JP2021139962A - Image reading device and image forming apparatus - Google Patents

Abstract

To provide an image reading device and an image forming apparatus that can reduce an operating force when opening document conveying means without impairing operability, compared with a case in which opening and closing drive is performed over all of the opening and closing angles of the document conveying means.SOLUTION: An image reading device comprises: document holding means that is openably and closably attached to a device main body with a rotation shaft and holds a document; and lifting force acting means that, when opening the document holding means, causes a driving force of a driving source to only temporarily act on the document holding means as a lifting force for lifting the document holding means in a direction to open the document holding means. The lifting force acting means has a lifting force acting member that is rotatably arranged inside the document holding means with the rotation shaft as a fulcrum, and a wire member that causes a lifting force in the direction to open the document holding means to act on an end located on the opposite side of the rotation shaft of the lifting force acting member.SELECTED DRAWING: Figure 9

Description

The present invention relates to an image reader and an image forming apparatus.

Conventionally, as a technique related to an image reading device, for example, those disclosed in Patent Document 1 and the like have already been proposed.

Patent Document 1 describes a mounting table glass on which a sheet is placed, an openable and closable sheet pressing portion that presses the sheet mounted on the mounting table glass from above, and a state in which the sheet is pressed from above by the sheet pressing portion. An image reading unit that reads the image of the sheet, an electric opening / closing unit that assists the manual opening / closing of the seat pressing unit, and a seat pressing unit that is operated by the electric opening / closing unit according to an external force applied to the seat pressing unit when the seat pressing unit is manually opened / closed. The seat pressing unit changes the opening / closing speed according to an external force based on the speed changing unit that changes the opening / closing speed of the seat, the opening / closing angle detection unit that detects the opening / closing angle of the seat pressing unit, and the detection signal from the opening / closing angle detection unit. It is determined whether the seat pressing portion is in the first region, the second region immediately before the sheet pressing portion is completely closed, or the third region immediately before the seat pressing portion is fully opened, and the sheet pressing portion is in the first region. When it is determined, the opening / closing speed is changed according to the external force, and when it is determined that the seat pressing portion has moved to the second region or the third region, the opening / closing speed is set to a preset opening / closing speed regardless of the external force. It is configured to include a part.

JP-A-2008-191197

An object of the present invention is an image reading device capable of reducing an operating force when opening a document transporting means without impairing operability, as compared with a case where opening / closing drive is performed over all opening / closing angles of the document transporting means. The purpose is to provide an image forming apparatus.

The invention according to claim 1 comprises a document holding means that is attached to a main body of an apparatus so as to be openable and closable via a rotation shaft and holds a document.
A pulling force acting means that causes the driving force of the drive source to act only temporarily as a pulling force that pulls the document holding means toward the document holding means in the opening direction when the document holding means is opened.
With
The pulling force acting means includes a pulling force acting member rotatably arranged inside the document holding means with the rotation axis as a fulcrum.
This is an image reading device having a wire member that applies a pulling force in a direction of opening the document holding means to an end of the pulling force acting member located on the side opposite to the rotation axis.

According to the second aspect of the present invention, the pulling force acting member has an acting arm that branches from an intermediate position along the longitudinal direction and exerts a pulling force in the opening direction on the document holding means. Item 2. The image reading device according to item 1.

According to a third aspect of the present invention, the pulling force acting means converts the moving direction of the wire member into the opening / closing direction of the document holding means via a pulley arranged in the middle of the wire member. The image reading device according to 2.

The image reading according to claim 1, wherein the invention according to claim 4 includes an absorbing means for absorbing the excessive force when an excessive force exceeding a predetermined value is applied to the pulling force acting means. It is a device.

The invention according to claim 5 is the fourth aspect of the present invention, wherein the absorbing means comprises an elastic member that absorbs the excessive force by elastically deforming when the excessive force acts on the pulling force acting means. The image reading device described.

The invention according to claim 6 comprises an image reading means for reading an image of the original document conveyed to a reading position by the document holding means.
The image reading device according to claim 1, wherein the driving source is a driving source of the image reading means.

According to a seventh aspect of the present invention, the document holding means is the image reading device according to the sixth aspect, wherein the energization is cut off when the document is opened and closed.

The invention according to claim 8 comprises an image reading means for reading an image of the original document and an image reading means.
An image forming means for forming an image of the original document read by the image reading means, and an image forming means.
With
An image forming apparatus using the image reading apparatus according to any one of claims 1 to 7 as the image reading means.

According to the first aspect of the present invention, it is possible to reduce the operating force when opening the document transporting means without impairing the operability, as compared with the case where the opening / closing drive is performed over all the opening / closing angles of the document transporting means. A possible image reader can be provided.

Further, according to the invention described in claim 1, the pulling force acting means includes a pulling force acting member rotatably arranged inside the document holding means with a rotation axis as a fulcrum, and a pulling force acting member. The configuration can be simplified as compared with the case where the wire member that exerts a pulling force in the opening direction of the document holding means is not provided at the end portion located on the opposite side of the rotation axis of the above.

According to the second aspect of the present invention, the pulling force acting member does not have an acting arm that branches from an intermediate position along the longitudinal direction and exerts a pulling force in the opening direction on the document holding means. Compared with the case, a large pulling force can be applied to the document holding means.

According to the third aspect of the present invention, the pulling force acting means exerts a pulling force by the wire member as compared with the case where the pulling force acting means does not have a pulley that converts the moving direction of the wire member into the opening / closing direction of the document holding means. You can freely set the position to make it.

According to the fourth aspect of the present invention, it is possible to avoid a malfunction when an excessive force is applied to the opening force acting means, as compared with the case where the absorbing means for absorbing the excessive force is not provided.

According to the fifth aspect of the present invention, the configuration of the opening force acting means can be simplified as compared with the case where the absorbing means is not composed of the elastic member.

According to the sixth aspect of the present invention, the number of parts can be reduced as compared with the case where the drive source of the image reading means is not used as the drive source.

According to the invention described in claim 7, the document transporting means can avoid the possibility of malfunction when the document transporting means is opened, as compared with the case where the energization is not cut off at the time of opening and closing.

According to the invention described in claim 8, when the document transporting means is opened without impairing the operability as compared with the case where the image reading device according to any one of claims 1 to 7 is not used as the image reading means. It is possible to provide an image forming apparatus capable of reducing the operating force of the above.

It is an overall block diagram which shows the image forming apparatus to which the image reading apparatus which concerns on Embodiment 1 of this invention is applied. It is a block diagram which shows the image reading apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the automatic document transporting apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows the state which opened the automatic document transporting apparatus of the image forming apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the automatic document transporting apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows the rotational moment required to open the automatic document transfer apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the reed switch. It is a block diagram which shows the closed state of the automatic document transfer apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the main part of the automatic document transfer apparatus which concerns on Embodiment 1 of this invention. It is a plane block diagram which shows the push-up device. It is a block diagram which shows the main part of the automatic document transfer apparatus which concerns on Embodiment 1 of this invention. It is a plane block diagram which shows the push-up device. It is a block diagram which shows the control device. It is a block diagram which shows the main part of the automatic document transfer apparatus which concerns on Embodiment 1 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
FIG. 1 is a configuration diagram showing an overall outline of an image forming apparatus to which the image reading apparatus according to the first embodiment of the present invention is applied.

