JPH0679132B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer using electrophotography, and more particularly, to a drive system for controlling reciprocal movement of a document table. Regarding the improvement of.

[Prior Art] Conventionally, in a document table moving type image forming apparatus represented by a copying machine or the like, in order to perform reciprocating control of the document table moving type, a driving force from a driving source is used as a document. A drive system in which a pair of one-way clutches for forward rotation and reverse rotation is interposed is present in a part of the drive system transmitted to the mounting table.

In such a drive system, a pair of latch members operated by a solenoid or the like are disposed in the vicinity of the clutch so as to face each other, and one of the clutches is latched by the operation of the solenoid, so that the driving force from the drive source is applied. The document table is selectively transmitted to the document table to control the reciprocating motion of the document table.

However, in such a drive system, when the timing of the operation of the solenoid is shifted or the solenoid is erroneously operated during the process of returning the original placing table, the elastic force of the spring for separating (returning) the latch member is further applied. In some cases, both of the one-way clutches were erroneously latched in the case of a weakening. In such a case, the rotation of the drive system is forcibly locked, and there is a possibility that seizure of the electric motor or other serious accident may occur.

For this reason, conventionally, various methods have been studied for preventing the timing deviation of the solenoid or the malfunction by using a control mechanism such as a micro switch, but when such an electric control mechanism is used, Not only does this lead to an increase in the number of parts, an increase in cost, a complicated mechanism, etc., but there is a problem in terms of reliability of operation.

Further, in the apparatus using the one-way clutch, since either one of the pair of one-way clutches for forward rotation and reverse rotation is always latched, therefore, even when the power is turned off, the original placing table is moved forward or backward. However, it is a major obstacle when splitting and opening the copying machine main body, and when performing jam processing or repair.

In the image forming apparatus having the above-mentioned configuration, each of the drive systems is individually mounted on the side wall surface of the main body of the copying machine to be assembled. However, in the method of individually assembling the drive units as described above, There were drawbacks such as difficulty in assembling accuracy, easy man-hours for assembly, and troublesome maintenance work.

Therefore, conventionally, it has been considered that the original placing table and the drive system for driving the photoconductor are integrally linked to form a unit, but in the conventional apparatus, the diameter of the photoconductor is 80 to 100 m.
There is also m, and as a result, the distance between the document mounting table and the photoconductor shaft center becomes large, and there is also room for the arrangement space for arranging the drive unit, but in order to achieve further downsizing of the apparatus, When the diameter of the photoconductor is reduced and the distance between the document mounting table and the photoconductor axis is narrowed, it is often effective to dispose a drive unit including a large number of gear trains including the one-way clutch. It was difficult.

[Problems to be Solved by the Invention] An object of the present invention is to provide an image forming apparatus capable of solving the drawbacks of the conventional art.

The present invention relates to an image forming apparatus having a movable document placing table, in which the driving unit can be effectively arranged even when the distance between the document placing table and the photoconductor axis is set small. The purpose is to provide a device.

Another object of the present invention is to achieve both of the one-way clutches even when there is a timing deviation or malfunction of the solenoid for operating the latch member, or when the elastic force of the spring for returning the latch member is weakened. An object of the present invention is to provide an image forming apparatus capable of completely preventing the risk of being accidentally latched.

Another object of the present invention is to make sure that only one of the one-way clutches can be latched without causing an increase in the number of parts, an increase in cost, a complicated mechanism, etc., and an operation error occurs. An object is to provide an image forming apparatus that does not have any problems.

Another object of the present invention is not to latch any one-way clutch for forward rotation or reverse rotation when the power is turned off, in other words, the document placing table is configured to be reciprocally movable when the power is turned off. An object of the present invention is to provide an image forming apparatus that is extremely practical when the main body is divided and opened, and when jam processing or repair is performed.

