JPH02193171A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To eliminate glaring when an original cover is opened immediately after an original platen reached home position by permitting the device to be under the condition that destaticizing is completed and that a light source for a destaticizing and exposing device is turned off when the original platen reached the home position and stopped. CONSTITUTION:A table 5 consists of the original platen 41 for placing an original D and an original cover 13, which is provided with a platen sheet 13a which is overlapped on the original platen 41 and holds the original D so as to adhere the original to the original platen 41. In the returning process of the table 5, when copying is for the last one, a table motor 77' revolves at slow speed by a control signal from a microcomputer 75, and the table 5 is shifted at slow speed so as to ensure the time for destaticizing process completion. When the table 5 returned to the home position and stopped, an exposing lamp 40 is turned off. Thus, when the original cover 13 is opened immediately after the table 5 stopped in order to replace the original D, the glaring caused by receiving light is eliminated.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electrophotographic copying device with a movable document table,
In detail, the exposure light source of the exposure means irradiates the document on the document table and guides the reflected light to the image carrier to form an electrostatic latent image, and the light source of the static eliminating means erases the image on the image carrier after image transfer. The present invention relates to an electrophotographic copying apparatus equipped with a static elimination/exposure device that can be used as a static electricity removal/exposure device.

(Prior Art) In recent years, electrophotographic copying apparatuses have become smaller in size, and various table-top types have been put into practical use.

Normally, this type of small electrophotographic copying device uses a document table moving method, and also uses a combination of exposure means and static elimination means to make it more efficient in terms of space and cost. .

However, in an electrophotographic copying apparatus equipped with a static eliminating and exposing device, the light source cannot be turned off until the entire circumference of the photoreceptor drum, which is an image bearing member, is neutralized.
Even after all means such as charging, transfer, and peeling are turned off,
The light source is on.

On the other hand, the document table reaches the home position and comes to a halt until the photosensitive drum is completely neutralized.

(Problem to be Solved by the Invention) Conventionally, even when the document table reaches the home position and stops, the light source of the static eliminator/exposure device remains on, and the user When I thought I had finished copying, I opened the document holder cover on the document table and tried to take out the previous document, but the light source was on and I felt dazzled.
There was a problem that it caused discomfort.

The present invention has been made based on the above-mentioned circumstances, and its purpose is to completely eliminate static electricity and turn off the light source of the exposure device that also functions as static elimination when the document table reaches the home position and stops. It is an object of the present invention to provide an electrophotographic copying apparatus which does not cause glare even if the document holding cover is opened immediately after the document table reaches the home position.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention illuminates a document on a reciprocating document table and guides the reflected light to an image carrier to form an electrostatic latent image. In an electrophotographic copying apparatus equipped with an exposure device that also serves as a charge remover, the light source of the exposure means for forming the image can be used as the light source of the charge remover for erasing the image on the image carrier after image transfer. a driving means for moving the driving means; a setting means for setting the number of times the driving means is driven; and a control means for reducing the driving speed of the driving means during the final return movement of the document table in accordance with the setting from the setting means. This configuration has the following features.

(Function) That is, according to the present invention, since the drive speed of the drive means decreases during the last backward movement of the document table, the document table returns to the Baume position at a low speed over time, and during this period, the exposure device for static elimination Mu is activated. When the static electricity removal is completed, the light source can be turned off. This makes it possible to provide an electrophotographic copying apparatus that does not cause glare or discomfort to the user even if the document holding cover is opened immediately after the document table reaches the home position.

(Example) An embodiment of the present invention will be described above 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.

Also, 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, and a copy number setting key (numeric keypad) for setting the number of copies. 7. Dimmer knob 8 for setting copy density
, a blink key (copy key) 9, a clear/stop key 10°, a total counter 1, etc., are arranged on the control panel] 2.

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 during warm-up, [0] is displayed on the display section 6.

