JPH07199571A - Drive transmission device between units - Google Patents

Abstract

PURPOSE:To reduce the rotational fluctuation and vibration of a member to be driven at the time of transmitting drive via a rocking gear by supporting the supporting point of the rocking of the rocking gear on its both ends by a first unit and a driving device. CONSTITUTION:A supporting shaft 44 is extended to the left in the figure more than a rocking bracket 43b and the tip of the supporting shaft 44 is inserted into a frame 19 as a part of a lower unit 1b. In other words, the supporting shaft 44 as the supporting point of the rocking of a rocking gear mechanism 40 is supported on its both ends by the side plate 33 of the driving device 30 and the frame 19 of the lower unit 1b. By such a constitution, the deflection of the supporting shaft 44 is reduced and the center distance between a transmission gear 20 and a second rocking gear 41b is kept without changing because the supporting shaft 44 as the supporting point of the rocking of the rocking gear mechanism 40 is supported on its both ends. Therefore, in an original carrying mechanism for a carrying roller 7 driven via the transmission gear 20, a reading roller and a paper ejecting roller, the rotational fluctuation and vibration never occur, so that the generation of the jitters can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has two units which are fitted together to form one device, one unit being a first unit with a drive and the other being driven by said drive. And a transmission gear that meshes with a rocking gear incorporated in the drive device provided in the first unit when the two units are matched with each other. The present invention relates to a drive transmission device between units, which is provided in a unit and in which the drive of the drive device is transmitted to a driven member via a swing gear and a transmission gear.

[0002]

2. Description of the Related Art An image forming apparatus having an upper and lower unit, an image reading apparatus, and the like are known as a device in which two units are combined to form one device. In the apparatus of the above-mentioned type, for example, in an image reading apparatus, one unit is a lower unit including a driving device and a reading sensor, and the other unit is an upper unit including a document feeding mechanism driven by the driving device. When the two units are matched with each other, the upper unit is provided with the transmission gear that meshes with the swing gear incorporated in the drive unit provided in the lower unit, so that the drive of the drive unit is transmitted to the swing gear. It is configured to be transmitted to the document conveying mechanism via a gear. In this conventional image reading device, the swing fulcrum of the swing gear is supported only on one side with respect to the drive device.

[0003]

However, if the fulcrum of the oscillating gear is supported on one side, the fulcrum of the oscillating gear is bent by the driving torque of the original conveying mechanism in the case of the document reading apparatus, and the original is conveyed. At this time, the center distance between the swing gear and the transmission gear fluctuates. Due to this fluctuation, rotation fluctuations and vibrations are generated in each roller of the document conveying mechanism, and there is a problem that so-called jitter occurs in which a diagonal line when the document is read becomes jagged.

The present invention has been made in view of the above-mentioned conventional problems.
It is an object of the present invention to provide a drive transmission device between units which is preferable for drive transmission of precision equipment by significantly reducing rotational fluctuation and vibration of a driven member even when drive is transmitted via an oscillating gear.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention comprises a first unit having two units which are fitted together to form a unit, one unit comprising a drive unit.
In the unit, the other unit is a second unit having a driven member driven by the driving device, and when the two units are matched, the second unit is incorporated in the driving device provided in the first unit. In the drive transmission device between the units, a transmission gear that meshes with an oscillating gear is provided in the second unit, and the drive of the drive device is transmitted to the driven member via the oscillating gear and the transmission gear. Both ends of the swing fulcrum of the dynamic gear are supported by the first unit and the drive device.

Further, in order to achieve the above object, the present invention is characterized in that the swing fulcrum of the swing gear also serves as positioning between the first unit and the drive unit.

Further, in order to achieve the above-mentioned object, the present invention is characterized in that when the oscillating gear and the transmission gear are meshed with each other, the oscillating gear is included in the reaction of the driving force on the pitch circle received by the oscillating gear. The oscillating gear, so that a component force orthogonal to a component force on a line connecting the fulcrum and the action point is inclined toward the transmission gear side with respect to a tangent line at the action point on the pitch circle.
The rocking fulcrum and the transmission gear are arranged.

[0008]

According to the above structure, since the swing fulcrum of the swing gear is supported at both ends by the first unit and the drive device, the center distance between the swing gear and the transmission gear does not change, Even if the drive is transmitted through the swing gear, the rotational fluctuation and vibration of the driven member can be significantly reduced.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of the overall configuration of an apparatus for applying a drive transmission device between units according to the present invention to an image reading apparatus.

In FIG. 1, reference numeral 1 is the apparatus main body,
The apparatus body 1 is an upper unit 1a as a second unit.
And a lower unit 1b as a first unit, and the upper unit 1a is attached to the lower unit 1b so as to be openable and closable around a fulcrum 2.
The upper unit 1a includes a pressing plate 3 for pressing the set original document, a spring 4 for pressing the original document, a blade 5 for separating the original document, and a spring 6 for pressing the blade.
And a feed roller 7 for feeding a document and a reading sensor 1
3, a reading roller 8 for bringing the original into close contact with the original 3 and conveying the paper, and a paper discharge roller 9 for discharging the original are arranged,
An upper guide plate 17 for guiding a document between the respective members
Is installed. The lower unit 1b includes a pickup roller 10 for feeding the set original document, a paper feed roller 11 on which the blade 5 is pressed, a conveyance driven roller 12 paired with the conveyance roller 7, and a lower portion of the reading roller 8. A reading sensor 13 provided in the above and a paper discharge driven roller 14 paired with the paper discharge roller are arranged, and a lower guide plate 18 for guiding a document is installed between the respective members. Therefore, when the upper unit 1a is opened with respect to the lower unit 1b around the fulcrum 2, the document conveying path is exposed so that the jammed document can be removed and the reading sensor 13 can be easily cleaned. There is.

In the image reading apparatus thus configured, the originals set on the original setting table 15 are sequentially transferred from the lower original to the paper feeding roller 11 by the pickup roller 10, and when the originals are overlapped and sent at this time. The sheets are separated by the blade 5, and are fed one by one in the arrow direction by the paper feed roller 11. The fed originals are conveyed by a pair of conveyance rollers 7 and 12.
To the reading section where the reading roller 8 and the reading sensor 13 are arranged. In the reading unit, the reading roller 8 conveys the document while being in close contact with the reading sensor 13, and the information of the document is read during that time. The read document is discharged by the pair of discharge rollers 9 and 14 and is stacked on the discharge tray 16.

The upper unit 1a has a document transport mechanism including a driven transport roller 7, a reading roller 8 and a paper discharge roller 9, but the drive unit does not have such a mechanism, and these drive members are included in the lower unit 1b. The drive device 30 shown in FIG. 2 is provided to drive the drive device.

FIG. 2 is an explanatory diagram showing a gear arrangement from the drive device 30 to the drive gear of the paper discharge roller 9. The upper unit 1a has a transmission gear 20 on the shaft of the conveying roller,
The transmission gear 20 is drivingly connected to a gear 22 provided on the shaft of the reading roller 8 through an idler gear train 21, and a gear provided on the shaft of the paper discharge roller 9 from the gear 22 to an idler gear train 23. 24 is drivingly connected.

Further, in the drive unit 30 installed in the lower unit 1b, the gear 31 provided on the motor shaft (not shown) and the transmission gear 20 when the upper unit 1a is closed to the lower unit 1b. The oscillating gear mechanism 40 is capable of meshing with each other, and the gear 31 and the oscillating gear mechanism 40 are drivingly connected via an idler gear train 32.

As shown in FIGS. 3 and 4, the oscillating gear mechanism 40 is an oscillating gear 41 formed as a two-stage gear integrally including a first oscillating gear 41a and a second oscillating gear 41b.
And rocking brackets 43a and 43b for fixedly supporting both ends of a shaft 42 on which the rocking gear 41 is rotatably mounted, and rocking gears 4a and 43b fixed to the rocking gear 4
It has a support shaft 44 as a fulcrum of No. 1 and an idler gear 45 provided on the support shaft 44. Idler gear 45
2, is drivingly connected to the gear 31 via an idler gear train 32, and is constantly meshed with the first swing gear 41a of the swing gear 41. Swing gear 4
The first swinging gear 41b is a gear that can mesh with the transmission gear 20 when the upper unit 1a is closed to the lower unit 1b.

The swing bracket 43a on the side plate 33 side of the drive device 30 is provided with a claw 46 at the tip of the swing side, and the claw 46 is loosely fitted in a hole 34 provided in the side plate 33. The hole 34 is an elongated hole extending in an arc shape centering on the support shaft 44, and the claw 46 has both ends 34 a and 34 b of the hole 34.
The oscillating gear 41 can move within the corresponding range. In addition, the spring 4 is provided between the claw 46 and the locking portion 35 of the side plate 33.
7 is provided, and the spring 47 urges the swing gear mechanism 40 with a turning force in a direction in which the pawl 46 always contacts the upper end 34a of the hole 34. Further, a convex portion 48 is formed on the upper portion of the other swing bracket 43b so as to come into contact with the bearing 25 of the transport roller 7 provided with the transmission gear 20 in the upper unit 1a. 1a
Is set in the lower unit 1b, the bearing 25 and the convex portion 4
The contact between the contact gears 8 keeps the center distance between the transmission gear 20 and the second swing gear 41b.

By the way, when the support shaft 44, which is the fulcrum fulcrum of the oscillating gear mechanism 40, is a one-sided support supported only by the side plate 33, the support shaft 44 is bent by the driving torque of the document conveying mechanism of the upper unit 1a. As described above, the problem arises because the distance between the centers of the gears cannot be maintained.

Therefore, in this embodiment, the support shaft 44 is extended to the left of the swing bracket 43b in the drawing, and the tip of the support shaft 44 is inserted into the frame 19 which is a part of the lower unit 1b. That is, the support shaft 44, which is the swing support point of the swing gear mechanism 40, is connected to the side plate 33 of the drive device 30 and the lower unit 1b.
Both ends of the frame 19 are supported.

With this structure, the swing gear mechanism 4
Since the support shaft 44, which is the swing support point of 0, is supported at both ends, the deflection of the support shaft 44 is greatly reduced, and the center distance between the transmission gear 20 and the second swing gear 41b is maintained and does not change. Therefore, rotation fluctuation and vibration do not occur in the document transport mechanism of the transport roller 7, the reading roller 8 and the paper discharge roller 9 which are driven via the transmission gear 20, and the occurrence of jitter is suppressed.

Further, the support shaft 44 is the side plate 33 of the drive unit 30.
By being supported by the frame 19 of the lower unit 1b, the support shaft 44 also serves as a positioning member for the drive device 30 and the lower unit 1b. Therefore, it is not necessary to provide any other member such as the positioning shaft 51, and the cost is reduced.

FIG. 5 is an explanatory view showing the arrangement of the idler gear 45, the second swing gear 41b and the transmission gear 20,
The arrows in the figure indicate the rotation direction of each gear.

In FIG. 5, of the component force of the reaction F'of the driving force F on the pitch circle of the second rocking gear 41b, it is on the line connecting the support shaft 44 of the second rocking gear 41b and the point of action A. A certain component force F'a and a component force F'b directed in the direct direction are inclined toward the transmission gear 20 side with respect to the tangent line B at the action point A of the pitch circle so that the support shaft 4
4, the second oscillating gear 41b and the transmission gear 20 are arranged at positions. The symbol α is the pressure angle.

According to this structure, the reaction F'of the driving force F on the pitch circle of the second rocking gear 41b is the second rocking gear 41b.
Does not act in a direction of increasing the center distance between the transmission gear 20 and the transmission gear 20, and the second swing gear 41b is always kept in the transmission gear 20 during driving.
Since the gears mesh with each other, the center-to-center distance between both gears is maintained, and the distance does not change. Therefore, it is preferable as a drive transmission device.

On the other hand, as shown in FIG. 6, the component force F '
b is the tangent line B at the point of action A of the pitch circle, the transmission gear 2
The support shaft 44 and the second swing gear 41b so as to incline to the side opposite to 0.
When the transmission gear 20 and the transmission gear 20 are arranged, the second swing gear 41b escapes from the transmission gear 20 during driving, and the center-to-center distance changes. Therefore, it is not preferable as a drive transmission device.

[0025]

According to the structure of claim 1, since the swing fulcrum of the swing gear is supported at both ends by the first unit and the drive device, the center distance between the swing gear and the transmission gear is increased. Does not fluctuate, and even if the drive is transmitted through the swing gear, the rotational fluctuation and vibration of the driven member can be greatly reduced. Therefore, when it is applied to an image reading device, fluctuations in rotation and vibration of the rollers that convey the document are eliminated, and the jitter of the read image is reduced.

According to the second aspect of the invention, since the swing fulcrum of the swing gear also serves as the positioning between the first unit and the drive unit, it is possible to reduce the number of positioning members for the drive unit and the unit, which leads to cost reduction. Become.

According to the structure of claim 3, when the oscillating gear and the transmission gear mesh with each other, the oscillating fulcrum and the action point are connected among the reaction of the driving force on the pitch circle received by the oscillating gear. Since the oscillating gear, oscillating fulcrum, and transmission gear are arranged so that the component force orthogonal to the component force on the line inclines toward the transmission gear side with respect to the tangent line at the point of action on the pitch circle, the reaction is oscillated. If the center distance between the gear and the transmission gear does not act in a changing direction and is applied to an image reading device, fluctuations in rotation and vibration of the document transport mechanism are eliminated, and jitter in the read image is reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of the overall configuration of an image reading apparatus to which a drive transmission apparatus between units according to the present invention is applied.

FIG. 2 is an explanatory diagram showing a gear arrangement from a drive device to a drive gear of a discharge roller.

FIG. 3 is a cross-sectional view of a swing gear mechanism.

FIG. 4 is a perspective view of a swing gear mechanism.

FIG. 5 is an explanatory diagram showing a preferred arrangement example of an idler gear, a second swing gear, and a transmission gear.

FIG. 6 is an explanatory view showing an unfavorable arrangement example of an idler gear, a second swing gear, and a transmission gear.

[Explanation of symbols]

 1 Device Main Body 1a Upper Unit 1b Lower Unit 7 Conveying Roller 8 Reading Roller 9 Discharging Roller 9 19 Lower Unit Frame 20 Transmission Gear 30 Drive Device 33 Drive Device Side Plate 40 Swing Gear Mechanism 41b Second Swing Gear 44 Spindle F Driving force F'Reaction F'b Reaction component

Claims (3)

[Claims] 1. A first unit having two units which are fitted together to form one device, one unit being a drive unit, and the other unit being a driven member driven by the drive unit. 2nd unit with 2
When the two units are matched, a transmission gear that meshes with a swing gear incorporated in the drive device provided in the first unit is provided in the second unit, and the drive of the drive device is performed by the swing gear. In a drive transmission device between units that is transmitted to a driven member via a transmission gear, both ends of a swing fulcrum of the swing gear are supported by the first unit and the drive device. Drive transmission device between units. 2. The drive transmission device between units according to claim 1, wherein the oscillating fulcrum of the oscillating gear also serves as positioning between the first unit and the drive device. 3. The drive transmission device between units according to claim 1, wherein when the oscillating gear and the transmission gear mesh with each other, among the reaction of the driving force on the pitch circle received by the oscillating gear, The oscillating gear and the oscillating gear are arranged so that a component force orthogonal to the component force on the line connecting the oscillating fulcrum and the action point is inclined toward the transmission gear side with respect to the tangent line at the action point on the pitch circle. A drive transmission device between units, wherein a dynamic fulcrum and a transmission gear are arranged.