JPS645296B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a toner replenishing device for co-feeding a certain amount of toner to a developing device in an electrophotographic copying machine.

BACKGROUND ART Generally, in the copying process of an electrophotographic copying machine, charging, exposure, development, transfer, fixing, etc. are sequentially performed to obtain a copy of an original. That is, the surface of a rotating photosensitive drum is charged with a certain amount of charge by a charger, then an optical image of the original to be copied is irradiated by an exposure means to form an electrostatic latent image, and then a developer is applied to the surface of the photosensitive drum. is deposited using a developing device and visualized. This visible image is then transferred onto a transfer sheet that is sent to the surface of the photosensitive drum by a conveying means, after which the sheet is separated from the surface of the photosensitive drum, the image is fixed by a fixing device, and the copying machine I'm sending it outside.

By the way, in order to perform the above-mentioned development well, many copying machines use developer powder (toner).
A two-component developer is used, which is a mixture of carrier and iron powder (carrier) at a predetermined ratio. and,
In order to produce this developer, conventionally, toner is supplied to a developing device from a reservoir containing only toner using a supply roller having a metering groove.

An example of this type of toner replenishment device is a replenishment roller that is rotatably installed in a toner reservoir and has a groove on its circumferential surface for conveying toner, and an arc-shaped replenishment roller on the roller circumferential surface of the groove. A toner replenishing device (Japanese Unexamined Patent Publication No. 54-42155) has been proposed, which is characterized by having a toner rubbing member having an arc-shaped contact portion longer than the length thereof, and a scraping member for scraping off toner from the groove. Ta. However, in such a device, the amount of toner supplied in the toner storage device cannot always be kept constant because an increase or decrease in the amount of toner stored in the toner storage device affects the amount of toner pushed into the measuring groove. .
Furthermore, since the toner rubbing member is composed of a plurality of elastic members, there is also a drawback that the structure thereof is complicated.

In addition, as another replenishment device, a replenishment roller having a plurality of protrusions protruding in the axial direction of the roller is provided at the bottom of a toner storage container which is curved close to the outer circumferential surface of the roller, and a brush is installed at the bottom of the toner reservoir. Japanese Utility Model Publication No. 31158/1983 has been proposed in which the toner pushed between the protrusions is scraped off into the developing device. However, even in such a device, the amount of toner supplied is not constant due to the increase or decrease of toner in the toner storage device, and if the storage device is not sealed from the outside air, the flow of toner may be affected by changes in the humidity of the atmosphere. However, it also has the disadvantage that the amount of toner supplied is not constant.

Purpose The present invention has been made in view of the above-mentioned problems, and its purpose is to be able to always perform stable replenishment without being affected by the increase or decrease of toner in the storage device or changes in the humidity of the atmosphere. It is an object of the present invention to provide a toner replenishing device with a simple configuration.

SUMMARY OF THE INVENTION In order to achieve the above object, a toner replenishment device according to the present invention is provided with a replenishment roller that is rotatably attached to a lower part of a reservoir that stores toner and has a measuring groove for conveying toner on its outer circumferential surface. and a metering blade that slides into contact with the surface of the replenishment roller in order to fill the metering groove with toner at a position where the outer peripheral surface of the replenishment roller is displaced upward from the bottom as the replenishment roller rotates. The gist is that.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a toner storage container (not shown) installed at a predetermined position inside a copying machine, and developer powder, ie, toner T, is stored therein. The storage device 1 is tapered at the bottom, and a toner replenishment roller 2 rotatable clockwise is provided at the lowest level, and an opening 3 through which the toner T falls is provided diagonally below the roller. . In addition, this roller 2
As shown in Fig. 2, there are eight measuring grooves 4 at 90° intervals with respect to the circumference on the outer circumferential surface of the
They are discontinuously provided in the direction of the roller shaft 2a, ie, 9 pieces, 8 pieces, 9 pieces. Conventionally, this groove 4 was continuous, that is, it was a single line connecting both ends of the roller 2, but if a divided groove is used as shown in the figure, the toner filled in the groove 4 can be This has the advantage that the amount of toner T is stabilized and that the toner T supplied to the developing device 6 can be sufficiently stirred and charged. The upper part of the storage container 1 is open, and when toner is to be replenished, the cover 5 is removed. Further, there is a developing device 6 (details not shown) below the storage container 1, and D inside the developing device 6 indicates a developer. Reference numeral 7 denotes an agitator that can swing around a rotating shaft 7a, and is provided to prevent the toner T from causing a crosslinking phenomenon within the storage container 1. Most of the outer circumferential surface of the roller 2 is embedded in the toner T, and a measuring blade is installed at a portion where the outer circumferential surface of the rotating roller 2 rises slightly from the bottom to fill the measuring groove 4 with the toner T. 8 is in sliding contact with the roller surface with a light pressing force. This blade 8 is made from a mylar sheet, and the blade 8 allows the measuring groove 4 to
The toner on other surfaces is wiped off, and only the toner in the measuring groove 4 is removed from the reservoir 1. Furthermore, since the amount of toner T taken out by the groove 4 is preset, it is possible to replenish the developing device 6 with a predetermined amount of toner by controlling the number of rotations of the roller 2 per unit time. The toner T filled in the groove 4 is then scraped off by a scraping blade 9 provided, and falls into the developing device 6 at the bottom. This blade 9 is made of a mylar sheet with a thickness of about 200 μm, and as shown in the figure, the tip of the blade cut into strips has a measuring groove 4.
The toner can be scraped off effectively because it acts over the entire width of the roller and adapts to the depression. Furthermore, roller 2
When it rotates, the surface of the diagonally upper part is rubbed by a sealing material 10 such as a sponge. In addition, 11
A shutter is used to prevent the toner T from spilling when the toner storage device 1 is removed from the developing device 6.

FIG. 3 shows the position where the metering blade 8 is rubbed against the outer peripheral surface of the roller 2. According to the inventor's experimental results, when the humidity is high at the position indicated by A in this figure, the toner T becomes lumpy, making it difficult to fill the measuring groove 4 sufficiently, and as a result, the amount of toner to be replenished decreases. There are disadvantages in that the desired image density cannot be obtained or it takes time to reach a predetermined density. Further, when the humidity is low, the fluidity of the toner T is high, so if the sealing with the roller 2 is not ensured, the toner may flow out from between. B or C is the position adopted in the apparatus of this embodiment. If the metering blade 8 is installed in such a position, filling of the toner T into the metering groove 4 can be done by filling the toner T in the storage container 1. The toner density is always constant because it is carried out in a place where no gravity is applied, that is, a place where the toner density does not change regardless of an increase or decrease in the amount of toner in the storage container 1. In addition, since the metering blade 8 is provided so as to lightly press and rub against the outer circumferential surface of the roller 2, the toner T is constantly transferred to the metering groove regardless of whether the humidity is high or low. Filled inside. Therefore, the amount of toner supplied to the developing device does not always change and is stable.

Effects As is clear from the above description, the present invention provides a replenishment roller that is rotatably attached to the lower part of a storage device that accommodates toner and has a measuring groove for conveying toner on the outer peripheral surface of the replenishment roller. A metering blade that slides into contact with the surface of the replenishment roller in order to fill the metering groove with toner at a position where the outer circumferential surface thereof is displaced upward from the lowest part as the roller rotates. Since it is a toner replenishing device, it is not affected by the increase or decrease of toner in the reservoir or changes in the humidity of the atmosphere, and can always perform stable toner replenishment, and its configuration is very simple.

[Brief explanation of drawings]

Fig. 1 is a side view of an embodiment of the toner replenishing device according to the present invention, Fig. 2 is a perspective view of the replenishing roller and scraping blade in this embodiment, and Fig. 3 is a measuring blade in sliding contact with the outer peripheral surface of the replenishing roller. FIG. 1... Toner storage device, 2... Replenishment roller, 4...
...Measuring groove, 8...Measuring blade, T...Toner.

Claims (1)

[Claims] 1. A replenishment roller that is rotatably attached to the lower part of a storage device that stores toner and has a measuring groove on its outer circumferential surface for conveying the toner, and as the replenishment roller rotates, its outer circumferential surface moves upward from the bottom. A toner replenishing device comprising: a metering blade that slides into contact with the surface of the replenishment roller in order to fill the metering groove with toner at a displaced position.