Abstract: To reduce the size and weight of an optical scanner, the present invention provides a mirrorless beam scanning unit. A flexible member, such as a multi-wire, flat, electrical cable is connected to the light emitter. Reciprocation of the light emitter during emission of light by the light emitter causes the light to scan a surface, such as a surface bearing a bar code label. The cable flexes during such reciprocation.

Abstract: A electro-optical memory includes a substrate on which is printed (or otherwise inscribed) a complex symbol or "label" or "bar code" of a high density two-dimensional symbology. The bar code contains component symbols or "codewords" which are placed in row and column formation, with a variable number of codewords per row, and a variable number of rows. The symbology utilizes implicit bar code encoding scheme for implicit encoding the number of rows and the number of columns of codewords, as well as a predetermined amount of error correction. The symbology is capable of supporting a fixed number of bar code variants, with each variant having a predetermined number of rows and columns of codewords, and a predetermined error correction capability. For some codewords the implicit encoding scheme is combined with a gray coding scheme to reduce the inter-row codeword crosstalk.

Abstract: A casing, including a grip portion and a head portion, houses a pair of light sources for illumination, an image sensing device, an optical system for forming an image on the image sensing device, a photosensor for detecting the luminance of symbol reading area, a signal processing circuit, and a light quantity detection circuit. The housing extends from the head portion towards the symbol reading area. An ambient light window is provided in the housing for introducing ambient light into the symbol reading area. A light source driving circuit controls an amount of light emitted by the light source, by increasing or decreasing the amount of light, such that the combined ambient light and light source illumination is between predetermined levels.

Abstract: There is disclosed a hand-held labeler for printing and applying labels and for printing tags. The labeler has a keyboard, a display, a scanner, and a battery-containing handle. The labeler is user-friendly and compact. The labeler can be easily loaded with label and tag webs of different widths. The labeler has a discharge chute for the carrier web which can be slid to a position outside the labeler for easy cleaning.

Abstract: A method and apparatus for decoding profiles which fail to resolve narrow elements in machine-readable symbols formed as relief patterns, first begins by identifying which elements in the profile are resolved. Second, the distances between the centers of the resolved elements are determined. Third, closure boundaries are determined, and the widths of resolved elements are determined at the closure boundary. The type of resolved element is determined based on its measured width. Thereafter, a unit distance is determined for 1-wide narrow elements unresolved in the profile. Based on the unit distance and the width of two adjacent resolved elements, a matrix is constructed for determining the number of narrow elements unresolved between two resolved elements. Based on the measured center distances, the resolved element widths and the matrix, all of the unresolved narrow elements are identified in the profile and the profile is subsequently decoded.

Abstract: A bar code reader comprises: a laser for projecting light; a polygon mirror for scanning a bar code with light from the laser; a way-in window allowing the reflecting light from the bar code to pass therethrough; and a light receiving surface including a photo diode, for receiving the reflecting light through the way-in window and transforming the reflecting light into an electrical signal, wherein the light receiving surface is formed to take a rectangle corresponding to a shape and a size of the way-in window, the light receiving surface is placed apart from the way-in window, while facing the way-in window, and no condenser lens is provided between the light receiving surface and the way-in window.

Abstract: A bar code scanner for reading a bar code tag includes a collection optical system, a two dimensional array of detectors, rotating means for imparting rotational movement to the array and displacement means for varying the position of one of the collection optical system and the array along an optical axis of the collection optical system.

Abstract: A computerized control system for driving an rotor which can carry a laser or a beam deflecting mirror and is actuated by a coil thereon electromagnetically coupled to a fixed magnet or a stepper motor coil. The rotor can be part of an electromechanical oscillatory system supported by flexures or the stepper motor can be electrically biased to produce, electrodynamically a restoring force. The back EMF of the coil is sensed, translated into successive digital signals which are processed in accordance with programs in firmware of the computer to generate driving pulses which are applied to the coil to obtain desired displacement motion of oscillation suitable for scanning the beam.

Abstract: A portable data collection device. The device includes an imaging assembly including a two dimensional (2D) photosensor array. The imaging assembly is selectively actuatable with a first trigger for reading a target dataform in the imaging assembly's target area and actuatable with a second trigger for capturing a color image of the target object in the target area. The imaging assembly further includes compression circuitry for compressing digital data representative of the target area when the imaging assembly is actuated to capture an image of the target area. The device also includes a viewing assembly to aid an operator in aiming and positioning the device with respect to a target dataform or target object. In one embodiment of the viewing assembly, a liquid crystal display screen is affixed to a pivoting member. When the viewing assembly is actuated an image of the target area is displaced on the display screen.

Abstract: A double side scanner and method for controlling the scanner. The double side scanner performs a scanning operation of a single sheet at a same time, and the double side scanner has a memory that can store the scanned image data. A data transfer device transfers the image data from the memory to an external device.

Abstract: A method and apparatus are provided for reading bar codes or other images while reducing or eliminating the need for self-generated illumination. An image reader comprises an efficient optical collection system including an aperture with a high aspect ratio and/or a multi-focal lens or lenses. A CCD detector receives collected light and is coupled to an adaptive exposure circuit for preventing saturation of a CCD detector at high illumination levels. A correlated double sampling circuit receives the output of the CCD detector to allow lower light levels to be detected by the system. The correlated double sampling circuit is connected to a signal processing block which uses a derivative based technique for enhanced edge detection. Edge detection information may be provided to a decoder for decoding. Various other embodiments may utilize some but not all of the above elements, or may include additional refinements, while obtaining the benefit of reducing or eliminating the need for self-generated illumination.

Abstract: A lighting apparatus includes: a plurality of light emitting diodes; a printed circuit board on which the light emitting diodes are arranged in one row; and a rod-like projection lens disposed in front of the light emitting diodes along a light emitting direction, for irradiating an object with light in a strip-like manner. Each of the light emitting diodes is a chip-type light emitting diode which has a substantially parallelpiped shape and which comprises a light-emitting face and a pair of electrode faces. The light-emitting faces are in a plurality of planes which are perpendicular to one common plane, respectively. An optical information reader has the lighting apparatus.

Abstract: A system and method for interposing stored images to moving video within multimedia computer programs, wherein the system recognizes specific identifiers upon an object or image that identify that the object or image is a visual aid to be incorporated into the multimedia program. In response to this recognition, a previously stored image associated with the identified object/image is retrieved and inserted into the multimedia computer program.

Abstract: A high efficiency multi-image scanning method is disclosed. It involves the use of a special scanning window, or panel, containing a plurality of rectangular fields provided therein. The scanning window also contains a plurality of fiducial marks which associates each rectangular field, respectively, with a pre-defined location relative to the fiducial mark and a pre-defined scanning area. Prior to the scanning operation, a plurality of documents to be scanned are placed inside the rectangular fields. A pre-scan operation is performed to find and identify the fiducial mark. Then the scanner is moved to a selected rectangular field according to the information contained in the fiducial mark to scan an image having the pre-defined scanning area. Optionally, the method further contains the step of determining whether an image is present in the rectangular field, and if so, then adjusting the scanning area to compensate for any inadvertent misplacement of the image in the rectangular field.

Abstract: A fixed position dataform reader reads a dataform printed on a substrate and passed through a desired target area. The reader comprises a housing, a first camera assembly, image processing and decoder circuitry, and a mounting support. The housing has a base surface, a face surface, and at least one side surface interconnecting the base surface to the face surface and defining an interior region. The face surface defines an aperture. The first camera assembly includes a two-dimensional photosensor array supported in the interior region and an optics assembly spaced from the two-dimensional photosensor array to focus an image of the dataform onto the two-dimensional photosensor array. The image processing and decoder circuitry is coupled to the camera assembly for generating decoded data representative of the dataform. The mounting support is secured to the housing for mounting the reader in a fixed position with respect to the desired target area.

Abstract: A scanner determines whether a target is a bar code symbol and, if so, whether that symbol is one-dimensional or two-dimensional. For two-dimensional symbols, the scanner aligns a scanning pattern with the symbol and expands the scanning pattern to reach only to the top and bottom edges of the symbol, not beyond. The scanner also has a microprocessor-control scanning engine that uses a coil to drive a scanning element and pick up feed back signals from the scanning element. A pulse-width-modulated regulator also provides fast and efficient operation for driving the coil. The scanning engine can also be designed to generate a pattern that precesses across the target, and a powerful interface to the scanning engine allows decoding and control logic to work efficiently with and independently of the scan engine.

Abstract: A code reader, for reading a code printed on a surface of a printing medium, includes a photoelectric device for converting light reflected from the code into an electric signal. An amplifier is provided for amplifying the electric signal converted by the photoelectric device. A gain adjusting device is provided for adjusting a gain of the amplifier such that a summit level of the electric signal can be raised to a predetermined upper limit level. A digitizing device is provided for converting the electric signal amplified by the amplifier into a binary signal, using a predetermined level.

