JP2000165597A - Roller drive transmitter and image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the control system of a driving system and to easily perform cleaning work by making a roller positively and inversely rotatable with a prescribed play amount by the finger manipulation of an operator. SOLUTION: The driving gear 20, driven gear 21 and white roller gear 23 of this roller drive transmitter transmit driving force from the driving system to a white background roller 13. The driving gear 20 and the driven gear 21 are freely rotatably supported by a roller holding member 14 through a shaft 22. Also, the white roller gear 23 is fixed to the shaft 24 of the white background roller 13. As for the circular driving gear 20, a hollow part the center of a surface of which contacts the driven gear 21 is hollowed out stepwise is formed and a shaft through-hole for passing through the shaft 22 hose center is hollowed out in a columnar shape is formed. On the inner surface of the hollow part of the driving gear 20, a projection part for transmitting the driving force to the driven gear 21 is provided. Thus, the rotation of the driven gear 21 is attained with play.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller drive transmitting device for transmitting a driving force to a roller, and an image reading apparatus to which the roller drive transmitting device is applied.

[0002]

2. Description of the Related Art In image reading apparatuses such as facsimile machines, copiers and scanners, when a document conveyed by a document conveying means passes through a white background roller, the document is irradiated with light and reflected light is received. Read the image on the document. Therefore, if the document stains adhere to the white background roller, when reading a document narrower than the document reading width of the white background roller, the stain of the white background roller in a portion where there is no document is recorded in black on the recording image, Further, when reading a thin document, the white background roller must be cleaned at all times because the stain on the white background roller penetrates through the document and is recorded in black on the recorded image.

In cleaning the white background roller, if the operator forcibly rotates the white background roller with fingers or the like, an excessive load is applied to the white background roller, and the roll shape is deformed, and The transport accuracy is reduced. Therefore, for example, a conventional document reading apparatus that solves the above problem is proposed in Japanese Patent Application Laid-Open No. Hei 2-107051.

In this conventional document reading apparatus, when the roller is cleaned, an operator operates a key of an operation unit to rotate the white background roller forward / reverse by a driving force from a driving system. Things.

[0005]

However, in the conventional document reading apparatus, a white background roller is rotated forward and backward by using a driving system shared with a roller for transporting the document such as a paper feed roller and a transport roller. Therefore, there is a problem that the drive system control requires a processing routine different from the transport processing at the time of normal document reading, and the control system becomes complicated.

Further, the operator has to perform roller cleaning while pressing a key of an operation unit for rotating the white background roller forward and backward, and there is a problem that the cleaning operation is troublesome.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and can simplify a control system of a driving system and can easily perform a cleaning operation. It is an object to obtain an apparatus and a document reading apparatus.

[0008]

According to a first aspect of the present invention, there is provided a roller drive transmission device in which a roller can be rotated forward and backward with a predetermined play amount by operating an operator's finger.

According to a second aspect of the present invention, there is provided a roller drive transmission device which is driven by a drive force from a drive system in a predetermined direction, and which is engaged with the drive gear to rotate by the torque of the drive gear. And a driven gear that can rotate forward and backward with a predetermined play amount when the drive gear is stationary, and that transmits a rotational force to the roller.

According to a third aspect of the present invention, there is provided a roller drive transmission device which rotates by a driving force in a predetermined direction from a driving system, and which is engaged with the driving gear to rotate by the rotational force of the driving gear. A driven gear capable of rotating forward and backward with a predetermined play amount when the driving gear is stationary, and a roller gear having a smaller diameter than the driven gear for transmitting the rotational force of the driven gear to the roller. It is.

According to a fourth aspect of the present invention, there is provided a roller drive transmission device in which a protrusion is provided at a fitting portion between a drive gear and a driven gear to generate a predetermined play amount.

According to a fifth aspect of the present invention, there is provided a roller drive transmission device including a one-way clutch capable of rotating a roller in only one direction.

