JPH0310505Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an optical system drive device for a copying machine, for example, for reciprocating an optical system in an electronic copying machine with a fixed document table.

2. Description of the Related Art There is an electronic copying machine with a fixed document table, in which an optical system such as an exposure lamp and a mirror is reciprocated along a fixed document table, and a document set on the document table is exposed and scanned to perform copying. The conventional optical system drive method in such copying machines is
The mechanism used a plurality of electromagnetic clutches to reciprocate the optical system by turning them on and off alternately. However, in such conventional drive systems, the document scanning start position is set by turning on and off multiple clutches using the output of a detector such as a microswitch, making the drive mechanism complex and unreliable. There was a problem with the lack of sex. In addition, since the optical system is moved by turning on and off the electromagnetic clutch, a large impact is applied to the optical system when it is turned on or off.
Another drawback was that various vibrations remained, which adversely affected the quality of copied images.

This idea was made in view of the above circumstances,
The purpose of this is to enable the setting of the original scanning start position for the optical system using a simple and accurate mechanism, to further improve reliability, and to reduce vibrations when the optical system is driven. The pulse motor can be removed and the pulse motor can step out while the object is moving from the detector to the stopper, and the pulse motor can be prevented from stepping out before the object is detected by the detector. The purpose of the present invention is to provide an optical drive device for a machine, etc.

An embodiment of this invention will be described below with reference to the drawings.

FIG. 1 schematically shows an electronic copying machine with a fixed document table according to this invention. The original set on the original platen 2 is read by an optical system 6 consisting of an exposure lamp 3 and mirrors 4 and 5 that reciprocates along the lower surface of the original platen 2 in the direction of the arrow in the figure. It is configured to be exposed and scanned. In this case, mirror 5 moves at half the speed of mirror 4 so as to keep the optical path length constant. The light reflected from the original by the scanning of the optical system 6, that is, the light reflected from the original by the exposure lamp 3, is reflected by the mirrors 4 and 5, passes through the lens 7, and is further reflected by the mirrors 8 and 9. The light is reflected and guided to the photoreceptor drum 10, and an image of the document is formed on the surface of the photoreceptor drum 10.

The photosensitive drum 10 rotates in the direction of the arrow shown in the figure, and its surface is first charged by the charger 11, and then an electrostatic latent image is formed by exposing the original image to slit light. The image is configured to be visualized by applying toner by a developing device 12. On the other hand, sheets P are stored in a paper feed cassette 13, taken out one by one by a take-out roller 14, and sent to a transfer section by a conveyance path 15. Paper P sent to the transfer section
is the portion of the transfer charger 16 that is connected to the photosensitive drum 10.
By coming into close contact with the surface of the photosensitive drum 10, the toner image on the photosensitive drum 10 is transferred by the action of the charger 16. After the photosensitive drum 10 has been transferred, the static electricity is removed by a charger 17, and residual toner is removed by a cleaner 18, so that the photosensitive drum 10 returns to its initial state. On the other hand, the paper P after transfer is transferred to the photosensitive drum 1 by the action of the peeling charger 19.
After being peeled off from 0, the transfer image is sent to the fixing device 20 via the conveyance path 15, and the transferred image is fixed by passing therethrough. Then, the sheet P after fixing is configured to be discharged to the paper discharge tray 21.

FIG. 2 schematically shows a drive mechanism for reciprocating the optical system 6, in which the mirrors 4 and 5
has a carriage 22 ₁ , 2 at each end thereof, respectively.
2 ₂ , 23 ₁ , 23 ₂ , and each of these carriages 22 ₁ , 22 ₂ , 23 ₁ , 23 ₂ is guided by round bar-shaped guide rails 24 ₁ , 24 ₂ and can freely move in parallel in the direction of the arrow in the figure. It is becoming. Thus, the pulse motor 25 drives the wire drum 27 via the deceleration mechanism 26. A driving wire 28 is wound around this wire drum 27.
One end of 8 is a pulley 29 and an idler (moving pulley) 3
0, and a spring 31 with one end fixed.
is fixed to the other end. Further, the other end of the wire 28 is fixed to a predetermined location via an idler 30. The idler 30 is rotatably fixed to the carriage 23 ₁ that supports the mirror 5, and the wire 23 between the wire drum 27 and the idler 30 is
A carriage 22 supporting the mirror 4 in the middle of the mirror 8
₁ are concatenated. Further, the wire 28 is provided with a detection tab (detection body) 32. This detection tab 32 is adapted to be detected by a detector 33 provided near the wire drum 27. This detector 33 is a well-known detector consisting of, for example, a light emitting element and a light receiving element. Further, a stopper 34 is provided between the wire drum 27 and the detector 33.
is placed. This stopper 34 sets the optical system 6 to the initial position by stopping the detection tab 32. In addition, the pulse motor 25
For example, a two-phase excitation system is used, and a third
As shown in the figure, the permanent magnet 25a is rotated by exciting the A-phase, B-phase, and B-phase coils 25 ₁ , 25 ₂ , 25 ₃ , and 25 ₄ . That is, as shown in the timing chart shown in FIG. 4, each time a driving pulse is supplied, the A phase,
B phase, phase, phase, A phase, etc. are excited.

As the motor 25 rotates,
The wire 28 wound around the wire drum 27 moves, and the mirror 4 moves accordingly. mirror 5
Since the mirrors move via the idler 30, in this case they move in the same direction at half the speed of the mirror 4.
Note that the moving speed of the mirrors 4 and 5 can be controlled by changing the rotational speed of the motor 25. Although not shown, the exposure lamp 3 also has a carriage 22 ₁ , which supports the mirror 4 .
22 ₂ via a mounting member, and is adapted to move together with the mirror 4.

FIG. 5 shows a control circuit for driving and controlling the pulse motor 25, which includes an input port 41 to which various signals are supplied from the main control section of the copying machine (not shown), and a processing program stored therein. A timer 43 has a ROM (read-only memory) 42 in which the time read out from the ROM 42 is set, measures the time using a clock pulse supplied from the main control section, and outputs a time-out signal when the set time is reached. , an output port 44 that outputs an excitation phase switching signal, which changes the excitation phase of the pulse motor 25 to A in accordance with the supplied excitation phase switching signal.
A driver 45 rotates the pulse motor 25 by switching to any one of phase, phase, B phase, and phase, and rotates the pulse motor 2 according to the supplied signal.
5, and a microprocessor 47 that controls each of the above components. The above microprocessor 47
The excitation voltage of the pulse motor 25 is set to "Vcc" by switching the movable contact 46 ₁ of the switch 46 to the fixed contact 46 ₂ side when an initial position setting signal is supplied from the main control section. Furthermore, the pulse motor 25 is rotated by sequentially outputting excitation phase switching signals. Furthermore, when the microprocessor 47 receives the detection signal from the detector 33, it switches the movable contact 46 ₁ of the switch 46 to the fixed contact 46 ₃ side, thereby lowering the excitation voltage of the pulse motor 25 to a level lower than "Vcc". By outputting an excitation phase switching signal for a predetermined number of steps, the pulse motor 25 is rotated for a predetermined distance. As shown in FIG. 6, the ROM 42 stores the output timing time of the excitation phase switching signal in one copying operation, and the pulse interval t ₁ ,
The value obtained by dividing t ₂ , . . . by the clock clock time t _c is stored.

Next, the operation in such a configuration will be explained. For example, if the power is turned on now, the microprocessor 47 will operate the movable contact 4 of the switch 46.
6 ₁ is set to the fixed contact 46 ₂ , and an excitation switching designation signal corresponding to a start signal and a rotation direction designation signal supplied from the main control unit of the copying machine (not shown) is output every time an excitation switching clock pulse is supplied. Output from port 44. As a result, the driver 45 connects each coil 25 ₁ ,
By sequentially exciting the permanent magnets 25a
Rotate. Therefore, the optical system 6 moves in the opposite direction to the scanning direction. Thereafter, when the optical system 6 is near the initial position, the detection tab 32 is detected by the detector 33, and the detection signal is supplied to the microprocessor 47. Then, the microprocessor 47 switches the movable contact 46 ₁ of the switch 46 to the fixed contact 46 ₃ side. As a result, the excitation voltage to the pulse motor 25 becomes low, and each coil 25
₁ , the excitation force due to... becomes weaker. In addition, the microprocessor 47 continues the above operation, that is, outputs an excitation switching designation signal corresponding to the rotation direction designation signal to the output port 4 every time an excitation switching clock pulse is supplied.
Output from. As a result, the driver 45 sequentially excites each coil 25 ₁ , . . . of the pulse motor 25, thereby rotating the permanent magnet 25a. When the detection tab 32 is stopped by the stopper 34, the detection tab 32 does not move any further, so the pulse motor 25 loses its synchronization and idles. When the pulse motor 25 rotates for a predetermined number of excitation switching clock pulses after the detector 33 detects the detection tab 32, the microprocessor 47
stops the pulse motor 25 by stopping the generation of the excitation switching designation signal. Therefore, the optical system 6 is set at the stop position by the stopper 34, that is, at the initial position. In this case, the initial position setting of the optical system 6 is based on only the position accuracy of the stopper 34 and the error of one phase of the pulse motor 25. In addition,
If the excitation voltage of the pulse motor 25 is not set high at the start of initial position setting, there is a risk that starting torque will not be obtained and the motor will step out from the beginning. As a result, unlike the case where the initial position of the optical system 6 is set using only the detector 33, the set position of the optical system 6 does not deviate greatly due to errors in the detector itself or mounting errors of the detector. You can set the initial position. Incidentally, the state of the main parts for explaining the above operation is as shown in FIG. Further, a flowchart of the above operation is shown in FIG.

Among the initial settings of the optical system 6 as described above, when the copying switch in the operation panel of the copying machine is turned on, the microprocessor 47 sets the movable contact 46 ₁ of the switch 46 to the fixed contact 46 ₂ side again. At the same time, the drive start is determined based on the supplied start signal and rotation direction designation signal, and the excitation switching timing pulse is generated as shown in FIG. 9b by operating the timer 43 according to the contents stored in the ROM 42. , outputs an excitation switching designation signal every time this pulse occurs. As a result, the driver 45
The permanent magnet 25a is rotated by sequentially exciting each coil 25 ₁ , . . . of the pulse motor 25. Therefore, the optical system 6 is driven with the relationship between speed and time as shown in FIG. 9a. Incidentally, the flowchart of the above operation is as shown in FIG.

11, 12, and 13 show modified examples of the carriage that supports the mirrors 4 and 5. Since the mirrors 4 and 5 are the same, only the carriage of the mirror 4 is shown. Note that the same parts as in FIGS. 1 and 2 are given the same reference numerals.
11 and 12 show one carriage 22 of the shape shown, with a guide rail 24 ₁ at one end.
A guide member 51 is provided which is slidably passed through the guide member 51, and the guide member 51 allows the guide member 51 to move in parallel on the guide rail ₂₄₁ . Also, the carriage 22
A rotatable roller 52 is provided at the other end, and this roller 52 guides the movement of the carriage 22 by rolling on the guide rail ₂₄₂ .

On the other hand, FIG. 13 differs from the carriage 22 in FIG. 11 only in the structure of the other end. That is, the other end of the carriage 22 has a bush 53 through which the guide rail ₂₄₂ can slide.
A bushing 53 is provided to guide the movement of the carriage 22. In this case, the bush 53 restrains the carriage 22 in the vertical direction with respect to the guide rail 24 ₂ and freely guides it in the horizontal direction.

In the above embodiments, the case where the application is applied to the optical system driving device of an electronic copying machine was explained, but the application is not limited to this, but is also applicable to, for example, a facsimile device or an image information retrieval device. The present invention can be applied to any device that forms an image corresponding to the image of the document on a moving image holding medium by scanning.

As described in detail above, according to this invention, the optical system can be set to the document scanning start position with a simple mechanism and accurately, and reliability is further improved. Also, the pulse motor can step out while the object is moving from the detector to the stopper, and the pulse motor can step out before the object is detected by the detector. It is possible to provide an optical drive device such as a copying machine that can prevent

[Brief explanation of the drawing]

Figures 1 to 10 show an embodiment of this invention, with Figure 1 being a schematic configuration diagram of an electronic copying machine with a fixed document table, and Figure 2 being a schematic diagram of the drive mechanism of the optical system. 3 is a diagram showing the configuration of the pulse motor, FIG. 4 is a timing chart showing the excitation state of each coil of the pulse motor, and FIG. 5 is a main part of the electric circuit of the electronic copying machine. Figure 6 is
FIG. 7 is a diagram showing the state of main parts when setting the initial position of the optical system; FIG. 8 is a flowchart for explaining the operation when setting the initial position of the optical system; 9a and 9b are diagrams showing the relationship between the excitation switching timing pulse and the moving speed of the optical system during the copying operation of the optical system, FIG. 10 is a flowchart during the reading scan of the optical system, and FIG. 13 is a front view showing a modified example of the carriage that supports the optical system, and FIG. 12 is a top view of the carriage shown in FIG. 11. 2... Original table, 3... Exposure lamp, 4, 5...
Mirror, 6... Optical system, 10... Photosensitive drum (image holding medium), 22, 22 ₁ , 22 ₂ , 23 ₁ ,
23 ₂ ... Carriage, 24 ₁ , 24 ₂ ... Guide rail, 25 ... Pulse motor, 25 ₁ , 25 ₂ ,
25 ₃ , 25 ₄ ... Coil, 25a ... Permanent magnet,
26...Reduction mechanism, 27...Wire drum, 28
... Drive wire, 29 ... Pulley, 30 ... Idler, 32 ... Detection tab (detection object), 33 ... Detector, 34 ... Stopper, 42 ... ROM, 43 ...
Timer, 45...driver, 46...switch,
47...Microprocessor.

Claims (1)

[Scope of utility model registration request] In a transfer machine or the like having a reciprocating optical system for exposing and scanning a document, a drive mechanism for reciprocating the optical system, a pulse motor providing power for reciprocating the optical system to the drive mechanism, a stopper for setting the optical system to an initial position; a detection means for detecting the optical system provided adjacent to the stopper; and when the detection means detects movement of the optical system toward the stopper. , comprising means for lowering the excitation current of the pulse motor and operating the pulse motor for a predetermined number of pulses greater than the number of pulses corresponding to the distance between the detection means and the restraint device. Optical system drive device for machines, etc.