JPH0695244B2 - Development device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a developing device equipped in an electrostatographic copying machine, a facsimile machine, or the like, and more specifically, to a developer accommodating case in which toner and carrier are mixed. A stirring means for stirring the developer in the case and the toner from the toner replenishing part and pumping the stirred developer to the developing sleeve, and removing the excess developer scraped from the developing sleeve. The present invention relates to a developing device in which a partition plate is provided to the agitating means for recirculating, and a plurality of guide ridges are provided on the upper surface of the partition plate to bias the recirculation direction of the developer to one side in the sleeve axis direction. is there.

(Prior Art) As a conventional stirring means in the above-mentioned developing device, a developer introduced into the inside of a cylindrical body from one side of the cylindrical body is rotatable around an axis parallel to the sleeve axis. A typical example is one in which a spiral blade that moves in the direction opposite to the guide direction by the ridge is built in, and a stirring blade in the axial direction of the cylinder is provided on the outer peripheral surface of the cylindrical body at intervals in the circumferential direction. is there.

Such a means is configured such that the developer is circulated toward the one side of the cylindrical body with the stirring blade to be refluxed, and the developer introduced into the cylindrical body is directed to the other side of the cylindrical body. By the transfer, in addition to the vertical swirl stirring by the stirring blade, the horizontal stirring by the transfer of the developer in the cylinder axis direction is performed.

(Problems to be Solved by the Invention) However, with the above means, it is not possible to increase the speed of the lateral stirring, and the replenishment toner and the developer inside the tubular body are not mixed, and the toner is Although the toner is newly replenished, the developer itself from the other side of the cylindrical body is unevenly supplied to the developing sleeve, and the toner concentration in the axial direction of the sleeve tends to vary. .

The present invention has been made in view of the above situation,
The purpose is to achieve high speed of lateral stirring and uniform toner concentration by a simple improvement.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a toner for replenishing the toner in an upper part of an accommodation case for accommodating a developer obtained by mixing a toner and a carrier. A replenishment section is provided,
Further, the agitating means for agitating the developer accommodated in the accommodating case and the toner dropped and replenished from the toner replenishing portion, and for agitating and supplying the agitated developer to the developing sleeve are provided. A partition plate, which is provided below the toner replenishing portion and is used to recirculate the excess developer scraped from the developing sleeve, is provided so that its tip faces directly above the stirring means, and the upper surface of the partition plate. In the developing device, a plurality of guide ridges for biasing the recirculation direction of the developer to one side in the sleeve shaft center direction are provided, wherein the agitating means is provided around the shaft center parallel to the sleeve shaft center. The rotationally driven tubular body and the outer circumferential surface of the tubular body are circumferentially spaced apart from each other and are vertically installed in a spiral shape in a direction opposite to the bidirectional direction of the guide ridges. The developer that is circulated is changed in its odd direction. Is a stirring blade that moves in the opposite direction, and a spiral blade that is provided in the cylindrical body to transfer the developer introduced into the cylindrical body in a direction opposite to the eccentric direction of the guide ridge. And on the front side in the rotation direction of the stirring blade in the tubular body, a hypotenuse portion formed in a direction along the front surface direction in the rotation direction of the stirring blade, and the axis of the tubular body. The first opening formed in a substantially right-angled shape having a long side portion notched in the direction and a short side portion notched in the circumferential direction of the tubular body, While being provided with a gap in the longitudinal direction of the agitator, on the rear surface side of the stirring blade in the rotation direction of the stirring blade, a hypotenuse portion cut out in a direction along the rotation direction rear surface portion of the stirring blade, and A long side portion formed by cutting out in the axial direction of the tubular body, and a notch in the circumferential direction of the tubular body. A second opening that is opened in a substantially right-angled triangular shape and a formed short side portion,
It is characterized in that it is provided with a gap in the longitudinal direction of the tubular body.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a stirring unit A, and FIG. 2 is a schematic sectional view of a developing device. In the case 2 containing the developer 1 in which toner and carrier are mixed, the photoconductor 3
Is provided with a non-magnetic developing sleeve 4 which rotates in the opposite direction to the photoconductor 3, and magnets 5 ... Are statically arranged inside the developing sleeve 4, and the toner replenishing case 6a is provided. A toner replenishing section 6 having a toner replenishing roller 6b arranged in a lower portion is continuously provided on the upper side of the developer accommodating case 2 and below the toner replenishing roller 6b with respect to the developer accommodating case 2. Providing stirring means A at the site,
Further, a partition plate 8 for circulating the excess developer 1 scraped from the developing sleeve 4 by the spike cutting member to the stirring means A is provided, and the excess developer 1 is provided on the upper surface of the partition plate 8. A plurality of guide ridges 9 ... Which biases the recirculation direction of the above into one side in the sleeve axial direction are continuously provided.

Thus, the sensor S arranged near the ear cutting member 7
When the toner density of the developer 1 is detected to decrease, the toner replenishing roller 6b is rotated accordingly, the toner is supplied to the upper part of the stirring means A, and the toner is stirred and mixed in the developer. The mixed developer 1 is pumped up and supplied onto the developing sleeve 4.

Then, as the developer 1 that has passed through the bristle cutting member 7 comes into contact with the surface of the photoconductor as the developing sleeve 4 rotates, the electrostatic latent image on the surface of the photoconductor is developed. .

Next, the specific structure of the stirring means A will be described. This is made by externally fitting a plurality of stirring tool units 10 on the rotary shaft 11, and the details of the stirring tool unit 10 are as follows. This is as shown in FIGS. 1 and 3 to 7.

That is, the unit body 10 is a boss body 13 that is fitted onto the rotary shaft 11 outside.
On the other hand, a fitting protrusion a is formed on one end side thereof, and a fitting recess b corresponding to the protrusion a is formed on the other end side thereof, and two spiral blades 14 that are slightly swirl in the same direction are formed on the boss body. A plurality of stirring blades that are connected to the spiral blade 14 and that have a cylindrical body 15 integrally connected to the outer peripheral end of the spiral blade 14 and that are twisted in the same direction as the spiral blade 14.
16 are provided on the outer peripheral surface of the tubular body 15 at intervals in the circumferential direction, and V-shaped notches c and d are formed on the end side of the tubular body 15.

Thus, in the unit body 10, 10 of its neighbor, its spiral wing 1
A plurality of the unit bodies 10 are externally fitted to the rotating shaft 11 so that the stirring blades 16 and 14 and the stirring blades 16 and 16 are connected in series, and the stirring blades 16 pump the stirring developer 1 to the sleeve 4. Along with the rotation (the direction of rotation is indicated by R) when feeding up,
In order to transfer the developer 1 introduced into the inside of the tubular body 15 and the developer 1 at the peripheral portion of the tubular body 15 in the direction opposite to the eccentric direction by the ridges 9 ... The spiral direction of the stirring blade 16 is set.

The V-shaped notches c and d are for connecting the inside and outside of the tubular body 15 with the plurality of unit bodies 10 fitted on the rotary shaft 11 outside.
To form an opening c and a second opening d, and two openings c and d each having a phase of 90 degrees around the cylinder axis are provided in the longitudinal direction of the rotary shaft 11. It is provided at intervals.

Therefore, the first and second openings c and d have the toner supply roller 6
In a state of facing b and the partition plate 8, the toner dropped and supplied from the roller 6b and the surplus developer 1 recirculated from the partition plate 8 are taken into the tubular body 15 through both openings c and d.
The surplus developer 1 is agitated and transferred in the cylindrical body 15 by the spiral blades 14 in a direction opposite to the direction biased by the guide ridges 9 of the partition plate 8. A high-speed and uniform stirring effect can be obtained.

Also, when the first and second openings c and d face in the lateral direction,
Due to the inertial force, a part of the developer 1 in the cylindrical body 15 is partially removed.
It is emitted to the outside through the openings c and d of. And the first and second
In a state in which the openings c and d of the stirring blade face downward, the developer 1 is pushed away by the stirring blade 16 rotating prior to the opening, and a gap is formed in the rear portion of the stirring blade 16, whereby the first and second
The openings c and d of will face the gap. Therefore, at that time, a part of the developer 1 in the cylindrical body 15 is dropped and discharged to the outside from the first and second openings c and d.

Then, in the process in which the first opening c faces upward, the developer 1 is opened c as if the stirring blade 16 scoops the developer 1.
Is introduced into the tubular body 15 from the second opening d.
In the process of turning upward, the stirring blade 16 rotating prior to the opening d acts so as to close the opening d, and as a result, the inflow of the developer 1 from the opening d into the cylindrical body 15 is restricted. As a result, the developer 1 in the cylindrical body 15 is released to the outside of the opening d by the action of centrifugal force.
That is, in addition to the introduction of the developer 1 from one side of the cylindrical body 15 group, the introduction of the developer 1 and the toner into the cylindrical body 15 and the outside of the cylindrical body 15 through the plurality of openings c and d. Is complicated and complicated and is performed at high speed. Therefore, the stirring and mixing of the developer 1 and the replenishment toner can be performed at high speed and efficiently, and the toner concentration in the axial direction can be made uniform. It can be achieved.

Now, regarding the shape of the openings c and d, the first opening c has a side portion in the direction along the cylinder axis, a side portion in the rotation direction, and a direction in the rotation direction front surface portion S ₁ of the stirring blade 16. The second opening d has a substantially right-angled triangular shape having a hypotenuse and a substantially right-angled triangle having the right-angled two sides as described above and the hypotenuse along the rear surface S ₂ in the rotation direction of the stirring blade 16. Of the replenishment toner that enters the first opening c of these, the _one that drops and abuts the front surface portion S ₁ corresponding to the hypotenuse portion is a spiral blade due to the force component of the front surface portion S _1. As a result of receiving the transfer force in the same direction as the transfer direction of the developer 1 by 14, the developer 1
There is an advantage that it can be smoothly merged and transferred.

By forming the first and second openings c and d in the shape of the right triangle as described above, when the first opening c faces upward, the toner and the reflux developer 1 raked by the stirring blade 16 Since the opening width is expanded in the flow direction of the developer, a good intake effect can be obtained without omission, and when the second opening d faces downward, the circumferential movement direction of the developer 1 in the cylindrical body 15 is reduced. Since the opening width is widened toward, that is, toward the long side portion, a good discharge effect can be obtained.

Although the stirring means A is mainly composed of a set of stirring tool units 10, a series of spiral blades 14 extending over substantially the entire length of the rotating shaft 11 are provided, and a plurality of stirring blades 16 are connected in series. By forming appropriate openings c and d in one tubular body 15,
This can be deformed by externally fitting it to the spiral blade 14 and fixing it.

Next, FIG. 8 shows an experimental result of stirring and mixing using the developing device having the above-mentioned configuration.

In the developing device used, the stirring blade 16 of the stirring means A is
Twelve pieces are provided at equal intervals in the circumferential direction of the cylindrical body 15 and have a twist angle of 10 degrees, two spiral blades 14 are provided with 4 pitches at a twist angle of 35 degrees, and a partition plate. Sixteen guide ridges a of 8 are provided at equal intervals.

Regarding the dimensions of each part of the stirring means, the outer diameter of the boss body 13 ... 12 mm, the inner diameter of the tubular body 15 ... 25 mm, the outer diameter of the tubular body 15 ... 28 mm, the circumferential flow rate L _{1 of the} unfolded tubular body 15 ... 97.34 mm the tubular body 15 Total length of the group L ₂ … 308 mm Height of the stirring blade 16 H ₁ … 4.0 mm Length of the partition plate 8 in the axial direction of the sleeve L ₃ … 307 mm Inclination direction length L ₄ … 32 mm Inclination angle θ ₁ … 60 Degree Horizontal upper end length L ₅ … 7mm Dimension between guide ridges 9 and 9 L ₆ … 20mm Deflection angle θ ₂ of guide ridge 9… 50 degrees About the first and second triangular openings c and d Side length in axial direction l ₁ … 23mm Side length in rotational direction l ₂ … 5.83mm Oblique side length l ₃ … 16.55mm Opening pitch P… 38.5mm in the same direction around the cylinder axis In the experiment, in FIG. 1, a relatively low-concentration developer 1 with sufficient stirring and mixing was supplied to the left half from the center of the group of cylindrical bodies 15 ... Supplying a developer 1 degrees, and the developing sleeve 4 is rotated at 200 rpm, rotates the rotary shaft 11 in 166.6Rpm.

Further, the relative concentration value of the developer 1 is measured by the first measurement before the start of stirring and mixing, and then at the 1st, 3rd, 5th and 10th minutes after the start of stirring and mixing, respectively. Measured. The measurement points are 5 points P _{1 to} P ₅ (in order from the low-concentration developer side) of each central part of the cylindrical body 15 ... Group divided into five, and the mixing ratio of the developer 1. The measurement of the above-mentioned 5 points P ₁ ~
The developer 1 at P ₅ was taken out with a spoon, and the ratio of the toner to the carrier was measured using a developer concentration measuring device known per se.

The obtained results are as shown in FIG. 8, in which the relative density value of the relatively low density developer is 0.0, the relative density value of the relatively high density developer is 1.0, and the predetermined time The relative density values of the developer at the above-mentioned 5 points P _{1 to} P ₅ after the elapse are shown.

As is apparent from FIG. 8, it can be easily understood that by using the developing device having the above-described configuration, sufficient stirring and mixing of the developer 1 in the width direction of the developing device was achieved at high speed. It should be additionally noted that the deviation of the developer in the width direction did not occur.

By the way, in the past, it took about 10 minutes to achieve stirring and mixing.
It took ~ 15 minutes, but in this apparatus, substantially uniform stirring and mixing was achieved in 5-6 minutes.

(Effects of the Invention) As described above, according to the developing device of the present invention, the stirring blade is provided with a twist angle so as to exert the function of transferring the developer, and
By providing the cylindrical body with an opening that communicates the inside and the outside of the cylindrical body, it has been possible to achieve high speed stirring of the developer in the width direction of the developing device, that is, lateral direction, and uniform toner concentration.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a perspective view of a stirring means in which a stirring tool unit is taken out and enlarged, and FIG. 2 is a sectional view of a developing device. FIG. 3 is a front view of a part of the tubular body group, and FIG. 4 is IV of FIG.
-IV line view, FIG. 5 is a V-V line view of FIG. 4, and FIG. 6 is a VI-VI line view of FIG. FIG. 7 is a developed view of the cylindrical body group, and FIG. 8 is a graph showing the experimental results of the stirring effect. 1 ... Developer, 2 ... Container case, 4 ... Development sleeve, 6 ... Toner supply section, 8 ... Partition plate, 9 ... Guide ridge, 14 ... Spiral blade, 15 ... Cylindrical body , 16 …… Stirring blade, A…
... stirring means, c ... first opening, d ... second opening.

Claims (1)

[Claims] 1. A toner replenishing section for replenishing toner is provided in an upper part of a housing case for housing a developer formed by mixing toner and a carrier, and the development housed in the housing case. An agitating unit for agitating the developer and the toner dropped and replenished from the toner replenishing unit and pumping up and supplying the agitated developer to the developing sleeve is provided below the toner replenishing unit. A partition plate for recirculating the excess developer scraped off from is provided so that its tip faces directly above the stirring means, and the developer recirculation direction is provided on the upper surface of the partition plate in the sleeve shaft. In a developing device provided with a plurality of guide ridges that are biased to one side in the core direction, the agitating means has a tubular body that is rotationally driven about an axis parallel to the sleeve axis, and the tubular body. Around the outer peripheral surface of An agitating blade that stands upright in a spiral shape in a direction opposite to the eccentric direction of the guide ridges and transfers the developer eccentric / refluxed by the guide ridges in the direction opposite to the eccentric direction. And a spiral blade provided inside the tubular body for transferring the developer introduced into the tubular body in a direction opposite to the eccentric direction by the guide ridge, and On the front side of the stirring blade in the rotation direction of the stirring blade, a hypotenuse portion cut out in a direction along the rotation direction front surface of the stirring blade and a length cut out in the axial direction of the tubular body. A first opening, which has a side portion and a short side portion formed by cutting out in the circumferential direction of the tubular body, and which is opened in a substantially right-angled triangular shape, forms a space in the longitudinal direction of the tubular body. On the other hand, the stirring blade is provided on the rear surface side in the rotation direction of the stirring blade in the tubular body. The hypotenuse part cut out in the direction along the rear face in the rotational direction, the long side part cut out in the axial direction of the tubular body, and the short side cut out in the circumferential direction of the tubular body. A developing device, characterized in that a second opening having a side portion and formed in a substantially right-angled triangular shape is provided at intervals in the longitudinal direction of the cylindrical body.