JP4093381B2 - Detection signal processing device for rotation sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotation sensor detection signal processing apparatus that detects a rotation direction and a rotation speed of a rotating body using two sensor elements.
[0002]
[Problems to be solved by the invention]
As a detection processing circuit of this type of rotation sensor, for example, there is a circuit disclosed in Japanese Utility Model Laid-Open No. 3-122364. That is, in this device, two magnetic sensors are arranged so as to face the rotating body, and the rotational direction and the rotational speed of the rotating body are detected based on the detection signal having a phase difference output from these. What has been disclosed is disclosed.
[0003]
By the way, in such a detection signal processing device of the rotation sensor, since the pulse signal is output from different output terminals corresponding to the rotation direction of the rotating body, the circuit configuration becomes complicated, and usually this is the case. In addition to an output terminal, a power supply terminal and a ground terminal are generally provided. Therefore, the number of wires between the part where the rotating body is disposed and the part using the signal is large. There is a problem that space is extra and signal processing is troublesome.
[0004]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a simple circuit configuration and wiring that can output a detection signal indicating the rotation direction and the number of rotations only by providing two external terminals. An object of the present invention is to provide a detection signal processing device for a rotation sensor that can reduce the number of the rotation sensors.
[0005]
[Means for Solving the Problems]
According to the invention of claim 1, with the rotation of the rotating body First and second of Magnetic sensor When the detection signal is output from the First and second of Magnetic sensor The determination signal corresponding to the rotation direction of the rotating body is output based on the detection signal, and the pulse signal generating means First and second magnetic sensors A pulse signal is output at the time when the level of the detection signal output from at least one of them changes, and the time width of the pulse signal is set to be different according to the determination signal of the rotation direction determination means and output, Further, the binary current output means causes a current to flow between the input / output terminals with different current amounts corresponding to the level change of the pulse signal output from the pulse signal generating means. As a result, the amount of current when power is supplied from the outside via the input / output terminal varies depending on the rotational direction and the rotational speed, so that these signals can be detected by performing at least two wirings. .
[0006]
The pulse signal generating means is composed of first and second pulse signal generating circuits and an output circuit, Set to different time span Since the pulse signals having the first and second time widths are output corresponding to either forward or reverse rotation of the rotating body according to the determination signal from the rotation direction determination means, the rotation direction and the rotation speed can be achieved with a simple configuration. It is possible to output a signal according to.
[0007]
Claim 2 According to the described invention, the first or second signal is generated by the pulse signal generating means. Magnetic sensor Since the pulse signal is output at both the rising and falling level change timings of the detection signal, the number of output of the pulse signal accompanying the rotation of the rotating body is doubled to improve the detection accuracy of the rotation number (rotation angle). Can do.
[0008]
Claim 3 According to the described invention, the first and second signals are generated by the pulse signal generating means. Magnetic sensor Since the pulse signal is output at both level change timings of the detection signal, the number of output of the pulse signal accompanying the rotation of the rotating body can be doubled to improve the detection accuracy of the rotation number (rotation angle).
[0009]
Claim 4 According to the described invention, the rotation direction erroneous determination preventing means is provided, and thereby, two of the two after the determination signal is output. Magnetic sensor During the period until the level change of the detection signal alternately occurs, the pulse signal generation means prohibits the output of the pulse signal, so that, for example, the vibration occurs when the rotation direction of the rotating body changes. Due to Magnetic sensor Even when the level of the detection signal output from the sensor changes in level that does not accompany the rotation of the rotating body, this can be invalidated to prevent erroneous detection and perform an accurate detection operation.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment in which the present invention is applied to a rotation sensor that detects the rotation speed and rotation direction of a vehicle wheel will be described below with reference to FIGS.
This is, for example, arranged in a rotation detector part provided on each wheel to detect the rotation state of the wheel necessary for control such as ABS (Antilock Brake System), and from low speed rotation to high speed rotation. The forward rotation and the reverse rotation are detected with high accuracy.
[0014]
A gear 1 as a rotating body that is a target for detecting the rotation direction and the number of rotations is provided so as to rotate integrally with an automobile tire (not shown), and is made of a magnetic material. The gear 1 is formed with a crest 1a and a trough 1b at a predetermined pitch on the outer periphery. The rotation detection device 2 is arranged corresponding to the gear 1 and detects the peak 1a and valley 1b of the gear 1 and outputs the detection signal.
[0015]
In this rotation detection device 2, the two magnetic sensors 3 and 4 as sensor elements are configured to output detection signals using magnetoresistive elements (MRE), both of which are the outer peripheral portions of the gear 1. The distance between them is set to a distance obtained by adding or subtracting a distance corresponding to 1/4 pitch to a distance that is an integral multiple of the pitch of the peak 1a. Then, as will be described later, rectangular detection signals Sa and Sb having a phase difference of 1/4 as shown in FIGS. 3A and 3B from the magnetic sensors 3 and 4 as the gear 1 rotates. Is output.
[0016]
The latch circuit 5 as the rotation direction determination means is composed of a D-type flip-flop. The data input terminal D is connected to the output terminal of the magnetic sensor 3, and the clock input terminal CL is connected to the output terminal of the magnetic sensor 4. Are connected, and the output terminal Q outputs a determination signal Sc indicating the rotation direction at the output level.
[0017]
The pulse signal generating means comprises first and second pulse signal generating circuits 6 and 7 and a signal selection circuit 8 as an output circuit. The output terminals of the second magnetic sensor 4 are connected to the input terminals of the first and second pulse signal generation circuits 6 and 7, respectively, and the pulse signals having the first time width T1 and the second time width T2 are respectively connected. Pulse signals Sd and Se are output. The two input terminals of the signal selection circuit 8 are connected to the output terminals of the first and second pulse signal generation circuits 6 and 7, respectively, and the control terminal is connected to the output terminal Q of the latch circuit 5. .
[0018]
The signal selection circuit 8 validates the output signal Sd of the first pulse signal generation circuit 6 and outputs the output signal Sf when the high-level determination signal Sc indicating the forward rotation of the gear 1 is given from the latch circuit 5. When the low level determination signal Sc indicating the reverse rotation of the gear 1 is given, the output signal Se of the second pulse signal generation circuit 7 is validated and output as the output signal Sf.
[0019]
The binary current output circuit 9 as the binary current output means outputs the output current Is at two different current value levels Isa and Isb, and the level of the output signal Sf supplied from the signal selection circuit 8 is low. Sometimes, the output current Isa is caused to flow at a low level current value corresponding to the current consumption of the entire device. When the level of the output signal Sf supplied from the signal selection circuit 8 is high level, a predetermined current is provided by a constant current source provided therein. The output current Isb is configured to flow at a high level current value obtained by adding the value Ic.
[0020]
The rotation detection device 2 is provided with two external terminals P1 and P2 as input / output terminals. The external terminal P1 is connected to the power supply terminals of each circuit provided in the apparatus, and functions as a power supply input terminal for supplying power to these circuits from an external power supply. The output terminal of the binary current output circuit 9 is connected to the external terminal P2, and an output current Is that is output corresponding to the rotation state of the gear 1 is output.
[0021]
Now, as shown in FIG. 2, such a rotation detection device 2 is connected to an arithmetic circuit unit disposed in a predetermined part of the automobile from two external terminals P1 and P2 via two signal lines 10a and 10b. Connected. In this case, the external terminal P1 is connected to the positive terminal of the in-vehicle battery 11 through the signal line 10a, and the external terminal P2 is connected from the signal line 10b to the ground terminal through the detection resistor 12. A voltage detection means 13 is connected to the detection resistor 12, and the detection voltage signal Vs is input to an arithmetic circuit section (not shown).
[0022]
Next, the operation of this embodiment will be described with reference to the time chart shown in FIG. FIG. 3 shows the waveform of the signal of each part when the gear 1 turns from the forward rotation to the reverse rotation. That is, when the gear 1 is rotating forward, the first and second magnetic sensors 3 and 4 output detection signals as shown in FIGS. 3 (a) and 3 (b), respectively.
[0023]
The magnetic sensors 3 and 4 output a high level detection signal when the peak 1a of the gear 1 is opposed, and output a low level detection signal when the valley 1b is opposed. Rectangular detection signals Sa and Sb are output for one pitch from the state facing 1a to the next peak 1a facing. The detection signals Sa and Sb are outputs that are out of phase by a quarter pitch due to the positional relationship between the magnetic sensors 3 and 4.
[0024]
Since the detection signal Sa from the magnetic sensor 3 is input to the data input terminal D of the latch circuit 5, and the detection signal Sb from the magnetic sensor 4 is input to the clock input terminal CL of the latch circuit 5, the latch circuit 5 When 1 is rotating forward, a high level signal is output as the determination signal Sc at the rising timing of the detection signal Sb. When the gear 1 is rotating in reverse, a low level signal is output as the determination signal Sc. It comes to output. That is, the determination signal Sc is a logical product (AND) of the detection signals Sa and Sb from the two magnetic sensors 3 and 4 and can be expressed as the following equation (1), and the waveform thereof is shown in FIG. As shown.
Sc = Sa · Sb (1)
[0025]
Next, the first pulse signal generation circuit 6 outputs the first pulse signal Sd having the first time width T1 at the rising timing of the detection signal Sb (see FIG. 4D), and the second pulse Similarly, the signal generation circuit 7 outputs the second pulse signal Se having the second time width T2 at the rising timing of the detection signal Sb (see (e) in the figure). In this case, the time width T1 of the first pulse signal Sd is set longer than the time width T2 of the second pulse signal Se (T1> T2).
[0026]
The signal selection circuit 8 validates the pulse signal Sd from the first pulse signal generation circuit 6 when the high-level determination signal Sc corresponding to the forward rotation is given from the latch circuit 5, and corresponds to the reverse rotation. When the low level determination signal Sc is given, the pulse signal Se from the second pulse signal generation circuit 7 is validated and output as the output signal Sf (see FIG. 5F).
[0027]
In this case, as shown in the following equation (2), the output signal Sf is the logical product (AND) of the determination signal Sc and the pulse signal Sd having the first time width T1, and the negation of the determination signal Sc and the second time. It can be expressed as a logical operation expression obtained by logical sum (OR) of the logical product with the pulse signal Se of width T2.
Sf = Sc · Sd + NOT (Sc) · Se (2)
However, NOT (A) indicates the negation of the logical value A
[0028]
When the output signal Sf obtained in this way is input to the binary current output circuit 9, when the output signal Sf is at low level, the output current Isa flows at a low level current value, and the output signal Sf is at high level. In this case, the output current Isb (= Isa + Ic) is caused to flow at a high level current value by adding and flowing the predetermined current Ic from the constant current source (see (g) in the figure). Moreover, this relationship is expressed by the following equation (3).
Is = Isa + Sf · Ic (3)
[0029]
As a result, the current supplied from the in-vehicle battery 11 flows between the external terminals P1 and P2 of the rotation detection device 2 as the output current Is, with a current value Isa or Isb depending on the rotation direction. . When the output current Is flows through the detection resistor 12, the terminal voltage Vs differs according to the current levels Isa and Isb, so that a pulse signal corresponding to the rotation speed of the gear 1 can be detected. By detecting the time of the current level Isb from the terminal voltage Vs, the rotation direction of the gear 1 can be detected.
[0030]
According to the present embodiment, the information corresponding to the rotation direction of the gear 1 is output by setting the time widths of the pulse signals indicating the rotation speeds to different time widths T1 and T2. Can be configured with only two of P1 and P2, the external wiring can be configured easily and inexpensively, and the problem that a high level current continues to flow due to the stop position of the gear 1 is solved. The current consumption and heat generation of the device can be suppressed.
[0031]
(Second Embodiment)
FIGS. 4 and 5 show a second embodiment of the present invention. Hereinafter, parts different from the first embodiment will be described. In the rotation detecting device 14 in this embodiment, the first and second pulse signal generating circuits 15 and 16 are respectively supplied with detection signals Sa and Sb (see FIG. a) and (b)) are input so that each outputs a pulse signal at both the rising timing and falling timing of the input signal.
[0032]
In this case, the pulse signal Sd output from the first pulse signal generation circuit 15 is set to the time width T1, and the pulse signal Se output from the second pulse signal generation circuit 16 is from the time width T1 described above. Is set to a short time width T2 (see FIGS. 5D and 5E).
[0033]
According to the second embodiment having such a configuration, the number of pulses to be output can be increased as compared with the first embodiment, and in particular, the amount of information can be increased in the low-speed rotation state of the gear 1. Therefore, the detection accuracy of the rotation speed of the gear 1 can be improved.
[0034]
In the above-described embodiment, the pulse signal generation circuits 15 and 16 are configured to always output a pulse signal at both the rising timing and falling timing of the input signal. Alternatively, a pulse signal can be output only.
[0035]
(Third embodiment)
FIGS. 6 and 7 show a third embodiment of the present invention. Hereinafter, parts different from the first embodiment will be described. In the rotation detection device 17 in this embodiment, when the rotation direction of the gear 1 is reversed, the rotation detection device 17 corresponds to the case where a short pulse signal is output from the magnetic sensors 3 and 4 by vibration or the like. The prohibition circuit 18 is provided as a rotation direction error determination preventing means for preventing erroneous detection of the direction.
[0036]
The inhibition circuit 18 includes first to third D-type flip-flops 19, 20, 21 and an exclusive OR circuit 22. The data input terminal D and the clock input terminal CL of the flip-flop 19 are connected to the output terminals of the magnetic sensors 3 and 4, respectively, and the output terminal Q 1 is connected to the data input terminal D of the flip-flop 20. The clock input terminal CL of the flip-flop 20 is connected to the output terminal of the magnetic sensor 3, and the output terminal Q 2 is connected to the data input terminal D of the flip-flop 21. The clock input terminal CL of the flip-flop 21 is connected to the output terminal of the magnetic sensor 4.
[0037]
Two input terminals of the exclusive OR circuit 22 are connected to the output terminals Q1 and Q3 of the flip-flops 19 and 21, respectively. The output terminal of the exclusive OR circuit 22 is connected to the control input terminals of the pulse signal generation circuits 6 and 7. Then, the exclusive OR circuit 22 outputs a prohibition signal Sg, which will be described later, as an output signal of the prohibition circuit 18 and prohibits the output of the pulse signal by the first and second pulse signal generation circuits 6 and 7. .
[0038]
According to the above configuration, even when there is an incorrect detection signal due to the occurrence of mechanical vibration of the device when the gear 1 turns from the normal rotation state to the reverse rotation in the same manner as described above. Detection operation can be performed. That is, when the position where the gear 1 is stopped is, for example, the boundary portion between the peak portion 1a and the valley portion 1b with respect to the first magnetic sensor 3, an illegal occurrence caused by vibration applied to the gear 1 from the outside. It is assumed that a pulse signal is output as the detection signal Sa.
[0039]
In this case, in the prohibition circuit 18, first, when the gear 1 rotates in the reverse direction, the output terminal Q1 of the flip-flop 19 outputs a low level signal (see FIG. 7 (i)). The logical OR circuit 22 outputs a high level signal as the inhibition signal Sg (see FIG. 4D). Thereafter, when a short pulse signal resulting from vibration is output from the magnetic sensor 3, the output terminal Q2 of the flip-flop 20 outputs a low-level signal (see FIG. 6 (j)), but at this time it is prohibited. Since the signal Sg is continuously output, the first and second pulse signal generation circuits 6 and 7 are prohibited from outputting pulse signals.
[0040]
Then, since the output signal Q3 of the flip-flop 21 changes to the low level at the rising timing of the detection signal Sb of the magnetic sensor 4 (see (k) in the figure), the inhibition signal Sg is inverted to the low level. As a result, the first and second pulse signal generation circuits 6 and 7 are released from the pulse signal output prohibition state, and therefore output the pulse signals Sd and Se at the subsequent rise timing of the detection signal Sa from the magnetic sensor 3, respectively. To come.
[0041]
According to the third embodiment, the level of the detection signals Sa and Sb is alternately inverted from the two magnetic sensors 3 and 4 immediately after the prohibition circuit 18 is provided and the rotation direction of the gear 1 is inverted. Since the prohibition signal Sg is output until it is generated and the output of the pulse signals Sd and Se is prohibited to the first and second pulse signal generation circuits 6 and 7, it is caused from the outside due to the stop position of the gear 1. Even when an illegal pulse signal is output from the magnetic sensors 3 and 4 when vibration is applied, it can be invalidated, so that an accurate detection operation can be performed.
[0042]
(Fourth embodiment)
FIGS. 8 to 10 show a fourth embodiment of the present invention. Hereinafter, parts different from the first embodiment will be described. In the rotation detection device 23 of the present embodiment, a time setting circuit 24 is provided as an extrinsic false detection prevention means for preventing false detection when receiving an extrinsic magnetic field.
[0043]
In the time setting circuit 24, the output terminals of the magnetic sensors 3 and 4 are connected to the two input terminals of the exclusive OR circuit 25, and the detection signals Sa and Sb given from the two magnetic sensors 3 and 4 are excluded. A logical OR is calculated and output as an output signal Sh. A series circuit of two npn transistors 27 and 28 is connected between the external terminal P1 and the ground terminal via the constant current source 26.
[0044]
The output terminal of the exclusive OR circuit 25 is connected to the base of the transistor 27 and is connected to the base of the transistor 28 via the inverter circuit 29. The emitter of the transistor 27 is connected to the non-inverting input terminal of the comparator 30 and is grounded via the capacitor 31. The inverting input terminal of the comparator 30 is grounded via a DC power supply 32 that provides a comparison threshold voltage Vth. The output terminal of the comparator 30 is connected to the input terminals of the first and second pulse signal generating circuits 6 and 7 so as to give an output signal Sj.
[0045]
In the above-described configuration, in the normal case where no extrinsic magnetic field acts, as shown in FIGS. 9A and 9B, the gear 1 rotates as shown in FIGS. 9A and 9B. Detection signals Sa and Sb having a phase difference of 2 are output from the magnetic sensors 3 and 4. In the exclusive OR circuit 25, the exclusive OR of these detection signals Sa and Sb is calculated and a signal Sh is output (see (c) in the figure). As a result, the transistor 28 is turned off and the transistor 27 is turned on, so that the capacitor 31 is charged with a constant current via the constant current source 26.
[0046]
At this time, in the normal case due to the rotation of the gear 1, there is always a phase difference of a predetermined time or more, so the high level period of the signal Sh is long, and the terminal voltage Vc of the capacitor 31 becomes higher than the threshold voltage Vth. (See (d) in the figure). Accordingly, the comparator 30 outputs the high level output signal Sj from the time when the terminal voltage Vc of the capacitor 31 exceeds the threshold voltage Vth.
[0047]
When the output signal Sh of the exclusive OR circuit 25 is inverted to a low level, the transistor 27 is turned off and the transistor 28 is turned on, so that the charge of the capacitor 31 is discharged, and the terminal voltage Vc becomes the threshold. When the value voltage becomes lower than Vth, the output signal Sj of the comparator 30 is inverted to the low level.
[0048]
On the other hand, when an extrinsic magnetic field such as a strong magnet acts in the vicinity of the magnetic sensors 3 and 4, the magnetic field changes in both the magnetic sensors 3 and 4 almost simultaneously, so FIGS. ), The phase difference between the detection signals Sa and Sb is output as being shorter than that described above. As a result, the high-level period of the output Sh of the exclusive OR circuit 25 is also short (see (c) in the figure), and the discharge operation is started before the terminal voltage Vc of the capacitor 31 exceeds the threshold voltage Vth. It will end up. As a result, in such a case, the output signal Sj output from the comparator 30 remains at a low level, and the output current Is having a high current value is not output from the binary current output circuit 9 as well. Can be prevented.
[0049]
(Fifth embodiment)
FIG. 11 and FIG. 12 show a fifth embodiment of the present invention. Hereinafter, parts different from the first embodiment will be described. In the rotation detection device 33 of the present embodiment, the output terminal of the first magnetic sensor 3 is connected to the external terminal P2 via the first constant current circuit 34 and to the pulse signal generation circuit 35. The first constant current circuit 34 outputs a current having a predetermined current value Ia during a period when a high level signal is applied.
[0050]
The pulse signal generation circuit 35 outputs a pulse signal Sk having a predetermined short time width T3, and its output terminal is connected to the input terminal of the second constant current circuit 36. The second constant current circuit 36 outputs a current having a predetermined current value Ib during a period when a high level signal is applied. The switch circuit 37 outputs the output current Ib of the second constant current circuit 36 to the external terminal P2. The switch circuit 37 is in an off state when the latch circuit 5 is provided with a high-level determination signal Sc indicating the normal rotation state. Thus, when the low-level determination signal Sc indicating reverse rotation is applied, the signal is turned on.
[0051]
According to the above configuration, when the gear 1 is rotating forward, the current of the current value Ia is output from the first constant current circuit 34 while the detection signal Sa of the magnetic sensor 3 is at a high level. (See FIGS. 11 (a) and 11 (e)), the second constant current circuit 36 outputs a pulse signal having a predetermined time width T3 at the rising timing of the detection signal Sa. In this state, since the high-level determination signal Sc is output from the latch circuit 5 (see FIG. 5C), the switch circuit 37 is held in the OFF state, so that the second constant current circuit 36 The output current Ib is not output to the external terminal P2. Therefore, in the forward rotation state of the gear 1, a current Ia having a waveform corresponding to the level of the detection signal Sa is output (see (g) in the figure).
[0052]
On the other hand, when the gear 1 turns to reverse rotation, the latch circuit 5 outputs the low level determination signal Sc (see FIG. 5C), so that the switch circuit 37 is turned on, and the first Then, the currents Ia and Ib of the second constant current circuits 34 and 37 are output (see (g) in the figure).
[0053]
As a result, when the gear 1 is rotating in the reverse direction, a short pulse-like current Ib is added to the head of the pulse-like current Ia corresponding to the detection signal Sa, and output is performed. By detecting the terminal voltage Vs of the resistor 12, the rotational direction and the rotational speed of the gear 1 can be detected. Further, in this case, since the current Ib indicating the reverse rotation state is added and output only for a short time, the generation of heat can be suppressed and the current consumption can be reduced.
[0054]
(Sixth embodiment)
FIG. 13 and FIG. 14 show a sixth embodiment of the present invention. Hereinafter, parts different from the fifth embodiment will be described. In this embodiment, in addition to the pulse signal generation circuit (first pulse signal generation circuit) 35 and the second constant current circuit 36, a second pulse signal generation circuit 38 and a third constant current circuit 39 are provided. Thus, the rotation detection device 40 is configured. In this case, the second pulse signal generation circuit 38 outputs a pulse signal Sm having a predetermined short time width T4 at the falling timing of the detection signal Sa of the magnetic sensor 3, and a period during which the pulse signal Sm is at a high level. In the middle, the third constant current circuit 39 outputs a predetermined current Ic. The current value Ic is set to be substantially the same level as the current value obtained by adding the current values Ia and Ib.
[0055]
According to the above configuration, at the time of reverse rotation of the gear 1, a short pulse current is applied to both the head and the tail of the output current Is at a high current level, so that the peak 1a of the gear 1 is moved to the magnetic sensor 3. Since the output current Is is increased from Ia to Ic once after the state stopped at the position opposed to the reverse rotation, it becomes a lower current level. Therefore, the rotational direction is changed as compared with the case of the fifth embodiment. It can be detected quickly.
[0056]
The present invention is not limited to the above embodiment, and can be modified or expanded as follows.
It can utilize as a structure which combined each said embodiment suitably. For example, it can also be set as the structure which combined the thing of the 1st thru | or 4th embodiment and the thing of the 5th or 6th embodiment.
The time width of the pulse signal and the current level by the constant current circuit can be set to appropriate values.
It can also be used as a vehicle speed detection signal.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of an external circuit.
FIG. 3 is a waveform diagram of output signals of each part.
FIG. 4 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.
FIG. 5 is a view corresponding to FIG.
FIG. 6 is a view corresponding to FIG. 1, showing a third embodiment of the present invention.
7 is a view corresponding to FIG.
FIG. 8 is a view corresponding to FIG. 1, showing a fourth embodiment of the present invention.
FIG. 9 is a view corresponding to FIG.
FIG. 10 is a view corresponding to FIG.
FIG. 11 is a view corresponding to FIG. 1, showing a fifth embodiment of the present invention.
12 is equivalent to FIG.
FIG. 13 is a view corresponding to FIG. 1, showing a sixth embodiment of the present invention.
14 is a view corresponding to FIG.
[Explanation of symbols]
1 is a gear (rotating body), 1a is a crest, 1b is a trough, 2, 14, 17, 23, 33, and 40 are rotation detection devices, 3 and 4 are magnetic sensors (sensor elements), and 5 is a latch circuit ( Rotation direction determination means), 6, 7, 15, 16, 35, and 38 are pulse signal generation circuits, 8 is a signal selection circuit, 9 is a binary current output circuit, 10a and 10b are signal lines, 11 is an in-vehicle battery, 12 Is a resistance for detection, 13 is a voltage detection means, 15 and 16 are pulse signal generation circuits, 18 is a prohibition circuit (rotation direction misjudgment prevention means), 19, 20 and 21 are flip-flops, and 22 and 25 are exclusive ORs. Circuit, 24 is a time setting circuit (exogenous false detection prevention means), 30 is a comparator, 31 is a capacitor, 32 is a DC power supply, 34, 36 and 39 are constant current circuits, 37 is a switch circuit, P1 and P2 are external terminals It is.

Claims (4)

A rectangular wave detection signal is output with a different phase from the first and second magnetic sensors with the rotation arranged opposite to the rotation body, and the rotation speed and rotation direction of the rotation body are detected based on these detection signals. In the detection signal processing device of the rotation sensor designed to
Rotation direction determination means for outputting a determination signal corresponding to the rotation direction of the rotating body based on detection signals of the first and second magnetic sensors;
First and second pulse signal generation circuits for outputting pulse signals of first and second time widths set to different time widths at a level change timing of a detection signal of the first or second magnetic sensor; and A pulse signal generation means comprising: an output circuit that validates one of the outputs of the first and second pulse signal generation circuits based on a determination signal from the rotation direction determination means;
Detection of a rotation sensor characterized by comprising binary current output means for supplying current between input and output terminals with different amounts of current corresponding to the level change of the pulse signal output from the pulse signal generating means Signal processing device. In the detection signal processing apparatus of the rotation sensor according to claim 1,
The rotation signal generator is configured to output the pulse signal at both rising and falling level change timings of the detection signal of the first or second magnetic sensor. Detection signal processing device. In the detection signal processing device of the rotation sensor according to claim 1 or 2,
The detection signal processing device for a rotation sensor, wherein the pulse signal generation means is configured to output the pulse signal at a level change timing of both detection signals of the first and second magnetic sensors. . In the detection signal processing apparatus of the rotation sensor according to any one of claims 1 to 3,
During the period from when the determination signal is output by the rotation direction determination means to when the level change of the detection signals of the two magnetic sensors occurs alternately, the pulse signal generation means prohibits the output of the pulse signal by the pulse signal generation means. A rotation sensor detection signal processing device comprising a rotation direction erroneous determination prevention means for controlling.

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