Abstract: A one-dimensional scanner system for two-dimensional image acquisition includes a flying spot scanner for scanning in a line at a first velocity in a first direction across an object which is moving at a second velocity in a second direction transverse to the first direction; the first and second velocities establish a first sample rate in the second direction for defining a pixel size in the second direction; a timing device for detecting the velocity of the object in the second direction and generating a sample rate in the first direction and a frame accumulator for reading and storing each line scanned, assembling a two-dimensional image of the object and reading out that image; the frame accumulator including a compensation device responsive to the second sample rate for normalizing the second sample rate with the first sample rate to eliminate distortions in the pixel size and two-dimensional image in the first direction.

Abstract: A high-speed, high-resolution optical scanner system includes a flying spot scanner for scanning a beam across an object bearing information to be read and a high-bandwidth, high-sensitivity optical receiver including an avalanche photodiode for sensing the variation in light intensity of the beam reflected from the object being scanned; a power source for biasing the avalanche diode proximate its reverse breakdown voltage to produce high current gain in response to incident light; and a charge collector circuit responsive to the avalanche photodiode for producing a voltage proportional to the light incident on the avalanche photodiode.

Abstract: An intensity compensated scanning system includes laser means for providing a laser beam; scanner means for sweeping the laser beam in an arcuate path across a surface to be scanned; means for sensing the return laser beam reflected from the surface to be scanned; means for quantifying the decrease in the intensity of the return laser beam at the scan extremity portion relative to the intermediate scan portion; and means responsive to the means for quantifying for varying the power to the laser means at the scan extremity portion relative to that at the intermediate scan portion for balancing the intensity of the return laser beam reflected from the surface to the means for sensing.

Abstract: A bar code reader system for reading bar code labels with highly specular spaces and bars with low contrast. The bar code label is illuminated with radiation polarized in a first direction. The radiation polarized in a first direction reflected from the bar code label is received and blocked by means of cross polarization. This blocked radiation is representative of the spaces and other radiation passing through unblocked is representative of the bars. The resulting radiation pattern representative of the bars and spaces is consequently inverted from its initial state into a secondary state. The radiation image passed by the block is detected in order to generate a signal representative of the bars and spaces. The strength of the signal representing the spaces is substantially diminished in intensity. The widths of the areas representing the bars and spaces is determined, and the widths representing the bars and spaces are interpreted to obtain the information of the bar code.

Abstract: An improved bar code reading system for reading bar codes having a wide range of intensity of reflected radiation includes repeatedly scanning a beam of radiation across a bar code containing bar and space code elements; monitoring the number of scans of the beam across the bar code; sensing the radiation reflected from the bar code and providing a bar code signal representative thereof; the bar code signals are amplified at one of a number of different gains, and a different gain is selected for each scan. Also disclosed is an improved bar code reader system for reading bar codes of diffuse bar elements and specular spaced elements.

Abstract: A follower response control circuit for a reference level establishing system having positive and negative follower circuits, each having means for defining a pre-established time constant producing, respectively, a positive peak signal and a negative peak signal in response to an input signal, and means responsive to the peak signals for establishing a reference level, including means for defining a second time constant for one of the follower circuits; switching means for selectively switching the means for defining a second time constant in and out of that one of the follower circuits; a direction detector circuit for determining whether the input signal level is moving toward the polarity of the peaks followed by that one of the follower circuits; a level detector circuit for determining whether the input signal is of the same polarity of the peaks followed by that one of the follower circuits; and a switch control responsive to the detector circuit for operating the switching means to introduce the means

Abstract: Apparatus for determining whether the ratio of the widths of a pair of signals is within acceptable limits including integrator means, including a first integrator responsive to a first signal to integrate in a first direction at a first rate and to a second signal to integrate in the opposite direction at a second rate and a second integrator responsive to the first signal to integrate in the first direction at the second rate and to a second signal to integrate in the opposite direction at the first rate; indicator means responsive to the integrator means for providing a data signal representative of the first and second signals have the proper ratio beginning in response to the second integrator reaching a first predetermined level and ending in response to the first integrator reaching a second predetermined level and control means, responsive to the end of the second signal occurring during the presence of the data signal to provide a clock signal validating the data signal and to the end of the second s

Abstract: A variable permeability magnetic object detection device including an electromagnetic sensing coil; a core disposed in the electromagnetic sensing coil having a first permeability when the core is magnetically saturated and a second different permeability when the core is magnetically unsaturated; a magnetic member proximate the electromagnetic sensing coil for providing a magnetic field in the core for operating the core in a magnetically saturated state without a magnetic object to be detected present in the area proximate the electromagnetic sensing coil, interacting with the magnetic field, and for operating the core in a magnetically unsaturated state with the magnetic object to be detected present in the area proximate the magnetic sensing coil, interacting with the field; and a detector responsive to said electromagnetic sensing coil to detect the presence of a magnetic object.

Abstract: A variable permeability magnetic object detection device including an electromagnetic sensing coil; a core disposed in the electromagnetic sensing coil having a first permeability when the core is magnetically saturated and a second different permeability when the core is magnetically unsaturated; a magnetic member proximate the electromagnetic sensing coil for providing a magnetic field in the core for operating the core in a magnetically saturated state without a magnetic object to be detected present in the area proximate the electromagnetic sensing coil, interacting with the magnetic field, and for operating the core in a magnetically unsaturated state with the magnetic object to be detected present in the area proximate the magnetic sensing coil, interacting with the field; and a detector responsive to said electromagnetic sensing coil to detect the presence of a magnetic object.