By cutting a jumper connector (not shown) inside the control panel 12, continuous copying can be performed for up to nine copies. During continuous copying, it is possible to manually feed one sheet by pressing the clear/stop key 10. Further, a document pocket 14 is formed on the -1 side 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).
mm/see and is rotated at the same speed as the moving speed of the 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. There is.

Around the photoreceptor drum 20, along the direction of rotation thereof, there are provided a charging charger 21 as a charging means, a charge removal/exposure device 22 as an electrostatic latent 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.

Two pairs of aligning rollers are arranged on the upstream side of the image transfer section 27 of this paper conveyance path 28, and on the downstream side, a fixing unit uni-soto 30 as a fixing means and a pair of paper rollers υ1 as a paper means. Further, an aligning switch 32 is provided near the aligning roller pair 29.

Note that 35 is an ozone filter that neutralizes ozone generated from each of the chargers 21, 24, and 25, and 36 is a cooling fan uni-soto that prevents the temperature inside the machine from rising. 37 is 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 2.

The charging device 21 is equipped with a grid 21a, and the voltage of the grid 21a is set to 750V 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.

The electrostatic latent image on the photoreceptor drum 20 is made visible by being opposed to the developer unit 23 and toner of positive polarity being 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 stripping charger 25 and is peeled off from the surface of the photoreceptor drum 20 and transported along the paper transport path 28 and along the fixing unit front guide 46. The image is sent to the fixing device unit 33. Then, the toner image is fixed to the fixing roller pair 4.
7, the paper P is fused and fixed, and then is discharged onto the paper discharge tray 3 via a pair of paper discharge rollers 31.

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, the press roller 47b is contaminated by the positive polarity toner and the offset. 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 is returned to the initial state. The static eliminating light is transmitted through a static eliminating light opening 49 as an opening formed in a reflecting member (hereinafter referred to as a reflector) 48.
The light is led out and passes through the static eliminating light filter 5o, and is made into an appropriate static eliminating light amount and wavelength, and is irradiated from the static eliminating light opening 51 of the cleaner unit 26 onto the surface of the photoreceptor drum 2o.

The main body 1 of the apparatus is divided into upper and lower halves with the paper transport path 28 as the border, and the upper unit is rotatable upward via a rotation fulcrum (not shown), so that the paper transport path 28 can be moved as needed. It is possible to expose most of the path 28 or to expose equipment facing the paper transport path 28. Further, it is possible to easily remove tangles of paper P 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 via a slider 59 to a horizontal piece 60a of a main body frame 60 that forms the rear edge of the upper surface of the apparatus main body 1. Further, a rack 61 is attached to the lower surface of the table frame 56, and this rack 61 is in a state of meshing with a pinion 62 as a table drive body provided on the apparatus main body 1 side. The table 5 is configured to reciprocate in the left-right direction (in the directions of arrows a and b in FIG. 7) by the forward and reverse rotation of the pinion 62.

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 7o 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 lower surface of the rear edge of the document holding cover 13 is attached to the table frame 56 via a hinge mechanism (not shown), and is rotatable in order to open and close the document table 41, and as required. It can be removed with one touch depending on the situation.

Further, as shown in FIG. 8, the ml and second detectors 65 and 66 are 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 process described above is started. At this time, the lamp 40 is at a high level necessary for exposure.

Then, as shown in FIG. 9(d), when scanning of the original is completed, that is, the left limit position detected object 68 stops 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 (
f), the home position detected object 69
stops at the position detected by the second detector 66.

In addition, in the return process of the table 5 shown in FIGS. 9(e) to 9(f), if the final copy is being made, the table motor 77 is rotated at 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 the document holding cover 13 is opened to replace the document tray immediately after the table 5 has stopped, the light will not enter the eyes and cause the user to feel uneasy and dazzling.

On the other hand, during this slow return process, the light intensity of the lamp 40 is switched to a low level by a control signal from the microcomputer 75, so that the light intensity 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 includes a charging device body 21b in which a corona wire 81 with a diameter of 60 μm is stretched in a shield case 80, and the grid 2], a.
Since the photosensitive drum 20 is negatively charged, it is necessary to cause negative discharge. Further, during negative discharge, since uneven charging tends to occur, the grid 2 is placed opposite the opening of the shield case 80.
1a to ensure uniform charging.

As the grid 21a, a mesh-like grid as shown in FIG. 11 is used. Note that the mesh width is, for example, 1 to
The width is about 2 mm. Further, the grid 21a is connected to the anode of a -750V Zener diode 82, and coupled to the ground terminal 83 of the device main body 1 through the cathode of the Zener diode 82.

Then, a high-voltage transformer (output -5, Ok
V, total current value of about 300 μA), a high voltage is applied,
The surface potential of the photosensitive drum 20 is kept constant at 700 V, which is slightly lower than the potential of the grid 21a. The diameter of the photoreceptor drum 20 is 60 mm, the distance MΩ1 between the corona wire 81 and the surface of the photoreceptor drum 20 is 8.0 mm, and the distance ρ2 between the grid 2 ]-a and the surface of the photoreceptor drum 20 is 2.0 mm. And so.

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 side frames 85, 85 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 frame 8585 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
Grid support surface 8 of side frame 8585 to which drum support shaft 87 is attached as shown in FIGS. 3 and 14
5a and 85a, and the distance ρ2 (10th
(see figure) 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 on 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, and a first plate spring 97 that presses the charger body 21b in the width direction. A second leaf spring 98 is also provided, so that 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 which are in a predetermined positional relationship from the drum support shaft 87, so that the corona wire 81, which tends to affect the charging characteristics, and the surface of the photoreceptor drum 20 F, (
(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 that scrapes off toner remaining on the surface of the photoreceptor drum 20, and a cleaning blade 26a located below the cleaning blade 26a so that the scraped toner is removed from the device. A toner scattering prevention member (hereinafter referred to as
(referred to as recovery blade) 100 and cleaner case 1
01 is equipped with a cover auger 102 for carrying out the toner collected in the toner collecting box (not shown). Further, the recovery blade 100 includes:
As shown in FIGS. 16 and 17, the lower end edge is supported by the recovery blade support part 105.

The recovery blade 100, as shown in FIG.
A conductive member 107 is coated on 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. 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 20 and weakens the adhesion to the photoreceptor drum 20, thereby improving the cleaning performance of the residual toner. Note that when a non-conductive adhesive cover blade is used as in the past, there is no neutralizing effect as described above, and as the number of copies increases, toner (-J) adheres to the front surface of the cleaning blade 26a, reducing cleaning performance. This caused deterioration.

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, a condensing light transmitting body 43, a glass guide 71, etc. are integrated into an optical system frame 115 to form a unit, and are screwed into the main body frame 60 by screws 11. .

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 of the support members 11.8, 118
It is held by being sandwiched between it and 118a. Note that the support member 118 is attached to the set screw 1.
The optical system frame 115 is attached to the attached end edge 115a of the optical system frame 115 via the glass guide 71.

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
15 (-The attachment of the J edge portion 115a to the main body frame 60 is determined by the position, and by considering the dimensional accuracy of the distance L1, the positional accuracy of the predetermined attachment can be ensured. .

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 condensing light transmitting body 43 has a light incident end surface 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). 12 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 /% rogen lamps that are connected alternately and in series, and it is bright and takes a short time to stabilize the illuminance, so there is no need for standby time.

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 R 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 49 are separated by ribs 140 serving as connecting members.
It is formed by a... And the rib 14
0... makes it possible to maintain the strength of the reflector 48 and prevent thermal deformation [1-]. Also, rib 140
. . has been subjected to heat resistance treatment, and has a heat resistance at least higher than that of the refrefter 48.

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 equalize the distribution of the amount of static electricity removal light on the top. 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 affected. 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, ] 56d, 156e is the S pole.

Further, the gap G between the sleeve 44a and the photosensitive drum 20 is 0, 9 to 1-, Onr+n, and
Gap G2 between doctor 153 and sleeve 44 is 0.8
It is set to ~0.9mm.

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. In this odd toner sensor 157, the sensor surface 157a is 12° from the vertical direction (el=12
°) inclination, and the angle between the developer receiver and the plate 158 is 59°.
(θ2-59°) is required to ensure environmental stability of the specific toner concentration and stability against variations in the magnetic force of the sleeve 44a.

In addition to forming a uniform flow of developer A in the above method, the sensor surface 157a is 0.7+nm from the five surfaces of the holder.
(t 1 = 0.7++++n) and that the gap G3 between the lower part of the holder 159 and the developer receiver plate 158 be 2.5 mm are necessary conditions for further improving stability.

Further, the developer cover] 60 of the developer unit 23 is formed with a toner cartridge mounting portion 161 as shown in FIGS. 22 and 23, and the toner cartridge 37 is now 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 pasted onto the top surface of the toner cartridge 37 without opening the top cover 65. Colored label 167
By looking at the color, it is possible to know which color developing unit 23 is housed. In the home position where the table 5 is placed on top of the table 5, the original holding cover 13 is opened to place the document tray so that the document can be viewed through the document table 41.

Further, the formation position of the color display section 166 is such that stray light R3 entering from the color display section 166 can be blocked by the top 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 between the arrival point of R6 and 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+n+n) of a are the same, and the rotating direction is opposite, and between them, first and second communication parts 1.71 and 172 are left on both ends. A partition plate] 70 is provided so that the developer A is circulated in the direction shown by arrow e in FIG.

Further, a toner replenishment port 173 (see FIGS. 27 and 23) is formed at the upstream side of the first developer stirring section 50a in which the first developer stirring body 154 is disposed. ing.

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 portion 171 for communicating with the blade portion 154a is the width W1 of the first communication portion 171 for communicating with the blade portion 154a.

The pitch p of the first developer stirring section 150a is set to be the same (W+ = p), that is, 25 mm.
The developer A smoothly flows from the upstream side of the developer stirring section 150b to the upstream side of the second developer stirring section 150b.

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 as follows:
The blade portion 154a.

The pitch is set to be larger than the pitch p of the second developer stirring section 155a (W2>p), that is, 35 mm.
This prevents the developer from spilling from the developing roller 44 side, which is caused by the developer A remaining in the
The developer is stored in the developer stirring section 150a, and is sufficiently stirred there. As a result, the density detected by the auto toner sensor 157 (see FIGS. 22 and 26) matches 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 driving force receiver whose one end is connected to the shaft 194 has a circular engagement protrusion 194a protruding from the shaft 194, and a latching groove 195 at the front end.
The claw member 195 having a shape is in a protruding state.

On the other hand, as shown in FIGS. 29 and 30, the toner cartridge mounting portion 161 of the developer cover 160 has
On the rear inner wall side, the driving force receiver is provided with a driving gear 196 having four arcuate engagement parts 196a that engage with the arcuate engagement protrusions 194a of the shaft 194. Further, a presser spring 197 has an engaging portion 197a curved in a dogleg shape that engages with a retaining groove 195a of the claw portion 195 on the front inner wall side.
is installed.

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 groove.
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 (-4 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.
The developer cover 16.0 is pushed up and opened by a shutter push-up protrusion 200 (see FIGS. 23 and 29) protruding from the toner replenishment area 173. As the toner transport auger 192 rotates, the toner t in the toner cartridge 37 is supplied to the developer storage section 150 through the toner supply port 190 and the toner supply port 173 of the developer cover 160. It has become.

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 through a driving force transmission system 204 consisting of gears 201 to 203. 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 driving 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 replenishment port 173, and the driving force receiver is placed on the support 194 and the claw member 195.
It is supported by. Therefore, when the shaft 194 of the driving force receiver is rotated in the direction of the arrow/% force as shown in FIG. It rotates in two directions and becomes a solid line state. 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.

