JP2001194889A - Developing device, process cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device where detection of residue developer inside a developer container can be carried out sequentially over a wide range from an early stage. SOLUTION: Relating to the developing device 4 that a toner container (the developer container) 16 with a plural arch-shaped parts and plural agitating members 12 and 13 agitating toner (the developer) T inside the toner container 16 are included and light transmitting windows for developer residue quantity detection 14a, 14b and 14c for detecting the residue quantity of the light transmitting type toner (developer) are arranged in the toner container by utilizing the rotation of the agitating members 12 and 13, 2 light transmitting surfaces 14a1 and 14a2 in different directions are formed in the light transmitting window for developer residue quantity detection 14a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a developing device, a process cartridge, and an image forming apparatus. Here, the image forming apparatus forms an image on a recording medium using an electrophotographic image forming method, and the process cartridge is formed by integrating a charging unit, a cleaning unit, a photoconductor, and a developing device. It is.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and a process means acting on the electrophotographic photosensitive member are integrated into a process cartridge. The cartridge system which can be attached and detached is adopted. According to this cartridge system, maintenance of the apparatus can be performed by the user himself without relying on a service person, so that operability can be significantly improved. For this reason, the cartridge system is widely used in image forming apparatuses.

FIG. 6 is a longitudinal sectional view of a laser beam printer 100 as an embodiment of an image forming apparatus for forming an image by an electrophotographic method.

In FIG. 6, reference numeral 101 denotes a photosensitive drum which rotates at a constant speed in a direction indicated by an arrow (clockwise), and the surface of the photosensitive drum 101 is uniformly charged by charging means 102. Then, the exposure means 1 is provided on the photosensitive drum 101.
When a laser beam corresponding to the image information is irradiated from 03, an electrostatic latent image is formed on the photosensitive drum 101, and this electrostatic latent image is developed by the developing device 104 to be visualized as a toner image.

[0005] The toner image formed on the photosensitive drum 101 is transferred by the transfer means 106 to the recording medium P transported by the transport means 105 from the paper supply unit. Then, the recording medium P on which the toner image has been transferred is fixed to the fixing unit 10.
After being conveyed to the fixing device 7 and having the toner image fixed thereon, the toner image is discharged out of the apparatus.

The transfer residual toner remaining on the photosensitive drum 101 after the transfer of the toner image is scraped off by a cleaning blade 108 and stored in a cleaning container 109. Further, a developing roller 110 carrying toner is arranged in the developing device 104, and a supply roller 111 is rubbed against the developing roller 110, and the toner that has not contributed to the development is scraped off and is always fresh. Toner is supplied.

Here, a conventional light transmission type toner remaining amount detection will be described.

In a toner container 116 for storing the toner T, a first stirring member 112 near the developing roller 110 is provided.
A second stirring member 113 is provided on the side farther from the supply roller 111, and the toner T is conveyed to the supply roller 111 by rotating the respective stirring members 112 and 113. As the consumption of the toner T progresses, the toner T disappears in the rotation area of the second stirring member 113, and the toner T remains only in the area of the supply roller 111 and the rotation area of the first stirring member 112. .

The light transmitting window attached to the toner container 116 containing the toner T is a lower light transmitting window 11 disposed below the rotation center of the first stirring member 112.
4a and the upper light transmission window 114b disposed above the rotation center of the stirring member 112 form an optical axis through which the light for detecting the remaining amount of toner passes. Then, the first stirring member 112 contacts the lower light transmitting window 114a and the upper light transmitting window 114b each time it rotates, and wipes off the toner T attached to the inside of each of the windows 114a and 114b. Then, the toner T is consumed, and as described above, the toner T
Disappears and the toner T remains only in the area of the supply roller 111 and the rotation area of the first stirring member 112,
The light is transmitted from the lower light transmitting window 114a to the upper light transmitting window 114b, and the remaining amount of the toner T can be detected.

