CN101608917A - Be used to measure the method and apparatus and the portable electronic equipment of magnetic offset of geomagnetic sensor - Google Patents

Abstract

A kind ofly be equipped in the method that the magnetic offset of geomagnetic sensor in the mobile information terminal apparatus with storer designs for measurement.This geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field and influenced by magnetization and cause magnetic biasing.In the method, measure the output of geomagnetic sensor, the measurement data of terrestrial magnetic field is provided continuously with the output of base area Magnetic Sensor.Measurement data is stored in the storer.When the number of the measurement data in being stored in storer reaches predetermined number, from storer, read measurement data, and estimate the off-set value of magnetic biasing based on the measurement data of the predetermined number that from storer, reads.

Description

Be used to measure the method and apparatus and the portable electronic equipment of magnetic offset of geomagnetic sensor

The application is based on dividing an application of No. 200510078958.3 applications (being used to measure the method and apparatus and the portable electronic equipment of magnetic offset of geomagnetic sensor) that proposed on June 13rd, 2005, below quotes its content.

Technical field

The present invention relates to a kind of method and apparatus that is used for measuring the magnetic offset of geomagnetic sensor that is equipped in mobile information terminal apparatus.

Background technology

Under the situation of Magnetic Sensor traditionally, when it being installed in the inside of portable phone (portable information terminal), owing to there is the magnetic field that leaks out from the loudspeaker that is installed together, the Metal Packaging of magnetization electronic component etc., so geomagnetic sensor is detected or even those noise magnetic fields of being produced by their.Therefore, have such example, that is, by be installed in geomagnetic sensor in the portable phone detect earth magnetism example, the orientation that the orientation that calculate in the magnetic field that exists according to portable phone inside can not indicating correct.

For example, in the portable phone that the geomagnetic sensor that has sensitive direction along mutually perpendicular two axles (X and Y direction) and have the sensitivity that is equal to each other on direction separately is installed, suppose that the angle that forms is θ between ground magnetic vector and X-axis, distinguish under the state of corresponding X and Y direction amount of magnetization at skew m and n, with obtain geomagnetic sensor at detected value Vx on the X-direction and geomagnetic sensor the detected value Vy on Y direction, detected value Vx and detected value Vy are as output, because the inner noise magnetic field that exists of portable phone, so, detected value Vx and detected value Vy obtain by additional calculation respectively, represent as (formula 1) and (formula 2).

Vx=R * cos θ+m ... (formula 1)

Vy=R * sin θ+n ... (formula 2)

(wherein R is a proportionality constant)

In other words, when (that is, applying constant outer magnetic field) under the situation that does not have at earth magnetism to change was arranged in unmagnetized geomagnetic sensor rotation on a certain fixed position, the detected value of geomagnetic sensor can be drawn the real circle with centre coordinate (0,0).Hereinafter, the circle of drawing by the detected value of geomagnetic sensor is called compass circle.On the other hand, when the rotation of magnetized geomagnetic sensor, as shown in figure 21, the detected value of geomagnetic sensor can be drawn have centre coordinate (m, real circle n).Method by following formation is used: wherein, derive the centre coordinate of compass circle, thereby derive the magnetized amount of magnetization of geomagnetic sensor of equal valuely, and, come detected value is proofreaied and correct to derive correct orientation thus by from the detected value of geomagnetic sensor, deducting the calculating of centre coordinate value (corrected value).

Particularly, at first derive the skew of centre coordinate value.For example, when making geomagnetic sensor, comprising in the plane of sensitive direction and turning around in the maintenance level, thereby derive geomagnetic sensor with respect to the detected value of all directions on X-axis and Y direction, and the maximal value of these detected values and minimum value remembered respectively make X _Max, Y _MaxAnd X _Min, Y _Min, (m n) is derived by following formula the off center coordinate.

M=(X _Max+ X _Min)/2 ... (formula 3)

N=(Y _Max+ Y _Min)/2 ... (formula 4)

In addition, when keeping level, detected value (the X1 that obtains when moving to precalculated position A at geomagnetic sensor, Y1) and at geomagnetic sensor move to the output valve (X2 that obtains when being located at 180 ° of position D on the reverse direction from position A, Y2), (m is n) as its mean value to derive centre coordinate by following formula.

M=(X1+X2)/2 ... (formula 5)

N=(Y1+Y2)/2 ... (formula 6)

Then, deduct the off center coordinate figure to proofread and correct by calculating.According to the centre coordinate of such derivation (m, n) and geomagnetic sensor at detected value Vx on the X-direction and geomagnetic sensor the detected value Vy on Y direction, derive azimuth angle theta by following formula.

When | Vy-n|＜| when Vx-m| and Vx-m＞0,

θ=tan ^-1((Vy-n)/(Vx-m)) ... (formula 7)

When | Vy-n|＞| when Vx-m| and Vy-n＞0,

θ=90[degree]-tan ^-1((Vx-m)/(Vy-n)) ... (formula 8)

When | Vy-n|＜| when Vx-m| and Vx-m＜0,

θ=180[degree]-tan ^-1((Vy-n)/(Vx-m)) ... (formula 9)

When | Vy-n|＞| when Vx-m| and Vy-n＜0,

θ=270[degree]-tan ^-1((Vx-m)/(Vy-n)) ... (formula 10)

Yet, in above-mentioned traditional method for calibrating terrestrial magnetism sensor, because the magnetized state of geomagnetic sensor is changing always, so when thinking that at every turn geomagnetic sensor has been magnetized, for maximal value and the minimum value that derives the geomagnetic sensor detected value, the user is necessary to make portable phone to turn around or multi-turn more.But the problem of this existence is: especially be difficult to when keeping the portable phone level it to be turned around or multi-turn more, the result is the possibility that exists portable phone to descend once in a while, even and to descend do not appear in portable phone, the data of acquisition also have deviation, therefore can not derive skew exactly.So, also there is such problem, that is, above-mentioned traditional method for calibrating terrestrial magnetism sensor is not suitable for portable equipment.

In view of these problems that exist, for example, patent documentation 1 has been described a kind of electronic bearing detection instrument, wherein whether the magnetic field judgment means is judged by the detected magnetic field intensity of Magnetic Sensor outside preset range, and when its outside this scope the time, judge that this Magnetic Sensor is magnetized, and when measuring, damping magnetic field makes its demagnetization to utilize the coil that applies bias voltage magnetic field to Magnetic Sensor to apply alternately to magnetized Magnetic Sensor.Yet, though the technology according to disclosure document can be demagnetized, but when the electronic bearing detection instrument is mobile in earth magnetism, in electronic bearing detection instrument inside, by for example permanent magnet etc. (regardless of the direction of earth magnetism, it can both produce magnetic field on the constant direction with respect to the direction of electronic bearing detection instrument) magnetic field that produces can not demagnetize to the induced field that soft magnetic bodies produces, the ferromagnet (for example, the lead-in wire of electronic component) of this soft magnetic bodies for relatively easily being magnetized or being demagnetized.Therefore, can not address the above problem.

On the other hand, patent documentation 2 is described a kind of azimuth detecting apparatus, this device judges whether the signal that is input to the arithmetic unit from geomagnetic sensor departs from the preset judgment district, thereby it is bigger to need not to rotate the amount of magnetization that just can identify geomagnetic sensor, and this is provided warning.Yet though it is big and provide warning to detect the amount of magnetization of Magnetic Sensor according to the technology of disclosure document, therefore the concrete technology that it does not disclose about output is proofreaied and correct can not address the above problem.

On the other hand, patent documentation 3 is described a kind of magnetic detection method, wherein, do not exist under the situation of above-mentioned soft magnetic bodies nearby, to be adjusted to certain value with respect to the detected value of the Magnetic Sensor of being scheduled to uniform magnetic field in advance, then from detected value (this detected value be exist under the state of soft magnetic bodies the direction from the magnetic sensitive axes obtains when the magnetic field) derivation correction coefficient, and, eliminate the induced field that produces around the soft magnetic bodies nearby by using predetermined computing formula according to correction coefficient.Yet, do not disclose about which type of situation needs according to the technology of disclosure document and to proofread and correct or carve the concrete technology of proofreading and correct when, therefore can not address the above problem.

On the other hand, patent documentation 4 is described a kind of control method that is used for the electronic bearing detection instrument, wherein by use magnetic field generator (it can produce the magnetic field that intensity is higher than earth magnetism), when changing magnetic field intensity according to predetermined sequence, the magnetic field that generation is used to regulate, and utilize the sequence that obtains the data of Magnetic Sensor according to predetermined sequence to obtain to regulate data, thereby regulate.Yet, have a problem, promptly except that the electronic bearing detection instrument, according to the technology of disclosure document also needs apply the magnetic field generator of external magnetic field.

In addition, patent documentation 5 has been described a kind of calibration steps that is installed in the Magnetic Sensor in the portable terminal device.In this technology, portable terminal device rotates with each predetermined angular, and goes out skew based on the data estimation of measuring in all angles by Magnetic Sensor, thereby the speed that need not to rely on rotation just can be carried out calibration.Yet,, also be necessary to allow the user be rotatably installed with the portable unit of Magnetic Sensor consciously, thereby it calibrated even in patent documentation 5 described methods.Therefore, improve to some extent,, concerning the user, still have problems owing to force the user to carry out calibration operation although this technology is compared with conventional art.And if the user ignores or forgets calibration, geomagnetic sensor just can not be operated with optimum condition so.

[patent documentation 1]

Uncensored patent publication No. Hei 6-174472

[patent documentation 2]

Uncensored patent publication No. Hei 6-249663

[patent documentation 3]

Uncensored patent publication No. Hei 7-151842

[patent documentation 4]

Uncensored patent publication No. 2002-48551

[patent documentation 5]

Uncensored patent publication No. 2004-12416

Summary of the invention

Therefore, consider above-mentioned situation and propose the present invention, (for example the purpose of this invention is to provide skew that a kind of correction causes by magnetization, only by Magnetic Sensor swingingly on surface level) method for calibrating terrestrial magnetism sensor, and a kind of portable information terminal of the correct operation by the Magnetic Sensor skew simplifiedly of user's bit data treatment facility, this bearing data treatment facility carries out the correction of geomagnetic sensor.

Consider above-mentioned variety of issue equally and propose the present invention, and a kind of portable electronic equipment and calibration steps thereof with direction detection function be provided, can be easily proofread and correct and do not increase burden to the user to being installed in orientation detection element (with the form of geomagnetic sensor) in the folding portable electronic installation.

In order to realize above-mentioned purpose, the present invention proposes following device.

In first scheme of the present invention, the method that provides a kind of measurement to be equipped in the magnetic offset of geomagnetic sensor in the mobile information terminal apparatus, this geomagnetic sensor has the magnetic sensitivity to the terrestrial magnetic field on a plurality of axle of coordinate system, and influenced by magnetization and cause magnetic biasing.Method of the present invention comprises: the DATA REASONING step, and a plurality of measurement data that it is measured the output of described geomagnetic sensor and obtains described terrestrial magnetic field, each measurement data is represented by data point in coordinate system; The offset estimation step, it estimates the off-set value of described magnetic offset of geomagnetic sensor according to a plurality of measurement data of described terrestrial magnetic field, described off-set value is represented by offset point in coordinate system; The mean value calculation step, it calculates corresponding to the offset point of described off-set value with corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate off-set value, and further calculates the mean value of the distance that has calculated between offset point and a plurality of data point; The standard deviation calculation step, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated; And the validity determining step, it judges the validity of the off-set value of estimation according to the standard deviation that calculates.

Preferably, this mobile information terminal apparatus has first memory and second memory, and the DATA REASONING step obtains measurement data from geomagnetic sensor continuously.Method of the present invention further comprises: the data storage step, it will store in the described first memory by the described measurement data that described DATA REASONING step obtains continuously, so that described offset estimation step reads a plurality of measurement data from described first memory, and estimate the off-set value of described magnetic biasing according to the described a plurality of measurement data that from described first memory, read; And the offset storage step, when its validity of off-set value when estimation is identified by described validity determining step, the offset data of described estimation is stored in the described second memory.

Preferably, this mobile information terminal apparatus has the first memory that is used to store described measurement data and is used to store the second memory of described off-set value, and described DATA REASONING step obtains to comprise the measurement data of previous measurement data and current measurement data continuously.Method of the present invention further comprises the distance calculation step, it calculates corresponding to the current data point of described current measurement data and corresponding to the distance between the prior data point of described previous measurement data, and described previous measurement data has been stored in the described first memory; Determining step, it judges that whether computed range between described current data point and the described prior data point is greater than preset distance; The data storage step, it is when the distance of determining to calculate during greater than preset distance, described current measurement data is stored in the described first memory, thereby by repeating described distance calculation step, the process of described determining step and described data storage step, measurement data is accumulated in the described first memory, be stored in measurement data number in the described first memory when reaching predetermined number with box lunch, described offset estimation step reads a plurality of described measurement data from described first memory, and estimates the off-set value of described magnetic biasing according to a plurality of described measurement data that reads from described first memory; And the offset storage step, when its validity of off-set value when estimation is identified by described validity determining step, the offset data of described estimation is stored in the described second memory.

Preferably, method of the present invention further comprises the circular step of circular user when judging that by described validity determining step the off-set value of described estimation is invalid.

Preferably, method of the present invention further comprises: the comparison step that a plurality of measurement data compare mutually, in described a plurality of measurement data each all be used for estimating off-set value and described a plurality of measurement data each represent by one group of coordinate components corresponding to one group of axle of coordinate system, so that compare poor with between the maximal value of the coordinate components that obtains each and the minimum value at each coordinate components at described measurement data, wherein, described validity determining step is except according to the described standard deviation that calculates, also according to obtain each the maximal value of coordinate components and the validity that the difference between the minimum value is judged the off-set value of described estimation.

Preferably, in the method for the invention, the DATA REASONING step is measured the output of geomagnetic sensor, and this geomagnetic sensor is to select from comprise giant magnetoresistance device, tunnel magnetoresistance device, permanent magnetism resistance device, Hall device, magnetoimpedance device and fluxgate sensor.

Preferably, the DATA REASONING step is measured the output of described geomagnetic sensor, described geomagnetic sensor is having magnetic sensitivity on two axles of two-dimensional coordinate system or on three axles of three-dimensional system of coordinate, so that each measurement data is represented by the data point in two-dimensional coordinate system or the three-dimensional system of coordinate.

Provide the another kind of method that is equipped in the magnetic offset of geomagnetic sensor in the mobile information terminal apparatus with storer of measuring at this, have the magnetic sensitivity of terrestrial magnetic field on a plurality of axles of described geomagnetic sensor in coordinate system and influenced by magnetization and cause magnetic biasing.This method comprises: the DATA REASONING step, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and current measurement data are provided continuously, each measurement data is represented by data point in coordinate system; Apart from determining step, it calculates corresponding to the current data point of described current measurement data and corresponding to the distance between the prior data point that is stored in the described previous measurement data in the described storer, and whether the described current data point that calculated of judgement and the distance between the described prior data point be greater than preset distance; The data storage step, it is when the distance of determining to have calculated during greater than preset distance, described current measurement data is stored in the described storer, thereby described measurement data is accumulated in the described storer, and offset estimation step, it reads described a plurality of measurement data from described storer, and estimates the off-set value of described magnetic biasing according to the described a plurality of measurement data that read from described storer.

Also provide a kind of measurement to be equipped in the method for the magnetic offset of geomagnetic sensor in the mobile information terminal apparatus with storer and inclination sensor at this, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on two axles of two-dimensional coordinate system and is subjected to magnetization to influence and cause magnetic biasing, and described inclination sensor detects the inclination angle of described mobile information terminal apparatus.Method of the present invention comprises: the DATA REASONING step, and it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and follow-up measurement data are provided continuously; The inclination measurement step, its measure output of described inclination sensor and provide continuously a plurality of angle-datas, described a plurality of angle-datas represent the inclination angle of mobile information terminal apparatus and comprise with the previous simultaneously-measured previous angle-data of measurement data and with the simultaneously-measured follow-up angle-data of follow-up measurement data; The data storage step, it is when the difference between another inclination angle of the inclination angle of the mobile information terminal apparatus of representing by described follow-up angle-data and the mobile information terminal apparatus represented by described previous angle-data during greater than predetermined difference, described follow-up measurement data is stored in the described storer, thereby, described measurement data is accumulated in the described storer by repeating the process of described DATA REASONING step, described inclination measurement step and described data storage step; And the offset estimation step, it reads the measurement data of a plurality of accumulations from described storer, and estimates the off-set value of described magnetic biasing according to the measurement data of described a plurality of accumulations of reading from described storer.

Preferably, when the measurement data number of accumulating in described storer reached predetermined number, described offset estimation step read the measurement data of described a plurality of accumulations from described storer.Method of the present invention further comprises the mean value calculation step, its calculate in two-dimensional coordinate system, define, corresponding to the offset point of the off-set value of estimation with in two-dimensional coordinate system, define, corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate described off-set value, and the described offset point that calculated of further calculating and the mean value of the distance between described a plurality of data point; The standard deviation calculation step, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated; The validity determining step, it judges the validity of the off-set value of estimation according to the standard deviation that calculates; And the offset storage step, when its validity when the off-set value of estimation is identified by described validity determining step, store the offset data of described estimation.

In this method that also provides a kind of measurement to be equipped in the magnetic offset of geomagnetic sensor in the mobile information terminal apparatus with storer, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field and influenced by magnetization and cause magnetic biasing.The present invention includes: the DATA REASONING step, it measures the output of described geomagnetic sensor, and the measurement data of described terrestrial magnetic field is provided continuously according to the output of described geomagnetic sensor; The data storage step, it is stored in described measurement data in the described storer; And offset estimation step, when the number of its measurement data in being stored in described storer reaches predetermined number, from described storer, read described measurement data, and estimate the off-set value of described magnetic biasing based on the described measurement data of the predetermined number that from described storer, reads.

According to first scheme of the present invention, judge by the validity determining step by the validity of the off-set value of offset estimation step estimation.Therefore, can constantly obtain suitable off-set value.Should be noted that in the distance between any measurement point (detected value) on the compass circle and be defined as " distance ".According to the present invention, judge by the validity determining step by the validity of the off-set value of offset estimation step estimation, and when validity was identified, the off-set value that is stored in first memory storage was updated.Therefore, can constantly suitable off-set value be stored in first memory storage.According to the present invention, only be positioned at one of distance formerly when the position of measurement point certain value or near a plurality of position the compass circle that forms by the measurement data of geomagnetic sensor, ability input measurement data when current measurement point.Therefore, even the swing of portable information terminal is inhomogeneous, also can make the distributing equilibrium of measurement data.According to the present invention, only when the detection output of the detection output of the geomagnetic sensor of current measurement point or inclination sensor with one formerly measurement point compare when having changed scheduled volume input measurement data.Therefore, can avoid, no matter through problem that how long measurement data is not also imported except earth magnetism directly the situation perpendicular to ground.According to the present invention, when off-set value is invalid, the user will obtain the sort of result's circular.Therefore, user's estimation that can identify off-set value is not also finished.According to the present invention, when off-set value is invalid, after confirming whether the user wishes so, the correction of this skew will be carried out once more.Therefore, can carry out correction, become effectively until off-set value, and can conveniently select according to the user to skew.According to the present invention, in the portable information terminal that the geomagnetic sensor with diaxon magnetic sensitive direction is installed, proofread and correct easily because the influence that output offset caused that the magnetization of geomagnetic sensor causes to measured data values.

Further in first scheme of the present invention, a kind of device that is used for measuring the magnetic offset of geomagnetic sensor that is equipped in portable information terminal is provided, has the magnetic sensitivity of terrestrial magnetic field on a plurality of axle of described geomagnetic sensor in coordinate system and influenced by magnetization and cause magnetic biasing.The inventive system comprises: the DATA REASONING part, a plurality of measurement data that it is measured the output of described geomagnetic sensor and obtains described terrestrial magnetic field, each measurement data is represented by data point in coordinate system; The offset estimation part, it estimates the off-set value of described magnetic offset of geomagnetic sensor according to a plurality of measurement data of described terrestrial magnetic field, described off-set value is represented by offset point in coordinate system; The mean value calculation part, it calculates corresponding to the offset point of described off-set value with corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate off-set value, and further calculates the mean value of the distance that has calculated between offset point and a plurality of data point; The standard deviation calculation part, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated; And the validity judgment part, it judges the validity of the off-set value of estimation according to the standard deviation that calculates.

At this device that provides another kind to be used for measuring the magnetic offset of geomagnetic sensor that is equipped in portable information terminal, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on a plurality of axle of coordinate system and influenced by magnetization and cause magnetic biasing.The inventive system comprises: the DATA REASONING part, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and current measurement data are provided continuously, each measurement data is represented by data point in coordinate system; Apart from the judgment part, it calculates corresponding to the current data point of described current measurement data and corresponding to the distance between the prior data point that is stored in the described previous measurement data in the described storer, and whether the described current data point that calculated of judgement and the distance between the described prior data point be greater than preset distance; Data-carrier store, it is stored described current measurement data, thereby accumulates described measurement data when the distance of determining to have calculated during greater than preset distance; And the offset estimation part, it reads described a plurality of measurement data from described data-carrier store, and estimates the off-set value of described magnetic biasing according to the described a plurality of measurement data that read from described data-carrier store.

Further provide a kind of device that is used for measuring the magnetic offset of geomagnetic sensor that is equipped in portable information terminal at this with inclination sensor, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on two axles of two-dimensional coordinate system and is subjected to magnetization to influence and cause magnetic biasing, and described inclination sensor detects the inclination angle of described portable information terminal.The inventive system comprises: the DATA REASONING part, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and follow-up measurement data are provided continuously; The inclination measurement part, it measures the output of described inclination sensor, and provide continuously a plurality of angle-datas, described a plurality of angle-datas represent the inclination angle of described portable information terminal and comprise and the previous simultaneously-measured previous angle-data of measurement data and with the simultaneously-measured follow-up angle-data of follow-up measurement data; Data-carrier store, it is when the difference between another inclination angle of the inclination angle of the portable information terminal of representing by described follow-up angle-data and the portable information terminal represented by described previous angle-data during greater than predetermined difference, store described follow-up measurement data, thereby partly accumulate described measurement data with described inclination measurement by repeatedly operating described DATA REASONING part; And the offset estimation part, it reads the measurement data of a plurality of accumulations from described data-carrier store, and estimates the off-set value of described magnetic biasing according to the described a plurality of cumulative measurement data that read from described data-carrier store.

Further provide a kind of device that is used for measuring the magnetic offset of geomagnetic sensor that is equipped in portable information terminal at this, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field and influenced by magnetization and cause magnetic biasing.The inventive system comprises: the DATA REASONING part, it measures the output of described geomagnetic sensor, and the measurement data of described terrestrial magnetic field is provided continuously according to the output of described geomagnetic sensor; Data-carrier store, it stores described measurement data; And offset estimation part, when its measurement data number in being stored in described data-carrier store reaches predetermined number, from described data-carrier store, read described measurement data, and estimate the off-set value of described magnetic biasing based on the measurement data of the predetermined number that from described data-carrier store, reads.

In addition, in first scheme of the present invention, the machine readable media that is used in the mobile information terminal apparatus with CPU and geomagnetic sensor is provided, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on a plurality of axle of coordinate system and influenced by magnetization and cause magnetic biasing, described medium comprises the programmed instruction of carrying out by CPU, so that mobile information terminal apparatus is carried out the method for measuring magnetic offset of geomagnetic sensor, wherein this method comprises: the DATA REASONING step, a plurality of measurement data that it is measured the output of described geomagnetic sensor and obtains described terrestrial magnetic field, each measurement data is represented by data point in coordinate system; The offset estimation step, it estimates the off-set value of described magnetic offset of geomagnetic sensor according to a plurality of measurement data of described terrestrial magnetic field, described off-set value is represented by offset point in coordinate system; The mean value calculation step, it calculates corresponding to the offset point of described off-set value with corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate off-set value, and further calculates the mean value of the distance that has calculated between offset point and a plurality of data point; The standard deviation calculation step, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated; And the validity determining step, it judges the validity of the off-set value of estimation according to the standard deviation that calculates.

Provide another kind to be used at this and have CPU, machine readable media in the mobile information terminal apparatus of storer and geomagnetic sensor, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on a plurality of axle of coordinate system and influenced by magnetization and cause magnetic biasing, described medium comprises the programmed instruction of carrying out by CPU, so that mobile information terminal apparatus is carried out the method for measuring magnetic offset of geomagnetic sensor, wherein said method comprises: the DATA REASONING step, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and current measurement data are provided continuously, each measurement data is represented by data point in coordinate system; Apart from determining step, it calculates corresponding to the current data point of described current measurement data and corresponding to the distance between the prior data point that is stored in the described previous measurement data in the described storer, and whether the described current data point that calculated of judgement and the distance between the described prior data point be greater than preset distance; The data storage step, it is stored in described current measurement data in the described storer, thereby described measurement data is accumulated in the described storer when the distance of determining to have calculated during greater than preset distance; And the offset estimation step, it reads a plurality of described measurement data from described storer, and estimates the off-set value of described magnetic biasing according to the described a plurality of measurement data that read from described storer.

This further provide a kind of be used in have CPU, machine readable media in the mobile information terminal apparatus of storer, geomagnetic sensor and inclination sensor, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on two axles of two-dimensional coordinate system and is subjected to magnetization to influence and cause magnetic biasing, and described inclination sensor detects the inclination angle of described mobile information terminal apparatus.Medium of the present invention comprises the programmed instruction of being carried out by CPU, so that mobile information terminal apparatus is carried out the method for measuring magnetic offset of geomagnetic sensor, wherein said method comprises: the DATA REASONING step, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and follow-up measurement data are provided continuously; The inclination measurement step, its measure output of described inclination sensor and provide continuously a plurality of angle-datas, described a plurality of angle-datas represent the inclination angle of mobile information terminal apparatus and comprise with the previous simultaneously-measured previous angle-data of measurement data and with the simultaneously-measured follow-up angle-data of follow-up measurement data; The data storage step, it is when the difference between another inclination angle of the inclination angle of the mobile information terminal apparatus of representing by described follow-up angle-data and the mobile information terminal apparatus represented by described previous angle-data during greater than predetermined difference, described follow-up measurement data is stored in the described storer, thereby, described measurement data is accumulated in the described storer by repeating the process of described DATA REASONING step, described inclination measurement step and described data storage step; And the offset estimation step, it reads the measurement data of a plurality of accumulations from described storer, and estimates the off-set value of described magnetic biasing according to the measurement data of described a plurality of accumulations of reading from described storer.

This further provide a kind of be used in have CPU, machine readable media in the mobile information terminal apparatus of storer and geomagnetic sensor, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field and influenced by magnetization and cause magnetic biasing.Medium of the present invention comprises the programmed instruction of being carried out by CPU, so that mobile information terminal apparatus is carried out the method for measuring magnetic offset of geomagnetic sensor, wherein said method comprises: the DATA REASONING step, it measures the output of described geomagnetic sensor, and the measurement data of described terrestrial magnetic field is provided continuously according to the output of described geomagnetic sensor; The data storage step, it stores described measurement data in the described storer into; And offset estimation step, when the number of its measurement data in being stored in described storer reaches predetermined number, from described storer, read described measurement data, and based on the described measurement data of the predetermined number that from described storer, reads to estimate the off-set value of described magnetic biasing.

In alternative plan of the present invention, a kind of portable electronic equipment with folded formation of handling by opening operation and closed procedure is provided, comprise: the orientation detection part, it has the geomagnetic sensor that is used to measure the earth magnetism of skew and exports the measurement data of described earth magnetism, make described measurement data may comprise the error that causes owing to described skew like this, and based on coming the detection orientation direction from the measurement data of described geomagnetic sensor; The opened/closed test section, it detects the opening operation and the closed procedure of described folded formation; And control section, its any one in detecting opening operation or closed procedure responds when operating, in order to begin obtaining a series of measurement data from described geomagnetic sensor, then according to the measurement data series estimation off-set value that obtains, and set the estimated value of described skew, the estimated value of described skew is used for proofreading and correct the error that is included in described measurement data during the detection orientation direction.

Preferably, described folded formation comprises a pair of unit that links together and by opening operation and closed procedure open and close each other, and opening with closed, in order to detect described opening operation and described closed procedure of described a pair of unit physically detected in wherein said opened/closed test section.

Preferably, described a pair of unit comprises fixed cell and mobile unit, described fixed cell is maintained fixed in described opening operation usually, described mobile unit responds described opening operation and moves with respect to described fixed cell, and wherein said geomagnetic sensor is installed in the described mobile unit.

Preferably, portable electronic equipment of the present invention further comprises display device, further comprises display device, and described display device shows the information relevant with the operation of described portable electronic equipment and is installed in the described mobile unit.

Preferably, described folded formation comprises the magnetic source that generation may cause the magnetic force of described geomagnetic sensor skew, and wherein said geomagnetic sensor is arranged in the described folded formation away from the position of described magnetic source, and such set-up mode is in order that reduce the magnetic influence of described magnetic source.

Preferably, portable electronic equipment of the present invention further comprises the validity judgment part, and it judges the validity of the estimated value of skew; The circular part, it is operated when invalid when the estimated value of described skew is judged as by described validity judgment part, carries out described opening operation or described closed procedure once more in order to point out the user.

Preferably, portable electronic equipment of the present invention further comprises the validity judgment part, and it judges the validity of the estimated value of described skew; The circular part, it is operated when invalid when the estimated value of described skew is judged as by the validity judgment part, in order to prompting the user further described opening operation of execution and described closed procedure when described folded formation is placed with different directions.

Preferably, wherein said folded formation is rotary-type, and it has the part of rotating in opening operation or closed procedure.

Preferably, described geomagnetic sensor is measured earth magnetism on three orthogonal axles, and wherein said rotary-type folded formation comprises and linking together with by opening operation and the closed procedure a pair of fixed cell and the mobile unit of open and close each other, described fixed cell is maintained fixed in described opening operation usually, and respond described opening operation, described mobile unit rotation is with displacement on the direction of three axles.

At this device that provides another kind to be used to measure magnetic offset of geomagnetic sensor, described geomagnetic sensor in coordinate system XYZ X, Y and the Z axle on have the magnetic sensitivity of earth magnetism and influenced by magnetization and cause magnetic biasing, described device comprises:

The DATA REASONING part, it measures the output of described geomagnetic sensor, and obtains a plurality of measurement data (x of described earth magnetism _i, y _i, z _i) (i=1 ..., N); And

The offset estimation part, it is according to a plurality of measurement data (x of described earth magnetism _i, y _i, z _i) (i=1 ..., N), estimate described magnetic offset of geomagnetic sensor off-set value (X0, Y0, Z0),

Wherein said off-set value (X0, Y0 Z0) estimate to (6) by following algorithm (1):

(1) supposition is in described coordinate system XYZ, and the compass ball of described geomagnetic sensor has radius R, and is each measurement data (x _i, y _i, z _i) (i=1 ..., N) constitutive equations (x _i-X0) ²+ (y _i-Y0) ²+ (z _i-Z0)=R ²

(2) be above-mentioned equation definition square error ε;

ε＝∑{(x _i-X0) ²+(y _i-Y0) ²+(z _i-Z0) ²-R ²} ²

＝∑{(x _i ²+y _i ²+z _i ²)-2x _iX0-2y _iY0-2z _iZ0+(X0 ²+Y0 ²+Z0 ²)-R ²} ²

(3) form following square error ε;

ε＝∑(a _i+b _iX0+c _iY0+d _iZ0+D) ²

Wherein, a=x _i ²+ y _i ²+ z _i ², b=-2x _i, c=-2y _i, d=-2z _iAnd D=(X0 ²+ Y0 ²+ Z0 ²)-R ²

(4) as follows, ε to variable X 0, Y0, Z0 and D differentiate, is used for square error ε is set to minimum;

$\left\{\begin{array}{c}\frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">X</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)b_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">Y</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)c_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">Z</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)d_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;D}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)=0\end{array}\right.$

(5) calculate the following simultaneous equation of acquisition by carrying out above-mentioned differentiate, wherein,, variable X 0, Y0, Z0 and D are considered as the independent variable of ε in order to simplify this calculating;

$\left[\begin{array}{cccc}\left[\mathrm{bb}\right]& \left[\mathrm{bc}\right]& \left[\mathrm{bd}\right]& \left[b\right]\\ \left[\mathrm{bc}\right]& \left[\mathrm{cc}\right]& \left[\mathrm{cd}\right]& \left[c\right]\\ \left[\mathrm{bd}\right]& \left[\mathrm{cd}\right]& \left[\mathrm{dd}\right]& \left[d\right]\\ \left[b\right]& \left[c\right]& \left[d\right]& N\end{array}\right]\left[\begin{array}{c}X0\\ Y0\\ Z0\\ D\end{array}\right]=\left[\begin{array}{c}-\left[\mathrm{ab}\right]\\ -\left[\mathrm{ac}\right]\\ -\left[\mathrm{ad}\right]\\ -\left[a\right]\end{array}\right]$

Wherein, the operational character [] expression of in above-mentioned equation, using:

$\left[m\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i,$ $\left[\mathrm{mn}\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i{n}_i$

(6) to these simultaneous equatioies find the solution with derive described estimation skew (X0, Y0, Z0).

At this bearing data calculation element that provides another kind to have geomagnetic sensor, comprise: data obtain part, it is used to import the signal from geomagnetic sensor, may cause the magnetic field that the magnetic field of skew mixes by terrestrial magnetic field and other to measure, thereby the measurement data in this magnetic field is provided, and it is represented by one group of coordinate components of a different set of corresponding to given coordinate system; The calculations of offset part, it calculates the off-set value of described skew based on a plurality of measurement data from measuring continuously from the input signal of geomagnetic sensor; Rating unit, it is according to the coordinate components of each, a plurality of measurement data that are used to calculate off-set value is compared mutually poor with between the maximal value of the coordinate components that obtains each and the minimum value; The judgment part, it judges that when each the difference that obtains during greater than predetermined difference the off-set value of calculating is effective; New portion more, it is judged as effective off-set value based on current, upgrades previous off-set value; And correction portion, it is proofreaied and correct measurement data according to the off-set value of upgrading, and comes the computer azimuth data according to the measurement data of proofreading and correct.

Further in alternative plan of the present invention, provide a kind of bearing measuring method of carrying out in the portable electronic equipment with geomagnetic sensor and folded formation, this folded formation is handled by opening operation and closed procedure.Method of the present invention may further comprise the steps: use described geomagnetic sensor measurement to have the earth magnetism of certain deviation, and export the measurement data of described earth magnetism, make described measurement data may comprise the error that causes owing to described skew like this; Based on coming the detection orientation direction from the measurement data of described geomagnetic sensor; Detect the opening operation and the closed procedure of described folded formation; When any one operation in opening operation that detects described folded formation or the closed procedure, begin to obtain a series of measurement data from described geomagnetic sensor; According to the measurement data series estimation off-set value that obtains; And the estimated value of setting described skew, the estimated value of described skew is used for proofreading and correct the error that is included in described measurement data during the detection orientation direction.

Provide a kind of method that is used to measure magnetic offset of geomagnetic sensor at this, this geomagnetic sensor has the magnetic sensitivity of earth magnetism on X, the Y of coordinate system XYZ and Z axle and influenced by magnetization and cause magnetic biasing.Method of the present invention comprises: the DATA REASONING step, it measures the output of described geomagnetic sensor, and obtains a plurality of measurement data (x of described earth magnetism _i, y _i, z _i) (i=1 ..., N); And

The offset estimation step, it is according to described a plurality of measurement data (x of described earth magnetism _i, y _i, z _i) (i=1 ..., N), estimate described magnetic offset of geomagnetic sensor off-set value (X0, Y0, Z0),

Wherein, described off-set value (X0, Y0 Z0) estimate to (6) by step (1):

(1) supposition is in described coordinate system XYZ, and the compass ball of described geomagnetic sensor has radius R, and is each measurement data (x _i, y _i, z _i) (i=1 ..., N) constitutive equations (x _i-X0) ²+ (y _i-Y0) ²+ (z _i-Z0)=R ²

(2) be above-mentioned equation definition square error ε;

ε＝∑{(x _i-X0) ²+(y _i-Y0) ²+(z _i-Z0) ²-R ²} ²

＝∑{(x _i ²+y _i ²+z _i ²)-2x _iX0-2y _iY0-2z _iZ0+(X0 ²+Y0 ²+Z0 ²)-R ²} ²

(3) form following square error ε;

ε＝∑(a _i+b _iX0+c _iY0+d _iZ0+D) ²

Wherein, a _i=x _i ²+ y _i ²+ z _i ², b _i=-2x _i, c _i=-2y _i, d _i=-2z _iAnd D=(X0 ²+ Y0 ²+ Z0 ²)-R ²

(4) as follows, ε to variable X 0, Y0, Z0 and D differentiate, is used for square error ε is set to minimum;

$\left\{\begin{array}{c}\frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">X</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)b_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">Y</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)c_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">Z</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)d_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;D}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)=0\end{array}\right.$

(5) calculate the following simultaneous equation of acquisition by carrying out above-mentioned differentiate, wherein,, variable X 0, Y0, Z0 and D are considered as the independent variable of ε in order to simplify calculating;

$\left[\begin{array}{cccc}\left[\mathrm{bb}\right]& \left[\mathrm{bc}\right]& \left[\mathrm{bd}\right]& \left[b\right]\\ \left[\mathrm{bc}\right]& \left[\mathrm{cc}\right]& \left[\mathrm{cd}\right]& \left[c\right]\\ \left[\mathrm{bd}\right]& \left[\mathrm{cd}\right]& \left[\mathrm{dd}\right]& \left[d\right]\\ \left[b\right]& \left[c\right]& \left[d\right]& N\end{array}\right]\left[\begin{array}{c}X0\\ Y0\\ Z0\\ D\end{array}\right]=\left[\begin{array}{c}-\left[\mathrm{ab}\right]\\ -\left[\mathrm{ac}\right]\\ -\left[\mathrm{ad}\right]\\ -\left[a\right]\end{array}\right]$

Wherein, the operational character [] expression of in above-mentioned equation, using:

$\left[m\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i,$ $\left[\mathrm{mn}\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i{n}_i$

(6) find the solution these simultaneous equatioies with the skew of deriving estimation (X0, Y0, Z0).

Provide a kind of azimuth data calculation method at this, comprise the steps: to import signal from geomagnetic sensor, may cause the magnetic field that the magnetic field of skew mixes by terrestrial magnetic field and other to measure, thereby the measurement data in this magnetic field is provided, and it is represented by one group of coordinate components of a different set of corresponding to given coordinate system; Based on a plurality of measurement data, calculate the off-set value of described skew from measuring continuously from the input signal of geomagnetic sensor; According to the coordinate components of each, a plurality of measurements that are used to calculate off-set value are compared mutually poor with between the maximal value of the coordinate components that obtains each and the minimum value; When each the difference that obtains during, judge that the off-set value of calculating is effective greater than predetermined difference; Based on the current previous off-set value of effective off-set value renewal that is judged as; And measurement data is proofreaied and correct, and come the computer azimuth data according to the measurement data of proofreading and correct according to the off-set value of upgrading.

Further in alternative plan of the present invention, provide a kind of bearing data calculation procedure that can carry out by computing machine, to carry out the processing of computer azimuth data.This processing comprises the steps: to obtain the signal from geomagnetic sensor, may cause the magnetic field that the magnetic field of skew mixes by terrestrial magnetic field and other to measure; The measurement data in this magnetic field is provided, and it is by representing corresponding to one group of coordinate components of a different set of axle in the given coordinate system; Based on a plurality of measurement data, calculate the off-set value of this skew from measuring continuously from the signal of geomagnetic sensor input; Coordinate components according to each compares mutually to a plurality of measurements that are used to calculate off-set value, poor with between the maximal value of the coordinate components that obtains each and the minimum value; When each the difference that obtains during, judge that the off-set value of calculating is effective greater than predetermined difference; Be judged as effective off-set value based on current, upgrade previous off-set value; And measurement data is proofreaied and correct, and come the computer azimuth data according to the measurement data of proofreading and correct according to the off-set value of upgrading.

In third party's case of the present invention, a kind of folded formation of handling by opening operation and closed procedure that has is provided, and produces the portable electronic equipment of leakage field.The inventive system comprises: the orientation detection part, it has the geomagnetic sensor that is used to measure the terrestrial magnetic field of skew and exports the measurement data of described terrestrial magnetic field, make described measurement data may comprise the error that causes owing to described skew like this, and described orientation detection part is based on coming the detection orientation direction from the measurement data of described geomagnetic sensor; The offset estimation part, it obtains a plurality of measurement data from described geomagnetic sensor, and estimates the value of described skew according to the measurement data that obtains, and described off-set value is used for proofreading and correct the error that is included in described measurement data during the detection orientation direction; The operation detection part, it detects the opening operation of described folded formation; And leakage field is removed part, it is operated when detecting the opening operation of described folded formation, in order to calculate the value of the described leakage field that in described folded formation, produces, and from the estimated value of described skew, deduct the calculated value of described leakage field, thereby from the estimated value of described skew, remove the influence of described leakage field.

Preferably, described folded formation comprises a pair of unit that links together with by opening operation and closed procedure open and close each other, and wherein the operation detection part physically detects opening of described a pair of unit, in order to detect described opening operation.

Preferably, when detecting the opening operation of described folded formation, described leakage field is removed part and is operated, and is used for obtaining a series of measurement data from described geomagnetic sensor, and calculates the value of described leakage field based on the measurement data that obtains.

Preferably, described operation detection part further detects the closed procedure of described folded formation, and wherein described offset estimation is partly operated when detecting described closed procedure, be used to begin obtain a series of measurement data, and estimate the value of described skew according to the measurement data series that obtains from described geomagnetic sensor.

A kind of magnetic sensor device that is equipped in the portable electronic equipment is provided, described portable electronic equipment has the folded formation of handling by opening operation and closed procedure and produces leakage field, described magnetic sensor device comprises: the orientation detection part, it has the geomagnetic sensor that is used to measure the terrestrial magnetic field of skew and exports the measurement data of described terrestrial magnetic field, make described measurement data may comprise the error that causes owing to described skew like this, and described orientation detection part is based on coming the detection orientation direction from the measurement data of described geomagnetic sensor; The offset estimation part, it obtains a plurality of measurement data from described geomagnetic sensor, and estimates the value of described skew according to the measurement data that obtains, and described off-set value is used for proofreading and correct the error that is included in described measurement data during the detection orientation direction; And leakage field is removed part, its opening operation to described folded formation responds, be used for calculating the value of the described leakage field that produces at described folded formation, and from the off-set value of estimation, deduct the calculated value of described leakage field, thereby the influence of from the estimated value of described skew, removing described leakage field.

Further in third party's case of the present invention, a kind of orientation detecting method of carrying out in portable electronic equipment is provided, the folded formation that this portable electronic equipment has Magnetic Sensor and handles by opening operation and closed procedure, and this portable electronic equipment produces leakage field.Method of the present invention comprises the steps: to use the geomagnetic sensor measurement to have the terrestrial magnetic field of skew, and the measurement data of output terrestrial magnetic field, makes measurement data may comprise the error that causes owing to skew like this; Based on measurement data from geomagnetic sensor, the detection orientation direction; Obtain a plurality of measurement data from described geomagnetic sensor, and estimate the value of described skew according to the measurement data that obtains, described off-set value is used for proofreading and correct the error that is included in described measurement data during the detection orientation direction; Detect the opening operation of described folded formation; When detecting the opening operation of described folded formation, calculate the value of the leakage field that produces by described portable electronic equipment; And the calculated value that from the estimated value of described skew, deducts described leakage field, thereby the influence of from the estimated value of described skew, removing described leakage field.

In this external third party's case of the present invention, provide a kind of being used in to have CPU, machine readable media in the portable electronic equipment of geomagnetic sensor and folded formation, leakage field is handled and produced to described folded formation by opening operation and closed procedure, described machine readable media comprises the measurement of bearing program of carrying out by CPU, so that carrying out the measurement of bearing that comprises the steps, handles portable electronic equipment: operate described geomagnetic sensor, be used to measure terrestrial magnetic field with certain deviation and the measurement data of exporting described terrestrial magnetic field, make described measurement data may comprise the error that causes owing to described skew like this; Based on coming the detection orientation direction from the measurement data of described geomagnetic sensor; Obtain a plurality of measurement data from described geomagnetic sensor, and estimate the value of described skew according to the measurement data of described acquisition, described off-set value is used for proofreading and correct the error that is included in described measurement data during the detection orientation direction; Detect the opening operation of described folded formation; When detecting the opening operation of described folded formation, calculate from the value of the leakage field of described folded formation generation; From the estimated value of described skew, deduct the calculated value of described leakage field, thereby from the estimated value of described skew, remove the influence of described leakage field.

According to first scheme of the present invention, just can proofread and correct the output offset of geomagnetic sensor owing to need not to rotate portable information terminal, need not effect so reached the output offset of the enough shirtsleeve operation corrections of energy geomagnetic sensor with reference to the service manual of portable information terminal by the user.

According to alternative plan of the present invention,,, make calibration comparatively convenient like this so can not force the user to carry out calibration operation because the calibration of azimuth detecting apparatus is to carry out automatically in the opened/closed operation of folding portable electronic installation.Traditionally, when the user ignored or forgets calibration operation, geomagnetic sensor can not be operated with optimum condition.Yet, in the present invention, because when portable electronic equipment during normal the use, calibration is to automatically perform when opened/closed is operated, so there is not such problem.

According to third party's case of the present invention,,, make calibration comparatively convenient like this so can not force the user to carry out calibration operation because the calibration of azimuth detecting apparatus is to carry out automatically in the opened/closed operation of folding portable electronic installation.Traditionally, when the user ignored or forgets calibration operation, geomagnetic sensor can not be operated with optimum condition.Yet, in the present invention, because when portable electronic equipment during normal the use, calibration is to automatically perform when opened/closed is operated, so there is not such problem.

Description of drawings

Fig. 1 illustrates the structured flowchart of the portable phone in the first embodiment of the invention.

Fig. 2 (a) illustrates the outside drawing of portable phone among the present invention first to the 3rd embodiment to Fig. 2 (d).

Fig. 3 is the floor map of the geomagnetic sensor 30 among the present invention first to the 4th embodiment.

Fig. 4 is the GMR element 31 of geomagnetic sensor 30 among Fig. 3 and the local amplification view of coil 41.

Fig. 5 is the planimetric map of GMR element 31 among Fig. 3.

Fig. 6 is for dissecing the diagrammatic cross-section of GMR element 31 and coil 41 along Fig. 4 center line 3-3.

Fig. 7 illustrates the stopcock membrane structure figure of GMR element 31 among Fig. 4.

Fig. 8 illustrates according to the external magnetic field, the change curve of GMR element 31 resistance values among Fig. 4.

Fig. 9 is the equivalent circuit diagram of X-direction geomagnetic sensor that comprises the GMR element 31 among Fig. 4 and have the GMR element 32 to 34 of same structure.

Figure 10 illustrates with respect at external magnetic field that changes on the X-direction and the magnetic field that changes on Y direction, the output voltage change curve of the X-direction geomagnetic sensor among Fig. 9.

Figure 11 illustrates with respect to the orientation in same embodiment, the curve map of the output of X-direction geomagnetic sensor and Y direction geomagnetic sensor.

Figure 12 is illustrated in the constitutional diagram that portable phone is swung among the same embodiment in the single plane of for example surface level.

Figure 13 is illustrated in the process flow diagram of offset calibration operation of the geomagnetic sensor 30 of portable phone among the same embodiment.

Figure 14 be illustrated in have three geomagnetic sensors among the same embodiment portable phone forward with backward the swing constitutional diagram.

Figure 15 is illustrated in the constitutional diagram perpendicular to the earth magnetism swing of the portable phone that has three geomagnetic sensors among the same embodiment.

Figure 16 is illustrated in the constitutional diagram perpendicular to the earth magnetism swing of the portable phone that has two geomagnetic sensors among the same embodiment.

Figure 17 illustrates the process flow diagram of offset calibration operation of the geomagnetic sensor 30 of portable phone in the second embodiment of the invention.

Figure 18 illustrates the structured flowchart of portable phone in the fourth embodiment of the invention.

Figure 19 (a) is illustrated in the outside drawing of portable phone among the same embodiment to 19 (d).

Figure 20 illustrates the process flow diagram of offset calibration operation of the geomagnetic sensor 30 of portable phone among the same embodiment.

Figure 21 illustrates the compass loop graph of drawing by the detected value of Magnetic Sensor traditionally.

Figure 22 illustrates the electronic structure block diagram of portable mobile terminal (portable terminal device), and this portable mobile terminal is an embodiment with portable electronic equipment of direction detection function of the present invention.

Figure 23 is the functional block diagram of same embodiment.

Figure 24 (a) illustrates the figure of portable terminal device coordinate system and earth axes to 24 (b).

Figure 25 is used to illustrate and the process flow diagram of calibrating relevant operation.

Figure 26 (a) to (b) illustrates the outside drawing of rotary-type portable terminal device (closure state and open mode).

Figure 27 illustrates the calibration steps according to rotary-type portable terminal device, the figure of portable terminal device swaying direction.

The figure (example) of Figure 28 on the XY plane, marking and drawing according to the measurement data of calibration steps sampling.

The figure (a example that θ less) of Figure 29 on the XY plane, marking and drawing according to the measurement data of calibration steps sampling

Figure 30 (a) to (b) illustrates the outside drawing of common Foldable portable terminal (closure state and open mode).

Figure 31 illustrates the calibration steps according to common Foldable portable terminal, the figure of portable terminal device swaying direction.

During illustrating according to another embodiment of the invention, Figure 32 is in the outside drawing of the portable terminal device of open mode.

Figure 33 is the curve map of the analog variation of expression Hy and Hz value.

Embodiment

Below, embodiments of the invention will be described with reference to the drawings.

