JPH115641A - Drive transmission device, feeding device, and image forming device - Google Patents

Abstract

(57) [Problem] To provide a drive transmission device, a feeding device, and an image forming device that realize a simplified configuration. SOLUTION: When a solenoid 23 is excited, a flapper 2 is provided.
3a is pulled, the lock with the control claw 22b is released, and the feed roller unit 20 rotates in the direction of the arrow by its own weight, and meshes with the input gear 24 to transmit the drive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive transmission device for transmitting the drive of a drive source, for example, a copying machine, a printer, a facsimile machine, etc. having a function of forming an image on a sheet. The present invention can be applied to a feeding device provided in the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as this type of image forming apparatus, for example, there are a copying machine, a printer, a facsimile machine and the like.

A copying machine generally has a function of reading an image of an original or the like and forms an image on a sheet based on the read image information. Some copiers have a function of inputting image information to be sent.

[0004] A printer is generally an external device,
For example, an image is formed on a sheet based on image information sent from an apparatus such as a computer, and a facsimile apparatus generally has a function of reading an image of a document,
Further, it has a communication function, sends read image information to the outside, and forms an image on a sheet based on information sent from the outside.

In such an image forming apparatus, there is provided a feeding device for feeding a sheet for forming an image, and the feeding device rotates a feeding roller for feeding the sheet. For this purpose, a drive transmission device for transmitting the drive of the drive source is provided.

In this drive transmission device, the drive transmission is canceled at a predetermined timing and turned on again so that an image is formed at an appropriate position on the sheet.

For example, a case of a feeding roller unit in a copying machine will be described as an example.

A driving force for applying rotation to the feeding roller is transmitted from a driving source, and finally reaches the feeding gear via the input gear.

Here, if the feed roller constantly transmits the drive, the feed roller continues to rotate and feeds the sheet without interruption. Therefore, it is necessary to turn ON / OFF the drive at a certain timing.

Therefore, a clutch mechanism is employed when the drive train is constituted by the same drive source as the gear train to which the driving gear is constantly transmitted.

The clutch mechanism is roughly classified into a method using an electromagnetic clutch and a one-turn clutch mechanism using a toothless gear and a solenoid.

The method of attaching the electromagnetic clutch to the feed gear requires a relatively small installation space, but has the disadvantage of significantly increasing the cost.

Therefore, in the one-rotation control of the feed roller, a clutch mechanism using a solenoid and a toothless gear is mainly used.

Hereinafter, a drive transmission device according to the prior art will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is a schematic configuration perspective view of a drive transmission device according to the related art, and FIG. 8 is a schematic configuration diagram of a drive transmission device according to the related art.

7 and 8, the feeding roller 9
And the cam 2 having the control claw 22b.
A feeding gear 22 as a toothless gear having 2a is stopped by a control claw portion 22b by a flapper 23a of a solenoid 23 and is stationary.

In this state, the input gear 2
Even if the drive is transmitted up to 4, the drive is not transmitted to the feed gear 22 because the toothless portion of the toothless gear 22 faces the input gear.

Next, the operation of the one-rotation clutch mechanism during feeding will be described in detail.

First, the solenoid 23 is excited and the flapper 23a is sucked to release the lock by the flapper 23a, and the feeding gear 22 is rotated by the amount of the missing teeth by the urging force of the feeding gear spring 30.

Then, the feed gear 22 meshes with the input gear 24, and the drive of the input gear 24 is transmitted.

Here, the solenoid 23 has a flapper 23a.
And the lock with the control claw 22b may be released once.
The non-excitation state is set during one rotation of the feeding gear 22.

Then, the control claw portion 22b of the feed gear 22 is locked again to the flapper 23a of the solenoid 23 in the non-excited state, and the toothless portion faces the input gear 24, so that the feed gear 22 Stops.

By exciting the solenoid at a desired timing in this manner, one rotation of the feed roller 9 can be controlled.

[0023]

However, when the solenoid 23 is excited to release the flapper 23a and rotate the feed gear 22, as in the above-described prior art, the tension spring 30 rotates in the rotational direction. The following problems have occurred due to the urging.

First, a spring must be mounted at a position sufficiently distant from the surface of the control claw 22b so that the feeding gear spring 30 does not interfere with the gear when the feeding gear 22 rotates, and a depth space of the entire apparatus is required. .

Further, a spring hooking member 22c is required on the cam surface of the feeding gear 22, and a fixed side spring hooking member 31 is required on the other side, so that the number of parts is increased and the assemblability is deteriorated.

Further, when the spring hooking member 22c is integrally formed on the cam surface of the feeding gear 22, the structure becomes complicated, and the cost is increased.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a drive transmission device, a feeding device, and an image forming apparatus which realize a simplified configuration. It is in.

[0028]

According to the present invention, there is provided a drive transmission device, wherein a drive tooth is driven by being transmitted by a drive source, and is disposed facing a drive gear. In a drive transmission device comprising: a drive transmission unit having a gear; and a regulating unit that regulates driving of the drive transmission unit, wherein the drive transmission unit is configured such that, when regulated by the regulation unit, the toothless portion The toothless portion of the gear stands by in opposition to the drive gear, and is released by the restriction of the restricting means so as to rotate by its own weight and mesh with the drive gear to start driving transmission.

Accordingly, when the regulation of the regulation means is released, the drive transmission means rotates by its own weight and meshes with the drive gear, so that an urging spring for rotating the drive transmission means is not required.

The regulating means has a solenoid and a locking member which moves in accordance with ON / OFF of the solenoid, and the movement of the locking member causes a locking portion provided in the drive transmission means to move. On the other hand, locking and unlocking may be performed.

Therefore, the drive transmission means is restricted by the locking of the locking member, and the restriction of the drive transmission means is released by releasing the lock.

It is preferable to provide a weight for rotating the toothless gear in a predetermined direction.

Therefore, the drive transmission means is rotated by the weight.

A weight for rotating in the predetermined direction may be provided on the rotating shaft of the toothless gear.

Further, in order to achieve the above object, the feeder according to the present invention is preferably provided with a feed roller for feeding a sheet onto a shaft of a toothless gear provided in the drive transmission device. .

The feed roller may be provided with a weight for rotating in a predetermined direction.

Accordingly, the drive transmission means is rotated by the weight provided on the feed roller.

Further, in order to achieve the above object, in the image forming apparatus of the present invention, it is preferable to provide an image forming means for forming an image on a sheet fed by the feeding apparatus.

[0039]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(Embodiment) FIGS. 1 and 2 show a drive transmission device and a feeding device according to an embodiment of the present invention.

FIG. 1 is a schematic perspective view of a feeder to which a drive transmission device according to an embodiment of the present invention is applied, and FIG. 2 is a perspective view of the drive transmission device according to the embodiment of the present invention. It is a schematic block diagram.

The same components as those in the prior art are denoted by the same reference numerals.

FIG. 3 shows a copying machine as an example of an image forming apparatus to which the drive transmission device and the feeding device according to the embodiment of the present invention are applied.

FIG. 3 is a schematic configuration diagram of a copying machine.

First, a copying machine as an example of an image forming apparatus will be described with reference to FIG.

As shown in the figure, a copying machine 1 irradiates a light image based on image information from a document reading means 2 having a light source 3, a mirror 4, a lens 5 and the like, and a photosensitive drum as an image carrier. After the latent image is formed on the toner image 6, the image of the developer (hereinafter referred to as toner) is formed by the developing means.

Then, in synchronization with the formation of the toner image, the recording medium (sheet) S is transported from the cassette 8 by the transport unit 7 including the feed roller 9, the transport roller 10, and the registration roller 11.

The toner image formed on the photosensitive drum 6 is transferred to the recording medium S sent to the image forming section by applying a voltage to a transfer roller 12 which is a transfer unit constituting the image forming unit.

Thereafter, the sheet is further conveyed to a fixing means 14 by a conveying belt 13, a permanent image is formed by heat and pressure, and the image is stacked on a sheet discharge tray 15.

Here, the feed roller 9 need only pick up only _one of the uppermost sheets S1 of the recording medium S and feed it to the downstream pair of conveying rollers. In this embodiment, the half-moon type is used. Is controlled by one rotation.

Next, a drive transmission device and a feeding device (particularly, a method for controlling one rotation of the feeding roller 9) will be described in detail with reference to FIGS.

The drive transmission device according to the embodiment of the present invention employs a one-turn clutch mechanism.

As shown in the drawing, a feed roller unit 20 constituting a feed device is generally composed of a feed shaft 21 on which the feed roller 9 is mounted, and a feed shaft 9 which is coaxial with the feed shaft 21.
And a feed gear 22, which is a toothless gear that constitutes a drive transmission unit for rotating the motor.

The feed gear 22 is moved in the axial direction by the cam surface 2.
2a and a control claw 22b, the control claw 2 being a locking portion.
At 2b, the solenoid 23 is locked by a flapper 23a, which is a locking member arranged to face the solenoid 23 in a non-excited state (the solenoid 23 is in an OFF state).

The regulating means is constituted by the solenoid 23 and the flapper 23a.

In the state where the feed gear 22 is locked by the flapper 23a, the missing tooth portion of the feed gear 22 is opposed to the input gear 24 as a drive gear and is stationary.

Therefore, even if the drive is transmitted by a drive source (not shown) and the input gear 24 is rotationally driven,
The drive is not transmitted to the feeding gear 22 and is on standby.

Here, when the solenoid 23 is excited (the solenoid 23 is turned on), the flapper 23a is pulled, and the engagement with the control claw 22b is released.

By releasing the lock in this manner, in this embodiment, the feed roller unit 20 including the drive transmission means rotates in the direction of the arrow by its own weight, and the input gear 2
It is characterized in that the driving force is transmitted by meshing with the gear 4.

Therefore, when the lock is released as in the prior art, there is no need to rotate the feed gear 22 or the like by a spring or the like, so that the configuration is simplified.

The image forming apparatus is not limited to a copying machine, but may be applied to, for example, a printer or a facsimile machine.

Hereinafter, more specific examples of the drive transmission device and the feeding device will be described.

[0063]

【Example】

(First Embodiment) A first embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic configuration diagram of a main part (feed roller 9) of the feed device according to the first embodiment of the present invention.

As shown in the figure, the feed roller 9 is roughly
It is composed of a rubber part 25 and a holder part 26, and is configured to be detachable from the feed shaft 21 by the holder part 26.

In the present embodiment, the feeding roller unit 20 is rotated by its own weight by making the rotation direction (arrow direction in the drawing) side of the holder 26 heavy.

That is, the weight member 27 is provided on the rotation direction side of the holder 26.

FIG. 4A shows a configuration in which the weight member 27 is externally attached, and FIG. 4B shows a configuration in which the weight member 27 is fitted.

Here, the condition that the feed roller unit 20 is rotated by its own weight is that the rotational moment due to the own weight of the feed roller unit 20 is the moment due to the frictional force at a bearing (not shown) in front of the feed shaft 21. It is to exceed.

That is, it is advantageous that the center of gravity of the feeding roller unit 20 is far from the axis and the weight is large.

Therefore, this embodiment is effective when the diameter or the thickness of the feeding roller 9 is large.

As a material of the weight member 27, lead, copper, iron or the like having a large specific gravity can be used.

As described above, in this embodiment, the feeding roller 9
By providing the weight member 27 on the holder member 26, the solenoid 23 rotates by its own weight when the flapper 23a of the solenoid 23 is pulled and the locking is released.

Therefore, there is no need for the conventional tension spring 30 for urging in the rotational direction, the feeding gear 22 and the fixed-side spring hook members 22c and 31 as in the prior art.

Further, since there are no such members, the depth space of the drive system can be reduced, and the size of the apparatus can be reduced.

Further, the cost can be significantly reduced as compared with the electromagnetic clutch system.

Instead of providing the weight as a separate member, it is also possible to use a conventionally provided component as the weight, an example of which will be described below.

As shown in FIG. 4C, a case is considered in which the feed roller 9 is provided with a roller member 28 at the end in the rotation direction.

The roller member 28 is a portion that comes into contact with the sheet when the feeding roller 9 rotates and comes into contact with the sheet, and is provided for reducing a shock. This has the effect of reducing the load on the system.

In this embodiment, the roller member 28 is also used as the weight member 27.

That is, the material of the roller member 28 is, for example,
A one-turn clutch mechanism is formed by forming the feed roller unit 20 from a lead, copper, or iron to sufficiently increase the rotational moment due to its own weight.

This embodiment is also effective when the diameter or thickness (thrust length) of the feeding roller 9 is large.

Further, as for the effects, the depth of the drive system can be reduced and the cost can be reduced as in the above embodiment.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention. In the first embodiment, the configuration in which the feed roller 9 is provided with the weight is shown. In the present embodiment, the configuration in which the feed gear 22 is provided with the weight is shown.

FIG. 5 is a schematic configuration diagram of a drive transmission device according to a second embodiment of the present invention.

As shown in FIG.
By mounting the weight member 27 at 2, the feed roller unit 20 generates a rotational moment by its own weight.

This method is effective when the diameter or thickness of the feeding gear 22 is large.

Further, as in the above-described embodiment, the present invention is effective in reducing the depth of the drive system and cost.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention. In the present embodiment, the feed roller shaft 21
A configuration in which a weight is provided above is shown.

FIG. 6 is a schematic perspective view of a feeder to which a drive transmission device according to a third embodiment of the present invention is applied.

As shown in the figure, a weight member 27 is provided on the feed roller shaft 21.

As the material of the weight member 27, lead, copper, iron and the like are effective as in the above-described embodiment, but may be a part instead of the whole part.

Also in this embodiment, it is possible to provide a one-rotation clutch mechanism that rotates by its own weight by generating a rotation moment due to the movement of the center of gravity of the feeding roller unit 20 by providing the weight member 27.

In this embodiment, the diameter of the outer peripheral surface of the weight member 27 can be increased as long as it does not exceed the diameter of the feeding roller 9.

In the thrust direction, the length of the feed shaft 21 other than the feed roller 9 can be increased, and a plurality of weight members 27 can be provided.

Therefore, without spending the depth of the drive system,
Empty space in the feed roller unit can be used effectively,
The size of the device can be reduced.

If the outer peripheral surface 27a of the weight member 27 has substantially the same diameter as the feed roller and has good slidability, even if the recording medium S in the cassette 8 is curled. , And a good feeding performance can be obtained.

(Other Embodiments) The weight member 27 may be one of the first to fourth embodiments, but two or more may be combined as needed.

The shape of the feeding roller is not limited to the half-moon shape, but may be a round shape.

Note that the drive transmission device shown in each of the above embodiments is not limited to the feed device, but may include a solenoid and a toothless gear.
It has wide versatility for all drive transmission mechanisms having a rotary clutch.

[0100]

As described above, in the drive transmission device of the present invention, when the regulation of the regulation means is released, the drive transmission means rotates by its own weight and meshes with the drive gear, so that the drive transmission means is rotated. No urging spring or the like is required, and the configuration can be simplified.

As the regulating means, a solenoid, a locking member which moves in accordance with ON / OFF of the solenoid,
The drive transmission means can be restricted by the locking of the locking member by the movement of the locking member, and the restriction of the drive transmission means can be released by the release of the locking.

The drive transmission means can be rotated by providing the missing gear with a weight that rotates in the predetermined direction.

By providing a weight for rotating in the predetermined direction on the rotating shaft of the toothless gear, the drive transmitting means can be rotated.

Further, a drive transmission device having a simple structure as described above can be applied to the feeding device of the present invention, and a feeding roller for feeding a sheet is provided with a weight for rotating in a predetermined direction. Thereby, the drive transmission means can be rotated.

Further, a feeder to which the drive transmission device having the simple structure as described above is applied can be applied to the image forming apparatus of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic configuration perspective view of a feeding device to which a drive transmission device according to an embodiment of the present invention is applied.

FIG. 2 is a schematic configuration diagram of a drive transmission device according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a copying machine.

FIG. 4 is a schematic configuration diagram of a main part of the feeding device according to the first embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a drive transmission device according to a second embodiment of the present invention.

FIG. 6 is a schematic configuration perspective view of a feeding device to which a drive transmission device according to a third embodiment of the present invention is applied.

FIG. 7 is a schematic configuration perspective view of a drive transmission device according to a conventional technique.

FIG. 8 is a schematic configuration diagram of a drive transmission device according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier 9 Feed roller 20 Feed roller unit 21 Feed roller shaft 22 Feed gear 23 Solenoid 23a Flapper 24 Input gear 27 Weight member

Claims (7)

[Claims] A drive source for driving and transmitting the drive;
In a drive transmission device, comprising: a drive transmission unit having a toothless gear disposed opposite to a drive gear; and a regulation unit for regulating the drive of the drive transmission unit. When the restriction is imposed on the drive gear, the toothless portion of the toothless gear stands by while facing the drive gear. A drive transmission device characterized in that the drive transmission is started. 2. The driving device according to claim 1, wherein the restricting means includes a solenoid, and a locking member that moves in accordance with ON / OFF of the solenoid. The drive transmission device according to claim 1, wherein the drive transmission device locks and unlocks the portion. 3. The drive transmission device according to claim 1, wherein a weight for rotating in a predetermined direction is provided on the toothless gear. 4. The drive transmission device according to claim 1, wherein a weight for rotating in a predetermined direction is provided on a rotation shaft of the toothless gear. 5. A feeding device comprising a feeding roller for feeding a sheet on a shaft of a toothless gear provided in the drive transmission device according to claim 1, 2, 3, or 4. 6. The feeding device according to claim 5, wherein a weight for rotating the feeding roller in a predetermined direction is provided on the feeding roller. 7. An image forming apparatus, comprising: an image forming means for forming an image on a sheet fed by the feeding apparatus according to claim 5. Description: