JPH0779599A - Stepping motor driving gear - Google Patents

Abstract

PURPOSE:To obtain an inexpensive stepping motor driving gear by driving a plurality of steeping motors by one driver. CONSTITUTION:In the case of driving a motor 1, a transistor (Tr) Q3 is turned on. In the case of exciting an A phase, an L signal is inputted to a gate G1 to cause a current to flow by the order of power supply Vcc TrQ3 A phase diode D7 TrQ1 resistor Rs; in the case that the current exceeds a preset value, the TrQ1 is turned off to cause a current to flow by the order of diode D6 A phase diode D3 power supply Vcc. Then the motor 1 and a motor 2 remain wired OR, but when a current of a loop L3 flows through the motor 1, a current to the motor 2 is impeded by a diode 11. In this way, the A phase of the motor 1 is excited.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a plurality of stepping motors.
The present invention relates to a stepping motor driving device capable of driving a motor.

[0002]

2. Description of the Related Art In recent years, a large number of stepping motors have been used as various transport drive sources for OA equipment. One O
When the equipment A requires a plurality of transport drive sources, a plurality of stepping motors are mounted, and accordingly, one drive circuit is mounted for each stepping motor.

[0003]

However, since the stepping motors are not always driven at the same timing as the transport driving sources, one driving circuit is mounted for each stepping motor. There is a problem in that the cost performance is not good.

The present invention has been made in view of the above points, and an object thereof is to provide a stepping motor driving device capable of driving a plurality of stepping motors with one driving circuit.

[0005]

A stepping motor driving device according to a first aspect of the present invention comprises a first stepping motor and a second stepping motor.
In a stepping motor drive device for driving the stepping motor of the first stepping motor, and a plurality of exciting coils provided in the first stepping motor and the second stepping motor, A plurality of exciting coils corresponding to the plurality of exciting coils;
Stepping motor and the second stepping motor
The excitation means that is commonly connected to the corresponding excitation coils and that supplies the excitation current at a predetermined timing, and the excitation current that this excitation means supplies to one of the commonly connected excitation coils Stepping motor and the above second
And a supply means for supplying the alternative stepping motor.

A stepping motor driving device according to a second aspect of the present invention is a stepping motor driving device for driving a first stepping motor and a second stepping motor, wherein a plurality of stepping motor driving devices are provided on the first stepping motor. Exciting coils, a plurality of exciting coils provided in the second stepping motor and corresponding to the plurality of exciting coils of the first stepping motor, the first stepping motor and the second stepping motor. Of the excitation coil corresponding to each phase of the first stepping motor and commonly connected to the corresponding excitation coil of the first stepping motor when the excitation current is supplied to the excitation coil of the first stepping motor. The first timing when the exciting current is supplied to the exciting coil of the second stepping motor at the first timing. Consists of a control means for controlling the exciting means so as to be different from the second timing.

According to a third aspect of the present invention, there is provided a stepping motor driving device which comprises a first stepping motor having a plurality of exciting coils, a first optical means driven by the first stepping motor, and the first stepping motor. Stepping mode
Second stepping motor having a plurality of exciting coils corresponding to a plurality of exciting coils of the motor, second optical means driven by the second stepping motor, the first optical means and the first optical means. In an image forming apparatus having an image forming means for forming an image by the optical image from the original by the second optical means, the phase correspondence of the first stepping motor and the second stepping motor To the exciting coil, which is commonly connected to the exciting coil and supplies an exciting current at a predetermined timing, and one of the exciting coils which is commonly connected to the exciting current supplied by the exciting means. The second stepping motor is selectively supplied in response to the use of the second stepping motor.

According to a fourth aspect of the present invention, there is provided a stepping motor driving device which comprises a first stepping motor having a plurality of exciting coils, and a first stepping motor which is driven by the first stepping motor to convey an image forming medium. Conveying means and a second stepping motor having a plurality of exciting coils corresponding to the plurality of exciting coils of the stepping motor,
An image is formed on a second conveying unit that is driven by the second stepping motor and that conveys the image forming medium, and on the image forming medium that is conveyed by the first conveying unit and the second conveying unit. In an image forming apparatus having an image forming means for forming, an exciting coil which is commonly connected to corresponding exciting coils of the first stepping motor and the second stepping motor and supplies an exciting current at a predetermined timing. Means and the exciting current supplied by the exciting means to one of the commonly connected exciting coils in response to the use of the first stepping motor and the second stepping motor. And a selection means for performing the selection.

