JPS61130939A - Exposing optical device - Google Patents

Abstract

PURPOSE:To decrease an error against a designated magnification, and to set easily and exactly an optional variable power rate by setting a lead of the screw part of a driving shaft so that the number of steps of a stepping motor corresponding to the minimum unit of a variable power quantity goes to an integer value. CONSTITUTION:A lens unit 144 which incorporates a lens 31 moves linearly by a rotation of the shaft 137 driven by a stepping motor, through a guide 162 engaged to a screw part 137a of the driving shaft 137 and changes a copying magnification. In such a case, the minimum unit of a variable power quantity is set as X%, and a lead of the screw part 137a is set so that the number of steps of the stepping motor corresponding to X% becomes an integer value. Accordingly, the designated magnification is obtained by a rotation of integer times of the motor, an error against the magnification is decreased, and the control is also executed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an exposure optical device applied to an image forming apparatus such as a copying machine.

[Technical background of the invention and its problems]

In recent years, zoom-type 1ii1# forming apparatuses have been developed in electronic copying machines and the like, in which the copying magnification can be arbitrarily set within a certain range.

This is done by the operator pressing the zoom key while looking at the magnification display on the operation panel, and by moving the lens unit containing the lens that focuses the original image onto the exposed area to a predetermined position. The copy magnification can be set arbitrarily.

Also, an example of how to move this lens unit! :
Conventionally, a stepping motor drives a drive shaft, and furthermore, the rotation of this drive shaft is converted into linear movement of a guide that engages with this threaded part, and a lens unit that is integrated with this guide is moved. There is something I did. This method provides a movement amount that corresponds to the number of steps of the threading motor, and is expected to be highly accurate.However, in the past, no consideration was given to the lead (pitch) of the threaded portion of the drive shaft. First, there is a problem that the error with respect to the specified magnification may become large, and control to correct this is extremely difficult.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its object is to provide a lens unit incorporating a lens that directs an original image to an exposed area, and a stepping seven.
A feed screw mechanism having a drive shaft that is driven in the evening and a guide that engages with a threaded portion of the drive shaft, converting the rotation of the drive shaft into Km movement of the lens unit via the guide, In the exposure optical device, the lens unit can be moved in accordance with the number of steps of the step motor to increase the copying magnification. It is an object of the present invention to provide an exposure optical device that allows easy and convenient settings.

[Summary of the invention]

In order to achieve such an object, the present invention provides the lead of the threaded portion of the drive shaft, when the minimum unit of magnification change is X%,
The number of steps of the step motor corresponding to X% is set to be an integer value.

[Embodiments of the invention]

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

(2) 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 9, and a KFi document cover 3 is provided on the document table 2 so as to be freely openable and closable.

Further, a paper feed cassette 4 is attached to the right side of the main body 1, and a paper discharge tray 5 is attached to the left side.

The paper feed cassette 4Fi is detachably attached to the paper feed section 6 provided on the lower right side of the main body 1. In the paper feed section 6, 7 receives paper P1 from the paper feed cassette 4 yen.
A paper feed roller 8 that peeks out one by one is a pair of aligning rollers that conveys the paper fed from the paper feed roller 7 (or the automatic paper feeder 1, which will be described later). A detector 9 consisting of a detection lever 9a for detecting paper and a microphone switch 9b is provided.

In addition, the cassette cover (top surface) of the paper feed cassette 4 serves as a paper feed table 10 for manually feeding paper (possible when an automatic paper feeder 1 to be described later is not installed) or automatically feeding paper as appropriate. , when an automatic paper feeder 1 is provided on this paper feeder 10, this automatic paper feeder @1)
There is a paper width adjustment guide 12 on the paper feed tray 10 on the paper insertion side.
is provided.

The above-mentioned automatic paper feeder 1) continuously feeds sheets of paper P set on the paper feed tray lo one sheet at a time to the paper feeder 6, and is detachable from the right side of the main body 1. I'll explain the details later.

Further, a photosensitive drum 13 is disposed approximately in the center of the main body 1. The photosensitive drum 13 is surrounded by an exposure optical system 14, a charging charger 15, a two-color color developing device 16, a transfer band IE device 17, a stripping charger 18, a cleaning device 19, and a static elimination lamp. 20 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 16a1 and the second developing device 16b are operated by a reciprocal motor (not shown) that rotates forward or reverse.
Therefore, only one of them can be selectively driven, and it is now possible to selectively display black or one other color, such as red, yellow, blue, or green. There is.

Further, each of the first 'fA imager 16h% and second developer 16b is equipped with a solenoid (hereinafter referred to as a developer solenoid) for controlling whether or not to enable development.
When this developer solenoid is turned on, the device is in a developing state (line brush forming state).

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 via the image transfer section 21 between the photosensitive drum 13 and the transfer charger 17. The image transfer section 2 of this paper conveyance path 22
The aligning roller pair 8 is disposed on the upstream side of KFi 1, and a fixing device 23 and a paper ejection roller pair 24 are disposed on the downstream side.

Here, the exposure optical system 14 has a reflector 25 at its back.
) Surrounded exposure lamp 26, mirrors 27 to 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, the document is uniformly charged by the charger 15 and uniformly irradiated with light by the exposure lamp 26, and an image is formed on the photoreceptor drum 13 by the optical optical system 14. to form an electrostatic latent image. The formed electrostatic latent image 4 is developed by a developing device and turned into a developer, which is sent to the transfer/transfer charger 17 side.

On the other hand, the paper P1 or P2 fed from the paper feed cassette 4 or the automatic paper feeder 1 is fed to the aligning roller pair 8, and the current dosing agent formed on the photoreceptor drum 13 is used for transfer. The image is transferred to the charger 12. The paper PI (PI) on which this developer image has been transferred is peeled off from the photosensitive drum 13 by a peeling charger 18, passed through a paper conveyance path 22, and guided to a fixing device 23, where it is transferred. After the paper is fused and fixed, it is ejected to the paper ejection tray 5 by the paper ejection roller pair 24.

On the other hand, after transferring 3J 儂agentwei onto paper p, (Pt),
The residual toner remaining on the photosensitive drum 13 is removed by a cleaning device 19.
The remaining charge on the photoreceptor drum 13 is erased by the static elimination lamp 201), and it is set as a trap in preparation for the next copying operation. Tonne: 41 is the developer replenishment device for the first developing device, 42 Fi is the current developer replenishing device for the second developing device, 43.44 is the developer concentration detector, 45
46 is a static elimination brush, and 47 is an exhaust fan.

