JPH08248755A - Image forming device - Google Patents

Abstract

PURPOSE: To prevent the outflow of liquid toner from a supplying unit to a developing unit by forming a part becoming high toward the downstream side of a toner carrying path provided on the supplying unit. CONSTITUTION: In a feeding pipe 52 provided on a toner hopper unit, the part becoming high toward the downstream side of the toner carrying path is formed and the pipe 52 is communicated with the developing unit on the further downstream side than the uppermost part of the part. A toner carrying screw 82 is disposed in the feeding pipe and the toner except a liquid toner can be carried up to the uppermost part of the feeding pipe 52 by rotation. The toner arriving at the upper most part is pushed out by the later supplied toner and passes through the uppermost part, to be supplied to the developing unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile or a printer, and more specifically, to prevent outflow of liquefied powder toner to a developing unit when toner is supplied to a toner container. Image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, a toner container for containing toner, a toner conveying path provided between the toner container and a developing unit, and a toner conveying member arranged in the toner conveying path. There is known an image forming apparatus that includes a supply unit that includes a toner supply member and that supplies the toner in the toner container to the developing unit as necessary. Here, there is also known a toner transfer member to which a coil spring is applied (e.g.
4455). Further, as the toner conveying member, there is also known one in which a screw in which a spiral blade portion is formed on a shaft (hereinafter referred to as a conveying screw) is applied (for example, Japanese Utility Model Laid-Open No. 3-129968, Japanese Patent Laid-Open No. 3-129968). See Japanese Patent Application No. 4-345373). The image forming apparatus as described above separates the toner in the toner container from the toner container by using the toner-conveying replenishing means including the coil spring and the conveying screw provided in the toner conveying path. Since it can be transported to a different place, the degree of freedom in laying out each device in the image forming apparatus can be increased by, for example, disposing the toner container on the side of the developing unit rather than on the upper side of the developing unit. It can contribute to miniaturization.

[0003]

By the way, in the image forming apparatus having the toner conveying member composed of the coil spring and the conveying screw, which is the object of the present invention, when the toner container is completely new, there is no toner. In the toner end state where there is almost no toner, the liquefied powder toner (hereinafter referred to as liquid toner) in the toner bottle, which is sufficiently agitated and contains air, is replenished to the toner container of the supply unit, The supply unit is set on the developing unit side, and there is no seal portion between the toner container and the developing unit, so that the liquid toner can move. At this time, depending on the user, the time from the replenishment of the liquid toner from the toner bottle into the toner container to the completion of the setting of the supply unit on the developing unit side (hereinafter referred to as the toner replenishment work time) may be short, In this case, a large amount of the liquid toner in the toner container flows out to the developing unit side through the toner conveying path in which the toner conveying member is arranged in the liquefied state. When a large amount of toner flows into the developing unit side, there are problems that the toner scattering inside the apparatus increases and the entire surface of the image is smeared.

In the image forming apparatus proposed in Japanese Utility Model Application Laid-Open No. 3-129968, since a toner end sensor is provided in the toner container, there is still a stage at which the toner end state is detected by this sensor. A certain amount of toner is present at the entrance of the toner transport path. For this reason, even if the liquid toner is replenished at the end of the toner, the toner at the entrance of the toner conveying path serves as a barrier to prevent the liquid toner from passing. Therefore, in the case of this configuration, the problem that the liquid toner flows out to the developing unit side occurs only when the product is new. Moreover, the above-mentioned Japanese Patent Application No. 4-345373.
The image forming apparatus proposed in No. 1 does not have a toner end sensor in order to reduce costs, so the user cannot know the toner end state, and the toner container is used up to a state where there is almost no toner. It Therefore, in the case of this configuration, the problem that the liquid toner flows out to the developing unit side occurs not only at the time of new product but also at the time of toner end.

Therefore, in order to prevent the toner from flowing out to the developing unit side, a detection means for detecting the attachment / detachment of the replenishment toner storage container with respect to the toner storage container of the supply unit, and the replenishment toner storage container are attached to the toner storage container. If it is detected by the detection means that the supply unit cannot be moved to the engagement position, and if the detection means detects that the replenishment toner storage container is removed from the toner container, replenishment is performed. There has been proposed an image forming apparatus provided with a supply unit movement control means for moving the supply unit to an engagement position after a predetermined time has elapsed since the toner storage container was removed from the toner storage container. (For example, Japanese Patent Application No. 5-
229480). However, the above-mentioned Japanese Patent Application No. 5-22
In the image forming apparatus shown in No. 9480, when the liquid toner approaches the solid state after the lapse of the predetermined time, it is possible to prevent the toner from flowing out to the developing unit side. However, there is a problem that the device is complicated and the cost is increased. Further, by making the supply unit immovable until a predetermined time elapses, the work time for replenishing toner from the supply unit to the developing unit is increased, and the work efficiency is reduced.

The present invention has been made in view of the above problems, and a first object thereof is a simple structure without increasing the toner replenishment work time from the supply unit to the developing unit. An object of the present invention is to provide an image forming apparatus capable of preventing liquid toner from flowing out to the developing unit side.

In particular, the object of the invention of claim 3 is to arrange the supply unit at a desired position with respect to the developing unit generally provided in the lower part of the apparatus main body in the inventions of claims 1 and 2. An object of the present invention is to provide an image forming apparatus that can realize the downsizing of the image forming apparatus.

[0008]

In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention comprises a developing unit and a toner in a toner container, and a toner conveying path disposed inside the toner conveying path. In an image forming apparatus that includes a supply unit that conveys a toner by a member and supplies the toner to the developing unit from a communicating portion between the toner conveying path and the developing unit, a portion that is higher on the downstream side of the toner conveying path is included in the toner conveying path. It is characterized by being formed.

An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein a part of the toner conveying path is higher than a toner height when a maximum amount of toner is accommodated in a toner container. It is characterized by having done.

According to a third aspect of the present invention, in order to achieve the first and second objects, the image forming apparatus according to the first or second aspect, the toner conveying member is made of a flexible material. Then, the toner conveying member is extended to the downstream side of the toner conveying path with respect to the highest part of the toner conveying path, and the communication portion between the toner conveying path and the developing unit is located at the highest position of the toner conveying path. It is characterized in that it is provided at a desired position on the downstream side of the toner conveying path with respect to the above portion. Here, as the flexible material, for example,
A coil spring can be used.

[0011]

According to the image forming apparatus of the present invention, in addition to the toner conveying member regulating the flow of the liquid toner entering the toner conveying path immediately after the toner is supplied to the supply unit, the conveying path provided in the toner conveying path. At the portion that rises in the downstream direction, the liquid toner is less likely to flow to the downstream side because it is affected by gravity. Therefore, even if the liquid toner generated immediately after being replenished to the supply unit flows into the toner conveying path as it is, the liquid toner does not flow out to the developing unit side due to the momentum of the replenishment.

According to another aspect of the image forming apparatus of the present invention, the toner height is higher than that when the maximum amount of toner that can be stored in the toner storage container is stored (hereinafter referred to as maximum toner storage). This portion is formed in the toner transport path. Assuming that the liquid toner is water, the toner in the toner transport path communicating with the container tries to maintain the same height as the toner height in the toner container.
Even if the liquid toner in the toner transport path has extremely high fluidity, the liquid toner tries to maintain the toner height at the time when the maximum toner is stored, and does not flow to a portion higher than that.

According to another aspect of the image forming apparatus of the present invention, a flexible member is used as the toner conveying member in order to obtain a degree of freedom in the conveying path, and the toner conveying path that has once turned upward is directed downward from the uppermost portion. The toner container is bent, and a communicating portion with the developing unit is provided at a desired position below the toner container. When the supply unit is housed in the apparatus body, the supply unit can be laid out at a desired position with respect to the developing unit.

[0014]

First, an example of a color copying apparatus which is an image forming apparatus to which the present invention can be applied will be described. FIG. 1 is a schematic configuration diagram of a color copying apparatus. A color image reading device (hereinafter, referred to as a color scanner) 1 forms an image of a document 3 on a color sensor 7 via an illumination lamp 4, a mirror group 5, and a lens 6 to obtain color image information of the document, for example, Each color separation light of blue (Blue, hereinafter B), green (Green, hereinafter G), and red (Red, hereinafter R) is read and converted into an electrical image signal. And B, G, obtained with this color scanner 1,
An image processing unit (not shown) performs color conversion processing based on the color separation image signal intensity level of R, black (hereinafter, referred to as Bk), cyan (Cyan, hereinafter referred to as C),
Magenta (hereinafter referred to as M), yellow (Y
ellow, hereinafter referred to as Y) color image data. This is visualized with Bk, C, M, and Y by a color image recording device (hereinafter referred to as a color printer) 2 described below, and the toner images thus obtained are superimposed to form a four-color full-color image. Form.

The writing optical unit 8 of the color printer 2 converts the color image data from the color scanner 1 into an optical signal, performs optical writing corresponding to the original image, and forms an electrostatic latent image on the photoconductor 9. . The photoconductor 9 rotates counterclockwise as indicated by the arrow, and around the photoconductor cleaning unit (including a pre-cleaning charge eliminator) 1
0, static elimination lamp 11, charger 12, potential sensor 13,
A Bk developing unit 14, a C developing unit 15, an M developing unit 16, a Y developing unit 17, an optical sensor 18 for detecting a development density pattern, an intermediate transfer belt 19 and the like are arranged.

Each developing unit has a developing sleeve (14a, 15a, 16a, 17a) which rotates by bringing the brush of the developer into contact with the surface of the photosensitive member 9 to develop the electrostatic latent image,
Developing paddles (14b, 15b, 16b, 17b) that rotate to draw up and stir the developer, and toner concentration sensors (14c, 15c, 16c, 17c) for the developer
Etc.

The outline of the copying operation will be described below by taking the example of the developing operation order (color image forming order) as Bk, C, M, and Y (however, the image forming order is not limited to this). . When the copying operation is started, the color scanner 1 starts reading Bk image data from a predetermined timing, and optical writing by a laser beam and latent image formation start based on the image data (hereinafter, electrostatic image by Bk image data is used. The latent image is referred to as a Bk latent image. C, M, and Y are referred to as a C latent image, an M latent image, and a Y latent image, respectively). Before the latent image front end reaches the developing position of the Bk developing unit 14 so that the front end of the Bk latent image can be developed, the developing sleeve 14a is started to rotate and the Bk latent image is developed with Bk toner. After that, the developing operation of the Bk latent image area is continued, and when the trailing edge of the latent image passes the Bk developing position, the developing operation is disabled. This is completed at least before the leading edge of the C latent image by the next C image data arrives.

The Bk toner image formed on the photosensitive member 9 is transferred onto the surface of the intermediate transfer belt 19 which is driven at the same speed as the photosensitive member (hereinafter, the toner image transfer from the photosensitive member to the intermediate transfer belt is referred to as belt transfer). ). The belt transfer is performed by applying a predetermined bias voltage to the transfer bias rollers 20a and 20b while the photoconductor 9 and the intermediate transfer belt 19 are in contact with each other. The intermediate transfer belt 19 has a photosensitive member 9
The Bk, C, M, and Y toner images sequentially formed on are sequentially aligned on the same surface to form a 4-color superposed belt transfer image, and then bulk transfer is performed on the transfer paper.

On the side of the photosensitive member 9, the Bk process is followed by the C process, but the C image data reading by the color scanner 1 starts at a predetermined timing, and the C latent image is formed by writing the laser light by the image data. The C developing unit 15 starts the rotation of the developing sleeve with respect to the developing position after the trailing edge of the previous Bk latent image has passed and before the leading edge of the C latent image reaches the C developing unit 15 so that the C latent image is C Develop with toner. After that, the development of the C latent image area is continued, and when the trailing edge of the latent image passes, the development is inoperable as in the case of the previous Bk developing unit. This is also completed before the leading edge of the next M latent image arrives. In each of the steps M and Y, the operations of reading image data, forming a latent image, and developing are performed in the same manner as the steps Bk and C described above.

The transfer paper 24 on which the four-color superposed toner images have been collectively transferred from the surface of the intermediate transfer belt is conveyed to the fixing device 28 by the paper conveying unit 27, and the fixing roller 28a and the pressure roller 28b are controlled at a predetermined temperature. Then, the toner image is fused and fixed, and is carried out to the copy tray 29 to obtain a full color copy.

The surface of the photosensitive member 9 after the belt transfer is cleaned by the photosensitive member cleaning unit 10,
Further, the static elimination lamp 11 uniformly eliminates the static electricity. In addition, the intermediate transfer belt 19 after the toner image is transferred onto the transfer paper 24
, The cleaning unit 22 is pressed again by the contacting / separating mechanism to clean the surface.

At the time of repeat copying, the color scanner 1
The operation and the image formation on the photosensitive member 9 proceed to the second Bk (first color) image process at a predetermined timing after the first Y (fourth color) image process. Further, in the intermediate transfer belt 19, the second Bk toner image is formed in the area where the surface is cleaned by the cleaning unit 22, following the batch transfer process of the first four-color superimposed image onto the transfer paper. Allow the belt to be transferred. After that, the same operation as the first sheet is performed. The transfer paper cassettes 30, 31, 32,
The reference numeral 33 stores transfer sheets of various sizes, which are fed and conveyed in the direction of the registration rollers 26 at a timing from a storage cassette of size sheets designated by an operation panel (not shown). Reference numeral 34 is a manual paper feed tray for OHP paper or thick paper.

The above is the description of the copy mode in which four full colors are obtained, but in the case of the three-color copy mode and the two-color copy mode, the same operation as above is performed for the designated color and the number of times. It will be. (Hereinafter, margin) FIG. 2 is a schematic configuration of the photoconductor 9 as viewed from the axial direction of the photoconductor 9, the developing units (14, 15, 16, 17) and a toner hopper unit 40 as a supply unit which will be described in detail later. It is a figure, Bk for the developing unit
The developing unit 14 will be described as an example. The Bk developing unit 14 (more precisely, the developing sleeve 14a) is arranged with a certain gap from the photoconductor 9 maintained. Development sleeve 1
4a is driven in the normal direction (during development) and the reverse direction (during ear cutting) by a sleeve motor 142 via a gear 141 which is supported between side plates of the developing unit 14 and is attached to one end of the shaft (left side in the drawing). The developing paddle 14b is a so-called dual mixer, and is configured such that the outer screw paddle 143 and the inner screw paddle 144 convey the developer in mutually opposite directions when rotating. The developer enters the inside through a developer intake port 145 formed near the end of the outer screw paddle 143 (on the right side in the drawing), and by the rotation of the inner screw paddle 144, the developer paddle 14 is rotated.
The inside of b is conveyed from the front side to the rear side (from the right side to the left side in the drawing), and goes out from the developer discharging portion 146 formed on the rear side (the left side in the drawing). The developer discharged to the outside is conveyed from the rear side to the front side (from the left side to the right side in the figure) by the rotation of the outer screw paddle 143, and the replenished toner is evenly dispersed to uniformly charge the toner. . Development paddle 1
4b is the rear side of the outer screw paddle 143 (left side in the figure)
Through the gear 147a provided on the paddle motor 14
Driven by 8. Also, the inner screw paddle 14
4 is a gear 147b, 1 provided on the front side (right side in the figure)
It is driven by 47c and 147d.

The developing sleeve 1 near the developing paddle 14b.
A toner concentration sensor 14c is provided at a substantially central portion of 4a in the longitudinal direction. The toner concentration sensor 14c detects the toner concentration based on the change in magnetic permeability of the developer existing in the developing device 14. The toner concentration value detected by the toner concentration sensor 14c is compared with a reference value, and when the toner concentration falls below a certain value and a toner shortage occurs, a toner replenishment signal having a magnitude corresponding to the shortage is supplied. It is designed to be output to the circuit.

The toner hopper unit 40 contains replenishment toner 41 therein, and a toner carrying screw 42 as a toner carrying member has a gear 421 provided at one end thereof.
The driving force from the toner replenishment motor 43 is transmitted via the rotation and rotates, and the toner is replenished to the developing portion from the toner replenishing port 149 formed in the developing unit 14. In FIG. 2, a horizontal toner transport path is provided from the opening of the toner hopper unit 40 to the toner replenishment port, but actually, a part of the toner transport path is formed to be high.
This toner transport path will be described later in detail.

Next, the toner hopper unit 40 will be described. FIG. 3 is a schematic configuration diagram of the toner hopper unit 40. The toner hopper unit 40 includes toner hopper unit portions 40Bk, C for the Bk developing unit 14.
A toner hopper unit portion 40C for the developing unit 15,
Toner hopper unit 40 for M developing unit 16
Toner hopper unit 4 for M, Bk developing unit 14
It has 0 parts Y.

Since the toner hopper unit portions (40Bk, 40C, 40M, 40Y) have substantially the same structure, the toner hopper unit portion 40Bk for the Bk developing unit 14 will be described below as an example.

The toner hopper unit 40Bk is provided with an agitator 44 as a toner agitating means for loosening and agitating the replenishment toner 41 (see FIG. 2) housed therein, which is rotatable about one end thereof. This agitator 44
As shown in FIG. 4, a stirring blade 441 divided into a plurality of blades of the same shape and a large blade at the end is fixed to a shaft 442 by a fixing member 443. The material of the stirring blades 441, 442 in this embodiment is rubber. By thus forming the stirring blades 441 and 442 with rubber, even if the toner in the toner hopper unit 40Bk aggregates due to vibration or the like, the aggregated toner can be effectively loosened. In addition, the toner hopper unit 40
Below the Bk agitator 44, the toner transport screw 42 is provided.

Next, driving of the agitator 44 and the toner transport screw 42 will be described. A toner replenishing motor 43 is provided in the toner hopper unit section 40Bk. The toner replenishing motor 43 has its drive shaft engaged with a large-diameter gear 451 of a helical gear 45 having a large-diameter gear 451 and a small-diameter gear 452. A gear 444 is attached to the agitator 44 at the end of the shaft 442, for example, and the gear 444 meshes with the small diameter gear 452 of the helical gear 45. A gear 421 (18Z) is attached to the toner carrying screw 42 at its end, for example (see FIG. 2). A gear 46 (19Z) is arranged between the gear 421 and the gear 444 so as to mesh with each other.

In the above structure, when the toner replenishment signal from the toner concentration sensor 14c (see FIG. 2) is output to the toner replenishment circuit as described above, the toner replenishment motor 43 starts to rotate, and its driving force is It is transmitted to the gear 45, the gear 444, the gear 46, and the gear 421 to drive the agitator 44 and the toner transport screw 42 to rotate.

Next, the toner replenishing work at the time of new product or toner end, and the operation of the connecting portion between the toner hopper unit 40 and the developing unit will be described. FIG. 5 is an explanatory diagram showing a procedure of toner replenishing work for replenishing toner to the toner storage chamber 51 of the toner hopper unit portion 40Bk, and FIG. 6 is a toner hopper unit 4 at the time of toner replenishing work.
FIG. 9 is an operation explanatory diagram of a joint portion between the 0-th portion Bk and the developing unit 14.

Developing unit (14, 15, 16, 17)
Of a plurality of toner hopper units 40Bk, 40C, 40 of the toner hopper unit 40 containing toner outside the printer
M and 40Y are located directly below the operation display panel unit 2a extending in the left-right (lateral) direction above the front of the color printer 2.
The movable frames 47 are arranged in parallel with each other, and a plurality of them are integrally configured. As shown in FIG. 7, the moving frame 47 is mounted on the main body frame 2c of the color printer 2 in the front-back direction via a pair of left and right slide mechanisms (guide members) 71 (not shown in FIGS. 5 and 6). It is movably supported. This slide mechanism 71
Is a pair of toner hopper unit support rail members 71 that are coupled in parallel via a plurality of balls (not shown).
The movable rail member 71a of the pair of toner hopper unit supporting rail members 71a and 71b is connected to the moving frame 47, and the other fixed rail member 71b is connected to the main body frame 2.
It is connected to c. As a result, the operation display panel unit 2
An engaging position for engaging the developing unit below a and an operation display panel section 2a spaced apart from the developing unit by a predetermined distance.
It is movable to and from the detached position in front. Further, means for locking the moving frame 47 or the toner hopper unit 40 to the main body frame 2c at the engaging position, for example, a so-called push-push type latch (not shown) is provided.

Further, the toner hopper unit 40Bk
6 is a toner storage chamber 51 as a toner storage container, a delivery pipe 52 as a toner transport path provided in the lower part of the toner hopper unit 40Bk, and a delivery pipe 52 inserted into the delivery pipe 52 and rotating as shown in FIG. A toner transport screw 4 including a shaft body 42a and a screw portion 42b, which serves as a toner transport member that transports toner in the arrow direction.
2, an outer cylinder 53 slidably attached to the outer circumference of the delivery pipe 52, a diameter slightly smaller than the outer cylinder 53, and attached to the tip of the toner transport screw 42 so as to be able to abut against the outer cylinder 53. A packing member 54, a gear 421 for transmitting a driving force to the toner carrying screw 42, and an outer cylinder 53.
And a wiper member 56 for wiping off the toner adhering to the outer periphery of the delivery pipe 52.

At the time of new product or toner end, for example, when the toner end display is turned on, first, as shown in FIG. 5 (a), the user opens the front cover 2b of the color printer 2 main body to cause the latch. When the toner hopper unit 40 set on the main body frame 2c of the color printer 2 is pushed by and is released from the latch, the state of the connecting portion between the toner hopper unit portion 40Bk and the developing unit 14 is changed from FIG. 6 (d). Change to (c). Next, as shown in FIG. 5B, the toner hopper unit 4
When the handle at the upper left of 0 is held and pulled out along the accuride 48, the state of the joint between the toner hopper unit 40Bk and the developing unit 14 changes from FIG. 6C to FIG. 6B.

Next, by vibrating the new toner bottle 60 or shaking the toner bottle 60 to agitate the toner in the toner bottle 60, air is introduced between the powder toners to liquefy the toner. , Make toner easy to replenish. At this time, the toner bulk density in the toner bottle 60 is, for example, from about 0.46 g / cm before stirring to about 0.27 g.
Change to / cm. Next, the toner hopper unit section 40B
Open the cap 49a on the upper part of k, align the Δ mark of the joint cartridge 49b and the ∇ mark of the toner bottle 60, and push down the toner bottle 60 to set it.
(C)). Next, when the toner bottle 60 is set upright and rotated about 180 degrees clockwise until it stops, the internal shutter is opened and the liquid toner in the toner bottle 60 is replenished in the toner storage chamber 51 (FIG. 5 (d). )).

Next, when toner supply is completed, the toner bottle 60 is rotated counterclockwise to remove the toner bottle 60 (FIG. 5 (e)). Next, as shown in FIG. 5F, the cap 49 on the toner hopper unit portion 40Bk.
When a is closed and the toner hopper unit 40 is set by pushing it toward the main body frame 2c side of the color printer 2, the outer cylinder 53 of the toner hopper unit 40Bk abuts against the inner protrusion 141d of the carry-in passage member 14d of the developing unit 14. (In the state of FIG. 6C), the toner is separated from the packing member 54, the delivery pipe 52 and the carry-in passage member 14d communicate with each other, and a toner supply path from the toner hopper unit 40Bk to the developing unit 14 is formed (FIG. 6C). (State of (d)).

The above replenishing work, structure and operation are as follows.
Other toner hopper unit parts (40C, 40M, 40
Y) and the developing unit (15, 1) for each
6 and 17), the same description is omitted.

Also in FIGS. 6 and 7, the sending pipe 52 as a toner carrying path is provided horizontally from the opening of the toner hopper unit to the communicating part with the developing unit. A part is formed to be high. The toner transport path will be described in detail later.

By the way, in the above toner replenishing work, depending on the user, from the removal of the toner bottle 60 to the completion of setting the toner hopper unit 40 in the color printer 2 main body frame 2c (shown in FIGS. 5 (e) and 5 (f)). The toner replenishment work (corresponding to the work) may be performed within a relatively short time. When the toner replenishment work time is short in this way, the replenished liquid toner in the toner hopper unit 40 passes through the delivery pipe 52 in which the toner transport screw 42 is arranged, and when the setting is completed, the delivery pipe 52 is delivered. There is a risk that a large amount will flow out to the side of the developing unit that is in communication with.

Therefore, the toner conveyance of the image forming apparatus capable of preventing the liquid toner from flowing out to the developing unit side will be described below. 8A is a front view of the toner hopper unit 40 as seen from the toner delivery pipe 52 side, and FIG. 8B is a side view of the same. The delivery pipe 5 provided in the toner hopper unit 40 of this embodiment
Reference numeral 2 has a horizontal portion that is connected to an opening on the bottom surface of the toner hopper unit 40 and that extends in the horizontal direction, and a vertical rising portion that extends upward at a substantially right angle along the side surface of the toner hopper unit 40. It is in communication. This vertical rising part
It is a portion formed on the sending pipe and becomes higher toward the downstream side of the toner carrying path. Also this delivery pipe 52
Makes a U-turn at the uppermost part of the vertical ascending portion, and communicates with the developing unit at a slightly lower position. Inside the delivery pipe 52, as shown in FIG. 8C, a horizontal toner carrying screw 81 is provided in the horizontal portion, and a vertical toner carrying screw 82 is provided in the vertical rising portion. Of these two screws, the horizontal toner transport screw 8
1 is rotationally driven in the arrow X direction by a drive system (not shown) via a gear, and conveys the toner 41 in the delivery pipe 52 to a vertically rising portion of the delivery pipe 52. In this rotation drive, the tip of the shaft 81a of the horizontal toner carrying screw projects outward from the delivery pipe 52 at the downstream end in the toner carrying direction, and the gear provided at the tip of the shaft 81a of the vertical toner carrying screw By engaging with a gear provided at the tip, the rotation direction is changed by 90 degrees and the change is transmitted to the vertical toner conveying screw 82. The vertical toner carrying screw 82 is rotationally driven in the direction of the arrow Y and is provided up to the uppermost part of the vertically rising portion of the delivery pipe 52.
The toner 41 sent from the horizontal part by rotation is carried to the uppermost part of the sending pipe 52. The toner 41 that has reached the uppermost portion is pushed out by the toner 41 that is sent later, further advances in the delivery pipe 52 to the downstream side in the transport direction, passes through the U-turned portion, falls downward, and passes through the communication portion. And then supplied to the developing unit.

FIG. 9 shows a modified example in the vicinity of the communicating portion of the delivery pipe 52 with the developing unit in FIGS. 8 (a), 8 (b) and 8 (c). In this example, instead of making the sending pipe 52, which has once risen, make a U-turn and communicating with the developing unit when it goes down a little, it is made to communicate with the developing unit at the uppermost part of the sending pipe 52. Toner transport screws 81, 82 provided inside
The shape and drive system of are the same as those described with reference to FIG. In this example, the delivery pipe 52 is bent 90 degrees at the uppermost portion of the vertical rising portion, the toner conveying path is extended in the horizontal direction, and the tip portion thereof is closed. Then, an opening is provided in the lower part of the extended delivery pipe 52, and this opening is connected to the developing unit, and the toner 41 is supplied from this to the developing unit.

10 (a) and 10 (b), the horizontal portion and the vertical rising portion of the delivery pipe 52 are integrally formed by bending one pipe. Sending pipe 5
2 has an end portion press-fitted and attached inside an opening formed in the bottom portion of the toner hopper unit 40, extends horizontally along the bottom surface portion of the toner hopper unit 40, and further rises along the side surface portion. , Is in communication with the developing unit in a shape protruding toward the developing unit at the uppermost portion. Although not shown, inside the delivery pipe 52, a flexible coil spring or the like as a toner conveying member extending from the upstream end of the horizontal portion in the toner conveying direction to the uppermost portion of the vertical rising portion is provided. The toner 41 is provided and rotated by a drive system (not shown) to convey the toner 41 in the delivery pipe 52 to the uppermost portion. The uppermost toner 41 is pushed out by the toner 41 sent later, further moves to the downstream side in the toner conveying direction, passes through the communicating portion, and is replenished to the developing unit.

Further, a toner conveying method for effectively preventing a large amount of toner 41 from flowing out to the developing unit side will be described. Therefore, in FIG. 8B, the uppermost part of the delivery pipe 52 is provided so as to be located above the uppermost surface 41a of the toner 41 when the maximum amount of the toner 41 is stored in the toner hopper unit 40. There is. Also,
This configuration can also be applied to other embodiments in which the delivery pipe 52 is provided with a rising portion.

Next, with reference to FIGS. 11 (a), 11 (b) and 12, a configuration will be described in which the toner supply unit can be laid out at a desired position of the developing device. Here, for example, a configuration in which the toner supply unit is arranged above the developing device will be described. FIG. 12 is a cross-sectional view of the toner hopper unit 40 and the delivery pipe 52 as seen from the side A of FIG. The delivery pipe 52 of this example has an end press-fitted and attached inside an opening formed in the bottom of the toner hopper unit 40, extends horizontally along the bottom surface of the toner hopper unit 40, and further has side surface portions. Along the top, makes a U-turn at the uppermost portion, extends downward, and projects downward toward the developing unit at the lower portion of the toner hopper unit 40. The tip of the pipe 52 having a shape projecting to the developing unit side is moved to the connecting position of the toner hopper unit 40 with the developing unit side, so that the developing unit side pipe connecting portion 120 including the guide portion 121 (see FIG. 12). ) Inside, and the inside of the toner hopper unit and the inside of the developing unit come to communicate with each other. As shown in FIG. 12, the inside of the delivery pipe 52 passes from the upstream end of the horizontal portion in the toner transport direction to the uppermost portion of the vertical rising portion, and further to the descending portion of the delivery pipe 52 on the downstream side in the toner transport direction. A flexible toner carrying screw 83 is provided. The shaft of the upstream end of the toner carrying screw 83 in the toner carrying direction projects to the outside and is rotationally driven by a drive system (not shown) to carry the toner 41 in the delivery pipe 52 to the uppermost part. With the above configuration, the toner 41 is supplied from the lower portion of the toner hopper unit 40 to the developing unit, so that the toner supply unit including the toner hopper unit 40 can be arranged above the developing unit. Further, the shape of the delivery pipe 52 can be freely formed so that the supply unit can be arranged at a desired position in the image forming apparatus.

Here, in the above-described embodiment, the structure in which the engaging portions of the toner hopper unit and the developing unit, which have been conventionally adopted during the toner replenishing work, are separated or re-engaged, is used. The present invention can also be applied to the case where toner is replenished while the hopper unit and the developing unit are engaged with each other.

[0046]

According to the present invention, since the liquid toner does not flow to the downstream side of the toner transport path from the portion where the toner transport path is formed high, the toner replenishment work time from the supply unit to the developing unit There is an excellent effect that the liquid toner can be prevented from flowing out to the developing unit side with a simple configuration in which the toner conveying path is directed upward without causing a long time.

In particular, according to the second aspect of the present invention, even if the liquid toner has a high fluidity like water, the position of the toner conveying path is higher than the toner height when the toner is accommodated in the toner container at maximum. Since it does not flow to the developing unit, there is an excellent effect that it is possible to more reliably prevent the toner having extremely high fluidity from flowing out to the developing unit.

In particular, according to the third aspect of the invention, since the communicating portion with the developing unit can be provided at a desired position on the toner transport path, the supply unit can be laid out at a desired position with respect to the developing unit. Therefore, there is an excellent effect that the size of the image forming apparatus can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a color copying apparatus according to an embodiment.

FIG. 2 is a schematic configuration diagram of a photoconductor, a developing unit, and a toner hopper unit of the photoconductor as viewed from a direction perpendicular to an axial direction of the photoconductor.

FIG. 3 is a front view showing a schematic configuration of a drive system of the toner hopper unit.

FIG. 4A is a front view showing a schematic configuration of an agitator.
(B) is a side view of the agitator shown in (a).

5A to 5F are explanatory views of toner replenishing work to a toner hopper unit.

FIG. 6A is a schematic configuration diagram of a toner feeding / replenishing unit of the toner hopper unit. FIG. 6B is an explanatory diagram before connecting the toner hopper unit and the developing unit. FIG. 6C is an explanatory diagram when the toner hopper unit and the developing unit are connected. FIG. 6D is an explanatory diagram when toner is replenished after the toner hopper unit and the developing unit are connected.

FIG. 7 is a schematic configuration diagram of a slide mechanism of the toner hopper unit.

FIG. 8A is a front view of the toner hopper unit according to the embodiment on the toner transport path side. FIG. 6B is a side view of the toner hopper unit. FIG. 7C is a layout diagram of the toner transport screw in the toner transport path.

FIG. 9 is a modified example of the communication portion of the toner conveying path with the developing unit according to the embodiment.

10A and 10B are other modifications of the toner transport path according to the embodiment.

FIG. 11A is a front view of a toner conveyance path according to another embodiment. FIG. 6B is a side view of the toner transport path.

FIG. 12 is a sectional view taken along line A in FIG.

[Explanation of symbols]

 14 Bk Developing Unit 40 Toner Hopper Unit 41 Replenishment Toner 41a Toner Height at Maximum Toner Storage 42 Toner Conveying Screw 42a Toner Conveying Screw Shaft 42b Toner Conveying Screw Wing 52 Outlet Pipe 81 Horizontal Toner Conveying Screw 82 Vertical Toner Conveying Screw

Claims (3)

[Claims] 1. A developing unit and a toner in a toner container are conveyed by a toner conveying member disposed inside a toner conveying path, and are supplied to the developing unit from a communicating portion between the toner conveying path and the developing unit. An image forming apparatus including a supply unit, wherein an upper portion of the toner conveying path is formed on a downstream side of the toner conveying path. 2. The image forming apparatus according to claim 1, wherein a part of the toner conveying path is made higher than a toner height when a maximum amount of toner is accommodated in the toner container. 3. The toner carrying member is made of a flexible material, and the toner carrying member extends to the downstream side of the toner carrying path with respect to the highest part of the toner carrying path. 3. The image according to claim 1, wherein the communication portion between the toner transport path and the developing unit is provided at a desired position on the downstream side of the toner transport path with respect to the highest part of the toner transport path. Forming equipment.