JPS61130122A - Image forming device - Google Patents

Abstract

PURPOSE:To smoothly guide paper without hooking it on the separation claw of a paper feed cassette, as the paper comes while being guided on a cassette cover, by fitting the cassette cover with a guide extending so as to cover the separation claw. CONSTITUTION:First guides 225, which are made of thin elastic plates and extend over the separation claws 215 of a paper feed cassette 4, are provided at the free ends of both the sides of a cassette cover 209, which is utilized as a paper feed rest 10. The first guides 225 have slits 226 extending in the direction of feed of paper, so that a force for pushing the paper taken out of the cassette 4 is kept constant regardless of the size of the paper. Because of the pushing action of the guides 225, the paper coming while being guided on the cassette cover 209 is smoothly guided without being hooked on the separation claws 215 and is prevented from jumping when it goes out from the separation claws at the time of the takeout of the paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus such as a copying machine, and particularly to an image forming apparatus with an improved paper feeder section.

[Technical background of the invention and its problems]

In recent years, image forming devices such as electronic copying machines have become smaller year by year), and this type of device usually
In order to easily replenish paper or change the paper size, cassette-type paper feeders with a removable paper feeder attached to the paper feeder are often used. Many also have a manual paper feeding device.

However, although this manual paper feeding device is very convenient because it allows you to use any paper you want each time you make a copy, it is very troublesome because it manually feeds one sheet each time you make a copy. There was a problem in that it was not possible to feed paper continuously like a cassette-type paper feeder.

Therefore, the inventors of the present invention have developed an image forming apparatus equipped with a paper feeding device that can feed paper continuously by simply placing and setting the required number of copies of paper on a paper feeding cassette each time an image is formed. It is progressing.

However, when an automatic paper feeder is installed, a separate paper feed guide is required to guide the sheets that are separated and fed by the automatic paper feeder, making the device more complex, larger, and more expensive. To address this problem, it has been proposed to use a cassette cover that covers the top surface of the paper feed cassette as one surface of the paper feed guide to guide the sheets separated and fed by the automatic paper feed device.

However, when the cassette cover is simply used as a paper feed guide, the leading edge of the fed paper gets caught in the separation claw exposed in the paper ejection opening of the paper cassette, making it impossible to guide it reliably and resulting in a jam. There is a problem of doing so.

[Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and its object is to provide a paper feed section that supplies paper stored in a paper feed cassette equipped with a separating claw. The main body of the image forming apparatus forms an image on the paper fed by the paper feed unit, and the plurality of sheets of paper attached to the main body of the image forming apparatus and set on the paper feed tray are sequentially fed into the paper feed unit, one by one. and an automatic paper feeder for feeding the paper to a paper feeder, and the paper is separated and fed by the automatic paper feeder using a cassette cover that covers an opening for taking out the paper in the paper feed cassette as a paper feed surface. In an image forming apparatus that guides paper, although it has an extremely simple configuration, the paper guided above the cassette cover can be guided smoothly without getting caught by the separation claw, and when paper is fed from the paper cassette. It is an object of the present invention to provide an image forming apparatus that can prevent multiple take-outs.

[Summary of the invention]

In order to achieve this object, the US invention provides a guide member that extends to cover the separating claw of the paper feed force section on the cassette cover, and the guide member separates and feeds the sheets by the automatic paper feeder. The structure is such that it guides the paper and also presses the paper taken out from the paper feed cassette with an appropriate pressing force to prevent the paper from expanding unintentionally.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view showing a two-color copying machine with a moving document table as an example of an image forming apparatus according to the present invention, and FIG. 2 is a longitudinal sectional front view. That is, 1 is a copying machine main body, and the top surface of this copying machine main body 1 is
A reciprocating document table 2 is provided on the document table 2, and a document cover 3 is provided on the document table 2 so as to be openable and closable. Further, a paper feed cassette 4 is attached to the right side of the main body l, and a paper discharge tray 5 is attached to the left side.

The paper feed cassette 4 is detachably attached to a paper feed section 6 provided on the lower right side of the main body 1. In the paper feed section 6, 7 is a paper feed roller that takes out sheets of paper P one by one from the paper feed cassette 4, and 8 is a paper feed roller that conveys the paper fed from this paper feed row 27 (or the automatic paper feed device 11, which will be described later). In front of the aligning roller pair 8, there is provided a detector 9 for detecting the paper, which includes a guide 9a and a microswitch 9b.

In addition, the paper feed cassette 40 (upper surface) serves as a paper feed table 10 for manually feeding paper as appropriate (possible when an automatic paper feed device 11 described later is not installed) or automatically feeding paper. An automatic paper feeder 11 is provided on this paper feeder 10, and a paper width adjustment guide 12 is provided on the paper feeder 10 on the paper insertion side of this automatic paper feeder 11. The automatic paper feeder 11 continuously feeds the sheets P placed on the paper feed tray IQ one by one to the paper feeder 6, and is detachable from the right side of the main body 1. The details will be explained later.

Further, a photosensitive drum 13 is disposed approximately in the center of the main body 1. Around the photosensitive drum 13, there are an exposure optical system 14, a charging charger 15, a two-color color developing device I6, a transfer charger 17, a stripping charger 18, a cleaning device 19, and a static elimination lamp. 217, etc. are sequentially arranged along the rotation direction.

Here, the developing device 16 is, for example, a first developing device 16.
The developing device 16b is divided into two parts, a developing device a and a second developing device 16b, both of which are magnetic brush type developing devices, and each of which is detachable from the main body 1.

The first developing device 16IL and the second developing device 16b are set as follows.
A reciprocal motor (not shown) rotates forward or backward to selectively drive one of the two, and this selects black or one other color, such as red, yellow, blue, or green, from K. It is a trap so that you can do it.

Further, the first developing device 16a1 and the second developing device 16b each include a solenoid (hereinafter referred to as a developing device solenoid) 9 for controlling whether or not to enable development. It is now in a developable state (a state in which a magnetic brush can be formed).

On the other hand, in the lower part of the main body 1, a sheet P or P is fed by a pair of aligning rollers 8.

A paper transport path 22 is formed that guides the image to the paper discharge tray 5 through the image transfer section 2 between the photosensitive drum 13 and the transfer charger 17. Then, the image transfer section 2 of this paper conveyance path Z2
The pair of aligning rollers 8 is provided on the upstream side of the printer 1, and the fixing device 23 and the pair of paper discharge rollers 24 are provided on the downstream side.

Here, the exposure optical system 14 has a reflector 25 at its back.
Exposure run f26 surrounded by mirrors 27-30.
and a lens 31 whose position is moved according to the set magnification.

Thus, the photosensitive drum 13 is driven by a drive mechanism (not shown) in the direction indicated by the arrow in the drawing in synchronization with the document table 2.

First, an image of the original is uniformly charged by the charger 15 and uniformly irradiated with light by the exposure land 26, and is formed on the photoreceptor P ram 13 by the exposure optical system 14, and A latent image is formed. The formed electrostatic latent image is developed into a developer image by the developing device 16 and sent to the transfer charger 17 side.

