JPH01179053A - Driving controller for recorder - Google Patents

Abstract

PURPOSE:To simplify the constitution of a driving mechanism and to prevent a rotary device from having an irregularity in rotation and generating noises, etc., by driving the rotary device directly by using an ultrasonic wave motor. CONSTITUTION:On the end surface of the cylinder part of a rotary body 75 which constitutes a rotary driving mechanism, the ultrasonic wave motor consisting of piezoelectric ceramic 61, an electrode 62 for feeding electricity to the piezoelectric ceramic 61, a rotor 6 which is pressed against one side part of an elastic body 63 where the piezoelectric ceramic 61 is stuck, and a ring-shaped spring 66 is formed integrally concentrically with the cylinder part. A drum is driven directly by this ultrasonic wave motor. Consequently, the device is obtained which is free from a decrease in driving force transmission efficiency by a gear and an irregularity in the rotation of the drum resulting from the manufacture accuracy of the gear and generates no noise.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to the rotation of a photoreceptor drum, a developing device, etc. that forms a toner image in a recording device that uses a xerography process, such as a copying machine or a printer. The present invention relates to a device for directly driving a driving member using an ultrasonic motor and for making it possible to rotate the rotational speed of the rotational driving member such as the photosensitive drum at an arbitrary speed.

(Prior Art) Devices such as copying machines, printers, and facsimile machines that use the xerography process are constructed as a combination of many components such as a paper conveyance device, a photosensitive drum, and a developing device. Many types of motors are used to drive the members, and each operating member is driven at a set speed.

An example of an apparatus using such a xerographic process will be described using a copying machine, for example. The copying machine is an apparatus configured as shown in FIG. 16. .

In the copying machine 10 shown in FIG. 16, a platen 11 is provided on the top surface of the main body of the copying machine, and an image reading device and an image reading device that move along one surface of the platen 11 and scan an image of a document. , an optical system for transmitting that light!
20 are placed.

Further, a charging corotron 13 and a developing device 30 are provided around the photosensitive drum 50 provided in the center of the copying machine.
．． Devices such as a transfer/peeling corotron 14 and a cleaning device 15 are arranged, and the light reflected from the document obtained by the image reading device is irradiated onto the photoreceptor drum via an optical system to form an electrostatic latent image. Then, toner is supplied from the developing device 30 to the static F1 latent image to form a toner image, and the toner image is transferred onto paper.

The paper P onto which the toner image created as described above is transferred is stored in a paper feed cassette 16 installed in the main body of the copying machine, fed by a paper feed roller 17, and delivered to a photoreceptor drum within a paper transport path 18. The toner is sent to the image transfer position by the transfer/separation corotron 14 in a state that is timed with the toner image to be formed.

Then, at the image transfer position, the toner image is transferred from the surface of the photoreceptor drum 50 by electric discharge by the transfer/peeling corotron, and while the unfixed toner image is carried,
The toner image is carried by a conveyor belt 19 and introduced into a fixing device 40, where the toner image is fixed and a copy is completed.

In the conventional copying machine as described above, the optical system provided below the platen of the copying machine main body consists of guide members 23. 23a, mirror 21.2
2 are slidably provided by slides 24 on both sides thereof, and each of these mirrors is attached to a wire 27 and driven by driving a pulley around which the wire is wound. A drive device for this purpose generally includes a motor 25, a speed reduction mechanism, a drive pulley 26 for driving the wire 27, and the like.

Then, according to commands from the control device of the copying machine, the motor is rotated in forward and reverse directions to move the lamps, mirrors, lenses, and other members according to the size of the document set on the platen, thereby creating an image of the document. The scanning light is transmitted to the photoreceptor drum.

Further, a developing device 30, which is provided on the side of the photoreceptor drum and is used to apply toner to the static R latent image formed on the photoreceptor drum, has a configuration as shown in FIG. is used. Developing device 3 shown in FIG.
0 uses a developing roller 31 placed very close to the surface of the photoreceptor drum 50, and the developer contained in the hopper 35 is attached to the surface of the photoreceptor drum via the developing roller 531. perform an action that causes

Further, in this embodiment of the developing device 30, the developer in the hopper 35 is supplied to the developing roller 532 by the supply row 532.
1, a layer forming member 33 is used to form a thin layer of a predetermined thickness on the developer adhered to the developing roller 31, and the thin layer of developer approaches the photoreceptor drum. It is being done.

In the above-described development process, the developing roller 31 and the photosensitive drum 50 rotate in the direction of the arrow at their contact portion, but the rotational speeds of the two are set to be different. Each drive system is provided separately.

The fixing device 40 shown in FIG. 19 is a heating roller type device, and the fixing device 40 shown in this conventional example
In this method, a sheet of paper is held and moved between a heating roller 41 and a pressure roller 42, and the toner image carried on the surface of the sheet is heated by the heating roller 41 and by a pressure roller 542. Made to apply pressure.

In this conventional example, both ends of the heating roller 41 are supported by bearings 43 against a frame 49 of the main body,
By applying electricity to the heat generating layer 41G formed on the surface of the [1-R main body 41a, the surface of the [1-R] is heated to a predetermined temperature, for example, 200° C., and the toner is melted by the heat. Welds the toner image to the paper.