<Overall configuration of image forming apparatus>
The image forming apparatus 1 according to the first embodiment is configured as a color copier that forms a color image by, for example, a so-called inkjet method. The image forming apparatus 1 includes an image reading device 3 as an example of an image reading means for reading an image of a document 6, and an image forming means for forming an image on a recording medium based on image data read by the image reading device 3 and the like. An image forming unit 2 is provided as an example. The image reading device 3 is arranged in a state of being supported by the support portion 4 above the device main body 1a accommodating the image forming portion 2. A space is formed between the image reading device 3 and the device main body 1a for discharging the recording medium on which the image is formed.

As shown in FIG. 1, the image reading device 3 has a control panel 66 as an operation unit for operating the image forming device 1 and the image reading device 3 on the upper portion of the front wall 311 located in front of the housing 31. Is provided. The control panel 66 has a touch panel 67 that also serves as a display unit for displaying operation menus, warnings, messages, etc. to the operator (user) and accepts various settings for the displayed operation menu, and a plurality of operation buttons 68. ..

The image forming unit 2 accommodates a plurality of inkjet heads 10 for forming an image by ejecting ink to a recording medium, and a required recording paper 5 as an example of a recording medium to be supplied to an image forming position of each inkjet head 10. It is provided with a paper feed device 50 for transporting the paper, and a transport device 40 and the like for transporting the recording paper 5 supplied from the paper feed device 50 to the image forming position and then discharging the paper. The device main body 1a is formed of a support structural member, an exterior cover, and the like. In the figure, the broken line indicates the transport path in which the recording paper 5 is transported inside the apparatus main body 1a of the image forming apparatus 1.

The inkjet head 10 is composed of inkjet heads 10Y, 10M, 10C, and 10K corresponding to inks of each color of yellow (Y), magenta (M), cyan (C), and black (K), respectively. The inkjet heads 10Y, 10M, 10C, and 10K of each color are arranged in order in the transport direction of the recording paper 5. Each inkjet head 10 forms an image on the recording paper 5 by ejecting ink droplets under the control of the control device 100.

The inkjet head 10 is formed by arranging a plurality of ink ejection ports (not shown) along a width direction that intersects the transport direction of the recording paper 5. Then, each inkjet head 10 ejects ink droplets from the ink ejection port to the recording paper 5 supplied from the paper feeding device 50 and conveyed by the conveying device 40 according to the image information. The method of ejecting ink droplets by the inkjet head 10 is not particularly limited. For example, a thermal method of ejecting ink droplets by heat or an ink droplet ejection method using a piezoelectric element or the like is applied by pressure. A piezoelectric method for discharging can be appropriately adopted.

Ink cartridges 30 supply ink of the corresponding color to each inkjet head 10. The ink cartridge 30 is composed of ink cartridges 30Y, 30M, 30C, and 30K corresponding to inks of each color of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Each ink cartridge 30 contains ink of each color. Specifically, the ink cartridge 30Y contains yellow ink, the ink cartridge 30M contains magenta ink, the ink cartridge 30C contains cyan ink, and the ink cartridge 30K contains black ink. Be housed.

Further, each ink cartridge 30 is configured to be detachably attached to the apparatus main body 1a of the image forming apparatus 1, and is connected to the corresponding inkjet head 10. Then, each ink cartridge 30 supplies ink of each color to each inkjet head 10 based on the control by the control device 100.

The paper feeding device 50 is arranged so as to exist at a position on the lower side of the inkjet head 10. The paper feeding device 50 is a sending device that feeds out a single (or a plurality of) paper accommodating bodies 51 that accommodate the recording paper 5 of a desired size, type, etc. in a loaded state, and one recording sheet 5 from the paper accommodating body 51. It is mainly composed of 52 and 53. The paper container 51 is attached so that it can be pulled out to the front side (side surface facing the operator during operation) of the device main body 1a, for example.

As the recording paper 5, in addition to non-coated paper such as plain paper, coated paper such as coated paper and art paper having lower ink absorption than non-coated paper can be used. The coated paper is a paper having a surface layer formed of a filler or a binder resin. As the filler, for example, calcium carbonate, magnesium carbonate, kaolin, talc, silica, alumina, titanium dioxide, aluminum hydroxide, zinc oxide and the like are used. Further, as the binder resin, for example, latex such as a styrene-butadiene copolymer and an acrylonitrile-butadiene copolymer is used.

The transport device 40 passes the recording paper 5 sent out from the paper feed device 50 through the image forming position, and transports the recording paper 5 to the discharge accommodating portion 48 provided in the upper part of the apparatus main body 1a. A paper transport path 47 composed of ~ 46 and a transport guide (not shown) is provided. The paper transport roller 42 arranged at a position immediately before the image forming position on the paper transport path 47 is configured as, for example, a roller (resist roller) for adjusting the transport timing of the recording paper 5. Further, the paper transport roller 46 arranged at a position immediately before the discharge storage unit 48 is configured as a discharge roller that discharges the recording paper 5 on which the image is formed to the discharge storage unit 48.

In the illustrated example, the fixing device S for fixing the image formed on the recording paper 5 by the inkjet head 10 is arranged on the downstream side of the inkjet head 10 along the conveying direction of the recording paper 5. The fixing device S does not necessarily have to be provided.

<Configuration of image reader>
FIG. 2 is a schematic configuration diagram showing the configuration of the image reading device according to the first embodiment.

The image reading device 3 is roughly classified into a housing 31 as an example of the main body of the image reading device 3 having a document reading surface (supporting surface) formed on the upper end surface, and is attached to the housing 31 so as to be openable and closable. The document feeding device (DADF: Duplex Automatic Document Feeder) 33 is provided as an example of the document holding means for holding the document 6. The automatic document transfer device 33 is provided with a document holding cover 32. The document holding means is not limited to the automatic document conveying device 33, and may be composed of the document holding cover 32 itself which does not include the automatic document conveying device 33.

Since the automatic document transfer device 33 separates the documents 6 set (placed) in the automatic document transfer device 33 one by one and transfers them to the reading position, a plurality of transfer members and a plurality of transfer members for transporting the documents 6 are transferred. It is equipped with a drive motor as a drive source for driving the transport member of the above. Therefore, the automatic document transporting device 33 tends to be heavier (weighted) as a whole.

The image scanning device 3 has a first scanning mode in which an image of the document 6 is read while the automatic document transporting device 33 automatically transports the documents 6 one by one according to the operation of the operator, and a document table 83 described later. It is configured to be automatically switchable to a second scanning mode for scanning the image of the document 6 placed on the document holding cover 32 and held by the document holding cover 32. FIG. 2 shows the state of each member when the document is read in the first reading mode.

The automatic document transfer device 33 is from the document accommodating unit 70 as an example of the sheet loading unit capable of loading and accommodating a plurality of sheets 6 with the reading surface (first surface) facing up, and the document accommodating unit 70. A nager roller 71 as an example of a feeding means for feeding the document 6, a feed roller 72 as an example of a feeding means for handling and supplying the document 6 sent by the nager roller 71 one by one, and a document 6 pressed by the feed roller 72. The pressing pad 72a that handles the documents one by one, the first transfer roller 73 that conveys the document 6 to the reading position, and the transfer roller 74 that conveys the document 6 conveyed by the first transfer roller 73 so as to pass through the reading position. , 75 and a document transfer mechanism including a discharge roller 77 as an example of a second transfer roller that discharges the document 6 to the discharge storage unit 76. These nager rollers 71, feed rollers 72, transfer rollers 73 to 75, and discharge rollers 77 are driven when the document 6 is read. The first transfer roller 73 is a resist roller that adjusts the transfer timing of the document 6 to the reading position. In the first embodiment, although not explicitly described as a roller pair, the terms transfer roller and discharge roller include a pair of rollers.

Further, the first transport roller 73 mechanically corrects the inclination of the document 6 with respect to the transport direction (hereinafter, referred to as “skew correction”), and corrects the edge of the document 6 in the same direction as the transport direction. Also works as. Of the first transfer rollers 73, the transfer roller 73b as a drive roller uses a drive motor or the like as a drive means to move from a stopped state to a forward rotation direction Ra in the figure at a predetermined timing, as shown in FIG. Driven to rotate. The transfer roller 73a, which is a driven roller, rotates according to the transfer roller 73b in a state of being in pressure contact with the transfer roller 73b.

In the first transfer roller 73, while the transfer roller 73b as the drive roller is stopped, the tip of the document 6 conveyed by the feed roller 72 located on the upstream side along the transfer direction of the document 6 is the transfer. It is abutted against the pressure contact portion between the roller 73b and the transport roller 73a. Then, the first transport roller 73 bends the tip region of the document 6 to align the tip of the document 6 with the axial direction of the first transport roller 73, and then starts transporting the document 6 to correct the skew. I do.

Further, the automatic document transfer device 33 is provided with a curved reading guide 78 that guides the document 6 to the reading position and guides the document 6 from the reading position in the ejection direction, and a document 6 provided on the reading guide 78 above the reading window 79. A back support member 80 that supports the back surface of the document, a first size detection sensor 81 that is provided in the document accommodating section 70 to detect the size of the document 6 in the sub-scanning direction, and a document 6 that is also provided in the document accommodating section 70. It has a second size detection sensor 82 that detects the size in the sub-scanning direction of the above.

The housing 31 of the image reading device 3 is formed as a rectangular parallelepiped box with a part of the upper end surface open. The housing 31 includes an upper wall 312 facing the document holding cover 32, a bottom wall 313 facing the upper wall 312, and a side wall 314 facing the sub-scanning direction (left-right direction in FIG. 2) with the bottom wall 313 in between. It has a side wall 315, a front wall 311 described above (see also FIG. 1), and a rear wall 316 facing the front wall 311 along the main scanning direction (direction orthogonal to the paper surface of FIG. 2). ing.

The upper wall 312 of the housing 31 is formed with a large flat rectangular opening 317 at a portion corresponding to the document reading position of the document 6 to be read in the second reading mode. A transparent document base 83 (platen glass) that supports the document 6 is arranged in the opening 317. Further, a transparent scanning window 79 for scanning the document 6 in the first scanning mode is provided on the automatic document transporting device 33 side of the document table 83. A guide member 84 having an inclined upper end surface is provided between the reading window 79 and the document base 83 to guide the document 6 that has passed the scanning position to the transport roller 75 in the first scanning mode.

The image reading device 3 has a light source 85 as an example of a lighting means including a lighting lamp, an LED, or the like that irradiates the light for illuminating the document 6 inside the housing 31, and one of the lights emitted from the light source 85. A reflector 86 that reflects the portion toward the document 6, a first mirror 87 that receives the reflected light from the document 6, a second mirror 88 that receives the reflected light from the first mirror 87, and a second mirror. As an example of an image reading means composed of a third mirror 89 that receives the reflected light from the mirror 88 and the reflected light from the third mirror 89, such as a CCD (Charge-Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor). It is provided with an image reading unit having an imaging lens 91 or the like that forms an image on the image reading element 90 of the above. The light source 85 irradiates light toward the document 6 and the reflector 86. The first to third mirrors 87 to 89 and the imaging lens 91 constitute a reading optical system for reading the image of the document 6 by the image reading element 90.

The light source 85, the reflector 86, and the first mirror 87 are arranged along the main scanning direction, which is the depth direction of the image reading device 3, and the drive source described later along the sub-scanning direction, which is the width direction of the image reading device 3. It is attached to a first moving body 92 including a carriage configured to be movable by the above. The first moving body 92 is guided by the first rail 93. The first moving body 92 illuminates the reading target area of the document 6 while moving along the sub-scanning direction, and the reflected light of the document 6 is transmitted by the first mirror 87 to the second moving body 94 of the second moving body 94. It reflects toward the mirror 88. The first rail 93 is arranged on the rear wall 316 of the housing 31 along the sub-scanning direction.

Further, the second mirror 88 and the third mirror 89 are attached to a second moving body 94 composed of a carriage arranged along the main scanning direction and movable by a driving means along the sub scanning direction. Has been done. The second moving body 94 reflects the reflected light of the document 6 toward the imaging lens 91 of the image reading unit while being guided by the second rail 95 and moving in the sub-scanning direction. The second rail 95 is arranged on the bottom wall 313 of the housing 31 along the sub-scanning direction. The first rail 93 and the second rail 95 are arranged one by one so as to face both ends along the main scanning direction.

As shown in FIG. 9, the first and second mobile bodies 92 and 94 have a drive pulley or a drive pulley (not shown) by a drive motor 34 as an example of a drive source arranged inside the housing 31 of the image reading device 3. It is driven so as to be able to reciprocate along the sub-scanning direction via a drive wire or the like.

As shown in FIG. 2, the image reading unit has an image reading substrate 97 on which the image reading element 90 is mounted. The imaging lens 91 and the image reading substrate 97 are attached to a base plate 96 supported by a bottom wall 313. In the image reading unit, the reflected light from the third mirror 89 passes through the imaging lens 91 to form an image on the image reading element 90 made of CCD, CMOS, or the like, and the image reading element 90 reads the image of the document 6 to obtain an image. Output data. The image data read by the image reading element 90 is subjected to predetermined image processing such as shading correction as necessary by an image processing device (not shown), and is sent to the control device 100 (see FIG. 1).

In the first reading mode, as shown by the solid line in FIG. 2, the first and second moving bodies 92 and 94 are stopped at the reading position set at the left end of the housing 31. The document 6 is automatically transported by the automatic document transfer device 33, the document 6 passing through the upper part of the reading window 79 is illuminated by the light source 85, and the reflected light image from the document 6 is second and second by the first mirror 87. It is reflected to the imaging lens 91 through the mirrors 88 and 89 of 3. The image reading unit forms an image of the reflected light image from the third mirror 89 on the image reading element 90 by the imaging lens 91, reads the image of the document 6 by the image reading element 90, and reads the image data from the image reading element 90. Output.

