WO2008110768A1

WO2008110768A1 - A device

Info

Publication number: WO2008110768A1
Application number: PCT/GB2008/000801
Authority: WO
Inventors: David Clark; Claude Georges Andre Blanchard
Original assignee: CRACOL DEVELOPMENTS Ltd
Current assignee: CRACOL DEVELOPMENTS Ltd
Priority date: 2007-03-10
Filing date: 2008-03-10
Publication date: 2008-09-18
Anticipated expiration: 2009-09-10
Also published as: GB0704655D0; GB0720994D0; GB2447444A

Abstract

A device for assisting the orientation of a user towards a predetermined location, comprising: a first processor; a GPS receiver; a compass; a memory device; and a first indicator for informing the user of the orientation of the device, wherein the GPS receiver provides current location data concerning the location of the device when located in a first location, the memory device stores the current location data, such that on movement of the device to a second location, orientation data concerning the orientation of the device in the second location is determined by the compass in conjunction with the current location data stored in the memory device, the device further comprising a magnetic field disturbance indicator (MFDI).

Description

A DEVICE

This invention relates to a device, in particular, to a non-navigation device for assisting the orientation of a user towards a predetermined location.

It is often desirable for an individual to know how to accurately orientate himself so that he is facing towards a particular location.

An example of such a situation is where a worshipper needs to orientate himself in a predetermined direction for worship. For instance, religions such as Judaism and Islam require their followers to pray, facing a predetermined direction a number of times during the day. Muslims are required to pray five times a day facing towards Mecca, and Jews are required to pray at least three times a day facing towards Jerusalem.

In order to meet their religious obligations, followers use indicators or ornaments to assist their alignment towards the required direction. For example, Jews hang a decoration called a Mizarach on a wall in their home or synagogue to indicate the preferred direction or orientation for prayer.

If the worshipper has to pray away from his home or a place of worship, he has to orientate himself towards the required direction for prayer without the guidance he is accustomed to. This can be very difficult as the required orientation in one location is likely to be different from the required orientation in another location.

In the western hemisphere, Mecca is situated towards the east and it is generally assumed that if a Muslim is facing east, then he is facing Mecca.

However, the precise direction of Mecca will depend on the location of an individual. For example, the precise direction of Mecca from New York is not the same as the precise direction of Mecca from Los Angeles, even though both cities are in the same country. As such, the assumption that a Muslim situated anywhere in the western hemisphere who faces east while praying, is facing Mecca, is inaccurate.

Therefore there is a need for a device that is simple to use and which assists the user in facing towards a predetermined location irrespective of where he is located. According to a first aspect of the present invention there is provided a device for assisting the orientation of a user towards a predetermined location, comprising: a first processor; a GPS receiver; a compass; a memory device; and a first indicator for informing the user of the orientation of the device, wherein the GPS receiver provides current location data concerning the location of the device when located in a first location, the memory device stores the current location data, such that on movement of the device to a second location, orientation data concerning the orientation of the device in the second location is determined by the compass in conjunction with the current location data stored in the memory device, the device further comprising a magnetic field disturbance indicator (M FDI).

Hence, the orientation of the user in the second location towards a predetermined location can be carried out indoors or outdoors, as the compass will use the most recent GPS position in the memory device to calculate the required orientation of the user when it is not possible to obtain location data directly from GPS satellites.

Preferably, the magnetic field disturbance indicator (MFDI) is integrated within the first processor.

The MFDI together with the compass together form an intelligent compass, and the term "intelligent compass" as used herein should be construed accordingly.

The device according to the first aspect of the present invention is a non-navigation device, and as a result, it is of a much simpler construction than a navigation device.

A navigation device is a device that plots a route and directs a user along a predetermined course to a desired location. The device calculates the user's heading, or direction of travel, by determining the movement of the user over time. Data is provided in order to orient a displayed map relative to the orientation of the navigation device in order to assist the user along a calculated path.

Navigation devices in general include extensive mapping information as well as provisions for uploading additional map information as desired. While navigation devices are useful in situations when a user requires help getting from a first location to a second location, for example, from London to Manchester, they are not practical for situations where the user requires, or is interested in, a single directional heading only.

By means of the invention therefore, an individual desiring to know accurately the orientation he must assume in order to face a predetermined location may readily acquire the required information.

The GPS receiver, the compass, the memory device the first indicator, and the magnetic field disturbance indicator are preferably operatively connected to one another via the first processor which controls the operation of these components.

When the device includes other components, the other components are also controlled by the first processor, and operatively connected to other components as necessary.

Disturbances occurring in the magnetic field may cause an error in the accuracy of all types of compass. Such disturbances are likely to be due to either a magnetic material or a material capable of containing magnetic flux causing the earth's magnetic field to become more concentrated.

The magnetic field disturbance indicator (MFDI) identifies whether there are any magnetic disturbances which could affect the accuracy of the orientation data determined by the compass.

The compass may be any desirable compass and may for example be an electronic compass having its sensors aligned along two orthogonal axes.

