JPH08334980A - Driving device for image forming device - Google Patents

Abstract

PURPOSE: To drive and control a developing device and a toner supply device by the motive power of a common driving motor. CONSTITUTION: A specified developing unit is driven by revolving a planet gear G15A or G15B connected by switching the rotating direction of the gear G10 of the driving motor either clockwise or counterclockwise, and further,the rotation of the gear G10 is transmitted to a sun gear G17 and a planet gear G18 through a gear G16. According as the rotating direction of the gear G10 is switched, the rotational motive power in a fixed direction is always transmitted to a gear G20 connected to the toner supply device through a gear G19A in the case where a supporting member 62 is turned clockwise and through a gear G19B and an intermediate gear G19C in the case where the member 62 is turned counterclockwise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device of an image forming apparatus for driving and rotating a plurality of developing devices provided in a color image forming apparatus and a toner replenishing drive for replenishing toner.

[0002]

2. Description of the Related Art Each developing device used in a color image forming apparatus contains a developer of a specific color and is driven individually in accordance with the timing of developing each toner image. As a driving power source, one driving motor is used as a common power source for the purpose of downsizing and cost reduction of the device, and the developing devices specified by switching the power transmission system are individually used. It has a working structure.

A toner replenishing device is also provided in each of these developing devices, but the drive motor is also used as a power source for the toner replenishing operation, and the replenishing power transmission system is used in the same way as the developing device is driven. A structure is adopted in which toner is supplied to the specified developing device by switching.

[0004]

However, the drive motor needs to be turned ON / OFF by utilizing the fact that the rotation direction is changed between forward rotation and reverse rotation as one of the power transmission system switching means for the developing device. Although the switching operation is simplified by reducing the number of OFF electrode clutches, it cannot be directly connected as a power source for toner replenishment, so that the power of the drive motor is constant with respect to the toner replenishing device regardless of the change in the rotation direction. It is necessary to have the function of transmitting with the rotation direction.

As a result of solving and improving this point, the present invention provides
The power of the drive motor, whose power transmission to the developing device is switched by switching between forward rotation and reverse rotation with an extremely simple mechanism, is always transmitted to the toner replenishing drive system as constant power in the rotation direction regardless of changes in the rotation direction. It is an object of the present invention to provide a driving device for an image forming apparatus that can be used.

[0006]

[Means for Solving the Problems] The above object has a driven shaft A whose rotational direction is changed, a driven shaft B whose rotational direction is one direction, and a power source for driving the driven shaft A and B. In the image forming apparatus, a sun gear that rotates by the power source, a planetary gear that meshes with the sun gear, a support member that has a rotation center in common with the sun gear and that swingably supports the planetary gear, and the power. When the rotation of the power source is in the first direction, the first transmission system for rotating the driven shaft B in the first direction via the planetary gear, and the planetary gear when the rotation of the power source is in the second direction. Via a second transmission system for rotating the driven shaft B in a first direction via a driving device for an image forming apparatus, a driven shaft in which a rotation direction changes, and a rotation direction in one direction. Drives a certain driven shaft B and the driven shaft A and B. In an image forming apparatus having a power source, a sun gear that is rotated by the power source, a planetary gear that meshes with the sun gear, and a support member that has a common rotation center with the sun gear and that swingably supports the planetary gear. When,
A first transmission system for rotating the driven shaft B in the first direction through the planetary gear when the rotation of the power source is in the first direction, and the planet when the rotation of the power source is in the second direction A second transmission system that rotates the driven shaft B in the first direction via a gear, and a position that prevents the support member from moving and the planetary gear does not mesh with either the first transmission system or the second transmission system. And a drive unit for the image forming apparatus, the drive unit for the image forming apparatus comprising:

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a color image forming apparatus provided with a driving device for rotationally driving a developing device and supplying toner according to the present invention.
It will be explained by.

FIG. 1 is a schematic block diagram showing an example of a color image forming apparatus of the present invention.

In the figure, reference numeral 10 denotes a photosensitive drum which is an image bearing member, for example, an OPC photosensitive member coated on the drum, which is grounded and driven and rotated clockwise. A scorotron charger 12 negatively and uniformly charges the peripheral surface of the photoconductor drum 10 by corona discharge by a grid held at a predetermined potential and a corona discharge wire to give a potential V _H.
Prior to the charging by the scorotron charger 12, exposure is performed by the PCL 11 using a light emitting diode or the like to remove the history of the photosensitive member up to the previous printing, and the peripheral surface of the photosensitive member is discharged.

After uniformly charging the photosensitive drum 10, the laser writing device 13 performs image exposure based on the image signal. In this image exposure, an image signal input from a computer or an image reading device is processed by an image signal processing unit and then input to the laser writing device 13 to form a latent image on the photosensitive drum 10.

The laser writing device 13 has a rotating polygon mirror 131 that rotates using a laser diode (not shown) as a light emitting source.
A plurality of reflecting mirrors M1, M2, M through the fθ lens 132 etc.
3, the optical path is bent to perform main scanning, and the rotation of the photosensitive drum 10 causes sub-scanning to form a latent image. In this embodiment, an image portion, which is an image forming area on the image carrier, is exposed on the basis of the image signal, and an inverted latent image whose absolute value of the potential at the exposed portion becomes V _L lower than V _H is formed. Form.

At the periphery of the photosensitive drum 10, there are respectively built-in developers consisting of negatively charged conductive toner such as yellow (Y), magenta (M), cyan (C), and black (K), and a magnetic carrier. The developing device 20 is provided, and first, the development of the first color is performed by the developing sleeve 21 which is a developer carrying member which contains a magnet body and holds and rotates the developer. The developer has a layer thickness of 0.05 to 0.5 mm on the developing sleeve 21 by a regulation blade which is a layer thickness regulating member (the thickness of the developer layer on the developer carrier in the development gap, The developer is held at a position (thickness from the surface of the developer carrier) and is conveyed to the developing area.

The gap between the developing sleeve 21 and the photosensitive drum 10 in the developing area is 0.2 to 1.0 mm, which is larger than the layer thickness (developer), and a direct current is applied between the developing sleeve 21 and the photosensitive drum 10. An AC bias voltage in which the _AC voltage V _AC is superimposed on the voltage V _DC is applied. Since the toner is charged with the same polarity (negative) as the DC voltage V _DC , the AC voltage V _AC
The toner, which has been given a chance to be separated from the carrier by the toner, does not adhere to the portion of V _H of the photosensitive drum 10 where the absolute value of the potential is higher than the DC voltage V _DC , and the portion of V _L where the absolute value of the potential is low. A toner amount corresponding to the potential difference from V _DC adheres to the toner, and the image is visualized (reverse development).

After the visualization of the first color is completed, the process for forming the second color image is started, the peripheral surface of the photosensitive drum 10 is uniformly charged by the scorotron charger 12, and the latent image is formed by the image data of the second color. Are formed by the laser writing device 13. At this time, P performed in the image forming process of the first color
The charge removal by CL11 is not performed because the toner attached to the image portion of the first color scatters due to the sudden decrease in the potential around it.

A latent image similar to that of the first color is formed and developed on the portion of the photoconductor having the potential of V _H all over the peripheral surface of the photoconductor drum 10 again without the image of the first color. However, in the portion where image exposure / development is performed again on the portion where the image of the first color is present, the potential V which is slightly higher in absolute value than V _L due to the light shielding by the toner adhering to the first color and the electric charge of the toner itself. A latent image of _T is formed, and development is performed according to the potential difference between V _DC and V _T. In the overlapping portion of the images of the first color and the second color, if the development of the first color is performed by forming a latent image of V _L , the balance between the first color and the second color is lost, so the exposure amount of the first color is reduced and the latent image is reduced. In some cases, the potential of V is set to an intermediate potential V _M where V _H > V _M > V _L.