As shown in Figure 2, the portable phone with structure shown in Fig. 1 comprises the lid 1 with operating key etc., and the lid 2 with LCDs part.The lid 1 and lid 2 skeleton views that are in open mode under of Fig. 2 (a) for being illustrated in portable phone, Fig. 2 (b) covers 2 o'clock front elevation for the lid 1 at portable phone is in to watch under the closure state with lid 2, Fig. 2 (c) under equal state, watch cover 1 with the side view that covers at 2 o'clock, and Fig. 2 (d) covers 1 o'clock rear view for watching under equal state.Shown in Fig. 2 (a), suppose to exist along lid 1 than the X-axis of minor face with along the Y-axis of covering 1 longer sides.Should be noted that X-axis is perpendicular to one another with Y-axis.

At this, each surface of each lid of portable phone is defined as follows.Particularly, the surface with lid 1 of operating key etc. is defined as operating surface, is defined as the back side with the operating surface opposite surfaces.On the other hand, the surface that is provided with LCDs part 18a in the surface of lid 2 is defined as main display surface, is defined as the front with main display surface opposite surfaces.

As shown in Figure 1, portable phone comprises RF (radio frequency) antenna 8, control section 10 (control device), ROM (ROM (read-only memory)) 12, RAM (random access memory) 14 (data storage, memory storage), display part 18a and 18b, key input part 20, switch 21, modem portion 22, CDMA (CDMA) part 23, RF part 24, microphone 27, receive loudspeaker 28, acoustic processing part 29, geomagnetic sensor 30, GPS (GPS) receiving unit 71, gps antenna 72, be used to detect the acceleration transducer 80 of the acceleration that is applied to portable phone, and bus 90.

Control section 10 is controlled the various piece of portable phone by carrying out telephony feature program and other program.In addition, control section 10 receives the measurement data of geomagnetic sensor 30, and computer azimuth (bearing data treating apparatus).Various telephony feature programs and the control program carried out by control section 10 when in ROM 12, being stored in emission or reception, and other various fixed datas.In RAM 14, set the workspace be used for temporarily being stored in control section employed data of 10 operating period etc. or similar zone.

The machine readable media of ROM 12 in mobile information terminal apparatus, using, this mobile information terminal apparatus has: be included in CPU and geomagnetic sensor 31-38 in the control section 10, this geomagnetic sensor 31-38 has the magnetic sensitivity of terrestrial magnetic field on a plurality of axle of coordinate system and influenced by magnetization and cause magnetic biasing.The medium of ROM 12 forms comprises can be by the programmed instruction of CPU execution, and this programmed instruction makes this mobile information terminal apparatus carry out the method for measuring magnetic offset of geomagnetic sensor.Below this method is described in detail.

24 pairs of signals that receive by RF antenna 8 or the like of RF part are carried out frequency conversion.The output signal of 22 pairs of RF parts 24 of modem portion is carried out demodulation, and this restituted signal is outputed in the CDMA part 23.CDMA part 23 is carried out spread spectrum (spread-spectrum) or despreading as follows.Particularly, CDMA part 23 was carried out despreading with the extraction signal to the output signal of modem portion 22 before spread spectrum, and this signal is outputed in the acoustic processing part 29.On the other hand, the output signal of 23 pairs of acoustic processing parts 29 of CDMA part is carried out spread spectrum, and spread-spectrum signal is outputed in the modem portion 22.Modem portion 22 receives from CDMA part 23 and will send to outside signal and modulate, and the signal after will modulating then outputs in the RF part 24.Then, 24 pairs of these signals of RF part are carried out frequency conversion, and the signal after the 8 emission frequency conversions of RF antenna.

Shown in Fig. 2 (a), key input part 20 has the initiating key 3 that uses, the end key 4 that uses, comprises ten keys 5 of numerical key and code key, heavily pulls out key 7 and switch 21 when terminated call when receipt of call.

The character information of the mail of being write when display part 18a and 18b are designed to show send Email, comprise the various data of various menu contents etc., and their further detailed contents or the like.Display part 18a is arranged on and covers on 1 the operating surface, and display part 18b is arranged on and covers on 2 the front.

Acoustic processing part 29 is by comprising the coded portion (CODER scrambler) as code device and forming as the decoding of code translator part (DECODER code translator), it is deciphered the voice signal of exporting from CDMA part 23, and decoded signal is outputed on the reception loudspeaker.On the other hand, 29 pairs of voice signals that are used to transmit from microphone 27 inputs of acoustic processing part compress and encode, and the signal that will be compressed and be encoded outputs on the CDMA part 23.

GPS receiving unit 71 receives from constituting the next signal of a plurality of gps satellite emissions of GPS by connected gps antenna 72, the signal from gps satellite that receives is carried out demodulation, calculate by the current location of navigator deriving its positional information (latitude and longitude) according to this restituted signal, and this information is outputed in the control section 10.The processing of this calculating current location and orthodox car navigational system or the computing of similarly carrying out in the system are identical.

As shown in Figure 3, geomagnetic sensor 30 comprises: Si (silicon) substrate 30a, it is formed with LSI (large scale integrated circuit), and this substrate 30a has each edge X-axis and the mutually perpendicular square shape of Y-axis, and perpendicular to the less thickness that has on the Z-direction of X-axis and Y-axis; Eight GMR (giant magnetoresistance) element 31 to 38 altogether, and it is formed on the substrate 30a; Initialization coil 41 to 48 is used for respectively GMR element 31 to 38 being applied initialization magnetic field; And driving circuit 51 to 58, it is connected respectively on the coil 41 to 48, and in the driving circuit 51 to 58 each is used to apply predetermined voltage to one of them two ends of corresponding coil 41 to 48.The temperature sensor 60 that should be noted that the temperature that is used to monitor geomagnetic sensor 30 also is set at substrate 30a.

Forming the first X-direction GMR element 31 with respect to the downside of the center section of the Y direction of substrate 30a and the position of contiguous X-axis negative direction end, this element 31 has the be fixed fixed bed (bolt layer) of (anchoring) of direction of magnetization, wherein is the negative direction of X-axis by the direction of magnetization of anchoring.Forming the second X-direction GMR element 32, wherein be the negative direction of X-axis by the direction of magnetization of anchoring with respect to the upside of the center section of the Y direction of substrate 30a and the position of contiguous X-axis negative direction end.Forming the 3rd X-direction GMR element 33 with respect to the upside of the center section of the Y direction of substrate 30a and the position of contiguous X-axis positive dirction end, is the positive dirction of X-axis by the direction of magnetization of anchoring on the bolt layer wherein.Forming the 4th X-direction GMR element 34 with respect to the downside of the center section of the Y direction of substrate 30a and the position of contiguous X-axis positive dirction end, is the positive dirction of X-axis by the direction of magnetization of anchoring on the bolt layer wherein.

On the other hand, forming the first Y direction GMR element 35 with respect to the left side of the center section of the X-direction of substrate 30a and the position of contiguous Y-axis positive dirction end, is the positive dirction of Y-axis by the direction of magnetization of anchoring on the bolt layer wherein.Forming the second Y direction GMR element 36 with respect to the right side of the center section of the X-direction of substrate 30a and the position of contiguous Y-axis positive dirction end, is the positive dirction of Y-axis by the direction of magnetization of anchoring on the bolt layer wherein.Forming the 3rd Y direction GMR element 37 with respect to the right side of the center section of the X-direction of substrate 30a and the position of contiguous Y-axis negative direction end, is the negative direction of Y-axis by the direction of magnetization of anchoring on the bolt layer wherein.Forming the 4th Y direction GMR element 38 with respect to the left side of the center section of the X-direction of substrate 30a and the position of contiguous Y-axis negative direction end, is the negative direction of Y-axis by the direction of magnetization of anchoring on the bolt layer wherein.

Except in the arranged direction on the substrate 30a with the position is different, GMR element 31 to 38 all has identical structure.Therefore, will be described as representational example with the first X-direction GMR element 31 below.

As illustrated in Figures 5 and 6, first directions X GMR element 31 shown in Figure 4 comprises: a plurality of shaped like narrow part 31a ... (each 31a forms by stopcock film SV 31a, and on Y direction, has a length direction), and magnetic bias film (rigid ferromagnet thin layer) 31b ... 31b (forms 31b below two ends on the Y direction of each shaped like narrow part 31a, this magnetic bias film 31b is made by such material: for rigid ferromagnetic material and have high-coercive force and high squareness ratio, such as cobalt (Co), chromium (Cr), platinum (Pt) etc.).Each shaped like narrow part 31a extends on the X-direction of the upper surface of magnetic bias film 31b, engages with the shaped like narrow part 31a with vicinity.

The stopcock film SV (its membrane structure is shown among Fig. 7) of the first X-direction GMR element 31 is formed by following each layer, promptly comprises: free layer (free layer, free magnetization layer) F, by copper (Cu) make and have 2.4nm (

) conduction interval layer S, the bolt layer P of film thickness, and by titanium (Ti) or tantalum (Ta) make and have 2.5nm (

) the overlayer C of film thickness, each layer is layered on the substrate 30a by specified order.

Free layer F is the layer that the direction of external magnetic field is depended in the change of direction of magnetization, and it is made of following each layer: the unbodied magnetosphere 31-1 of cobalt (Co) zirconium (Zr) niobium (Nb), its have 8nm (

) film thickness and being formed directly on the substrate 30a; Nickel (Ni) iron (Fe) magnetosphere 31-2, its have 3.3nm ( ) film thickness and being formed on the unbodied magnetosphere 31-1 of CoZrNb; And CoFe layer 31-3, its have about 1 to 3nm (10 to

) film thickness and being formed on the NiFe magnetosphere 31-2.Unbodied magnetosphere 31-1 of CoZrNb and NiFe magnetosphere 31-2 form above-mentioned soft ferromagnetic thin layer.CoFe layer 31-3 is in order to the diffusion of the Cu 31-4 of the Ni that prevents Ni Fe layer 31-2 and wall S.Should be noted that in order to keep the uniaxial anisotropy of free layer F, magnetic bias film 31b ... 31b goes up in Y direction (representing the Y-axis negative direction by the width arrow in the Figure 4 and 5) free layer F is applied bias magnetic field.

Bolt layer P by have 2.2nm (

) film thickness CoFe magnetosphere 31-5 and by Pt manganese (Mn) alloy of the Pt that comprises 45 to 55 moles of % make and have 24nm (

) the antiferromagnetism film 31-6 of film thickness constitutes, they are laminated in together.CoFe magnetosphere 31-5 is reverse in the exchange mode by magnetized antiferromagnetism film 31-6, so that its direction of magnetization is by the negative direction of anchoring in X-axis.

The first X-direction GMR element 31 with this spline structure, represent as solid line among Fig. 8, show at-Hc and be proportional to the resistance value that changes along external magnetic field that X-axis changes in the scope of+Hc basically, represent as dotted line among Fig. 8 simultaneously, show the resistance value of substantial constant with respect to the external magnetic field that changes along Y-axis.

As shown in Figure 9, in geomagnetic sensor 30, by the X-direction geomagnetic sensor that first to the 4th X-direction GMR element, 31 to 34 full-bridges are linked together and are formed for detecting magnetic field on the X-direction.In Fig. 9, on the GMR element 31 to 34 arrow of mark represent respectively on the bolt layer of GMR element 31 to 34 by the anchoring direction of magnetization.In this structure, apply constant potential difference (PD) by the node Vb between the node Va between the second X-direction GMR element 32 and the 3rd X-direction GMR element 33 and the first X-direction GMR element 31 and the 4th X-direction GMR element 34, so that the potential difference (PD) (Vc-Vd) between the node Vd between the node Vc between the first X-direction GMR element 31 and the 3rd X-direction GMR element 33 and the second X-direction GMR element 31 and the 4th X-direction GMR element 34 is taken out as sensor output Vout.

Therefore, the X-direction geomagnetic sensor demonstrates: represent that as solid line among Figure 10 output voltage V xout is proportional to the external magnetic field that changes along X-axis at-Hc basically to the variation in the scope of+Hc; Demonstrate simultaneously: represent that as dotted line among Figure 10 with respect to the external magnetic field that changes along Y-axis, output voltage is essentially " 0 ".

As the X-direction geomagnetic sensor, by being linked together, first to the 4th Y direction GMR element, 35 to 39 full-bridges form the Y direction geomagnetic sensor, it demonstrates: in the scope of+Hc, output voltage V yout is proportional to the external magnetic field that changes along Y-axis basically at-Hc; Demonstrate simultaneously: with respect to the external magnetic field that changes along X-axis, output voltage is essentially " 0 ".As mentioned above, geomagnetic sensor 30 detects the external magnetic field.Should be noted that the temperature information that obtains according to temperature sensor 60, geomagnetic sensor 30 is carried out the temperature compensation of magnetic characteristic by using not shown temperature-compensation circuit.

Next, with the description that provides about the bearing measuring method principle, the bearing data treating apparatus of this method by portable phone carries out, and the operating surface of supposing this portable phone is placed on the substantial horizontal state and the external magnetic field that is applied on the geomagnetic sensor 30 only is an earth magnetism.At this, under the situation of the operating surface basic horizontal of the lid 1 of this portable phone, the vectorial orientation at center, coupling part is represented to point to from this end parts (for example microphone 27) of the operating surface of this portable phone in the position angle of supposing this portable phone, for example points to the vector of Y-axis positive dirction.In this manual, azimuthal benchmark (0 °) is defined as the west, and when rotating to north, east, and during south, the position angle becomes 90 °, 180 ° and 270 ° respectively by named order.

Incidentally, earth magnetism is the magnetic field from southern energized north.Therefore, when the operating surface of the lid 1 of portable phone is level substantially, with respect to the position angle of as shown in Figure 11 portable phone 10, the X-direction geomagnetic sensor of geomagnetic sensor 30 and the output of Y direction geomagnetic sensor change with cosine wave (CW) mode and sinusoidal wave mode respectively.Suppose that sensor output Sx among Figure 11 and Sy are by standardization.This be standardized as by with the actual output of X-direction geomagnetic sensor divided by the maximal value of X-direction geomagnetic sensor output and 1/2 acquisition result of calculation of the difference of minimum value, after standardization, this result of calculation is set at output Sx, wherein, the maximal value of X-direction geomagnetic sensor output and minimum value are acquisitions during with 360 ° of its rotations when the operating surface of the lid 1 of portable phone is in horizontality substantially.Similarly, this is standardized as by the actual output of Y direction geomagnetic sensor is obtained result of calculation divided by 1/2 of difference between the maximal value of Y direction geomagnetic sensor output and the minimum value, after standardization, this result of calculation is set at output Sy, the maximal value of Y direction geomagnetic sensor output and minimum value are when the operating surface of the lid 1 of portable phone is in horizontality substantially, obtain when it is rotated 360 °.

From as can be known above-mentioned,, can derive the position angle of portable phone based on the classification of following situation (a) to (d).

(a) when determine corresponding to Sx and Sy Sx＞0 and | Sx|＞| during Sy|, position angle=tan ^-1(Sy/Sx).

(b) when definite Sx＜0 and | Sx|＞| during Sy|, position angle=180 °+tan ^-1(Sy/Sx).

(c) when definite Sy＞0 and | Sx|＜| during Sy|, position angle=90 °-tan ^-1(Sx/Sy).

(d) when definite Sy＜0 and | Sx|＜| during Sy|, position angle=270 °-tan ^-1(Sx/Sy).

Should be noted that when the position angle of deriving by above-mentioned (a) any situation in (d) when negative, will be by adding that 360 ° of values that obtained are set at the position angle to a position angle of deriving.On the other hand, when the position angle of deriving is 360 ° or when bigger, will be set at the position angle by from the position angle of deriving, deducting 360 ° of values that obtained.

Yet, as mentioned above, in portable phone, comprise with loudspeaker 28 being many permanent magnet elements of representative, and from these elements, leak out magnetic field.Therefore, the leakage field (external magnetic field except earth magnetism) that is produced by these permanent magnet elements can be applied on the geomagnetic sensor 30 that is arranged on precalculated position in the portable phone.As a result, (parallel motion) output corresponding to leakage field X-axis component is moved in the output of X-direction geomagnetic sensor, and the output corresponding to leakage field Y-axis component is moved in the output of same Y direction geomagnetic sensor.This output is moved and is called skew, and will be on X-direction and Y direction separately amount of movement be set at off-set value.Therefore,, be necessary these output is proofreaied and correct, for example from the output valve of X-axis and Y-axis, deduct above-mentioned off-set value respectively in order in portable phone, to measure correct orientation.At this, as mentioned above, because off-set value is based on the caused influence of the soft ferromagnetic that is arranged on portable phone inside, so, be necessary truly each point to be measured and judged its validity at this.

Next, be given in the bearing data treating apparatus when earth magnetism and leakage field are applied on the geomagnetic sensor 30 as the external magnetic field, about the description of the method principle that is used to as mentioned above estimate off-set value and judge its validity.

