JPH0337686A - developing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device for an image forming apparatus that employs an electrophotographic method, such as a copying machine or a printer.

(Prior Art) A developing device used in a copying machine or the like is a static image formed on a photosensitive drum 7, which is an image carrier, based on an original image. The WFff image is converted into a Jgl image using a developer (toner) and converted into a toner image.

That is, an example of such a developing device will be explained with reference to FIG.
The developing device Zoo includes a developing sleeve 11 that rotates in a fixed direction.
a developing section 110 that supplies 1lli:ta of internal toner t to the photosensitive drum 200 via the developing section 1;
4R from a hopper section 120, etc., which is disposed on one side of the 10 through an opening 122 and supplies the toner t inside to the developing section 110 via an agitator 121 that rotates the toner t inside in the direction of the arrow shown in the figure. being intimidated.

The developing sleeve ill attracts the toner t in the developing section 110, which holds a predetermined amount of electric charge, to its outer surface by magnetic force via an internal Macnet roller, and transports it while rotating in the direction of the arrow in the figure. Toner t is supplied to the photosensitive tram 200. The toner t in the developing section 110 is frictionally charged by the developing sleeve 111 as the developing sleeve 111 rotates, so that it has a certain electric charge.

Here, toner t is stored in the hopper section 120 and the developing section 110.
When there is a shortage of toner, the toner detector 112 issues a toner shortage alarm, so one worker opens the toner supply lid 123 on the top of the hopper section 120 and removes the toner supply container 130.
The toner t inside is supplied into the hopper section 120.

(Problem to be Solved by the Invention) However, since a large amount of toner t is replenished to the hopper portion 120 at once, the replenishment toner t is
22 to the developing section 110,
This results in rapid mixing with the charged toner t charged to a predetermined amount in the developing section 110.

For this reason, develop! The amount of newly supplied uncharged toner t around the developing sleeve 111 in the developing sleeve 110 increases, and the toner is insufficiently adsorbed to the outer surface of the developing sleeve 111, resulting in images such as uneven density on the toner image on the photosensitive drum 200. The product may be defective or may survive.

The present invention has been made in view of the above problem, and its purpose is to prevent image defects such as density unevenness on the image on the image carrier even if new developer is replenished into the hopper section of the developing device. The problem lies in supplying a developing device that does not produce any color.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a developing section that uses magnetic force to supply internal charged developer toward an image carrier through a developing sleeve that can rotate five times; A hopper section is disposed on one side of the developing section through the opening of the developer replenishing section, supplies uncharged developer therein toward the developing section, and has a hopper section formed as a developer replenishing section. In the developing device, when replenishing the developer to the hopper part, a buffer means is provided on the hopper part side to prevent the supplied developer from rapidly moving to the developing part through the opening part. shall be.

(Function) When replenishing the developer into the hopper from the developer replenishing section formed at the upper part of the hopper, the supply is done via the buffer means, so there is a gap between the developing section and the hopper when replenishing the developer. The replenishing developer does not suddenly move toward the developing section through the opening.

Therefore, should it be used in an appropriate amount in the developing section? The charged developer does not mix with the uncharged replenishment developer, and a predetermined amount of charged developer can be secured around the developing sleeve in the developing section. Charged developer can be supplied toward the image carrier.

Incidentally, the uncharged developer supplied to the developing section is gradually triboelectrically charged by the developing sleeve as the developing sleeve rotates.

(Example) An example of the present invention will be described below with reference to the accompanying drawings, taking a copying machine as an example.

First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. Incidentally, since FIGS. 3 and 4 are modified embodiments, they will be explained later in the explanation of the first embodiment.

In FIG. 1, reference numeral 1 denotes a photosensitive drum which is an image bearing member. After being uniformly charged via a primary charger (not shown), this photosensitive drum l is exposed to image light based on the original image and has an electrostatic potential. An image is formed. On one side of the photosensitive tram 1, there is a developing section 10 and a hopper section 2 for supplying developer (toner) t to the developing section 10.
A developing device 2 consisting of 0 or the like is provided, and the developing device 2 develops the electrostatic latent image on the photosensitive drum 1 through the toner t and converts it into a toner image. The toner image is transferred onto the transfer paper via a transfer charger (not shown), and fixed onto the transfer paper by a fixing device (also not shown).

