JP2002359998A - Motor drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sequentially drive a plurality of motors different in number of loads or control method by a single driver IC configuration. SOLUTION: A motor drive unit comprises a drive circuit portion which drives a plurality of loads contained in a plurality of the motors M1 to M4, and a control circuit portion which controls the drive circuit portion to sequentially drive a plurality of the motors M1 to M4. The drive circuit portion is divided into two channels CH1 and CH2 which are controlled in parallel by the control circuit portion, and one channel is controlled by the control circuit portion so that a plurality of loads can be alternatively controlled. When a motor M1 containing at least two loads is sequentially driven together with the other motors M2 to M4, one of the loads of the motor M1 is allocated to one channel CH1 and the other load of the motor M1 is allocated to the other channel CH2, and thus the one motor M1 is driven through the two channels CH1 and CH2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive circuit for driving a plurality of loads (coils and the like) included in a plurality of motors incorporated in a camera, for example, and a plurality of motors by controlling the drive circuit. The present invention relates to a motor driving device including a driver IC integrally formed with a control circuit unit that drives sequentially.

[0002]

2. Description of the Related Art Taking a still camera as an example, a plurality of motors are built in as driving sources for various mechanical components. In one example, a total of three stepper motors, iris motors, and DC motors may be used. The stepping motor is used, for example, for driving a lens for autofocus. The iris motor is used for driving a shutter and an aperture. The DC motor is used for winding a film or driving a zoom lens. Conventionally, a driver IC for driving and controlling each motor has been used. In the above example, a stepper motor,
Three driver ICs were separately used corresponding to the iris motor and the DC motor.

[0003] A stepping motor is composed of, for example, a multi-pole magnetized rotor, a stator, and two-phase coils.
The load is two coils. Therefore, a driver IC for a stepping motor having two pairs of four output terminals capable of driving two loads is used. Normally, one H-type bridge circuit is provided for a pair of output terminals. Therefore, a driver IC for a stepping motor is a 2H type having two H-type bridge circuits. Further, in driving a lens for auto-focusing, it is preferable that the stepping motor be driven at a constant voltage, so that a driver IC of a constant voltage control type is used. The iris motor includes a two-pole magnetized rotor and one coil. Therefore, the corresponding driver IC is a 1H type having a pair of output terminals. In particular, when the shutter and the aperture are driven, constant current control is preferable. Therefore, the driver IC for driving the iris motor uses a constant current control method. Further, for driving the DC motor, for example, a 1.5H type driver IC is used. 1.
The 5H type has three output terminals, an intermediate output terminal is shared with the output terminals on both sides, and can selectively drive two loads. When film winding or zoom driving is performed by a DC motor, there is no need to perform constant current driving or constant voltage driving, so that saturation current driving is performed by an ordinary bridge circuit.

[0004]

As described above, in order to sequentially drive a plurality of motors, separate driver ICs have been provided. In particular, when the control method differs depending on the motor, such as constant current drive, constant voltage drive, and saturation current drive, it is necessary to configure a driver IC for each control method. Therefore, the number of driver ICs is generally required by the number of motors, and the circuit configuration of the motor driving device is complicated, resulting in an increase in cost.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, the present invention makes it possible to drive a plurality of motors with a single driver IC configuration regardless of the type of motor or the control method. It is an object of the present invention to provide a motor drive device that rationalizes a drive circuit unit and a control circuit unit and is cost-effective. The following measures have been taken to achieve this objective. That is, the driving circuit unit includes a driving circuit unit that drives a plurality of loads included in the plurality of motors, and a control circuit unit that controls the driving circuit unit to sequentially drive the plurality of motors. At least two channels are controlled in parallel by the circuit section, and each channel is at least divided in a motor drive device controlled by the control circuit section so that a plurality of loads can be selectively driven. When one motor including both loads is sequentially driven with another motor, one load of the motor is assigned to one channel, the other load of the motor is assigned to the other channel, and two motors are assigned. It is characterized in that the one motor is driven by a channel.

Specifically, the number of the channels is n (n is 2
N + 1 output terminals for connecting a load of the above (integer), a pair of output terminals are allocated to drive one load, and at least one of the pair of output terminals is connected to two loads. The control circuit unit controls each output terminal of the channel so that a plurality of loads are not driven simultaneously in one channel. Preferably, a bridge circuit is connected between each pair of output terminals corresponding to each load, and each bridge circuit can supply a bidirectional drive current to the corresponding load according to control of the control circuit unit. It is. In this case, it is preferable that at least one of the plurality of bridge circuits includes a constant current circuit and drives a corresponding load with a constant current, while the remaining bridge circuits include a constant current circuit. And the corresponding load is driven by the saturation current. In this case, the bridge circuit including the constant current supply circuit supplies a constant current when driving the corresponding load in one direction, and supplies a saturation current when driving the corresponding load in the other direction. Further, the bridge circuit including the constant current circuit further includes a constant voltage circuit, and a constant voltage is applied to the load when the corresponding load is driven in the other direction. It is possible to switch between constant-current driving and constant-voltage driving according to the driving direction.

Preferably, the control circuit section includes an input / output logic circuit, and a first type control signal for selecting one or both of the two channels according to sequence data input from the outside. And a second type control signal for designating a load to be driven by the selected channel to control the drive circuit unit. In this case, the control circuit unit outputs a first type of control signal representing four logical states with two bits, uses the three logical states for channel selection designation, and designates the other logical state as load braking designation. Used for Preferably, the drive circuit unit can be driven using only one channel when a predetermined current is supplied to the load, and can be driven using both channels when the current exceeds a predetermined current. Preferably, the drive circuit unit including two channels and the control circuit unit are integrated on a single IC chip.

Preferably, the drive circuit section is connected so as to drive two motors provided in a lens barrel of a camera, and each of the two motors is a stepping motor including two loads. Motor, and the two loads included in one stepping motor are separately allocated to two channels included in the drive circuit section, and the two loads included in the other stepping motor are also allocated to the two channels. It is divided into two channels and assigned separately.
In this case, the drive circuit unit includes a flexible wiring board formed with a wiring pattern for connecting the two channels to the two stepping motors, and connects the two loads included in each stepping motor to the two stepping motors. Wiring patterns that are divided into channels and connected are arranged symmetrically with respect to the optical axis of the lens barrel.

According to the present invention, in a motor drive device comprising a driver IC in which a drive circuit section and a control circuit section are integrally formed integrally, the drive circuit section is divided into two channels, and each channel has a plurality of channels. The load can be driven. Here, when driving a stepping motor including two loads, by assigning one load to one channel and assigning the other load to the other channel,
It is also compatible with motors having multiple loads. When driving a motor having a single load, it may be assigned to one channel. This makes it possible to sequentially drive a plurality of motors having different numbers of loads (coils) via two channels.
Further, by adding a constant current control function or a constant voltage control function to at least a specific output terminal pair of one channel, it is possible to cope with driving of a motor of a different control system.
As described above, a single driver I with two channels
By using C, a plurality of motors having different numbers of loads and different control methods can be sequentially driven.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic circuit diagram showing a first embodiment of a motor drive device according to the present invention.
As shown in the figure, the present motor drive device includes a drive circuit unit that drives a plurality of loads included in a plurality of motors, and a control circuit unit that controls the drive circuit unit and drives the plurality of motors sequentially. Have been. The drive circuit unit has two channels C controlled in parallel by the control circuit unit.
H1 and CH2. One of the channels CH1 is controlled by a control circuit so that a plurality of loads can be driven alternatively. The other channel CH2 is also controlled by the control circuit so that a plurality of loads can be selectively driven.

Here, the motor driving device according to the present invention comprises:
When one motor including at least two loads is sequentially driven with another motor, one load of the motor is assigned to one channel, and the other load of the motor is assigned to the other channel. The motor is driven by one channel. In the present embodiment, the motor driving device sequentially drives four motors M1 to M4. M1 is a stepping motor including a two-phase coil (that is, two loads). In this example, the stepping motor is built in the camera and used for automatic focusing of the lens. One load of the stepping motor M1 is represented by 1/2, and the other load is represented by 2/2. M2 is also a two-phase coil type stepping motor, in which one load is represented by 1/2 and the other load is represented by 2/2. The stepping motor M2 is used for zooming of the camera. The motor M3 is a one-phase coil type iris motor, and is used for a shutter operation of a camera. The motor M4 is also a one-phase coil type iris motor and is used for setting the aperture of the camera. However, the above-described selection of the motor is merely an example, and various motors are adopted according to the function of the camera. This motor drive device can sequentially drive various combinations of motors with a single driver IC. Here, when the stepping motor M1 including two loads (coils) is sequentially driven with the other motors M2, M3, M4, one of the loads (1
/ 2) is assigned to one channel CH1, the other load (1/2) of the stepping motor M1 is assigned to the other channel CH2, and the stepping motor M1 is driven by the two channels CH1 and CH2. Similarly, for the stepping motor M2, one load (1/2) is assigned to the channel CH1, and the other load (2/2) is assigned to the other channel CH2, and the stepping motor M2 is assigned to the two channels CH1 and CH2. Is driving.

In general, a channel has n + 1 output terminals for connecting n (n is an integer of 2 or more) loads, and a pair of output terminals are assigned to drive one load. I have. At least one of the pair of output terminals is shared between the two loads. For this reason, the control circuit controls each output terminal of the channel so that a plurality of loads are not driven simultaneously in one channel. In the present embodiment, n = 3, and the channel CH1 has four output terminals OUT1 to OUT4 for connecting three loads, and a pair of output terminals is assigned to drive one load. . For example, to drive M1 (1/2), OU
T1 and OUT2 are assigned. OUT2 and OUT3 are assigned to drive M2 (1/2). M3
OUT3 and OUT4 are assigned to drive.
Here, at least one of the pair of output terminals is shared between the two loads. For example, OUT2 is M1 (1
/ 2) and M2 (1/2). OU
T3 is also shared between M2 (1/2) and M3.
In this connection, the control circuit sequentially controls the output terminals OUT1 to OUT4 of the channel CH1 so that the plurality of loads M1, M2, and M3 are not simultaneously driven in the channel CH1. In cameras, M1, M2, M3
Are driven sequentially instead of simultaneously,
As shown, some output terminals can be shared. Similarly,
Also for channel CH2, four motor terminals M1 (2/2), M2 (2/2), and M4 are sequentially driven by the four output terminals, and OUT6 and OUT7 are shared by adjacent loads. . Even if the output terminals are shared, no malfunction occurs because the adjacent loads are not driven at the same time. The control circuit can control the channels CH1 and CH2 simultaneously and in parallel. Therefore, even if the two coils included in one stepping motor M1 are divided and assigned to the channels CH1 and CH2, the normal driver I
As in the case of C, the stepping motor M1 can be driven normally. Of course, the control circuit unit may alternatively select only one of the pair of channels according to the sequence data.

A bridge circuit is connected between each pair of output terminals corresponding to each load. Each bridge circuit is connected between a power supply line VCC and a ground line GND, and can supply a bidirectional drive current to a corresponding load according to control of a control circuit unit. For example, focusing on the channel CH1, a bridge circuit HA including four transistors Q1 to Q4 is connected between a pair of output terminals OUT1 and OUT2 corresponding to the load M1 (1/2). The bridge circuit HA supplies a bidirectional drive current to the corresponding load M1 (1/2) according to the control of the control circuit unit. Thus, the stepping motor M1 can rotate bidirectionally. Specifically, of the four transistors constituting the bridge circuit HA, Q1 and Q4 are turned on and Q
2. When Q3 is turned off, a drive current in the positive direction flows through the load M1 (1/2). Conversely, Q1 and Q4 turn off and Q2
When Q3 is turned on, a drive current in the opposite direction flows through the load M1 (1/2). Similarly, a bridge circuit HB including transistors Q3 to Q6 is connected between a pair of output terminals OUT2 and OUT3 corresponding to the load M2 (1/2). Here, the transistors Q3 and Q4 are shared between the bridge circuits HA and HB. A bridge circuit HC including transistors Q5 to Q8 is connected between a pair of output terminals OUT3 and OUT4 corresponding to the load M3. Channel CH2 is the channel CH1 described above.
A bridge circuit HD is connected between OUT5 and OUT6, a bridge circuit HE is connected between OUT6 and OUT7, and a bridge circuit HF is connected between OUT7 and OUT8. Eight transistors Q9 to Q16 are used to form three bridge circuits HD, HE, and HF.

The control circuit section includes an input / output logic circuit 2, a first type control signal for selecting one or both of the two channels CH1 and CH2 according to sequence data input from the outside, A second type control signal designating a load to be driven by the selected channel is output to control the drive circuit unit. Specifically, a first type control signal and a second type control signal are output according to the sequence data input to the six input terminals IN1 to IN6,
A control signal (base current) for turning on / off is supplied to each of the transistors Q1 to Q16 of the bridge circuit included in the channels CH1 and CH2. In particular, the input / output logic circuit 2 outputs a first-type control signal representing four logic states with two bits. In the present embodiment, three of the four logical states are used to select and specify a channel.
The remaining one logical state is used for load braking designation (with or without braking). In this embodiment, a drive circuit section including two channels CH1 and CH2 and a control circuit section including the input / output logic circuit 2 are integrated on a single driver IC chip 1.

Of the plurality of bridge circuits HA to HF, at least one bridge circuit HC has a constant current circuit and drives the corresponding load M3 at a constant current, while the remaining bridge circuits HA, HB, HD, and HE and HF do not have a constant current circuit, and drive the corresponding loads M1, M2 and M4 with normal saturation current. This constant current circuit includes a differential amplifier OP1 connected to the base of a transistor Q8 constituting a bridge circuit HC, a current detection resistor RD connected to the emitter of the transistor Q8, and a reference voltage circuit 3 for supplying a reference voltage VREF. It is configured. In this example, the amplifier OP1 and the reference voltage circuit 3 are built in the driver IC1, and the current detection resistor RD is externally provided. However, the present invention is not limited to this, and the inside and the outside can be appropriately changed. A reference current IAD obtained by dividing VREF by voltage dividing resistors R1 and R2 is supplied to a positive input terminal of the difference amplifier OP1, and a detection current IM is supplied to a negative input terminal via an external current detection resistor RD. Is done. OP1 controls the base current of transistor Q8 so that IM matches IAD, and thereby bridge circuit HC
Constant current control is realized. This bridge circuit HC
Supplies the above-described constant current when driving the corresponding load M3 in the positive direction, and supplies a normal saturation current when driving the corresponding load M3 in the negative direction. That is, in the bridge circuit HC, constant current control is performed when the transistors Q5 and Q8 are turned on to supply a current in the positive direction, and normal saturation current driving is performed when the transistors Q6 and Q7 are turned on and a driving current flows in the negative direction. Become.
Further, the bridge circuit HC includes a constant voltage circuit, and when driving the corresponding load M3 in the negative direction, the load M3
Is applied with a constant voltage. This makes it possible to switch between constant current drive and constant voltage drive according to the drive direction of the load M3. In particular, in this example, the iris motor M3 is used for driving the shutter of the camera. When opening the shutter, turn the iris motor M3 forward (clockwise in this example).
At this time, constant current driving is preferable in order to obtain a stable shutter opening locus. Conversely, when closing the shutter, the iris motor M3 is driven in the reverse direction. At this time, a rapid shutter closing operation is required, so that a constant voltage drive capable of obtaining a large output is preferable. Therefore, the iris motor M3 used for driving the shutter can be connected to a bridge circuit HC having a constant current control function and a constant voltage control function. Note that the above-described constant voltage circuit is configured by a differential amplifier OP2 connected to the base of the transistor Q7. The reference voltage VM is applied to the negative input terminal of OP2 via external voltage dividing resistors R3 and R4, and the collector of the transistor Q7 is connected to the positive input terminal via internal voltage dividing resistors R5 and R6. . The difference amplifier OP2 controls the base current of the transistor Q7 so that the collector voltage of the transistor Q7 matches the constant reference voltage VM. Thus, when driving the motor M3 in the reverse direction, constant voltage control can be performed. In this example, the collector voltage of the transistor Q7 is controlled to be constant. Alternatively, constant voltage control may be performed so that the collector voltage of the transistor Q6 is constant.

As described above, in the present invention, the ground line (GND) side of the bridge circuit HC corresponding to M3 is separated, and the emitter of the transistor Q6 is connected to the other bridge circuits HA, HB, HD, HE, HF. Similarly, while connected to GND, the emitter of the transistor Q8 is connected to the current detection resistor R
It is connected to GND via D. The detection resistor RD, the differential amplifier OP1, and the reference voltage circuit 3 constitute a constant current circuit. This constant current circuit includes a plurality of motors M
Among M1 to M4, it works only when M3 connected between OUT3 and OUT4 operates. When M3 operates, the other motors M1, M2, M4 do not operate.
There is no current sneak through the common output terminal OUT3. Also, a dedicated output terminal OUT4 is connected to the motor M3.
By applying constant current control to the transistor Q7 side of
The type of control differs depending on the driving direction of No. 3. As a result, M3 is independent of the other motors M1, M2 and M4.
Bidirectional control is possible. That is, by placing one of the transistors Q7 and Q8 connected to the dedicated output terminal OUT4 assigned to the motor M3 under constant current control and placing the other under constant voltage control, the rotation direction of the load is controlled by one bridge circuit. , Different controls can be realized.

FIG. 2 is a table showing a truth table of the input / output logic circuit 2 shown in FIG. The left side of the table shows the logic levels of the six input terminals IN1 to IN6, and the right side shows the control outputs for the channels CH1 and CH2. As shown in the drawing, IN is used to select the motor to be driven (motor select).
Two-bit data of 1, IN2 is used. Channel C
Two-bit data IN3 and IN4 are used for selecting H1 and CH2. Also, two-bit data IN5 and IN6 are used to specify the direction of motor energization. In this manner, four motors including six independent loads can be controlled by a six-bit input signal, and the number of input terminals can be rationalized as compared with the conventional case. First, in the motor selection, when IN1 / IN2 is L / L, all the motors M1 to M4 are placed in a standby state. H
When / L, M1 is selected, when L / H, M2 is selected,
When H / H, M3 or M4 is selected. In this way, the motor select selects and specifies the first, second, or third load for each channel independently of the channel select. Next, in channel select, IN3
When / IN4 is L / L, both channel 1 and channel 2 are selected; when H / L, CH2 is selected; when L / H, CH1 is selected.
Select Since the remaining H / H does not need to be used for channel selection, it is used here to specify the braking of the motor (whether or not there is a brake). A brake may be required when driving a DC motor. At this time, by designating the brake, the output terminals connected to the bridge circuit corresponding to the DC motor can be short-circuited. This short circuit
Large braking is applied to the DC motor. As described above, by combining the motor select and the channel select, a plurality of loads can be sequentially controlled, and the number of input terminals of the driver IC 1 can be reduced as compared with the related art. The energizing direction of each motor is controlled by the logical state of IN5 / IN6.

FIG. 3 shows an input / output truth table for IN5 / IN6. FIG. 3 shows, in particular, IN1 / I
9 is a truth table when the stepping motor M1 is selected when N2 is H / L. When IN5 / IN6 on the input side is L / L, both coils of M1 are controlled so as to be energized in the forward direction. At the time of H / L, reverse energization is performed on the coil allocated to the channel CH1 side, and positive energization is performed on the coil allocated to the channel CH2 side. At L / H, the coil on the CH1 side is energized forward, and the coil on the CH2 side is energized reversely. At the time of H / H, reverse energization is performed on the coil on the CH1 side and reverse energization is also performed on the CH2 side. This enables forward and reverse bidirectional two-phase control of the stepping motor M1.

As described above, the power switch and the three-stage output stage mode are set by IN1 and IN2. The output stage three mode setting is a setting of which coil is energized.
In this embodiment, both channels 1 and 2 are switched simultaneously. IN3 and IN4 specify the three mode selection of the channel and the specification of the brake mode. I
At N5 and IN6, four modes of the conduction direction of two channels are set. In general, when three modes of the energizing channel are set with six coils, 6 × 3 = 18 types of settings are obtained, and a 7-bit input is obtained by adding a 5-bit input and 2 bits for direction setting.
On the other hand, in the present invention, the motor selection by two channels is shared, and the channel selection is applied to the on / off function of the motor, thereby enabling six-coil control with six-bit input, and further controlling the brake mode of each coil. Is also possible. Generally, when a driver IC including two bridge circuits individually such as a step motor drive is used,
Three inputs are required for the minimum control, and nine inputs are used for six coil control using three sets, and the input / output scale is large.
Further, adding a brake mode or the like further increases the complexity. On the other hand, in the present invention, by adopting the above-described input / output configuration, the control circuit of the driver IC can be rationalized. In this configuration, when the motors M1 and M2 are stepping motors, as shown in the truth tables of FIGS. , Single driver IC
It becomes feasible. According to the truth table, the above-described stepping motors M1 and M2 can be energized in one to two phases in addition to the two-phase energization, and the relation between the function and the input signal can be greatly reduced as compared with the related art. I have.

FIG. 4 is a circuit diagram showing a second embodiment of the motor drive device according to the present invention. Basically, it is the same as the first embodiment shown in FIG. 1, and corresponding portions are denoted by corresponding reference numerals to facilitate understanding. A different point is that a DC motor including one coil is used as the motor M1 instead of a stepping motor having a two-phase coil. That is, in the first embodiment, the lens driving for automatic focus adjustment is performed by the stepping motor.
In this embodiment, the lens is driven using a DC motor. A single load included in the DC motor M1 is connected between the output terminals OUT1 and OUT2 on the channel CH1 side. A pair of output terminals OUT5, O of channel CH2
No load is connected between the UTs 6. That is, instead of the two-load stepping motor, the one-load DC motor M1 is used.
Therefore, a pair of output terminals OUT5 and OUT6 are left. In this case, OUT6 is M2 (2/2)
OUT5 is left alone. Therefore, OUT1 and OUT5 are connected in parallel, and when the DC motor M1 is driven in the forward direction, part of the drive current flowing in the bridge circuit HA is diverted to one side of the bridge circuit HD to reduce the voltage drop of the transistor Q1. . As described above, the drive circuit unit of the driver IC 1 is driven by only one channel when a relatively light load such as the coil of the stepping motor is used and the current within the allowable current of one channel is applied. Heavy load,
When the current is supplied beyond the allowable current of one of the channels, both channels can be driven in common.

FIG. 5 is a circuit diagram showing a third embodiment of the camera motor driving device according to the present invention. Parts corresponding to those of the second embodiment shown in FIG. 4 are denoted by corresponding reference numerals to facilitate understanding. The difference from the second embodiment is that the stepping motor M2 is further removed. The stepping motor M2 is used for driving a zoom lens. In a camera without a zoom function, it is not necessary to use the stepping motor M2. Therefore, in the third embodiment, the stepping motor M2 is omitted, and in this relation, a pair of output terminals OUT on the CH2 side are used.
5, OUT6 is empty. In the present embodiment, the vacant pair of OUT5 and OUT6 is used for driving the heavy load DC motor M1. That is, the DC motor M1 is driven in parallel by the bridge circuit HA on the channel CH1 side and the bridge circuit HD on the channel CH2 side. As described above, when a heavy load is used, the driving capability can be increased because a current larger than the allowable current of one channel can flow by parallel connection between the channels. I
The output terminal of C can be used effectively.

FIG. 6 is a schematic plan view showing a connection wiring structure between the stepping motors M1 and M2 shown in FIG. 1 and the driver IC1. As shown in the figure, a stepping motor M1 and a stepping motor M2 are incorporated in the lens barrel 6, respectively, are arranged so as to surround the lens opening 7, and perform automatic focusing and zooming of the lens. On the other hand, the motor M1,
A driver IC1 for driving M2 is incorporated. The motors M1 and M2 and the driver IC 1 are connected by a flexible wiring board 9. The flexible wiring board 9 has a single-sided wiring structure, and includes a circular portion 9a on the side of the motors M1 and M2, a rectangular portion 9c on the side of the driver IC1, and an intermediate portion 9 connecting the circular portion 9a and the rectangular portion 9c to each other.
b. As shown, the two loads 1 and 2 included in the stepping motor M1 are separately allocated to two channels CH1 and CH2 included in the driver IC1. Specifically, the load 1 of M1 is C
H1 is connected between OUT1 and OUT2, and load 2 is connected to CH1
It is connected between OUT5 and OUT6 on the second side. Similarly, the two loads 1 and 2 included in the other stepping motor M2 are also divided into two channels CH1 and CH2 and are separately allocated. Specifically, the load 1 of M2 is connected to OUT2 and OUT3 of CH1,
Are connected to OUT6 and OUT7 of CH2. Here, the wiring pattern 10 connected to OUT2 is M1 and M2.
Is shared with The wiring pattern 10 connected to OUT6 is also shared by M1 and M2. As described above, the flexible wiring board 9 has two channels CH.
1, a wiring pattern 10 for connecting CH2 to two stepping motors M1 and M2 is formed. In particular, in the circular portion 9a disposed in the lens barrel 6 of the flexible wiring board 9, a wiring pattern for connecting the two loads included in each stepping motor into two channels CH1 and CH2 is connected to the lens barrel. 6 are arranged symmetrically with respect to the optical axis 8. For example, focusing on the stepping motor M1, the wiring pattern connected to OUT1 and OUT2 and the wiring pattern connected to OUT5 and OUT6 are symmetrically arranged about the optical axis 8. Similarly, focusing on the stepping motor M2, the wiring pattern connected to OUT2 and OUT3 and the wiring pattern connected to OUT6 and OUT7 are symmetrically arranged about the optical axis 8.

FIG. 7 is a schematic diagram showing a conventional wiring structure. A driver IC 11 is provided for M1 and M2
, Another driver IC 12 was used. Each of the driver ICs 11 and 12 has a four-output terminal configuration. In the conventional structure in which two stepping motors are mounted on the lens barrel, the motors M1 and M2 and the driver IC 1
When connecting 1 and 12 with a flexible wiring board, four wiring patterns were required for one motor. In the lens barrel, each motor can be set to be driven sequentially, and the output terminal can be shared with the load when the driver IC according to the present invention is used. Therefore, the wiring pattern can be reduced by the number of shares. As described above, when the stepping motor is used for sequential driving of the lens barrel, each motor is selectively driven, so it is possible to simplify the drive circuit unit and reduce the wiring pattern by focusing on this point. Becomes In an actual wiring pattern, as shown in FIG. 6, the stepping motors M1 and M2 are arranged so as to surround the lens barrel optical axis 8. When wiring for the two stepping motors M1 and M2 is taken, wiring for coils connected to different channels is made symmetrical with respect to the optical axis 8 so that the wiring pattern is circular over 360 degrees around the lens opening 7. By expanding to the portion 9a, the flexible wiring board 9 having a single-sided wiring structure can be used without using the front and back wiring structure.

[0024]

Conventionally, when controlling a plurality of driving loads,
Even when the load has a two-coil configuration such as a stepping motor or a single-coil load, the control driver ICs are individually used when the control method is different. On the other hand, in the present invention, it is possible to sequentially drive a plurality of motors having different numbers of loads and different control systems with one driver IC configuration, thereby achieving a significant cost reduction. Further, in the driver IC, the configurations of the drive circuit section including the bridge circuit and the control circuit section including the input / output logic circuit can be greatly rationalized.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a motor drive device according to the present invention.

FIG. 2 is a table showing a truth table used for explaining the operation of the first embodiment;

FIG. 3 is a table showing a truth table used for explaining the operation of the first embodiment;

FIG. 4 is a circuit diagram showing a second embodiment of the motor drive device according to the present invention.

FIG. 5 is a schematic diagram showing a third embodiment of the motor drive device according to the present invention.

FIG. 6 is a schematic plan view showing the mounting structure of the first embodiment.

FIG. 7 is a schematic diagram showing a conventional example.

[Explanation of symbols]

1 ... Driver IC, 2 ... Input / output logic circuit, 3 ...
..Reference voltage circuit, CH1, channel, CH2
・ Channel, M1 to M4 ... motor, OUT1 to OU
T8: output terminal, HA to HF: bridge circuit,
Q1 to Q16: transistor, OP1: differential amplifier, OP2: differential amplifier, RD: current detection resistor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 9/08 G02B 7/04 E 5H580 H02P 7/67 Z 8/00 A H02P 8/00 Q F term ( Reference) 2H002 ZA03 2H044 BE03 DA01 DA02 DB03 2H080 AA45 2H081 BB17 5H572 AA20 BB03 CC02 DD01 DD08 EE04 FF09 HA08 HC06 JJ02 LL22 5H580 AA04 BB10 CA02 CA12 DD01 EE02 FA13 FB03 FB05 GG03

Claims (12)

[Claims] 1. A driving circuit unit for driving a plurality of loads included in a plurality of motors, and a control circuit unit for controlling the driving circuit unit to sequentially drive the plurality of motors, wherein the driving circuit unit is , A motor driving device controlled by the control circuit unit so that each of the channels can selectively drive a plurality of loads. When driving one motor including at least two loads sequentially with another motor, assign one load of the motor to one channel and assign the other load of the motor to the other channel. A motor drive device, wherein the one motor is assigned to drive two channels. 2. The channel has n + 1 output terminals for connecting n (n is an integer of 2 or more) loads, and a pair of output terminals is assigned to drive one load. At least one of the pair of output terminals is shared between two loads, and the control circuit controls each output terminal of the channel so that a plurality of loads are not driven simultaneously in one channel. The motor drive device according to claim 1, wherein: 3. A bridge circuit is connected between each pair of output terminals corresponding to each load, and each bridge circuit supplies a bidirectional drive current to the corresponding load under the control of the control circuit unit. 3. The motor driving device according to claim 2, wherein the motor driving device can supply the electric power. 4. At least one of the plurality of bridge circuits includes a constant current circuit and drives a corresponding load with a constant current, while the remaining bridge circuits include a constant current circuit. 4. The motor drive device according to claim 3, wherein a corresponding load is driven by a saturation current. 5. The bridge circuit having the constant current supply circuit supplies a constant current when driving a corresponding load in one direction and a saturation current when driving a corresponding load in the other direction. Item 5. The motor driving device according to item 4. 6. The bridge circuit having the constant current circuit further includes a constant voltage circuit, and a constant voltage is applied to the load when the corresponding load is driven in the other direction. 6. The motor drive device according to claim 5, wherein the constant current drive and the constant voltage drive can be switched according to the drive direction of the load. 7. The control circuit section includes an input / output logic circuit, and a first type control signal for selecting one or both of two channels according to sequence data input from the outside; 2. The motor drive device according to claim 1, wherein a second type of control signal for designating a load to be driven by the selected channel is output to control the drive circuit unit. 8. The control circuit section outputs a first type of control signal representing four logical states in two bits, uses the three logical states for channel selection designation, and uses the remaining one logical state as a load state. 8. The motor driving device according to claim 7, wherein the motor driving device is used to designate braking. 9. The drive circuit unit can be driven using only one channel when a predetermined current is supplied to a load, and can be driven using both channels when a predetermined current is supplied. The motor drive device according to claim 1, wherein: 10. The motor drive device according to claim 1, wherein the drive circuit unit including two channels and the control circuit unit are integrated on a single IC chip. 11. The driving circuit section is connected to drive two motors provided in a lens barrel of a camera, and each of the two motors includes a stepping motor including two loads. The two loads included in one stepping motor are separately allocated to two channels included in the drive circuit unit, and the two loads included in the other stepping motor are also assigned to the two channels. The motor drive device according to claim 1, wherein the motor drive device is divided into two channels and separately allocated. 12. The drive circuit unit includes a flexible wiring board on which a wiring pattern for connecting the two channels to the two stepping motors is formed. 2. A wiring pattern, which is divided into two channels and connected to each other, is arranged symmetrically with respect to an optical axis of the lens barrel.
2. The motor drive device according to 1.