The design portable phone makes and can measure external magnetic with predetermined time interval like this.Then, as shown in figure 12, portable phone is (as the plane that comprises X-axis and Y-axis magnetic sensitive direction) swing on single plane, for example surface level; And between shaking peroid, carry out the measurement of external magnetic field, thereby judge the validity of the off-set value of estimation according to measurement data at a plurality of measurement points.

At this, suppose that the off-set value that will derive is X ₀And Y ₀, and be R by the radius of the compass circle drawn from the value of geomagnetic sensor 30 output, then determine following relation.

(X-X ₀) ²+(Y-Y ₀) ²＝R ²

∴R ²-X ₀ ²-Y ₀ ²+2XX ₀+2YY ₀＝X ²+Y ²

(formula 11)

And the external magnetic field of measuring at measurement point is designated as coordinate figure (Xi, Yi) (i=1,2,3 ..., N), and least squares error ε is defined as follows.Then, derive the initial point of the compass circle of geomagnetic sensor 30, thereby estimate off-set value (offset estimation step) (offset estimation device) by the least square method (making least squares error ε minimum) of utilizing the coordinates computed value.

[expression formula 1]

ε＝∑{(X _i-X ₀) ²+(Y _i-Y ₀) ²-R ²} ²

=∑ { (X _i ²+ Y _i ²)-2X _iX ₀-2Y _iY ₀+ (X ₀ ²+ Y ₀ ²)-R ²} ²(formula 12)

At this, provide a _i=(X _i ²+ Y _i ²), b _i=-2X _i, c _i=-2Y _i, and D=(X ₀ ²+ Y ₀ ²)-R ², obtain [expression formula 2].

[expression formula 2]

ε=∑ (a _i+ b _iX ₀+ c _iY ₀+ D) ²(formula 13)

The condition that makes least squares error ε minimum is by using variable X ₀, Y ₀, D differentiates to ε and obtains, and represented by [expression formula 3].At this, calculate for simplifying, with variable X 0, Y0 and D are considered as the independent variable of ε.

[expression formula 3]

By finding the solution following equation to (formula 16), derive off-set value X0 and Y0 according to (formula 14).(X0 Y0) becomes the initial point (center) of compass circle to the coordinate that obtains from value X0 and Y0.

[expression formula 4]

$\left[\begin{array}{ccc}\left[\mathrm{bb}\right]& \left[\mathrm{bc}\right]& \left[b\right]\\ \left[\mathrm{bc}\right]& \left[\mathrm{cc}\right]& \left[c\right]\\ \left[b\right]& \left[c\right]& N\end{array}\right]\left[\begin{array}{c}X0\\ Y0\\ D\end{array}\right]=\left[\begin{array}{c}-\left[\mathrm{ab}\right]\\ -\left[\mathrm{ac}\right]\\ -\left[a\right]\end{array}\right]$ (formula 17)

Wherein provide [expression formula 5]

$\left[k\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{k}_i.$ $\left[k1\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{k}_i{1}_i$ (formula 18)

Next, will provide about from each measured value m _iWith each measured value m _iMean value A derive the method for standard deviation.Value m _iRepresent each coordinate figure in the coordinate system (Xi, Yi) (i=1,2,3 ..., N) with the initial point (X of compass circle ₀, Y ₀) between distance, (Xi Yi) is illustrated in the external magnetic field data that each measurement point is measured to this each coordinate figure.This method comprises the following steps: mean value calculation step and standard deviation calculation step.This standard deviation is by following formulate.

[expression formula 6]

$=\sqrt{\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}({m_i}^2-2A{m}_i+A^2)}$

$=\sqrt{\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m_i}^2-\frac{2A}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i+A^2}$

[expression formula 7]

$A=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i$

At this, final owing to [expression formula 7] obtains [expression formula 8].

[expression formula 8]

$=\sqrt{\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m_i}^2-{\left(\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i\right)}^2}$

$=\sqrt{\frac{N\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m_i}^2-{\left(\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i\right)}^2}{N^2}}$ (formula 19)

Estimate in the method for off-set value validity in the judgement of present embodiment, because each measured value m _iProvide by [expressing 9], so the validity of estimation off-set value is to judge by radius (deriving by using the estimation off-set value) and the measurement data of utilizing compass circle, shown in (formula 21) of following note (judgment means).

[expression formula 9]

$m_i=\sqrt{{(X_i-X_0)}^2+{(Y_i-Y_0)}^2}$ (formula 20)

[expression formula 10]

(formula 21)

Next, with the method (validity determining step) (validity judgment means) that provides about the validity of judging the off-set value of estimating by said method.

As mentioned above, if most measurement data is different to a great extent with respect to the mean radius that distributes according to each measurement data that forms compass circle by geomagnetic sensor 30 output, so measurement data be judged as invalid.Therefore, the validity of measurement data is judged based on following formula.

σ＜F ... (formula 22)

In this case, because the normal specification that requires of geomagnetic sensor is to distinguish 16 orientation, so be necessary to make the error of off-set value to be not more than amount corresponding to earth magnetism 1/5.Therefore, if because be under the situation of 2 σ within 1/5 scope of error at earth magnetism at the radius of compass circle, this error judgment is acceptable so, so F as noted above is preferably the amount corresponding to 0.030e (Austria), promptly equals the quantity of magnetism of 1/10 earth magnetism.

Next, will provide about description according to the offset calibration operation of the performed geomagnetic sensor 30 of the bearing data treating apparatus of the portable phone of present embodiment.This calibration steps comprises the steps, promptly, measurement may cause the magnetic field that mix in the external magnetic field of change skew by pure land magnetic field and other, based on the measurement data in magnetic field, calculate the off-set value of this change skew, and by sampling and measuring data repeatedly and calculate off-set value and upgrade previous off-set value based on new off-set value.

At first, open the power supply of portable phone so that start the operation of portable phone.Below, will be with reference to the operation of the offset calibration of the geomagnetic sensor 30 of the flow chart description portable phone shown in Figure 13.Suppose that the off-set value that previous operation obtains is stored among the RAM 14.

At first, the calibration start button (triggering key) that is used to specify the calibration of skew in the portable phone turn on (step Sa1) that is opened is so that control section 10 order geomagnetic sensors 30 are measured external magnetic (step Sa2).Then, control section 10 reads measurement data (step Sa3) and with data storage (step Sa4) to RAM 14 from geomagnetic sensor 30.Then, judge by control section 10 whether the data number that is stored among the RAM 14 has reached predetermined number.If judged result is " NO ", because the data number that is stored among the RAM 14 does not also reach predetermined number, so wait for 0.1 second (step Sa6) afterwards control section 10 make flow process turn back to step Sa2, to repeat the operation (data storage device) of later step Sa2 to Sa5.

On the other hand, when the judged result in step Sa5 was " YES ", flow process proceeded to step Sa7, control section 10 estimation off-set values in step Sa7.Whether effectively then, control section 10 calculates above-mentioned standard deviation, and judge this estimation off-set value (step Sa8) (validity determining step) (validity judgment means).If judged result is " YES ", under the control of control section 10, this off-set value is stored in (step Sa9) among the RAM 14 (offset storage device) so.Should be noted that under the control of control section 10, the off-set value that before was stored among the RAM 14 is updated to the off-set value that calculates in step Sa9.Then, finish the offset calibration operation of the geomagnetic sensor 30 of portable phone.On the other hand, when judged result is " NO " in step Sa8, finish the offset calibration operation of the geomagnetic sensor 30 of portable phone, and need not to update stored in the off-set value among the RAM 14.In this case, formerly upgrade in the calibration operation and the off-set value that is kept among the RAM 14 is used directly as off-set value according to present appearance.

As mentioned above, according to present embodiment, need not just can be by the offset calibration of shirtsleeve operation place of execution Magnetic Sensor with reference to detailed service manual, and wherein whether portable phone judges offset calibration success, so that only when carrying out suitable calibration, can upgrade off-set value.Therefore, can utilize simple operations and still carry out the correction of measurement data reliably.

In the present embodiment, adopt the diaxon geomagnetic sensor, even but by using three geomagnetic sensors also can realize similar operation as geomagnetic sensor.Since it is so, under the situation of diaxon, can realize calibration by portable phone is swung left and to the right in the plane that comprises two sensitive direction, simultaneously, under three situation, as shown in figure 14, also can by with portable phone in the plane that comprises three both directions in the sensitive direction swing left and to the right and further up and down (forward and backward) swing realize calibration.

As shown in figure 15, under the situation of this specific position relation when portable phone is placed on paper, earth magnetism points to the horizontal direction of paper, even by with portable phone up and down during (forward and backward) (just on the direction perpendicular to paper) swing, the relativeness between geomagnetic sensor and the earth magnetism does not change yet.In this case, can calibrate by portable phone is swung on other direction.

On the other hand, as shown in figure 16, under the situation of diaxon geomagnetic sensor, even when carrying out above-mentioned calibration, if earth magnetism vertically points to paper, even pass through as shown oscillation gauge like that so, the relativeness between geomagnetic sensor and the earth magnetism does not change yet.Yet equally in this case, when Magnetic Sensor output radius was zero compass circle potentially, skew can be through arithmetic processing and is correctly derived.

In addition, in the present embodiment, adopt the GMR element as geomagnetic sensor.Yet, the type of geomagnetic sensor is not limited thereto, and can be for such as any kinds such as magneto-resistance effect elements, all (tunnel magnetoresistive) elements of TMR in this way of this magneto-resistance effect element or MR (permanent magnetism resistance) element, Hall element, MI (magnetoimpedance) element, or magnetic flux transducer etc.

Especially, under the element situation as Hall element (showing marked change on the characteristic owing to temperature), it can be used in the offset variation that correction is caused by temperature.On the other hand, under the element situation as the MI element that is magnetized easily, it is effective as the method for eliminating because of the caused influence of magnetization of this element itself.

Next, second embodiment of the present invention will be described.

Identical among the modular construction of the portable phone in this second embodiment and first embodiment, but the offset calibration of control section 10 is handled and is different among first embodiment.Below, present embodiment is described with reference to the drawings.

As shown in figure 17, carry out the processing of step Sb1 and Sb2.This processing is identical with the processing of step Sa1 shown in Figure 13 and Sa2.Then, control section 10 reads measurement data from geomagnetic sensor 30, after this, further reads measurement data (step Sb3) (data fetch device) after with predetermined anglec of rotation motion.Then, by judging in step Sb3 whether the distance between the current data and past data surpasses preset distance in coordinate system, judge whether current data should be stored in (step Sb4) among the RAM 14 (data storage judgment means), this past data for from geomagnetic sensor 30 be stored among the RAM 14 in previous sampling.Will be described later the method that is used for this judgement.When judged result was " YES ", flow process entered into step Sb5, current data was stored into (step Sb6) (data storage device) among the RAM 14 in step Sb5.Then, judge whether the data number that is stored among the RAM 14 has reached predetermined number.If judged result is " NO ", because the data number that is stored among the RAM 14 does not also reach predetermined number, so waiting for 0.1 second (step Sb7) afterwards, flow process turns back to step Sb2, to repeat subsequently step Sb2 to the operation of Sb6.

On the other hand, when judged result was " NO " in step Sb4, flow process entered into step Sb7, and after waiting for 0.1 second, turned back to step Sb2, to repeat subsequently step Sb2 to the operation of Sb6.

On the other hand, when judged result was " YES " in step Sb6, flow process entered into step Sb8, and execution in step Sb8 is to the processing of Sb10.This processing is identical to the processing of Sa9 with step Sa7 shown in Figure 13.Through above-mentioned processing, finish the offset calibration operation of the geomagnetic sensor 30 of portable phone.

Next, will provide about judge among the step Sb4 whether the data that read from geomagnetic sensor 30 are the descriptions that store the method for the data the RAM 14 in step Sb3.At this, suppose that the data that will store through judgement are X, Y, and the data that stored among the RAM 14 are X before being right after acquisition data X, Y _p, Y _p, only when satisfying following condition, just data X, Y are stored among the RAM 14.

[expression formula 11]

$d<\sqrt{{(X_p-X)}^2+{(Y_P-Y)}^2}$ (formula 23)

As mentioned above, according to present embodiment, can avoid following problem.Particularly, can avoid such problem: in first embodiment, when in the mobile hardly portable phone of user, obtaining data data be concentrated in certain a bit near, perhaps the user to move the speed of portable phone be not at the uniform velocity so that density data become inhomogeneous.

At this, when measurement range was 90 ° (anglec of rotation of geomagnetic sensor), the measurement point number was preferably 20 or more, and therefore, the required distance in coordinate system between the measurement point is less than 1/10 of the compass circle radius.In view of the foregoing, can be provided with: do not carry out from the processing of geomagnetic sensor 30 reading of data with each specified time interval, but by so that the distance between the measurement point less than 1/10 of the compass circle radius such anglec of rotation rotatably Magnetic Sensor 30 carry out.

Next, the third embodiment of the present invention will be described.

The modular construction of the portable phone in the 3rd embodiment is identical with modular construction among first or second embodiment, but the offset calibration of control section 10 to handle be the combination of first and second embodiment.Below, this embodiment will be described.Should be noted that process flow diagram is Figure 13 and 17 combines, and omit its explanation.

In this case, step Sa2 among Figure 13 handles to the processing of Sb7 is parallel to processing and the step Sb2 among Figure 17 of Sa6, and, carry out the offset estimation in step Sa7 or Sb8 when one of them is stored in data among the RAM 14 when outnumbering predetermined number by above-mentioned processing.With regard to predetermined number, be necessary and be set at greater than data number by the data number of handling among Figure 13 by handling among Figure 17.For example, preferably the former is set at 10 times of the latter.

As mentioned above, according to present embodiment, can avoid following problem.Particularly, can avoid such problem: promptly, in a second embodiment, as shown in figure 16, when the portable phone with diaxon geomagnetic sensor is swung perpendicular to earth magnetism, because the variation of the measured value of geomagnetic sensor can't surpass certain value, so can not detect the swing of this portable phone, consequently no matter through the time how long, data are not stored among the RAM 14 yet.

Next, the fourth embodiment of the present invention will be described.

Similar among the structure of block diagram of the portable phone among the 4th embodiment (Figure 18) and the operation and first to the 3rd embodiment, but increased inclination sensor 81 as parts.In addition, the offset calibration of control section 10 handle with second embodiment in have part different.Below, will be described present embodiment with reference to the accompanying drawings.

As shown in figure 19, the portable phone according to present embodiment is equipped with inclination sensor 81.An example as inclination sensor 81, for example can be, it is fixing and have with a certain interval fixed electorde respect to one another and movable electrode that the variable displacement type sensor closes on geomagnetic sensor 30, wherein when inclination sensor 81 tilted, the interval variation between movable electrode and the fixed electorde was so that form the capacitance that therefore changes.

Next, with reference to process flow diagram shown in Figure 20 calibration operation according to geomagnetic sensor 30 magnetic biasing of the portable phone of present embodiment is described.Because the step in the offset calibration of the geomagnetic sensor 30 of the portable phone operation in the present embodiment except step Sc3 (promptly, step Sc1 and Sc2 and step Sc4 are to Sc10), all with second embodiment in step Sb1 and Sb2 and step Sb4 identical to Sb10, so only difference is described.

Particularly, in step Sc3, control section 10 not only read by the testing result of geomagnetic sensor 30 for earth magnetism with the constant time interval, and read by inclination sensor 81 for the testing result that tilts.Calculate current angle of inclination data and poor by between the previous previous angle of inclination data that detect of inclination sensor 31.If the difference that calculates surpasses predetermined poor, the current measurement data with earth magnetism is input among the RAM 14 so.

As mentioned above, according to present embodiment, can avoid following problem.Particularly, except the situation of the vertical directed towards ground of earth magnetism, can avoid such problem by the swing that utilizes inclination sensor 81 identification portable phones: promptly, in a second embodiment, when the portable phone with diaxon geomagnetic sensor is swung perpendicular to earth magnetism, because the variation of the measured value of geomagnetic sensor does not surpass a certain value,, no matter make through how long data can not store among the RAM 14 yet like this so can not detect the swing of this portable phone.In addition, can make packing density in the user swings the scope of portable phone evenly, and need not to depend on the speed that the user swings portable phone.Moreover the testing result of inclination sensor 81 can be used in the correction at inclination angle in the orientation demonstration.

In the present embodiment, the variable displacement type sensor is as inclination sensor 81.Yet the type of inclination sensor is not limited thereto, and it can be any kind.

In addition, when judging that the skew of estimating is invalid, display part 18a or 18b can be set show such result.

In addition, can be arranged on the skew that shows estimation be judged as invalid after, just can carry out offset calibration once more by the special keys operation.

When carrying out offset calibration once more, it is desirable to new measurement data and compare mutually with the measurement data that is stored among the RAM14, and only with suitable data storage in RAM 14.For example, it is desirable to derive distance and the off-set value between off-set value and the new measurement data and be stored in distance between the measurement data among the RAM 14, and will have data storage near the distance of compass circle mean radius in RAM 14.

Though be described in detail with reference to the attached drawings first to the 4th embodiment of the present invention above, concrete structure is not limited to these embodiment, and is also included within the design variation within the scope that does not break away from main idea of the present invention.

Below, referring to figs. 22 to 31 additional embodiments of the present invention is described.Figure 22 illustrates the electronic structure block diagram according to the portable mobile terminal (hereinafter referred to as portable terminal device) of CDMA (CDMA) communication system, and it is an embodiment with portable electronic equipment of direction detection function of the present invention.Hereinafter, specified same numeral for those shared parts of each reference diagram.

The portable terminal device 1 of present embodiment has the so-called accordion structure that comprises two casings (terminal unit-1 and terminal unit-2).Particularly, these two casings are connected to each other by unshowned coupling part, so that can open and close terminal unit-1 and terminal unit-2 with respect to the turning axle of this coupling part.Folding mobile terminal comprises common folded form and so-called rotary-type: in common folded form, be from these two states that the unit overlaps each other, these two unit are opened perpendicular to the principal plane (plane that terminal unit under closure state-1 and terminal unit-2 overlap each other) of portable terminal device, and be further rotated with respect to turning axle by this way; In rotary-type, terminal unit-1 and terminal unit-2 is parallel to the principal plane rotation of portable terminal device so that with they open and closes.In the present embodiment, although when special distinguish common can distinguish when collapsible and rotary-type they two,, stipulate that here rotary-type portable terminal device is also included within the Foldable portable terminal.

Next, will the electronic structure of the portable terminal device 1 of present embodiment be described.

Antenna 101 shown in Figure 22 is carried out the radiowave that transmits and receives corresponding to unshowned radio base station.RF part 102 is carried out the processing relevant with reception with the emission of signal.RF part 102 has local oscillator or the like.When receiving, RF part 102 is mixed the local oscillation signal of preset frequency with the received signal of exporting from antenna 101, thereby received signal is converted to the reception IF signal of intermediate frequency (IF), and this signal is outputed in the modem portion 103.On the other hand, in when emission, RF part 102 is mixed the local oscillation signal of preset frequency with the emission IF signal of intermediate frequency, be transmitting of transmission frequency thereby will launch the IF conversion of signals, and this is transmitted outputs to antenna 101.

Modem portion 103 is carried out demodulation process to received signal and the signal that will launch is carried out modulation treatment.Modem portion 103 has local oscillator etc., and it will be the baseband signal of preset frequency from the reception IF conversion of signals of RF part 102 outputs, again this baseband signal is converted to digital signal, and it is outputed in the CDMA part 104.On the other hand, modem portion 103 will be converted to simulating signal from the emission digital baseband signal of CDMA part 104 outputs, be the emission IF signal of preset frequency with this analog signal conversion again, and it is outputed in the RF part 102.

The signal that 104 pairs of CDMA parts will be launched is carried out encoding process and is carried out decoding to received signal and handle.104 pairs of baseband signals from modem portion 103 outputs of CDMA part are deciphered.On the other hand, 104 pairs of CDMA parts transmit encode and with the coding baseband signal output in the modem portion 103.

Acoustic processing part 105 is carried out the processing relevant with sound when conversation.When conversation, acoustic processing part 105 will be converted to digital signal from the analoging sound signal of microphone (MIC) output, and it is outputed in the CDMA part 104 as transmitting.On the other hand, when conversation, according to the indicator signal of the voice data of deciphering by CDMA part 104, acoustic processing part 105 produces and is used for driving the analog drive signal of loudspeaker (SP) and it is outputed to loudspeaker (SP).Based on the sound of user's input, microphone (MIC) produces voice signal and it is outputed in the acoustic processing part 105.Based on the signal from 105 outputs of acoustic processing part, loudspeaker (SP) sends the sound of partner.

Gps antenna 106 receives from the radiowave of each unshowned gps satellite emission, and based on this radiowave received signal is outputed in the GPS receiving unit 107.107 pairs of these received signals of GPS receiving unit are carried out demodulation, and obtain the correct time information of gps satellite and such as the information such as travel-time of radiowave based on this received signal.According to the information that obtains, GPS receiving unit 107 calculates the distance of three or more gps satellites, and according to principle of triangulation, calculates the position (longitude, latitude, height etc.) in three dimensions.

Main control part 108 is formed by CPU (central processing unit) or the like, and the various piece of control portable terminal device 1 inside.Main control part 108 is carried out with respect to RF part 102, modem portion 103, CDMA part 104, acoustic processing part 105, GPS receiving unit 107, sensing data by bus and is obtained part 201 (being described below), ROM 109, and the I/O of the control signal of RAM 110 or data.ROM 109 wherein stores the various programs of being carried out by main control part 108, the temperature sensor that records and the initial performance values of inclination sensor when the shipment check.The data that RAM 110 interim storage main control parts 108 are handled etc.

ROM 109 is a kind of machine readable media that uses in the portable electronic equipment 1 with CPU, geomagnetic sensor and collapsible body, leakage field is handled and produced to this folded formation by opening operation and closed procedure.This machine readable media is made up of ROM 109, and this ROM 109 comprises the usefulness of CPU execution so that portable electronic equipment 1 is carried out the measurement of bearing program that measurement of bearing is handled, and it will be described in detail later.

For example, aviso device 111 comprises loudspeaker, Vib., light emitting diode etc., and by using sound, vibration, light or similar method circular user to receive calling, receives mail or the like.Timer section 112 has the clocking information of clocking capability and generation such as year, month, day, week, time etc.The shift key that main operation part 113 comprises the enter key that is used for input character, be used for changing between Chinese character, numeral etc., be used for operational light target cursor key, electric power on/off key, assignment key, heavily pull out key etc., and the signal of output expression user operating result is to main control part 108.Opened/closed switch (SW) the 114th is used to detect the switch of opening (opening operation) beginning and closed (closed procedure) end of Foldable portable terminal.

Sensing data obtains part 201 and comprises: the Magnetic Sensor (1) that is used for detecting respectively magnetic force (magnetic field) on the X-axis that is perpendicular to one another, Y-axis and Z-direction is to (3); The temperature sensor that is used for detected temperatures; Be used to detect the physical quantity transducer of the inclination of portable terminal device 1; And the sensor control section that is used for the testing result of above-mentioned each sensor is handled (A/D conversion etc.).

Electro-photographic part 202 comprises optical lens and such as CCD imaging apparatuss such as (charge-coupled image sensors).Electro-photographic part 202 will be converted to simulating signal by the object images that optical lens forms by imaging apparatus on the shooting surface of imaging apparatus, be digital signal with this analog signal conversion, and this digital signal is outputed to main control part 108.Display part 203 has LCDs etc., and based on coming display image, character etc. from the shows signal of main control part 108 outputs.Touch pad 204 is an one with the surface combination that is arranged on the LCDs in the display part 203.Non-productive operation part 205 has the button that uses in showing switching, or the like.

At this, will the functional block diagram shown in Figure 23 be described.

Should be noted that at the bearing data calculating section 307 shown in the same figure corresponding to the main control part 108 shown in Figure 22, and display device 316 is corresponding to the display part shown in Figure 22 203.

Magnetic Sensor part 301 comprises Magnetic Sensor (1) to (3) and is used for after opening power each Magnetic Sensor being carried out initialized sensor initializing device (1) to (3).Because when applying high-intensity magnetic field, Magnetic Sensor (1) to the direction of magnetization of the magnet of (3) can be made mistakes, so sensor initializing device (1) is set to (3), is used for Magnetic Sensor (1) to (3) is reset to original state.

Inclination sensor part 302 comprises physical quantity transducer (inclination sensor), inclination sensor initial value memory storage and inclination sensor means for correcting.This inclination sensor initial value memory storage is the initial value of the skew of storage representation physical quantity transducer output valve in advance, sensitivity equivalence during fabrication, the initial value that the inclination sensor means for correcting is stored based on inclination sensor initial value memory storage when measuring is proofreaied and correct the output of physical quantity transducer.

Temperature sensor section 303 comprises temperature sensor, temperature sensor initial value memory storage and temperature sensor means for correcting.This temperature sensor initial value memory storage is used for during fabrication the initial value of the skew of storage representation temperature sensor output valve in advance, sensitivity equivalence, the initial value that the temperature sensor means for correcting is stored based on temperature sensor initial value memory storage when measuring is proofreaied and correct the output of temperature sensor.

Switching device shifter 304 switches between the output of Magnetic Sensor part 301, inclination sensor part 302 and temperature sensor section 303, and will be input to from the simulating signal of these one of them outputs of Sensor section the A/D change-over circuit 305.A/D change-over circuit 305 is a digital signal with this analog signal conversion.Sweep limit setting device 306 for each sensor setting when the output voltage to each sensor quantizes change with combine digital, as the voltage range of conversion unit and quantifying unit (for example, to every 0.1mV execution quantification, or the like).

Whether in bearing data calculating section 307, data storage judgment means 308 is carried out the processing relevant with data storage, for example, in when calibration, judge by the represented measurement data of digital signal corresponding to the output of Magnetic Sensor and should store in the memory storage.Offset estimation device 310 is offset (will be described in detail later) based on the measurement data estimation that obtains when calibration.Validity judgment means 311 is judged the validity (will be described in detail later) by the skew of offset estimation device 310 estimations.Memory storage 309 storage of measurement data etc.

When orientation calculation element 312 calculates in the orientation based on the measurement data computer azimuth that obtains.When calculating in the orientation, from the measurement data that obtains, removes skew removal device 313 skew.When being necessary to carry out the temperature correction of measurement data, the temperature correction that temperature correction device 314 is carried out with respect to measurement data.When being necessary to carry out dip correction, the dip correction that dip correction device 315 is carried out with respect to measurement data.Display device 316 will show as image by the orientation that orientation calculation element 312 calculates.

At this in detail, the operation of bearing data calculating section 307 will be described.

In when calibration, will be input to the data storage judgment means 308 from the measurement data that sensing data obtains part 201 outputs.Data storage judgment means 308 judges based on the data storage evaluation algorithm whether measurement data should be stored in the memory storage 309.As the result who judges, if judge that measurement data should be stored in the memory storage 309, data storage judgment means 308 stores measurement data in the memory storage 309 into so.In addition, 308 pairs of numbers that are stored in the measurement data in the memory storage 309 of data storage judgment means are counted, and when the number of measurement data reaches predetermined number, stop measurement data being stored in the memory storage 309, and order offset estimation device 310 estimation skews.

When the 308 order estimation skews of data storage judgment means, offset estimation device 310 reads measurement data from memory storage 309, and based on the offset estimation algorithm this skew is estimated.In addition, the offset estimation device 310 estimation result that will be offset circulates a notice of validity judgment means 311.When the estimation by these skews of offset estimation device 310 circular as a result the time, validity judgment means 311 reads measurement data from memory storage 309, judges based on the validity evaluation algorithm whether this estimation is offset effective.When this estimation skew is effective, validity judgment means 311 with this offset storage in memory storage 309.

When calculating in the orientation, the measurement data that obtains part 201 outputs from sensing data is input to the orientation calculation element 312.This measurement data is magnetic data, temperature data and tilt data.Orientation calculation element 312 outputs to magnetic data and temperature data in the skew removal device 313.When these measurement data of input, skew removal device 313 reads skew from memory storage 309, proofread and correct by remove Offset portion from magnetic data, and the magnetic data after will proofreading and correct outputs in the orientation calculation element 312.

In addition, as required, 313 pairs of magnetic data of orientation calculation element 312 order skew removal devices are carried out temperature correction.Respond this instruction, skew removal device 313 outputs to temperature data in the temperature correction device 314.In when calibration, temperature correction device 314 is reading temperature data from memory storage 309, and based on Current Temperatures the temperature during with calibration, the result is proofreaied and correct and will be proofreaied and correct to current magnetic data circulate a notice of to be offset removal device 313.According to this correction result, the magnetic data of skew removal device 313 excess temperature correction after removing skew outputs in the orientation calculation element 312.

Particularly, suppose when calibration temperature be that the skew of T0, estimation is that 0F, temperature system are A (this in the shipment check time measured and be stored among the ROM 109), temperature when measuring is T, and the measured value of Magnetic Sensor is S0, and the magnetic data S1 (excess temperature correction) that removes after the skew is given by following formula:

S1＝S0-{0F+A(T-T0)}

In addition, as required, orientation calculation element 312 is carried out slant correction.

At this, will describe slant correction in detail.

Here, the coordinate system of portable terminal device 1 is defined as shown in Figure 24 (a).Particularly, the deflection of supposing the antenna 101 of portable terminal device 1 is that α, its elevation angle are β, and torsion angle (with respect to the rotation angle of antenna axis) is γ.The symbol of the direction of arrow shown in the figure is for just.In addition, suppose that the vector of unit length on antenna direction is Vy, be Vz perpendicular to the vector of unit length on plane (for example plane of label 99 parts among Figure 24) direction that forms by terminal unit 2 (be provided with antenna 101 with Magnetic Sensor part 301 sides), and be Vx perpendicular to the vector of unit length of Vy and Vz.The direction of arrow shown in the figure is positive dirction.Shown in Figure 24 (b), earth axes represented by X, Y and Z, and Y-axis be defined as the north to.

At this, suppose gravity in earth axes be G=(0,0, Gz).In addition, suppose gravity at portable coordinate system be g=(gx, gy, gz).Suppose by inclination sensor and can detect gravity in the portable coordinate system.Certainly, the gravity in earth axes is known.

Then, express the gravity G among the gravity g and earth axes in the portable coordinate system by following formula.

(Gx，Gy，Gz)BC＝(gx，gy，gz)

Wherein

[expression formula 12]

$B=\left[\begin{array}{ccc}1& 0& 0\\ 0& \cos \mathrm{\&beta;}& \sin \mathrm{\&beta;}\\ 0& -\sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\end{array}\right]$

[expression formula 13]

$C=\left[\begin{array}{ccc}\cos \mathrm{\&gamma;}& 0& -\sin \mathrm{\&gamma;}\\ 0& 1& 0\\ \sin \mathrm{\&gamma;}& 0& \cos \mathrm{\&gamma;}\end{array}\right]$

Therefore, BC is by following equation expression.

[expression formula 14]

$\mathrm{BC}=\left[\begin{array}{ccc}\cos \mathrm{\&gamma;}& 0& -\sin \mathrm{\&gamma;}\\ \sin \mathrm{\&beta;}\sin \mathrm{\&gamma;}& \cos \mathrm{\&beta;}& \sin \mathrm{\&beta;}\cos \mathrm{\&gamma;}\\ \cos \mathrm{\&beta;}\sin \mathrm{\&gamma;}& -\sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\cos \mathrm{\&gamma;}\end{array}\right]$

Therefore, the gravity g in portable coordinate system is by following equation expression.

[expression formula 15]

$(\mathrm{gx},\mathrm{gy},\mathrm{gz})=(\mathrm{0,0},\mathrm{Gz})\left[\begin{array}{ccc}\cos \mathrm{\&gamma;}& 0& -\sin \mathrm{\&gamma;}\\ \sin \mathrm{\&beta;}\sin \mathrm{\&gamma;}& \cos \mathrm{\&beta;}& \sin \mathrm{\&beta;}\cos \mathrm{\&gamma;}\\ \cos \mathrm{\&beta;}\sin \mathrm{\&gamma;}& -\sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\cos \mathrm{\&gamma;}\end{array}\right]$

$=\mathrm{Gz}(\cos \mathrm{\&beta;}\sin \mathrm{\&gamma;},-\sin \mathrm{\&beta;},\cos \mathrm{\&beta;}\cos \mathrm{\&gamma;})$

Derive elevation angle β and torsion angle γ by this formula.

[expression formula 16]

$\mathrm{\&beta;}=\arctan (-\frac{\mathrm{<figure-callout\; id="2"\; label="gy\; gx"\; filenames="A2009101520470064H1.png,A2009101520470064H2.png"\; state="\{\{state\}\}">gy</figure-callout>}}{\sqrt{{\mathrm{gx}}^{}}})$

[expression formula 17]

$\mathrm{\&gamma;}=\left\{\begin{array}{cc}\arctan \left(\frac{\mathrm{gx}}{\mathrm{gz}}\right)& \mathrm{gz}\&GreaterEqual;0\\ 180\left(\mathrm{deg}\right)+\arctan \left(\frac{\mathrm{gx}}{\mathrm{gz}}\right)& \mathrm{gz}<0\end{array}\right.$

Elevation angle β and torsion angle γ according to such derivation can derive the elevation angle theta of direction angle alpha and earth magnetism.At this, suppose earth magnetism in portable coordinate system be h=(hx, hy, hz), and the earth magnetism in earth axes be H=(0, Hy, Hz), then

(0，Hy，Hz)ABC＝(hx，hy，hz)

Set up, wherein

[expression formula 18]

$A=\left[\begin{array}{ccc}\cos \mathrm{\&alpha;}& -\sin \mathrm{\&alpha;}& 0\\ \sin \mathrm{\&alpha;}& \cos \mathrm{\&alpha;}& 0\\ 0& 0& 1\end{array}\right]$

[expression formula 19]

$B=\left[\begin{array}{ccc}1& 0& 0\\ 0& \cos \mathrm{\&beta;}& \sin \mathrm{\&beta;}\\ 0& -\sin \mathrm{\&beta;}& \cos \mathrm{\&beta;}\end{array}\right]$

[expression formula 20]

$C=\left[\begin{array}{ccc}\cos \mathrm{\&gamma;}& 0& -\sin \mathrm{\&gamma;}\\ 0& 1& 0\\ \sin \mathrm{\&gamma;}& 0& \cos \mathrm{\&gamma;}\end{array}\right]$

Therefore, obtain following formula.