Next, the driving force transmission system will be explained with reference to FIGS. 3 to 6. FIG. 3 shows the internal mechanisms of the copying machine main body 1 and the automatic paper feeder 1 viewed from the back side, and FIG. 4 shows the upper unit 50 separated from the lower unit 5 to open the paper transport path 22. Indicates the state of In the figure, 53 is a driving gear directly connected to the main motor 48, and the driving force of this driving gear 53 is transmitted to the drum driving gear 5 through driven gears 54 to 56.
It is designed to transmit 7KIIK power.

Further, 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 the 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. The @ impact due to load fluctuations before and after the start of driving of the lining roller pair 8 is not directly transmitted to the drum drive teeth Hsy, and image blur due to the impact can be prevented.

Further, the paper feed roller drive gear 65 is always in mesh with a driving wheel 69 that meshes with the driven force transmission gear 68 of the automatic paper feeder 1, and the paper feed roller drive gear 65 is always in mesh with a drive wheel 69 that meshes with the driven force transmission gear 68 of the automatic paper feeder 1.
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 paper feeding speed, improve the paper separation mechanism, and achieve reductions in size, weight, and cost.

In addition, the driven force of the automatic paper feed bag fllll is transmitted to J[
68 and the copying machine itself! The meshing state with the side drive 1) iIijI 169 is released when the upper unit 51 is opened as shown in Fig. 4, and the power transmission system can be driven by manual operation of the automatic paper feeder 1), which prevents clogging. Processing, maintenance, inspection, etc. can be easily performed.

Further, reference numeral 7 shown in FIGS. 3, 4, and 6 is a scanning motor, and this scanning motor 7 is decelerated by a gear head and rotates a pulley 72. Here, as shown in FIG. 6, a wire 74 whose one end is fixed to the tip of the document table 2 and whose other end is supported by a spring (not shown) at the rear end of the document table 2 is connected to an idle pulley 75 and a spring. The wire 74 is wound around the pulley 72 via a tension pulley 77 which applies tension to the wire 74 by r6.

Therefore, as shown in FIG.
When rotated in the s direction (clockwise), the document table 2 moves forward in the a1 direction and is attached to the Ms table 2! When the magnet 78 is detected by the limit switch 79, the pulley 72 moves to C!
The document table 2 rotates in the z direction and moves back in the z direction.

1ft-1 scanning motor rlFi encoder disk 8
0 and the main motor 48 by the 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, according to the detection signal of the paper start switch 85,
operating a clutch mechanism (not shown) built into the paper feed roller l and one roller of the pair of aligning rollers 8;
K to feed and restart paper at the specified timing.
In addition, 86 shown in FIGS. 3 and 4 is a motor gear for the developing device, 87, 81) are driven gears, 139.90 is a driving gear for the developing device, 9 is a driving gear for the lower discharge roller, 92 is an upper heat roller layer wJ gear.

Further, 93 is a heater lamp, 94 in FIG. 6 is a document glass on which the document A is 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 51Vc, which can be rotated 0e, includes an optical system 14, a charging device 15, an exposure lamp 26, a developing device 16, a cleaning device fl19%, a static elimination lamp 20, etc. around the photoreceptor drum 13, and is modified by appropriate means. In addition, the document platen 2, the paper feed roller 7, the upper roller 8a of the aligning roller 8, and the upper row 223a of the heat roller 23 are attached.
% and an upper roller 24a of the paper discharge roller 24 are attached.

Lower unit 5oKFi, paper feed cassette 4, lower roller 8b1 of aligning roller 8, transfer charger 1),
Peeling charger 18, lower roller 23 of heat roller 23
b, lower roller 24b of paper ejection roller 24, paper ejection tray 5
, a main motor 48, etc. are attached by appropriate means.

After rotating the front cover of the main body 1 and removing it, the paper Pt is almost opened via a housing opening/closing support device (not shown).
(P*) is configured so that it can be opened and closed along the paper conveyance path 22 for conveying (P*). Furthermore, an operation panel 100 is provided at the upper end of the front side of the main body 1, as shown in FIG. ing.

FIG. 7 shows the operation 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, and a numeric keypad for setting the number of copies, etc. 103, color selection key 104 for selecting copy color (for example, black, red, blue, green), color display section 105 for displaying available colors for copying, automatic paper feeding by paper cassette 4 or automatic paper feeding device 1) A paper feed selection key 106 for selecting automatic paper feeding, 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 108d, the number display section 09 for displaying the number of copies, and the number of copies! ! A status display section 1)0 for displaying various operating states such as color display and toner supply, a warm-up display section 1)1, a ready display section 1)2, and a selected color provided corresponding to the color display section 105. Color instruction section 1)
3 Displays automatic paper feeding mode using paper cassette 4'
Cassette paper feeding mode display section 1) 4, Paibanu paper feeding mode display section 1) 5 that displays the automatic paper feeding mode using the automatic paper feeding device 1, Automatic exposure mode display section 1) 6, Settings for manual exposure mode It consists of an exposure amount display section 1)7.

Also, auto exposure key 1) to set auto exposure mode
, ljl Manual exposure key for manually setting the light intensity 1) 9, Magnification setting key 120 for selecting and setting a specific predetermined copying magnification, Zoom key 121 for setting an arbitrary copying magnification 1) Magnification for displaying the set magnification A display section 122 and the like are also provided.

Next, the exposure optical system 14 having a displacement function will be explained with reference to FIGS. 8 to 16.

The exposure optical system 14 is integrated into a unit except for an exposure lamp 26 whose back is surrounded by a beam 7 and a reflector 25, a first mirror 27, and a fourth mirror 30. Figures 8 and 9
In the figure, reference numerals 130 and 131 are a rear frame provided parallel to the base assembly 129, and 7 is a front frame! '
% 7 A guide plate 132 is provided on the rear frame 130 and protrudes toward the rear frame 130 . On this guide plate 132, the front side of the lens carriage 133 on which the lens 3 is mounted and the mirror 28 are attached.
．． The front side of the mirror carriage 134 on which the mirror 29 is mounted is slidably supported via guided members 135 and 136, respectively.

On the other hand, a drive shaft 131 is disposed near the inner side of the rear frame 131 and parallel thereto. Auxiliary frame 1 of this drive shaft 137F1 base assembly 129
31). The bearing x4o attached to the shaft 139 is rotatably supported by the zaIK, and the drive shaft 7
Slideable guide 142゜J externally marked on 137
42 and 143, the lens carriage 1
33 and the rear end of the mirror carriage 134 are attached.

As shown in FIG. 10, the lens carriage 133 on which the lens 3 is mounted, that is, the lens unit 144, is in a state where it can reciprocate in the direction of arrow A in FIG. 9 using the guide plate 132 and drive shaft I37 as guides. It is becoming.

Also, mirror 21). Similarly to the lens unit 144, the mirror carriage 134 on which the lens unit 29 is mounted, that is, the mirror unit 145, is also movable back and forth in the direction of arrow A in FIG. 1
Stepping motor 1 via 46,147.1413
K is set to be moved by 49.

On the other hand, a cam assembly 155 is fixed to the lens unit 144 by screws, and a link assembly 156 is rotatably supported by the base assembly 129. The roller 15 is attached to the L-shaped link 161 of the link assembly 156.
7, 15 & are looked into, the link assembly 156 is connected to the cam 1596 through the roller 151 through the arc-shaped hole 159 &
Also, the mirror unit 145 via the row 2158
It is connected to the elongated hole 160a of the bracket 160.

In addition, as shown in Figure 1), the cam 159 has a guide 1.
62 is rotatably installed, and the drive shaft 7) JJ
The feed screw mechanism 150 is engaged with the threaded portion 137a of the lens unit 144 to convert the rotation of the stepping motor 1490 into linear movement of the lens unit 144. When the drive shaft 137 is rotated, the lens unit 144 screwed to the cam assembly 155 moves in the direction of arrow A via the guide 162.

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).
This is done by changing the distance up to 3). That is, during maximum reduction copying, the lens 3 and the mirror 28, which is integrally connected with mirror 29, are at the solid line position in FIG. They are each displaced to the positions indicated by the two-dot chain lines.

The lens unit 144 is moved along the following path. That is, the driving force of the stepping motor 149 is
The lens unit is transmitted to the drive shaft 131 through the JiMs 148, 147, and 146 sequentially, moves the guide 162 as the drive shaft 1370 rotates, and is in an integral relationship with the cam assembly 155 provided with the guide 162. K is set to move 144. lens 3
The amount of movement of
decide. Note that the relationship between the lens movement amount and the motor rotation angle will be described later.

In addition, the mirror unit 145 is moved in the following path by the movement of the lens unit 144. That is, the circular movement of the cam 159 is caused by the movement of the cam assembly 155, which is in an integral relationship with the lens unit 144. arc-shaped hole 15
The roller 157 engaged with the L-shaped link 16 moves, thereby rotationally displacing the L-shaped link 161 of the υ link assembly 156, and the rows 158 scattered on the L-shaped link 16 also move. Displace. The mirror unit 145, which has a long hole 160a that engages with the roller 158 and is integrally connected to the nine bracket 161, is moved.

The amount of movement of the mirrors 28 and 29 is determined by the rotation angle of the L-shaped link 1610 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, and when the cam 159 moves a distance L in the direction of the arrow C, the L-shaped link 161 rotates by an angle α in the direction of the arrow C. . In addition, 165 is link 16
It is the rotation fulcrum of 1.

FIG. 13 also shows the link assembly 156 and the bracket 16.
0, and the L-shaped link 161 is α in the direction of arrow C.
When the bracket 160 is rotated in the direction of the arrow KS
The object will move by a distance of .

Note that the 166d optical sensor 167 shown in FIG. 9 is a light shielding plate, and constitutes a same-magnification detection means 16B that detects the magnification position of the lens unit 144. Also, 169...
. . are positioning pins provided on the pneumatic assembly 129, and the optical unit is positioned by fitting these pins 169 into holes formed in the frame of the main body 1. 170 is a document density detection sensor.

Furthermore, when changing the copying magnification by moving the lens 3 in this way, if the minimum unit of the magnification change amount is X%, the number of steps of the stepping motor 149 corresponding to X% becomes an integer value. The lead of the screw portion 137a of the drive shaft 137 is set as follows.

By setting the magnification in this manner, there is less error with respect to the specified magnification, and the control can be made easier. Note that the minimum unit of the amount of magnification of a normal zoom variable magnification copying machine is 1%. There is a magnification display section 122 on the operation panel 100, and the user presses the zoom key 121 while looking at it to set the desired magnification. Inside the copier, depending on the specified magnification,
The lens 3, mirror 28°29, etc. are moved. still,
These operations are controlled by a microcomputer.

Next, the relationship between the amount of lens movement and the change in magnification 1 will be explained with reference to FIG. In addition, in the figure, f: focal length of the lens.

M: My magnification F: Front focus F': Back focus A: Object distance B: Image distance. There is a relationship between the lens, the object, and me as shown in Figure 14. If the lens position is expressed by the distance B from my surface, then B=f4-fM... (1
) The amount of change Δ in B when changing the magnification from Ml to M
B is ΔB=(flM,)-(f+fM,)=f(M,-F/l,)...
... Since (1), the change t in B (that is, the amount of lens movement) and the amount of change in magnification are in a proportional relationship.

Further, the relationship between the amount of lens movement and the number of Tanabata steps is as follows. In other words, lens movement amount ΔB1 drive shaft screw part glue, dllL% motor rotation angle: α(
dog), the following equation holds true. (However, the gear ratio between the motor←→shaft is 1:1) The rotation angle α of the motor 149d nutepping motor used in this machine is given by the following formula.

α== r@N ………… ■However, r: rotation angle (deg) per step of the motor, N: number of steps input to the motor (2), and formula (5).

Therefore, the relationship between the amount of change in magnification and the number of steps is given by formula Ql) and formula (to), and since r and fFi are constants, change in magnification A'
m s −M * is determined by the number of steps NVC.

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

For example, if the setting is 1% → 7.3 steps, then 5% → 7.3 Well, for 0.5 nuts,
This appears as an error in magnification.