As a light transmission method, detection light L is emitted from a light emitting portion 115a attached to the image forming apparatus main body 100, and the detection light L is transmitted to a lower light transmission window 114a.
And the upper light transmitting window 114b is transmitted, and the transmitted detection light L is received by the light receiving unit 115b attached to the image forming apparatus main body 100.

[0012] While monitoring how long the detection light L is received during one rotation of the first stirring member 112 is monitored, when the amount of the toner T in the toner container 116 decreases, the amount of the toner T in the toner container 116 decreases. The configuration is such that the time for receiving the detection light L increases, and when a specific light reception time is detected, the user is notified that the toner in the toner container 116 is running out.

[0012]

However, the lower light transmission window 1 disposed below the rotation center of the first stirring member 112
In the conventional configuration in which the optical axis of light transmission for detecting the remaining amount of toner is formed by the upper light transmission window 114b disposed above the horizontal center of the rotation center of the stirring member 112 and the rotation center of the stirring member 112, Since the transmission of the detection light L starts after the remaining amount of T becomes close to 0, the toner T is considerably low when the user is to be notified of the absence of toner. Therefore, if the next process cartridge for replacement is not prepared, there is a possibility that printing may not be possible due to the absence of toner before the replacement process cartridge is purchased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a developing device and a process cartridge capable of detecting the remaining amount of developer in a developer container in a wide range from an early stage. And an image forming apparatus.

[0014]

In order to achieve the above object, the present invention is directed to a developer container having a plurality of arc-shaped portions, and a plurality of stirring devices for stirring the developer in the developer container. A developing device having a member and having at least a pair of light transmission windows for detecting the remaining amount of developer in the developer container for detecting the remaining amount of developer by using the rotation of the stirring member. Wherein two light transmitting surfaces having different directions are provided in the developer remaining amount detecting light transmitting window.

According to a second aspect of the present invention, in the first aspect of the present invention, the light transmitting window for detecting the remaining amount of the developer is substantially the center of rotation of the two stirring members whose one light transmitting surfaces are adjacent to each other. The intermediate portion is located on the bottom surface side of the developer container at a position to be wiped by the stirring member on the upstream side in the developer conveyance direction, and the other light transmission surface is wiped by the stirring member on the downstream side in the developer conveyance direction. It is characterized by being arranged to be located at a site.

According to a third aspect of the present invention, in the second aspect of the present invention, each of the light-transmissive windows for detecting the remaining amount of the developer on the upper surface side of the developer container faces two different light-transmitting surfaces. The second and third light transmitting windows for detecting the remaining amount of the developer are arranged at the position (1).

According to a fourth aspect of the present invention, there is provided a process cartridge in which an electrophotographic photosensitive member is integrated with a cleaning unit, a charging unit and a developing unit which act on the electrophotographic photosensitive member. It is characterized by comprising the developing device described in 1, 2, or 3.

According to a fifth aspect of the present invention, there is provided an image forming apparatus in which a developing means or a process cartridge is detachable.
The developing means is constituted by a developing device according to claim 1, 2, or 3, or is constituted by a process cartridge according to claim 4.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing a schematic configuration of the entire image forming apparatus according to the present invention.

The image forming apparatus A shown in FIG. 1 includes a drum type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) 1 as a first image carrier. The photosensitive drum 1 is driven to rotate in a direction indicated by an arrow (clockwise) by driving means (not shown). Around the photosensitive drum 1, a charging device 2 for uniformly charging the surface of the photosensitive drum 1, and an exposure device for irradiating a laser beam based on image information to form an electrostatic latent image on the photosensitive drum 1 3, a developing device 4 for attaching toner to the electrostatic latent image to develop the electrostatic latent image as a toner image, a transfer device 6 for transferring the toner image on the photosensitive drum 1, and remaining on the surface of the photosensitive drum 1 after the transfer A cleaning blade 8 and the like for removing the transfer residual toner are provided.

Here, the photosensitive drum 1, the charging device 2, the cleaning blade 8 and the developing device 4 are integrated into a process cartridge, and this process cartridge is detachable from the image forming apparatus A.

In addition, the image forming apparatus A has a recording medium S
And a fixing device 7 for fixing the toner image to the recording medium S on which the toner image has been transferred.

Hereinafter, the photosensitive drum 1 will be described in detail.

The photosensitive drum 1 is formed by applying an organic photoconductor layer (OPC photosensitive member) on the outer peripheral surface of an aluminum cylinder. The photosensitive drum 1 is rotatably supported at both ends by a support member, and is driven to rotate in the direction indicated by an arrow by transmitting a driving force from a driving motor (not shown) to one end. .

As the charging device 2, a so-called contact charging type (see Japanese Patent Application Laid-Open No. 63-149669) can be used. The charging device 2 is constituted by a conductive roller formed in a roller shape. The conductive roller 2 is brought into contact with the surface of the photosensitive drum 1, and the conductive roller 2 is charged by a power source (not shown). By applying the bias voltage, the surface of the photosensitive drum 1 is uniformly charged.

The exposure device 3 has a polygon mirror (not shown), and the polygon mirror is irradiated with image light corresponding to an image signal by a laser diode (not shown). Here, the polygon mirror is rotated at a high speed by a scanner motor (not shown), and selectively exposes the reflected image light to the charged surface of the photosensitive drum 1 via an imaging lens, a reflection mirror 3a, and the like (not shown). As a result, an electrostatic latent image is formed on the photosensitive drum 1.

In the developing device 4, the developing roller 10 is disposed so as to be opposed to the photosensitive drum 1 with a small gap (about 300 μm). The electrostatic latent image on the photosensitive drum 1 is developed. The development of the electrostatic latent image is performed as follows.

That is, the toner T in the toner container 16 of the developing device 4 is sent to the supply roller 11 by the first stirring member 12 and the second stirring member 13, and the supply roller 1 is rotated.
1 and the toner regulating blade 10a
A thin layer of toner T is applied to the outer periphery of
(Charge by friction). And the developing roller 1
By applying a developing bias between the photosensitive drum 1 and the photosensitive drum 1, the toner T adheres to the electrostatic latent image on the photosensitive drum 1 to develop the electrostatic latent image as a toner image.

The transfer device 6 transfers the toner image formed on the photosensitive drum 1 to the recording medium S.

The cleaning blade 8 removes untransferred toner remaining on the surface of the photosensitive drum 1 without being transferred after the toner T transferred onto the photosensitive drum 1 by the developing device 4 is transferred by the transfer device 6. The transfer residual toner scraped off by the cleaning blade 8 is accumulated in the cleaning container 9.

The feeder 5 feeds the recording medium S to the image forming section, and is driven in accordance with the image forming operation to separate and feed the recording medium S one by one.

The fixing device 7 fixes the toner image transferred to the recording medium S on the recording medium S. And
The recording medium S on which the toner image has been fixed is discharged to the outside by a paper discharge device.

Next, the light transmission type toner remaining amount detection will be described.

A first stirring member 12 closer to the developing roller 10 and a second stirring member 13 farther from the developing roller 10 are provided in the toner container 16 for storing the toner T. As the toner 13 rotates, the toner T is transported to the supply roller 11.

By the way, the first stirring member 12 has a second upper light transmission window 14c disposed above the rotation center of the first stirring member 12 of the toner container 16 containing the toner T, and the first and second stirring members. The second light transmitting surface 14a2 of the lower light transmitting window 14a disposed on the bottom surface side of the intermediate portion of the rotation center of the stirring members 12 and 13 of FIG.
And the second stirring member 13 is connected to the first upper light transmitting window 14b and the lower light transmitting window 14a disposed above the rotation center of the second stirring member 13 of the toner container 16. The surface 14a1 is wiped off (see FIG. 2).

