JP2002268368A - Developing device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out stable toner detection, even when the fluidity of toner is deteriorated. SOLUTION: In the device, an opening part 5a is provided in a sensor-cleaning member 5 attached to an agitating film 23 of a toner-agitating part 2, a sensor surface 4a is cleaned with a leading tip part 5c, when the sensor surface 4a is rubbed, and the toner passes through the opening part 5a and made to remain in the vicinity of the sensor surface 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for forming an electrostatic latent image on a photosensitive drum as a toner image on paper and an image forming device provided with the same, and more particularly, to detecting the amount or density of a developer. The present invention relates to a sensor cleaning member for cleaning a surface of a sensor to be cleaned.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 10 (a) to 10 (c), the amount or concentration of a developer (toner) in a developing device is provided in an electrophotographic image forming apparatus. And a sensor cleaning member 50 for periodically wiping and cleaning the sensor surface 4a. The sensor cleaning member 50 is a flat member, and is attached to the toner stirring unit 2 so as to rub against the sensor surface 4a as the developer stirring unit 2 rotates. The sensor cleaning member 50 prevents toner from sticking to the sensor surface 4a, and after sliding by the sensor cleaning member 50,
The toner around the sensor 4 flows into the sensor surface 4a,
This toner is detected by the sensor 4.

[0003]

However, according to the developing device provided with the sensor cleaning member 50 as described above,
If the fluidity deteriorates due to a change in physical properties of the toner during durability, the toner around the sensor 4 does not flow into the sensor surface 4a after the sensor cleaning member 50 rubs the sensor surface 4a, and the toner remains in the developing device. Nevertheless, there has been a problem that toner cannot be detected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a developing method capable of accurately detecting toner even when the fluidity of toner is deteriorated while reliably cleaning the sensor surface. It is an object to provide an apparatus and an image forming apparatus.

[0005]

In order to achieve the above object, the present invention provides a sensor for detecting the amount or concentration of a developer,
A sensor cleaning member for rubbing and cleaning the sensor surface with the rotation of the developer stirring portion, wherein the sensor cleaning member has an opening.
For example, the opening has a shape larger than the sensor surface in the rotation axis direction of the developer stirring section. According to this configuration, while the function of the sensor cleaning member rubbing and cleaning the sensor surface is maintained, the developer near the sensor passes through the opening and remains near the sensor. It is possible to prevent a situation in which the cleaning member scrapes and moves out of the sensor detection range.

Further, the sensor cleaning member may be attached to the developer stirring section so as to be bent at a portion where the opening is formed by contact with the sensor surface. According to this configuration, the developer easily passes through the opening of the sensor cleaning member when cleaning the sensor surface, and the amount of the developer scraped off by the sensor cleaning member is further reduced, so that the sensor detection is more stable.

Further, the sensor cleaning member may be made of a sheet-like elastic body, for example, a polyethylene terephthalate film. According to this configuration, since the sensor cleaning member has flexibility, the sensor cleaning member has excellent durability against bending when coming into contact with the sensor surface, and does not damage the sensor surface when the sensor surface is rubbed.

Further, the sensor cleaning member may be attached to the developer stirring section with its tip end side inclined in the direction opposite to the rotation direction of the developer stirring section. According to this configuration, the burden on the sensor cleaning member due to bending at the time of contact with the sensor surface is reduced.

Further, the developer stirring section has a spiral blade formed around a rotation axis and a stirring film member disposed outside the spiral blade. A cleaning member may be attached.

[0010] The developer stirring section may have a spiral blade formed around a rotation axis, and the sensor cleaning member may be attached to the spiral blade.

According to these configurations, the sensor cleaning member can be configured to rub against the sensor surface without having to be configured separately and independently from the developer agitating section, so that the number of parts can be reduced. it can.

Further, the present invention is an image forming apparatus for forming an electrostatic latent image on a photosensitive drum as a toner image on a sheet, comprising the developing device according to any one of claims 1 to 8. Things.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a developing device and an image forming apparatus according to one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of an image forming apparatus provided with a developing device according to the present invention. As shown in FIG.
In the copying machine (an example of an image forming apparatus) 1, in a copying machine main body 101, a photosensitive drum 103 rotating in a direction A in the drawing is uniformly charged by a charging unit 102 and read by a document reading unit 104. An electrostatic latent image is formed on the photosensitive drum 103 by a laser beam from a laser scanning unit (LSU) 105 based on the scanned original image.
As a result, a developer (hereinafter, referred to as toner) adheres to the electrostatic latent image to form a toner image. The developing device 100 includes a toner stirring unit described later, a sensor for detecting toner,
And a sensor cleaning member. The supply of the toner to the developing device 100 is performed from a toner container (toner supply container) 107.

The paper is conveyed from the paper feeding mechanism 200 via the paper conveying path 204 toward the photosensitive drum 103 on which the toner image is formed as described above, and the toner on the surface of the photosensitive drum 103 is transferred by the transfer roller 108. The image is transferred to the paper. Then, the sheet on which the toner image has been transferred is separated from the photosensitive drum 103 and conveyed to the fixing roller pair 109, and the sheet after fixing the toner image is left as it is (or reversed by a switchback unit (not shown) to perform double-sided copying). Is discharged to the discharge section 111 by the discharge roller pair 110.

A cleaning unit 112 removes residual toner and the like on the photosensitive drum 103. The paper feeding mechanism 200 is detachably attached to the copying machine main body 101 and has a paper feeding cassette 20 for storing paper.
1 and 202 and a stack bypass (bypass tray) 203 provided thereabove, and these are connected to an image forming unit by a paper transport path 204.

Next, the developing device 100 according to the present invention will be described. 2A is a cross-sectional view schematically showing a developing device according to the present invention, FIG. 2B is a cross-sectional view showing a contact portion between the sensor cleaning member and the sensor surface, FIG. 2C is a front view showing the sensor cleaning member, FIG. 3 is a diagram showing the internal configuration of the present developing device.
FIG. 5 is a diagram illustrating a toner stirring unit and a sensor to which a sensor cleaning member is attached. The developing device 100 according to the present invention includes:
Toner stirring section 2 composed of a rotating shaft having spiral blades
And a sensor 4 for detecting toner remaining in the main body case 3, and a sensor cleaning member 5 attached to the toner stirring section 2.

The toner stirring section 2 includes a rotating shaft 21, a spiral blade 22 provided around the rotating shaft 21, and a blade 2.
2 and a stirring film 23 attached to the rotating shaft 21 so as to be positioned outside the rotating shaft 21.
When rotated in the direction of the arrow, the blade 22 and the stirring film 2 are rotated.
3, the toner is agitated. The sensor 4 detects the amount of toner or the toner concentration in the developing device 100 by detecting the toner flowing into the vicinity of the sensor surface 4a, and is attached to the inner wall surface of the main body case 3.

The sensor cleaning member 5 is made of a sheet-like elastic body made of a polyethylene terephthalate film or the like.
It is attached to the stirring film 23. When the toner stirring section 2 rotates, the sensor cleaning member 5
The sensor surface 4a is bent so as to come into contact with the surface a, and is set to a size capable of rubbing the sensor surface 4a. FIG.
As shown in (c), an opening 5 a is formed at a substantially central portion of the sensor cleaning member 5, and the opening 5 a is larger than the sensor surface 4 a in the rotation axis direction of the toner stirring section 2. Is formed. Then, FIG.
As shown in FIG. 5, the base end 5b is attached to the stirring film 23 such that only the portion of the sensor cleaning member 5 where the opening 5a is formed projects from the stirring film 23, and the sensor cleaning member 5 contacts the sensor surface. Then, the sensor cleaning member 5 is set to be bent at the opening 5a. As a result, only the tip 5c of the sensor cleaning member 5 rubs the sensor surface 4a, and the base 5b and the side 5d.
Are designed not to contact the sensor surface 4a.

The sensor cleaning member 5 configured as described above rotates with the rotation of the toner agitating section 2 to rotate the sensor surface 4a.
Contact with the sensor surface 4a due to the rubbing of the tip 5c.
Is removed, but the toner passes through the opening 5a and remains near the sensor surface 4a.
Accordingly, the amount of toner scraped off from the vicinity of the sensor surface 4a by the sensor cleaning member 5 can be reduced without impairing the performance of cleaning the sensor surface 4a by the tip end portion 5c. Detection of the toner density can be performed. When the sensor cleaning member 5 rubs the sensor surface 4a, the tip 5c of the sensor cleaning member 5 and the opening 5a
The cleaning effect of the sensor surface 4a is exerted at the boundary portion of.

Next, a second embodiment of the present invention will be described. FIG. 5 is a diagram showing the internal configuration of the developing device according to the second embodiment, FIGS. 6 and 7 are diagrams showing a sensor cleaning member, a toner stirring section and a sensor in the developing device, and FIG. FIG. 3 is a diagram showing a positional relationship with the data. In this embodiment, the toner stirring section 2 includes a rotating shaft 21 and a blade 22, and the sensor cleaning member 5 is attached to the blade 22 of the toner stirring section 2. In this embodiment, the sensor cleaning member 5 is attached in a direction substantially tangential to the outer periphery of the blade 22, thereby saving the space of the toner stirring section 2. According to this, as shown in FIG. 8, when the sensor cleaning member 5 rotates, the amount of bending due to contact with the sensor surface 4a is small, so that the load on the sensor cleaning member 5 due to the bending is reduced.

It should be noted that the present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the first embodiment, the sensor cleaning member 5 is attached in a direction normal to the cross section of the toner agitating section 2. However, as shown in FIG. The agitating unit 2 may be attached to the agitating film 23 while being inclined in the opposite direction to the rotation direction (the direction of the arrow in FIG. 9). This can reduce the load on the sensor cleaning member 5 and the portion attached to the toner agitating section 2 due to bending at the time of contact with the sensor surface 4a.

In each of the above embodiments, the opening 5a of the sensor cleaning member 5 is formed substantially at the center of the sensor cleaning member 5, and is larger than the sensor surface 4a in the rotation axis direction of the toner stirring section 2. Although the shape is a shape, the present invention is not limited to this, and the position, size, number, and the like of the openings 5a can be appropriately changed. Further, in the above embodiment, the sensor cleaning member 5 is made of a sheet-like elastic body such as a polyethylene terephthalate film, but the material of the sensor cleaning member 5 is not limited to this.

[0023]

As described above, according to the present invention, while the sensor cleaning member maintains the function of rubbing and cleaning the sensor surface, the developer in the vicinity of the sensor passes through the opening and adheres to the sensor surface. Since the developer remains, when the developer remains in the developing device, the sensor can surely detect the developer.

Further, if the sensor cleaning member is bent at the opening when it comes into contact with the sensor, the developer easily passes through the opening of the sensor cleaning member when cleaning the sensor surface, and the sensor cleaning member scrapes the developer. Since the amount of developer to be used is further reduced, sensor detection is more stable.

If the sensor cleaning member is made of a sheet-like elastic body, for example, a polyethylene terephthalate film, the durability of the sensor cleaning member against bending at the time of contact with the sensor surface is improved because the sensor cleaning member has flexibility. Excellent, and does not damage the sensor surface when the sensor surface is rubbed.

If the tip of the sensor cleaning member is inclined to the direction opposite to the rotation direction of the developer agitating portion and is attached to the developer agitating portion, the sensor cleaning due to bending at the time of contact with the sensor surface is performed. The burden on the members is reduced.

Further, if the sensor cleaning member is attached to the spiral blade or the stirring film member of the developer stirring section, the sensor surface can be slid even if the sensor cleaning member is not formed separately from the developer stirring section. Since it can be configured to be rubbed, the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a schematic configuration of a copier including a developing device according to the present invention.

2A is a cross-sectional view schematically showing a developing device according to the present invention, FIG. 2B is a cross-sectional view showing a contact portion between a sensor cleaning member and a sensor surface, and FIG. 2C is a front view showing the sensor cleaning member. FIG.

FIG. 3 is a diagram illustrating an internal configuration of the developing device.

FIG. 4 is a front view showing a toner stirring unit to which a sensor cleaning member is attached and a sensor.

FIG. 5 is a diagram illustrating an internal configuration of a developing device according to a second embodiment of the present invention.

FIG. 6 is a front view illustrating a sensor cleaning member, a toner stirring section, and a sensor in the developing device.

FIG. 7 is a perspective view showing a sensor cleaning member, a toner stirring section, and a sensor in the developing device.

FIG. 8 is a diagram showing a positional relationship between the sensor cleaning member and a sensor.

FIG. 9 is a diagram illustrating another example of attachment of the sensor cleaning member to the toner stirring section.

10A and 10B are diagrams illustrating a conventional developing device, in which FIG. 10A is a cross-sectional view schematically illustrating the developing device, FIG. 10B is a cross-sectional view illustrating a contact portion between a sensor cleaning member and a sensor surface, and FIG. FIG. 4 is a front view showing a sensor cleaning member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier (image forming apparatus) 2 Toner stirring part 4 Sensor 4a Sensor surface 5 Sensor cleaning member 5a Opening 21 Rotation shaft 22 Blade 100 Developing device

Claims (9)

[Claims] 1. A developing device comprising: a sensor for detecting an amount or a concentration of a developer; and a sensor cleaning member for rubbing and cleaning a sensor surface with rotation of a developer stirring section, wherein the sensor includes: A developing device, wherein an opening is formed in the cleaning member. 2. The developing device according to claim 1, wherein the opening has a shape larger than a surface of the sensor in a rotation axis direction of the developer stirring section. 3. The developing device according to claim 1, wherein the sensor cleaning member is attached to the developer agitating portion so as to be bent at a portion where the opening is formed by contact with the sensor surface. 3. The developing device according to 2. 4. The sensor agitating member according to claim 1, wherein the sensor cleaning member is attached to the developer agitating portion such that a front end portion thereof is inclined in a direction opposite to a rotation direction of the developer agitating portion.
The developing device according to claim 3. 5. The developing device according to claim 1, wherein said sensor cleaning member is made of a sheet-like elastic body. 6. The sensor cleaning member is made of a polyethylene terephthalate film.
3. The developing device according to claim 1. 7. The developer stirring section includes a spiral blade formed around a rotation axis, and a stirring film member disposed outside the spiral blade. The developing device according to claim 1, further comprising a cleaning member. 8. The sensor according to claim 1, wherein the developer stirring section has a spiral blade formed around a rotation axis, and the sensor cleaning member is attached to the spiral blade. 7. The developing device according to any one of 6. 9. An image forming apparatus for forming an electrostatic latent image on a photosensitive drum as a toner image on a sheet, comprising the developing device according to claim 1. Description: Image forming apparatus.