JP2935933B2 - Charged body structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a charged body structure.
For details, needle electrode and screen grid are integrally molded
The present invention relates to a charged body structure fixed to a holding member provided .

[0002]

2. Description of the Related Art As is well known, an electrophotographic copying machine is composed of process units for charging, exposing, developing, transferring and fixing. That is, in the copying process, first, an electrostatic latent image is formed by exposing the surface of a photoreceptor, to which a uniform charge has been given by a corona-charged charged body, with reflected light of an original image through an optical system, A toner (developer) is electrostatically attached to the image and developed to form a toner image on the photoconductor. Next, the toner image is transferred onto recording paper by static electricity having a polarity opposite to that of the toner on the transfer body, and then the toner is heated and fixed to fix an image corresponding to the original image on the recording paper. As the photoconductor, a material having a high dark resistance and a high photocarrier generation rate, for example, selenium or the like is used. The charge to the photoreceptor is given by corona discharge. Typical examples of the charged body that gives corona discharge include a method using a corona wire and a method using a saw-tooth electrode (hereinafter, referred to as a needle electrode). is there.

The charged body of the corona wire has a size of 25 to 90 μm.
A (micrometer) thick tungsten or stainless steel corona wire is stretched through an insulator in an electrode case that opens to the metal photosensitive zone side, and a power supply is connected to the corona wire. Corona discharge occurs. Further, the needle-shaped electrode charging body is a charging body having a needle-shaped electrode having a sharp saw-toothed end with respect to a corona wire of a corona wire type charged body and performing corona discharge from the end.

When these charged bodies are used for a long period of time, toner and dust adhere to the electrodes and a stable corona discharge cannot be obtained. As a result, the charged charges on the photosensitive body become uneven and the image quality is deteriorated. Cleaning for removal is performed. Conventionally, as a method of cleaning a corona wire of a charged body using a corona wire, a corona wire which is opened toward a photoreceptor and shielded at both ends in an electrode case which shields the corona wire is sandwiched between cleaning members. The cleaning is performed by moving the cleaning member along a corona wire using the electrode case or the like as a guide member. In addition, when cleaning the charged body using the needle-shaped electrode, the cleaning member is moved with the electrode case as a guide while the cleaning member is in contact with one surface of the needle-shaped electrode.

[0005] A grid is disposed between the discharge electrode and the photoreceptor of the charged body, and the electrostatic current of the charged body is controlled by controlling the electrostatic current of the charged body by the position of the grid with respect to the discharge electrode and the voltage applied to the grid. Is stipulated. In a charged body in which the discharge electrode uses a needle electrode, the needle electrode has a saw-toothed electrode formed on one long side of a strip, and both sides are sandwiched between members made of two insulators. The grid is a screen grid formed by forming a screen on a strip-shaped metal plate. The grid is at a right angle to the electrode surface, so that it is on both sides of the needle electrode. And a holding member for attaching the grid to the vehicle. As described above, the needle electrode and the screen grid are separate members, the separation between them is kept constant, and the charging voltage of the photoconductor is determined only by the voltage applied to the charging body and the screen grid. I have to.

FIG. 10 is a view for explaining an example of a conventional discharge electrode cleaner. A charging member 27 includes a needle-like electrode 28 facing a photosensitive drum (not shown) and an electrode fixing member 2.
9 and fix the electrode fixing member 29 to the electrode case 3.
It is fixed in 0. The electrode case 30 is formed of a long metal plate having a U-shaped cross section with one end opened toward the photoconductor, and a guide window 30a is opened on one surface.
The resin film (for example, made of polyester resin,
One side of DuPont (trade name: Mylar, etc.) is fixed and can be opened and closed in the electrode case 30. On the other hand, the discharge electrode cleaner 22 has a sliding plate 23 having a guide projection 24.
And a discharge electrode cleaner guide 25 having a cleaning member 26 disposed at the tip.

When cleaning the needle electrode 28,
Holding the handle 22 of the discharge electrode cleaner 21, the discharge electrode cleaner guide 25 is opened while pressing the resin film 31 and inserted into the guide window 30a to insert the cleaning member 26.
Is brought into contact with the needle electrode 28. Then, while pressing the right-angled surface formed by the sliding plate 23 and the guide projection 24 against the edge of the electrode case 28, the edge of the electrode case 28 is used as a guide member, and the charging member 7 is moved in the longitudinal direction (at right angles to the paper surface). Cleaning).

FIGS. 11 (a) and 11 (b) are diagrams for explaining the operation of a conventional discharge electrode cleaner. FIG. 11 (a) shows a case where the discharge electrode cleaner is located at the end of a corona discharge device.
(B) is a diagram showing a case where the discharge electrode cleaner is located at the center of the corona discharge device. In the case of FIG. The bending rigidity is high, and the cleaning member 26 and the needle-shaped electrode 28 are separated from each other by a predetermined fixed value. However, when the discharge electrode cleaner 21 is located at the center of the electrode case 30 as shown in FIG. , Discharge electrode cleaner 21
The electrode case 30 is deformed by the pressing, and the needle electrode 28 and the cleaning member 26 come into abnormal contact with each other, deforming the needle electrode 28 sandwiching the needle portion, and in the worst case, causing damage.

[0009]

THE INVENTION Problems to be Solved] traditional charging body, saw
A member for fixing the formic re-teeth electrodes, and the members for fixing the screen grid is a separate member, is member number for these are assembled processed many took assembling steps. In assembling, it is necessary to keep the distance between the tip of the needle electrode and the screen grid constant, but the distance is likely to vary due to separate assembly, and furthermore, the tip of the needle electrode and the screen grid are likely to vary. The slit is likely to be displaced.

[0010]

According to the present invention, in order to solve the above-mentioned problems, the present invention is arranged in such a manner that the photosensitive member is disposed in parallel with the photosensitive member and the photosensitive member is statically moved.
A needle electrode that is electrically charged, and an intermediate position between the needle electrode and the photoconductor.
That controls the current that electrostatically charges the photoreceptor
In the charged body consisting of lean grid, strip-shaped metal
The plate has a saw-toothed end on one long side and fixed at both ends
Needle electrode with a fixed hole and the center of the strip metal plate
Screen with a screen in the opposite direction and mounting holes opened at both ends
And a plurality of sandwiches for sandwiching the needle-shaped electrode from both sides.
The screen grid with the rib portion having
Needle-shaped electrode and locked at a predetermined distance from both ends of the needle-shaped electrode
A hooking claw portion, and the rib portion and the hooking claw portion
An integrally formed holding member and a supplement for shielding the rib portion
And an auxiliary electrode case .

[0011]

[Action]

(1) An electrode case of a charged body having a needle-shaped electrode and a high-rigidity guide member are disposed in parallel. The discharge electrode cleaner is guided by the guide member and slides on the upper surface. Since no bending force acts on the electrode case because it is merely a positioning of the discharge electrode cleaner, the electrode case does not deform and the needle-shaped electrode and the cleaning member always contact at a fixed distance, and by cleaning, The needle electrode is not damaged. (2) Since the needle-shaped electrode and the screen grid are fixed to the integrally formed holding member having a predetermined distance, the distance between the needle-shaped electrode and the screen grid can be reduced without special consideration for assembly. In addition, there is no error in the interval between the tip of the needle electrode and the slit of the screen grid.

[0012]

1 is a sectional view for explaining a discharge electrode cleaner related to the present invention. In the figure, 1 is a discharge electrode cleaner, 2 is a handle, 3 is a sliding plate, 4 is a guide projection, 5 is a discharge electrode cleaner guide, 6 is a cleaning member, 7 is a charged body, 8 is a needle electrode, 9 is an electrode fixing member, 10 is an electrode case, 11 is a resin film (for example, made of polyester resin, a product of DuPont). Name: Mylar), 12 is a guide member.

The discharge electrode cleaner 1 is a resin material in which a handle 2 is integrally formed on one surface of a slide plate 3 having a guide projection 4 and a discharge electrode cleaner guide 5 extending obliquely downward from the other surface of the slide plate 3. A cleaning member 6 such as a resin brush is provided at the tip of the discharge electrode cleaner guide portion 5. On the other hand, the charging member 7 is provided in an electrode case 10 in which the needle-shaped electrode 8 is fixed to the upper surface of the electrode fixing member 9 and the needle-shaped portion of the needle-shaped electrode 8 is opened toward the photoconductor (not shown). ing. The electrode case 10 is spaced apart in parallel with the axis of the photoconductor,
It is made of a metal plate having a U-shaped cross section and being long in the direction of the photoconductor. A guide window 10a is opened in a longitudinal direction on a surface in contact with the sliding plate 3, and a resin film 11 is hingedly opened and closed at a side 11a on one side of the guide window 10a in the longitudinal direction. It is fixed. The guide member 12 is arranged in parallel with the electrode case 10 at a distance from the electrode case 10. The guide member 12 is made of a resin member or the like integrated with the outer casing of the copying machine, but is a highly rigid body that does not deform when the discharge electrode cleaner 1 is pressed.

In the above configuration, the discharge electrode cleaner 1
In the sliding plate 3, the guide projection 4 is inserted between the electrode case 10 and the guide member 12, and the bottom surface 3a slides on the guide member 12. At this time, the discharge electrode cleaner guide portion 5 pushes the resin film 11 and is inserted into the electrode case 10 through the guide window 10a, and the cleaning member 6 contacts the needle-like portion of the needle-like electrode 8 with a predetermined length. The electrode case 10 is simply positioned to be in contact with a corner surface formed by the sliding plate lower surface 3 b of the discharge electrode cleaner 1 and the guide projection 4, and the horizontal position is defined by the guide member 12. Therefore, the positional relationship between the needle electrode 8 and the cleaning member 6 does not change due to the sliding of the discharge electrode cleaner 1.

FIGS. 2A, 2B, and 2C are diagrams related to the present invention.
FIG. 4 is a view for explaining the order in which cleaning is performed by interposing a continuous discharge electrode cleaner on a charged body, in which parts having the same functions as in FIG. 1 are denoted by the same reference numerals as in FIG. 1. . (A) Figure: Holding the discharge electrode cleaner 1 and bringing the cleaning member 6 closer to the resin film 11 of the electrode case 10. (B) Figure: The resin film 11 is pushed down by the cleaning unit 6 to bring the cleaning member 6 into contact with the needle electrode 8. (C) Figure: Guide projection 4 is connected to electrode case 10 and guide member 1
The discharge electrode cleaner 1 is slid in the longitudinal direction of the electrode case 10 (a direction perpendicular to the plane of the paper) while pressing the slide plate 3 against the guide member 12 by inserting the discharge electrode cleaner 1 into the guide member 12. In this case, the cleaning member 6 and the needle electrode 8 are in contact with each other while maintaining a certain length.

FIG. 3 is a partial rear view of a copying machine for explaining cleaning by a discharge electrode cleaner related to the present invention. FIG. 4 is a partial side view of FIG. 1 is a photosensitive drum, and 15 is a screen grid, and the same reference numerals as in FIG.

The photosensitive drum 14 of the copying machine 13 and the needle electrode 8 are arranged axially parallel and spaced apart from each other.
a is opposed to the photosensitive drum 14, and a screen grid 15 for controlling the charging voltage of the photosensitive drum 14 to be constant is provided between the photosensitive drum 14 and the photosensitive drum 14. Discharge electrode cleaner 1
The cleaning member 6 slides in the cleaning direction indicated by the arrow while the reciprocating sliding plate 3 is pressed against the guide member 12 by bringing the cleaning member 6 into contact with the needle electrode portion 8a to clean the needle electrode 8.

FIG. 5 is a perspective view for explaining the structure of the charged body in the present invention. In FIG.
1 is a holding member, 42a and 42b are ribs, 43a and 43
b is a sandwiching rib, 44 is a hooking claw, 45 is a hooking claw, 46 is a needle electrode, 47 is a screen grid, and 48 is an auxiliary case.

FIG. 6 is a plan view of FIG. 5, in which 50 is a discharge electrode, 51 is a grid electrode, 52 is a photosensitive unit,
53 is a photoreceptor (OPC) drum.

FIG. 7 is a front view of FIG. 5. In FIG. 7, reference numeral 49 denotes a positioning boss. In FIGS. 6 and 7, parts having the same functions as those in FIG. doing.

In the upper figure, the charging member comprises a holding member 41 integrally formed of resin or the like, a needle electrode 46, a screen grid 47, and an auxiliary electrode case 48. The holding member 41 is a molding material for fixing the needle electrode 46 and the screen grid 47 to the photoconductor unit 52 so as to be axially parallel to the photoconductor drum 53, and attaches the needle electrode 46 and the screen grid 47 with one touch. It is a structure that can be done. The needle electrode 46 is a rib 42
The positioning boss 49 is inserted between the a and 42b for positioning. The needle-shaped electrode 46 is formed of a strip-shaped metal plate, and has a sawtooth-shaped sharp discharge portion 46a provided on one of the long sides, and fixing holes for inserting the needle-shaped electrode 46 into the positioning boss 49 at both ends. 46b is open.
The ribs 42a and 42b are respectively provided with sandwiching ribs 43.
“a” and “43b” are alternately arranged in a direction perpendicular to the needle electrode 46, and the tips of the ribs 43 a and “a” 43 b face each other with an interval t about the thickness of the needle clamp electrode 46. For this reason, the needle electrode 46 is accurately positioned in the length direction, the thickness direction, and the front-back direction.

The hooking claws 44 are provided at both ends of the holding member 41 at positions separated from the needle-like electrodes 46. The hooking claw portion 44 has a hooking claw 45 into which a mounting hole 47a opened to the screen grid 47 is inserted at the tip and which elastically locks the screen grid 47. For this reason, the needle electrode 46 and the screen grid 47 necessarily maintain a fixed positional relationship. In order to apply a voltage, a discharge electrode 50 is connected to the needle electrode 46, a grid electrode 51 is connected to the screen grid 47, and the rib portions 42 a and 4 are further connected.
An auxiliary case 48 having a U-shaped cross section, which is fixed by a spring force, for electrostatic shielding is inserted into 2b to form an integral charged body structure 40. The charging member is attached to the mounting hole 4 of the holding member 41.
At 1a and 41b, the photosensitive member unit 52 is screwed.

FIG. 8 is an exploded perspective view for explaining another embodiment of the charged body structure according to the present invention. In the figure, reference numeral 60 denotes a charged body structure, 61 denotes a holding member, 62 denotes an electrode mounting portion, and 63 denotes an electrode mounting portion.
a and 63b are positioning bosses, 64 is a hook, 65 is an electrode case locking rib, 66 is a needle electrode, 67 is a positioning hole,
69 is a screen grid, and 72 is an electrode case.

FIG. 9 is a view from the back of FIG. 8. In FIG. 9, reference numeral 68 denotes a positioning pin, reference numeral 70 denotes an adhesive portion, reference numeral 71 denotes a discharge electrode. The same reference numbers are given.

The charging member structure 60 shown in FIG. 8 differs from the charging member structure 40 shown in FIG. 5 in the method of attaching the needle electrodes 66, and the holding member 61 has a structure according to this attachment method. That is, as shown in FIG.
A long flat surface corresponding to the needle electrode 66 is formed, and the needle electrode 66 is bonded and fixed to the bonding portion 70 with an adhesive or the like on this flat surface. At this time, a plurality of positioning holes 67 are provided in the needle-shaped electrode 66, and positioning pins 68 are inserted into the positioning holes 67, and the needle-shaped electrode 66 is moved back and forth, right and left, and up and down in the back of the electrode mounting portion 62. Is positioned and fixed. The screen grid 69 has a grid 69a, and, similarly to the charged body structure 40 of FIG. 5, fixes the positioning hole 69b to the hook portion 64 by one-touch using elasticity. Next, the electrode case 72 is inserted according to the locking rib 65, and the positioning bosses 63 a and 63 b are inserted into the positioning holes 73 a and 73 b of the electrode case 72 to insert the holding member 61, the needle-like electrode 66, the screen grid 69 and the electrode case 72.
Are integrally configured.

[0026]

As is clear from the above description, according to the present invention , the needle electrode and the screen grid can be mounted in a state of being integrally formed, and the mounting method can be extremely easily performed with one touch. Moreover, since the tip of the needle-shaped electrode can always be located at the center between the grids, no special positioning adjustment is required, and the charged body can be formed at low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a discharge electrode cleaner related to the present invention.

FIG. 2 is a view for explaining a sequence of performing cleaning by interposing a discharge electrode cleaner related to the present invention on a charged body.

FIG. 3 is a partial rear view of the copying machine for explaining cleaning by a discharge electrode cleaner related to the present invention.

FIG. 4 is a partial side view for explaining cleaning by a discharge electrode cleaner related to the present invention.

FIG. 5 is a perspective view for explaining the structure of a charged body in the present invention.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is a front view of FIG. 5;

FIG. 8 is an exploded perspective view for explaining another embodiment of the charging member structure in the present invention.

FIG. 9 is a view from the back of FIG. 8;

FIG. 10 is a diagram for explaining an example of a conventional discharge electrode cleaner.

FIG. 11 is a view for explaining the operation of a conventional discharge electrode cleaner.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-217276 (JP, A) Japanese Utility Model Application Sho 62-51348 (JP, U) Japanese Utility Model Application Utility Model Sho 62-94343 (JP, U) (58) Field (Int.Cl. ⁶ , DB name) G03G 15/02 G03G 15/16 H01T 19/00

Claims (1)

(57) [Claims] 1. A photosensitive member and the needle-like electrode parallel axially arranged therein electrostatically charging the photosensitive member, an intermediate position between the needle-shaped electrode and the photoreceptor
That controls the current that electrostatically charges the photoreceptor
In the charged body consisting of lean grid, strip-shaped metal
The plate has a saw-toothed end on one long side and fixed at both ends
Needle electrode with a fixed hole and the center of the strip metal plate
Screen with a screen in the opposite direction and mounting holes opened at both ends
And a plurality of sandwiches for sandwiching the needle-shaped electrode from both sides.
The screen grid with the rib portion having
Needle-shaped electrode and locked at a predetermined distance from both ends of the needle-shaped electrode
A hooking claw portion, and the rib portion and the hooking claw portion
An integrally formed holding member and a supplement for shielding the rib portion
A charged body structure comprising an auxiliary electrode case .