JP2003072975A - Image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing device with high quality with reduced image shock amount generated when a sheet passes through a sheet carrying means. SOLUTION: A paper sheet discharging main gear 11a is provided with a paper sheet discharging sub-gear 11b which is coaxial with the paper sheet discharging main gear 11a, has the same number of teeth to be engaged with a middle gear 10, and is energized by a tension spring 15 to the paper sheet discharging main gear 11a in the direction of clamping teeth of the middle gear 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading unit or an image forming unit, such as a scanner, a copying machine, a printer, or a facsimile machine, for reading an image of an original or forming an image on a sheet. The present invention relates to a provided image processing device.

[0002]

2. Description of the Related Art Conventionally, as an image processing apparatus of this type, for example, as sheet conveying means, a sheet feeding roller as a sheet feeding and rotating member for feeding a sheet original and a sheet discharging roller as a sheet discharging roller for discharging a sheet original. In a sheet document reading device such as a facsimile in which an image sensor for reading an image is located between a paper roller and a gear attached to a paper feed roller shaft and a paper discharge roller shaft, and a motor from the gear. A spur gear is mainly used as a gear that is connected to transmit the drive of the motor and reduce the rotation speed of the motor.

[0003]

However, in the case of the above-mentioned prior art, the following problems have occurred.

When the spur gears are connected as described above, backlash occurs between the gears. Then, the paper feed roller is pressed against the roller at the opposite portion for applying the document conveying force, and the paper feed roller is in a bent state. However, the image is shocked by the fact that the elastic force of the rubber that returns by the bending of the paper feed roller causes it to fly forward, and the paper ejection roller advances by the amount of the backlash between the gear attached to the roller shaft and the gear that transmits the drive thereto. Happens.

Therefore, there is a problem that the image is disturbed at that portion.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a high-quality image in which the amount of image shock generated when the sheet leaves the sheet conveying means is reduced. It is to provide a processing device.

[0007]

In order to achieve the above object, according to the present invention, in an image processing apparatus having at least two sheet conveying means and comprising a conveying drive means, the conveying drive means is driven. A transmission gear, at least one of the drive transmission gears is provided coaxially with the drive transmission gear, has the same number of teeth, and is engaged with the other gear; It is characterized in that it is provided with an auxiliary gear which is biased in a direction in which the teeth of the other gear are sandwiched with respect to the drive transmission gear.

The sheet conveying means has a feeding rotating member and a discharging rotating member capable of simultaneously conveying the same sheet,
It is also preferable to include a feed gear and a discharge gear that are coaxially supported by the feed rotation member and the discharge rotation member, respectively.

The urging means includes a first protrusion that is provided on the drive transmission gear so as to project in the axial direction and penetrates a through hole provided in the auxiliary gear, and the first protrusion on the auxiliary gear. It is also preferable that the auxiliary gear is supported by a second protrusion that is provided so as to project in the same direction as the portion, and biases the auxiliary gear with respect to the drive transmission gear in a direction that sandwiches the teeth of the other gear. .

It is also preferable that the tip of the first protrusion is provided with a restricting portion that restricts the auxiliary gear after penetrating the through hole.

It is also preferable that the biasing means is a tension spring or a compression spring.

It is also preferable that the auxiliary gear is provided in at least one of the discharge gear and the feeding gear.

It is also preferable that one of the drive transmission gears engages with the discharge gear and the feed gear, and that the auxiliary gear is provided in the drive transmission gear.

The image processing apparatus described above is also preferably a sheet original reading apparatus.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
The material, the shape, and the relative arrangement of them should be appropriately changed depending on the configuration of the device to which the invention is applied and various conditions, and the scope of the invention is not limited to the following embodiments.

With reference to FIGS. 1 to 11, a sheet original feeding drive system provided in the image processing apparatus according to the present embodiment will be described. In this embodiment, as the sheet document feeding drive system, a drive system in an image reading unit of a facsimile machine as an image processing device is exemplified (the image processing device of the present embodiment is suitable as a sheet document reading device. Applied to).

As for the order of the description, the schematic structure of the image reading unit of the facsimile apparatus will be described first, and then the image shock will be described. Then, the configuration of the document feeding drive system to which the present invention is applied and the configuration of the scissors gear including the auxiliary gear, which is the characteristic configuration of the present embodiment, will be described, and finally, the result of measuring the image shock amount will be shown.

First, the schematic structure of the image reading unit of the facsimile apparatus will be described with reference to FIG.

In FIG. 1, the image reading unit 1 presses the original S on an original placing table 2 on which a plurality of originals S can be placed and a contact image sensor 3 as a reading means for reading image information of the original S. Document pressing means 4 and the document table 2
A document transport unit 5 as a sheet transport unit that sequentially feeds the documents S placed on the sheet one by one and carries them out through the contact image sensor 3, and an upper document guide that forms a transport path of the document S. 6 and a lower original guide 7.

The original document table 2 is provided with a slider 2a which is slidable in a width direction perpendicular to the conveying direction of the original document S, and both ends of the original document S placed on the original document table 2 are moved by the sliders 2a. You can arrange them.

The contact type image sensor 3 as the reading means irradiates the image information surface of the document S with light from the LED array as the light source, and the reflected light (image light) reflected by the image information surface is self-locked. The lens (registered trademark) forms an image on the sensor element to read image information.

In the document transport section 5, first, the document S is sandwiched between the separation roller 5a and the preliminary pressure contact arm 5b which is in pressure contact with the separation roller 5a,
Set. After that, when the conveyance of the document S is started, it is sent to the separation pad 5c by the separation roller 5a. Then, the sheets are separated and fed one by one by the separating roller 5a and the separating pad 5c in pressure contact with the separating roller 5a, and reach the sheet feeding roller 5e as a feeding rotating member.

The original S is further conveyed to the contact type image sensor 3 by the paper feed roller 5e which is in pressure contact with the paper feed roller 5f pressed by the pressing spring 5d, and the original pressing means 4 is pressed.
With this, the image information of the document S is read while pressing the document S against the contact-type image sensor 3 and bringing them into close contact with each other while sequentially feeding the lines. After that, the document S is discharged by a discharge roller 5g as a discharge rotating member that is in pressure contact with the discharge roller 5h pressed by the pressing spring 5d. During this time, the original S is placed on the upper original guide 6 and the lower original guide 7.
Guided by.

Next, the image shock will be described with reference to FIG.

As shown in FIG. 2A, when the document S leaves the paper feed roller 5e, the elastic force of the bending of the rubber of the paper feed roller forming the paper feed roller 5e causes the document S to move forward. The force to fly is added. Moreover, on the side of the paper discharge roller 5g, since the paper discharge roller gear 8 mounted coaxially with the paper discharge roller 5g and the gear for transmitting the drive to the paper discharge roller 5g have backlash, the amount of backlash is equivalent to this backlash.
Is ready to proceed. Therefore, the original is entirely skipped forward (to the downstream side). When an image shock is actually generated in a document with a hatched line, image distortion as shown in FIG. 2B occurs. This image shock amount was measured and compared between the case of using the scissors gear according to the present embodiment and the case of using a spur gear as in the related art, which will be described later.

Next, a drive system to which the present invention is applied will be described with reference to FIG.

This is a case where the paper discharge scissors gear 11 is attached only to the paper discharge roller shaft 13. The driving force of the motor as the conveyance driving means is the motor gear 9 attached to the motor.
It is transmitted to a paper discharge scissors gear 11 and a paper feed roller gear 12 as a feed gear via an intermediate reduction gear (hereinafter, referred to as an intermediate gear) 10 as a drive transmission gear. Then, the paper discharge roller shaft 13 and the paper discharge roller 5g attached thereto are driven, and the paper feed roller shaft 14 and the paper feed roller 5e attached thereto are driven.

Next, the structure of the paper discharge scissors gear 11 will be described with reference to FIG. FIG. 4A is a schematic diagram for explaining the discharge scissors gear 11, and FIG. 4B is the same diagram as FIG.
Is viewed from the side, and FIG. 7C is a view of FIG.

The paper discharge scissors gear 11 is composed of a paper discharge main gear 11a as a discharge gear and a paper discharge sub gear 11b as an auxiliary gear. The paper discharge sub-gear 11b is rotatably fitted to the shaft portion 11ab of the paper discharge main gear, and is attached to the paper discharge main gear 11a. At that time,
Projection 11a as the first projection of the paper discharge main gear 11a
a is a hole portion 11bb as a through hole of the paper discharge sub gear 11b
By inserting the sheet into the main body 11a of the protrusion 11aa and regulating it by a regulating portion provided at the tip of the protrusion 11aa so as not to separate the paper discharge sub gear 11b from the paper discharge main gear 11a in the axial direction. In addition, the protrusion 11 serving as the second protrusion of the paper discharge sub gear 11b
There are notches 11bc and 11ac on the ba and the protrusion 11aa of the paper discharge main gear 11a, respectively, and the tension spring 15 is supported by hooking both ends of the tension spring 15 as biasing means. It is attached to the paper discharge scissors gear 11.

When assembled in the apparatus, the paper discharge subgear 11b is rotated in the X direction with respect to the paper discharge main gear 11a as shown in the drawing, and the tension spring 15 is applied with a tension force so that the intermediate gear 10 and Engage. Then, the intermediate gear 10 is sandwiched between the paper discharge main gear 11a and the paper discharge sub gear 11b. Here, the X direction is a direction opposite to the rotation direction of the paper discharge main gear 11a driven by the intermediate gear 10.

Here, the paper feed roller gear 12 and the intermediate gear 1
FIG. 5 shows a schematic diagram when the paper discharge scissors gear 11 is driven. Note that FIG. 5 shows a state in which the paper discharge scissors gear 11 shown in FIG.

As shown in the figure, the discharge scissors gear 11
When the intermediate gear 10 rotates in the direction of the arrow in the figure after engaging the intermediate gear 10 with the intermediate gear 10, a force is exerted on the tension spring 15 so as to return to the natural length. The sheet ejection main gear 11a is urged in the direction sandwiching the sheet ejection direction (the rotation direction of the sheet ejection main gear 11a), that is, in the backlash direction Y with respect to the sheet ejection main gear 11a. Thereby, the backlash can be corrected.

Similarly, FIG. 6 shows a drive system in the case where the paper feeding scissors gear 16 is attached to the paper feeding roller shaft 14, and FIG. 7 is a schematic diagram of the gear.

Similarly, in the paper feeding scissors gear 16, the paper feeding subgear 16b as an auxiliary gear is biased in the backlash direction Z with respect to the paper feeding main gear 16a as a feeding gear to correct the backlash.

Next, the outer diameters of the paper feed roller 5e and the paper discharge roller 5g are changed to determine the document transport speed when the scissors gear is attached only to the paper discharge side and both the paper feed side and the paper discharge side. , And the amount of image shock was measured.

FIG. 8 shows a method of measuring the image shock amount.

As shown in FIG. 8, the laser emitted from the laser Doppler measuring device 17 is applied to the original at the contact sensor 3 part, and the conveyance speed thereof is 100 μs for the sampling time.
Then, the image shock amount was obtained.

At the time of measurement, as shown in FIG. 9, the outer diameters of the paper feed roller 5e and the paper discharge roller 5g are each 0.05.
The document conveyance speed relationship was changed by changing the value in units of mm to ± 0.2 mm. In A, the document feeding speed of the paper feed roller is the same as that of the paper discharge roller, and the paper discharge roller becomes faster as it goes down and the paper feed roller becomes faster as it goes up. FIG. 10 shows a graph in which the image shock amount was measured 10 times for these 9 types and the average value was plotted. Photos and business cards were used for the manuscript.

It can be seen from the figure that the image shock amount is reduced to 0.1 mm or less when the gear is a scissors gear. If both the paper feed side and the paper discharge side are attached,
The amount of image shock was slightly smaller than when attached only to the paper discharge side.

FIG. 11 shows a comparison of images at that time. The upper row shows the case of a photograph, and the lower row shows the case of a business card. In addition, in the case of the photograph shown in the figure, edging was performed to make the image easy to understand.

It can be seen from FIG. 11 that when the scissors gear is used, the image shock is reduced so that it is almost invisible even when visually observed.

As described above, according to the present embodiment, the backlash between the gears can be eliminated, so that it is possible to reduce the image shock to a level that cannot be seen even by visually observing the image. Become.

In the present embodiment, the description has been given of the case where the above-mentioned scissors gear is provided on the paper discharge roller side and the paper feed roller side, but the intermediate gear 10 can of course be a scissors gear. In this case, the auxiliary gear of the intermediate gear 10 is urged in the direction of sandwiching the discharge roller gear or the paper feed roller gear together with the intermediate gear 10 (the direction opposite to the rotation direction of the intermediate gear 10), that is, the intermediate gear 10
Is biased in the direction of the backlash with respect to the paper discharge roller gear or the paper feed roller gear, whereby the backlash can be corrected.

Further, in the present embodiment, the tension spring 15 is used as the urging means, but the present invention is not limited to this, and a compression spring may be used, for example.

Further, it is not necessary to limit to the above-mentioned image reading section, it can be used also for an image forming section for forming an image on a conveyed sheet, and it is not limited to a facsimile machine and can be used for a copying machine or the like. It is possible.

[0046]

As described above, according to the present invention,
The image shock that occurs when the sheet original or the sheet leaves the sheet conveying unit can be significantly reduced to the extent that the image cannot be seen. Therefore, it is possible to provide a high quality image processing device.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an image reading unit of a facsimile apparatus according to this embodiment.

FIG. 2 is a diagram for explaining the principle of image shock.

FIG. 3 is a diagram showing a reading unit drive system according to the present embodiment.

FIG. 4 is a structural explanatory view of a scissors gear according to the present embodiment.

FIG. 5 is a schematic diagram of gears of a reading unit drive system according to the present embodiment.

FIG. 6 is a diagram showing a reading unit drive system according to the present embodiment.

FIG. 7 is a schematic diagram of gears of a reading unit drive system according to the present embodiment.

FIG. 8 is an explanatory diagram of a method of measuring an image shock amount.

FIG. 9 is a diagram showing a relationship between outer diameters of rollers when measuring an image shock amount.

FIG. 10 is a diagram illustrating a measurement result of an image shock amount.

FIG. 11 is a diagram comparing images obtained in the conventional case and the case of the present embodiment.

[Explanation of symbols]

1 Image reading section 2 Document placing table 2a slider 3 Contact image sensor 4 Pressing means 5 Document feeder 5a Separation roller 5b Pre-pressing arm 5c Separation pad 5d pressing spring 5e Paper feed roller 5f paper feed roller 5g paper ejection roller 5h Paper ejection roller 6 Upper manuscript guide 7 Lower manuscript guide 8 Paper ejection roller gear 9 motor gear 10 Intermediate reduction gear 11 Paper discharge scissors gear 11a Paper ejection main gear 11aa, 11ba protrusion 11ab shaft 11ac, 11bc Notch 11b Paper ejection sub gear 11bb hole 12 Paper feed roller gear 13 Paper ejection roller shaft 14 Paper feed roller shaft 15 Tension spring 16 Paper feeding scissors gear 16a Paper feed main gear 16b Paper feed sub gear 17 Laser Doppler measuring instrument

Claims (8)

[Claims] 1. An image processing apparatus comprising at least two sheet transporting means and comprising transporting drive means, wherein the transporting drive means has a drive transmission gear, and at least one of the drive transmission gears is a drive transmission gear. The gear is coaxial with the transmission gear, has the same number of teeth, is engaged with the other gear, and is urged by the urging means in a direction in which the tooth of the other gear is sandwiched with respect to the drive transmission gear. An image processing device, comprising: 2. The sheet conveying means has a feeding rotating member and a discharging rotating member capable of simultaneously conveying the same sheet,
The image processing apparatus according to claim 1, further comprising a feeding gear and a discharging gear that are coaxially supported by the feeding rotating member and the discharging rotating member, respectively. 3. The first biasing means is provided on the drive transmission gear so as to project in the axial direction and penetrates through a through hole provided on the auxiliary gear, and the first protrusion is provided on the auxiliary gear. A second protrusion that is provided so as to project in the same direction as the protrusion of, and urges the auxiliary gear in a direction in which the teeth of the other gear are sandwiched with respect to the drive transmission gear. The image processing apparatus according to claim 1 or 2. 4. The image processing apparatus according to claim 3, wherein a regulating portion that regulates the auxiliary gear after penetrating the through hole is provided at a tip of the first protrusion. . 5. The image processing apparatus according to claim 1, wherein the urging means is a tension spring or a compression spring. 6. The image processing apparatus according to claim 1, wherein the auxiliary gear is provided in at least one of the discharge gear and the feeding gear. 7. One of the drive transmission gears engages with the discharge gear as well as the feed gear, and the auxiliary gear is provided in the drive transmission gear. The image processing device according to claim 1, wherein 8. The image processing apparatus according to claim 1, wherein the image processing apparatus is a sheet document reading apparatus.