On the other hand, in the second reading mode, the first moving body 92 and the second moving body 94 are driven by a drive source described later, and while the first moving body 92 moves along the sub-scanning direction, the document The amount of movement of the second moving body 94 is halved of the amount of movement of the first moving body 92 so that the optical path length from the image reading position of No. 6 to the image reading element 90 does not change. .. In FIG. 2, the alternate long and short dash line indicates the positions of the first moving body 92 and the second moving body 94 when the first moving body 92 moves to the vicinity of the end portion of the document 6 in the sub-scanning direction.

As shown in FIG. 3, the image reading device 3 separates the documents 6 as an example of the sheets accommodated in the document accommodating unit 70 one by one and conveys them to the reading position, and also transfers the sheets that have passed the reading position to the reading position. It is provided with a sheet transfer device 320 that switches back and transfers the image back to the reading position in a state where the front and back sides are reversed. The sheet transfer device 320 is a nudger roller 71, a feed roller 72, a pressing pad 72a, a first transfer roller 73, transfer rollers 74 and 75, a discharge roller 77, and a drive source for driving these rollers. The drive motor 321 and the constant direction rotation mechanism 322 that rotates the first transfer roller 73 in a fixed direction regardless of the rotation direction of the drive motor 321. It has a first drive transmission switching means 323 for switching to, and a second drive transmission switching means 324 for switching between a state in which the driving force is transmitted to the feed roller 72 and the nager roller 71 and a state in which the driving force is not transmitted. In FIG. 3, the broken line indicates the transmission path of the driving force.

As shown in FIG. 3, the sheet transfer device 320 conveys the document 6 conveyed by the nager roller 71 so as to pass through the feed roller 72, the first transfer roller 73, the transfer rollers 74, 75, and the discharge roller 77. The normal transport path 325 and the document 6 whose rear end is held by the discharge roller 77 are reversed in the rotation direction of the discharge roller 77 to reverse the front and back of the document 6 and are transported again to the first transport roller 73. It is provided with an inverted transport path 326 to be used. The normal transport path 325 is divided into a plurality of parts along the normal transport path 325, and has guide members 325a and 325b for guiding the front and back of the document 6, a reading guide 78, and a back support member 80. The reverse transfer path 326 has guide members 326a and 326b that guide the front and back of the document 6. Further, at the branch position where the normal transport path 325 and the reverse transport path 326 are separated, a switching gate 327 for switching the transport path of the document 6 from the normal transport path 325 to the reverse transport path 326 is provided. The switching gate 327 is formed of an elastically deformable synthetic resin film or the like having a substantially Y-shaped cross section. The switching gate 327 is usually arranged so that a part thereof diagonally crosses the normal transport path 325 as shown in FIG. When the document 6 is transported to the discharge roller 77 along the normal transport path 325, the switching gate 327 is elastically deformed so as to be pushed by the document 6 to open the normal transport path 325, and the document 6 is transported in the transport direction. Is switched to the discharge roller 77. On the other hand, the switching gate 327 reverses the rotation direction of the discharge roller 77 while the discharge roller 77 holds the rear end of the document 6, and causes the document 6 to rotate along the reverse transfer path 326 of the first transfer roller 73. When the document 6 is conveyed by the discharge roller 77, the transfer path of the document 6 is switched from the normal transfer path 325 to the reverse transfer path 326.

The sheet transfer device 320 includes a document sensor 328 that detects the tip of the document 6 at a position corresponding to the nager roller 71. Further, a pre-registration sensor 329 for detecting the tip of the document 6 is provided on the upstream side of the first transfer roller 73 along the transport direction of the document 6. Further, the sheet transfer device 320 is arranged on the downstream side of the transfer roller 74 along the transfer direction of the document 6, and is aligned with a registration sensor (not shown) for detecting the tip of the document 6 and the document 6 of the discharge roller 77. It is arranged on the upstream side and includes an inverter sensor (not shown) that detects the rear end of the document 6.

The sheet transport device 320 is configured to read the image on the back surface of the document 6 by transporting the document 6 to the reverse transport path 326, but instead of providing the reverse transport path 326, it is a normal sheet transport device 320. By arranging a second image reading element (not shown) that reads the image of the back surface (second surface) of the document 6 in the middle of the transport path 325, the images on both the front and back sides of the document 6 are not reversed. May be configured to be readable.

In this case, the reverse transfer path 326 is unnecessary, but it is necessary to newly arrange a second image reading element. Therefore, in the image reading device 3, since the second image reading element itself has a certain weight, the automatic document transporting device 33 may be further weighted.

<Structure of the main part of the image reader>
As shown in FIG. 4, the image reading device 3 according to the first embodiment includes an automatic document conveying device 33 as an example of the document holding means. As described above, the automatic document transfer device 33 is provided with the document holding cover 32. On the lower surface of the document holding cover 32, a holding member 32a formed in the shape of a white sheet that holds a document (not shown) placed on the document table 83 is provided. The pressing member 32a is formed in a flat rectangular shape having a size substantially equal to that of the platen 83. The automatic document transfer device 33 separates the documents 6 set in the automatic document transfer device 33 one by one and conveys them to the reading position. A transport member such as the transport roller 73, the transport rollers 74, 75, and the discharge roller 77 of No. 1 and a drive motor 321 (see FIG. 3) as a drive source for driving these are provided. Therefore, as described above, the automatic document transporting device 33 tends to become heavier (weighted) as a whole.

In the second scanning mode, the image reading device 3 requires the operator to manually open and close the automatic document conveying device 33 when the document 6 is placed on the document table 83 and the image of the document 6 is read. be. Therefore, as the weight of the automatic document transporting device 33 increases, the operating force required for opening and closing the automatic document transporting device 33 also increases in the image reading device 3. Therefore, it is desired that the image reading device 3 improves the operability by reducing the operating force when opening and closing the automatic document transporting device 33.

As a technique capable of improving the operability when opening and closing the automatic document transporting device 33, as described in Patent Document 1 described above, the automatic document transporting device 33 detects the opening / closing angle of the automatic document transporting device 33. A technique for controlling the opening / closing speed of the automatic document transporting device 33 according to the opening / closing angle of the automatic document conveying device 33 has already been proposed.

However, when the image reading device 3 is configured to detect the opening / closing angle of the automatic document transporting device 33 and control the opening / closing speed of the automatic document transporting device 33 according to the opening / closing angle of the automatic document transporting device 33, the automatic document transporting device 33 is automatically opened and closed. When an operation for opening and closing the automatic document transfer device 33 is performed, such as when a heavy object such as a book is placed on the transfer device 33, an excessive load is applied to the drive means for opening and closing the automatic document transfer device 33, and the automatic document transfer device 33 is driven. There is a possibility that the gear of the means or the like may be damaged or the opening / closing operation may malfunction, which poses a technical problem that the operability is impaired.

Therefore, the image reading device 3 according to the first embodiment is mounted on the housing 31 so as to be openable and closable, and is driven when the automatic document transporting device 33 that transports the document 6 to the scanning position and the automatic document transporting device 33 are opened. It is configured to include a pulling force acting means that acts only temporarily as a pulling force that pulls the driving force of the motor 34 in the opening direction of the automatic document transporting device 33.

Further, in the image reading device 3 according to the first embodiment, the pulling force acting means is a pulling force acting member rotatably arranged inside the automatic document transporting device 33 with a rotation axis as a fulcrum, and a pulling force acting member. It is configured to have a wire member that exerts a pulling force in the direction of opening the automatic document transporting device 33 at an end portion of the force acting member located on the opposite side of the rotation axis.

That is, in the image reading device 3 according to the first embodiment, as shown in FIG. 4, the automatic document transporting device 33 has the first and second shaft support members 43 ₁ in the housing 31 of the image reading device 3. It is openably mounted via 43 _2. The first and second shaft support member ₄₃ 1, 43 _2, a bearing portion ₄₄ 1, 44 ₂ provided on the housing 31 side of the image reading device 3, reading provided in the automatic document feeder 33 side rotation and a section ₄₅ 1, 45 _2. Bearing portions ₄₄ 1, 44 ₂ and reading the rotation unit ₄₅ 1, 45 _2, as shown in FIG. 5, is rotatably connected around a rotation shaft ₄₆ 1, 46 _2. The reading rotating unit 45 _1, 45 _2, to reduce the load when opening and closing the automatic document feeder 33, a counterbalance (not shown) exerts a rotational moment in the direction of opening the automatic document feeder 33 is incorporated ing. The counterbalance includes a coil spring (not shown) or the like that causes a rotational moment in the opening direction to act on the automatic document transfer device 33 according to the opening / closing angle of the automatic document transfer device 33. Incidentally, the counter balance, of course may be arranged on the bearing unit ₄₄ 1, 44 ₂ side.

Further, the document 6 whose image is read by the image reading device 3 is not limited to the document 6 cut into a desired size such as A4 size or A3 size, and a plurality of pages such as a book in which a plurality of documents 6 are closed. A so-called book manuscript or the like having the manuscript 6 over the range is also included. In order to read the image of the book document by the image reading device 3, as shown in FIG. 4, the image of the page to be read of the book document is placed on the platen 83 with the image of the page to be read of the book document facing down with the automatic document transporting device 33 open. , The operation of closing the automatic document transfer device 33 is performed.

At that time, book original, because it has a certain thickness, if the automatic document feeder 33 is simply provided to be opened and closed first and second shaft support member 43 _1, 43 ₂ as a fulcrum Even if the automatic document transfer device 33 is closed when reading the image of the book document, the automatic document transfer device 33 is in an inclined state with respect to the upper surface of the book document, and the entire surface of the book document cannot be pressed.

Therefore, the first and second shaft support member 43 _1, 43 ₂ for openably supporting the automatic document feeder 33, as shown in FIG. 5 (b) (c), the housing of the image reading device 3 bearing portion ₄₄ 1 which is disposed on the 31 side, 44 ₂ a cylindrical lift part ₄₄ 1 a, 44 ₂ a is provided. Bearing portions ₄₄ 1, 44 ₂ of the lifting part ₄₄ 1 a, 44 ₂ a is inserted removably inserted into the hole portion 31a provided in the housing 31. The first and second shaft support member 43 _1, 43 _2, when reading the image of an original 6 having a certain thickness such as a book original, inserted into the holes 31a provided in the housing 31 has been moved bearing unit 44 _1, 44 ₂ of the lifting part 44 1 _a, 44 2 _a is upward, the automatic document feeder 33 can hold the entire surface of the book document to be a top surface substantially parallel to the book document It is configured to be possible.

As shown in FIG. 4, the automatic document transfer device 33 has a weight at the left end portion in the drawing in which a transfer means for automatically transporting the document 6 is built-in heavier than that at the right side. As a result, the center of gravity of the automatic document transporting device 33 is located at a position biased to the left side in the drawing in which the transporting means for automatically transporting the document 6 is built in, rather than the central portion along the width direction. Therefore, counterbalance mounted in the first and second shaft support member 43 _1, 43 _2, the direction of the first counterbalance disposed left side in the drawing is a drive side of the automatic document feeder 33, The rotational moment given to the automatic document transfer device 33 is set to be larger than the second counterbalance arranged on the right side, which is the non-driving side of the automatic document transfer device 33.

6, rotation and rotational moment M1 that is required to open from the closed automatic document feeder 33 (opening angle = 0 °), a first shaft support member 43 ₁ has on the automatic document feeder 33 a moment M2, a rotational moment M3 of the second shaft support member 43 ₂ has on the automatic document feeder 33, the synthetic rotational moment the first and second shaft support member ₄₃ 1, 43 ₂ has on the automatic document feeder 33 It is a graph which showed the result of having obtained each value of MT according to the opening / closing angle of the automatic document transporting apparatus 33.

In the image reading device 3 according to the first embodiment, in order to reduce the operating force of the operator when opening the automatic document transporting device 33 as much as possible, the automatic document transporting device 33 is predetermined to be about 5 to 25 degrees. when in the opened angle theta (e.g. 10 degrees), a rotation moment M1 required to open the automatic document feeder 33, the values of the first and second shaft support member 43 _1, 43 ₂ of the composite torque MT It is set to be equal. Further, when the opening angle of the automatic document transporting device 33 exceeds a predetermined angle θ, the first and second shaft support members 43 ₁ and 2 from the rotational moment M1 required to open the automatic document transporting device 33, 43 _2/5 synthetic torque MT is set to be larger. As a result, the operator can easily perform the operation of opening the automatic document transfer device 33 in the angle region exceeding the predetermined angle θ even when the weight of the automatic document transfer device 33 increases. However, the first and second shaft support member 43 _1, 43 _2, even when the opening angle of the automatic document feeder 33 exceeds the angle θ predetermined, operator automatic document feeder 33 It is desirable to prevent the automatic document transfer device 33 from being unintentionally opened when the opening operation is stopped. Therefore, the first and second shaft support member 43 _1, 43 _2, even when the opening angle of the automatic document feeder 33 exceeds the angle θ predetermined, operator automatic document feeder 33 It is configured so that a frictional force that maintains the opening angle when the hand is released from the body acts.

The automatic document feeder 33 is completely even in closed state (open angle = 0 °), the first and second shaft support member 43 _1, 43 opened by the _two directions of the composite torque MT acts ing. In this case, the required synthesis torque MT that acts on the automatic document feeder 33 by the first and second shaft support member 43 _1, 43 _2, as shown in FIG. 6, open the automatic document feeder 33 The value is slightly smaller than the rotational moment M1 required for.