The motor 46 for driving the heating roller is provided with a deceleration mechanism 47, and a gear 48 provided on the output shaft of the deceleration device meshes with a gear 45 provided at the end of the roller body. The rollers will be driven.

As described above, in devices such as copiers, printers, and facsimiles that use conventional xerography processes, photoreceptors are used to form toner images using dry toner and transfer the toner images to paper. drum, optical system device of image reading device, developing device,
Many types of rotational drive members are used, such as fixing devices and the like.

As in the case of general drive mechanisms, each of the above-mentioned devices can be driven directly by a DC servo motor with a reduction gear, or driven by a drive that engages with the teeth of a sprocket such as a timing belt or chain. A method is used in which the rotational force of the drive means is transmitted as the rotational force of the zero-rolling member using a force transmission means or a drive transmission means wound around a bobbin such as a flat belt or wire.

For example, in the case of a photoreceptor drum, its rotational speed is set in accordance with the conditions for the number of copies set for the copying machine to be 7, and for this purpose, a gear mechanism is provided on the flange of the drum. The rotation of the DC servo with a speed reducer is transmitted while being decelerated between the DC servo and the drive shaft.

In that case, for example, the rotation speed of the drive shaft of the motor is 150
If the rotation speed of the drum is 0 rpm and the rotation speed of the drum is 33 rpm, the reduction ratio of the reduction mechanism provided between the two is 1/45.
degree, and it is necessary to set a very large reduction ratio.

(Problems to be Solved by the Invention) As mentioned above, setting a very large reduction ratio of about 1/45 between the motor and the drum in the drive mechanism of the photoreceptor drum requires many Since it is necessary to use meshing gears, the configuration of the gear transmission mechanism becomes complicated, making it difficult to miniaturize the device and causing the machine size to increase.

Furthermore, by increasing the gear ratio in the reduction mechanism, the speed fluctuation ratio in the gear becomes large (approximately ±5% per gear).
, /45, the speed fluctuation ratio becomes very large because three gears are used. Therefore, with the above configuration, it becomes difficult to maintain a constant rotational speed of the photoreceptor drum, and rotational unevenness occurs, resulting in a toner image formed on the surface of the photoreceptor drum. , local elongation, shrinkage, etc. may occur,
This also causes disturbances in the toner image.

In addition, in the case of conventionally used drive mechanisms, the drive efficiency decreases due to the use of many gears, so the motor performance is required to be greater than necessary. , it is required to improve the machining accuracy of the gears, etc., which not only causes an increase in the manufacturing cost of the copying machine but also causes problems such as noise due to the meshing of the gears.

In other words, even if the noise generated by the meshing of gears is about 45 db in a normal device, if three sets of them are installed, the noise will rise to about 50 db, and the number of such gear combinations is large. In this case, the noise generated from office equipment such as copying machines becomes extremely loud, causing a large impact on the office environment.

(Object of the Invention) The present invention is intended to eliminate the drawbacks such as noise and uneven rotation of the drive device of the rotating device in the above-mentioned apparatus using the conventional xerographic process, and to use an ultrasonic motor. The purpose of the present invention is to provide a device that simplifies the configuration of the drive mechanism by directly driving the rotating device using the rotating device, and also prevents uneven rotation and noise from occurring in the rotating device. .

(Background of the Invention) A motor using ultrasonic vibration is disclosed in, for example, Japanese Patent Application Laid-Open No. 1986-
As shown in Japanese Patent No. 148682, the technical means for a single motor is known and is actually commercially available. The basic principle of this ultrasonic motor is
As shown in FIG. 13(a), a small piece of piezoelectric ceramic 2 is attached to one surface of an elastic body 3, and the polarity of the piezoelectric ceramic 2 is set to be different depending on the darkness of the adjacent small piece. A predetermined voltage is applied to each piezoelectric ceramic from electrodes provided on both sides of the piezoelectric ceramic.

In other words, when a voltage is applied as shown in (b) of the same figure, and when a voltage is applied as shown in (C), each piezoelectric ceramic undergoes an "expansion" or "shrinkage" state. . Then, the side where the piezoelectric ceramic stretches becomes a valley on the surface of the elastic body, and the side where the piezoelectric ceramic contracts becomes a mountain on the surface of the piezoelectric ceramic, thereby causing mutual strain. When the polarity of the voltage applied to the piezoelectric ceramics 2 is reversed, the mutual strain of each piezoelectric ceramic is also reversed.

In this embodiment, the elastic body 3 can be made of phosphor bronze, stainless steel, or other metal materials, and the piezoelectric ceramic 2 can be made of, for example,
, N-61J (manufactured by Tohoku Kinzoku Co., Ltd.) can be used.

Then, the vibrating body 1 is configured as described above, and FIG.
As shown in d), when an AC voltage is applied from the power source 4, each piezoelectric ceramic "stretches" depending on the frequency.
Since the "shrinkage" is repeated alternately, the vibrating body 1 generates vibrations at a predetermined frequency, as shown in FIG. 2(e).

The flexural standing wave generated in the vibrating body as described above is
This is a wave that occurs repeatedly at the same location, but in reality, a sinusoidal standing wave like a sinusoidal curve is generated on the surface of an elastic body.

Therefore, when the movable body 5 is brought into contact with the surface of this elastic body, as shown in FIG. An action is performed to move the body 5 in the direction of the arrow.

An ultrasonic motor as shown in FIG. 15 utilizes the vibration generation principle described above. In this illustrated ultrasonic motor, the stator 9 is constituted by an elastic body 3 and a piezoelectric ceramic 2 integrally provided on the surface of the elastic body 3, and the rotor 6 is constituted by a rotating body 7 having the same diameter as the stator 9. It is configured so that it is brought into contact with the elastic body 3 via the lining material 8.

When voltages of different polarities are alternately applied to the piezoelectric ceramics 2 in the ultrasonic motor configured as described above, the standing deflection waves of the elastic body 3 cause the rotating body to move in the direction in which the standing deflection waves travel. Since it is rotated in the opposite direction, it can be used as a motor by outputting the rotation of the support shaft of the rotating body.

The ultrasonic motor based on the above-mentioned principle is described in the above-mentioned publication, and is also disclosed in Japanese Patent Application Laid-Open No. 62-14
There are known examples as shown in Japanese Patent Application Laid-open No. 7973, Japanese Patent Application Laid-Open No. 62-147974, and Japanese Patent Application Laid-Open No. 62-147975.

(Means and effects for solving the problems) The present invention has the following features:
This device uses the principle of the ultrasonic motor as described above, and is configured so that the motor is integrally provided at the end of the drum of the rotating member to directly drive the rotating member.

That is, the present invention is a rotary drive! An ultrasonic motor consisting of piezoelectric ceramics, an elastic body, a pressing means, etc. is integrally formed on the end face of the cylindrical part of the rotating body constituting the 11 mechanism, concentrically with the cylindrical part, and the piezoelectric motor of the ultrasonic motor is This device is configured to rotate the cylindrical portion at a constant speed via an elastic body by applying an alternating current voltage to ceramics. By applying an alternating current voltage with shifted transfer to the piezoelectric ceramic, a traveling wave is generated in the elastic body that is pressed against the end surface of the cylindrical part of the rotating body, and the rotating body can be rotated at a predetermined speed. It is configured as follows.

In addition, in the device of the present invention, the rotational speed of the rotating body is controlled by changing the frequency and/or voltage value of the AC voltage applied to the piezoelectric ceramics with respect to the ultrasonic motor provided integrally with the rotating body. By doing this and changing the phase of the AC voltage, reversible rotation can be controlled.

Therefore, in the drive control device for a recording device of the present invention, it is possible to directly drive a rotating member using an ultrasonic motor that is characterized by low speed rotation and high torque output.
It is possible to form the drum shaft and the motor shaft in one piece. Furthermore, since the device of the present invention does not use gears or the like, it forms a drive system for rotating members that does not reduce the driving force transmission efficiency due to gears or generate noise as in the case of conventional devices. I can do it.

Furthermore, in the apparatus of the present invention, since the ultrasonic motor rotates at a low speed and has good speed control efficiency, it is possible to drive the rotating member in a state that corresponds to the process speed of the recording device. .

For example, when the apparatus of the present invention is used for a photoreceptor drum, it is possible to form toner particles on the surface of the photoreceptor drum in a good condition since there is no unevenness in the rotational speed of the drum. I can do it.

(Configuration of Apparatus) The configuration of the drive control device of the recording apparatus of the present invention will be described according to the illustrated example.

1 and 2 show the general configuration of the present invention, and as shown in these figures, an ultrasonic motor 60 configured as a drive device for a rotating device is a general ultrasonic motor. As in the case of the motor, piezoelectric ceramics 61 and
an electrode 62 for supplying power to the piezoelectric ceramic 61; an elastic body 63 to which the piezoelectric ceramic 61 is attached;
It is composed of a rotor 64 pressed against the other side of the elastic body 63, and a ring-shaped spring 66 for pressing the rotor 64.

Of these members, the rotor 64 is integrally provided inside a protrusion provided on the side of the drum, but the elastic body 63 is prevented from rotating by a stopper 67 against a ring-shaped spring 66. A piezoelectric ceramic 61 is pasted on the inner surface.

Further, in this embodiment, the rotating body main body 75 is provided with seven flange 77 with respect to the shaft inside the drum 76,
A cylindrical portion is provided on the side of one of the flanges with the drum 76 protruding therefrom, and each component constituting the ultrasonic motor is arranged concentrically inside the cylindrical portion.

In the illustrated embodiment, as described above, the rotor 64 is integrally disposed inside the cylindrical portion, and furthermore, an elastic body 63 is disposed inside the rotor 64, and a piezoelectric ceramic 61 is formed on the inner surface of the elastic body 63. are arranged, and an electrode 62 for feeding power to the piezoelectric ceramic 61 is arranged as shown in FIG.

In addition, inside these concentrically arranged members,
A ring-shaped spring 66 is provided so as to be able to press the elastic body 63 with a predetermined pressure against the rotor 64 which rotates together with the drum 76.

Then, a sine wave and a COS wave are supplied to the piezoelectric ceramic 61 placed on the inner surface of the elastic body 63 from electrodes 62a and 62b placed as shown in FIG. , the piezoelectric ceramics 61
The rotor 64 is rotated by the flexural standing wave generated in the elastic body 63 by a161b, and the drum 76 is provided to rotate at a predetermined speed.

The rotating member 75 as a device to which the present invention is applied has an end flange 77.77a supported by a bearing 72.72a, and a rotating member 75 rotatably provided with respect to a shaft 71. 71 is provided in a non-rotatable state with respect to a shaft support portion provided on a main body frame 70, 70 of the device that supports the rotating device.

As shown in FIG. 2, the piezoelectric ceramic 61 in this ultrasonic motor 60 supplies power to vibrators 61a and 61b approximately concentrically with respect to a cylindrical elastic body 63. electrodes 62a, 62b1 and
A phase detection electrode 65 is arranged.

The vibrators 61a, 6 arranged in the substantially semicircular shape
1b has a large number of piezoelectric ceramics arranged with their polarities facing opposite to each other, and as described above,
The transducer 61a is supplied with sin N pressure from the terminal 62a, and the other transducer 61b is supplied with cosine pressure from the terminal 62b.
Li pressure is supplied to each of them. Also,
The phase detection electrode 65 has the above two (cos, s
It is placed in the middle of a vibrator (vibrated by in-waves) and used to detect a frequency proportional to the vibration.

The voltages supplied to these vibrators 61a and 61b are high frequency voltages (40K Hz, ±
120V). When a predetermined voltage is supplied to the vibrator, a traveling wave is excited in the vibrator, thereby causing the rotor of the ultrasonic motor 60 to rotate in a predetermined direction.

Furthermore, in the ultrasonic motor of the present invention, the state of rotation thereof is detected by the phase detection electrode 65, and the detection signal is output as a feedback signal to the control device, as described later. For the rotation speed of the ultrasonic motor and other control operations, the signal output from the phase detection electrode 65 is used as a feedback signal to the control device, as will be described later.

In addition, in the ultrasonic motor 60 of the present invention, the rotational torque of the ultrasonic motor 60 is determined by the applied voltage applied through the terminals 62a, 62b and the pressing force of the spring 66 on the 0-Taro 4. This can be set arbitrarily by changing the above two conditions.

Note that, as described above, the ultrasonic motor 60 of the present invention includes:
It is used as a drive device for photoconductor drums and other rotating devices in copying machines and other devices, and by integrating it with the seven lunges of the rotating device, it forms a so-called direct drive drive mechanism. However, it is possible to simplify the configuration of the motor body, for example, compared to direct drive using a conventionally used pulse motor.

Furthermore, since the ultrasonic motor of the present invention described above does not require the use of a gear mechanism or the like for converting the rotational speed, the drum rotational speed may be reduced due to the low efficiency due to gears or the influence of gear manufacturing precision. There is no unevenness in the image or uneven rotation of the photosensitive drum, and problems such as the toner image formed on the photoreceptor drum becoming unclear occur as in the case of conventional devices. This can be prevented.

Furthermore, the motor used in the photoreceptor drum drive device of the present invention has a high torque output, but the motor mechanism is simple and small and lightweight, so the drive mechanism can be simplified and the motor can be used in copying machines, etc. This can also contribute to downsizing of the recording device itself.

Further, the ultrasonic motor configured as described above can be easily applied to, for example, a drive pulley as shown in FIG. 3.

For example, when the ultrasonic motor of the present invention is used to drive a photosensitive drum of a copying machine, the rotating body 75 can be used as the photosensitive drum, and the drum 76 of the rotating body 75 and , the ultrasonic motor 60 of the present invention is arranged at the gate between the ring-shaped spring 66 and the ring-shaped spring 66.

In an embodiment in which this ultrasonic motor is applied to the photoreceptor drum 80, it can be formed as a rotating device drive device having almost the same configuration as the ultrasonic motor 60 in FIG. , piezoelectric ceramics 61,
An electrode 62 for supplying power to the piezoelectric ceramic 61 is supported in a non-rotatable manner on a main body frame 70, and a rotor 64 and a pressing member are provided on the photosensitive drum side with respect to the flange 81. .

Therefore, in the case of this embodiment, the photosensitive drum is directly driven by the ultrasonic motor 60, and its rotation speed etc. can be set arbitrarily.

As described above, when an ultrasonic motor is used to drive the photoreceptor drum of the present invention, the photoreceptor drum used in an ordinary small or medium-sized copying machine has a diameter of 8.
The rotation speed (circumferential speed) is 160 s/sec.
The drive is performed at a certain level.

In this case, the torque required to drive the photoreceptor drum is 2 to 4 klJ even when using a blade cleaning device.
The driving torque of that level is approximately f-g, and the driving torque of that level is the commercially available [
Even N-611 can sufficiently handle this problem. Also,
In order to drive the photoreceptor drum as described above, the pressing force applied to the rotor 64 by the spring 66 is 30 to 40, which is about 10 times the driving torque! It is necessary to set the value to about 1lf-a.

Further, the rotating body main body 75 of the present invention can also be used as an O-ra member of a paper feed roller, a fixing device, a developing device, etc. In this case, the size etc. of the rotating body main body 75 can be changed to suit each device, but it is possible to apply it to various types of rotating bodies without changing the main configuration of the motor part. is possible.

The embodiment shown in FIG. 3 can be applied to a pulley used as a drive device for the optical system shown in FIG. In contrast, an ultrasonic motor 60 of the present invention is provided.

A wire or belt is then wrapped around the pulley 80, which is directly driven by the ultrasonic motor 60, to transmit the driving force to other driven members.
This can be done via a wire wrapped around the boom, and it can drive not only the optical system but also other moving devices.

Furthermore, if a sprocket is provided in place of the above-mentioned boob according to the present invention, it becomes possible to drive a chain, timing belt, etc., thereby eliminating the need for a motor, speed reduction mechanism, or other components. , the drive mechanism of the rotating device can be simplified.

As mentioned above, when driving the carriage of the optical system, the diameter of the pulley is 3 ojIII, and the driving torque when driving the normal carriage is the maximum speed of 1
Even when setting it to about 00011111/Sec,
The torque at startup is approximately 0.5 to 1 kof-α, and the torque at startup is approximately 3 to 5 kof-α. Even in such a case, the above-mentioned commercially available piezoelectric ceramics can sufficiently handle the problem.

In the embodiment of the present invention shown in FIG. 4, the end of the drum 76 constituting the rotary body is formed into a tapered shape, and the rotor 64, the elastic body 63, and the piezoelectric ceramic 61 are attached to the tapered portion 76a. Each tapered layer is arranged concentrically, and the outer periphery of each layer is pressed by a ring-shaped spring 66.

In this embodiment, the ring-shaped spring 66 is pressed from the body frame 70 side toward the rotating body water body 75, and the contact pressure between the elastic body 63 and the rotor 64 can be set by the pressing force. Possible, and in addition, to the rotating body body 75. On the other hand, it is also possible to provide means for applying a pressing force from the right side of the figure.

When configured as described above, it is possible to arbitrarily set the pressing force on the ultrasonic motor,
In addition to being made of an elastic body, the ring-shaped spring 66 is also made of a metal member having a simple tapered inner surface, and the pressure required for the ultrasonic motor is applied by means such as pressing the two together with a spring or the like. can be set.

In addition, in the above-mentioned embodiment, the tapered portion is formed on the inner surface of the end of the drum, and other members are configured to be inserted into the taper, and arranged on the inner surface of the end of the rotary body. Of course, it is also possible to use means such as

(Configuration of Control Device) The ultrasonic motor configured as described above for driving a rotating member such as a photoreceptor drum uses a control device as shown in FIGS. The drive is controlled by applying an alternating current voltage to the motor.

That is, the control device in the apparatus of the present invention is configured as a control mechanism 100 as shown in the block diagram of FIG. The ultrasonic motor 104 directly drives the drum unit 105.

Further, the rotation detection signal of the ultrasonic motor 105 is transmitted by a phase detection electrode 103 disposed on the motor or a detection member disposed at a predetermined position on the drum of the rotating body in the same way as the vibration detection electrode in FIG. , the signal from the phase detection electrode 103 is outputted from the encoder attached thereto, and the signal from the phase detection electrode 103 is output as a feedback signal 106.
1 and is input to Ill ill by the control circuit 101.
used as a signal.

The control circuit 101, as shown in FIG.
The drive circuit 102 includes a distributor 11G and a programmable counter 111.
12, a driver 113, a boost coil 114, etc.

In addition, each of the above-mentioned constituent members includes the CPU 110
For example, in addition to Intel's r8085J, rZ8
0J, R87ADJ, etc., the programmable counter 111 can be configured with a commercially available microchip such as R8253J manufactured by Intel, and the distributor 112 can be configured with a commercially available microchip such as R8713J manufactured by Fujitsu. It is also possible to use other types of microchips that can exhibit similar performance to those described above.

In each component constituting the control device of the present invention as described above, the CPU 110 receives a copy start signal from the control device of the copying machine main body, and controls the ultrasonic motor Ill.
It outputs the data necessary for tll and a clock signal to the programmable counter 111, and also outputs a signal indicating the rotation direction of the ultrasonic motor to the distributor 112. Furthermore, it receives a feedback signal from the encoder 116 and outputs it. Outputs signals for value correction, etc.

Further, the programmable counter 111 outputs a lock signal to the distributor 112 when the driving of the ultrasonic motor is necessary, and based on the clock output from the programmable counter 111, the distributor 1
12 towards the driver 113, each phase is 90°
Distribute the clock in a staggered manner.

Then, the driver 113 rectifies the pulse wave, and the boost coil 114 amplifies it to apply a COS wave voltage to the piezoelectric ceramic 115 and a sine wave voltage to the piezoelectric ceramic 115a. I have to.

The vibration frequency generated by each of the piezoelectric ceramics described above is detected by the encoder 116 and sent back to the CPU 110 as a feedback signal to change the clock output value and correct the pulse output from the distributor 112. It becomes something that can be done.

Specifically, the block diagram of the control device shown in FIG. 6 constitutes a circuit as shown in FIG. 7. In the circuit diagram shown in FIG. 7, the start switch signal is sent from the control panel of the device main body to CPU11G
and a clock signal from the CPU 110;
Data necessary for controlling the motor is output to the programmable counter 111, and in response to the signal, the programmable counter 111 outputs the data to the distributor 1.
Outputs a clock toward 12.

In the programmable counter 111 of the present invention,
In order to increase the resolution per pit of the CPU output,
P L L (ph
ase 1ocked 1oop ) 117 is provided to increase the resolution of the final output stage per 1 bit. That is, in the device of the present invention, when controlling the rotation speed of the motor, it is necessary to be able to change the rotation of the motor in steps of l rpm.

To that end, as shown in Figure 7a, a counter
In the relationship between the input frequency fi of 111 and the output frequency pO from the output frequency fO1PLL, the value of pO is set to 5.
It is necessary to configure it variably in units of 0H2.

Therefore, the output from the counter 111 is multiplied by 256 by the PLL circuit 111 to increase the resolution per 1 bit of the output value.

Expressing this relationship mathematically, po -256x f.

fo-fi/M,', DO-(f i /M) X 25Bwhere, M
=1~6553B (16bit) po -150Kll
Z ~170KHz When M=4800 po -3xlOx 256/480G -160KH
When zM -4801 po' -3xlOx 256/4801-159,9
6667KH2pO°-po<50H2 As mentioned above, by providing a PLL circuit and amplifying the output from the counter, even if the output value from the counter changes by 1 bit, the value of the change can be accurately transmitted to the driver. Therefore, the rotation speed of the motor can be controlled in a good manner.

In other words, in the device of the present invention, even if the clock output from the programmable counter 111 is about 6508Z, the clock is converted to P L L 117 and 1/
A closed circuit is constructed by n dividers. Then, the PLL 117 amplifies the frequency output from the programmable counter 111 by 256 times,
160K for manual effort by driver 113)
l Z and set that clock to Distributor 1.
12 can be entered.

In addition, in the distributor 112, the input 160KH2 clock is divided into four different phase φ1 clocks.
, φ2, φ3, and φ4 and output it to the driver 113, and based on these clocks, the piezoelectric ceramic 115.11
Drives Sa.

Furthermore, the phase detection circuit used in the circuit of the present invention is
It is constructed as shown in FIG. In other words, one of the distribution signals θi output from the distributor 112 and the piezoelectric ceramic 115a of the boost coil 115
The signal θf from the drive section to the CP is input to the phase comparator 121, the two signals are operated on (θi - θf), the value is converted by the control signal fi, and the feedback signal CP It will be output towards U11G.

The output from the phase comparator 121 in this case is as shown in FIG. 8a. That is, when the motor rotation speed matches the set value, the output from the phase comparator 121 is a constant value of 2.5V, but in the case of a leading state,
If output higher than 2.5v is delayed, 2.5v
Output is performed between and Ov.

The output is then sent to the CPU1 as a feedback signal.
When 1G is input, the CPU IG performs a control operation to equalize the advance or lag state to 2.5V, thereby adjusting the rotation speed of the ultrasonic motor to the set value. Control will be performed to make them match.

That is, when outputting the feedback signal by the phase comparator 121 described above, as shown in the graph of FIG. 8b, the vertical axis represents the feedback signal Vout, and the horizontal axis represents (
If we take θi-θr), the range of control is (θi-θr).
f)=-2π and (θi-θf)-2π.

Therefore, the case of (θi-θr>=o is set as a normal state, the state of (θi-θ[)>O is set as a lag, and the state of (θi-θf)〉0 is set as a forward state. state, the delay or lead signal from the comparator 121 is y
This will be fed back as out.

Obtained by the phase comparator 121 of the present invention described above, CP
The phase lead and delay signals output as the vout signal to U11G are controlled in accordance with the 70-chart shown in FIG. 8C.

In other words, (θ1-θf) is determined in step C, and if the normal value is (θi-θf)-0, step C
The control is performed sequentially at each step from -1 to step C-3, and in the case of an advanced phase of (θi-θt)>0,
This is performed in steps C-5 to B.

Furthermore, in the case of a delay phase of (θi - θf) 0, the control operation is performed between the CPU 110 and the distributor 112 in each step C-10 to C-13, and thereby, The motor is made to rotate in the normal state, that is, (θi-θr>-0. - To further explain the above-mentioned Fig. 8C, when (θi-θt)-0 in step C, (Step C-1), leave the data frequency division value of counter 11H8253) as is in step C-2,
The previous state is maintained, and a repeating signal is output from the end step of step C-3, and the process proceeds to step C-3.
Control is performed such that a signal for executing the main program No. 15 is output and returned to step C as an interrupt signal.

