JPH06103761B2 - 4-phase differential rotation sensor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a four-phase differential rotation sensor, and more specifically, a four-phase difference having a structure capable of improving sensitivity and withstanding use at high temperatures. Regarding dynamic rotation sensor.

[Prior Art] An example of a conventional four-phase differential rotation sensor will be described with reference to FIGS. 4 to 6.

In the 4-phase differential rotation sensor 51 shown in FIG.
Are electrode parts, and 61 to 68 are semiconductor magnetoresistive elements.

The semiconductor magnetoresistive element 61 is one in which a stripe of InSb extending in the Y direction is reciprocated once and electrode portions 52 and 53 are provided at both ends thereof. Short bars are formed on the stripes.

The semiconductor magnetoresistive element 62 is also similar to the semiconductor magnetoresistive element 61 except that the electrodes are 52a and 54, and the electrode 52a is an electrode.
It is connected to the electrode 52 via 52b.

The other semiconductor magnetoresistive elements 63 to 68 are similarly configured.

As shown in FIG. 5, the distance between the semiconductor magnetoresistive elements 61 to 68 is 1/4 of the pitch P of the teeth of the rotation detecting gear, and the central distance is 3 / 4P. Therefore, the spacing ratio is 1: 1: 1: 3: 1: 1: 1.

As shown in the figure, the power supply voltage Vin is connected to the electrodes 52 and 56, Gnd is connected to the electrodes 55 and 59, the electrode 53 is the A phase output terminal, the electrode 54 is the phase output terminal, and the electrode 57 is the phase output terminal. And the electrode 58 as the output terminal of the B phase.

FIG. 6 is a characteristic diagram showing the relationship of the current I flowing through one semiconductor magnetoresistive element at the power supply voltage Vin. a is temperature 25 ℃, b
Is 70 ℃, c is 80 ℃, d is 90 ℃, and e is 100 ℃.

[Problems to be Solved by the Invention] In the above-mentioned conventional four-phase differential rotation sensor 51, the power supply voltage is
If Vin is larger than 5V, the current I becomes too large, so the operating temperature limit becomes lower than 25 ° C and it cannot be used for practical use. On the other hand, if the power supply voltage Vin is smaller than 5V,
Since the output signal becomes too small, the S / N becomes insufficient and it cannot be put to practical use.

Therefore, the power supply voltage Vin is usually set to 5V.

However, in order to improve the sensitivity, the power supply voltage Vin is preferably higher than 5 V, and the operating temperature limit is preferably at least about 80 ° C.

Therefore, an object of the present invention is to provide a four-phase differential rotation sensor capable of increasing the power supply voltage Vin and increasing the operating temperature limit to 80 ° C. or higher.

[Means for Solving the Problems] The four-phase differential rotation sensor of the present invention is a magnetic-sensitive semiconductor Y
The semiconductor magnetoresistive element in which the stripe extending in the direction is made to reciprocate once and half and the electrode portions are provided at both ends thereof is arranged in eight rows in the X direction
The structural feature is that the interval ratio of each row is set to 2: 1: 2: 1: 2: 1: 2.

[Operation] In the four-phase differential rotation sensor of the present invention, since the stripe of the magnetic sensitive semiconductor makes one and a half round trips, the resistance value of each semiconductor magnetoresistive element becomes larger than that of the one and two round trips. Therefore, the current I is limited, so that the power supply voltage Vin can be increased and the sensitivity can be increased.

Also, the spacing between the rows of the semiconductor magnetoresistive elements is 2k, k, 2k, k, 2k, k, 2k, where k is a proportional constant, and k = with respect to the tooth pitch P of the rotation detection gear. P / 4 is suitable for A
It becomes possible to take out phases, phases, phases, and B phases.

[Examples] The present invention will be described in more detail below with reference to the examples shown in the drawings. The present invention is not limited to this.

In the 4-phase differential rotation sensor 1 shown in FIG.
Is an electrode part, and 11 to 18 are semiconductor magnetoresistive elements.

The semiconductor magnetoresistive element 11 is one in which a stripe of InSb extending in the Y direction is made to reciprocate once and half and the electrode portions 2 and 3 are provided at both ends thereof. Short bars are formed on the stripes. Further, the width of the stripe is also made narrower than before.

The semiconductor magnetoresistive element 12 is also similar to the semiconductor magnetoresistive element 11, except that the stripe is made between the electrode 3 and the electrode 4 one and a half times.

The other semiconductor magnetoresistive elements 13 to 18 have the same structure.

The semiconductor magnetoresistive elements 11 to 18 are arranged in the X direction, and their intervals are such that 1/2 and 1/4 of the tooth pitch P of the rotation detecting gear are alternated as shown in FIG. There is. The spacing ratio is
It is 2: 1: 2: 1: 2: 1: 2.

As shown in the figure, the power supply voltage Vin is connected to the electrodes 2, 6 and 10 and the Gnd is connected to the electrodes 4 and 8.

If the teeth of the rotation detecting gear move in the X direction, the electrode 3 moves to the B
The phase output terminal, the electrode 5 serves as the phase output terminal, the electrode 7 serves as the phase output terminal, and the electrode 9 serves as the A phase output terminal.

FIG. 3 shows the power supply voltage in the four-phase differential rotation sensor 1 described above.
It is the characteristic view which measured the relationship between Vin and the electric current I which flows into one semiconductor magnetoresistive element. a is temperature 25 ℃, b is temperature 70 ℃, c
Is 80 ℃, d is 90 ℃, and e is 100 ℃.

Since the resistance value of each of the semiconductor magnetoresistive elements 11 to 18 is larger than the conventional value, the current I is about 1/3 of the conventional value with respect to the same value of the power supply voltage Vin as the conventional value. Therefore, if the operating temperature is the same as the conventional one, the power supply voltage Vin can be increased to about three times that of the conventional one, and the sensitivity can be improved. Also, if the power supply voltage Vin is the same as the conventional one, it will be able to withstand operating temperatures of 100 ° C or higher.

[Effect of the Invention] According to the four-phase differential rotation sensor of the present invention, the resistance value of each semiconductor magnetoresistive element increases and the current is limited, so that the supply voltage can be increased and the sensitivity can be improved. Moreover, it becomes possible to withstand use at high temperatures.

[Brief description of drawings]

FIG. 1 is a plan view of a main portion of a 4-phase differential rotation sensor according to an embodiment of the present invention, FIG. 2 is a connection diagram of power supply / signals for the 4-phase differential rotation sensor of FIG. 1, and FIG. 3 is FIG. Fig. 4 is a voltage-current characteristic diagram of the 4-phase differential rotation sensor of Fig. 4, Fig. 4 is a plan view of the main part of an example of a conventional 4-phase differential rotation sensor, and Fig. 5 is a connection of power supply / signal to the 4-phase differential rotation sensor of Fig. 6 and 6 are voltage-current characteristic diagrams of the four-phase differential rotation sensor of FIG. (Description of symbols) 1 ... 4-phase differential rotation sensor 2-10 ... Electrode section 11-18 ... Semiconductor magnetoresistive element.

Claims (1)

[Claims] 1. A semiconductor magnetoresistive element in which a stripe extending in the Y direction of a magnetic sensitive semiconductor is made to reciprocate once and a half and electrode portions are provided at both ends thereof in eight rows in the X direction, and a spacing ratio of each row is 2:
4-phase differential rotation sensor characterized by 1: 2: 1: 2: 1: 2.