Psc Inc.

Anna M Quinn

Jay M Eastman

Scott R Grodevant

John A Boles

Gregory William Forbes

James M Zavislan

James M Tavislan

Kevin Whitcomb

A unitary hand-held bar code scanner and reader produces an elliptical beam, oriented with its major axis along the direction of the bars, utilizing optics employing far field diffraction effects to shape the beam and maintain its elliptical aspect (length to width ratio) constant over a distance in front of the scanner were bar codes may be located. The optics eliminates parallax even though the photodetector and light source (preferably a laser diode) are located offset from each other on a board on which the optics are mounted. A housing assembly has channels which mount the board therein without shock absorbing devices. A digital microcomputer controller and peripheral devices regulate the optical power output from the laser diode and prevents catastrophic failure, if the electrical current through the laser diode exceeds safe limits. Digital control of the gain of the electronic circuits which provide the signals from which bar code information can be decoded and for the operation and control of a motor for oscillating a deflector which scans the beam across the code are also provided utilizing the microcomputer. The microcomputer also controls interface circuits to provide compatibility with auxiliary equipment and host computers which generate commands and requires data inputs of various polarity and format.

Optical system for scanning and reading bar codes which is adapted to be

Optical system for scanning and recording bar codes which is adapted to

In order to control the width of the scanning beam in the scanning direction over a significant range in front of the scanner, an optical assembly including a phase mask is utilized through which the beam passes after being configured into curved wavefronts, as by a lens which provides a focus in the vicinity of the far end of the range. The F/ number of the optical assembly is high and the cone of the beam in the scanning direction is small, for example, less than 5.degree.. The mask is preferably transparent and has a region which may be rectangular, elliptical or circular forming a step through which the center of the beam passes which imposes a phase change with respect to the phase of the wavefronts which do not propagate via the region. The phase change may be uniform or in the form of a weak quadratic phase variation in this region of the mask which changes phase and thus slightly refocuses the beam. The transmissivity of the region may also be varied and reduced with respect to the transmissivity of the mask outside of the region. The beam may be scanned via a scanning mirror or by scanning the optical assembly.

Optical assembly for controlling beam size in bar code scanners

A miniature scan engine for scanning a beam of monochromatic (laser) light across a bar code and receiving return light at a detector that provides electrical signals representing the code, utilizes an integral assembly of a laser (laser diode), the detector and a light collector mounted on flexures and rotated so as to scan the beam and receive the return light from the code. The collector is a body of material transmissive at the laser wavelength. The body presents an orientable surface so that the return light is incident at or close to perpendicular to the surface. In the body, parallel to the surface, is a volume hologram grating having Bragg planes arranged in rings around a center region in alignment with the detector. The angles of the Bragg planes vary progressively and decreases in a direction toward the center region so that light incident on the collector at angles of incidence, which vary from perpendicular to the surface by about + or -5.degree., are diffracted and propagate by guided mode propagation, including reflections at the internal surfaces of the body and transmission through the grating (because the light propagating along the paths intersects the grating Bragg planes off Bragg that is at an angle other than the Bragg angle) to the detector. Efficient collection of the light returned from the bar code symbol is obtained. The entire scan engine may occupy a volume of less than 1.25 cubic inch, thereby enabling bar code scanning and reading facilities in devices such as hand-held data collection terminals where space is at a premium.

Bar code scanning and reading apparatus and diffractive light collection

An improved miniature scanning module for scanning and reading data fields having images or symbols such as bar codes, adapted to be included in a scanning application such as a portable transaction terminal. The scan engine of the module has an oscillator apparatus in which at least one side of a vertical coil cuts lines of magnetic force from an independent fixed magnet assembly and has a rotor and a stator which are molded interconnect devices in which electrical circuits are formed by surface plating or printing during multiple-shot molding of the parts. The rotor is supported by a plurality of metal alloy flexures depending from the stator, which flexures both mechanically support the rotor and transmit electrical power and signals between control circuitry on one or more printed circuit boards on the stator and electrical elements on the rotor. A semiconductor laser diode mounted on the rotor scans in one dimension when the rotor oscillates. A collection optic such as a parabolic mirror mounted on the rotor adjacent to the scanning laser also oscillates with the rotor and collects and directs return light to a photodetector mounted on the stator at the focal point of the collection optic. The flexures define an axis passing through the photodetector, about which the rotor oscillates, and thus return light from which data representing bar codes can be derived is detectable at all angles of oscillation.

Bar code scanning and reading apparatus with an oscillating scanning

Optical system for scanning and reading barcodes with manually

A miniature scan engine module for bar code reading and data collection systems utilizes a light source and a light collector flexurally supported on a platform which reciprocates on pivots defined by flexures. The light received from the code, as it is scanned, is collected along an optical collector having a surface area approximately equal to the surface area of one side of the scan engine. The optical collector in which the gratings are embedded faces the bar code and pivots with the scanning beam source (a laser diode). A pair of diffraction gratings in a surface of the optical collector which faces away from the code directs the incoming light so that it propagates internally in a substrate within the body of the collector, i.e. in the optic itself to photodetectors via reflective and light concentrating surfaces over the photodetector. Efficient light collection capability, without the need for special optics such as lenses and collection mirrors, enables the scan engine to be configured so that it occupies a miniature volume. A data collection system, in the form of a portable terminal, has a housing which provides the handle for a scanning accessory which is the scan engine module.

Optical symbol (bar code) reading systems having an electro-optic

In order to control laser beam propagation, working range and beam cross-section in a bar code scanner, diffractive optics are used to modify the amplitude and/or phase distribution of the beam in the scanner. The beam is diffracted by a mask which has a plurality of apertures in the form of segments which are arranged across the beam cross-section in the vicinity of a converging lens. The segments are sized and their transmission functions selected (one segment having for example 100% transmission and the other 50% transmission) such that bar codes close in and far out from the scanner are in regions of far field diffraction of different segments, or where such regions overlap, thereby extending the working range of the scanner where bar codes of high density can be resolved.

Growing community of inventors

Rochester, NY, United States of America

Anna M Quinn