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: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.

Abstract: A portable laser diode scanning head, aimable at each symbol to be read, emits and receives non-readily-visible laser light, and is equipped with a trigger-actuated aiming light arrangement for visually locating and tracking each symbol. A compact laser diode optical train and an optical folded path assembly, as well as an interchangeable component design and an integral window construction for the head also are disclosed.

Abstract: A hand-mounted scanning system for reading indicia having parts of different light reflectivity, including a housing having a window and an actuatable electro-optical scanner in the housing for projecting a light beam through the window to indicia to be read, for scanning the indicia. The system further detects light of variable intensity that is reflected off the indicia to generate an electrical signal representative of the indicia. The housing is mounted on a glove worn on an operator's hand and the scanner initiates reading of the indicia upon movement of the operator's hand, or automatically by object recognition.

Abstract: A portable laser diode scanning head, aimable at each symbol to be read, emits and receives non-readily-visible laser light, and is equipped with a trigger-actuated aiming light arrangement for visually locating and tracking each symbol. A compact laser diode optical train and an optical folded path assembly, as well as an interchangeable component design and an integral window construction for the head also are disclosed. Also disclosed is an optic means mounted in the laser diode scanning head including a focusing lens and an aperture stop for forming the emitted laser light to have a beam cross-section of an altered size within a working distance range.

Abstract: A system for representing and recognizing data in machine readable graphic image form in which data to be encoded is entered into the system and a processor encodes the data into a two-dimensional bar code symbol and generates transfer drive signals representative of the symbol. A transferring device such as a printer transfers an image of the two-dimensional bar code symbol onto a carrier such as a card or paper document in response to the transfer drive signals. A recognition device converts the image on the carrier into electrical signals representative of the symbol by scanning the image. A low-level decoder decodes the signals by decoding each scan line into a vector of codeword values corresponding to the codewords in the two-dimensional bar code symbol, assigning a row number to each of the codeword values, and then filling in a two-dimensional matrix with the codeword values. A high-level decoder further decodes the codeword values into data which can then be output for processing or use.

Abstract: A method for decoding bar code symbols in which a bar code reader and associated components scan a bar code symbol produce a representation of the symbol, and attempt to decode that representation in order to produce a character message. The method consists of the steps of storing a first representation of the bar code symbol corresponding to a first scan path through a first portion of said symbol smaller than the entire symbol, and storing a second representation of the bar code symbol corresponding to a second scan path through the symbol. The method then processes these representations in the event a successful decode has not taken place by utilizing the signal from a first scan with the signal from a subsequent scan to determine whether the information from successive scans can be concatenated to form a combined signal. The process is repeated with different subsequent scans until successful decoding of the combined signal.

Abstract: A system for reading bar code symbols or the like, including one- or two-dimensional bar code symbols having a scanner for generating a laser beam directed toward a target and producing a narrow first raster scanning pattern that enables the user to manually aim and direct the beam to the location desired by the user and a second raster scanning pattern that increases in height which sweeps an entire symbol to be read, and a detector for receiving reflected light from such symbol to produce electrical signals corresponding to data represented by such symbol.

Abstract: An optical reader/scanning system eliminates the need for and the use of a separate system receiver mounted exteriorly of a laser diode package. Instead, a monitor photodiode within the laser diode package is used as the system receiver. A fresnel lens increases the collection efficiency of the monitor photodiode. The fresnel lens may be mounted interiorly or exteriorly of the laser diode package.

Abstract: A radio transceiver for use in data communications uses a single phase-locked loop to control the frequency of the receiver portion while simultaneously providing coarse control of the frequency of the transmitter portion. The output of the receiver portion is also used to provide an error signal for fine tuning the transmitter frequency after the component of the error signal caused by modulation of the transmitter portion has been removed.

Abstract: Apparatus for reading bar code symbols including a laser light source, an optical component for scanning a reference plane, and a sensor for detecting the light of variable intensity reflected from the target. A processor determines whether the reflected light represents a spatial variation that could represent a bar code and generates an enabling signal and a controller is provided for modifying the light beam in response to the enabling signal.

Abstract: A portable, conveniently usable, and inexpensive non-contact bar code verifier permits testing of bar code labels at some arbitrary but constant distance from the verifier. Means are provided for analog analysis of bar code label contrast levels, and for derivation of new, instructive indices characterizing the readability and print quality. Additionally, a new method for determination of absolute bar code label dimensions is disclosed. The method of calibration for arbitrary scanning distance and angle standardizes not only the verifier's ability to measure absolute dimensions at unknown distances, but also its ability to discern contrast under arbitrary lighting conditions and scanning equipment. This is accomplished by employing calibration standards of known characteristics. Bar code verification information may be stored and/or employed for a variety of control and analytical functions as recognized in the art.

Abstract: An optical bar code scanner and method which achieves an extended depth of focus by employing a multifocal length collection optical system. A radiation beam is generated for illuminating a field of view, either by a laser or nonlaser source. The embodiments specifically disclosed herein employ nonlaser sources such as LEDs. The multifocal length collection optical system consisting of a plurality of lenses or mirrors having at least a near range focal length and a long range focal length, simultaneously collects radiation reflected from objects in the field of view, and directs it to an optical detector for detection and generation of an electrical output signal indicative thereof. The electrical output signal of the detector is then passed through a high pass filter which filters out a DC background electrical signal, thereby improving the depth of modulation of the signal.

Abstract: Electrical power consumption is saved in a low-cost scanner for reading bar code symbols by oscillating one of the scanner components either by mechanical power alone or by a low-power electrical drive.