Abstract: An efficient method and apparatus for determining the location and approximate orientation of a barcode on a substrate. The inventive method is preferably implemented by an omnidirectional barcode locator including an application specific integrated circuit that includes one or more field programmable gate arrays (FPGAs). The digit image is a one-bit (i.e., black/white) representation of a standard eight-bit grey scale video image produced by the CCD camera. The use of a one-bit digital video signal reduces the amount of mass storage memory required to store images of barcodes and facilitates the manipulation of the video signal by the application specific integrated circuit. The omnidirectional barcode locator processes, in real-time, a digital video signal defining a pixelized image of a conveyor carrying parcels through the field of view of a CCD camera.

Abstract: An optical scanner for optically scanning a bar code includes a housing having a window formed on a selected surface thereof, a first scanning system, housed in the housing, for emitting a first scanning beam from the housing through the window and a second scanning system, housed in the housing, for emitting a second scanning beam from the housing through the window. The first scanning beam moves in a first scanning pattern and the second scanning beam moves in a second scanning pattern which is different from the first scanning pattern. Additionally, the second scanning pattern may be used for scanning a bar code having a selected special form.

Abstract: There is disclosed a hand-held labeler for printing and applying labels and for printing tags. The labeler has a keyboard, a display, a scanner, and a battery-containing handle. The labeler is user-friendly and compact. The labeler can be easily loaded with label and tag webs of different widths. The labeler has a discharge chute for the carrier web which can be slid to a position outside the labeler for easy cleaning.

Abstract: A bar code scanner employs an electronic means for causing the light beam to scan a bar code symbol, rather than using a mechanical device to generate the scan. A linear array of light sources, activated one at a time in a regular sequence, may be imaged upon the bar code symbol to simulate a scanned beam. Instead of a single linear array of light sources, a multiple-line array may be employed, producing multiple scan lines. The multiple scan lines may be activated in sequence, or activated simultaneously (time-division or frequency-division multiplexed. The multiple scan lines can provide signal enhancement, noise reduction or fault correction if directed to the same bar code pattern. Multiple scan lines may be generated using a single light source and a beam splitter, with mechanical scanning, as well as by the sequentially-activated light sources. Multiple simultaneous scan lines may be employed to generate a raster scan at lower mechanical scan frequency.

Abstract: An automatic projection laser scanning system for reading bar code symbols. The system is supportable on or above a countertop surface, and includes a laser scanning device having a compact housing from which it automatically produces an object detection field of volumetric expanse for automatic detection of objects, and a scan field including at least one scanning plane for automatic laser scanning of code symbols on detected objects. Both the object detection field and the scan field spatially arranged with respect to each other and the compact housing to facilitate easy scanning of a bar code symbol presented within the scan field after the associated object has been detected within the object detection field, thereby improving the scanning efficiency of the system.

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 light emitter in response to a motive force, for example as might be applied by a combination of a permanent magnet coupled to the light emitter and a fixedly mounted electromagnet driven by an alternating current signal. Reciprocation of the light emitter during emission of light by the light emitter causes the light to scan a surface, such as a surface beating a bar code label.

Abstract: A portable terminal has a housing with a motion detector housed therein. Movement of the housing from a a rest position is detected by sensing the motion of a coil or magnet located within the housing. A controller activates circuitry within the housing responsive to the detected movement. The terminal may include a touch sensitive display, on a flat front surface of the housing. A light emitter and an optical detector may also be disposed within the housing. Preferably, the terminal also houses a sensor for sensing different specific positional orientations of the terminal and activating or deactivating terminal functions depending on the sensed orientation.

Abstract: An apparatus and method for reading data in the form of indicia on a surface of a target, the indicia having a preferred reading direction, including a light source for illuminating a portion of the surface to be read with a laser beam in a scanning pattern at a predetermined scanning angle so as to scan spatially adjacent portions of the surface. A detector and a processor is provided that is operative for detecting at least a portion of the light reflected from the indicia and storing representations thereof, and further determining the angular difference between the preferred reading direction and the scanning angle. An optical component disposed adjacent the light source is provided for optically directing the laser beam along a path toward the surface and is capable of controlling and setting the predetermined scanning angle. Furthermore, the optical component may be automatically rotated so as to align the direction of scan with the preferred reading direction of the indicia.

Abstract: In order to that optically readable small code marks can be correctly read by a reader, an optically readable code mark 15 is marked on an surgical instrument 14 at an optional location by using a laser, the code mark being in the form of recesses and projections which are apparently different in magnitude from roughness of the instrument surface at that location. Thus, the code mark is marked on the surgical instrument itself by laser marking and is optically read, resulting in correct reading of the mark and a considerable improvement in durability of the mark.

