摘要:
A bar code reader and method of reading a bar code symbol successively generates scan patterns at different times on the symbol. Preferably, two light sources are alternately energized to alternately produce two scan lines across the symbol. Each scan line reflects light from the symbol. The reflected light is detected by a photodetector which, in turn, generates an electrical signal. This signal is decoded into data corresponding to the symbol.
摘要:
A bar code scanner and method for scanning a bar code symbol that splits a light beam using a liquid crystal device and directs the split light beams toward a bar code symbol using a moveable mirror. The light reflected by the symbol from each of the split light beams is added summed and converted to an electrical signal indicative of the bar code symbol. The electrical signal is processed to decode the bar code symbol and, if the decoding is unsucessful, the liquid crystal device is changed to affect the number of split light beams incident on the bar code symbol.
摘要:
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. In another embodiment, a tunable laser may be employed to provide a scan without moving parts; a laser beam from the tunable laser is reflected from a diffraction grating that produces an angular deviation dependent upon the wavelength of the laser output. As the frequency of the tunable laser is varied in some selected pattern, the laser beam will scan accordingly.
摘要:
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 suorces. Multiple simultaneous scan lines may be employed to generate a raster scan at lower mechanical scan frequency. In another embodiment, a tunable laser may be employed to provide a scan without moving parts; a laser beam from the tunable laser is reflected from a diffraction grating that produces an angular deviation dependent upon the wavelength of the laser output. As the frequency of the tunable laser is varied in some selected pattern, the laser beam will scan accordingly.
摘要:
A bar code scanner and method for scanning a bar code symbol that splits a light beam using a liquid crystal device and directs the split light beams toward a bar code symbol using a moveable mirror. The light reflected by the symbol from each of the split light beams is summed and converted to an electrical signal indicative of the bar code symbol. The electrical signal is processed to decode the bar code symbol, but, if decoding is unsuccessful, the liquid crystal device is changed to affect the number of split light beams incident on the bar code symbol.
摘要:
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. In another embodiment, a tunable laser may be employed to provide a scan without moving parts; a laser beam from the tunable laser is reflected from a diffraction grating that produces an angular deviation dependent upon the wavelength of the laser output. As the frequency of the tunable laser is varied in some selected pattern, the laser beam will scan accordingly.
摘要:
In order to improve security for holographic labels which are positioned on a substrate base, a bar code symbol with regions of different light reflective properties is holographically recorded on the base. The base may be, for example an information card, such as a credit card, a label, or a container for a product. The bar code symbol can be recorded so that it is visible to the eye in white light (e.g., as a rainbow hologram) or so that it requires an appropriate reference beam for reconstruction. A reading apparatus (e.g., a bar code reader) directs light at the holographic bar code symbol and detects the reflected optical information with a detector such as a CCD array. The reading apparatus can be a stand-alone device or, in the case of a credit card, can be incorporated into a conventional swiper for reading magnetic information on a strip on the card. A non-holographic bar code symbol can also be provided on or near a holographic display element, e.g., a rainbow hologram. The bar code can be positioned adjacent the display, or placed in a window within the display, or etched or embossed on the display. A system is also provided for authenticating a holographic display on an information card such as a credit card. A display is illuminated and a reflected beam directed at a holographic record which was previously produced from a signal, known to be authentic, and a reference. The reflected beam is used to reconstruct a reference beam. A sensor receives the reconstructed reference and it is then determined if the display is authentic.
摘要:
A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.
摘要:
An information processing system adapted to be worn on the body of a user, the system a module for processing data capable of being worn by a user; and a band secured to the module and adapted to be secured around a part of the user's body so as to support the module and to allow the user to utilize the module, the band incorporating a battery for powering the module.
摘要:
A miniaturized electro-optical, retro-reflective scanning module. The module has a base, a first circuit board, and a second circuit board mounted substantially orthogonal to the first circuit board. The base supports a light emitter for producing a scanning beam and optical elements for directing and collecting light energy. The emitted beam reflects off a fold mirror onto a reflector mounted on a drive for oscillation. The oscillating reflector, in turn, redirects the beam onto an indicia being read. The reflected light is reflected off the oscillating reflector and directed to the collection mirror before reaching a detector. The detector included in the module senses light reflected from an indicia scanned by the beam. The reflector is driven by an electro-magnetiz driven system, including a flexure and an actuation arm.