In addition, in the case of leading phase, (θ1-
of)>0, the frequency division value M of the counter 111 is set to M-1 in step C-6. and,
Proceed to step C-7, output f2 in this step,
The process moves from step C-8 to step C-15.

Apart from this, in case of delayed phase, step C-10
Then, (θi-θf)〉0 is determined, and in step C-11, the counter data is divided by the frequency division value M.
+1, output the signal f1 in step C-12,
Move on to the step of repeating that action.

Therefore, in the tIIJtIl device of the invention, the phase of the rotation of the motor is determined by a phase comparator and its (
Based on the information of θi-θf), the CPU outputs a control signal so that the output from the phase comparator becomes (θi-θt)-0.

Note that instead of the phase detection circuit 120 described above, as shown in FIG. 7, an encoder 116 is used, and the encoder allows a reading means to detect a detection member such as a reading mark provided on the rotating part of the ultrasonic motor. It is also possible to detect the signal and input the signal to the CPU 110.

In the control device of the present invention configured as described above,
The timing signal for the drive is set as shown in the timing chart in Figure 9, and the drive signal for the motor and the drive signal are set as shown in the timing chart in Figure 9. , a rotation direction signal is output, and 0 is output as necessary, and based on that information, the programmable counter 111
Each of the following devices is activated.

In addition, the clocks φ1 to φ4 outputted from the distributor 112 are such that each output φ1, φ2, . . .
By combining the above outputs, a COS wave voltage is supplied to the vibrator 115, and a sin wave voltage is supplied to the other vibrator 115a.
The wave voltage is supplied with a roar.

In addition, when setting the rotation direction of the motor, if the clock is distributed in each direction of arrow CW, the motor will be rotated clockwise, and on the other hand, if the clock is distributed in the direction of arrow CCWh, then , the motor is rotated counterclockwise. In the control device of the present invention, each voltage is set to ±120v, and the frequency is set according to the rotation speed of the drum unit.

Next, the control operation in the control device of the present invention will be explained in the eleventh section.
This will be explained with reference to the figure and the flowchart of FIG.

The flowchart shown in FIG. 11 shows the case of sequence control. When a copy start signal is input in step A-1, the CPU sets the rotation direction of the motor in step A-2, and Outputs the signal to the programmable counter.

Then, in step A-3, the number of outputs from the distributor is set. In this case, the seventh
As explained in figure a, for the maximum number of cloves,
The number of clocks obtained by dividing by the multiple amplified by the PLL is set, and the set number of clocks, for example, 650 Hz, is obtained from the counter in step A-
4 is output.

With the clock set as described above, A-
Step 5 is performed using the distributor and driver to operate the motor and perform the required work. In step A-6, after one copy cycle is completed, a motor reversal signal is output, and the cycle ends.

The flowchart shown in FIG. 12 is for servo control, and shows the control operation at steps A-3 and A-4 in FIG. 11.

In this flowchart, when the programmer counter data is set in step B-1, the input value from the encoder is canceled in step B-2, and the motor is started in step B-3 according to a command from the CPU. .

Then, in step B-4, the motor is rotated by the main program of the system, but when the motor is rotated, the rotation speed and the operation of the device are controlled by the program built into the CPU. Become. The steps up to step 8-4 described above indicate the initial setting conditions for the main body of the device, but the steps from B-5 onwards indicate one example of motor control, and the conditions are set in each drive cycle of the motor. ,8 as shown below
By repeating steps -5 to B-8, the motor drive operation IIIg is performed.

When the information from the encoder is input to the CPU as described above, in step B-5, the clock signal input by the synchronization counter of the CPU is compared with the set value,
The two are compared in steps B-6 and B-7, and if the comparison values are exactly the same, the process moves to step B=8, and the motor continues to be driven in that state.

In addition, if the comparison values of the two differ in step B-7,
Proceeding to step B-9, if the set speed HL>EA (encoder output), return to step A-3 from steps B-11 and 12, and perform an operation to change the output clock setting. Based on the set value, a clock is outputted to drive the motor.

Furthermore, if HL<EA in step B-9, the process moves to steps B-12 and 13, where the frequency division value of the counter is changed, and the changed clock is output to drive the motor. The operation of proceeding through step B-8 and proceeding to step B-5 is repeated. Incidentally, the operation of ill @ after step B-5 as described above is not particularly limited to such a method, and any other control means may be used.

These ill m operations are performed every time a clock is output, and as a result, the deviation from the set value is detected every rotation of the motor, and the deviation is corrected. Rotation can be controlled with high precision.

In the above-described embodiments of the present invention, the ultrasonic motor is mainly used as a drive mechanism for the photoreceptor drum of a copying machine. The present invention can be used as a developing roller driving means of a developing device, an O-roller driving means of a constant monitoring system, an optical system driving means, a driving means of a paper conveying device, etc.

Furthermore, the direct drive type motor of the present invention is not limited to copying machines, but can also be used for image formation, paper feeding, and other arbitrary means in devices such as printers and facsimile machines that use xerography processes. That's what you get.

Note that the ultrasonic motor of the present invention described above is not limited to the configuration shown in the drawings;
It is easy to arbitrarily change some of the constituent members, or to deform them in accordance with the shape and structure of the rotating member to which they are applied, as necessary.