Therefore, it is necessary to limit the value of the coefficient of N (j - T) in formula (b).In this, γ is a value (integer) determined by the motor used, and f teeth,
This is the unique value of the lens used. On that point, L
Since Fi can be set freely, the easiest method is to satisfy the above conditions by selecting a value for L.

When changing the magnification in 1% increments, L is Mt- in equation (7).
It is obtained by setting M = 0.01.

For example, in the case of this machine, f=1)0 (Tml), r=7
, 5 (deg), N = 8, L = 6.6 (jEIl
).

In addition, in the case of a motor controlled by a microcomputer, it is more convenient to set the value of N to the condition that N=2 (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 held on the drive shaft 137 and the guide plate 132 of the base assembly 129 via the guides 142, 142, 143. It is limited to the direction A in Figure 15. For this reason, for example, a component force F of its own load W is always acting on the lens unit 144 in the direction E 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 may cause looseness and prevent the lens unit 744 from being in a stopped state. becomes unstable pressure.

However, in the case of this machine, the lens unit 144 is stabilized in the normal pressure state shown in FIG. 16 by the aforementioned force F, and the stopped state does not change due to play.

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

Note that when the moving direction is horizontal, the V-scum unit 144 and the mirror unit 145 are centered at ML, which is equilateral to the axis of the drive shaft 137, as shown in FIG. There is wobbling on both sides in the range of angles θ□ and θ, and the image becomes unstable.

Next, referring to FIGS. 17 to 21, the developing device 1
6 will be explained in detail. As shown in detail in FIG. 17, it has a first developing row 2171° and a 23rd Jll# roller 171, and these developing rollers 1), 171. is selectively driven to produce black (first color) or one other color (second color), such as red, yellow, blue, green, etc.

- K is set so that development can be performed. That is, the developing device igFi, the first developing roller 121. A first developing unit (first developing unit) J6a including a second developing roller 1) 1
It is divided into two parts: a second developing unit (second developing unit) 16b including a first developing unit 16b, and a second developing unit 16b including a first developing unit 16b; 2nd current mine 16 &, 1
6b are both detachable from the main body 'IK.

In this case, the first developing device 16IL 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 maintained and inspected by a service person. When carrying out such operations, the structure is such that it can be attached to and detached from the main body l. And the frequently used black toner T,
is used in the lower second printer 16b, and the color toner TI
is used in the first developing device 16IL in the upper stage.

It is composed of the first developing device 16hFi, a developing mechanism section 172□, and a toner replenishing section 173.

The developing mechanism section 172. Id, casing 18 to be described later
A developing roller 1721 that supplies toner T1 to the photoreceptor drum 13 through a 1 m opening 181a, and a developer magnetic brush 17 formed on the surface of the developing roller 17.
5. The sliding contact portion with the photosensitive drum 13, that is, the developing position 176, is also provided on the upstream side, that is, the second developing device 16b@, and the developer magnetic brush 175. A doctor (regulating member) 177X for regulating the thickness of the developing roller 171.X and a developing position 1761 are also provided downstream. The developer magnetic brush 1751 on the surface of the developer container 12 is used as a scraper.
Nuclepa 179m leading to 81 and developer storage section 178
．． The developer stirring body 180□ housed in the casing 1
It has a configuration in which it is housed within 8cm. Incidentally, at a position corresponding to the upper part of the developing row 217C of the casing 18C, a developer GK is formed by magnetically detecting a change in the magnetic permeability of the developer G (toner T1% and carrier at). A toner concentration detector 41 is attached to detect the concentration of toner T1 inside.

Further, the developing roller 171) includes the photosensitive drum 1) 30.
Angle α (approximately 51°) from the center of rotation to the horizontal #L
A straight line L drawn to a state where ! A magnetic roll (magnet) x8s is provided with its center located at the top, and a Nuleap (carrying body) 184 is fitted onto the magnetic roll 183 and rotates clockwise in the figure. It is composed of.

The magnetic roll 1831 has five magnetic pole parts 1851 to 18.
9, of which the magnetic pole part is.

1)17. , 189. FiN pole, magnetic pole part 1) 161
．． 1881 is Srt, and the magnetic pole part 1851 and 1
The angle θ1 between the magnetic pole portion 186.861 and the magnetic pole portion 186. The angle θ between and 1871 is approximately 71°, the angle θ between the magnetic pole part 187° and 1881 is approximately 60°, and the angle θ between the magnetic pole part 187° and 1881 is approximately 60°.
1 and 189. The angle θ4 between them is set to about 60'.

Further, the toner replenishing section 173j is connected to the toner replenishing port 19.
The hopper 191. A toner replenishment roller 192 is provided within the hopper 19 and closes the current agent replenishment port 1901. , and a hopper 191 to convey the toner T1 to the toner supply roller 192N side.
) two pairs of stirring rollers 1931 for stirring the toner in the
192. It has a configuration with.

Further, the second developer 16b is the @1 developer 16 described above.
It has almost the same basic configuration as a, and the toner supply section 17
3 goose hopper 191. shape and 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,
Other identical components are designated by symbols with the suffix character changed from "1" to "!", and detailed description thereof will be omitted. Note that the doctor 177 is the developing roller 17I.

Also, the developing roller 171 . magnetic roll 18
3. has four magnetic pole parts 185. ~188. , of which a magnetic pole portion 185. ．． 187. is the north magnetic pole part 186! ,
18B is the S pole, and the magnetic pole part 185! and 186
．． The angle θ, Fi approximately 90' between the magnetic pole portion 186. and 18
7. The angle θ6 between the magnetic pole portion 187. and 188. The angle between them is set to about 800, respectively. Finally, the magnetic roll 183 passes through the center of rotation of the photoreceptor drum 13 at an angle β (
The center is located above a straight line drawn to approximately IQ).

On the other hand, the magnetic rolls 1), 131.1g, 3, and h1 of the first developing device 16h and the second developing device 16b are configured to be able to be rotated at a rotation angle of about 35 degrees, respectively. Along with this rotational displacement movement, the current *--217
1,,172, and a developer magnetic brush 175. ．． 1
75. It is now possible to take a picture of the character that has been formed.

Then, 183. K is switched to a predetermined position by a magnetic roll drive means (not shown).
Developing rollers 171□, 171. of either the first developing device 16a or the second developing device 16b. Developer only on the surface of the magnetic brush 1) 5. ．． 175. is starting to form.

That is, when operating the first developing device 16h side,
As shown in FIG. 17, the magnetic roll 183m on the side of the first developing device 16a is moved to the developing position 1 by a magnetic pole portion (developing magnetic pole) 187.
76, that is, in a state in which the doctor 1) is located in the J portion of the opening 181, and in a state in which the doctor 1) 1) is located approximately midway between the magnetic pole parts 1851 and 1861,
Magnetic roll J83 on the second dispenser 16b side. The magnetic pole part (developing magnetic pole) 187. is the casing 181. from the opening 1)1)a2. The magnetic pole portion 185 located inside the doctor 177. K: K to face him.

The developer magnetic brush 1751 is formed only on the surface of the developing roller 171°0 on the side of the first developing device 16h.

9. When operating the second developing unit 16b@, the first
As shown in FIG. 8, the magnetic roll 18 on the first developing device 16a side
3, by rotating about 35 degrees clockwise from the position shown in Fig. F, so that the magnetic pole part 1851 faces the doctor 1771, and the magnetic pole part 181□ is located inside the opening 181al of the casing 18, and , magnetic roll 183 on the second developing device 16b side. The magnetic pole portion 187. is rotated approximately 35 degrees counterclockwise from the position shown in FIG. is the development position fl
zve*, that is, located at the opening 181a, and the magnetic pole portions 45 and 186. Dokuno 177 is located approximately in the middle of N). Then, the developer magnetic brush 125 is applied only to the surface of the developing row 2171 on the side of the second developer IJ device 16b. is starting to form.

In addition, magnetic roll 1) 13. , 183. magnetic pole part ll
l5. , 185. Doctor 177 made of non-magnetic material
1.777, the developing roller 171°, 17
1. Developer magnetic brush 175□ on the surface.

The reason why the magnetic pole portions 1851.175 and 1851.
185. Since the density of the magnetic brush is in a slender state, the force of adsorbing the developer G s = G t is weak, and therefore the doctor 177, . This is because simple JIK regulation can be carried out in 177, and this allows the system sleeve 184. .

Even if 184 rotates, the developer G,,G,
,,17!7. Avoid passing through the section.

Note that 195° shown in FIGS. 17 and 18 is the hopper 191 of the second developing device 16b! This is a toner remaining amount detection device that detects when the amount of toner T, within the container has become less than a predetermined value, and a detection lever 1 that rotates and displaces according to the amount of toner T,
Permanent magnet 19 attached to actuator 197 integrated with 96
8 is configured to operate multiple times by being close to a reed switch 199 as a detector provided outside the hopper 19. Further, although not shown, a remaining toner amount detecting device having a configuration similar to the above-mentioned remaining toner amount detecting device fl1952 is also provided for the hopper 191 of the first current device 16a.

Next, the developing operation of the developing device 16 will be explained. First, when the first magnetic roller 16a2 side is selected to operate using the color selection key, the magnetic rolls 1) 138, 183, . reaches the state shown in FIG. 17, and the sleeve 1841 of the first developing roller 17c rotates clockwise in the state shown in FIG. developer magnetic brush 1 on the surface of
75. form. Then, the electrostatic latent image previously formed on the photoreceptor drum 13 is transferred to a color developer G1.
I will write it down in writing. In this way, when the development of the electrostatic latent image is completed, the magnetic roll 1831 is rotated by about 25 degrees so that the magnetic pole part 185 degrees faces the doctor 177, and the 3JlS agent magnetic brush is applied onto the sleeve 1841. The new formation of 175I is stopped, and in this state, the sleeve 184 is further rotated a predetermined amount to remove the developer magnetic brush 175m. At this time, the developer magnetic brush 175 is also applied to the second developing roller 171. is not formed, so that even if either of the current payload units 16h or J6b 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 183. ．． 183° becomes the state shown in FIG. 18, and the second developing row 2171! sleeve 1
84 is rotated clockwise in the state shown in FIG. 18, and the sleeve 184. developer magnetic brush 175. form. Then, in the same manner as described above, the photoreceptor drum 1 is
After developing the electrostatic latent image on the sleeve 184° to black, the developer magnetic brush 175. The developing operation ends with the removed.

In addition, as shown in FIG. 19, developer concentration detectors 43.44#'j provided in each developer 16m and 16b indicate that the casing 1ex1<1)1)! ), and has a head section 201 with a built-in coil 200, 200 that generates a magnetic field inside, and carriers C, C, which are magnetic substances in the developer Gl (G, ), flowing on the surface of the head section 201.
The magnetic permeability that changes depending on the mixing ratio of toner TI (Ct) and non-magnetic toner TI (T) is converted into a change in magnetic permeability → a change in the magnetic field created by the coil → a change in the inductance of the coil.
It is designed to detect the density of the toner T1 (T1) in the developer G1 (G1).

Then, -H toner T1 (T!) is attached to a conventional probe, which is irradiated with light, and the toner concentration in developer a,... (Gt) is detected by the reflected light. In comparison, it does not require a separate drive mechanism, is unaffected by changes in the environment, keeps the developer concentration constant, and can obtain stable images.

On the other hand, as shown in FIGS. 20 and 21, the developer concentration detector 44 on the second developer unit 16b side detects one developer agitator J80! The developer agitator 180. The gap H between the outer circumference locus and the detection surface 201a is set to 0.271) to 1u to ensure stable detection operation. Developer agitator 18
When 0 rotates, the rotated developer G receives an outward force, so the developer G is always on the detection surface 201a.
be forced to. 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, if this gap I is made smaller and the layer thickness of the developer G that is pressed is made thinner, the developer G and Fi will flow without hardening.
．． 2 to III. Note that depending on the detection result of the developer concentration detector 44, the hopper 173. (By rotating the toner sleeve supply roller 192, the toner T in the developer stirring body 180! Replenish on top.

Next is 1e! The configuration of the paper feed cassette 4 and the paper feed tray 10 which also serves as a cover 7209 of the paper feed cassette 4 will be described with reference to FIGS. 22 to 24.

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 P1 in a stacked state, and both side end surfaces of the paper P in this cassette main body 210. Side guide plate 21), 2
1), a rear guide plate 212 that supports the rear end of the paper P1, and push-up springs 213, 213. The paper P1 is constantly urged upward by the zz4, and the paper P1 is pushed so that both corners of the uppermost paper P1 in the take-out direction come into contact with the separation claws 215, 215VC integrally formed on the side guide plates 21), 21). The structure includes a support plate 216 for supporting the support plate 216.

(9) The side guide plates 21), 21) 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. It looks like this. For example, legal size, A
4 sizes or Bs-As sizes, etc., as appropriate.

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 portion 219 closed at 8 is formed, and the upper surface of the free end side of the cassette cover 209 is formed with a sheet feeding guide surface 22.
It is 0. A plurality of guide lips 221 are protruded from the paper feeding guide surface 220 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 sheets P, . . . that are manually fed in bulk. . These side guide plates 12, 12 are held by a holding device (not shown), and by simply positioning one of them, the other is automatically positioned. A guide lip 222 is provided between these side guide plates 12, 12 to protrude along the paper feeding direction.

Further, an auxiliary paper feed tray 223 is pivotally attached to the pivot end side of the cassette cover 209 in such a manner that it can fit onto the upper surface of the cassette cover 209. When necessary, such as when setting the camera, it can be opened approximately 180 degrees as shown by the two-dot lead line in Figure 24.

Furthermore, on both sides of the free end side of the cassette cover 209, which is used as the paper feed tray 10, as shown in FIGS. A first guide member 225 consisting of
225 is provided. The first guide members 225, 225 are provided with separation claws 215.
215 gal size, A4 size% B 5, A
s size, etc. 1) Even when the paper is in the tK position, the top surface can be covered, and slits 226 and 226 are formed along the paper feeding direction, so that the paper can be fed regardless of the size of the paper P or V. The paper P2 taken out from the cassette 4 is pressed with a constant force.

Therefore, the guide part paulownia 2 covers the separation claws 215, 215.
Since paper P passes over 25,225, paper P! This prevents the leading edge of the paper P1 from getting caught in the separation claws 215, 215 and causing a jam, and also prevents the paper P1 from flying up when it is pulled out from the separation claws 215, 215 when taking out the paper from the paper feed cassette 4. It is possible to improve the effect of preventing overlapping.

Furthermore, the space between the first guide members 225, 225 is as follows:
A brake plate 227 provided on the support plate 216,
a second guide member 228 extending over 227;
, 228 are provided, and the paper P is stored in the paper feed cassette 4.
, are all gone, the paper P2 passing over them does not come into contact with the brake plates 221, 227 and interfere with the conveying operation.

The above-mentioned first guide members 225, 225 and second guide members 226, 226 are integrally formed from a single elastic thin plate member such as mylar (trade name), which is semi-transparent in yellow color, and are bonded on both sides. It is adhesively fixed to the back surface of the free end side of the cassette cover 209 via tape.

Also, 1st. The second guide members 225 and 226 are colored to alert the operator and prevent bending.

Further, as shown in FIG. 23, the paper feed cassette 4 is
When K is installed, paper cassette 4
The upper surface of the tip end, that is, the part where the brake plates 227 and 227 are arranged is the paper feed roller 7.7 (only one is shown) of the paper feed section 6.
A paper feed guide surface 220 formed on the top surface of the distal end of the cassette cover 209 faces the automatic paper feed device 1).

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

Further, the portions of the paper width adjustment guides 12, 12 of the paper feed table 10 formed by the cassette cover 2091)C are arranged to protrude outward from the automatic paper feed device Rxz.

Next, the automatic paper feeder 1) will be explained with reference to FIG. 23 and FIGS. 25 to 34. 23 and 25 show an automatic paper feeder 1) installed corresponding to the paper feeder 6 of the main body l, and this automatic paper feeder 1 is shown in FIGS. 25 and 26. Mounting plate portion 23 of housing 230
0fL, 230aC Only one of which is shown in the figure] The mounting screw 232 is screwed into the main body 1 through the formed daruma holes 231, 231.
, 232, and then tighten the screws 2.12, 232.
The housing 230 is attached and fixed to the main body 1 by screwing in the housing 230. Furthermore, the lower part of the housing 230 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 10 as shown in FIGS. 23 and 25.

A take-out roller 235 that feeds the paper P, a feed roller 236 that feeds the most end (uppermost) paper P fed by the take-out roller 235, and a feed roller 236 that feeds the paper P that is the most end portion (uppermost end) fed by the take-out roller 235; a reversing roller 237 that returns the paper Pt after the first one;
A relay roller 238 is provided at a position on the advancing direction side of the feeding roller 236 and receives and conveys the sheet P fed by the feeding roller 236, and a relay roller 238 is provided near the output roller 235. provided, the existence of paper P (tsuma υ
Paper P is placed on the paper feed table 10.

paper detection means 2 for detecting whether paper is set or not.
It is open to the public with 39.

Furthermore, this paper supply 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, causes the feeding roller 236 to move in the feeding direction, and also rotates the reverse roller 237 in the feeding direction. The driving force transmission control means 24 feeds one sheet of paper P by making it rotatable in the returning direction and driving the intermediate feeding roller 238 in the feeding direction.
0.

Note that the sheets P fed one by one by this sheet supply means 234 are transported through a conveyance path 243 formed by the upper and lower pulley members 241 and 242 IC, and the aforementioned cassette cover 20.
The sheet is guided to the aligning roller pair 8 through the sheet feed guide surface 2201 of No. 9 and the lower surface side of the sheet a-rough, and then sent to the image transfer section 2 by the rotation of the aligning roller pair 8. become. Next, the driving force transmission control means 240t 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 applied to the ON state of the solenoid 253.
The driving force is transmitted to a feeding roller shaft 255 to which a feeding roller 236 is attached via a spring clutch 254 that disconnects the driving force by turning OFF.

Further, a gear 256 is torn to the feed roller shaft 255 and interlocks with a gear 259 attached to the relay roller shaft 258 via the intermediate gear 252. At the same time as being driven, the relay roller 238 is also driven in the same direction.
) Relay roller 23 of the relay roller shaft 258
8. Gears 260a, 26 are installed on both outer parts of the mounting part of 238.
0b is attached, and these gears 260a, 260b
is connected to the separation roller shaft 2 via intermediate gears 261a and 261b.
It is adapted to interlock with gears 263a and 263b attached to 62. Further, the separation roller shaft 2621C is connected to a limited power transmission means 2 consisting of a spring clutch, which will be described later.
A reversing roller 237 is attached via 63. Then, the reversing roller 237 is peered into the shaft 2.
62 rotates the reversing roller 237 to the paper P.

The reversing roller 262 is rotating in the direction of rotating the paper P in the direction of returning the paper P.

Due to the balance between the frictional force between the friction force and the limited power of the limited power transmission means, if there is no paper P, or if one sheet of paper P is taken out, the paper P! In the direction of sending out the paper P! If multiple sheets of paper P are fed, the second and subsequent sheets P,
It is designed to rotate so that it returns.

Further, the take-out rollers zss and zs5#-L are mounted on a rotating shaft 265 that is rotatably held at the free end portions of a pair of arms 264 and 264 whose rotation centers are the feeding roller shaft 255.

A rotating shaft 265 to which the take-out rollers 235, 235 are attached
There are gears 266. at both ends. a, 266b are attached, and the gear 267 is attached to the feed roller shaft 255.
ft, 267b and chains 268m, 268b.

Also, an arm 264.2 supporting the blowing roller shaft 265
Support protrusions 264a, 264& are protrudingly provided on the pivot end side of 64, and these support protrusions 264a, 264& are engaged with locking claws 269.2σ9 that are rotated as necessary to reach the next state. There is.

The locking claws 269, 269 are bearings 270°2701fC
It is attached and fixed to a locking pawl shaft 271 which is rotatably supported. The locking pawl shaft 271 is always biased by a spring 272 in a predetermined direction, that is, in a direction in which the locking pawls 269, 269 push down the support protrusions 264a, 264a of the arms 264, 254, so that the lever 273 can be viewed. It is attached. Further, a plunger 274a of a solenoid 224 is connected to the lever 273 via a link 275, so that the lever 223 can be rotated against the urging force of the spring 272 as necessary.

Therefore, the take-out rollers 235, 235 normally
b5, and when the solenoid 274 is turned on by a paper feed start command, the locking claws 269, 26
The arms 264, 264 rotate downward under the weight of the take-out rollers 235, 235, and the take-out rollers 235, 235 release the locking of the support protrusions 264a, 264&. It is adapted to be pressed onto the paper Pt.

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 loading f1) is turned off, and the paper P is placed on the main body 1 side.

When conveying the material, the separation roller 237 that acts as a load separates from the feeding roller 236, and the relay roller 238 is weakly stirred by 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 Further, the pressurizing load on the paper P is eliminated, and the transfer press and the like are eliminated. In addition, the feeding row 223
6 is a feed roller shaft 2 via a one-way clutch (not shown).
It is attached to 55 and is spinning idly.

That is, as shown in FIGS. 29 and 30, the one-separation roller shaft 262 and the relay roller shaft 258 are rotatably supported horizontally via a pair of swing levers 281 having a support shaft 280, and are in good condition. ing. In addition, these swing levers 28
Spring 282 is connected to each of 1 and 281, 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 is rotatable around the feeding roller shaft 255.
A spring 284 is attached to one horizontal end of the cam 283, and a link 28 is attached to the other horizontal end.
The granger 286a of the solenoid 286 is connected to the solenoid 286 via the solenoid 286.

Further, the vertical lower end of the cam 283 is connected to the separation 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 spring 284 to rotate the swing lever 281 clockwise against the biasing force of the spring 282. is in a state of

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 spring 284, and the cam 283 is rotated against the swing lever 284.
81. And cam 28
3 is rotated counterclockwise by the biasing force of the spring 282, and the separation roller 237 is the feeding roller 236K.

Further, the intermediate feed 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.
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.

In addition, the driving force of the separation roller shaft 262 is transferred to the separation roller 2237.
The limited power transmission means 263 that transmits the power to the
The configuration is as shown in FIG. 33.

That is, the separation roller shaft 262KFi first arm 29
0. Second arm 2910 separation roller 237 is removed from boss 292. are fitted in sequence, and the first aperture:! Separation roller shaft 262 via 90Q pin 293
Fixed. In addition, the second Arpa 29no and Bonu 2
It is coupled to 92 so that they rotate together.

Furthermore, the first. A coil spring 294 is fitted onto the second arm 290, 291, and the first arm 290
The driving force is transmitted to the second arm 291 via the coil spring 294.

Therefore, there is no external force greater than a predetermined torque on the separation roller 2371C, that is, the paper P, and the feed roller 236 is directly connected to the feed roller 2371C.
If one sheet of paper P is separated by the separation roller 2,
37 and the feeding roller 236, the driving force of the separation roller shaft 262 is not transmitted and the separation roller 237 idles in the direction of arrow A in FIG. That is, the paper P is interposed between the separating roller 237 and the feeding roller 236, and in the next case, the paper P is rotated in a direction to return the second and subsequent sheets.

Furthermore, as shown in FIGS. 31 and 32, the bonnu 292 is integrally molded with a nuleep 292a that completely covers the outside of the coil spring 294 to protect the coil spring zs4 from external dust, paper powder, etc. In addition to protecting the coil spring 294, the oil applied to the surface of the coil spring 294 is prevented from scattering around, stabilizing the idling torque, and
Next, the separation and feeding operation of the paper P will be explained with reference to FIG. 23 and FIGS. 34(a) to 34(d).

First, as shown in (a), the paper feed tray 10 is in the Vζ empty state.
When busy sheets P, . Light.゛Next, after setting the number of copies from the operation unit 100, press the copy key 101.
), 45 seconds have elapsed since the copy key 101 was pressed.
After o m Bec, the take-out roller 235 descends and stands still for 430 m5ec.

Then, as shown in FIG.
, the spring clutch 254 is connected, and the dispensing roller 235, the feeding roller 236 . b and the reversing roller 237 rotate. 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 P is sent between the feeding roller 236 and the reversing roller 237 through the outlet -2235.

Note that at this time, two or more sheets of paper P! are present between the feeding roller 236 and the reversing roller 237! If there is an intervention, the direction of rotation 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 P2 taken out as a single sheet by the feeding roller 236 and the separation 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 the first sheet. Second guide member 225,2
28 and is sent to the aligning roller pair 8 side.

The paper P is the l of aligning roller pair 8! 210 m sec fit after turning on the detector 9 installed in the iJ stage
, the spring clutch 254 is disconnected, and the take-out roller 23
5. The feeding roller 236, separation roller 237, and relay roller 238 stop.
Detector 9 within 2730m see from the start
If it doesn't reach that point, it will jam.