[Means for Solving the Problem] The present invention relates to an image forming apparatus in which a drive unit for transmitting a driving force to each of the photoconductor and the document placing table is arranged between the photoconductor axis and the document placing table moving member. In particular, the drive unit is arranged with a pair of gear mounting plates along a direction orthogonal to the photoconductor axis, and a gear train, a one-way clutch, a latch member, and a solenoid are arranged on the mounting plates as appropriate. The first main purpose is to make it possible to effectively arrange the drive unit between the manuscript mounting table and the photoconductor axis center even if the distance between the manuscript mounting table and the photoconductor axis center is narrowed, more specifically, 80 mm or less. The second main purpose is to ensure the switching control of the one-way clutch that controls the reciprocating movement of the document placing table, and especially to latch both one-way clutches for forward rotation and reverse rotation when the power is turned off. Let In other words, in other words, when the power is turned off, the document placing table is configured to be reciprocally movable, which makes it possible to provide an extremely practical image forming apparatus when the copying machine main body is divided and opened, and when jam processing or repair is performed. To provide.

A first feature of the present invention for satisfying such a feature is a drive gear for moving the document placing table on one mounting plate 12.
14, a first control gear 26 that meshes with the drive gear 14, and a second control gear 27 that meshes with the first control gear 26, and the rotary shafts 22 of the respective control gears 26, 27 are supported. , 23 are inserted into the side of the other mounting plate 11 and are axially supported by the other mounting plate 11 via the one-way clutches 24, 25 and the shaft gears 20, 21 for relaying, respectively, and the driving gear of the photosensitive drum 7 is also supported. A driven gear 16 which rotates by receiving rotation from 19 is pivotally supported by another mounting plate 11 so as to be able to mesh with the two shaft gears 20 and 21.

The second characteristic is that the one-way clutches 24, 25 are
On the respective sides of the clutches 24, 25, there are tip claws 30c, 31e which can be meshed with the ring-shaped gears 28, 29 fitted around the clutches 24, 25. A pair of latch members 30 and 31 urged by elastic forces 34 and 35 in a direction separating from them are rotatably supported by the mounting plates 11 and 12, and the elastic force 3
The tip claw portions 30c and 31e are opposed to the ring gears 28 and 29 against 4,35.
A pair of solenoids 36 and 37 for swinging the latch members 30 and 31 in the direction of engaging with are attached to the attachment plates 11 and 12.

And the third characteristic is that the latch members 30, 3 are
1 predetermined portions 30e, 31d on the side facing each other are extended in a direction in which they engage with each other, and the tip claw portions 30c, 31e of one latch member 30, 31 are driven by the solenoids 36, 37 so that the ring gears
When extended in a direction that meshes with 28,29, the extension parts 30e, 3
1d presses the extension parts 31d, 30e of the other latch members 31, 30, and the tip claws 31e, 30c of the other latch members 31, 30 can be swung in the direction forcibly separated from the ring gears 29, 28. The third feature is that, for example, the extending portions 30e and 31d are vertically arranged side by side.

A fourth characteristic is that the extension portions 30e and 31d swing to follow the separation and contact of the tip claw portions 30c and 31e of the both latch members 30 and 31 from the ring gears 28 and 29. By setting the moving directions to the same direction, when the solenoids 36 and 37 are both deactivated, the elastic force 34 and 35 urged by the respective latch members 31 and 30 causes the tip claw portions 31e Even when 30 and 30c move away from the one-way clutches 24 and 25, the extending portions 30e and 31d can swing while maintaining the separated state.

[Operation] According to the technical means, the pair of gear mounting plates are arranged to control the reciprocating movement of the document moving table so as to transmit the driving force of the photoconductor along the direction orthogonal to the photoconductor axis located on the photoconductor axis end side. Effectively utilizing the mounting plate, a gear train incorporating a one-way clutch is further arranged on the left and right sides thereof, so that a pair of latch members and solenoids are arranged, in other words, the gear train, Since the pair of latch members and the solenoid are prevented from expanding in the vertical direction as much as possible and are configured to expand in the horizontal direction, the drive is performed smoothly even in a narrow space where the distance between the document mounting table and the photoconductor axis is 80 mm or less. You can control it.

Further, according to the present invention, the predetermined portions 30e and 31d on the opposite sides of the latch members 30 and 31 are extended in a direction in which they engage with each other, and the solenoids 36 and 37 are driven so that the tip claw portions of one latch member 30 and 31 are driven. When the 30c and 31e are swung in the direction in which they mesh with the ring-shaped gears 28 and 29, the extending portions 30e and 31d cause the other latch members 3
The extended portions 31d and 30e of the 1,30 are pressed, and the other latch members 31,30
Since the tip claw portions 31e, 30c of the are configured to be swingable in the direction in which they are forcibly separated from the ring-shaped gears 29, 28, by rotating one latch member in the latch direction, the latch is forced. It can be canceled.

Therefore, even if the elastic force of the springs 34, 35 that apply the elastic force to the latch members 30, 31 is weakened, or even if the solenoids 36, 37 are operated by mistake, the latch members 30, Only one of the 31 is latched, and as a result, both of the one-way clutches 24 and 25 are not latched by mistake, and seizure of the electric motor can be completely prevented.

By the way, since the extending portions 30e, 31d and the tip claw portions 30c, 31e are integrated with the latch members 30, 31, respectively, they both follow the swing of the latch members 30, 31 and therefore swing. But
Install both extension parts 30e and 31d at the tip claw part 30.
When installed on the side opposite to the mounting position of c and 31e, the solenoid 3
When the operation of both 6 and 37 is released, the tip claw portions 31e and 30c are separated from the one-way clutches 24 and 25 by the elastic forces 34 and 35 urged by the respective latch members 31 and 30. When extended, the extending portions 30e and 31d swing in the directions intersecting with each other, in other words, the tip claw portion.
When both 30c and 31e try to separate from each other at the same time, the extending portions 30e and 31d come into contact with each other, and work so as to prevent simultaneous separation of the tip claws 30c and 31e.

To solve such a problem, one extension portion 31d is provided on the opposite side of the tip claw portion 31e attachment position, and the other extension portion 30e is provided on the same side as the tip claw portion 30c attachment position, By setting the swinging directions of the extending portions 30e, 31d that follow the separation / contact of the tip claw portions 30c, 31e from the ring gears 28, 29 to the same direction, the solenoids 36, 37
When the operation is released, each of the latch members 3
The elastic force 34,35 urged by 1,30 causes the tip claws 31e, 3
Even when 0c moves in the direction of separating from the one-way clutches 24 and 25, the extending portions 30e and 31d can be swung while maintaining the separated state, and the problem can be solved.

Accordingly, when the solenoids 36 and 37 are both in the deactivated state while the copying is stopped, the elastic members 34 and 3 can smoothly separate the latch members 30 and 31 from the one-way clutches 24 and 25. Result The control gears 26, 27
Is not connected to the shaft gears 20 and 21, and is maintained in a free state, so that the original placing table 3 can be manually reciprocated, and when the copying machine main body is divided and opened, This is effective when performing jam clearance or repair.

[Embodiment] An embodiment of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative positions and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely examples, unless otherwise specified. Not too much.

FIG. 1 is a cross-sectional view of the main parts showing the structure of the main parts of a copying machine according to an embodiment of the present invention in which a part of the structure of a drive system unit is omitted.

Reference numeral 1 denotes a drum-shaped photoconductor having a photoconductive layer formed on the surface thereof, and a photoconductor shaft 1a projecting from the axial ends of both ends of the photoconductor shaft 1a. It is formed so that it can be inserted and fixed.

3 is an original placing table, which is made of a transparent glass plate and is a mounting member.
A slide rail 3b and a rack 3c are arranged on the lower surface of 3a, and the original mounting table 3 is rotated by the forward and reverse rotations of a drive gear 14 axially supported by another mounting plate 12 constituting the drive system unit 2.
Are reciprocally movable.

Reference numeral 4 denotes an optical system unit, which guides the light source lamp (not shown) that illuminates the surface of the document and the reflected light from the light source lamp to the surface of the photoconductor 1 to form an electrostatic latent image corresponding to the document image. The SELFOC lens 4c and the like in the shape of a slender rod are formed, and these are integrally assembled by the frame 5. Further, the frame body 5
Is a bottom plate extending between the body frames 6 arranged on both left and right sides
51 and side plates 52 provided upright at both ends of the bottom plate 51. The side plate 52 has a notch 11a formed in the mounting plate 11 of the drive system unit 2 vertically above the axis of the photoreceptor 1. Projecting pins 52a and pin holes 52b are formed at positions corresponding to the pin members 11b.

