JPS63106766A - Developing device - Google Patents

Abstract

PURPOSE:To prevent the increase of torque, the occurrence of bearing lock, on the like by providing a groove on the part, which are brought into contact with a seal material of d doctor roll in the peripheral direction. CONSTITUTION:Excessive toner and scraped toner near the part where a doctor roll 5 and a developing roll are brought into contact with each other and the part where the doctor roll 5 and a scraper 7 are brought into contact with each other are moved from the center of the doctor roll 5 toward end parts. However, seal members 8 and 9 are provided in both end parts of the developing roll 1, the doctor roll 5, and the scraper 7 and the toner carried along these rolls and blade toward end parts is stopped from moving toward end parts by seal members 8 and 9. The toner caught between the seal member 9 and the peripheral surface of the doctor roll 5 is forcibly returned inward on the roll by a spiral groove 10 provided on the peripheral surface of the doctor roll 5 and the implanting action of fur on the seal member 9. Dropping of the toner from end parts of the developing roll 1 and the increase of torque, the occurrence of bearing lock, or the like accompanied with this dropping are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a developing device for an electrostatic recording device using a non-magnetic one-component developer.

Prior Art A developing device for an electrostatic latent image formed on a photoreceptor in an electrostatic recording device such as an electrophotographic copying machine, a facsimile machine, or an electrostatic printer uses a nonmagnetic one-component developer. It is widely used because it is simple.

In a developing device that uses a non-magnetic one-component developer (hereinafter referred to as toner), the toner in the developer container is stirred by a stirring member and charged by friction, and the toner is turned by rotation of a developing roller pivotally supported on the side plate of the container. is electrostatically attracted to the electrostatic latent image on the photoreceptor which is attached to the surface of the developing roller and comes into contact with the developing roller, and development is performed.

As shown in FIG. A doctor blade 4 whose tip is in contact with the developing roller l with a predetermined doctor gap is generally used on the upstream side of the developing area 3 in contact with the developing roller l. As shown by the arrow inside, it moves outward from the center of the roller along the doctor blade 4, flows down from the ends of the developing roller 1 at both ends, adheres to the bearing provided on the side plate of the developing device, and generates torque. Problems such as an increase in the number of bearings and bearing locks were occurring.

Purpose The present invention eliminates the above-mentioned drawbacks of the developing device of an electrostatic recording device using a conventional non-magnetic one-component developer having the above-mentioned configuration. It is an object of the present invention to provide a developing device that can prevent the occurrence of torque increase, bearing lock, etc. due to this.

Structure: In order to achieve the above object, the developing device of the present invention includes: a doctor roller which rotates in pressure contact with the developing roller and regulates the thickness of the developer layer on the developing roller; a doctor roller whose tip is in contact with the doctor roller; a scraper for scraping off the developer adhering to the developer roller; a sealing material for contacting and sealing the ends of the developing roller, doctor roller, and scraper; grooves are provided in the circumferential direction in the portion of the doctor roller that contacts the sealing material; It is characterized by having been provided.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the apparatus of this embodiment, as shown in FIGS. 1 and 2,
In place of the doctor blade 4 (FIG. 4) of the conventional device, a doctor roller 5 is shown as a toner thickness regulating member that presses against the developing roller l with an appropriate pressing force using its own weight or a cross-pressure means. It is rotatably supported on the side plate of the developer container through a bearing 6, and is driven to rotate in the opposite direction at the point of contact with the developing roller L, as shown by the arrow in FIG. The non-toner layer is formed into a thin layer with a predetermined thickness. The toner that has not been formed into a thin layer adheres to the doctor row 25 and is transported. A scraper 7 is provided in contact with the doctor roller 5 on the downstream side of the contact point of the doctor roller 5 with the developing roller l. The excess toner adhered to the doctor row 25 and conveyed is scraped off by the scraper 7 and falls into a toner reservoir in the developer container.

Both ends of the developing roller I are sealed with a sealing material 8 such as sponge or rubber within a range that does not interfere with the photoreceptor 2. Further, a sealing material 9 made of flocked hair is in contact with the areas where the toner adheres at both ends of the doctor row 25 and the scraper 7. A spiral groove 10 is provided in the area of the doctor roller 5 in contact with the sealing material 9, in which the roller is wound several times in the circumferential direction.

The direction of the spiral of this groove is such that when the doctor roller 25 rotates in the direction shown by the arrow, the toner in the groove 10 is moved from the end of the roller to the center by the bristles of the sealing material 9. There is.

Therefore, during development, the single layer of toner that adheres to the developing roller l and is conveyed is made into a thin layer by the doctor roller 5, which is pressed against this with an appropriate pressing force, and the remaining toner that is not made into a thin layer is transferred to the developing roller l. The toner particles adhere to the doctor roller rotating in the opposite direction at the point of contact with the toner roller 21 and are conveyed in the rotational direction of the doctor roller, and are scraped off by the blade 7 and fall into the toner pool in the developer tank.

In the vicinity of the contact area between the doctor roller 5 and the developing roller and the contact area between the doctor roller 25 and the scraper 7, excess toner and scraped toner move from the center toward the ends. However, seal members 8 and 9 are provided at both ends of the developing row 21, doctor roller 5, and scraper 7, respectively, and the toner transferred toward the ends along these rollers and blades is sealed by the seal members 8 and 9. movement to the end is prevented by.

The toner that has entered between the sealing material 9 and the circumferential surface of the doctor roller 5 is forced into the inside of the roller by the action of the helical groove lO provided on the circumferential surface of the doctor roller 5 and the flocking of the sealing material 9. He is taken back towards the place.

As a result, the toner falling from the end of the developing roller 1 and the accompanying increase in torque and occurrence of bearing lock, etc., are prevented.

Note that simply cutting an annular groove in place of the spiral groove provided at both ends of the doctor roller has the effect of preventing the toner from spreading outward.

Effects As described above, according to the present invention, it is possible to prevent problems such as increase in torque and bearish lock caused by toner falling from the end of the developing roller.

[Brief explanation of the drawing]

FIG. 1 is a front view of a developing roller and a doctor roller according to an embodiment of the present invention, FIG. 2 is a sectional view of an end thereof, FIG. 3 is a perspective view of one end thereof, and FIG. 4 is a conventional non-contact roller. FIG. 1 is a perspective view showing an example of a developing device that uses a magnetic one-component developer. 1...Developing roller 2...Photosensitive drum 3...
・Development area 4...Doctor blade 5...
Doctor row 26, 11... Bearing 7... Scraper 8, 9... Seal material Figure 1 Figure 2

Claims (2)

[Claims] (1) In a developing device of an electrostatic recording device using a non-magnetic one-component developer, a doctor roller rotates in pressure contact with the developing roller and regulates the thickness of the developer layer on the developing roller, the tip of which is in contact with the doctor roller. a scraper that scrapes off the developer adhering to the doctor roller; a sealing material that contacts and seals the ends of the developing roller, doctor roller, and scraper; A developing device characterized by having grooves in the direction. (2) The above-mentioned groove is a spiral groove in a direction in which the developer adhering to the doctor roller as it rotates is conveyed inward by a sealing material. The developing device described.