[0009]

The current from one constant current source is selectively selected and supplied to the phases of a plurality of motors.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A stepping motor drive circuit according to an embodiment of the present invention will be described below with reference to the drawings. Figure 1
Is an equivalent circuit diagram showing the main part of the stepping motor drive circuit, FIG. 2 is a part of the circuit diagram of the stepping motor drive circuit for driving and controlling the two stepping motors, and FIG. 3 is the two stepping motors. Drive control stepping mode
Part of the circuit diagram of the motor drive circuit, FIG. 4 is a block diagram of a control device for driving and controlling two stepping motors using the stepping motor drive circuit, and FIG. 5 is a temporal change of the rotation speed of each motor. FIG. 6, FIG. 6 is a flowchart showing the basic operation of the copying machine, FIG. 7 is a schematic vertical sectional front view of the copying machine, and FIG. 8 is a perspective view of the copying machine with the document table removed. 9 is a perspective view showing the moving mechanism of the optical system of the copying machine, FIG. 10 is a side view showing the moving mechanism of the lens block of the copying machine, and FIG.
Is a plan view of an operation panel of the copying machine, and FIG. 12 is a block diagram showing a control system.

First, an electronic copying machine equipped with a plurality of stepping motors and having a variable magnification function will be described with reference to FIG. That is, 11 is a main body of a copying machine, and an original table (transparent glass plate) 12 for supporting an original O is provided on the upper surface of the main body 11, and an original cover 13 can be freely opened and closed on the original table 12. It is provided. Then, the original O set on the original table 12 is read by the exposure lamp 14
The mirrors 15, 16 and 17 reciprocate along the lower surface of the document table 12 in the direction of the arrow shown in the figure, so that exposure scanning is performed during the forward movement. In this case, Mira-1
6 and 17 are 1/15 of the mirror 15 to keep the optical path length constant.
Move at speed of 2. The light reflected from the document O by the illumination of the exposure lamp 14 is reflected by the mirrors 15, 16, 17 described above.
After passing through the lens 18 after being reflected by
The photosensitive drum 20 which is reflected by 9 and serves as an image carrier
And the image of the document O is formed on the surface of the photoconductor drum 20. The photosensitive drum 20 rotates in the direction of the arrow in the figure, the surface is charged by the charging charger 21, and then the image of the original O is slit-exposed to form an electrostatic latent image. Is the developing device 2
The toner is attached by 2 to form a visible image.

On the other hand, the paper P is fed from the upper paper feed cassette 23 or the lower paper cassette 24, which is detachably provided at the lower right end of the main body 11, to the paper feed cassette 25 or 26.
The sheets are taken out one by one by way of the paper and guided to the registration roller 29 through the paper guide path 27 or 28.
It is sent to the transfer section by the la 29. The sheet P sent to the transfer unit is brought into close contact with the surface of the photoconductor drum 20 at the transfer charger 30, so that the toner image on the photoconductor drum 20 is transferred by the action of the charger 30. . After the transfer, the photosensitive drum 20 is discharged by the discharging charger 31, the cleaner 32 removes the residual toner on the surface, and the discharging lamp 33 erases the residual image to restore the initial state. Is composed of. On the other hand, the paper P after transfer is electrostatically peeled from the photoconductor drum 20 by the action of the peeling charger 34, and then conveyed to the heater 36 as a fixing device by the paper conveyance path 35. The transferred image is heated and fixed by passing through this. Then, the sheet P after fixing is configured to be ejected to the tray 38 outside the main body 11 by the sheet ejection roller 37.

Further, when performing reduction or enlargement copying, the magnification ratio of the magnification varying means is variably controlled by setting a copying magnification provided on an operation panel described later. That is, the moving speed (scanning speed) of the exposure lamp 14 and the mirror 15 and the photosensitive drum 2 are set according to the set copy magnification.
The size in the scanning direction is changed by changing the relative ratio (speed ratio) to the rotational speed of 0, and the positions of the mirrors 16, 17 and the lens 18 are moved to change the optical path length from the document O to the lens 18 and the lens. By changing the ratio (optical path length ratio) from 18 to the exposure body drum 20 to change the size in the scanning direction and the orthogonal direction, it is possible to obtain a copy of the set magnification.

Next, with reference to FIG. 8, a mechanism relating to the change of the velocity ratio and the optical path length ratio, which is the main part of the present invention, will be described. FIG. 8 is a view seen from the rear side in a state where the original table 12 is removed in FIG. In FIG. 8, reference numeral 41 denotes a first carriage, and the first carriage 41 has an exposure lamp 14 and a mirror which constitute means for optically scanning the original O.
15 is attached. Further, 42 is a second carriage, and the mirrors 16 and 17 are mounted on the second carriage 42. The second carriage 42 is driven by the scanning motor 43 together through a mechanism that moves at a speed half that of the first carriage 41. That is, as shown in detail in FIG. 9, the first and second carriages 41, 42
Is guided by a guide shaft 44 and a guide rail 45 so as to be reciprocally movable. A drive pulley 46 driven by the scanning motor 43 is provided on one end side of the guide shaft 44, and a driven pulley 47 is provided on the other end side thereof. An endless toothed belt 48 is stretched between 47. Then, one point of the belt 48 is fixed to a fixing portion 49 provided so as to project from the first carriage 41.

On the other hand, the guide shaft support portion 50 of the second carriage 42 is rotatably mounted with pulleys 51 and 52 at predetermined intervals in the axial direction of the guide shaft 44. A wire 53 is hung between 52. Then, 54 of this wire 53, one end to the fixing member 54,
The other end is fixed to the fixing member 54 via a coil spring 55.
It is fixed to each. Moreover, one point of the wire 53 is fixed to the fixing portion 49 of the first carriage 41. As a result, the pulleys 51 and 52 function as a moving pulley, so that the second carriage 42 can move at a 1/2 no speed with respect to the first carriage 41. Also,
On the lower end surface of the fixing member 54, the mirror moving motor 5 is attached.
A rack (not shown) that meshes with the pinion 57 driven by 6 is formed, and only the second carriage 42 can be moved by operating the motor 56.

Further, as shown in FIGS. 8 and 10, the lens 18 is held by a lens block 58, and the lens block 58 is connected to a cam shaft 60 via a cam follower portion 59 fixed to the lens block 58. is doing. The cam shaft 60 is driven by a lens moving motor 61, and the lens block 58 is moved forward or backward depending on the rotation direction of the motor 61. The second carriage 42 moves in synchronization with the movement of the lens block 58, which constitutes means for changing the optical path length. Note that FIG. 10 shows the coupled state of the cam follower portion 59 and the cam shaft 60. The cam follower 6 fitted in the cam follower portion 59 is shown in FIG.
By moving 2 along the spiral groove 63 formed on the cam shaft 60, the entire lens block 58 moves.

Further, as shown in FIG. 8, the photosensitive drum 20 includes a scanning motor 43, a mirror moving motor 56,
It is driven by a dedicated drum driving motor 64 provided separately from the lens moving motor 61, and these four motors 43, 56, 61, 64 respectively use pulse motors. And independently controlled.

FIG. 11 shows the operation panel 71.
A power switch 72, a copy key 73 for executing a copy operation, a numeric keypad 74 for setting the number of copies, a number display section 75 for displaying the number of copies, a status display section 76 for displaying the operation state, a copy density A density adjuster 77 for adjusting and a copy magnification setting unit 78 for setting a copy magnification are provided respectively. The copy magnification setting unit 78, magnification setting keys -81 _{1-81 5,} indicator that these specific magnification is set for selecting and setting one specific magnification - by (e.g. published diode Do) 82 _{1-82 5} Composed.

