JP2017013595A - Driver circuit for mirror - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a circuit scale.SOLUTION: A driver circuit 10 for a mirror is configured so that: respective second terminals of a storage motor 21, an adjustment motor 31 and an adjustment motor 32 are connected to intermediate points between a transistor T27 and a transistor T28. A first driver and a second driver, and the transistor T27 and the transistor T28 are on/off controlled, and the storage motor 21 is driven. In addition, a third driver and a fourth driver, and the transistor T27 and the transistor T28 are on/off controlled and the adjustment motor 31 is driven. In addition, a fifth driver and the transistor T28 are on/off controlled and the adjustment motor 32 is driven. In the configuration, the transistor T27 and the transistor T28 are shared among the storage motor 21, the adjustment motor 31 and the adjustment motor 32.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mirror driver circuit.

  Conventionally, a vehicle includes a vehicle mirror device (outer rear view mirror) for rearward confirmation. This vehicle mirror device tilts the mirror by operating an adjustment switch provided in the vicinity of the driver's seat (see, for example, Patent Document 1). The mirror driver circuit connected to the motor for tilting the mirror has, for example, an H-type bridge circuit. The mirror driver circuit causes a drive current to flow to the motor via the H-type bridge circuit according to the operation of the adjustment switch. The motor rotates forward or backward depending on the direction in which the drive current flows. The rotation of the motor causes the mirror to tilt.

JP 2005-161936 A

By the way, in the driver circuit of the vehicle mirror device, reduction of the circuit scale is required.
The present invention has been made in view of such a situation, and an object thereof is to provide a mirror driver circuit capable of reducing the circuit scale.

  In order to solve the above-described problems, a mirror driver circuit includes a storage motor that expands and retracts a housing of a vehicle door mirror, a first adjustment motor that adjusts an angle of a mirror disposed in the housing, and a second adjustment motor. A driver circuit for a mirror for driving the adjustment motor, and a first driver and a second driver that are connected in series and connected to the intermediate point of the first terminal of the storage motor. A fifth driver and a sixth driver, which are connected in series with a third driver and a fourth driver to which the first terminal of the first adjustment motor is connected, and are connected to the first terminal of the second adjustment motor at an intermediate point. A seventh driver and an eighth driver that are connected in series with a second terminal of each of the storage motor, the first adjustment motor, and the second adjustment motor that are connected in series, A control circuit that controls on / off of the first driver to the eighth driver, and the control circuit controls the first driver, the second driver, the seventh driver, and the first driver when the storage motor is driven. 8 drivers are turned on / off to drive a drive current to the storage motor and control the direction of the drive current. When the first adjustment motor is driven, the third driver, the fourth driver, and the seventh driver are controlled. The driver and the eighth driver are turned on / off to drive the drive current to the first adjustment motor and control the direction of the drive current. When the second adjustment motor is driven, the fifth driver to The eighth driver is controlled to flow a driving current to the second adjustment motor and to control the direction of the driving current.

  According to this mirror driver circuit, the second terminals of the storage motor, the first adjustment motor, and the second adjustment motor are connected in common to the intermediate point between the seventh driver and the eighth driver. Then, the first driver, the second driver, the seventh driver, and the eighth driver are on / off controlled, and the storage motor is driven. In addition, the third driver, the fourth driver, the seventh driver, and the eighth driver are on / off controlled, and the first adjustment motor is driven. Then, the fifth to eighth drivers are on / off controlled, and the second adjustment motor is driven. As described above, the seventh driver and the eighth driver are shared for the retracting motor, the first adjusting motor, and the second adjusting motor. As a result, the number of drivers is reduced and the circuit scale can be reduced.

In the mirror driver circuit, the first driver and the second driver are sized according to the storage motor, and the third driver to the eighth driver are the first adjustment motor and the second driver. It is formed in a size according to the adjustment motor,
The control circuit performs on / off control of the first driver and the second driver by a drive signal in a first state based on the storage motor, the first driver, and the second driver, and also controls the storage motor and the second driver. The storage motor is driven to rotate by controlling the seventh driver and the eighth driver on and off by a drive signal in a second state based on the seventh driver and the eighth driver, and the first adjustment motor and the second driver The third driver, the fourth driver, the seventh driver, and the eighth driver are controlled to be turned on / off by a drive signal in a third state corresponding to the adjustment motor, and the first adjustment motor is driven to rotate. Preferably, the fifth driver to the eighth driver are on / off controlled by a drive signal in three states to rotationally drive the second adjustment motor.

  According to this mirror driver circuit, the drive currents corresponding to the respective motors are stored via the seventh driver and the eighth driver shared by the storage motor, the first adjustment motor, and the second adjustment motor having different characteristics. To obtain the required characteristics.

  The mirror driver circuit of the present invention can reduce the circuit scale.

The circuit diagram of the driver circuit for mirrors of one embodiment. Schematic of the mirror device for vehicles.

Hereinafter, an embodiment will be described.
As shown in FIG. 2, a vehicle mirror device 2 is provided on the door 1 of the vehicle. The door 1 is, for example, a driver's seat door. The vehicle mirror device 2 is an outer rear view mirror and is sometimes called a door mirror.

  The vehicle mirror device 2 includes a stay 3 and a housing 4. The stay 3 is attached to the door 1. The stay 3 supports the housing 4 in a rotatable manner. The stay 3 is provided with a storage mechanism including a storage motor described later. The housing 4 has a use position (shown by a solid line) in a state of projecting from the door 1 toward the side of the vehicle by a storage mechanism, and a storage position (shown by an alternate long and short dash line) along the door 1. Rotate between.

  The housing 4 accommodates a mirror 5 (shown by a broken line). The mirror 5 is supported by a tilting mechanism (not shown) accommodated in the housing 4. The tilting mechanism includes an adjusting motor described later, and tilts the mirror 5 by the rotation of the adjusting motor.

  As shown in FIG. 1, the vehicle mirror device 2 includes a mirror driver circuit 10. The mirror driver circuit 10 is constituted by, for example, one semiconductor chip or an electronic component mounted on one wiring board. The mirror driver circuit 10 drives a storage motor 21 that rotates (deploys / stores) the housing 4 shown in FIG. 2 and adjustment motors 31 and 32 that tilt the mirror 5 shown in FIG.

  The high potential voltage VBB is supplied from the battery 41 to the power supply terminal PP1 of the mirror driver circuit 10 as an operation power supply. The mirror driver circuit 10 operates based on the high potential voltage VBB. In FIG. 2, the power supply terminal PP1 is directly connected to the battery 41, but the high potential voltage VBB is a so-called accessory voltage supplied based on, for example, operation of an ignition switch. The power supply terminal PP2 of the mirror driver circuit 10 is connected to the ground GND. The ground GND is a member that is set to the same potential as the negative terminal of the battery 41.

  The input terminals PI1, PI2, PI3 of the mirror driver circuit 10 are connected to the mirror switch 42. The mirror switch 42 is disposed on the instrument panel, for example. The mirror switch 42 has a storage button and a mirror adjustment button. The storage button is an operation button for rotating (deploying) the housing 4 shown in FIG. 2 to the use position and rotating (storage) to the storage position. The mirror adjustment button is an operation button for instructing the adjustment direction (tilting direction) of the mirror 5 shown in FIG. The mirror switch 42 outputs an operation signal S11 corresponding to the operation of the storage button. The mirror switch 42 outputs operation signals S12 and S13 according to the operation of the mirror adjustment button.

  The output terminal PO1 of the mirror driver circuit 10 is connected to the first terminal of the storage motor 21, and the second terminal of the storage motor 21 is connected to the output terminal PO4. The output terminal PO2 of the mirror driver circuit 10 is connected to the first terminal of the adjustment motor 31, and the second terminal of the adjustment motor 31 is connected to the output terminal PO4. The output terminal PO3 of the mirror driver circuit 10 is connected to the first terminal of the adjustment motor 32, and the second terminal of the adjustment motor 32 is connected to the output terminal PO4. That is, the output terminals PO1, PO2, and PO3 of the mirror driver circuit 10 are connected to the first terminals of the storage motor 21 and the adjustment motors 31 and 32, respectively. The second terminals of the storage motor 21 and the adjustment motors 31 and 32 are connected to a common output terminal PO4.

  Based on the operation signal S11 output in response to the operation of the mirror switch 42, the mirror driver circuit 10 causes the storage motor 21 to pass a drive current in the direction corresponding to the operation signal S11. The storage motor 21 rotates forward or reverse based on this drive current. The housing 4 shown in FIG. 2 is rotated by the rotation of the storage motor 21. The mirror driver circuit 10 causes a drive current in a direction corresponding to the operation signal S12 to flow through the adjustment motor 31 based on the operation signal S12 output according to the operation of the mirror switch 42. The adjustment motor 31 rotates forward or reverse based on this drive current. Due to the rotation of the adjustment motor 31, the mirror 5 shown in FIG. Further, the mirror driver circuit 10 causes a driving current in a direction corresponding to the operation signal S13 to flow through the adjustment motor 32 based on the operation signal S13 output according to the operation of the mirror switch 42. The adjustment motor 32 rotates forward or reverse based on this drive current. Due to the rotation of the adjustment motor 32, the mirror 5 shown in FIG.

  The mirror driver circuit 10 includes a control circuit 11 and driver circuits 12 and 13. Operation signals S11 to S13 are input to the control circuit 11. The control circuit 11 controls the driver circuits 12 and 13 based on the operation signals S11 to S13.

  The driver circuit 12 has two transistors T21 and T22. Transistors T21 and T22 are, for example, N-channel MOSFETs (Metal Oxide Semiconductor Field-effect Transistors). The drain terminal of the transistor T21 is connected to a wiring to which the high potential voltage VBB is supplied (hereinafter, high potential wiring VBB), and the source terminal of the transistor T21 is connected to the drain terminal of the transistor T22. The source terminal of the transistor T22 is connected to the ground GND. In other words, the two transistors T21 and T22 are connected in series between the high potential wiring VBB and the ground GND. A connection point (intermediate point) N1 between the transistors T21 and T22 is connected to a first terminal of the storage motor 21 via an output terminal PO1. The gate terminals of the transistors T21 and T22 are connected to the control circuit 11. The control circuit 11 outputs control signals S21 and S22 based on the operation signal S11. The transistors T21 and T22 are turned on / off based on the control signals S21 and S22.

  The driver circuit 13 has six transistors T23, T24, T25, T26, T27, and T28. Transistors T23 to T28 are, for example, N-channel MOSFETs.

  The drain terminal of the transistor T23 is connected to the high potential wiring VBB, and the source terminal of the transistor T23 is connected to the drain terminal of the transistor T24. The source terminal of the transistor T24 is connected to the ground GND. That is, the two transistors T23 and T24 are connected in series between the high potential wiring VBB and the ground GND. A connection point N2 between the transistors T23 and T24 is connected to the first terminal of the adjustment motor 31 via the output terminal PO2.

  The drain terminal of the transistor T25 is connected to the high potential wiring VBB, and the source terminal of the transistor T25 is connected to the drain terminal of the transistor T26. The source terminal of the transistor T26 is connected to the ground GND. That is, the two transistors T25, T26 are connected in series between the high potential wiring VBB and the ground GND. A connection point N3 between the transistors T25 and T26 is connected to the first terminal of the adjustment motor 32 via the output terminal PO3.

  The drain terminal of the transistor T27 is connected to the high potential wiring VBB, and the source terminal of the transistor T27 is connected to the drain terminal of the transistor T28. The source terminal of the transistor T28 is connected to the ground GND. That is, the two transistors T27 and T28 are connected in series between the high potential wiring VBB and the ground GND. A connection point N4 between the transistors T27 and T28 is connected to the output terminal PO4. The output terminal PO4 is connected to the second terminal of the storage motor 21 and the second terminals of the adjustment motors 31 and 32.

  The gate terminals of the transistors T23 and T24 are connected to the control circuit 11. The control circuit 11 outputs control signals S23 and S24 based on the operation signal S12. The transistors T23 and T24 are turned on / off based on the control signals S23 and S24.

  The gate terminals of the transistors T25 and T26 are connected to the control circuit 11. The control circuit 11 outputs control signals S25 and S26 based on the operation signal S13. The transistors T25 and T26 are turned on / off based on the control signals S25 and S26.

  The gate terminals of the transistors T27 and T28 are connected to the control circuit 11. The control circuit 11 outputs control signals S27 and S28 based on the operation signals S11 to S13. The transistors T27 and T28 are turned on / off based on the control signals S27 and S28.

The transistors T21 to T28 are formed in a shape (size) corresponding to the motor to be driven.
The electrical characteristics of the transistors T21 and T22 included in the driver circuit 12 are set according to the storage motor 21 connected to the output terminal PO1. For example, a current flowing through the transistor T21 flows to the storage motor 21 via the output terminal PO1. The storage motor 21 rotates the housing 4 shown in FIG. 2 by torque generated based on the current. The housing 4 includes a mirror 5 and a mechanism for tilting the mirror 5. That is, the current flowing through the transistors T21 and T22 is a drive current for driving the storage motor 21. The electric characteristics (drive current) of the transistors T21 and T22 are set so that the housing 4 shown in FIG.

  Similarly, the electrical characteristics of the transistors T23 to T28 included in the driver circuit 13 are set according to the adjustment motors 31 and 32 connected to the output terminals PO2 and PO3. The electrical characteristic is the amount of current that flows between the source terminal and the drain terminal with respect to the voltage of the signal supplied to the gate terminal. For example, the current flowing through the transistor T23 flows to the adjustment motor 31 via the output terminal PO2. The adjustment motor 31 tilts the mirror 5 shown in FIG. 2 by the torque generated based on the current. That is, the current flowing through the transistors T23 to T28 is a drive current for driving the adjustment motors 31 and 32. The electrical characteristics (drive current) of the transistors T23 to T28 are set so that the mirror 5 shown in FIG.

  The storage motor 21 rotates the housing 4 shown in FIG. 2 and the mechanism part included in the housing 4. The adjustment motors 31 and 32 tilt the mirror 5 accommodated in the housing 4 shown in FIG. Therefore, the torque required for the storage motor 21 is larger than the torque of the adjustment motors 31 and 32. The torque of the motor corresponds to the current (drive current) flowing through each motor. The drive current in the storage motor 21 is larger than the drive current of the adjustment motors 31 and 32. Therefore, the transistors T21 and T22 included in the driver circuit 12 are formed larger than the transistors T23 to T28 included in the driver circuit 13.

  In the present embodiment, the second terminal of the storage motor 21 is connected to the output terminal PO4. The output terminal PO4 is connected to a connection point (intermediate point) N4 between the transistors T27 and T28. Therefore, when the storage motor 21 is rotated, a current (drive current) flowing through the storage motor 21 flows to the ground GND via the transistor T28. In addition, a current (drive current) flows from the high potential voltage VBB to the storage motor 21 via the transistor T27. Further, the drive currents of the adjustment motors 31 and 32 flow through these transistors T27 and T28.

  In the present embodiment, the control circuit 11 controls the transistors T27 and T28 according to the motors to be driven (the storage motor 21 and the adjustment motors 31 and 32). For example, the control circuit 11 outputs control signals S21 to S28 for controlling the transistors T21 to T28. Control signals S21 to S28 are, for example, pulse signals. Each of the transistors T21 to T28 is turned on in response to an H level (for example, high potential voltage VBB level) control signals S21 to S28, and is turned off in response to an L level (for example, ground GND level) control signals S21 to S28. .

  In the pulse signal, the H-level pulse width for one cycle is called duty. The amount of current flowing through the transistor changes according to the duty. For example, when the duty is high, the amount of current that substantially flows through the transistor increases, and when the duty is low, the amount of current decreases.

  The control circuit 11 performs on / off control of the transistors T21, T22, T27, T28 by duty control signals S21, S22, S27, S28 according to the drive current of the storage motor 21. As described above, the size (transistor size) of the transistors T21 and T22 is larger than the size (transistor size) of the transistors T27 and T28. Therefore, the control circuit 11 makes the duty of the control signals S27 and S28 supplied to the transistors T27 and T28 higher than the duty of the control signals S21 and S22 supplied to the transistors T21 and T22. That is, the control circuit 11 performs on / off control of the transistors T21 and T22 by the control signals S21 and S22 in the first state, and controls on and off of the transistors T27 and T28 by the control signals S27 and S28 in the second state. The control signals S27 and S28 in the second state have a higher duty than the control signals S21 and S22 in the first state.

  Further, the control circuit 11 performs on / off control of the transistors T23, T24, T27, and T28 by duty control signals S23, S24, S27, and S28 corresponding to the drive current of the adjustment motor 31. The sizes of the transistors T23, T24, T27, and T28 are equal to each other. Therefore, the control circuit 11 outputs control signals S23, S24, S27, and S28 having the same duty. The torque (current amount) required for the adjustment motor 31 is less than the torque (current amount) required for the storage motor 21. Therefore, the control circuit 11 makes the duty of the control signals S27 and S28 for the transistors T27 and T28 when driving the adjustment motor 31 smaller than the duty of the control signals S27 and S28 when driving the storage motor 21. That is, the control circuit 11 performs on / off control of the transistors T23, T24, T27, and T28 by the control signals S23, S24, S27, and S28 in the third state. Similarly, the control circuit 11 performs on / off control of the transistors T25, T26, T27, and T28 by control signals S25, S26, S27, and S28 having a duty (third state) corresponding to the drive current of the adjustment motor 32.

(Function)
Next, the operation of the mirror driver circuit 10 will be described.
The mirror driver circuit 10 drives the storage motor 21 and the adjustment motors 31 and 32 based on operation signals S11 to S13 input based on the operation of the mirror switch 42 shown in FIG. The control circuit 11 generates and outputs control signals S21 to S28 based on the operation signals S11 to S13, and performs on / off control of the transistors T21 to T28.

  For example, the control circuit 11 outputs L level control signals S22 and S27. The transistors T22 and T27 are turned off in response to the L level control signals S22 and S27. The control circuit 11 outputs a control signal S21 in the first state and a control signal S28 in the second state. A current corresponding to the duty of the control signals S21 and S28 flows through the transistors T21 and T28. Therefore, a current (drive current) flows from the first terminal of the storage motor 21 toward the second terminal, and the storage motor 21 rotates (for example, forward rotation). The housing 4 shown in FIG. 1 is rotated (deployed) from the storage position to the use position by the rotation (normal rotation) of the storage motor 21.

  On the other hand, the control circuit 11 outputs L level control signals S21 and S28. The transistors T21 and T28 are turned off in response to the L level control signals S21 and S28. The control circuit 11 outputs a control signal S22 in the first state and a control signal S27 in the second state. A current corresponding to the duty of the control signals S22 and S27 flows through the transistors T22 and T27. Therefore, a current (drive current) flows from the second terminal of the storage motor 21 toward the first terminal, and the storage motor 21 rotates (for example, reversely rotates). The housing 4 shown in FIG. 1 is rotated (stored) from the use position to the storage position by the rotation (reverse rotation) of the storage motor 21.

  Therefore, the transistors T21 and T22 included in the driver circuit 12 and the transistors T27 and T28 included in the driver circuit 13 function as an H-type bridge circuit that rotates (forward / reversely rotates) the storage motor 21. That is, the transistors T21 and T22 function as a bridge circuit 12a connected to the first terminal of the storage motor 21, and the transistors T27 and T28 function as a bridge circuit 13c connected to the second terminal of the storage motor 21.

  The control circuit 11 outputs L level control signals S24 and S27. The transistors T24 and T27 are turned off in response to the L level control signals S24 and S27. Further, the control circuit 11 outputs the control signals S23 and S28 in the third state. A current according to the duty of the control signals S23 and S28 flows through the transistors T23 and T28. Therefore, a current (drive current) flows from the first terminal of the adjustment motor 31 toward the second terminal, and the adjustment motor 31 rotates (for example, forward rotation). Due to the rotation (forward rotation) of the adjustment motor 31, the mirror 5 shown in FIG. 1 tilts upward (toward the paper surface in FIG. 2).

  On the other hand, the control circuit 11 outputs L level control signals S23 and S28. The transistors T23 and T28 are turned off in response to the L level control signals S23 and S28. The control circuit 11 outputs the control signals S24 and S27 in the third state. A current corresponding to the duty of the control signals S24 and S27 flows through the transistors T24 and T27. Therefore, a current (drive current) flows from the second terminal of the adjustment motor 31 toward the first terminal, and the adjustment motor 31 rotates (for example, reversely). Due to the rotation (reverse rotation) of the retracting motor 21, the mirror 5 shown in FIG. 1 tilts downward (backward in FIG. 2).

  Therefore, the transistors T23, T24, T27, and T28 included in the driver circuit 13 function as an H-type bridge circuit that rotates (forward / reversely rotates) the adjustment motor 31. That is, the transistors T23 and T24 function as a bridge circuit 13a connected to the first terminal of the adjustment motor 31, and the transistors T27 and T28 function as a bridge circuit 13c connected to the second terminal of the adjustment motor 31.

  Similarly, the control circuit 11 outputs L level control signals S26 and S27. The transistors T26 and T27 are turned off in response to the L level control signals S26 and S27. The control circuit 11 outputs the control signals S25 and S28 in the third state. A current corresponding to the duty of the control signals S25 and S28 flows through the transistors T25 and T28. Therefore, a current (drive current) flows from the first terminal of the adjustment motor 32 toward the second terminal, and the adjustment motor 32 rotates (for example, forward rotation). The rotation (normal rotation) of the adjustment motor 32 tilts the mirror 5 shown in FIG. 1 in the right direction (downward in FIG. 2).

  On the other hand, the control circuit 11 outputs L level control signals S25 and S28. The transistors T25 and T28 are turned off in response to the L level control signals S25 and S28. Further, the control circuit 11 outputs the control signals S26 and S27 in the third state. A current according to the duty of the control signals S26 and S27 flows through the transistors T26 and T27. Therefore, a current (drive current) flows from the second terminal of the adjustment motor 32 toward the first terminal, and the adjustment motor 32 rotates (for example, reversely). Due to the rotation (reverse rotation) of the retracting motor 21, the mirror 5 shown in FIG. 1 tilts leftward (upward in FIG. 2).

  Accordingly, the transistors T25 to T28 included in the driver circuit 13 function as an H-type bridge circuit that rotates (forward / reversely rotates) the adjustment motor 32. That is, the transistors T25 and T26 function as a bridge circuit 13b connected to the first terminal of the adjustment motor 32, and the transistors T27 and T28 function as a bridge circuit 13c connected to the second terminal of the adjustment motor 32.

  By the way, for example, an H-type bridge circuit may be used as a circuit for rotating the motor forward and backward. The H-bridge circuit includes a pair of transistors connected to both terminals of the motor, that is, four transistors. As described above, the vehicle mirror device 2 includes the storage motor 21 that deploys and stores the housing 4 and the two adjustment motors 31 and 32 that adjust the angle of the mirror 5 disposed in the housing 4. Therefore, when driving the motor of such a vehicle mirror device 2, three H-bridge circuits, that is, 12 transistors are required.

  On the other hand, in the mirror driver circuit 10 of the present embodiment, the second terminals of the adjustment motors 31 and 32 are connected to the connection point N4 (intermediate point) between the transistors T27 and T28 via the output terminal PO4. Therefore, the bridge circuit 13c including the transistors T27 and T28 is shared by the two adjustment motors 31 and 32. Thereby, the number of transistors used is reduced, and the circuit scale is reduced.

  Further, in the mirror driver circuit 10 of the present embodiment, the second terminal of the storage motor 21 is connected to the connection point N4 (intermediate point) between the transistors T27 and T28 via the output terminal PO4. The control circuit 11 performs on / off control of the transistors T21 and T22 to which the first terminal of the storage motor 21 is connected by the control signals S21 and S22 in the first state, and the transistors T27 and T22 by the control signals S27 and S28 in the second state. T28 is on / off controlled. The adjustment motors 31 and 32 and the storage motor 21 have different required characteristics (torque). Thus, by changing the control signals S27 and S28 of the transistors T27 and T28, the transistors T27 and T28 are shared by the storage motor 21 and the adjustment motors 31 and 32 having different characteristics. Thereby, the number of transistors used is reduced, and the circuit scale is reduced.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In the mirror driver circuit 10, the second terminals of the storage motor 21, the adjustment motor 31, and the adjustment motor 32 are connected in common to an intermediate point between the transistors T27 and T28. Then, the first driver and the second driver, the transistor T27 and the transistor T28 are on / off controlled, and the storage motor 21 is driven. Further, the third driver and the fourth driver, the transistor T27 and the transistor T28 are on / off controlled, and the adjustment motor 31 is driven. Then, the fifth driver to transistor T28 are on / off controlled, and the adjustment motor 32 is driven. As described above, the transistor T27 and the transistor T28 are shared by the storage motor 21, the adjustment motor 31, and the adjustment motor 32. As a result, the number of transistors is reduced, and the circuit scale can be reduced.

  (2) The control circuit 11 performs on / off control of the transistors T21 and T22 by the control signals S21 and S22 in the first state, and performs on / off control of the transistors T27 and T28 by the control signals S27 and S28 in the second state. The control circuit 11 performs on / off control of the transistors T23, T24, T27, and T28 by the control signals S23, S24, S27, and S28 in the third state. Further, the control circuit 11 performs on / off control of the transistors T25, T26, T27, and T28 by control signals S25, S26, S27, and S28 having a duty (third state) corresponding to the drive current of the adjustment motor 32. A current corresponding to the state of the control signals S27 and S28 flows through the storage motor 21 and the adjustment motors 31 and 32 via the transistors T27 and T28. Therefore, according to the mirror driver circuit 10, the drive currents corresponding to the respective motors are passed through the transistor T27 and the transistor T28 shared by the storage motor 21, the adjustment motor 31, and the adjustment motor 32 having different characteristics. Necessary characteristics can be obtained.

  (3) The transistors T21 to T28 are composed of N-channel MOSFETs. A P-channel MOSFET is often used for the transistor connected to the high potential voltage VBB side. However, the P-channel MOSFET has a larger shape (transistor size) for flowing the same current than the N-channel MOSFET. Therefore, the circuit area can be reduced by making each of the transistors T21 to T28 N-channel MOSFETs.

In addition, you may change the said embodiment as follows.
In the above embodiment, the sizes of the transistors T27 and T28 are the same as the sizes of the transistors T23 to T26. On the other hand, the sizes of the transistors T27 and T28 may be the same as the sizes of the transistors T21 and T22. Then, the duty of the control signals S27 and S28 for controlling on / off of the transistors T27 and T28 is set according to the size and the motor to be driven. In this way, the circuit scale can be reduced as compared with a circuit in which the retracting motor 21 and the adjusting motors 31 and 32 are respectively driven by an H-type bridge circuit.

In contrast to the above embodiment, the transistor on the high potential voltage VBB side may be a P-channel MOSFET.
In the above embodiment, each of the transistors T21 to T28 is a MOSFET, but may be a bipolar transistor or a Bi-CMOS transistor.

  DESCRIPTION OF SYMBOLS 10 ... Mirror driver circuit, 11 ... Control circuit, 21 ... Storage motor, 31, 32 ... Adjustment motor, S21-S28 ... Control signal, T21-T28 ... Transistor (driver).

Claims (2)

A mirror driver circuit that drives a retract motor that deploys and retracts a housing of a vehicle door mirror, and a first adjustment motor and a second adjustment motor that adjust an angle of a mirror disposed in the housing. And
A first driver and a second driver connected in series and connected to the first terminal of the storage motor at an intermediate point;
A third driver and a fourth driver connected in series and connected to the first terminal of the first adjustment motor at an intermediate point;
A fifth driver and a sixth driver connected in series and connected to the first terminal of the second adjustment motor at an intermediate point;
A seventh driver and an eighth driver that are connected in series and in which a second terminal of each of the retracting motor, the first adjusting motor, and the second adjusting motor is commonly connected to an intermediate point;
A control circuit for controlling on / off of the first driver to the eighth driver;
Have
The control circuit controls the on / off of the first driver, the second driver, the seventh driver, and the eighth driver to drive the storage motor and to drive the storage motor while driving the storage motor. When the first adjustment motor is driven, the third driver, the fourth driver, the seventh driver, and the eighth driver are turned on / off to drive the first adjustment motor. While flowing the current and controlling the direction of the drive current, when driving the second adjustment motor, the fifth driver to the eighth driver are controlled to flow the drive current to the second adjustment motor. Controlling the direction of the drive current;
Mirror driver circuit. The first driver and the second driver are formed in a size corresponding to the storage motor,
The third driver to the eighth driver are formed in a size corresponding to the first adjustment motor and the second adjustment motor,
The control circuit performs on / off control of the first driver and the second driver by a drive signal in a first state based on the storage motor, the first driver, and the second driver, and also controls the storage motor and the second driver. The storage motor is driven to rotate by controlling the seventh driver and the eighth driver on and off by a drive signal in a second state based on the seventh driver and the eighth driver, and the first adjustment motor and the second driver The third driver, the fourth driver, the seventh driver, and the eighth driver are controlled to be turned on / off by a drive signal in a third state corresponding to the adjustment motor, and the first adjustment motor is driven to rotate. On-off control of the fifth driver to the eighth driver by a drive signal in three states to drive the second adjustment motor to rotate;
The mirror driver circuit according to claim 1.