An image forming process similar to that for the second color is performed for the third and fourth colors, and four steps are performed on the peripheral surface of the photosensitive drum 10.
A color toner image is formed. The photosensitive drum 10 holding the toner image in this way is transferred in the next transfer step.

On the other hand, the paper feeding roller 4 is fed from the paper feeding cassette 40.
1, 42 and the timing roller 43 feed the recording paper P in synchronization with the toner image on the photosensitive drum 10.
Has a resistance of 10 ⁸ to 10 ¹⁴ Ω · cm and a thickness of 0.4 to
A transfer belt device 30 in which a transfer belt 31 made of a 1.0 mm endless rubber belt is stretched is used to transfer the recording paper against the photosensitive drum and to transfer the toner image on the photosensitive drum onto the recording paper. The multicolor toner images on the peripheral surface of the photoconductor drum 10 are collectively transferred onto the recording paper P by being fed to the transfer area where the electric field is applied.
The transfer belt is an endless rubber belt having a width larger than the width of the recording paper.The recording paper is electrostatically adsorbed and loaded onto the transfer area and carried out of the transfer area. It is a member that acts as a medium that is pressed against the photosensitive drum with a prescribed pressure and that provides a transfer electric field for transferring the toner image on the photosensitive drum onto the recording paper.

A high DC voltage is applied to the shaft 32a of the upstream holding roller 32 with respect to the approach direction of the recording paper P of the holding rollers 32 and 33 which stretches the transfer belt 31, and the shaft 32a. A conductive brush 34 is installed in a grounded state as a charging unit for charging the recording paper P at a position in contact with the transfer belt 31. The fed recording paper P enters between the brush 34 and the transfer belt 31, and electric charges are injected into the recording paper P from the brush 34, so that the recording paper P
An attraction force is generated between the transfer belt 31 and the transfer belt 31. After that, the recording paper P enters the nip portion (transfer area) 35 formed by the photosensitive drum 10 and the transfer belt 31, and the transfer belt 31
A transfer electric field is applied from the back surface by the corona discharger 36 or a bias roller instead of the corona discharger 36, and the multicolor toner image is transferred and transferred onto the recording paper P.

The recording paper P holding the transferred multicolor toner image is a holding roller 3 on the downstream side on which the transfer belt 31 is stretched.
The shaft 33a of No. 3 is used as a counter electrode, and is separated from the transfer belt 31 after being subjected to static electricity removal by AC corona discharge or while receiving AC corona discharge. A cleaning blade 37 removes the toner attached to the rotating transfer belt 31. The transfer belt 31 of the transfer belt device 30 is rotated clockwise about the shaft 33a of the holding roller 33 on the downstream side and separated from the photosensitive drum 10 during the formation of the multicolor toner image.

The recording paper P, which holds the multicolor toner image separated from the transfer belt device 30, is transferred to a fixing device 50 which is composed of two pressure-bonding rollers having a heater at a close position inside or outside one of the rollers. The attached toner is conveyed and melted by applying heat and pressure between the pressure-bonding rollers, fixed on the recording paper P and fixed, and then discharged to the tray portion 59 by the discharge rollers 56, 57, and 58.

After the transfer, the residual toner remaining on the peripheral surface of the photosensitive drum 10 is subjected to static elimination by a static eliminator 15 using an AC corona discharger, and then reaches a cleaning device 16 to abut the rubber on the photosensitive drum 10. The material is scraped off into the cleaning device 16 by the cleaning blade 16a made of a material, and discharged or stored by a screw or the like.

The photoconductor drum 10 from which the residual toner has been removed by the cleaning device 16 is exposed by the PCL 11 and then uniformly charged by the scorotron charger 12 to start the next image forming cycle. During the formation of the multicolor toner image, the cleaning blade 16a is separated from the surface of the photoconductor, and the AC neutralization by the static eliminator 15 is deactivated.

