JPS5937571A - Developing device - Google Patents

Abstract

PURPOSE:To perform excellent and stable development with simple constitution, by setting properly the edge shape, arrangement position, etc., of a developer specifying body which specifies the layer thickness of a magnetic developer sticking to the outer circumference of a developer supply body. CONSTITUTION:A developing roll 36 consists of a sleeve and a magnet roll arranged therein, and magnetic toner is carried on the sleeve by being specified by a dector 41 into a uniform layer. The angle alpha of the edge of the dector 41, i.e. angle alpha between the surface of a toner hopper side and a tanget drawn from the point where said surface is extended and strikes a developing roll 36 is >=0 deg. and <=90 deg. and the closest part of the edge of the dector 41 to the developing roll 36 is positioned facing the circumference of the developing roll 36 within the range that an angle from right above the developing roll 36 is 30-90 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an apparatus for developing electrostatic latent dust using a powder developer.

[Technical background of the invention and its problems]

In recent years, in electrophotographic apparatuses and the like, magnetic blank apparatuses using one-component magnetic toner as a powder developer have come to be widely used. FIG. 1 is a representative 1911 of a conventional field unit device. This includes a magnet roller 2 having a plurality of magnetic poles facing the photoreceptor I as a part on the verge of failure, and a cylindrical sleeve 3 surrounding this.
A current (8) roller 4 consisting of: Then, the magnet roller 2 and the sleeve 3 are rotated in opposite directions (the magnet is in the C direction and the sleeve is in the b direction).
As a result, a toner layer (magnetic brush) 5' of the magnetic toner 5 is formed, and the toner layer (♂) is pressed to a constant thickness by a doctor 6 serving as a developer regulator, and rubbed onto the photoreceptor 1.

Note that the conveying direction of the magnetic toner 5 is the C direction.

Note that an arrow 8 in the figure indicates the flow of the magnetic toner 5 (toner loose) within the small toner bag z. By the way, in this method, one of the key points to avoid good image interference is to always keep the gap between the doctor 6 and the sleeve 3 constant, and to keep the gap between the doctor 6 and the sleeve 3 constant. , the following problems occur with the image: 1. Nbi.

(1) Occurrence of white streaks (both f-images! parallel to the a-line direction).

[Cause] This occurred because the magnetic toner 5 adhered to the tip of the doctor 6, and the number of needles for conveying the magnetic toner 5 in that area decreased.

There are two reasons for the adhesion of toner:

■Adhesion due to mechanical and electrostatic factors.

■ Dust or paper powder that has entered the developing device becomes clogged between the doctor blade 6 and the sleeve 30, and the magnetic toner 5
is attached.

(11) Occurrence of kaze (a phenomenon in which the white background becomes dirty).

[Cause] This occurred because the magnetic toner 5 of the toner layer (magnetic brush) 5' contained insufficient charge.

(Ill) The line perpendicular to the direction of the squadron's movement becomes unclear.

[Cause] Since the magnetic brush b' rotates in only one direction, the fine lines in the Ichikawa direction, that is, the magnetic toner 5 with weak adhesion, are easily swept away by the magnetic brush 5'.

Ov) Occurrence of agricultural fluctuations.

[Cause] ■ The stress applied to the magnetic toner causes the magnetic toner to lose its shape and change its characteristics. ■Magnetic toner is not charged uniformly. ■The image density changes depending on the amount of toner in the toner hopper 7. Specifically, when the amount of toner in the toner hopper 7 is small, the density is also low. ■ Blocking of the magnetic toner 5 occurs between the doctor 6 and the sleeve 3.

There was a question of profit.

[Purpose of the invention]

The present invention has been made based on the above-mentioned Japanese literature, and its purpose is to provide a visual imaging device that has an extremely simple configuration and yet can perform good and stable motion. be.

[Question of invention! In order to achieve the above-mentioned object, the present invention provides a tip shape, arrangement position, etc. of a magnetic material removal regulating body that regulates the magnetic material removal layer II that adheres to the outer periphery of the developer supplying member. is set to an outdated state.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 to 7. FIG. 2 shows a good electronic copying machine that employs the developing device according to the present invention, and numeral 11 in the figure is the main body. A document mounting table 12 is provided on the upper surface of the main body 11, and is reciprocated by a motor 13 provided within the main body 11. Further, a photoreceptor 14 serving as a drum-shaped iron carrier is pivotally supported approximately at the center of the main body 11, and is rotated in synchronization with the document mounting table 12. An exposure system 17 consisting of a lamp I5, a converging light transmitter 16, etc. is provided between the photoreceptor I4 and the original platen 12, and illuminates the original on the original platen 12 and directs the reflected light to the photoreceptor. 14-H to form an image of the manuscript group. From this image forming position, along the rotational direction of the photoreceptor 14, a developing device 18, a transfer corona discharger 19, a masticator 20, etc., which will be described later, are arranged in this order. Cleaner 21 and SF? ii: R:4
22 are arranged. Further, at the bottom of the main body 11, there is provided a transport path 25 for copy paper 24 as a recording medium, which passes through a transfer section 23 formed between the photoreceptor 14 and the transfer corona discharger 19. Manual feed guide 26 at the end
and a paper feed section 28 having a paper feed device 27 , the end of which faces a paper discharge tray 30 via a fixing device 29 . Note that 31° 31 is a conveyance roller.

The surface of the photoreceptor 14 is first charged by the charger 22, and then the charges are selectively erased by exposure from the exposure system 170, forming an electrostatic latent image. Next, this electrostatic latent image is visualized by adhering magnetic toner by the developing device 18, thus forming a developer layer. This one image of the inking agent is transferred by the corona discharge of the transfer corona discharger 19 onto the copy paper 24 fed from the paper feed section 28 and guided by the guide plate.

Further, the developing device 18 has a configuration shown in FIG. 3. That is, in the figure, numeral 32 is a toner hopper serving as a developer storage tank, and this toner hopper 32 has a pair of side frames 33, 33 (only one shown), and both longitudinal ends of the side frames 33, 33 are fixed to these side frames 33, 33. It is assembled integrally from the plates 34 and 35, and has a supply opening 32a.
and a display opening 32b.

Then, the toner hopper 3 is placed in a state where the developing roller 36 serving as a developer supplying member is partially exposed from the developing opening 32b.
It is housed within 2. This developing roller 36 is a cylindrical rotating body made of materials such as aluminum and stainless steel.
(hereinafter referred to as a sleeve) 37 and a magnet row 238 disposed within this sleeve 37,
By appropriate means, the sleeve 37 is rotated in the direction of arrow A, and the magnet roller 38 is rotated in the direction of arrow B in synchronization with this rotation.

At the top, a predetermined small gap (Dr-8L gap) 39 is formed between the outer circumferential surface of the bisleeve 37 and the outer circumferential surface of the photoreceptor 14 rotating in the direction of arrow 1C in the figure. ing. The magnetic toner 40 in the toner hopper 32 is attracted to the outer circumferential surface of the sleeve 37 through the magnetic force of the upper three-pin magnet row 238, and is transported in the direction of the arrow 8'C. A predetermined gap (Dc
-8c) 42 to form a uniform toner i4o/ on the sleeve 37. Here, reference numeral 43 denotes a doctor adjusting plug that is attached integrally with the doctor 41, and is moved up and down with the doctor minor adjustment screw 44 to set a predetermined gap (Dc-8c gap) 42, and then adjusted with the doctor fM constant nut 45. Fix it.

Further, a developing opening cover 46 and a sealing member 47 are attached. Further, a sub-magnetic roller 48 is disposed below the developing opening 32b and is rotated in the D direction to collect the S-type toner 4o attached to the non-image area on the photoconductor 14 and collect the S-type toner 4o attached to the non-image area on the photoconductor 14, It plays the role of magnetically attracting the magnetic toner 40 scattered downward from the roller 36 and collecting it to the developing roller 36. Reference numeral 49 denotes a lid body that closes the supply opening 32a above the toner hopper 32, and a sealing member 50a.
Prevents toner from scattering between the VC and the opening.

The sleeve 37 is formed by the developing device I8 configured as described above.
The magnetic toner adsorbed is formed into a uniform toner r@4o' by the doctor 41, and is conveyed over the sleeve 37 by the rotation of the magnetic roller 38 while taking on an almost upright soft brush shape, and is then conveyed to the gap (Dr- s
(c) Through the gap 39, the electrostatic latent image formed on the surface of the photoreceptor 140 is attracted, and good development is performed. Here, an AC bias is applied to the developing roller 36 by a bias power source 51 in order to appropriately determine the rate of change between original density and copy density (hereinafter referred to as γ characteristics), but it is also sufficient to simply ground it. .

FIG. 4 shows magnetic toner 40 in the toner hopper 32.
This shows the flow of the process. This flow (referred to as the post-U toner loop 52) is caused by the rotation of the developing roller 36 and the doctor 4.
Created by 1. That is, the magnetic toner 40 in the toner hopper 32 is attached to the outer periphery of the sleeve 37 by the magnet roller 38 of the developing roller 36 (and further transported to the doctor 41 side by the rotation of the sleeve 37 and the magnet roller 38. and sleeve 3
Since there is a slight time between the conveyed internal toner 40 and the sleeve 37 surface V (a part of the conveyed internal toner 40 passes through the gap and is conveyed to the photoreceptor 14 side, the remaining magnetic toner As shown in FIG. 4, the toner 40 is separated from the sleeve 37 below the doctor 41 and then falls under its own weight.Then, it is again attracted to the sleeve 37 by the magnetic roller 38 and transported as described above.Toner hopper The magnetic toner 4o in the toner 32 repeats this movement and is consumed from k.

- On the other hand, one point in order to obtain good image quality using the one-component development method using the magnetic l-toner 40 is to create a uniform toner layer 40' on the sleeve 32.

Therefore, in the present invention, as shown in detail in FIG. 5, the angle α of the tip of the doctor 41 is set within a certain angular range, that is, the angle α of the toner hopper 32 lul+ among the surfaces forming the edge of the optical end of the doctor 4I. surface and that surface with the developing roller 36.
The angle α formed with the tangent line drawn from the point where it extends to the side and hits the developing roller 36 is greater than 09 and less than 90° (Oo〈α〈9
0°).

By setting the angle of the tip of the doctor 41 in this way, the flow of the magnetic toner 40 near the tip of the doctor 4I becomes smoother, and dust and paper particles that have entered the developing device are removed between the doctor 4I and the sleeve 37. Without any delay,
The toner is forcibly conveyed together with the magnetic toner 40. The magnetic toner 4θ that attempts to adhere mechanically or electrostatically to the surface of the doctor 41 also has jfj% of the magnetic toner 40.
Due to the feeding power, it is turned into a parrot.

For this reason, there is no possibility that the tip of the sand pillar toner 4o doctor 41 will stick to that area and the conveyance of the toner 4o in that area will be reduced, making it possible to produce good songs with even density. It is possible.

Furthermore, in the present invention, Id, ? f', as shown in Figure 6,
The largest part of the phase 1 roller 36VC at the tip of the developer 41 has an angle β from directly above the developing roller 36 in the range of 30° to 90° (30′<β(90′)). 1
ν "The part of the doctor 41 that faces the circumference of the J-ra 36 and is closest to the toner hopper 32 in the horizontal direction is the same as the outer periphery of the opening 36, or the toner hopper,
The position near 9211111, that is, the position rt where l≧r
t, vc are set.

Then, under the condition of 30°<β<900, the loop 52 of the magnetic toner 4o, which was explained with reference to FIG. 4, is made small, and the following effect is obtained. (1) Uncharged toner 4θ is supplied to the sleeve 37 to reduce fogging.

■Reducing the stress applied to the magnetic toner 4o, thereby preventing the magnetic toner 4o from becoming pulverized (proceeding pulverization leads to poor cleaning) and reducing the amount of magnetic powder exposed on the surface of the magnetic toner 40. prevent increase. (Does not damage the surface of the photoreceptor z4, which has little density variation.

) ■ By extending the time it takes for the magnetic toner 40 to reach the photoreceptor 14 after passing through the doctor 41 , the magnetic toner 40 is uniformly charged (stabilized density) and the spikes of the magnetic toner 4o are softened (■ Improve line reproducibility.

- Decrease the driving torque of the magnet roll 38.

etc. effect.

Furthermore, from the condition l≧r, ■ the weight of the magnetic toner 4o in the toner hopper 32 is directly
It does not hang between the sleeve 37 and the doctor 41, and does not affect the eyebrows of the magnetic toner 40 that passes through the doctor 41. This prevents lt, 1 degree from changing depending on the amount of magnetic toner 40 in the toner hopper 32.

(2) The weight of the magnetic toner 40 in the toner hopper 32 is no longer directly applied between the sleeve 37 and the doctor 4, and a phenomenon such as blocking of the magnetic toner 40 does not occur in this area. It has a powerful effect.

Furthermore, as shown in FIGS. 7(a) and 7(b), the doctor 41 has a flat surface 4Ja which is substantially parallel to the surface of the ψ roller 360 at the part of the doctor 41 that is closest to the phenomenon roller 36.
It is configured with the following.

The doctor 41 is made of a metal plate such as iron, stainless steel, etc., but these have a certain f! i! It has a degree of warpage. However, the warpage of the doctor 41 causes a change Vζ in the gap (Dc-8L gap) 42 between the doctor 41 and the sleeve 37, resulting in a defective image 'tq.

Therefore, I attached a flat surface (cut 1ll) to the tip of Doctor 4I.
By providing () 41a, it is possible to reduce the influence of warpage and obtain good image quality.

This will be explained in more detail with reference to FIG.

Fig. 7 (a) is a view of the doctor 41 seen from the side, and Fig. 7 (b) is a view seen from the direction of arrow E. The doctor 41t (having a warp as shown in Fig. 1) That is, the position corresponding to a VC is b at the center, and the position corresponding to d is e.At this time, the gap is from 42a to 42b.
K changes. That's why I don't want to go to Doctor 4I 41tx
If you add , the line in the longitudinal direction of this part becomes a drawing line as shown by C, and the gap becomes only 42CO'l'tf.

In other words, by providing the flat surface (cut portion) 41a, the gap 42 becomes less susceptible to the effects of warping.

〔Effect of the invention〕

As explained above, the present invention provides a developer supplying body that is provided opposite to the developed area, conveys powder developer, and supplies it to the developed area, and a developer supplying body that causes the developer to adhere to the developer supplying body. A developer regulating body for regulating the layer thickness of the developer is provided, and the developer after the layer thickness has been regulated by the developer regulating body is supplied to the viewed waste portion. In a developing device that performs image cutting, among the edges constituting the tip of the developer regulating body, there is a ring on the upstream side of the developer conveyed by the ring 1 image cutting supply body and between the developer supply body and the developer regulating body. The angle between the surface forming the flow path of the developer and the tangent drawn to the surface of the developer supply body at the position where it extends toward the developer supply body and touches the developer supply body is greater than θ°. The angle is less than 90°. Therefore, a uniform developer layer can be formed on the developer supplying body without the developer adhering to the tip of the developer/cutting regulating body, and the generation of white streaks parallel to the direction of movement of the 1IIIi ridge can be ensured. It is possible to prevent IF and obtain a good-looking image with no unevenness in intensity.

Furthermore, since a flat surface that is approximately parallel to the surface of the sludge scraping regulator is provided at the part of the developer regulating body closest to the developer supply body, developer regulation due to warping of the slag scraping regulator is provided. The shadow balance due to the change in the gap between the body and the developer supply body can be reduced by (1), and a better image Vt can be obtained.

゛Also, there is a developer supplying body which is provided opposite to the to-be-developed surface 11 and supplies the magnetic developer 1 by magnetic force to the image area (a), A developer tank +t>Q tank that stores the developer supplied by the body, and a
It is a component of the cutting storage tank, and in the current 14g device which is equipped with a cutting regulating body for regulating the above-mentioned condition, the Qlf image at the tip of the salt cutting regulating body is The part closest to the cutting supply body is located within the range of 30° to 90° on the circumference of the developer supplying body from directly above the cutting supply body, and the developer mj in the horizontal direction. The part of the regulating body closest to the developer storage tank is either the same as the outer periphery of the developer supply body or closer to the developer storage tank side (J: set to jPI).

Therefore, it is possible to reduce the loop of 1$ reduction of 1$ of liQ material, and also to reduce the weight of magnetic particles in the developing storage 1Al1 tank. Effects such as 11- can prevent negative effects, prevent LE from occurring such as fogging, blurred curved lines in both R-shaped advancing directions, and density fluctuations, and enable good and stable development. play.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a conventional example, and Figs. 2 to 7 (a) and (b) show an embodiment of the present invention. A↓Figure 2 is a schematic vertical side view of a copying machine employing the present invention, Figure 3 is a schematic vertical side view of a developing device, and Figure 4 is an explanatory diagram showing the flow of cutting. , Fig. 5 1 is an explanatory diagram showing the state of the tip angle of the doctor, Fig. 6 is an explanatory diagram showing the setting state of the doctor, and Figs. FIG. 6 is a side view and a bottom view showing a state of correction by forming a surface. 14... Iron carrier (photoreceptor), I8... Developing device,
32...Developer storage tank (toner hopper), :te-.
. L”A (developing supply body (developing roller), 40... developer (toner), 41... developer regulating body (doctor),
40'...Toner fa, 41a...Flat surface. Applicant's agent Patent attorney Takehiko Suzue 1 N 1N4 Figure 5 Figure 1N7 Commissioner of the Japan Patent Office 1 Kazuo Wakasugi 1. Table 71 of the small matter, Patent Application No. 148805/1983 (1) Invention/Development Apparatus 3, ? City 11: Name to do! I"Relationship to the case Special fraud applicant (307) Tokyo Shibaura Tanuki Co., Ltd. 11 Agent 6, ?+Ii+l-suburbs]9 (1) Details 1;, !59B 4th line F' (I) r
SL gap)" is f (DrSL gap f)
” he corrected. (2) Similarly, line 911 and line 16 0r (Da
-8c gear gap)" should be corrected to "(D c -S L gap)." (31 Similarly, page 10, line 8, "5oa" is replaced with "
50,” he corrected. (4) Similarly, in the 11th negative line, the word "41 side" is changed to "41 side". (As shown in Figure 3 of the attached drawing 1, a leader line numbered ``50'' is added, and the number r 4 s J?r indicating the sealing member close to the photoreceptor 14 side is added.
47 Correct it to J.

Claims (3)

[Claims] (1) To be viewed [a developer supply body that is provided opposite to the umbrella part, conveys the developer and supplies it to the first quadrant to be viewed, and a layer of developer that is attached to this developer supply body A developing device is provided with a developer regulating body for regulating the thickness, and the developer after the layer thickness is regulated by the developer regulating body is supplied to the visually impaired area to perform development. , among the surfaces constituting the edge of the tip of the developer regulating body, a surface that is on the upstream side of the developer conveyed by the developer supplying body and forms a flow path for the developer; A developing device, which is extended toward the developer supply body, and has an angle with a tangent drawn to the surface of the developer supply body at a position where it contacts the developer supply body, and is greater than 0° and less than 90°. (2) Claims characterized in that a flat surface that is substantially parallel to the surface of the present cleaning agent supply body is provided in the portion of the salt one-sided cutting regulating body that is closest to the current one-sided cutting supply body. Developing device for use in Section 1. (3) A developer supplying body which is provided opposite to the viewed r umbrella section, conveys the developer and supplies it to the viewed section, and stores the developer supplied by this developer supplying body. In a developing device equipped with a developer storage tank and a developer regulating body for regulating the layer thickness of the developer adhering to the developer supplying body, a developer supplying body at the tip of the developing agent regulating body; The part nearest to
The angle is between 0° and 90°, and the part of the developer regulating body closest to the developer storage tank in the horizontal direction is the same as the outer periphery of the developer supplying body, or is closer to the developer storage tank side. A developing device characterized by being located at