JPH02193161A - Electrifying device - Google Patents

Abstract

PURPOSE:To obtain stable electrifying characteristics and to realize excellent image formation by supporting an electrostatic charging nonuniformity preventing member by pressing it to a second supporting plane of a supporting member which supports an image carrier. CONSTITUTION:The device is provided with an electrifier main body 21b, an electrifier main body supporting member 86, which is installed using a first supporting plane 85a of the image supporting member 85 and removably supports the electrifier main body 21b, the electrifying nonuniformity preventing member 21a, which is installed on the side of an opening which passes through ion current of the electrifer main body 21b, an elastic member 91, which elastically connects the electrifying nonuniformity preventing member 21a with the electrifier main body supporting member 86, and a means which supports the electrifying nonuniformity preventing member 21a by pressing the member 21a to the second supporting plane 85b of the supporting member 85. Excellent dimension accuracy for supporting the electrifier main body 21b and the electrifying nonuniformity preventing member 21a is obtained having the member 86 which is integrated with the image carrier 20 is position as a position reference. Thus, steady electric discharge is always obtained and the excellent image formation is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Field of Application) The present invention relates to a charging device applied to an electrophotographic copying apparatus or the like that forms images using an electrophotographic process.

(Prior Art) In recent years, as a charging device adopted in electrophotographic copying machines,
In addition to a charger body equipped with a wire for supplying an ion flow, a charger equipped with a grid as a means for preventing uneven charging by making the ion flow uniform and preventing uneven charging has been put into practical use.

Conventionally, in this type of charging device, the charger main body has been attached to a charger frame as a charger main body holding member attached to the main body frame or the like.

Further, the grid has been fixed to the shield case of the charger main body, which is frequently removed during internal inspection, cleaning, jam removal, etc., or to the main body frame, where dimensional accuracy cannot be very strict.

A charging device comprising:

(Problems to be Solved by the Invention) As described above, in the past, the charger main body and the grid were attached with a part intervening where the dimensional accuracy could not be very strict. For this reason, charging characteristics are likely to be affected.
There is a problem in that dimensional accuracy between the wire of the charger main body and the image carrier, and dimensional accuracy between the image carrier and the grid cannot be obtained, resulting in uneven charging and, eventually, defective images.

The present invention has been made based on the above circumstances, and aims to improve the dimensional accuracy between the wire that supplies the ion flow of the charger body and the image carrier, and the image carrier while having a simple structure. It is an object of the present invention to provide a charging device that can achieve dimensional accuracy between the body and the charging unevenness prevention member, can obtain stable charging characteristics without charging unevenness, and can form good images.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a charging device that charges an image bearing member on which an image is formed by supplying an ion flow. a charger main body having a supply wire; a charger main body holding member that is attached using a first support surface of a support member that supports the image carrier and holds the charger main body in a detachable manner; A charging unevenness preventing member is provided to prevent charging unevenness and is provided on the ion flow passage side of the charger main body held by the charger main body holding member; A structure comprising: an elastic member elastically connected to the member; and support means for the uneven charging member that supports the uneven charging member in a pressed state against the second support surface of the support member. It is.

(Function) In other words, since the charger main body including the wire and the charging unevenness prevention member are supported using a member that is in an integral positional relationship with the image carrier as a positional reference, the charger main body, which easily affects the charging characteristics, is supported. The dimensional accuracy between the wire and the image carrier and the dimensional accuracy between the image carrier and the grid can be obtained in a constant state. As a result, stable discharge can always be obtained and good image formation can be achieved.

In addition, since the charging unevenness prevention member is elastically connected to the charger main body holding member by an elastic member, and the charging unevenness prevention member is supported while being pressed against the support surface, it is possible to use the same method for positioning during assembly. Workability can be improved without requiring special adjustment or skill.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows the appearance of an electrophotographic copying apparatus equipped with a static eliminating and exposing device.

In the figure, reference numeral 1 denotes a main body of the apparatus, and a paper feed cassette 2 is attached to the right side of the apparatus main body 1, and a paper ejection tray 3 is attached to the left side. The paper feed cassette 2 has a manual paper feed tray 4 on its upper surface for manually feeding paper P as a transfer material.
is equipped.

Further, on the top surface of the device main body 1, there is a
, b) is provided with a reciprocating document table table (hereinafter simply referred to as a table) 5.

In addition, on the front edge of the top surface of the main body 1, there is a display section 6 that notifies and displays the operating status of each part and the occurrence of the above, and displays the set number of copies, a copy number setting key (numeric keypad) for setting the number of copies, and a ) 7, a control panel 12 having a dimming knob 8 for setting copy density, a print key (copy key) 9, a clear/stop key 10°, a total counter 1, etc. is arranged.

Continuous copying is possible up to 99 copies by using the copy number setting key 7, and a count is displayed on the display section 6 using a subtraction method. Also, when auto clearing, [1
] is displayed, and [0] is displayed on the display section 6 during warm-up.

Incidentally, continuous copying can be made up to nine copies by cutting a jumper connector (not shown) inside the control panel 12. During continuous copying, clear/
By pressing the stop key 10, it is possible to manually feed one sheet. Further, a document pocket 14 is formed on the upper surface of the document holding cover (platen cover) 13 of the table 5, and a document pocket 14 can be stored therein as required.

Next, with reference to FIG. 3, the internal mechanism (
The electrophotographic process configuration mechanism) will be explained.

A photoreceptor drum 20 as an image carrier is arranged approximately in the center of the apparatus main body 1, and the photoreceptor drum 20 is moved at a copying speed of 95 in the direction of arrow C by a drive mechanism (not shown).
It is rotated at the same speed as mu/see and the moving speed of table 5. The photosensitive drum 20 is made of a negatively chargeable organic photoconductor (OPC), and has a structure in which a charge generation layer and a charge transport layer covering the charge generation layer are formed on the surface of an aluminum cylinder. .

Around the photoreceptor drum 20, along the rotational direction thereof, there are provided a charging charger 21 as a charging means, a static eliminating/exposure device 22 as an electrostatic image forming means, a developing device unit 23 as a developing means, and a transfer means. A transfer charger 24 as a transfer charger, a peeling charger 25 as a peeling means, and a cleaner unit 26 as a cleaning means are arranged in this order.

Further, inside the apparatus main body 1, paper P fed from the paper feed cassette 2 via the paper feed means 33 and a manual paper feed tray 4 are stored.
A paper transport path 28 that guides the paper P manually fed from the photosensitive drum 20 and the transfer charger 24 to the paper output tray 3 mounted on the left side of the apparatus main body 1 via the image transfer section 27. is formed.

A pair of aligning rollers 29 is arranged on the upstream side of the image transfer section 27 of the paper transport path 28, and a fixing unit 30 as a fixing means and a pair of paper ejecting rollers 31 as a paper ejecting means are arranged on the downstream side. has been done. Further, an aligning switch 32 is provided near the aligning roller pair 29.
is provided.

Note that 35 is an ozone filter that neutralizes ozone generated by each charger 21, 24, and 25, and 36 is a cooling fan unit that prevents a rise in temperature inside the machine. Reference numeral 37 denotes a toner cartridge installed in the developing unit 23.

As the photoreceptor drum 20 rotates in the direction of arrow C, the surface of the photoreceptor drum 20 is charged to -700V by the charger 21.

The charging device 21 is equipped with a grid 21a, and the voltage of the grid 21a is set to 1750V during charging.

The negatively charged photoreceptor drum 20 is transferred to an exposure device 2 that also serves as a charge remover.
A light-condensing optical transmitter (trade name, SELFOC lens array) 43 transmits an original image on an original platen 41 made of transparent glass, which is uniformly illuminated by a lamp 40 as a rod-shaped light source constituting a light source. An image is formed on the surface of the photoreceptor drum 20 to form an electrostatic latent image on the surface of the photoreceptor drum 20.

Next, the electrostatic latent image on the photoreceptor drum 20 is made visible by being opposed to the developer unit 23 and having positive polarity toner attached thereto.

The developing unit 23 uses a positive polarity two-component magnetic brush system, and the sleeve 44a of the developing roller 44, which is a toner layer holding member, is moved in the direction of arrow d at a speed higher than that of the photoreceptor drum 20 (approximately 3.3 ~3.5 times) and a bias voltage of -200V is applied.

On the other hand, in synchronization with this toner image forming operation, the paper P taken out from the paper feed cassette 2 or manually fed from the manual paper feed table 4 is sent to the image transfer section 27 via the aligning roller pair 29.

The paper P fed into the image transfer section 27 is fed by a pre-transfer guide 45 so as to come into close contact with the surface of the photoreceptor drum 20, and the toner image previously formed on the photoreceptor drum 20 is transferred to the transfer charger 24. The image is transferred to the paper P due to the negative charging effect. Next, the paper P on which the toner image has been transferred is AC-charged by the peeling charger 25 and peeled off from the surface of the photoreceptor drum 20, and is conveyed through the paper conveyance path 28.
It is sent into the fixing device unit 33 along the fixing device front guide 46. Then, the toner image is fixed to the fixing roller pair 47.
is fused and fixed onto the paper P by the paper ejection roller pair 3.
1 onto the paper ejection tray 3.

The fixing roller pair 47 includes a lower roller 47a coated with Teflon-based resin on an AΩ core metal and having a built-in heater 52, and a press roller 47 made of silicone rubber.
Since the surface of the fuser roller 47a is negatively charged, offset with positive polarity toner and staining of the press roller 47b occur. In this device, PTFE in which carbon black is dispersed is applied to the lower roller 47a.
The resin layer is coated with a resin layer to lower its resistance, and is grounded by a leaf spring (not shown) to prevent charging.

Note that after the toner image is transferred onto the paper P, the residual toner remaining on the photosensitive drum 20 is scraped off by the cleaning blade 26a of the cleaner unit 26. Furthermore, after this, the afterimage on the surface of the photoreceptor drum 20 is erased by the static eliminating light from the static eliminating/exposure device 22, and the image returns to the initial state. The above-mentioned static elimination light is led out from four static elimination light openings as aperture lines formed in a reflecting member (hereinafter referred to as a reflector) 48, passes through a static elimination light filter 50, and is converted into an appropriate static elimination light amount and wavelength to be sent to the cleaner unit 26. The surface of the photoreceptor drum 20 is irradiated with the light from the static elimination light opening 51 .