As shown in FIG. 5A, the image reading device 3 includes a reed switch 220 and a magnetic member 221 as an example of a detecting means for detecting the opening / closing of the automatic document transporting device 33. The housing 31 of the image reading device 3 is provided with, for example, a reed switch 220 on the front side of the reading window 79. As shown in FIG. 7, the reed switch 220 has a first lead 222 made of a ferromagnet having one end magnetized on the S pole and the other end magnetized on the N pole, and one end on the N pole. A second reed 223 made of a ferromagnetic material whose portion is magnetized to the S pole is sealed inside the switch body 224. The other end of the first lead 222 and the other end of the second lead 223 are provided with first and second contact portions 225 and 226, respectively. The reed switch 220 is attached so that the second reed 223 is located on the surface side of the housing 31.

On the other hand, the magnetic member 221 is attached to the automatic document transfer device 33 at a position corresponding to the reed switch 220 of the housing 31 of the image reading device 3. The magnetic member 221 is composed of an elongated permanent magnet in which S pole and N pole are magnetized at both ends. The magnetic member 221 is arranged so that the magnetic pole of the S pole is located on the lower surface side of the automatic document transfer device 33.

Then, as shown in FIGS. 7B and 8, when the automatic document transfer device 33 is closed, the reed switch 220 has a magnetic member 221 on the second contact portion 226 of the S pole of the second lead 223. The S poles are close to each other, the second contact part 226 of the S pole is magnetically repulsive, and the first contact part 225 of the N pole is magnetically attracted. Contact the first contact portion 225 of the north pole of the first lead 222 and is turned on. On the other hand, as shown in FIGS. 5A and 7A, when the automatic document transfer device 33 is opened, the S pole of the magnetic member 221 is separated from the Reed switch 220 and the lead switch 220 is separated from the N pole. Due to the elastic restoring force of the first contact portion 225 and the second contact portion 226 composed of S poles, the second contact portion 226 in the second reed 223 becomes the first contact portion 225 in the first reed 222. It is separated from and turned off.

In this way, the reed switch 220 can detect the opening and closing of the automatic document transfer device 33 with a simple configuration and with high accuracy by determining whether it is in the on state or the off state.

The detection means for detecting the opening / closing of the automatic document transporting device 33 is not limited to the combination of the reed switch 220 and the magnetic member 221. The automatic document transporting device is located near the opening / closing fulcrum of the automatic document transporting device 33. A mechanical switch having a contact member that appears and disappears when the 33 is opened and closed, an optical switch that optically detects the opening and closing of the automatic document transfer device 33, and the like may be used.

As shown in FIG. 5, the image reading device 3 according to the first embodiment applies the driving force of the drive source to the automatic document transporting device 33 when the operator opens the automatic document transporting device 33. A pulling device 200 as an example of a pulling force acting means that acts only temporarily as a pulling force for pulling the device 33 in the opening direction is provided on the back side inside the housing 31 of the image reading device 3.

In the first embodiment, as shown in FIG. 9, the pulling device 200 does not have its own drive source, and the drive motor 34 that drives the reading optical system of the image reading device 3 is used as the driving source. ing. Of course, the pulling device 200 may be provided with its own drive source.

As shown in FIG. 10, a drive gear 202 for driving the pulling device 200 together with a drive pulley 201 for driving the reading optical system is attached to the drive shaft 341 of the drive motor 34. As shown in FIG. 9, a timing belt 204 is hung on the drive pulley 201 with a driven pulley 203 that drives the reading optical system of the image reading device 3.

As shown in FIG. 10, the drive motor 34 is rotationally driven in the forward rotation direction and the reverse rotation direction when reading the image of the document 6 in the second reading mode. The drive gear 202 is meshed with a drive force transmission gear 205 having a built-in electromagnetic clutch 205c as an example of a switching means for switching whether or not to transmit the rotational drive force of the drive motor 34 to the pulling device 200. The driving force transmission gear 205 has a first driving force transmission gear 205a having a relatively large outer diameter on the input side and a second driving force transmission gear 205b having a relatively small outer diameter on the output side. .. The second driving force transmission gear 205b is meshed with a reciprocating gear 208 that reciprocates the driving wire 206 as an example of the wire member.

The reciprocating gear 208 is provided with an engaging pin 209 protruding laterally from the outer peripheral end of one side surface thereof. One end of the drive wire 206 is rotatably engaged with the engagement pin 209.

As shown in FIG. 9, the drive wire 206 is hung around a first pulley 210 rotatably provided inside the housing 31 of the image reading device 3 at its end along the horizontal direction. Its tip is turned upward along the vertical direction. The tip of the drive wire 206 is hung on a second pulley 211 rotatably provided at a position corresponding to the _first shaft support member 431 on the back surface of the automatic document transfer device 33, and then the automatic document transfer is performed. It is introduced inside the device 33.

Inside the automatic document feeder 33, as shown in FIG. 5 (a), the opening motion arm member 212 which is formed in an elongated plate shape is rotating the rotary shaft 46 ₁ of the first shaft support member 43 ₁ as a fulcrum Arranged as possible. The opening arm member 212 extends so that its tip portion is located near the front end portion of the automatic document transporting device 33. The tip of the drive wire 206 is connected and fixed to the tip 212a of the opening arm member 212. The opening arm member 212 is integrally provided with a short acting arm 212c that branches upward along the vertical direction from an intermediate portion along the longitudinal direction thereof. The tip of the working arm 212c of the opening arm member 212 is in contact with the ceiling wall 33a provided on the upper part of the automatic document transporting device 33.

When the reciprocating gear 208 is rotated in a required direction by rotationally driving the drive motor 34, the pulling device 200 is rotatably engaged with one end of the engagement pin 209 provided on the reciprocating gear 208. The drive wire 206 is pulled to the left in FIG. 9 and moves. The movement of the drive wire 206 is transmitted to the opening arm member 212 arranged inside the automatic document transporting device 33 via the first and second pulleys 210 and 211, and the opening arm member 212 rotates clockwise in FIG. Rotate in the direction. When the opening arm member 212 rotates in the clockwise direction in FIG. 5, the tip of the working arm 212c abuts on the ceiling wall 33a provided on the upper part of the automatic document transporting device 33, and the automatic document transporting device 33 is moved in the clockwise direction. Pull up along.

Then, as the opening arm member 212 rotates clockwise in the drawing, the ceiling wall 33a of the automatic document transporting device 33 is pulled up by the acting arm 212c of the opening arm member 212, and the operator can perform the automatic document transporting device 33. It is designed to assist the opening operation.

The tip portion 212a of the opening arm member 212 along the longitudinal direction is a force point to which a pulling force is applied by the drive wire 206. Further, the opening arm member 212 is a point of action in which the tip of the acting arm 212c located in the middle along the longitudinal direction of the opening arm member 212 actually exerts a pulling force on the ceiling wall 33a of the automatic document transporting device 33. Therefore, in the pulling device 200, the distance from the base end portion 212b to the tip end portion 212a and the base end portion 212b with respect to the rotational moment in which the drive wire 206 rotates the tip end portion 212a of the opening arm member 212 in the clockwise direction in the drawing. A large pulling force acts due to the action of the lever in proportion to the distance from the acting arm 212c.

When the operator opens the automatic document transfer device 33, the drive motor 34 is driven only temporarily for a predetermined time T, pulls up the automatic document transfer device 33 via the drive wire 206, and pulls up the automatic document transfer device 33. Is opened by a set angle several degrees (1 to 2 degrees) larger than the predetermined angle θ, then stopped, and immediately rotationally driven in the opposite direction to end the pulling operation of the automatic document transfer device 33.

The drive wire 206 is not rotatably connected to the reciprocating gear 208 via an engaging pin 209, but is provided with a take-up reel (not shown) instead of the reciprocating gear 208, and one end of the drive wire 206 is covered. It may be fixed to the take-up reel and configured to take up the drive wire 206 by the take-up reel.

By the way, in the image reading device 3 according to the first embodiment, when the automatic document transporting device 33 is closed, a heavy object such as a book is placed on the automatic document transporting device 33. Even if the drive wire 206 is driven, the automatic document transfer device 33 does not open, and there is a possibility that an excessive load is applied to the drive motor 34 that drives the drive wire 206.

Further, in the image reading device 3 according to the first embodiment, after the operator once opens the automatic document transporting device 33, the automatic document transporting device 33 opens the automatic document transporting device 33 by a predetermined angle θ. The operation of closing the device 33 may be performed. Then, the image reading device 3 forcibly closes the automatic document transporting device 33 while driving the driving wire 206 to open the automatic document transporting device 33 by a predetermined angle θ, and pushes the driving wire 206. There is a risk that an excessive load will be applied to the drive motor 34 to be driven.

Therefore, the image reading device 3 according to the first embodiment includes an absorbing means 240 that absorbs the excessive force when an excessive force exceeding a predetermined value is applied to the pulling device 200. The absorbing means 240 is composed of, for example, an elastic member that absorbs an excessive force by elastically deforming when an excessive force is applied to the pulling device 200.

Further, in the image reading device 3, a coil spring 241 as an example of the absorbing means 240 is interposed in the middle of the driving wire 206 that transmits the driving force of the driving motor 34 to the automatic document transporting device 33 as a pulling force. .. The coil spring 241 has a required spring constant. The spring constant of the coil spring 241 is larger than the tension acting on the drive wire 206 when the drive wire pulls up the automatic document transfer device 33, and the spring constant is larger than the tension acting on the drive wire 206, as in the case where a heavy object is placed on the automatic document transfer device 33. The value is set to be smaller than the tension when a load exceeding a predetermined value is applied to the pulling device 200. Therefore, the coil spring 241 extends to a certain length L2 when the drive wire pulls up the automatic document transfer device 33, but the length L2 of the coil spring 241 is a pulling device as shown in FIG. It is shorter than the length L3 when a load exceeding a predetermined value is applied to 200. The coil spring 241 has a length of L1 before tension is applied to the drive wire 206.

In the first embodiment, when an excessive load is applied to the drive motor 34, the coil spring 241 is extended to absorb the excessive load acting on the drive motor 34. Therefore, it is possible to prevent the drive motor 34 from generating heat due to overload and disconnecting, and to prevent the teeth of the reciprocating gear 208 that transmits the driving force from being chipped or stepped out.

FIG. 13 is a block diagram showing a control device 100 of the image forming apparatus 1 according to the first embodiment.

As shown in FIG. 13, the control device 100 includes a control unit 101 as an example of control means, a timekeeping unit 102 for measuring time, and a storage unit 103 as an example of storage means.

The control unit 101 comprehensively controls the operation of the image forming device 1 including the image reading operation by the image reading device 3 by executing the program stored in the storage unit 103. The control unit 101 drives an image forming unit 2 composed of yellow (Y), magenta (M), cyan (C), and black (K) inkjet heads 10 (Y, M, C, K) and the like. , Performs the formation operation of a color image or the like.

Further, the control unit 101 controls the reading operation of the image reading device 3 via the time measuring unit 102, the storage unit 103, and the like.

At that time, when the control unit 101 detects that the automatic document transfer device 33 has changed from the closed state to the open state based on the open / close signal of the automatic document transfer device 33 input from the reed switch 220, the drive motor The 34 is driven for a predetermined time T (only temporarily). Here, the predetermined time T is set to, for example, the time required for the drive motor 34 to open the automatic document transfer device 33 by a set angle several degrees (1 to 2 degrees) larger than the predetermined angle θ. Will be done.

At the same time, when the timekeeping unit 102 detects that the automatic document transfer device 33 has changed from the closed state to the open state based on the open / close signal of the automatic document transfer device 33 input from the reed switch 220, the elapsed time is set. measure. Then, the timekeeping unit 102 outputs a progress signal to the control unit 101 when it measures that a predetermined time T has elapsed.

Upon receiving the progress signal output from the timekeeping unit 102, the control unit 101 controls to stop the drive motor 34 and then rotate the drive motor 34 in the reverse direction for a predetermined time T to stop the drive motor 34. do.

Further, the control unit 101 drives the electromagnetic clutch 205c on and off at a required timing. The timing at which the control unit 101 turns on the electromagnetic clutch 205c is set when it detects that the automatic document transfer device 33 has been opened based on the open / close signal of the automatic document transfer device 33 input from the reed switch 220. NS. Further, the timing at which the control unit 101 turns off the electromagnetic clutch 205c is set when a predetermined time T has elapsed since the electromagnetic clutch 205c was turned on.

<Operation of image reader>
In the image forming apparatus 1 to which the image reading apparatus 3 according to the first embodiment is applied, when the image of the original 6 is copied or the image of the original 6 is read and transmitted by the fax machine function or the like as follows. As compared with the case where the automatic document transfer device 33 in the image reading device 3 is opened and closed over all the opening and closing angles, it is possible to reduce the operating force when opening the automatic document transfer device 33 without impairing the operability. It has become.

That is, in the image reading device 3 of the image forming device 1, as shown in FIG. 4, when reading the image of the document 6 in the second reading mode, the automatic document transporting device 33 functioning as the document holding means is opened to open the image. The document 6 is placed on a platen (platen glass) 83 provided on the upper end surface of the housing 31 of the scanning device 3, and after the automatic document transporting device 33 is closed, the control panel 66 of the image forming apparatus 1 desires the document 6. Execute a copy operation, etc.

The image reading device 3 reads the image of the document 6 by the image reading device 3 according to the operation specified by the control panel 66, and forms the image of the document 6 on the recording paper 5 by the image forming unit 2 of the image forming device 1. Or, the image of the document 6 read by the image reading device 3 is transmitted to a personal computer (not shown), or the image of the document 6 read by the image reading device 3 is transmitted by the facsimile function.

The image reading device 3 for reading the image of the document 6 is relatively provided with a transport member, a drive motor 321 and the like for the automatic document transport device 33 to automatically transport the document 6 in the first reading mode. The weight is large. Therefore, in the image reading device 3, in the second reading mode, when the document 6 is pressed by the automatic document transporting device 33 with the document 6 placed on the document table 83 and the image of the document 6 is read, the relative It is necessary for the operator to open and close the heavy automatic document transfer device 33.

