JP2003156944A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus in which bringing down of the cost can be achieved by eliminating space for a detecting means for each unit and the cost by having a toner full detecting means carrying out the detection of the existence of an intermediate transfer unit or a cleaning unit as well and simplifying the construction. SOLUTION: When a cleaning unit 23 is not loaded, the absence of the cleaning unit 23 is detected by constituting so that an optical path of the toner full detecting sensor 52 is intercepted by a flag 56a of a shutter 56.

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 or a printer which uses an electrophotographic system or an electrostatic recording system.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an intermediate transfer member has been widely used as an image forming apparatus having a full-color or multiple image forming function. In this type of image forming apparatus, an image carrier such as an electrophotographic photosensitive member or an electrostatic recording dielectric member is provided with a component color toner corresponding to a plurality of color component images of a target full color image or multiple images by an appropriate image forming process means. Images are sequentially formed, and toner images of these component colors are sequentially superimposed and transferred to an intermediate transfer member, which is generally a rotating belt type, at a primary transfer portion, and thereby a desired full-color image or a multiplex image is formed on the intermediate transfer member. A full-color toner image and a multi-toner image corresponding to the image are compositely formed. Then, a full-color image-formed product is obtained by introducing a toner image of synthetic formation onto the intermediate transfer member from the secondary transfer unit to the fixing unit to fix the image.

The structure of a conventional image forming apparatus using an intermediate transfer belt as an intermediate transfer member will be described with reference to FIG. FIG. 16 is a cross-sectional explanatory view showing the structure of the intermediate transfer belt. Component color toner images corresponding to a plurality of color component images formed on the photoconductor drum 101 serving as an image carrier are sandwiched between the photoconductor drum 101 and the primary transfer counter roller 102.
The target full-color image is formed on the intermediate transfer belt 103 by sequentially superposed and transferred at the next transfer portion T ₁ .

A full-color image on the intermediate transfer belt 103 is collectively transferred onto a transfer material P at a secondary transfer portion T ₂ sandwiched by a secondary transfer roller 116 and a secondary transfer counter roller 105, and is transferred by a fixing portion (not shown). By fixing the image, a full-color image-formed product is obtained.

The intermediate transfer belt 103 is stretched around three axes of a driving roller 104, a secondary transfer counter roller 105 and a tension roller 106, and a compression spring 108 presses a bearing 107 of the swingable tension roller 106. Thus, the tension of the intermediate transfer belt 103 can be kept constant.

A cleaning unit 11 for cleaning the residual toner remaining on the intermediate transfer belt 103 without being transferred by secondary transfer around the intermediate transfer belt 103.
Three are provided. The cleaning unit 113 is provided with a cleaning blade 111 that is in contact with the intermediate transfer belt 103 at a predetermined angle as a cleaning unit.

The cleaning blade 111 is held in the cleaning container 110, and the cleaning blade 111 is
A tension roller 106 is arranged as a backup roller at the opposing portion of. The cleaning container 110 is fitted in a positioning portion (not shown) provided in the intermediate transfer belt unit 109 so as to be positioned and fixed, and detachable.

Since the cleaning container 110 is configured to be attachable to and detachable from the intermediate transfer belt unit 109, the cleaning blade 111 and the intermediate transfer belt 103 are separately replaced at the end of their respective lives without being influenced by their respective lives. It is possible and economical.

A waste toner carrying screw 112 for carrying the waste toner collected by the cleaning blade 111 is arranged in the cleaning container 110, and the waste toner carried by the waste toner carrying screw 112 is transferred to the main body of the image forming apparatus. The waste toner container 115, which is arranged separately from the cleaning container 110, is conveyed and stored through the arranged connecting member 114.

Further, there is provided a toner filling sensor (not shown) for detecting the filled state so that the waste toner collected in the waste toner container 115 does not overflow from the waste toner container 115. Further, sensors (not shown) for detecting that the intermediate transfer belt unit 109, the cleaning unit 113, and the waste toner container 115 are properly attached to the image forming apparatus body correspond to the image forming apparatus body. It is arranged.

[0011]

However, in the above-mentioned conventional example, the intermediate transfer belt unit 109, the cleaning unit 113, and the waste toner container 115 are replaced by each user for each unit, so that replacement by life or other units is performed. When replacing the unit, there is a risk that the unit will be temporarily removed and then forgotten. If the unit is forgotten, good output cannot be obtained, and in the worst case, other normal units or the main body of the image forming apparatus may be damaged. In order to prevent such a problem, a detection unit such as a sensor for detecting that each unit is properly mounted is provided in each unit.

If each unit is provided with a detection means such as a sensor individually, a space and a cost for the detection means are required, and there is a problem that the structure becomes complicated and the cost is increased.

The present invention is to solve the above problems,
The purpose of this is to reduce the space and cost of the detection means of each unit by also using the toner filling detection means to detect the presence or absence of the intermediate transfer unit or the cleaning unit, and to achieve cost reduction with a simple structure. The purpose of the present invention is to provide an image forming apparatus that can be used.

