JPH0572645A - Image forming device - Google Patents

Abstract

PURPOSE:To secure safety measure or a normal action by mechanically regulating the erroneous movement of an original platen when the original platen is set under a free state. CONSTITUTION:When the original platen is returned to a home position after exposure and scanning, an abutting arm 613 at an abutting position abuts on a stopper 620 by gravity and the original platen is stopped at a prescribed position. When the driving of the original platen is stopped, an electric solenoid 800 is turned off and a plunger 811 is lowered. Thus, a pushing-up member 831 is elevated and the arm 613 is moved to an upper retreat position. Then, an abutting state is cancelled. Besides, a pushing-up member 832 is elevated by interlocking with the pushing-up member 831 and engaged with the recessed part 711 of a lock part 700. Then, the movement of the original platen in both advancing and retreating directions is regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for exposing and scanning a document by reciprocating a document table on which a document is placed, and particularly to retreating and advancing the document table after the driving of the apparatus is stopped. The present invention relates to a prevention mechanism that preferably prevents erroneous movement in the direction.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, an optical system moving type and a document table moving type are known as an exposure scanning system for a document. The exposure scanning is configured to be performed by moving both in the horizontal direction.

In the above-mentioned document moving type image forming apparatus, when a document is set on the platen and a copy instruction is issued, the platen moves from the home position in a predetermined direction to perform exposure scanning of the document. After the exposure scanning, the movement is controlled to the initial home position. Then, after the movement of the platen is completed, the control of the platen is released and the platen is put into a free state.

[0004]

Conventionally, image forming apparatuses mainly for office use are relatively large, and tilting the main body is not considered in a normal use mode. But,
In recent years, copiers and the like have been required to be expanded from office use to general household use in order to fully meet the diverse needs thereof. For that purpose, it is required to reduce the size and weight of the apparatus and reduce the cost.

By the way, in the case of such a compact and lightweight copying machine, there are many occasions where the main body is tilted to one side in order to open the bottom of the main body due to movement of the installation place, paper jam, and the like. Therefore, when the platen is in a free state, the platen moves unexpectedly, which causes damage to the device such as a collision with the floor and damage to the platen. It is not preferable in terms of safety measures. In particular, in the portable type, it is necessary to fix the document table on at least one side in order to move it while holding the handle provided on the side portion of the main body when carrying it.

Further, in the case of the image forming apparatus in which the home position of the document table is set to the central position on the main body side so as not to occupy the placement position, erroneous tilt movement in the forward or backward direction occurs, A mechanism for preventing erroneous movement in at least one direction is required.

Further, there is an image forming apparatus in which switches are provided at the front and rear ends in order to perform movement control while confirming the movement position of the document table, and the reciprocating control is performed by detecting the switching state of both switches. For example, if the platen is erroneously moved in the free state and the switching state of the switch is changed, the platen will not be moved normally when the copy is made later. Causes paper jams.

The present invention has been made in view of the above problems, and when the platen is in a free state, it mechanically restricts erroneous movement of the platen to ensure safety measures or normal operation. An object of the present invention is to provide an image forming apparatus capable of achieving the above.

[0009]

SUMMARY OF THE INVENTION According to the present invention, in an image forming apparatus in which a document table on which a document table is placed reciprocates to perform exposure scanning of a document, the document table side is set to a stop member described below by its own weight. The apparatus main body side is provided with a driving means for driving the document table and a moving means for moving the document table, the contact member being swingable between a contact position and a retracted position for retracting above the stop member. A stop member for abutting the abutting member to stop the platen at the home position, an operating member for moving the abutting member to the retracted position to release the abutting state of the abutting member, When the driving of the driving means is started,
And an operation control means for operating the operation member.

According to the present invention, in the image forming apparatus in which the document table on which the document table is placed reciprocates to perform the exposure scanning of the document, the document table side is brought into contact with the following stop member by its own weight and the following stop. The apparatus main body side includes a drive means for driving the document table and the abutting member. A stop member that abuts and stops the document table at the home position; an operating member that moves the abutting member to the retracted position to release the abutting state to the stopping member; An engaging member that engages with the engaged member only when the contact member moves to the retracted position, and an operation control unit that operates the operating member when the drive of the driving unit is stopped. It is a thing.

[0011]

According to the first aspect of the invention, when the driving of the document table is started, the exposure scanning is started, and when the document table returns to the home position after the exposure scanning is completed, the contact member is stopped. The platen is brought into contact with the member and stopped at the home position. As a result, when the document table is not driven, the abutting member contacts the stop member, and movement of the document table in one direction is restricted. On the other hand, when the driving of the original table is started again to perform the exposure scanning, the operating member moves the contact member to the upper retracted position, and the contact state of the contact member is released. This enables the exposure scanning of the document table.

According to the second aspect of the present invention, when the platen returns to the home position, the contact member comes into contact with the stop member to stop the platen at the home position. When the driving of the document table is stopped, the operating member moves the contact member to the upper retracted position to release the contact state of the contact member, and the engaging member causes the engaged portion of the document table to move. Is held in engagement with. As a result, when the document table is not driven, movement of the document table in both forward and backward directions is restricted.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 10 is a schematic configuration diagram showing an embodiment of the image forming apparatus according to the present invention. The image forming apparatus includes a document table 30 and a device body 40. The document table 30 is composed of a document placing plate 31 made of a transparent resin on which a document is placed, and a document retainer 32 which shields outside light, and reciprocates on the upper surface of the apparatus body 40 from side to side. An image forming unit including an image reading unit, a photosensitive drum, and peripheral devices, which will be described later, is provided inside the apparatus main body 40.

As shown in FIG. 11, the document placing plate 31 is
It is attached to an attachment member 36 provided on the back side of the document table 30. The attachment member 36 is a strip-shaped body extending in the left-right direction, and the rack 33 extending in the left-right direction is attached to the lower surface thereof. Further, direction switching members 34 and 35 are attached near the left and right ends of the lower surface. The direction switching members 34 and 35 are, as shown in FIG.
35a, contact members 34b, 35b held by the tubes 34a, 35a and partially protruding, and compression springs 3 for urging the contact members 34b, 35b housed in the tubes 34a, 35a outward.
It consists of 4c and 35c. The direction switching members 34, 35
The rack 33 and the rack 33 will be described later in detail with reference to FIGS.

Returning to FIG. 10, the apparatus main body 40 comprises an upper main body and a lower main body, which are separable from each other.
An exposure hole 41 is formed substantially in the center of the upper surface of the upper body. An image reading section including a light source 42 such as a fluorescent lamp and a condenser lens 43 is provided below the hole 41. A photosensitive drum 44 is disposed below the image reading unit, and a charging device 45, a developing device 46, and a cleaning device 47 are disposed in the peripheral portion of the photosensitive drum 44 from the upstream side. A handle 62 for carrying the image forming apparatus is provided on the right side surface of the upper main body.

The lower main body includes a transfer / separation device 48, a fixing device 49, a paper feed tray 60 for supplying the transfer paper to the right side surface thereof, and a discharge tray for discharging the image-formed transfer paper on the left side surface thereof. 61 is provided. The fixing device 4
9 is provided on the left side of the photosensitive drum 44, and an upper portion thereof is an accommodating portion 47a for the toner collected by the cleaning device 47.
Are formed. Further, the bottom surface portion 63 below the photosensitive drum 44 can be opened and closed so that a paper jam can be processed.

At the upper left end of the upper body, there is provided movement control means CM having a driving means for moving the document table 30 to the left and right and a stop lock means. These means will be described in detail later.

The copying operation of this image forming apparatus is as follows. When the transfer paper is inserted into the paper feed tray 60 after the original is placed at a predetermined position on the original placing plate 31, the transfer paper is detected by a transfer paper detection sensor (not shown), and the copy operation is started by this detection signal. To be done.

The transfer paper is conveyed to a predetermined position (point P) in the transfer paper supply path by the paper feed roller 52 and is put in a standby state. During this time, the original table 30 located at the substantially central home position (state of FIG. 10) in the initial state is temporarily
When it moves to the left (reverse direction) and its right end reaches above the document reading unit, the movement direction is switched from left (reverse direction) to right (forward direction) to start exposure scanning of the document. To be done. The light source 42 is turned on in synchronism with the start of driving the document table 30, and is set to a light amount level capable of being exposed by the start of the exposure scanning of the document.

The light radiated through the exposure hole 41 is reflected on the original surface, and the reflected light is projected onto the photosensitive drum 44 by the condenser lens 43. The photosensitive drum 44 is rotated to the exposure position while the drum surface is charged to a predetermined potential by the charging device 45, and the electrostatic latent image of the original image is formed on the drum surface by the projection of the reflected light. This electrostatic latent image is developed into a toner image by the developing device 46 with toner.

On the other hand, the transfer sheet waiting at the point P is conveyed at a predetermined timing, and the toner image on the photosensitive drum 44 is transferred onto this transfer sheet by the transfer / separation device 48. And
The transfer paper on which the toner image has been transferred is separated from the photosensitive drum 44, fixed by the fixing device 49, and then discharged to the discharge tray 61. The residual toner on the surface of the photosensitive drum 44 after the transfer is removed by the cleaning unit 47.

The document table 30 which has completed the exposure scanning of the document during the image forming operation is reversed from the right direction to the left direction and returned to the home position. The movement time from the start of movement of the document table 30 to the return to the home position is preset in the control unit 500 (see FIG. 4) that controls the entire image forming apparatus.

Next, the drive means and the switching means will be described with reference to FIGS. As shown in FIG. 4, the drive means includes a drive motor 50 and a drive conversion mechanism 100 that converts the torque of the drive motor 50 into left and right movement of the document table. The switching means is a toggle mechanism 20 for switching the moving direction.
0 (see FIG. 3).

The drive motor 50 has a gear 51, and when the power is supplied, the drive motor 50 is always rotated in a fixed direction with a predetermined torque. The power supply to the drive motor 50 is controlled by the control unit 500.

The drive conversion mechanism 100 includes a gear 110 that meshes with the gear 51 of the drive motor 50, a left moving drive gear 120 that meshes with the gear 110, and a left moving drive gear 120.
An intermediate gear 130 that meshes with the intermediate gear 130, a right-moving drive gear 140 that meshes with the intermediate gear 130, and a left-moving driven gear 12 that interlocks with the left-moving drive gear 120 and a clutch 121.
2. The rack mounted on the lower surface of the original table 30 meshing with the right-moving driven gear 142, the right-moving driven gear 142, the intermediate spur gear 150, the intermediate gear 151, the gear 152, and the gear 152, which are interlocked with each other through the right-moving drive gear 140 and the clutch 141. It consists of 33.

The clutches 121 and 141 are toggle mechanisms 20.
By interlocking with 0 and switching the toggle mechanism 200, the operating state and the non-operating state can be switched. Clutch 1
When 21 is put into operation, the left moving drive gear 120
Is transmitted to the left-moving driven gear 122 and the clutch 141 is put into the operating state, the right-moving driving gear 1
The torque of 40 is transmitted to the right-moving driven gear 142.

The torque of the drive motor 50 is transmitted to the right moving drive gear 140 via the gear 51, the left moving drive gear 120, and the intermediate gear 130, and among the torques of the left moving drive gear 120 and the right moving drive gear 140. One of them is a toggle mechanism 200, and one of the corresponding clutches 121 and 141 is in an operating state and is transmitted to the corresponding left-moving driven gear 122 or right-moving driven gear 142, and the intermediate gears 150 and 15 are transmitted.
1 is transmitted to the gear 152, the torque of the gear 152 is transmitted to the rack 33, and the document table is moved to the right or left.

The transmission direction of the drive conversion mechanism 100 is as follows. The gear 51 is always rotated counterclockwise. Therefore, the gear 110 always rotates clockwise, the left movement drive gear 120 rotates counterclockwise, the intermediate gear 130 rotates clockwise, and the right movement drive gear 140 always rotates counterclockwise. Here, when the clutch 121 is engaged, the torque of the left-moving drive gear 120 is transmitted to the left-moving driven gear 122. As shown in FIG. 5, the left-moving driven gear 122 rotates counterclockwise in the same manner as the left-moving driving gear 120, the intermediate gears 150 and 151 rotate clockwise, and the gear 152
Rotates counterclockwise and moves the platen to the left.

On the contrary, when the clutch 141 is engaged, the torque of the right moving drive gear 140 is transmitted to the right moving driven gear 142. As shown in FIG. 6, the right-moving driven gear 14
2 rotates counterclockwise like the right-moving drive gear 140, the left driven gear 122 meshing therewith rotates clockwise, the intermediate gears 150 and 151 rotate counterclockwise, and the gear 152 rotates clockwise. Rotate to move the platen to the right. That is, by switching the toggle mechanism 200, one of the clutches 121 and 141 is activated, and the left and right movements of the document table are controlled.

Next, the structure of the clutches 121 and 141 will be described. First, as shown in FIG. 7, the clutch 121 includes an angular coil spring 123, a spring holding cylinder 124,
It comprises a friction cylinder 125 fitted on the outer peripheral surface of the spring holding cylinder 124, and a ratchet wheel 126 fitted on the outer peripheral surface of the friction cylinder 125. A ratchet 127 is formed on the outer peripheral surface of the ratchet wheel 126 and serves as a toggle mechanism 20.
It is linked to 0. Both ends of the rectangular coil spring 123 are bent to form mounting portions 123a and 123b.

On the other hand, the spring holding cylinder 124 has square coil spring holding notches 124a and 124b formed at both ends thereof. A square coil spring holding hole 120a is formed at an appropriate position on the inner surface of the left movement drive gear 120. The square coil spring 123 is housed inside the spring holding cylinder 124, the mounting portion 123a is fitted into the square coil spring holding notch 124a of the spring holding cylinder 124, and the mounting portion 123b is fitted into the holding hole 120a of the left moving drive gear 120. The left movement drive gear 120 and the spring holding cylinder 124 are mechanically connected.

The rectangular coil spring holding notch 124a has the same shape as the rectangular coil spring holding notch 144a formed in the spring holding cylinder 144 of the clutch 141 described later. As a result, the torque of the left movement drive gear 120 is transmitted to the spring holding cylinder 124.

Ratchet wheel 126 and spring holding cylinder 1
24 are fitted in frictional contact with the friction cylinders 125, respectively, so as to rotate integrally when no external force is applied.

On the other hand, when an external force is applied, that is, when the ratchet wheel 126 is stopped by the toggle mechanism 200,
The spring holding cylinder 124 is adapted to rotate while making a sliding contact with the friction cylinder 125.

The inner diameter of the rectangular coil spring 123 changes depending on the relative speed between the rotation of the left-moving drive gear 120 and the rotation of the spring holding cylinder 124. When the spring holding cylinder 124 freely rotates according to the torque on the driving side, the inner diameter of the square coil spring 123 does not change. However, when an external force is applied to the spring holding cylinder 124 and braking is applied to its rotation, a relative speed is generated and the angular coil spring 123 is
The inner diameter of is smaller.

When the clutch is not operating, that is, when the ratchet wheel 126 is not stopped by the toggle mechanism 200, the spring holding cylinder 124 can freely rotate together with the ratchet wheel 126, and the angular coil spring 123 can be rotated. Is not twisted in the tightening direction.
Therefore, the torque of the left movement driving gear 120 is not transmitted to the left movement driven gear 122.

On the other hand, when the rotation of the ratchet wheel 126 is stopped by the toggle mechanism, a braking force is applied to the spring holding cylinder 124 rotating by the torque of the left movement drive gear 120 via the friction cylinder 125, As a result, the rotation speed of the spring holding cylinder 124 becomes slow, and the angular coil spring 12
3 is twisted in the tightening direction to shrink the inner diameter, tightens the boss of the left-moving driven gear 122, and
Is transmitted to the left-moving driven gear 122.

Further, the inner diameter of the square coil spring 123 is such that in the normal state where no external force is applied, the left-moving driven gear 1
It is larger than the outer diameter of the 22 bosses. That is,
The left-moving driven gear 122 can freely rotate without contacting the angular coil spring 123. Therefore, in the state where the torque of the drive motor is transmitted to the right-moving driven gear 142, the torque transmitted to the right-moving driven gear 142 via the freely rotating left-moving driven gear 122 does not decrease significantly. It is transmitted to the intermediate gear 150.

The structure of the clutch 141 is the same as that of the clutch 121, and includes a rectangular coil spring 143, a spring holding cylinder 144, a friction cylinder 145, and a ratchet 147 on the peripheral surface.
The ratchet wheel 146 is formed.

The spring holding cylinder 144 has square coil spring holding notches 144a and 144b formed at both ends thereof. The ratchet wheel 146 is interlocked with the toggle mechanism 200. Both ends of the rectangular coil spring 143 are bent to form mounting portions 143a and 143b.
In the notch 144b for holding the rectangular coil spring formed in 44,
The right moving drive gear 140 and the spring holding cylinder 144 are mechanically connected to each other by being fitted into the square coil spring holding holes 140a formed at appropriate positions on the inner surface of the right moving drive gear 140.

The rectangular coil spring holding notch 144b is the same as the rectangular coil spring holding notch 124b formed in the spring holding cylinder 124. As a result, the torque of the right movement drive gear 140 is transmitted to the spring holding cylinder 144.

The function of the rectangular coil spring 143 is that the clutch 12
This is the same as the rectangular coil spring 123 of No. 1. Also, the outer diameter of the boss of the right-moving driven gear 142 is smaller than the inner diameter of the square coil spring 143 as in the clutch 121.
When the clutch is not operating, the right-moving driven gear 14
2 can rotate freely. Therefore, in the state where the torque of the drive motor is transmitted to the left-moving driven gear 122, the torque transmitted by the co-rotating left-moving driven gear 142 is not significantly reduced.

The toggle mechanism 200, as shown in FIG.
It includes a switching actuator 210, a stop member 220, and a rotation link 230 connecting them.

The switching actuator 210 has a rotation fulcrum 211 at the center thereof, and has two abutting portions 212 and 213 radially extending at different angles on the upper portion thereof. Abutment 2
12 is a direction switching member 3 provided at the right end of the lower surface of the document table.
4, the contact member 213 is provided so as to be displaced in the front-rear direction so as to contact the direction switching member 35 provided at the left end portion. An arm 215 is formed below, and an engagement pin 214 is attached to the lower end of the arm 215.

The rotation link 230 has a rotation fulcrum 23 at the center.
1, an elongated hole 232 that engages with the engaging pin 214 of the switching actuator 210 is formed at the upper end, and an engaging pin 233 is attached at the lower end.

The stop member 220 is formed in a cross shape, has a swing fulcrum 221 in the center thereof, and has an arm 2 extending left and right.
The ratchet wheels 126, 146 of the clutches 121, 141 have ratchet wheels 127, 14 at the tips of the ratchet wheels 126, 146.
The claws 224 and 225 which engage with 7 are formed.

An elongated hole 227 that engages with the engaging pin 233 of the rotary link 230 is formed at the tip of the arm 226 extending upward. Arm 2 extending downward
A pin 229 is provided at the lower end of the spring 28, and the spring 2 is provided between the pin 229 and the engaging pin 214 of the switching actuator 210.
It is multiplied by 40. The elastic force of the spring 240 causes the stop member 220 to always engage with one of the clutches 121 and 141.

Next, the operation will be described. Platen 30
Is normally stopped at the central position, and when the driving is started, as described above, first, the control unit 500 is moved to the left.
Is set to. The toggle mechanism 200 is in the state of the phantom line in FIG. That is, the stop member 220 is the clutch 1
21 and the torque of the left-moving drive gear 120 is transmitted to the left-moving driven gear 122 to move the document table to the left.

Then, the document table 30 moves to the left,
The direction switching member 34 comes into contact with the contact portion 212, and the spring 24
When the contact portion 212 is tilted to the left against the elastic force of 0, the toggle mechanism 200 enters a state as shown by the solid line in FIG. 3, the stop member 220 engages with the clutch 141, and the right-moving drive gear. The torque of 140 is transmitted to the right-moving driven gear 142, and the document table 30 moves to the right. At this point, the exposure scanning of the document starts.

When the document table 30 moves to the right and reaches the position where the image reading of the document is completed, the direction switching member 35 contacts the contact portion 213 and resists the elastic force of the spring 240. Then, the contact portion 213 is tilted to the right, and the toggle mechanism 2
00 is brought into a state as shown by a virtual line in FIG. The stop member 220 engages with the clutch 121, and the left movement drive gear 1
The torque of 20 is transmitted to the left-moving driven gear 122, and the document table 30 moves leftward.

The control unit 500 manages the movement time from the start of the movement of the platen 30, and stops the drive motor 50 after a predetermined time has passed until the platen 30 is surely returned to the home position. There is.

Note that the toggle mechanism 200 cannot be switched at the time when the document table 30 returns to the home position. Therefore, when the next transfer sheet is set and copying is started, as described above, the transfer sheet temporarily moves to the left and then to the right for the exposure scanning.

In the above embodiment, the switching actuator 210 is provided with the two contact portions 212, 213 displaced in the front-rear direction. However, in the present invention, it is not necessary to provide two contact members, and only one contact member may be provided.

FIG. 8 shows another drive conversion mechanism 1000. Compared with the drive conversion mechanism 100, the drive conversion mechanism 10
00, the intermediate gear 130 is not located between the left moving drive gear 120 and the right moving drive gear 140, but is moved to the left moving driven gear 1
22 and the right-moving driven gear 142. The drive motor 50 is arranged on the right side. further,
The intermediate gear 151 is omitted. Clutch 121,1
The same 41 as that used for the drive conversion mechanism 100 is used.

The transmission direction of the drive conversion mechanism 1000 is
It is as follows. The gear 51 is always rotated counterclockwise, so that the left movement drive gear 120 always rotates clockwise and the right movement drive gear 140 always rotates counterclockwise. When the clutch 121 is engaged, the left-moving driven gear 122 rotates clockwise like the left-moving driving gear 120, the intermediate gear 130 rotates counterclockwise, and the right-moving driven gear 14 moves.
2 rotates clockwise, the intermediate gear 150 rotates counterclockwise,
The gear 152 rotates counterclockwise to move the document table to the left.

On the contrary, when the clutch 141 is put in, the right-moving driven gear 142 rotates counterclockwise in the same manner as the right-moving driving gear 140, and the intermediate gear 15 meshing therewith.
0, the gear 152 rotates clockwise and moves the document table to the right.

FIG. 9 shows another toggle mechanism 2000.
This toggle mechanism 2000 is applied to the drive conversion mechanism 1000, and has basically the same configuration as the toggle mechanism 200 except for the swinging direction of the stop member 2200.

The stop member 2200 has a swing fulcrum 2210 provided at the upper part thereof, and the lower end of the rotary link 2300 is rotatably connected to a pivot point 2270 provided at the lower part of the stop member 2200. When the document table 30 is in the stopped state, the toggle mechanism 2000 is placed in the state of the phantom line in FIG. 9, the stop member 2200 engages with the clutch 121, and the left moving drive gear 1
The torque of 20 is transmitted to the left-moving driven gear 122 to move the document table to the left. When the document table 30 moves to the left and the direction switching member 34 comes into contact with the contact portion 212, and the contact portion 212 is tilted leftward against the elastic force of the spring 240,
The toggle mechanism 2000 is brought into the state shown by the solid line in FIG. 9, the stop member 2200 is engaged with the clutch 141, the torque of the right moving drive gear 140 is transmitted to the right moving driven gear 142, and the document table 30 is moved to the right. Move to.

Next, the stop lock means provided in the movement control means CM will be described with reference to FIGS. 1 and 2. The stop lock means includes a stop means 600, a lock portion 700, and an operating mechanism 800.

The operating mechanism 800 includes an electromagnetic solenoid 81.
0, a swing frame 820, push-up members 831 and 832, and arms 841 and 842, which are attached to the main body side.

The electromagnetic solenoid 810 constitutes a lock driving device, and the push-up member 832 constitutes a lock member. The electromagnetic solenoid 810 includes a plunger 811. The lower end of the plunger 811 has an operating pin 812 extending in the left-right direction. The plunger 811 moves up when power is supplied to the electromagnetic solenoid 810, and moves down by its own weight or the elastic force of a spring (not shown) when the power is stopped. Power is supplied to the electromagnetic solenoid 810 by the document table 30.
This is performed at the same timing when power is supplied to the drive motor 50 that moves the.

The swing frame 820 has a swing fulcrum 8 at the center.
21 and two foot portions 822 and 823 on the left side thereof, and a support portion 824 supporting the arms 841 and 842 on the right side thereof. The push-up members 831 and 832 are attached to the left end portions of the foot portions 822 and 823, respectively, and are slidable in the vertical direction by an appropriate guide member.

The upper portions of the arms 841 and 842 are bent rearward and are arranged so as to sandwich the plunger 811 in the left-right direction. Further, the bent portion of the arm 841 and the bent portion of the arm 842 are arranged in different steps so as to sandwich the actuating pin 812 in the vertical direction.

When power is supplied to the electromagnetic solenoid 810, the plunger 811 rises, the swing frame 820 swings counterclockwise, and the push-up members 831 and 832 descend. When the power supply to the electromagnetic solenoid 810 is stopped, the plunger 811 descends, the swing frame 820 swings clockwise, and the push-up members 831 and 832 rise.

The stopping means 600 comprises an operating member 610, a stopper 620 and a block 630. Actuating member 610
Has a swing shaft 611, a front contact arm 612 extending leftward from the front end of the swing shaft 611, and a rear contact arm 613 extending leftward from the rear end of the swing shaft 611. The front contact arm 612 is the contact portion 21 of the switching actuator 210.
A position changing unit that abuts 2 is configured. Push-up member 831
When the platen 30 comes to the home position, it contacts the lower surface of the contact arm 613 and swings the operating member 610 in the clockwise direction as the push-up member 831 rises. Further, the rear side contact arm 613 is the contact part 6 of the stopper 620 described later.
Abutting 22.

The operating member 610 is attached to the document table 30, and comes into contact with the stopper 620 at the contact position and the pushing member 8.
It swings between push-up positions that are pushed up as 31 moves up. The push-up member 831 constitutes an operating member of the operating mechanism 800 that operates the rear contact arm 613.

The stopper 620 is provided with a rotating shaft 621, a contact portion 622, and a weight 623. A block 630 is provided on the left side of the stopper 620. Stopper 62
0, the block 630 is attached to the main body.

At normal times, as shown in FIG.
The weight of 23 keeps the contact portion 622 slightly inclined to the right. That is, the state of the solid line in FIG. 1 is maintained. When the rear contact arm 613 of the operating member 610 abuts the stopper 620, the moving force of the document table 30 to which the operating member 610 is attached overcomes the weight of the weight 623 and the abutting portion 622 reaches the block 630. It is raised until it hits (Fig. 2 (b)). Thereafter, the block 630 stops further rotation of the abutment portion 622, and the operating member 6
Stop moving 10 to the left. That is, the movement of the document table 30 is stopped.

When the operating member 610 is stopped by the stopper 620 and the block 630, at the same time, the operating member 6 is stopped.
The front contact arm 612 of the switch 10 has the switching actuator 21.
The stop mechanism member 220 of the toggle mechanism 200 is swung to a position slightly separated from the clutch 121 to bring the toggle mechanism 200 into a neutral state.

The lock portion 700 is a block-shaped regulating member 7.
10, and a recess 711 is formed on the lower surface thereof. The recess 711 engages with the push-up member 832. The recess 711 is formed to be slightly larger than the width of the push-up member 832 so that when the push-up member 832 is engaged, some play is generated in the left-right direction. Note that a long hole in the left-right direction may be formed instead of the recess 711.

Next, the operation of the stop lock means will be described in detail with reference to FIGS.

As described above, when the copy operation is started, the document table 30 first moves to the left from the home position, then moves to the right for the exposure scanning, and is further changed in direction when the exposure scanning ends. To the left to return to the home position. 12 to 18 show each state of the series of movements in detail.

In the above drawings, (a) shows the regulating member 71.
0 and the push-up member 832, (b) shows the relationship between the stopper 620, the rear contact arm 613 of the operating member 610, and the lifting member 831, and (c) shows the switching actuator 210 and the operating member 610. Front contact arm 612
Shows the relationship with.

FIG. 12 shows a state in which the document table 30 is locked. The push-up member 832 is pushed upward by the operating mechanism 800 and engages with the concave portion 711 of the regulating member 710 to prevent the document table 30 from moving left and right (FIG. 12).
(A)). At the same time, the operating member 610 is rotated clockwise by the push-up member 831, the rear contact arm 613 is above the contact portion 622 of the stopper 620, and the front contact arm 612 is connected to the contact portion 212 of the switching actuator 210. It is pushed up (Figs. 12 (b) and 12 (c)).

When the copying operation is started, the drive motor 50
Power is supplied to the electromagnetic solenoid 810. As a result, the plunger 811 of the electromagnetic solenoid 810 rises and the push-up members 831 and 832 descend, resulting in the state shown in FIG. That is, the push-up member 832 is disengaged from the recess 711 of the regulation member 710, and the lock of the document table 30 is released (FIG. 13A). The operating member 610 rotates counterclockwise, and the front contact arm 612 moves the switching actuator 210.
The rear contact arm 613 is stopped above the contact portion 622 of the stopper 620 (FIG. 13B), so that the original table 30 moves to the left. When starting, the front contact arm 612 slides on the upper end surface of the contact portion 212, the rear contact arm 613 does not contact the contact portion 622, and the document table 30 is free to move leftward. (Fig. 13 (c)).

In FIG. 14, the document table 30 moves to the left,
The state in which the direction switching member 34 attached to the right end portion is in contact with the contact portion 212 is shown. Then, the document table 30 is moved slightly further to the left, and the direction switching member 34 rotates the contact portion 212 of the switching actuator 210 to the left,
The stop means 220 of the toggle mechanism 200 is engaged with the clutch 121 to switch the moving direction of the document table 30 to the right.

In FIG. 15, the rear contact arm 613 of the actuating member 610 hits the contact portion 622 and the stopper 620 is rotated clockwise while the document table 30 moves to the right. The state of getting over 622 is shown.

The front side contact arm 612 is connected to the contact portion 2
Since 12 is on the lower side, it passes by in a non-contact state (FIG. 15 (c)).

In FIG. 16, the document table 30 moves to the right,
The state in which the direction switching member 35 attached to the left end is in contact with the contact portion 213 is shown. As a result, the document table 30 is moved to the right a little further, and the direction switching member 35 is moved to the contact portion 2.
13 is rotated to the right to engage the stop member 220 of the toggle mechanism 200 with the clutch 141 to switch the moving direction of the document table 30 to the left (the state shown by the phantom line in FIG. 16C). This causes the platen 30 to move to the left again.

In FIG. 17, the document table 30 is moved to the left and the rear contact arm 613 is moved to the contact portion 6 of the stopper 620.
22 shows a state in which the stopper 620 is brought into contact with 22 and is raised up to the block 630. That is, the document table 30
Shows the state where the stopper 620 and the block 630 have stopped. At this time, the front abutment arm 612 abuts the abutment portion 212 of the switching actuator 210 to rotate the abutment portion 212 slightly leftward (state shown by a solid line in FIG. 17C). As a result, the stopping means member 2 of the toggle mechanism 200
20 is swung to a position slightly separated from the clutch 121, and the clutch 121 is released.

The drive motor 50 and the electromagnetic solenoid 8
The power supply time to 10 is preset in the control unit 500. The set time is set to be slightly longer than the time required for the document table 30 to start moving from the home position and return to the home position. The reason for providing this excess time is as follows.

Even when the drive motor 50 is turned off at the moment when the rear contact arm 613 of the actuating member 610 abuts the stopper 620 and stops the original table 30, the original table 30 stops exactly at the home position. It's difficult. The document table 30 has an inertial force, and a reaction force is generated when the rear side contact arm 613 comes into contact with the stopper 620, and the rear side contact arm 613 retracts slightly from the stopper 620 to the right. Is possible. In order to eliminate the backward movement due to this reaction force, even if the document table 30 is temporarily stopped by the stopper 613, the drive motor 50 is driven a little more and the rear side contact arm 613 retracted to the right is brought into contact with the stopper 620 again. This is for surely stopping the document table 30 at the home position by stepping on it.

The reason why the clutch is in the neutral state is as follows.
This is because the drive conversion mechanism 100 is driven in an idle state for a while after the completion of the copying work to adjust the engagement state of the gears so that the drive conversion mechanism 100 can be smoothly restarted when the copying work is restarted. FIG. 18 shows a push-up member 832.
Is pushed up and is engaged again with the concave portion 711 of the regulating member 710 to lock the document table 30.

That is, the power supply to the drive motor 50 and the electromagnetic solenoid 810 is stopped, and the electromagnetic solenoid 8
Plunger 811 of 10 descends to push up members 831 and 8
32 is slid upwards. When the push-up member 831 rises, the operating member 610 rotates clockwise, the rear contact arm 613 reaches above the upper end surface of the contact portion 622 of the stopper 620, and the stopper 620 is tilted from its vertical position by its own weight. (The state shown by the phantom line in FIG. 7B). Further, the front contact arm 612 is connected to the switching actuator 210.
Of the toggle mechanism 2 is reached above the end surface of the contact portion 212 of the
The stop means 220 of 00 reengages the clutch 121 to operate the clutch 121 (state shown by phantom line (c) in the figure). On the other hand, the push-up member 832 is also slid upward and engages with the recess 711 of the regulating member 710 to be in the state of FIG. 12 (FIG. 12A).

In the above embodiment, the moving time of the document table 30 set in the control section 500 is set to be slightly longer than the time required for the document table 30 to reach the home position. However, the present invention does not necessarily have to provide such an excess time.

For example, the stopper 620 is attached to the rear contact arm 6
A sensor for detecting the contact of the rear contact arm 13 is provided, the sensor detects the contact of the rear contact arm 613 and transmits it to the control unit 500 as a contact signal, and the control unit 500 drives the drive motor based on the contact signal. You may make it stop 50.

FIG. 19 shows another stop locking means of the present invention. The stop lock means does not prevent the document table 30 from moving in both left and right directions when the copying operation is not performed, but merely prevents the document table 30 from moving to the left.

The structure of this stop lock means is such that the recess 711 is formed.
1 except that there is no restriction member 710 in which a stopper is formed and a push-up member 832 that engages with the recess 711, that the stopper is formed of one member, and that the operating mechanism is different. It is substantially the same as the stop lock means shown.

As shown in FIG. 19, the stopper 6200 provided in this stop lock means is composed of one block, and an inclined surface 6210 is formed in the upper left portion. As will be described later, the inclined surface 6210 causes the rear contact arm 613 to stop when the document table 30 moves to the right.
This is to make it easier to get over 200. Stopper 62
00 is placed at a position where it abuts the rear abutting arm 613 when the document table 30 moves to the home position.

The actuating mechanism includes an electromagnetic solenoid 8100 having a vertically movable plunger 8110, a push-up member 831, and a swing member 8200 and a plunger 8110 which move the push-up member 831 and the plunger 8110 to the push-up member 831 in the upward direction. And a spring 8120 that urges the spring 8120.

When power is supplied to the electromagnetic solenoid 8100, the plunger 8110 descends against the elastic force of the spring 8120, moving the push-up member 831 upward,
The rear contact arm 613 is pushed up above the stopper 6200. When the power supply is stopped, the plunger 8110
Rises due to the elastic force of the spring 8120 and moves the push-up member 831 downward. Therefore, the rear contact arm 613 also swings counterclockwise, and the rear contact arm 613 comes into contact with the stopper 6200.

Next, the operation of the stop lock means will be described with reference to FIGS. In these drawings, (a) shows the relationship between the stopper 6200, the rear contact arm 613 and the push-up member 831 of the operating member 610, and (b) shows the switching actuator 210 and the operating member 61.
The relationship with the front contact arm 612 of 0 is shown.

Before the copying work is started, FIG.
As shown in FIG.
The original table 30 is prevented from moving to the left by coming into contact with 200.

When the copying work is started, as shown in FIG. 21, power is supplied to the drive motor 50 and the electromagnetic solenoid 8100, the plunger 8110 of the electromagnetic solenoid 8100 descends and the push-up member 831 rises, and the rear The side contact arm 613 is pushed up in the clockwise direction (Fig. 21).
(A)). After that, when the document table 30 starts moving leftward, the rear contact arm 613 slides on the upper surface of the push-up member 831 and the upper surface of the stopper 6200 and moves leftward.
Thereafter, as in FIG. 14, the direction switching member 34 rotates the contact portion 212 of the switching actuator 210 to the left, and the stop member 220 of the toggle mechanism 200 is engaged with the clutch 121 to move the document table 30 in the moving direction. To the right. This moves the document table 30 to the right.

22 corresponds to FIG. 15, and the rear contact arm 613 of the operating member 610 contacts the inclined surface 6210 of the stopper 6200 while the front contact arm 612 is in contact with the front contact arm 612 while the document table 30 is moving to the right. It shows a state of hitting the contact portion 213 and rotating clockwise to get over the stopper 6200 and the contact portion 212.

The electromagnetic solenoid 8100 stops supplying power when a predetermined time has elapsed, and the plunger 8110
Is raised by the spring 8120 and the push-up member 831 is lowered. Thereafter, as in FIG. 16, the direction switching member 35 attached to the left end contacts the contact portion 213 to rotate the contact portion 213 rightward, and the toggle mechanism 200 is rotated.
The stop means 220 is engaged with the clutch 121 to switch the moving direction of the document table 30 to the left. As a result, the document table 30 moves to the left again.

Thereafter, the platen 30 moves to the left,
Returning to FIG. 20, the rear contact arm 613 is provided with the stopper 620.
The original table 30 is stopped by the stopper 6200 when it comes into contact with 0. The front contact arm 612 is a switching actuator 210.
Abutting the contact portion 212 of the clutch 1 and rotating the contact portion 212 to the left a little, and swinging the stop means 220 of the toggle mechanism 200 to a position slightly separated from the clutch 121 to disengage the clutch 1.
21 is released and waits for resuming copying work.

This stop lock means cannot prevent the original table 30 from moving to the right when the copying operation is not performed, but the structure can be simplified.

[0099]

As described above, according to the present invention,
The contact member at the contact position is brought into contact with the stop member by its own weight to stop the platen at the home position, and
When this original contact state is maintained and the drive of the platen is started again, the contact member is moved to the upper retracted position to release the contact state, so the drive of the original plate is stopped. , The movement of the document table in one direction is restricted, and the document table is prevented from accidentally moving in one direction.Therefore, when lifting the handle on the side of the main body or lifting the other for jam clearance, The table is prevented from being damaged.

When the abutment member at the abutment position is brought into abutment against the stop means by its own weight to stop the document table at the home position and the drive of the document table is stopped, the corresponding contact member is moved to the upper retracted position. The contact member is released from the contact state and the engaging member is engaged (locked) with the regulating member only when the contact member is in the retracted position, so that the document table is free even when the document table is free. The platform does not move accidentally,
Prevents damage to equipment and ensures the safety of workers and carriers.

Further, since the original table does not accidentally move in the free state due to the lock, it is possible to prevent an erroneous operation at the time of copying later, and to eliminate a miscopy and a paper jam due to this erroneous operation. it can.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a stop lock unit of the image forming apparatus according to the present invention.

2A and 2B are diagrams showing a configuration of a stop means for stopping a document table at a home position, wherein FIG. 2A is a view showing a state before a stop operation, and FIG. 2B is a view showing a state after the stop operation. .

FIG. 3 is a schematic front view showing the structure of a toggle mechanism used in the drive conversion mechanism of the image forming apparatus according to the present invention.

FIG. 4 is a horizontal sectional view showing a configuration of a drive conversion mechanism of the image forming apparatus.

FIG. 5 is a schematic front view showing one transmission direction of the drive conversion mechanism.

FIG. 6 is a schematic front view showing the other transmission direction of the drive conversion mechanism.

FIG. 7 is an exploded perspective view showing a configuration of a clutch used in the drive conversion mechanism.

FIG. 8 is a diagram showing the configuration of another drive conversion mechanism.

FIG. 9 is a schematic front view showing the configuration of another toggle mechanism.

FIG. 10 is a schematic configuration diagram showing an embodiment of an image forming apparatus according to the present invention.

FIG. 11 is a perspective view showing a contact glass of the image forming apparatus and a mounting state thereof.

12A and 12B show a state of stop lock means when the platen is locked at a home position, FIG. 12A shows a state in which a push-up member is engaged with a regulating member, and FIG. The figure which shows the state of the stop means when engaged,
(C) is a figure which shows the relationship between the contact arm of a stop means, and the contact part of a toggle mechanism when a push-up member is engaged.

13A and 13B show a state of stop lock means when the platen is unlocked, FIG. 13A is a diagram showing a relationship between a push-up member and a regulating member, and FIG. 13B is a contact arm of the stop means. FIG. 6C is a diagram showing the relationship with the stopper, and FIG. 7C is a diagram showing the relationship between the contact arm of the stopping means and the contact portion of the toggle mechanism.

14A and 14B are views showing the state of the stop lock means when the platen is moved leftward, in which FIG. 14A shows the state of the push-up member, FIG. 14B shows the state of the stop means, and FIG. 8] is a view showing a relationship between a contact portion of the toggle mechanism and a direction switching member.

15A and 15B are views showing a state of stop lock means during movement of a document table to the right, FIG. 15A is a diagram showing a relationship between a push-up member and a regulating member, and FIG. FIG. 6 is a diagram showing the relationship between the contact arm and the stopper, and FIG. 7C is a diagram showing the relationship between the contact portion of the toggle mechanism and the direction switching member.

16A and 16B are views showing the state of the stop lock means when the platen is moved rightward, in which FIG. 16A shows the state of the push-up member, FIG. 16B shows the state of the stop means, and FIG. 8] is a view showing a relationship between a contact portion of the toggle mechanism and a direction switching member.

17A and 17B are views showing a state of the stop lock means when the platen is returned to the home position, FIG. 17A is a view showing a relationship between the push-up member and the regulating member, and FIG. 17B is a contact arm of the stop means. And (c) is a diagram showing the relationship between the contact portion of the toggle mechanism and the direction switching member.

FIG. 18 is a view showing a state of stop lock means when the platen is returned to the home position and is locked again.
(A) is a diagram showing a state in which the push-up member is engaged with the regulating member,
(B) is a figure which shows the state of a stop means when a push-up member is engaged, (c) is a relationship between the contact arm of a stop means and the contact part of a toggle mechanism when a push-up member is engaged. FIG.

FIG. 19 is an exploded perspective view showing the configuration of another stopping means.

FIG. 20 is a view showing a state of the other stop lock means before the copy operation is started, (a) is a diagram showing a relationship between the stop means and the stopper, and (b) is a contact arm of the stop means. It is a figure which shows the relationship between the contact part of a toggle mechanism.

21A and 21B show the states of the other stop lock means when the copy operation is started, where FIG. 21A shows the relationship between the stop means and the stopper, and FIG. 21B shows the contact arm of the stop means. It is a figure which shows the relationship with the contact part of a toggle mechanism.

22A and 22B show the states of the other stop lock means while the platen is moving to the right; FIG. 22A shows the relationship between the stop means and the stopper; and FIG. 22B shows the stop means. It is a figure which shows the relationship between the contact arm and contact part of a toggle mechanism.

[Explanation of symbols]

30 original table 31 original placing plate 32 original pressing plate 33 racks 34, 35 direction switching member 36 mounting member 40 device body 41 exposure hole 42 light source 43 condenser lens 44 photoconductor drum 45 charging device 46 developing device 47 cleaning device 47a Toner storage 48 Transfer / separation device 49 Fixing device 50 Drive motors 51, 110, 152 Gears 52 Paper feed rollers 60 Paper feed trays 61 Discharge trays 62 Handles 100, 1000 Drive conversion mechanism 120 Left movement drive gears 121, 141 Clutch 122 Left-moving driven gear 123,143 Square coil spring 124,144 Spring holding cylinder 125,145 Friction cylinder 126,146 Ratchet wheel 127,147 Ratchet 130,151 Intermediate gear 140 Right-moving driving gear 142 Right-moving driven gear 15 0 Intermediate spur gear 200,2000 Toggle mechanism 210 Switching actuator 211,231 Rotation fulcrum 212,213 Abutment member 214,233 Engagement pin 215 Arm 220,2200 Stop member 221,821,210 210 Swing fulcrum 222,223,226 , 228, 841, 842 Arm 224, 225 Claw 227, 233 Long hole 229 Pin 230, 2300 Rotating link 500 Control part 600 Stopping means 610 Actuating member 611 Swing shaft 612, 613 Abutting arm 620, 6200 Stopper 622 Abutting Part 623 Weight 630 Block 700 Lock part 710 Control member 711 Recessed part 800 Actuating mechanism 810 Electromagnetic solenoid 811 Plunger 820 Swing frame 822,823 Foot part 831,832 Push-up member 2700 Pivot point 6210 Inclination Surface CM movement control means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tsutomu Sugaya 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Engineering Co., Ltd.

Claims (2)

[Claims] 1. In an image forming apparatus in which a document table on which a document table is placed reciprocates to perform exposure scanning of a document, on the document table side, the contact position of the following stop member due to its own weight and the following stop member The apparatus main body side is provided with a contact member that is swingable between retreat positions that are spaced apart and retracted upward, and the apparatus main body side abuts the contact member during the movement of the document table and the drive means. A stop member for stopping the document table at the home position, an operating member for moving the contact member to the retracted position to release the contact state with the stop member, and driving of the drive means are started. An image forming apparatus comprising: an operation control unit that operates the operation member. 2. In an image forming apparatus in which a document table on which a document table is placed reciprocates to perform exposure scanning of a document, on the document table side, the contact position of the following stop member due to its own weight and the following stop member An abutting member swingable between retreat positions that are separated upward and retracted, and an engaged member, and the apparatus main body side abuts the abutting member with a driving unit that drives the document table. A stop member for stopping the platen at the home position,
An operating member that moves the contact member to the retracted position to release the contact state with the stop member, and the engaged member only when the contact member moves to the retracted position in cooperation with the operating member. An image forming apparatus comprising: an engagement member that engages with a member; and an operation control unit that operates the operation member when the drive of the drive unit is stopped.