JPS63151975A - Fitting structure for doctor blade - Google Patents

Abstract

PURPOSE:To omit gap adjusting work and to improve gap accuracy by allowing a doctor blade energized by an energizing means to abut upon a sleeve of a magnet roll at a spacer forming part and using spacers with proper thickness. CONSTITUTION:The doctor blade 17 is unitedly provided with projections having extruding height (g) on both the end parts, supported by a fixed shaft 1a extruding from a sidewall 21 so as to be moved forward/backward in an arrow B-B' direction and energized by springs 22 in an arrow B direction. The projections 20 are abutted upon the sleeve 19 by the energizing force of the springs 22 and a doctor gap is formed between the doctor blade 17 and the sleeve 19. The doctor gap regulates ear height. Since the doctor blade 17 energized by the springs 22 is only abutted upon the sleeve 19, its assembling can be made easily, and because the price of the doctor gap is determined only by the accuracy of parts, i.e. the height of the projections 20, accuracy up to about + or -0.05mm can be obtained.

Description

[Detailed Description of the Invention] [Summary] The purpose of the present invention is to easily attach a doctor blade while maintaining an accurate doctor gap when assembling a developing device for an electrophotographic device. This objective is achieved by allowing the blade to be attached by pressing the fixing sleeve of the magnetic roller through a spacer.

[Industrial application field]

The present invention relates to a doctor blade mounting structure for a developing device used in an electrophotographic apparatus.

In recent years, electrophotographic devices have become smaller and cheaper, and compact desktop page printers and personal-use copiers have become available on the market.

Since such electrophotographic apparatuses are characterized by low cost, they are required to be assembled and adjusted as easily as possible. Among these, the doctor gap of the doctor blade requires considerable precision depending on the device, and its adjustment requires considerable skill, so improving this is an important issue.

[Conventional technology]

A conventional doctor blade mounting structure is shown in FIG.

Figure 6 (al is a side view, Figure 6 (bl is a front view, ■ in the figure, ■ is a magnet roller, 2 is a doctor blade. The magnet roller 1 has a non-rotating thin cylindrical sleeve 3. It also incorporates a rotating cylindrical magnet (details not shown).

The doctor blade 2 is attached to a support member 4 with a screw 5 and faces the magnet roller 1, and a doctor gap g is formed between the tip of the doctor blade 2 and the sleeve 3.

This doctor gap g is secured by inserting a feeler gauge 6 of an appropriate thickness between the doctor blade 2 and the magnet roller 1 and tightening the screw 5 with a screwdriver 7, as shown in FIG. .

[Problem that the invention seeks to solve]

In such a conventional mounting structure, variations occur in the doctor gap, and the accuracy is usually only about ±0.15 mm, and even a highly skilled worker has a limit of jo, In+m.

If the accuracy of the doctor gap is poor, the following problem will occur.

That is, if the doctor gap is too wide, developer will overflow in the developing section, and if it is too narrow, developer will clog at the doctor blade.

Therefore, installation work requires careful work, which increases work time and increases assembly costs.

[Means for solving problems]

The present invention provides a doctor blade mounting structure that can solve the above-mentioned problems, and the principle thereof is shown in FIG.

In FIG. 1, 101 is a magnet roller, 102 is a doctor blade, 103 is a spacer, and 104 is enemy means, which are provided in the developing tank of the developing device along with other members.

The magnet roller 101 is a non-rotating cylindrical sleeve 1
05 has a built-in rotary mag spear (not shown).

The doctor blade 102 can move forward and backward in the directions of arrows A and A', and is energized by the enemy means 104 in the six directions of arrows.

The spacer 103 is integrally provided at both ends of either the doctor blade 102 or the sleeve 105.

[Effect]

During assembly, the doctor blade 102 energized by the enemy force means 104 is inserted into the spacer 103 forming part.
It is only necessary to bring it into contact with the sleeve 105 of the magnet roller, making the assembly work simple.

By using the spacer 103 with an appropriate thickness, a desired value of the doctor gap g can be ensured with high precision.

〔Example〕

The present invention will now be described in detail with reference to FIGS. 2 to 5.

A first embodiment is shown in FIGS. 2 to 4.

FIG. 2 is a side view showing the structure of a developing device for an electrophotographic apparatus to which the present invention is applied. A magnetic roller 16, a doctor blade 17, and a scraper 18 are provided. The magnet roller 16 has a non-rotating cylindrical sleeve 19 containing a rotating cylindrical magnet (details not shown).

This developing device is an example of a developing device that uses a mixed two-component developer, and the developer at an appropriate mixing ratio is placed in the tank 13 in advance. The developer in the tank is guided to the surface of a magnet roller 16 by a scraping roller 15. Thereafter, the developer is transported by the magnet roller 16 to a developing position, where the latent image formed on the surface of the photosensitive drum or the like is developed. The toner hopper 12 is replenished with toner components that are consumed during development.
When the developer concentration in the tank 13 becomes low, the supply roller 1
4 supplies toner to the developing tank 13, so that the amount of developer in the developing tank 13 is always constant. The doctor blade 17 regulates the height of the developer conveyed by the magnet roller 16 . The developer that did not contribute to the development is scraped off by the scraper 18 whose one end is in contact with the magnet roller 16, and is reused following the above-described process.

The doctor blade 17, as shown in detail in FIG.
Both ends are integrally provided with projections (spacers) 20 with a projection height g, and are supported by a fixed shaft 21a protruding from the side wall 21 so as to be movable in the directions of arrows B and B' in FIG. means) 22 in the direction of arrow B.

The urging force of the spring 22 causes the protrusion 20 to abut against the sleeve 19, thereby forming a doctor gap between the doctor blade 17 and the sleeve 19.

This doctor gap is for controlling the hot height described above.

In this way, in this example, the doctor gap is formed simply by bringing the doctor blade 17, which is energized by the spring 22, into contact with the sleeve 19, which simplifies the assembly. Since it is determined only by the height of the protrusion 20, it is possible to achieve an accuracy of about ±0.05 mm.

FIG. 4 shows another example of forming a spacer. In this case, a ring-shaped spacer 23 is integrally provided at both ends of the sleeve 19, and the doctor blade 17 does not have a protrusion that serves as a spacer. It has not been. The effects of this structure are similar to those of FIG. 3.

FIG. 5 shows a second embodiment.

FIG. 5 (al is a side view showing the doctor blade attachment structure, FIG. 5 (bl is a front view of the same), in which 31 is a doctor blade and 32 is a magnet roller having a sleeve 33.

The doctor blade 31 is attached to an arm 35 that is rotatably supported by a fixed shaft 34, and is integrally provided with projections (spacers) 36 at both ends of the tip. Arm 35 is
A spring (
The protrusion 36 is urged clockwise in FIG.

In the case of this example as well, the same effect as the previous example can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to achieve the following various excellent effects.

It is only necessary to bring the doctor blade, which is activated by the enemy means, into contact with the sleeve of the magnetic roller, and there is no need for gap adjustment work.

(2) Since the structure is such that the doctor gap accuracy is determined by the spacer accuracy, the gap accuracy can be increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a side view showing the structure of a developing device for an electrophotographic apparatus according to the first embodiment of the present invention, and FIG. 3 is a perspective view showing the doctor blade mounting structure. Fig. 4 is a perspective view showing the procedure for forming a spacer in the same area, and Fig. 5 is an explanatory diagram of the doctor blade attachment structure of the second embodiment of the present invention (Fig. ) is a front view), and Figure 6 is an explanatory diagram of the conventional doctor blade installation structure (
Fig. 6 (al is a side view, Fig. 6 (b) is a front view) and Fig. 7 are explanatory diagrams of the procedure for adjusting the doctor blade gap of the structure shown in Fig. 6. In the figures, ' 11 is a developing device, 16.32 , 101 is a magnet roller, 17.31,
102 is a doctor blade, 19.33, 105 is a cylindrical sleeve, 20.23, 36, 103 is a spacer, 2
2.38,104 is enemy force means.

Claims (1)

[Claims] A magnet roller (101) having a rotating magnet built into a non-rotating cylindrical sleeve (105), and a doctor blade (102) facing the magnet roller with a doctor gap interposed therebetween. In the developing device for an electrophotographic apparatus, the doctor blade is provided so as to be movable toward the magnet roller, and a doctor gap is appropriately formed at both ends of either the doctor blade or the sleeve. A spacer (103) is integrally provided to keep the doctor blade in place, and an urging means (103) is provided which presses the doctor blade in the forward direction to abut the sleeve at the spacer forming portion.
4) A doctor blade mounting structure characterized by providing the following.