JPH05232796A - Developing apparatus - Google Patents

Abstract

PURPOSE:To suppress the cost for a developing apparatus of an electrophotographic recording device of a structure not causing toner leakage during transit of a developing apparatus cartridge. CONSTITUTION:A developing apparatus producing a visible image by attaching a toner 10 to an electrostatic latent image on a photo-sensitive drum by the use of a magnet roller 5 is equipped with a toner storing casing 11 for storing the toner 10, magnet roller 5 exposed at an opening 12 in the toner storing casing 11, a transport seal 17 inserted removably in a doctor gap 15 between the magnet roller 5 and the oversurface of the opening 12, and a toner leak hindering plate 19 which is inserted in and fixed to the gap between magnet roller 5 and the undersurface of the opening 12 and hinders leakage of the toner 10 from the casing 11. The plate 19 is in pressure contact with the magnet roller 5 with a pressure which does not scratch off the toner 10 remaining on the roller 5 and allows transit to the casing 11, or put confronting the magnet roller 5 with a certain gap 16 reserved which allows passage, or is formed from a magnetic material and attracted magnetically to the magnet roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a developing device in an electrophotographic recording device.

[0002]

2. Description of the Related Art In an electrophotographic recording apparatus to which the present invention is applied, an electrostatic latent image embodied on a photosensitive member such as a photosensitive drum in accordance with image information is converted into a toner image by a developing device, and the toner image is formed on a sheet. Recording is performed by transferring and fixing with heat or pressure.

The recording process is composed of charging, exposing, developing, transferring, fixing and cleaning steps. In the charging process, as shown in the side view of FIG. 2, the surface of the photosensitive drum 1 moving at the same speed as the medium transport speed is charged to a uniform potential by the high-voltage charger (for example, scorotron) 2. .

The photosensitive drum 1 has on its surface a photosensitive layer whose conductivity changes in response to light. In the exposure step, the surface of the photosensitive drum 1 is scanned with laser light by the optical means 3 to change the amount of charge on the photosensitive drum 1 to form an electrostatic latent image according to an image signal.

In the developing process, the developing device 4 uses the magnet roller 5 to supply the toner to the photosensitive drum 1 by the potential difference from the surface of the photosensitive drum 1 to make the toner adhere thereto, thereby making the electrostatic latent image visible.

In the transfer step, the paper 6 and the photosensitive drum 1 are brought into contact with each other and moved, and the transfer device 7 charges the toner image from the back surface of the paper 6 with a polarity opposite to the polarity of the toner to attract the toner image to the paper 6. .

Thereafter, the sheet 6 is pressed or heated by the fixing device 8 to fix the toner image. Then, the surface of the photosensitive drum 1 is collected and removed by the cleaning device 9 using, for example, a blade cleaner, such as residual toner and paper dust.

As shown in the side view of FIG. 3, the developing device 4 includes a toner storage case 11 for storing the toner 10 and a toner storage case.
The magnet roller 5 whose surface is partially exposed from the opening 12 of the nozzle 11, the stirring blade 13 that stirs the toner 10, and the gap between the magnet roller 5 located above the opening 12 are 0.2 m, for example.
Doctor blade for precise adjustment to dimensions of m to 0.4 mm
It is composed of 14 mag.

The toner 10 in the toner storage case 11 is agitated by the agitating blade 13, adheres to the magnet roller 5 rotating counterclockwise, passes through the doctor gap 15 set by the doctor blade 14, and is evenly distributed. The toner 10 adheres to the electrostatic latent image on the photosensitive drum 1 with a predetermined thickness.

Toner remaining on the magnet roller 5
The toner 10 passes through the gap 16 below the magnet roller 5 and is collected in the toner storage housing 11 for reuse.

[0011]

The developing device having the above-described structure is attached to the device as a developing device cartridge packaged separately from the device or sold as a consumable item. However, when the developing device cartridge is transported, it is a toner storage box. There arises a problem that the toner leaks to the outside from the gap above and below the magnet roller provided at the opening of the body.

In order to prevent this, as shown in the partially enlarged side view of FIG. 4, the doctor gap 15 of about 0.2 mm to 0.4 mm is used.
Then, in order to absorb an error in manufacturing and assembling, a worker holds a grip 17 at the rear end in a gap 16 at the bottom of the opening which is about 1 mm to 2 mm.
The carrier seals 17 and 18 were inserted while grasping a and 18a as shown in FIG.

The transport seal 17 is made of, for example, one piece of polyester film having a thickness of about 0.25 mm, and the grip 17a at the rear end is gripped and the tip 17b is inserted into the doctor gap 15. As shown in FIG. 2B, the conveying seal 18 has a wedge-shaped tip, and the gap 16 below the magnet roller 5 may be large, so that the sponge 18e is sandwiched between the two polyester films 18c and 18d. Then, the ends of the polyester film were bonded together to form a wedge shape.

Due to such a structure, the transport seal 18 has a high unit price, and it is inserted as deep as 40 mm along the entire width of the gap below the magnet roller 5 so that there is no gap around the transport seal 18. Since it has to be hermetically sealed, it requires more insertion man-hours as compared with the transport seal 17 and leads to an increase in the cost of the device.

Further, after the delivery to the customer, the user has to remove the transport seals 17 and 18 at the time of starting the use, but as shown in the enlarged side view of the main part of FIG. 5, the transport seal 17 inserted in the doctor gap 15 is shown. Since the size of the gap is small, the toner does not adhere to the tip portion 17b so much, but the conveyance seal 18 inserted into the gap 16 below the opening has a large gap size, and therefore the amount of toner attached to the tip portion 18b. However, there were problems such as getting the user's hands dirty.

An object of the present invention is to reduce the cost of the structure that prevents toner leakage during the transportation of the developing device cartridge.

[0017]

In the present invention, FIG.
As shown in the side view of the main part of FIG. 1, a toner storage housing 11 for storing the toner 10, a magnet roller 5 whose surface is partially exposed from an opening 12 of the toner storage housing 11, and a magnet roller 5
And a toner storage housing 11 fixedly inserted in a gap 16 between the magnet roller 5 and the lower surface of the opening 12 and a transport seal 17 that is removably inserted in a doctor gap 15 between the upper surface of the opening 12 and the opening 12.
Toner leakage prevention plate 19 for preventing the toner 10 inside from leaking to the outside
The toner leakage prevention plate 19 is pressed against the magnet roller 5 with a pressure that allows the toner 10 remaining on the magnet roller 5 and returning to pass through the toner storage housing 11 without being scraped off, or The magnet roller 5 has a gap that allows the toner 10 remaining on the magnet roller 5 and returning to pass through the toner storage housing 11 without being scraped off.
Or a toner leakage prevention plate 19
Is formed of a magnetic material so that the magnet roller 5 is pressed against the magnetic attraction force.

[0018]

By the toner leakage prevention plate 19, the toner attached to and remaining on the magnet roller 5 is collected in the toner storage housing 11 without being removed.

On the other hand, the toner in the toner storage case 11 is prevented from leaking to the outside.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the side view of the essential part of FIG. 1, the developing device 4 according to the present invention comprises a toner storage housing 11 for storing toner 10 and an opening 12 of the toner storage housing 11. The magnet roller 5 whose surface is partially exposed, the conventional transport seal 17 that is insertably inserted into the doctor gap 15 between the magnet roller 5 and the upper surface of the opening 12, and the lower surface of the magnet roller 5 and the opening 12. And a toner leakage prevention plate 19 which is a spring plate and is formed in a dogleg shape to prevent the toner 10 in the toner storage housing 11 from leaking to the outside.

The toner leakage prevention plate 19 is made of a polyester film or a metal thin plate, and is bent by being pressed by the toner without scraping off the toner 10 remaining on the magnet roller 5 and returning, and collecting the residual toner. In the toner storage case 11 without pressing the magnet roller 5 against the magnet roller 5 with a pressure (line pressure 10 g / 300 mm) that passes through the case 11 or scraping back the toner 10 remaining on the magnet roller 5 and returning. Gap of toner thickness (1 μ
The magnetic roller 5 is opposed to the magnet roller 5 with a thickness of about 10 m.

One end of the toner leakage prevention plate 19 has an opening 12
Is adhered to the lower portion 12a, or is locked to a pin protruding from the opening 12, and is fixed by a method such as melting and welding the pin.
Alternatively, the toner leakage prevention plate 19 may be made of a magnetic material, and the magnetic attraction of the magnet roller 5 may be used to bring the leakage prevention plate 19 into pressure contact.

[0023]

According to the present invention, it is not necessary to insert a carrier seal, which is expensive and requires a lot of man-hours for insertion, in the gap between the lower portion of the magnet roller and the opening of the toner storage housing, and the cost of the apparatus can be reduced. At the same time, a great effect is achieved economically and industrially such that the user does not get his hands dirty when the transport seal is removed.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a developing device of the present invention,

FIG. 2 is a side view of an electrophotographic recording apparatus to which the present invention is applied,

FIG. 3 is a side view of a conventional developing device,

FIG. 4 is a partially enlarged side view showing an opening of a conventional developing device, (a) is a diagram showing a state in which a conveyance seal is inserted, and (b) is an enlarged partial view of a lower conveyance seal.

FIG. 5 is an enlarged side view of a main part showing a removed transport seal.

[Explanation of symbols]

1 photosensitive drum, 4 developing device, 5
Magnet roller, 10 toner, 11
Toner storage housing, 12 openings, 12a
Lower part, 15 doctor gap, 16 gap, 17, 18 transport seal, 19 toner leakage prevention plate,

Claims (4)

[Claims] 1. A developing device (4) for visualizing an electrostatic latent image on a photosensitive drum by attaching toner (10) with a magnet roller (5).
In the toner storage housing (11) for storing the toner (10), the magnet roller (5), the surface of which is partially exposed from the opening (12) of the toner storage housing (11), A transport seal (17) insertably inserted into a doctor gap (15) between the magnet roller (5) and the upper surface of the opening (12), the magnet roller (5) and the opening (12). And a toner leakage prevention plate (19) which is fixedly inserted into a gap (16) between the toner storage case (11) and the lower surface of the toner storage case (11) to prevent external leakage of the toner (10) in the toner storage housing (11). . 2. The toner leakage prevention plate (19) according to claim 1, passes through the toner storage casing (11) without scraping off the toner (10) remaining on the magnet roller (5) and returning. A developing device characterized in that the magnet roller (5) is brought into pressure contact with the applied pressure. 3. The toner leakage prevention plate (19) according to claim 1, wherein the toner (10) remaining on the magnet roller (5) and returning is passed through the toner storage casing (11) without being scraped off. A developing device characterized in that it faces a magnet roller (5) with a gap that allows it. 4. The developing device according to claim 1, wherein the toner leakage prevention plate (19) is made of a magnetic material and is brought into pressure contact with the magnet roller (5) by an attractive force.