At the time of transmitting light, detection light L1, L2 is emitted from the light emitting portions 15a, 15b attached to the image forming apparatus A.
2 are emitted, and these detection lights L1 and L2 pass through the two light transmission surfaces 14a1 and 14a2 of the lower light transmission window 14a, and then pass through the upper transmission windows 14b and 14c, and the image forming apparatus A
The light is received by the light receiving units 15c and 15d attached to the.

Here, the time t during which the detection light beams L1 and L2 are received by the light receiving units 15c and 15d per one rotation of the first stirring member 12 and the second stirring member 13 and the toner container 16
FIG. 3 shows the relationship with the remaining toner T.

Next, how to reduce the toner T in the toner container 16 and how to transmit the detection light L1 and L2 accompanying the reduction will be described.

As shown in FIG. 4, the first stirring member 12 supplies the toner T to the supply roller 11 side after wiping one light transmission surface 14a2 of the lower light transmission window 14a. The remaining toner that has supplied the shortage is returned as it is. Then, the toner T is discharged onto the lower light transmission window 14a to block light.

On the other hand, the second stirring member 13 supplies the toner T to the rotation area of the first stirring member 12, but if the toner T is sufficient in the area of the first stirring member 12, the second It is brought back to the rotation area of the stirring member 13. Further, the first stirring member 12 on the supplied side also discharges the toner T to the rotation area of the second stirring member 13 if the toner T is sufficient. For this reason, until the toner T in the rotation area of the second stirring member 13 runs out, the toner T is kept in the rotation area of the first stirring member 12 at a substantially horizontal height of the rotation center of the first stirring member 12. During this time, the detection light L2 passing through the rotation area of the first stirring member 12 during this time cannot pass through the inside of the toner container 16.

Accordingly, as the consumption of the toner T progresses from the initial state, first, as shown in FIG. 2, the lower half area of the rotation area of the second stirring member 13, the area of the supply roller 11, and the first area.
The toner T remains in the lower half area of the rotation area of the stirring member 12. Then, when the toner T is further consumed and the toner T in the rotation area of the second stirring member 13 starts to decrease, the detection light L1 is transmitted from the first light transmitting surface 14a1 of the lower light transmitting window 14a to the upper light transmitting window 14b. At this point, the toner T is transmitted, and the remaining amount of the toner T can be detected for the first time. It is at point C1 in FIG. 3 that the detection light L1 starts transmitting,
This is about 55 of the toner capacity (life) in the toner container 16.
% Means that the detection light L1 has been transmitted. From this point, the toner remaining amount detection by the light transmission method can be started. From here, when the toner T in the rotation area of the second stirring member 13 gradually decreases, the transmission time of the detection light L1 gradually increases. Therefore, the transmission time of the detection light L1 should be monitored sequentially. Accordingly, the user can be notified of the remaining amount of the toner T in the toner container 16 sequentially.

When the remaining amount of the toner T in the rotation area of the second stirring member 13 becomes small as shown in FIG. 5, the detection light L1 is periodically shielded only by the rotation of the second stirring member 13. The transmission time of the detection light L1 is constant (about 25% of the life). Around this, the amount of the toner T in the rotation area of the first stirring member 12 also starts to change, and the detection light L2 passing through this area starts to be detected by the light receiving unit 15b. This corresponds to point C2 in FIG.
The remaining amount of toner in the toner container 16 indicates about 30% of the life. Thereafter, as in the case of the toner T in the rotation area of the second stirring member 13, the transmission time of the detection light L2 increases as the toner T in the rotation area of the first stirring member 12 decreases. By monitoring this, it is possible to sequentially notify the user of the remaining amount of the toner T in the toner container 16. When the remaining amount of the toner T in the rotation area of the first stirring member 12 becomes small, the detection light L2 is only periodically shielded only by the rotation of the first stirring member 12, and the detection light L2 The transmission time is constant. This is about 15% of the toner capacity (life) in the toner container 16.

As described above, the light transmission time of the detection light transmitted through the toner container and received by the light receiving portion is determined by the toner amount within a certain range of the toner amount in a certain divided space in the toner container. Changes linearly with respect to.

Therefore, the two stirring members 12, 13 and the three light transmitting windows 14a, 14b, 14 described in this embodiment are used.
c, which passes through the developing device 4
In a configuration in which the two detection lights L1 and L2 are received by the light receiving units 15c and 15d attached to the image forming apparatus A, the toner T in the toner container 16 is monitored by monitoring the light transmission time of the two detection lights L1 and L2. About 55% remaining
It is possible to sequentially notify the user of the remaining amount of toner within the range of 残 量 15%.

In the above-described embodiment, two stirring members are used. However, even when there are three or more stirring members, the remaining amount of toner in the toner container can be detected in a wide range by using the same configuration. be able to.

Thus, the user can prepare a new process cartridge at an appropriate timing in accordance with the coming life of the process cartridge in consideration of the information provided and the print volume of the user. .

[0048]

As is apparent from the above description, according to the present invention, a developer container having a plurality of arc-shaped portions and a plurality of stirring members for stirring the developer in the developer container are provided. ,
In the developing device, the developer container includes at least a pair of light transmission windows for detecting the remaining amount of the developer for performing the light transmission type remaining amount detection of the developer using the rotation of the stirring member. Since two light transmitting surfaces having different directions are provided in the light transmission window for remaining amount detection, an effect is obtained that the detection of the remaining amount of the developer in the developer container can be sequentially performed in a wide range from an early stage.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating a schematic configuration of an entire image forming apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view of a toner container of the process cartridge according to the present invention.

FIG. 3 is a diagram illustrating a relationship between a remaining amount of toner in a toner container and a light transmission time.

FIG. 4 is a longitudinal sectional view of a toner container of the process cartridge according to the present invention.

FIG. 5 is a longitudinal sectional view of a toner container of the process cartridge according to the present invention.

FIG. 6 is a longitudinal sectional view of a conventional image forming apparatus (laser beam printer).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photosensitive drum (electrophotographic photosensitive member) 2 Charging device (charging means) 4 Developing device (developing means) 8 Cleaning blade (cleaning means) 12, 13 Stirring member 14a-14c Light transmission window 14a1, 14a2 Light transmission surface 16 Toner container (Developer container) A Image forming device T Toner (developer)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takeshi Arimitsu 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. 2H071 BA03 BA13 DA08 2H077 AC04 AD06 AD13 AD35 AE03 BA08 BA09 DA15 DA34 DA64 DA80 DA93 EA16

Claims (5)

[Claims] 1. A developer container having a plurality of arc-shaped portions, and a plurality of agitating members for agitating the developer in the developer container, wherein light transmission type development is performed using rotation of the agitating member. In a developing device having at least a pair of developer remaining amount detecting light transmitting windows for detecting the remaining amount of developer, two light beams having different directions from the developer remaining amount detecting light transmitting window are provided. A developing device comprising a transmission surface. 2. The developer-transparent window for detecting the remaining amount of developer, the developer-transporting window being disposed on the bottom side of the developer container substantially at the center of the rotation center of two stirring members whose one light-transmitting surfaces are adjacent to each other. Wherein the light transmission surface is located at a position that is wiped off by the stirring member on the downstream side in the developer transport direction. Item 2. The developing device according to Item 1. 3. A second and a third developer remaining amount detection at respective positions facing two light transmitting surfaces in different directions of the developer remaining amount detection light transmitting window on the upper surface side of the developer container. 3. The developing device according to claim 2, further comprising a light transmission window. 4. A process cartridge comprising an electrophotographic photosensitive member and a cleaning means, a charging means, and a developing means acting on the electrophotographic photosensitive member, wherein the developing means is provided. A process cartridge, comprising: a developing device. 5. An image forming apparatus in which developing means or a process cartridge is detachable, wherein said developing means is constituted by the developing device according to claim 1, 2, or 3, or is constituted by the process cartridge according to claim 4. An image forming apparatus comprising: