JP2907528B2 - Image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image forming apparatus using electrophotographic technology.

[Prior Art] FIG. 3 shows a conventional image forming apparatus such as a laser printer using a process cartridge in which process means are integrated. In the image forming apparatus, a process cartridge 7, a paper discharge unit 16, and a paper discharge tray 17 are disposed on an upper frame body 11, and a laser scanner unit 18, a paper supply unit 13, a transfer unit 14, a fixing unit 15, and the like are disposed below. The upper frame 11 is rotatably attached to the frame 12 by a hinge 10. Therefore,
When the process cartridge 7 is exchanged or the transfer paper is jammed, the upper frame 11 is opened so that the work can be performed.

Next, a developing device used in the process cartridge 7 will be described with reference to FIG.

In FIG. 4, a developer container 1 has an opening in a surface facing a photosensitive drum 2 serving as a latent image carrier rotating in the direction of arrow A, and a developing sleeve 3 serving as a developer carrier is provided in the opening. Are rotatably arranged in the direction of arrow B. Inside the developing sleeve 3, there is a magnet roller (not shown) as a magnetic field generating means, and a developing blade 4 as a developer regulating member regulates the toner layer carried on the surface of the developing sleeve 3 to a predetermined thickness. doing. This toner layer is conveyed by the rotation of the developing sleeve 3 and is supplied to the photosensitive drum 2.

On the other hand, in order to prevent leakage of the developer (toner) at the lower portion of the developing sleeve, as shown in FIG. By disposing a sheet metal (not shown) under the developing sleeve 3, a magnetic field is created with the magnet roller inside the developing sleeve to prevent the toner from leaking to the outside by the magnetic cut. Further, in the axial direction of the developing sleeve, an end seal member is provided on both sides of the toner layer so that the toner does not leak outside, as shown in FIG.
The component precision and the assembly precision have been improved so as to minimize the gap d between the end seal member and the tape.

As described above, in the developing device used for the process cartridge, toner contamination during the replacement operation is prevented by preventing toner leakage.

[Problems to be Solved by the Invention] However, according to the above conventional example, there are the following problems. That is, when the developer container 1 is increased in capacity in order to suppress the running cost, and when a small particle size toner is used to obtain a high-definition image, when the closing operation of the upper frame 11 shown in FIG. There was a problem that the toner leaked due to the impact.

This is because strong stress is applied to the end of the tape member 5 (mylar tape or the like) below the developing sleeve 3 due to the increase in the capacity, and the gap d between the end seal and the tape due to the reduction in the particle size of the toner. (Conventionally, this gap had a size of about 0.5 to 1.0 mm), and the toner in the developer container leaked.

As a result of such toner leakage, there is a problem in that the paper passing portion and the like in the image forming apparatus become dirty, and as a result, the paper becomes dirty.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that solves the above-described problems and does not cause toner contamination due to toner leakage even when the developer container has a large capacity and a small toner particle size. I have.

[Means for Solving the Problems] According to the present invention, the object is to provide a developer container accommodating a developer, a developer carrier rotatably disposed at an opening of the developer container, At the longitudinal end of the developer carrier, an end seal member provided so as to slide on the peripheral surface of the carrier, and at the lower portion of the developer carrier,
An image forming apparatus comprising: a flexible sheet material that abuts along the longitudinal direction of the carrier to prevent leakage of the developer; and a gap is provided between the end seal member and the flexible sheet material. And a sealing member for contacting the side surface of the end seal member and the back surface of the flexible sheet material to seal the gap.

[Operation] The sealing member of the present invention reliably seals the gap between the end portion of the flexible sheet material and the end sealing member, and as a result, prevents leakage of the developer.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings. Note that the same reference numerals are given to the same parts as those in the conventional apparatus shown in FIGS. 3 to 5, and the description will be omitted.

In this embodiment, a developer container (hereinafter, referred to as a toner container)
It is intended to prevent toner leakage that occurs when using a large-capacity toner or using a small-diameter toner (particle diameter of about 6 μm).
1 and 2 show an apparatus of the embodiment.

In FIG. 1, a mylar tape 5 as a flexible sheet material is in contact with a lower portion of a developing sleeve 3 as a developer carrier to prevent toner leakage. Is sealed by an end seal member 6 so that toner does not leak outside the developing sleeve 3. However, the distance between the end seal member 6 and the Mylar tape 5 is usually 0.5 to 0.5 in the range of component tolerance and assembly tolerance.
There is a gap d of about 1.0 mm. If a small particle size toner is used to increase the capacity and increase the definition of the toner, the toner leaks from the gap d. This is because the increase in the capacity increases the pressure of the toner around the gap and easily leaks due to the small particle size toner.

Therefore, in this embodiment, the gap d is covered to prevent the toner leakage, and the sealing member is shown in FIG. 2 as a sealing member so as to be in close contact with both the rear surface of the mylar tape 5 and the side surface of the end sealing member 6. The seal member 8 having a triangular prism shape shown was attached. The sealing member 8 is in close contact with the toner container 1, the Mylar tape 5, and the respective surfaces of the end sealing member 6 so as not to apply a stress that restricts the Mylar tape 5 and the toner layer of the developing sleeve 3. The shape was triangular. For this reason, the opening on the photosensitive drum 2 side of the toner container 1 is completely sealed, so that toner leakage can be prevented.

Further, by attaching the seal member 8, it is possible to widen the accuracy of the parts of the Mylar tape and the accuracy of the attachment to some extent.

In the present invention, the contact condition of the mylar tape to the developing sleeve may be arbitrary, and the shape of the seal member 8 may be determined according to the condition.

Further, the main body of the image forming apparatus is not limited to the upper and lower frames.

[Effects of the Invention] As described above, according to the present invention, a gap is provided between the end seal member and the flexible sheet material, and the side surface of the end seal member contacts the back surface of the flexible sheet material. Since a sealing member that seals the gap is provided, no pressure is applied to the flexible sheet material from the end face, and there is no leakage from the gap. can get.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a first embodiment of the apparatus of the present invention, FIG. 2 is a partially cutaway perspective view showing a schematic configuration of a seal member of the apparatus shown in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a schematic configuration of the apparatus, FIG. 4 is a cross-sectional view showing a schematic configuration of a developing device of the apparatus in FIG. 3, and FIG. 5 is a front view of the apparatus in FIG. DESCRIPTION OF SYMBOLS 1 ... Developer container (toner container) 3 ... Developer carrier (developing sleeve) 5 ... Flexible sheet material (Mylar tape) 6 ... End seal member 8 ... Seal member

Claims (1)

(57) [Claims] A developer container for storing a developer; a developer carrier rotatably disposed at an opening of the developer container;
An end seal member provided so as to be in sliding contact with the peripheral surface of the developer carrier at the longitudinal end of the developer carrier, and abuts on the lower portion of the developer carrier along the longitudinal direction of the carrier. In an image forming apparatus having a flexible sheet material for preventing leakage of a developer, a gap is provided between the end seal member and the flexible sheet material, and the side surface of the end seal member is flexible. An image forming apparatus, comprising: a sealing member that contacts a back surface of a sheet material to seal a gap.