JPS58116558A - Developing device - Google Patents

Abstract

PURPOSE:To perform development with uniform density by providing a quantitative supplying means of developer in front of a friction charging member, and rubbing a developer supplied quantitatively to a developer carrier against the edge of the friction charging member and thus charging the developer uniformly. CONSTITUTION:A toner supply roll 8 only supplies toner quantitatively and has cuts 8a-8c at its circumferential part, and the toner is supplied quantitatively from a toner tank to those cuts 8a-8c and further supplied to a developing roll 2 through the rotation of the roll. The surface of the roll 2 is rugged finely by sand blast, etc., to charge the toner easily by friction. A charging blade 3' rubs the toner against the developing roll 2 to charge the toner and also causes friction by its edge so that a toner layer on the developing roll 2 is made thin.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a developing device, and particularly to an electrophotographic developing device that develops by jumping toner.
A fixed amount of toner is supplied to the developing roller, and this uniformly supplied toner is rubbed with the edge of a frictional charging member to evenly distribute the toner.
Made it possible to obtain more charged Tona. It relates to a developing device.

(2) Background of the Technology For example, in data processing equipment, a printing device using an electrophotographic developing device is used as an output device. As shown in FIG. 1, this electrophotographic developing device supplies toner from a toner reservoir 1 to a developing roller 2.
The toner is then frictionally charged by the charging plate 3, held on the roller 22, and conveyed by the rotation of the developing roller 2. This toner is then transferred to the photosensitive drum 4 on which a latent image has been formed. In order to hold the toner on the developing roller 2, the toner is impregnated with a magnetic material and held by the magnetic force of a magnet attached to the developing roller 22. Since the toner is transferred by direct contact, there are problems associated with direct contact, so a non-contact dust image device that causes the toner to jump using electrostatic attraction is also often used. This 5-contact type developing device has a large number of unevenness of 10 to 30 microns on the surface of the developing roller 2, and holds the toner that is negatively abraded between the charging blade 3 and the elephant roller 2 on these four parts. death,
Further, the grid electrode 5 to which a positive DC bias voltage and an AC bias voltage are applied by the DC power source E and the AC power source 2 causes the toner to jump and is transferred to the photosensitive drum 4. It should be noted that among the jumped toner particles, those that flew towards the non-moving part of the photosensitive drum 4 or the already developed Ikkatsuto are pulled back by the grid electrode 5 biased to the glass, causing them to move back and forth. become. Note that 6 is a grounded cleaner electrode for neutralizing residual toner, and 7 is a case. In such a non-contact type developing device, the toner must be uniformly colored in order to make the developed density uniform. For this purpose, it is necessary to form one or two distinct layers on the surface of the fA image roller using toner.

(3) Prior Art and Problems In the conventional non-contact type developing device, toner is sent out from the toner reservoir 1 as shown in the first dot 1, and the toner is transferred to the so-called belly of the charging blade 3 made of an elastic material such as urethane rubber. The part is triboelectrically charged. However, in this device, the toner delivery lid is not constant and the contact of the charging blade 3 is surface contact, so the toner layer is not one or two thin layers but a thick layer, so the toner distribution state and charge distribution evenly,
Since the toner may be applied non-uniformly to the formed image, there is a problem in that the developed density becomes uneven.

(4) Purpose of the Invention As described above, the present invention aims to improve the problem that conventional non-contact developing devices cannot uniformly distribute toner onto a developing roller and charge it uniformly. To provide a developing device which facilitates stationary supply and control of toner thickness.

(5) Structure of the invention In order to achieve this object, the developing device of the present invention has the following features:
Using a component developer, the mackerel rod charging member is brought into contact with the support member, and the development uniformity j is unipolarly charged. Each developer carrier, electrostatic carrier,
An alternating electric field is applied to each grid electrode, and a DC electric field is also applied to each of the developer carrier and the grid electrode. The development is carried out between S, the grid electrode, and the developer carrier.
A cleaner electrode prevents the developer from sticking by causing one particle to move back and forth at the same time, and keeping a small distance from the developer carrier, which is grounded, to form one residual development on the developer carrier. In a photocopy developing device with a 10-hole mechanism such as the above, a fixed amount of developer is sequentially supplied while rotating to the developer carrier, which is located in front of the upper eye d separation charging member. The present invention is characterized in that a developer supplying means is provided, and the developer supplied to the developer carrier is evaporated at the edge of the friction charging member.

(6) Embodiment of the Invention Next, an embodiment of the present invention will be explained based on FIGS. 2 and 3.

FIG. 2 is a schematic diagram of this embodiment, and FIG. 3 is an explanatory diagram of the usage state of the charging blade.

In the figure, the same reference numerals as those in FIG. 1 indicate the same early forming parts, 8 is a toner supply roller, and 31 is a charging blade.

The toner supply roller 8 is for supplying toner, and has a notch 8a as shown in the circumferential side of the roller.
, 8b, 8C, and these notches 8a, 8b, 8C
A certain amount of toner sent out from the toner reservoir 1 is supplied to
This supplied toner is supplied to the developing roller 22 as the roller rotates. At this time, countless minute irregularities are formed on the surface of the roller 2 by sandplast, liquid wood honing, or the like, which makes it easy for the toner to roll on and cause frictional electrification.

The charging blade 31 charges the toner by rubbing the toner with the image roller, and also rubs the toner on the developing roller with its edge so that the toner layer on the developing roller becomes Jv4. It is.

The angle that the edge of the charging blade 6 forms with the surface of the developing roller 2 is as shown in Figure 3. In this way, one layer of toner is formed thinly.

Next, the operation of this embodiment shown in FIGS. 2 and 3 will be explained.

First, toner is placed in the toner container 1. Then, when the developing roller 2 and the toner supply roller 8 are operated in the direction of the arrow shown in the figure, the toner is transferred to the notch 8a of the toner supply roller 8,
8b, 8cKJ- are then supplied, and then as this roller rotates, the toners in these notches Ba, Bb, and sc are sequentially supplied to the current single roller 2. This fixed amount of supplied +ner is rubbed by the edge of the charging blade 3' as shown in FIG. 3, becomes negatively charged, and is held on four parts of the surface of the developing roller 2. The toner in this recess is then caused to jump by the lid 5, and is adsorbed to the latent image of the sound-light tram 4, resulting in a non-image! The toner that has flown to the fM section is pulled back by the grid 5. The remaining toner is removed from the cleaner electrode 6.
It is liberated by , this toner is used together with the toner that has been sent out. In this way, the series of visual image operations continues, but in the developing process, the toner is supplied at a constant rate and is formed into a thick layer by the Teigan blade, so the toner density becomes uniform and the toner is uniformly distributed. There is less unevenness in the viscous developer density.

(7) As described in detail of the invention (after all, according to the present invention, the developer is fixedly supplied to the developer carrier and the developer is formed into a thin layer by the edge of the abrasive charging member, so the developer The charging is performed uniformly, and as a result, development with uniform density and no density unevenness can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional developing device, and Fig. 2 [Q14'! ,
FIG. 3 is a block diagram of an embodiment of the present invention; FIG. 3 is an enlarged view of the strip in use. In the figure, 1 is a toner roller, 2 is a developing roller, 3 and 31 are hk
Denzublade 4 is a photosensitive drum, 5 (Mag 1 knot 1kL
Pole, 6 is the cleaner electrode, 7 (case, 8 (toner supply roller, 3a, 8b, 8c & i+, l) is missing. Applicant Fujitsu Ltd. Representative Patent Attorney Eisai Yamatani 1 Figure

Claims (1)

[Claims] (1) - Using a component developer, the developer is charged to one polarity by contacting the triboelectric charging member with the developer carrier, and the developer carrier and the electrostatic image carrier are opposed to each other with a gap through a grid electrode. An alternating electric field is applied to each developer carrier, electrostatic carrier, and grid electrode, and a countercurrent electric field is also applied to each developer carrier and grid electrode, whereby the electrostatic image on the electrostatic carrier is is developed, and the developer particles are caused to move back and forth between the non-image area, the grid electrode, and the developer carrier, and the remaining #1. on the developer carrier is removed. In an electrophotographic developing device that has means such as preventing the developer from sticking with a cleaner electrode that maintains a short distance from the grounded developer carrier, the developer is placed in front of the frictional charging member. A developer quantitative supply means is provided to sequentially supply the developer to the carrier while rotating at a constant rate, and the developer supplied to the developer carrier at a constant rate is rubbed by the edge on the side of the frictional charging section. A developing device characterized by: