JP2000075613A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the residual quantity of developer to be precisely detected. SOLUTION: A developing device used in an image forming device is provided with a developer container 31 for housing the developer, light transmitting windows 36a and (36b) formed at the container 31, a light detection system developer residual quantity detection means (detecting light emitting part and detecting light receiving part), a stirring member 39 stirring the developer and stirring blade 40 fitted to the stirring member 39 so as to clean the windows 36a and (36b). Besides, a slit 41 is formed so as to be positioned at a boundary between the part 40a of the blade 40 cleaning the windows 36a and (36b) and the part 40b other than it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an electrostatic latent image on an image carrier by, for example, an electrophotographic system or an electrostatic recording system.
The present invention relates to a developing device for visualizing the latent image and an image forming apparatus including the developing device, such as a copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, for example, an image forming apparatus such as a printer using an electrophotographic system uniformly charges an electrophotographic photosensitive member (photosensitive member) as an image carrier, and forms image information on the surface of the photosensitive member. To form an electrostatic latent image, visualize the electrostatic latent image with a developer containing toner to form a toner image, transfer the toner image to a recording material, and fix it by heat and pressure. This forms an image.

[0003] Such an image forming apparatus involves toner supply and maintenance of various process means related to image formation. Therefore, in order to facilitate toner replenishment work and maintenance, the developing device is detachably attached to the image forming apparatus main body, or an image carrier and a charging unit and a developing unit (developer) acting on the image carrier are used. A process cartridge such as a carrier and a cleaning unit that is integrally formed into a cartridge to form a process cartridge detachable from the image forming apparatus main body has also been put to practical use.

FIG. 5 shows a schematic configuration of an electrophotographic color laser beam printer capable of forming a full-color image.

In the image forming apparatus main body G, a drum-shaped electrophotographic photosensitive member as an image carrier, that is, a photosensitive drum 1 is provided rotatably in the direction of an arrow. Also, the photosensitive drum 1
A rotary developing device as a developing device 3 is provided at a position where it can act on the surface, and the rotary developing device stores four color toners of magenta, cyan, yellow, and black one by one as developers. Color developing device 3M,
3C, 3Y, and 3B.

[0006] Four-color developing devices 3M, 3C, 3Y, 3B
Is rotatably arranged with respect to the shaft 3a. Also, shaft 3a
Is provided with a revolving gear. Each of the developing devices 3M, 3M is linked to a rotating gear disposed on the outer periphery of the revolving gear.
The rotation of each of C, 3Y, and 3B keeps the attitude of each of the developing devices 3M, 3C, 3Y, and 3B constant.

For example, when a full-color image is formed, when an image forming operation is started, a charging roller 2 as a charging unit uniformly charges the surface of the photosensitive drum 1 and an optical system according to color-separated image information. 4 exposes the surface of the photosensitive drum 1 to form an electrostatic latent image according to the first color image information.

[0008] Of the developing devices 3M, 3C, 3Y and 3B,
The developing device of the color corresponding to the first-color electrostatic latent image is stopped at a position facing the photosensitive drum 1, and the toner is visualized by flying the toner onto the electrostatic latent image, and the toner image is formed on the photosensitive drum 1. Form.

On the other hand, the recording material P stored in the cassette 8
Is the transfer drum 1 fed into the image forming apparatus main body G.
6, the transfer drum 16 is carried and conveyed to a contact portion with the photosensitive drum 1 by the rotation of the transfer drum 16 in the direction of the arrow.

When the toner image on the photosensitive drum 1 and the recording material P carried on the transfer drum 16 reach the contact portion (transfer area) between the photosensitive drum 1 and the transfer drum 16 in synchronization, the recording material P The first color toner image is electrostatically transferred by the transfer unit 6.

The rotation of the transfer drum 16 allows the recording material P to repeatedly pass through the transfer area. The above-described steps of forming and transferring the toner image are also performed for the remaining three colors. A full-color unfixed toner image formed by superimposing four colors is formed thereon.

Thereafter, the recording material P is separated from the transfer drum 16 and then conveyed to the fixing device 7, where the unfixed toner image is permanently fixed by heat and pressure, and then discharged out of the image forming apparatus. The transfer residual toner remaining on the photosensitive drum 1 after the transfer is removed by a cleaner blade 15 as a cleaning unit.

Next, a developing device 3Y used in the above-described conventional image forming apparatus will be described with reference to FIGS. The other developing devices 3M, 3C, 3B have the same configuration.

The developing device 3Y stores a yellow toner as a developer in a developer container 31. At the opening of the developing device 3Y, a developing sleeve 32 as a developer carrier is provided rotatably in the direction of the arrow.
Reference numeral 2 is made to face the surface of the photosensitive drum 1 with a very small interval.

A stirring member 39 and a stirring blade 40 attached to the stirring member 39 are provided in the developer container 31 so as to be rotatable in the direction of the arrow. The toner is stirred by these members and is conveyed to the developing sleeve side. Is done. A supply roller 33 is in sliding contact with the developing sleeve 32, and supplies toner to the surface of the developing sleeve 32 by rotating in the direction of the arrow. Further, a developer layer thickness regulating member 34 is in contact with the developing sleeve 32, and the toner supplied onto the developing sleeve 32 passes through the contact portion with the developer layer thickness regulating member 34, so that it is sufficient. To form a thin layer of charged toner.

The toner reaching the opposing portion (developing position) between the developing sleeve 32 and the photosensitive drum 1 with the rotation of the developing sleeve 32 is charged by the developing bias voltage applied to the developing sleeve 32 during the developing operation. The upper electrostatic latent image is developed to form a toner image. Further, the toner that has not contributed to the development is continuously carried and conveyed by the developing sleeve 32, and is scraped off by the supply roller 33 slidably contacting the developing sleeve 32. Thereby, fresh toner is always supplied to the developing sleeve 32.

Conventionally, a developing device is provided with a developer remaining amount detecting means for detecting the remaining amount of toner consumed during image formation. As shown in FIGS. 6 and 7, conventionally, a developer remaining amount detecting means employing a light transmission method is known. Next, this will be described.

Weld receiving portions 35a, 35 of developer container 31
Light transmission windows 36a and 36b for detecting the remaining amount of the developer are welded to b by using a method such as ultrasonic welding. Further, a detection light emitting portion 38a, which is a light emitting element, is provided on the image forming apparatus main body G side, and the detection light D emitted from the detection light emitting portion 38a is transmitted through a light transmitting member formed by a light transmitting member. Window 3
The remaining amount of the developer is detected by being transmitted through the light transmission window 6a and further transmitted through the light transmission window 36b and received by the detection light receiving unit 38b such as a light receiving element provided on the image forming apparatus main body G side. .

Here, when detecting the remaining amount of toner, the stirring member 39 provided in the developer container 31 rotates, and the stirring blade 40 attached to the stirring member 39 rotates the light transmitting window 3.
Cleaning is performed by wiping the inner surfaces of 6a and 36b, and the remaining amount is detected by detecting the detection light D at that time.

That is, when the remaining amount of toner is large, even if the stirring blade 40 cleans the light transmission windows 36a and 36b, the toner is immediately covered, so that the detection light D is not transmitted. Since the time required to cover the light transmitting windows 36a and 36b again becomes longer, the detection light D transmits longer. Thus, the remaining amount of toner can be detected.

[0021]

However, when the conventional light transmission type developer remaining amount detecting means is employed, there are the following problems.

That is, in the developer container 31, the light transmitting windows 36a and 36b have a shape protruding from the inner wall of the developer container 111 to the inside of the developer container.
End of the light transmission window 36a, 36b, the bending of the stirring blade 40 occurs.
a, the toner cannot be completely wiped from 36b,
As a result, there has been a problem that accurate detection of the remaining amount of the developer is not performed.

Further, even if the light transmitting windows 36a and 36b do not protrude from the inner wall of the developer container 31 as shown in the conventional example, the stirring blades 40 can be connected to the light transmitting windows 36a and 36b and other portions of the developer container 31. In some cases, resistance occurs at the boundary with the inner wall of the agitator, and the agitating blade 40 may bend.

For example, FIG. 8 (a) is located at the longitudinal center of the developer container 31, and FIG. 8 (b) is located at the longitudinal end of the developer container 31, respectively. Window 36
a (a window on the side of the detection light emitting portion 38a) of the developing device, the stirring blade 40 of the developing device is caught by the light transmitting window 36a, and the center portion of the longitudinal length of the stirring blade 40 is bent. ing. The bending of the stirring blade 40 in this manner prevents the stirring blade 40 from completely wiping the light transmission window 36a.

As means for solving such a problem,
It is conceivable to provide a member for wiping the toner from the light transmission windows 36a and 36b in addition to the stirring blade 40, but this has a problem that the configuration becomes complicated and the cost increases.

Accordingly, an object of the present invention is to provide a simple structure, which can reliably wipe off and clean the toner from the light transmitting window at a low cost without providing any special means other than the agitating blade. An object of the present invention is to provide a developing device capable of detecting the remaining amount of developer and an image forming apparatus including the same.

[0027]

The above object is achieved by a developing device and an image forming apparatus according to the present invention. In summary, the present invention relates to a developing device for visualizing an electrostatic latent image formed on an image carrier, a developer container for containing a developer, and a light transmission device provided in the developer container. A window, a developer remaining amount detection unit of a light detection system, a stirring member for stirring the developer, and a stirring blade attached to the stirring member to clean the light transmission window, A developing device characterized in that a slit is provided at a boundary between a portion for cleaning the light transmitting window of the stirring blade and another portion.

According to another aspect of the present invention, in an image forming apparatus provided with a developing device for visualizing an electrostatic latent image formed on an image carrier, the developing device contains a developer. Developer container, a light transmitting window provided in the developer container, a light detection type developer remaining amount detecting unit, a stirring member for stirring the developer, and cleaning the light transmitting window. A stirring blade attached to the stirring member, and a slit is provided at a boundary between a portion of the stirring blade that cleans the light transmitting window and a portion other than the portion. An image forming apparatus is provided.

According to one embodiment of the present invention, each of the stirring blades has a length from the slit to a tip of a portion for cleaning the light transmission window, and a length of another portion of the stirring blade. It is shorter than it is. Preferably, the light transmitting window is disposed above and below the developer container, and the developer remaining amount detecting means is provided in the image forming apparatus main body near the light transmitting window. The light receiving element receives light emitted from the light emitting element when the light transmitting window is cleaned.

Further, in each of the above-mentioned present inventions, according to one embodiment, the developing device is unitized and is detachable from the image forming apparatus main body. According to another embodiment, the developing device is unitized with the image carrier to form a process cartridge, which is detachable from the image forming apparatus.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a developing device and an image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows a schematic configuration of an embodiment of the image forming apparatus according to the present invention. According to this embodiment, the present invention
It is embodied in a color printer capable of forming a full-color image. However, it should be understood that the present invention is not limited to this, and can be applied to, for example, a copying machine, a facsimile, a word processor, and the like, and of course, can be applied to a monochrome image forming apparatus.

According to this embodiment, the image forming apparatus is a drum-shaped electrophotographic photosensitive member as an image carrier that rotates at a constant speed, that is, a toner for each color according to color-separated image information on the surface of the photosensitive drum 1. An image is formed, and the toner image is superimposed on the intermediate transfer body 5 and transferred to form a full-color toner image. Thereafter, the full-color toner image is collectively transferred to the transfer material P. The recording material P is transported to the fixing device 7 and
The unfixed toner image is permanently fixed on the recording material P by heat and pressure, and the recording material P is discharged to the discharge unit 17 on the upper part of the image forming apparatus main body G. That is, the image forming apparatus of this embodiment is a so-called intermediate transfer type image forming apparatus.

Next, the image forming apparatus of this embodiment will be described in more detail along the image forming process.

First, in this embodiment, the photosensitive drum 1
Is formed by applying an organic photoelectric layer to the outside of an aluminum cylinder having a diameter of about 62 mm. A charging roller 2 as charging means for uniformly charging the surface of the photosensitive drum 1 and a cleaner blade as cleaning means for removing residues on the surface of the image carrier 4 are provided on the outer peripheral side surface of the photosensitive drum 1. 15 are arranged. The photosensitive drum 1 includes a container for storing a residue removed from the surface of the photosensitive drum 1 by the cleaning unit 15;
Cleaning container 1 also serving as holder for photosensitive drum 1
8 and rotatably supported, and together with the charging roller 2 and the cleaner blade 15 are integrally unitized to form a process cartridge U. The process cartridge U is supported detachably with respect to the image forming apparatus main body G, and the unit can be easily replaced in accordance with the life of the photosensitive drum 1.

The photosensitive drum 1 is driven by a drive motor (not shown).
When the driving force is transmitted from the motor, the motor rotates in the direction of the arrow. In the present embodiment, the charging roller 2 is a conductive roller, and uniformly charges the surface of the photosensitive drum 1 using a contact charging method.

When the surface of the photosensitive drum 1 is uniformly charged,
The surface is then exposed. The exposure is performed by a laser beam L from a scanner unit 4 which is an optical system disposed above the image forming apparatus main body G. That is, when an image signal is given to a laser diode (not shown), this laser diode irradiates the polygon mirror 4a with image light corresponding to the image signal. This polygon mirror 14
Is rotated at a high speed by a scanner motor, and the image light reflected by the polygon mirror 4a selectively exposes the surface of the photosensitive drum 1 rotating at a constant speed via the imaging lens 4b and the reflection mirror 4c according to the image information. Then, an electrostatic latent image is formed on the surface of the photosensitive drum 1.

In the image forming apparatus of this embodiment, a developing device 3 for visualizing an electrostatic latent image formed on the photosensitive drum 1
Are a yellow developing device 3Y, a magenta developing device 3M, and a cyan developing device 3 which are detachable from a rotatable color developing device rotary 3R provided in the image forming apparatus main body G.
C, and a black developing device 3B detachably provided to the image forming apparatus main body G separately from the color developing device rotary 3R.

The black developing device 8B is a fixed developing device, and supplies black toner as a developer to an electrostatic latent image according to black image information on the photosensitive drum 1 at a position facing the photosensitive drum 1. The developing sleeve as a developer carrier is arranged at a minute interval (300 μm) with respect to the surface of the photosensitive drum 1.
m) and a black toner image is formed by causing the toner to fly to the electrostatic latent image.

On the other hand, three color developing devices 3Y, 3M,
Reference numeral 3C denotes a developer cartridge, which contains toner corresponding to 6000 pages (A4 size, 5% printing) as a developer of each color, and is detachably supported on a color developing rotary 3R which rotates about a shaft 3a. ing.
When the image formation is started, the color developing rotary 3R rotates around the axis 3a, and the color developing devices 3Y, 3M, 3C stop at the desired timing at the positions facing the photosensitive drum 1, and the image of each color is formed. Yellow, magenta, and cyan toners of corresponding colors are supplied to the electrostatic latent image formed on the photosensitive drum 1 according to the information. The developing sleeve as a developer carrying member is arranged at a minute interval (about 300 μm) with respect to the surface of the photosensitive drum 1, and applies toner of each color to the electrostatic latent image corresponding to image information of each color on the photosensitive drum 1. To form a toner image. FIG.
3 shows a state in which the yellow developing device 3Y is positioned to face the photosensitive drum 1 and is stationary.

According to the present embodiment, the image forming apparatus has an intermediate transfer drum 5 as an intermediate transfer body rotatably in the direction of an arrow. For example, when performing full-color image formation, the intermediate transfer drum 5 Each time the color developing rotary 3R rotates, the color developing devices 3Y, 3M, 3M rotate.
C, and then, in the order of the black developing device 3B, the process of forming and developing an electrostatic latent image according to the image information of each color is performed, and further, in the contact area (primary transfer nip N1) between the photosensitive drum 1 and the intermediate transfer drum 5 Is primarily transferred onto the intermediate transfer drum 5. In this way, a full-color toner image is formed on the intermediate transfer drum 5.

That is, the intermediate transfer drum 5 receives four times of multiple transfer of the toner image on the photosensitive drum 1 visualized by the developing devices 3Y, 3M, 3C and 3B when forming a full-color image. The intermediate transfer drum 5 which rotates in synchronization with the peripheral speed of the photosensitive drum 1 and receives multiple transfer
The intermediate transfer to the recording material P is performed by sandwiching and transporting the separately transported recording material P at a contact portion (secondary transfer nip N2) with the transfer roller 6 as a transfer unit to which a bias voltage is applied. The full-color toner image on the drum 5 is secondarily transferred collectively.

The intermediate transfer drum 5 in this embodiment has a structure in which an outer periphery of an aluminum cylinder 5a having a diameter of 186 mm is covered with an elastic layer 5b of medium resistance sponge, medium resistance rubber or the like. Further, the intermediate transfer drum 5 is driven and rotated by a gear (not shown) fixed integrally.

On the other hand, each developing device 3Y, 3M, 3C, 3B
After the toner images respectively formed on the photosensitive drum 1 are transferred to the intermediate transfer drum 1, the toner remaining on the photosensitive drum 1 is removed by the cleaner blade 15 unitized with the photosensitive drum 1 as described above. Removed. The removed waste toner is supplied to the photosensitive drum 1.
Is stored in the cleaning container 18 also serving as a holder. The waste toner does not fill the cleaning container 18 earlier than the life of the photosensitive drum 1. Therefore, the cleaning container 18
They are exchanged together.

A feeding unit for conveying the recording material P to a contact area (secondary transfer nip N2) between the intermediate transfer drum 5 and the transfer roller 6 includes a cassette for accommodating a plurality of transfer materials P. 8. Pickup roller 9 and feed roller 10 for feeding recording material P out of the cassette, retard roller 11 for preventing double feeding, feeding guide 12 for further guiding recording material P
A registration roller 23 for timing the entry of the recording material P into the secondary transfer nip N2;
And the like.

That is, when the image forming is started, the pickup roller 9 is driven to rotate in accordance with the image forming operation, and feeds out the recording material P in the cassette 8.
The recording material P is separated and fed one by one by the cooperation of the feeding roller 10 and the retard roller 11. Further, it is guided by the feeding guide 12 and reaches the registration roller 14 via the transport roller 13. During the image forming operation, the registration roller 14 performs a non-rotational operation of causing the recording material P to stand still and
The rotation operation of transporting the transfer material P toward the intermediate transfer drum 5 is performed in a predetermined sequence, and the image and the recording material P in the secondary transfer process are aligned.

The transfer roller 6 is swingable, has a configuration in which a medium-resistance foam elastic body is wound around the outer periphery of a metal shaft, is movable as indicated by an arrow in the drawing, and is driven to rotate.

That is, while the four-color toner image is being formed on the intermediate transfer drum 5, that is, while the intermediate transfer drum 5 is repeatedly rotated for the primary transfer, the image on the surface is not disturbed. The transfer roller 6 is retracted downward and is separated from the intermediate transfer drum 5. Thereafter, when a full-color toner image is formed on the intermediate transfer drum 5, the recording material P
The transfer roller 6 in accordance with the timing of the secondary transfer
Is pressed against the intermediate transfer body 5 with a predetermined pressure via the transfer material P by a cam member (not shown). At the same time, a bias voltage is applied to the transfer roller 6, and the full-color toner image on the intermediate transfer drum 5 is transferred to the recording material P.

Here, the intermediate transfer drum 5 and the transfer roller 6
Are driven independently of each other, the recording material P sandwiched between them is conveyed at a predetermined speed at the same time as the secondary transfer process is performed, and is directed toward the fixing device 7 which is the next process. Conveyed.

The fixing device 7 includes a transfer roller 7a for applying heat to the full-color unfixed toner image collectively transferred onto the recording material P, and a pressing roller 7b for pressing the recording material P against the fixing roller 7a. And The fixing roller 7a and the pressure roller 7b are hollow rollers, each having a heater inside. The recording material P is nipped and conveyed by the fixing roller 7a and the pressure roller 7b, and the unfixed toner image is permanently fixed on the recording material P by applying heat and pressure. It is discharged outside the forming apparatus.

Next, the developing device 3 used in the image forming apparatus of this embodiment will be described in more detail by taking the yellow developing device 3Y as an example.

FIG. 2 shows a yellow developing device 3 according to the present invention.
1 shows a schematic cross section of one example of Y. Yellow developing device 3Y
The yellow toner serving as a developer is contained in a developer container 31, and the developing sleeve 32 and the supply roller 33 are brought into contact with each other by rotating the stirring member 39 and the stirring blade 40 attached thereto in the direction of the arrow. To the bordering area,
The toner is transported and agitated.