At this time, the separation roller 237 is lowered, and the feeding roller 23
6 is formed between KR and relay roller 2.
38 is displaced upward and comes into a state in which it is in weak contact with the leaf spring 226. This completes the feeding operation for one sheet of MP.

On the other hand, after the leading edge of the paper P2 is detected by the detector 9, 1) 80/l! sea Aligning roller lj
&, 8b begins to rotate and feeds the paper P2 into the image transfer section 2. In addition, a one-way clutch is engaged in the relay roller 238, and the paper P! It rotates idly as it is transferred.

When the number of copies is set to be a plurality of copies, the take-out roller 235 is lowered again by a paper feeding start command after a predetermined time has elapsed, and the same operation as described above is repeated. In this way, automatic paper feeding by the automatic paper feeding device 1 is performed.

Furthermore, the casing 230 of the automatic paper feeder 1) is connected to the copying machine main body 1.
A gap KPJ 300 is formed between the front end of the top plate 23071 and the main body 1 so as not to interfere with the opening/closing operation of the upper unit 5.
As shown in FIG. 5, the slidable cover 30IVc is closed to prevent the upper unit 51 from being pinched or dropping pins, clips, etc. when the upper unit 51 is opened.

The cover 301 is interposed between the guide pace so;r* of the support frame 302 of the automatic paper feeder 1 and the top plate portion 230a of the casing 230. A support protrusion 303 is formed on the lower surface of this cover 301 and projects to the lower surface side of the guide pace 302a through a slit 304 formed with a guide pace 5ozaVc. A spring 304 is connected between the cover 3ozf3 and the spring support shaft 303, and the cover 3ozf3 is always biased to the left in the state shown in FIG. When the upper unit 51 is opened and the side plate portion of the main body enters the state shown by the two-dot chain line, the cover 301 moves to the right in the figure against the biasing force of the spring 304.

〔Effect of the invention〕

As explained above, the present invention includes a lens unit incorporating a lens for directing the original image 9 onto an exposed area, a drive shaft driven by a stepping motor, and a threaded portion of the drive shaft. A feed screw mechanism having an engaging guide and converting rotation of the drive shaft into linear movement of the lens unit via the guide, and moving the lens unit according to the number of steps of the step motor. In an exposure optical device that changes the copying magnification, the lead of the threaded part of the drive shaft is set so that when the minimum unit of magnification change is X%, the number of steps of the step motor corresponding to X% becomes an integer value. It is set to . Therefore, it is possible to provide an exposure optical device that has few errors with respect to the designated magnification, is easy to control, and can easily and reliably set an arbitrary copying magnification.

[Brief explanation of the drawing]

The first drawing is an external perspective view of an image forming apparatus to which an embodiment of the exposure optical device of the present invention is applied, and the second drawing is a schematic longitudinal sectional front view.
Figure 3 is a diagram of the internal mechanism seen from the rear side, Figure 4 is a diagram also showing the upper unit in the open state, Figure 5 is an explanatory diagram schematically showing the driving force transmission system, and Figure 6 is the original view. 7 is a plan view of the operation panel, 8 to 16 are exposure optical systems, 8 is a longitudinal side view, and 9 is a schematic side view showing the drive system of the rehearsal table. A plan view, Figure 10 is a front view of the lens unit, Figure 1) is a sectional view showing the mechanism that converts the rotation of the drive shaft into reciprocating motion of the lens carriage, and Figure 12 is the relationship between the cam assembly and link assembly. FIG. 13 is an explanatory diagram showing the relationship between the link assembly and the bracket.
Figure 4 is a diagram for explaining the relationship between 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 tilted mounting of the optical unit, and Figure 16 is diagram for tilted mounting of the optical unit. 17 to 21 are explanatory diagrams showing the holding state of the lens unit, FIGS. 17 to 21 show the developing device, FIGS. 17 and 18 are longitudinal sectional front views showing different operating states, and FIG. FIG. 20 is a side view showing the developer concentration detector in the running state, FIG. 21 is a plan view of the same, and FIGS. 22 to 24 show the paper feed cassette section. Fig. 22 is a perspective view of the cassette cover that also serves as a paper feed tray, with the cover open, Fig. 23 is a sectional view showing the cassette that is attached to the paper feed section of the main body (1), and Fig. 24 is a cassette that also serves as a paper feed tray. A perspective view showing the cover, FIGS. 25 to 35 show the automatic paper feeding device, FIG. 25 is a schematic vertical side view showing the state in which it is attached to the main body, and FIG. 26 is a front view showing the attachment part. Fig. 27 is an explanatory view schematically showing the configuration of the internal mechanism, Fig. 28 is an exploded perspective view of the main parts, and Fig. 2p and Fig. 30 are schematic side views showing the contact and separation operation states of the separation roller. , 31st
The figure is a partially cutaway front view of the limited power transmission means, FIG. 32 is a side view, FIG. 33 is an exploded perspective view, and FIG.
a) to (d) are explanatory diagrams showing the paper feeding state, and FIG. 35 is a schematic longitudinal sectional side view showing the cover attachment state. 4. Exposure optical device, 3. Lens, 137.
...Drive shaft, 137a...Threaded part, 144...
・Lens unit, 149...Stepping motor,
150...Feed screw mechanism, 162...Guide. Applicant's agent Patent attorney Takehiko Suzue 1) 5 Figure et al. 7 Figure 6 Figure 12 Figure 13 Figure 14 Figure 34 Figure 34 Figure 220238276209237242239a P
2Figure 35

Claims (2)

[Claims] (1) It has a lens unit incorporating a lens that focuses the original image on the exposed area, a drive shaft driven by a stepping motor, and a guide that engages with the threaded part of this drive shaft, and the drive shaft rotates. In an exposure optical device, the exposure optical device is provided with a feed screw mechanism that converts the lens unit into a linear movement of the lens unit via the guide, and the copying magnification is changed by moving the lens unit according to the number of steps of the step motor. The minimum unit of magnification of the lead of the threaded part of the drive shaft is X%.
An exposure optical device characterized in that the exposure optical device is set to an integer value of the number of steps of a step motor corresponding to X%. (2) The exposure optical device according to claim 1, wherein the minimum unit of the amount of magnification change is 1%.