AN IMAGE TRANSFER DEVICE

Abstract: An image transfer device, comprising at least one camera unit (1), a transmitter unit (2) connected to the camera unit (1), and a receiver unit (4). The transmitter unit (2) is arranged to transmit image information by signals representing an image registered by the camera unit (1) to the receiver unit (4) via an already existing general electricity supply system (3) or via the air. The receiver unit (4) is arranged to forward the image information to at least one image displaying unit (8) via a network (6) for the communication between computer units (5, 7).

Description: An image transfer device BACKGROUND OF THE INVENTION AND PRIOR ART The present invention concerns an image transfer device, comprising at least one camera unit, a transmitter unit connected to the camera unit, and a receiver unit, wherein the transmitter unit is arranged to transmit signals representing an image registered by the camera unit to the receiver unit via an already existing general electricity supply system or via the air. Devices of this kind are already known. For example, the document W093/18594 shows a supervising system comprising a camera equipment which is connected to a transmitter unit in order to, with the help of the latter, form and transmit an electrical image signal over the electricity supply system. In at least one monitor unit there is a receiving element for receiving image information which is transmitted in electrical form over the electricity supply system, and a display unit for displaying image information in the monitor unit. In particular the idea of the invention is to make it possible to get access, from one or more monitor units in a building, to image information from a camera unit arranged at the entrance of the building. The system may also comprise several transmitter units, to which one or more monitor units can be connected via the electricity supply system in order to supervise several different places in the building. Another document, WO90/04306, concerns the transmission of signals between two or more places by use of an already existing electricity supply system. In particular a solution is suggested to the problem of transferring video signals from one unit to another via the electricity supply system without exposing the transfer to too large interferences caused by the varied loads to which the electricity supply system is exposed. Also audio or data signals can be transmitted via the electricity supply system in question. It is clear that the video signals can be digitalized and introduced into the electricity supply system in digital form with a clock frequency of approximately 40 MHz and then be taken out from the electricity supply system at some other place and transformed to analogue form before they are converted up to UHF-frequency levels. It is known from products existing on the market that signals corresponding to an image registered by a camera may be transmitted from a transmitter, which is directly connected to the camera unit, to a receiver via the air. The transmitter thereby uses a high frequency, more precisely of the magnitude 2.4 GHz. The receiver is directly connected to some kind of image displaying unit, such as a television monitor or a display connected to a PC. The above mentioned systems and products have in common that the receiver unit comprises or is directly connected to a monitor unit for displaying the image registered by the camera unit. In case a plurality of monitor units, possibly located at a considerable physical distance from each other, is to be supplied with an image or images registered by the camera unit or by a plurality of camera units, a receiver unit is arranged at the respective monitor unit (see for example W093/18594). Furthermore, it is obvious that the transmitter and the receiver are supposed to be arranged within the same transformer area when a general electricity supply system is used for transferring the signals from a respective transmitter unit to a respective receiver unit and to a monitor unit belonging thereto, that is, within an area where the voltage is essentially the same over the whole electricity supply system. Prior technology does not solve the problem of delivering image signals from a transmitter unit to a receiver unit and from that location further on to a plurality of monitor units which may be located in separate transformer areas and in transformer areas which are separate from the receiver unit itself. SUMMARY OF THE INVENTION A purpose with the present invention is to obtain an image transfer device of the type initially defined, arranged to deliver, via the receiver unit, image information which represents the image registered by the camera unit to one or more image displaying units, that is, monitor units, which may be arranged in a transformer area which is separate from that within which image signals are possibly transmitted from a transmitter unit connected to the camera unit to the receiver unit, and where different image displaying units which are supplied with the mentioned information may be arranged in separate transformer areas as well. This is obtained by an image transfer device as defined in the introduction, wherein the receiver unit is arranged to forward the image information to at least one image displaying unit via a network for the communication between computer units. With the possibilities which this opens concerning the use of existing telecommunication networks, it is thus easily understood which possibilities the invention opens concerning the transmission of image information from the camera unit to one or more image displaying units, arranged at a short as well as a large physical distance from the receiver unit itself and also at a short or large internal distance without limiting the configuration of the electricity supply system within which possible image information signals are transmitted from transmitter unit to receiver