A RADIO COMMUNICATION UNIT FOR VEHICLES

Abstract: A radio communication unit for vehicles comprises means for radio communication with devices outside the vehicle and means (24) for communicating with a person inside the vehicle, such as a display window and keys (25). The unit (6) is divided in an exterior part (7), which is arranged together with the means for the exterior radio communication and is arranged to be mounted at the outer side of the vehicle, preferably at the windshield (3) thereof in a height position suited for achieving good communication conditions, and an interior part (8), which is arranged together with the means (24) for communicating with a person and arranged to be mounted inside the vehicle close to the first exterior part which is arranged on the outer side of the vehicle.

Description: TITLE A radio communication unit for vehicles TECHNICAL FIELD The present invention relates to a radio communication unit for vehicles and in a particular such a unit which includes a transponder for communicating using microwaves. STATE OF THE ART It is previously known to communicate with passing vehicles from road side stations by means of microwaves. Communication using such waves has in that context the advantage that it makes it possible to maintain a selective communication with individual passing vehicles because of the little spatial extension of the waves. Such communication is widely used for registering traffic fees when passing toll stations, see for example EP A2 0 425 961 (Pierluigi) . In order that it will be possible to reach the communication eguipment of the vehicle using microwaves it is generally required that the receiving part thereof is located in a position that can be seen from the transmitter. Mostly, as a receiving and also retransmitting part in the vehicle equipment is a transponder used which can receive an information carrying signal from the road side transmitter and retransmit it modulated in such a way that response information can be transferred. A position of the transponder which is advantageous from many points of view has appeared to be inside the windshield of the vehicle. When approaching a road side transmitter it will then be facing it and can receive and retransmit the radio signal which penetrates the wind- shield, the vehicle unit then being arranged in a protected position inside the vehicle. The location inside the vehicle means, in addition to protection against weather and theft, also results in that the unit is accessible to the vehicle driver, what is necessary in those cases where some operating means have to be influenced or display means have to be observed. However, in the development of vehicles the tendency has arisen to introduce windshields having metal based layers. They can have a function of filtering incident light radiation or serve as an electric heating element for a forced heating of the windshield glass. Such metal shields have a tendency to influence radio communication using microwaves and can give a strong shielding thereof. There is then a risk of jeopardizing the operation of vehicle units of the kind described above which are located inside the windshield of the vehicle. DESCRIPTION OF THE INVENTION The object of the invention is to provide a vehicle unit which can obtain a position in the vehicle which makes it possible to use all its functions, also for vehicles which are provided with windshields, which shield against radio waves used for communication. According to the invention this object is achieved by dividing the vehicle unit in an exterior and an interior part having predetermined locations in relation to each other at each side of a vehicle pane. For the internal communication between the parts a particular arrangement is provided. BRIEF DESCRIPTION OF THE DRAWINGS In the following an embodiment of the invention will be described with reference to the accompanying drawings in which Fig. 1 is a cross-sectional view of the windshield of a vehicle having two parts of a vehicle unit placed at the windshield and shown partly in cross- sectional views, Fig. 2 is a cross-sectional view of the windshield corresponding to that shown in Fig. 1 having the two parts of the vehicle unit shown in an elevational view in a somewhat other functional position than that illustrated in Fig. 1, and Fig. 3 is a front view of the interior part of the vehicle unit in the functional position shown in Fig. 2 (corresponding to a view from the right hand side in Fig. 2) . PREFERRED EMBODIMENT In Fig. 1 the upper portion of the windshield of a vehicle is denoted by 1, the outer side being denoted by 2 and the inner side by 3. The windshield is attached to the vehicle frame, for example by means of adhesive bonding, the frame being indicated by a portion of a vehicle roof 4. The vehicle unit, denoted by 6, consists of an exterior part 7 attached to the outer side 2 of the windshield pane and an interior part 8, mounted at the inner side 3 of the windshield, the parts being located opposite each other. Both parts have in a direction towards the wind- shield a frame construction having marginal ribs 9 and 10 respectively for mounting the parts, the surface of the ribs being used for mounting the parts by bonding them adhesively to the surfaces of the windshield. In the exterior part 7 the mounting rib 9 constitutes part of a frame-like housing 12 , for example made of plastics. It has a frame-like window 13 at its exterior side. In this window is a transponder element mounted. Its main part is the very transponder circuit, which thus is an IC-circuit arranged to receive microwaves carrying information, to modulate them in order to carry response information and to retransmit them in order to be re- ceived by the sender-transmitter with which the transponder communicates. The transponder element also includes such electronic components which are required for performing this communication. Behind the transponder element 14, on the surface of the exterior part 7 which faces the windshield is a signalling element 15 arranged. The interior part 8 of the vehicle unit 6 is provided with a housing 18, for example made of plastics, which in a direction towards the inner surface 3 of the pane is terminated by the frame-like mounting surface 10 mentioned above. On the same side of the interior part is a signalling element 19 provided, which in a mounted position of the two parts is in a position opposite to the signalling element 15 of the exterior part. In addition, the housing contains IC-circuits 20 for data processing and for storing data. On the outer side of the housing, which faces inwards, towards the compartment of the vehicle, in the lower edge thereof is a hinge 22 arranged. A plate shaped element 23 is rotatably mounted to the hinge in order to form an operating unit intended to be influenced by the vehicle driver. In the folded-in position illustrated in Fig. 1 the operating element 23 is folded up to be located aligned with the rear side of the housing 18. In this folded-away position the element is not accessible for being operated on. By means of the hinge 22 the element 23 can be folded down to the position illustrated in Fig. 2. Then its margin portion 24 will be freely located. Along this margin portion are keys 25 arranged. It is visible in Fig. 3 that in the embodiment shown seven keys are arranged which are constructed as a flexible diaphragm having underlying contact elements on the side facing away from the windshield. The contact elements can be influenced by pressing the diaphragm inwards, approximately at the centre of projecting wave-like portions 26, which indicate the locations of the seven keys. Also other embodiments of the keys are possible, such that they may have the shape of keys to be activated by depressing them and their number, distance, etc. can of course be varied within wide limits. Furthermore, the interior part 8 is provided with a display for displaying characters and/or one or more light indicators. In the embodiment shown a display 30 is placed on the operating element 23 inside the margin portion 24 and on that side which in the folded-out position shown in Fig. 2 faces outwards, away from the windshield. Thus, in this position the display can be observed by the driver. Naturally, however, it is possible to place a display and/or like indicators on other surfaces of the housing 18 of the interior part, for example on the surface 31 thereof, which in the folded-in position of the operating element illustrated in Fig. 1 is located behind it. The operating elements together with their contact elements and possible displays and/or light indicators are connected to the IC-circuit 20 of the interior part. Also some sound indicator can be arranged, which is in that case also connected to the IC-circuit. For its function the vehicle unit receives influencing signals from the transmitter and receiver equipment of the road side by means of microwaves, which are received and processed in the transponder element 14 in the exterior part of the unit. Thereby can communication between the vehicle unit and the road side be made, such as identifying operations made at both sides and operations for carrying out the registering operation for a toll fee intended to be collected in a road toll station. For making the required data processing and storing of data it is presupposed that a portion of these operations are executed in the IC-circuit 20 of the interior part 8 of the vehicle unit. Furthermore it is presupposed that some results of the processing are to be indicated to the driver by means of the interior part 8 by the display thereof and possibly existing light and/or sound indicators thereof. It is also assumed that the driver will in certain cases be capable of influencing the processing by depressing the keys. These functions which are distributed on the two parts require that data communication is arranged therebetween. For this purpose are the two signalling elements 15 and 19 provided. By means thereof is internal data transmission between the two parts carried out, through the windshield 1. In the embodiment shown it is supposed to be made by means of light, preferably IR-light. Such light penetrates the windshield even if it is provided with a metal coating - however, the windshield must always be transparent to light in order to perform its main function. Communication arranged by means of light signals presupposes that each signalling element contains both a light emitting element which can be controlled by the respective IC-circuit to issue a coded signal having the shape of light pulses and a photosensitive element for receiving and converting such light pulses to electric pulses in order to control the respective IC- circuit. However, the invention is not restricted to internal communication of this kind and for example, means such as induction pulses can constitute other communication means. However, the internal communication is presupposed to be always made wirelessly through the windshield so that there is no need for making a hole through the windshield or for arranging wires around an edge of the windshield. For driving the vehicle unit some supply of electric energy is required. It can be obtained by mounting one or several electric battery cells or by supplying electric current from the vehicle system through a wire. The latter method can relatively simply be arranged for the interior part but is not suitable for the exterior part 7, since then a wire must be arranged to the exterior side of the vehicle. Also, providing batteries in the exterior part is unsuitable considering that in that case there must be a lid for executing a replacement operation, which can easily result in leakage into that part. To the extent that electric current supply is also needed by the exterior part it can be conceived that a suitable arrangement is that the relatively small necessary amount of energy, which is required, can be wirelessly transferred between the parts. It can for example be made by arranging a light transmitter in the interior part and in the outer part a photosensitive element which converts the light to an electric current. Another alternative is transferring an electric current using electric induction. It should also be added that the vehicle unit can be provided with or connected to other functional parts such as a terminal for using so-called smart cards. Such cards which comprise data processing and data storing equipment are to some extent used for paying operations. Then data corresponding to an amount of money which, by operations on data, can be transferred to service places such as road toll stations as a payment for services/goods. In the case where no need for communication with the driver exists, the vehicle unit can have the position shown in Fig. 1, thus having the operating element 23 folded in. When the vehicle unit is to be used and the driver wished to have access to the information which is provided by display and/or light indicators the operating element 23 is folded down to the position illustrated in Fig. 2. At the same time the keys 26 will be free to be operated by depressing the respective key and thereby the contact means thereof using the thumb in the pinching operation as described. The preferred embodiment of the vehicle unit is thus as described above: it comprises two parts having a limited size, an exterior part mounted at the outside of the windshield and an interior part mounted at the inner side thereof in positions opposite to or facing each other and wireless internal communication for data, exchange through the windshield. This embodiment will little deviate from conventional constructions used up to now including a vehicle unit made in one part and mounted inside the windshield in a height position suitable for the communication, however, the invention makes communication by means of microwaves possible, independently of the capability of the windshield of letting such radio waves through. Another advantageous feature of the invention is the described arrangement of operating keys and the display which allows the simple integrated form of the interior part. However, the scope of the following claims does not exclude the vehicle unit to be constructed otherwise, both in respect of its outer configuration and its inner functional parts. The location illustrated in the em- bodiment close to the upper edge of the windshield is generally suitable for private cars. In buses and trucks having higher windshields a position some distance below the upper edge can make the driver's control of the unit more comfortable.

Claims: Claims 1. A radio communication unit for vehicles comprising receiver and transmitter means for radio communication with transmitter and receiver installations outside the vehicle and means (24) for communicating with a person inside the vehicle, preferably the driver of the vehicle, which means comprise elements such as display windows (30) and/or other visual communication means, operating elements such as keys (25) and/or elements for sound signalling, characterized in that the unit (6) is divided in an exterior part (7) , which is arranged together with the means for the exterior radio communication and is arranged to be mounted at the exterior side of the vehicle, preferably the windshield (3) thereof, in a height position suited for achieving good communication conditions, and an interior part (8) , the internal part being arranged together with the means (24) for communicating with a person and arranged to be mounted inside the vehicle close to or at the first, exterior part, which is mounted at the exterior side of the vehicle, and preferably being mounted on the windshield of the vehicle in a position opposite the exterior part. 2. A radio communication unit according to claim 1, characterized in that the exterior part (7) and the interior part (8) are each provided with equipment (15, 19) for internal communication between the two parts. 3. A radio communication unit according to claim 2 , characterized in that it is intended and arranged to be mounted at the windshield (3) of the vehicle having its two parts (7, 8) placed in opposite positions in relation to each other, and that the means (15, 19) for internal communication is arranged for a exchanging signals through the windshield, preferably by means of light signals such as by infrared light. 4. A radio communication unit according to any of the preceding claims, characterized in that the interior part (8) is provided with a key device (25) on a plate-shaped element (23) , which is capable of being folded out from the main body (18) of the part, so that in a folded-in position of the element the size of the interior part is substantially limited by the main body, whereas in a folded-out position the key device is accessible to be operated on. 5. A radio communication unit according to claim 4, characterized in that the keys (25) on the plate-shaped element (23) are arranged, so that they can be operated on by a pinching movement around the edge of the plate- shaped element, whereby the plate-shaped element and thereby the interior part considered as one unit when being operated on will be influenced by limited free forces. 6. A radio communication unit according to claim 4 or 5, characterized in that a display window (30) is placed on the interior part (8) in such a position that it is hidden by the plate-shaped element (23) , when it is in its folded-in position. 7. A radio communication unit according to claim 6, characterized in that the display window (30) is located on that side of the plate-shaped element (23) , which in the folded-in position of the element faces inwards, towards the main body (18) of the interior part (8) .

Inventors: JOHANSSON ALF, JOHANSSON, ALF
Applicants: COMBITECH TRAFFIC SYST AB, JOHANSSON ALF, COMBITECH TRAFFIC SYSTEMS AB, JOHANSSON, ALF
Application year: 1997
Main classification: G07B15
IPC codes: G07B15, H01Q1