According to a sixth aspect of the present invention, as in the first aspect, the roller drive transmitting device for transmitting the driving force to the roller at the document reading position is replaced with the roller drive transmitting device by operating a finger of an operator. Are configured to be rotatable forward and backward with a predetermined play amount.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a sectional view showing a schematic configuration of the document reading apparatus. In FIG. 1, a document transport unit 1 includes
The originals are fetched one by one, conveyed to the original reading position, and after the image reading of the originals is completed, the originals are discharged from the original outlet. The image reading unit 2 irradiates a document at a document reading position with light, receives reflected light, and reads an image of the document.

In the document transport unit 1, a paper feed roller 3 is for taking a document into the apparatus. The paper feed roller 3 is arranged at a document inlet of a document conveyance path, and rotates around an axis by transmitting a driving force from a driving system (not shown).

The separating roller 4 separates a plurality of originals so that the originals are taken into the apparatus one by one. The separation roller 4 is a separation roller bracket 4A.
And the driving force (rotational force) of the transport roller 6 via the gears 5A and 5B.
Is transmitted in the opposite direction to the feed roller 3 about the axis. Further, the separation roller 4 is provided with a torque limiter (not shown) so as to run idle when a predetermined torque or more is applied. , And rotates in the same direction as the paper feed roller 3.

The separation roller bracket 4A has one end rotatably fixed to the axis of the transport roller 12 and the other end fixed to the inner surface of the apparatus housing via a pressing spring 6.
The separation roller 4 is pressed against the paper feed roller 3 by the urging force of (1).

The pickup roller 7 has a document table 19.
The upper document is conveyed to a document inlet (pressing portion between the paper feed roller 3 and the separation roller 4). The pickup roller 7 is disposed in a pickup roller bracket 7 </ b> A above the document table 19, and the driving force of the sheet feeding roller 3 is transmitted via a gear 8, so that the sheet feeding roller 3 is rotated about its axis. And rotate in the same direction.

The pickup roller bracket 7A has one end rotatably fixed to the shaft of the paper feed roller 3 and the other end fixed to the inner surface of the apparatus housing via a holding spring 9. The urging force of the holding spring 9 is provided. Is held at the document transport standby position by the document feeder, but when the paper feed roller 3 rotates, the document table 1
9 to rotate the pickup roller 7 to the original table 1.
9 against the upper surface of the original.

The skew preventing roller 10 corrects skew of the document. The skew preventing roller 10 is disposed on a transport path in the apparatus, and is transmitted in the same direction as the sheet feeding roller 3 about the shaft by transmitting the driving force of the sheet feeding roller 3 via the gear 11. Rotate.

The transport roller 12 transports a document. The transport roller 12 is arranged on a transport path in the apparatus, and rotates around an axis by transmitting a driving force from a drive system. The belt 13 presses the document against the transport roller 12 to transport the document, and is in pressure contact with the transport roller 12.

The white background roller (roller) 13 prevents the document from floating from the document reading surface and conveys the document to the document discharge port. This white background roller 1
Reference numeral 3 is arranged on a document reading position, and rotates around an axis by transmitting a driving force from a driving system.
The white background roller 13 includes a driving gear 20 and a driven gear 2.
2 is supported by the roller holding member 14 (see FIG. 2).
reference).

The discharge roller 15 discharges a document outside the apparatus. The discharge roller 15 is arranged at a document discharge port, and rotates around an axis when a driving force from a driving system is transmitted.

In the image reading unit 2, the image reading section 16 irradiates a document at a document reading position with light, receives reflected light thereof, and reads an image of the document. The image reading unit 16 is arranged in the image reading unit housing 17 and is movable in the image reading unit housing 17 in the sub-scanning direction of the document. The image reading unit 16
Is composed of a lamp 16A for irradiating the original with light and a CCD 16B for receiving reflected light from the original and reading an image of the original.

At a standby position of the image reading unit 16 on the inner surface of the image reading unit housing 17, a white reference sheet 18 serving as a reference color of document image data is stuck.

FIG. 2 is a configuration diagram showing a roller drive transmission device according to Embodiment 1 of the present invention. In FIG.
A drive gear (roller drive transmission device) 20, a driven gear (roller drive transmission device) 21, and a white roller gear (roller gear, roller drive transmission device) 23 include a drive system (not shown).
Is transmitted to the white background roller 13. The drive gear 20 and the driven gear 21 are rotatably supported by the roller holding member 14 via a shaft (center) 22. The white roller gear 23 is fixed to the shaft 24 of the white background roller 13.

FIG. 3 is a sectional view showing the structure of the drive gear 20, FIG. 4 is a plan view showing the structure of the drive gear 20, and FIG.
FIG. 2 is a perspective view showing a configuration of a drive gear 20. As shown in FIGS. 3, 4 and 5, the circular drive gear 20 has a hollow portion 20 </ b> A in which the center of a surface that comes into contact with the driven gear 21 is stepped and rounded, and the center has a cylindrical shape. A hollow shaft through hole 20B through which the shaft 22 penetrates is formed. Hollow portion 20A of drive gear 20
A projection 20C for transmitting a driving force to (the projection 21C of) the driven gear 21 is provided on the inner surface of the.

FIG. 6 is a sectional view showing the configuration of the driven gear 21, FIG. 7 is a plan view showing the configuration of the driven gear 21, and FIG.
FIG. 2 is a perspective view showing a configuration of a driven gear 21. As shown in FIGS. 6, 7 and 8, the circular driven gear 21 is formed with a cylindrical protrusion 21A that fits (fits) into the hollow portion 20A of the drive gear 20 and has a center. A shaft through hole 21 </ b> B that is hollowed out into a cylindrical shape and through which the shaft 22 penetrates is formed. In addition, a protrusion 21 </ b> C to which the driving force from the drive gear 20 is transmitted is provided on an outer surface of the protrusion 21 </ b> A of the driven gear 21.

As described above, the gear for transmitting the driving force (rotational force) to the white background roller 13 is divided into the driving gear 20 and the driven gear 21, and the projections are formed on the driving gear 20 and the driven gear 21, respectively. By providing 20C and 21C, play can be given to the rotation of the driven gear 21. In other words, even when the driving gear 20 is stationary, the driven gear 21 can rotate slightly less than one rotation (because of the width of the projections 20C and 21C).

Next, the operation will be described. (1) Document transport and document reading operation (basic operation) of the document reader will be described. First, when an operator sets a document on the document table 19 and turns on a document transport switch (not shown), the image reading unit 16 of the image reading unit 2 moves the white reference sheet 18 to the standby position. The data is read and the white reference value of the document is set. Next, the image reading unit 1
Reference numeral 6 denotes a state in which the image reading unit housing 17 moves parallel to the original in the sub-scanning direction and stops at the original reading position, and waits for reading of the original image data until the original is conveyed.

Next, when the motor (not shown) of the driving system rotates, the paper feed roller 3, the transport roller 12, the white background roller 13, and the discharge roller 15 start rotating in the direction of transporting the original. In addition, the pickup roller 9 and the skew prevention roller 10 start rotating in the direction in which the document is conveyed, when the driving force (rotational force) of the paper feed roller 3 is transmitted via the gear 8 and the gear 11, respectively. .

On the other hand, the separating roller 4 transmits a driving force in a direction opposite to the direction of transporting the original via the gears 5A and 5B.
A torque is applied to the separation roller 4, and the torque limiter acts when the torque limiter exceeds the maximum value.

The frictional force between the paper feed roller 3 and the separation roller 4 generates a moment about the paper feed roller 3 axis. (Rotation direction). When the pickup roller bracket 8 rotates, the pickup roller 7 rotates and the document table 1 is rotated.
The document is brought into pressure contact with the upper surface of the document set on the document 9 and is conveyed to the document inlet (the pressure contact portion between the sheet feeding roller 3 and the separation roller 4).

When the document enters the pressure contact portion between the paper feed roller 3 and the separation roller 4, the frictional force between the paper feed roller 3 and the separation roller 4 changes to the frictional force between the paper feed roller 3 and the document. Since the frictional force is reduced, the moment about the axis of the feed roller 3 is also reduced, and the pickup roller bracket 8 is lifted by the holding spring 9 and returns to the standby position.

The original is fed by a feed roller 3 and a separation roller 4.
, The frictional force between the separation roller 4 and the paper feed roller 3 changes to the frictional force between the separation roller 4 and the original, and the frictional force of the maximum value of the torque limiter of the separation roller 4 ( Torque), there is no co-rotation with the paper feed roller 3 and the paper feed roller 3 starts to rotate in a direction that impedes document conveyance (a direction opposite to the direction in which the paper feed roller 3 rotates). Until the end of the document feed.

