BACKGROUND TO THE INVENTION A vehicle, once it is stolen, generally has its appearance and all identifying data such as chassis and engine numbers changed to reduce the possibility that it can be identified by its rightful owner. Quite often the vehicle is re-sprayed to a different colour.

Car theft syndicates are then usually able to re- register the vehicle using false papers so as to obtain a new registration number. Stolen vehicles quite often cross from one state to a neighbouring state at a remote border post where there is very little prospect that the officers on duty will be able to detect that the vehicle is a stolen one.

BRIEF DESCRIPTION OF THE INVENTION According to the present invention there is provided a system for enabling a vehicle to be identified which system includes a memory device fitted to the vehicle, the memory device having a read only memory (ROM) which has stored therein in unalterable form data pertaining to the vehicle to which the memory device is fitted, and the system further including a unit for reading the information off the memory device and for displaying it so that a comparison can be made between the vehicle and/or the numbers carried thereby and the information in the memory device, the unit and memory device communicating via a radio frequency link when the unit is proximate the memory device.

The information in the memory device can also include information pertaining to the owner of the

vehicle including addresses and telephone contact numbers. Thus an officer inspecting the vehicle can contact the owner for further information if the owner is not with the vehicle.

According to a further aspect of the present invention there is provided a method of enabling a vehicle to be positively identified which comprises storing in the read only memory (ROM) of a memory device information pertaining to a specific motor vehicle, fixing the memory device to an appropriate place on the vehicle so that the information on the memory device is available to an officer inspecting the vehicle, and reading the information off the memory device by means of a unit which communicates with the memory device via a radio frequency link when the unit is proximate the memory device.

DETAILED DESCRIPTION OF THE INVENTION A procedure in accordance with the present invention will now be described in detail by way of example.

Memory devices, commonly referred to as "chips", are available from various sources. The type of chip required has a unique serial number which is in a read only memory (ROM) in unalterable form.

When a motor vehicle is first registered, full details of the vehicle and of the owner are recorded, again in unalterable form, in the memory device. The information that is recorded about the vehicle can include the following:- 1. Registration number.

2. Engine number.

3. Chassis number.

4. Vehicle make and model type.

5. Year of first registration.

6. Engine capacity.

7. The number of any other piece of equipment on the vehicle which has its own serial number e.g. the gear box.

8. Vehicle colour.

This is not intended to be an exhaustive list and any other information that the registering authority believes is relevant can be included.

Insofar as the owner is concerned, full names, address, driving licence details, any identification number issued by the state and contact telephone numbers can be recorded. Details of any insurance on the vehicle or financial matters pertaining to the vehicle can also be recorded. For example, details of the insurance company and of the policy number can be provided. If the vehicle is the subject of any finance agreement, then details of the finance company and contract number can be included.

The programmed memory device is then secured to the vehicle at an appropriate place within the vehicle preferably on the inside of the windscreen or one of the windows.

Traffic and border control authorities are provided with a unit capable of reading the information on the memory device. The unit includes means for activating the memory device once the unit is within, say, 80mm of the memory device. Such means can be a radio frequency transmitter. The memory device itself includes a radio frequency transmitter which transmits all the information off the memory device to the unit.

This two way communication can take place through the glass. The preferred radio frequency range is 125 MHz

to 800 MHz.

The unit includes a display. Once all the information on the memory device has been read into the unit, the officer can scroll through the information checking each item of information against the information carried by the vehicle. For example, he can see on the display the registration number, the engine number, chassis number, vehicle type and colour.

He can then physically check the vehicle to ensure that it conforms to the details given on the display. If any of the details do not conform then clearly he will be entitled to be suspicious and he can then use the owner's information to make contact and ensure that the vehicle has not been stolen but is on an authorized journey.

If it is obligatory for a vehicle to have a memory device, any vehicle which is not carrying a memory device is quite clearly suspect immediately and the officer has the opportunity of detaining the vehicle whilst further investigations are made.

The ability to check information pertaining to the vehicle immediately by comparing the physical features and numbers of the vehicle with information stored on the memory device is important at remote border posts which is where many stolen vehicles leave one state for another. The facilities at some of these are such that it is not possible for an official, even if suspicious of a motor vehicle, to check back to a remote data base to see whether the vehicle is recorded as having been stolen. Where the vehicle has been altered or numbers changed, the procedure described will reveal such changes.

The unit may, however, also be used to

identify suspect vehicles in circumstances where the information on the memory device is the same as that on the vehicle, i.e. where neither the information on the vehicle nor the vehicle itself has been altered. In order to do so, information regarding a vehicle which an authority wishes to trace can be electronically distributed from various sources, such as police stations, to the various places where the units are being used. The distributed information can include the registration number, chassis number, engine number and so on, of each vehicle that is to be traced. It can also include the reason why the information pertaining to a particular vehicle is being distributed, for instance that the vehicle is stolen, or that there are unpaid traffic fines or licence fees in respect of the vehicle. Updated information can be distributed on a regular basis and downloaded onto the unit periodically, for example, when the unit's batteries are recharged. The information read from a memory device can then be compared with the distributed information. If a vehicle is, for example, stolen but the markings of the vehicle have not been altered, then a comparison between the information on the memory device and the physical features of the vehicle and the numbers on the vehicle will not indicate that the vehicle is a stolen vehicle. However, comparison of the information on the memory device with the distributed information will reveal the vehicle to have been stolen.

Where the above procedure is to be followed, each unit may be equipped with its own memory so that the information can be loaded onto the memories of the units. In this case each unit can further be capable of comparing the information loaded into its memory and the information read from the memory device on a vehicle, and of emitting an audible and/or visual alarm

signal when the information in the vehicle's memory device and that in the unit's memory tally.

Because the memory device can have data added thereto but not removed therefrom it is possible for the memory device eventually to contain a history of the vehicle in terms of ownership. When a change of ownership is recorded the memory device has to be updated with details of the new owner. Alternatively, a new memory device can be issued each time a change of ownership is recorded with the licensing authority.

The information is recorded in the memory device in encrypted format and may only be viewed using authorized equipment. Any unauthorized attempt to add information to the memory device can be detected when the device is subsequently read using authorized equipment.

It is also possible to construct the memory device with a "telltale" or "self-destruct" system.

This system is activated if the memory device is removed from the glass to which it is fixed. It either, when the device is next read, reveals that the device has been moved or simply wipes-off all the data in the memory.