Pitney Bowes Inc.

Other

Henry Stalzer

Peter C DiGiulio

Donald T Dolan

Warren G Hafner

Hugh St Dannatt

An electronic postage meter with a non-volatile memory security circuit apparatus is disclosed. The security circuit comprises means for limiting the amount of time the memories may be continuously enabled, means for preventing simultaneous enabling of both memories and means for preventing the write enabling of a memory if the write enable signal is active before a memory select signal is active. The circuit prevents memory access when a conflict is sensed across in an output related to the non-volatile memories. The security circuit provides additional protection to the non-volatile memory so that valuable critical accounting information located therein cannot be modified or destroyed.

Postage meter with a non-volatile memory security circuit

A method and apparatus for providing enhanced security to the non-volatile memory of an electronic postage meter during power up and power down of the meter is disclosed. The apparatus comprises means for detecting a regulated voltage level of the meter, means for detecting an unregulated voltage level of the meter, means for detecting a predetermined frequency from a system clock associated with the meter and a reset delay circuit responsive to the detected unregulated voltage, detected regulated voltage and the predetermined clock frequency for allowing access to the non-volatile memories if the unregulated voltage level, the regulated level and the clock frequency have reached their appropriate levels and preventing access to the memories otherwise. Through the use of this circuitry the critical accounting information within the memories is protected during the powering up and powering down of the postage meter.

Electronic postage meter having power up and power down protection

This invention relates to apparatus for electronically recording using a xerographic machine and, more particularly, to an assembly of monoliths containing light emitting diodes (LED's) that yields a relatively long array of LED's with high light density and a contiguous set of light centers. A fiber optic cover is placed over the exposed surfaces of the LED's to counter the effects of the divergent angle of light emitting from the LED's and to protect the LED's from damage. A gel having a relatively high refractive index is applied between the LED's and the fiber optic cover to further counter the effects of the divergent angle of light.

Light emitting diode assembly

An electronic postage meter having an improved memory selection circuit is disclosed. A custom memory map decoder circuit with resolution down to a single byte location is used to provide selection enabling signals to insure the selection of an appropriate device only when the addresses appropriate to that device are communicated. In accordance with the invention, at least two nonvolatile memories are provided. Writing to either of these nonvolatile memories is inhibited unless one and only one memory is selected. The circuit also prevents the selection of either of the nonvolatile memories in the event that the write strobe signal to the memories is held active.

Electronic postage meter having a nonvolatile memory selection means

An electronic postage meter with a circuit to provide for a delay period before operation of a postage meter is disclosed. The circuit provides a fixed delay which is triggered when three input signals provided to the circuit become active. The input signals will be active in this embodiment to indicate satisfactory regulated voltage level, a satisfactory unregulated voltage level, and a satisfactory external clock frequency respectively. The output of the delay circuit upon acceptance of these active signals provides a reset delay signal to a system processor and also controls the signals that are provided to the non-volatile memories and the system printer. The circuit uses advantageously logic devices to provide the delay of the output signal rather than the traditional utilization of R-C network. The delay circuit is particularly useful in a system such as postage meter that utilizes a microprocessor and a non-volatile memory, to protect the contents of the non-volatile memory.

Reset delay circuit for an electronic postage meter

This invention relates to circuitry for non-impact printers that use light emitting diodes (LED's) to produce an image on a photoconductor and for controlling the output of each LED of a light emitting diode array that is part of the printer. A binary weighted duty cycle control is used to obtain substantial uniformity in the light emitted from each LED. The binary cycle is time related so that through use of a four-bit code, sixteen outputs are available which yield sixteen periods during which an LED may be enabled.

Control of a light emitting diode array

A non-impact printer in which a source of image information such as a computer, facsimile machine, word processor or the like provides image information to an image transfer device which transfers the image to a moving image receiving surface for printing of the image as hard copy. A motion encoder senses the motion of the image receiving surface and creates a digital timing signal representative of the motion. A logic circuit selectively delays the input of the image information signal to the image transfer device in response to digital timing signal to synchronize motion of the image receiving surface with transfer of the image to the image receiving surface.

Method and apparatus for compensating for irregular motion

This invention relates to a system for non-impact printers such as those that use light emitting diodes (LEDs) to produce an image on a photoconductor. In such devices, a discontinuity is generally created in a line of printed characters because of the movement of the imaging surface relative to the LED array. The system of this invention eliminates such discontinuity through adjustment in the enabling sequence of the LEDs of the array.

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Danbury, CT, United States of America

Henry Stalzer