Abstract: A scanning arrangement in a scanner which is operative for repetitively scanning indicia having parts of different light reflectivity; for example, such as bar code symbol, and also pertains to the operation of a scanning arrangement of that type at high scanning speeds in two-dimensional or multi-axes scan patterns. A resonance asymmetric scan element (RASE) in which a scan element, which is preferably constituted of a mirror, is in effect attached along the upper side edges thereof to oscillation-imparting spring-means and not at the center of mass of the mirror as heretofore. This allows for higher frequencies of operation for the scan element at lower encountered stresses in that the fast axis of rotation of the scan element or mirror; in essence, the axis of oscillatory rotation about which the mirror is rotated at high frequencies substantially coincides with its center of mass.

Abstract: A signal processor for reading a bar code symbol having alternating dark and light portions includes a photodetector for receiving light reflected from the bar code symbol and for forming a sense signal representing the intensity of the reflected light. A differentiator circuit coupled to the photodiode generates a first derivative of the sensed signal, and an offset circuit generates an offset signal which is displaced slightly from the first derivative. An output circuit generates an output signal which indicates changes in the intensity of the reflected light when the first derivative signal and the offset signal have approximately equal amplitudes.

Abstract: To reduce the size and weight of an optical scanner, the present invention provides a mirrorless beam scanning unit wherein the light emitter itself moves back and forth. In the preferred embodiments the light emitter is a visible light diode (VLD) mounted on the axis of a rotatable shaft. The VLD emits light in a direction perpendicular to the axis of the shaft. A lever arm attached to the shaft and an induction motor for moving the arm repeatedly rotate the shaft back and forth through a small rotational arc. The mirrorless scanner is mounted on a finger sized ring. This allows a user to wear the miniature optical scanner on a finger. A separate unit houses the other components of the scanning system, such as the analog signal processing circuitry, digitizer, decoder and any necessary interface to a data processing system. The separate unit can be worn on the user's belt or in a pocket, and a cable connects the separate unit to the ring mounted scanner.

Abstract: A circuit for digitizing an analog electric signal generated from a photoelectronic conversion of reflected light when scanning indicia having spatially-separated, light-reflective portions includes a differentiator circuit for generating a first derivative signal representing a first derivative of the analog signal. A comparison signal generating circuit generates a comparison signal and an output circuit, coupled to the differentiator circuit and to the signal generating circuit, compares the first derivative signal and the comparison signal to generate an output signal indicating a change in the intensity of the reflected light. An output controller, coupled to the output means, controls passage of the digital output signal.

Abstract: In bar code symbol scanning systems employing laser, optical and sensor components, a mirrorless scanner arrangement mounts one or more of these components on a drive for repetitive reciprocating movement either about an axis or in a plane to effect scanning.

Abstract: A two-dimensional bar code is used to identify a traveler's luggage, permitting the luggage to be tracked and, if desired be delivered to the traveler's ultimate destination (e.g., a hotel). If the traveler is traveling on an airline, a corresponding two-dimensional bar code is applied to the traveler's boarding pass. A two-dimensional bar code reader is used to read the boarding-pass bar code of each enplaning passenger; comparison of these bar codes with luggage bar-code data permits an alarm to be raised if each item of checked luggage is not matched by an enplaned passenger. The boarding-pass bar code may take the form of an integrated passenger identification code for use by e.g., rental car companies, hotels, and the like.

Abstract: A nonvolatile electro-optical read-only memory includes a substrate on which is printed (or otherwise inscribed) a complex symbol or "label" with a high density two-dimensional symbology, a variable number of component symbols or "codewords" per row, and a variable number of rows. Codewords in alternating rows are selected from mutually exclusive subsets of a mark pattern such as a (17,4) mark pattern. The subsets are defined in terms of particular values of a discriminator function, which is illustrated as being a function of the widths of bars and spaces in a given codeword. In the illustrated embodiment, each subset includes 929 available codewords; that, plus a two-step method of decoding scanned data, permitting significant flexibility in defining mappings of human-readable symbol sets into codewords. The memory may be used in conjunction with a scanner and a suitable control system in a number of applications, e.g., robotic operations or automated microfilm searching.

Abstract: A method of manufacturing a bar code reader of the type including a scanner for generating a moving light beam directed toward a target and sweeping the bar code symbol to be read. A photodetector receives the reflected light from such symbol, and processing circuitry determines whether the signal received represents a valid symbol. The processing circuitry has adjustable gain, bandwidth, and digitizer threshold characteristics which are set during the manufacturing process.

Abstract: A scanning head for reading bar code symbols includes a laser source producing a beam which is scanned across a symbol to be read by a moving mirror arrangement, and a photodetector responsive to light reflective from the symbol. The signal from the photodetector is digitized and decoded to recover bar code data. The scanning heads includes a keyboard for entering data, and a display from showing data, and an integrated circuit for data collection and/or data processing. A transmitter and receiver may be located in the scanning head for communication with a central computer, and a battery included in the heads as a power supply, so that the scanning head need not be connected by a cable to a terminal.

