Document conveying device and image reading device

Abstract

To provide a document conveying device and an image reading device that, when an ejection tray becomes full and thereby reading of images of a plurality of document sheets is interrupted, facilitate removal of the document sheets placed on the ejection tray.SOLUTION: A controller 51, before the completion of reading of images of a plurality of document sheets, (a) when an ejection tray full sensor 16 senses that an ejection tray 14 becomes full with the document sheets, determines whether a paper feed tray sheet sensor 41 senses a document sheet on a paper feed tray 11, (b1) when determining that the document sheet on the paper feed tray 11 is not sensed, controls a lifting device 22 to move the paper feed tray 11 to a predetermined upper limit height position, and (b2) when determining that the document sheet on the paper feed tray 11 is sensed, controls the lifting device 22 to lower the paper feed tray 11 by a predetermined distance.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a document conveying device and an image reading device.

Background Art

[0002] A certain document conveying device raises and lowers a paper feed tray according to the height of the document sheets (sheet bundle) stacked on a discharge tray so that the distance from the upper surface of the sheet bundle of the document sheets stacked on the discharge tray to the paper feed tray becomes a predetermined interval after the image reading of a plurality of document sheets is completed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described document conveying device, when the discharge tray becomes full of document sheets before the image reading of a plurality of document sheets is completed and the image reading is interrupted, if the interval between the upper surface of the sheet bundle of the document sheets stacked on the discharge tray and the paper feed tray is narrow, it is difficult to remove the document sheets stacked on the discharge tray.

[0005] The present invention has been made in view of the above problems, and an object thereof is to obtain a document conveying device and an image reading device that facilitate the removal of the document sheets stacked on the discharge tray when the image reading of a plurality of document sheets is interrupted due to the discharge tray being full.

Means for Solving the Problems

[0006] The document conveying device according to the present invention includes a paper feed tray on which a plurality of document sheets are placed, a discharge tray for the document sheets, a conveying device that conveys the document sheets along a conveyance path from the paper feed tray to the discharge tray, a lifting device that raises and lowers the paper feed tray, a paper feed tray sheet sensor that detects the document sheets on the paper feed tray, a discharge tray full sensor that detects that the discharge tray is full of the document sheets, and a controller that controls the lifting device to change the height position of the paper feed tray. And, before completion of image reading of the plurality of document sheets, the controller: (a) when it is detected by the discharge tray full sensor that the discharge tray is full of the document sheets, determines whether the document sheets on the paper feed tray are detected by the paper feed tray sheet sensor; (b1) when it is determined that the document sheets on the paper feed tray are not detected, controls the lifting device to move the paper feed tray to a predetermined upper limit height position; (b2) when it is determined that the document sheets on the paper feed tray are detected, controls the lifting device to lower the paper feed tray by a predetermined distance.

[0007] The image reading device according to the present invention includes the above-described document conveying device and an image sensor that reads an image of the document sheet at a predetermined position in the conveyance path.

Effect of the Invention

[0008] According to the present invention, there are provided a document conveying device and an image reading device that facilitate removal of the document sheets stacked on the discharge tray when image reading of a plurality of document sheets is interrupted due to the discharge tray being full.

[0009] The above or other objects, features, and advantages of the present invention will become more apparent from the following detailed description together with the accompanying drawings.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] Embodiment 1.

[0013] Figure 1 is a side view showing the internal configuration of the image reading apparatus according to an embodiment of the present invention. The image reading apparatus shown in Figure 1 is a device such as a scanner, a copier, a facsimile machine, a multifunction machine, etc., and includes an automatic document feeder as a document conveyance device.

[0014] The image reading apparatus shown in Figure 1 includes a device main body 1, contact glasses 1a, 1b disposed on the upper surface of the device main body 1, an image sensor 2, and a document cover 3. The document cover 3 includes an automatic document feeder 4.

[0015] The contact glass 1a is a transparent member on which a document is placed when performing image reading without using the automatic document feeder 4. Further, the contact glass 1b is a transparent member through which the document passes when performing image reading of the document image while automatically conveying the document by the automatic document feeder 4.

[0016] The image sensor 2 reads the original image from the original sheet. Specifically, when the image sensor 2 reads the image of the original while automatically conveying the original by the automatic document feeder 4, it is a sensor that optically reads the original image of the original passing through a predetermined image reading position in the conveyance path of the original. The image sensor 2 reads the original image one line at a time. The image sensor 2 includes a light source (such as a light-emitting diode) and a light-receiving element (such as a line sensor), emits light with the light source, detects the reflected light reflected by the original or the like through the contact glasses 1a and 1b with the light-receiving element, and outputs an electrical signal corresponding to the amount of the reflected light. The controller 51 described later receives this electrical signal and generates an original image (that is, image data of the original image) based on this electrical signal.

[0017] The document cover 3 is a member that can be in surface contact with the contact glass 1a and is rotatably installed, which makes the original adhere closely to the contact glass 1a and prevents ambient light from entering the inside of the apparatus from the contact glasses 1a and 1b during image reading. Further, the automatic document feeder 4 includes a paper feed tray 11 on which the original sheet is placed, and a conveyance device 21 that conveys the original sheet from the paper feed tray 11 to the discharge tray 14 via the reading position of the image sensor 2. The conveyance device 21 passes the original sheets placed on the paper feed tray 11 one by one over the contact glass 1b and discharges them to the discharge tray 14. Specifically, the conveyance device 21 includes a paper feed unit 12 and conveyance rollers 13 along the conveyance path, and the paper feed unit 12 feeds the original sheet and conveys it by the conveyance rollers 13. The paper feed unit 12 includes a paper feed roller 12a, a driving roller 12b, a driven roller 12c, a conveyance belt 12d, and an auxiliary roller 12e, and the paper feed roller 12a draws the original sheets on the paper feed tray 11 one by one along the conveyance belt 12d into the conveyance path.

[0018] The image sensor 2 can change its image reading position by a driving device (not shown). When performing image reading using the automatic document feeder 4, the image reading position of the image sensor 2 is set to the passing position of the document on the contact glass 1b. The image sensor 2 optically reads the image of the document conveyed by the automatic document feeder 4 when the document passes over the contact glass 1b. Here, the image sensor 2 is a color image sensor and reads document images of multiple colors such as RGB at different image reading positions in the conveyance direction. In this embodiment, a CIS (Contact Image Sensor) is used as the image sensor 2, and when performing image reading using the automatic document feeder 4, the image sensor 2 is disposed directly below the contact glass 1b.

[0019] Note that the paper feed roller 12a, the drive roller 12b, and the conveyance roller 13 are driven by a driving device (not shown) such as a motor.

[0020] The discharge tray 14 is a tray on which the document sheets discharged and dropped from the discharge port 15 at the end of the conveyance path are stacked. The discharge port 15 discharges the document sheets to the discharge tray 14 at the end of the conveyance path.

[0021] The discharge tray full sensor 16 is a sensor that detects that the discharge tray is full of document sheets and is, for example, an optical sensor. Specifically, when the document sheets are stacked on the discharge tray 14 up to a position a predetermined distance lower than the discharge port 15, the discharge tray full sensor 16 detects that the discharge tray is full of document sheets.

[0022] Furthermore, the image reading device shown in FIG. 1 includes a lifting device 22 that lifts and lowers the paper feed tray 11 by an existing lifting method.

[0023] Figure 2 is a block diagram showing the electrical configuration of the image reading apparatus shown in Figure 1. As shown in Figure 2, the image reading apparatus further includes a paper feed tray sheet sensor 41, a controller 51, and an operation panel 52.

[0024] The paper feed tray sheet sensor 41 detects the document sheet on the paper feed tray 11 and outputs a sensor signal indicating the presence or absence of the document sheet.

[0025] The controller 51 includes a processor that executes a program, an ASIC (Application Specific Integrated Circuit), etc., controls the automatic document feeder 4 (such as the transport device 21 and the lifting device 22) to transport the document sheet, and executes image reading by the image sensor 2 to acquire image data of the image of the document sheet (document image).

[0026] Also, the controller 51 controls the lifting device 22 to change the height position of the paper feed tray 11.

[0027] Furthermore, before the completion of image reading of a plurality of document sheets placed on the paper feed tray 11, when the discharge tray full sensor 16 detects that the discharge tray 14 is full of document sheets, the controller 51 determines whether a document sheet on the paper feed tray 11 is detected by the paper feed tray sheet sensor 41. And when it is determined that no document sheet on the paper feed tray 11 is detected, the controller 51 controls the lifting device 22 to move (raise) the paper feed tray 11 to a predetermined upper limit height position. On the other hand, when it is determined that a document sheet on the paper feed tray 11 is detected, the controller 51 controls the lifting device 22 to lower the paper feed tray 11 by a predetermined distance.

[0028] At this time, this predetermined distance is a distance sufficient for the document sheet on the paper feed tray 11 to be separated from the paper feed roller 12a. When the document sheet on the paper feed tray 11 is separated from the paper feed roller 12a during the lowering of the paper feed tray 11, the controller 51 immediately stops the paper feed tray 11.

[0029] Further, the operation panel 52 is disposed on the surface of the housing of the image reading apparatus, and includes a display device (such as a liquid crystal display) for displaying various information to the user and an input device (such as a touch panel) for receiving user operations.

[0030] Next, the operation of the image reading apparatus will be described. FIG. 3 is a flowchart for explaining the operation of the image reading apparatus according to the first embodiment.

[0031] When a plurality of document sheets are placed on the paper feed tray 11 and a predetermined user operation is detected by the operation panel 52, the controller 51 starts the image reading operation (scan job) of the document sheet (step S1). When starting the image reading operation, the controller 51 monitors the sensor output of the discharge tray full sensor 16 (step S2), and conveys the document sheets on the paper feed tray 11 one by one to the discharge tray 14 until the paper feed tray becomes empty (step S3), and executes image reading with the image sensor 2. At this time, as the document sheets on the paper feed tray 11 decrease, the controller 51 changes the height position of the paper feed tray 11 so that the uppermost document sheet on the paper feed tray 11 abuts against the paper feed roller 12a.

[0032] Then, when the controller 51 detects that the discharge tray 14 is full of document sheets by the discharge tray full sensor 16, the controller 51 interrupts the image reading operation of the document sheet (step S4), and determines whether a document sheet on the paper feed tray 11 is detected by the paper feed tray sheet sensor 41 (step S5).

[0033] When it is determined that no document sheet is detected on the paper feed tray 11, the controller 51 controls the lifting device 22 to move the paper feed tray 11 to a predetermined upper limit height position (step S6).

[0034] When it is determined that the original sheet on the paper feed tray 11 is detected, the controller 51 controls the lifting device 22 to lower the paper feed tray 11 by a predetermined distance (step S7). After that, until the original sheet on the discharge tray 14 is removed and the discharge tray 14 becomes empty (step S9), when the paper feed tray 11 becomes empty (step S8), immediately, the controller 51 controls the lifting device 22 to move the paper feed tray 11 to the predetermined upper limit height position (step S6).

[0035] As described above, according to the first embodiment, before the completion of the image reading of a plurality of original sheets, when (a) it is detected by the discharge tray full sensor 16 that the discharge tray 14 is full of original sheets, the controller 51 determines whether the original sheet on the paper feed tray 11 is detected by the paper feed tray sheet sensor 41. When it is determined that (b1) no original sheet on the paper feed tray 11 is detected, the controller 51 controls the lifting device 22 to move the paper feed tray 11 to the predetermined upper limit height position. When it is determined that (b2) an original sheet on the paper feed tray 11 is detected, the controller 51 controls the lifting device 22 to lower the paper feed tray 11 by a predetermined distance.

[0036] Thereby, when the image reading of a plurality of original sheets is interrupted due to the discharge tray being full, if there is no original sheet on the paper feed tray 11, it becomes easier to remove the original sheet stacked on the discharge tray 14. If there is an original sheet on the paper feed tray 11, it becomes easier to remove the original sheet on the paper feed tray 11.

[0037] Embodiment 2.

[0038] FIG. 4 is a flowchart for explaining the operation of the image reading apparatus according to the second embodiment.

[0039] As shown in FIG. 4, in the second embodiment, when the discharge tray full sensor 16 detects that the discharge tray 14 is full of document sheets during the image reading operation (step S2), and when it is determined that a document sheet on the paper feed tray 11 is detected (step S5), if a predetermined user operation (here, pressing a document removal key (soft key) displayed on the operation panel 52) is not detected on the operation panel 52 within a predetermined time, after the discharge tray full sensor 16 no longer detects that the discharge tray 14 is full of document sheets (steps S21 and S22), the image reading is resumed without lowering the paper feed tray 11 (step S23).

[0040] On the other hand, at that time, if the user operation is not detected within the predetermined time, the controller 51 controls the lifting device 22 to lower the paper feed tray 11 by a predetermined distance to separate the uppermost document sheet on the paper feed tray 11 from the paper feed roller 12a, in the same manner as in the first embodiment (step S7). Thereby, the user can remove the document sheet from the paper feed tray 11.

[0041] Note that the other configurations and operations of the image reading apparatus according to the second embodiment are the same as those of the first embodiment, and thus the description thereof is omitted.

[0042] Note that various changes and modifications to the above-described embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the subject matter and without diminishing the intended advantages. That is, it is intended that such changes and modifications be included in the claims.

[0043] For example, in the second embodiment above, when there is an original sheet on the paper feed tray 11 as in the first embodiment, the first mode (steps S6, S7) of immediately lowering the paper feed tray 11, and when there is an original sheet on the paper feed tray 11 as in the second embodiment, either the second mode in which the user can select resuming the original reading or removing the original sheet from the paper feed tray 11 may be selectable by the user. In that case, according to the setting data set by the user, the controller 51 selects the first mode or the second mode.

Industrial Applicability

[0044] The present invention is applicable to, for example, an image reading apparatus.

Explanation of Signs

[0045] 2 Image sensor 4 Automatic document feeder (an example of a document conveying device) 11 Paper feed tray 12a Paper feed roller 14 Discharge tray 16 Discharge tray full sensor 21 Conveying device 22 Lifting device 41 Paper feed tray sheet sensor 51 Controller

Claims

1. A paper feed tray on which a plurality of document sheets are placed, A discharge tray for the document sheets, A conveying device that conveys the document sheets along a conveyance path from the paper feed tray to the discharge tray, A lifting device that raises and lowers the paper feed tray, A paper feed tray sheet sensor that detects the document sheets on the paper feed tray, A discharge tray full sensor that detects that the discharge tray is full of the document sheets, A controller that controls the lifting device to change the height position of the paper feed tray, and before completion of image reading of the plurality of document sheets, the controller: (a) when it is detected by the discharge tray full sensor that the discharge tray is full of the document sheets, determines whether the document sheets on the paper feed tray are detected by the paper feed tray sheet sensor; (b1) when it is determined that the document sheets on the paper feed tray are not detected, controls the lifting device to move the paper feed tray to a predetermined upper limit height position; (b2) when it is determined that the document sheets on the paper feed tray are detected, controls the lifting device to lower the paper feed tray by a predetermined distance. A document conveying device characterized by the above.

2. The document conveying device according to claim 1, wherein when the controller determines that the document sheets on the paper feed tray are detected and then the document sheets on the paper feed tray are no longer detected after the paper feed tray is lowered by a predetermined distance, the controller immediately controls the lifting device to move the paper feed tray to a predetermined upper limit height position.

3. The document conveying device according to claim 1, wherein when the controller determines that the document sheets on the paper feed tray are detected: (a) if there is no predetermined user operation within a predetermined time, after it is detected by the discharge tray full sensor that the discharge tray is no longer full of the document sheets, resumes the image reading without lowering the paper feed tray; (b) if there is the predetermined user operation within the predetermined time, controls the lifting device to lower the paper feed tray by the predetermined distance.

4. The controller adjusts the height position of the paper feed tray so that the uppermost original sheet on the paper feed tray contacts the paper feed roller in the paper feed device during the image reading, and controls the lifting device to lower the paper feed tray by the predetermined distance to separate the uppermost original sheet on the paper feed tray from the paper feed roller if there is no predetermined user operation within the predetermined time. The document conveying apparatus according to claim 3, characterized in that.

5. A document conveying apparatus according to any one of claims 1 to 4, An image sensor that reads an image of the original sheet at a predetermined position in the conveyance path, An image reading apparatus, characterized in that it comprises.

Images