Abstract: A method and apparatus for decoding a two-dimensional bar code symbol using a charge-coupled device (CCD) camera, charge-modulation device (CMD) camera, or other bar code reading device such as a hand-held reader, light pen or wand, scan mouse, or stationary laser scanner. The CCD/CMD camera or reading device optically images the bar code symbol to obtain digital image data, which is stored in a memory.

Abstract: An integrated laser scanning device including: a substrate of semiconductor and/or electro-optical material, a laser light source disposed on the substrate; and a scanner disposed on the substrate in the path of the laser beam for repetitively and cyclically moving the laser beam so as to form a scanning beam for repetitively scanning a target for reflection therefrom. In particular, the scanner comprises a layer of reflective material disposed on a moveable structure on the substrate, the plane of such layer being disposed at an acute angle with respect to the laser beam so that the beam is directed along an optical path toward indicia located in the vicinity of a reference plane lying in the optical path so as to scan spatially adjacent portions of the reference plane along a relatively elongated scanning line.

Abstract: A method and apparatus for maintaining a constant optical path length when scanning objects at different distances. The apparatus has a reading device that reads data carrying symbology on an object being scanned, and an optical system having a plurality of optical paths between the object being scanned and the reading device, where each of the plurality of optical paths has a different path length. The apparatus also has a size detector that determines a dimension of the size of the object being scanned and outputs a signal based on the dimension, and a selecting device that selects one of the plurality of optical paths of the optical system based on the signal output by the size detector to maintain an optical path length between the object being scanned and the reading device within a predetermined range.

Abstract: According to a two-dimensional code recognition method of the present invention, first, a two-dimensional image is input in step S1, and an edge is detected in step S2. This edge detection is performed by scanning pixels on a scanning line every several dots. A straight line is extracted in accordance with the Hough transform and the least square approximation in step S3, and a combination of straight lines is selected in step S4. Then, the size of a figure is detected in step S5. In step S6, two remaining straight lines are extracted, and the figure is extracted. In step S7, matrix information is extracted from the extracted figure, and codes are recognized. The flow returns to the selection of a combination of straight lines in step S4 until the straight line detection and the figure recognition can be accurately performed in steps S5, S6, and S7.

Abstract: A self-adjusting adaptive scanning system includes a scanner, responsive to coordinate control signals, for directing a light beam in a pattern at a bar code symbol, for detecting a reflected portion of the light beam, and for generating feedback signals reflecting successful decodes. A microprocessor, responsive to the feedback signals, generates pattern control signals. A pattern generator generates the coordinate control signals in response to the pattern control signals to select a desirable light beam pattern.

Abstract: A mark sheet reading apparatus is disclosed which can correct the coordinates of a binary signal read from a mark sheet when the mark sheet is in skew with an angle. A mark sheet having a plurality of marking areas arranged in a matrix of rows and columns thereon additionally has a reference row mark in the form of a continuous straight line provided in parallel to a row of the matrix and extending over a length covering the overall length of the row. The mark sheet reading apparatus comprises a reference row mark detection section for discriminating a successive condition of dots from among data read by an image sensor to detect the reference row mark of the mark sheet, a skew detection section for detecting an inclination rate of the reference row mark thus detected, and a skew correction section for correcting coordinates of binary data read by the image sensor in accordance with the inclination rate of the thus detected reference row mark.

Abstract: The sensor device includes a planar code carrier on one object, and on another object, a scanning device for an angle of view for determining a viewing direction lying therein, and also a computing circuit. A photodetector detects an illumination density during the course of the scanning of the angle of view according to the direction of light incidence. On the code carrier there is arranged a rectangular code field with its center line parallel to the scanning plane. The code field includes at least two rectangular positioning fields and a rectangular interfield lying in between. The positioning fields contain positional information on the objects which can be evaluated by the scanning device. In at least one interfield, the code includes at least one boundary line obliquely intersecting the center line, the scanning of which boundary line produces a distinct variation of the illumination density in dependence on the direction of light incidence, which corresponds to a viewing direction to be established.

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: The system 10 for identifying a vehicle includes a code generator 12 which generates a code in response to the provision of predetermined data relating to features of the vehicle. The code is generated on a slip of paper which is affixed to the vehicle. A number of code readers 14 is provided for reading the code, decrypting the code and extracting information relating to the features of the vehicle from the code to determine whether or not the code applies to that vehicle.

