One method as shown in United States Patents No. 5,970,227 allows a host computer to disable a device upon unauthorized removal from the operating space.

However, this operating system only monitors unauthorized removal of the devices.

The operating system fails to monitor which user is present in the operating space simultaneously while monitoring the devices. It does not prevent the unauthorized users from removing authorized devices from the operating space.

SUMMARY OF THE INVENTION AND ADVANTAGES The invention provides a method of monitoring a plurality of electronic devices positioned in an operating space which are accessible by a plurality of users. The method includes the steps of compiling a user database comprising a plurality of user

codes for authorized users and compiling a device database comprising a plurality of device codes identifying each one of the devices. Each user has a user token for emitting a user code and each device has a device token for emitting a device code. The user code and the device code are then detected. The method is characterized by compiling a linking database linking each user code to at least one of the device codes to indicate that the user code is authorized to remove the device from the operating space in response to detecting the user code linked to the device code.

Accordingly, the subject invention provides a method of monitoring devices which are accessible by a plurality of users by simultaneously registering which user is within the operating space and which device the user is removing. Certain users may be allowed to remove any and all devices while other users are only granted access to specific devices.

BRIEF DESCRIPTION OF THE DRAWINGS Other avantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: Figure 1A & 1B is a flowchart showing the steps of monitoring a plurality of electronic devices positioned in an operating space and accessible by a plurality of users; Figure 2 is a schematic view of a system capable of monitoring the operating space which includes a host computer; Figure 3 is a schematic view of the operating space having a plurality of devices and a user disposed therein; and Figure 4 is a representation of one embodiment of a linking database which links the plurality of users to the plurality of devices.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the Figures, wherein like numerals indicate lilce or con-esponding parts throughout the several views, a method of monitoring a plurality of electronic devices positioned in an operating space and accessible by a plurality of users is shown generally in Figure 1A & 1B.

A first step in the method includes compiling a user database 10 comprising a plurality of user codes for authorized users and compiling a device database 12 comprising a plurality of device codes for identifying each one of the devices. These databases are accessible by an independent operating system 52 which can only be altered by a system administrator. The independent operating system 52 may be a computer spaced apart from the operating space or a database kept on a local or shared network. The operating space, as shown in Figure 3, may be defined by any area having an egress 34 or an ingress. The system administrator can add or delete user and device information from their respective databases, as necessary. The plurality of devices may include any electronic equipment such as laptop computers, printers, scanners, or cellular phones.

The second step includes emitting a user code 14 from a user token 16 which is carried by a user 22. The emitting of the user code 14 may include generating a signal which is received or a field which is disturbed, such as a magnetic field. A host computer 26 is disposed within or adjacent the operating space for detecting the user code 14. The host computer 26 searches the user database 10 for the detected user code 14. The user database 10 includes any personal information about the user 22 which may have been input by the system administrator.

The next step involves emitting a device code 18 from a device token 20 which is attached to a device 24. The emitting of the device code 18 may include generating a signal which is received or a field which is disturbed, such as a magnetic field. There may be a plurality of devices disposed within the operating space and each may be emitting the device code that is unique to that device. The host computer 26 detects the

device code 18 and searches the device database 12 for that device 24. The device database 12 includes information about the device 24 such as the serial number, the model number, type of device, and any other information that is input by the system administrator.

The user token 16 and the device token 20 each include a power source 36, a controller 38, and a token radio transceiver 40. The token radio transceiver 40 transmits and receives signals from the host computer 26. The controller 38 sends a signal to the token radio transceiver 40 to emit the user code 14. The user token 16 is also able to receive a signal from the host computer 26 and transmit the signal to the controller 38.

The controller 38 responds to the action requested by the host computer 26. The device token 20 is also able to receive signals from the host computer 26 in the same manner as the user token 16. Alternately, the user token 16 or device token 20 may include an RFID tag, as is known in the art, having a chip mounted within the user token 16 or device token 20 containing the user code 14 or device code 18.

The step of detecting the user code 14 and the device code 18 is further defined by connecting the host computer 26 to a circuit 28 which may be integrated into the host computer 26 or positioned adjacent to the host computer 26. In the preferred embodiment, the circuit 28, as shown in Figure 2, includes a first radio transceiver 46, an antenna 30, a signal measurement device 48 and controller 50. In an alternative embodiment, the step of detecting the user code 14 and device code 18 includes a host computer 26 emitting a magnetic or an electric field. The field is broken by the user token 16 entering the field and the chip becoming excited The computer 26 is then able to detect the user code 14. The device token 20 operates in the same manner when present in the field.

Once the user code 14 or the device code 18 is detected, a signal is sent to the signal measurement device 48 to measure the strength of the user code 14 and the device code 18. The strength of the user code 14 would increase proportionally with the strength of the device code 18 which would indicate which device 24 was selected

by the user 22. The signal measurement device 48 then transmits the user code 14 and the device code 18 to the controller 50. The controller 50 transmits the codes to the host computer 26 which is connected to the independent operating system 52 for retrieving information from the databases for the user code 14 and the device code 18.

Alternately, the user code 14 and device code 18 may be detected simultaneously when present together in the magnetic or electric field.

The host computer 26 also monitors the plurality of devices which were not selected by the user 22. The host computer 26 compares the device database 12 to the device codes which are being detected by the circuit 28. If the device code 18 maintains a consistent code strength measurement, then the device is not being selected by the user 22. If the strength of the device code 18 increases without the user code 14 being detected in the operating space, the host computer 26 transmits an alarm signal to the system administrator.

Alternately, the host computer 26 could transmit a signal to the controller 50 requesting the user token 16 or the device token 20 to transmit the user code 12 or the device code 18. The controller 50 sends the signal to the radio transceiver 46 and emits the signal through the antenna 30. The radio transceiver 46 enters a detection mode.

In the detection mode, the radio transceiver waits for a return signal to be received by the plurality of antennas 30.

The next step involves compiling a linking database 42 which is accessible by the host computer 26. The linking database 42 links each user code 14 to a plurality of device codes as shown in Figure 4. For instance, User A is authorized to remove Devices 1 through 9, whereas User D in only authorized for Devices 3 through 7. User B can only remove the even numbered devices and User C can only remove the odd numbered devices. When the host computer 26 receives the user code 14 and the device code 18, the host computer 26 recognizes the user 22 and the device 24 from their respective databases. The host computer 26 searches the linking database 42 to determine if the user 22 is authorized to remove the device 24. If the user 22 is linked

to the device 24, the host computer 26 creates a log of which device 24 was removed and by which user. The host computer 26 also registers the linked device code 18 into the logging database in response to each linked device 24 re-entering the operating space.

However, if the user 22 and the device 24 are not linked, the host computer 26 enters an alarm mode. In this mode, the host computer 26 may transmit a disabling signal, a prevention signal, or a security signal. If the host computer 26 transmits the disabling signal, the device 24 will not be operable. If the host computer 26 transmits the prevention signal, then the user 22 will only be able to operate certain functions or programs contained within the device 24. The security signal would notify the system administrator that the device 24 was being removed from the operating space by the user 22 and that the user 22 was not linked to the device 24 in the linking database 42.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims, wherein that which is prior art is antecedent to the novelty set forth in the"characterized by"clause. The novelty is meant to be particularly and distinctly recited in the"characterized by"clause whereas the antecedent recitations merely set forth the old and well-known combination in which the invention resides. These antecedent recitations should be interpreted to cover any combination in which the incentive novelty has utility. In addition, the reference numerals in the claims are merely for convenience and are not to be read in any way as limiting.