JP2002119077A - Drive unit using oscillating motor, device therewith, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that the heat generated by friction between an oscillator and a contact body has an adverse effect upon driving while an oscillating motor is being operated. SOLUTION: This drive unit uses the oscillating motor 401 which outputs driving force by relative movement of the oscillator of which oscillation is energized by electric-mechanical energy conversion to the contact body in contact with the oscillator. The drive unit operates in accordance with the operation of the oscillating motor and includes a cooling fan 402 which cools the oscillating motor. The cooling fan operates with the operating start of the oscillating motor and stops with the stopping of the oscillating motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving apparatus using a vibration type motor, and more particularly to a driving apparatus suitable for an image forming apparatus such as a printer, a copying machine, and a facsimile.

[0002]

2. Description of the Related Art A vibration type motor includes a vibrating body in which a piezoelectric element group is attached to a metal elastic body formed in, for example, an annular shape, and a ring-shaped contact body which presses and contacts the elastic body. By applying a plurality of frequency signals having different phases to the piezoelectric element group, vibration is excited in the elastic body, and the elastic body and the contact body are utilized by utilizing the friction between the elastic body and the contact body. Are driven relative to each other.

[0003] Such a vibration wave motor can control the rotational position with a high degree of accuracy and has a strong property against transient load fluctuations. For this reason, it is used as a drive source that is advantageous for preventing color misregistration and pitch unevenness and for preventing paper feed shock when driving an image forming operation unit (for example, a photosensitive drum or a transfer belt) in an image forming apparatus such as a copying machine. I have.

[0004]

When the above-described vibration type motor is operated, heat is generated due to friction between the elastic body and the contact body. Then, due to the frictional heat, a small amount of shavings generated from the surface of the elastic body (specifically, the sliding material stuck to the surface of the elastic body) sticks to the surface of the elastic body, thereby lowering the friction coefficient of the elastic body. Therefore, the torque of the vibration type motor may be reduced.

[0005]

In order to solve the above-mentioned problems, in the present invention, a vibrating body whose vibration is excited by electric-mechanical energy conversion and a contact body that comes into contact with the vibrating body are relatively moved. In a driving device using a vibration type motor that outputs a driving force, a cooling fan that operates according to the operation of the vibration type motor and cools the vibration type motor is provided.

That is, by providing a cooling fan exclusively for cooling the vibration type motor, heat generated in the vibration type motor (in particular,
Heat generated by friction between the vibrating body and the contact body) can be efficiently radiated, and torque reduction due to sticking of shavings to the vibrating body surface can be prevented.

[0007] The cooling fan may be operated in response to the start of the operation of the vibration type motor, and may be stopped in response to the stop of the vibration type motor.

In the case where there is a detecting means for detecting an operating state such as a rotation speed of the vibration type motor, an operating signal for operating the detecting means (for example, a signal for turning on a light emitting element in an optical encoder) is provided. The cooling fan may be used to cool the vibration motor with a simple configuration without providing a control circuit or the like dedicated to the cooling fan.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIG. 3 shows the configuration of a digital color copying machine using a driving device according to an embodiment of the present invention. In FIG. 3, a reader unit is arranged at an upper part, and a printer part is arranged at a lower part.

(Configuration of Reader Unit) In FIG.
Is a CCD, 311 is a substrate on which the CCD 101 is mounted, 3
Reference numeral 12 denotes an image processing unit including a portion excluding the CCD 101 from the digital image processing unit and portions 201 to 205 shown in FIG. 2, reference numeral 301 denotes a platen glass, and reference numeral 302 denotes a document feeder (DF). There is also a configuration in which a mirror pressure plate (not shown) is mounted instead of the device 302), 303, 30
Reference numeral 4 denotes a light source (halogen lamp or fluorescent lamp) for illuminating the original, and 305 and 306 denote reflectors for condensing the light from the light sources 303 and 304 onto the original.

Reference numerals 307 to 309 denote mirrors, reference numeral 310 denotes a lens for condensing reflected light or projection light from the original on the CCD 101, and reference numeral 314 denotes light sources 303, 304 and reflectors 305, 30.
Reference numeral 315 denotes a carriage that houses the mirrors 308 and 309, and 313 denotes an interface (I / F) unit with another IPU or the like.

The entire surface of the document is scanned by mechanically moving the carriage 314 at a speed V and the carriage 315 at a speed V / 2 in a direction perpendicular to the electrical scanning (main scanning) direction of the CCD 101. (Sub scanning).

FIG. 4 shows a detailed configuration of the digital image processing unit 312.

The original on the original platen glass 301 is
3, 304, and the reflected light is reflected by the CCD 10
1 and converted into an electric signal. The CCD 10
1 is a color sensor, and RGB color filters are 1
A line CCD may be placed in-line in the order of RGB, or a 3-line CCD in which an R filter, a G filter, and a B filter are arranged for each CCD.
It may be different from the CD.

Then, the electric signal (analog image signal) is input to an image processing unit 312, and clamp & Am
p. & S / H & A / D unit 102 sample and hold (S
/ H), the dark level of the analog image signal is clamped to the reference potential, amplified to a predetermined amount (the processing order is not limited to the notation order), A / D converted, and, for example, RGB.
Each is converted to an 8-bit digital signal.

The RGB signals are subjected to shading correction and black correction by the shading section 103 and then input to the link & MTF correction & original detection section 10. CCD1
If 01 is a three-line CCD, the splicing process differs in the reading position between the lines. Therefore, the delay amount for each line is adjusted according to the reading speed, and the signal timing is corrected so that the reading positions of the three lines become the same. .

In the MTF correction, since the reading MTF changes depending on the reading speed and the magnification, the change is corrected, and the document detection recognizes the document size by scanning the document on the platen glass.

The digital signal whose read position timing has been corrected is input to a CCD 101 by an input masking unit 105.
And the light sources 303, 304 and the reflector 305,
The spectral characteristics 306 are corrected. Input masking unit 10
The output of No. 5 is input to a selector 106 which can be switched with an external I / F signal.

The signal output from the selector 106 is subjected to color space compression, background removal & LOG conversion 107 and background removal 1
15 is input. After the signal input to the background removal unit 115 is removed from the background, the signal is input to a black character determination unit 116 that determines whether or not the document is a black character in the document, and a black character signal is generated from the document.

The color space compression & background removal & LOG conversion unit 107 to which the output of the other selector 106 is input.
Then, color space compression determines whether the read image signal is within the range that can be reproduced by the printer, and if so, corrects it so that the image signal is within the range that can be reproduced by the printer. . Then, a background removal process is performed, and the CMY signals are converted from the RGB signals by LOG conversion.
Convert to a signal.

Color space compression, background removal, and LOG to correct the signal and timing generated by black character determination unit 116
The output signal of the conversion unit 107 is adjusted in timing by the delay unit 108. These two types of signals are used as the moiré removing unit 109
The moiré is removed at step 110, and at step 110, scaling processing is performed in the main scanning direction.

Reference numeral 111 denotes a UCR & masking & black character reflecting unit which generates a CMYK signal from the CMY signal processed by the scaling unit by UCR processing, and the signal is corrected by the masking processing unit into a signal which has been output from the printer. The determination signal generated by the black character determination unit 116 is fed back to the CMYK signal.

UCR & Masking & Black Character Reflection Unit 111
Is subjected to density adjustment by the γ correction unit 112 and then subjected to smoothing or edge processing by the filter unit 113. The signal smoothed or edge-processed by the filter unit 113 is output to the head shading unit 117 by an LED.
Head shading correction is performed to correct unevenness of the head in the main scanning direction.

The data used for the head shading is obtained by reading a predetermined image printed by the CCD 101 and subjecting the data subjected to the A / D conversion of 102 to thinning and averaging by the head shading sampling unit 118. Use the stored data.

The signal processed as described above is converted from an 8-bit multi-level signal into a binary signal by the binary converter 201 shown in FIG. As the conversion method, any of a dither method, an error diffusion method, and a method in which error diffusion is improved may be used.

(Configuration of Printer Unit) In FIG.
7, Y image forming unit, 318, M image forming unit, 319, C image forming unit
An image forming unit 320 is a K image forming unit. Since the configuration of each image forming unit is the same, the Y image forming unit 317 will be described in detail here, and the description of the other image forming units will be omitted.

In the Y image forming section 317, reference numeral 342 denotes a photosensitive drum, which is driven by a vibration type motor 357 used in the driving device of this embodiment. Photosensitive drum 3
A latent image is formed on the surface of the light source 42 by light from the LED array 210.

Reference numeral 321 denotes a primary charger, which is a photosensitive drum 342.
Is charged to a predetermined potential to prepare for latent image formation.

A developing unit 322 develops the latent image on the photosensitive drum 342 to form a toner image. Note that the developing device 322 includes a sleeve 352 for applying a developing bias to perform development.

Reference numeral 323 denotes a transfer charger, which is a transfer belt 333.
, The toner image on the photosensitive drum 342 is transferred to a recording paper or the like on the transfer belt 333. In the present embodiment, the cleaner section is not provided because the transfer efficiency is high, but the cleaner section may be mounted.

Next, a procedure for forming an image on a recording medium such as recording paper will be described. Recording paper cassettes 340, 34
Recording paper etc. stored in the pickup roller 33
9, 338, the sheet is fed one by one,
At 6337, it is supplied onto the transfer belt 333. The fed recording paper is charged by the adsorption charger 346.

Reference numeral 348 denotes a transfer belt roller, which is driven by the vibration type motor 361 used in the driving device of this embodiment. The transfer belt roller 348 drives the transfer belt 333 and charges the recording paper or the like in pairs with the attraction charger 346 to cause the transfer belt 333 to attract the recording paper or the like.

Reference numeral 347 denotes a paper edge sensor, which is a transfer belt 33.
3 to detect the leading edge of the recording paper or the like. The detection signal of the paper leading edge sensor 347 is sent from the printer unit to the color reader unit, and is also used as a sub-scanning synchronization signal when a video signal is sent from the color reader unit to the printer unit.

Thereafter, the recording paper or the like is conveyed by the transfer belt 333, and is transferred to the image forming units 317 to 320 in the Y direction.
A toner image is formed on the surface in the order of MCK. The recording paper or the like that has passed through the K image forming unit 320 is transferred to the transfer belt 33.
In order to facilitate the separation from the transfer belt 333, the toner is removed from the transfer belt 333 after the charge is removed by the charge removing charger 349.

Reference numeral 350 denotes a peeling charger, which prevents image disturbance due to peeling discharge when recording paper or the like is separated from the transfer belt 333. The separated recording paper or the like is charged by pre-fixing chargers 351 and 352 in order to compensate for toner attraction and prevent image disturbance, and then the toner image is heat-fixed by fixing unit 334, and thereafter, Output tray 335
Is discharged to

Next, the LED image recording will be described. The binary Y generated by the image processing unit shown in FIGS. 4 and 2
The MCK image signal is set to four colors by adjusting the difference in the distance between the paper edge sensor 347 and each image forming unit by the delay units 202 to 205 based on the paper edge signal from the paper edge sensor 347. Can be printed at the position. LED drives 206 to 209 are LEDs
A signal for driving 210 to 213 is generated.

Next, the transfer belt 333, the photosensitive drum 34
A driving device that drives each of the vibration type motors 357, 358, 359, 360, and 361 for driving the motors 2,343,344,345 will be described with reference to FIG. Since the configuration of the five driving devices is the same, one driving device will be described in detail here.

In FIG. 1, reference numeral 401 denotes a vibration type motor, and the vibration type motors 357, 358,
359, 360, and 361.

This driving device is provided with a rotary encoder (detection means) 403 for detecting the rotation speed of the vibration type motor 401. The rotary encoder 403 detects the light output of the LED (light emitting element) 406 reflected by the code wheel 411 attached on the output shaft of the vibration type motor 401 with the photodiode 407 through the lens 410 and the signal output through the signal processing circuit 408. It is configured to output two detection signals of A phase and B phase.

In this embodiment, a case where a so-called reflection encoder is used will be described, but a transmission encoder may be used.

A-phase and B-phase output from the rotary encoder 403 indicating the rotation speed of the vibration type motor 401
The two phase detection signals are input to a drive frequency generator (not shown) in the vibration type motor drive circuit 404. The drive frequency generator performs a difference operation between the predetermined target speed and the detected rotation speed, performs frequency control based on the result, and generates a two-phase drive pulse having an appropriate drive frequency.

The two-phase drive pulses are input to a drive voltage generator (not shown) mainly composed of a transformer, where two frequency drive voltages having different phases are generated. When this frequency drive voltage is applied to the piezoelectric element group of the vibration type motor 401, two standing waves are excited on the elastic body in the vibration type motor 401, and bending vibration is generated by combining these standing waves. A progressive oscillatory wave is formed.

On the other hand, for example, a ring-shaped contact member is in pressure contact with the elastic member by a pressing member such as a spring, and friction between the contact member and the elastic member on which the traveling vibration wave is formed is generated.
The elastic body and the contact body are relatively driven to rotate.
An output shaft is connected to the elastic body or the contact body so as to be integrally rotatable.
Output the driving force.

In this embodiment, the LED 406 is turned on only when the vibration type motor 401 is driven in consideration of the long life of the LED 406 in the rotary encoder 403.

Specifically, when the encoder LED_ON signal is output from the encoder LED control circuit 405 when starting the driving of the vibration type motor 401, the transistor TR1 is turned on by the encoder LED_ON signal, and the 5V power supply is turned on by the LED 406. Supplied to the LED 406
Emits light.

On the other hand, after the vibration type motor 401 stops,
After waiting for a certain time, the encoder LED control circuit 40
5 stops outputting the encoder LED_ON signal (outputs the encoder LED_OFF signal).
406 is turned off.

A motor cooling fan 402 is provided exclusively for cooling the vibration type motor 401 (that is, provided separately from a fixing fan, a main body cooling fan, and the like provided in the copying machine). Fan).

For example, of the motor cooling fan 402,
The one that cools the vibration type motor for driving the transfer belt is arranged above a mounting plate of a motor driver board (not shown). Further, the vibration type motor 401 itself is attached to a transfer unit mainly including a transfer belt and a transfer belt roller.

In addition, the positional relationship among the motor, fan, and motor driver is from the top.

Further, the direction in which the cooling air is sent from the motor cooling fan 402 to the vibration type motor 401 is set in a direction in which the cooling air hits the motor from directly below the motor in the axial direction and upward.

For example, the fixing fan rotates at full speed during copy standby, and rotates at half speed during copying. Further, the main body cooling fan rotates while the main body power is on. On the other hand, the motor cooling fan 402 operates only when the motor is driven as described later.

In this embodiment, although not shown, the motor cooling fan 402 is disposed on the front side of the main body, and the other cooling fans are disposed on the rear side of the main body.

In this embodiment, the motor cooling fan 4 uses this encoder LED_ON / OFF signal.
02 is turned on / off.

Specifically, when the encoder LED_ON signal is output, the transistor TR2 is turned on by the encoder LED_ON signal, and the transistor TR3 is turned on with the turning on of the transistor TR2.
4V power is supplied to the motor cooling fan 402, and the cooling fan 402 operates.

Thus, the vibration type motor 401 can be reliably cooled when the vibration type motor 401 is driven without outputting a command signal for driving the motor cooling fan 402 from a CPU (not shown) or the like.

As a result, the heat generated by the friction between the elastic body and the contact body inside the vibration type motor 401 can be efficiently radiated, and a slight shaving of the sliding material provided on the surface of the elastic body can be achieved. Can be prevented from sticking to the surface of the sliding member, and the torque of the vibration type motor 401 can be prevented from decreasing.

When the vibration type motor 401 is stopped (not driven), the motor cooling fan 402 is also stopped (the transistors TR2 and TR3 are turned off by the output of the encoder LED_OFF signal), so that no image formation is performed (standby). ) And power consumption can be suppressed.

In the above embodiment, the case where the driving apparatus of the present invention is used in a digital color copying machine has been described. However, the driving apparatus of the present invention is applicable to all image forming apparatuses for driving a photoconductor and a transfer body. The present invention can be applied to various apparatuses other than the image forming apparatus.

[0059]

As described above, according to the present invention,
A dedicated cooling fan that operates in response to the operation of the vibration type motor and cools the vibration type motor is provided, so the heat generated in the vibration type motor (especially due to the friction between the vibration body and the contact body) Heat) can be efficiently dissipated,
It is possible to prevent torque reduction and the like due to sticking of shavings to the surface of the vibrating body.

Further, if the cooling fan is operated in response to the start of the operation of the vibration type motor and is stopped in response to the stop of the vibration type motor, extra noise and wastefulness during standby of the drive of the apparatus are obtained. Power consumption can be reduced.

Further, when a detecting means for detecting an operating state such as a rotation speed of the vibration type motor is provided, an operating signal for operating the detecting means (for example, a signal for turning on a light emitting element in an optical encoder) is transmitted. If the cooling fan is used to operate, the vibration type motor can be cooled with a simple configuration without providing a control circuit or the like dedicated to the cooling fan.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a driving device using a vibration type motor according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of an image processing unit in an image forming apparatus using the driving device.

FIG. 3 is a cross-sectional view illustrating an internal configuration of the image forming apparatus.

FIG. 4 is a diagram illustrating a configuration of an image processing unit in the image forming apparatus.

[Explanation of symbols]

 101 CCD 301 Platen glass 302 Document feeder 303, 304 Light source 307 to 309 Mirror 314.315 Carriage 317 to 320 Image forming unit 333 Transfer belt 340, 341 Recording paper cassette 342 Photosensitive drum 334 Fixing device 335 Discharge tray 401 ( 357 to 360) Vibration type motor 402 Motor cooling fan 403 Rotary encoder 404 Vibration type motor drive circuit 405 Encoder LED control circuit 406 LED 407 Photo diode 408 Signal processing circuit 411 Code wheel TR1, TR2, TR3 Transistor

Claims (7)

[Claims] A driving device using a vibration type motor that outputs a driving force by relatively moving a vibrating body whose vibration is excited by electro-mechanical energy conversion and a contact body that comes into contact with the vibrating body, A driving device using a vibration-type motor, comprising: a cooling fan that operates according to the operation of the vibration-type motor and cools the vibration-type motor. 2. The vibration motor according to claim 1, wherein the cooling fan operates in response to the start of the operation of the vibration motor and stops in response to the stop of the vibration motor. Drive. 3. The cooling fan according to claim 1, further comprising detection means for detecting an operation state of the vibration type motor, wherein the cooling fan is operated using an operation signal for operating the detection means. Or a driving device using the vibration type motor according to 2. 4. The driving using the vibration type motor according to claim 3, wherein the operation of the vibration type motor is controlled based on the operation state of the vibration type motor detected by the detection means. apparatus. 5. The detecting means for detecting an operating state of the vibration type motor using light emitted from a light emitting element, wherein an operating signal for operating the detecting means causes the light emitting element to emit light. 4. A signal for turning on a light.
Or a drive device using the vibration type motor according to 4. 6. An apparatus comprising the driving device according to claim 1, wherein the apparatus is driven by a driving force from the vibration type motor. 7. An image forming apparatus comprising the driving device according to claim 1, wherein the driving device is driven by a driving force of the vibration type motor to perform an image forming operation on a recording medium.