|
|
Disclosed is a method of protecting the reading device for data medium in form of a card from unauthorised evaluation or copying of magnetically encoded data which are recorded on the reading device for the data medium in form of a card. A magnetic interference field is generated using an interference field coil. The arrangement of at least one interference field coil is such that an authorised magnetic reading head when reading magnetically encoded data on the data medium in form of a card is also under the effect of the interference field of the interference field coil. An output or resultant signal of the authorised magnetic reading head formed by the useful signal of the data medium in form of a card and the effect of the interference field is detected. The effect of the interference field of the interference field coil on the output or resultant signal of the authorised magnetic reading head is compensated for or filtered, or the useful signal is selectively filtered off from the output or resultant signal of the authorised magnetic reading head. |
|
Apparatus for access control, and read/write device Access control device has a lock with a locking element, an actuating element for the locking element, an electronic key, a receiver unit for receiving key identification data and a processing circuit for determining access authorisation based on the received identification data, wherein the processing circuit interacts with the actuating element and/or the locking element for selectively locking or unlocking the lock, the electronic key includes means for generating a capacitive near field via which the identification data are transmitted, and a device for coupling the capacitive near field to the person carrying the key, wherein the receiver unit is designed as a wall or table reading device separate from the lock and the actuating element, and has at least two electrodes and includes at least one capacitive coupling surface such that, at a contact of the capacitive coupling surface or an approach of the capacitive coupling surface by said person, an alternating current circuit is closed and an electric current flows through the receiver unit, which can be detected by the receiver unit. |
|
Mark, method of making said mark and data carrier Mark has first sections lying at a distance from each other on a base, the said sections including at least one electroconductive material whose electroconductivity exceeds a given threshold value, and second sections lying between the first sections and having electroconductivity which is less than or equal to the said threshold value. According to the invention, at least two first sections are essentially distinguished from each other by electroconductivity. |
|
System for contactless reading of chip-cards located on objects Contactless reading system containing chip-card fixed on flat carrying surface of object (e.g. book) (11) for its identification according to data contained in card chip and mobile reading device (16) provided with antenna for card data reading. Antenna of reading device (16) consists of coil of smaller size connected in series with coil of larger size, at that, the coils are concentric and with winding in one direction. Maximum value of electromagnetic field component (H) (antenna generated field) is achieved at certain distance from antenna. Detection of antenna transmitted electromagnetic signals by chip-card will be maximal when antenna is positioned at right angle to card-carrying surface and at certain distance from the card. |
|
Electromagnetic label deactivator Electromagnetic label deactivator containing casing, metal plate with fixed permanent magnets forming magnetic field for label deactivation (labels, tabs, markers, etc) comprises as constant magnets the ferrite ring magnets with opposite magnetising polarity placed on the plate and mutually shifted, enabling magnetic field of longitudinal and transverse asymmetric distribution. This field structure of deactivator provides label deactivation within initial or final stage of single moving along deactivator surface. |
|
Device for identification and method for scanning the same Identification device contains code elements positioned on substrate with different coercive intensity. Each code element is made of magnetic-soft material, to which through non-magnetic insert connected magnetically are grouped together, having similar shape and dimensions, of same domain during magnetization in direction of axis of light magnetization, discontinuous elements, which possess greater coercive intensity than magnetic-soft material. Method for scanning device includes serial magnetization by means of external field of elements with varying coercive intensity, registration of electromagnetic impulses occurring during that and their processing, while for magnetization alternating-sign magnetic fields are used with varying speed of their change in time. |
Another patent 2513053.