The apparatus main body 1 is divided into upper and lower halves with the paper transport path 28 as the border, and the upper unit can be rotated upward via a rotation fulcrum (not shown). It is possible to expose most of the paper transport path 28 or to expose equipment facing the paper transport path 28. This makes it easy to remove paper jams and perform maintenance, inspection, and replacement of equipment.

Next, the above-mentioned main components will be explained in detail with reference to other figures.

First, the configuration and movement of the table 5 will be explained with reference to FIGS. 4 to 9 and FIG. 3.

As shown in FIG. 3, the table 5 is roughly divided into a document table 41 on which a document is placed, and a platen sheet 1 which is superimposed on the document table 41 and presses the document in close contact with the document table 41.
3a and a document holding cover 13.

As shown in FIGS. 4 and 5, the document table 41 has
The rear end edge is fixed to a table frame 56 via a glass holder 55, and as shown in FIG. A frame member 58 is attached to each of the frame members 58.

Further, as shown in FIGS. 6 and 7, the table frame 56 is attached to the horizontal piece 60a of the main body frame 60 forming the rear edge of the upper surface of the apparatus main body 1 via the slider 59. ing. Furthermore, a rack 61 is attached to the lower surface of the table frame 56,
This rack 61 is in mesh with a pinion 62 as a table driving body provided on the device main body 1 side, and the table 5 is moved in the left and right directions (arrows a and b in FIG. 7) by the forward and reverse rotation of the pinion 62. It is configured to reciprocate in the direction).

Further, on the apparatus main body 1 side, a first detector 65 for detecting the left and right limit positions of the table 5 and a second detector 66 for detecting the home position of the table 5 and the paper start position are arranged in parallel. In addition, on the table 5 side, there are a left limit position detected object 67, a right limit position detected object 68, and a home position detected object 69.
, and paper start position detection object 70 are respectively arranged.

Note that 71.71 is a plastic glass guide disposed corresponding to the arrangement portion of the condensing light transmitting body 43, and is on the glass holder 55 side of the document table 41 and the lower surface side of the frame member 58. It is designed to support and hold in place. Further, the document holding cover 13 is attached to the table frame 56 at the lower rear edge and surface portion via a hinge mechanism (not shown), and is rotatable to open and close on the document table 41. It can be removed with one touch if necessary.

Further, as shown in FIG. 8, the first. Second detector 6
5.66 is connected to a microcomputer 75 as a control means. Further, the lamp 40 is connected to the microcomputer 75 via the control panel 12, a table motor 77 that drives the pinion 62 via a table driver 76, and a lamp driver 78 as a lamp drive source.

Then, the movement of the table 5 and the exposure amount are adjusted as shown in FIG. 9.

First, as shown in FIG. 9(a), when the print key 9 is pressed, the table 5 starts moving to the left (in the direction of arrow a). Then, as shown in FIG. 9(b), the right limit position detected object 67 stops at the position detected by the first detector 65.

Then, as shown in FIG. 9(C), the table 5 starts moving rightward (in the direction of the arrow), and the original document is scanned. Then, the electrostatic latent image forming step described above is started. At this time, the lamp 40 is at a high level necessary for exposure.

]5 Then, as shown in FIG. 9(d), the left limit position detection object 68 stops at the time when scanning of the original is completed, that is, at the position detected by the first detector 65.

Then, as shown in FIG. 9(e), the table 5 starts moving leftward (in the direction of arrow a). And Figure 9 (
As shown in f), the six home position detection objects stop at the positions detected by the second detector 66.

In the return process of the table 5 shown in FIGS. 9(e) to 9(f), if it is the final cohesion time, the table motor 77 is rotated at a low speed by the control signal from the microcomputer 75. Then, the table 5 is moved at a low speed so as to secure time until the static elimination process is completed. When the table 5 returns to the home position and stops, the exposure lamp 40 is turned off. Therefore, even if you open the document holding cover 13 to replace the document tray immediately after the table 5 stops,
I don't have to worry about the light shining into my eyes or making me feel uneasy.

On the other hand, during this slow return step, the light intensity of the lamp 40 is switched to a low level by a control signal from the microcomputer 75, and is reduced to the amount necessary for static elimination. and,
This is to prevent the temperature of the photosensitive drum 20 from increasing.

In addition, in the return process of the table 5 shown in FIGS. 9(e) to 9(f), if it is not the final copy but continuous copy, the table motor is activated by the control signal from the microcomputer 75. 77 rotates at high speed, table 5
is moved at about twice the speed of copying, and the next copying operation begins. Also during the return process during continuous copying, the light intensity of the lamp 40 is switched to a low level by a control signal from the microcomputer 75, and is reduced to the amount necessary for static elimination.

Next, as shown in FIGS. 10 to 15, a charging device 21 as a charging means will be described.

As shown in FIG. 10, the charging device 21 is composed of a scorotron consisting of a charging device main body 21b in which a corona wire 81 with a diameter of 60 μm is stretched in a shield case 80, and the grid 21a. Photosensitive drum 20
Since it is negatively chargeable, it is necessary to cause a negative discharge.

In addition, during negative discharge, since uneven charging tends to occur, the grid 21a is placed opposite the opening of the shield case 80.
are arranged to ensure uniform charging.

The grid 21a has a mesh shape as shown in FIG. 11. Note that the mesh width is, for example, 1
It is approximately 2 mm+. Furthermore, the grid 21a
is connected to the anode of a -750V Zener diode 82, and coupled to the ground terminal 83 of the device body 1 through the cathode of the Zener diode 82.

The charging device 21 configured as described above is connected to a high voltage transformer (not shown) on the device main body 1 side (output -5,0k
V, total current value 300. A high voltage is applied from about czA), and the surface potential of the photoreceptor drum 20 reaches the grid 21a.
The potential is kept constant at 700V, which is slightly lower than the potential of . In addition,
The diameter of the photoreceptor drum 20 is 60 mm, the distance Ω1 between the corona wire 81 and the surface of the photoreceptor drum 20 is 8.0 mm,
Grid 2], the distance ρ2 from a to the surface of the photoreceptor drum 20 was set to 2.0+++ m.

Regarding the actual charging property, as shown in FIG. 12, it can be seen that even if the current value fluctuates somewhat, the surface potential is stabilized by using the grid 21a.

Further, the charging device 21 is attached to a side frame 8585 of the cleaner unit 26 via a charger frame 86, as shown in FIG. Note that the drum support shaft 87 of the photosensitive drum 20 is supported by the side frames 85 and 85 of the cleaner unit 26.

As shown in FIG. 14, the charger frame 86 has a charger main body accommodating portion 88 for accommodating the charger main body 21b on its upper surface side, and has a charger main body accommodating portion 88 for accommodating the charger main body 21b at both longitudinal ends thereof. First and second grid support parts 8
9.90 has been formed.

As shown in FIG. 14, the grid 21a has an engagement hole (not shown) formed at one end that is engaged with the first grid support part 89, and an engagement hole (not shown) formed at the other end. (not shown) is retained by being locked to the second grid support portion 90 via a coil spring 91. Further, the lower surfaces of both ends of the grid 21a are connected to the first
As shown in FIGS. 3 and 14, the drum support shaft 87 is supported by the grid support surfaces 85a, 85a of the side frame 85. N2 (see FIG. 10) can be obtained with high accuracy, and good charging characteristics can be obtained.

Further, as shown in FIG. 15, the shield case 80 of the charger main body 21b is provided with a plastic latch claw 95 that engages with a holding frame 96 integrally formed with the charger frame 86. The charger main body 21b accommodated in the charger main body accommodating portion 88 is mechanically held. Furthermore, as shown in FIG. 15, the charger body accommodating portion 88 of the charger frame 86 includes a first leaf spring 97 that presses the charger body 21b downward.
A second leaf spring 98 that presses the charger main body 21b in the width direction
The charger main body 21b accommodated in the charger main body accommodating portion 88 can be positioned with high precision.

As a result, the charger frame 86 is screwed by the charger frame support surfaces 85b, 85b of the side frames 85.85 that are in a predetermined positional relationship from the drum support shaft 87, and the corona wire 81, which tends to affect the charging characteristics, is removed. Distance R1 (
(see Figure 10) can be obtained with high accuracy,
Good charging characteristics can be obtained.

Further, as shown in FIG. 13, the cleaner unit 26 includes a cleaning blade 26a for scraping off toner remaining on the surface of the photoreceptor drum 20, and a cleaning blade 26a installed below the cleaning blade 26a so that the scraped toner can be removed from the cleaning blade 26a. A toner scattering prevention member (hereinafter referred to as
The device includes a recovery blade (referred to as a recovery blade) 100, and a recovery auger 102 for transporting toner collected in a cleaner case 101 to a toner collection box (not shown). Further, the recovery blade 100 is in a state where its lower end edge is supported by a recovery blade support member 105, as shown in FIGS. 16 and 17.

The recovery blade 100, as shown in FIG.
A conductive member 107 is applied to the surface so as to sandwich a non-conductive elastic member 106, and this is attached to the vertical piece 105a of the recovery blade support member 105 via a double-sided adhesive tape 108. Conductive adhesive 10
9, the conductive member 107 of the recovery blade 100
and the recovery blade support member 105 are bonded together. Then, the recovery blade 100 is attached to the ground.

This neutralizes the charging property of the residual toner on the photoreceptor drum 2o and weakens the adhesion to the photoreceptor drum 2o, thereby improving the cleaning performance of the residual toner. In addition, when a non-conductive glue cover blade is used as in the past, there is no neutralizing effect as described above, and as the number of copies increases, toner adheres to the back surface of the cleaning blade 26a, causing deterioration of cleaning performance. It became.

Next, with reference to FIGS. 18 to 21 and FIG. 1, the static elimination/exposure device 22 will be described.

As shown in FIG. 18, the reflector 48, the lamp 4
0, the condensing light transmitting body 43, the glass guide 71, etc. are integrally assembled into the optical system frame 115 to form a unit, and are screwed to the main body frame 60.

At this time, as shown in FIG.
Attached edge portion 11 to which the condensing light transmitting body 43 is attached
5a, 115a pass through an opening 116 formed in the main body frame 60, and their lower surfaces are in contact with a positioning portion 117 consisting of the lower end surface of the opening. The positioning portion 117 is set at a predetermined distance L1 from the drum support shaft 87.

Furthermore, when attaching the condensing light transmitting body 43 to the optical system frame 115, attach the mounting portions 43a, 43a (only one shown) formed at both ends of the condensing light transmitting body 43 to the optical system frame 115. The lower surfaces of the attached end edges 115a, 115a and the elastic tongue pieces 118a, 1 of the support member 118.118.
It is held by being sandwiched between it and 18a. Note that the support member 118 has a set screw 119.
Optical system frame 11 together with glass guide 71 via
It is attached to the attached end edge 115a of No. 5.

Therefore, the surface of the photoreceptor drum 20 and the condensing light transmitting body 4
The distance L2 from the optical frame 1 to the light emitting end surface 43b of the optical frame 1 is
The attachment of the attached edge portion 115a of No. 15 to the main body frame 60 is determined by the position, and by considering the dimensional accuracy of the distance L1, positional accuracy can be ensured for predetermined attachment.

In addition, the light incident end surface 4 of the document table 41 and the condensing light transmitting body 43 is
3c is determined by the thickness of the attached end edge 115a of the optical frame 115, the position of attachment to the main body frame 60, and the dimensional accuracy of the glass guide 71, and the dimensional accuracy of the distance L1 and the attached Edge portion 115a
By considering the thickness accuracy of the glass guide 71 and the dimensional accuracy of the glass guide 71, a predetermined accuracy can be ensured.

In addition, conventionally, the condensing light transmitting body 43 is screwed to the optical system frame 115, and a positional shift is likely to occur between them. Furthermore, without using the glass guide 71, the slider 59 which has a large backlash in the vertical direction can be used.
The configuration is such that it is supported by For this reason, there was a problem in that the dimensional accuracy of the distance L3 varied due to the influence of backlash of the slider 59, but these problems can be solved by configuring as in this embodiment.

Note that 120 is an elastic member such as rubber that is interposed between the mutually opposing surfaces of the document table 41 and the glass holder 55, and when a pushing force is applied by the glass guide 71, the document table 4
1 can escape upward, so that no strong contact force is generated between the glass guide 71 and the document table 41.

Furthermore, as shown in FIG.
An auxiliary reflector 125 made of a cut and raised piece formed on the optical system frame 115 is provided near the optical system frame 115 . Further, the light-condensing light transmitting body 43 has a light incident end face 43c exposed through the opening 126 after the auxiliary reflector 125 is formed. In addition, the light-condensing light transmitting body 43 is attached to the rear opening 12.
6 is closed by a black synthetic resin plate 127 and a soft foamed resin member 128 to prevent the exposure light R1 from leaking to the photosensitive drum 20 side through this portion.

Note that the static elimination optical filter 50 is provided to close an opening formed in the optical system frame 115, and is held via a holding member (not shown). 129 is an optical system cover, 130 is a temperature fuse, and 131 is a reflector 48 to increase the operating sensitivity of the temperature fuse 130.
It is an opening formed in.

Further, as shown in FIG. 1, the lamp 40 includes a filament 135 as a light emitting part and a short circuit part 136 as a non-light emitting part.
It is made up of 2 x 2 x 2 x 2 x 2 x 2 x 2 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 2 x 2 x 2 x 2.

On the other hand, the static elimination light opening 49 formed in the reflector 48 surrounding the lamp 40 made of this halogen lamp to guide the static elimination light R2 toward the photosensitive drum 20 is not an integral slit as in the conventional case, but a first As shown in the figure, a plurality of openings 4 are separated by ribs 140 serving as connecting members.
9a... is formed. And the above rib 1
40... makes it possible to maintain the strength of the flapper 48 and prevent thermal deformation. Also, rib 140・
... has been subjected to heat resistance treatment, and has a heat resistance that is at least higher than that of Rifter 48. ing.

Further, as shown in FIG. 21, the ribs 140 are disposed at positions corresponding to the short-circuit portions 136, which are non-light-emitting portions of the exposure lamp 40, and
This makes it possible to make the distribution of the amount of static electricity removal light uniform on zero. Further, the length of the ribs 140 in the longitudinal direction of the lamp 40 is at least shorter than the width of the short circuit portion 136, which is the non-light emitting portion.

Note that if the ribs 140 are arranged at positions corresponding to the filament part 135, which is the light emitting part of the lamp 40, a loss of the static elimination light R2 will occur, and the distribution of the amount of static elimination light on the photoreceptor drum 20 will be uneven. It becomes uniform, which is not desirable.

Next, the developing unit 23 will be explained with reference to FIGS. 22 to 29.

As shown in FIG. 22, the developing unit 23 includes a developing roller 44 provided in a casing 151 having a developer accommodating portion 150 in a state that can face the photosensitive drum 20, and a developing roller 44 provided in the casing 151 having a developer accommodating portion 150. 150, a two-component developer A consisting of toner (colored powder) t and carrier (magnetic powder) C;
is accommodated. Further, a developer magnetic brush A' formed on the surface of the developing roller 44 is in sliding contact with the photoreceptor drum 20, that is, on the upstream side of the development position 152 in the rotational direction of the photoreceptor drum 20. A doctor 153 is provided to regulate the thickness of the brush A'. Further, the developer storage section 150 includes a first. Second developer stirring bodies 154 and 155 are accommodated.

Further, the developing roller 44 has five magnetic pole parts 156a to 156a.
156e, and a non-magnetic sleeve 44a that is fitted onto the magnetic roll 44b and rotates counterclockwise (direction of arrow d) in the figure.

Among the five magnetic pole parts 156a to 156e of the magnetic roll 44, the magnetic pole part 156a facing the development position 152 and the magnetic pole part 156C located almost opposite thereto are N poles, and the other magnetic pole parts 156b, 156d, and 156e are N poles. It is the S pole.

Further, the gap Gl between the sleeve 44a and the photosensitive drum 20 is 0.9 to 1.0 m+, and the gear lug G2 between the doctor 153 and the sleeve 44 is 0.8 to 0.9 n+.
m is set.

Further, above the second developer stirring body 155, an automatic toner sensor 1 for controlling the toner specific concentration of the two-component developer A is provided.
57 are provided. This auto toner sensor 157
The sensor surface 157a is 12° from the vertical direction (el −
12') In addition, the angle between the developer receiver and the plate 158 is required to be 59° (θ2-59°) in order to ensure environmental stability of the specific toner concentration and stability against variations in the magnetic force of the sleeve 44a. be done.

In addition to forming a uniform flow of the developer A in the above method, the sensor surface 157a is 0.0 mm lower than the surface of the holder 159. 7mm
(t 1 = 0., 7 mm) and that the gap G3 between the lower part of the holder 159 and the plate 158 between the lower part of the holder 159 and the plate 158 is 2.5 mm is a necessary condition for improving stability. Become.

Further, the developer cover 160 of the developer unit 23 is formed with a toner cartridge covering upper part 161 as shown in FIGS. 22 and 23, and the toner cartridge 37 is mounted as shown in FIGS. 23 and 3. It is designed to be installed. Furthermore, the developing unit 23 is provided with a carrying handle (not shown), and as shown in FIG.
By opening the top cover 165, it can be taken out upward.

For example, four developing units 23 are prepared, each using black, red, blue, and brown toner, and are selectively used.

At this time, as shown in FIGS. 24 and 25, a color display section 166 consisting of an opening is formed in the top cover 165, and the color display section 166 is attached to the top surface of the toner cartridge 37 without opening the top cover 165. color label 167
By looking at the color, it is possible to know which color developing unit 23 is housed. And in the home position where table 5 is above this,
By opening the document holding cover 13 to place the document tray, it can be visually observed through the document table 41.

Further, the formation position of the color display section 166 is such that the stray light R3 entering from the color display section 166 can be blocked by the upper surface of the toner cartridge 37, as shown in FIG. The stray light R3 is located at a position where a distance L4 is formed up to the arrival point of the stray light R3.
This prevents the liquid from leaking to the photosensitive drum 20 side.

Since the color display section 166 is formed from a simple opening in this way, it is possible to electrically detect which color developer unit is being used using a conventional deep switch, etc., and also to display information on the control panel 12. Compared to a display that lights up the part corresponding to that color, the configuration is simpler and the cost is lower, and moreover, it is easier to see when opening the document holding cover 13 to set the document tray. The operator can be informed with certainty.

In addition, as shown in FIGS. 22, 26, and 27, the first. The second developer agitator 154, 155 has blade portions 154a, 155.
The winding direction and pitch p (p = 25 mm) of a are the same, the rotation direction is opposite, and there is a partition between them with first and second communication parts 171 and 172 left on both ends. A plate 170 is provided so that the developer A is circulated in the direction indicated by arrow e in FIG.

Further, a toner replenishment port 173 (see FIGS. 27 and 23) is formed upstream of the first developer stirring section 150a in which the first developer stirring body 154 is disposed. There is.

The downstream side of the first developer stirring section 150a where the first developer stirring body 154 is disposed, and the upstream side of the second developer stirring section 150b where the second developer stirring body 155 is disposed. The width W1 of the first communication part 171 for communicating with the blade part 154a155a is the same as the pitch p of the blade part 154a155a (Wl = p
), that is, 25 degrees, and from the downstream side of the first developer stirring section 150a to the second developer stirring section 150.
The developer A flows smoothly to the upstream side of b.

Furthermore, the downstream side of the second developer stirring section 150b where the second developer stirring body 155 is disposed, and the first developer stirring section 150a where the first developer stirring body 154 is disposed. The width W2 of the second communication portion 172 for communicating with the upstream side is
It is larger than the pitch p of the blade portions 154a155a (W
2>p), that is, 35 y, is set to prevent the developer from spilling from the developing roller 44 side, which is caused by the developer A staying in the second developer agitating section 150a, and also prevents the developer A from being The developer is stored in the first developer stirring section 150a and sufficiently stirred there. This results in
The density detected by the auto toner sensor 157 (see FIGS. 22 and 26) is made to match the toner density on the developing roller 44 side.

Note that 174 shown in FIG. 26 is the auto toner sensor 15.
This is a protective sheet that covers the front side of 7 to protect it from moisture, etc., and is designed to be removed during assembly.