As shown in FIG. 2, each of the developing devices 20 is provided with a pair of gears G1 on the side surface of the developing container 20A, which are coaxially united with a pair of agitating members (not shown) to be housed therein. Gear G2 connected to a developing device driving device described later
It is designed to be rotated through.

Further, the gear G1 is coaxial with the pulley P.
1 and the idle roller R1 and the developing sleeve 2 described above.
1 and the toner supply roller (not shown) are respectively pulleys P.
2 and a pulley P3 are coaxially integrated, and a timing belt T biased by a tension roller R2 is stretched around the pulleys P1, P2 and P3.

Therefore, when the gear G2 is rotated by the connection with the developing device driving device, the pair of agitating members rotate at the same speed in opposite directions to convey the developer in the developing container 20A in the direction perpendicular to the paper surface. , And the toner and the carrier are mixed by stirring so that the carrier and the carrier are evenly distributed. On the other hand, the conveyance of the timing belt T rotates the developing sleeve 21 and the toner supply roller to start the development of the latent image on the photosensitive drum 10. .

When the developing device 20 continues to develop the latent image and consumes the toner contained in the developer, the detecting device (not shown) detects the toner.
Toner replenishment is automatically started from the adjacent toner hopper to recover the toner ratio in the developer to a predetermined ratio.

The toner is replenished to the developing unit 20 by utilizing the thrust by rotating the toner conveying screw 121 in the replenishing pipe 120 connected to the toner hopper in a predetermined direction by the toner replenishing drive device of the present invention. .

FIG. 3 shows the developing device driving device and the toner replenishing driving device of the present invention connected thereto.

A gear G10 of a drive motor (not shown) meshes with a gear G11 and further transmits rotation to a gear G13 via a gear G12 coaxially integrated with the gear G11.

The gear G13 meshes with a pair of gears G14A and G14B, which are also called driven shafts, and the gears G14A and G14B each have a pair of gears G1.
Disks 60A and 60B having 5A or G15B attached thereto are coaxially and rotatably provided.

When the gear G10 is rotated in the clockwise direction by the forward rotation of the drive motor in the state where the one engaging pawl S1 of the actuator is separated from the notch 61A of the one disk 60A by the action of the solenoid SOL1, the above-mentioned operation is performed. Gear G1
4A rotates in the counterclockwise direction, whereby the disk 60A rotates in the counterclockwise direction and the gear G15A meshes with the gear G2 shown in FIG. 2 to the developing device 20 containing the specified magenta developer, for example. Power is transmitted. On the other hand, the other locking claw S
The gear G15B on the disk 60B, which is prevented from rotating by the engagement of 2, idles and does not transmit power.

When the drive motor is switched to the reverse rotation in this state, the rotation of the gear G14A rotates clockwise, and as a result, the disk 60A reverses clockwise and the gear G15A of the developing device 20 containing, for example, a yellow developer. It meshes with the gear G2 to transmit power.

On the other hand, by the action of the solenoid SOL1, the other locking claw S2 provided in the actuator is disengaged from the notch 61B of the other disk 60B, and the above locking claw S2 is provided.
When the engagement with the disc 60B is released, the forward rotation of the gear G10, that is, the clockwise rotation is the counterclockwise rotation of the gear G14B, and the disc 60B rotates counterclockwise. The gear G2 of the developing device 20 containing the black developer is meshed to transmit the power of the drive motor, and when the drive motor is switched to the reverse rotation, the disk 60 is generated.
B rotates clockwise, and as a result, the gear G15B meshes with the gear G2 of the developing device 20 containing the cyan developer, for example, to transmit power. In this case, the locking claw S1 engages with the notch 61A of the disc 60A to keep the gear G15A in a free running state.

In this way, by switching the rotation direction of the drive motor and switching the operation of the solenoid SOL1, the developing devices 20 containing the yellow, magenta, cyan and black developers respectively start their developing operations in accordance with the timing of development. To be done.

The gear G12 is also meshed with the gear G16 on the toner replenishment drive device side, and the rotation of the drive motor is also used as power for replenishing toner to each developing device 20.

The above-mentioned gear G16 is a gear G17 which is coaxial with the gear G17 and which is coaxially meshed with the gear G17.
A supporting member 62 for pivotally supporting is swingably supported.

The gear G17 and the gear G18 are in the relationship of the sun gear and the planet gear, and when the gear G10 is rotated in the clockwise direction by the forward rotation of the drive motor, the sun gear, the gear G17, is rotated in the clockwise direction. The gear G18, which is a planetary gear due to its rotation, revolves to the right as the support member 62 swings as shown in FIG.
A and a gear G19A in G19B which is the second transmission system mesh with each other, and the gear G20 is rotated counterclockwise via the gear 19A.

When the gear G10 is rotated in the counterclockwise direction by the reverse rotation of the drive motor, the gear G17 is rotated counterclockwise to rotate the gear G18 to the left as the support member 62 swings as shown in FIG. Revolves in the direction of gear G19B
The gear G20 is also rotated counterclockwise via the intermediate gear G19C.

Therefore, the gear G20, which is also referred to as the driven shaft B, is always driven and rotated in the clockwise direction regardless of the change of the rotation direction of the drive motor. Become.

A gear G21 meshes with the gear G20 as shown in FIG. 3, and a gear G22 pivotally mounted on a support plate 63 that freely rotates about its rotation center meshes with the gear G21. There is.

The counterclockwise rotation of the gear G20 is
This is transmitted as a clockwise rotation to the gear G21, and as a result, as shown in FIG. 7, the support plate 63 rotates clockwise and at the same time transmits power to the gear G22, and via the gear G23 and the gear G24. The gear G25 is driven and rotated.

FIG. 8 shows the main part of the toner replenishing drive device as seen from the direction of arrow A in FIG.
The rotation of 25 is transmitted to a gear G26 arranged in a right angle direction through a turning gear pair 80, and further, a plurality of intermediate gears G27.
Is transmitted to the four gears G28 and G28A via.

Each of the above-mentioned gears G28 and G28A is provided with support levers 64 and 64A which are freely rotatable around the center of rotation as a fulcrum, a protrusion 65 is formed at one end, and each gear is provided at the other end. A gear G29 that meshes with G28 and G28A is provided.

The toner replenishment driving device is further provided with a stepping motor for controlling toner replenishment, and the gear G30 of the control motor (not shown) shown in FIG. 3 rotates counterclockwise in response to the toner replenishment signal. And the coaxial gear G
The gear 33 is driven and rotated counterclockwise via 31 and G32.

The gear 33 is meshed with a gear G34 which is pivotally mounted on a support plate 66 which freely rotates about its center of rotation, and the gear G33 rotates counterclockwise as shown in FIG. As shown, the gear G34 is rotated leftward to transmit power to the gear G35.

The gear G35 is provided with four cam members 70Y, 70M, 70C and 70K on the coaxial shaft 70 as shown in FIG. The control motor is rotated a predetermined number of times according to the color of the toner to be replenished, and each of the cam members is rotated by a quarter.

For example, when a toner replenishment signal is input to the developing device 20 containing the magenta developer, the cam member 70M is rotated by the drive of the control motor, and the notch is formed in the protrusion 65 of the support lever 64. Face to face.

As a result, the support lever 64 is rotated counterclockwise by its own weight to engage the protrusion 65 with the notch of the cam member 70M, and at the same time, to equip the gear G29 with the magenta toner conveying screw 121. The toner is started to be conveyed to the developing device 20 by meshing with the gear G40M. On the other hand, cam members 70Y, 70C and 70K other than the cam member 70M
In each case, the notch is the protrusion 65 of the respective support lever 64.
Since each gear G29 does not face the gears G40Y, 40C, or 40K of the toner conveying screw 121, the toner is not supplied to the yellow, cyan, and black developing devices 20. I don't know.

Thus, the cam members 70Y, 70M,
By sequentially switching the phases of the notch portions of 70C and 70K, the replenishment of toner to each developing device 20 is alternately performed.

In forming a single-color image by the specified developing device 20, the rotation direction of the drive motor is temporarily reversed at the time when a predetermined amount of toner has been replenished, so that the above-mentioned gear is rotated as shown in FIG. G18 to gear G1
9A or G19B is brought into a neutral state in which it does not mesh, and at the same time, the solenoid SOL2 is turned off to engage the locking claw S3 serving as a blocking means with the notch 62A of the support member 62, thereby causing the above-described gear G.
The operation of toner replenishment can be interrupted by keeping the neutral state of 18.

[0051]

According to the present invention, it is possible to operate and control a plurality of developing devices and a toner replenishing device provided in a color image forming apparatus, respectively, using a common drive motor as a power source, resulting in a compact device. A drive device for an image forming apparatus that is low in cost has been provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus.

FIG. 2 is a main part diagram of a developing device and a toner hopper.

FIG. 3 is a configuration diagram of an operation system of a drive device of the present invention.

FIG. 4 is a main part diagram (part 1) of an operating system of the toner replenishing drive device.

FIG. 5 is a main part diagram of an operation system of the toner replenishment drive device (No. 2).

FIG. 6 is a main part diagram (part 3) of the operating system of the toner replenishing drive device.

FIG. 7 is a main part diagram (part 4) of the operation system of the toner replenishing drive device.

FIG. 8 is a configuration diagram of a control system of the toner replenishing drive device.

[Explanation of symbols]

 10 Photoconductor drum 12 Charging device 13 Laser writing device 20 Developing device 21 Developing sleeve 30 Transfer belt device 40 Paper feeding cassette 50 Fixing device 60A, 60B Disc 62 Supporting member 63, 66 Supporting plate 64, 64A Supporting lever 65 Protrusion 70 Shaft 70Y , 70M, 70C, 70K Cam member 80 Directional gear pair 120 (toner) replenishing pipe 121 Toner conveying screw

Claims (4)

[Claims] 1. An image forming apparatus having a driven shaft A whose rotational direction changes, a driven shaft B whose rotational direction is one direction, a driven shaft A, and a power source for driving B The sun gear that rotates by, a planetary gear that meshes with the sun gear, a support member that shares the center of rotation with the sun gear and supports the planetary gear in a swingable manner, and the rotation of the power source in the first direction. When there is a first transmission system that rotates the driven shaft B in the first direction via the planetary gear, and when the rotation of the power source is in the second direction, the driven shaft B is driven via the planetary gear. A driving device for an image forming apparatus, comprising a second transmission system that rotates in a first direction. 2. The image according to claim 1, wherein the driven shaft A is a developing drive shaft for driving at least one developing device, and the drive shaft B is a toner supply shaft for driving a toner supply device. Forming device drive. 3. An image forming apparatus having a driven shaft A whose rotational direction changes, a driven shaft B whose rotational direction is one direction, a driven shaft A, and a power source for driving the B shaft, The sun gear that rotates by, a planetary gear that meshes with the sun gear, a support member that shares the center of rotation with the sun gear and supports the planetary gear in a swingable manner, and the rotation of the power source in the first direction. When there is a first transmission system that rotates the driven shaft B in the first direction via the planetary gear, and when the rotation of the power source is in the second direction, the driven shaft B is driven via the planetary gear. A second transmission system that rotates in the first direction, and a blocking unit that blocks the movement of the support member and sets the planetary gear in a position that does not mesh with either the first transmission system or the second transmission system. And a driving device for the image forming apparatus. 4. The driving device for an image forming apparatus according to claim 3, wherein the driven shaft B is a toner replenishing shaft for driving the toner replenishing device.