Preferably, the compass comprises any suitable sensor or sensors. Advantageously the compass comprises two magneto-inductive magnet sensors positioned at substantially 90° to one another. For example, each sensor may comprise a SEN-S65 from PNI Corporation.

Each of the sensors forming the compass is designed such that the inductance of the sensor changes with changes in magnetic field strength. During calibration of the compass, measurements are taken by both sensors while the sensors are rotated through 360°, and preferably through 720° by rotating the device through 360° or 720° as required. The maximum and minimum magnetic fields are logged during this calibration. During calibration it is assumed that the compass is in free space and affected only by the earth's magnetic field.

In other embodiments of the invention, calibration of the compass may be effected using a different method to suit the type of compass used in the device. For example it may be necessary to rotate the device through an angle of rotation that is less than 360° or greater than 720°

The output of each sensor approximates to a sine wave with each sensor being effectively 90° out of phase with the other. As a result, if the squares of the sensor outputs are summed together, a substantially constant value is recorded and is maintained as part of the calibration data.

The earth's magnetic field will usually remain constant over distances of several hundred miles.

During calibration, therefore, a measurement of the ambient magnetic field at the current location is taken.

In use, providing the compass is used in the same geographical area as it was calibrated (usually within a few hundred miles), the earth's magnetic field should be substantially similar to the calibration values and the readings from each sensor should not exceed the maximum values recorded during calibration. As such, the sum of the squares of each sensor output also remains constant to the calibration value.

If there is a disturbance in the magnetic field while the electronic compass is being used, by means of the MFDI, such an error can be detected since the output of one or both axes of the compass will be increased due to the disturbance, resulting in the sum of the squares of the sensor outputs exceeding the calibration value. In such a situation an error can be indicated to a user. In particular, the MFDI compares the current value of the magnetic field with the ambient value obtained during calibration, and causes an alert to be activated to warn the user when a significant variation is measured.

Advantageously, the device comprises a sensitivity adjuster operatively connected to the first processor for adjusting the sensitivity of the MFDI. By adjusting the sensitivity of the MFDI, the magnitude of the magnetic disturbance required to cause an alert to be activated by the MFDI can be varied.

The sensitivity adjuster allows a user to adjust the sensitivity of the MFDI by enabling the magnitude of the variation between the current value and the ambient value of the magnetic field needed for the MFDI to cause an alert to be varied. If the sensitivity of the MFDI is increased, a smaller variation between the current value and the ambient value of the magnetic field will cause an alert to be activated.

On the other hand, if the sensitivity of the MFDI is reduced, a larger variation between the current value of the magnetic field and the ambient value of the magnetic field will be required in order for an alert to be activated. Thus, by means of the sensitivity adjuster, a user may set the sensitivity of the MFDI to meet his or her requirements.

Calibration of the compass by the user of the device allows the strength of the local magnetic field to be measured and recorded. This value is used by the MFDI when detecting disturbances in the magnetic field.

Preferably, the device further comprises a calibration prompt operatively connected to the first processor for prompting a user to calibrate the device.

Preferably the calibration prompt will prompt the user to calibrate the device whenever the device is being used more than a predetermined distance away from where it was previously used, and/or when the device was previously calibrated over a year ago. Preferably, the calibration prompt will prompt the user to calibrate the device whenever the device is being used more than 300 miles away from where it was previously used. However, the calibration prompt could be set to prompt a user to calibrate the device at different time frequencies or under different conditions. The calibration prompt will also prompt the user to calibrate the device if a previous calibration is no longer valid because it has been lost or corrupted.

Preferably, the device further comprises a magnetic variation compensator operatively connected to the first processor.

By means of the magnetic variation compensator an appropriate correction may be applied to the calculated orientation to account for the difference between true North and Magnetic North at that particular location.

The magnetic variation compensator may make use of magnetic variation look-up tables.

Magnetic variation (also called magnetic declination) varies both from place to place and with the passage of time. The difference between true North and magnetic North may vary considerably around the world. For example, in the United States, the variation between true North and magnetic North varies from 20° West in Maine to 0° in Florida to 10° East in Texas. This means that a compass adjusted at the beginning of a journey passing through these locations would have a true North error of over 30° if no magnetic variation compensator was included in the device.

Advantageously, the magnetic variation compensator is adapted to apply an appropriate correction to account for the difference between true North and magnetic North for any location in the world.

Conveniently, this may be achieved by storing within the device, preferably within the memory device, magnetic variation look-up tables which provide data for any location in the world.

Advantageously, the device further comprises a disturbance alert for alerting the user of the presence of a magnetic field disturbance that may affect the accuracy of the compass.

The disturbance alert may take any convenient form, and may for example be visual or audible.

Preferably, the device further comprises a power management unit. The power management unit controls the supply of power to the components of the device, and is adapted to power down (or switch off) the GPS receiver after a particular event has taken place, or a predetermined time after the device was last switched on.

Preferably the power management unit is adapted to power down the GPS receiver after the memory device has stored the current location data.