On the other hand, the paper P or P fed from the paper feed cassette 4 or the automatic paper feed device 11 is fed to the pair of aligning rollers 8, and the developer image formed on the photoreceptor drum 13 is used for transfer. The image is transferred by the charger 17. The paper P1 (P2) to which this developer image has been transferred is peeled off from the υ photoreceptor drum 13 by a peeling charger 18, passes through a paper conveyance path 22, and is led to a fixing device 23, where the transferred image is After being fused and fixed, the sheet is discharged onto the ejection tray 5 by a pair of ejection rollers 24.

On the other hand, after the developer image is transferred onto the paper p+(pt), the residual toner remaining on the photosensitive drum 9 is removed by the cleaning device 19.
Furthermore, the residual image on the photosensitive drum 13 is erased by the static elimination rung 20, and the image is readied for the next copying operation. A developer replenishing device for the developing device, 42 a developer replenishing device for the second developing device, 43 and 44 a developer concentration detector, 45 a paper discharge switch, 46 a static elimination brush, and 47 an exhaust fan.

Next, the driving force transmission system will be explained with reference to FIGS. 3 to 6. Figure 3 is the main body of the copying machine! FIG. 4 is a diagram of the internal mechanism of the automatic paper feeder 11 viewed from the back side, and FIG. 4 shows a state in which the upper unit 50 is separated from the lower unit 51 and the paper conveyance path 22 is opened. In the figure, 53 is a drive gear directly connected to the main motor 48, and the driving force of this drive gear 53 is transmitted to the drum drive gear via driven gears 54 to 56.
The driving force is transmitted to 57.

Still, the driving force of the driving gear 53 is transmitted to the aligning roller driving gear 6 via the driven gears 58 to 62 as shown in FIG.
3, and is further transmitted to the paper feed roller drive gear 65 via the driven gear 64.

In this way, the driving force of the driving gear 53 is transferred to the drum driving gear 57.
When transmitting power to the aligning roller driving gear 63, the drum driving power transmission system 66 and the aligning roller driving power transmission system 67 are separated and transmitted independently, so that the aligning roller The impact caused by load fluctuations before and after the start of driving of the pair 8 is not directly transmitted to the drum drive gear 57, and image blur caused by the impact can be prevented.

Further, the paper feed row 2 drive gear 65 is always in mesh with a drive gear 69 that meshes with the driven force transmission gear 68 of the automatic paper feeder 1, and the automatic paper feeder 1 of the automatic separation type
The configuration is such that a sufficiently large driving force is obtained from the copying machine main body 1 side via a driving force transmission mechanism 70. In addition, compared to a device having its own drive source, it is possible to improve the paper feeding speed, improve the paper separation mechanism, and reduce the size, weight, and cost.

Further, the meshing state between the driven force transmission gear 68 of the automatic sheet feeding device 11 and the driving gear 69 on the copying machine main body 1 side is released when the upper unit 51 is opened as shown in FIG. The power transmission system can be driven by manual operation of the device 1, making it easier to handle paper jams, maintain, inspect, etc.

Further, reference numeral 71 shown in FIGS. 3, 4, and 6 is a scanning motor, and this scanning motor 21 is decelerated by a gear head and rotates the goofleaf 2. Here, the sixth
As shown in the figure, a wire 74 whose one end is fixed to the tip of the document table 2 and whose other end is supported by a sedge ring (not shown) at the rear end of the document table 2 is connected to the idle relief 5 and the suge ring 76 by the wire 74. The tension 3 is wound around the gourd 2 via a goury 77 which applies tension to the tension 3.

Therefore, as shown in FIG.
When the document table 2 rotates in the direction (clockwise), the document table 2 moves forward in the AT force direction, and when the magnet 78 attached to the document table 2 is detected by the limit switch 79! -ri 72 rotates in the direction C1, and the document table 2 moves back in the direction a.

Further, the scanning motor 71 is synchronized with the main motor 48 by an encoder disk 80 and an encoder sensor 81.

Note that 83 is a magnet attached to the document table 2, 84 is a home switch, and 85 is a paper start switch.

Then, based on the detection signal of the paper start switch 85,
A clutch mechanism (not shown) incorporated in the paper feed roller 7 and one roller of the pair of aligning rollers 8 is operated;
The paper is fed and restarted at a predetermined timing. In addition, 86 shown in FIGS. 3 and 4 is a motor gear for the developing device, 87, 88 is a driven gear, and 89° and 90 are for the developing device. The drive gear 91 is a drive gear for the lower discharge roller, and 92 is a drive gear for the upper heat roller.

Further, 93 is a heater rung, 94 in FIG. 6 is a document At--a document plus to be placed, and 95 is a support roller.

In addition, the paper feed section 6 side is pivotally supported via the support shaft 52, and the
The unit 51, which can be rotated by 0 degrees, includes a photosensitive drum 1.
3, an optical system 14, a charging device 15, an exposure rung 26, a developing device 16, a cleaning device 19, a static elimination rung 20, etc. are attached by appropriate means, and furthermore, a document table 2, a paper feed roller 7 , the upper roller 8a1 of the aligning roller 8, the upper roller 231 of the heat roller 23,
and an upper roller 24 & of the paper ejection roller 24 are attached.

The lower unit 50 also includes a paper feed cassette 4, a lower roller 8b of the aligning row 28, a transfer charger 17, a peeling charger 18, and a lower roller 23b of the heat roller 23.
1 the lower roller 24b of the paper ejection roller 24, the paper ejection tray 5,
A main motor 48 and the like are attached by appropriate means.

After rotating and removing the 70-ton cover of the main body I, the paper p
Paper transport path 22 for transporting (pt). Further, at the upper end of the front side of the main body 1, as shown in FIG. 1, an operation/main panel 100 is provided.

FIG. 7 shows the operation/control panel 100, which includes a copy key 101 for executing a copy operation, an interrupt key 102 for specifying an interrupt mode for interrupt copying, setting the number of copies, etc. numeric keypad IO3 for copying, color selection key 1o4 for selecting copying color (for example, black, red, blue, green), color display section 1o5 for displaying available colors for copying, paper feed cassette 4
A paper feed selection key 106 for selecting automatic paper feeding by automatic paper feeding or automatic paper feeding by automatic paper feeding device 11, a total counter 107 for counting the total number of copies, and a liquid crystal display section 108 are provided.

The liquid crystal display section 108 includes a number display section 109 that displays the number of copies, a status display section 110 that displays various operating states such as paper jams and toner replenishment, a warm-accuracy display section 111, a ready display section 112, and a color display section 105. A color instruction section 113 is provided corresponding to the color instruction section 113 for indicating the selected color.
, a cassette paper feeding mode display section 114 that displays the automatic paper feeding mode using the paper feeding cassette 4, a bi/4' paper feeding mode display section II5 that displays the automatic paper feeding mode using the automatic paper feeding device 11, and an automatic exposure mode display. 116, and a set exposure amount display section 117 in manual exposure mode.

In addition, an automatic exposure key 11g for setting automatic exposure mode,
A manual exposure key 119 for manually setting the exposure amount, a magnification setting key 120 for selecting and setting a specific predetermined copying magnification, and a zoom key 121 for setting an arbitrary copying magnification.
, a magnification display section 122 for displaying the set magnification, etc. are also provided.

Next, the exposure optical system 741C having a displacement function will be explained with reference to FIGS. 8 to 16.

