DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Now, a description will be given in more detail of a preferred embodiment of the present invention with reference to the accompanying drawings.

[0024] FIG. 1 is a block diagram showing a system in accordance with an embodiment of the present invention, which is mounted on a portable telephone. In the figure, reference numeral 1 denotes a GPS receiving portion that functions as position detecting means which calculates the present longitude and latitude by electric waves of a GPS satellite which are received by an antenna.

[0025] Reference numeral 2 denotes a geomagnetic sensor that functions as orientation detecting means which is formed of a sensor substrate in which a magnetic field detection coil substrate 4 and an exciting coil substrate 5 are laminated on the upper and lower surfaces of a sensor core 3 so as to be opposed to each other. FIG. 2 shows the exploded diagram of a specific example of the magnetic sensor.

[0026] The sensor core 3 is formed of an amorphous core resulting from cutting an amorphous thin plate into a ring shape and then etching the ring plate so that a toroidal core is wound on the ring plate.

[0027] The magnetic field detection coil substrate 4 is formed of a first detection coil substrate 41 having coil patterns 41 a for formation of an x-axial component magnetic field detection coil and a second detection coil substrate 42 having coil patterns 42 a for formation of a y-axial direction component magnetic field detection coil. The first detection coil substrate 41 includes two x-coil substrates 411 which are laminated on each other in a conducting manner so as to sandwich the sensor core 3 from the upper and lower sides thereof. Each of those x-coil substrates 411 is formed in such a manner that the coil patterns 41 a for formation of the x-axial direction component magnetic field detection coil are formed on a surface of an epoxy substrate, and through-holes 41 b for terminals that connect the respective x-coil patterns 41 a are defined in a peripheral edge portion of the epoxy substrate. Likewise, the second detection coil substrate 42 includes two y-coil substrates 421 which are laminated on each other in a conducting manner so as to sandwich the sensor core 3 from the upper and lower sides thereof. Each of those y-coil substrates 421 is formed in such a manner that the coil patterns 42 a for formation of the y-axial direction component magnetic field detection coil are formed on a surface of an epoxy substrate, and through-holes 42 b for terminals that connect the respective y-coil patterns 42 a are defined in a peripheral edge portion of the epoxy substrate.

[0028] Also, the exciting coil substrate 5 includes two exciting coil substrates 51 and 52 which are laminated on each other in a conducting manner so as to sandwich the sensor core 3 from the upper and lower sides thereof. The respective exciting coil substrates 51 and 52 are formed in such a manner that exciting coil patterns 51 a and 52 a are formed on the surface of an epoxy substrate, and through-holes 51 b and 52 b for terminals that connect the respective exciting coil patterns are defined in the peripheral edge portion of the epoxy substrate.

[0029] The magnetic sensor 2 is formed by sequentially laminating the sensor core 3 , the magnetic field detection coil substrate 4 and the exciting coil substrate 5 on the sensor core 3 in the stated order and then pressing those laminated members to form a laminate.

[0030] Reference numeral 6 denotes a CPU that conducts a given arithmetic operating process on the basis of a position signal inputted from the GPS receiving portion 1 and an orientation signal from the magnetic sensor 2 to measure the present position (the longitude, the latitude and the orientation). Then, the CPU 6 reads map information that coincides with the present position information from a map information storing portion 7 and displays the map information together with a present place index on a display 91 of a position information display portion 9 . At the same time, the position information display portion 9 auditorially displays the present position, the orientation, etc., by a synthetic voice.

[0031] The positional information from the GPS receiving portion 1 and the orientation information from the magnetic sensor 2 conduct mutual complement. The orientation information can be obtained from a change in the positional information of the GPS receiving portion 1 with the movement of the portable terminal device through arithmetic operation. The orientation information and the orientation information from the magnetic sensor 2 are compared with each other, and if the orientation information from the magnetic sensor 2 is set to be positive, a start point can be found out. As a result, the positional information of the GPS receiving portion 1 can be returned to the start point, and the integrated and accumulated error information can be returned to 0.

[0032] A map information display processing portion 8 subjects the map information of the present place displayed on the display 91 to rotation scroll by a required angle if necessary and processes the display in such a manner that the forward direction (directed to a direction of the magnetic sensor) of the present place index is always directed toward the upper side of the display 91 on the map information of the present place. A description will be given with reference to FIG. 3 . The orientation signal from the magnetic sensor 2 is inputted to the CPU as the analog values obtained by decomposing the detected geomagnetism into an x-axial direction (zonal direction) magnetic field vector value and a y-axial direction (meridional direction) magnetic field vector value. The CPU analog-to-digital converts the input signal into a digital signal. The magnetic field vector values in the x-axial direction and the y-axial direction are enhanced in resolution by using a given correction parameter stored in an EEP-ROM. If the meridional direction is set to be 0°, the clockwise rotating angle (orientation angle) θ° which reaches the synthetic vector T (representative of a direction of the magnetic sensor) of the x-axial magnetic field vector value X 1 and the y-axial magnetic field vector value Y 1 is obtained by the following expression.

θ=tan −1 X 1 /Y 1

[0033] The calculation of the orientation angle is enabled by a calculating logic not using the correction parameter for the magnetic field vector values in the respective directions.

[0034] The processing steps of the map information display processing portion 8 will be described with reference to FIGS. 4 to 6 . For example, it is assumed that a user of the portable terminal device now exists in a corner portion of Kogakuin University on a Chuo-street of Shinjuku station and is directed toward a direction of North-East (orientation angle is 45°). The map information of the longitude and the latitude in question (refer to FIG. 4 ) is read from the map information storing portion 7 in accordance with the position signal from the GPS receiving portion 1 . Then, the map information in an area that matches the size of a display screen (for example, 200 dots×200 dots) with the present position P as a center is sectioned and selected. In this situation, the selected map information A is the map information in an area where it rotates by the orientation angle θ obtained by the orientation signal from the magnetic sensor 2 clockwise (refer to FIG. 5 ). Then, when the map information is displayed on the display 91 , the map information A selected by the above display processing portion 8 is rotationally processed to the orientation angle counterclockwise direction and displayed in a corrected manner (refer to FIG. 6 ). As a result, the map information B becomes a map in which the direction (forward direction) of the magnetic sensor 2 is always directed toward the upper side of the display 91 . Every time the orientation of the forward direction is changed with the movement of the portable terminal, the display processing portion 8 conducts the same processing as the above-described processing and displays the map information in which the forward direction is always directed toward the upper side of the display. Those sequential processings are conducted at a high speed and at a real time.

[0035] Also, the map information display processing portion 8 maintains the characters and the marks contained in the map information displayed on the display 91 at the original positional relation with respect to the upper side direction of the display without conducting any rotating process when the map information is rotationally processed on the basis of the orientation angle. In FIG. 6 , the characters and so on are rotated by the orientation angle without conducting the above processing and displayed. The characters and the marks mentioned in a horizontal direction maintain a manner in which they are mentioned horizontally even in the case where the map information is rotationally displayed, likewise. As a result, the information of the characters, etc., is readily visible.

[0036] The destination may be inputted such as by using a key of the portable terminal device. In this case, the shortest route and the required period of time up to the destination are calculated on the basis of the map information and then displayed on the display of the position information display portion or by a voice output portion.

[0037] Also, if the positional information of the GPS receiving portion and the orientation information of the magnetic sensor which have been received or measured are temporarily stored, a locus along which the portable terminal device has moved can be confirmed on the basis of the stored information later.

[0038] As was described above, according to the present invention, the following advantages can be obtained.

[0039] Since a flux gate type magnetic sensor consisting of a sensor substrate in which a magnetic field detection coil substrate and an exciting coil substrate are laminated on the upper and lower surfaces of a sensor core, or a geomagnetic sensor using a hole element, a magnetic resistant element or the like is employed as the orientation detecting means used together with the GPS position detecting means, the accurate present position of a user can be displayed together with the map information on a display of a small-sized portable terminal device, in particular, a portable telephone.

[0040] Also, since the map information is subjected to rotating scroll by the map information processing means on the basis of the orientation angle obtained from the magnetic field vector value of the magnetic sensor, the map information can be displayed in such a manner that the forward moving direction of the portable terminal device is always directed toward the predetermined specified direction within a plane of the display portion, and the orientation of the map information coincides with the forward direction so that the user has no strange feeling and can dynamically understand the accurate orientation and position.

[0041] Further, since the positional information by the GPS is complemented by the orientation information by the geomagnetic sensor, the error information accumulated by the integrating system can be permanently eliminated so as to provide a position display system high in precision.

[0042] The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.