Thereafter, the skew of the document is prevented by the skew preventing roller 10 and the transport roller 12 while the skew of the document is prevented.
The document is transported to the document reading position. When the document is transported to the document reading position, the image is read by the image reading unit 16 of the image reading unit 2 while the document is prevented from floating from the document reading surface due to the pressing of the white background roller 13.

When reading a document narrower than the document reading width, the image reading section 16 reads the white color of the white background roller 13 as a portion having no document. The image reading unit 16
Reads the white color of the white background roller 7 even in the case of a thin original that transmits light.

After the image reading unit 16 completes reading the image of the original, the original is conveyed to the original discharge port by the white background roller 13 and discharged from the original discharge port by the discharge roller 15.

(2) The cleaning operation (cleaning work) of the white background roller 13 will be described. When dust or dirt adhered to the original adheres to the white background roller 13, when reading an original narrower than the original reading width of the white background roller 13,
When reading a thin original, the stain on the white background roller 13 is recorded in the recorded image in black, so the operator cleans the white background roller 13.

The operator lifts the document transport unit 1 upward and separates it from the image reading unit 2. here,
As described above, the protrusions 20C and 21C are provided at the fitting portions of the drive gear 20 and the driven gear 21. Therefore, when the driving gear 20 is rotated by the driving force from the driving system, the projections 20C and 21C come into contact with each other, transmit the rotating force, and the driven gear 21 also rotates.

On the other hand, since there is play in the rotation of the driven gear 21, the driven gear 21 can be rotated slightly less than one rotation and can rotate forward and reverse, and the white background roller 13 also rotates forward and reverse through the white roller gear 23. Can be done. Therefore, the operator can clean the white background roller 13 by rotating the white background roller 13 forward and backward with fingers.

Although the play of the fitting portion between the drive gear 20 and the driven gear 21 is slightly less than one rotation, the number of teeth of the white roller gear 23 is made smaller than the number of teeth of the driven gear 21. By making the diameter of the roller 23 smaller than the diameter of the driven gear 21, the white background roller 13 can be rotated one or more rotations. Therefore, the operator can easily remove the dirt adhered to the white background roller 13 and can clean the entire periphery of the roller without wiping the dirt on the roller surface.

As described above, according to the first embodiment, the protrusions 20C and 21C are provided at the fitting portions of the drive gear 20 and the driven gear 21, and the rotation of the driven gear 21 is provided with play. White roller gear 2 with white background roller 13
3 can be rotated forward and reverse. Therefore, the operator can easily clean the white background roller 13 by rotating the white background roller 13 forward and backward with fingers. Further, by the driving gear 20 and the driven gear 21,
The play amount is generated mechanically to correct the white background roller 13
Since it is configured to be able to rotate in the reverse direction, the control system of the drive system of the image reading apparatus does not become complicated.

Since the number of teeth of the white roller gear 23 is smaller than the number of teeth of the driven gear 21, the number of teeth of the driven gear 21 is one.
While the rotation is weak, the white roller gear 23 (white background roller 1)
3) can be rotated more than once, and the white background roller 13
Can be cleaned all around.

Embodiment 2 In the first embodiment, the gear for transmitting the rotational force from the drive system to the white background roller 13 is divided into two parts, a drive gear 20 and a driven gear 21, in order to rotate the white background roller 13 forward and backward. , Drive gear 2
0 and the driven gear 21 have protrusions 20C, 21C
Was provided to allow play for the rotation of the driven gear 21,
The present invention is not limited to this, and the driving gear 20 and the driven gear 21
Instead, a one-way clutch rotatable in only one direction may be provided.

The one-way clutch integrates the drive gear 20 and the driven gear 21 and is provided between the shaft through-hole and the shaft 22 of the integrated gear. As described above, even with the provision of the one-way clutch, the white background roller 13 can be freely rotated in one direction (the direction in which the document is conveyed).
Can be easily cleaned, and the roller surface can be cleaned over the entire circumference.