The machine body frame 6 is arranged at a right angle to the photoconductor shaft 1a, and a circular opening 6a through which the photoconductor shaft 1a can be inserted is formed on the wall surface thereof, and the pin member 11 of the mounting plate 11 is provided above the opening 6a.
A pin hole 6b into which b can be inserted, and an oval notch in which the optical system unit 4 can be engaged with the upper end surface above the pin hole 6b.
Form 6c.

The pin hole 6b and the cutout portion 6c are provided in the optical system unit 4
Of the projection plate 52a and the pin member 11b of the mounting plate 11 to the notch 11a of the mounting plate 11 and the pin hole 52b of the optical system unit 4 are provided with a mere guiding function for engaging or inserting. You may form in.

The drive system unit 2 includes a pair of mounting plates 1 arranged in parallel.
1 and 12, and a drive system integrally mounted on the mounting plates 11 and 12 for driving the photoconductor 1 and the document table 3 in synchronization. The detailed configuration of the drive system unit 2 will be described with reference to FIGS. 2 to 6.

2 to 6 show the structure of each part of the drive system unit, FIG. 2 is a plan view, FIG. 3 is a diagram taken along the line AA ′ in FIG.
FIG. 4 is a view seen from the rear surface of FIG. 3, and FIGS. 5 to 6 are schematic explanatory views showing the states of the forward and backward movements of the document placing table.

First, the mounting plate 11 that constitutes the drive system unit 2 will be described.

The mounting plate 11 located on the machine frame 6 side has a circular opening 11c at a position corresponding to the photoconductor 1 into which the photoconductor shaft 1a can be inserted.
And a pin member 11b which can be inserted into the pin hole 52b of the optical system unit 4 is formed above the opening 11c, and the optical system unit 4 is provided on the upper end surface above the pin member 11b.
The oval notch 11a that can be engaged with the protruding pin 52a is formed so that the optical system unit 4 can be positioned and fixed.
Further, the mounting plate 11 has an inverted L-shaped branch plate 11d fixed to the back side of the circular opening 11c, and the branch plate 11d is provided as shown in FIG.
And the main shaft 13 is fixed between the other mounting plate 12.

Reference numeral 11e is a screw hole for fixing the mounting plate to the machine body frame 6.

The drive shaft 13 has one end extending into the space sandwiched between the branch plate 11d and the one mounting plate 11, and the drive gear 19 is fixed to the end side of the drive shaft 13 and the photoconductor shaft is located on the end face axis. A mounting hole 13a into which 1a can be inserted and fixed is formed.

Then, a transmission gear 15 meshing with the main gear 19 is provided on the side of the main gear 19, and a relay gear 16 is diagonally above the main gear 15, and a relay gear 16 is attached to the mounting plate 11 via support shafts 17 and 18, respectively. It is rotatably supported. A pair of relay gears 20 and 21 of the same shape, which mesh with the driven gear 16 respectively, are provided symmetrically on both sides of the relay gear 16 via the rotating shafts 22 and 23, respectively.

The rotating shafts 22 and 23 are mounted on the relay gears 20 and 21 via one-way clutches 24 and 25, respectively, to attach the mounting plates 11 and 12 to each other.
The rotary shafts are rotatably supported between the two one-way clutches 24, 25, and the other rotary shaft ends 22a, 23a are projected to the outside of the other mounting plate 12.

In the normal state, the one-way clutches 24, 25 do not apply a rotational force to the other ends 22a, 23a of the rotary shafts even if the relay gears 20, 21 rotate, and are annularly provided on the outer peripheral surfaces of the one-way clutches 24, 25, respectively. By rotating the ring-shaped gears 28, 29 described above, the rotational force of the gears is transmitted to the other ends 22a, 23a of the rotating shafts. The description is omitted.

On the other hand, on the side of the ring gears 28 and 29, the latch members 30 and 31 are supported by the support shafts 32 and 33 so as to face the ring gears 28 and 29.
It is rotatably attached to the attachment plates 11 and 12 via.

Latch members 30 and 31 both apply elastic force to springs 34 and 35, which are provided around support shafts 32 and 33, in a direction away from ring-shaped gears 28 and 29, and to other mounting plate 12. The latch members 30, 31 are attached by the attached solenoids 36, 37.
Is configured to be capable of latching the corresponding ring-shaped gears 28, 29 against the elastic force.

The configuration of the latch members 30 and 31 will be described in more detail,
The one latch member 30 has a substantially horizontal L-shape, and the base portion 30a is provided around the support shaft 32 and the one side arm portion 30b extending upward.
The distal end is connected to a solenoid shaft 36a which extends and contracts in the horizontal direction via a ring member 38, while the other arm 3 of the latch member 30 is connected.
Reference numeral 0d extends substantially horizontally along the lower space of the ring gear 28, and a claw portion 30c that meshes with the ring gear 28 is formed on the upper end of the tip thereof. Further, the other side arm portion 30d is further extended in the horizontal direction, and the tip 30e of the other side arm portion 30d is opposed to the other latch member 3
They are arranged side by side so as to be engageable with the one branch arm portion 31d.

The other latch member 31 has a substantially inverted T-shape, and its base portion 31a is provided around the support shaft 33, and one side arm portion 31b extending outward in a substantially horizontal direction is attached to a solenoid shaft 37a which extends and contracts in the vertical direction. To connect. Further, another arm portion 31c extending upward from the base portion 31a
Is formed in an arc shape along the ring-shaped gear 29, and a claw portion 31e that meshes with the ring-shaped gear 29 is formed on the tip side portion thereof. On the other hand, the latch member 31 is a branch arm portion that extends horizontally from the base portion 31a along the space below the ring gear 29.
31d, the branch arm portion 31d is extended to face above the tip 30e of the other side arm portion 30d of the latch member 30, and as described above, the branch arm portion 31d is juxtaposed so as to be engageable with the tip 30e of the latch member 30. Has been done.

In this way, the latch member 31 has the branch arm portion 31d arranged at a position facing the claw portion 31e with the one-way clutch 25 interposed therebetween,
Since the tip end of the branch arm portion 31d is juxtaposed with the tip end 30e of the latch member so as to be engageable with each other, when one of the latch members 30 or 31 is rotated in the latching direction by the operation of the solenoid shafts 36a and 37a, other When the latch member 31 or 30 maintains the latched state, the latch member tips 30e, 31e press the other latch member tips 31e, 30e, and the other latch member 30 is forced.
Can be rotated in the anti-latching direction.

Next, the configuration of the back side of the other mounting plate 12 is constructed based on FIG.

On the rear surface side of the other mounting plate 12, as described above, the one-way clutches 24, 25 are provided with the other ends 22a, 23a of the rotary shafts with which the one-way clutches 24 are interposed, and the control gears 26 meshing with the other ends 22a, 23a, respectively. 2
Fix 7 The control gears 26 and 27 set the gear ratio to 1: 2, respectively, the control gear 27 is the control gear 26 fixed to the other end 22a, and the control gear 26 is the document table driving gear 14 Are meshed with each other. The drive gear 14 is located diagonally above the gear and is arranged so that the outer ring projects above the mounting plate 12 so that it can mesh with the latch 3c provided on the lower surface of the document table 3. There is.

Next, the copying operation of the copying machine according to the embodiment will be described.

When the copy switch is turned on after the original is placed on the original placing table 3 in advance, the solenoid 37 is actuated to latch the one-way clutch 25 via the latch member 31, and the one-way clutch 25 is interposed. Relay gear 20 via rotating shaft 23
And the control gear 27 are connected.

At the same time, it receives rotation from an electric motor (not shown)
19 rotates, the rotation of the drive gear 19 causes the photoconductor 1 to rotate at a predetermined speed via the drive shaft 13, and at the same time, the transmission gear 15
Also, the pair of relay gears 20 and 21 are rotated via the driven gear 16.

The rotation shaft 22 is rotated by the rotation of the pair of relay gears 20 and 21.
And 23 rotate, and as a result, since the one-way clutch 25 of the rotary shaft 23 is latched as described above, the rotary shaft 23
The rotation of the relay gear 20 is transmitted to the control gear 27 via.
On the other hand, since the one-way clutch 24 interposed on the other rotary shaft 22 is not latched, the other rotary shaft 22 idles,
The control gear 26 fixed to the other end 22a of the rotating shaft is in a free state.

Therefore, the rotation of the control gear 27 is transmitted to the drive gear 14 via the control gear 26 in a free state, and the drive gear 14
Rotate in reverse. Then, by the reverse rotation of the drive gear 14, the document placing table 3 is reversed to a predetermined position via the latch 3c. At this time, since the gear ratios of the control gears 26 and 27 are set to 1: 2, the document placing table 3 is reversed at a speed twice as fast as the normal rotation described later. (See FIG. 6) Next, after the document table 3 is reversed to a predetermined position, the latch member 31 is elastically actuated by releasing the operation of the solenoid 37 and operating the other solenoid 36 by a control mechanism (not shown). Then, the latch of the one-way clutch 25 is released, the latch member 30 on the other side is rotated, and the one-way clutch 24 interposed on the other rotation shaft 22 is latched.

As a result, the gear 20 fixed to both ends of the rotary shaft 22 and the control gear 26 are connected via the one-way clutch 24, and the rotary shaft 22
The rotation of the gear 20 is transmitted to the control gear 26 via the control gear 26. As a result, the drive gear 14 is rotated forward by the rotation of the control gear 26, and the original placing table 3 is moved forward via the rack 3c to perform the copying process. Be started. (See FIG. 5) On the other hand, since the one-way clutch 25 interposed on the rotary shaft 23 is unlatched, the control gear 27 fixed to the other end 23a of the rotary shaft is in a free state, It does not hinder the rotation of the gear 26.

When the original placing table 3 is moved forward to a predetermined position and the copying process is completed, the solenoid 36 is deactivated and the other solenoid 37 is activated. As a result, the original placing table 3 is returned in the same manner as described above. The process is started, and the document placing table 3 is returned to a predetermined position at a speed twice as fast as the normal rotation. (6th
(Refer to the figure) This is repeated below.

On the other hand, the latch members 30 and 31 are connected to each other by operating the solenoid shafts 36a and 37a as described above.
When 1 rotates in the latching direction, for example, when the other latch member 31 or 30 maintains the latched state, the latch member tips 30e, 31e press the other latch member tips 31e, 30e, forcibly. Since the other latch member is configured to rotate in the anti-latch direction, the latch can be forcibly released by rotating one latch member in the latch direction.

Therefore, even if the elastic force of the springs 34, 35 that apply the elastic force to the latch members 30, 31 is weakened, or even if the solenoids 36, 37 are operated by mistake, the latch members 30, Only one of the 31 is latched, and as a result, both of the one-way clutches 24 and 25 are not latched by mistake, and seizure of the electric motor can be completely prevented.

On the other hand, when the copying is stopped, the solenoids 36 and 37 are both in the released state, so that the elastic members of the springs 34 and 35 separate the latch members 30 and 31 from the one-way clutches 24 and 25. As a result, the control gear
Neither 26 nor 27 are connected to the relay gears 20 and 21,
Since it is maintained in a free state, it is possible to manually reciprocate the document placing table 3, which is effective when the main body of the copying machine is divided and opened, and when jamming or repair is performed.

As is clear from the above description, according to the present invention, a pair of gear mounting plates are arranged between the photoconductor axis and the document mounting table moving member along the direction orthogonal to the photoconductor axis, and the gear mounting plates are vertically arranged on the mounting plate. Without unnecessarily expanding the gear train, the gear train, one-way clutch, latch member, etc.
Also, since the solenoids etc. are arranged, the distance between the document mounting table and the photoconductor axis can be smoothly narrowed, and more specifically, it can be set to 80 mm or less.

Further, since the gear train, the one-way clutch, the latch member, the solenoid, and the like are all mounted on the pair of gear mounting plates, it is possible to make the drive unit thinner along with the axial direction of the photoconductor along with the unitization. .

Further, according to the present invention, it is possible to ensure the switching control of the one-way clutch that controls the reciprocating movement of the document placing table, and it is possible to release the latch of any one-way clutch for forward rotation and reverse rotation especially when the power is turned off. In other words, when the power is turned off, the original placing table is configured to be capable of reciprocating, so that it is possible to provide an extremely practical image forming apparatus when the copying machine main body is divided and opened, and when jam processing or repair is performed. .

Also, when the timing of the solenoid for operating the latch member is shifted or malfunction occurs, or when the elastic force of the spring for returning the latch member is weakened,
The risk of accidentally latching both of the one-way clutches is completely eliminated, and as a result, serious accidents such as seizure of the motor resulting from the forced lock of the rotation of the drive system can be completely prevented.

Further, according to the present invention, the other latch members that maintain the latched state are separated from each other by the movement of the one latch member, so that there is no risk of an operation error. Absent.

Further, according to the present invention, since the above-described operation is performed by engaging a part of the latch members with each other, there is no room for increasing the number of parts, increasing the cost, complicating the mechanism, etc. It has extremely high practical value as a safety mechanism.

It has various remarkable effects.

[Brief description of drawings]

1 to 6 each show an embodiment of the present invention,
FIG. 1 is a cross-sectional view of the main parts showing the structure of the main parts of a copying machine according to an embodiment of the present invention in which a part of the structure of a drive system unit is omitted. 2 to 6 show the structure of each part of the drive system unit, FIG. 2 is a plan view, FIG. 3 is a diagram taken along the line AA ′ in FIG.
FIG. 4 is a view seen from the rear surface of FIG. 3, and FIGS. 5 to 6 are schematic explanatory views showing the states of the forward and backward movements of the document placing table.

Claims (1)

[Claims] 1. An image forming apparatus in which a drive unit for transmitting a driving force to each of the photoconductor and the document placing table is provided between the photoconductor axis and the document placing table moving member, in a direction orthogonal to the photoconductor axis. A pair of gear mounting plates are arranged along the drive gear, a driving gear for moving the document placing table on the one mounting plate, a first control gear meshing with the driving gear, and a first control gear meshing with the driving gear. The second control gear is pivotally supported, the rotary shafts of the respective control gears are inserted into the other mounting plate side, and the second control gear is pivotally supported by the other mounting plate via the one-way clutch and the relay shaft gear, respectively. , A driven gear that rotates by receiving rotation from a drive gear of the photosensitive drum is pivotally supported by another mounting plate so as to be meshable with the two shaft gears, and on the other hand, on the respective sides of the one-way clutch, around the clutch. Tip claw that can be meshed with the ring-shaped gear A pair of latch members, each of which has a claw portion and is elastically biased in a direction of separating from the ring-shaped gear, are pivotally supported by the mounting plate in a swingable manner, and the tip claw is resisted against the elastic force. A pair of solenoids for swinging the respective latch members in the direction in which the parts mesh with the ring-shaped gear are attached to the mounting plate, and further, predetermined portions of the latch members facing each other are extended in a direction in which they engage with each other, When the tip claw portion of one latch member swings in the direction in which it meshes with the ring-shaped gear due to the driving of the solenoid, the extending portion presses the extending portion of the other latch member, thereby The tip claw portion is configured to be swingable in a direction in which the tip claw portion is forcibly separated from the ring gear, and the extending portion of the extension portion that swings following the separation and contact of the tip claw portions of the both latch members with respect to the ring gear. Same swing direction The extension portion is set even when the tip claws of the two solenoids move in a direction away from the one-way clutch due to the elastic force urged by the respective latch members following the deactivation of the solenoids. The image forming apparatus is characterized in that it is swingable while maintaining the separated state.