Abstract:
A hierarchical communication system (30), arranged in a spanning tree configuration, is described in which wired and wireless communication networks (37, 40, 41) exhibiting substantially different characteristics are employed in an overall scheme to link portable or mobile computing devices (35, 36). Copies of data, program code and processing resources are migrated from their source toward requesting destinations based on request frequency, communication link costs and available local storage and/or processing resources. Each appropriately configured network device (33, 35, 36) acts as an active participant in network migration. In addition, portable two dimensional (2-D) code reading terminals (43, 44, 45) are configured to wirelessly communicate compressed 2-D images towards stationary access servers (33) that identify the code image through decoding and through comparison with a database of images that have previously been decoded and stored.
Abstract:
A programmable apparatus for generating a frequency modulated signal at a selected center frequency in accordance with digital data with at least first and second data levels. A modulator (331) is responsive to an input modulation signal for generating the frequency modulated signal at a frequency dependent on a quiescent voltage appearing at its input. A circuit (380) is provided for sampling and storing a value of the quiescent voltage. An addressable memory (301) stores a plurality of offsets. A programmable adding circuit (345) adds a downloaded offset voltage to the stored value of the quiescent voltage to output a high modulation voltage. A programmable subtracting circuit (349) subtracts a downloaded offset voltage from the stored value of the quiescent voltage to provide a low modulation voltage. An addressing circuit addresses the memory in accordance with a data transmission parameter for downloading a corresponding offset to the adding and subtracting circuits. A switch or multiplexor (346) is coupled to the subtracting and adding circuits for generating and applying to the modulator input an input modulation signal.
Abstract:
A scanner for reading two-dimensional optical information sets is described which includes a housing for supporting a photosensitive array associated with an optical string adapted to focus optical information on the array. Also provided are array and optical string controls for controlling the array and optical string such that the output of selected images on the array are processed via pattern recognition means. Images recognized to contain decodable optical information are displayed and highlighted by a display. In this fashion a user is assisted in aiming, recognizing, confirming the decodability, and decoding images of optical information incident on the array.
Abstract:
Method and apparatus for reading and focusing a bar code using a photosensitive array (112B) and determining the rate of intensity change with respect to time and focusing the image according to the output of the photosensitive array. A data collection module (48) comprising a bar code reader and a radio transceiver is also disclosed.
Abstract:
A housing (11) of a battery pack (10) contains in addition to standard power cell elements (14-16) a voltage converter (75). The voltage converter (75) is interposed between the power cell elements (14-16) and external output contacts (29, 30, 100) of the housing (11). The voltage converter (75) regulates the output voltage applied to the output contacts (29, 30, 100) of the battery pack (10), such that the supply voltage of the battery pack (10) remains at a predetermined value which is independent of the voltage supplied by the power cell elements (14-16) to the voltage converter (75) and does not vary over the discharge cycle of the power cell elements (14-16). Excess battery voltage available particularly during the initial portion of the discharge cycle of the power cell elements (14 - 16) is efficiently converted to the predetermined output voltage value which reduces the overall current delivered by the power cells (14-16) to extend the useful life of the battery pack (10) between charges.
Abstract:
A high reliability access point for RF communications in a wireless local area network. The high reliability access point includes a central processing unit (13) for handling high level protocol functions and for interfacing with the infrastructure of the local area network (26). The high reliability access point also includes at least two wireless adapters (15, 16). Each wireless adapter includes a radio (17), a media access control (MAC) processor (19) for handling low level protocol functions, and at least one antenna (21). The multiple wireless adapters (15, 16) allow the access point to perform self monitoring, reduce the effects of multipath interference, reduce some occurrences of collisions at the access point and provide infrastructure backup in the event of an infrastructure failure. The access points also allow for wireless network infrastructure communication for connection of one or more remote access points to the infrastructure. A backup power supply for the access point is also shown.
Abstract:
The present invention utilizes two-dimensional photosensitive arrays (SR, SL) for decoding two-dimensional optically readable information sets which provides a best focus. A lens is provided for each of the photosensitive arrays movable in a trajectory (k-k', m-m') such that as the lens moves away from the photosensitive array, the distance between the lenses decreases. The varying distance between the lenses provides image zones (A, B, C) having the same overlap in each zone.
Abstract:
A data communication network for providing dynamic routing through both wireless and wired subnetworks to support wireless communication devices and wired remote stations is disclosed. In the wireless network (103), the wireless communication devices (116, 118) can be mobile RF terminals, while the wired remote stations (111) might be personal computers attached to a wired subnet (101), such as an ethernet coaxial cable. The wireless network architecture utilizes a spanning tree configuration which provides for transparent bridging between wired subnets and the wireless subnets. The spanning tree configuration provides dynamic routing to and from wireless communication devices and remote stations attached to standard IEEE 802 LANs.
Abstract:
The present invention is a focusing system for focusing optically readable information over a substantial range of distances. The focusing system (10) includes a first optical wedge (12) and a second optical wedge (14) with a reciprocating drive for moving the prisms relative to each other.
Abstract:
A portable optical reader system for reading optical information over a substantial range of distances includes a casing having a light receiving opening for alignment with optical information. Further included is a reading sensor for converting a reflected light image of optical information into an information signal and reflected light optical elements for forming a reflected light image. The optical system is adjustable to tend to focus a reflected light image of optical information, located within a substantial range of distances, onto the reading sensor. A light beam generator is associated with the casing and directed relative to the optical elements and the light receiving opening such that a light beam generated thereby will impinge on an information carrier, having optical information to be read, and will be reflected therefrom through the light receiving opening and via the optical elements to the reading sensor. Since the position of impingement of the reflected light beam on the reading sensor is a function of the range of the information carrier from the image sensor, the optical system may be adjusted to focus a reflected light image of optical information associated with the information carrier, at least in part, according to the position of impingement of the reflected light beam on the reading sensor.