When the operator opens the automatic document transfer device 33, the image reading device 3 detects that the automatic document transfer device 33 has been opened by the reed switch 220.

As shown in FIG. 13, when the control unit 101 of the control device 100 detects that the automatic document transfer device 33 has been opened by shifting the signal from the reed switch 220 from the on state to the off state, the driving force At the same time that the electromagnetic clutch 205c of the transmission gear 205 is turned on, the drive motor 34 is rotationally driven (only temporarily) for a predetermined time T.

As shown in FIG. 9, in the image reading device 3, when the drive motor 34 is rotationally driven, the drive force transmission gear 205 is rotationally driven by the drive motor 34. Since the electromagnetic clutch 205c of the driving force transmission gear 205 is turned on, the rotational driving force from the drive motor 34 is transmitted to the second driving force transmission gear 205b, and the reciprocating gear 208 is counterclockwise in the drawing. It is rotationally driven by a required angle in the rotational direction.

Then, a tension that pulls to the left in the drawing acts on the drive wire 206 whose one end is connected to the reciprocating gear 208, and the automatic document transfer device 33 passes through the coil springs 241 and the first and second pulleys 210 and 211. The tip portion 212a of the opening arm member 212 arranged inside the above is pulled up in the clockwise direction.

When the opening arm member 212 is pulled up in the clockwise direction by the drive wire 206 connected to the tip portion 212a, the opening arm member 212 itself also rotates in the clockwise direction. Then, the acting arm 212c provided in the middle of the opening arm member 212 abuts on the ceiling wall 33a of the automatic document transfer device 33 and pulls up in the direction of opening the automatic document transfer device 33 to open the automatic document transfer device 33.

Therefore, when the operator opens the automatic document transfer device 33, the operation of opening the automatic document transfer device 33 is assisted by the pulling operation of the drive wire 206, so that the operator does not care about the weight of the automatic document transfer device 33. The operation of opening the transfer device 33 can be easily performed.

Further, as shown in FIG. 6, the angle at which the drive wire 206 opens the automatic document transport device 33 is set to a set angle that is several degrees (1 to 2 degrees) larger than the predetermined angle θ. Thus, the operator, after the operation of opening the automatic document feeder 33 by the drive wire 206 is assisted synthesis rotating moment acting the first and counter balance built second to the shaft support member 43 _1, 43 ₂ The MT makes it possible to easily open the automatic document transfer device 33 to the fully open position.

When the time T of the time T determined by the time measuring unit 102 has elapsed, the control unit 101 of the control device 100 immediately rotates in the opposite direction for a predetermined time T after stopping the drive motor 34. Let me. Further, the control unit 101 stops the drive motor 34 and at the same time turns off the electromagnetic clutch 205c.

Then, as the drive motor 34 rotates in the opposite direction, as shown in FIG. 9, the drive wire 206 whose one end is connected to the reciprocating gear 208 moves to the right in the drawing to move the drive wire 206. Move to the right in the figure.

When the drive wire 206 moves to the right in the drawing, the opening arm member 212 connected to the inside of the automatic document transfer device 33 via the first and second pulleys 210 and 211 also rotates in the counterclockwise direction. It is separated from the ceiling wall 33a of the automatic document transfer device 33.

Further, in the first embodiment, when the electromagnetic clutch 205c is turned off, the second driving force transmission gear 205b of the driving force transmission gear 205 can freely rotate, and the operation of pulling the drive wire 206 is released. Will be done.

As described above, in the image reading device 3 according to the first embodiment, the operation of opening the automatic document transporting device 33 by the operator is detected by the reed switch 220, and the drive motor 34 is driven to open the drive wire 206 and the drive wire 206. The arm member 212 pushes up the automatic document transfer device 33 only temporarily. Therefore, even when the automatic document transfer device 33 has a relatively large weight to some extent, the operation of opening the automatic document transfer device 33 by the operator is assisted by the drive motor 34, and the operation of opening the automatic document transfer device 33 is performed. It can be done easily.

Further, in the image reading device 3 according to the first embodiment, when a heavy object such as a book (not shown) is placed on the automatic document transporting device 33, or during the operation of the operator opening the automatic document transporting device 33. Even when the closing operation is performed, as shown in FIG. 14, since the coil spring 241 is interposed in the middle of the drive wire 206, the coil spring 241 extends by the length L3 to apply an excessive load. It absorbs and avoids excessive load acting on the drive motor 34.

Therefore, according to the image reading device 3 according to the first embodiment, when the automatic document transporting device 33 is opened without impairing the operability, as compared with the case where the automatic document transporting device 33 is opened and closed over all the opening and closing angles. It is possible to reduce the operating force of.

In the above embodiment, the case where the image reading device is applied to a color copier as an example of the image forming device has been described, but the present invention is not limited to this, and the image reading device is used as a scanner, a fax machine, or the like. Of course, it is okay.

Further, in the above-described embodiment, the case where the coil spring is used as the absorbing means has been described, but as the absorbing means, a torque limiter for limiting the driving torque may be provided in the driving force transmission gear 205 or the like. ..

1 ... Image forming device 1a ... Image forming device main body 3 ... Image reading device 31 ... Image reading device housing 33 ... Automatic document transfer device 34 ... Drive motor 206 ... Drive wire 207 ... Link mechanism 210 ... First pulley 211 ... Second pulley 212 ... Opening arm member

Claims (8)

A document holding means that is attached to the main body of the device so that it can be opened and closed via a rotating shaft to hold the document,
A pulling force acting means that causes the driving force of the drive source to act only temporarily as a pulling force that pulls the document holding means toward the document holding means in the opening direction when the document holding means is opened.
With
The pulling force acting means includes a pulling force acting member rotatably arranged inside the document holding means with the rotation axis as a fulcrum.
An image reading device having a wire member that applies a pulling force in a direction of opening the document holding means to an end of the pulling force acting member located on the side opposite to the rotation axis. The image reading device according to claim 1, wherein the pulling force acting member has an acting arm that branches from an intermediate position along the longitudinal direction and exerts a pulling force in the opening direction on the document holding means. The image reading device according to claim 2, wherein the pulling force acting means converts the moving direction of the wire member into the opening / closing direction of the document holding means via a pulley arranged in the middle of the wire member. The image reading device according to claim 1, further comprising an absorbing means for absorbing the excessive force when an excessive force exceeding a predetermined value is applied to the pulling force acting means. The image reading device according to claim 4, wherein the absorbing means comprises an elastic member that absorbs the excessive force by elastically deforming when the excessive force is applied to the pulling force acting means. An image reading means for reading an image of the document conveyed to the reading position by the document holding means is provided.
The image reading device according to claim 1, wherein the driving source is a driving source of the image reading means. The image reading device according to claim 6, wherein the document holding means is cut off when the power is opened and closed. An image reading means for reading the image of the document and
An image forming means for forming an image of the original document read by the image reading means, and an image forming means.
With
An image forming apparatus using the image reading apparatus according to any one of claims 1 to 7 as the image reading means.

Images