JP3641957B2 - Roller drive transmission device and image reading device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a roller drive transmission device that transmits a driving force to a roller, and an image reading apparatus to which the roller drive transmission device is applied.
[0002]
[Prior art]
In an image reading apparatus such as a facsimile, a copying machine, or a scanner, when an original conveyed by an original conveying means passes through a white background roller, the original is irradiated with light and reflected light is received to read an image of the original. . Therefore, when the original stains adhere to the white background roller, when the original narrower than the original reading width of the white background roller is read, the white background roller stains where there is no original are recorded in black on the recording image, Further, when reading a thin document, the white background roller is contaminated through the document and is recorded black on the recorded image. Therefore, it is necessary to always clean the white background roller.
[0003]
When 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, the roll shape is deformed, and the document conveyance accuracy is improved. It will decline. In view of this, for example, Japanese Patent Laid-Open No. 2-107051 proposes a conventional document reading apparatus that solves the above problem.
[0004]
This conventional document reading apparatus is configured to rotate the white background roller forward / reversely by the driving force from the driving system by operating the key of the operation unit when the roller is cleaned. .
[0005]
[Problems to be solved by the invention]
However, the conventional document reading apparatus is configured to rotate the white background roller in the forward and reverse directions using a drive system shared with a document transport roller such as a paper feed roller and a transport roller. The control requires a processing routine different from the conveying process at the time of normal document reading, and there is a problem that the control system becomes complicated.
[0006]
In addition, the operator has to perform roller cleaning while pressing the key of the operation unit for rotating the white background roller forward and backward, and there is a problem that the cleaning work is troublesome.
[0007]
The present invention has been made to solve the above-described problems, and can simplify a drive system control system and can easily perform a cleaning operation and a manuscript. An object is to obtain a reading device.
[0008]
[Means for Solving the Problems]
A roller drive transmission device and an image reading device according to the present invention include a roller gear having a diameter smaller than that of a driven gear so that the roller can be rotated forward and backward by one or more rotations by an operation of an operator's finger. Each of the driven gears is characterized in that one protrusion is provided at each fitting portion .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below.
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a schematic configuration of the document reading apparatus. In FIG. 1, a document transport unit 1 takes in a document one by one and transports it to a document reading position, and discharges the document from a document discharge port after the image reading of the document is completed. The image reading unit 2 irradiates a document at a document reading position with light and receives reflected light to read an image on the document.
[0015]
In the document transport unit 1, the paper feed roller 3 takes the document into the apparatus. The paper feed roller 3 is disposed at a document take-in port of the document transport path, and rotates around an axis when a driving force from a drive system (not shown) is transmitted.
[0016]
The separation roller 4 separates a plurality of stacked documents so that the documents are taken into the apparatus one by one. The separation roller 4 is disposed in the separation roller bracket 4A and at a position opposite to the paper feed roller 3, and the driving force (rotational force) of the transport roller 6 is transmitted through the gears 5A and 5B. It rotates in the direction opposite to the paper feed roller 3 around the axis. Further, the separation roller 4 is provided with a torque limiter (not shown) so as to run idle when a torque exceeding a certain level is applied. Then, it idles and rotates in the same direction as the paper feed roller 3.
[0017]
One end of the separation roller bracket 4 </ b> A is rotatably fixed to the shaft of the transport roller 12, and the other end is fixed to the inner surface of the apparatus housing via a pressing spring 6. The separating roller 4 is urged by the urging force of the pressing spring 6. Is brought into pressure contact with the paper feed roller 3.
[0018]
The pickup roller 7 conveys a document on the document table 19 to a document take-in port (a press-contact portion between the paper feed roller 3 and the separation roller 4). The pickup roller 7 is disposed in the pickup roller bracket 7A above the document table 19, and the driving force of the sheet feeding roller 3 is transmitted through the gear 8 so that the sheet feeding roller 3 is centered on the shaft. And rotate in the same direction.
[0019]
One end of the pickup roller bracket 7A is rotatably fixed to the shaft of the paper feed roller 3, and the other end is fixed to the inner surface of the apparatus housing via a holding spring 9, and the document is conveyed by the biasing force of the holding spring 9. Although being held at the standby position, when the paper feed roller 3 rotates, it rotates in the direction of the document table 19 and presses the pickup roller 7 against the upper surface of the document on the document table 19.