Abstract: The present invention relates to a method and an apparatus for enhancing the optical image of information-containing symbols captured off reflective surfaces/using a conventional optical scanning camera. The method involves positioning the imaging assembly of the camera atop an information-containing coded symbol located on a component surface, where the imaging assembly includes a diffuser element and LED lighting array for illuminating the symbol, illuminating the surface and the symbol, and moving the diffuser element to a location between the coded symbol and the camera lens such that only light returning directly from the symbol is able to pass through the voided region of the diffuser element, before imaging the coded element.

Abstract: In an encoded symbol reader for decoding a two-dimensional encoded symbol, an image of the symbol is read and primary image data which directly corresponds to the symbol is generated. Further, from the primary data, secondary image data having less information than the primary image data is generated. The edge of the encoded symbol is detected using the secondary image data, and then decoding of the encoded symbol using the primary image data within the area defined by the detected edge.

Abstract: A system for scanning a symbol that has a plurality of modes including a learning mode and an adaptive mode. When the scanner is in a learning mode, a plurality of scans are generated using a plurality of sets of operating parameters. A decoder decodes the plurality of scans generated by the scanner. A data collector collects readability data indicating whether the generated scan decodes successfully or unsuccessfully for each of the sets of operating parameters. A processor determines whether the readability data is acceptable for each of the sets of operating parameters. An optimal set of operating parameters is selected from the acceptable sets of operating parameters. The optimal set of operating parameters is stored along with data identifying the symbol so that the optimal set of operating parameters may be recalled for use in scanning symbols of a similar type or in a similar environment.

Abstract: A scanner determines whether a target is a bar code symbol and, if so, whether that symbol is one-dimensional or two-dimensional. For two-dimensional symbols, the scanner aligns a scanning pattern with the symbol and expands the scanning pattern to reach only to the top and bottom edges of the symbol, not beyond. The scanner also has a microprocessor-control scanning engine that uses a coil to drive a scanning element and pick up feed back signals from the scanning element. A pulse-width-modulated regulator also provides fast and efficient operation for driving the coil. The scanning engine can also be designed to generate a pattern that precesses across the target, and a powerful interface to the scanning engine allows decoding and control logic to work efficiently with and independently of the scan engine.

Abstract: A apparatus for reading film information provided in plural stages on an outer surface of a cartridge containing a film. The apparatus comprises a light source; a pocket including a main body having a space for containing the cartridge in the main body and a window for exposing the film information of the cartridge contained in the space to outside, and a support unit for movably supporting the main body in a direction of varying the stages of the film information; an actuator for moving the main body of the pocket; and a reading mechanism for detecting light emitted from the light source, and reflected at an area of the film information through the window. The film information such as bar codes provided in two or more stages on the outer surface of the cartridge can be automatically read by one sensor, so that labor saving and downsizing of the apparatus can be achieved.

Abstract: A scanner communicates with a microcomputer over a serial communications link utilizing the serial I/O port of the microcomputer. Both signals representing the data which is scanned and signals representing commands to the scanner and commands from the scanner indicative of the status thereof (e.g., scanner trigger actuation) are communicated over a plurality of lines in the communication link. These lines may be of the type utilized for transmission of data and commands in accordance with a communications protocol, such as the RS-232 protocol. Interrupts are generated when the scanner is connected to the serial port via the communication link and the microcomputer is available for decoding. Then appropriate interrupts are generated to actuate the scanner and to respond to the data. The scanner may be a laser or optical beam scanner or a wand which is moved across a bar code symbol. The symbol has bars which are relatively opaque and reflective (black or white).

Abstract: A single width bar code exhibiting inherent self clocking characteristics is provided so as to be particularly useful in the identification of semiconductor wafers in very large scale integrated circuit manufacturing processes. The codes described herein are robust, reliable and highly readable even in the face of relatively high variations in scanning speed. The codes are also desirably dense in terms of character representations per linear centimeter, an important consideration in semiconductor manufacturing wherein space on the chips and the wafer is at a premium. Additionally, a preferred embodiment of the present invention exhibits a minimum number for the maximum number of spaces between adjacent bars in code symbol sequences.

Abstract: A bar code scanner employs an electronic means for causing the light beam to scan a bar code symbol, rather than using a mechanical device to generate the scan. A linear array of light sources, activated one at a time in a regular sequence, may be imaged upon the bar code symbol to simulate a scanned beam. Instead of a single linear array of light sources, a multiple-line array may be employed, producing multiple scan lines. The multiple scan lines may be activated in sequence, or activated simultaneously (time-division or frequency-division multiplexed. The multiple scan lines can provide signal enhancement, noise reduction or fault correction if directed to the same bar code pattern. Multiple scan lines may be generated using a single light source and a beam splitter, with mechanical scanning, as well as by the sequentially-activated light sources. Multiple simultaneous scan lines may be employed to generate a raster scan at lower mechanical scan frequency.

Abstract: A symbology reader which reduces the effects of specular reflection. A plurality of illumination sources emit light toward a target object. A first polarization filter receives the unpolarized light from the illumination sources and transmits only light polarized in a first direction. Light reflected from the target object travels back to the reader where it is received by a second polarizer which is oriented to block light polarized in the first direction and transmit only light polarized in a second direction orthogonal to the first polarization direction. Non-specularly reflected light reflected from the target object is largely transmitted by the second polarizer to a detector assembly within the symbology reader. In one embodiment the polarization filters are part of a window which covers an output aperture of the reader. The polarization filters are implemented as discrete pieces of laminar polarizing film attached to a transparent window base.

Abstract: A method and apparatus for decoding profiles which fail to resolve narrow elements in symbologies employing one element type having only a single width, first begins by producing a series of counts from the symbol using standard waveshaping and counting circuitry. Second, an X-dimension for the 1-wide elements is determined based on the first few counts corresponding to bars after the counts corresponding to the quiet zone. The Start and Stop characters are located and the method determines whether the symbol is in focus. If the symbol is out-of-focus, then groups of an odd number of 1-wide elements are converted to large counts that correspond to pseudo elements (e.g., wide bars in a symbology containing only 1-wide narrow bars). The method groups counts into individual characters, and divides all pseudo elements into individual 1-wide elements. The method thereafter decodes the symbol.

Abstract: A portable terminal includes a housing and a sensor for sensing different specific positional orientations of the housing. In one positional orientation sensed by the sensor, the terminal performs a first function. In another positional orientation sensed by the sensor, the terminal performs a second function which is different from the first function.

Abstract: A two-dimensional matrix symbology reader comprises a fixed housing having a slot disposed in a side of the housing to receive a card medium having a two-dimensional matrix symbology affixed thereto. The matrix symbology is illuminated within the housing once the medium has reached maximum axial extent of the slot. An aperture is disposed within the housing adjacent to the slot relative to the matrix symbology such that the light reflected from the matrix symbology is transmitted therethrough. The reflected light is then converted to information signals representative of the matrix symbology. Due to the controlled environment and uniform depth of field requirement within the housing, a pin hole aperture or lens can be utilized without the need for additional focusing or aperture control.

Abstract: A method and apparatus reliably and robustly decode single width bar codes that may be placed on a variety of materials. The decoding is independent of whether or not the bar code represents dark bars on a light background or light bars on a dark background. The decoder may be implemented either in hardware or as part of a program in a stored program general purpose computer. The signal processing approach taken generates gap sequence information from width sequence information to match predetermined gap sequence patterns. The method and apparatus of the present invention are also particularly amenable to independent creation of the gap sequences from three different techniques which are independent and which thus add robustness to the system. Lastly, the decoding method of the present invention takes advantage of a preprocessing function to remove any certain forms of noise that may be present in the scanned data.

Abstract: A method of photoelectrically reading information recorded in the form of a Fresnel hologram, which makes it possible to eliminate the effect on the reading accuracy of a scratch, a stain, etc., on the hologram surface when the recorded information is reconstructed by applying a light beam having a small diameter to the hologram. The surface of the hologram is illuminated by scanning it with a light beam having a cross-section smaller than the hologram recording region, thereby reconstructing and reading the same recorded information separately from different hologram regions, and thus compensating for momentary disability to reconstruct the recorded information due to a scratch or stain. At the same time, since a light beam having a small beam diameter is used for reconstruction, the depth of focus of the reconstructed image increases, so that the number of restrictions on the installation position of the read sensor decreases.

Abstract: A system for scanning bar code symbols on articles moving at a given speed senses an article at a predetermined location and determines an orientation of a bar code symbol on the article using an imaging camera. In response to determinations of a symbol location, orientation, size or type, the scanning system adjusts a scanning speed, shape and/or orientation of the light beam pattern and a location of the light beam pattern. The resulting light beam is directed at the bar code symbol location and a signal corresponding to the reflected light beam portion is generated. If the decode is not valid, the bar code symbol is rescanned.