unit. According to a preferred embodiment, the transmitter unit is arranged to transmit the signals within a high frequency range, over 2 GHz, preferably larger than or equal to 2,4 GHz. By this embodiment good image reproduction is made possible and also transmission via the air and other matter, such as walls or similar matter over shorter distances when one wishes to use transmission via such media instead of an existing electricity supply system. Thanks to the use of such a high frequency range, the device avoids, in addition, traditionally for other purposes already occupied frequency ranges during the transmission of the image information signals over an existing general electricity supply system. According to another preferred embodiment, the device comprises a computer unit, arranged to receive image information from the receiver unit. The computer unit is thereby preferably directly connected to the receiver unit. This connection may either be via an ordinary connecting line, via an already existing general electricity supply system or via the air. By means of the computer unit, it is possible to handle image information from the receiver in such a way that it can be transferred via the network to the image displaying unit or the image displaying units. According to a further preferred embodiment, the computer unit has its own network address. By this measure, the invention offers the possibility to call the computer unit from some further computer unit connected to the network and to get access, via the first mentioned computer unit, to the image information which this computer unit has received from the receiver. According to a further preferred embodiment, the network is at least one of a local network for the communication between a plurality of computer units and a network having a larger physical extension for the communication between a plurality of computer units. The local network may be of the kind which is normally called a LAN (local area network), while the network with a larger physical extension preferably is of the kind which is called WAN (wide area network). According to a further preferred embodiment, the image displaying unit forms part of a computer unit, arranged to be connected to the network. For example, it can constitute a screen belonging to a PC. The invention thus offers the possibility to obtain, from a large number of places, where already today computer units which are arranged to be connected to the network are set up, connection with the computer unit directly connected to the receiver unit and to obtain, via this computer unit, image information corresponding to an image registered by the camera unit in question. The computer directly connected to the receiver unit is preferably arranged to supply simultaneously a plurality of computer units connected to the network with the mentioned image information and this independently of the existence of each other. According to a further preferred embodiment, the receiver unit or the computer unit connected thereto is arranged to only forward image information from the camera unit to the image displaying unit under the condition that it from the computer unit which includes the latter receives a predetermined information, preferably a code. Thereby, the accessibility of the image information may be limited to only those operators and/or computer units which have access to and can transmit the predetermined information to the computer unit connected to the receiver unit. This is advantageous when the image transfer device defines or forms a part of a supervising system and when it is preferred that only certain operators and/or computer units are given access to the image information for the reproduction at a specific displaying unit of the image registered by the camera unit. According to another preferred embodiment, the image transfer device comprises a plurality of camera units together with transmitter units connected thereto, and the receiver unit is arranged to allow the possibility of instructing, from the computer unit of which the image displaying unit forms a part, from which camera unit image information is to be directed to the image displaying unit. Such commands are given via the computer unit directly connected to the receiver unit. The computer unit is therefore arranged to deliver, from the signals which it receives from the computer unit of the image displaying unit, such signals to the receiver unit that the latter is activated to choose from which transmitter unit or transmitter units it is to receive and pass on image information. Thereby, a user is given the possibility to choose from which of a plurality of camera units he or she wishes to receive image information at a certain occasion. According to another preferred embodiment, the image transfer device comprises a drive member for adjusting the position of the camera unit, which drive member is arranged to be controlled by commands from the receiver unit. The receiver unit and the computer unit connected directly thereto are thereby arranged to receive, from further computer units connected to the network, with image displaying units connected thereto, commands which initiate the mentioned control of the drive member. Thereby an operator is offered the possibility to control, from an image displaying unit/computer unit, the position of the camera unit and thereby the subject of the image which is to be registered. The computer unit connected to the receiver unit is preferably arranged so that only one operator or further computer unit at a time can initiate the mentioned control of the drive member. The computer unit may thereby be arranged so that it requests special information, for example a code, from an operator who via some further computer unit wishes to control the drive member. Alternatively, the computer unit may be arranged to only allow for this possibility for certain specific, predetermined further computer units. According