[0047]

As described above, claims 1 and 6 are as described above.
According to the invention described above, the roller drive transmission device is configured so that the roller can be rotated forward and backward with a predetermined play amount by the operation of the operator's finger, thereby simplifying the control system of the drive system of the image reading device. It is possible to achieve the effect that the cleaning operation can be easily performed by the operator.

According to the second aspect of the present invention, a drive gear that is rotated by a drive force from a drive system in a predetermined direction, is fitted with the drive gear and is rotated by the torque of the drive gear, and the drive gear is Positive with a predetermined amount of play when stationary
Since the apparatus is provided with the driven gear that can rotate in the reverse direction and transmits the rotational force to the roller, the effect of claim 1 can be achieved without complicating the configuration of the roller drive transmission device.

According to the third aspect of the present invention, the driving gear which is rotated by a driving force in a predetermined direction from the driving system, is fitted with the driving gear and rotated by the rotating force of the driving gear, and the driving gear is rotated by the driving force. Positive with a predetermined amount of play when stationary
Since the driven gear includes a driven gear that can rotate in the reverse direction and a roller gear that transmits the rotational force of the driven gear to the roller and has a smaller diameter than the driven gear, the roller gear is rotated one or more rotations while the driven gear makes one rotation. This makes it possible to clean the entire periphery of the roller.

According to the fourth aspect of the present invention, the projection is provided at the fitting portion between the driving gear and the driven gear to generate a predetermined amount of play. Is produced.

According to the sixth aspect of the present invention, since the one-way clutch capable of rotating the roller in only one direction is provided,
As described above, there is an effect that the operator can easily clean the roller and can clean the roller surface over the entire circumference.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a document reading apparatus.

FIG. 2 is a configuration diagram illustrating a roller drive transmission device according to Embodiment 1 of the present invention;

FIG. 3 is a cross-sectional view illustrating a configuration of a drive gear.

FIG. 4 is a plan view showing a configuration of a drive gear.

FIG. 5 is a perspective view showing a configuration of a drive gear.

FIG. 6 is a sectional view showing a configuration of a driven gear.

FIG. 7 is a plan view showing a configuration of a driven gear.

FIG. 8 is a perspective view showing a configuration of a driven gear.

[Explanation of symbols]

Reference Signs List 13 white background roller (roller) 20 drive gear (roller drive transmission device) 20C protrusion 21 driven gear (roller drive transmission device) 21C protrusion 23 white roller gear (roller gear, roller drive transmission device)

Claims (6)

[Claims] 1. A roller drive transmission device for transmitting a driving force in a predetermined direction from a driving system to a roller, wherein the roller is configured to be capable of rotating forward and reverse with a predetermined play amount by an operation of an operator's finger. Characteristic roller drive transmission device. A driving gear that rotates by a driving force in a predetermined direction from a driving system; a driving gear that is fitted with the driving gear and rotates by the rotating force of the driving gear; A roller drive transmission device comprising: a driven gear that can rotate forward and backward with a predetermined play amount and that transmits a rotational force to a roller. 3. A drive gear that is rotated by a drive force in a predetermined direction from a drive system, and is engaged with the drive gear and rotated by the torque of the drive gear, and when the drive gear is stationary. A roller drive transmission device comprising: a driven gear capable of rotating forward / reversely with a predetermined play amount; and a roller gear having a smaller diameter than the driven gear for transmitting a rotational force of the driven gear to a roller. 4. The roller drive transmission according to claim 2, wherein each of the drive gear and the driven gear has a protrusion at a fitting portion to generate a predetermined play amount. apparatus. 5. A roller drive transmission device for transmitting a driving force in a predetermined direction from a drive system to a roller, wherein a one-way clutch capable of rotating the roller in only one direction is provided. 6. A document is taken in, the document is conveyed to a document reading position by a roller which is rotated by a driving force in a predetermined direction from a drive system, light is irradiated on the document at the document reading position, and reflected light is received. In an image reading apparatus that reads an image of a document, a roller drive transmission device that transmits a driving force to a roller at a document reading position is configured such that the roller can be rotated forward and reverse with a predetermined play amount by an operation of an operator's finger. An image reading apparatus comprising: