JP2023142031A - Manuscript transportation device and image formation device having the same - Google Patents

Abstract

To provide a manuscript transportation device capable of suitably controlling a manuscript transportation speed and an image formation device having the same.SOLUTION: A manuscript transportation device comprises a lift motor 90 (a rotation drive part), a lifting device for lifting a lifting tray using drive force of the lift motor 90, a manuscript transportation part for pulling-in a manuscript on the lifting tray at a predetermined manuscript height position and transporting on a manuscript transportation path, a manuscript detection sensor 64 (manuscript reaching detection means) for detecting an uppermost manuscript among the manuscripts on the lifting tray to reach at the manuscript height position and a control part 7 (manuscript transportation control means), and the control part 7 determines a load of the manuscript on the basis of a rotation amount of the lift motor 90 during the time from a lifting start timing at which the lifting tray starts to ascend from a predetermined height position lower than the manuscript height position to a timing at which the manuscript detection sensor 64 detects the uppermost manuscript reaches at the manuscript height position, and determines the transportation speed of the manuscript by the manuscript transportation part on the basis of the determined load.SELECTED DRAWING: Figure 5

Description

The present invention relates to a document transport device and an image forming apparatus equipped with the same.

2. Description of the Related Art In image forming apparatuses, a document conveying device is sometimes used that automatically conveys documents stacked on a tray sequentially to an image reading position. In order to make the document conveyance device quieter, it is desirable to lower the document conveyance speed, but when a large amount of documents are loaded, it is recommended to increase the document conveyance speed in order to speed up the document conveyance process. is required.

As a means for determining the amount of loaded documents, for example, a technique using a sensor that detects the position of the uppermost layer of documents stacked on a tray is known (for example, see Patent Document 1).

Japanese Patent Application Publication No. 9-208109

However, in the above-mentioned conventional technology, there is still room for improvement in the accuracy of determining the amount of loaded documents.

The present invention has been made in order to solve the above-mentioned conventional problems, and provides a document conveying device that can accurately determine the amount of loaded documents and, in turn, can suitably control the conveyance speed of documents. An object of the present invention is to provide an image forming apparatus including the same.

In order to achieve the above object, the document conveying device described in the present application includes a rotational drive section and an elevating tray on which documents can be stacked, and an elevating device that uses the driving force of the rotational drive section to raise and lower the elevating tray. , a document transport unit that pulls in the document on the elevating tray at a predetermined document height position and transports it on a document conveyance path; and an uppermost document among the documents on the elevating tray reaches the document height position. A document conveying device comprising: document arrival detection means for detecting that the document has been reached; and document conveyance control means; The document is rotated based on the amount of rotation of the rotary drive unit during the time period from the start of raising the document to the timing at which the document arrival detecting means detects the arrival of the top layer document at the document height position. The present invention is characterized in that a loading amount of the document is determined, and a conveying speed of the document by the document conveying section is determined based on the determined loading amount.

Further, in the document conveying device, the elevating device further includes a rotary lever section rotatably provided around a rotation axis along a direction perpendicular to a paper feeding direction in which the document is drawn into the document conveying section. The rotary lever section may be rotationally driven by the driving force of the rotational drive section, and the lifting tray may be raised by the rotational drive.

The document feeding device further includes a tray detection means for detecting that the elevating tray is at a lower limit position, and the rising start timing is a timing when the tray detecting means no longer detects the elevating tray. Good too.

Further, in the document conveying device, the rising start timing may be a timing at which the rotation drive unit starts rotating.

Another document conveying device described in the present application includes a document loading tray capable of loading documents, a rotational drive section, and a driving force of the rotational drive section to pull out the document on the document stacking tray and guide the document through the document conveyance path. A document conveyance device comprising: a document conveyance section for conveying; a document passage detection means disposed on the document conveyance path for detecting passage of the document; and a document conveyance control means, the document conveyance control means comprising: , determining the loading amount of the originals based on the amount of rotation of the rotational driving unit in the time from the timing when the rotational driving unit starts rotating to the timing when the original passage detecting means detects passage of the original; The present invention is characterized in that the conveyance speed of the document by the document conveyance section is determined based on the determined loading amount.

Further, in the document conveyance device, the document conveyance control means lowers the conveyance speed below a predetermined initial value when the loading amount is less than or equal to a predetermined reference loading amount; When the reference loading amount is exceeded, the conveyance speed may be increased above the initial value.

Further, in the document transport device, the document transport control unit may not cause the document transport section to start transporting the document when the loading amount is a predetermined overload amount.

Further, the document conveying device may further include a notification means for notifying a user of overloading of documents when the loading amount is the overloading amount.

Further, in the document conveying device, the rotation driving section may be a stepping motor.

Further, in the document conveying device, the rotation drive section may be a DC motor with an encoder.

The image forming apparatus described in the present application is characterized in that it includes the document conveying device.

According to the present invention, the document conveyance speed can be suitably controlled.

FIG. 1 is a schematic side view of an image forming apparatus. 1 is a schematic side view of a document conveying device in Embodiment 1. FIG. FIG. 2B is a schematic side view showing a portion of the document conveyance device of FIG. 2A. It is a schematic perspective view showing a lifting device. FIG. 3 is a schematic perspective view showing a part of the document transport section. 2 is a schematic block diagram showing a control configuration in Embodiment 1. FIG. 5 is a timing chart showing determination times in Embodiment 1. FIG. FIG. 6 is a schematic diagram for explaining the relationship between the amount of loaded documents and the amount of rotation of a rotation lever section. FIG. 7 is another schematic diagram for explaining the relationship between the amount of documents loaded and the amount of rotation of the rotary lever section. 7 is a timing chart showing a modified example of the determination time in Embodiment 1. FIG. 5 is a flowchart illustrating an example of a processing procedure by a control unit in the first embodiment. FIG. 3 is a schematic side view of a document conveying device in Embodiment 2. FIG. 3 is a schematic block diagram showing a control configuration in Embodiment 2. FIG. 7 is a timing chart showing determination times in Embodiment 2. FIG. 7 is a flowchart illustrating an example of a processing procedure by a control unit in Embodiment 2. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same components in each of the embodiments described below are given the same reference numerals, and overlapping explanations of these components will be omitted.

(Embodiment 1)
-Overall configuration of image forming device-
First, the configuration of the image forming apparatus 100 in this embodiment will be explained.

FIG. 1 is a schematic side view of an image forming apparatus 100. In the figure, the symbol X indicates the width direction (depth direction), the -X direction (minus X direction) is the front direction, and the +X direction (plus X direction) is the rear direction. The symbol Z indicates the vertical direction, with the -Z direction (minus Z direction) being the downward direction, and the +Z direction (plus Z direction) being the upward direction. These settings are the same in subsequent embodiments.

The image forming apparatus 100 is a multifunction device having a scanner function, a copy function, a printer function, a facsimile function, etc., and transmits an image of a document read by an image reading apparatus to the outside (corresponding to a scanner function). Forms an image on paper in color or monochrome from a read image of a document or an image received from an external source (corresponds to a copying function, a printer function, and a facsimile function).

An document transport device 5 (ADF) is provided above the image reading unit 41 and is supported so as to be openable and closable relative to the image reading unit 41 . A document conveyance path Sc for conveying the document to above the image reading section 41 is provided in the document conveyance device 5 . The image reading unit 41 reads stacked originals or originals conveyed from the original conveyance device 5 to generate image data.

The image forming apparatus 100 includes an optical scanning device 10, a developing device 11, a photosensitive drum 12, a drum cleaning device 13, a charger 14, an intermediate transfer belt 2, a secondary transfer section 15, a fixing section 3, a paper feed cassette 16, and a stacking device. It is equipped with a tray 17, etc. A paper transport path S for transporting paper is provided within the image forming apparatus 100.

The image forming apparatus 100 generates image data corresponding to a color image using each color of black (K), cyan (C), magenta (M), and yellow (Y) or a monochrome image using a single color (for example, black). be treated. The image forming apparatus 100 is provided with four developing devices 11, a photosensitive drum 12, a drum cleaning device 13, and a charger 14 for forming four types of toner images, each of which has a black, cyan, magenta, and yellow toner image. Four image stations Pa, Pb, Pc, and Pd are configured in association with each other.

The drum cleaning device 13 removes and collects residual toner on the surface of the photoreceptor drum 12 . The charger 14 uniformly charges the surface of the photoreceptor drum 12 to a predetermined potential. The optical scanning device 10 exposes the surface of the photoreceptor drum 12 to form an electrostatic latent image. The developing device 11 develops the electrostatic latent image on the surface of the photoreceptor drum 12 to form a toner image on the surface of the photoreceptor drum 12 . Through the above series of operations, toner images of each color are formed on the surface of the photoreceptor drum 12 at each image station Pa, Pb, Pc, and Pd.

The intermediate transfer belt 2 is stretched around a transfer driving roller 21 and a transfer driven roller 22, moves around in the direction of arrow C, and removes and collects residual toner by a belt cleaning device 23, cleaning the surface of each photoreceptor drum 12. The toner images of each color formed on the intermediate transfer belt 2 are sequentially transferred and superimposed to form a color toner image on the surface of the intermediate transfer belt 2.

A nip area (secondary transfer position) is formed between the transfer roller 11a of the secondary transfer unit 15 and the intermediate transfer belt 2, and the paper conveyed through the paper conveyance path S is sandwiched in the nip area. transport. When the paper passes through the nip area, the toner image on the surface of the intermediate transfer belt 2 is transferred to the paper, and the paper is conveyed to the fixing section 3 .

The fixing unit 3 includes a fixing roller 30 and a pressure roller 31 that sandwich the paper. The fixing unit 3 sandwiches the paper onto which the toner image has been transferred between the fixing roller 30 and the pressure roller 31, heats and presses the paper, and fixes the toner image onto the paper.

The paper feed cassette 16 is a cassette for storing paper used for image formation, and is provided below the optical scanning device 10. The paper is pulled out from the paper feed cassette 16 by the paper pickup roller 16a, transported through the paper transport path S, passes through the secondary transfer section 15 and the fixing section 3, and is transferred to the stacking tray 17 via the paper ejection roller 4c. It will be carried out. In the paper conveyance path S, after the paper is temporarily stopped and the leading edge of the paper is aligned, the paper is transferred in accordance with the transfer timing of the color toner image in the nip area between the intermediate transfer belt 2 and the transfer roller 11a. A paper registration roller 4b that starts conveyance, a conveyance roller 4a that promotes conveyance of the paper, and a paper discharge roller 4c are arranged.

Further, when forming an image not only on the front side of the paper but also on the back side, the paper is conveyed in the opposite direction from the paper ejection roller 4c to the paper reversing path Sr. In the paper reversing path Sr, the paper is reversed from front to back through the reversing roller 4d, and the paper is guided again to the paper registration roller 4b. Thereafter, an image is formed on the back side in the same manner as on the front side, and the paper is conveyed to the stacking tray 17.

-Document transport device-
FIG. 2A is a schematic side view of the document conveying device 5 in the first embodiment. FIG. 2B is a schematic side view showing a part of the document conveying device 5 of FIG. 2A.

In this embodiment, the document conveyance device 5 includes an elevating tray 50, an elevating device 51, and a document conveying section 6 (see FIG. 2A). After the originals are stacked on the elevating tray 50, they are fed to the original transport unit 6 in the feeding direction F.

Although not shown in FIGS. 2A and 2B, in addition to the above-mentioned configuration, the document conveying device 5 includes a lift motor 90 (rotary drive unit in this embodiment) for driving the lifting device 51, and a lifting tray. It includes a document set sensor 95 that detects that a document is stacked on the document 50, and a control section 7 (document conveyance control means). In this embodiment, lift motor 90 is a stepping motor. As for the original set sensor 95, a well-known one is used, so the explanation thereof will be omitted. The control unit 7 will be detailed later.

<Elevating tray>
The elevating tray 50 is capable of stacking originals on a loading surface 500, and is inclined to become lower toward the original transport unit 6 (see FIG. 2B). Hereinafter, for convenience of explanation, the end of the document on the paper feeding direction F side will be referred to as a leading edge.

The elevating tray 50 is provided rotatably in a rotational direction R1 around a tray rotation axis 501 along a direction perpendicular to the paper feeding direction F (in this embodiment, the width direction X) on the opposite side to the paper feeding direction F. There is. In this specification, "rotation" is a concept that includes rocking in a rotational direction. When the elevating tray 50 rotates around the tray rotation axis 501, the leading edge of the document on the elevating tray 50 moves up and down.

In the elevating tray 50, a housing portion 502 capable of accommodating the elevating device 51 is recessed on the lower surface side of the document transport unit 6 side.

<Lifting device>
FIG. 3 is a schematic perspective view showing the elevating device 51. As shown in FIG.

The lifting device 51 raises and lowers the lifting tray 50 using the driving force of the lift motor 90, and includes a rotating lever section 510, a tray detection sensor 511 (tray detection means), and a detection piece 512. (See Figure 2B). The elevating device 51 is disposed within a housing section 502 in the elevating tray 50. The elevating device 51 raises the uppermost document Mt among the documents on the elevating tray 50 to a predetermined document height position H at which it can be fed to the document transport section 6 . Note that in FIG. 2B, illustration of the document height position H is omitted.

The rotary lever section 510 is rotatably provided in a rotation direction R2 around a lever rotation shaft 513 along a direction perpendicular to the paper feeding direction F (in this embodiment, the width direction X) (FIGS. 2B and 3). reference). The lever rotation shaft 513 is rotationally driven by the driving force of the lift motor 90. When the lever rotating shaft 513 is rotationally driven, the tip of the rotating lever section 510 moves up and down. The rotating lever section 510 raises the elevating tray 50 at its tip by rotating the lever rotating shaft 513. By using such a rotary lever portion 510, the elevating tray 50 can be easily raised.

When the rotary lever portion 510 is at the lower limit position, the elevating tray 50 is also at the lower limit position.

The tray detection sensor 511 is provided below the rotation lever section 510 (see FIG. 2B). The tray detection sensor 511 is, for example, an optical sensor, and detects an object intervening between the light emitting part 514 and the light receiving part 515 depending on whether the light emitted from the light emitting part 514 toward the light receiving part 515 reaches the light receiving part 515. Detection is performed (see FIGS. 2B and 3). The light emitting section 514 and the light receiving section 515 are arranged so as to be able to receive the object to be detected in the rotation direction R2 of the rotary lever section 510.

The detection piece 512 intervenes between the light emitting part 514 and the light receiving part 515 of the tray detection sensor 511 as the rotary lever part 510 rotates, and is inserted from the opposite side (distal end side) of the rotation base end of the rotary lever part 510. It protrudes in the circumferential direction around the lever rotation shaft 513. The detection piece 512 is arranged so as to intervene between the light emitting part 514 and the light receiving part 515 of the tray detection sensor 511 when the rotation lever part 510 is at the lower limit position. In other words, the tray detection sensor 511 detects that the elevating tray 50 is at the lower limit position.

<Original transport unit>
FIG. 4 is a schematic perspective view showing a part of the document transport section 6. As shown in FIG.

The document conveyance section 6 pulls in the document on the elevating tray 50 at the document height position H and conveys it along the document conveyance path Sc, and includes a pickup roller 60, a paper feed roller 61, a separation roller 62, and a roller holder. 63, a document detection sensor 64 (document arrival detection means), and a sensor arm 65 (see FIG. 2B). A drive belt (not shown) is suspended between the pickup roller 60 and the paper feed roller 61.

The pickup roller 60 pulls out the uppermost document Mt from among the documents on the elevating tray 50, and rotates around the roller rotation axis 600 along the direction perpendicular to the paper feeding direction F (in the present embodiment, the width direction X). It is rotatably installed. The pickup roller 60 rotates as the drive belt rotates due to the rotation of the roller rotation shaft 610. The roller rotation shaft 610 is rotated by the driving force of the paper feed motor 91.

The paper feed roller 61 feeds the top layer document Mt pulled out by the pickup roller 60 to the document conveyance path Sc, and is configured to feed the top layer document Mt pulled out by the pickup roller 60 to the document conveyance path Sc, and is configured to feed the document Mt along the direction perpendicular to the paper feed direction F (width direction X in this embodiment). It is provided rotatably around a roller rotation axis 610. The paper feed roller 61 is rotated by rotation of the roller rotation shaft 610.

The separation roller 62 separates the uppermost layer original Mt from other originals when one or more other originals are pulled out in succession to the uppermost original Mt. It is rotatably provided around a rotation axis (not shown) so as to face 61 . The separation roller 62 is driven to rotate as the top layer document Mt is conveyed when the top layer document Mt passes, but one or more other documents are pulled out in succession to the top layer document Mt. In this case, it does not follow the rotation and acts to prevent other documents from being conveyed.

The roller holder 63 holds the pickup roller 60 rotatably around the roller rotation shaft 610 of the paper feed roller 61. When the pickup roller 60 receives pressure from the uppermost document Mt, the roller holder 63 rotates around the roller rotation axis 610 of the paper feed roller 61.

The roller holder 63 includes a holder main body 630 and an arm pressing portion 631 (see FIG. 4). The arm pressing portion 631 presses a sensor arm 65, which will be described later, from below, and is integrally formed at the tip of the holder body 630 on the pickup roller 60 side. The arm pressing portion 631 protrudes from the tip of the holder main body 630 in a direction along a straight line connecting the rotation center of the pickup roller 60 and the rotation center of the paper feed roller 61.

The document detection sensor 64 is provided above the roller holder 63. The document detection sensor 64 is, for example, an optical sensor, and detects an object intervening between the light emitting part 640 and the light receiving part 641 depending on whether the light emitted from the light emitting part 640 toward the light receiving part 641 reaches the light receiving part 641. Perform detection. The light emitting section 640 and the light receiving section 641 are arranged so as to be able to receive a detected object in the rotational direction of the sensor arm 65, which will be described later.

The sensor arm 65 includes a pressed bar 650 that receives pressure from the arm pressing portion 631 of the roller holder 63, and a pair of extending portions (a first extending portion 651 and a second extending portion 652) that rotatably supports the pressed bar 650. (See FIG. 4).

The pressed bar 650 is formed along a direction perpendicular to the paper feeding direction F (in the present embodiment, the width direction X). The first stretching section 651 and the second stretching section 652 are each rotatably locked to a shaft section (not shown) in the document transport section 6 .

A locking portion 653 for locking to the shaft portion is provided at the rotation base end portion of the first extension portion 651. The first extending portion 651 is connected to the pressed bar 650 on the opposite side of the rotating base end. Similarly, a locking portion 654 for locking to the shaft portion is provided at the rotational base end portion of the second extending portion 652. The second extending portion 652 is connected to the pressed bar 650 on the opposite side of the rotating proximal end portion.

A detection piece 655 is provided on the outer side of the second extending portion 652 in the width direction X. The detection piece 655 protrudes in the width direction X and is arranged so as to intervene between the light emitting section 640 and the light receiving section 641 of the document detection sensor 64 when the roller holder 63 is at a predetermined height position. In this embodiment, the predetermined height position of the roller holder 63 refers to the height position of the roller holder 63 when the uppermost document Mt among the documents on the elevating tray 50 reaches the document height position H. refers to In other words, the document detection sensor 64 detects that the top layer document Mt has reached the document height position H.

<Control unit>
By the way, in order to make the document transport device 5 including the document transport section 6 quieter, it is desirable to lower the speed at which the document is transported by the document transport section 6 (hereinafter simply referred to as "original transport speed"). When the amount of loaded documents is large, it is necessary to increase the document conveyance speed in order to speed up the document conveyance process. Therefore, the control unit 7 is configured to determine the document conveyance speed based on the amount of documents loaded on the elevating tray 50. Thereby, depending on the amount of documents loaded on the elevating tray 50, it is possible to appropriately adjust the balance between making the document conveyance section 6 quieter and speeding up the document conveyance process.

FIG. 5 is a schematic block diagram showing the control configuration in the first embodiment. FIG. 6 is a timing chart showing the determination time T in the first embodiment.

In this embodiment, the control section 7 includes a processing section 70, a storage section 71, an input section 72, an output section 73, and a notification section 74 (notification means) (see FIG. 5). These are interconnected by bus lines (not shown). A document set sensor 95, a tray detection sensor 511, and a document detection sensor 64 are communicably connected to the input section 72, and a lift motor 90 and a feed sensor are connected to the output section 73 via the controller 9. A paper motor 91 and a conveyance motor 92 are communicably connected.

The processing unit 70 includes a CPU (Central Processing Unit) and the like, and has a loading amount determining unit 700 that determines the amount of documents loaded on the elevating tray 50, and a conveying speed determining unit 701 that determines the document conveying speed. ing.

In the present embodiment, the loading amount determining unit 700 determines whether the top layer document Mt is at the document height position from the lift start timing T1 (timing at which the lift motor 90 starts rotating) when the elevating tray 50 starts rising from the lower limit position. The amount of loaded documents is determined based on the amount of rotation of the lift motor 90 during the determination time T (see FIG. 6) up to the document arrival timing T2 which reaches H.

FIG. 7 is a schematic diagram for explaining the relationship between the loading amount of documents and the amount of rotation of the rotation lever section 510. FIG. 8 is another schematic diagram for explaining the relationship between the loading amount of documents and the amount of rotation of the rotation lever section 510.

For example, as shown in FIG. 7, when only a few documents are stacked on the elevating tray 50, as shown in FIG. 8, even more documents are stacked on the elevating tray 50. The amount of rotation of the rotary lever section 510 in the elevating device 51 until the uppermost document Mt rises to the document height position H is larger than that in the case. That is, the fewer documents there are on the lifting tray 50, the greater the amount of rotation of the lift motor 90 that drives the lever rotation shaft 513 in the rotation lever section 510. Therefore, the amount of rotation of lift motor 90 depends on the amount of documents loaded.

In this embodiment, since the lift motor 90 is a stepping motor, the loading amount determination section 700 determines the loading amount of documents based on the number of steps Px of the lift motor 90 at the determination time T. The smaller the loaded amount of documents, the larger the number of steps Px of the lift motor 90 during the determination time T.

In this embodiment, as shown in FIG. 6, the lift start timing T1 is the timing at which the lift motor 90 starts rotating, that is, the processing unit 70 sends a signal to the controller 9 instructing the lift motor 90 to start rotating. This is the timing when it was output. Thereby, the rise start timing T1 can be easily grasped.

In the present embodiment, the document arrival timing T2 is the timing at which the document detection sensor 64 detects the arrival of the top layer document Mt at the document height position H (see FIG. 6).

The specific processing of the conveyance speed determination unit 701 will be described in detail later with reference to a flowchart.

The storage unit 71 includes a nonvolatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory). The storage unit 71 stores a control program 710, a loading amount determination reference value 711, and a conveyance speed setting value 712.

The control program 710 is stored in the ROM of the storage unit 71. Under the control of the processing unit 70, the control program 710 stored in the ROM is read out and loaded onto the RAM, thereby executing the control program 710. Note that the control program 710 is not limited to the above, and may be read from a recording medium such as an HDD, or may be downloaded from a network such as a LAN (Local Area Network).

The loading amount determination reference value 711 is a value used as a reference when the loading amount determining section 700 of the storage section 71 determines the loading amount of documents. Expressed as a number of steps. The loading amount determination reference value 711 includes threshold values P1 to P3, and the relationship P3<P2<P1 holds true. When the loaded amount of documents is a predetermined overloaded amount, the number of steps Px of the lift motor 90 at the determination time T becomes smaller than the threshold value P3.

The conveyance speed setting value 712 is a value for setting the document conveyance speed. In this embodiment, the conveying speed setting value 712 includes setting values V1 to V3, and the relationship of V1<V2<V3 holds true as the document conveying speed. That is, among the set values V1 to V3, V3 is the fastest document conveyance speed. In this embodiment, V1, V2, and V3 are 600 dpi, 400 dpi, and 300 dpi, respectively. Further, in this embodiment, the initial value of the document conveyance speed is set to V2.

In the present embodiment, the notification unit 74 transmits the following information when the amount of documents loaded on the elevating tray 50 is overloaded, that is, when the number of steps Px of the lift motor 90 at the determination time T is smaller than the threshold P3. This is to notify the user of overloading of documents. Specifically, the notifying unit 74 notifies the user of an alert urging the user to reduce the amount of loaded documents by outputting audio and displaying text images on a display unit (not shown). This can contribute to early resolution of overloading of documents.

FIG. 9 is a timing chart showing a modified example of the determination time T in the first embodiment.

Note that the ascent start timing T1 may be the timing at which the tray detection sensor 511 no longer detects the elevating tray 50, as shown in FIG. Thereby, the tray detection sensor 511 can be used to more accurately grasp the rise start timing T1.

<Processing procedure>
FIG. 10 is a flowchart illustrating an example of a processing procedure by the control unit 7 in the first embodiment.

Next, with reference to FIG. 10, the processing procedure of the control section 7 described above will be explained.

In step ST1, the processing unit 70 of the control unit 7 acquires information from the document set sensor 95 that detects the document placed on the elevating tray 50 by the user.

In step ST2, the processing unit 70 instructs the controller 9 to start rotating the lift motor 90 (corresponding to the ascent start timing T1). The lifting device 51 raises the lifting tray 50 by rotation of the lift motor 90 .

In step ST3, the processing unit 70 acquires information from the document detection sensor 64 that detects the top layer document Mt that has reached the document height position H (corresponds to document arrival timing T2). The processing unit 70 instructs the controller 9 to stop the rotation of the lift motor 90.

In step ST4, the loaded amount determining section 700 of the processing section 70 determines the loaded amount of documents based on the number of steps Px of the lift motor 90 during the determination time T from the ascent start timing T1 to the document arrival timing T2.

If the number of steps Px of the lift motor 90 during the determination time T is equal to or greater than the threshold value P1, the loading amount determination section 700 determines that the loaded amount of documents is less than or equal to a predetermined first reference loading amount, and proceeds to step ST5. . In step ST5, the conveyance speed determining section 701 of the processing section 70 lowers the document conveyance speed from the set value V2 to the set value V1. By lowering the document conveyance speed from the set value V2 to the set value V1, the document conveyance device 5 can be made quieter. Subsequently, in step ST9, the processing section 70 passes the setting value V1 to the document transport section 6 to execute the document transport process, and the image forming apparatus 100 executes the job.

Similarly, if the number of steps Px of the lift motor 90 in the determination time T is greater than or equal to the threshold value P2 and less than the threshold value P1, the loading amount determination unit 700 determines that the loading amount of documents exceeds a predetermined first reference loading amount, but the second It is determined that the loading amount is equal to or less than the standard loading amount, and the process proceeds to step ST6. In step ST6, the conveyance speed determination unit 701 maintains the document conveyance speed at the set value V2. Subsequently, in step ST10, the processing section 70 passes the set value V2 to the document transport section 6 to execute the document transport process, and the image forming apparatus 100 executes the job.

Furthermore, if the number of steps Px of the lift motor 90 in the determination time T is equal to or greater than the threshold value P3 and less than the threshold value P2, the loading amount determination unit 700 determines that the loading amount of the document exceeds the predetermined second standard loading amount, but the third standard It is determined that it is less than the loading capacity, and the process proceeds to step ST7. In step ST7, the conveyance speed determining unit 701 increases the document conveyance speed from the set value V2 to the set value V3. By increasing the document conveyance speed from the set value V2 to the set value V3, the document conveyance process can be speeded up. Subsequently, in step ST11, the processing section 70 passes the set value V3 to the document transport section 6 to execute the document transport process, and the image forming apparatus 100 executes the job.

Then, if the number of steps Px of the lift motor 90 during the determination time T is less than the threshold value P3, the loading amount determining section 700 determines that the loaded amount of documents is a predetermined overloading amount, and transfers the documents to the document transporting section 6. The image forming apparatus 100 does not start conveyance of the job, and does not execute the job. This makes it possible to prevent document jams caused by overloading of documents.

As described above, in the document conveying device 5, the loading amount determination section 700 in the control section 7 determines the current loading amount based on the rotation amount of the lift motor 90 during the determination time T from the ascent start timing T1 to the document arrival timing T2. By determining this, it is possible to accurately determine the amount of documents loaded on the elevating tray 50. In addition, the conveyance speed determination section 701 determines the document conveyance speed based on the loading amount determined by the loading amount determination section 700, so that the document conveyance section 6 can be made quieter and the original can be It is possible to accurately adjust the balance between speeding up the conveyance process and, in turn, suitably control the document conveyance speed.

Further, as explained above, when the loading amount of documents determined by the loading amount determining section 700 is equal to or less than the predetermined first reference loading amount, the conveying speed determining section 701 in the control section 7 determines the document conveying speed. When the initial value V2 is lowered to the set value V1, and on the other hand, the document loading amount determined by the loading amount determination section 700 exceeds a predetermined second reference loading amount, the conveyance speed in the control section 7 The determining unit 701 increases the document conveyance speed from the initial value set value V2 to the set value V3. Thereby, the document conveyance speed can be appropriately set in stages.

By the way, as the originals on the elevating tray 50 are sequentially fed to the original transport unit 6, that is, as the amount of remaining originals loaded decreases, the elevating device 51 uses the driving force of the lift motor 90 to move up and down. Elevating tray 50 is known. Here, by keeping the temporal change in the amount of rotation (number of steps) of the lift motor 90 constant, it is possible to easily estimate the remaining time required to feed the document based on the amount of rotation of the lift motor 90. becomes.

A stepping motor can be suitably used as the lift motor 90 described above.

Further, as the lift motor 90, a DC motor with an encoder can be suitably used instead of a stepping motor. In this case, the processing unit 70 obtains the rotation amount of the lift motor 90 based on the number of output pulses of the encoder.

Incidentally, the rising start timing T1 is not limited to the timing when the lifting tray 50 starts rising from the lower limit position, and is not limited to the timing when the lifting tray 50 starts rising from a predetermined height position other than the lower limit position and lower than the document height position H. It may be the timing to start.

(Embodiment 2)
FIG. 11 is a schematic side view of the document conveying device 5 in the second embodiment.

Hereinafter, regarding the second embodiment, only the points different from the first embodiment described above will be described.

In the embodiment, the document transport device 5 includes a document stacking tray 8 and a document transport section 6 (see FIG. 11). Although not shown in FIG. 11, in addition to the above-described configuration, the document transport device 5 includes a paper feed motor 93 (rotation drive section in this embodiment) for driving the document transport section 6, and a The apparatus includes a document set sensor 95 that detects that a document is stacked on the document sheet, and a control section 7 (document conveyance control means). In this embodiment, the paper feed motor 93 is a stepping motor.

The document stacking tray 8 is capable of stacking documents on a loading surface 80, and is inclined downwardly toward the document transport section 6 (see FIG. 11). The document stacking tray 8 is fixed to a support (not shown).

In the second embodiment, the document transport section 6 includes a pickup roller 60, a paper feed roller 61, a separation roller 62, a roller arm 66, and a document passage detection sensor 67 (document passage detection means). (See Figure 11).

The pickup roller 60 and separation roller 62 are the same as those in Embodiment 1, so their description will be omitted.

The paper feed roller 61 is rotationally driven by the driving force of the paper feed motor 93.

The roller arm 66 holds the pickup roller 60 rotatably around the roller rotation shaft 610 of the paper feed roller 61. The roller arm 66 swings down the pickup roller 60 toward the document on the document stacking tray 8 by rotation of the roller rotation shaft 610.

The document passage detection sensor 67 detects the passage of the document, and is, for example, a reflective optical sensor, and is disposed downstream of the paper feed roller 61 on the document conveyance path Sc.

FIG. 12 is a schematic block diagram showing the control configuration in the second embodiment. FIG. 13 is a timing chart showing the determination time T' in the second embodiment.

In the second embodiment, a document set sensor 95 and a document passage detection sensor 67 are communicably connected to the input section 72 of the control section 7 , and the output section 73 is connected to the input section 72 of the control section 7 so as to allow the document to be fed through the controller 9 . The motor 93 and the transport motor 92 are communicably connected (see FIG. 12).

As explained above, the roller arm 66 swings down the pickup roller 60 toward the documents on the document stacking tray 8 by the rotation of the roller rotation shaft 610. The amount of rotation of the paper feed motor 93 that drives the paper feed motor 93 increases. Therefore, the amount of rotation of the paper feed motor 93 depends on the amount of documents loaded.

Therefore, in the second embodiment, the loading amount determination unit 700 makes a determination from the paper feeding start timing T3 when the paper feeding motor 93 starts rotating to the original passing timing T4 when the original passing detection sensor 67 detects the passing of the original. The amount of loaded documents is determined based on the amount of rotation of the paper feed motor 93 at time T' (see FIG. 13).

In this embodiment, since the paper feed motor 93 is a stepping motor, the stacking amount determining section 700 determines the stacking amount of documents based on the number of steps Py of the paper feeding motor 93 at the determination time T'. The smaller the amount of loaded documents, the larger the number of steps Py of the paper feed motor 93 during the determination time T'.

The loading amount determination reference value 711 includes a threshold value Pt expressed as the number of steps of the paper feed motor 93 depending on the loading amount of documents.

The conveying speed setting value 712 includes setting values V _L and V _H , and the relationship of V _L < V _H holds true as the document conveying speed.

FIG. 14 is a flowchart illustrating an example of a processing procedure by the control unit 7 in the second embodiment.

Next, with reference to FIG. 14, the processing procedure of the control unit 7 in the second embodiment described above will be described.

In step ST1, the processing unit 70 of the control unit 7 acquires information from the document set sensor 95 that detects the document placed on the elevating tray 50 by the user.

In step ST2, the processing unit 70 instructs the controller 9 to start rotating the paper feed motor 93 (corresponding to paper feed start timing T3). The roller rotation shaft 610 is rotationally driven by the rotation of the paper feed motor 93, and the roller arm 66 swings down the pickup roller 60 toward the document on the document stacking tray 8. A pickup roller 60 pulls out the uppermost original Mt from among the originals on the original stacking tray 8, and a paper feed roller 61 sends the uppermost original Mt to the original transport path Sc.

In step ST3, the processing unit 70 acquires information indicating that the passage of the uppermost layer original Mt has been detected from the original passage detection sensor 67 (corresponding to the original passage timing T4). The processing unit 70 instructs the controller 9 to stop the rotation of the paper feed motor 93.

In step ST4, the loading amount determining section 700 of the processing section 70 determines the loading amount of documents based on the number of steps Py of the paper feed motor 93 during the determination time T' from the paper feeding start timing T3 to the document passing timing T4. .

If the number of steps Py of the paper feed motor 93 at the determination time T' is equal to or greater than the threshold value Pt, the loading amount determination unit 700 determines that the loaded amount of documents is less than or equal to a predetermined reference loading amount, and proceeds to step ST5. . In step ST5, the conveyance speed determining section 701 of the processing section 70 sets the document conveyance speed to a set value _VL . Subsequently, in step ST7, the processing section 70 passes the setting value _VL to the document transport section 6 to execute the document transport process, and the image forming apparatus 100 executes the job.

On the other hand, if the number of steps Py of the paper feed motor 93 at the determination time T' is less than the threshold value Pt, the loading amount determining section 700 determines that the loading amount of documents exceeds the predetermined reference loading amount, and performs step ST6. Proceed to. In step ST6, the conveyance speed determining section 701 of the processing section 70 sets the document conveyance speed to a set value _VH . Subsequently, in step ST8, the processing section 70 passes the setting value _VH to the document transport section 6 to execute the document transport process, and the image forming apparatus 100 executes the job.

Even when the document stacking tray 8 is used as in the second embodiment described above, the amount of rotation of the paper feed motor 93 during the determination time T' from the paper feed start timing T3 to the document passage timing T4 is It is possible to determine the loading amount of originals, and according to the determined loading amount of originals, accurately adjust the balance between making the original transport section 6 quieter and speeding up the original transport processing, and, as a result, The document conveyance speed can be suitably controlled.

The above embodiments and examples are illustrative in all respects and are not the basis for restrictive interpretation. Therefore, the technical scope of the present invention should not be interpreted only by the above-described embodiments and examples, but should be defined based on the claims. In addition, all changes within the meaning and scope of equivalents to the scope of the claims are included.

100 Image forming device 5 Document conveyance device 50 Lifting tray 501 Tray rotation shaft 51 Lifting device 510 Rotation lever section 511 Tray detection sensor 512 Detection piece 513 Lever rotation shaft 6 Document conveyance section 60 Pick up roller 61 Paper feed roller 62 Separation roller 63 Roller holder 64 Document detection sensor 65 Sensor arm 66 Roller arm 67 Document passage detection sensor 7 Control section 70 Processing section 700 Loading amount determining section 701 Conveying speed determining section 71 Storage section 711 Loading amount determination reference value 712 Conveying speed setting value 72 Input section 73 Output Section 74 Notification section 8 Document stacking tray 80 Placement surface 90 Lift motor 91 Paper feed motor 92 Conveyance motor 93 Paper feed motor 95 Document set sensor F Paper feeding direction Mt Top layer document Sc Document transport path T1 Ascent start timing T2 Document arrival Timing T3 Paper feeding start timing T4 Original passing timing X Width direction

Claims (11)

a rotation drive unit;
an elevating device having an elevating tray on which documents can be stacked, and elevating and lowering the elevating tray using the driving force of the rotation drive unit;
a document conveyance unit that pulls in the document on the elevating tray at a predetermined document height position and conveys the document on a document conveyance path;
document arrival detection means for detecting that the uppermost document among the documents on the elevating tray has reached the document height position;
A document conveyance device comprising a document conveyance control means,
The document conveyance control means includes:
The timing at which the document arrival detection means detects the arrival of the top layer document at the document height position from the rising start timing when the elevating tray starts rising from a predetermined height position lower than the document height position. The loading amount of the document is determined based on the amount of rotation of the rotary drive unit during the time period, and the conveyance speed of the document by the document conveyance unit is determined based on the determined loading amount. Document transport device. The document conveying device according to claim 1,
The lifting device is
further comprising a rotary lever section rotatably provided around a rotation axis along a direction perpendicular to a paper feeding direction in which the document is drawn into the document transport section;
The document conveying device is characterized in that the rotary lever section is rotationally driven by the driving force of the rotational drive section, and raises the elevating tray by the rotational drive. The document conveying device according to claim 2,
Further comprising a tray detection means for detecting that the elevating tray is at a lower limit position,
The rise start timing is
A document conveying device characterized in that the timing is when the tray detection means no longer detects the elevating tray. The document conveying device according to claim 1 or claim 2,
The rise start timing is
A document conveying device characterized in that the timing is when the rotation drive unit starts rotating. A document loading tray that can load documents;
a rotation drive unit;
a document transport unit that uses the driving force of the rotation drive unit to pull out the original on the document stacking tray and transport it on a document transport path;
a document passage detection means disposed on the document conveyance path and detecting passage of the document;
A document conveyance device comprising a document conveyance control means,
The document conveyance control means includes:
Determining the loading amount of the original document based on the amount of rotation of the rotary driving unit in the time from the timing when the rotational driving unit starts rotational driving to the timing when the original passage detecting means detects passage of the original document, and making a determination. A document conveying apparatus characterized in that a conveyance speed of the document by the document conveyance section is determined based on the loaded amount. The document conveying device according to any one of claims 1 to 5,
The document conveyance control means includes:
When the loading amount is less than or equal to a predetermined reference loading amount, lowering the conveyance speed below a predetermined initial value,
On the other hand, the document conveying device is characterized in that when the loading amount exceeds the reference loading amount, the conveying speed is increased above the initial value. The document conveying device according to any one of claims 1 to 6,
The document conveyance control means includes:
A document conveying device characterized in that the document conveyance unit does not start conveying the document when the loading amount is a predetermined overload amount. The document conveying device according to claim 7,
A document conveying apparatus further comprising a notification means for notifying a user of overloading of documents when the loading amount is the overloading amount. The document conveying device according to any one of claims 1 to 8,
The document conveying device, wherein the rotational drive section is a stepping motor. The document conveying device according to any one of claims 1 to 8,
The document conveying device, wherein the rotational drive section is a DC motor with an encoder. An image forming apparatus comprising the document conveying device according to any one of claims 1 to 10.

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