[expression formula 21]

(0，Hy，Hz)A＝(hx，hy，hz)C ^-1B ^-1≡(hx′，hy′，hz′)

Therefore, (hx ', hy ', hz ')=(Hysin α, Hycos α, Hz).Because derive elevation angle β and torsion angle γ in advance and record earth magnetism h in portable coordinate system, so determined (hx ', hy ', hz ').At this, suppose that the earth magnetism H in earth axes is known, then derive direction angle alpha.In addition, also derive elevation angle theta by following formula.

[expression formula 22]

$\mathrm{\&theta;}=\arctan \frac{{\mathrm{hz}}^{\&prime;}}{\sqrt{{\mathrm{hx}}^{\&prime;2}+{\mathrm{hy}}^{\&prime;2}}}$

Based on the magnetic data after proofreading and correct as mentioned above, 312 computer azimuths of orientation calculation element, and with the orientation circular display device of calculating 316.For example, the information of display device 316 indicator gauge pictorial map upper positions.

Next, data of description is stored evaluation algorithm.

Making measurement data concentrate near azimuth circle or compass ball (describing below) are gone up same point when the mobile hardly portable terminal device 1 of user when, import data or owing to user's operating speed is not that at the uniform velocity the packing density that makes becomes under the uneven situation, the data storage evaluation algorithm is used to prevent to store the measurement data that can not be used to calibrate.When obtaining such measurement data, can prevent to be stored in the memory storage 309.

When portable terminal device 1 at surface level (at this, suppose that the XY plane parallel that forms by Magnetic Sensor (1) and Magnetic Sensor (2) axle separately is in this surface level) when rotating, the output X that is converted to the Magnetic Sensor (1) of magnetic field value changes in sinusoidal wave mode, and the output Y that is converted to the Magnetic Sensor (2) of magnetic field value simultaneously changes in the cosine wave (CW) mode that has phase quadrature with respect to output X.Suppose that skew is for (X0 Y0), sets up following relational expression, is referred to as azimuth circle.

(X-X0) ²+(Y-Y0) ²＝R ²

Under three-dimensional situation, also set up similar relational expression, be referred to as the compass ball.

(X-X0) ²+(Y-Y0) ²+(Z-Z0) ²＝R ²

Particularly, the data of supposing just to store among the RAM 110 are (X _p, Y _p, Z _p), and the data that will judge through storage are that (Z), only when satisfying following condition, (X, Y Z) store among the RAM 110 the data storage evaluation algorithm with data for X, Y.The value of should be noted that d is preferably about 1/10 of azimuth circle radius.

[formula 23]

$d<\sqrt{{(X_p-X)}^2+{(Y_P-Y)}^2+{(Z_p-Z)}^2}$

Next, the offset estimation algorithm will be described.

Suppose that measurement data is (x _i, y _i, z _i) (i=1 ..., N), be offset to (Z0), the radius of compass ball is R, sets up following relational expression for X0, Y0.

(x _i-X0) ²+(y _i-Y0) ²+(z _i-Z0)＝R ²

In this case, least squares error ε is defined as follows.

[expression formula 24]

ε＝∑{(x _i-X0) ²+(y _i-Y0) ²+(z _i-Z0) ²-R ²} ²

＝∑{(x _i ²+y _i ²+z _i ²)-2x _iX0-2y _iY0-2z _iZ0+(X0 ²+y0 ²+Z0 ²)-R ²} ²

At this, suppose

a _i＝x _i ²+y _i ²+z _i ²

b _i＝-2x _i

c _i＝-2y _i

d _i＝-2z _i

D＝(X0 ²+Y0 ²+Z0 ²)-R ² …(24)，

ε is provided by following formula.

[expression formula 25]

ε＝∑(a _i+b _iX0+c _iY0+d _iZ0+D) ²

The condition of least squares error ε minimum is passed through ε variable X ₀, Y ₀, Z0 and D obtain differentiate, and expressed by [expression formula 26].Here, calculate, variables D is considered as independent variable for simplifying.

[expression formula 26]

$\left\{\begin{array}{c}\frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">X</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)b_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">Y</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)c_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">Z</figure-callout>}0}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)d_i=0\\ \frac{\&PartialD;\mathrm{\&epsiv;}}{\&PartialD;D}=2\mathrm{\&Sigma;}(a_i+{\mathrm{<figure-callout\; id="0"\; label="b\; i\; X"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">b</figure-callout>}}_{i}X0+{\mathrm{<figure-callout\; id="0"\; label="c\; i\; Y"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">c</figure-callout>}}_{i}Y0+{\mathrm{<figure-callout\; id="0"\; label="d\; i\; Z"\; filenames="A2009101520470069H2.png,A2009101520470078H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_{i}Z0+D)=0\end{array}\right.$

Therefore, set up following formula.

[expression formula 27]

$\left[\begin{array}{cccc}\left[\mathrm{bb}\right]& \left[\mathrm{bc}\right]& \left[\mathrm{bd}\right]& \left[b\right]\\ \left[\mathrm{bc}\right]& \left[\mathrm{cc}\right]& \left[\mathrm{cd}\right]& \left[c\right]\\ \left[\mathrm{bd}\right]& \left[\mathrm{cd}\right]& \left[\mathrm{dd}\right]& \left[d\right]\\ \left[b\right]& \left[c\right]& \left[d\right]& N\end{array}\right]\left[\begin{array}{c}X0\\ Y0\\ Z0\\ D\end{array}\right]=\left[\begin{array}{c}-\left[\mathrm{ab}\right]\\ -\left[\mathrm{ac}\right]\\ -\left[\mathrm{ad}\right]\\ -\left[a\right]\end{array}\right]$

Wherein, the operational character [] expression of in above-mentioned equation, using:

[expression formula 28]

$\left[m\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i,$ $\left[\mathrm{mn}\right]=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{m}_i{n}_i$

These simultaneous equatioies are found the solution, derive X0, the Y0, Z0 and the D that make least squares error ε minimum.And, also can from formula (24), derive R.

Next, the validity evaluation algorithm will be described.

In the processing according to this algorithm, according to the radius of estimation skew, compass ball (or azimuth circle) and be stored in measurement data among the RAM 110, the value that is calculated as follows.

[expression formula 29]

$\mathrm{\&sigma;}=\frac{1}{R}\sqrt{\frac{N\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\{{(x_i-x0)}^2+{(y_i-Y0)}^2+{(z_i-Z0)}^2\}-{\left(\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\sqrt{{(x_i-x0)}^2+{(y_i-Y0)}^2+{(z_i-Z0)}^2}\right)}^2}{{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="A2009101520470064H1.png,A2009101520470064H2.png"\; state="\{\{state\}\}">N</figure-callout>}}^2}}$

[expression formula 30]

$W_x=\frac{\mathrm{Max}\left(x_i\right)-\mathrm{Min}\left(x_i\right)}{R}$

[expressing 31]

$W_y=\frac{\mathrm{Max}\left(y_i\right)-\mathrm{Min}\left(y_i\right)}{R}$

[expressing 32]

$W_z=\frac{\mathrm{Max}\left(z_i\right)-\mathrm{Min}\left(z_i\right)}{R}$

Max (x wherein _i) expression measurement data x ₁..., x _NAmong maximal value, and Min (x _i) expression measurement data x ₁..., x _NAmong minimum value.In addition, σ represents standard deviation.Judge whether to satisfy following criterion according to above-mentioned value, and when satisfying criterion, the skew of estimation is judged as effectively.

σ＜F

w _x＞G

w _y＞G

w _z＞G

At this, O.1 F is preferably about and G is preferably about 1.

Next, describe in further detail with reference to figure 2 and calibrate relevant operation.

[situation of rotary-type portable terminal device]

In structure example shown in Figure 22, each Magnetic Sensor is disposed in terminal unit-2 side, and terminal unit-2 side is along opening the side that direction moves when portable terminal device 1 is opened or is closed.On the other hand, when opening or during closed portable terminal device 1, terminal unit-1 is maintained fixed by user's hand usually.Under portable terminal device 1 was rotary-type situation, Magnetic Sensor was installed on the side of opening rotation when closed (referring to Figure 26).Preferably the position of Magnetic Sensor layout is near terminal unit-1 and terminal unit-2 position connected to one another (certainly, also can be arranged in terminal unit-1 side).This be since this position usually away from microphone that produces magnetic or the position that loudspeaker is arranged.Portable terminal device 1 is provided with opened/closed switch (SW) 114, so that can discern the opened/closed operation in the stage of opening beginning and closed end.Magnetic Sensor part 301 can be formed by two axial magnetic sensors or magnetic sensor.

(1) calibration steps 1

At first, when detecting by opened/closed switch (SW) 114 when beginning to open a terminal unit-2, start (step S101) in this time trigger.In this case, the terminal unit-2 that Magnetic Sensor part 301 is installed has begun rotation (opening operation), so that the last angle θ (as shown in figure 26) that forms with respect to terminal unit-1.

Main control part 108 command sensor control sections are measured (step S102) by using each sensor to carry out.From each sensor readings, and beginning data sampling (step S103).At this, the output of each Magnetic Sensor is taken a sample the schedule time continuously.

Then, according to above-mentioned data storage evaluation algorithm, judge whether to store measurement data among the RAM 110 (step S104).

When in step S104, being judged as No, waiting for 0.1 second (step S105) afterwards, flow process turns back to step S102.

When step S104 is judged as Yes, stores measurement data among the RAM 110 (step S106), and judge further whether the number that is stored in the measurement data among the RAM 110 has reached predetermined number (step S107).

When being judged as No in step S107, flow process enters into step S105.On the other hand, when in step S107, being judged as Yes, stop sampling, read storage measurement data thereon, and estimate skew (step S108) according to the offset estimation algorithm from RAM 110 to measurement data.

Subsequently, based on above-mentioned validity evaluation algorithm, judge whether the off-set value of estimation is effective value (step S109).When being judged as Yes based on this judged result, the offset storage that will estimate in step S108 is in RAM 110, so that finish to upgrade processing (step S110).On the other hand, when in step S109, being judged as No, finishing a series of processing and do not upgrade skew (step S111).

When step S109 is judged as No, for example the skew of estimating in step S108 is judged as when invalid, can design like this with order further open and close portable terminal device 1 of user or order user and on a plurality of directions, portable terminal device 1 be opened or closure, thereby further obtain measurement data from each Magnetic Sensor.Utilize this structure, increase the data number of measuring so that improve the precision of offset estimation.Order is passed to the user to be carried out by the command context of utilizing aviso device 111 to give a warning sound and to be shown to the user on display part 203.

When Magnetic Sensor part 301 is formed by two axial magnetic sensors, carry out aforesaid calibration (according to calibration steps 1).When Magnetic Sensor part 301 is formed by magnetic sensor, in the step S107 of above-mentioned calibration steps 1, be judged as Yes after, further carry out calibration according to following calibration steps 2.

(2) calibration steps 2

Begin sampling along with the predetermined button of pressing main operation part 113 (calibration knob).In this calibration steps 2, require the user with the direction of arrow among Figure 27 swing portable terminal device 1 (this operation that the supposition user carries out is indicated to the user by service manual etc. in advance).

Then, the output of each Magnetic Sensor is taken a sample the schedule time continuously.In rotary-type, when terminal unit-2 was consequently opened fully with respect to terminal unit-1 rotation, mobile terminal unit-2 was with the angle θ of last formation with respect to the principal plane (front is described) of portable terminal device 1.In other words, the response opening operation, mobile unit-2 is rotated and displacement on X, Y and three direction of principal axis of Z.Thereby the Magnetic Sensor part 301 in the terminal unit-2 moves so that changes with respect to these three axles respectively.As accidental hour of θ, require the user to swing portable terminal device 1, so that obtain the little variation that measurement data is used for replenishing θ.

When aforesaid data acquisition is finished, according to the data estimation skew that obtains.Then, upgrade the skew that is kept among the RAM 110 with the skew of this estimation.

According to the offset data of this acquisition and the comparison between the offset data before the renewal, only when judgement was necessary to carry out offset correction, processing (definite respectively this criterion) was upgraded in the skew that just may carry out in above-mentioned calibration steps 1 and 2.

Replacedly, can be configured to:, make the selection of whether when portable terminal device 1 opened/closed, carrying out data acquisition based on whether skew has reached the judgement that is necessary the level (critical field) of its renewal according to preassigned.

At this, with the description that provides about the offset estimation method in rotary-type portable terminal device 1 (another example).

Though can derive the estimation of skew according to above-mentioned offset estimation algorithm, when considering the angle θ that forms by terminal unit shown in Figure 27-1 and terminal unit-2, also can be as follows with its derivation.

(a) situation about forming by two axial magnetic sensors in Magnetic Sensor part 301

When the measurement data of sampling in calibration steps 1 use with respect to X sensor (being used to detect the Magnetic Sensor) value of abscissa axis at earth magnetism magnetic force on the X-direction and with respect to the Y sensor (being used to detect the Magnetic Sensor of earth magnetism magnetic force on perpendicular to the Y direction of X-axis) of axis of ordinates when value is marked and drawed (for example, plot right X sensor output value and Y sensor output value at XY plane subscript), the result is as shown in figure 28.This track is an oval part, and its aspect ratio depends on θ among Figure 27 and the angle that forms between earth magnetism and Plane of rotation (formed plane when by the mobile Magnetic Sensor of rotation).Owing to is known, so, can obtain the angle that forms between the skew of X, Y and earth magnetism and the Plane of rotation by deriving oval aspect ratio and centre coordinate at this θ.

(b) situation about forming by magnetic sensor in Magnetic Sensor part 301

Can derive skew as the diaxon situation of above-mentioned (a) on the XY plane.Same with respect to skew in Z-direction, when θ big relatively (θ＞30 °),,, can derive the off-set value of Z by using the track of measurement data when the XZ plane calibration as the situation of diaxon.Yet, when θ hour, low precision.This be because: as shown in figure 29, track is so flat so that be essentially straight line.

Under these circumstances, the skew of Z can be derived from the sampled data the calibration steps 2.In calibration steps 2, require the user to swing portable terminal device 1.Yet, also can be designed as: when the user has changed the inclination of terminal when in measurement of bearing the time, thereby the output of Magnetic Sensor is taken a sample to use those measurement data.

[situation of common Foldable portable terminal]

In said structure example as shown in Figure 22, each Magnetic Sensor is arranged in terminal unit-2 side, and this terminal unit-2 side is for opening the side that direction moves when opening with closed portable terminal device 1.On the other hand, when opening or during closed portable terminal device 1, unit-1 is maintained fixed by user's hand usually.In other words, suppose terminal unit-2 is called lid that then Magnetic Sensor is installed in the lid side (referring to Figure 30) of wanting open and close.Preferably as rotary-type, the position that Magnetic Sensor is arranged is near terminal unit-1 and terminal unit 2 positions connected to one another.Portable terminal device 1 is provided with opened/closed switch (SW) 114, so that opening beginning (terminal unit-2 is opened predetermined angular or stage of wide-angle more with respect to terminal unit-1) and the closed stage that finishes, can recognize the opened/closed operation.At this, suppose that Magnetic Sensor part 301 is formed by magnetic sensor.

Equally, under the situation of common Foldable portable terminal, can utilize the processing procedure of calibration steps 1 with the calibration steps 2 of above-mentioned rotary-type situation.Yet, in this calibration steps 2, when the output of each Magnetic Sensor is taken a sample, require the user to swing portable terminal device 1 as shown in figure 31.Under portable terminal device 1 is as shown in figure 30 common folding situation, when opening terminal unit-2 with Magnetic Sensor part 301 from terminal unit-1, though itself there is variation to a great extent on the plane that is formed by track, but upward change little in direction (directions X) perpendicular to this track, therefore, in order sizable variation on this direction, to occur, require the user with the swing of the direction of arrow shown in Figure 31 portable terminal device 1, thereby obtain measurement data.

As mentioned above, when portable terminal device 1 is common Foldable portable terminal,, can estimate the skew of Y-axis and Z-direction according to the measurement data that calibration steps 1 obtains.According to the measurement data that obtains by above-mentioned calibration steps 2, can estimate the skew on the X-direction.By using those measurement data that obtained when the user changes direction in measurement of bearing, also can estimate skew.

It should be noted that above-mentioned flow operations is an example, so the present invention is not limited to above-mentioned treatment scheme.

Provide description above with reference to the accompanying drawings about embodiments of the invention.Yet much less, concrete structure is not limited to these embodiment, but also comprises the structure in the scope that does not break away from essence of the present invention.

In above-mentioned example, be to carry out calibration, but also can after the portable terminal device closure, carry out calibration in the moment that the user opens portable terminal device.This be because: follow hard on after the closed portable terminal device, the user makes such as putting into portable terminal device in the bag or placing it in the first-class action of table, causes the portable terminal device closure after soon its direction variation.Therefore, can within during this section, take a sample to the output of Magnetic Sensor, and according to those measurement data estimation skews.

In addition,, calibration can be carried out always, or calibration can be when the user confirms in open and close, whether begun in the moment of user's open and close portable terminal device.

The method and apparatus that is used for compensating the leakage field that mobile communication terminal produces is pointed in ensuing description.

In the structure example shown in Figure 22, each Magnetic Sensor is disposed in opens terminal unit-2 side that moves on the direction.On the other hand, opening or during closed portable terminal device 1, unit-1 is maintained fixed by user's hand usually.Suppose terminal unit-2 is called lid that Magnetic Sensor is installed in the lid side (referring to Figure 32) of wanting open and close.Though the optimum seeking site that Magnetic Sensor is arranged is near terminal unit-1 and terminal unit-2 part connected to one another (certainly, also can be arranged in terminal unit-1 side), also can be positioned at other any parts.Portable terminal device 1 is provided with opened/closed switch (SW) 114, so that can discern the opened/closed operation in the stage of opening beginning and closed end.At this, suppose that Magnetic Sensor part 301 is formed by magnetic sensor.

(1) calibration steps

In conjunction with Figure 25 basic calibration steps is described.At first, when detecting the closed end of terminal unit-2 by opened/closed switch (SW) 114, start (step S101) in this time trigger.After this, the user makes such as portable terminal device 1 being put into bag or being placed on the first-class action of table.Therefore, after portable terminal device 1 is closed soon, itself direction variation.

Main control part 108 command sensor control sections are measured (step S102) by using each sensor to carry out, from each sensor readings, and beginning data sampling (step S103).At this, the output of each Magnetic Sensor is taken a sample the schedule time continuously.When XYZ space is marked and drawed the measurement data of sampling like this, data point is dispersed on certain sphere.

Then, according to above-mentioned data storage evaluation algorithm, judge whether to store measurement data among the RAM 110 (step S104).

When step S104 is judged as No, waiting for 0.1 second (step S105) afterwards, flow process turns back to step S102.

When step S104 is judged as Yes, stores measurement data among the RAM 110 (step S106), and judge further whether the measurement data number that is stored among the RAM 110 has reached predetermined number (step S107).

When step S107 is judged as No, flow process enters into step S105.On the other hand,, stop sampling, from RAM 110, read storage measurement data thereon, and estimate skew (step S108) according to above-mentioned offset estimation algorithm to measurement data when when step S107 is judged as Yes.

Subsequently, based on above-mentioned validity evaluation algorithm, judge whether the skew of estimation is effective value (step S109).When being judged as Yes, the offset storage estimated among the step S108 in RAM 110, is handled (step S110) so that finish interim the renewal based on this judged result.On the other hand, when in step S109, being judged as No, finishing a series of processing and do not upgrade skew (step S111).

According to the offset data of this acquisition and the comparison between the offset data before the renewal, only when judgement was necessary to carry out offset correction, processing (definite respectively this criterion) was upgraded in the skew (temporarily) that just may carry out in the above-mentioned calibration steps.

Replacedly, can be configured to:, make the selection of whether when the opened/closed of portable terminal device 1, carrying out data acquisition based on judging according to preassigned whether skew has reached the level (or critical field) that is necessary its renewal.

At this, will another example of calibration steps be described.

Generally speaking, because after portable terminal device 1 closure, and uncertain user's action,, exist data point to concentrate on situation on the specific plane so if mark and draw the measurement data of in step S103, taking a sample in XYZ space as mentioned above.For example, when data centralization is on the XY plane, even, can not derive the value of Z exactly according to those data by deriving the center of orientation ball.

In this case, according to above-mentioned data storage evaluation algorithm, can prevent that the measurement data that can not be used for calibrating from storing memory storage 309 into.Yet, equally in this case, measurement data is stored in the memory storage 309, and estimates skew according to above-mentioned offset estimation algorithm.Then,, derive the least squares error of the orientation radius of a ball, move when a certain amount of when being offset then, further derive least squares error in Z-direction as the validity evaluation algorithm.When the difference between these two least squares error in this case during less than predetermined value, be invalid with respect to the skew of Z axle, and the only interim skew of upgrading with respect to X-axis and Y-axis.

Next, will the correction of leakage field be described.

The skew of Dao Chuing is the skew of deriving under the state that portable terminal device 1 is closed as mentioned above.Generally speaking, loudspeaker, microphone etc. is installed in such as in the portable terminal devices such as portable phone, and uses permanent magnet therein.Have a kind of situation, promptly the influence that is applied in the Magnetic Sensor skew by the leakage field from permanent magnet is being different between the state of portable terminal device 1 closure and the state that it is opened.In this case, be necessary to proofread and correct the skew of deriving corresponding to before such difference.

Usually, when opening portable terminal device 1, determine this operation.In addition, known permanent magnet of incorporating into and the position between Magnetic Sensor relation.When opening portable end 1 (for example, from beginning to open portable terminal device 1) to the output sampling of Magnetic Sensor and when XYZ space is marked and drawed measurement data, the curve of describing in XYZ space by measurement data is limitary, and when the intensity of relative angle between the magnetization, earth magnetism and the portable terminal device 1 of permanent magnet and earth magnetism is determined, determine it is unique.

In this supposition direction of magnetization is the Z direction, has the magnetic field of magnetization M by following formulate by permanent magnet formation around geomagnetic sensor.Should be noted that when the position of permanent magnet givenly during as initial point, x, y and z are the coordinates of geomagnetic sensor.In addition, H _xThe X component in expression magnetic field, H _yThe Y component in expression magnetic field, and H _zThe Z component in expression magnetic field.

[expression formula 33]

$H_x=\frac{1}{4\mathrm{\&pi;}{\mathrm{\&mu;}}_0}\frac{3M\&CenterDot;x\&CenterDot;z}{{(x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A2009101520470064H1.png,A2009101520470064H2.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2)}^{\frac{5}{2}}}$

[expression formula 34]

$H_y=\frac{1}{4\mathrm{\&pi;}{\mathrm{\&mu;}}_0}\frac{3M\&CenterDot;y\&CenterDot;z}{{(x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A2009101520470064H1.png,A2009101520470064H2.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2)}^{\frac{5}{2}}}$

[expression formula 35]

$H_z=\frac{1}{4\mathrm{\&pi;}{\mathrm{\&mu;}}_0}(\frac{3M\&CenterDot;z^2}{{(x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A2009101520470064H1.png,A2009101520470064H2.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2)}^{\frac{5}{2}}}-\frac{M}{{(x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A2009101520470064H1.png,A2009101520470064H2.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2)}^{\frac{3}{2}}})$

Now, known x, y and z are the function of the opened/closed angle θ (referring to Figure 32) of portable terminal device 1.And the geomagnetic sensor that is installed in the terminal unit-2 is also derived as the function of θ with respect to the relative direction of terminal unit-1 part.In addition, earth magnetism also is known with respect to the relative direction and the intensity of terminal unit-1 part.Therefore, the earth magnetism during based on opened/closed portable terminal device 1, it also is known that the output of geomagnetic sensor changes.

At this, for portable terminal device 1 between the moving period from the closure state to the full open position variation in magnetic field make simulation.The formulate that this simulation is used is produced around geomagnetic sensor by permanent magnet has magnetized magnetic field.When simulation from the Hy1 in the magnetic field of permanent magnet and the relation between the Hz1, from the Hy2 in earth magnetism magnetic field and the relation between the Hz2, and each is, and (during=concerning Hy1+Hy2) and between the Hz3 (Hz1+Hz2), this analog result for example can become as shown in Figure 33 from magnetic field of permanent magnet with from the Hy3 of earth magnetism magnetic field sum.In the figure, first curve representation is from the Hy2 in earth magnetism magnetic field and the relation between the Hz2, second curve representation is from concerning between the Hy1 of magnetic field of permanent magnet and the Hz1, and the 3rd curve representation each be from magnetic field of permanent magnet with from the Hy3 of earth magnetism magnetic field sum and the relation between the Hz3.Figure 33 represents the analog variation of Hy and Hz value.Also can comprise the expansion simulation of Hx and Hy and Hz.

In Figure 33, curve 2 and 3 changes along with the variation of magnetization M.Here, use magnetization M that curve 3 is carried out match as parameter so that curve 3 along intensive measurement data by match, this measurement data obtains from geomagnetic sensor during portable terminal device 1 opening operation process continuously, thereby obtains magnetization M.

Next, the magnetization M based on obtaining, carry out following calculating: promptly, the magnetic field value under the state of calculating portable terminal device 1 closure, and another value of calculating magnetic field under portable terminal device 1 open mode., when changing to full open position, closure state also changing at portable terminal device 1 from the magnetic field of permanent magnet.The variation in magnetic field is by curve 2 expressions of the magnetization M with acquisition.Here, the relative end points of curve 2 comes the comfortable portable terminal device 1 closure state magnetic field of the magnet of observation down corresponding to the magnetic field of the magnet that observes under comfortable portable terminal device 1 full open position.Therefore, the relative end points that calculates at curve 2 has the magnetic field value that obtains magnetization M, with the magnetic field value of acquisition under portable terminal device 1 closure state, and the magnetic field value under portable terminal device 1 full open position.

In addition, calculate magnetic field value under portable terminal device 1 closure state and poor between the magnetic field value under portable terminal device 1 full open position.This difference is corresponding to the magnetic field value that geomagnetic sensor is influenced from the magnet with magnetization M.

At last, it is poor to deduct this calculating from the off-set value of before estimating under portable terminal device 1 closure state, thus compensation leakage field and renewal skew formally.

As mentioned above,, further carry out the leakage field calibration of skew, need not to force the user to carry out special operational so that realize more accurate calibration when the calibration of under the state of portable terminal device 1 closure, carrying out Magnetic Sensor, when then the user opens portable terminal device 1.

In above-mentioned, the main control part 108 of portable terminal device 1 is carried out the processing of estimation skew and leakage field correction.Yet, can be configured to: the processing section that in sensing data acquisition part (magnet sensor arrangement) 115, is provided for carrying out this processing, the closure signal that indication portable terminal device 1 has been closed is transported to sensing data acquisition part 115 from main control part 108, and respond this closure signal, sensing data obtains part 115 and carries out above-mentioned offset estimation processing, simultaneously, the opening signal that indication portable terminal device 1 has been opened is transported to sensing data acquisition part 115 from main control part 108, and respond this opening signal, sensing data obtains part 115 and carries out above-mentioned leakage field treatment for correcting.

Claims (8)

1. a measurement is equipped in the method for the magnetic offset of geomagnetic sensor in the mobile information terminal apparatus with storer and inclination sensor, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on the axle of two dimension or three-dimensional system of coordinate and influenced by magnetization and cause magnetic biasing, described inclination sensor detects the inclination angle of described mobile information terminal apparatus, and described method comprises:

The DATA REASONING step, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and follow-up measurement data are provided continuously;

The inclination measurement step, its measure output of described inclination sensor and provide continuously a plurality of angle-datas, described a plurality of angle-datas represent the inclination angle of mobile information terminal apparatus and comprise with the previous simultaneously-measured previous angle-data of measurement data and with the simultaneously-measured follow-up angle-data of follow-up measurement data;

The data storage step, it is when the difference between another inclination angle of the inclination angle of the mobile information terminal apparatus of representing by described follow-up angle-data and the mobile information terminal apparatus represented by described previous angle-data during greater than predetermined difference, described follow-up measurement data is stored in the described storer, thereby, described measurement data is accumulated in the described storer by repeating the process of described DATA REASONING step, described inclination measurement step and described data storage step; And

The offset estimation step, it reads the measurement data of a plurality of accumulations from described storer, and estimates the off-set value of described magnetic biasing according to the measurement data of described a plurality of accumulations of reading from described storer.

2. method according to claim 1, wherein, when the measurement data number in being stored in described storer reaches predetermined number, described offset estimation step reads the described measurement data of described a plurality of accumulations from described storer, and estimates the off-set value of described magnetic biasing according to the described measurement data of the predetermined number that reads from described storer.

3. method according to claim 1, wherein, when the measurement data number of accumulating in described storer reached predetermined number, described offset estimation step read the measurement data of described a plurality of accumulations and estimates off-set value from described storer, and described method further comprises:

The mean value calculation step, its calculate in described coordinate system, define, corresponding to the offset point of the off-set value of estimation with in described coordinate system, define, corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate described off-set value, and the described offset point that calculated of further calculating and the mean value of the distance between described a plurality of data point;

The standard deviation calculation step, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated;

The validity determining step, it judges the validity of the off-set value of estimation according to the standard deviation that calculates; And

The offset storage step when its validity when the off-set value of estimation is identified by described validity determining step, is stored the offset data of described estimation.

4. method according to claim 2 further comprises:

The mean value calculation step, its calculate in described coordinate system, define, corresponding to the offset point of the off-set value of estimation with in described coordinate system, define, corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate described off-set value, and the described offset point that calculated of further calculating and the mean value of the distance between described a plurality of data point;

The standard deviation calculation step, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated;

The validity determining step, it judges the validity of the off-set value of estimation according to the standard deviation that calculates; And

The offset storage step when its validity when the off-set value of estimation is identified by described validity determining step, is stored the offset data of described estimation.

5. method according to claim 1 further comprises:

The mean value calculation step, its calculate in described coordinate system, define, corresponding to the offset point of the off-set value of estimation with in described coordinate system, define, corresponding to the distance between a plurality of data points of a plurality of measurement data that are used to estimate described off-set value, and the described offset point that calculated of further calculating and the mean value of the distance between described a plurality of data point;

The standard deviation calculation step, it calculates the standard deviation of the distance that has calculated according to the range averaging value that has calculated;

The validity determining step, it judges the validity of the off-set value of estimation according to the standard deviation that calculates; And

The offset storage step when its validity when the off-set value of estimation is identified by described validity determining step, is stored the offset data of described estimation.

6. method according to claim 3 further comprises the circular step of circulating a notice of the user when judging that by described validity determining step the off-set value of described estimation is invalid.

7. method according to claim 3, further comprise: the comparison step that a plurality of measurement data compare mutually, in described a plurality of measurement data each all be used for estimating off-set value and described a plurality of measurement data each represent by one group of coordinate components corresponding to one group of axle of coordinate system, so that compare poor with between the maximal value of the coordinate components that obtains each and the minimum value at each coordinate components at described measurement data, wherein, described validity determining step is except according to the described standard deviation that calculates, also according to obtain each the maximal value of coordinate components and the validity that the difference between the minimum value is judged the off-set value of described estimation.

8. device that is used for measuring the magnetic offset of geomagnetic sensor that is equipped in portable information terminal with inclination sensor, described geomagnetic sensor has the magnetic sensitivity of terrestrial magnetic field on the axle of two dimension or three-dimensional system of coordinate and influenced by magnetization and cause magnetic biasing, described inclination sensor detects the inclination angle of described portable information terminal, and described device comprises:

The DATA REASONING part, it measures the output of described geomagnetic sensor, and a plurality of measurement data of the described terrestrial magnetic field that comprises previous measurement data and follow-up measurement data are provided continuously;

The inclination measurement part, it measures the output of described inclination sensor, and provide continuously a plurality of angle-datas, described a plurality of angle-datas represent the inclination angle of described portable information terminal and comprise and the previous simultaneously-measured previous angle-data of measurement data and with the simultaneously-measured follow-up angle-data of follow-up measurement data;

Data-carrier store, it is when the difference between another inclination angle of the inclination angle of the portable information terminal of representing by described follow-up angle-data and the portable information terminal represented by described previous angle-data during greater than predetermined difference, store described follow-up measurement data, thereby partly accumulate described measurement data with described inclination measurement by repeatedly operating described DATA REASONING part; And

The offset estimation part, it reads the measurement data of a plurality of accumulations from described data-carrier store, and estimates the off-set value of described magnetic biasing according to the described a plurality of cumulative measurement data that read from described data-carrier store.

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