to another preferred embodiment, the image transfer device comprises image recording means connected to the receiver unit for recording image information received by the receiver unit. By such image recording means it is thus possible to record the image information received from one or more camera units and to keep this recorded image information stored such that it may be viewed at a later occasion. In particular, the network for the communication between computer units may in some cases make it difficult to view moving images from a camera unit at an image displaying unit forming part of a computer unit which is connected to the network. It is therefore advantageous to have such images recorded for later observation. According to a further embodiment of the invention, the image transfer device comprises control means for controlling the image recording means. Thereby an operator has the possibility to control, for example, when a recording should begin and when it should end. Preferably, the image transfer device is arranged such that the operator may control the image recording means from a computer unit which is connected to the network and of which the image displaying unit forms a part. The operator may thus observe images from one or more camera units transferred via the network, and when the operator makes a relevant observation from a camera unit, the operator may, via the computer unit, give commands to start the image recording means to record the image information received from the camera unit. The operator may also give a command when the image recording should end. Furthermore, the operator may control from which camera unit the image information should be recorded. The image recording means may thus record moving images from the camera units. These moving images may then be viewed at a later occasion. It is also possible to include more than one image recording means. Thereby it is made possible to record image information from a plurality of camera units simultaneously. The computer unit directly connected to the receiver unit may be arranged to request special information, for example a code, from an operator who via some further computer unit wishes to control the image recording means. Further features and advantages of the image transfer device according to the invention will be clear from the following description and from the additional, dependent claims. BRIEF DESCRIPTION OF THE DRAWING The invention will now be described more in detail in an exemplifying but not limiting manner with reference to the enclosed drawing, on which Fig 1 schematically shows an embodiment of an image transfer device according to the invention. 8 DETAILED DESCRIPTION OF AN EMBODIMENT The image transfer device comprises a number of camera units 1 , each of which is connected with a respective transmitter unit 2 which in its turn is arranged to transmit data via an already existing electricity supply system 3 or via the air to a receiver unit 4, and also to receive data from the receiver 4 via the electricity supply system 3 or via the air. The data transfer between the transmitter unit 2 and the receiver unit 4 is carried out within a high frequency range, in this case approximately 2.4 GHz. Data which in signal form are transmitted from the transmitter 2 to the receiver 4 contain image information and represent an image which is registered by the camera unit 1. Data which are transmitted from the receiver unit 4 to any of the transmitter units 2 comprise preferably commands which activate or deactivate the respective transmitter and/or camera or which control some drive member or similar device for adjusting the position/direction of the camera unit 2 in question. The data transfer is done via a RC-link when an already existing electricity supply system 3 is used for the transfer. The electricity supply system 3 is arranged within a transformer area, for example within an area where the voltage is 220 V, which is the case in for example buildings and homes. The receiver unit 4 is directly connected to a computer unit 5. This connection may either be via an ordinary connecting line, via an already existing general electricity supply system or via the air. The computer unit 5 comprises such software that it is arranged to control the data communication, that is commands from the receiver unit 4 to the respective transmitter unit 2. Furthermore, the computer unit 5 defines a server, which is arranged to distribute functionality and information over the Internet (WAN). The computer unit 5 is thereby arranged to communicate via the Internet 6 with at least one of a plurality of further computer units 7, which are connected to the Internet and which each preferably comprises an image displaying unit 8 in the form of a display or a screen. In order to be able to communicate with the server, the computer unit 5 the additional to the network connected computer units 7 comprise a so-called client application. The latter is here implemented in the program language JAVA, with the purpose to be used in a so-called WWW-browser (for example Netscape Navigator or Microsoft Internet Explorer). The server/computer unit 5 comprises software which makes it possible to control, from at least one of the additional to the network connected computer units 7, via the network 6 the communication with the receiver unit 4 and thereby to control the commands of the receiver unit 4 to the respective transmitter unit 2. The server/computer unit 5 thereby comprises a so-called application server which on one hand is arranged to constitute a connection node for the connection from many clients 7, and, on the other hand, to relieve these clients from resource demanding functionality or functionality which is not supported by the software platforms of the respective client 7. The image transfer device may also comprise image recording means 9 connected to the receiver unit 4 for recording image information received by the receiver unit 4. Such image recording means may, for example, comprise a video tape recorder or a CD or DVD recording apparatus. The image recording means 9 may be directly connected to the receiver unit 4 or connected to the computer unit 5 which receives the image information from the receiver unit 4. Furthermore, the image transfer device may comprise control means 10 for controlling the image recording means 9. The server/computer unit 5 comprises software which makes it possible to control, from at least one of the additional to the network connected computer units 7, via the network 6, the control means 10 and thereby the image recording means 9. It is thereby possible for an operator to control the image recording means 9 from the computer unit 7 which is connected to the network 6 and of which the image displaying unit 8 forms a part. An operator may thereby start and stop recordings and also control from which camera or cameras 1 recording is to be made. The 10 image recording means 9 are preferably of the kind arranged to record moving images in colour. The server/computer unit 5 has its own network address. In order to prevent non-authorized access to the image information from the camera units 1 , the server/computer unit 5 is additionally arranged to only allow communication between it and the camera units 1 and the transmitter units 2 via the receiver unit 4 under the condition that it receives a given name and password from the further computer unit 7. It is evident that a number of modifications and alternatives of the image transfer device according to the invention will be obvious for a person skilled in the art without this person thereby leaving the scope of the invention. For example, the camera units 1 and/or the transmitters 2 may be connected to different types of alarm sensors, such as magnetic contacts and/or infrared sensors. The transmitter devices 2, the receiver device 4 and the server/computer unit 5 may thereby be arranged to release an alarm on the activation of the mentioned alarm sensors, for example by calling one or more of a predetermined number of further computer units 7 connected to the network. It is also conceivable to integrate the receiver in the server/computer unit 5. The image transfer device defines advantageously a supervising system. Thanks to this system it is for example possible to receive image information from specified camera units via a portable computer and a mobile telephone connected thereto, which thus together form a further computer unit 7. This advantage is thought to be of great importance for, for example, guards and policemen on duty.

Claims: 1 1 Claims 1. An image transfer device, comprising at least one camera unit (1 ), a transmitter unit (2) connected to the camera unit (1 ), and a receiver unit (4), wherein the transmitter unit (2) is arranged to transmit image information by signals representing an image registered by the camera unit (1 ) to the receiver unit (4) via an already existing general electricity supply system (3) or via the air, wherein the receiver unit (4) is arranged to forward the image information to at least one image displaying unit (8) via a network (6) for the communication between computer units (5,7). 2. An image transfer device according to claim 1 , wherein the transmitter unit (2) is arranged to transmit the signals within a high frequency range, over 2 GHz, preferably 2.4 GHz. 3. An image transfer device according to claim 1 or 2, wherein it comprises a computer unit (5), arranged to receive image information from the receiver unit (4). 4. An image transfer device according to claim 3, wherein the computer unit (5) is connected to the network (6). 5. An image transfer device according to claim 3 or 4, wherein the computer unit (5) has its own network address. 6. An image transfer device according to any one of claims 1 -5, wherein the network (6) is at least one of a local network for the communication between a plurality of computer units (5, 7) or a network having a larger physical extension for the communication between a plurality of computer units (5, 7). 7. An image transfer device according to any one of claims 1-6, wherein the image displaying unit (8) forms part of a computer unit (7), arranged to be connected to the network (6). 12 8. An image transfer device according to any one of claims 3-7, wherein the receiver (4) or the computer unit (5) connected thereto is arranged to only forward image information from the camera unit (1 ) to the image displaying unit (8) under the condition that it from the image displaying unit receives a predetermined information, preferably a code. 9. An image transfer device according to claims 7 or 8, wherein it comprises a plurality of camera units (1 ) together with transmitters (2) connected thereto, and that the receiver unit (4) is arranged to allow the possibility of instructing, from a computer unit (7), of which the image displaying unit (8) forms a part, from which camera unit (1 ) image information is to be directed to the image displaying unit (8). 10. An image transfer device according to any one of claims 1 -9, wherein it comprises a drive member for adjusting the position of the camera unit (1 ), which drive member is arranged to be controlled by commands from the receiver unit (4). 1 1. An image transfer device according to any one of claims 1 -10, comprising image recording means (9) connected to the receiver unit (4) for recording image information received by the receiver unit (4). 12. An image transfer device according to claim 1 1 , comprising control means (10) for controlling the image recording means (9).

Inventors: DOMAR AAKE, FRANZEN RUNE, MYRSETH THORMOD, SOBIECKI JAN, DOMAR, AAKE, FRANZEN, RUNE, MYRSETH, THORMOD, SOBIECKI, JAN
Applicants: DOMAR AAKE, FRANZEN RUNE, MYRSETH THORMOD, SOBIECKI JAN, DOMAR, AAKE, FRANZEN, RUNE, MYRSETH, THORMOD, SOBIECKI, JAN
Application year: 1999
Main classification: H04N7
IPC codes: H04B3, H04N7