JPH08292201A - Trigonometric function data transforming circuit and meter device - Google Patents

Abstract

PURPOSE: To suppress the generated amount of transformation error to the least with a simple circuit configuration when sin function data or cos function data is read out of a ROM in which sin function data is stored. CONSTITUTION: A ROM 30 is provided which is addressed by n bit binary data representing variable in a quadrant among variable range 0-2πradian of trigonometric function, stores the function data, wherein the correspondence relation between the address and sin function data and the correspondence relation between the address and cos function data are symmetrical with respect to an intermediate angle of variable as reference, and outputs a ROM 30 where the function data according to the specified address. And, this device comprises a circuit 20 controlling inversion/non-inversion of logical level of address input according to whether the function data of ROM 30 is read out as sin function data or as con function data, and a circuit 40 which separates the function data read out of the ROM 30 as the sin function data or as cos function data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trigonometric function data conversion circuit and a meter device using the trigonometric function data conversion circuit.

[0002]

2. Description of the Related Art An automobile speedometer or tachometer uses a frequency data converter for inputting a pulse signal having a frequency corresponding to speed information or rotational speed information, processing the pulse signal, and converting the data into another data. The meter indication is controlled using the output of this frequency data converter.

FIG. 8 shows a conventional example of an analog pointer type speedometer device mounted on an automobile. Here, 70 is an analog pointer type meter body, and 80 is a meter control device integrated into a circuit.

FIG. 9 is a perspective view schematically showing the structure of the meter body 70 shown in FIG. This analog pointer type meter main body 70 has electromagnetic coils 71 and 72 wound corresponding to two bobbins arranged so as to be orthogonal to each other, a rotary shaft 73 provided in a direction orthogonal to these, The rotating shaft 73 is provided with a permanent magnet 74 arranged in the middle part thereof and arranged inside the bobbin, and a pointer 75 arranged at the tip of the rotating shaft 73 and arranged outside the bobbin.

In the meter controller 80, a cycle counter 81 receives a pulse signal (meter control signal) having a cycle corresponding to speed information, counts this cycle, and generates data representing a frequency amount.

The designated angle quantified data generation circuit 82 generates data (indicated angle quantified data) representing a digital amount corresponding to the meter designated angle in accordance with the frequency amount of the output data of the cycle counter 81.

The trigonometric function data conversion circuit 83 converts the output data of the indicated angle quantified data generation circuit 82 into trigonometric function data (SIN, COS), and a ROM for sin (read-out) that stores the SIN function data. A dedicated memory) 831 and a cos ROM 832 that stores COS function data. The ROM for the above sin
A decoder that decodes input data and outputs SIN function data and COS function data may be used instead of the ROM 832 for 831 and cos.

The DA conversion circuit 84 converts the output data of the trigonometric function data conversion circuit 83 into a current or a voltage by D / A conversion (or pulse width modulation; PWM).
The meter drive circuit 85 supplies a current amount according to the output of the DA conversion circuit 84 to the two electromagnetic coils 71 and 72 of the meter body 70.

FIG. 10A shows the relationship between the indicated angle and the output data in the indicated angle quantified data generating circuit 82, and FIG. 10B shows the indicated angle in the meter body 70 and two electromagnetic waves. Amount of current flowing through coils 71 and 72 (S
(IN θ, COS θ) and the orientation are shown. The pointing angle of the pointer 75 is determined by drivingly controlling the rotational position of the permanent magnet 74 according to the vector sum of the magnetic fields (X, Y) generated by the electromagnetic coils 71, 72.

FIG. 11A and FIG. 11B are the same as FIG.
FIG. 3 is a block diagram showing a trigonometric function data conversion circuit therein and a timing diagram showing an operation example thereof. By the way, the above-mentioned conventional trigonometric function data conversion circuit 83 is for sin, c
Since the os ROM or the two decoders are used, there is a problem that the cost becomes high.

To solve this problem, for example, FIG.
Paying attention to the symmetry of the SIN function and the COS function in the first quadrant of the variable range 0 to 2π radians of the trigonometric function as shown in FIG. One R storing SIN function data by diverting as COS function data up to 0 °
It is possible to use the OM also as a ROM for cos.

In this case, SI is associated with an address designated by a plurality of bits of binary data representing a variable.
It is considered that N function data is stored and the function data is read by controlling the inversion / non-inversion of the logical level of the binary data of the address input according to the reading of the SIN function data or the COS function data. To be

However, SIN function data and COS function data corresponding to 16-step variables (π / 2) × n / 16 (n is 0 to 15) designated by an address input consisting of 4-bit binary data are, for example, , 45 °
It is not a target when observed around (π / 4).