[0014]

A typical structure of an image forming apparatus according to the present invention for achieving the above object is an image carrier carrying a toner image, and a toner formed on the image carrier. An intermediate transfer unit having an intermediate transfer body to which an image is transferred, a cleaning means for removing the residual toner on the intermediate transfer body, and a toner carrying means for carrying the residual toner collected by the cleaning means to a toner collecting container. A cleaning unit having: a toner collecting container; a sealing unit provided at a toner inlet of the toner collecting container to prevent the toner once collected in the toner collecting container from leaking out of the toner collecting container; And a toner filling detection unit that detects that the toner is full, and the cleaning unit is independent of the intermediate transfer unit. And the cleaning unit is positioned and fixed with respect to the intermediate transfer unit, and the presence or absence of the intermediate transfer unit and / or the cleaning unit can be detected by the toner filling detection unit. Characterize.

Since the present invention is configured as described above, for example, if both the intermediate transfer unit and the cleaning unit are not mounted in a proper state, the sealing means provided at the toner inlet of the toner recovery container is used. It is possible to detect that the mounting state of the intermediate transfer unit and the cleaning unit is incomplete by configuring so as not to open and warning is given by the toner filling detection unit when the sealing unit is closed. I can.

Therefore, the toner filling detecting means can detect the toner filling as well as the presence / absence of the intermediate transfer unit and the cleaning unit. Therefore, the space and cost of the detecting means of each unit can be reduced and the structure can be simplified. The cost can be reduced.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in the case of being applied to a color laser printer as an example of an image forming apparatus according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a sectional explanatory view showing the constitution of an image forming apparatus according to the present invention, FIG. 2 is a sectional explanatory view showing the arrangement constitution of an intermediate transfer unit and a cleaning unit, and FIG. 3 is a constitution of a contact / separation means of the intermediate transfer unit. FIG. 4 is a perspective explanatory view showing the structure of the contact / separation means of the intermediate transfer unit, and FIG. 5 is a perspective explanatory view showing the mounting structure of the intermediate transfer unit and the cleaning unit.

Further, FIG. 6A is a sectional explanatory view showing a state in which the cleaning unit is in the attachment / detachment position, FIG. 6B is a sectional explanatory view showing a state in which the cleaning unit is being attached, and FIG. 7B is a sectional explanatory view showing a state in which the cleaning unit is mounted, and FIG. 7B is a sectional explanatory view showing a state in which the cleaning unit is released from the intermediate transfer unit.

FIG. 8 is a plan view showing the structure of the cleaning unit, FIG. 9 is a front view showing the arrangement of the toner collecting container, the cleaning unit and the toner filling detecting means, and FIG. 10 is the toner collecting container and the cleaning unit. FIG. 11 is a cross-sectional explanatory view showing a state in which is mounted, FIG. 11 is a cross-sectional explanatory view showing a connection state between the toner recovery container and the cleaning unit, and FIG.

Further, FIG. 13 is a front explanatory view showing a state where only the toner collecting container is set in the image forming apparatus main body, and FIG.
FIG. 15 is a sectional explanatory view showing a state in which only the toner recovery container is set in the image forming apparatus main body, and FIG. 15 is a sectional explanatory view showing a state in which the toner recovery container is about to be mounted.

First, the overall configuration of the image forming apparatus according to the present invention will be described with reference to FIG. In FIG. 1, an image forming apparatus A, which is a color laser printer, has a yellow,
Photoreceptor drum 1 (1 _Y , 1 _M , 1 _C , which becomes an image carrier that rotates at a constant speed for each color of magenta, cyan, and black,
1 _K ) and a developing unit 4 (4 _Y , having a developing unit for each color)
4 _M , 4 _C , 4 _K ) and an image forming section, in which the color images developed and multiply transferred in the image forming section are held.
An intermediate transfer unit 13 having an intermediate transfer belt 18 which serves as an intermediate transfer member for further transferring to the transfer material P fed from the transfer material feeding portion is provided.

The transfer material P onto which the color image has been transferred from the intermediate transfer belt 18 is conveyed to the fixing section 38 to fix the color image, and then the upper surface of the main body of the image forming apparatus A by the discharge roller pairs 41 to 43 and 58. The sheet is discharged onto the discharge tray 44 or the discharge tray 2. 4 color developing units 4 _Y , 4 _M ,
4 _C and 4 _K are detachably attached to the main body of the image forming apparatus A, respectively.

The photosensitive drum 1, which serves as an image bearing member for bearing a toner image, includes a developing container 3 (3 _Y , 3 _Y ,
3 _M , 3 _C , 3 _K ) and the developing unit 4
Is detachably supported on the main body of the image forming apparatus A, and each unit can be easily replaced according to the life of the photosensitive drum 1.

The photosensitive drum 1 is constructed by coating an organic photoconductive layer on the outer side of an aluminum cylinder, and is rotatably supported by a developing container 3 holding the photosensitive drum 1. Then, by transmitting the driving force of a drive motor (not shown) provided on the rear side of the paper surface of FIG.
Is rotated in the counterclockwise direction in FIG. 1 in accordance with the image forming operation.

Charging roller 3a (3 _{Y a} , 3
_{M a} , 3 _{C a} , 3 _{K a} ) uses a roller charging method, and uniformly charges the surface of the photosensitive drum 1 by applying a charging bias voltage to the charging roller 3a. is there.

The exposure of the photosensitive drum 1 is performed by the scanner unit 6 (6 _Y , 6 _M , 6 _C , 6 _K ) which serves as an exposing means.
That is, when the image signal is given to the laser diode, the laser diode irradiates the polygon mirror 6a (6 _Ya , 6 _Ma , 6 _Ca , 6 _Ka ) with the image light corresponding to the image signal.

