JPH02193168A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To surely attain accuracy of the distance between a lens body and an image carrier and to obtain steady image quality by installing the lens body at the device by using a positioning part formed on a supporting member which supports the image carrier as a reference. CONSTITUTION:The lens body 43 is installed at the device by using the positioning part 117, which is formed on the supporting member 60 which supports the image carrier 20, as the reference. Namely, the accuracy of the distance between the lens body 43 and the image carrier 20 is surely attained only by having the accurate sizes of the installation position of the image carrier 20 and the positioning part 117 by installing the lens body (a condensing light transmitting body) 43 at the device by using the positioning part 117 formed on the supporting member (a main body frame) 60 which supports the image carrier (a phtosensitive drum) 20 as the reference. Thus, the stable image quality is attained.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention irradiates a document on a document table with light from an exposure light source and directs the reflected light to an image carrier through a lens body. The present invention relates to an electrophotographic copying apparatus that temporarily forms an electrostatic latent image on an image carrier by guiding the image.

(Prior Art) In recent years, electrophotographic copying apparatuses have become more compact, and various table-top types with a movable document table have been put into practical use. Normally, in this type of small electrophotographic copying machine, light from an exposure light source is irradiated onto the document on a movable document table, and the reflected light is reflected by a condensing light transmitting body (product name), which is a lens body. , SELFOC lens array) to a photoreceptor drum, which is an image carrier, to once form an electrostatic latent image corresponding to the original on the photoreceptor drum, and then After developing the developer image, the developer image is transferred to a transfer material.

Furthermore, in the case of using such a condensing light transmitting body, the accuracy of the distance between the light emitting end face of the condensing light transmitting body and the image carrier greatly affects the image quality.

However, in the past, the condensing light transmission body was screwed to the optical system frame, which was a separate member from the support member that supported the image carrier, and there was a gap between the optical system frame and the support member. Due to misalignment and misalignment between the optical system frame and the condensing light transmitting body, it is difficult to obtain accurate distance between the light emitting end surface of the condensing light transmitting body and the image carrier, and assembly Not only is the performance poor, but the manufacturing precision of each component must be improved, which increases manufacturing costs. Also, screws may become loose and may become misaligned during use.
There is a problem that image quality may deteriorate.

(Problem to be Solved by the Invention) In this way, in the past, the lens body such as the condensing light transmitting body is screwed to a member different from the support member that supports the image carrier, so the lens It is difficult to achieve accurate distance between the body and the image carrier, and there are problems with ease of assembly, manufacturing cost, stability of image quality, etc.

The present invention has been made based on the above-mentioned circumstances, and its purpose is to reliably obtain accurate distance between the lens body and the image carrier to obtain stable image quality, and to improve assembly efficiency. It is an object of the present invention to provide an electrophotographic copying apparatus that allows manufacturing costs to be reduced.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention irradiates light from an exposure light source onto a document on a M-type document table, and directs the reflected light through a lens body. In an electrophotographic copying apparatus that forms an electrostatic latent image on an image carrier by guiding the electrostatic latent image to the image carrier,
The lens body is attached with reference to a positioning portion formed on a support portion that supports the image carrier.

(Function) That is, in the present invention, since the lens body is attached with reference to the positioning part formed on the support member that supports the image carrier, the dimensional accuracy between the mounting position of the image carrier and the positioning part can be improved. By simply taking the lens, the distance accuracy between the lens body and the image carrier can be reliably obtained. This provides stable image quality.

Furthermore, it is possible to improve assembly efficiency and reduce manufacturing costs compared to conventional methods that require precision of individual parts.

(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.

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. A control panel 12 is provided with a dimming knob 8 for setting copy density, a print key (copy key) 9, a clear/stop key 10, a total counter 1, and the like.

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.

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/
It is possible to manually feed one sheet using the stop key L10. 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 the moving speed of the table 5, which is 11 m/see. The photoreceptor 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. ing.

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.

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. 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 21.

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.

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 device unit 23 uses a positive polarity two-component magnetic brush system to connect the sleeve 4 of the developing port 44, which is a toner layer holding member.
4a is rotated by a drive mechanism (not shown) in the direction of arrow d at a faster speed (approximately 3.3 to 3.5 times) than the photosensitive drum 20, and is applied with a bias voltage of -200V.

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 A9 core metal and having a built-in heater 52, and a press roller 47 made of silicone rubber.
Since the surface of the lesser roller 47a is negatively charged, offset with positive polarity toner and dirt on the press rollers 47 and b occur. In this device, the PTFE with carbon black dispersed is
7a to lower the resistance of the resin layer, and also to reduce the resistance of the leaf spring (
(not shown) is grounded 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 neutralizing light from the defrosting/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. 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. The frame portions 58 are each attached to the frame portions 58.

Further, as shown in FIGS. 6 and 7, the table frame 56 is attached via a slider 59 to the horizontal piece 60a of the main body frame 6° that forms the rear edge of the upper surface of the apparatus main body 1. It has become. 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 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 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 leftward (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 4o 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 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 4o 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 6 mm is stretched in a shield case 80, and the grid 21a. Since the photoreceptor drum 2o is negatively charged, it is necessary to cause negative discharge. Further, during negative discharge, since uneven charging tends to occur, the grid 21a is arranged opposite to the opening of the shield case 80 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 (not shown) on the device main body 1 side (output -5,0k
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 was 60 mm, the distance p1 between the corona wire 81 and the surface of the photoreceptor drum 20 was 8.0 mm, and the distance Ω2 between the grid 21a and the surface of the photoreceptor drum 20 was 2.0 mm. .

Regarding the actual charging property, as shown in FIG. 12, it can be seen that even if the current value changes 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 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. Ω2 (first
(see Figure 0) can be obtained with high precision, 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. Further, as shown in FIG. 15, the charger body accommodating portion 88 of the charger frame 86 includes the charger body 21. a first leaf spring 97 that presses b downward;
A second leaf spring 98 that presses the charger body 21b in the width direction is provided, so that the charger body 21b accommodated in the charger body housing 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, which affects the charging characteristics and crystallizes the corona wire 81. and the surface of the photoreceptor drum 20 p1
(See FIG. 10) can be obtained with high accuracy, and 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 a recovery blade) 100 whose free end is brought into contact with the surface of the photoreceptor drum 20 to prevent it from scattering into the main body 1, and a toner collection box (hereinafter referred to as a recovery blade) which collects toner in a cleaner case 101. The structure includes a cover auger 102 for carrying out the work (not shown). Further, the recovery blade 100
As shown in FIGS. 16 and 17, the lower end edge is supported by the recovery blade support member 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 chargeability 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.

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 optical transmitter 43, the glass guide 71, etc. are integrated 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. 19, the optical system frame 11
Attached edge portion 1 to which the condensing light transmitting body 43 of No. 5 is attached
15a, 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, 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 plate thickness of the attached end edge 115a of the optical frame 115, the position of attachment to the main frame 60, and the dimensional accuracy of the glass guide door 1, and the dimensional accuracy of the distance L1 and the attached Mounting edge 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). 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 starting part and a short circuit part 136 as a non-light emitting part.
It is made up of halogen 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. 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.

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 in the figure (in the direction of arrow d).

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 G1 between the sleeve 44a and the photosensitive drum 20 is set to 0.9 to 1.0 mm, and the gap G2 between the doctor 153 and the sleeve 44 is set to 0.8 to 0.9 n+m.

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 (θ1=1
2°), and the angle between the developer receiver and the plate 158 is 5°.
9° (e2=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 with the above method, the sensor surface 157a is located 0.7 mm from the surface of the holder 159.
(t1-0.7TO11) protruding, and the gap G between the lower part of the holder 159 and the plate 158 is 2.5 mm, which are necessary conditions for further improving stability. .

Further, the developer cover 160 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 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. Then, at the home position on table 5 or above,
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 R9 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 R1 is located at a position where a distance L4 is formed between the reaching point of the stray light R1
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 easy to notice when opening the document holding cover 13 to set the document tray. This allows the operator to be informed.

Further, as shown in FIGS. 22, 26, and 27, the first. The second developer stirring body 154 and 155 have blade portions 154a and 15.
Winding direction and pitch of 5a p(1)""25+n++
+) are the same and the rotation direction is opposite, and there are first and second communication portions 171.1 on both ends between them.
A partition plate 170 is provided except for 72, 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 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 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.

Same as pitch p of 155a (Wl-p), i.e. 2
5 mm, and the first developer stirring section 150a
The developer A smoothly flows from the downstream 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:
Said blade portion 154a.

The pitch is larger than the pitch p of the second developer stirring section 150a (W2>p), that is, the pitch is set in the order of 35.
In addition to preventing the developer from spilling from the developing roller 44 side due to the developer A being stagnant in the developer A, the developer A is stored in the first developer agitating section 150a and is sufficiently agitated 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 1.
This is a protective sheet that covers the front side of 57 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, 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 drive gear 196 having an arcuate engagement recess 196a that engages with an arcuate engagement protrusion 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 member 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 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 provided.
The developer cover 160 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 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 convex direction of the arrow as shown in FIG. It rotates in the direction shown by the solid line. Furthermore, 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 sill 4 ('205) and becomes in the state shown by the two-dot chain line.In this way, the toner cartridge 37 swings every time the toner is replenished. and level the toner t stored inside.
Good supply status can be maintained.

In addition, as described above, the document on the movable document table 41 is irradiated with light from the lamp 40 as an exposure light source, and the reflected light R□ is transmitted through the condensing light transmitting body 43 as a lens body. In an electrophotographic copying apparatus in which an electrostatic latent image is once formed on the photoreceptor drum 20 by guiding the light to the photoreceptor drum 20 as an image carrier, the light condensing light transmitting member 43
is attached with reference to a positioning portion 117 formed on the main body frame 60 as a support member for supporting the photoreceptor drum 20.

Therefore, according to the present invention, by simply ensuring the accuracy of the dimension L1 between the mounting position of the condensing light transmitting body 43 and the positioning portion 117 of the photoconductor drum 20, the condensing light transmitting body 43 and the photoconductor drum 20 can be The accuracy of the distance L2 can be reliably obtained. This provides stable image quality. Furthermore, it is possible to improve assembly efficiency and reduce manufacturing costs compared to conventional methods that require precision of individual parts.

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, the distance accuracy between the lens body and the image carrier can be reliably obtained, and stable image quality can be obtained. This has the effect of providing an electrophotographic copying apparatus that enables cost reduction.

[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. FIG. 14 is a diagram showing the positioning of the grid of the charging device, and FIG. 15 is a diagram showing the positioning of the charger body of the charging device. , FIG. 16 is a schematic perspective view of the glue cover blade of the cleaner unit, FIG. 17 is a partially sectional side view, FIG. 18 is a schematic perspective view of the static eliminating/exposure device, and FIG. 19 is the static eliminating/exposure device. Figure 20 is a diagram schematically showing the installation state of the condensing optical transmitter, Figure 20 is a diagram schematically showing the structure of the static elimination/exposure device and its surroundings, and Figure 21 is a diagram showing the orientation characteristics and the ribs of the static elimination light aperture. Diagram showing the positional relationship with
Fig. 2 is a schematic cross-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. An explanatory diagram showing the stray light prevention state, 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, and FIG. 28 29 is a perspective view of the mounting portion of the auto-toner adjustment circuit board of the developing device unit, FIG. 29 is a diagram showing the drive system of the toner conveying auger incorporated in the toner cartridge, and FIG. 30 is an explanatory diagram showing the state in which the toner cartridge is installed. , FIG. 31 is an explanatory diagram showing the swinging state of the toner cartridge during toner replenishment. 20... Photosensitive drum (image carrier), 40... Lamp (exposure light source), 41... Original table, 43... Condensing light transmission body (lens body), 60... Main body Frame (supporting member), 117... Positioning part, L2... Distance between the condensing light transmission body and the photosensitive drum. Applicant's agent Patent attorney Takehiko Suzue] 2 Figure Figure Figure Figure Dimensions 31, J Figure Figure 4

Claims (1)

[Scope of Claims] An electrostatic latent image is formed on the image carrier by irradiating light from an exposure light source onto a document on a document table and guiding the reflected light to the image carrier through a lens body. An electrophotographic copying apparatus according to the present invention, wherein the lens body is attached with reference to a positioning portion formed on a support member that supports the image carrier.