JPH04204574A - Developing powder supply device - Google Patents

Abstract

PURPOSE:To improve a carrying property with possibility, remaining developers in a bottom part of a casing due to insufficient carrying, eliminated by fitting the shape of a carrying auger to a tapered surface of the casing to make a tapered state. CONSTITUTION:A casing 1 is manufactured by the injection molding of synthetic resin, and has a tapered state expanded to a cover body 1a. Also a carrying auger 3 is made a tapered state in which its tip part is slightly narrow and it is expanded to a base part. Setting a supply device filled with developers causes the engaging of a drive mechanism and an engaging piece 3b to rotate the auger 3. This rotation turns a stirring rotations member 2 via a gear 3a and a driven gear 2c. This rotation of the member 2 stirs the developers, and a part of them is carried in a supply port 4 direction via the auger 3. Consequently the developers are gradually reduced, however are totally discharged from the supply port 4 without remaining in a bottom part because the outer peripheral edge of the auger 3 is parallel to the bottom surface of a housing part 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a powder supply device for development, and more particularly to an improvement of a powder supply device for development used in an electrophotographic copying device.

(Prior Art) Conventionally, as a supply device for developing powder (hereinafter simply referred to as developer) used in an electrophotographic copying apparatus, a rotating member accommodating section for stirring and an auger accommodating section for conveyance are connected to each other and arranged in parallel. A rotating member for stirring and an auger for conveyance are each rotatably provided in a casing made of a metal casing. The powder was supplied to the developer storage section of the development unit through a supply port provided near the tip of the auger.

However, it has been found that this conventional developing powder supply device has a problem in that the developer is not completely conveyed between the conveying auger and the bottom of the casing and remains there.

Therefore, as a result of investigating the cause, we found that casings are conventionally molded with a draft angle of about 1-3 degrees to remove the mold during molding, and the resulting casing has a tapered shape as a whole. On the other hand, regardless of the shape of the casing, the diameter of the screw crest and the diameter of the trough are constant, and the overall outer diameter of the conveyance auger is the same.As a result, the conveyance auger It has been found that a considerable gap is created between the auger and the bottom of the casing, which causes developer to remain between the conveying auger and the bottom of the casing.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a powder supply device for development that has good developer transportability without the risk of the developer remaining at the bottom of the casing. shall be.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention takes a measure of tapering the shape of the conveying auger to match the tapered surface of the casing.

That is, the present invention provides a casing having a substantially cylindrical shape and including a stirring means housing part and a developing powder conveying means housing part which is provided in communication with and in parallel with the stirring means housing part, and the stirring means housing part. a stirring means rotatably provided in the part and having a driven gear attached to one end; and a rotation drive rotatably provided in the developing powder conveying means accommodating part and meshing with the driven gear of the stirring means at one end. a developing powder conveying means to which a developing gear is attached and the other end protrudes outward from the casing and has an engaging piece for rotational driving; and a developing powder conveying means provided in the casing near the tip of the developing powder conveying means. A developing powder supply device having a developing powder supply port, wherein the casing has a tapered shape based on the die cutting slope, and the developing powder conveying means also corresponds to the tapered shape of the casing. Provided is a developing powder supply device, characterized in that the outer peripheral edge of the developing powder conveying means is formed in a tapered shape and is parallel to the bottom surface of the developing powder conveying means accommodating portion of the casing. It is something to do.

(Function) In the developing powder supply device of the present invention, the slope of the bottom surface of the developing powder conveying means accommodating portion of the casing and the tapered surface of the developing powder conveying means are parallel to each other. Therefore, there is no possibility that the developing powder will ultimately remain on the bottom surface of the developing powder conveying means accommodating portion of the casing.

(Example) Hereinafter, the present invention will be explained with reference to the illustrated embodiments.

First, with reference to FIG. 3, a general internal mechanism (electrophotographic process configuration mechanism) of an image forming apparatus to which the developing powder supply device of the present invention is applied will be explained.

FIG. 3 schematically shows a side view of the image forming apparatus, in which a photoreceptor drum 20 as an image carrier is arranged approximately in the center of the apparatus main body.
is a copying speed of 95 in the direction of arrow C by a drive mechanism (not shown).
mm/see and is rotated at the same speed as the moving speed of the table 5. The photosensitive drum 20 is made of a negatively chargeable organic photoconductor (OPC), and has a structure in which a charge generation layer and a charge transport layer covering the charge generation layer are formed on the surface of an aluminum cylinder. There is.

Around the photoreceptor drum 20, along the direction of rotation thereof, there are provided a charging charger 21 as a charging means, a charge removal/exposure device 22 as an electrostatic latent image forming means, a developing device unit 23 as a developing means, and a transfer means. A transfer charger 24 as a transfer charger, a peeling charger 25 as a peeling means, and a cleaner unit 26 as a cleaning means are arranged in this order.

Further, inside the main body of the apparatus, paper P fed from the paper feed cassette 42 via the paper feed means 33 and a manual paper feed tray 5 are provided.
The paper P manually fed from 3 is transferred to the photosensitive drum 20.
A paper transport path 28 is formed which leads to a paper discharge tray 54 mounted on the left side of the main body of the apparatus via an image transfer section 27 between the image transfer unit 24 and the transfer charger 24.

A pair of aligning rollers 29 is arranged on the upstream side of the image transfer section 27 of the paper transport path 28, and a fixing unit 30 as a fixing means and a pair of paper ejecting rollers 31 as a paper ejecting means are arranged on the downstream side. has been done. Furthermore, an aligning switch 32 is installed near the two pairs of aligning rollers.
is provided.

Note that 35 is an ozone filter that neutralizes ozone generated by each charger 21, 24, and 25, and 36 is a cooling fan unit that prevents a rise in temperature inside the machine. 37 is a toner cartridge installed in the developing unit 23.

As the photoreceptor drum 20 rotates in the direction of arrow C, the surface of the photoreceptor drum 20 is charged to -700V by the charger 21. The charging device 21 is equipped with a grid 21a, and the grid 21a is used during charging.
The voltage of 1a is set to 1750v.

The negatively charged photoreceptor drum 20 is transferred to an exposure device 2 that also serves as a charge remover.
A light-condensing optical transmitter (trade name, SELFOC lens array) 43 transmits an original image on an original platen 41 made of transparent glass, which is uniformly illuminated by a lamp 40 as a rod-shaped light source constituting a light source. An image is formed on the surface of the photoreceptor drum 20 to form an electrostatic latent image on the surface of the photoreceptor drum 20.

Next, the electrostatic latent image on the photoreceptor drum 20 is made visible by being opposed to the developer unit 23 and having positive polarity toner attached thereto.

The developing unit 23 uses a positive polarity two-component magnetic brush system, and the sleeve 44a of the developing roller 44, which is a toner layer holding member, is moved in the direction of arrow d at a speed higher than that of the photoreceptor drum 20 (approximately 3.3 ~3.5 times) and a bias voltage of -200V is applied.

On the other hand, in synchronization with this toner image forming operation, the paper P taken out from the paper feed cassette 42 or manually fed from the manual paper feed table 53 is sent to the image transfer section 27 via the aligning roller pair 29.

The paper P fed into the image transfer section 27 is fed by a pre-transfer guide 45 so as to come into close contact with the surface of the photoreceptor drum 20, and the toner image previously formed on the photoreceptor drum 20 is transferred to the transfer charger 24. The image is transferred to the paper P due to the negative charging effect. Then, the paper P on which the toner image has been transferred is AC-charged by the peeling charger 25 and peeled off from the surface of the photoreceptor drum 20 and transported along the paper transport path 28 and along the fixing device front guide 46. The image is sent to the fixing device unit 33. Then, the toner image is fixed to the fixing roller pair 4.
7, the paper P is fused and fixed, and then is discharged onto the paper discharge tray 54 via the paper discharge roller pair 31.

The fixing roller pair 47 includes a lower roller 47a coated with Teflon-based resin on an 8Ω core metal, and a heater 52 built inside, and a press roller 4 made of silicone rubber.
Since the surface of the lower roller 47a is negatively charged, it attracts positive polarity toner, causing offset or staining of the press roller 47b. In this device, the lower roller 47a is coated with PTFE in which carbon black is dispersed to lower the resistance of the resin layer, and is grounded by a leaf spring (not shown) to prevent charging.

Note that after the toner image is transferred onto the paper P, the residual toner remaining on the photosensitive drum 20 is scraped off by the cleaning blade 26a of the cleaner unit 26. Furthermore, after this, the afterimage on the surface of the photoreceptor drum 20 is erased by the static eliminating light from the static eliminating/exposure device 22, and the image returns to the initial state. The static eliminating light is transmitted through a static eliminating light opening 49 as an opening formed in a reflecting member (hereinafter referred to as a reflector) 48.
The light is guided out from the static elimination light filter 50, is made into an appropriate amount and wavelength, and is irradiated onto the surface of the photoreceptor drum 20 from the static elimination light opening 51 of the cleaner unit 26.

The table 55 is roughly divided into a manuscript table 41 on which a manuscript is placed.
and a platen sheath (13aGfitfr) which is superimposed on the document table 41 and presses the document in close contact with the document table 41.
The document cover 13 is made up of a paper cover 13.

In the figure, 2 is a stirring rotating member for stirring the toner;
56 is a container for accommodating a toner supply member, 57 is an auto toner sensor, and 58 is a top cover for taking out a developing unit and the like.

The main body of the apparatus is divided into upper and lower halves with the paper transport path 28 as the border, and the upper unit is rotatable upward via a rotational fulcrum (not shown), so that the paper transport path 28 can be rotated as needed. 28 or expose most of the paper transport path 2.
8, the equipment can be exposed. This makes it easy to remove paper jams and perform maintenance, inspection, and replacement of equipment.

Next, the developing powder supply device according to the present invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view of a developing powder supply device according to the present invention, showing a casing 1, a stirring rotating member 2, an auger 3 for conveying developing powder, and a casing near the tip of the auger 3. 1 and a developing powder supply port 4 provided at 1.

More specifically, the casing 1 is shown in FIG.
As shown in the figure, it has a substantially cylindrical shape, and includes a stirring rotating member accommodating section 5 and an auger accommodating section 6 for powder conveyance, which is provided in communication with and in parallel with the rotating member accommodating section 5. This casing is usually
It is made of synthetic resin by injection molding, and is therefore molded with a mold cutting slope of 1 to 3 degrees, and has a tapered shape with a diameter that slightly increases toward the lid 1a portion.

The stirring rotating member 2 is composed of a rotating shaft 2a, two rod-like bodies 2b spirally provided around the rotating shaft 2a, and a driven gear 2C pivotally supported at one end, with the driven gear 2c side being It is rotatably provided in the stirring rotary member accommodating portion 5 of the casing so as to be located on the lid 1a side of the casing. Note that there is no particular restriction on the shape of the stirring rotating member 2, and in addition to the above two rod-shaped bodies provided in a spiral shape, the rotating shaft 2a-12
= It is possible to select any known shape such as one with a protruding rod-like body or a plate-like body.

The auger 3 for conveying powder for development is also usually made of synthetic resin, and has a rotation drive gear 3a attached to its base that meshes with the driven gear 2C, and a rotation drive engagement protruding outward from the casing 1 at its tip. It has a mating piece 3b, and is rotated via this rotationally driving engaging piece 3b by an external drive mechanism (not shown).

The auger 3 for conveying the developing powder has a tapered shape that is slightly narrow at the tip and widened by about 1 to 3 degrees toward the base in accordance with the tapered shape of the casing 1.

The developing powder supply port 4 opens downward at the bottom of the powder conveying auger accommodating section 6 near the tip of the auger 3, and
From here, developer can be supplied to a developer storage section of a developing unit (not shown).

Next, the operation of the developing powder supplying device according to the present invention will be explained. First, the developing powder supplying device filled with developer is set at a predetermined position of the electrophotographic copying machine, and The drive connection portion of the drive mechanism that is not connected to the drive mechanism and the rotation drive engagement piece 3b at the tip of the auger 3 are engaged with each other. Then, this drive mechanism is started to rotate the auger 3. This rotation of the auger 3 causes the stirring rotating member 2 to rotate via the rotational drive gear 3a and the driven gear 2c.

The rotation of the stirring rotating member 2 stirs the developer inside, and a part of it is passed through the auger 3 to the developing powder supply port 4.
direction.

As a result of being conveyed in this manner, the amount of developer gradually decreases, and eventually only a small amount remains.However, as mentioned above, the outer peripheral edge of the auger 3 is parallel to the bottom surface of the auger accommodating portion 6 of the casing 1. , all of the developer is discharged from the developing powder supply port 4 without substantially remaining at the bottom of the casing 1.

(Effects of the Invention) As explained above, according to the developing powder supply device of the present invention, since the conveying auger is formed in the same tapered shape corresponding to the tapered shape of the casing, the conveying auger The outer periphery of the casing is parallel to the bottom of the auger housing part,
As a result, even if the amount of the filled developer decreases as a result of use, all of it can be discharged from the developing powder supply port 4 without remaining substantially at the bottom of the casing 1, resulting in wasted developer. can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the developing powder supply device, FIG. 2 is a cross-sectional view taken along line 1--2 in FIG. 1, and FIG. 3 is a side view showing the internal mechanism of the entire image forming apparatus. 1... Casing, 2... Rotating member for stirring, 2a.
...Rotating shaft, 2C... Driven gear, 3... Auger for conveying developing powder, 3a... Rotating drive gear, 3b
... Engagement piece for rotational drive, 4... Powder supply port for development,
5: Stirring rotating member accommodating portion; 6: Powder conveyance auger accommodating portion.

Claims (1)

[Claims] (1) A casing having a substantially cylindrical shape and having a stirring means housing part and a developing powder conveying means housing part provided in communication with and in parallel with the stirring means housing part; a stirring means which is freely provided and has a driven gear attached to one end thereof; and a rotary drive gear which is rotatably provided in the developing powder conveying means accommodating part and meshes with the driven gear of the stirring means at one end. a developing powder conveying means attached to the casing and having an engagement piece for rotational driving whose other end protrudes outward from the casing; and a developing powder provided in the casing near the tip of the developing powder conveying means. A developing powder supply device having a body supply port, wherein the casing has a tapered shape based on the die cutting slope, and the developing powder conveying means also has a tapered shape corresponding to the tapered shape of the casing. A developing powder supply device characterized in that the outer peripheral edge of the developing powder conveying means is parallel to the bottom surface of the developing powder conveying means accommodating portion of the casing.