Abstract: In a bar code reader, a field of view which includes a symbol to be read is imaged upon a light-responsive array such as a CCD imager device. The output of this array is transferred to a memory array to provide a bit-mapped type of binary representation of the image including the symbol. The memory is scanned (instead of the field of view itself being mechanically scanned) to recognize and decode the symbol. Because the angular orientation of the symbol is variable, this binary representation may be interpreted to determine how the memory array is to be scanned to recognize the bar code symbol. For example, the distinctive patterns of characters used in bar codes may be found by scanning the memory and the relative positions of these patterns interpreted to determine the position, size and shape of the symbol in the memory, thereby defining at what angular displacement the memory array need be addressed to traverse the rows of the bar code symbol.

Abstract: A flexible merchandise checkout system utilizes a portable two-dimensional bar code scanner/data terminal as part of an auxiliary checkout station for use during times of peak customer traffic, permitting two or more checkers to empty a shopping cart at once for higher throughput. The checkout system includes separable modules for scanning purchased items and for receiving customer payments, respectively. Customer checks tendered in payment may be processed in real time via electronic funds transaction (EFT) orders. Depleted inventory is replaceable using a system wherein replacement inventory items are labeled with two-dimensional bar-coded information describing the ultimate destination, and packed into a container for shipment to a receiving/distribution center, at which the destination information is scanned and decoded to enable proper routing of the replacement inventory items.

Abstract: A device for reading indicia on a target in which the indicia has regions of differing light reflectivity. The device directs a light beam toward the indicia, and collects reflected light from the indicia. The focus of the light beam is varied to enable the device to read indicia at different working distances, and the maximum scanning angle of the light beam is varied in operative correlation with the focus.

Abstract: A hand held bar code reader or scanner includes a universal locking cable connector assembly attaching a signal cable to the handle of the scanner. Signals and/or power to and from the scanner are carried by the signal cable. The signal cable is removably connected to a connector recessed in the handle of the scanner. The signal cable includes (i) a connector member attached to a terminal end thereof and engagable with the connector of the scanner handle and (ii) a collar adjacent the connector. A plastic retaining member is positionable over the collar and includes an internal stepped bore forming a collar at one end of the retaining member for engaging the collar portion of the signal cable within the bore. A manually lockable bayonet or threaded portion of the retaining member is formed at an opposite end and cooperates with an internal surface of the scanner for securing the retaining member to the housing.

Abstract: To reduce the size and weight of an optical scanner, the present invention provides a mirrorless beam scanning unit. A flexible support structure, such as one or more strips of mylar, movably mounts the objective lens in front of the light emitter. The objective lens is laterally reciprocated in response to a motive force, for example as might be applied by a combination of a permanent magnet coupled to the objective lens and a fixedly mounted electromagnet driven by an alternating current signal. Reciprocation of the objective lens during emission of light by the light emitter causes the light to scan a surface, such as a surface bearing a bar code label.

Abstract: In an optical scanner, a component for producing a beam scanning motion is mounted on a first flexible strip or planar spring. One or more additional flexible strips, adjacent the first flexible strip, provide additional support to prevent droop by the first flexible strip under the weight of the scanning component. The additional flexible strips also frictionally damp the low frequency motion of the first flexible strip to prevent interference with scanning due to vibration induced from movement of the scanner by an operator. In two-dimensional scanners, where the component moves in two orthogonal directions at two different speeds, the additional strip type frictional damping is applied to the planar spring which provides the necessary flexible support for motion in the slow speed scanning direction.

Abstract: A height- or width-modulated bar code is decoded by scanning an oblong laser beam across the bar code. Light reflected from the bar code varies in intensity as the laser beam traverses dark and light regions of the bar code. The bar code can be decoded by locating the valleys in the variation of intensity of the reflected light, and comparing the depth of these valleys; the deepest valleys correspond to tall or wide bars and the remainder correspond to short or narrow bars.

Abstract: Bar code scan data is corrected for spot-speed variation by processing the data to determine a spot-speed profile having non-zero acceleration within at least some of the characters of the bar code symbol being scanned, and then using the speed profile to normalize the scan data. Preferably, average spot speeds across individual characters are determined, and a speed profile is fit to these average spot speed data points in such a manner that the curve is not forced to pass through every data point. In this way, a spot-speed profile is derived that does not incorrectly attribute, to speed variation, errors due to other sources, e.g., random edge errors from printing. Preferably, the spot-speed profile consists of a plurality of straight line segments. The segments may be slightly disjoint, and each segment is from two to four characters in length, depending on the density of the bar code symbol.

Abstract: An electronic stylus, for use with a computer having a digitizer, has a light emitter for emitting light to illuminate optically encoded information. A photodetector senses light reflected from the illuminated optically encoded information and produced an electrical signal representative of the optically encoded information. Stylus electronics provide positional input data by contacting a digitizer tablet with the stylus. The stylus housing contains the light emitter, photodetector and stylus electronics. A tip at a fore end of the housing is adapted for contact with the digitizer tablet and the light is emitted from other than the fore end of the housing.

Abstract: In bar code symbol scanning systems employing laser, optical and sensor components, mirrorless scanner arrangement mounts one or more of these components on a drive for repetitive reciprocating movement either about an axis or in a plane to effect scanning. The system has a movable exit port to permit scanning from opposite sides of a housing.