FIG. 12 shows the main part of the control section.
That is, reference numeral 91 denotes a main control unit, which is mainly composed of a CPU (central processing unit) and its peripheral circuits and controls the entire copying machine. The key input of the control panel is connected to the input of the main control unit 91. The outputs of the main control unit 91 include the scanning motor 43, the mirror moving motor 56, the lens moving motor 61, the drum driving motor 64, and the display unit of the control panel. Connected. Further, the main controller 91 is connected to a pulse generator 93 which generates clock pulses for driving control of the pulse motor and periodically sensing various switches on the operation panel 71. Then,
The main control unit 91 periodically senses the magnification setting key -81 _{1-81 5} by using the clock pulse from the pulse generator 93, and updates the display of the indicator 82 _{1-82 5} according to the result At the same time, it controls the mirror moving motor 56 and the lens moving motor 61. And copy key 73
When the depression of the button is sensed, the scanning motor 43 and the drum driving motor 64 are operated to perform the copying operation.

Next, the operation of this structure will be described with reference to the flowchart shown in FIG. Now, when the power is turned on, the process proceeds to step S1, the specific magnification is set to an initial value (for example, 100%), and the process proceeds to step S2.
In step S2, if it is pressed by checking whether the magnification setting key -81 _{1-81 5} is depressed,
The magnification is set in step S3.

At step S2, the magnification setting key is pressed.
If 81 _{1-81 5} is not pressed, the process proceeds to step S4. In step S4, it is checked whether or not any other key on the operation panel 71 is pressed, and if it is pressed, the process proceeds to step S5. In step S5, the pressed key
Is performed and the process proceeds to step S6. Step S
In step 6, it is checked whether or not the above process is completed. If not completed, the process returns to step S5 to continue the above process, and if completed, the process proceeds to step S7. Step S above
If no other key is pressed in step 4, step S5,
The process jumps to S6 and proceeds to step S7. Step S7
Then, it is checked whether or not the copy key 73 is pressed, and if not pressed, the process proceeds to step S10. In step S10, it is checked whether or not there is no key operation on the operation panel 71 for a predetermined time (for example, 30 seconds) or more. If not, the process returns to step S2 and the same operation as described above is repeated. When a predetermined time or more has elapsed in step S10, the process returns to step S1 and the same process as above is repeated.

That is, if the copy key 73 or another key is not pressed within a predetermined time (for example, 30 seconds) after the setting of the copy magnification (or after the end of the previous copying operation), the magnification range and the copy magnification are automatically set. The initial value can be restored.

On the other hand, if the copy key 73 is pressed in step S7, the flow advances to step S8 to start the copy process, and then advances to step S9. In step S9, it is checked whether or not the copying process is completed. If it is not completed, the process returns to step S8 to continue the copying process,
When finished, the process returns to step S2. That is, when the setting of the copy magnification is completed as described above, the main controller 91
In order to change the magnification in the orthogonal direction with respect to the scanning direction of the original, the mirror moving motor 56 and the lens moving motor 61 are respectively driven, so that the optical path length from the original O to the lens 18 and the lens 18 are increased. The second carriage 42 (mirrors 16 and 17) and the lens block 58 (lens 18) are moved to positions where the ratio from the optical path length to the photoconductor drum 20 corresponds to the set magnification. In this case, the longest or shortest optical path length is determined by the physical size of the copying machine, and since the same lens 18 is always used, the position of the lens 18 can be uniquely determined. Therefore, the CPU is used as the main control unit 91,
Moreover, by using the pulse motor as the mirror moving motor 56 and the lens moving motor 61, the movement amount can be calculated very easily, and the number of pulses given to the pulse motor can be counted. The position can be accurately determined.

However, when the user sets the number of copies after setting the magnification and then presses the copy key 73, the main control unit 91 starts the copying operation, and the scanning motor 43 and the drum driving unit are driven. By driving the motors 64 respectively,
The document O set on the document table 12 is optically scanned to form an electrostatic latent image on the photoconductor drum 20, and these processes are as described above. In this case, the magnification in the document scanning direction is determined by the ratio (speed ratio) of the moving speed of the first carriage 41 supporting the exposure lamp 14 and the mirror 15 to the rotating speed of the photosensitive drum 20, With respect to the movement of the carriage 41 and the rotation of the photosensitive drum 20, the scanning motor 43 and the drum driving motor 64 which are independent of each other are provided, so that the above speed ratio can correspond to the set magnification. . That is, the scanning motor 43
Since the drum driving motor 64 and the drum driving motor 64 are pulse motors, respectively, the rotation speed is controlled by counting the number of pulses given to the respective motors so that the speed ratio matches the set magnification. When the copying process is completed, the process returns to step S2 to prepare for the next copying operation.

By the way, in this embodiment, as shown in FIG. 4, the scanning motor 43 and the mirror driving motor 56 are controlled by one driver 101.
A power source Vcc is supplied to the scanning motor 43 through the switch means 1.
Is supplied to the mirror moving motor 56 via the switch means 2.

The A, Eq. 1, B, Eq. 2 signals from the main control unit 91 are input to the driver 101. The switch means 1 and 2 are on / off controlled by a signal from the main controller 91.

[0027]

[Equation 1]

[0028]

[Equation 2]

By the way, the scanning motor 43 needs to be operated in proportion to the copying speed, and a high speed operation is required, and a hybrid type stepping motor is used. Further, the mirror moving motor 56 is a scanning motor 43.
It uses a PM type stepping motor, which can be operated at a lower speed than that of, and is inexpensive. Therefore, the operating speed varies depending on the motor used.

FIG. 5 shows the speed rates of the scanning motor 43 and the mirror moving motor 56. n1 to n3 are scanning modes
This is a typical speed rate of the data 43, and n2 is a magnification of 100%.
, N1 indicates the speed rate at the time of contraction, and n3 indicates the speed rate at the time of expansion.
Reference numeral n4 is a speed rate for moving the mirror. Although the best rate is selected from the motor characteristics and used, it is much slower than the scanning motor.

The speed rate is controlled by changing the phase excitation switching time. As a concrete example, US
P4,540,927 and the like. In this embodiment, when the magnification is set, the mirror moving motor is driven and moved to a position matching the magnification. At this time, the switch means 2 of FIG. 3 is turned on,
The switch means 1 is turned off. When the excitation phase is switched at the speed rate of n4, the mirror moving motor 56 is driven. When the setting of the magnification is completed, the switch means 2 is turned off. During the copying operation, the switch means 1 is turned on to switch the excitation phase at one of the speeds n1 to n3 corresponding to the magnification setting. The main control unit 91 determines the timing for switching the excitation phase.
Stored in a memory (not shown).

Next, referring to FIG. 1, the scanning motor 43 (or the mirror moving motor 56) in the driver 101.
An equivalent circuit diagram focusing on the electromagnetically coupled A-3 phase is described.

[0033]

[Equation 3]

That is, in FIG. 1, the connection point between the exciting coil A and the number of exciting coils 4 is connected to the above-mentioned anode of the power source Vcc. Further, one end of the exciting coil A is grounded via the transistor Q1 and the resistor Rs, and one end of the exciting coil number 5 is connected to the non-grounded side of the resistor Rs described above via the transistor Q2. The transistors Q1 and Q
Diodes D1 and D2 that allow a current from the emitter side to the collector side are connected between the two emitters and collectors, respectively.

[0035]

[Equation 4]

[0036]

[Equation 5]

By the way, the bases of the transistors Q1 and Q2 are
The output signals of the AND gates G1 and G2 are input to the respective gates. The A signal and the number 6 signal are inverted and input to one of the input terminals of the AND gates G1 and G2, respectively.

[0038]

[Equation 6]

By the way, the voltage of the non-grounded terminal of the resistor Rs is input to the negative terminal of the operational amplifier OP1,
The reference voltage Vref1 is input to the + terminal of OP1. Further, the output of the operational amplifier OP1 is connected to the connection point between the resistor R and the capacitor C, and the voltage at the connection point is input to the-terminal of the operational amplifier OP2. Where the op amp
The reference voltage Vref2 is input to the + terminal of OP2, and power is supplied to one end of the resistor R.

In FIG. 1, when driving the A phase, a low level signal is input to the AND gate G1 and the transistor Q
1 is turned on. Therefore, the current of the loop L1 shown by the broken line flows, the potential of the non-grounded side terminal of the resistor Rs rises,
When the set current value Vref1 is exceeded, the operational amplifier OP1 is inverted,
The output of the operational amplifier OP1 becomes LOW level, and the output of the operational amplifier OP2 becomes HIGH level.

The output of the operational amplifier OP2 is the AND gate G1.
The output of AND gate G1 is LO
The transistor Q1 is turned off and the transistor Q1 is turned off. At this time, since the A-number 7 phase of the stepping motor is electromagnetically coupled, a current flows as indicated by a loop L2 indicated by a dashed line. At this time, the input of the-terminal of the operational amplifier OP1 becomes LOW level from Vref1 and the output of the operational amplifier OP1 becomes open level (the output of the operational amplifier OP1 is an open collector type). At this time, the operational amplifier OP2 input is Vre
The output of the operational amplifier OP2 continues to be HIGH level until the RC time constant is charged up to f2 level. When the charge is raised, the AND gate G1 and the transistor Q1 are turned on again, and the current of the loop L1 shown by the broken line starts to flow.

[0042]

[Equation 7]

Next, a stepping motor drive circuit according to an embodiment of the present invention will be described with reference to FIGS. In FIG. 2 and FIG. 3, the connection point between the A phase and the number 8 phase of the motor 1 (that is, the scanning motor 43) is connected to the anode of the power source Vcc through the transistor Q3. 2 and 3, the same parts as those in FIG.
Detailed description thereof will be omitted.

[0044]

[Equation 8] Further, the motor 2 (that is, the motor 56 for moving the mirror)
The connection point between the A'phase and the number 9 phase is connected to the anode of the above-mentioned power source Vcc through the transistor Q4.

[0045]

[Equation 9]

Diodes D3 and D4 for allowing a current from the collector to the emitter are connected between the emitter and collector of the transistors Q3 and Q4, respectively.
Both ends of the above-mentioned series connection body of the A phase and the A bar phase are grounded through diodes D5 and D6 connected in opposite directions. Further, one end of the series connection body of the A-phase and several tens of phases is connected to the collector of the transistor Q1 via the diode D7 connected in the forward direction. The other end of the serially connected body of the A phase and the number 11 phase is connected to the collector of the transistor Q2 via the diode D8 connected in the forward direction.

[0047]

[Equation 10]

[0048]

[Equation 11]

Both ends of the above-mentioned series connection body of the A'phase and the several 12 phases are grounded through the diodes D9 and D10 connected in opposite directions. Further, one end of the series connection body of the A'phase and the several 13 phase is connected to the diode D1 connected in the forward direction.
1 is connected to the collector of the transistor Q1.
The other end of the serially connected body of the A'phase and the number 14 phase is connected to the transistor Q via the diode D12 connected in the forward direction.
2 collectors connected.

[0050]

[Equation 12]

[0051]

[Equation 13]

[0052]

[Equation 14]

The emitters of the transistors Q1 and Q2 are connected to each other and are grounded via the resistor Rs described above. The connection point between the B phase of the motor 1 (that is, the scanning motor 43) and the equation 15 is connected to the anode of the power source Vcc through the transistor Q3 described above.

[0054]

[Equation 15]

Further, the connection point between the B'phase and the several 16th phase of the motor 2 (that is, the motor for motor movement 56) is connected to the anode of the power source Vcc mentioned above through the transistor Q4 mentioned above. It

[0056]

[Equation 16]

Both ends of the series connection body of the B phase and the number 17 phase described above are grounded through diodes D13 and D14 connected in opposite directions. Furthermore, one end of the series connection body of the B phase and the number 18 phase is connected to the diode D15 connected in the forward direction.
Connected to the collector of the transistor Q5. The other end of the serially connected body of the A phase and the number 19 phase is connected to the collector of the transistor Q6 via the diode D16 connected in the forward direction.

[0058]

[Equation 17]

[0059]

[Equation 18]

[0060]

[Formula 19]

Both ends of the series connection body of the B'phase and several 20 phases described above are connected in opposite directions to diodes D19 and D20.
Grounded through. Further, one end of the series connection body of the B'phase and the number 21 phase is connected to the diode D in the forward direction.
It is connected via 19 to the collector of the transistor Q5. The other end of the series connection body of the B'phase and the number 22 phase is connected to the collector of the transistor Q6 through the diode D20 connected in the forward direction.

[0062]

[Equation 20]

[0063]

[Equation 21]

[0064]

[Equation 22]

The emitters of the transistors Q5 and Q6 are connected to each other and are grounded via the resistor Rs described above. First, the case of driving the motor 1 will be described. When the motor 1 is driven, an L level signal is output to the base of the transistor Q3 and this is turned on.

To excite the A phase, an L level signal is input to the gate G1 and the power supply Vcc → transistor Q3 → A phase → diode D7 → transistor Q1 → resistor Rs loop L3. When a current flows through the transistor Q1 and the current exceeds the set value, the transistor Q1 is turned off and the diode D6 is turned on.
→ Several 23 phases → Diode D3 → Power supply Vcc loop L4.

[0067]

[Equation 23]

By the way, the motor 1 and the motor 2 are wired.
However, when the current of the loop L3 is flowing in the motor 1, the current to the winding to the motor 2 is blocked by the diode D11.

In this way, the A phase of the motor 1 is excited. The B-phase excitation of the motor 1 may be performed by inputting an L level signal to the gate G3 while the transistor Q3 is conducting.

In this embodiment, two motors are connected by wire.
Although the connection is made by the door-or, the two or more motors can be connected by the wire-or. In this embodiment,
Wire the scanning motor 43 and the mirror movement motor 56.
Although it is driven by one constant current driver, it is only the scanning motor 43 and the drum driving motor 64 that operate simultaneously as described in the above operation flow and description, and for the lens movement. Even if the motor 61 and the drum driving motor 64 are wired OR, the same effect can be obtained.

Further, conventionally, as shown in FIG. 15, it is general to give each motor driver each phase output of A, Eq. 24, B, Eq. 25, but two motors as in the present invention. The wire
In the case of a door-or-door operation, <each phase output> + <motor drive source switch output> = <6 output>, and it goes without saying that two output lines of the main control section can be saved.

[0072]

[Equation 24]

[0073]

[Equation 25]

Further, it is clear from the fact that each motor power supply switching means is provided that the wired-ORed motors can operate without any problem even if they are excited to have different speeds. It is also clear from the scanning motor 43, the mirror moving motor 56, and the wire-or which the speed varies depending on the magnification.

In the above embodiment, the case where the circuit for driving the two stepping motors by one driver is applied to the copying machine has been described, but the present invention is not limited to the copying machine.
It can also be applied to a stepping motor used in a transport system for transporting different types of paper as described with reference to FIGS.

In FIG. 13, 110 is a first stack for storing size A paper, 111 is a second stack for storing the same size A paper, and 112 is a size B paper different from the size A. This is the third stack. The motor M1 is a stepping motor that is driven when the size A paper stored in the stack 110 is transferred to the transport path 113, and the motor M2 is the size A paper stored in the stack 111. Of the stepping motor and the motor M3, which are driven when the sheet is transferred to the transport path 113,
This is a stepping motor that is driven when the size B sheets stored in No. 2 are transferred to the transport path 113.

The motor M4 is a stepping motor for driving the transport path 113.
A paper outlet 114 is installed at the end of the paper outlet 1.
A gate 115 for permitting or blocking the passage of the paper is provided in front of 14.

As described above, since the stacks 110 and 111 store sheets of the same size, it is not necessary to drive the motors M1 and M2 at the same time. Therefore, motor M1 and motor
By configuring the driver for driving the motor M2 and one driver as in the above-described embodiment, two motors can be driven by one driver. Note that FIG.
No. 4 turns on the motor M4, first drives the transport path 113, turns on the motor M1 (or M2) only once to transfer the size A paper to the transport path 113, and then -Turn on M3 only twice to transfer the size B paper to the transport path 11
I am trying to transfer to 3. Here, the gate 115 is turned on last, and the paper is ejected from the paper ejection port 114.

[0079]

As described above in detail, according to the present invention, 1
Since one driver can drive a plurality of stepping motors, it is possible to provide an inexpensive stepping motor driving device.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram showing a main part of a stepping motor drive circuit according to an embodiment of the present invention.

FIG. 2 is a part of a circuit diagram of a stepping motor driving device for driving and controlling two stepping motors according to one embodiment.

FIG. 3 is a block diagram of a control device that drives and controls two stepping motors using a stepping motor drive circuit according to an embodiment.

FIG. 4 is a block diagram showing a schematic configuration of one embodiment.

FIG. 5 is a diagram showing a change with time of the rotation speed of each motor of the copying machine according to the embodiment.

