Abstract: A method and a system of access control between a main processor and peripherals connected by a communication bus, including assigning, to all or part of the programs to be executed by the main processor, at least one token selectively authorizing access to one or several of said peripherals, said token being provided at least initially by an auxiliary processor exploiting a memory distinct from that of the main processor; and checking, for each request of access of one of said programs to one of said peripherals, the presence of said authorization token for the access to the concerned peripheral.

Abstract: The secure circulation of digital documents to be reproduced includes providing each user with a smart card containing identification information associated therewith, and identifying from a server connected to a digital data transmission network the smart card connected thereto. Information identifying a document to be played back is transmitted to the server from a terminal connected to the smart card. In response, a decryption key specific to the document to be reproduced is transmitted to the smart card for storing therein. The document to be played back is decrypted using an adapted reader connected to the smart card, and includes the stored decryption key for document playback with the reader. Information identifying the readers is inserted into the smart card, and fraudulent use of the smart card is determined according to the reader identification information stored in the smart card.

Abstract: A method and a system of access control between a main processor and peripherals connected by a communication bus, consisting of: assigning, to all or part of the programs to be executed by the main processor, at least one token selectively authorizing access to one or several of said peripherals, said token being provided at least initially by an auxiliary processor exploiting a memory distinct from that of the main processor; and checking, for each request of access of one of said programs to one of said peripherals, the presence of said authorization token for the access to the concerned peripheral.

Abstract: The secure circulation of digital documents to be reproduced includes providing each user with a smart card containing identification information associated therewith, and identifying from a server connected to a digital data transmission network the smart card connected thereto. Information identifying a document to be played back is transmitted to the server from a terminal connected to the smart card. In response, a decryption key specific to the document to be reproduced is transmitted to the smart card for storing therein. The document to be played back is decrypted using an adapted reader connected to the smart card, and includes the stored decryption key for document playback with the reader. Information identifying the readers is inserted into the smart card, and fraudulent use of the smart card is determined according to the reader identification information stored in the smart card.

Abstract: A joystick that detects position and movement using a capacitive sensor. The joystick has a stick mounted to allow movement within a housing, a conductive element at a first end of the stick, and a capacitive sensor. The capacitive sensor may be a capacitive touchpad. It determines position by measuring the change in capacitance on a set of conductive traces. The capacitive sensor may be shaped as a plane or may be hemispherically-shaped. The conductive element may also be triangular or other distinctive shape to allow detection of movement. An advantage of such a joystick is that absolute positioning may be determined, along with relative positioning.

Abstract: A touchpad having the advantages of resistive and capacitive type sensors. A capacitive sensor is stacked above a 5-wire resistive sensor. The touchpad is of integrated manufacture with one of conductive plates of the resistive sensor printed on a first substrate, and the other conductive plate printed on the second substrate with the capacitive sensor. The touchpad is configurable to distinguish between a finger and a pen, and operate in different modes depending on which is being used.

Abstract: The present invention provides a touch pad which can detect a simply stylus using a change capacitance. The touch pad is made flexible, so that the stylus pressure compresses an insulating layer between a conductive reference layer and matrix of conductive traces. The compression causes a change in capacitance due to either the two capacitive conductive surfaces being closer to each other, or a variation of the dielectric value of the insulating layer due to the replacement of air in air gaps by the material of the insulating layer.

Abstract: An improved flexible substrate for a touchpad, with the flexible substrate having conductive ink for forming a sensor array. A printed circuit board is also used, but only for the components which need to connect to the array, and not the array, thus giving a smaller printed circuit board. The printed circuit board can have the components compactly mounted on it taking advantage of the close spacing available in PC board technology. The PC board itself has wider spacing on its contacts at its outer edges, allowing it to be attached by conductive glue to the flexible substrate.

Abstract: Method and apparatus for sensing the simultaneous proximity of one or more fingers or other appropriate objects to a capacitive touch sensor. A modulator/demodulator pair drive and sense either a single trace or a pair of traces. In a dual trace embodiment, differentially sensed signals are then peak detected converted from voltage to current. The output signal is then calibrated to adjust for trace variations, followed by appropriate gain and level shifting, and analog-to-digital conversion for use as the input to a microcontroller.

Abstract: Method and apparatus for detecting an operative coupling between one or more fingers or other appropriate objects and a touch pad includes processes for detection of multiple maxima with intermediate minima in appropriate sequences to emulate the operations of cursor control and button actuations in a pointing and control device.

Abstract: Method and apparatus for determining small variations in capacitance, typically in a capacitive touch sensing device, includes a reference signal of a first frequency and a sample signal of a second frequency. The reference and sample signals are mixed and filtered to isolate the beat frequency therebetween, which is then measured to provide an indication of the variation in the sample frequency. The measurement can then be manipulated by a microprocessor or microcontroller to provide desired control signals. The apparatus is susceptible of digital implementation and single chip implementation.