That is, when the 4-bit address input is (0000) = 0 °, for example, assuming that the address input is not inverted when reading the SIN function data, SIN0
The ° data is read. On the other hand, when reading COS function data, the address input is inverted (11
11) = 90 ° × 15/16, and COS (90 ° ×
Since (15/16) data (not COS 90 ° data) is read, a conversion error occurs in the function data corresponding to 90 ° × 1/16 which is 1 LSB of the address input.

When a conversion error of the function data occurs as described above, an error in the meter indication occurs, so that one R
To use the OM as the ROM for SIN and COS, it is necessary to devise a circuit.

[0016]

As described above, in the conventional trigonometric function data conversion circuit and the meter device using the same, one ROM storing SIN function data or COS function data is a ROM for SIN and COS. However, if one function data is simply used as the other function data, a conversion error of the trigonometric function data may occur.

The present invention has been made to solve the above problems, and one ROM storing SIN function data or COS function data is used as an R for SIN and COS.
A trigonometric data conversion circuit and a meter device using the trigonometric data conversion circuit, which can suppress the generation amount of conversion error of the function data as much as possible when the one function data is also read as the other function data as the OM, can be achieved. The purpose is to provide.

[0018]

A trigonometric function data conversion circuit of the present invention is designated by a plurality (n) -bit binary data representing a variable in one quadrant of a variable range of a trigonometric function of 0 to 2π radians. Corresponding to the input
A data output circuit that outputs one of SIN function data and COS function data that is targeted based on the intermediate angle of the variable in the one quadrant, and a COS function that reads the SIN function data from the data output circuit. An input inversion control circuit that controls the inversion / non-inversion of the logic level of the binary data input according to whether data is read and inputs the data to the data output circuit, and the function data read from the data output circuit is input to the input circuit. Corresponding to the switching control in the inversion control circuit, SIN function data or CO
And a SIN / COS separation circuit for separating as S function data.

Further, by correcting the input by a predetermined amount at regular intervals of the read cycle of the data output circuit, the function data read from the data output circuit a plurality of times corresponding to a certain input is It is desirable to provide an address input correction circuit that brings the average value closer to the function data read corresponding to the theoretical angle.

[0020]

When, for example, a ROM is used as the data output circuit, an address is designated by the binary data, and the correspondence relationship between the address and the SIN function data and the correspondence relationship between the address and the COS function data are in the one quadrant. One of the SIN function data and the COS function data to be targeted with reference to the intermediate angle of the variable is stored, and the function data is output according to the designated address.

In this case, the variable range 9 of the SIN function or the COS function designated by the n-bit address input
1/2 of the minimum divided angle for every 0 ° divided into 2 ⁿ
One ROM that stores the SIN function data or COS function data corresponding to the angle obtained by adding the amount of is also used as the SIN ROM and the COS ROM, and one function data is transferred to the other by performing the address input inversion control. By reading as function data, address input and S
Correspondence with IN function data and address input and CO
It becomes possible to read out almost accurate function data whose correspondence with the S function data is targeted with reference to the intermediate angle of the variable. Moreover, the circuit configuration required for this is simple, and the cost can be reduced. Further, by adding the address input correction circuit, it is possible to suppress the generation amount of the conversion error of the function data as much as possible.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a first embodiment of the trigonometric function data conversion circuit of the present invention. This trigonometric function data conversion circuit includes an address input inversion control circuit 20 and one ROM.
30 and a SIN / COS separation circuit 40.

The ROM 30 has a variable range 0 for trigonometric functions.
One of SIN function data and COS function data corresponding to an address designated by a plurality of (n) -bit binary data representing a variable in one quadrant (upper quadrant in this example) of 2π radians Is stored and the above function data is output according to the designated address.

In this case, in the ROM 30, as shown in FIG. 2, the correspondence relationship between the address (variable) and the SIN function data and the correspondence relationship between the address and the COS function data are variable intermediate angles (45 ° in this example). ) Is stored as a reference for almost accurate function data.

That is, when SIN function data is stored, SIN {90 ° × (N / 2 ⁿ ) + 90 ° × (1
/ 2 ⁿ ) × (1/2)} is stored in advance, and the COS function data is stored in the COS function data.
{90 ° × (N / 2 ⁿ ) + 90 ° × (1/2 ⁿ ) × (1 /
2)} is stored.

Here, the stored data in the case of n = 4 is: SIN {90 ° × N / 2 ⁿ + 90 ° × (1/2 ⁿ ) × (1/2)} = SIN {90 ° × N / 16 + 45 ° / 16} ...... (1) COS {90 ° × N / 2 ⁿ + 90 ° × (1/2 ⁿ ) × (1/2)} = COS {90 ° × N / 16 + 45 ° / 16} ...... ( 2) That is, the function data shown in FIG. 2 is obtained by dividing the variable range 90 ° of the SIN function or the COS function specified by the n-bit address input into 2 ⁿ angles,
Divided minimum angle (angle of 1 LSB of address input = 90
SI corresponding to the angle obtained by adding 1/2 the amount of ° / 2 ⁿ ).
It is N function data or COS function data.

As a result, SIN {90 ° × N / 16 + 45 ° × / 16} = COS {90 ° × (15−N) / 16 + 45 ° × / 16}.

In this example, the ROM 30 is assumed to store SIN function data. In addition, the ROM3
Instead of 0, it is also possible to use other storage means or a decoder that decodes input data and outputs the SIN function data and COS function data as described above.

The address input inversion control circuit 20 inverts / non-inverts the logic level of the binary data of the address input according to whether the function data stored in the ROM 30 is read out as SIN function data or COS function data. Is to control.

As a concrete example of the address input inversion control circuit 20, as shown in FIG. 3, an address input is inputted to each one input terminal of the exclusive OR gate circuit group 21, and S
A switching control signal c / s for designating whether to read as IN function data or COS function data is input to each of the other input terminals of the exclusive OR gate circuit group 21, and each of the exclusive OR gate circuit group 21 is input. The output is R
It is configured to input to the OM 30.

The SIN / COS separation circuit 40 corresponds to the switching control by the switching control signal c / s, and the ROM 3
The function data read from 0 is separated as SIN function data or COS function data, and is controlled by the switching control signal c / s.

The address input inversion control circuit 20 described above is used.
The SIN / COS separation circuit 40 may be formed on the same chip as the ROM 30 or on a different chip. FIG. 4 shows the timing of an operation example of each part in the trigonometric function data conversion circuit of FIG.

According to the trigonometric function data conversion circuit of the first embodiment, the S specified by the n-bit address input.
One R that stores SIN function data corresponding to an angle obtained by adding 1/2 of the divided minimum angle for each angle obtained by dividing the variable range 90 ° of the IN function or the COS function by 2 ⁿ
The OM 30 is also used as a ROM for SIN and COS, and by performing inversion control of the address input, one function data is read out as the other function data, and the correspondence relationship between the address input and the SIN function data and the address input. It becomes possible to read out almost accurate function data whose correspondence relationship with the COS function data is the target on the basis of the intermediate angle of the variable of 45 °. Moreover, the circuit configuration required for this is simple, and the cost can be reduced.

When the function data shown in FIG. 2 is read from the ROM 30, the correspondence between the address input (horizontal axis) and the function data (vertical axis) is the theory of the SIN function variable or the COS function variable. 1 for entering an address for a corner
½ of LSB, that is, 90 ° × (1/2 ⁿ ) ×
A conversion error is included due to the shift (addition) by (1/2). Second to solve this point
An example is shown below.

FIG. 5A shows a second embodiment of the trigonometric function data conversion circuit of the present invention. This trigonometric function data conversion circuit is different in that an address input correction circuit 10 is added to the input side of the trigonometric function data conversion circuit of the first embodiment in order to correct the conversion error. The same reference numerals are attached.

The address input correction circuit 10 is a ROM
When repeatedly reading the function data from 30, the address input is corrected by a predetermined amount at regular intervals (every two cycles) of the read cycle (in this example, −90 ° × / 2).
By adding ⁿ ), the average value of the function data read from the ROM 30 a plurality of times corresponding to a certain address input is brought closer to the function data read from the ROM 30 corresponding to the theoretical angle.

That is, even if the function data read in a certain read cycle includes a conversion error corresponding to a shift of 90 ° × (1/2 ⁿ ) × (1/2), it is read in the next read cycle. The issued function data is -90 ° x / 2
^The conversion error corresponding to the shift of ⁿ is included.

As a result, if the process of taking the average value of the function data read corresponding to the above two address inputs (for example, the process of DA after the read function data is integrated) is performed, It can be considered that the conversion error is almost eliminated.

As a specific example of the address input correction circuit 10, the address input is input to one input terminal A of the adder circuit 11, and 0 or -1 is alternately applied every read cycle.
Is input to the other input terminal B of the adder circuit 11, and the output D (= D0 to D3) of the adder circuit 11 is input to each one input terminal of the exclusive OR gate circuit group 21. There is. The address input correction circuit 10
May be formed on the same chip as the address input inversion control circuit 20 or on a different chip.

FIG. 5B shows an operation example of each part in the trigonometric function data conversion circuit of FIG. 5A. In the trigonometric function data conversion circuit of the second embodiment, as in the trigonometric function data conversion circuit of the first embodiment, the SIN function or C specified by the n-bit address input is used.
S corresponding to the angle obtained by adding 1/2 of the divided minimum angle for each angle obtained by dividing the variable range 90 ° of the OS function by 2 ⁿ
1 that stores IN function data or COS function data
One ROM is also used as the ROM 30 for SIN and COS, and by performing the inversion control of the address input, one function data is read as the other function data, and the correspondence relationship between the address input and the SIN function data and the address input. It becomes possible to read out almost accurate function data such that the correspondence between the COS function data and the COS function data is the target with reference to the intermediate angle of the variable of 45 °. Moreover, since the address input correction circuit 10 is added, the generation amount of the conversion error of the function data can be suppressed as much as possible.

FIG. 6 shows an address input before correction (theoretical input angle), an address input after correction (actual input angle θ), and S in the trigonometric function data conversion circuit of the second embodiment.
IN function data, COS function data, θt = tan
^-1 (SINθ / COSθ) and the conversion error (θt−θ) are shown as verification results.

Further, in each of the above embodiments, for example, 8
Of the bit address inputs, the upper 2 bits are quadrant designating data for designating one quadrant in the variable range of the SIN function or the COS function, and the remaining lower bits designate the variables in the one quadrant. In the case of the data for executing the above, a polarity processing circuit for processing the polarity (+-) of the function data read from the ROM according to the quadrant designating data is added to the output side of the SIN / COS separation circuit. It is possible to

That is, when the first quadrant is designated, the polarity of the function data read from the ROM is processed as +. When the second quadrant is specified, the polarity of the data read from the ROM as the SIN function data is processed as +, and the polarity of the data read as the COS function data is processed as the −. . When the third quadrant is specified, the polarity of the function data read from the ROM is processed as-. If the fourth quadrant is specified, the S
The polarity of the data read as the IN function data is processed as −, and the polarity of the data read as the data of the COS function is processed as +.

Although the polarity processing circuit can digitally process the function data read from the ROM, the data read from the ROM is DA converted, for example, to perform meter driving circuit. It is also possible to indirectly process such as controlling the applied polarity when applied to the. Alternatively, the trigonometric function may be output by a decoder instead of the ROM.

FIG. 7A shows a block configuration of an example of a meter device in which the trigonometric function data conversion circuit of the present invention is applied to a vehicle-mounted speedometer or tachometer.
In FIG. 7 (A), an analog pointer type meter body 70
2 are arranged so as to be orthogonal to each other as shown in FIG.
The pointing angle of the pointer is determined according to the vector sum of the magnetic fields generated by the currents flowing through the one electromagnetic coil.

The digital data processing circuit 76 receives a pulse signal having a cycle corresponding to the information to be metered and converts it into binary data having a metering angle amount corresponding to the cycle of the pulse signal. .

In the digital data processing circuit 76, the cycle counter 81 receives a pulse signal (meter control signal) having a cycle corresponding to speed information, counts this cycle, and generates data representing a frequency amount. The designated angle quantified data generation circuit 82 generates data (indicated angle quantified data) representing a digital amount corresponding to the meter designated angle in accordance with the frequency amount of the output data of the cycle counter 81.

The trigonometric function data conversion circuit 77, SIN for designating the pointing angle of the pointer according to the binary data obtained by the digital data processing circuit 76,
The data is converted into COS trigonometric function data, as shown in FIG.
It has the configuration of the embodiment as described above with reference to FIG.

DA conversion circuit (or PWM circuit) 84
Is the SI output from the trigonometric function data conversion circuit 77.
The N function data and the COS function data are converted into current or voltage by D / A conversion (or PWM).

The meter drive circuit 85 outputs a current amount corresponding to the output of the DA conversion circuit (or PWM circuit) 84 (that is, a current amount corresponding to the SIN function data and the COS function data) to the meter main unit 70. The electromagnetic coils 71 and 72 are supplied.

FIG. 7B shows a block configuration of an example of a meter device in which the trigonometric function data conversion circuit of the present invention is applied to an on-vehicle fuel meter or temperature meter. Figure 7
The meter device shown in FIG. 7B is different from the meter device shown in FIG. 7A in that an analog data processing circuit 78 is used instead of the digital data processing circuit 76, and the other parts are the same. Therefore, the same reference numerals as those in FIG. The analog data processing circuit 78 receives an analog signal having a level corresponding to the information to be metered and converts it into binary data having a metering angle amount corresponding to the level of the analog signal.

It is needless to say that the present invention is not limited to the above embodiment and various modifications can be made. For example, there is a meter main body using a stepping motor, and the meter main body using this stepping motor can also be controlled by the same control method as described above.

[0053]

As described above, according to the trigonometric function data conversion circuit of the present invention and the meter device using the same, the SI
When one ROM storing N function data or COS function data is also used as a ROM for SIN and COS and one function data is read out as the other function data, the cost can be reduced and the function can be achieved by a simple circuit configuration. The amount of data conversion error generated can be suppressed as much as possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a trigonometric function data conversion circuit of the present invention.

FIG. 2 is a diagram for explaining a correspondence relationship between an address input to a ROM in FIG. 1 and SIN function data and a correspondence relationship between an address and COS function data.

FIG. 3 is a circuit diagram showing a specific example of an address input inversion control circuit in FIG.

FIG. 4 is a timing diagram showing an operation example of each unit in the trigonometric function data conversion circuit of FIG.

FIG. 5 is a block diagram showing a second embodiment of the trigonometric function data conversion circuit of the present invention and a timing chart showing an operation example of each unit.

6 is a diagram showing a result of verifying a conversion error in the trigonometric function data conversion circuit of FIG.

FIG. 7 is a block diagram showing a different example of a meter device according to an application example of the trigonometric function data conversion circuit of the present invention.

FIG. 8 is a block diagram showing a conventional example of an analog pointer type speedometer device mounted on an automobile.

9 is a perspective view schematically showing the structure of a meter body in FIG.

10 is a characteristic diagram showing a relationship between a pointing angle and output data in the pointing angle quantified data generation circuit in FIG. 8 and a relationship between a pointing angle in the meter body in FIG. 8 and a current amount and direction to flow in an electromagnetic coil.

11 is a block diagram showing a trigonometric function data conversion circuit in FIG. 8 and a timing diagram showing an operation example thereof.

FIG. 12 shows one ROM that stores SIN function data as a modification of the trigonometric function data conversion circuit in FIG.
SIN function, C when it is also used as a ROM for
The figure shown in order to demonstrate the symmetry of an OS function.

[Explanation of symbols]

10 ... Address input correction circuit, 11 ... Addition circuit, 20 ...
Address input inversion control circuit, 30 ... ROM, 40 ... SI
N / COS separation circuit, 70 ... Analog main body of meter, 71, 72 ... Electromagnetic coil, 73 ... Rotating shaft, 74 ... Permanent magnet, 75 ... Pointer, 76 ... Digital data processing circuit,
Reference numeral 77 ... Trigonometric function data conversion circuit, 78 ... Analog data processing circuit, 81 ... Cycle counter, 82 ... Indication angle quantified data generation circuit, 85 ... Meter drive circuit.

Claims (9)

[Claims] 1. A variable in one quadrant corresponding to an input designated by a plurality (n) -bit binary data representing a variable in one quadrant of a variable range 0 to 2π radians of a trigonometric function. A data output circuit that outputs one of the target SIN function data and COS function data based on the intermediate angle, and whether the SIN function data is read from the data output circuit.
An input inversion control circuit that controls the inversion / non-inversion of the logic level of the binary data input according to whether to read the function data and inputs the data to the data output circuit, and the function data read from the data output circuit as described above. A trigonometric function data conversion circuit comprising: a SIN / COS separation circuit that separates as SIN function data or COS function data corresponding to switching control in an input inversion control circuit. 2. The trigonometric function data conversion circuit according to claim 1, wherein the data output circuit corresponds to one of SIN function data and COS function data corresponding to an address specified by the binary data. Between SIN function data and address and C
A read-only memory (ROM that stores the function data whose correspondence with the OS function data is based on the intermediate angle of the variable in the one quadrant and outputs the function data according to the designated address ) Or a decoder, a trigonometric data conversion circuit. 3. The trigonometric function data conversion circuit according to claim 2, wherein the function data stored in the ROM is:
For each angle obtained by dividing the variable range 90 ° of the SIN function or the COS function specified by the n-bit address into 2 ⁿ , the function data corresponding to the angle obtained by adding 1/2 of the divided minimum angle is added. Characteristic trigonometric data conversion circuit. 4. The trigonometric function data conversion circuit according to claim 2, wherein the ROM corresponds to an address N, SIN {90 ° × (N / 2 ⁿ ) + 90 ° × (1/2 ⁿ ).
A trigonometric function data conversion circuit characterized by storing SIN function data proportional to x (1/2)}. 5. The trigonometric function data conversion circuit according to claim 2, further comprising correcting a predetermined amount of address input at regular intervals of a read cycle of the ROM, Triangle characterized by comprising an address input correction circuit for bringing an average value of the function data read from the ROM a plurality of times in response to an address input to approach the function data read from the ROM in correspondence with the theoretical angle. Function data conversion circuit. 6. The trigonometric function data conversion circuit according to claim 5, wherein when the address input correction circuit repeatedly reads the function data from the ROM, the address input correction circuit is −90 ° with respect to the address input every two read cycles. × /
A trigonometric function data conversion circuit characterized by adding 2 ⁿ . 7. The trigonometric function data conversion circuit according to claim 2, wherein the upper 2 bits of the plurality of bits of the binary data designating the address are S.
It is quadrant designating data for designating one quadrant of the four quadrants, which is the variable range of the IN function or the COS function, and the remaining lower bits are data for designating a variable within the one quadrant, A trigonometric function data conversion circuit for processing the polarity of function data read from the ROM according to the quadrant designating data. 8. An analog pointer type meter main body configured so that a pointing angle of a pointer is determined by a magnetic field generated by a current flowing through two electromagnetic coils and a magnetic field of a permanent magnet on a pointer shaft, and a meter pointing object. A digital signal processing circuit for inputting a pulse signal having a cycle corresponding to the information and converting it into binary data having a meter indicating angle amount corresponding to the cycle of the pulse signal, and a variable range 0 to 2 of a trigonometric function.
A SIN that corresponds to an input designated by a plurality of (n) -bit binary data representing a variable in one quadrant of π radian and is targeted with reference to the intermediate angle of the variable in the one quadrant. Function data and C
A data output circuit for outputting one of the OS function data, and an average value of the function data read a plurality of times corresponding to an input from the data output circuit is brought close to the function data read corresponding to the theoretical angle. For correcting the binary data input from the digital data processing circuit by a predetermined amount, and depending on whether SIN function data or COS function data is read from the data output circuit. Corresponding to the input inversion control circuit for controlling the inversion / non-inversion of the logical level of the nary data input and inputting it to the data output circuit, and the switching control of the function data read from the data output circuit in the input inversion control circuit. Then SIN function data or C
A SIN / COS separation circuit that separates as OS function data, and a meter drive circuit that supplies a current amount corresponding to the SIN function data and COS function data output from the SIN / COS separation circuit to the two electromagnetic coils of the meter body. A meter device comprising: 9. An analog pointer type meter main body configured so that a pointing angle of a pointer is determined by a magnetic field generated by a current flowing through two electromagnetic coils and a magnetic field of a permanent magnet on a pointer axis, and a meter pointing object. And an analog data processing circuit for inputting an analog signal having a level according to the information and converting it into binary data having a meter indicating angle amount according to the level of the analog signal, and a variable range of the trigonometric function of 0 to 2π radian. SIN function data that becomes a target based on the intermediate angle of the variable in the one quadrant, corresponding to the input designated by the multiple (n) -bit binary data representing the variable in one quadrant, and A data output circuit for outputting one of the COS function data and a plurality of times read out corresponding to an input from the data output circuit. Provided to bring the average value of the function data to the function data to be read corresponding to the theoretical angle, an input correction circuit for performing a predetermined amount of correction on the binary data inputted from the analog data processing circuit,
An input inversion control circuit for controlling inversion / non-inversion of a logical level of a binary data input according to whether to read SIN function data or COS function data from the data output circuit and input the data to the data output circuit; SIN / COS that separates the function data read from the data output circuit into SIN function data or COS function data corresponding to the switching control in the input inversion control circuit.
A meter comprising: a separation circuit; and a meter drive circuit that supplies a current amount corresponding to the SIN function data and the COS function data input from the SIN / COS separation circuit to the two electromagnetic coils of the meter body. apparatus.