FIG. 6 is a flowchart showing the basic operation of a copying machine to which the present invention is applied.

FIG. 7 is a schematic vertical sectional front view of the copying machine.

FIG. 8 is a perspective view of the copying machine with a document table removed.

FIG. 9 is a perspective view showing a moving mechanism section of an optical system of the copying machine.

FIG. 10 is a side view showing a moving mechanism section of a lens block of the copying machine.

FIG. 11 is a plan view of an operation panel of the copying machine.

FIG. 12 is a diagram showing a control system.

FIG. 13 is a diagram showing a schematic configuration of a transport system using four stepping motors.

FIG. 14 is a timing chart showing driving of four motors.
To

FIG. 15 is a block diagram showing a conventional stepping motor drive circuit.

[Explanation of symbols]

O ... manuscript, 12 ... manuscript table, 14 ... exposure lamp, 15, 1
6, 17, 19 ... Mirror, 18 ... Lens, 20 ... Photosensitive drum, 43 ... Scanning motor, 56 ... Mirror moving motor
Motor, 61 ... lens moving motor - motor, 64 ... drum driving motor - motor, 78 ... copy magnification setting unit, 81 _{1-81 5} ... magnification setting key -, 82 ₁ to 82 ₅ ... indicator, 91 ... main Control part, Q
1-Q6 ... Transistors, D1-D18 ... Diodes,
Rs ... resistance

Claims (4)

[Claims] 1. A stepping motor driving device for driving a first stepping motor and a second stepping motor, wherein a plurality of exciting coils provided in the first stepping motor and the second stepping motor are provided. Common to a plurality of exciting coils provided on the motor and corresponding to a plurality of exciting coils of the first stepping motor, and to corresponding exciting coils of the first stepping motor and the second stepping motor. Connected to the
An exciting means for supplying an exciting current at a predetermined timing and an exciting current supplied by the exciting means are supplied to one of the commonly connected exciting coils of the first stepping motor and the second stepping motor. A stepping motor driving device comprising: a supply means for selectively supplying according to use. 2. A stepping motor drive device for driving a first stepping motor and a second stepping motor, wherein a plurality of exciting coils provided in the first stepping motor and the second stepping motor are provided. Common to a plurality of exciting coils provided on the motor and corresponding to a plurality of exciting coils of the first stepping motor, and to corresponding exciting coils of the first stepping motor and the second stepping motor. Connected to the
When the exciting current is supplied to the exciting coil of the first stepping motor by the exciting means for supplying the exciting current at a predetermined timing and the selecting coil, the exciting coil of the second stepping motor is supplied at the first timing. A stepping motor drive device, comprising: a control means for controlling the exciting means so as to have a second timing different from the first timing when an exciting current is supplied to the exciting coil. 3. A first stepping motor having a plurality of exciting coils, and a first stepping motor driven by the first stepping motor.
Optical means, a second stepping motor having a plurality of exciting coils corresponding to the plurality of exciting coils of the first stepping motor, and a second stepping motor driven by the second stepping motor.
And an image forming unit that guides an optical image from a document by the first optical unit and the second optical unit and forms an image by the optical image. The stepping motor and the second stepping motor are commonly connected to the corresponding exciting coils.
Use of the first stepping motor and the second stepping motor in one of the exciting means for supplying the exciting current at a predetermined timing and the exciting coil commonly connected with the exciting current supplied by the exciting means. The stepping motor drive device is provided with a selection means for selectively supplying the stepping motor. 4. A first stepping motor having a plurality of exciting coils, first conveying means for conveying an image forming medium driven by the first stepping motor, and a plurality of the stepping motors. Second stepping motor having a plurality of exciting coils corresponding to the exciting coils, second conveying means for conveying the image forming medium driven by the second stepping motor, and the first conveying. And an image forming means for forming an image on an image forming medium conveyed by the second conveying means, the phase of the first stepping motor and the second stepping motor Commonly connected to the corresponding excitation coil,
An exciting means for supplying an exciting current at a predetermined timing and an exciting current supplied by the exciting means are supplied to one of the commonly connected exciting coils of the first stepping motor and the second stepping motor. A stepping motor driving device, comprising: a selecting means for selectively supplying in response to use.