Abstract: Apparatus and method for scanning a surface. An optical system generates a light beam to illuminate a surface. A carrier supports the surface for reciprocating motion with respect to the light beam to form one axis of a raster. A propulsion system moves the carrier at a substantially constant speed and a position sensor provides an output signal representing the surface position with respect to the light beam. A control system responsive to the output signal modulates a sample period reciprocally to carrier speed to achieve substantially constant scan length per sample and to control data acquisition timing.

Abstract: Systems consistent with the present invention allow a user to scan document text and then automatically recognize and organize that text into a format for display by the user. The system preferably includes a hand-held device operable by the user for scanning the text of the document. The hand-held device stores the scanned text information and can then transfer the stored text information to a computer. The computer automatically recognizes the scanned text based on the format and context in which the text is found in the document. Further, the computer automatically creates data entries describing the scanned text and organizes these data entries for display to the user.

Abstract: A multifunctional scanner having a first processor, an image scanner, a laser scanner, and a host interface port is provided. The image scanner scans documents to detect the presence of images imprinted thereon, generates image data based on the detected images, generates mark-sense row/column data based on downloaded data masks, and forwards the image data to the first processor. The laser scanner scans documents to detect the presence of bar-code symbols imprinted thereon, decodes the bar code symbols, generates bar code information based on the decoded bar code symbols, and forwards the bar code information to the first processor. The host interface port electrically couples the first processor to an external host processor. The first processor receives the image data from the image scanner, converts the image data into a host datastream, and forwards the host datastream to the external host processor via the host interface port.

Abstract: An image capture system (100) having an image capture module (102) and a terminal unit (104) captures both photo images and coded images. An alterable optical path of the system (100) operates in a first configuration when capturing coded images and in a second configuration when capturing photo images. Captured images are presented on a display (114) as they are captured. A user of the system (100) may parse through captured images to select one or more of the captured images for permanent storage and/or transmission to a remote location. The system (100) operates to identify coded targets within captured images, to prompt the user to select one or more of the identified coded targets and to decode the selected coded targets. The image capture system (100) may direct a user to reposition the system (100) so that a decodable coded image will be captured. The image capture system (100) communicates over wireless and wired networks with remote computer systems (307), personnel, and mobile units (307).

Abstract: A user interface is implemented using visual indicia and a background for the visual indicia that encodes address information. The background appears visually as a stipple pattern, but is implemented using glyphs which form an address carpet that encodes address information uniquely identifying each location of the user interface. An image capture device is used to capture an area of the address carpet that is at or near visual indicia of interest to the user while selecting a location in the visual indicia. The image capture device captures the area of interest, and transmits the image area to a computer for processing. The computer first determines the proper orientation of the image, and then decodes the information encoded by the glyphs. The decoding results in an X, Y address identifying the location of the captured area in the address carpet and, by reference, the address of the selected location. Based on the address, the computer may perform an operation associated with the area.

Abstract: A scanner having a serviceable circuit board assembly with a stair-stepping configuration. The scanner has a card cage for mounting circuit boards in the rear of the scanner. The card cage has an access opening. A first circuit board and a second circuit board are mounted inside the card cage. The first circuit board forms a notch. The second circuit board has a viewable portion that is viewable and accessible through the access opening and the notch. The test points and light emitting diodes are positioned within the viewable portion of the second circuit board.

Abstract: A data structure is disclosed encoded on the surface of an object comprising a series of block data regions with each of the block data regions including: an encoded data region containing data to be decoded in an encoded form; a series of clock marks structures located around a first peripheral portion of the encoded data region; and a series of easily identifiable target structures located around a second peripheral portion of the encoded data region. The block data regions can further include an orientation data structure located round a third peripheral portion of the encoded data region. The orientation data structure can comprises a line of equal data points along an edge of the peripheral portion. The clock marks structures can include a first line of equal data points in addition to a substantially adjacent second line of alternating data points located along an edge of the encoded data region. The clock mark structures can be located on mutually opposite sides of the encoded data region.

Abstract: An optical or symbol reader including CMOS circuitry preferably integrated on a single chip. A CMOS optical reader chip comprises a CMOS imaging array having a plurality of pixels each with a dedicated pixel-site circuit. Charge is accumulated at each pixel location transferred upon demand to a common bus. In a preferred embodiment, exposure time of the imaging array is controlled using a feedback loop. One or more exposure control pixels are positioned adjacent to or within the imaging array and receive light along with the imaging array. The charge of the exposure control pixel or pixels is measured against a threshold level, and the amount of time taken to reach the threshold level determines the time exposure of the pixels of the imaging array. CMOS signal processing circuitry is employed which, in combination with the exposure control circuitry, minimizes time-to-read over a large range of light levels, while performing spatially optimal filtering.

Abstract: Apparatus for automatically acquiring and verifying, relative to pre-established rules, information affixed to relatively flat articles transported along a transport path comprises weighing means for measuring weight of articles being processed, image acquisition means for acquiring a representation of indicia appearing on an article, processing means for recognition of the indicia appearing on an article, and processing means for verifying acquired data against the pre-established rules.

Abstract: Bar code data may be automatically inserted into an associated data field by first determining whether bar code data has been received, and, if so, matching a field code included with the bar code data to the associated data field. Subsequently, the bar code data may be inserted into the associated data field.

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: The present invention relates to an optical scanner (20) comprising a radiation source (24) for generating a radiation beam, and means (22), (26) for giving the radiation beam a scanning movement in a first direction through an angular range &Dgr;&thgr;1 and in a second direction through an angular range &Dgr;&thgr;2. The radiation source (24) is, for example a diode laser and is tunable in wavelength, and the means comprise a rotating reflecting element and a grating.

Abstract: An optical or symbol reader including CMOS circuitry preferably integrated on a single chip. A CMOS optical reader chip comprises a CMOS imaging array having a plurality of pixels each with a dedicated pixel-site circuit. Charge is accumulated at each pixel location transferred upon demand to a common bus. In a preferred embodiment, exposure time of the imaging array is controlled using a feedback loop. One or more exposure control pixels are positioned adjacent to or within the imaging array and receive light along with the imaging array. The charge of the exposure control pixel or pixels is measured against a threshold level, and the amount of time taken to reach the threshold level determines the time exposure of the pixels of the imaging array. CMOS signal processing circuitry is employed which, in combination with the exposure control circuitry, minimizes time-to-read over a large range of light levels, while performing spatially optimal filtering.

Abstract: A ink that is printed under a printed information-based indicia so that the information-based indicia will not require a Facing Identification Mark (FIM). The ink provides the foregoing result by being both fluorescent and phosphorescent. Current desk top printers and color photocopiers are not capable of duplicating fluorescence and phosphorescence at the same time.

Abstract: A test tube includes a dot code on the surface thereof which is readable with an optical reading mechanism wherein the dot code is formed on the test tube by laser burning.

Abstract: A system for high speed acquisition and decoding of a barcode symbol locates potential barcode candidates within a scanned image and filters the candidates to eliminate invalid data. The system permits computational resources to be focused on decoding information most likely to be an actual barcode symbol. Once a potential barcode candidate has been located, the barcode symbol is processed to determine the barcode orientation and symbology. Each element of the barcode symbol is then located, even if all elements are not visible in the original image, and the barcode symbol is decoded in accordance with the specific symbology.

Abstract: An optical or symbol reader including CMOS circuitry preferably integrated on a single chip. A CMOS optical reader chip comprises a CMOS imaging array having a plurality of pixels each with a dedicated pixel-site circuit. Charge is accumulated at each pixel location transferred upon demand to a common bus. In a preferred embodiment, exposure time of the imaging array is controlled using a feedback loop. One or more exposure control pixels are positioned adjacent to or within the imaging array and receive light along with the imaging array. The charge of the exposure control pixel or pixels is measured against a threshold level, and the amount of time taken to reach the threshold level determines the time exposure of the pixels of the imaging array. CMOS signal processing circuitry is employed which, in combination with the exposure control circuitry, minimizes time-to-read over a large range of light levels, while performing spatially optimal filtering.

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: An information based indicia (IBI) that does not require a FIM and is able to be read by Advanced Facer Canceller Systems. The foregoing is accomplished by printing on the mail piece an upper layer IBI indicia over a lower layer invisible ink. The lower layer ink is a dual luminescent ink that is invisible to the naked eye and the upper layer IBI indicia is printed with an ink that is visible to the naked eye. The lower layer may also be produced by two inks, one of which is fluorescent and the other of which is phosphorescent. The fluorescent ink will be printed in one area of the lower layer and the phosphorescent inks will be printed in another area of the lower layer.

Abstract: A tractor and trailer tracking system is provided including a plurality of tractor/trailers at least one of which has a bar code positioned thereon. Also included is at least one checkpoint post having a code scanner for reading the code upon the same passing therethrough whereby the code is ascertained. Next provided is a central monitoring unit connected to the bar code reader of the checkpoint post and including a time circuit for tracking a current time and date. The central monitoring unit also has a database of vehicle information relating to each of the tractor/trailers and the codes. In use, the central monitoring unit serves to store in another database an entry upon each passing of one of tractor/trailers through one of the checkpoint posts. Each entry includes a time of the passing of the checkpoint post and the vehicle information relating to the tractor/trailer that has passed the checkpoint post.

Abstract: A scanning reader of an optical code placed on a front wall of an article in movement comprises generators that form at least one first and one second light beam lying on planes inclined by a first and by a second prefixed angle (.alpha., .beta.) with respect to the front wall so as to explore a first and a second area of the front wall by at least one first and one second scanning line and read the optical code within an overall distance range, along the direction of forward movement of the article, greater than the useful range of reading distance that can be reached by one light beam only.

Abstract: The invention is optical assembly for use in a barcode reader that includes a frame having a rear housing and a pair of arms outwardly extended from the housing. An optical card containing an imaging lens is slidably received in a rear guideway situated between the arms. An aperture card is slidably received in a front guideway situated between the arms in front of the lens. Lamp support brackets are also mounted to either side of the arms. Each bracket contains a pair of LEDs that are aligned in coplanar relation with the imaging lens. A cylindrical lens is mounted in front of the lamp support brackets within the arms of the frame to magnify and focus the illumination from the LED upon a target in barcode space. A horizontally extended field stop aperture is positioned in front of each LED.

Abstract: A scanner for the acquisition of optical information, in particular bar codes, is proposed, which has a laser device (3), a receiving device (23), which detects laser light (25) reflected from the surface, carrying the optical information, of the object (13), and a measuring device (27), which emits a control signal corresponding to the distance from the object (13). The scanner (1) is distinguished by the fact that the laser device (3) has a single laser light source (37), and that a focusing device (31) is provided which can receive the control signal of the measuring device (27) and enables the scanner (1) to be adapted to the distance from the object (13), on the surface of which the optical information or the bar code (15) is present.

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: The method is for use in a bar code reader. By means of a special illumination of the bar code applied to a reflecting surface/wafer and special receiver optics, bright-field illumination is implemented. Optimum contrasts between the images of the marking elements and the surrounding reflecting areas offer a high recognition reliability.

Abstract: A system that scans and reads IBI in accordance with the United State Postal Service Specification. This invention also improves both the readability and security of the Information-Based Indicia. The apparatus of this invention utilizes a postage meter that prints an Information-Based Indicia, scans and checks the Information-Based Indicia and prints an invisible, secure message, i.e., bar code over the Information-Based Indicia. The apparatus may also audit the franking process by immediately scanning and verifying the bar code that was printed over the Information Based-Indicia.

Abstract: An accountability system for keeping track of firefighters at a fire scene. The system includes an identification card containing specific personal information represented by a bar code. A bar code reader is adapted to read the bar code and to communicate the data from the bar code to a computer. A data entry device is connected to the computer and is adapted to allow entry of additional data by a user. The computer is in communication with the bar code reader and data entry device and is programmed to process data received from the bar code reader and data entry device and provide a number of predetermined outputs, a display, and an alarm adapted to provide an alert to the Accountability Officer corresponding to a predetermined output. In the preferred embodiment, the computer is programmed to calculate the elapsed time after the bar code reader reads the identification card, and to trigger an alarm when the elapsed time exceeds a predetermined maximum safe breathing time.

Abstract: A system for high speed acquisition and decoding of a barcode symbol locates potential barcode candidates within a scanned image and filters the candidates to eliminate invalid data. The system permits computational resources to be focused on decoding information most likely to be an actual barcode symbol. Once a potential barcode candidate has been located, the barcode symbol is processed to determine the barcode orientation and symbology. Each element of the barcode symbol is then located, even if all elements are not visible in the original image, and the barcode symbol is decoded in accordance with the specific symbology.

Abstract: Improved assistance is provided to an operator to balance an out-of-proof transaction at a balancing workstation of an image-based financial document processing system used to process transaction items including debit and credit items. A number of suspect tests are invoked. The suspect tests have been previously arranged in an order which is based upon at least one characteristic data collected over a previous time period. The invoked suspect tests are applied to the debit items and the credit items in the particular order to improve assistance to the operator to balance the out-of-proof transaction.

Abstract: An improved method and apparatus for enhancing the resolution of an image of an object by a sensor is described by operating the sensor to capture a two-dimensional image of the object. In particular, one of the sensor and the object is moved with respect to the other from a first position to a second position. In the second position, electrical signals are outputted by the sensor's pixels aligned with a sampling line that is disposed at an acute angle with respect with a reference line of the object, whereby the resolution of the resultant object image is enhanced.

Abstract: A method and device for storing and using information associated with multiple logical volumes stored on a single physical volume associated with a data storage system. The invention uses writable labels to read and write metadata associated with the multiple logical volumes. Metadata stored on a writable label associated with each physical volume is available without either reading the physical volume itself or accessing a host computer's control data set.

Abstract: An electro-optical bar code symbol reader initiates reading of a symbol when a target bearing the symbol is detected within a predetermined distance of the reader. The reader is mounted on an operator's arm by being strapped around the operator's wrist. A keyboard and a display are provided on the reader for data entry and display.

Abstract: A scanner has a window in its housing through which the scanning beam emerges to impinge upon an indicia to be read. The beam scans in a raster fashion over the window, and as it does so it impinges upon beam position indicating means which locate the position of the beam with respect to the scanner in at least certain portions of the scan pattern. Specifically, the beam position indicating means determines the position of the beam in a direction perpendicular to the overall scanning direction. In a preferred embodiment, the beam position indicating means may comprise one or more CCD's which provide electrical output signals dependent upon the position of the beam when it impinges upon them. Alternatively, the beam position indicating means may comprise passive code means such as a stacked series of bar code symbols. The location of the beam when it scans across the symbol can be determined by the unique pattern of reflections.

Abstract: A system for processing a plurality of response forms containing subsets of questions from an entire set of question is disclosed. This system includes an optical scanner for creating an optical image of the response form. The optical image is stored in an image file within a storage means by a processor. The form contained in the optical image is identified by comparing vertical and horizontal histograms of the image within the image file to vertical and horizontal histograms of prototype form images in a prototype library using the processor and a form recognition engine. Data is extracted from the form based on a comparison of response zones on the image to a library of sets of response prototypes describing completed and uncompleted responses. The closest response zone match using the histogram technique to describe the response zone and the samples becomes the data, yes or no; that is reported.

Abstract: A bar code symbol reading system includes a memory for storing a plurality of reading gate locations, each reading gate location defining coordinates for a reading gate area surrounding one of the bar code symbols. The memory also stores a lookup table containing an identifier for the object and a pointer to configuration data relating each reading gate for the object to a specific component on the object. The object is scanned by a charge-coupled device scanner for scanning each bar code symbol according to the stored reading gate locations. A processor determines the identifier for each object and relates each read bar code symbol to a component on the object based on the configuration data.

Abstract: A scanning system is capable of open or closed loop operation for generating arbitrary rotatable multi-dimension with frequency compensation of scanning element. The system includes at least two scan elements positioned substantially orthogonally to each other for generating the arbitrary rotatable multi-dimensional scanning patterns. A power supply is responsive to respective control signals from a set of drive waveforms as inputs to the at least two scan elements. A controller includes an information processing system to store in digital form the desired set of arbitrary rotatable multi-dimensional scan patterns. In a closed loop mode, the controller stores feedback parameters for each scan element with a particular rotational angle and a feedback value at a particular frequency.

Abstract: A code information reading section selects recording codes which are respectively recorded on a plurality of recording media one at a time, and sequentially optically reads the recording codes in order to make it possible to synthesize a plurality of audio information items which are previously coded and recorded in an optically readable form and to simultaneously output them. A code information decoding section sequentially decodes the recording codes read by the code information reading section. A decoded information synthesizing section sequentially synthesizes digital audio signals sequentially decoded by the code information decoding section. A D/A converter converts the digital audio signal synthesized by the decoded information synthesizing section into an analog audio signal. An audio output section outputs the analog audio signal converted by the D/A converter as an audio output.

Abstract: An electro-optical reader reads indicia having parts of different light reflectivity within a limited working range of distances relative to the reader. The reader includes a laser for emitting a laser beam, a photosensor for detecting light over a field of view and generating an analog signal indicative of the indicium being read, and a scanning motor for scanning the laser beam and/or the field of view. A digitizer for digitizing the analog signal, a laser drive for energizing the laser, and a motor drive for activating the motor are all mounted on a single chip integrated circuit mounted within the reader.

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 multiple-sided, parallelepiped enclosure has a base at one side for supporting a laser diode, a planar member at another side, a circuit board overlying the base at still another side, and an opening at yet a further side of the enclosure. The diode emits a laser beam through the opening to a bar code symbol. Light reflected off the symbol is detected by a photodiode over a field of view. A scanning component scans the laser beam and/or the field of view in a compact optical scanning module for reading symbols.

Abstract: An optical scanner for reading two-dimensional indicia such as bar code symbols and the like includes a scan element arranged to create a two-dimensional raster pattern which may be scanned across the indicia to be read. In order to improve linearity of response in the vertical direction, perpendicular to the direction of the scan lines, the scan element is driven in that direction by a modified triangle waveform in which the amplitude and/or the phase of at least one of the harmonics has been altered. A scanning synchronization signal is provided by a long thin photodetector which is swept by the scanning beam at the left hand end of each scan path. This enables reading of vertically-modulated bar code symbologies such as POSTNET and PostBar.

Abstract: A system for using OCR processing to read human readable characters that correspond to an unsuccessfully decoded code word in a bar code symbol. An imaging system captures an image of a label that includes a bar code symbol and corresponding human readable characters. The system attempts to decode the bar code symbol by decoding each of the constituent bar code characters. If a bar code characters is not successfully decoded, the system locates the associated human readable text and segments the text into individual character images. The unsuccessfully decoded bar code character is mapped to one or more of the alphanumeric character images, which are converted into text characters. The resulting ASCII data is used to create a substitute bar code character in the bar code symbology. After the bar code symbol is decoded using the substitute bar code character, the symbol is validated through check summing or other means.

Abstract: In a method of coding an electronic text document, the length of a space preceding a word in a line of text data of an electronic document relative to the length of a space following the word is modulated with the value of a bit of signature data. The signature data are thus embedded into the text data of the electronic document, not being easily discernible to illicit readers.

Abstract: A small-sized optical reading device for performing the high-speed optical scanning of an object to be read, and for returning light irregularly reflected by the object. In this device, a first reflector element is driven in such a manner as to perform reciprocative rotations or vibrations clockwise and counterclockwise. Further, a medium, on which a bar code, namely, the object is recorded, is scanned by light beams reflected by the first reflector element. The light beams irregularly reflected by the medium are returned to a reflector element array consisting of second reflector elements of a reciprocative vibration reflector. Independent drive signals are provided concurrently to the first reflector element and the reflector element array. The reflecting surface of the first reflector element has a size sufficient to the extent that the entire spotlight caused by a semiconductor laser can be reflected.

Abstract: A portable non-contact label imager captures an image of two-dimensional information indicia on a label. The captured image data is decoded by a decoder. The label imager forms a part of a data terminal, which includes a keypad, display and signature capture pad. Upon receipt of a start signal from the data terminal's circuitry, the label imager automatically carries out the steps required to capture the label information indicia. The label imager provides aiming indicia to allow the user to properly aim the camera. A position sensing device determines when the target label is within the camera's depth of field. At that time, the label imager determines the shutter speed required for a correct exposure by measuring the light reflected from the label. The label imager then captures the label image, which is decoded by the decoder. Corresponding output data is then provided to the data terminal.

Abstract: An image capture system (100) having an image capture module (102) and a terminal unit (104) captures both photo images and coded images. An alterable optical path of the system (100) operates in a first configuration when capturing coded images and in a second configuration when capturing photo images. Captured images are presented on a display (114) as they are captured. A user of the system (100) may parse through captured images to select one or more of the captured images for permanent storage and/or transmission to a remote location. The system (100) operates to identify coded targets within captured images, to prompt the user to select one or more of the identified coded targets and to decode the selected coded targets. The image capture system (100) may direct a user to reposition the system (100) so that a decodable coded image will be captured. The image capture system (100) communicates over wireless and wired networks with remote computer systems (307), personnel, and mobile units (307).

Abstract: A portable ID card verification apparatus is disclosed. The apparatus includes a housing defining an interior region supporting electrical circuitry including a processor. A two dimensional imaging assembly is at least partially enclosed within the housing. A display screen in electrically coupled to the imaging assembly. An upper surface of the housing supports a glass window on which an ID card is positioned for reading a dataform imprinted thereon. The dataform includes a compressed digitized representation of an attribute of the authorized card holder, such as a photograph of the card holder. The imaging assembly images and decodes the 2D dataform on the ID card and the processor in conjunction with display driver circuitry causes an image of the card holder's photograph to be displayed on the display screen.

Abstract: A system and method for capturing hand-marked cells from a lottery selection slip. The lottery slip includes a conventional play region of cells (labelled sequentially from 1 to 49, for example) for receiving indicia to be captured, after receiving indicia said play region of cells includes a plurality of occupied cells defined by marked cells and a plurality of non-occupied cells defined by unmarked cells. The lottery slip also includes row-identifier bar codes located at opposite boundaries of the play region. The bar codes are electro-optically scannable and readable and are arranged in a plurality of ordered rows tiered along the transverse direction over the transverse distance of the play region.

Abstract: A method and apparatus for reading bar codes or other images while reducing or eliminating the need for self-generated illumination. An image reader is preferably embodied as a handheld unit and comprises an efficient optical collection system including an aperture with a high aspect ratio and/or a multi-focal lens or lenses. An optically transmissive spacer affixed to the front of the handheld unit allows ambient light to be collected at close range, and a diffuser may be used to reflect ambient light from the handheld unit to provide additional illumination at close range. A masked CCD detector with rectangular pixels receives collected light and is coupled to an adaptive exposure circuit for preventing saturation of the CCD detector at high illumination levels. A correlated double sampling circuit coupled to the adaptive exposure circuit rejects common mode noise and allows operation in lower light levels.

Abstract: Distance L between best focus surface BF to reading opening 22 is in a range satisfying the condition: 2 mm.ltoreq..vertline.L.vertline..ltoreq.2a.multidot..omega./D, where "D" represents the size of a short side of an elongated hole of a diaphragm 34a, "a" represents a distance from an objective-side principal point of an imaging lens 34 to the best focus surface BF, ".omega." represents a minimum width of a module of bar code 8, "L" represents a distance measured from the best focus surface BF toward imaging lens 34, and .vertline.L.vertline. represents an absolute value of distance L. With this arrangement, adverse effect of stains, wounds and scratches of bar code 8 can be averaged or decentralized along the longitudinal direction of the bar of bar code 8 without deteriorating a reading accuracy in the lateral direction.