[0020]
The skew prevention roller 10 corrects the skew of the document. The skew prevention roller 10 is disposed on the conveyance path in the apparatus, and the driving force of the paper feed roller 3 is transmitted through the gear 11 so that the feed roller 3 is driven in the same direction around the shaft. Rotate.
[0021]
The conveyance roller 12 conveys a document. The conveying roller 12 is disposed on a conveying path in the apparatus, and rotates around an axis when a driving force is transmitted from a driving system. The belt 13 presses and conveys the document to the transport roller 12 and is in pressure contact with the transport roller 12.
[0022]
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. The white background roller 13 is disposed on the original reading position, and rotates around the shaft when the driving force from the driving system is transmitted. The white background roller 13 is supported by the roller holding member 14 together with the drive gear 20 and the driven gear 21 (see FIG. 2).
[0023]
The discharge roller 15 discharges the document outside the apparatus. The discharge roller 15 is disposed at the document discharge port, and rotates around an axis when the driving force from the driving system is transmitted.
[0024]
In the image reading unit 2, the image reading unit 16 irradiates the document at the document reading position with light and receives the reflected light to read the image of the document. The image reading unit 16 is disposed in the image reading unit casing 17 and can move in the image reading unit casing 17 in the sub-scanning direction of the document. The image reading unit 16 includes a lamp 16A for irradiating light on the original and a CCD 16B that receives reflected light from the original and reads an image on the original.
[0025]
A white reference sheet 18 serving as a reference color of the document image data is attached to the standby position of the image reading unit 16 on the inner surface of the image reading unit housing 17.
[0026]
FIG. 2 is a block diagram showing a roller drive transmission device according to Embodiment 1 of the present invention. In FIG. 2, 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 generate white driving force from a drive system (not shown). This is transmitted to the background roller 13. The drive gear 20 and the driven gear 21 are rotatably supported by the roller holding member 14 via a shaft (core) 22. The white roller gear 23 is fixed to the shaft 24 of the white background roller 13.
[0027]
3 is a cross-sectional view showing the configuration of the drive gear 20, FIG. 4 is a plan view showing the configuration of the drive gear 20, and FIG. 5 is a perspective view showing the configuration of the drive gear 20. As shown in FIGS. 3, 4, and 5, the circular drive gear 20 has a hollow portion 20 </ b> A formed by rounding the center of the surface that contacts the driven gear 21 in a stepwise manner, and the center is formed in a cylindrical shape. A shaft through hole 20B through which the shaft 22 passes is formed. On the inner surface of the hollow portion 20 </ b> A of the drive gear 20, a projection 20 </ b> C that transmits a driving force to the driven gear 21 (projection 21 </ b> C thereof) is provided.
[0028]
6 is a cross-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. 8 is a perspective view showing the configuration of the driven gear 21. As shown in FIGS. 6, 7, and 8, the circular driven gear 21 is formed with a cylindrical protruding portion 21 </ b> A that fits (fits) into the hollow portion 20 </ b> A of the drive gear 20 and has a center. A shaft through hole 21B through which the shaft 22 penetrates is formed. Further, a protrusion 21 </ b> C to which the driving force from the driving gear 20 is transmitted is provided on the outer surface of the protruding portion 21 </ b> A of the driven gear 21.
[0029]
As described above, the gear that transmits 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 protrusions 20 </ b> C and 21 </ b> C are respectively formed on the driving gear 20 and the driven gear 21. By providing this, play can be given to the rotation of the driven gear 21. That is, even when the drive gear 20 is stationary, the driven gear 21 can rotate slightly less than one rotation (because the protrusions 20C and 21C have a width).
[0030]
Next, the operation will be described.
(1) Document conveyance and document reading operation (basic operation) of the document reading device will be described.
First, when the 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 sets the white reference sheet 18 at the standby position. Read the data and set the white reference value of the document. Next, the image reading unit 16 translates in the image reading unit housing 17 in the document sub-scanning direction, stops at the document reading position, and enters a document image data reading standby state until the document is conveyed.
[0031]
Next, when a drive system motor (not shown) rotates, the paper feed roller 3, the transport roller 12, the white background roller 13 and the discharge roller 15 start to rotate in the direction of transporting the document. Further, the pickup roller 9 and the skew feeding prevention roller 10 start to rotate in the direction in which the document is conveyed when the driving force (rotational force) of the paper feed roller 3 is transmitted through the gear 8 and the gear 11, respectively. .
[0032]
On the other hand, the separation roller 4 is transmitted with a driving force in the direction opposite to the direction in which the document is conveyed via the gears 5A and 5B, but torque is generated in the separation roller 4 by the frictional force generated by the pressure contact with the paper feed roller 3. Therefore, the torque limiter is acted upon exceeding the maximum value, and is idled and rotated in the same direction as the paper feed roller 3 (the direction in which the document is conveyed).
[0033]
In addition, a frictional force between the paper feed roller 3 and the separation roller 4 generates a moment around the axis of the paper feed roller 3, and this moment causes the pickup roller bracket 8 to rotate clockwise (the direction of rotation of the paper feed roller 3). To turn. When the pickup roller bracket 8 is rotated, the pickup roller 7 is rotated and brought into pressure contact with the upper surface of the document set on the document table 19, and the document take-in port (the pressure contact between the paper feed roller 3 and the separation roller 4). Part).
[0034]
When the original enters the pressure contact portion between the paper feed roller 3 and the separation roller 4, the frictional force between the paper supply roller 3 and the separation roller 4 changes to the frictional force between the paper supply roller 3 and the original, and the frictional force. Therefore, the moment around the axis of the paper feed roller 3 is also reduced, and the pickup roller bracket 8 is lifted by the holding spring 9 and returned to the standby position.
[0035]
When the original enters the pressure contact portion between the paper feed roller 3 and the separation roller 4, the frictional force between the separation roller 4 and the paper supply roller 3 changes to the frictional force between the separation roller 4 and the original, and the separation is performed. Since it is smaller than the frictional force (torque) of the maximum value of the torque limiter of the roller 4, there is no rotation with the paper feed roller 3, and the document conveyance is obstructed (the direction opposite to the direction in which the paper feed roller 3 rotates). And the next original is prevented from being fed until the current original passes through the paper feed roller 3.
[0036]
Thereafter, the document is transported to the document reading position by the skew prevention roller 10 and the transport roller 12 while preventing the document from skewing. When the original is conveyed to the original reading position, the image is read by the image reading unit 16 of the image reading unit 2 while being prevented from floating from the original reading surface by the pressing of the white background roller 13.
[0037]
When reading an original having a width smaller than the original reading width, the image reading unit 16 reads the white color of the white background roller 13 as a portion without the original. Further, the image reading unit 16 reads the white color of the white background roller 7 even in the case of a thin document that transmits light.
[0038]
After the image reading of the document by the image reading unit 16 is completed, the document is conveyed to the document discharge port by the white background roller 13 and discharged from the document discharge port by the discharge roller 15.
[0039]
(2) The cleaning operation (cleaning operation) of the white background roller 13 will be described.
When dust or dirt adhering to the document adheres to the white background roller 13, when reading a document narrower than the document reading width of the white background roller 13 or reading a thin document, the dirt on the white background roller 13 is recorded on the recorded image. Therefore, the operator cleans the white background roller 13.
[0040]
The operator lifts the document conveying unit 1 upward and separates it from the image reading unit 2. Here, as described above, the protrusions 20 </ b> C and 21 </ b> C are provided at the fitting portion 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 protrusions 20C and 21C come into contact with each other, transmit the rotating force, and the driven gear 21 also rotates.
[0041]
On the other hand, since the rotation of the driven gear 21 is given play, the driven gear 21 can be rotated forward / reverse for less than one rotation, and the white background roller 13 can be rotated forward / reverse via the white roller gear 23. it can. Therefore, the operator can clean the white background roller 13 by rotating the white background roller 13 forward and backward with fingers.
