JP3397762B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various electrophotographic or electrostatic recording type image forming apparatuses such as color electrophotographic copying machines, computer printers, and facsimile output units, and more particularly, to such an image forming apparatus. The present invention relates to a toner replenishing device for replenishing toner to a developing device used for developing a latent image in an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic system, an electrostatic latent image formed on the surface of an image bearing member such as a photoconductor is developed by a developing device and visualized as a toner image. I am doing it.

Conventionally, when the toner in the developing device becomes less than a predetermined density, the toner replenishing device replenishes the toner to the developing device. However, the amount of toner stored in the toner replenishing device has decreased. In this case, toner must be replenished to the toner replenishing device from the outside.
The supply means are roughly classified into two forms.
One of them has a configuration in which the container itself that stores the toner is replaced when replenishing the toner. In the toner replenishing device of this form, for example, in a color electrophotographic copying machine, it becomes very difficult to share the container for each of the yellow toner, magenta toner, cyan toner, and black toner, and thus to share the container with other models. . As a result, the number of types of the above-mentioned containers to be replaced each time the toner is replenished increases, and there is a problem inevitably increasing costs.

The other form of the toner replenishing device is the one to which the present invention is directed, in which toner is replenished from the outside to another toner container of the toner replenishing device. is there. In the toner replenishing device of this form, for example, in a color electrophotographic copying machine, the shape of the container for replenishing the toner of each color from the outside is not restricted by the inside of the device, so that it can be made common, and by extension, other models. This is advantageous in that the container can be commonly used.

A toner replenishing device of this type is generally known in the art in which the toner replenishing device is formed on the front surface in consideration of the workability of the user and is pulled out before the toner is replenished.

Next, another conventional apparatus will be described.
An image forming apparatus such as a conventional color copying machine has three or four developing devices. In recent years, since UCR and the like can be performed by digital processing, four colors, that is, cyan, magenta, and
An increasing number of devices have four developing devices in which black is added to the three primary colors of yellow. However, since it is difficult to efficiently store the hoppers of the respective colors in the developing device having such a large number of colors, a small hopper having a reduced hopper capacity has been arranged compactly.

[0007]

[0008]

[0009]

[0010]

[SUMMARY OF THE INVENTION In the hopper in the above-mentioned color copying machine has the following problems.
In other words, in the type in which the developing device, which has been widely practiced in the past, moves in parallel or rotationally in the device, the position of the developing device with respect to the photosensitive drum is constant, so there is still freedom in the size and arrangement of the hopper. When a developing device that does not move around the drum is provided, the toner is usually dropped and replenished in front of the developing device, so that the developing device arranged above is likely to interfere with the toner supply to the next adjacent developing device. Further, the hopper that replenishes the developing device disposed above has a problem in that the length of the hopper in the height direction is difficult to obtain, and the capacity of the hopper is further reduced. In particular, even in a color copying machine, since the number of black-and-white copies is large, the black toner replenishment frequency tends to be inevitably higher than other colors.

[0011]

An object of the present invention is to ensure a predetermined capacity and to perform a simple operation even when there are restrictions on the placement of the hopper.
Therefore, an object of the present invention is to provide an image forming apparatus that can replenish toner .

[0013]

[0014]

According to the present invention, the above objects are achieved by an image carrier for carrying a latent image, a black toner and a toner.
Zenta toner, cyan toner, and yellow toner respectively
Black developer, magenta developer, shear
Development device and yellow development device, black development
In an image forming apparatus in which the apparatus is arranged above other developing apparatuses, it is provided between the front and rear side plates of the image forming apparatus.
The black toner replenishment is supplied from above the black developing device.
Provided between the hopper and the front plate and front door of the image forming device.
The above magenta developing device, cyan developing device, yellow
Magenta replenishing toner from above the developing device
It has a hopper, a cyan hopper, and a yellow hopper.
To magenta hopper, cyan hopper, yellow hopper
Refilling can be done from above by opening the front door.
To replenish toner to the black hopper,
From above by opening the door provided at a different position from the door
This is achieved by having a feasible configuration .

[0015]

According to the present invention, the amount of consumption is less than that of color toner.
The number of times black toner is replenished due to
Is more frequent than color toner,
-In addition to the front door for replenishing (magenta, cyan, yellow)
In addition, there is a separate door for black toner replenishment
The user can easily replenish black toner.
You can

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention are described below as reference examples.
Along with this, description will be made with reference to the accompanying drawings.

Reference Example 1 A reference example 1 according to the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 shows a reference example in which the image forming apparatus is embodied in an electrophotographic copying machine for forming a full-color copy image.

As shown in FIG. 1, a photosensitive drum 220 as an image bearing member carrying an electrostatic latent image of this embodiment is rotatably carried in the arrow direction. Around the photosensitive drum 220, a corona charger 202, an exposure optical device 203, a developing device 204, a transfer system 205, a cleaning device 206 and the like are arranged.

Further, a document reading system 207 is arranged above the device, and has a document scanning unit 207a and a photoelectric element 207b having a color separation filter, and the optical device 203 is color separation. An electrostatic latent image is formed on the photosensitive drum 220.

Further, the developing device 204 includes, for example, a yellow developing unit 204Y using yellow toner, a cyan developing unit 204C using cyan toner, a magenta developing unit 204M using magenta toner, and a black developing unit 204BK using black toner.
Equipped with one developing unit.

On the other hand, the transfer system 205 includes the gripper 20.
The recording material supported by the transfer drum 205b is provided on the photosensitive drum 22b by the transfer drum 205b having the transfer drum 205b.
The toner image is charged to the opposite polarity to the toner development of 0, and the toner image is transferred from the photosensitive drum 220 to the recording material at the transfer position. This is sequentially repeated for each toner to form a full-color image on the recording material. The recording material is supplied from the cassette 208 or the manual feed unit 209. When the transfer is completed, the recording material is separated from the transfer drum 205b by the separating unit 210, conveyed to the fixing unit 211, and fixed, and then the tray. It is stored on 212.

FIG. 2 shows the developing units 204Y and 2Y.
The relationship between the arrangement of 04C, 204M, and 204BK and the arrangement of each toner storage portion (hopper) with respect to this is shown.

The toner replenishing device 200 includes a yellow toner hopper 200Y, a cyan toner hopper 200C, a magenta toner hopper 200M, and a black toner hopper 200BK which store color toners to be replenished in respective developing units.
The photosensitive drum 220 in the same order as the developing unit.
Is fixed to a support frame 200a provided on one end side of the. The support frame 200a is pivotally supported by a pivot 203, and is used for maintenance of the photosensitive drum 220, for example.
Although the hopper can be taken out to a proper position outside the apparatus by rotating about 3 and the space behind it can be opened, it is substantially fixedly held to the developing device 204.

Each hopper has a replenishing port 201 (201Y, 201C, 201) for replenishing toner from the outside.
M, 201BK).

The developing units 204Y, 204C, 2
04M and 204BK are the toner receiving ports 250 (25
0Y, 250C, 250M, 250BK) through the toner replenishing device 200 (200Y, 200C, 200
M, 200BK) to contribute toner to the development.

Next, the toner replenishing method in this embodiment will be described. FIG. 3 is an external view of the full-color electrophotographic copying machine. A document reading device 27 is provided on the upper surface of the copying machine.
1 and an operation unit 213 including an execution unit 214 that executes copying and a display unit 215 that displays the execution state. The operating portion 213 is rotatably supported around a pivot 213a.

When the toner is replenished to the toner replenishing device from the outside, as shown in FIG. 4, the operation portion is rotated in the direction of the arrow to replenish the supply port 201 (201) of the toner replenishing device.
Y, 201C, 201M, 201BK) are opened.

Then, for example, when replenishing the black toner, as shown in FIG.
The toner is dropped into the black toner hopper 200BK by being joined to the replenishment port 201BK to replenish the toner.

At this time, the toner replenishing device 200 is in a fixed state and is kept connected to the developing device (not shown).

< Reference Example 2> Next, a reference example 2 according to the present invention will be described with reference to FIG. The same parts as those in Reference Example 1 will be designated by the same reference numerals.

This reference example has a structure in which only the upper portion of the toner replenishing device 200 is rotated about the pivot 213b and opened. In the illustrated example, since the toner replenishing device 200 is at the right end, the operating portion movable portion 213b is formed at the right end, but the position may be any position within the range of the operating portion 213 depending on the position of the toner replenishing device 200.

In the illustrated example, the execution part 214 is formed on the movable part side and the display part 215 is formed on the fixed part side, but this may be reversed. Further, the execution unit 214 and the display unit 215 may be formed on the movable unit side.

Reference Example 3 Next, a reference example 3 according to the present invention will be described with reference to FIG. The same parts as those of Reference Example 1 are designated by the same reference numerals, and the description thereof will be omitted.

In this reference example , the operation portion 213 is the guide member 2.
The upper part of the toner replenishing device 200 is opened by pulling out the upper part 17 horizontally. In the illustrated example, the entire operation unit 213 is pulled out, but the toner supply device 20
It is also possible to open only the upper part of 0.

Although the above-mentioned Reference Examples 1 to 3 are premised on the structure in which the toner replenishing device and the developing device can be attached / detached, they may be an integral structure in which they cannot be attached / detached.

[0037] <Embodiment 1> Next, a description will be given of a first embodiment of the present invention in FIGS. 7 to 10.