The exposure optical system 14 is formed into a unit except for an exposure land 26 whose back is surrounded by a reflector 25, a first mirror 27, and a fourth mirror 30. Figures 8 and 9
In the figure, reference numerals 130 and 131 denote a rear frame and a front frame provided in parallel to the pace assembly 129, and the front frame 1soK has a guide plate 132 protruding toward the rear frame 130. The front side of a lens carriage horn 133 on which the lens 31 is mounted and the front side of a mirror carriage horn 134 on which the mirrors 28 and 29 are mounted can slide on this guide plate 132 via guided members 135 and 136, respectively. is supported by

On the other hand, a drive shaft 137 is disposed near the inner side of the rear frame 13 and parallel thereto. This drive shaft 137 is connected to the auxiliary frame 13 of the pace assembly 129.
Bearing installed on 8,139! 4σ, 141! 7@
A drive shaft 1 rotatably supported and with
37, slidable f-id 142142,
and the lens carrier 13 through O:143.
3 and the rear end of the mirror carriage 134 are attached.

Therefore, the lens carrier horn 133 on which the lens 31 is mounted is mounted. That is, as shown in FIG. 10, the lens unit 144 is in a state in which it can reciprocate in the direction of arrow A in FIG. 9 using the side plate 132 and drive shaft 137 as guides.

Mata, Mirror Calitsuno I equipped with Mirror 28.29
34. That is, like the lens unit 144, the mirror unit 145 is also in a state where it can reciprocate in the direction of arrow A in FIG.
Stepping motor 1 via 46,147.1411
On the other hand, a cam assembly 155 is fixed to the lens unit 144 by a screw, and a link assembly 156 is rotatably supported to the pace assembly 129. There is. The roller 15 is attached to the L-shaped link 161 of the link assembly 156.
7.15g is attached, and the link assembly 156 is connected to the arc-shaped hole 159a of the cam 159 via the roller 157.
And also, the mirror unit 145 via the roller 158
It is connected to the elongated hole 160m of the bracket 160.

Further, as shown in FIG. 11, the cam 159 has a guide 1.
62 is rotatably attached to the drive shaft 13.
7 and constitutes a feeding mechanism 150 that converts the rotation of the stepping motor 149 into linear movement of the lens unit 144. When the drive shaft 137 is rotated, the cam assembly 155VC is screwed through the guide 162.
#The unit 144 moves in the direction of arrow A.

Note that the magnification can be changed by moving the lens 31, mirror 28, and mirror 29 to change the optical path length (from original A to photoreceptor drum 1).
(distance up to 3). That is, during maximum reduction copying, the lens 31. and mirror 29
The mirror 28, which is in an integral relationship with the mirror 28, is displaced to the position shown by the solid line in FIG. .

The lens unit 144 is moved along the following path. That is, the driving force of the stepping motor 149 is transferred to the gear 1419. 747. 146 is sequentially valved to be transmitted to the drive shaft 137, and as the drive shaft 1370 rotates, the shaft 162 is moved to move the lens unit 144 which is in an integral relationship with the cam assembly 155 provided with this guy P162. It is supposed to move. lens 3
The amount of movement 1 is determined by the rotation angle of the stepping motor 149. The relationship between the lens displacement and the motor rotation angle will be described later.

Mata, mirror unit 145/d lens unit 144
By moving, it is moved by the following path. That is, as the cam assembly 155, which is in an integral relationship with the lens unit 144, moves, the arc-shaped hole 1 of the cam 159 opens.
The roller 157 engaged with 59& moves, thereby rotationally displacing the L-shaped link 161 of the syringe link assembly 156, and the roller 158 attached to the L-shaped link 161 also displaces. Then, the mirror unit 145, which is integrally connected to the bracket 16 having the elongated hole 160a that engages with the row 2158, is moved.

The amount of movement of the mirrors 28 and 29 is determined by the rotation angle of the L-shaped link 161 of the link assembly 156, and the rotation angle is determined by the shape of the arc-shaped hole 159b of the cam 159.

FIGS. 12 and 13 illustrate these movements. That is, FIG. 12 shows the relationship between the cam assembly 155 and the link assembly 156. When the cam 159 moves a distance L in the direction of the arrow, the L-shaped link 16 is rotated by an angle α in the convex direction of the arrow. do. In addition, I65 is link 16
This is the pivot point of I.

FIG. 13 also shows the link assembly 156 and the bracket 16.
0, and the L-shaped 161 is α in the convex direction of the arrow.
When the bracket I60 is rotated by
It will move a distance of .

Note that the groove 6 shown in FIG. 9 is an optical sensor, and the reference numeral 167 is a light shielding plate, which constitutes a same-magnification detection means 168 that detects the same-magnification position of the lens unit 144. Also, 169...
. is a positioning pin provided on the base assembly 129, and the optical unit is positioned by fitting these pins 169 into holes formed in the frame of the main body l. Reference numeral 170 denotes a document hardness detection sensor.

Further, when changing the copying magnification by moving the lens 31 in this way, the number of steps of the stepping motor 149 corresponding to 1% is set to an integer value, assuming that the minimum unit of the amount of magnification change is x%. The leads of the threaded portion 137 & of the drive shaft 7 137 are set at .

By setting in this way, there is little error in the specified magnification, and the control can be made easy. Note that the minimum unit of the amount of magnification of a normal zoom variable magnification copying machine is 1%. operation·! There is a magnification display section 122 on the panel 100, and the user uses the zoom key 121 while looking at it to set the desired magnification. Inside the copying machine, the lens 3, mirrors 28, 29, etc. are moved according to the designated magnification. Note that these operations are controlled by a microcomputer.

Next, the relationship between the amount of lens movement and the amount of change in magnification will be explained with reference to FIG. In the figure, f: focal length of lens M: magnification of image F: front focal point F'a rear focal point A: object distance B: image distance. There is a relationship between the lens, object, and image as shown in Figure 14.If the lens position is expressed by the distance B from the image plane, then s=t+tyt...(1) Magnification is changed from M to M, The amount of change ΔB in B when changing it to
-Mt ) □(6), so the amount of change in B (
In other words, there is a proportional relationship between the amount of lens movement) and the amount of change in magnification.

Further, the relationship between the amount of lens movement and the number of steps of the motor is as follows. That is, the lens movement amount ΔB, and the lead of the screw portion of the drive shaft: L.

When the rotation angle of the motor is α (d6g), the following formula is formed)
stand. (However, the gear ratio between the motor and the shaft is 1:1.) The motor 149 used in this machine is a stepping motor, and the rotation angle α is given by the following equation.

α= r −N (■) However, r: Rotation angle per step of the motor (d@g),
N: The number of steps input to the motor (III) and the formula (TV). Therefore, the relationship between the amount of change in magnification and the number of steps is ([[) and formula (V). Here, r , f is a constant, so the amount of change in magnification M,
-M is determined by the number of steps NK.

By the way, when trying to change the magnification in 1% increments, it is inconvenient that the number of steps corresponding to 1% must be an integer.

For example, 1% → 7.3 steps! If the setting is 5 steps → 7.3 x 5 = 36.5 steps, the motor will be rotated at either 36 steps or 37 steps, and the 0.5 steps is due to the error in magnification. It appears as

Therefore, the coefficient (r-'''; part) of N in equation (VI)
It is necessary to limit the number of In this, r is a numerical value (integer) determined by the motor used, and f is a unique value of the lens used. That point,
Since L can be set freely, the easiest method is to satisfy the above conditions by selecting a numerical value for L.

When changing the magnification in 1% increments, M of the (vr) formula,
-M2=0.01 and is calculated as 3.6f.

For example, in the case of this machine, f = 110 (mm),
r-=7.5 (deg), N=8, L=6.
6 (hawk).

In addition, in the case of a motor controlled by a microcomputer, it is more convenient to set the numerical value of N to the following condition: N=2rl (n≧O).

In addition, the optical unit of this machine is as shown in Figure 15.
The lens unit 144 and the mirror unit 145 are arranged obliquely with respect to the horizontal plane, and the moving directions of the lens unit 144 and the mirror unit 145 are also inclined in the same direction.

As described above, the lens unit 144 and the mirror unit 145 are supported on the drive shaft 137 and the guide plate 132 of the base assembly 129 via guides 9142, 142, 143.

Therefore, its moving direction is limited to the A direction in FIG. 15. Therefore, for example, a component force F of the load W of the lens unit 144 is always acting in the width direction in FIG. 15.

Incidentally, a slight gap is provided between the guide 142 of the lens unit 144 and the drive shaft 137 in order to improve movement, but this gap causes the lens unit 144 to move when it is in a stopped state. becomes unstable.

However, in the case of this camera, the lens unit 144 is always stabilized in the state shown in FIG. 16 due to the above-mentioned force F, and the stopped state does not vary depending on the evening or the evening.

This effect is the same for the mirror unit 145 as well.

Note that when the moving direction is horizontal, the lens unit 144 and the mirror unit 145 are arranged on both sides of a line perpendicular to the axis of the drive shaft 137 as shown in FIG. θ8. Sunset occurs in the angle range of θ2, and the image becomes unstable.

Next, with reference to FIGS. 17 to 21, the developing device 1
6 will be explained in detail. K as detailed in Figure 17.
, 1st current roller 121. and a second developing roller 171. ．． 171. is selectively driven to perform color development of black (first color) or one color other than black (second color), such as red, yellow, blue, and green. That is, the developing device 1
6 is a first developing device (first developing device) including a first developing roller 1711;
It is divided into two parts: a developing unit) 16m and a second developing unit (second developing unit) 16b including a second developing roller 17, and both the first and second developing units 16h and 16b are connected to the main body. It is detachable from 1. in this case,
The first developing device 16a in the upper stage is configured to be easily attached and detached so that the user can pull it out upward in the figure, and the second developing device 16b in the lower stage is designed to be easily attached and detached by the user when performing maintenance, inspection, etc. , has a structure that can be attached to and detached from the main body 1. For black toner, which is frequently used, the second
The color toner T is used in the developing device 16b, and the color toner T is
The first developing device 16m, which is used in the developing device 16a, includes a developing mechanism section 172.degree., a toner replenishing section 173. It is composed of.

The above-mentioned developing mechanism section I72. is a casing 181 which will be described later.
A developing roller 1721 that supplies toner 1 to the photosensitive drum JJK through an opening 181□-1 of 1, and a developer magnetic brush I75 formed on the surface of this developing roller 17.
．． The sliding contact portion with the photoreceptor drum 13, that is, the development position 1
76, a doctor (regulating member) 177 which is provided on the upstream side, that is, on the side of the second developing unit 16b, and which regulates the thickness of the developer magnetic brush 1751; Developer magnetic brush 175 on the surface of 17C. Scrape off the developer container 178.
Suclay 4179. and developer storage section 1781
a developer stirring body 18θ housed in the casing 18;
It has a configuration in which it is housed within 11. Note that in a position corresponding to the upper part of the developing roller 17C of the casing 1811, developer Gl()'ner T and carrier C+
A toner concentration detector 41 is attached to detect the concentration of the toner T in the developer G1 by magnetically detecting changes in the magnetic permeability of the developer G1.

The developing roller 17C is a straight line that passes through the center of rotation of the photoreceptor drum 13 and forms an angle α (approximately 51°) with respect to the horizontal line L1.

A magnetic roll (i-gnet) 183 provided with its center located at the top. Sleeves (transporting bodies) 1 & 4 are fitted around this magnetic roll 183□ and rotate clockwise in the figure.
It is composed of.

The magnetic roll 183. are five magnetic pole parts 185I to 18
9I, of which the magnetic pole portion 185. , 1117.
.

1891 is the N pole, and the magnetic pole part 1116. ．． 113&, is the S pole, and the magnetic pole part I85. and 186. The angle θ between the magnetic pole portion 186. The angle θ between the magnetic pole parts 1871 and 1871 is about 71°, the angle θ between the magnetic pole parts 1871 and 1881 is about 60', and the angle θ between the magnetic pole parts 1811. and 189. The angle θ4 between them is set to about 60°.

Further, the toner supply section 173. is toner supply port 19
0. The developing mechanism section 172. A hopper 19 facing the developer accommodating portion 178, and a developer replenishing port 190 within the hopper 4191. Toner replenishment roller 192. , and toner on this toner supply roller 1921 side.

Hora 14191. a pair of stirring rollers 193 for stirring the toner inside. ．． 193. It has a configuration with.

Further, the second developing device 16b is the first developing device 16 described above.
It has almost the same basic configuration as a, and the toner supply section 17
3. The shape of the hopper 41912 and the developing roller 171
! magnetic roll 183. The arrangement structure of the magnetic poles and the mounting position of the toner concentration detector 44 are different. Therefore, for other identical components, the code suffix letter rtJ
The reference numeral changed from ``2'' to ``2'' will be given, and detailed explanation will be omitted. Note that the doctor I77 is located on the side opposite to the first developing device 16b with respect to the developing row 21712.

Further, the developing roller 171. magnetic roll 183. has four magnetic pole parts 185. ~188. M, of which the magnetic pole portion 11j5. ．． ,187! is the N pole, the magnetic pole part 186. ,
Z,! l J, is the S pole, and the magnetic pole part 185.
and 186. The angle θ between is approximately 900, and the magnetic pole part 186
．． And 187! The angle θ between the magnetic pole part 18 is approximately 70'.
72 and 188. and the angle θ, is set to about 80', respectively. Further, the magnetic roll 1832 is arranged at an angle β with respect to the horizontal line passing through the rotation center of the photoreceptor drum 13.
(approximately 1°), with the center located above the straight line.

On the other hand, the magnetic rolls 11331 and 183 degrees of the first developing device 16h and the second developing device 16b are configured to be able to rotate at rotation angles of approximately 35 degrees. Due to the dynamic displacement operation, the developing roller 17
1. .

172, developer magnetic powder is applied to the surface of 175. ,175t
can be formed or removed.

Then, the magnetic calls 183□, 183t of the first developing device 16a and the second developing device 16b are switched to predetermined positions by the magnetic roll driving means (not shown) K.
Developing roller 171 of either the first developing device 16m or the second developing device 16b. ．． 171. Developer is applied only to the surface of the magnetic brush 175. ．． 175. K is set so that .

That is, when operating the first developing device 161 side,
As shown in FIG. 17, the magnetic roll 1831 on the first developing device 161 side is connected to a magnetic pole portion (developing magnetic pole) 187. is development position 1
76.1C Opposing state, ie opening 1131 &1
185I and 186.
The doctor 177 is positioned approximately midway between the magnetic roller 183 and the magnetic roller 183 on the second developing device 16b side. A magnetic pole part (developing magnetic pole) of 1 gv is inserted into the casing 181. from the opening 181 a2. Located inside and magnetic pole part 1
85 is arranged to face the doctor 177.

The developer magnetic brush 175I is formed only on the surface of the developing roller 1711 on the side of the first developing device 16a.

In addition, when operating the second developing device 16b side, the first developing device 16b side is operated.
As shown in FIG. 8, the magnetic roll 18 on the first developing device 16a side
31 clockwise by approximately 35 degrees from the position shown in FIG. 17, so that the magnetic pole part 185 faces the doctor 177, and the magnetic pole part 187I is moved from the opening 181h1 to the casing 181. Magnetic roll 183. located inside and on the second developing unit 16b side. The magnetic pole portion 187. is rotated approximately 35 degrees counterclockwise from the position shown in FIG. is development position 1
76, that is, located at the a2 portion of the opening 181, and the magnetic pole portions 45° and 186. Doctor 177 is almost in the middle! position. and,
Developing roller 171 on the second developing device 16b side. The developer magnetic graphite/1752 is formed only on the surface of the developer.

Note that the magnetic roll 1113. , 183. When the magnetic pole parts 1115, 11152 of , are opposed to the doctors 177□, 1772 made of non-magnetic material, the developing roller 171
．． .

Developer magnetic brush 175. on the surface of 17. , 175
The reason why the magnetic pole part 185. .

185! At this point, the density of the magnetic brush is in a state of flux, so the developer Gl+G! The suction force of the doctor 177, . This is because the sleeve 184. can be easily regulated by the sleeve 177. .

Even if 184 rotates, the developer Gly G! is doctor 17
7. 177, the first
1952 shown in FIG. 7 and FIG. 18 is the second developing device 16b.
Hola) 4191. This is a toner remaining amount detection device that detects when the amount of toner T in the toner T is below a predetermined value. The permanent magnet 198 is 4191. It is configured to operate by approaching a reed switch 199 as a detector provided on the outside of the sensor. Although not shown, the first developing device 16m
The above toner remaining amount detection device 1 also applies to
95. A toner remaining amount detection device having a similar configuration is provided.

Next, the developing operation of the developing device 16 will be explained. First, when the first developer 16h side is selected to operate using the color selection key, the magnetic rolls 183, . 183. is the first
7, the sleeve 1841 of the first developing roller 1711 rotates clockwise in the state shown in FIG. 17, and the developer magnetic brush 17 is applied to the surface of the sleeve 184□.
51 is formed. Then, the electrostatic latent image previously formed on the photoreceptor drum 13 is developed with the color developer G1. When the development of the electrostatic latent image is completed in this way, the magnetic roll 183I is rotated by about 25 degrees, and the magnetic pole portion 1851 faces the P lid 1 □, so that the developer is transferred onto the sleeve 1841. magnetic brush 17
New formation of 5I is stopped, and in this state, the sleeve 184 is further rotated by a predetermined amount to remove the developer magnetic brush 1751. At this time, the developer magnetic brush 175. is also applied to the second developing roller 17I. is not formed, so that even if one of the developing devices 16a, 16b is selected next, problems such as color mixing will not occur.

Further, when the second developing device 16b is selected for black color development, the magnetic roll 1113. , 183□ reach the state shown in FIG. 18, and the sleeve 184. of the second developing roller 17). rotates clockwise in the state shown in FIG. 18, and the sleeve 184. Developer magnetic brush 1752 on the surface of
form. After developing the electrostatic latent image on the photoreceptor drum 13 to black in the same manner as described above, the sleeve 184
The developing operation is completed with the developer magnetic brush 1752 removed from the surface of the developer.

Furthermore, as shown in FIG. 19, the developer concentration detectors 43 and 44 provided in each of the developing units 16m and 16b face the inside of the casing 18H (781,) and have a coil 200° that generates a magnetic field inside. Head part 2 with built-in 200
The developer Gl flowing on the surface of the head section 201
(The magnetic permeability changes depending on the mixing ratio of carrier at (ct), which is a magnetic material in G, and toner TI (T2), which is a non-magnetic material.) Change in magnetic permeability → f of the magnetic field created by the coil → coil inductance is converted into a change in developer Gl (G2
) The density of toner T+ (Tz) inside is detected.

Then, once the toner 'r + ('rt) is applied to the conventional probe.
Compared to the method in which the toner concentration in the developer Gl + (G2) is detected by attaching Gl + (G2) and irradiating it with light, this method does not require a separate drive mechanism and is not affected by changes in the environment. The developer density is always kept constant and stable images can be obtained.

On the other hand, as shown in FIGS. 20 and 21, the developer concentration detector 44 on the second developing device 16b side is in a state in which it is close to the developer stirring body 1802 and the detection surface 201 & of the head portion 201 is vertical. The developer agitating body 180. The gap H between the outer periphery locus and the detection surface 201a is set to 0.2 - 1.0 mm to ensure stable detection operation. When the developer stirring body 180 degrees rotates, the rotated developer G receives an outward force, so that the developer G is always pressed against the detection surface 201a. At this time, if the gap H is large, the developer G will solidify there, making it impossible to detect an appropriate toner concentration.

Therefore, by making this gap H smaller, the developer G that can be pressed
If the layer thickness t is made thinner, the developer G2 will flow without solidifying. Through experiments, the gap H was set to 0, 1 to 1++w. Based on the detection result of the developer concentration detector 44, the toner T within 4173 degrees is transferred to the toner replenishing roller 192. By rotating the developer agitator 1
Replenish 80 on top.

Next, with reference to FIGS. 22 to 24, set the paper feed cassette 4.
The configuration of the paper feed table 10 which also serves as the cutting case 209 of the paper feed cassette 4 will be explained.

As shown in FIGS. 22 and 23, the paper feed cassette 4 includes a cassette main body 210 that collectively accommodates a large number of sheets of paper p, . . . in a stacked state;
side guide plates 211 that guide both side end surfaces of the paper P inside;
211 and the rear guide plate 212 that supports the rear end of the paper P.
and separation claws 215-., which are constantly urged upward by the push-up sugerings 213, 213, 214, and which are integrally molded with the side guide plates 211, 211 at both corners of the top sheet P in the direction of taking out. 215tlC, and a support plate 216 that supports the paper P1 so as to come into contact with it.

Further, the side guide plates 211, 211 are screwed to the bottom surface of the cassette body 210 via a plurality of set screws, and the distance between them can be selected to be an appropriate distance according to the purpose of use. For example, Lee is large size, A4
The size can be set as appropriate, or B, A, size, etc.

Further, the cassette cover 209 on which the paper feed table 10 is formed has a structure as shown in FIG. 24. That is, the rear end of the cassette cover 209 has a connecting part 217 that connects to the rear end of the paper feed cassette 4, and is configured to be rotatable so that the top opening of the paper feed cassette 4 can be opened and closed. There is.

(See FIG. 22) In addition, a transparent plate 21 is provided at the center of the upper surface of the cassette cover 209 so that the presence of paper P in the paper feed cassette 4 can be confirmed.
A window 219 is formed that is closed at
It is 0. A plurality of guide ribs 22 are provided on the paper feeding guide surface 220 in a protruding manner along the paper feeding direction.
The paper P is fed smoothly.

Furthermore, side guide plates 12, 12 are disposed at the center of the upper surface of the cassette cover 209 as width determining means for guiding both side end surfaces of the sheets P2 that are manually fed all at once. These side J-id plates 12, 12 are held by a holding mechanism (not shown), and are configured such that simply by positioning one, the other is automatically positioned. Further, a guide lip 222 is provided to protrude between these side guide plates 12, 12 along the paper feeding direction.

In addition, an auxiliary paper feed tray 223 is pivotally attached to the pivot end side of the cassette cover 209 so that it can be stacked on the upper surface of the cassette cover 209. As shown by the two-dot chain line in FIG. 24, it can be opened approximately 180 degrees for use.

Further, on both sides of the free end side of the cassette cover 209 used as the paper feed table 10, there are elastic thin plate members extending to the upper surface side of the separating claws 215 and 215, as shown in FIGS. 23 and 24. A first buoy member 225 consisting of
225 is provided.

The first guide members 225, 225 are the separating claws 215,
215 is legal size, A4 size, B5. A.? Even when placed in various positions such as the
In addition, slits 226 and 226 are formed along the paper feeding direction so that paper P! Paper P taken out from paper cassette 4 regardless of the size of
, the pressing force can be kept constant.

Therefore, the guide member 2 covering the separation claws 215, 215
Since the paper P passes over the separation claws 25 and 225, the leading edge of the paper P1 does not get caught in the separation claws 215 and 215 and squeaks. It is possible to prevent splashing when pulling out from 215, 215, and to further improve the effect of preventing overlapping.

Further, the first guide member 225. Between 225 and 225 is a brake plate 227 provided on the support grate 216.
, 227, the second guide member 22 extends to cover the top.
Fl, 22B are provided, and even in the state 5 when all the paper P is empty in the paper feed cassette 4, the paper P2 passing over this contacts the brake plates 227, 227,
The transfer operation is not obstructed.

The first guide members 225, 225 and the second guide members 226, 226 are integrally formed from a single piece of elastic thin plate member such as mylar (trade name), which is semi-transparent in yellow color, and are made of a double-sided adhesive plate. via cassette cover 2
It is adhesively fixed to the back surface of the free end side of 09.

Also, 1st. Since the second guide members 225 and 226 are colored, they can alert the operator and prevent bending.

In addition, as shown in FIG. 23, the paper feed cassette 4 is
When the paper feed gusset 4 is attached to
A paper feed guide surface 220 formed on the top surface of the tip of the cassette cover 209 faces the automatic paper feed device 11 as well as facing the paper feed rollers 7.7 (only one is shown) of the paper feed section 6. .

Further, the paper feed roller 7.7 is formed into a half-moon shape, and when the paper is not fed from the paper feed cassette 4, its flat surface portions 7h, 7* are in a state along the paper feeding direction. It also serves as a guide member that guides the upper surface side of the fed paper P2.

Furthermore, the portion of the paper feed table 10 formed by the cassette cover 209 where the paper width adjustment guides 12, 12 are disposed protrudes outward from the automatic paper feed device 11 as well.

Next, the automatic paper feeder 11 will be described with reference to FIG. 23 and FIGS. 25 to 34. 23 and 25 show the automatic paper feeder 1 installed in correspondence with the paper feeder 6 of the main body I, and this automatic paper feeder II has a housing as shown in FIGS. 25 and 26. Mounting plate portion 23 of body 230
0h.

Daruma hole 23 formed at 230h (only one shown)
1. Mounting screw 232.23 screwed 231 onto main body 1
After the housing 230 is once hooked to the main body 1, the housing 230 is fixed to the main body 1 by screwing in the mounting screws 232 and 232.

Further, the lower part of the housing 23θ is a cassette insertion part 233, and the upper part of the housing 230 is a paper supply means 23.
4 is now accommodated.

This paper supply means 234 supplies the paper P on the paper feed table 1θ as shown in FIGS. 23 and 25.

A take-out roller 235 that feeds the paper P2, a feed roller 236 that feeds the most end (uppermost) sheet P2 fed by the take-out roller 235, and a 2 paper provided opposite the feed roller 236. a reversing row 2237 that returns the paper P after the first sheet;
A relay roller 238 which is located on the traveling direction side of the feeding roller 236 and receives and conveys the paper P fed by the feeding roller 236, and a relay roller 238 near the take-out row 2235. , and the presence of paper P (paper P is placed on the paper feed tray 10).

paper detection means 2 for detecting whether paper is set or not.
39. Furthermore, this paper feeding means 234 rotates the take-out roller 235 in the feeding direction in accordance with the rotation of the drive gear 69 on the main body 1 side, and also causes the feeding roller 236 to feed. direction, and also the reversing roller 237
By making it possible to rotate the paper P in the direction to return the paper P, and driving the relay roller 238 in the feeding direction, one paper P2
The configuration includes a driving force transmission control means 240 that feeds the driving force.

Note that the sheets P fed one by one by this sheet feeding means 234 are transported through a transport path 243 formed by upper and lower f-id members 241 and 242, and the aforementioned cassect cover 209.
The paper is guided to the pair of aligning rollers 8 through the paper feed guide surface 2201 and the lower surface side of the paper feed roller 7 , and thereafter, by the rotation of the pair of aligning rollers 8 , it is sent to the image transfer section 2 . Next, the driving force transmission control means 2
40 will be described in detail with reference to FIGS. 27 and 28.

That is, a gear 250 is integrally attached to the driven force transmission gear 68 that meshes with the drive gear 69 on the main body 1 side, and the driving force of this gear 250 is transmitted to the gear 252 via the chain 25. The configuration is as follows.

Further, the driving force of the gear 252 is 0N of the solenoid 253.
-The driving force is inherited by the OFF operation.

The feed roller 236 is attached to the feed roller shaft 255 so that it is transmitted to the feed roller shaft 255 via a spring clutch 254 of 11Fr.

Further, a gear 256 is attached to the feed roller shaft 255, and interlocks with a gear 259 attached to the relay roller shaft 258 via an intermediate gear 257. At the same time as the relay roller 238 is driven, the relay roller 238 is also driven in the same direction. Gears 260 m are provided on both outer sides of the mounting portion of the relay roller 238 and 238 of the relay roller shaft 258.

260b is attached, and these gears 260*.

260b is adapted to interlock with gears 263h and 263b attached to the separation roller shaft 262 via intermediate gears 261m and 261b. In addition, the separation roller shaft 262
A reversing roller 237 is attached via a limited power transmission means 263 consisting of a spring clutch to be described later. Then, the reversing roller shaft 262 to which the reversing roller 237 is attached rotates the reversing roller 237 to the paper P! The reversing roller 26
2 is the paper P' when there is no paper P2 or when one paper P is taken out due to the frictional force between the feeding roller 236, paper P, etc. and the limited power of the limited power transmission means. In addition, when a plurality of sheets of paper P are fed, the rotation is such that the second and subsequent sheets of paper P are returned.

Further, the take-out rollers 235, 235 are connected to the feed roller shaft 25.
The arm 264 is attached to a rotating shaft 265 that is rotatably held at the free end of a pair of arms 264 with the rotation center at 5.

Rotating shaft 265 to which takeout rollers 235, 235 are attached
Gears 266IL and 266b are attached to both ends of the gear 26, which is attached to the feed roller shaft 255.
7*, 267b and chain 268th.

They are linked via H.268b.

Also, an arm 264.2 supporting the take-out roller shaft 265
A support protrusion 264h is provided on the pivot end side of 64.

264a are provided protrudingly, and these support protrusions 264&.

264a is a locking claw 269°2 that rotates as required.
69 is in a locked state.

The locking pawls 269, 269 are fixedly attached to a locking pawl shaft 271 rotatably supported by bearings 270°270. A lever 273 is attached to the locking pawl shaft 271 by a suge ring 272, and is always biased in a predetermined direction, that is, in a direction in which the locking pawls 269, 269 push down the support protrusions 264g, 264* of the arms 264° 264. ing. Further, a gland 274a of a solenoid 274 is connected to the lever 273 via a link 275, so that the lever 273 can be rotated against the biasing force of the spring 272 as required.

Therefore, the take-out rollers 235, 235 normally
, and when the solenoid 274 is turned on by a paper feed start command, the locking pawl 269 . 2
69 rotates upward to support protrusions 264&, 264
By releasing the lock of h, the take-out rollers 235, 2
The arms 264, 264 rotate downward under their own weight, and the take-out rollers 2.15, 235 are brought into pressure contact with the top of the paper P.

Further, the separating roller 237 is configured to be able to approach and separate from the feeding roller 236 via a roller release means 287, so that the paper P reaches the pair of aligning rollers 8 in the main body 1 and is automatically fed. The drive of the paper device 11 is turned off, and the paper P is placed on the main body 1 side.

When conveying K, the separation roller 237 serving as a load separates from the feeding roller 236, and the relay row 2238 is weakly attached to the leaf spring 276 formed integrally with the tip (left end) of the lower guide member 242. It is configured to be displaced in the direction of contact. Further, it is designed to eliminate pressurizing load on the paper P and to eliminate transfer blur and the like. Note that the feeding roller 23
6 is a feed roller shaft 2 via a one-sided clutch (not shown).
55 and rotates at a medium speed.

That is, as shown in FIGS. 29 and 30, the separation roller shaft 262 and the relay roller shaft 258 are in a state in which they are horizontally supported for rotation via a pair of swing levers 281 having a support shaft 280. ing. In addition, these swings Δ-21
A spring 282 is connected to each of 11 and 2F11, and is always rotated counterclockwise around the support shaft 280, that is, in the direction in which the separation roller 237 is pressed against the feeding roller 236, and the relay roller 238 is pressed against the leaf spring 276. It is in an energized state.

On the other hand, a substantially T-shaped cam 283 that is rotatable around the feed roller shaft 255 is attached.
The spring 284 is connected to one horizontal end of the cam 283, and the plunger 286a of the solenoid 286 is connected to the other horizontal end of the cam 283 via a link 285. Roller shaft 262
It is in a state opposite to one swing lever 281 which is pivotally supported.

As shown in FIG. 29, when the solenoid 286 is turned off, the cam 283 is biased clockwise by the sliding ring 284, and the swing lever 28 is rotated clockwise against the biasing force of the spring 282. It is in a state of letting go.

Then, the separating roller 237 is separated from the feeding roller 236 by Hl.
The relay roller 238
is in weak contact with the leaf spring 276.

Further, as shown in FIG. 30, when the solenoid 286 is turned on, the cam 283 is rotated counterclockwise against the biasing force of the sedge ring 284, and the cam 283 is rotated against the swing lever 284.
81. And cam 28
3 is rotated counterclockwise by the urging force of the spring 282, and the separation roller 237 is brought into contact with the feeding roller 236, and the relay roller 238 is brought into contact with the leaf spring 276 with a predetermined pressure.

Further, as described above, the separation roller shaft 26 is equipped with the separation roller 237 that can freely approach and separate from the feeding roller 236.
2 and the paper P on the paper feed tray 10! A take-out roller shaft 26 is attached with a take-out roller 235° 235 that can freely move toward and away from the take-out roller shaft 26.
Since the driving force is transmitted from both ends of the roller 5, it is possible to reliably convey thick paper, which cannot be provided with a stable conveying force because the rollers vibrate up and down when driven on one side.

Also, the driving force of the separation roller shaft 262 is transferred to the separation roller 237.
The limited power transmission means 263 that transmits the power to the
The configuration is as shown in FIG. 33.

That is, the first aperture 290 is attached to the separation roller shaft 262.
．． Second Arpa 291. A screw 292 into which the separation roller 237 is fitted. are fitted in sequence, and the first aperture 290 is fixed to the separation roller shaft 262 via a pin 293. In addition, the second Arpa 291 and Guess 292
They are coupled to each other so that they rotate together.

Furthermore, the first. A coil spring 294 is fitted onto the second apertures 290 and 291, and a coil spring 294 is fitted onto the second apertures 290 and 291.
The driving force of 90 is transmitted to the second arbor 291 via the coil curdle 294.

Therefore, an external force of more than a predetermined torque is applied to the separation row 2237.
In other words, if there is no paper P and it is in direct contact with the feed roller 236, or if one paper P is in direct contact with the separation roller 23
7 and the feeding roller 236,
The driving force of the separation roller shaft 262 is not transmitted and the separation roller 2
237 rotates moderately in the direction of arrow A in FIG. It is designed to rotate in the direction of returning.

Furthermore, as shown in FIGS. 31 and 32, the guide 292 has three parts that completely cover the outside of the coil guide ring 294. 292a is integrally molded, which protects the coil spring 294k from external dust, paper powder, etc., and also prevents the oil applied to the surface of the coil spring 294 from scattering around, stabilizing the idling torque and protecting the paper. P
K is designed to prevent oil stains.

Next, the separation and feeding operation of the paper P will be explained with reference to FIGS. 23 and 34 (Todoroki) to (d).

First, as shown in (a), when paper P, ... is set on the empty paper feed tray 10, the detection lever 239a of the paper detection means 239 is rotated and displaced as shown in (b). , the paper feed mode display section 115 provided on the operation section 100 lights up.Next, after setting the number of sheets from the operation section 100, when the copy key 101 is pressed, as shown in (C),
450 m5ec after the copy key 101 is pressed, the take-out row 2235 descends, and the i! 430 m5e
cStand still.

Then, as shown in (d), the separating roller 237 contacts the feeding roller 236, and the relay roller 238 contacts the leaf spring 276.
, the spring clutch 254 is connected, and the take-out roller 235°, the feeding roller 236. And the reversing roller 237 rotates. At this time, the reversing roller 23
7 is in direct contact with the feed roller 236, so paper P
.

It is rotating in the direction that sends out.

Then, the uppermost sheet Pt is sent by the take-out roller 235 between the feeding roller 236 and the reversing roller 237.

At this time, if two or more sheets of paper P are interposed between the feeding roller 2236 and the reversing roller 2237, the rotation direction of the reversing roller 237 changes, and the second and subsequent sheets of paper P,
is returned by a reversing roller 237 rotating in the opposite direction.

Next, the sheet P taken out as a single sheet by the feeding roller 236 and the separating roller 237 is transferred by the relay roller 238 and the leaf spring 276, and is transferred to the sheet feeding guide surface 220 of the cassette cover 209. and 1st. Second guide member 225,2
28 and is sent to the aligning roller pair 8 side.

210 m5ea after the paper P turns on the detector 9 provided at the front stage of the pair of aligning rollers 8, the spring clutch 254 is disconnected and the take-out roller 235. The feeding roller 2361, the separation row 2237°, and the relay roller 238 stop. Note that if the detector 9VC is not reached within 2730 m1lee after each of the rollers 235 to 238 starts rotating, a jam occurs.

At this time, the separation row 2237 is lowered, and the feeding row 223
A gap H1 is formed between the relay roller 2 and the relay roller 2.
38 is displaced upward and comes into weak contact with the leaf spring 276. This completes the feeding operation for one sheet of paper P.

On the other hand, 1180 msec after the detector 9 detects the leading edge of the paper P, the aligning rollers 8m and 8b
begins to rotate, and the paper P is fed into the image transfer section 21.

Note that the relay row 2238 is fitted with a one-sided clutch so that it rotates idly as the sheet P is transferred. If the number of copies is set to multiple copies, after a predetermined period of time has elapsed, a command to start feeding the paper is sent to the take-out row 223.
5 descends and repeats the same operation as above. In this way, automatic paper feeding by the automatic paper feeding device II is performed.

Furthermore, the casing 230 of the automatic paper feeder 11 is connected to the copying machine main body 1.
A gap 300 is formed between the front end of the top plate portion 230a and the main body 1 so as not to interfere with the opening/closing operation of the upper unit 51, but this gap 300 is formed as shown in FIG. The upper unit 51 is closed by the sliding force 301, and when the upper unit 51 is opened, the hand is held in place.
It is designed to prevent pins, chestnuts, etc. from falling into it.

The cover 301 includes the guide pace 302a of the support frame 302 of the automatic paper feeder 1 and the top plate portion 2 of the housing 230.
30a.

A guide base 302 is connected to the lower two surfaces of this cover 301 through a slit 304 formed in a void space 302a.
A support protrusion 3θ3 protruding from the lower surface side of a is formed, and the support protrusion 301a and the support frame 302
A spring 304 is connected between a spring 304 and a support shaft 303 that is suspended horizontally.
In the state shown in FIG. 5, it is biased to the left and is in pressure contact with the side surface of the main body 1. When the upper unit 51 is opened and the side plate portion of the main body 1 is in the state shown by the two-dot chain line, the cover 301 resists the biasing force of the spring 304.
It will move to the right in the figure.

〔Effect of the invention〕

As explained above, the present invention has a paper feed section that supplies paper stored in a paper feed cassette equipped with a separation claw,
An image forming apparatus main body that forms an image on paper fed by the paper feed unit, and a plurality of sheets of paper attached to the image forming apparatus main body that sequentially feed the paper one by one set on a paper feed table. and an automatic paper feeder for feeding the paper to the automatic paper feeder, and the paper is separated and fed by the automatic paper feeder using a cassette cover that covers the top surface of the paper feed cassette leaving an opening for taking out the paper as a paper feed guide surface. The image forming apparatus is configured to guide paper, and the cassette cover is provided with a guide member that extends to cover the separation claw of the paper feed cassette, and the guide member separates and feeds the paper by the automatic paper feeder. The paper feed cassette is configured to guide the paper taken out from the paper feed cassette and to press the paper taken out from the paper cassette with an appropriate pressing force to prevent it from inadvertently bulging out. Therefore, although the configuration is extremely simple, the paper being guided on the cassette cover can be smoothly guided without being caught by the separating claw, and image formation can be made that can prevent multiple ejections when feeding paper from the paper feed cassette. This has the effect of being able to provide a device.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an external perspective view of an image forming apparatus, FIG. 2 is a schematic longitudinal sectional front view, and FIG.
Figure 3 is a diagram of the internal mechanism seen from the rear side, Figure 4 is a diagram showing the upper unit in the same open state, Figure 5 is an explanatory diagram schematically showing the driving force transmission system, and Figure 6 is the original document. A schematic side view showing the drive system of the stand, Fig. 7 is a plan view of the operation/quantization channel, Fig. 8
Figures 1 to 16 show the exposure optical system. Figure 8 is a vertical side view, Figure 9 is a plan view, Figure 10 is a front view of the lens unit, and Figure 11 shows the rotation of the drive shaft. FIG. 12 is an explanatory diagram showing the relationship between the cam assembly and the link assembly; FIG.
The figure is an explanatory diagram showing the relationship between the link assembly and the bracket notebook,
Figure 14 is a diagram to explain the relationship between the amount of lens movement and the amount of change in magnification, Figure 15 is a diagram showing the direction of the component force of the load associated with tilting the optical unit, and Figure 16 is the tilt of the optical unit. Explanatory diagrams showing the holding state of the lens unit during installation, Figures 17 to 21 show the developing device;
18 are longitudinal sectional front views showing different operating states, FIG. 19 is a perspective view of the developer concentration detector, and FIG. 20 is a perspective view of the developer concentration detector.
The figure is a side view showing the mounting state of the developer concentration detector.
The figure is also a plan view, Figures 22 to 24 show the paper feed cassette section, Figure 22 is a perspective view with the cassette cover that also serves as a paper feed table opened, and Figure 23 is a paper feeder of the main body. Fig. 24 is a perspective view showing the cassette paddle which also serves as a paper feed tray, Figs. 25 to 35 show the automatic paper feed device, and Fig. 25 shows the automatic paper feed device. Fig. 26 is a front view showing the mounting part; Fig. 27 is an explanatory diagram schematically showing the configuration of the internal mechanism; Fig. 28 is an exploded perspective view of the main parts. Figures 29 and 30
31 is a partially cutaway front view of the limiting power transmission means, FIG. 32 is a side view, FIG. 33 is an exploded perspective view, and FIG.
Figures (,) to (d) are explanatory diagrams showing the paper feeding state;
FIG. 5 is a schematic longitudinal sectional side view showing the state in which the cover is attached. 1... Image forming apparatus main body, 4... Paper feed cassette, 6
...Paper feed unit, 10...Paper feed stand, 11...Automatic paper feeder, 209...Cassette cup #-1215...Separation claw, 225...Guide member, 226--Slit ,
PI +P, ...paper. Applicant's agent Patent attorney Takehiko Suzue 115 Figure 7 Figure 6 Figure 12 Figure 13 Figure 14 Figure 34 Figure 34 Figure 220238276209237242239a P
2Figure 35

Claims (3)

[Claims] (1) An image forming apparatus main body, which has a paper feed section that supplies paper stored in a paper feed cassette equipped with a separation claw, and forms an image on the paper fed by the paper feed section; an automatic paper feeder that is attached to the forming apparatus main body and sequentially feeds a plurality of sheets of paper set on a paper feed tray to the paper feed section one by one; In an image forming apparatus in which a cassette cover covering an opening is used as a paper feeding guide surface to guide sheets separated and fed by the automatic paper feeding device, a separating claw of a paper feeding cassette is attached to the cassette cover. An image forming apparatus comprising a guide member that extends to cover the image forming apparatus. (2) The image forming apparatus according to claim 1, wherein the guide member is made of an elastic thin plate member. (3) The image forming apparatus according to claim 2, wherein a slit is formed in the elastic thin plate member along the paper feeding direction.