The developing section 10 of the developing device 2 is composed of a developing section main body 11, a developing sleeve 12, a coating member 13, a stirring member 14, a toner detector 15, etc., and a certain amount of toner t is held in the developing section main body 11. At the same time, on the side adjacent to the photosensitive drum 1, there is a developing sleeve 1 that rotates in the direction of the arrow shown in the figure and supplies the toner t inside toward the photosensitive drum l.
2 are arranged. The developing sleeve 12 is made of a cylindrical non-magnetic material, and has an immovable magnet roller inside, and the developing section body 12 is charged to a predetermined value through the magnetic force of the magnetic roller. The toner t inside is adsorbed on its outer surface, and as the toner t rotates, it is conveyed and supplied toward the photosensitive tram l.

The coach ink section 13 is the developing sleeve 1 of the developing section main body 11.
The stirring member 14 controls the toner t adsorbed on the outer surface -L of the developing sleeve 12 to a constant thickness and supplies the toner t toward the photosensitive tram l. This is for rotating the toner t in the developing section main body 11 toward the developing sleeve 12 by rotating in the direction of the arrow in FIG. Also, toner detector 1
5 is a case where the toner t in the developing unit main body 11 is insufficient.

That is, when there is a shortage of toner t in the hopper section 20 for replenishing the developing section 10 with toner t, an alarm is issued to prompt the hopper section 20 to be supplied with toner t.

The hopper section 2o of the developing device 2 includes a hopper main body 21, a stirring member 22. The one that is configured with an opening 23 etc.
It is provided on the negative side of the developing section 1° through the opening 23, holds a predetermined amount of toner t, and transfers the toner t to the opening 23.
This is for supplying the liquid to the developing section 10.

Toner t is held in the hopper body 21, and as the stirring member 22 provided in the hopper body 21 rotates in the direction of the arrow in FIG. is supplied to A cylindrical part 21a for toner replenishment with a slightly wider angle than a semicircle is provided at the upper part of the hopper main body 21, and after a cylindrical toner replenishment container 40 is installed into the cylindrical part 21a from above the plane of the paper in FIG. Hold the toner supply container 40 with its supply hole 40a facing downward by approximately 18 cm.
The toner t in the toner supply container 40 is supplied into the hopper main body 21 by rotating 0 degrees.

Here, the developing device 2 together with the photosensitive drum 1 etc. is attached to an opening/closing door 3 provided at the upper part of the main body of the apparatus.
When the developing device 2 is opened centering on one end for jam removal or maintenance within the main body of the device, the developing device 2 is lifted obliquely with the opening/closing door 2 with the hopper section 20 facing slightly L as shown in FIG. position. The replenishment of toner t to the hopper section 20 of the developing section 2I2 is performed when the opening/closing door 3 or the developing device 2 is opened and lifted in an oblique position as described above.

That is, when the photosensitive tram 1 is exposed to image light and the photosensitive drum 1 starts to form an image, the developing section 1O
The developing sleeve 12 and stirring member 14 are rotated, and the developing sleeve 12 adsorbs toner t on its outer surface and supplies the toner t toward the photosensitive tram l.
4 moves the toner t in the developing section main body 11 toward the developing sleeve 12. Also, the stirring member 22 in the hopper section 20
The hopper body 2 also rotates with the start of image forming work.
1 is supplied to the developing section 10 through the opening 23.

Now, if a toner shortage signal is generated in the hopper section 20 via the toner detector 15, the opening/closing door 3 of the main body of the apparatus
After opening, the empty toner replenishing device 40 is pulled out from the cylindrical portion 21a at the top of the hopper main body 21 of the hopper section 20, a new toner replenishing container 40 is attached to the cylindrical portion 21a, and the toner replenishing container 40 is held at a predetermined angle. Rotate the supply hole 4
With 0a facing downward, toner t is replenished into the hopper main body 21.

Here, even if a toner shortage signal is issued by the toner detector 15, a certain amount of toner t is retained in the developing section 10, and the toner t is transferred to the developing sleeve 12 by rotation of the developing sleeve 12. 12 to a given charge J! It is triboelectrically charged so that it can be easily attracted to the developing sleeve 12 electrically and magnetically.

Therefore, if the toner t is rapidly replenished from the toner replenishing container 4° into the hopper section 20, the toner t having sufficient fluidity will flow from the opening 23 toward the developing section IO, and the appropriate amount of the toner t in the developing section 10 will be filled. It will be sufficiently mixed with the charged toner t. In this case, as shown in FIG. 2, since the developing device 2 is positioned obliquely and the hopper section 20 is located slightly above the developing section 10, this tendency becomes even more pronounced. Therefore, the amount of uncharged toner t in the developing section 10 increases rapidly, and the adsorption of the toner t to the developing sleeve 12 becomes insufficient, causing image defects in the toner image on the photosensitive drum 1. becomes.

Therefore, in this embodiment, as shown in FIG. 1, a closing means 30 is provided in the opening 23 between the hopper section 20 and the developing section 10 as a buffering means for the toner t, so that the toner t flows into the hopper section 20 forcefully. The replenishment toner t is prevented from rapidly flowing toward the developing section 10.

That is, a blocking member 32 for closing the opening 23 is housed in a recess 31 above the opening 23 of the hopper section 20, and this blocking member 32 is not required when replenishing the toner t into the hopper section 20. Developing section 1
0 is closed. The opening and closing of this blocking member 32 is performed by the hopper main body 21 of the hopper section 20.
A pin member 33 is attached to the convex portion 32a of the blocking member 32 that protrudes outward from the hopper body 21, and the pin member 33 and the outside of the hopper body 21 are connected to the lower part 21b using a spring member 34, and the pin member 33 is attached to the device. This is done by engaging the push-up member 4 on the main body side.

If a toner shortage signal is generated in the developing device 2 via the toner detector 15, the opening/closing door 2 on the main body side of the device is opened and the developing device 2 is opened together with the opening/closing door 3 as shown in FIG. Lift upwards. In this case, the opening 23 between the hopper section 20 and the developing section 10 is closed by the bruise member 32 via the pin member 33 due to the elastic force of the spring member 34. Therefore, the toner supply container 40 is placed in the hopper section 20.
Therefore, even if the toner t is suddenly replenished, the toner t does not suddenly flow toward the developing section 10.

When the supply of toner t to the hopper section 20 is completed, the opening/closing door 3 of the apparatus main body is closed, and the developing section 2t2'# is returned to the approximately horizontal predetermined image forming position (the position shown in FIG. 1). In this case, the push-up member 4 on the device main body side or the developing device 2
As it descends, it gradually engages with the pin member 33, pushes up the blocking member 32 into the recess 31 against the elastic force of the spring member 34, and closes the opening 23 between the hopper section 20 and the developing section 10.
gradually open. In this way, a part of the toner t in the hopper part 20 moves slowly toward the developing part 10 and does not rapidly mix with the charged toner t in the developing part 10. Most of the toner t becomes the charged toner t, and the toner t is sufficiently adsorbed to the developing sleeve I2, so that it does not interfere with the subsequent developing operation.

In addition, as a modified example of this embodiment, as shown in FIGS. 3 and 4, for a fixed type developing device 2 that does not move together with the opening/closing door of the main body of the device, the developing section 10 in the hopper section 20 and A similar blocking member 32 is provided in the opening 23 of
This may be done by using the solenoid 35 and the spring member 34 via the solenoid 35 and the spring member 34.

That is, when replenishing the toner t to the hopper section 20, the replenishment groove 24 of the hopper section 20 is opened and the hopper main body 21 is
At the same time, the toner supply container 41 is attached to the toner supply container 41, the solenoid 35 is turned off, and the cutoff member 32 is pushed down by the spring member 34 to close the opening 23 of the hopper section 20. Once the toner supply is completed, the toner is removed. supply container 4
1, close the supply layer 24, and close the solenoid 3.
5 is turned ON, the blocking member 32 is pushed up against the elastic force of the spring member 34, and the opening 23 is opened. In such a case, the same effect as in the above-mentioned embodiment can be obtained.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 7. It should be noted that components having the same functions as the devices and the like according to the first embodiment are given the same reference numerals, and their explanations will be omitted.

In this embodiment, the blocking member 32 is not provided in the opening 23 between the hopper section 20 and the developing section 10, and the toner t attached to the cylindrical section 21a, which is the toner supply section of the hopper section 20, acts as a buffer for the toner t. By gradually rotating the replenishment container 40, the toner replenishment container 40 is placed inside the hopper section 20.
I started to slowly replenish the toner t.

That is, as shown in FIG. 5, at the end of the cylindrical part 21a of the hopper body 21 of the hopper part 20 (on the front side from the plane of the paper),
A rotatable link member 36 is attached to the cylindrical portion 21a, and a gear 36a is formed on the outer periphery of the link member 36. Further, the size of the inner peripheral part of the ring member 36 is the same as the size of the inner peripheral part of the cylindrical part 21a of the hopper main body 21, and a recess is formed for engaging and rotating the toner supply container 40 in a predetermined position of the link member 36. A groove 36b is provided.

On the other hand, a gear 5a is formed on the apparatus main body side as well, which meshes with the gear 36a of the ring member 36 along the locus of movement of a part of the ring member 36 of the developing device 2 as the opening/closing door 3 of the apparatus main body opens and closes. The link rotating member 5 is attached.

When the toner detector 15 issues a signal indicating that there is a shortage of toner in the developing device 2, the opening/closing door 3 of the device main body is opened, and the developing device 12 is closed to the main body of the device, as shown in FIG. It is lifted obliquely upward from the Then, the toner supply container 40 is attached to the cylindrical portion 21a of the hopper portion 2o with its supply hole 40a facing upward. In this case, the convex portion 40b provided on the outer periphery of the end of the toner supply container 40 is engaged with the groove 36b of the ring member 3ε, so that the toner supply container 40 can be rotated together with the link member 36.

Next, when the opening/closing door 3 of the apparatus main body is slowly closed, as the developing device 2 is lowered, as shown in FIGS. 5 and 6,
The gear 36a of the link member 36 meshes with the gear 5a of the ring rotation member 5 on the apparatus main body side, and the link member 36 slowly rotates in the direction of the arrow in FIG. As a result, the toner replenishment container 4o also rotates slowly in the same direction as the ring member 36, and its replenishment hole 40a also slowly moves relative to the cylindrical portion 21a of the hopper section 20. Therefore, the replenishment hole 40a of the toner replenishment container 40 is gradually opened from the cylindrical portion 21a to the lower part of the hopper main body 21, and the toner t in the toner replenishment container 40 is slowly supplied into the hopper main body 21 of the hopper section 20. It happens.

In this way, the toner t in the toner supply container 40 is removed from the opening/closing door 3.
The opening 23 between the hopper section 20 and the developing section 10 is gradually supplied into the hopper section 20 as the hopper section 20 closes.
Even if there is no blocking member 32 in
It is possible to obtain the same effect as the first embodiment without abruptly moving toward the direction.

Incidentally, a buffer member such as a damper may be attached to the opening/closing door 3 of the main body of the apparatus to prevent it from being forced to close twice.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, since the buffer means is provided on the hopper side of the developing device, when the developer is replenished to the hopper, the uncharged replenishment The developer does not suddenly move from the hopper section to the developing section containing the charged developer through the opening.Therefore, even when the hopper section is replenished with developer, the charged developer in the developing section is removed by the developing sleeve. The toner particles can be sufficiently magnetically attracted and supplied to the image carrier, and image defects such as density unevenness will not occur in the toner image on the image carrier.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the developing device according to the first embodiment, which is disposed at a predetermined position in the main body of the image forming apparatus, and FIG. 2 shows the developing device moved to the developer replenishing position together with the opening/closing door of the main body of the device. Figures 3 and 4 are sectional views of the developing device according to the modified embodiment of the first embodiment, and Figures 5 to 7 are sectional views of the developing device according to the modified embodiment of the first embodiment.
A cross-sectional view of the developing device according to the embodiment (Figure 5 shows the state in which the opening/closing door of the main body of the apparatus is moving, Figure 6 shows the opening/closing door in the most open state, and Figure 7 shows the opening/closing door in the closed state. (indicates the status)
, FIG. 8 is a diagram showing the prior art. 1... Photosensitive drum (image carrier), 2... Developing device. 5... Ring rotating member (buffer means), 1O... Developing section, 12... Developing sleeve, 20... Hopper section,
21a...Cylindrical part (developer replenishing part), 23...Opening part, 30...Closing means (buffer means), 36...Link member (buffer means>).

Claims (2)

[Claims] (1) A developing section that has a magnetic effect and supplies the internal charged developer toward the image carrier via a rotatable developing sleeve, and an opening for supplying the developer on one side of the developing section. In a developing device which has a hopper section in which a developer replenishing section is formed and which supplies the internal uncharged developer toward the developing section and is disposed through the A developing device characterized in that a buffer means is provided on the hopper side to prevent the supplied developer from rapidly moving to the developing section through the opening. (2) The developing device according to claim 1, wherein the buffer means is a closing means for blocking an opening between the hopper section and the developing section when the hopper section is being replenished with developer. .