Document conveying device and image forming apparatus

A document conveying device is used in common for a double-sided reading specification in which images on one face and the other face of a document conveyed along a conveying path are read and for a single-sided reading specification in which the image on the one face of the document is read. The document conveying device includes a recess, a cover member and a supporting part. In the recess, a member dedicated to the double-sided reading specification is supported at the double-sided reading specification. The member dedicated to the double-sided reading specification is used for reading the image on the other face. The cover member closes the recess at the single-sided reading specification. By the supporting part, the member dedicated to the double-sided reading specification is detachably supported at the double-sided reading specification and the cover member is detachably supported at the single-sided reading specification.

INCORPORATION BY REFERENCE

This application is based on and claims the benefit of priority from Japanese Patent application No. 2016-180726 filed on Sep. 15, 2016, which is incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to a document conveying device which conveys a document and to an image forming apparatus including the document conveying device.

A document conveying device which conveys a document along a conveying path may be attached to an image forming apparatus. The document conveying device is provided with a reading unit configured to read an image on the conveyed document. Based on the read image, the image forming apparatus forms an image on a sheet.

The document conveying device is sometimes used in common for both a double-sided reading specification and a single-sided reading specification. In the double-sided reading specification, images on both faces (a front face and a back face) of the document are read by one-time conveying of the document along the conveying path. In the single-sided reading specification, the image on one face (the front face) of the document is read by one-time conveying of the document along the conveying path. Such a document conveying device has a member dedicated to the double-sided reading specification. The dedicated member is attached to a storage space which is formed in a guide for guiding the document along the conveying path. By attaching the dedicated member to the storage part, it becomes possible to change the document conveying device from the single-sided reading specification into the double-sided reading specification.

The above described document conveying device is provided with a lid which covers the storage part when changed into the single-sided reading specification. The lid is configured to be placed and adhered around the storage part. Thereby, an attachment and detachment work of the lid is not carried out easily. Additionally, it is difficult to change the document conveying device into the double-sided reading specification again after changed into the single-sided reading specification.

SUMMARY

In accordance with an aspect of the present disclosure, a document conveying device is used in common for a double-sided reading specification in which images on one face and the other face of a document conveyed along a conveying path are read and for a single-sided reading specification in which the image on the one face of the document is read. The document conveying device includes a recess, a cover member and a supporting shaft. In the recess, a member dedicated to the double-sided reading specification is supported at the double-sided reading specification. The member dedicated to the double-sided reading specification is used for reading the image on the other face. The cover member closes the recess at the single-sided reading specification. By the supporting part, the member dedicated to the double-sided reading specification is detachably supported at the double-sided reading specification and the cover member is detachably supported at the single-sided reading specification.

In accordance with an aspect of the present disclosure, the image forming apparatus forms an image based on an image on the document conveyed by the above described document conveying device.

DETAILED DESCRIPTION

Hereinafter, with reference to the attached drawings, a document conveying device and an image forming apparatus according to one embodiment of the present disclosure will be described.

With reference toFIG. 1, an entire structure of a color printer1will be described.FIG. 1is a front view schematically showing an entire structure of the color printer1. In the following description, a near side of a paper plan ofFIG. 1is defined to be a front side of the color printer1, and a left-right direction is defined based on the direction in which the printer1is viewed from the front side. Fr, Rr, L and R shown in each figure respectively show the front, rear, left and right sides of the color printer1.

The color printer1includes an image forming apparatus2and a document conveying device3disposed on the image forming apparatus2, as shown inFIG. 1. The document conveying device3is configured to convey a document automatically and to read images on both faces (a front face and a back face) or an image on one face (a front face) of the conveyed document. The image forming apparatus2is configured to form an image according to the image read by the document conveying device3on both faces or one face of a sheet.

With reference toFIG. 1andFIG. 2toFIG. 4, the document conveying device3will be described.FIG. 2is a perspective view showing a document conveying unit of the document conveying device,FIG. 3is a side sectional view showing a conveying part of the document conveying device for a double-sided reading specification, andFIG. 4is a side sectional view showing the conveying part of the document conveying device for a single-sided reading specification.

As shown inFIG. 1, the document conveying device2includes a document conveying unit4and a reading unit5. The document conveying unit4is configured to convey the document automatically in a predetermined conveying direction and to read the image on the one face (the back face) of the document. The reading unit5is configured to read the image on the other face (the front face) of the document. The document conveying unit4is disposed on the reading unit5.

Firstly, the reading unit5will be described with reference toFIG. 1,FIG. 3andFIG. 4. The reading unit5is formed into a shallow approximately parallelepiped rectangular shape capable of being placed on an upper face of the image forming apparatus2, as shown inFIG. 1. As shown inFIG. 3andFIG. 4, on a left end portion of an upper face of the reading unit5, a window11is formed along a width direction perpendicular to the conveying direction for the document. The window11is covered with a contact glass12. Below the window11, a contact image sensor13configured to read the image on the front face of the document is provided.

Next, the document conveying unit4will be described. As shown inFIG. 1andFIG. 2, the document conveying unit4includes a base part20, a conveying part22and a document placement part23. The base part20is configured to be attached on the upper face of the reading unit5. The conveying part22is provided on a left half of an upper face of the base part20and configured to form a conveying path21along which the document is conveyed in the conveying direction. The document placement part23on which the document to be conveyed is placed is supported by the conveying part22.

The base part20is a member capable of being placed on the upper face of the reading unit5. As shown inFIG. 2, the base part20has two legs20awhich positions the document conveying unit4with respect to the reading unit5.

As shown inFIG. 3andFIG. 4, the base part20has a window31facing the window11of the reading unit5at the left end portion. The base part20further has an outer guide plate32and an ejection tray33which are formed continuously from a right side edge of the window31. The outer guide plate32is inclined in the right upper direction to form a part of an outer circumferential side guide face of the conveying path21. At a right side end portion of the outer guide plate32, a conveying roller storage recess34is formed. The ejection tray33is gradually inclined in the right upper direction from the conveying roller storage recess34.

The conveying part22has front and rear side plates41and42, an inner guide plate43as an example of a guide member and outer covers44A and44B. The front and rear side plates41and42facing each other in the front-rear direction are formed along almost left halves of front and rear edges of the base part20. The inner guide plate43has a horizontally laid U-shaped cross section (refer toFIG. 3andFIG. 4). The inner guide plate43is supported between the front and rear side plates41and42such that both side edges of the inner guide plate43in the width direction are fixed to center portions of the front and rear side plates41and42in the upper-lower direction. Each of the outer covers44A and44B is supported by a left end portion of the base part20in a turnable manner around its left end so as to cover outer faces of the front and rear side plates41and42, and an upper side and a left side of the inner guide plate43.

As shown inFIG. 2, the document placement part23is a rectangular plate-shaped member having a document placement face37on which the predetermined size document is placed. On the document placement face37, side cursors38are supported in a slidable manner in the width direction so as to align the document in the width direction. The document placement part23is supported by the front and rear side plates41and42above the ejection tray33with a posture inclined downward toward the conveying part22.

Next, the conveying part22will be described in detail with reference toFIG. 3andFIG. 4, andFIG. 5toFIG. 8.FIG. 5is a perspective view showing the conveying part for the double-sided reading specification when viewed from the upper side,FIG. 6is a perspective view showing the conveying part for the single-sided reading specification when viewed from the upper side,FIG. 7is a perspective view showing the conveying part for the double-sided reading specification when viewed from the lower side andFIG. 8is a perspective view showing the conveying part for the single-sided reading specification when viewed from the lower side.

As shown inFIG. 3andFIG. 4, an outer face of the inner guide plate43forms an inner circumferential side guide face43aof the conveying path21. An inner face of each of the outer covers44A and44B forms the outer circumferential side guide face44aof the conveying path21. The conveying path21is formed between the guide face43aof the inner guide plate43and the guide face44aof each of the outer covers44A and44B and between the guide face43aof the inner guide plate43and the guide face of the outer guide plate32of the base part20. The conveying path21extends leftward from an upper inlet21a, curves downward in an arc shape and then extends rightward to a lower outlet21b, like a horizontally lied U-shape.

The guide face43aof the inner guide plate43will be described. On the guide face43aof the inner guide plate43, a document placement portion50, a first conveying roller opening51as an example of a recess, a document detection sensor opening52as an example of a recess (refer toFIG. 5), a reading sensor storage recess53, a second conveying roller opening54, a third conveying roller opening55, a pressing member storage recess56and a fourth conveying roller opening57are formed in the order in the conveying direction.

The document placement portion50is formed on the upstream side of the inlet21ain the conveying direction. The document placement portion50continuous to the document placement part23so that a leading portion of the document is placed thereon. On the document placement portion50, a plurality of ribs are formed along the conveying direction.

The first to fourth conveying roller openings51,54,55and57each have two rectangular openings arranged at a predetermined interval in the width direction. The first conveying roller opening51is formed at the inlet21aof the conveying path21. The second conveying roller opening54is formed on the upstream side of the curved path of the conveying path21in the conveying direction. The third conveying roller opening55is formed at the curved path of the conveying path21. The fourth conveying roller opening57is formed at the outlet21bof the conveying path21. The fourth conveying roller opening57faces the conveying roller storage recess34via the conveying path21.

As shown inFIG. 5andFIG. 6, the document detection sensor opening52has a rectangular shape long in the conveying direction, and is formed at a front side portion between the two openings of the first conveying roller opening51. As shown inFIG. 7andFIG. 8, on a face opposite to the guide face43aof the inner guide plate43(a face opposite to the conveying path21), two bearing pieces58are formed as a bearing part which is an example of a supporting part. The bearing pieces58protrude downward from both sides of the document detection sensor opening52in the width direction. The bearing pieces58are elastically deformable, and have bearing holes aligned on the same axis along the width direction.

As shown inFIG. 3andFIG. 4, the reading sensor storage recess53has a horizontally long rectangular shaped cross-section, and is formed along the width direction. The pressing member storage recess56has a horizontally long rectangular shaped cross-section, and is formed along the width direction. The pressing member storage recess56faces the window31.

Next, the guide face44aof each of the outer covers44A and B will be described. The guide face44ais different in shape for the double-sided reading specification and for the single-sided reading specification.

First, with reference toFIG. 3, the outer cover44A for the double-sided reading specification will be described. On the guide face44aof the outer cover44A, a holder storage recess60, a first conveying roller storage recess61, a pressing roller storage recess62, a second conveying roller storage recess63and a third conveying roller storage recess64are formed in the order in the conveying direction.

The holder storage recess60faces the document placement portion50of the inner guide plate43. The first to third conveying roller storage recesses61,63and64respectively face the first to third conveying roller openings51,54and55of the inner guide plate43via the conveying path21. The pressing roller storage recess62faces the reading sensor storage recess53of the inner guide plate43via the conveying path21.

With reference toFIG. 4, the outer cover44B for the single-sided reading specification will be described. On the guide face44aof the outer cover44B, the holder storage recess60, the second conveying roller storage recess63and the third conveying roller storage recess64are formed in the order in the conveying direction.

The holder storage recess60faces the document placement portion50of the inner guide plate43. The second and third conveying roller storage recesses63and64respectively face the second and third conveying roller openings54and55of the inner guide plate43via the conveying path21.

Next, the conveying path21for the double-sided reading specification and for the single-sided reading specification will be described with reference toFIGS. 3 to 8.

First, the conveying path21for the double-sided reading specification will be described with reference toFIG. 3,FIG. 5andFIG. 7. On the conveying path21, a feed holder70, first conveying rollers71, a document detection sensor72(refer toFIG. 7), a contact image sensor73and a first pressing member74, second conveying rollers75, third conveying rollers76, a second pressing member77and fourth conveying rollers78are provided in the order in the conveying direction. Here, members dedicated to the double-sided reading specification are the first conveying rollers71, the document detection sensor72and the contact image sensor73.

The feed holder70is stored in the holder storage recess60of the outer cover44A. The feed holder70is formed into an approximately parallelepiped rectangular box shape whose lower face is opened, as shown inFIG. 5andFIG. 6. Through a left end portion of the feed holder70, a drive shaft81is penetrated. The feed holder70is supported by the drive shaft81in a turnable manner in the upper-lower direction. Both ends of the drive shaft81are supported by the front and rear side plates41and42in a rotatable manner. Between the feed holder70and the drive shaft81, a torque limiter (not shown) is provided. When a torque acting on the feed holder70from the drive shaft81is smaller than a predetermined value, the torque limiter transmits a rotation of the drive shaft81to the feed holder70to turn the feed holder70together with the drive shaft81. When the torque exceeds the predetermined value, the torque limiter idles the drive shaft81with respect to the feed holder70.

The feed holder70supports a feed roller82and a pickup roller83. The feed roller82is supported by the drive shaft81via a one-way clutch (not shown) in a rotatable manner. The one-way clutch transmits the rotation of the drive shaft81in the conveying direction (the clockwise direction inFIG. 3andFIG. 4) to the feed roller82and rotates the feed roller82together with the drive shaft81in the conveying direction. The one-way clutch idles the feed roller82with respect to the drive shaft81when the feed roller82is rotated in the conveying direction by being driven by the document conveyed in the conveying direction. The pickup roller83is coupled to the drive shaft81via an idle gear or a timing belt (not shown) such that the rotation of the drive shaft81is transmitted to the pickup roller83.

The first to fourth conveying rollers71,75,76and78respectively have drive rollers71a,75a,76aand78aand driven rollers71b,75b,76band78b. As shown inFIG. 3andFIG. 5, the drive rollers71a,75a,76aand78aare supported by the inner guide plate43in a rotatable manner, and expose to the guide face43athrough the first to fourth conveying roller openings51,54,55and57respectively. The driven rollers71b,75band76bof the first to third conveying rollers71,75and76are supported by the first to third conveying roller storage recesses61,63and64of the outer cover44A in a rotatable manner, and pressed against the first to third drive rollers71a,75aand76a. The driven roller78bof the fourth conveying rollers78is supported by the conveying roller storage recess34of the outer guide plate32in a rotatable manner, and pressed against the forth drive roller78a. When each drive roller are rotated, each driven roller is driven to be rotated in a direction opposite to the rotating direction of each drive roller.

As shown inFIG. 7, the document detection sensor72includes an actuator85and an optical sensor86. The actuator85has a rotating shaft85aand an abutment piece85brotated together with the rotating shaft85a. Both ends of the rotating shaft85aare supported by the bearing holes of the bearing pieces58of the inner guide plate43in a rotatable manner. The abutment piece85bis turned to the downstream side of the conveying direction from a protruding position where it protrudes above the guide face43athrough the document detection sensor opening52to a retracting position where it retracts under the guide face43a. The actuator85biases by a biasing member (not shown) so as to be turned into the protruding position. When the leading edge of the document conveyed along the conveying path21abuts on the abutment piece85b, the actuator85is turned into the retracting position from the protruding position against a biasing force of the biasing member.

The optical sensor86has a light projecting part and a light receiving part. The optical sensor86is attached on the face opposite to the guide face43aof the inner guide plate43. When the abutment piece85bis turned into the retracting position, it passes a space between the light projecting part and the light receiving part of the optical sensor86. When a light projected from the light projecting part is blocked by the abutment piece85b, it is detected that the document is conveyed on the conveying path21.

As shown inFIG. 3, the contact image sensor73is stored in the reading sensor storage recess53of the inner guide plate43. The reading sensor storage recess53is covered with a contact glass88.

The first pressing member74is a shallow rectangular parallelepiped hollow member long in the width direction. The first pressing member74is stored in the pressing roller storage recess62of the outer cover44A, and is pressed against the contact glass88by a biasing member.

The second pressing member77is a shallow rectangular parallelepiped hollow member long in the width direction. The second pressing member77is stored in the pressing member storage recess56of the inner guide plate43, and is pressed against the contact glass12of the reading unit5through the window31by a biasing member.

Next, the conveying path21for the single-sided reading specification will be described with reference toFIG. 4,FIG. 6andFIG. 8. On the conveying path21, the feed holder70, a first cover plate90as an example of a cover member, a second cover plate91, the second conveying rollers75, the third conveying rollers76, the second pressing member77and the fourth conveying rollers78are arranged in the order in the conveying direction.

The feed holder70, the second to fourth conveying rollers75,76and78, and the second pressing member77are formed in the same way as the double-sided reading specification. On the other hand, in the single-sided reading specification, the first cover plate90is provided in place of the first conveying rollers71and the document detection sensor72, and the second cover plate91is provided in place of the contact image sensor73.

The first cover plate90will be described with reference toFIG. 9AandFIG. 9B.FIG. 9Ais a perspective view showing the first cover plate when viewed from the upper side andFIG. 9Bis a perspective view showing the first cover plate when viewed from the lower side.

The first cover plate90is a plate like member long in the width direction, and has a base part95at a center in the width direction and a pair of first closing parts96at both ends in the width direction. On a left front corner portion of the base part95, two openings95aalong the conveying direction are formed at a predetermined interval in the width direction. Between the two openings95a, a table portion95bis formed. On both side faces of the table portion95bin the width direction, supporting shafts97are formed protruding in the openings95aon the same axis. On an upper face of the table portion95b, a second closing part98is protruded. The second closing part98is formed into a parallelepiped rectangular shape long in the conveying direction.

The first closing parts96each have a rectangular plan shape, and extend in opposite directions in the width direction from step portions stood along right half portions of side edges of the base part95in the width direction. Upper faces of the first closing parts96and an upper face of the second closing part98are on the same plane higher than the upper face of the base part95.

When the first cover plate90is attached to the inner guide plate43, the first closing parts96are positioned so as to correspond to the openings of the first conveying roller opening51from an inside of the inner guide plate43(from the side opposite to the guide face43a). After that, as the supporting shafts97are fitted in a space between the bearing pieces58, the bearing pieces58begins to be elastically deformed outward. Then, when the first closing parts96are fitted into the openings of the first conveying roller opening51and also the second closing part98is fitted into the document detection sensor opening52, the bearing pieces58are elastically returned inward and the supporting shafts of the first cover plate90are fitted into the bearing holes of the bearing pieces58. Thereby, the openings of the first conveying roller opening51are closed with the first closing parts96and the document detection sensor opening52is closed with the second closing part98. Additionally, the first closing parts96and the second closing part98forms a part of the inner circumference side guide face of the conveying path21(the guide face43aof the inner guide plate43).

The second cover plate91is a plate like member having a shape capable of closing the reading sensor storage recess53.

In the document conveying device3having the above described configuration, document conveying operations for the double-sided reading specification and the single-sided reading specification will be described. In the both specifications, during a standby state, the feed holder70is turned upward around the drive shaft81, and a space is formed between the pickup roller83and the document placement portion50. Through the space, the documents are placed on the document placement portion50and the document placement part23. The placed documents are aligned in the width direction by the side cursors38.

The document conveying operation for the double-sided reading specification will be described with reference toFIG. 3. When the document conveying is started, the drive shaft81rotates in the clockwise direction ofFIG. 3to turn the feed holder70downward. Then, the pickup roller83abuts on an upper face of the documents placed on the document placement portion50. After that, the pickup roller83is driven by the drive shaft81to be rotated in the clockwise direction ofFIG. 3to feed the uppermost document toward the conveying path21. At the same time, the feed roller82is rotated together with the drive shaft81to feed the document fed by the pickup roller83into the conveying path21.

The fed document is applied with a conveying force by the first conveying rollers71. After the document is passed through the first conveying rollers71, the leading edge of the document abuts on the abutment piece85bof the actuator85, the abutment piece85bprotruding upward above the guide face43aof the inner guide plate43. Then, the actuator85is turned to the downstream side in the conveying direction against the biasing force of the biasing member, and the abutment piece85bis passed through the space between the light projecting part and the light receiving part of the optical sensor86. As a result, it is detected by the optical sensor86that that the leading edge of the document is passed.

At a suitable timing after it is detected that the leading edge of the document is passed, the image on the back face of the document is read by the contact image sensor73. At this time, the document is conveyed at a stable conveying speed by the first conveying rollers71and is pressed against the contact glass88by the first pressing member74so that the image on the back face can be correctly read.

After that, the document is conveyed to the window31by the second and third conveying rollers75and76, and the image on the front face of the document is read by the contact image sensor13of the reading unit5at the window31. At this time, the document is pressed against the contact glass12by the second pressing member77so that the image on the front face can be correctly read. After the images on the both sides of the document are read, the document is ejected by the fourth conveying rollers78into the ejection tray33.

Next, the document conveying operation for the single-sided reading specification will be described with reference toFIG. 3,FIG. 4andFIG. 6. When the double-sided reading specification is changed into the single-sided reading specification, the outer cover is replaced from the double-sided reading type outer cover44A (refer toFIG. 3) into the single-sided reading type outer cover44B (refer toFIG. 4).

In addition, the drive roller71aof the first conveying rollers71, the document detection sensor72, the contact image sensor73and the contact glass88are removed from the inner guide plate43.

After that, the supporting shafts97of the first cover plate90are supported by the bearing pieces58of the inner guide plate43, as described above, and, as shown inFIG. 6, the openings of the first conveying roller opening51are closed with the first closing parts96and the document detection sensor opening52is closed with the second closing part98. Additionally, the reading sensor storage recess53is closed with the second cover plate91. In this way, the first conveying roller opening51and the document detection sensor opening52remained after the first conveying rollers71and the document detection sensor72, which are used for the double-sided reading specification only, are removed are closed with the first closing parts96and the second closing part98, respectively.

Additionally, the reading sensor storage recess53remained after the contact image sensor73and the contact glass88, which are used for the double-sided reading specification only, are removed is closed with the second cover plate91. Thereby, the first cover plate90and the second cover plate91can form a part of the guide face43aof the inner guide plate43.

As described above, in the document conveying device3according to the present disclosure, the document detection sensor72only used for the double-sided reading specification and the first cover plate90only used for the single-sided reading specification are detachably attached to the bearing pieces58of the inner guide plate43so that it becomes easy to change from the double-sided reading specification into the single-sided reading specification or from the single-sided reading specification into the double-sided reading specification. Additionally, the inner guide plate43can be used in common for the double-sided reading specification and the single-sided reading specification so that it becomes possible to decrease a cost.

Furthermore, by supporting the first cover plate90to the bearing pieces58, the first cover plate90closes not only the document detection sensor opening52but also the first conveying roller opening51so that there is no need for preparing a member for closing the first conveying roller opening51. Accordingly, a number of the members can be reduced.

The first cover plate90is attached to the inner guide plate43from the inside of the inner guide plate43so that the first cover plate90is not exposed to the guide face43aother than the first conveying roller opening51and the document detection sensor opening52. Thereby, even if the first cover plate90is attached, the document can be smoothly conveyed along the guide face43a.

While the preferable embodiment and its modified example of the document conveying device and the image forming apparatus of the present disclosure have been described above and various technically preferable configurations have been illustrated, a technical range of the disclosure is not to be restricted by the description and illustration of the embodiment. Further, the components in the embodiment of the disclosure may be suitably replaced with other components, or variously combined with the other components. The claims are not restricted by the description of the embodiment of the disclosure as mentioned above.