In FIG. 7, reference numeral 301 denotes a document pressure plate, which is a document 3
02 is pressed against the original glass 303. The original 302 is illuminated by an illumination lamp 304, and a first mirror 305 that moves at a speed v, a second mirror 306 that moves at a speed v / 2, and a lens 307 make an image sensor 308.
Connect the light image to. The signal from the image sensor 308 is the image processing unit 30.
It is input to the laser scanner 310 via 9.

The uppermost sheet of the copy paper 320 is picked up by the paper feed roller 321, then sent by the lower registration roller 322, and passed through the lower guide 323 to the registration roller 324.
Is sent to the transfer drum 328 at an appropriate timing. The copy paper 320 sent to the transfer drum 328 passes through the guide 325 and the suction brush 327 and the suction roller 326.
Is electrostatically attracted to a transfer drum 328 which is made of a cylindrical resin film and rotates in the direction of the arrow in the figure.

On the other hand, the image forming drum 311 rotates in the direction of the arrow shown and is uniformly charged by the primary charger 312. A fan or duct for venting air is provided on the back surface of the primary charger 312 so that ionized air, ozone, or the like will not accelerate deterioration of the image forming drum 311.

On the uniformly formed image forming drum 311, an image is written on the image forming drum 311 at a position of an image writing section 315 by a laser scanner through a polygon mirror 313 and a deflecting mirror 314, and an electrostatic latent image is formed. To be done. The electrostatic latent image is visualized with magenta toner by the magenta developing device 316, and is transferred by the transfer brush 329 to the copy paper attracted to the transfer drum. By the same process, the cyan developing device 317, the yellow developing device 318, and the black developing device 319 transfer the toners of four colors in total onto the same copy paper. Next, with the external static eliminator 331 and the internal brush 330, the transfer drum 32
8. Remove electricity from the copy paper 320, and push up the roller 332
While pushing up the resin film of the transfer drum,
The separation claw 333 is pressed against the resin film to peel off the electrostatically adsorbed copy paper.

Next, the copy paper is sent to the entrance guide 336 by the conveyor belt 334 suspended by the roller 335.
A suction fan 337 is provided in the transport belt 334 for the purpose of stabilizing the transport of copy paper by the transport belt 334, and the suction fan 337 draws air from the back surface of the transport belt. The copy paper thus conveyed enters the pressure contact portion between the fixing roller 338 and the pressure contact roller 339, and the toner is fixed on the copy paper at the pressure contact portion.
The sheet is discharged onto the tray 342 by the sheet discharge roller 341 through the sheet discharge guide 340.

In the apparatus of the present embodiment as described above, the uppermost developing device 319 is a developing device for performing jumping development with a one-component insulating toner, and uniformly drops and replenishes the developing device in the generatrix direction of the photosensitive drum. It has a hopper type toner replenishing device for performing. Disposing a developing device for developing black at this location is a large-capacity hopper 403.
Is also advantageous in that it can be arranged above the developing device 319. Considering the toner used for jumping development, although it is a single component, it contains various additives, so if the toner is dropped and replenished at one end (for example, the front side) of the developing device and sent by a screw Since the mixing ratio of the additive and that of the additive change from the front to the back, the development characteristics change, which is not preferable, but uniform drop replenishment can solve such a defect.
Further, in jumping development, the developer does not develop in contact with the photosensitive drum, so it is not necessary to separate the developing device from the photosensitive drum even when developing other than black, and the developing bias is simply turned off and the developing sleeve does not rotate. Therefore, it is best to place it at the most upstream position in the case of contact type development of other colors without disturbing or developing the latent image on the photosensitive drum. Is.

Next, the arrangement of the hopper and the position of the toner supply opening to the developing device will be described with reference to FIG. 8 when the hopper is seen from above and FIG. 9 when seen from the front side of the front.

In FIG. 8, reference numeral 401 denotes a device back side plate, and 402.
Has a replenishment opening 403a at the bottom of the hopper 403 for the black toner. Replenishment is performed by a known method, for example, by rotating a magnet roller or a sponge roller provided in the replenishment opening, uniform replenishment is performed at any position in the longitudinal direction of the opening.

A magenta toner hopper 404 has an opening 404a at the bottom. Supply is a known method,
For example, as shown in FIG. 18, toner is sent by a screw 404b toward the opening 404a of the magenta developing device 316 to perform drop replenishment.

Similarly, 405 is a hopper for cyan toner, 405a is its opening, and 406 is a hopper for yellow toner, 406a is its opening. Since the magenta hopper is located at a high position in relation to the replenishing port of the developing device, the magnifying hopper is configured to have a larger lateral dimension and the same capacity as the cyan and yellow hoppers. .
407 is a hinge central axis that can open and close the entire hopper in the direction of the arrow, and in the opened state, the developing device can be inserted / removed and other maintenance can be performed. The black hopper was placed between the front and back plates of the machine, so magenta, cyan,
The yellow hopper can have a capacity of 33% or more larger than the conventional one, and the black hopper can have an extremely large capacity.

Next, the replenishment of toner to the hopper will be described. To replenish the magenta, cyan, and yellow toners, since the hopper is arranged outside the front plate 402 of the apparatus, the front door (not shown) can be opened and the toner can be replenished from the top of the hopper by a known method. That is, the lid 404c is opened and the bag is replenished with a bag or a replenishing container.

Replenishment of black toner is troublesome because the black hopper is still hidden behind the magenta, cyan and yellow hoppers even when the front door is opened. Therefore, as shown by the chain double-dashed line in FIG. 7, the door 343 on the right side is opened, the refill container 408 is inserted from the side by guiding it and the shutter 408a is opened, and refilling can be performed. is there. As another replenishment method, as shown in FIG. 10, the replenishment bottle 409 can be connected to the hopper 403 to replenish from the upper portion of the apparatus. In the case of this method, the space between the front side plate and the back side plate of the device can be effectively used, and thus a hopper having a larger capacity can be obtained.

To replenish the magenta, cyan, and yellow toner, a large front door is opened, and further necessary operations are performed, for example, the operation panel is opened, and then the lid of the hopper is opened, and the replenishing container is combined with the hopper to drop and replenish. However, since the consumption of color toner is not so great as black, it is less frequent, so it may be a little complicated for practical use. However, black is more frequent, so simpler is preferable.

In any of the above cases, the method is simpler than the conventional example in which the front door is always opened for operation, and is suitable for a method of replenishing black toner. In particular, the latter method is easy since it is only necessary to open the lid on the hopper and connect the refill bottle.

When the developer is a one-component toner which does not require a carrier, the hopper portion is not necessarily required. Therefore, the developing container may be made large and the toner may be directly supplied to the container. Of course.

[0053]

[0054]

As it is evident from the foregoing description, according to the present invention, consumption
Black due to more than color toner
The toner is replenished more frequently than color toner.
Even color toner (magenta, cyan, yellow)
In addition to the front door for charging, there is a separate door for replenishing black toner.
Since it is provided in the middle, the user can easily
The effect that replenishment can be performed is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a full-color electrophotographic copying machine according to Reference Example 1 of the present invention.

FIG. 2 is a perspective view of a toner replenishing device in the device of FIG.

FIG. 3 is a perspective view showing the vicinity of an operation unit of the apparatus shown in FIG.

FIG. 4 is a diagram illustrating a method of replenishing toner to the apparatus in FIG. 1 from the outside.

FIG. 5 is a diagram showing a positional relationship between a toner replenishing port and an operation portion of a toner replenishing device according to a second reference example of the present invention.

FIG. 6 is a diagram showing a positional relationship between a toner replenishing port and an operating portion of a toner replenishing device according to a third reference example of the present invention.

FIG. 7 is a sectional view of the image forming apparatus according to the first embodiment of the present invention.

FIG. 8 is a top view of the toner supply device of the apparatus of FIG.

9 is a front view of the toner replenishing device of the device of FIG. 7. FIG.

FIG. 10 is a cross-sectional view illustrating another toner replenishing method in the apparatus of FIG.

[Explanation of symbols]

316 Magenta color developing device 317 cyan color developing device 318 Developing device for yellow color 319 Black developing device (developing device located above) 403 Black hopper (toner supply device) 404 Magenta color hopper (toner supply device) 405 Cyan hopper (toner supply device) 406 Yellow color hopper (toner supply device)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 4-190372 (JP, A) JP 3-217870 (JP, A) JP 4-250468 (JP, A) Special table 5- 508035 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/08 G03G 15/01

Claims (2)

(57) [Claims] 1. An image bearing member carrying a latent image, and a black dot.
Toner, magenta toner, cyan toner, yellow toner
Black developing device and magenta developing device
Unit, a cyan developing device, and a yellow developing device.
In the image forming apparatus in which the developing device is arranged above the other developing devices , the black developing device is provided between the front and rear side plates of the image forming device.
Black hopper that replenishes toner from above the developing device
And provided between the front side plate and the front door of the image forming apparatus.
Magenta developing device, cyan developing device, yellow developing device
Magenta hopper that replenishes toner from above,
It has a cyan hopper and a yellow hopper, and goes to the magenta hopper, cyan hopper, and yellow hopper.
Toner replenishment can be performed from above by opening the above front door
Functioning , the toner supply to the black hopper is different from the front door
Can be executed from above by opening the door provided at the position
An image forming apparatus having a configuration . 2. A door provided at a position different from that of the front door.
The image forming apparatus according to claim 1 , wherein the open guide serves as an insertion guide for the replenishing container in the opened state .