Document conveying device and image reading device

Abstract

To provide a document conveying device and an image reading device that prevent a variation in the positions of document sheets placed on an ejection tray.SOLUTION: An ejection sheet sensor 41 senses document sheets on an ejection tray 14. A controller (a) lifts an ejection port 15 together with placement of the document sheets on the ejection tray 14 during a document reading operation, and (b) when an ejection sheet sensor 41 no longer senses the document sheets on the ejection tray 14 during the document reading operation, lowers the ejection port 15.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] One document transport device includes a liftable paper feed tray and a paper discharge tray, and transports document sheets along a transport path from the paper feed tray to the paper discharge tray via a discharge port (see, for example, Patent Document 1). In this document transport device, when the paper feed tray moves up and down depending on the thickness of the document sheet stack on the paper feed tray, the discharge port also moves up and down in conjunction with the paper feed tray. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-95258 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned document transport device, the discharge outlet is linked to the paper feed tray regardless of the thickness of the document sheet stack on the discharge tray, so if the document sheets are removed from the discharge tray during the document reading operation, the distance from the discharge outlet to the top surface of the sheet stack on the discharge tray becomes large, which may cause the position of the document sheets loaded on the discharge tray to vary due to the sheets falling from the discharge outlet.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide an original transport device and an image reading device that suppress variation in the positions of original sheets loaded on a discharge tray. [Means for solving the problem]

[0006] The manuscript conveying device according to the present invention includes a paper feed tray on which a manuscript sheet is placed, a discharge tray for the manuscript sheet, a conveying device that conveys the manuscript sheet along a conveyance path from the paper feed tray to the discharge tray, a discharge port that discharges the manuscript sheet to the discharge tray at the end of the conveyance path, a discharge sheet sensor that detects the manuscript sheet stacked on the discharge tray, a lifting device that raises and lowers the discharge port and the discharge sheet sensor, and a controller that controls the lifting device to change the height position of the discharge port. And the controller: (a) raises the discharge port along with the stacking of the manuscript sheet on the discharge tray during the manuscript reading operation; (b) lowers the discharge port when the discharge sheet sensor no longer detects the manuscript sheet on the discharge tray during the manuscript reading operation.

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

Effects of the Invention

[0008] According to the present invention, a manuscript conveying device and an image reading device are obtained in which variations in the position of the manuscript sheet stacked on the discharge tray are suppressed.

[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

Figure 5

Figure 6

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

[0012] Embodiment 1.

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

[0014] The image reading apparatus shown in FIG. 1 includes an apparatus main body 1, contact glasses 1a and 1b disposed on the upper surface of the apparatus 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 document image from the document sheet. Specifically, when the image sensor 2 reads the image of the document while automatically conveying the document by the automatic document feeder 4 (that is, in the document reading operation), it is a sensor that optically reads the image of the document sheet passing through a predetermined image reading position in the document conveyance path. The image sensor 2 reads the document image line by line. 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 document or the like through the contact glasses 1a, 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 a document image (that is, the image data of the document 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 document adhere closely to the contact glass 1a and prevents ambient light from entering the device interior from the contact glasses 1a, 1b during image reading. Also, the automatic document feeder 4 includes a paper feed tray 11 on which the document sheet is placed and a conveyance device 21 that conveys the document sheet from the paper feed tray 11 to the discharge tray 14 through the reading position of the image sensor 2. The conveyance device 21 passes the document 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 document sheet and conveys it by the conveyance rollers 13. The paper feed unit 12 includes a paper feed roller 12a, a drive roller 12b, a driven roller 12c, a conveyance belt 12d, and an auxiliary roller 12e, and the paper feed roller 12a draws the document 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] 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, and a lifting device 23 that lifts and lowers the discharge port 15. Specifically, the lifting device 23 pivots the end conveyance path 16 together with the conveyance roller 13 at the end of the conveyance path about a predetermined fulcrum to lift and lower the discharge port 15.

[0022] FIG. 2 is a block diagram showing the electrical configuration of the automatic document feeder 4 in FIG. 1. As shown in FIG. 2, the automatic document feeder 4 further includes a discharge sheet sensor 41.

[0023] The discharge sheet sensor 41 is a sensor that detects the document sheet stacked on the discharge tray 14. The discharge sheet sensor 41 is, for example, an optical sensor. Further, the discharge sheet sensor 41 is disposed at the discharge port 15, is lifted and lowered in conjunction with the discharge port 15, and detects the presence or absence of a document sheet on the discharge tray 14 at a height position corresponding to the height position of the discharge port 15.

[0024] The controller 51 includes a processor that executes a program, an ASIC (Application Specific Integrated Circuit), etc., controls the automatic document feeder 4 (transport device 21, lifting devices 22, 23, etc.) to transport the document sheet, and executes an image reading operation with the image sensor 2 to acquire image data of the image of the document sheet (document image).

[0025] Further, the controller 51 controls the lifting device 22 to change the height position of the paper feed tray 11, and controls the lifting device 23 to change the height position of the discharge port 15.

[0026] FIG. 3 is a diagram for explaining the height position of the discharge port 15 in a state where a document sheet is stacked on the discharge tray 14. FIG. 4 is a diagram for explaining the height position of the discharge port 15 after the document sheet is removed from the discharge tray 14.

[0027] Specifically, as shown in FIG. 3 for example, the controller 51 changes the height position of the paper feed tray 11 so that the upper surface of the document sheet 101 (sheet bundle) on the paper feed tray 11 abuts against the paper feed roller 12a. Further, as shown in FIG. 3 for example, the controller 51 raises the discharge port 15 along with the stacking of the document sheet 102 on the discharge tray 14 during the document reading operation, and as shown in FIG. 4 for example, during the document reading operation, when the document sheet 102 is removed from the discharge tray 14 and the discharge sheet sensor 41 no longer detects the document sheet 102 on the discharge tray 14, the discharge port 15 is lowered.

[0028] In Embodiment 1, when the controller 51 no longer detects the document sheet 102 on the discharge tray 14 by the discharge sheet sensor 41 during the document reading operation, the controller 51 interrupts the document reading operation and then lowers the discharge port 15.

[0029] Also, in that case, when the discharge port 15 reaches a predetermined lower limit height or the discharge sheet sensor 41 detects the document sheet 102 on the discharge tray 14, the controller 51 ends the lowering of the discharge port 15 and resumes the document reading operation. The fact that the discharge port 15 has reached the predetermined lower limit height is detected by a sensor (not shown).

[0030] Next, the operation of the above image reading apparatus will be described. FIG. 5 is a flowchart for explaining the operation of the image reading apparatus according to Embodiment 1.

[0031] When the controller 51 receives a request for a document reading operation, it sets the value of the discharge port status data to "stopped" (step S1) and starts the document reading operation (step S2).

[0032] After starting the document reading operation, the controller 51 monitors the value of the sensor output of the discharge sheet sensor 41, whether the sensor output value of the discharge sheet sensor 41 is on (there is a document sheet 102) and whether a predetermined time has elapsed since the sensor output value of the discharge sheet sensor 41 became on (steps S3, S4), and whether the sensor output value of the discharge sheet sensor 41 is off (there is no document sheet 102) and whether the value of the discharge port status data is "stopped" (steps S5, S6). Note that the discharge port status data is stored, for example, in a storage device (such as a memory) in the controller 51.

[0033] When the sensor output value of the discharge sheet sensor 41 is on and a predetermined time has elapsed, the controller 51 controls the lifting device 23 to raise the discharge port 15 (step S11) and changes the value of the discharge port status data to "ascending" (step S12).

[0034] After that, the controller 51 monitors whether the sensor output value of the discharge sheet sensor 41 has turned off (step S13). When the sensor output value of the discharge sheet sensor 41 turns off, the controller 51 controls the lifting device 23 to stop the discharge port 15 (step S14) and lower it (step S15).

[0035] After that, the controller 51 monitors whether the sensor output value of the discharge sheet sensor 41 has turned on (step S16). When the sensor output value of the discharge sheet sensor 41 turns on, the controller 51 controls the lifting device 23 to stop the discharge port 15 (step S17) and change the value of the discharge port status data to "stopped" (step S18).

[0036] In this way, as the stacking amount of the original sheet 102 on the discharge tray 14 increases during the original reading operation, the discharge port 15 is raised accordingly.

[0037] On the other hand, when the sensor output value of the discharge sheet sensor 41 is off and the value of the discharge port status data is "stopped", the controller 51 interrupts the original reading operation (step S21), changes the value of the discharge port status data to "lowering" (step S22), and controls the lifting device 23 to lower the discharge port 15 (step S23).

[0038] After that, the controller 51 monitors whether the discharge port 15 has reached a predetermined lower limit height or whether the original sheet 102 on the discharge tray 14 has been detected by the discharge sheet sensor 41 (steps S24, S25). When the discharge port 15 reaches the predetermined lower limit height or the original sheet 102 on the discharge tray 14 is detected by the discharge sheet sensor 41, the controller 51 stops the discharge port 15 (step S26), changes the value of the discharge port status data to "stopped" (step S27), and resumes the original reading operation (step S28).

[0039] As described above, when the document sheet 102 on the discharge tray 14 is removed during the document reading operation, the discharge port 15 is immediately lowered regardless of the amount of the document sheet 101 on the paper feed tray 11.

[0040] As described above, according to the first embodiment, the elevating device 23 elevates and lowers the discharge sheet sensor 41 that detects the document sheet 102 stacked on the discharge tray 14 and the discharge port 15 that discharges the document sheet 102 to the discharge tray 14 at the end of the conveyance path. The controller 51 (a) raises the discharge port 15 together with the stacking of the document sheet 102 on the discharge tray 14 during the document reading operation, and (b) lowers the discharge port 15 when the discharge sheet sensor 41 no longer detects the document sheet 102 on the discharge tray 14 during the document reading operation.

[0041] Thereby, when the document sheet 102 on the discharge tray 14 is removed during the document reading operation, the discharge port 15 is immediately lowered, and the falling distance of the document sheet 102 from the discharge port 15 is reduced, so that the variation in the position of the document sheet stacked on the discharge tray 14 is suppressed.

[0042] Second Embodiment.

[0043] In the second embodiment, the setting data specified by the user is stored in the non-volatile storage device in the controller 51, and when the discharge sheet sensor 41 no longer detects the document sheet 102 on the discharge tray 14 during the document reading operation, the controller 51 determines whether to interrupt the document reading operation and then lower the discharge port 15 based on the setting data.

[0044] FIG. 6 is a flowchart for explaining the operation of the image reading apparatus according to the second embodiment.

[0045] In the second embodiment, as in the first embodiment, when the controller 51 receives a request for a document reading operation, it sets the value of the discharge port status data to "stop" (step S1) and starts the document reading operation (step S2).

[0046] Also, similar to Embodiment 1, after the start of the document reading operation, the controller 51 checks whether the sensor output value of the discharge sheet sensor 41 is on and whether a predetermined time has elapsed since the sensor output value of the discharge sheet sensor 41 became on (steps S3, S4), and whether the sensor output value of the discharge sheet sensor 41 is off and the value of the discharge port status data is "stopped" (steps S5, S6).

[0047] When the sensor output value of the discharge sheet sensor 41 is on and a predetermined time has elapsed, the controller 51 performs a discharge port raising operation in the same manner as in Embodiment 1 (step S31). The discharge port raising operation is the same as the operations in steps S11 to S18 in Embodiment 1.

[0048] On the other hand, when the sensor output value of the discharge sheet sensor 41 is off and the value of the discharge port status data is "stopped", the controller 51 determines whether the above-described setting data indicates the interrupt mode (step S41). If the setting data indicates the interrupt mode, the controller 51 performs a discharge port lowering operation accompanied by interruption of the document reading operation (step S42). The discharge port lowering operation (step S42) is the same as the operations in steps S21 to S28 in Embodiment 1.

[0049] On the other hand, if the setting data does not indicate the interrupt mode, the controller 51 immediately performs a discharge port lowering operation without interruption of the document reading operation (step S42). The discharge port lowering operation (step S42) is the same as the operations in steps S22 to S27 in Embodiment 1. That is, in this case, the document reading operation is not interrupted or restarted, and the document reading operation continues in parallel with the discharge port lowering operation, and the document reading is completed in a relatively short time.

[0050] Note that since the other configurations and operations of the image reading apparatus according to Embodiment 2 are the same as those in Embodiment 1, the description thereof is omitted.

[0051] 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, such changes and modifications are intended to be included within the scope of the claims.

Industrial Applicability

[0052] The present invention is applicable to, for example, an image reading apparatus.

Explanation of Signs

[0053] 4 Automatic document feeder (an example of a document conveying device) 14 Discharge tray 15 Discharge port 16 Terminal conveyance path 21 Conveying device 23 Lifting device 41 Discharge sheet sensor 51 Controller

Claims

1. A paper feed tray on which an original sheet is placed, A discharge tray for the original sheet, A conveying device that conveys the original sheet along a conveyance path from the paper feed tray to the discharge tray, A discharge port that discharges the original sheet to the discharge tray at the end of the conveyance path, A discharge sheet sensor that detects the original sheet stacked on the discharge tray, A lifting device that raises and lowers the discharge port and the discharge sheet sensor, A controller that controls the lifting device to change the height position of the discharge port, and The controller: (a) raises the discharge port along with stacking of the original sheet on the discharge tray during an original reading operation; (b) lowers the discharge port when the original sheet on the discharge tray is no longer detected by the discharge sheet sensor during the original reading operation. An original sheet conveying device, characterized by the above.

2. The controller interrupts the original reading operation and then lowers the discharge port when the original sheet on the discharge tray is no longer detected by the discharge sheet sensor during the original reading operation. The original sheet conveying device according to Claim 1, characterized by this.

3. When the original sheet on the discharge tray is no longer detected by the discharge sheet sensor during the original reading operation, the controller interrupts the original reading operation and then, when the discharge port reaches the lower limit height or the original sheet on the discharge tray is detected by the discharge sheet sensor after lowering the discharge port, ends the lowering of the discharge port and resumes the original reading operation. The original sheet conveying device according to Claim 2, characterized by this.

4. Set data specified by a user, and When the original sheet on the discharge tray is no longer detected by the discharge sheet sensor during the original reading operation, the controller determines whether to interrupt the original reading operation and then lower the discharge port based on the set data. The original sheet conveying device according to Claim 1, characterized by this.

5. An original sheet conveying device according to any one of Claims 1 to 4, and An image sensor that reads an image of the original sheet at a predetermined position on the conveyance path during the original reading operation. An image reading device, characterized by including the above.

Images