Further, as shown in FIG. 28, an auto-toner adjustment circuit board 181 incorporating an adjustment volume 180 for adjusting the level of the auto-toner sensor 157 is attached to the developing unit 23. The auto toner adjustment circuit board 181 includes a signal cable 183 connected to the auto toner sensor 157 via a first connector 182.
, a signal cable 186 connected to a toner replenishment motor 185 (see FIGS. 23 and 29), which will be described later, via a second connector 184, and a control section on the apparatus main body 1 side via a third connector 187. A signal cable 188 for transmitting and receiving an output detection signal is connected to each of the terminals.

Then, each developing device unit 23 for each color is first adjusted by turning the adjustment volume 180 using a tool such as a screwdriver so that a predetermined output is obtained with developer A of a specified concentration. By doing this, there is no need for troublesome control such as providing an adjustment volume on the apparatus main body 1 side, memorizing the adjustment level for each developing device unit 23, and switching it each time, as in the past. , a predetermined output level can be obtained simply by installing the developing unit 23.

Further, as shown in FIGS. 3 and 29, the toner cartridge 37 includes a container 191 having a toner replenishment port 190 at the bottom, a toner transport auger 192 for feeding toner t into the container 191, and a toner transport auger 192 that supplies toner t to the container 191. The agitation member 193 rotates in conjunction with the rotation of the toner transport auger 192.
The drive force receiver whose one end is connected to the shaft 194 has a protruding arcuate engagement protrusion 194a, and a locking groove 195 at the front end.
A claw member 195 having a shape is in a protruding state.

On the other hand, as shown in FIGS. 29 and 30, in the toner cartridge/solidity mounting portion 161 of the developing device cover 160, the driving force receiver is provided on the rear inner wall side with an arcuate engagement protrusion of the shaft 194. A drive gear 196 having an arcuate engagement recess 196a that engages with the portion 194a is provided. Further, the presser spring 19 has an engaging portion 197a curved in a dogleg shape that engages with the retaining groove 195a of the claw member 195 on the front inner wall side.
7 are arranged.

Then, as shown in FIG. 30, the toner cartridge 37
After inserting the toner cartridge 37 in the direction of arrow A with the rear end side (the driving force receiver is on the shaft 194 side) facing the inclined lower end, insert the toner cartridge 37
By pushing down the front end of the toner cartridge 37 in the direction of the arrow, the toner cartridge 37 can be easily attached to the toner cartridge mounting portion 161 as shown by the two-dot chain line.

It can also be easily removed by performing the reverse operation.

Note that the driving force receiver is formed by the arcuate engagement protrusion 19 of the shaft 194.
4a is formed with a cross-shaped protrusion, and the arc-shaped engagement recess 196a of the drive gear 196 is formed with a cross-shaped bay.
When the toner cartridge 37 is installed in the toner cartridge mounting portion 161, these elements are engaged with each other. These engaging operations are reliably performed by pushing the toner cartridge 37 by the urging force of the pushing spring 197.

Further, in the driving force receiver, the shaft 194 has an arcuate engagement protrusion 19.
4a, and the reliability against damage to this part during engagement and disengagement is extremely high compared to the conventional case where the drive force is received by a spur gear.

Further, when the toner cartridge 37 is installed in the toner cartridge mounting portion 161, a shutter (not shown) that closes the toner supply port 190 of the toner cartridge 37 is closed.
It is pushed up and opened by a shutter push-up projection 200 (see FIGS. 23 and 29) protruding from the toner replenishment slot 173 of the developing device cover 160.

As the toner transport auger 192 rotates, the toner t in the toner cartridge 37 is transferred to the toner replenishing port 190.
The toner is supplied to the developer storage section 150 through the toner supply port 173 of the developer cover 160.

Further, the drive gear 196, as shown in FIG.
The driving force of the toner supply motor 185, which is a driving source, is transmitted via a driving force transmission system 204 consisting of gears 201 to 20B. When the toner replenishment motor 185 is driven by the toner replenishment signal from the auto toner sensor 157, the toner cartridge 37
The toner replenishment auger 192 inside rotates, so that the toner t in the toner cartridge 37 is replenished into the developer storage section 150 through the toner replenishment port 190 and the toner replenishment port 173 of the developer cover 160. It has become.

Also, at this time, the toner cartridge 37 is
As shown in FIGS. 1 and 23, the developer cover 160
The drive force receiver is placed on a sealing material 205 made of a soft foamed resin material such as maltblane that is attached to the toner supply port 173, and the driving force receiver is placed on the shaft 194 and the claw member 195.
It is supported by. Therefore, when the shaft 194 of the drive force receiver is rotated in the direction of the arrow shown in FIG. It rotates in the direction shown by the solid line. Further, when the shaft 194 stops, the driving force receiver is pushed back in the two directions opposite to the arrows by the restoring force of the sealing material 205, and becomes in the state shown by the two-dot chain line.

In this manner, the toner cartridge 37 swings each time a toner replenishment operation is performed, leveling out the toner t contained therein, and maintaining a good replenishment state.

Further, as described above, the present invention provides a supporting member that is in an integral positional relationship with the photosensitive drum 20 as an image carrier, that is, the first support member of the side frame 85, 85 of the cleaner 26.
The grid 21a, which is an antistatic member that equalizes the ion flow and prevents uneven charging, is supported using the supporting surfaces (grid supporting surfaces) 85a, 85a as positional references.

Therefore, the dimension g between the image carrier and the uneven charging member
An accuracy of 2 is obtained under constant conditions. Further, support members that are in an integral positional relationship with the photosensitive drum 20 as an image carrier, that is, second support surfaces (charger frame support surfaces) 85b and 85 of the side frames 85 and 85 of the cleaner 26 are provided.
A charger frame 86 as a charger main body holding member is attached with b as a positional reference, and the charger main body 21b provided with the wire 81 is held on this charger frame 86. Therefore, the accuracy of the dimension Ω1 between the wire 81 of the charger main body 21b and the image carrier can be maintained in a constant state. As a result, stable discharge can always be obtained and good image formation can be achieved.

Further, the grid 21'a was elastically connected to the charger frame 86 by a coil spring 91, which is an elastic member, and the grid 21a was pressed against the first support surfaces (grid support surfaces) 85a, 85a. This results in
During assembly, no special adjustment or skill is required for positioning, making it possible to improve work efficiency.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without changing the gist.

[Effects of the Invention] As explained above, according to the present invention, although the configuration is simple, the dimensional accuracy between the wire that supplies the ion flow of the charger body and the image carrier, and the relationship between the image carrier and the charger body are improved. It is possible to obtain dimensional accuracy between the charging unevenness prevention member, to obtain stable charging characteristics without charging unevenness, and to provide a charging device that enables good image formation.

In addition, since the charging unevenness prevention member is elastically connected to the charger main body holding member by an elastic member and is supported in a state where the charging unevenness prevention member is pressed against the support surface, there is no need for positioning during assembly. This has the effect of improving workability without requiring any special adjustment or skill.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing the configuration of the main parts of the static elimination/exposure device, FIG. 2 is an external perspective view of the entire electrophotographic copying device,
Figure 3 is a schematic longitudinal sectional front view showing the internal structure;
The figure is a side view showing the supporting mechanism of the document table, FIG. 5 is a plan view of the document table part, FIG. 6 is a schematic side view showing the table drive mechanism and position detection mechanism, and FIG. 7 is also a schematic side view. A perspective view, FIG. 8 is a block diagram showing part of the control system for the table motor and lamp, FIG. 9 is an explanatory diagram showing the moving state of the table, and FIG. 10 is an embodiment of the charging device of the present invention. Fig. 11 is a plan view showing a part of the grid of the charging device, and Fig. 12 shows the change in charging current and surface potential due to changes in the shape of the grid of the charging device. An explanatory diagram showing the relationship, Fig. 13 is a diagram showing the state in which the charging charger is attached to the cleaner unit, Fig. 14 is a diagram showing the positioning state of the grid of the charging charger, and Fig. 15 is a diagram showing the state in which the charging charger is attached to the cleaner unit. A diagram showing the positioning state of the charger body of the device,
FIG. 16 is a schematic perspective view of the cleaner unit glue cover blade, FIG. 17 is a partially sectional side view, and FIG.
The figure is a schematic perspective view of the exposure device that also serves as a static eliminator, Figure 19 is a diagram schematically showing how the light-concentrating light transmitter is installed in the exposure device that also serves as a static eliminator, and Figure 20 is a diagram of the exposure device that also serves as a static eliminator and its surroundings. A diagram schematically showing the configuration, FIG. 21 is an explanatory diagram showing the light distribution characteristics and the positional relationship between the ribs of the static elimination light aperture, FIG. 22 is a schematic cross-sectional view of the developing device unit, and FIG. 23 is a diagram showing the developing device cover. Partial perspective view, FIG. 24 is a perspective view of the device with the table moved, FIG. 25 is an explanatory diagram showing the state of preventing stray light from the color display section, and FIG. 26 is the developer cover of the developer unit. FIG. 27 is a perspective view showing the flow state of the developer in the developer storage section. FIG. 28 is a perspective view of the part where the auto toner adjustment circuit board is installed in the developing unit. The figure shows the drive system of the toner conveying auger built into the toner cartridge, FIG. 30 is an explanatory diagram showing the toner cartridge installation state, and FIG. 31 is an explanatory diagram showing the swinging state of the toner cartridge during toner replenishment. It is. 20... Image bearing member (photosensitive drum), 21... Charging device (charging device), 21a... Charging unevenness prevention member (
grid), 21b...Charger body, 81...Wire, 85...Support member (side frame of cleaner)
, 85a...first support surface (grid support surface), 85b
...Second support surface (charger frame support surface), 8
6... Charger body holding member (charger frame),
91...Elastic member (coil spring). Applicant's agent Patent attorney Takehiko Suzue] 2 Figure 2

Claims (1)

[Scope of Claims] A charging device that charges an image carrier on which an image is formed by supplying an ion stream, comprising: a charger main body having a wire that supplies the ion stream; and a charger body that supports the image carrier. A charger body holding member that is attached using a first support surface of a support member and detachably holds the charger body; and a charger body holding member that is held by the charger body holding member, through which an ion flow passes. The charging unevenness preventing member is provided with a charging unevenness preventing member located on the mouth side for preventing charging unevenness, and an elastic member elastically connecting the charging unevenness preventing member to the charger main body holding member. A charging device comprising: support means for a charging unevenness prevention member that is supported in a pressed state against a second support surface of the support member.