[0042]
Further, the play amount of the fitting portion between the drive gear 20 and the driven gear 21 is slightly less than one rotation, but the number of teeth of the white roller gear 23 is made smaller than the number of teeth of the driven gear 21, that is, the diameter of the white roller gear 23. Is smaller than the diameter of the driven gear 21, the white background roller 13 can be rotated one or more times. Accordingly, the operator can easily remove the dirt adhering to the white background roller 13 and can clean the entire periphery of the roller without leaving any dirt on the roller surface.
[0043]
As described above, according to the first embodiment, the protrusions 20C and 21C are provided in the fitting portion of the drive gear 20 and the driven gear 21, and the rotation of the driven gear 21 is provided with play. 13 can be rotated forward / reversely via the white roller gear 23. Therefore, the operator can easily clean the white background roller 13 by rotating the white background roller 13 forward and backward with fingers.
Further, the drive gear 20 and the driven gear 21 mechanically generate a play amount so that the white background roller 13 can be rotated forward and backward, so that the control system of the drive system of the image reading apparatus is complicated. There is nothing.
[0044]
Further, since the number of teeth of the white roller gear 23 is smaller than the number of teeth of the driven gear 21, the white roller gear 23 (white background roller 13) can be rotated one or more times while the driven gear 21 is weakened by one rotation. The entire periphery of the roller 13 can be cleaned.
[0045]
Embodiment 2. FIG.
In the first embodiment, in order to rotate the white background roller 13 forward / reversely, the gear that transmits the rotational force from the drive system to the white background roller 13 is divided into the drive gear 20 and the driven gear 21. The protrusions 20C and 21C are provided in the fitting portion between the drive gear 20 and the driven gear 21 to allow the rotation of the driven gear 21. However, the invention is not limited to this, and the drive gear 20 and the driven gear 21 are not limited thereto. Instead of this, a one-way clutch that can rotate in only one direction may be provided.
[0046]
The one-way clutch integrates the drive gear 20 and the driven gear 21 and is provided between the shaft through hole of the integrated gear and the shaft 22. As described above, by providing the one-way clutch, the white background roller 13 can be freely rotated in one direction (the direction in which the document is conveyed), and the operator can easily clean the white background roller 13. At the same time, the roller surface can be cleaned all around.
[0047]
【The invention's effect】
As described above, according to the first and second aspects of the present invention, the roller drive transmission device and the image reading device are configured so that the roller can be rotated forward and backward by one or more rotations by operating the finger of the operator. comprises a small diameter roller gear than the driven gear, in the drive gear and the driven gear, respectively, since the protruding portion by one location has the configuration provided in the mating portion, with mechanically simple construction, operation The person can easily perform the cleaning operation around the entire circumference of the roller .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a document reading apparatus.
FIG. 2 is a configuration diagram showing a roller drive transmission device according to Embodiment 1 of the present invention;
FIG. 3 is a cross-sectional view showing 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 cross-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]
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 (2)

A driving gear that rotates by a driving force in a predetermined direction from the driving system;
Rotates the drive gear with the rotational force of the drive gear and rotates in the forward / reverse direction when the drive gear is stationary, for transmitting the rotational force of the drive gear to the roller . In the roller drive transmission device with a driven gear,
A gear for transmitting the rotational force of the driven gear to the roller so that the roller can be rotated forward and reverse by one or more rotations by an operator's finger operation . The gear is fitted to the driven gear and the roller. A roller gear having a diameter smaller than that of the driven gear,
Each of the drive gear and the driven gear is provided with one protrusion at a fitting portion, respectively. A document is taken in and conveyed to a document reading position by a roller that rotates with a driving force in a predetermined direction from a drive system. In the image reading device,
Roller drive transmission device for transmitting the driving force to the roller of the document reading position,
In order to enable forward and reverse rotation of the roller by one or more rotations by operating the fingers of the operator
A driving gear that rotates by a driving force in a predetermined direction from the driving system;
In order to transmit the rotational force of the drive gear to the roller, which is engaged with the drive gear and is rotated by the rotational force of the drive gear, and can be rotated forward and backward when the drive gear is stationary. The driven gear of
A gear that transmits the rotational force of the driven gear to the roller, and is fitted to the driven gear and fixed to the shaft of the roller, and includes a roller gear having a smaller diameter than the driven gear,
An image reading apparatus, wherein the driving gear and the driven gear are each provided with one protrusion at a fitting portion.

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