The polygon mirror 6a is rotated at a high speed by a scanner motor, and the image light reflected by the polygon mirror 6a is rotated at a constant speed via an imaging lens 6b (6 _Yb , 6 _Mb , 6 _Cb , 6 _Kb ). The surface of the body drum 1 is selectively exposed, and as a result, an electrostatic latent image is formed on the photoconductor drum 1.

The developing means is a developing unit 4 for visualizing the electrostatic latent image formed on the surface of the photosensitive drum 1.
And a developing device capable of developing each color of yellow, magenta, cyan and black. In each of the four color developing devices, a developing sleeve 5 (5 _Y , 5 _M , 5 _C , 5 _K ) is arranged at a position facing the photoconductor drum 1 with a minute interval with respect to each photoconductor drum 1. A visible image is formed on the photosensitive drum 1 by the toner of each color.

The developing device in the developing unit 4 for each color sends the toner in the developing container 3 by the toner feeding mechanism, and the powder obtained by mixing the non-magnetic toner and the magnetic developer to the outer circumference of the developing sleeve 5 is rotated clockwise in FIG. The outer circumference of the developing sleeve 5 rotating in the direction is coated. After that, the toner in the powder is developed according to the electrostatic latent image on the photosensitive drum 1.

The intermediate transfer belt 18, which serves as an intermediate transfer member, is provided for multiple transfer of the toner images on the photosensitive drum 1 visualized by the developing device of each developing unit 4 during the color image forming operation. The intermediate transfer belt 18, which rotates in the clockwise direction in FIG. 1 in synchronism with the outer peripheral speed of the drum 1, undergoes multiple transfer and sandwiches the transfer material P with the secondary transfer roller 22 to which a transfer bias voltage is applied. By being conveyed, the toner images of respective colors on the intermediate transfer belt 18 are simultaneously and multiple-transferred onto the transfer material P.

The intermediate transfer belt 18 of this embodiment is formed of a resin belt having a peripheral length of about 1000 mm, and the driving rollers 14, 2
It is stretched by three axes of the next transfer opposing roller 15 and the tension roller 16, and the compression spring 19 is applied to both ends of the tension roller 16, so that the circumference of the intermediate transfer belt 18 changes with temperature and humidity in the main body of the image forming apparatus A and changes with time. Even if it changes due to, it is configured to be able to absorb the amount of change.

The intermediate transfer belt 18 is supported by the main body of the image forming apparatus A with the driving roller 14 as a fulcrum.
The intermediate transfer belt 18 is configured to rotate in the clockwise direction of FIG. 1 in accordance with an image forming operation by transmitting the driving force of a drive motor (not shown) provided at the rear of the paper surface of FIG. Further, the intermediate transfer belt 18 can be attached and detached rightward in FIG.

The sheet feeding section provided in the lower portion of the image forming apparatus A feeds the transfer material P to the image forming section, and includes a sheet cassette 7 containing a plurality of transfer materials P,
A feeding roller 8 for feeding the transfer material P from the sheet cassette 7, a retard roller pair 9 for separating and feeding the transfer material P fed by the feeding roller 8, a feeding guide 11, a registration roller pair 12, and a conveyance. It is configured to have a pair of rollers 10 and the like.

At the time of image formation, the feeding roller 8 and the retard roller pair 9 are rotationally driven in accordance with the image forming operation to separate and feed the transfer materials P in the sheet cassette 7 one by one, and the feeding guide 11 as well. It is guided by and is inverted, and reaches the registration roller pair 12. This registration roller pair
Reference numeral 12 denotes an image at the time of the secondary transfer process, in which a non-rotating operation for holding the transfer material P in a stationary state during the image forming operation and a rotating operation for transporting the transfer material P toward the intermediate transfer belt 18 are controlled at a predetermined timing. And the transfer material P are aligned.

The secondary transfer portion T ₂ are being configured with a pivotable secondary transfer roller 22, the secondary transfer roller 22 and below the Figure 1 by winding a medium-resistance foamed elastic body on a metal shaft It is configured to be movable in any direction. While four color toner images are formed on the intermediate transfer belt 18, that is, the intermediate transfer belt 18
The secondary transfer roller 22 is retracted to the lower position shown by the broken line in FIG. 1 and separated from the intermediate transfer belt 18 so as not to disturb the image until the upper toner image reaches the secondary transfer portion T ₂ . .

Thereafter, the secondary transfer roller 22 is transferred to the intermediate transfer belt 18 via the transfer material P at an upper position shown by the solid line in FIG. 1 by a cam member (not shown) at the timing of transferring the color image onto the transfer material P. It is pressed with a predetermined pressure.

At this time, a transfer bias voltage is simultaneously applied to the secondary transfer roller 22 so that the toner image on the intermediate transfer belt 18 is transferred onto the transfer material P. Where the intermediate transfer belt
Since the 18 and the secondary transfer roller 22 are both rotationally driven, the transfer material P sandwiched between the two is simultaneously conveyed at a predetermined speed in the left direction in FIG.
It is sent toward the fixing unit 38.

The cleaning unit 23 for removing the residual toner on the intermediate transfer belt 18 includes a cleaning blade 24 as a cleaning means and a compression spring for pressing the cleaning blade 24 against the intermediate transfer belt 18.
29, and a cleaning container 27 for holding them and the like.

The cleaning blade 24 is made of polyurethane rubber so that a metal plate is sandwiched between the cleaning blade 24 and the swing shaft 25 held in the cleaning container 27 as a rotation center. Since they are pressed against each other, they can evenly contact the intermediate transfer belt 18.

A tension roller 16 is arranged as a backup roller on the opposite side of the cleaning blade 24, and the cleaning blade 24 can contact the intermediate transfer belt 18 with a predetermined contact pressure.

When the cleaning blade 24 comes into contact with the intermediate transfer belt 18, the residual toner is scraped off from the intermediate transfer belt 18 to clean the intermediate transfer belt 18. The waste toner scraped off by the cleaning blade 24 is a cleaning container.
A waste toner carrying screw which is collected in 27 and serves as a toner carrying means arranged at the bottom of the cleaning container 27.
By 28, it is sent to and collected by a waste toner bottle 37 which is a toner collection container separately arranged in the main body of the image forming apparatus A.

The waste toner carrying screw 28 is configured to rotate in the carrying direction of the waste toner carrying screw 28 by transmitting a driving force of a drive motor (not shown) to the rear side of the paper surface of FIG.

The fixing unit 38 is a developing unit 4 which serves as a developing means.
The toner image formed on the transfer material P is fixed via the intermediate transfer belt 18 by the fixing roller 39 for applying heat to the transfer material P, as shown in FIG. And a pressure roller 40 for pressing the transfer material P to the fixing roller 39.

The fixing roller 39 and the pressure roller 40 are hollow rollers, each having a heater (not shown) therein. Then, the rotational driving force is transmitted from a driving source (not shown) to rotate the toner, and the toner image is fixed while the transfer material P is nipped by the fixing roller 39 and the pressure roller 40 and is conveyed while being heated and pressed.

Next, the operation when an image is formed by the image forming apparatus A having the above structure will be described. First, Fig. 1
The transfer material P in the sheet cassette 7 is fed out by rotating the feeding roller 8 shown in FIG. 1, and is separated and fed one by one by the retard roller pair 9 and conveyed to the registration roller pair 12.

On the other hand, the photosensitive drum 1 and the intermediate transfer belt 18
And the photosensitive drum 1 rotate counterclockwise in FIG. 1 at predetermined peripheral speeds (process speeds), respectively, and the intermediate transfer belt 18
Rotates in the clockwise direction in FIG.

[0047] When the arbitrary point periphery of an intermediate transfer belt 18 comes to a position S in FIG. _{1 (S 1, S 2,} S 3, S 4), a charging unit charging roller 3a (3 _{Y a} , 3 _{M a} , 3 _{C a} ,
Photoreceptor drum 1 whose surface is uniformly charged by 3 _{K a} )
(1 _Y , 1 _M , 1 _C , 1 _K ) is the exposure position E (E _Y , E _M ,
E _C , E _K ) receives a laser exposure to form an electrostatic latent image,
Each color developing unit 4 supplies each color toner to form a toner image of each color.

Exposure position E (E _Y , E _M ,
From E _C , E _K ) in the counterclockwise direction in FIG. 1, the primary transfer portion T ₁ (T _1Y , T _1M , T _1C , T) which is a contact portion with the intermediate transfer belt 18
A distance L ₁ to _1K), the position S of the intermediate transfer belt 18
From (S ₁ , S ₂ , S ₃ , S ₄ ) to the primary transfer portion T ₁ (T _1Y ,
The distances L _{2 to} T _1M , T 1C, T _1K ) are configured to be equal to each other, so that the exposure position E (E _Y , E _M , E _C , E) at the beginning of image writing after a predetermined time has elapsed. _K ) and the position S (S ₁ , S ₂ , S ₃ , S ₄ ) on the intermediate transfer belt 18 are 1
The positions of the next transfer portions T ₁ (T _1Y , T _1M , T _1C , T _1K ) coincide with each other. That is, the image is at the position S with respect to the intermediate transfer belt 18.
It is formed counterclockwise in FIG. 1 with (S ₁ , S ₂ , S ₃ , S ₄ ) at the tip.

In the above structure, when a yellow image is formed, the surface of the photosensitive drum 1 _Y uniformly charged by the scanner unit 6 _Y is irradiated with laser light of the yellow image to form an electrostatic latent image of the yellow image. Form. The charging polarity of the photosensitive drum 1 _Y as yellow toner to the electrostatic latent image on the electrostatic latent photosensitive drum 1 by driving the yellow developing device of the yellow developing unit 4 _Y simultaneously with the formation of image _Y adheres Yellow development is performed by applying voltages having the same polarity and substantially the same potential.

At the same time, the primary transfer portion T slightly downstream of the developing portion
_{At 1Y} , the yellow toner image on the photosensitive drum 1 is primarily transferred onto the outer circumference of the intermediate transfer belt 18. At this time, a transfer bias voltage having a polarity opposite to that of the yellow toner is applied to the intermediate transfer belt 18 to perform the primary transfer. Here, the image to be formed is A
In the case of 3 sizes, the length is 420 mm, and the intermediate transfer belt
An image is formed from the outer peripheral position S _{1 of} 18 to a position having a length corresponding to this.

Next, when forming a magenta image,
Similarly, when the outer peripheral position S ₁ (front end of the yellow image) of the intermediate transfer belt 18 reaches the outer peripheral position S ₂ , the scanner unit 6 _M
The laser irradiation of the magenta image is started by the above, the magenta toner image is developed on the electrostatic latent image on the photoconductor drum 1 _M in the same manner as the above-mentioned yellow, and the magenta toner image on the photoconductor drum 1 _M is primarily transferred. Intermediate transfer belt 18 at section T _1M
The magenta toner image is transferred on top of the yellow toner image.

Next, when a cyan image is to be formed, when the outer peripheral position S ₁ of the intermediate transfer belt 18 (the leading ends of the yellow image and the magenta image) reaches the outer peripheral position S ₃ , the cyan image is similarly scanned by the scanner section 6 _C. Laser irradiation of the image is started, the cyan toner image is developed on the electrostatic latent image on the photoconductor drum 1 _C in the same manner as the magenta described above, and the cyan toner image on the photoconductor drum 1 _C is transferred to the primary transfer portion T. _{At 1C} , the cyan toner image is transferred onto the intermediate transfer belt 18 so as to be superimposed on the yellow and magenta toner images.

Next, when forming a black image,
When the outer peripheral position S ₁ of the intermediate transfer belt 18 (the leading ends of the yellow image, the magenta image, and the cyan image) reaches the outer peripheral position S ₄ , similarly, the laser irradiation of the black image is started by the scanner unit 6 _K and the above-mentioned cyan image is generated. Similarly the black toner image developed on the electrostatic latent image on the photosensitive drum 1 _K, yellow on the intermediate transfer belt 18 the black toner image on the photosensitive drum 1 _K at the primary transfer portion T _1K, magenta, A black toner image is transferred so as to be superimposed on each cyan toner image.

As described above, the formation of the electrostatic latent image in the order of yellow, magenta, cyan, and black, the development, and the transfer of the toner image onto the intermediate transfer belt 18 are performed in the respective primary transfer portions T _1Y , T ₁ .
T _1M , T _1C , and T _1K are performed to form a full-color image on the surface of the intermediate transfer belt 18 with four types of toners of yellow, magenta, cyan, and black.

Before the transfer of the black toner to the intermediate transfer belt 18 is completed, that is, the black toner of the fourth color is
The transfer material P that has been kept on standby by the above-mentioned registration roller pair 12 before the outer peripheral position S _{1 which} is the image front end of the intermediate transfer belt 18 on which the full-color image has been formed after the completion of the secondary transfer reaches the secondary transfer portion T ₂ . The conveyance is started at the same timing.

When an image of each color is formed on the intermediate transfer belt 18 of the above four colors, the intermediate transfer belt 18 is retracted downward in FIG.
The secondary transfer roller 22 that was in a non-contact state is simultaneously moved upward in FIG. 1 by a cam (not shown) to press the transfer material P at the secondary transfer portion T ₂ of the intermediate transfer belt 18 and at the same time the secondary transfer is performed. By applying a transfer bias voltage having a polarity opposite to that of the toner to the roller 22, the full color image on the intermediate transfer belt 18 is transferred onto the transfer material P at once in four colors.

The transfer material P that has passed through the secondary transfer portion T ₂ is peeled from the intermediate transfer belt 18 and conveyed to the fixing portion 38, and after the toner is fixed, the discharge path is switched by the flapper 57 and the image forming apparatus A is formed. If the paper is discharged face down to the discharge tray 44 provided at the top of the
Is guided to the discharge roller pair 41, 42, 43 by the discharge tray 44
Discharged on top.

When the sheet is discharged face-up onto the discharge tray 2, the flapper 57 guides it to the discharge roller pair 58 and discharges it onto the discharge tray 2.

In FIG. 2, the intermediate transfer belt 18 includes a driving roller 14, a secondary transfer counter roller 15 and a tension roller.
The tension roller 16 is stretched by three axes of 16
The bearing members 17a and 17b of the intermediate transfer belt 18 are pressed by a compression spring 19 so as to absorb changes in the circumferential length of the intermediate transfer belt 18 due to temperature and humidity in the main body of the image forming apparatus A and changes with time.

Further, the rotation driving force of a drive motor (not shown) provided at one end portion on the rear side of the paper surface of FIG.
2 is transmitted to the intermediate transfer belt 18 at a predetermined peripheral speed in the clockwise direction in FIG. 2 according to the image forming operation.

As shown in FIG. 3 and FIG. 4, the intermediate transfer unit 13 in which the intermediate transfer belt 18, the driving roller 14, the secondary transfer counter roller 15, the tension roller 16 and the like are integrally unitized is an image forming apparatus. A lever 47 is fixed to a predetermined position shown in FIG. 3 by a stay 47 arranged on the main body side plate 53 of the A main body, four cams 48, a shaft 46 connecting the two stays 47, and a contact / separation means constituted by a lever 45. By moving to the contact position α and the separation position β respectively, the four cams 48 move the intermediate transfer unit.
By moving 13 up and down, it is possible to create a contact state and a separated state.

As shown in FIG. 2, a cleaning blade 24 for cleaning the intermediate transfer belt 18 is arranged in the cleaning container 27 at a portion facing the tension roller 16, and an intermediate portion around a swing shaft 25 as a rotation center. Transfer belt 18
Is held so as to abut at a predetermined angle.

The cleaning blade 24 is a compression spring.
It is configured to come into contact with each other with a predetermined contact pressure by 29. The cleaning blade 24 is fixed to the blade holding plate 26.