The power management unit may also be adapted to power down other components of the device at the same time that it powers down the GPS receiver. The device may thus be partially or completely powered down by the power management unit.

By means of the power management unit, the power consumption of the device is kept to a minimum.

In an embodiment of the invention in which the power management unit is adapted to cause the device to switch off completely after the memory device has stored the current location data, when a user wishes to use the current location data stored in the memory device for obtaining orientation in a second location, the user may activate the compass and the first indicator in order that the user may be informed of the orientation of the device in the second location.

Because the power management unit causes the GPS receiver to switch off after the current location data has been stored in the memory device, the device does not continuously receive GPS signals and therefore does not constantly track the location of the device.

In a preferred embodiment, when a user switches on the device, the first processor activates the intelligent compass. A user of the device may therefore benefit from the MFDI every time the device is switched on to obtain current location data.

Preferably, the device further comprises a clock for displaying to a user the current time at the current location.

Advantageously, the first processor further comprises a calculator for calculating the sunrise and sunset times at the current location. The sunrise and sunset times may be determined using date and time information obtained from the GPS receiver, and latitude and longitude data also obtained from the GPS receiver. In some embodiments, altitude data from the GPS receiver may also be used to calculate sunrise and sunset times.

Advantageously, the device further comprises an alarm for alerting a user at a predetermined time.

Advantageously, the alarm comprises a sunrise alarm operatively connected to the calculator, which sunrise alarm is adapted to alert a user at predetermined interval of time before sunrise is due to occur at the location of the device.

Preferably, the alarm is adapted to provide an audible alert at a predetermined interval of time before sunrise.

This means that if, for example, a user wishes to be alerted 70 minutes before sunrise, the time at which the alarm will be activated will depend upon the time of sunrise that has been calculated by the calculator. The user could, however, choose to be alerted at any desired interval of time before the calculated sunrise time. For example, the predetermined interval may fall within the range of 130 minutes to 0 minutes before sunrise

Conveniently, the device further comprises a sunset alarm operatively connected to the calculator and adapted to alert a user at a predetermined interval of time before a calculated sunset time.

In some embodiments of the invention, the sunrise and sunset alarms may be incorporated into a single alarm.

The calculator may comprise look-up tables and/or algorithms for calculating sunrise and sunset times at the current location.

Preferably, the first indicator comprises a direction display, which may be in the form of, for example a light, an arrow or a multi-segment LCD display, for indicating to a user which direction he needs to turn to correctly align himself towards a predetermined location. Other types of indicator may be used. For example, the first indicator may be audible.

Conveniently the first indicator comprises an alert device that indicates when the user is correctly aligned in the required direction.

Advantageously the first indicator comprises an optical pointer to assist alignment of a user towards a predetermined location. The optical pointer may be powered by a light source such as a laser and may project a line across, for example a floor and/or wall when the orientation device is correctly aligned, depending on the location of the user.

The alert device may also be activated to indicate when the current location data is successfully stored in the memory device.

The alert device may further include other discemable alerts such other visual alerts, such as an LED, or a vibrating alert.

The alert device may include an audible alert and/or a visual alert. An audible or vibrating alert will enable blind or visually impaired users to use the device without assistance.

Preferably the audible alert is in the form of a beep, and the visual alert is in the form of a light source that illuminates on activation of the visual alert.

Advantageously the device comprises a plurality of first indicators.

Conveniently, the direction display also acts as the disturbance alert. In such embodiments it is not necessary to have a separate disturbance alert, since the direction display is adapted to indicate to a user the presence of a disturbance in the earth's magnetic field.

Preferably the first processor includes a Great Circle and a Rhumb line algorithm for calculating a directional heading.

The Great Circle algorithm will calculate the directional heading according to a Great

Circle method, which will indicate the direction of the shortest route to the predetermined location. The Rhumb line algorithm will calculate the directional heading according to a Rhumb line method, which will indicate the direction of the predetermined location along a constant compass heading.

A user is able to select the algorithm, and hence a pre-set method, by which the orientation data concerning the orientation of the device in the second location is determined.

Advantageously, the device further comprises a second indicator, to indicate to a user the pre-set method used.

Data concerning the predetermined location may be pre-loaded into the memory device.

In such embodiments, a user is not required to input any data into the device in order to orientate himself towards the predetermined location, further simplifying the process of orientation.

Conveniently data concerning more than one predetermined location is pre-loaded into the memory device.

Alternatively, or in addition, data contained in the memory device may be modified.

Preferably, the device further comprises an input port. Conveniently, the input port comprises a USB port.

Preferably data may be preloaded in the memory device, or existing data may be modified by inputting data into the memory device via an input port. Thus, data concerning more than one predetermined location may be loaded into the memory device via the input port.

In embodiments of the invention comprising a magnetic variation compensator which uses magnetic variation tables, the magnetic variation look-up tables may be updated by inputting data into the device via the input port. In addition, the software and functionality of the device may be updated via the input port.

By means of the present invention it is therefore possible to enhance the functionality and data contained within the device by downloading relevant information into the device via the USB port. Advantageously the device is designed to be compact and portable. For example, the device may be handheld, or may be in the form of a necklace, thereby allowing an individual to easily carry the device from one location to another.

Preferably the device further includes an integrated power source so that the device can be used both outdoors and indoors without the need to connect the device to a separate external power source such as an electrical mains outlet.

Conveniently the device is powered through the integrated power source, which may be operated by means of a battery. Alternatively, the power source may be operated by means of solar panels or a combination of solar and battery power.

Preferably the battery is a rechargeable battery, and the device further comprises a charging jack to allow a user to recharge the rechargeable battery.

Advantageously, the device forms part of a telephone, preferably a mobile telephone, and more preferably a telephone equipped with a GPS receiver.

The invention is particularly suited to integration within a GPS telephone, since components forming part of the GPS telephone, such as the processor of the telephone may be used as the first processor forming part of the device, a GPS antenna and processor forming part of the GPS telephone may form the GPS receiver of the device, and the memory of the GPS telephone may form the memory device of the device.

In such an embodiment it will be necessary only to add the compass forming part of the device according to the present invention to the hardware of the GPS telephone in order that the device may operate as described hereinabove in conjunction with operation of the telephone.

When a device according to the present invention forms part of a telephone, the processor of the telephone will serve as the first processor of the device.

When a device according to the first aspect of the present invention is incorporated into a telephone comprising an RF module, the telephone may be operated in at least one of two modes. In a first mode, _s the telephone operates in a usual manner to allow a user to make and receive calls.

In a second mode, known as the orientation mode, the processor of the telephone disables the RF module of the telephone. The disablement of the RF module allows the user to determine his orientation without the compass being affected by wireless signals which could otherwise compromise the accuracy of the compass.

In use, a user may indicate to the processor that the telephone should operate in the orientation mode. The processor then disables the RF module of the telephone. Once a user wishes to turn the telephone to its first mode, the user indicates to the first processor that the first mode should be resumed. At this point the first processor reactivates the RF module.

A user may switch between the first mode and the second mode by any known means.

One use of the device according to the present invention is to enable a worshipper to orientate himself towards a location of religious interest. If the device is being used by such a worshipper the orientation mode may be referred to as a prayer mode.

According to a second aspect of the present invention there is provided a method for assisting the orientation of a user towards a predetermined location, comprising, the steps of: positioning a device at a first location, the device including: a first processor; a

GPS receiver; a compass; a memory device; a first indicator for informing a user of the orientation of the device in a first location; and a magnetic field disturbance indicator; switching on the device to receive GPS signals; obtaining current location data concerning the location of the user in the first location from the GPS receiver; storing the current location data in a memory device; calculating the direction of the predetermined location in a second location using the compass and the current location data stored in the memory device to obtain orientation data concerning the orientation of the user; indicating the orientation data to the user in the second location via a first indicator; and indicating to a user any disturbances in the magnetic field.

The magnetic field disturbance indicator is used to determine whether there are any magnetic field disturbances that could affect the accuracy of the compass, and the user is alerted of any such disturbances.

In addition, any variations in the magnetic field are taken into account when calculating the direction of the predetermined location at the second location. In particular, a correction is applied to the orientation data in order to indicate accurately the direction of the predetermined location to the user when the user is in the second location.

Advantageously, the method comprises the further step of calibrating the device.

By calibrating the device, a measurement of the ambient magnetic field at the current location may be taken.

Conveniently, the method comprises the further step of alerting a user when the current value of the magnetic field varies by a predetermined amount from the ambient magnetic field.

Preferably, the method comprises the further step of adjusting the sensitivity of the MFDI. By adjusting the sensitivity of the MFDI, the magnitude of the variation between the current value of the magnetic field and the ambient value required to cause an the user to be alerted can be varied.

Advantageously, the method comprises the further step of prompting a user to calibrate the device.

The compass may be calibrated on a regular basis for example whenever the device is switched on. Alternatively, the device may be calibrated under certain circumstances, for example whenever the device is used more than 300 miles away from where it was last used, and/or whenever the device was last calibrated over a year ago.

This calibration enables the first processor to store a value for the magnetic field at the current location, and to update this value every time the compass is calibrated. When the user has moved to the second location and is using the device to obtain orientation data concerning the orientation of the device in the second location, the MFDI compares the value of the magnetic field obtained at the second location with the stored value of the magnetic field obtained at the first location in order to determine whether there has been a disturbance in the earth's magnetic field that could affect the accuracy of the compass.

If the MFDI detects a disturbance that could affect the accuracy of the compass, the user is alerted by any convenient means.

Preferably, the method comprises the further step of determining the difference between true North and magnetic North at the location of the device, and making an appropriate correction to the calculated orientation to account for this difference.

Preferably the method comprises the further step of switching off the GPS receiver after the current location data has been stored. The GPS receiver may be switched off automatically after current location data has been stored by means of a power management unit forming part of the device.

Because the GPS receiver is switched off after the current location data has been stored in the memory device, the power consumption of the device may be kept to a minimum.

Other of the components forming the device may also be switched off when not in use, and therefore the device may be completely switched off after the current location data has been stored in the memory device.

Because, in a preferred embodiment, the device is automatically switched off after current location data has been stored, whenever a user requires the current location data to be updated, the user must switch on the device in order to reactivate the GPS receiver. Preferably, the magnetic field disturbance indicator comprises two magneto-inductive sensors which are positioned at substantially right-angles to one another. Each sensor may be a SEN-S65 magneto-inductive sensor from PNI Corporation.

When such sensors are used, the step of calibrating the compass may comprise rotating the device through substantially 360° and preferably 720°.

Preferably the step of calculating the direction of the predetermined location in a second location uses a pre-set method to obtain orientation data concerning the orientation of the user in the second location.

Preferably the pre-set method is either a Great Circle method or a Rhumb line method.

Preferably, the method comprises prior to the step of calculating the direction of the predetermined location in the second location, the further steps of: determining orientation data concerning the orientation of the user in the first location, using the current location data and directional data from the compass in the first location; indicating the orientation data to the user in the first location via the first indicator.

When the device according to the first aspect of the present invention forms part of a telephone comprising a GPS receiver and an RF module, the method preferably comprises the further step of switching the telephone to an orientation mode in which the

RF module is disabled by the first processor.

The invention will now be described by way of non-limiting example with reference being made to the accompanying drawings in which:

Figure 1 is block diagram of a device according to the first aspect of the present invention;

Figure 2 is a perspective view of the device of Figure 1;

Figures 3 to 6 are detailed schematic representations of alternative displays forming part of the device of Figure 2; and Figure 7 is a schematic representation of a device according to a preferred embodiment of the first aspect of the present invention incorporated into a GPS telephone.

Referring initially to Figures 1 and 2, a device according to the first aspect of the present invention is designated generally by the reference numeral 2. The device comprises a first processor 4 which serves to operatively connect together and control the other components in the device which will be described hereinbelow.

The device further comprises a GPS receiver 6, an electronic compass 8, a memory device 10, a clock 12, a display 14, a plurality of first indicators 16, an input key 18, a USB port 20, a power management unit 22 and a battery 24. The GPS receiver 6 comprises an antenna 26 and a GPS processor 28.

The electronic compass 8 comprises two magneto-inductive sensors 32 orientated substantially at right-angles to one another, and an application-specific integrated circuit (ASIC) 34 for driving the two sensors 32.

The sensors may be any suitable type and for example, may each comprise an SEN-S65 magneto inductive sensor from PNI Corporation.

The device further comprises a magnetic field disturbance indicator (MFDI) 30 and a magnetic variation compensation 31 integrated within the central processor.

The display 14 may take any convenient form, and may, for example, comprise an LED panel.

The plurality of first indicators 16 includes an audio alert 36 adapted to emit sound, for example in the form of a beep, a visual indicator, for example an LED, and an optical pointer 37 which may be powered by any suitable light source such as a laser. Some or all of the first indicators may be deactivated if required.

The device 10 further comprises a plurality of display icons 40 which indicate to a user whether any of the first indicators 16 have been activated or deactivated. In this embodiment, the display icons 40 include an icon 50 to indicate to a user the status of the battery 24, and an icon 52 to indicate to a user whether the GPS receiver 6 is switched on and if so, the strength of the GPS signal received by the GPS receiver.

The device 2 further comprises a multi-segment LCD orientation ring 44 forming part of the display 14.

The clock 12 may be used to indicate the present time at the current location and may also be used to indicates the times of sunrise and sunset at the current location. These times may then be displayed to the user by means of the display 14.

The USB port 20 allows data to be input into the memory device 10 in order to modify the data stored therein, or to augment the data stored therein.

In other embodiments, data concerning the predetermined location may be pre-loaded into the memory device 10. The user is then not required to input any data into the device 10 in order to orientate himself towards the predetermined location.

Magnetic variation tables may also be input into the device 10 via the USB port 20. The magnetic variation compensator may then make use of such magnetic variation look-up tables in order to apply an appropriate correction to the calculated orientation to account for the difference between true North and a magnetic North at the location of the device.

In some embodiments of the invention, data concerning one predetermined location only may be stored in the memory device 10 at any time. Each time a user wishes to be able to orientate towards a different predetermined location to that currently stored in the device 2, data concerning the new predetermined location may be loaded into the device 2.

Data concerning the new predetermined location may be loaded onto the device 2 via the USB port 20. Data concerning the current predetermined location stored in the memory device 10 will thus be overwritten by the new data. Once the new data has been uploaded, the device 2 will assist the orientation of the user towards the new predetermined location.

The orientation of a user towards a predetermined location is obtained by initially positioning the device 2 in a first location so as to receive GPS signals. The input key 18 located on the device is pressed for approximately 2 seconds to start a GPS engine within the GPS receiver 6. A user should press and hold the input key 18 until the display icon indicating that the GPS receiver has been activated is illuminated.

In order to ensure that the GPS receiver 6 is able to receive GPS signals to thereby provide current location data, a user should preferably find a location outside with a clear view of the sky.

Once the GPS receiver has been switched on by pressing the input key 18, the user may be prompted to calibrate the compass.

The user may be prompted to rotate the device through 720° in order to carry out the calibration procedure. However, in preferred embodiments of the device, a user will be prompted to calibrate the device only under certain circumstances, such as when the device is located more than say 300 miles from its previous location, or when the device was last calibrated over a year ago, for example.

During the calibration process, segments in the orientation ring 44 will illuminate one after the other. A user should rotate the device slowly so that the illuminated segment is always in the position indicated in Figure 2 by reference numeral 46. The compass calibration is completed when the device has been rotated through 720°.

When the calibration is complete, or if the user is not prompted to calibrate the compass, the GPS receiver 6 will search for satellites. During this process, which may take up to a minute, the segments on the orientation ring are illuminated sequentially. If a GPS fix is obtained, all the segments in the orientation ring will be illuminated together with the GPS icon. If the device has been unable to obtain a GPS fix, none of the segments in the orientation ring will be illuminated, and the GPS icon will flash.

When the GPS engine has located a sufficient number of satellites, the latitude and longitude coordinates of the device 2 are calculated to provide current location data concerning the location of the device 2. This current location data is stored in the memory device 18. The power management unit causes the device 2 to power down after the current location data has been stored. As such, the device 2 will switch itself off after a few seconds, in order to conserve battery life.

The user can now go to a second location, which may be shielded from GPS signals. At the second location, the user turns on the device 2 by pressing the power button 38 briefly. Orientation data concerning the orientation of the device 2 in the second location is determined by using the electronic compass 8, the current location data stored in the memory device 10, and the magnetic variation compensator 31 to calculate the direction of the predetermined location.

In other words, the stored location data, in conjunction with directional data determined from the electronic compass 8 and any correctional data from the magnetic variation compensator 31, is used to determined orientation data of the device 2 at the second location.

If there is a disturbance in the earth's magnetic field this will be detected by the MFDI 30 integrated within the first processor, and the user will be alerted of the disturbance by the disturbance indicator display, which will flash. If the disturbance continues, the optical pointer will not illuminate, even if the device is correctly aligned.

In this embodiment the orientation ring acts as the disturbance indicator. In the event of a disturbance in the earth's magnetic field being detected, a segment of the orientation ring will flash.

The first processor 4 includes a Great Circle and a Rhumb line algorithm for calculating a directional heading. The method for determining the orientation data concerning the orientation of the device in the second location towards the predetermined location may thus be selected by a user from either a Great Circle method or a Rhumb line method.

That is to say, the processor takes the current location data and the predetermined location data from the memory device- and uses the Great Circle or Rhumb line algorithm, depending on the method selected, to calculate a heading. The calculated heading is then used in conjunction with directional data determined from the electronic compass 8 and any correctional data from the magnetic variation compensator to determine the orientation data at the second location. The orientation ring will indicate to a user in which direction he needs to turn in order to be appropriately orientated. For example, if a user needs to turn in a clockwise direction, a segment to the right of segment position 46 (when the device is orientated as shown in Figure 2) will be illuminated. The further away from position 46 is the illuminated segment, the greater the turn required in order that the user is appropriately orientated. As the user moves towards the correct orientation, the segments will be illuminated sequentially, such that segments closer to position 46 are sequentially illuminated.

Once the user is appropriately aligned, a first indicator may be activated to alert the user that he is in the correct orientation. In this embodiment, the optical pointer 37 is activated and an optical beam 54 is produced which points in the appropriate direction.

In this embodiment, the optical beam 54 is produced by a laser, and is thus very fine. A very accurate indication of orientation may thus be obtained.

Other first indicators 16 may also be activated to alert the user to the fact that he is correctly aligned.

The processor may contain algorithms and/or look-up tables for determining sunrise and sunset.

The device 2 is powered by means of a rechargeable battery and comprises a charging jack 60 for recharging the rechargeable battery. The charging jack is integrated with the USB port 20.

The device 2 may further include a second indicator 62 to indicate to a user which method of orientation is being used, i.e. whether the method of orientation is a Great Circle or a Rhumb line method or some other method. In this embodiment, the second indicator is in the form of a display icon.

Turning now to Figures 3 to 6, alternative displays 140 for the device 2 shown in Figure 2 are shown. Parts of each display that correspond to the display 14 shown in Figure 2 have been given corresponding reference numerals for ease of understanding. Figure 4 illustrates a display that will be visible to a user when the device has just been switched on, and is receiving GPS signals.

Figure 5 shows the display that will be visible to a user at the start of the calibration process.

Figure 6 shows the display that would be visible to a user during a sensitivity adjustment process.

Let us consider the situation where the predetermined location/point of interest is Mecca and the device 2 according to the invention is to be used by a worshipper who wants to orientate himself towards Mecca.

The worshipper would first position the device 2 in a location with a clear view of the sky (and/or satellites) and activate the device 2. The user may be prompted to calibrate the device using the procedure outlined above depending on the settings of the calibration prompt.

The icon 52 will inform the worshipper that the GPS position has been recorded once the location data is stored in the memory device 10.

The worshipper can now go to a place of prayer, which can be inside or outside. When the worshipper is in the position where the worshipper would like to pray, the device 2 is held flat and turned on.

The worshipper will then choose which method he would like the device 2 to use to calculate the direction of Mecca i.e. the Great Circle or Rhumb line method.

The precise direction of Mecca will now be calculated, using the stored location data in conjunction with the compass 8 and the first processor 4. The worshipper will then turn in the direction shown by a flashing or illuminated segment of the LCD orientation ring 44 of the display 14, holding the device 2 flat in his hands.

As the worshipper turns in the direction towards Mecca, a respective segment of the LCD orientation ring 40 will flash or be illuminated to guide the worshipper in the right direction. A first indicator will be activated when the device 2 is pointing precisely towards Mecca, and the optical pointer 37 will be energised to further assist alignment. The worshipper now aligns his prayer mat in the direction indicated by the optical beam 54 emitted by the optical pointer 37, in the knowledge that he is pointing precisely towards Mecca.

If the audible alert is also activated, a pulsing beep will be emitted once the user is within ±10° of the direction of Mecca. The frequency of the beep will increase as the user turns the device towards Mecca, and will decrease as the user turns the device away from Mecca. When the device is directly facing Mecca the pulsing beep will become a continuous tone. The continuous tone will sound for a brief period of time before being switched off. Once the continuous tone has been achieved the audible alert will not sound again unless the user moves further than ±10° from the direction of Mecca.

The optical pointer 37 will be activated only when the device 2 is pointing precisely towards Mecca, and will turn off if the worshipper turns beyond the direction of Mecca.

If there is a disturbance in the earth's magnetic field, the MFDI integrated within the first processor will detect the disturbance, and the user will be alerted of the disturbance.

Referring now to Figure 7, a GPS telephone is designated generally by the reference numeral 700. The telephone has incorporated therein an electronic compass 8 of the type illustrated in Figure 1 and described hereinabove.

The telephone 700 comprises a processor 710 to which the components forming the telephone are operatively connected such that they are controlled by the processor 710.

Telephone 700 comprises the following further components controlled by the processor 710 which components operate in a known way: antenna RF module 712; GPS receiver 714 comprising an antenna 715 and a GPS processor 716; a display 718; a memory 720; a clock 722; input keys 724; a power management system 726; a battery 728 and an input port 730.

Each of these components is operatively connected to the processor 710 and operation of the components is controlled by the processor 710 in a known manner. The components of the telephone 700 also serve as components of a device according to an embodiment of the first aspect of the invention, such as device 2 illustrated in Figure 1.

Set out below is a table showing how the components of the telephone 700 equate to the components of the device 2 illustrated in Figure 1 :

Components of Telephone 700 Components of the Device 2 illustrated illustrated in Figure 7 in Figure 1

Processor 710 Central processor 4

GPS receiver 714 GPS receiver 6

Memory 720 Memory 10

Clock 722 Clock 12

Display 718 Display 14

Key 247 Input key 18

Input port 730 USB port 20

Battery 728 Battery 24

Power management system 726 Power management unit 22

The device according to an embodiment of the first aspect of the present invention of the type illustrated in Figure 1 is thus effectively incorporated into the telephone 700 by connecting the compass 8 to the processor 710 of the telephone. It is thus not necessary to duplicate components since the components of the telephone serve also as the components of the device 2 as explained hereinabove.

A GPS signal may then be received in the usual way, and the location of the telephone 700 may be accurately determined.

The telephone 700 may be operated in two modes. In the first mode, the telephone operates as usual, and a user may make and receive telephone calls, text messages etc in the usual way.

In a second mode, known as the orientation mode, the antenna RF module 712 is disabled by processor 710. When a user wishes to orientate himself towards a predetermined location he indicates to the processor 710 via an input key 247 that the telephone should be switched to the orientation mode. The processor 710 then disables the RF module 712.

The device may then be operated as described hereinabove with reference particularly to Figures 1 to 6 in the accompanying description.

Although the use of the device according to the invention has been described with particular reference to a Muslim requiring to orientate himself towards Mecca, it is to be understood that the invention is not limited to such use but can be used in circumstances where a user wishes to orientate himself towards a predetermined location, which may be for religious or non-religious reasons.

For instance, a broadcasting company could give a device according to the invention pre-loaded with the position of a particular satellite to installation engineers or correspondents in order to assist with precise alignment of receiving equipment.

It is also possible that the army may supply its personnel with a device according to the invention pre-loaded with the precise location of a target or their base to enable them to know the direction in which they should move.

Claims

1. A device for assisting the orientation of a user towards a predetermined location, comprising: a first processor; a GPS receiver; a compass; a memory device; and a first indicator for informing the user of the orientation of the device, wherein the GPS receiver provides current location data concerning the location of the device when located in a first location, the memory device stores the current location data, such that on movement of the device to a second location, orientation data concerning the orientation of the device in the second location is determined by the compass in conjunction with the current location data stored in the memory device, the device further comprising a magnetic field disturbance indicator (MFDI).

2. A device according to Claim 1 wherein the MFDI is integrated within the first processor.

3. A device according to Claim 1 or Claim 2 wherein the GPS receiver, the compass, the memory device, the first indicator, and the magnetic field disturbance indicator are operatively connected to one another via the first processor.

4. A device according to any one of the preceding claims wherein the compass comprises two magneto-inductive magnet sensors positioned at substantially 90° to one another.

5. A device, according to any one of the preceding claims further comprising a sensitivity adjuster for adjusting the sensitivity of the MFDI.

6. A device according to any one of the preceding claims further comprising a calibration prompt operatively connected to the first processor for prompting a user to calibrate the device.

7. A device according to any one of the preceding claims further comprising a magnetic variation compensator operatively connected to the first processor.

8. A device according to any one of the preceding claims further comprising a disturbance alert.

9. A device according to any one of the preceding claims further comprising a power management unit.

10. A device according to Claim 9 wherein the power management unit is adapted to power down the GPS receiver after a particular event has taken place.

11. A device according to Claim 9 or Claim 10 wherein the power management unit is adapted to power down the GPS receiver a predetermined time after the device was last switched on.

12. A device according to Claim 9 or any claim dependent thereon wherein the power management unit is adapted to power down more than one component of the device.

13. A device according to any one of the preceding claims further comprising a clock.

14. A device according to any one of the preceding claims wherein the first processor further comprises a calculator for calculating the sunrise and sunset times at the current location.

15. A device according to Claim 14 wherein the calculator comprises look-up tables and/or algorithms.

16. A device according to Claim 15 further comprising a sunrise alarm operatively connected to the calculator.

17. A device according to Claims 15 or Claim 16 further comprising a sunset alarm operatively connected to the calculator.

18. A device according to any one of the preceding claims wherein the first indicator comprises a direction display.

19. A device of according to any one of the preceding claims wherein the first indicator comprises an optical pointer.

20. A device according to any one of the preceding claims wherein the first indicator comprises an alert device.

21. A device according to any one of the preceding claims including a plurality of first indicators.

22. A device according to any one of the preceding claims wherein the processor includes a Great Circle and a Rhumb line algorithm for calculating a directional heading.

23. A device according to any one of the preceding claims further comprising an input port.

24. A device according to any one of the preceding claims further comprising a second indicator.

25. A device according to any one of the preceding claims forming part of a telephone.

26. A device according to Claim 25 forming part of a mobile telephone equipped with a GPS receiver.

27. A telephone comprising a device according to any one of the preceding claims.

28. A method for assisting the orientation of a user towards a predetermined location, comprising, the steps of: positioning a device at a first location, the device including: a first processor; a

29. A method according to Claim 28 comprising the further step of calibrating the device.

30. A method according to Claim 28 or Claim 29 comprising the further step of prompting a user to calibrate the device.

31. A method according to any one of Claims 28 to 30 comprising the further step of alerting a user when any disturbances in the magnetic field are greater than a predetermined value.

32. A method according to any one of Claims 28 to 31 comprising the further step of adjusting the sensitivity of the MFDI.

33. A method according to any one of Claims 28 to 32 comprising the further step of determining the difference between true North and magnetic North at the location of the device, and making an appropriate correction to the calculated orientation to account for this difference.

34. A method according to any one of Claims 28 to 33 comprising the further step of: switching off the GPS receiver after the current location data has been stored in the memory device.

35. A method according to Claim 34 wherein the step of switching off the GPS receiver occurs automatically.

36. A method according to any Claim 29 or Claim 30 or any claim dependent on claim 29 or claim 30 wherein the step of calibrating the compass includes the step of rotating the device through 720°.

37. A method according to any one of Claims 28 to 36 further including the step of activating the first indicator when the location data has been stored in the memory.

38. A method according to any one of Claims 28 to 37 further including the step of activating the first indicator when the user is orientated with the predetermined location.

39. A method according to any one of the Claims 28 to 38 wherein the step of calculating the direction of the predetermined location in a second location utilises a preset method to obtain orientation data concerning the orientation of the user in the second location.

40. A method according to any one of Claims 28 to 39 including, prior to the step of calculating the direction of the predetermined location in the second location, the further steps of determining orientation data concerning the orientation of the user in the first location, using the current location data and directional data from the compass in the first location; indicating the orientation data to the user in the first location via the first indicator.

41. A method according to any one of Claims 28 to 40, wherein the device forms part of a telephone comprising a GPS receiver and an RF module, and the method further comprises the step of: switching the telephone to an orientation mode in which the RF module is disabled by the first processor.

42. A device substantially as hereinbefore described with reference to the accompanying drawings.

43. A telephone substantially as hereinbefore described with reference to the accompanying drawings.

44. A method substantially as hereinbefore described with reference to the accompanying drawings.