(Effects of the Invention) The device of the present invention has the above-described configuration, and by using a drum direct drive method using an ultrasonic motor, there is no reduction in driving force transmission efficiency by gears,
It is possible to provide a device that is free from the effects of uneven rotation of the drum, such as smearing in the quality of toner images due to the manufacturing precision of the gears.

In addition, when the photoreceptor drum is directly driven using the motor of the present invention, the speed fluctuation ratio is about ±5% because a reduction gear is used in the case of driving with a conventional DC motor. The position W1' error is ΔX "p1 process speed ■ p1 variation ratio EO-p.

If the frequency is πf, ΔXrp −vp XEO−1
) /πt −156x0.05/πX20=124μ
ΔXrD −Vp XEO− D/πr −156x0
．． 02/.pi.

In addition, the ultrasonic motor used as the drive mechanism for the rotating body of the present invention can be configured to be small and lightweight while having a high torque output. This will greatly contribute to the miniaturization of.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the ultrasonic motor of the present invention installed on a rotating body, Fig. 2 is a developed view of the vibrator portion of the motor of the present invention, and Fig. 3 is a cross-sectional view of the ultrasonic motor of the present invention mounted on a pulley. 4 is an explanatory diagram of another embodiment when the motor of the present invention is applied to a rotating body; FIG. 5 is a side view when the motor of the present invention is applied to a pulley device; FIG. 5 is an explanatory diagram showing the general configuration of the drive control device of the present invention, FIG. 6 is a 10-step diagram of the tIIJ111 circuit of the present invention, FIG. 7 is a circuit diagram showing FIG. 6 in detail, and FIG. 7a 8 is an explanatory diagram of the PLL circuit, FIG. 8 is a circuit diagram of the phase detection circuit provided in the circuit of the present invention, FIG. 8a is an explanatory diagram of the state of the output of the phase comparator, and FIG. (θ; -θf), Figure 8C is a flowchart showing the phase control operation, Figure 9 is a timing chart of the control device of the present invention, and Figure 10 is the clock output from the distributor. FIGS. 11 and 12 are timing charts showing the states of sine and cosine waves, respectively.
13(a) to 13(e) are explanatory diagrams of the operating principle of the ultrasonic motor of the present invention, FIG. 14 is an explanatory diagram of the driving principle of a moving body in the ultrasonic motor, and FIG. 15 is a general diagram. FIG. 16 is an explanatory diagram showing the configuration of a general copying machine, FIG. 17 is a perspective view of the optical system of the copying machine, and FIG. 18 is a sectional view of the developing device. FIG. 19 is a longitudinal sectional view of the fixing device. Reference numeral 1 in the figure: Vibrating body, 2: Piezoelectric ceramics, 3: Elastic body, 10: Copying machine,
20...Optical system device, 30...Developing device, 31...Developing roller, 40...Fixing device, 41...Heating O -Ra, 50...
・Photoconductor drum, 60-...Ultrasonic motor, 61
...Piezoelectric ceramics, 62 ... Electrode, 63 ... Elastic body, 64 ... Rotor,
65... Phase detection electrode, 66... Spring, 70... Body frame, 71...
...Axis, 75...Rotating body, 76...
・Drum, 80...Pulley, 10G...
-Control device, 101... Control circuit, 104...
...Ultrasonic motor, 11G...CPU, 1
11...Programmable counter, 112.
... Distributor, 113 ... Driver, 114 ... Boost coil, 115 ...
...Piezoelectric ceramics, 116...Encoder, 117...PLL circuit, 120...
...Phase detection circuit, 121... Phase comparator. Figure 7α Figure 8 Figure 8a Figure 2.5Y Through hole 4 (Deaf ---111--------
-One. Figure 8C Figure 13! Figure 14 Figure 15 Figure 16

Claims (3)

[Claims] (1) In an apparatus provided with a rotary drive mechanism for forming images, conveying paper, fixing toner images, etc. of an image recording device such as a copying machine using a xerography process, the rotary drive mechanism is configured. For the cylindrical part of the rotating body,
An ultrasonic motor consisting of a concentric elastic body, a pressing means, a rotor, piezoelectric ceramics, a power supply member, etc. is integrally formed, and an alternating current voltage with a phase shift is applied to the piezoelectric ceramics of the ultrasonic motor from the power supply circuit. By doing so, a traveling wave is generated in an elastic body provided concentrically with the cylindrical portion of the rotating body, and the rotating body is rotated at a constant speed via a rotor that is pressed against the elastic body. A drive control device for a recording device, characterized by: (2) A patent claim characterized in that the ultrasonic motor is configured such that variable speed control of the rotating body can be performed by changing the frequency and/or voltage value of the AC voltage applied to the piezoelectric ceramics of the ultrasonic motor. A drive control device for a recording device according to item 1. (3) The ultrasonic motor is configured such that the rotating body can be reversibly rotated by changing the phase of the AC voltage applied to the piezoelectric ceramics of the ultrasonic motor. A drive control device for a recording device according to item 2.