automatic clamp level control system.

Abstract: An acquisition device for digitizing highly dynamic signals. After amplification in a fixed gain amplifier, the signals are applied to a sample and hold unit, the output of which is connected to an analog-to-digital converter to which a variable reference voltage is applied. This reference voltage is available at the output of a multiplexer to the inputs of which voltages are applied derived from sub-divisions of a calibrated voltage. The choice of the reference voltage is effected by a logic assembly as a function of the comparisons made by comparators between the sampled voltage and the derived voltages. The digitized signals are represented by a digital word from the converter and a digital word of gain G from the logic assembly.

Abstract: An exponential analog-to-digital converter comprises two gain stages, each of which includes a binary-weighted capacitor array. The capacitors are switched in succession to multiply the gain of a sampled analog input signal, while a counter counts down for each switching step from an initial setting of binary 111. When the gain signal has a value outside a predetermined reference voltage range, a 3-bit binary digital word representative of the analog input signal sample is registered in the counter. If the gain signal produced after all the capacitors have been switched in to provide the maximum gain does not fall outside the reference range, then the binary word stored in the counter for the sample of the analog signal is 000.

Abstract: A video system suitable for use in an endoscope/borescope and includes keyboard actuated circuits for dynamically controlling analog to digital converters to minimize noise interference and maximize information obtainable from the image displayed on a TV type display system.

Abstract: A circuit for automatically matching the gain and offset of a time-shifted digitizing channel in a data acquisition circuit which includes a reference digitizing channel, having a fixed voltage reference, and at least one time-shifted digitizing channel having components that are adjustable for gain and offset. Feedback is provided by examining the dynamic range and average value of a known input signal which is digitized, sent through the time-shifted digitizing channel and stored in memory. A microprocessor reads the stored data and, by separately varying the gain and offset parameters, computes optimal values for each parameter. Digital-to-analog converters (DAC's) allow the microprocessor to communicate with one fixed-gain variable-offset amplifier in the front end and with one fixed-gain variable-offset amplifier and one analog-to-digital converter (ADC) in each time-shifted digitizing channel.

Abstract: An adaptive single-bit encoder and decoder has its adaptive function determined by dynamically dividing the message frequency band into delta-sigma and delta modulation regimes of operation. In a practical embodiment this is accomplished by varying the corner frequency of a variable-frequency low-pass filter in a leaky integrator so that below the corner frequency the operation is that of delta-sigma modulation and above the corner frequency the operation is that of delta modulation. An adaptation control circuit removes the clock signal component from the encoded bit stream to provide an analog signal representative of bit stream information or loading for use in generating the control signal. The analog signal is peak rectified, smoothed, and (optionally) non-linearly processed to provide the control signal.

Abstract: The same analog signal is inputted to an 8-bit AD converter and to a 4-bit AD converter to obtain an 8-bit digital data and a 4-bit digital data for the same sample value of the analog signal. Values of the 8-bit digital data and 4-bit digital data are compared with each other. The 8-bit digital data is outputted as a digital signal for the sample value of the analog signal when a difference between these values is not greater than one-half the quantity that corresponds to the least significant bit of the 4-bit digital data, and the 4-bit digital data is outputted as a digital signal for the sample value of the analog signal in other cases. There is realized AD conversion which operates apparently at high speeds maintaining high accuracy.

Abstract: An A/D converter circuit generates a precise digital signal which accurately corresponds to an analog input signal. The A/D converter comprises a converter element, having a first and second, input terminal for receiving control signals, and having an output terminal, and further having at least one analog input terminal. The analog input signal is coupled to the analog input terminal, for converting the analog input signal to an uncorrected digital signal. The uncorrected digital signal includes inaccuracies of the parameter differentials of the converter element. A memory unit, stores information defining the actual parameter values of the converter element. A processor, controls the conversion of the analog input signal to the precise digital signal, wherein the actual parameter values are applied to the uncorrected digital signal thereby removing the inaccuracies of the converter element to obtain the precise digital signal.

Abstract: A digital signal processing circuit for processing input analog signals such as audio signals and video signals in the form of digital signals comprises an analog-to-digital converter for converting an input analog signal to a digital signal, a digital signal processing section for subjecting an output digital signal of the analog-to-digital converter to a digital signal processing including a processing for digitally amplifying the signal, a digital-to-analog converter for converting an output signal of the digital processing section to an analog signal, and an attenuator provided on the input side of the digital signal processing section for attenuating the digital signal provided by the analog-to-digital converter to a value which is below a value at which the digital signal processing section overflows.

Abstract: Apparatus for control of the range of input voltage values to be measured and for compensation of the changes in the supply voltage of an analog to digital dual slope converter circuit is described. The selection of a range for input voltage measurements in the analog to digital converter circuit permits the conversion to take place over a relatively long time period, thereby increasing the resolution of the resulting conversion. Changes in the supply voltage are combined with the input analog signal (during the capacitance charging period) and with the reference voltage (during the capacitance discharge cycle) providing compensation for the effects of time, temperature and the tolerance of the supply voltage.

Abstract: A transient electromagnetic apparatus for use in detecting irregularities on conductive walls of containers forms a multichannel distributed system and includes at least one transmitting antenna, at least one transmitter unit, plural receiving antennas, plural receiver units, and a computer for controlling the transmitter and receiver units. The receiver units each include elements that suppress noise in the received signals. Each receiver unit has a preamplifier, first and second low pass Bessel type filters, a gain ranging amplifier, and an A/D converter. The gain ranging amplifier receives feedback from the output of the A/D converter and provides increased small signal resolution. Each receiver unit also rejects common mode noise with a choke and balanced input impedances in the preamplifier. The apparatus allows an arbitrary number of receiving antennas, receiver units, and even transmitting antennas, and transmitting units, so that the apparatus can be configured to a variety of containers.

Abstract: The object of the present invention is the improvement of logarithmic amplifiers and/or converters and the applications of such devices in particular to photometric analyzer apparatuses.These amplifiers are characterized by the fact that they are linear with an amplification gain programmable by the .mu.P computer and that they may be preceded optionally by a reference voltage system.Application to the measurement of light transmitted by samples.

Abstract: A high resolution analog to digital (A/D) converter amplifies and filters a magnitude difference between a pulse width modulated offset voltage and an input voltage to produce an amplified filtered difference voltage, the duty cycle of offset voltage modulation being adjusted such that the magnitude of the difference voltage is within a narrow input voltage range of a recirculating remainder A/D converter. The amplified, filtered difference voltage is converted to representative digital data by the recirculating remainder A/D converter. A microprocessor, which controls the offset voltage, combines the result with the magnitude of the offset voltage to produce a comparatively high resolution digital representation of the input voltage.

Abstract: In this transducer, for converting an analog input signal into an analog output signal whose level corresponds to the level of the analog input signal, there are included: an A/D converter for converting the analog input signal into a digital signal; an input device comprising a plurality of switches; an upper limit setting means for setting an upper limit value for the analog input signal, according to operation of the switches; a lower limit setting means for setting a lower limit value for the analog input signal, according to operation of the switches; a storage device, for storing a current value of the digital signal output by the A/D converter; a comparison means for comparing the current value of the digital signal output by the A/D converter as converted from the analog input signal, and the upper limit value and the lower limit value, all of which are stored in the storage device; an output means for producing an output when the comparison executed by the comparison means indicates that the current

Abstract: Apparatus for measuring current over a wide range generates an eight bit accurate, 16-bit dynamic range digital signal from a current transformer secondary. Two signals proportional to the rectified secondary current, one generated by a large burden resistor and the other by an amplifier with programmable gain and an overrange indication, are applied through a multiplexer to an eight bit analog to digital converter which has three selectable reference voltages. A microprocessor selects the input signal, converter reference voltage, and one of four levels of amplifier gain which provide the greatest resolution for the magnitude of the current being measured, and provides an appropriate scale factor, from 2.sup.0 to 2.sup.8, for the eight bit accurate digital signal generated by the analog to digital converter.

Abstract: An automatic level control circuit for a multi-level quadrature amplitude-modulated (QAM) demodulator having a QAM detector, which produces baseband in-phase (P) and quadrature (Q) signals in response to an input QAM camer wave, and two analog-digital (A/D) convertors which convert the Q and P signals into two parallel digital signals. Automatic level control of the input level of the baseband signal to the A/D convertor is maintained constant by the combination of a reference signal generator in a feed back loop with each A/D convertor. The A/D convertor produces a decoded digital signal and the reference voltage generator, in response to those signals, provides reference voltage to the A/D convertor that are optimized in response to variations in input signal level.

Abstract: A variable gain analog to digital compression encoder apparatus and method is operational for `on the fly` gain adjustments without introducing significant distortion or noise in telephone conversation. An incoming analog signal is fixed gain reproduced as a first stabilized mid-operating point analog signal. A second stabilized mid-operating point analog signal is produced in inverse proportion to the first stabilized mid-operating point analog signal, in response to a signal tapped along a signal division of a difference between the first and second signals. The second signal is compression encoded at a predetermined rate to produce pulse code modulated signal samples. The tap may be varied to change the encoding gain, at any time, in accordance with operating requirements of a telephone apparatus.

Abstract: A received multi-level signal is demodulated and when drift of the received signal is comparatively small, an error signal is selected, integrated and added to the received signal to correct the drift. The error signal is indicative of a condition of an anglog-to-digital conversion or decision level of the received signal. The condition of the decision level is monitored and when, on the basis of the monitored decision level it is detected that drift of the received signal is large, the error signal is selected corresponding to a specified range and includes bit signals of higher order than a most significant bit and of lower order than a least significant bit of the converted digital signal. The selected error signal is then integrated and added to the demodulated received multi-level signal. A pseudo pulling condition in feedback control is thereby prevented.

Abstract: Apparatus including an analogue-to-digital converter 26 having a given number of digits, includes a variable gain amplifier (23) for the input (VA) to the converter (26). If any one instantaneous value (21A) of the input (VA) is less than is necessary to saturate the converter (26), i.e. to use all the digits of the converter (26), the gain of the amplifier (23) is automatically set to amplify the instantaneous input (21A) to the extent necessary to saturate the converter (26). By such selective amplication of different outputs (VA), each instantaneous value (21A) is digitized by the full number of digits of the converter (26) and the resolution of the apparatus is the same for all inputs (VA) regardless of their magnitude. On the other hand the converter is not over-saturated such as could be the case if the different inputs (VA) were amplified by a common gain.

Abstract: An analog-to-digital conversion circuit comprises a level detection circuit for detecting the level of an analog input, an amplifier for amplifying the analog input with its amplification degree increased when the detected level is smaller than a predetermined level and decreased when the detected level is larger than a predetermined level, an analog-to-digital converter for analog-to-digital converting the output the amplifier and an attenuator provided in a posterior stage of the analog-to-digital converter for attenuating the digital output of the analog-to-digital converter in association with the amplification degree of the amplifier to maintain a total gain between the analog input and the digital output substantially constant irrespective of the level of the input signal.

Abstract: An oversampled A/D converter which utilizes digital error correction is provided. In one form, the present invention is used with a sigma delta modulator having a plurality of rank ordered quantization loops, Each quantization loop contains an analog integrator circuit of predetermined gain which is subject to variation, thereby introducing errors. When the product of a reciprocal of the analog integrator gain and the gain of a digital gain stage of a subsequent quantization loop equals one, minimum noise exists in the data conversion. A digital gain control circuit is coupled to the digital gain stage for adjusting the gain of the digital gain stage during a calibration mode to provide minimum noise in the converter, thereby compensating for errors attributable to the analog integrator circuit.

Abstract: In a device which is for use in a receiver of a multivalued digital communication system and which includes a reference voltage producing circuit (51) for producing signal discriminating reference voltages and signal regenerating reference voltages related to one another, a level discriminating circuit (31) for discriminating a multivalued received signal with reference to the signal discriminating reference voltages to produce a local encoded signal, a signal decoding circuit (32) for decoding the local encoded signal into a decoded signal, a signal regenerating circuit (33) responsive to the local encoded signal for regenerating a multivalved regenerated signal having the signal regenerating reference voltages, a comparator (34) for comparing the received and the regenerated signals to produce a result of comparison, and an integrator (35) for integrating the result of comparison to produce a result of integration, the signal discriminating and regenerating reference voltages are regulated by the result of

Abstract: An analog-to-digital converting apparatus includes an analog controllable gain amplifier (A.sub.1) connected to an input of an analog-to-digital converter A/N. A gain control signal of the amplifier (A.sub.1) is obtained from at least one comparator (D16, D240, D224) for making a binary comparison between an output level of the analog-to-digital converter (A/N) and at least one predetermined threshold, and circuitry (SEL2, S.sub.2, I.sub.2) for controlling with respect to time the gain of the amplifier (A.sub.1) as a function of the result of the comparison.

Abstract: An adaptive range circuit (10) suitable for use with an analog to digital convertor (11) having operating range control inputs. The invention includes a peak detection unit (12) that can include a positive peak detector (13) and a negative peak detector (14) that provide signals representative of positive and negative peaks for the incoming analog signal to be digitized. These representative signals can be utilized to control the operating range of the A/D convertor (11).

Abstract: A floating point analog-to-digital converter providing a variety of analog representations of the analog signal value to be converted, each of which representations is converted to a digital equivalent from which the floating point result is obtained.

Abstract: An analog-to-digital conversion system for converting an analog signal to a digital signal for recording is configured to detect a low level period of the analog signal, amplify a low noise in the analog signal in the detected period by a predetermined multiplying ratio or by an amount corresponding to the signal amplitude, and subtract from the converted digital signal a number of bits corresponding to the amplification degree in the same period after analog-to-digital conversion, so as to reduce the influence of a noise entering in the analog signal before analog-to-digital conversion.