As shown in FIG. 5, the bearing members 17a and 17b of the tension roller 16 that stretches the intermediate transfer belt 18 are provided with bosses 20a for positioning the cleaning unit 23.
Two 20b are arranged facing each other. Boss 20a, 20b
Is integrally formed with the bearing members 17a and 17b at both ends of the tension roller 16, and even if the tension roller 16 moves, the shaft 16a of the tension roller 16 and the bosses 20a and 20b at both ends are formed.
It is always kept parallel to the axis 20c of b.

Bearing member 17b arranged rearward of the plane of FIG.
The screw drive input 34 of the cleaning unit 23
A round long hole 21 into which is inserted is formed, and when the cleaning unit 23 is set, the round long hole 21 serves as a rotation stop.

The cleaning unit 23 is provided with a detent member 30 arranged on the front side of the paper surface of FIG. 5, and a bearing member arranged on the front side of the paper surface of FIG. 5 in a hole 30a formed on the detent member 30. The boss 17c provided on the 17a is inserted and the detent member 30 is positioned by the bearing member 17a.

Further, the positioning grooves 31a and 31b provided in the cleaning unit 23 are fitted into the bosses 20a and 20b,
Further, the cleaning unit 23 can be positioned and fixed to the intermediate transfer unit 13 by the latches 32a and 32b.

As a method of setting the cleaning unit 23, as shown in FIGS. 6 to 8, the cleaning unit 23 is separated from the main body of the image forming apparatus A in a direction orthogonal to the traveling direction of the intermediate transfer belt 18 as shown in FIGS. It is inserted from the front side of the paper, and is pushed in until it hits an abutting part (not shown) on the back side of the intermediate transfer unit 13 in FIGS. 6 and 7.

Then, in the pushed state, as shown in FIG.
As shown in FIG. 6B, holding the lever 36 provided in the cleaning unit 23, the cleaning unit 23 is placed around the shaft of the waste toner carrying screw 28 in FIG.
It is rotated clockwise in (b) and pushed up until the latches 32a, 32b are caught by the bosses 20a, 20b, and then mounted.

On the contrary, when removing the cleaning unit 23, as shown in FIG. 7 (b), the levers 36 are rotated in the directions of the arrows so that the latches 32a, 32b are brought into contact with the bosses 20a, 20b.
, The cleaning unit 23 is separated, and the cleaning unit 23 is pulled out to the front side of the paper surface of FIG. 7B. As a result, the cleaning unit 23 can be replaced independently of the intermediate transfer unit 13.

In FIG. 9, the waste toner 51 collected by the cleaning blade 24 is transported to the front side of the paper surface of FIG. The waste toner bottle 37 is dropped and collected from the connection portion of the toner bottle 37.

The waste toner carrying screw 28 is rotated by the rotation driving force transmitted from a driving motor (not shown) to the screw driving input portion 34 shown in FIG. Waste toner transport screw
The drive source of 28 is also used as a fixing drive source such as the fixing roller 39 of the fixing unit 38, thereby reducing the number of drive motors and simplifying the structure.

As shown in FIGS. 9 to 15, a waste toner bottle
The reference numeral 37 designates a waste toner inlet 37a which serves as a toner inlet above the waste toner bottle 37 which serves as a toner recovery container while being retained by the waste toner bottle holding member 50 disposed on the main body side plate 53 of the image forming apparatus A main body. Waste toner outlet 27 that serves as a toner outlet for the cleaning container 27 of the cleaning unit 23
It is positioned by inserting a and fitting and connecting.

At this time, the waste toner bottle 37 is held by the waste toner bottle holding member 50 with a predetermined gap in the horizontal direction as shown in FIG. 10, and the positioning unit for the cleaning unit 23 and the waste toner bottle 37. Is configured so that the posture of the waste toner bottle 37 can be maintained without affecting the above.

Therefore, the positional change of the tension roller 16 in the left-right direction in FIG. 3 due to the change over time of the intermediate transfer belt 18 and the expansion and contraction due to heat, that is, the waste toner discharge port 27a of the cleaning unit 23 moves in the left-right direction in FIG. Even if the position of the waste toner bottle 37 changes and the connecting portion of the waste toner bottle 37 changes in the left-right direction of FIG. 3, the waste toner bottle holding member 50 can hold the waste toner bottle 37.

The waste toner bottle holding member 50 is configured to be slidable in the vertical direction with respect to the main body side plate 53, and the shaft 49 provided on the stay 47 connected to the lever 45 for contacting and separating the intermediate transfer unit 13 from each other. The contact and separation operation of the intermediate transfer unit 13, that is, the movement of the lever 45, can be moved up and down in synchronization with the intermediate transfer unit 13.

Therefore, the cleaning unit 23 fixed to the intermediate transfer unit 13 and the waste toner bottle 37 held by the waste toner bottle holding member 50 can move together while being connected.

With the above structure, the weight of the waste toner bottle 37, which increases when the waste toner 51 is accumulated in the waste toner bottle 37, can be supported by the waste toner bottle holding member 50, and the cleaning container 27 of the cleaning unit 23 can be supported. The waste toner discharge screw 27a is configured so that an unnecessary external force is applied to the waste toner conveying screw 28 to bend it and cause a noise or an increase in driving torque.

Further, in the contact and separation operation of the intermediate transfer unit 13, the cleaning unit 23 and the waste toner bottle 37 are similarly processed.
It is configured so that no unnecessary external force is applied to the connection part with.

As described above, since the waste toner bottle 37 is configured to move in synchronization with the cleaning unit 23, the cleaning unit 23 can be directly connected to the waste toner bottle 37 without a connecting member, and the number of parts can be reduced. The configuration can be simplified.

Further, since the connecting portion can be fitted, the sealing performance can be improved without using a separate sealing member. Further, as the waste toner bottle 37 moves up and down, vibration is added to the accumulated waste toner 51, the packing density of the waste toner 51 increases, and the waste toner 51 can be collected to the full capacity of the waste toner bottle 37.

Further, the waste toner bottle holding member 50 is provided with a toner filling detection sensor 52 serving as toner filling detection means for detecting that the waste toner bottle 37 serving as a toner collecting container is filled with the waste toner 51. .

The toner fullness detection sensor 52 is a transmission type optical sensor, and as shown in FIGS.
A light emitting portion 52a and a light receiving portion 52b are arranged on both sides near the lower side of a.

The waste toner bottle 37 includes a light emitting portion 52a and a light receiving portion.
The portion on the optical axis connecting to 52b is formed of a transparent member, which allows the sensor light to pass therethrough. The collected waste toner 51 is accumulated in the waste toner bottle 37,
As shown in FIG. 12, when the sensor light of the toner fullness detection sensor 52 is blocked, a warning is given to a display unit such as an operation panel (not shown) so as to replace the waste toner bottle 37.

In the waste toner bottle 37 serving as a toner collecting container, the waste toner 51 once collected in the waste toner bottle 37 when leaked from the main body of the image forming apparatus A leaks out of the waste toner bottle 37 through the waste toner inlet 37a. To prevent this, a shutter 56 is provided as a sealing means at the waste toner inlet 37a.

A sealing member 54 is attached to the shutter 56, and the shutter 56 is provided with a spring 55 to take in the waste toner.
The waste toner intake 37a is completely sealed while being urged by the 37a.

Then, as shown in FIG. 10, the shutter 56, which serves as a sealing means, operates when the waste toner discharge port 27a of the cleaning container 27 of the cleaning unit 23 is inserted into the waste toner intake port 37a of the waste toner bottle 37. Waste toner bottle 37
It is configured to be pushed open along the guides that are arranged in.

As shown in FIGS. 13 and 14, when the shutter 56 is closed, that is, when the shutter 56 is biased by the spring 55 toward the waste toner inlet 37a, the shutter 56 is closed.
A light emitting portion 52a and a light receiving portion 52b which constitute a toner fullness detecting sensor 52 which is an optical sensor by a flag 56a provided on 56.
Is configured to block the optical path of. By providing the shutter 56 with the flag 56a, a simple structure can be obtained.

Therefore, when the cleaning unit 23 is not mounted at a predetermined position in the main body of the image forming apparatus A, the waste toner bottle 37 is set on the waste toner bottle holding member 50 as shown in FIG. Since the shutter 56 does not open, the toner filling detection sensor 52 is in a state where the optical path is blocked, that is, the toner filling state.

Even when the intermediate transfer unit 13 is not attached, the cleaning unit 23 cannot be attached and fixed at a predetermined position, so that the shutter 56 is opened even when the waste toner bottle 37 is set on the waste toner bottle holding member 50. Since the toner fullness detection sensor 52 has no light path, that is, the toner fullness detection sensor 52 is in the toner full state.

At this time, "the attachment of the intermediate transfer unit 13 and the cleaning unit 23 is confirmed, or the waste toner bottle 37
If a warning such as “replace” is displayed on the display screen of the operation panel (not shown), the presence or absence of the intermediate transfer unit 13 and the cleaning unit 23 can be detected by the toner filling detection sensor 52 serving as toner filling detection means.

Therefore, it is not necessary to dispose a sensor only for detecting the presence or absence of each of the intermediate transfer unit 13 and the cleaning unit 23, the number of parts can be reduced, the cost can be reduced, and the configuration can be simplified. You can

[0093]

Since the present invention has the above-mentioned structure and operation, the toner filling detecting means can detect the presence or absence of the intermediate transfer unit and / or the cleaning unit, and therefore the number of sensors can be reduced to reduce the cost. Therefore, the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a configuration of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional explanatory diagram showing an arrangement configuration of an intermediate transfer unit and a cleaning unit.

FIG. 3 is an explanatory cross-sectional view showing a configuration of a contact / separation unit of the intermediate transfer unit.

FIG. 4 is an explanatory perspective view showing a configuration of a contact / separation unit of the intermediate transfer unit.

FIG. 5 is a perspective explanatory view showing a mounting configuration of an intermediate transfer unit and a cleaning unit.

FIG. 6A is a cross-sectional explanatory view showing a state in which the cleaning unit is in the attachment / detachment position, and FIG. 6B is a cross-sectional explanatory view showing a state in which the cleaning unit is being attached.

7A is a sectional explanatory view showing a state in which a cleaning unit is mounted, and FIG. 7B is a sectional explanatory view showing a state of releasing the cleaning unit from the intermediate transfer unit.

FIG. 8 is an explanatory plan view showing a configuration of a cleaning unit.

FIG. 9 is a front view showing the arrangement of a toner recovery container, a cleaning unit, and a toner filling detection unit.

FIG. 10 is an explanatory cross-sectional view showing a state in which a toner recovery container and a cleaning unit are attached.

FIG. 11 is an explanatory cross-sectional view showing a connection state between the toner recovery container and the cleaning unit.

FIG. 12 is a front explanatory view showing a state where the toner collection container is filled with toner.

FIG. 13 is a front view illustrating a state in which only the toner collection container is set in the image forming apparatus main body.

FIG. 14 is a cross-sectional explanatory view showing a state in which only the toner collection container is set in the image forming apparatus main body.

FIG. 15 is an explanatory cross-sectional view showing a state where a toner collection container is about to be mounted.

FIG. 16 is a diagram illustrating a conventional example.

[Explanation of symbols]

A ... Image forming apparatus, E, E_Y, E_M, E_C, E_K… Exposure position
Placement, P ... Transfer material, S, S ₁, S₂, S₃, S_Four... perimeter position,
T₁, T_1Y, T_1M, T_1C, T_1K… Primary transfer part, T₂… Secondary
Transfer part, 1, 1_Y, 1_M, 1_C, 1_K… Photosensitive drums, 2…
Discharge tray, 3,3Y, 3M, 3C, 3K ... Developing container,
3a, 3_Ya, 3_Ma, 3_Ca, 3_Ka... Charging roller, 4,
Four_Y, 4_M, 4_C, 4_K... Development unit, 5, 5_Y, 5_M, 5
_C, 5_K... Development sleeves, 6,6_Y, 6_M, 6_C, 6_K…Love
Trap section, 6a, 6_Ya, 6_Ma, 6_Ca, 6_Ka... Polygon Mira
ー 、 6b 、 6_Yb, 6_Mb, 6_Cb, 6_Kb… Imaging lens, 7…
Sheet cassette, 8 ... Feed roller, 9 ... Retard roller
Pair, 10 ... Conveyor roller pair, 11 ... Feeding guide, 12 ... Registration
Roller pair, 13 ... Intermediate transfer unit, 14 ... Drive roller, 15
… Secondary transfer counter roller, 16… Tension roller, 16a…
Shaft, 17a, 17b ... Bearing member, 17c ... Boss, 18 ... Intermediate transfer
Belt, 19 ... Compression spring, 20a, 20b ... Boss, 20c ... Shaft
Line, 21 ... Round hole, 22 ... Secondary transfer roller, 23 ... Cleaning
Unit, 24 ... cleaning blade, 25 ... swing axis,
26 ... Blade holding plate, 27 ... Cleaning container, 27a ... Waste
Toner outlet, 28 ... Waste toner conveying screw, 29 ... Compression
Spring, 30 ... Detent member, 30a ... Hole, 31a, 31b ... Position
Grooves, 32a, 32b ... Latch, 34 ... Screw drive input
Part, 36 ... Lever, 37 ... Waste toner bottle, 37a ... Waste toner
Inlet, 38 ... Fixing unit, 39 ... Fixing roller, 40 ... Pressure low
La, 41, 42, 43 ... Ejection roller pair, 44 ... Ejection tray, 45 ...
Lever, 46 ... Shaft, 47 ... Stay, 48 ... Cam, 49 ... Shaft, 50 ...
Waste toner bottle holding member, 51 ... Waste toner, 52 ... Toner filling
Full detection sensor, 52a ... Light emitting part, 52b ... Light receiving part, 53 ... Main body
Side plate, 54 ... Sealing member, 55 ... Spring, 56 ... Shutter, 56a
... Flag, 57 ... Flapper, 58 ... Discharge roller pair

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H071 BA03 BA15 BA16 BA20 BA23                       BA27 BA29 BA36 DA08 DA12                       DA32 EA18                 2H134 GA06 JA02 JA07 JB02 JB07                       KA25 KA26 KB12 KB15 KC02                       KG04 KH11 KH16                 2H200 FA12 GA16 GA23 GA34 GA44                       GA45 GA47 GA53 GB25 HA03                       HA28 HB12 HB22 JA02 JB10                       JC04 JC09 JC12 LB02 LB13                       LB17 LB33 LB35 LB40 MA03                       MA20 PB15 PB39

Claims (4)

[Claims] 1. An image carrier for carrying a toner image, an intermediate transfer unit having an intermediate transfer member to which the toner image formed on the image carrier is transferred, and residual toner on the intermediate transfer member is removed. A cleaning unit that has a cleaning unit that performs cleaning, and a toner transport unit that transports the residual toner collected by the cleaning unit to a toner collection container; and a toner that is once collected in the toner collection container and leaks out of the toner collection container. The cleaning unit includes a sealing unit provided at a toner inlet of the toner collecting container for preventing the toner collecting unit, and a toner filling detecting unit for detecting that the toner collecting container is filled with toner. The cleaning unit is replaceable independently of the unit, and the cleaning unit is positioned with respect to the intermediate transfer unit. Fixed Te, the image forming apparatus characterized by being configured so as to detect the presence or absence of the intermediate transfer unit and / or the cleaning unit by the toner filling detecting means. 2. The image forming apparatus according to claim 1, wherein the sealing unit is configured to open when a toner discharge port of the cleaning unit is inserted into a toner intake port of the toner recovery container. apparatus. 3. The toner filling detection means is composed of an optical sensor, and the optical path of the optical sensor is cut off by the sealing means when the sealing means is closed. Alternatively, the image forming apparatus according to claim 2. 4. The cleaning means comprises a cleaning blade.
The image forming apparatus according to any one of 3 above.