JPH0155455B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer stirring device for a developing machine that uses a two-component developer consisting of toner and carrier.

In a developer using a two-component developer consisting of toner and carrier, the mixing ratio and mixing state of the toner and carrier have a large effect on image quality.

For example, if the toner density is uneven in the axial direction (that is, in the axial direction of the developing roll), the image on the photosensitive material becomes uneven in the axial direction, making it impossible to obtain a uniform copy.

Additionally, if the amount of toner in the developer suddenly increases due to variations in the amount of toner supplied to the developer, the toner and carrier will not be mixed sufficiently, and the toner with insufficient charge will be carried to the development area, causing the photosensitive material to be damaged. It adheres to the background area and causes fogging on the copy.

To this end, various types of stirring devices have been proposed to stir the toner and carrier, but they have not produced satisfactory results, and when replenishing toner, the amount of toner supplied must be uniform in the axial direction, which requires complicated methods. No means have been proposed that would yield a sufficiently satisfactory result.

In other words, in conventional developing machines, the developer after development is dropped directly into the housing of the developing machine, and toner is also supplied directly to the developer in the housing, making it difficult to mix and stir the toner and carrier. In addition, since uniformity in the axial direction is strictly required when toner is supplied, the above-mentioned problems occur.

In addition, in order to completely replace the developer in the housing of a conventional developing machine, the developing machine body such as the developing roll must be removed from the housing, the developer must be drained, and then the developer must be filled with new developer and replaced. ing.

For this reason, there are problems in that the task of discharging the developer becomes very troublesome, and the task of replacing the developer also becomes very troublesome.

The present invention was made in view of the above circumstances, and its purpose is to transport the developer of the developing machine, mix it in a dedicated mixing chamber, stir it, and then transport it into the housing of the developing machine, thereby sufficiently mixing toner and carrier. To provide a developer stirring device for a developing machine that can mix and stir the developer in a housing and easily discharge the developer in the housing.

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

FIG. 1 is a perspective view, in which a housing 2 of a developing machine A is provided facing a drum-shaped photosensitive material 1, and the housing 2 has a bottom wall 2a curved in a substantially U-shape and a pair of housings that cover openings on both sides of the bottom wall 2a. A pair of developing rolls 3 ₁ , 3 ₂ and a conveyance paddle 4 are rotatably provided between the pair of side walls 2 b, and a scraping plate 5 is in contact with the second roll 3 ₂ . In addition, a U-shaped groove 6 is formed continuously with the scraping plate 5 and extends between the pair of side walls 2b (that is, continuous in the axial direction of the developing roll 3). A first auger 7, which is open outward from the opening 2'b and serves as a first conveyance means, is provided in the groove 6 so as to be rotatable in the longitudinal direction.

A second auger 8 serving as a second conveying means is rotatably supported in the axial direction of the conveying paddle 4, and one end 8' of the second auger 8 is connected to the side wall 2.
It protrudes outward from the opening 2''b formed in b.

9 is an auxiliary housing fixed to the side wall 2b, and one end portion 7' of the first and second augers 7, 8;
A chamber 10 dedicated to conveyance and mixing is formed at an intermediate position between the first auger one end 7' and the second auger one end 8'. A conveying and mixing blade 11 is rotatably provided in the mixing chamber 10, and a toner box 12 is located above the first auger end 7'.
An auger 13 serving as a replenishment toner conveying means connected to
is coming.

Reference numeral 14 denotes an ear stand adjustment member.

Note that the first and second developing rolls 3 ₁ and 3 ₂ are magnets 3
A sleeve 3b is rotatably provided around a.

The bottom wall 9a of the auxiliary housing 9 has a substantially U-shape with a flat bottom portion 9'a and rising portions 9''a, 9''a at both ends. , between the mixing blade 11 and the second auger 8), an opening 20 serving as a discharge port is formed, and the opening 20 is closed with a cover 21.

The cover 21 has both end walls 22 having an inverted V shape,
22, and mounting flanges 23, 23 integrally formed on both end walls 22, 22.
22 is fitted so that the vertical portions 22a, 22a of the opening 20 come into contact with the opposing end surfaces 20a, 20a,
Attach the mounting flanges 23, 23 to the bottom 9'a with bolts 2.
4, the cover 21 is removable, and is conveyed by both end walls 22, 22 of the cover 21, conveyed through the lower part of the mixing chamber 10, and connected to the mixing blade 11 side and the second auger. It is divided into 8 sides.

The photosensitive material 1 is transported by the developing roll 3.
The developer that has passed through the developing area A, which is opposite to the developer area A, falls and accumulates in the groove 6 even if it is separated by the scraping plate 5.

The toner concentration in the developer in the groove 6 is lower than the toner concentration in the developer in the housing 2, and the toner concentration in the axial direction (developing roll axial direction) is non-uniform.

The developer in the groove 6 is then transported and dropped by the first auger 7 into the transport mixing chamber 10 while being mixed, and then transported and dropped from the auger 13 by the transport mixing blade 11 rotating within the transport mixing chamber 10. The toner is conveyed and supplied to one end 8' of the second auger 8 while being mixed with the replenishment toner.

The second auger 8 transports and supplies the developer with a transport mixing blade 11, further mixing the supplied developer through the mixing action of the auger, and transports the developer into the transport paddle 4, where it is deposited onto the developer inside the transport paddle 4, such as through the slits on the outer wall of the auger. It falls and is sequentially supplied to the developing roll 3.

The developer supplied to the developing roll 3 in the above manner always has a uniform toner concentration in the axial direction, and the toner and carrier are sufficiently mixed to maintain the toner in a normally charged state. .

Further, since the toner replenishing mechanism does not need to uniformly supply replenishing toner over the entire axial direction, the toner replenishing mechanism can be made simple in structure and inexpensive.

Also, when discharging the developer, use the bolt 24.
The cover 21 may be removed from the opening 20 by loosening it, and the developer may be allowed to fall and be discharged from the opening 20.

Therefore, the developer can be discharged without removing the developing machine main body within the housing 2, and the developer discharge operation can be easily performed.

Further, since the cover 21 has an inverted V shape and is provided between the conveyance/mixing blade 11 and the second auger 8, a large amount of developer spills out from the opening 20 when the cover 21 is removed. In addition, one end wall 22 of the cover 21 serves as a conveyance guide for the second auger 8, so the second auger 8 smoothly conveys the developer to the paddle. 4, and the cover 21 and the auger conveyance guide can be made into one member, simplifying the structure.

In the above embodiment, an auger is used to transport the developer to the mixing chamber 10, but other transport means may be used, such as one using an inclined plate and a vibration effect, or one using an air flow.

Furthermore, the shape of the conveying and mixing blades 11 is not limited to the shape shown in the drawings, and the toner replenishment mechanism and toner replenishment position are not limited to the above embodiments and may be the same as conventional ones.

In the present invention as described above, since the toner and carrier are sufficiently mixed and stirred to obtain a sufficient amount of charge, good development can be performed without toner adhering to the background portion of the sensitive material.

Furthermore, by removing the cover 21, the developer inside the housing 2 can be discharged from the discharge port 20, and the developer inside the housing 2 can be discharged without removing the main body of the developing machine inside the housing 2 as in the conventional case. Therefore, the developer can be easily discharged.

In addition, since the cover 21 has an inverted V shape,
When the cover 21 is removed, a large amount of developer is not discharged at once, and the operator's hands are less likely to get dirty, and the cover 21 rotates on one inclined end wall 22 of the inverted V-shape. The blades 11 constitute a transport/mixing section to define an area where the new toner and the developer used for development are sufficiently mixed, while the other inclined end wall 22 functions as a transport guide for the second auger 8. Therefore, the developer can be smoothly transported into the housing 2.

In this way, the cover 21 is effective because it plays the three roles of cover, conveyance/mixing section constituent material, and conveyance guide with one member, and also has the effect of facilitating the production of the auxiliary housing main body. There is also.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of an auxiliary housing portion, and FIG. 3 is a longitudinal cross-sectional view. 1 is a photosensitive material, 2 is a housing, 3 is a developing roll,
6 is a groove portion, 7 is a first conveying means, 8 is a second conveying means (second auger), 9 is an auxiliary housing, 10 is a dedicated chamber for conveying and mixing, 20 is a discharge port, and 21 is a cover.

Claims (1)

[Claims] 1 All or part of the developer that has passed through the development area and has been used for development is transported by the first transport means to a dedicated transport and mixing chamber equipped with a toner replenishing means at the upper part, and the transport and mixing are carried out by the first transport means. The developer in the dedicated chamber is transported into the housing of the developing machine A by a second transport means, and a rotary blade is provided in the dedicated transport and mixing chamber adjacent to an auger serving as the second transport means.
A discharge port is formed between the rotary vane on the bottom wall of the mixing chamber and the auger of the second conveying means, and a cover in an inverted V shape is removably provided at the discharge port.
The bottom wall of the mixing chamber is configured such that one inclined end wall of the inverted V-shaped cover constitutes a conveying and mixing section for the rotating blade, and the other inclined end wall constitutes a conveying guide for the auger. A developer stirring device for a developing machine characterized by the following features.