The supply roller 33 rotates in an arrow direction (counter rotation direction with respect to the rotation of the developing sleeve 32) so as to rub the developing sleeve 32, and charges the toner on the developing sleeve 32 in advance. To supply.

The thickness of the toner supplied onto the developing sleeve 32 by the supply port 33 is regulated by a developing blade 34 as a developer layer thickness regulating member pressed against the outer periphery of the developing sleeve 32. Then, a thin layer of toner is applied to the surface of the developing sleeve 32 which is sufficiently charged by frictional charging and rotates in the direction of the arrow.

The developing sleeve 32 carries a thin layer of toner and conveys it to a developing position facing the photosensitive drum 1 on which the electrostatic latent image is formed, and develops the toner by a developing bias voltage applied to the developing sleeve 32. The toner image is formed by flying onto the sleeve and selectively adhering toner to the electrostatic latent image, thereby visualizing the electrostatic latent image to form a toner image. The toner remaining on the developing sleeve 32 without contributing to the development at the developing position is thereafter scraped off by the supply roller 33 and the developer container 31
And fresh toner is supplied onto the developing sleeve 32 at all times.

Although detailed description is omitted, the magenta developing device 3M and the cyan developing device 3C have the same configuration as the above-described yellow developing device 3Y, and form a toner image. When the color developing device rotary 3R is driven to rotate and each color developing device reaches the developing position, a high-voltage power supply and driving means for each developing device provided in the image forming apparatus main body G and each developing device are used. Are connected, and a voltage is sequentially and selectively applied to each of the developing sleeves 32.
A rotation drive is performed.

Next, the developer remaining amount detecting means will be described using the developing device 3Y as an example. As shown in FIG. 2, in the present embodiment, the developing device 3Y has a developer remaining amount detecting unit of a light transmission type.

First, the developer container 31 is provided with first and second light transmission windows 36a and 36b. 1st, 2nd
The two light transmitting windows 36 are located near the light transmitting windows 36a and 36b.
A first light guide 38a 'and a second light guide 38b' are provided so as to face the first and second light guides 38a 'and 38b', respectively. The detected light D from the detected light emitting section 38a is supplied to the developer container 3 through the first light transmission window 36a.
The second light guide 38b 'guides the detection light D passing through the second light transmission window to a detection light receiving portion such as a light receiving element provided in the image forming apparatus main body G. 3
8b.

In this manner, the developer remaining amount detecting means includes the detecting light emitting portion 38a → the first light guide 38a ′ → the first light transmitting window 36a → the inside of the developer container 31 → the second light transmitting window 3
6b → second light guide 38b ′ → detection light receiving unit 38
The optical circuit of the detection light is configured in the order of b.

The tip of the stirring member 39 has a stirring blade 40.
When the remaining amount of toner is small due to the rotation of the stirring member 39 in the direction of the arrow, the stirring blade 40 wipes and cleans the toner from the first and second light transmission windows, thereby forming the optical path of the detection light. Is configured to provide.

That is, when the remaining amount of toner in the developer container 31 is large, even if the stirring blade 40 cleans the light transmitting windows 36a and 36b, these are immediately covered with the toner, so that the detection light is not transmitted. As the amount of remaining toner decreases, the time required for the stirring blade 40 to clean the light transmission windows 36a and 36b until the toner covers them again becomes longer, so that the time required for the detection light to pass through the detection light path increases.

The light transmission type developer remaining amount detecting means detects the remaining amount of toner by the above-described mechanism. As described above, in order to accurately detect the remaining amount of toner, the stirring blade 40 is required. It is necessary to surely wipe and clean the light transmitting windows 36a and 36b.

Therefore, the present invention is intended to ensure that the stirring blade 40 can clean the light transmitting windows 36a and 36b.
FIG. 3 shows a state in which the developer container 31 of the developing device 3Y of this embodiment is viewed from the photosensitive drum 1 side. FIG. 4 shows the stirring blade 4.
0 and the vicinity of the first light transmission window 36a are shown.

As can be understood from FIG. 3, according to the present embodiment, the light transmitting windows 36a and 36b are closer to the center of the longitudinal length of the stirring blade 40, that is, the light transmitting window 36 of the stirring blade 40.
A slit 41 is provided at the boundary between the portion for wiping a and 36b and the other portion.

That is, the stirring blade 40 is hooked on the portion where the light transmission 36 a and 36 b protrudes from the inner wall of the developer container 31, and the force for bending the entire stirring blade 40 is cut off by the slit 41.

With such a configuration, the stirring blade 40
In this embodiment, the central portion of the longitudinal length of the stirring blade 40 can be prevented from bending as shown in FIG. 8B by hooking the light transmitting windows 36a and 36b. On the other hand, the light transmitting windows 36a and 36b can be sufficiently cleaned at the light transmitting window equivalent portion 40a of the stirring blade 40, and it is possible to accurately detect the remaining amount of toner.

Further, with the slit 41 as a boundary, the stirring blade 4
The length X of the tip of the portion 40a for wiping the 0 light transmitting windows 36a and 36b and the length X ₀ of the tip of the other portion 40b.
And the length X of the tip of the portion 40a for wiping the light transmitting windows 36a and 36b of the stirring blade 40 is changed to the other portion 40b.
Is shorter than the length X ₀ of the tip. That is, the light transmission window 36
The length X of the tip of the agitating blade 40 of the portion 40a is equal to the amount that the a and 36b protrude from the inner wall of the developer container to the inside.
It can be adjusted according to the wiping ability, for example, by shortening the length.

As described above, by adjusting the amount of the stirring blade 40 penetrating into the inner wall of the developer container 31 and the light transmitting windows 36a and 36b, in addition to the effect obtained by the slit 41,
Further, the light transmission windows 36a and 36b can be reliably cleaned.

As described above, according to the image forming apparatus of the present invention, the toner can be reliably wiped and cleaned from the light transmitting window at a low cost with a simple configuration without providing any special means other than the stirring blade. It has become possible.

In this embodiment, the light transmitting windows 36a, 36
Since the position b is the end in the longitudinal direction of the stirring blade 40, the slit 41 is located on the side of the light transmission windows 36a and 36b from the center of the longitudinal length of the stirring blade 40, but the position of the slit 41 is It is needless to say that the present invention is not limited to this. That is, according to the present invention, the portion 40a for wiping the light transmission windows 36a and 36b of the stirring blade 40 and the other
It is intended that a slit 41 be provided in a boundary portion with 0b.

In the above embodiment, the color developing devices 3Y, 3M, and 3C are detachable from the color developing device rotary 3R provided in the main body of the image forming apparatus.
The black developing device 3B is used alone as the image forming apparatus main body G.
It has been described that the cartridge is a so-called developer cartridge which is detachable with respect to. However, the principle of the present invention is not limited to this, and can be applied to a developing device fixed to the image forming apparatus main body G and an image forming apparatus provided with such a developing device.

Further, in the above embodiment, the photosensitive drum 1, the charging roller 2, the cleaner blade 15, and the cleaning container 18 are integrally unitized to form the main body G of the image forming apparatus.
However, the principle of the present invention is that, for example, the photosensitive drum 1, the charging roller 2, the developing device 3 (for example, a single black color), the cleaner blade 15, the cleaning container 18 and the like are selectively used. Process cartridges that are unitized in a frame,
Further, the present invention can be applied to an image forming apparatus provided with a mounting unit for removably mounting such a process cartridge.

The process cartridge is a cartridge in which a charging means, a developing device or a cleaning means and an image carrier such as a photosensitive drum are integrally formed into a cartridge, and this cartridge is detachably mountable to the main body of the image forming apparatus. Or at least one of a charging unit, a developing device, and a cleaning unit and an image carrier are integrally formed as a cartridge so that the cartridge can be attached to and detached from an image forming apparatus main body. The image carrier and the image carrier are integrally formed as a cartridge so as to be detachable from the image forming apparatus main body.

[0074]

As described above, according to the present invention,
In a developing device for visualizing the electrostatic latent image formed on the image carrier, a developer container for housing the developer,
A light transmission window provided in the developer container, a light detection type developer remaining amount detection unit, a stirring member for stirring the developer, and a stirring blade attached to the stirring member to clean the light transmission window. And a slit is provided at the boundary between the portion for cleaning the light transmission window of the stirring blade and the other portion, so that special means other than the stirring member and the stirring blade are provided. Therefore, the toner can be reliably wiped off from the light transmitting window and cleaned at a low cost with a simple configuration. Furthermore,
Since the length of the stirring blade to the tip of the part that cleans the light transmission window from the slit is shorter than the length of the other parts of the stirring blade, the light transmission window should be more reliably cleaned. Can be. Therefore, the developing device of the present invention and the image forming apparatus having the same can accurately detect the remaining amount of the developer.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a schematic sectional view showing one embodiment of a developing device according to the present invention.

FIG. 3 is a perspective view of a developer container of the developing device according to the present invention as viewed from an image carrier.

FIG. 4 is a schematic diagram showing the vicinity of a stirring blade of a developing device according to the present invention.

FIG. 5 is a schematic configuration diagram illustrating an example of a conventional image forming apparatus.

FIG. 6 is a schematic sectional view showing an example of a conventional developing device.

FIG. 7 is a perspective view of a developing container of a conventional developing device as viewed from a side opposite to an image carrier.

FIG. 8 is a view showing a state in which a stirring blade is bent.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photosensitive drum (image carrier) 2 Charging roller (charging means) 3 Developing device 3R Color developing device rotary 4 Optical system (canner part) 5 Intermediate transfer drum (intermediate transfer body) 6 Transfer roller (transfer means) 7 Fixing device 15 Cleaner blade (cleaning means) 18 Cleaning container 31 Developer container 32 Developing sleeve (developer carrier) 33 Supply roller 34 Developing blade (developer layer thickness regulating member) 36a, 36b Light transmission window 38a Detection light emitting portion 38b Detection light Light receiving unit 38a ', 38b' Light guide 39 Stirring member 40 Stirring blade 41 Slit

Claims (10)

[Claims] 1. A developing device for visualizing an electrostatic latent image formed on an image carrier, a developer container for containing a developer, a light transmission window provided in the developer container, A light detection type developer remaining amount detection unit, a stirring member for stirring the developer, and a stirring blade attached to the stirring member so as to clean the light transmission window; A developing device, wherein a slit is provided at a boundary between a portion for cleaning the light transmitting window and another portion. 2. A length of the stirring blade to a tip of a portion for cleaning the light transmitting window from the slit is shorter than lengths of other portions of the stirring blade. The developing device according to claim 1, wherein 3. The light transmitting window is provided on the developer container.
Each of the developer remaining amount detecting means is disposed in a downward direction, and has a light emitting element and a light receiving element provided in the image forming apparatus main body in the vicinity of the light transmitting window, and the light transmitting window is cleaned when the light transmitting window is cleaned. The developing device according to claim 1, wherein the light receiving element receives light emitted from the light emitting element. 4. The developing device according to claim 1, wherein the developing device is unitized and is detachably attached to an image forming apparatus main body. 5. The image forming apparatus according to claim 1, wherein the process cartridge is formed as a unit with the image carrier, and is detachably mountable to an image forming apparatus main body. Developing device. 6. An image forming apparatus provided with a developing device for visualizing an electrostatic latent image formed on an image carrier, the developing device comprising: a developer container for containing a developer; A light transmission window provided in the developer container; a light detection type developer remaining amount detection unit; a stirring member for stirring the developer; and a stirring member attached to the stirring member to clean the light transmission window. An image forming apparatus, comprising: a blade; and a slit provided at a boundary between a portion for cleaning the light transmission window of the stirring blade and another portion. 7. A length of the stirring blade to a tip of a portion for cleaning the light transmitting window from the slit is shorter than lengths of other portions of the stirring blade. 7. The image forming apparatus according to claim 6, wherein: 8. The light transmitting window is provided on the developer container.
Each of the developer remaining amount detecting means is disposed in a downward direction, and has a light emitting element and a light receiving element provided in the image forming apparatus main body in the vicinity of the light transmitting window, and the light transmitting window is cleaned when the light transmitting window is cleaned. The image forming apparatus according to claim 6, wherein the light receiving element receives light emitted from the light emitting element. 9. The image forming apparatus according to claim 6, wherein the developing device is formed as a unit and is detachably provided to an image forming apparatus main body. 10. The image forming apparatus according to claim 6, wherein the developing device is unitized with the image carrier to form a process cartridge, and is provided detachably with respect to an image forming apparatus main body. The image forming apparatus according to the item.