Short title: Device for indicating unauthorized use of an automobile .
The invention relates to a device for indicating unauthorised use of a vehicle, the device comprising: a control unit for producing a first control signal in response to receiving a certain access code, - a display unit visible from outside the vehicle and connected to the control unit for displaying the license number of the vehicle in response to the first control signal and displaying a message indicative of unauthorised use in the absence of the first control signal . A device of this kind is disclosed in European Patent Application EP 0,146,328.
In this Prior Art device, a visual display is used to alert others to the fact that the vehicle is stolen. To this end the display, which is affixed to a window of the vehicle, may show various messages. A key pad serves to enter an access code. When the vehicle is used without the access code being entered, a message stating "stolen" or the like is displayed.
Although such a device is useful, it requires an additional unit, that is, the theft indicating display to be mounted in the vehicle.
Many passenger cars are presently equipped with a third or auxiliary brake light, which is already mandatory in several countries. Such a third brake light is usually mounted behind the rear window of the vehicle. Installing both a third brake light and a theft indicating display may clutter the rear window, reducing the rear view of the driver. In addition, installing two separate devices is laborious and uneconomical.
Another vehicle theft indicating device is disclosed in
United States Patent US 4,768,027. The device of said US Patent has a display unit which may be bolted onto the vehicle. In this way, cluttering the rear window is avoided at the expense of installing a separate unit.
International Patent Application WO 94/20335 discloses a device which comprises an LCD display which may be glued onto a vehicle window. This also requires two units, i.e. the third
brake light as well as the display to be installed. In addition, it is relatively easy to tamper with this Prior Art device by peeling the display off the window.
It is therefore an object of the present invention to provide a device for indicating unauthorized use of a vehicle which requires no additional space in the rear window of the vehicle.
It is another object of the present invention to provide a device for indicating unauthorized use of a vehicle which is economical to install in a vehicle.
It is a further object of the present invention to provide a device for indicating unauthorized use of a vehicle which cannot be tampered with.
It is a yet further object of the present invention to provide a device capable of indicating both authorized and unauthorized use of a vehicle.
Accordingly, these and other objects are achieved by a device as defined in the preamble, which according to the present invention is characterized in that the device is coupled to the brake circuit of the vehicle so as to make the display unit act as an auxiliary brake light in response to a second control signal .
By providing a device having a display which acts both as theft indicating display and third brake light, only a single unit needs to be installed in the vehicle. That is, the display unit may replace the third brake light, thus eliminating the need for the latter being installed. Alternatively, the third brake light already present in most cars may easily be modified to also act as theft indicating display, thus eliminating the need for installing a separate theft indicating display.
The display may be coupled directly to the electrical brake circuit of the vehicle. Preferably, however, the brake circuit is connected to the control unit so as to produce the second control signal in response to an activation signal originating from the brake circuit. In this way, the control unit may generate appropriate signals, or an appropriate combination of signals, in response to the presence of the access code and/or of a brake activation signal.
Advantageously, the display unit is arranged between layers
of a rear window of the vehicle. This prevents the display from being tampered with, thus improving the security of the device. The power for energizing the display may in this case be obtained from (separate leads of) the rear window heating circuit. The separate leads make the display independent of the activation of the rear window heating circuit.
Preferably, the display unit comprises a programmable electronic circuit for storing the license number. In this way, it is ascertained that the display can only show the actual license number of the car, even if the control unit is tampered with. Especially when the display including the programmable- electronic circuit (e.g. a PROM-type memory chip) is arranged between layers of the rear view window, it is virtually impossible to alter the stored license number. To this end, it is advantageous when the programmable electronic circuit for storing the licence number is not reprogrammable. This makes it impossible to even remotely altering the license number stored in the display circuit. Reprogramming may be completely excluded by making use of a programmable electronic circuit comprising a fuse matrix, such that programming causes certain connections in the fuse matrix, including the writing line of the matrix, to burn through.
The licence number of the vehicle being visible in the display of the device is in principle an indication of authorized use. If this indication does not correspond with reality, the unauthorized user may wish to mount plates with a different licence number in order to render tracing via the usual licence plates more difficult. Mounting different licence plates, however, immediately renders the vehicle suspicious because of the difference between the licence number appearing on the display and that appearing on the newly mounted plates . A "solution" for the unauthorized holder would be reprogramming of the electronic circuit (chip) belonging to the display. For this a programming device would be required, which, however, is not part of the vehicle.
A practical embodiment of the device according to the invention is adapted to the use of a personal chip card as a unique information carrier for carrying the access code. Suitable personal chip cards are those, which are commonly used and are
provided with a unique serial number . As an example an electronic transaction card, such as the "Chipper", could be suitably used. Advantageously, the display is arranged and controlled such that when the unique information carrier is removed the normal interruption of the (first) code control of the display caused thereby will result in the lightening of the display in the form of information indicative of theft. This enables the rightful owner, who may during use be summoned under threat to part with his car, to comply with the summon while he cautiously removes the unique information carrier. In such a case the -engine will keep running, so that subsequently the thief will be clearly visibly driving in a stolen car. When subsequently the engine is turned off via the usual ignition lock, restarting will be impossible due to a starter blocking circuit being activated in the absence of the unique information carrier.
The display may be of the LCD-type with background illumination (electroluminiscence) or of the LED-matrix type. By using the available techniques such a display may be manufactured with adequate flexibility and with a sufficient size and requires very little power. Also a display of the LEP type (LEP = Light Emitting Polymers) can be used. In this way a very thin, flexible and in addition inexpensive display may be obtained. The display may be suitably carried out as a dot matrix. The display is then particularly suitable to function as a third brake light, as is either usual or even obligatory in many countries. For this purpose the display may be easily incorporated into the brake light circuit of the vehicle. Conversely one could also say that the third brake light in a suitable design may also serve as a display of the device according to the present invention.
In consideration of the advantages to be gained in the theft combatting field it would be attractive for a legislator to prescribe a "third licence number expression" in addition to the third brake light.
The invention further provides a vehicle window for use with a theft indicating device.
Further features and advantages of the device of the
invention will be hereinafter further explained with reference to the accompanying drawings .
Fig. 1 schematically shows, by way of example, a first embodiment of the device of the present invention. Fig. 2 schematically shows, by way of example, a second embodiment of the device of the present invention.
In fig. 1, an embodiment of the device of the present invention as installed in a vehicle (not shown separately) is depicted. Reference numerals 1 and 2 designate the upper (outer) and lower (inner) layer respectively of a laminated rear window screen of the vehicle, such as an automobile (e.g. a car). Between these layers 1 and 2 there is provided a rear window heating circuit 3. A display 4 is advantageously powered through the heating circuit 3 and an additional lead 30. A programmable electronic integrated circuit (chip) 8 for storing a licence number is arranged in the display 4.
Communication leads 5 and 6 connect the display 4 to a control unit 7 which may e.g. be built in the dashboard of the vehicle. The leads 5 and 6 may be connected to the display 4 either directly, as shown, or indirectly, i.e. via the power leads 3 and 30. The control unit 7 comprises a chip card reader and a circuit which is capable of recognizing a certain code or unique information, said code (or information) being provided in a chip card (IC card) 9. The chip card 9, which comprises an integrated circuit capable of securely storing at least one access code, can be placed into its operative position within the control unit 7 through a card slot 10. Alternatively, the control unit 7 may be provided with a key pad for entering the access code. The control unit 7 is, in the embodiment shown, coupled via leads 14 and 15 to a start blocking circuit 18, which is part of the starter circuit of the vehicle. On inserting the chip card 9 into the control unit 7, the access code stored in the card can be checked. On a positive check, the control unit 7 controls the start blocking circuit 18 in such a way that the starter circuit is closed so as to allow the engine to be started.
LEDs 16 and 17 indicate the proper functioning of the device and a programming mode respectively.
A programming unit 20 (which is normally not present in the vehicle) may be connected to the control unit 7 by means of are removable leads 11 and 12. With the aid of programming unit 20 the chip 8 cooperating with (or comprised in) the display 4 may be programmed through the control unit 7 in such a way, that the licence number belonging to the vehicle is stored in said chip. To facilitate this programming, the programming unit 20 is provided with a keyboard 21 and a display 22.
As indicated above, the programming step may be a once-only step, wherein certain connections in a fuse matrix, including the writing line at the end of the programming act are caused to burn through. This unalterably stores the licence number of the vehicle in the chip 8 of the display 4.
The operation of the device is as follows. By inserting a chip card 9 comprising the correct information (i.e. the preferably predetermined access code) the starter circuit will be closed by means of the start blocking circuit 18 so that the engine of the vehicle can be started. Simultaneously first control signals are transmitted through the leads 5 and 6 which cause the display 4 to lighten in accordance with the information stored in the associated chip 8. The licence number 13 of the vehicle thus appears on the display 4. This situation is representative of the normal authorized use of the vehicle. If in said normal use situation the chip card 9 is removed, while the engine of the vehicle is kept running, this results in an interruption of the transmission of (first) control signals from the control unit 7 to the display 4, so that the licence number is no longer visible on the display. Instead, in the absence of the (first) control signals, the display 4 automatically shows the indication "STOLEN" or a similar indication.
Advantageously, the licence number is also stored in the control unit 7, e.g. to include the licence number in the generation of the above-mentioned first code signals. The insertion of a chip card 9 carrying the correct access code may also start a programming mode, by means of which additional cards (parallel cards) , if any, may be made valid or invalid. In the embodiment of Fig. 2, the removable leads 11 and 12 between the programming unit 20 and control unit 7 have been
replaced by a transceiver set . By providing the programming unit 20 with a transmitter (or transceiver) having an antenna 29 and the control unit 7 with a receiver (or transceiver) having an antenna 28, remote programming and control is made possible. In this respect, it is in the first place possible to remotely initialize the device by remotely programming the license number of the vehicle into the circuit 8 of the display 4, and possibly also into a suitable circuit of the control unit 7. In the second place, it is possible to remotely block the vehicle, for instance when the vehicle as well as the chip card 9- are stolen. To this end, the device according to the invention is preferably arranged in such a way that on receipt of certain blocking information the start blocking circuit 18 is controlled so as to interrupt the starter circuit, or possible even the ignition of the vehicle. In addition the receipt of certain blocking information information indicative of theft is preferably shown in the display 4, such as the word "STOLEN" .
In this way, an effective protection against theft is achieved.
The blocking information preferably comprises a serial number of the device which may also be stored in the control unit 7 and/or (the circuit 8 of) the display 4. Possibly the blocking information also comprises the license number in order to enable an extra check. To prevent fraud the blocking information comprises, in addition to the serial number, preferably a secret extension. For instance, an extension of four digits may be appended to a serial number of 12 digits. Although it is possible for the extension to be related to the serial number, making it possible to derive the extension from the serial number, a greater resistance against fraud is achieved by not or not directly relating the extension to the serial number. In that case, the extension may be a secret code, such a so-called pincode.
By means of this embodiment it is possible to remotely control the device in such a way, that non-authorised use of the vehicle is discouraged or is made completely impossible. To this end the rightful user can for example dial a predetermined telephone number and enter his license number, the serial number and the extension. The programming unit 20 can in this case be connected to a so called "server", which
is assigned to his telephone number, and receives from this "server" the data entered. Subsequently the programming unit 20 transmits, by means of its transmitter, the blocking information to the control unit 7 of the vehicle concerned. In that case the blocking information may comprise, in addition to the data mentioned above, a blocking code.
As already noted the display 4 is, for example in the dot- matrix embodiment, suitable to be used as third brake light. To this end the control unit 7 is coupled, via the leads 25 and 26, to the brake light circuit 27 of the vehicle in such a way that engaging the brake pedal of the vehicle causes the complete lightening up of the display. That is, the leads 25 and 26 may be connected to the brake switch, which is a part common to many vehicles, so as to provide the control unit 7 with an electrical activation signal indicative of the brake pedal of the vehicle being engaged. In response to this activation signal, the control unit 7 produces a second control code which is carried, via the leads 5 and 6, to the display 4 so as to give a brake indication. To this end, e.g. all pixels of a dot matrix display may lighten simultaneously.
It will be understood that the invention is not limited to the embodiments shown and that many additions and modifications may be made without departing from the scope of the present invention. The coupling 14, 15 between the control unit 17 and the start blocking circuit 18 may for example be omitted. In this way an indication of the legitimate use may still be given, even in a vehicle in which no start blocking circuit is present.