Furthermore, as described above, the electrophotographic copying apparatus of the present invention includes:
It is a movable document table that reciprocates a table 5 as a document table, and also irradiates the document table on the table 5 and guides the reflected light R to the photosensitive drum 20 as an image carrier to form an electrostatic latent image. The lamp 40, which serves as a light source for the exposure means that forms the image, can be used as the light source for the static elimination means that erases the image on the photoreceptor drum 20 after image transfer. .

Furthermore, a table driver 76 as a driving means for reciprocating the table 5;
a control panel 12 as a setting means for setting the number of times the table is driven; and a microcomputer 75 as a control means for reducing the driving speed of the table driver 76 during the final return movement of the table 5 in accordance with the setting from the control panel 12. It has a configuration comprising:

Then, during the final return movement of the table 5, the driving speed of the table driver 76 decreases, and the table 5 returns to the home position at a low speed over time. The light will turn off. Thereby, even if the document holding cover 13 is opened immediately after the table 5 reaches the home position, the user will not be dazzled and the user will not feel uncomfortable.

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, when the document table reaches the home position and stops, static elimination is completed and the light source of the static elimination/exposure device is turned off. Therefore, it is possible to provide an electrophotographic copying apparatus that does not cause glare even if the document holding cover is opened immediately after the document table reaches the home position.

[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 a diagram showing the basic configuration of the charging device.
FIG. 11 is a plan view showing a part of the grid of the charging device, FIG. 12 is an explanatory diagram showing the relationship between the charging current and surface potential due to changes in the shape of the grid of the charging device, and FIG. 13 is the charging device. Figure 14 shows the positioning of the grid of the charger in the cleaner unit. Figure 15 shows the positioning of the charger body of the charger. , FIG. 16 is a schematic perspective view of the cleaner unit glue cover blade, FIG. 17 is a partially sectional side view, FIG. 18 is a schematic perspective view of the exposure device that also serves as static elimination, and FIG. 19 is a static elimination FIG. 20 is a diagram schematically showing the installation state of the condensing light transmission body of the dual-purpose exposure device; FIG.
The figure shows the positional relationship between the orientation characteristics and the ribs of the static elimination light aperture.
Fig. 22 is a schematic sectional view of the developing unit, Fig. 23 is a perspective view of a part of the developing unit cover, Fig. 24 is a perspective view of the device with the table moved, and Fig. 25 is a view from the color display section. FIG. 26 is a perspective view of the developer unit with the developer cover removed. FIG. 27 is a diagram showing the flow state of the developer in the developer storage section. The figure shows the auto l-suit adjustment circuit board (=J) of the developing unit I.
Figure 29 is a diagram showing the drive system of the toner conveying auger built into the toner cartridge, Figure 30 is a diagram showing the installed state of the toner cartridge, and Figure 31 is 1. FIG. 3 is an explanatory diagram showing the swinging state of the toner car I ridge in the state shown in FIG. 5... Original table (table), 12... Setting means (control panel), 2o/image carrier (photosensitive tram)
, 22... Static elimination/exposure device, 4o light source (lamp)
75... Control means (microcomputer) 76... Drive means (table driver), R1... Reflected light, R2...
Static elimination light. If applicant's agent Patent attorney Takehiko Suzue 1z Figure] 2 Figure 2 Figure 26 Figure 4

Claims (1)

[Scope of Claims] A light source of an exposure means that irradiates a document on a reciprocating document platen and guides the reflected light to an image carrier to form an electrostatic latent image is connected to the image on the image carrier after image transfer. In an electrophotographic copying apparatus equipped with a static eliminating/exposure device that can be used as a light source for a static eliminating means for erasing, a driving means for reciprocating the document table and a setting for setting the number of times the driving means is driven. 1. An electrophotographic copying apparatus comprising: means; and a control means for reducing the driving speed of the driving means during the final return movement of the document table in accordance with the settings from the setting means.