CN111479028A - Determination device, conveyance device, image reading device, and image forming apparatus - Google Patents

Abstract

The invention provides a determination device, a conveying device, an image reading device and an image forming apparatus. Even when a plurality of types of objects are sequentially conveyed in a conveyance path, whether or not overlapped conveyance is present can be determined for each type of object. The acquisition processing unit acquires a signal based on an ultrasonic wave emitted to an object conveyed in a specific direction. The determination processing unit determines whether or not a first time during which the level of the signal changes from a first level threshold that is set in advance to a second level threshold that is smaller than the first level threshold is equal to or greater than a first time threshold that is set in advance.

Description

Determination device, conveyance device, image reading device, and image forming apparatus

Technical Field

The invention relates to a determination device, a conveyance device, an image reading device, and an image forming apparatus.

Background

Generally, in an image reading apparatus or an image forming apparatus, it is determined whether or not overlapped conveyance occurs in a conveyance path. The overlapped conveyance is a conveyance of a plurality of sheet-like objects in an overlapped state in the conveyance path.

In the related art image forming apparatus, the type of the object (for example, an envelope or a sheet) is set according to a user operation. The image forming apparatus is provided with an ultrasonic sensor that emits ultrasonic waves to the object conveyed in the conveyance path and outputs a signal having a level corresponding to an incident wave from the object. In the image forming apparatus, when the type of the object is set as an envelope and a change with time of the signal does not satisfy a first specific condition set for the envelope, the conveyance of the plurality of envelopes is stopped as the overlapped conveyance occurs. Further, when the type of the object is set as a sheet, the conveyance of the plurality of sheets is stopped when the change with time of the output signal does not satisfy a second specific condition different from the first specific condition set for the sheet.

However, in the image reading apparatus and the like, whether or not the double feed has occurred is determined based on a specific condition that differs for each type of the object. Therefore, when a plurality of types of objects are sequentially conveyed in the conveyance path, it is not possible to accurately determine whether or not overlapped conveyance occurs in the conveyance path for at least one of the plurality of types of objects.

Disclosure of Invention

The invention aims to provide a determination device, a conveying device, an image reading device and an image forming device, which can determine whether overlapped conveying exists on various objects even when the objects are conveyed in sequence in the conveying channel.

The present invention provides a determination device, including: an acquisition processing unit that acquires a signal based on an ultrasonic wave emitted to an object conveyed in a specific direction; and a determination processing unit configured to determine whether or not a first time during which a level of the signal changes from a first level threshold that is set in advance to a second level threshold that is smaller than the first level threshold is equal to or greater than a first time threshold that is set in advance.

The present invention provides a conveying device, comprising: a sensor unit that emits an ultrasonic wave to the object and outputs the signal whose level changes in accordance with an incident wave from the object; and the above-mentioned judging device.

The present invention provides an image reading apparatus including the above-described judging device or the above-described conveying device.

The present invention provides an image forming apparatus including the above determining device or the above conveying device.

According to the present invention, it is possible to provide a determination device, a conveyance device, an image reading device, and an image forming apparatus capable of determining whether or not overlapped conveyance is performed for various objects even when a plurality of objects are sequentially conveyed in the conveyance path.

The present specification will be described with reference to the accompanying drawings as appropriate, in order to simplify the summary of the concepts described in the following detailed description. The present specification is not intended to limit the important features and essential features of the subject matter described in the claims, nor is it intended to limit the scope of the subject matter described in the claims. The object of the claims is not limited to the embodiments for solving some or all of the disadvantages described in any part of the present invention.

Drawings

Fig. 1 is a schematic diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention.

Fig. 2A is a schematic view showing a cross-sectional shape of the first object when viewed from the back side and a cross-sectional shape when viewed from the width direction of the first object along the two-dot chain line III-III.

Fig. 2B is a schematic view showing the first object placed on the first placing unit shown in fig. 1.

Fig. 3 is a schematic view showing a second object when viewed from the front.

Fig. 4A is a graph showing a change in signal with time when a second object is conveyed in the first conveyance path shown in fig. 1.

Fig. 4B is a graph showing a change with time of a signal when two second objects are conveyed in the first conveyance path shown in fig. 1 without being deviated from the first direction.

Fig. 4C is a graph showing a change with time of a signal when two second objects are conveyed in a state deviated from the first direction in the first conveyance path shown in fig. 1.

Fig. 4D is a graph showing a change in signal with time when a first object is conveyed in the first conveyance path shown in fig. 1.

Fig. 5 is a block diagram showing a configuration of the image forming apparatus shown in fig. 1.

Fig. 6A is a flowchart showing a first part of the processing procedure of the control unit shown in fig. 5.

Fig. 6B is a flowchart showing a second part of the processing procedure of the control unit shown in fig. 5.

Fig. 7 is a schematic diagram showing a detailed configuration of the image reading apparatus shown in fig. 1.

Detailed Description

Embodiments of the present invention will be described below in order to understand the present invention with reference to the accompanying drawings. The following embodiments are merely examples embodying the present invention, and do not limit the technical scope of the present invention.

In fig. 1, arrows X1, Y1, and Z1 indicate the front-rear direction, the left-right direction, and the up-down direction of the image forming apparatus 100.

The image forming apparatus 100 is a copier, a printer, a facsimile machine, a complex machine, or the like. The multifunction peripheral has a copy function, a print function, a facsimile function, and the like. Image forming apparatus 100 includes main body apparatus 200 and image reading apparatus 300. Further, the image forming apparatus 100 may not include the image reading apparatus 300.

The main body device 200 includes a first placement unit 22, a first conveyance unit 23, a first sensor unit 24, an image forming unit 25, a first discharge unit 26, and a control unit (i.e., a determination device) 27. In the main body apparatus 200, the conveyance apparatus 400 includes at least the first conveyance unit 23, the first sensor unit 24, and the control unit 27.

The main body apparatus 200 is provided therein with a first conveyance path CP1 for conveying the object a 1. The first transfer passage CP1 passes from the first upstream end CP11 to the first downstream end CP 12. Specifically, the first upstream end CP11 and the first downstream end CP12 are provided at predetermined vertical positions on the right side portion 200A and the left side portion 200B of the main body apparatus 200, respectively.

The first placement portion 22 is a manual tray, and extends from a position directly below the upstream end CP11 to an obliquely upper right side on the right side portion 200A. The first placement unit 22 can be loaded with a plurality of types of objects a 1. The multiple object a1 includes a first object a11 (see fig. 2A) and a second object a12 (see fig. 3).

In fig. 2A, arrows X2, Y2, and Z2 respectively indicate the longitudinal direction, the width direction, and the thickness direction of the first object a 11. A block F1 of fig. 2A indicates the first object a11 when viewed from one side in the width direction along a cross section of a two-dot chain line III-III parallel to the longitudinal direction.

The first object a11 is an unused envelope or the like, and has a main body portion B11 and a flap portion B12. The body portion B11 has a substantially rectangular shape as viewed from the thickness direction. The body portion B11 also has a bag-like shape in which a plurality of sheets are stacked in the thickness direction. Specifically, as shown in block F1, main body B11 is open at one side in the longitudinal direction, and constitutes inlet B13. As shown in a block F1, the other longitudinal side of the body B11 is closed to form a closed portion B14. The flap part B12 extends from the other side of the main body part B11, and is folded back to close the loading port B13. As shown in fig. 2B, the first object a11 is placed on the first placing portion 22 in such a manner that the closing portion B14 is along the upstream end CP 11.

In fig. 3, arrows X3, Y3, and Z3 respectively indicate the longitudinal direction, the width direction, and the thickness direction of the second object a 12. The second object a12 is an unused sheet of paper, a film (an OHP sheet), or the like, and is a sheet having a constant thickness over the entire area in the longitudinal direction and the width direction. Further, the image forming apparatus 100 can form images on the second object a12 having a plurality of thicknesses different from each other.

In fig. 1, the first conveyance section 23 includes a pickup roller and a conveyance roller pair, feeds an object a1 from a first upstream end CP11 into the first conveyance path CP1, and conveys the object a1 in the first conveyance path CP1 at a predetermined speed V1 in a first direction D11. The first direction D11 is a downstream direction of the first feed passage CP1, and is a first example of a specific direction in the present invention. The speed V1 is the first example of the specific speed in the present invention.

The first sensor unit 24 is a first example of the sensor unit of the present invention, and is a transmission type ultrasonic sensor. As shown in fig. 2B, the first sensor section 24 includes a transmitting section 241 and a receiving section 242.

The transmitting unit 241 can transmit ultrasonic waves (hereinafter, referred to as measurement waves) to a preset detection position DP1 on the first conveyance path CP1 immediately downstream of the first conveying unit 23. The amplitude level of the measurement wave is preset.

The receiving unit 242 is disposed at a position facing the transmitting unit 241 with the detection position DP1 therebetween. The receiving unit 242 outputs a signal ES1 based on the measurement wave emitted to the object a1 passing through the detection position DP1 to the control unit 27. Specifically, the signal ES1 has a level (i.e., a voltage value) that changes in accordance with the ultrasonic wave incident on the receiving unit 242 (hereinafter referred to as an incident wave) in accordance with the measurement wave. The level of the signal ES1 is related to the total thickness of the object a1 passing through the detection position DP1, and more specifically, to the type and number of the objects a 1.

The category and number of objects a1 can be roughly classified into: (1) a case where the second object a12 passes through the detection position DP1 (see fig. 4A); (2) when two or more second objects a12 pass through the detection position DP1 in a state of being aligned together in the first direction D11 (see fig. 4B); (3) a case where two or more second objects a12 pass through the detection position DP1 while being shifted from each other in the first direction D11 (see fig. 4C); and (4) a case where the first object a11 passes through the detection position DP1 (see fig. 4D).

(1) In the case of (1), as shown in fig. 4A, the signal ES1 indicates the first level L11 in the first time interval T11 in which one second object a12 does not pass through the detection position DP1, and in the case of the first time interval T11 in which two or more second objects a12 (see fig. 4B and 4C) and one first object a11 (see fig. 4D) do not pass through the detection position DP1, the signal ES1 indicates the first level L11, (1), and in the second time interval T12 in which one second object a12 passes through the detection position DP1, the signal ES1 indicates the second level L12 smaller than the first level L11.

(2) As shown in fig. 4B, the signal ES1 shows a level lower than the second level L12 in the third time interval T13, and fig. 4B illustrates a case where the signal ES1 shows the third level L13 in the third time interval T13, in the third time interval T13, two second objects a12 pass through the detection position dp1 in a superimposed state, and when three or more second objects a12 pass through the detection position DP1, the level of the signal ES1 also changes with time similarly to fig. 4B.

(3) In the case of (1), as shown in fig. 4C, the signal ES1 indicates a level (for example, the third level L13) lower than the second level L12 in the third time interval T13, indicates the second level L12 in the fourth time interval T14, and only one of the two second objects a12 passes through the detection position DP1 in the fourth time interval T14.

(4) In the case of the body portion B11 of the first object a11, although the case of (2) is the same as the case of (2) in terms of overlapping a plurality of sheets, the case of (2) is different from the case of (2) in terms of connecting a plurality of sheets by the closing portion B14 or the like, and therefore, in the fifth time interval T15 from the time when the body portion B11 starts to pass through the detection position DP1 to the time when a specific time elapses, the level of the signal ES1 decreases with time and reaches the third level L13, for the following reason.

The vibration generated when the measurement wave hits the first region R11 is not greatly attenuated as indicated by an arrow E1 in a frame F2 of fig. 4D, and propagates from the first region R11 of the body B11 to the second region R12 of the body B11 through the blocking portion B14, the first region R11 is a region on the sheet on the transmitting portion 241 side close to the blocking portion B14, the second region R12 is a region on the sheet on the receiving portion 242 side close to the blocking portion B14, the vibration having propagated to the second region R12 propagates to the receiving portion 242 through air, the vibration having propagated to the second region R12 decreases with the passage of time, since the first object a11 is conveyed in the first direction D11, the propagation distance from the first region R11 to the blocking portion B14 increases with the passage of time, and therefore, the vibration propagated to the second region R12 decreases with the passage of time, as indicated in fig. 4D, the vibration having propagated to the second region R11 decreases with the passage of time, and the material thickness of the blocking portion 8653, and the material thickness of the blocking portion 8672, which is determined according to the time interval T828653, the time interval 3653, and the time interval of the fifth object a 36867.

In the case of (4), as shown in fig. 4D, the signal ES1 indicates the third level L13 in the sixth time interval T16, and indicates the second level L12 in the seventh time interval T17, the sixth time interval T16 is a time interval after the fifth time interval T15 elapses in the time interval in which the main body portion B11 passes through the detection position DP1, and the flap B12 (see fig. 2A) of the first object a11 passes through the detection position DP1 in the seventh time interval T17.

In fig. 1, the image forming unit 25 forms an image based on the image data transmitted from the control unit 27 on the object a1 conveyed in the conveyance path CP1 at a position downstream of the first sensor unit 24 in the first conveyance path CP 1. The image forming unit 25 discharges the object a1 on which the image has been formed to the first discharge unit 26, which is a paper output tray or the like. Further, the image forming portion 25 forms the image by an electrophotographic method or an ink-jet method.

The control unit 27 is also the determination device 27. The control unit 27 includes a processor, a program storage unit such as a ROM, and a work area such as a RAM. The processor executes a program stored in advance in the program storage unit using the work area. Thereby, the control section 27 controls the respective sections of the image forming apparatus 100 as a whole. The control unit 27 may be an electronic circuit such as an asic (application specific Integrated circuit) or a Digital Signal Processor (Digital Signal Processor). When the image forming apparatus 100 includes the image reading apparatus 300, the control unit 27 may be provided in the image reading apparatus 300

In the image forming apparatus of the related art, whether or not the double feed has occurred is determined according to a condition that differs for each type of the object to be fed in each feed path. Therefore, when a plurality of types of objects are sequentially conveyed in the conveyance path, it is not possible to accurately determine whether or not the overlapped conveyance occurs in the conveyance path for at least one of the plurality of types of objects. In contrast, according to the image forming apparatus 100 of the present invention, even when a plurality of types of objects are sequentially conveyed in the conveyance path, overlapped conveyance determination can be performed for each type of object.

In the image forming apparatus 100, as shown in fig. 5, the control section 27 includes an acquisition processing section 27A, a determination processing section 27B, a timing processing section 27C, a detection processing section 27D, and a conveyance control section 27E. The control unit 27 functions as an acquisition processing unit 27A, a determination processing unit 27B, a timing processing unit 27C, a detection processing unit 27D, and a conveyance control unit 27E by the processor executing the program.

The obtaining processing portion 27A obtains the signal ES1 from the first sensor portion 24.

The determination processing unit 27B determines whether or not the first time ET1 (see fig. 6A) during which the level of the signal ES1 changes from the first level threshold L T1 (see fig. 4A to 4D) to the second level threshold L T2 is equal to or greater than the first time threshold TT1 (see fig. 4D).

The first level threshold L T1, the second level threshold L T2, and the first time threshold TT1 are preliminarily specified by experiments or simulations at the design and development stage of the image forming apparatus 100, and are recorded in the program.

First level threshold L T L and second level threshold L T L are set based on the thickness of object a L in second direction D L intersecting first direction D L, second direction D L is a first example of the intersecting direction of the present invention, specifically, a direction along the up-down direction, specifically, as shown in fig. 4B, first level threshold L T L has a value close to second level L312 between second level L and third level L, second level threshold L T L is smaller than first level threshold L T L, specifically, a value close to third level L is provided between second level L and third level L, more specifically, as shown in fig. 4A, first level threshold L is set such that the level of signal ES L exceeds second level L when second object a L passes detection position DP L, first level threshold L is set such that first level L a is equal to or less than second level L B, and second object a plurality of levels L a detection signal ES is set as shown in fig. 4A, and when a second object a first object a L a first object a signal L B passes detection position DP, second object a detection position L B is equal to or less than second object DP.

In addition, the first time threshold value tt1 shown in fig. 4D is set based on the speed V1 and the distance from the end of the object a1 on the first direction D11 side in the direction opposite to the first direction D11, and therefore, the time at which the level of the signal ES1 becomes the second level L and the third level L13 is the initial time T0 and the final time T1 of the fifth time period T15. the first time threshold value TT1 is the time from the initial time T0 to the time T2 near the final time T1 of the fifth time period T15. more specifically, the distance D31 at which the level of the signal ES1 changes from exceeding the third level L to being lower than the first time threshold value TT 42 is set in advance to a value of dividing the speed V1 by the distance D31 or less in the above, by the above experiment or the simulation.

When the level of the signal ES1 is equal to or lower than the first level threshold L T1, the timer processing unit 27C measures the elapsed time from the time of judgment by the judgment processing unit 27B, and the elapsed time is used as the first time ET1 and the second time ET2 by the judgment processing unit 27B.

Specifically, the determination processing unit 27B further determines whether or not, in the overlapped feeding determination, a second time ET2 (see fig. 6B) during which the level of the signal ES1 is equal to or less than the first level threshold L T1 is equal to or greater than a second time threshold TT2 (see fig. 4C) which is longer than the first time threshold TT1 (see fig. 4D).

The second time threshold TT2 is preset in accordance with the speed V1 and the length of the specific object a1 in the first direction D11. Specifically, the specific object a1 is the second object a12 having the shortest length in the first direction D11 among the second objects a12 that the image forming apparatus 100 can form an image. The second time threshold TT2 is a time obtained by dividing the speed V1 by the length of the specific object a 1.

The detection processing unit 27D determines whether or not the object a1 is being conveyed in an overlapping manner based on the determination result obtained by the determination processing unit 27B. Specifically, when the determination processing unit 27B determines that the first time ET1 is equal to or greater than the first time threshold TT1, the detection processing unit 27D detects that the double feed is not performed. At this time, the conveyance controller 27E conveys the object a1 further downstream in the first direction D11. When the determination processing unit 27B determines that the first time ET1 is not equal to or greater than the first time threshold TT1, the detection processing unit 27D detects that the double feed is present. At this time, the conveyance controller 27E may stop conveying the object a1 in the first direction D11.

Next, the processing and control of the control unit 27 in the image forming apparatus 100 will be described in more detail.

First, the user loads a plurality of objects a1 (see fig. 1) on the first placement unit 22. The plurality of objects a1 includes a first object a11 and a second object a 12. Further, the control unit 27 obtains image data indicating an image to be formed. Specifically, the control section 27 receives the image data from an information processing apparatus (not shown) communicably connected to the image forming apparatus 100 via a network. When the image forming apparatus 100 includes the image reading apparatus 300, the control section 27 may receive the image data from the image reading apparatus 300. Upon receiving the image data, the control unit 27 repeats the processing of fig. 6A to 6B a required number of times for one object a1, and forms images indicated by the image data on a required number of objects a 1. However, since the double feed may occur in the first feed path CP1, the processing of fig. 6A to 6B includes the double feed detection processing.

In step S101 of fig. 6A, the control unit 27 functions as a conveyance control unit 27E. The conveyance controller 27E controls the first conveyor 23 to start conveyance of the object a1 on the first placement unit 22.

Next, the control unit 27 functions as the obtaining processing unit 27A in step S102 to obtain the signal ES1 from the first sensor unit 24, next, the control unit 27 functions as the judging processing unit 27B in step S103 to judge whether or not there is a possibility that the double feed is currently generated, the judging processing unit 27B judges whether or not the level of the signal ES1 is equal to or less than a first level threshold L T1 (refer to fig. 4A and the like), when the level is not equal to or less than a first level threshold L T1, the judging processing unit 27B judges that the double feed is not currently generated, the process proceeds to step S104, and when the level is equal to or less than a first level threshold L T1, the process proceeds to step S106.

The control unit 27 functions as the detection processing unit 27D and the conveyance control unit 27E in step S104. The detection processing unit 27D detects that the double feed does not occur in the first feed path CP 1. At this time, the conveyance controller 27E controls the first conveyor 23 to continue the conveyance of the object a 1.

Next, in step S105, the conveyance control unit 27E determines whether or not the timing of stopping the pickup roller in the first conveyance unit 23 is reached. The stop timing is immediately after the rear end of the object a1 in the first direction D11 passes through the pickup roller. Specifically, the conveyance control unit 27E determines whether or not the stop timing is based on an output signal of an optical sensor or the like provided in the vicinity of the first upstream end CP 11. If the stop timing is the stop timing, the conveyance control unit 27E stops the pickup roller, and then ends the processing of fig. 6A to 6B to wait for the next object a1 to start conveyance. If the stop time is not the stop time, the conveyance control unit 27E returns the process to step S102.

When one second object a12 is conveyed in the first conveyance path CP1 (see fig. 4A), the processing loop configured in the order of steps S102 to S105 is repeatedly executed. At this time, the image forming unit 25 forms the image on the second object a12 being conveyed. Then, the second object a12 on which the image has been formed is discharged onto the first discharge portion 26.

The control section 27 functions as the time counting processing section 27C in step S106 to count the elapsed time from the start of execution of step S106, and then the control section 27 functions as the obtaining processing section 27A in step S107, obtains the signal ES1 from the first sensor section 24, and then the control section 27 functions as the judgment processing section 27B in step S108 to judge whether or not overlapped conveyance has occurred in the first conveyance path CP1 by judging whether or not the level of the signal ES1 is equal to or lower than the second level threshold L T2 (refer to fig. 4B to 4D), and when the level is equal to or lower than the second level threshold L T2, the judgment processing section 27B judges that one first object a11 (refer to fig. 4D) or a plurality of second objects a12 (refer to fig. 4B, 4C) is conveyed in the first conveyance path CP1, and advances the processing to step S109. when the level is not equal to or lower than the second level L T2, the judgment processing section 27B judges that the first object a is a conveyance path a, and advances the processing section 5392 to the first conveyance path 114B, and advances the processing section 5396B to step S9B.

When the processing returns to step S107, the obtaining processing section 27A obtains the signal ES1 a plurality of times at intervals of time. When the time interval is set to Δ T, Δ T is a time shorter than the first time threshold TT 1. The image forming apparatus 100 is designed to cause the obtaining processing section 27A to obtain the signal ES1 at the time interval Δ T.

The control unit 27 functions as the determination processing unit 27B, and executes steps S109 and S110 in this order. The determination processing unit 27B obtains the elapsed time from the timer processing unit 27C as the first time ET1 in step S109, and determines whether or not the first time ET1 is equal to or greater than the first time threshold TT1 in step S110, thereby determining whether or not the double feed has occurred in the first conveyance path CP 1. When the determination processing unit 27B determines that the first time ET1 is equal to or greater than the first time threshold TT1, the routine proceeds to step S111. When the first time ET1 is equal to or greater than the first time threshold TT1, the plurality of second objects a12 (see fig. 4B and 4C) are conveyed in the first conveyance path CP1, and the determination processing unit 27B determines that the double conveyance has occurred, and advances the process to step S114 in fig. 6B.

The control unit 27 functions as the timer processing unit 27C in step S111, ends the timer, and then advances the process to step S112. In step S112, the control unit 27 functions as a detection processing unit 27D, and detects that the object a1 being conveyed is one first object a11 (see fig. 4D), and the double conveyance does not occur in the first conveyance path CP 1. The controller 27 also functions as a conveyance controller 27E in step S112 to convey the first object a11 further downstream in the first direction D11. Until the conveyance control unit 27E determines in step S113 that the stop time has come, step S112 is repeatedly executed.

According to the processing of fig. 6A to 6B, in steps S105 to S110, when the first time ET1 (see fig. 6A) before the level of the signal ES1 changes from the first level threshold L T1 (see fig. 4D) to the second level threshold L T2 is equal to or greater than the predetermined first time threshold TT1 (see fig. 4D), the detection processing unit 27D detects that one first object a11 is passing through the detection position DP1 and the double feed does not occur, that is, even if the user does not set the type of the object a1 (i.e., the first object a11 or the second object a12), the control unit 27 can automatically determine that the object a1 being fed within the first feeding path CP1 is the first object a 3611. then, the processing loop constituted by steps S112 and S113 is repeatedly executed, the image forming unit 25 forms the image on the first object a11 during feeding, and the first object a11 is discharged onto the first object a 3626.

The control unit 27 functions as the determination processing unit 27B in steps S114 and S115. The determination processing portion 27B obtains the elapsed time from the timer processing portion 27C as the second time ET2 in step S114. The determination processing unit 27B determines whether or not the second time ET2 is equal to or greater than the second time threshold TT 2. When the determination processing unit 27B determines that the second time ET2 is equal to or greater than the second time threshold TT2, the process proceeds to step S116, and when the second time ET2 is equal to or greater than the second time threshold TT2, the process proceeds to step S117.

The control unit 27 functions as the conveyance control unit 27E in step S116 to continue conveying the plurality of second objects a12 in the first conveyance path CP 1.

At step S117, the control unit 27 functions as the timer processing unit 27C and ends the timer. Next, the control unit 27 functions as a detection processing unit 27D in step S118, and detects that the plurality of second objects a12 pass through the detection position DP1 (see fig. 4B and 4C) in the first conveyance path CP1 and the double conveyance is occurring. The controller 27 also functions as the conveyance controller 27E in step S114 to stop conveyance of the plurality of second objects a12 in the first direction D11. Specifically, the conveyance controller 27E controls the first conveyor 23 to convey the plurality of second objects a12 in the first conveyance path CP1 in the direction opposite to the first direction D11, and to discharge the objects from the upstream end CP11 to the first placement unit 22.

According to the processing shown in fig. 6A to 6B, it is possible to provide the determination device 27, the conveyance device 400, and the image forming apparatus 100 capable of determining whether or not the objects a1 are conveyed in an overlapping manner even when the objects a1 (the first object a11 and the second object a12) of plural types are loaded on the first placement unit 22 and the objects a1 of plural types are conveyed in sequence in the first conveyance path CP 1.

After determining in step S108 that the level of the signal ES1 is not equal to or lower than the second level threshold L T2, the control unit 27 may determine whether or not the level of each signal ES1 obtained at the time interval Δ T is equal to or higher than the second time threshold TT2 until the second time ET2 is determined in step S115 to be equal to or higher than the second time threshold TT2, as the first level threshold L T1.

When it is determined in the determination step S110 that the first time ET1 is not equal to or greater than the first time threshold TT1, the control unit 27 may execute steps S117 and S118 without executing steps S114 to S116.

In fig. 7, the image reading apparatus 300 is provided in an upper portion of the main apparatus 200. Further, image reading apparatus 300 may be a scanner or the like independent from image forming apparatus 100.

The image reading apparatus 300 includes an adf (automatic Document feeder)310, a cover 320, a contact portion 330, an image reading portion 340, and the like, optically reads an image expressed by an object a2 to be conveyed, generates image data, and outputs the image data to the control portion 27 (see fig. 1 and 5).

The ADF310 is a document feeding device, and is provided integrally with a cover 320 on the upper surface of the main body device 200. The ADF310 includes a second placing section 31, a second conveying section 32, a second sensor section 33, and a second discharging section 34. In the image forming apparatus 100, the conveyance device 400 is provided in the image reading apparatus 300, and includes at least the second conveyance unit 32, the second sensor unit 33, and the control unit 27 (see fig. 1 and 5).

Further, a second conveying path CP2 for conveying the object a2 is provided inside the ADF 310. The second transfer passage CP2 passes from the second upstream end CP21 to the second downstream end CP 22. Specifically, the second upstream end CP21 is provided in the ADF310 at a position above and near the center in the left-right direction. The second downstream end CP22 is disposed at a position below the second upstream end CP21 in the ADF 310. In the second transfer passage CP2, the upstream portion is leftward from the second upstream end CP21, and the intermediate portion thereof is bent downward between the upstream portion and the downstream side portion of the second transfer passage CP 2. The downstream side portion is directed obliquely upward to the right from the intermediate portion to a second downstream end CP 22.

The second placing section 31 is a supply tray, and is provided in the upper right portion of the image reading apparatus 300. The second placement unit 31 can be loaded with a plurality of types of objects a 2. The multiple object a2 includes a first object a21 and a second object a 22. The first object a21 is different from the first object a11 only in that it is an envelope in which the addressee name is recorded. The second object a22 differs from the second object a12 only in the paper or film on which images and the like are recorded. Therefore, in the following, in the first object a21 and the second object a22, portions corresponding to the first object a11 and the second object a12 are given the same reference numerals, and the respective descriptions thereof are omitted, and fig. 2A and fig. 3 are referred to. As shown in fig. 7, the first object a21 is placed on the second placing portion 31 with the closing portion B14 along the upstream end CP 21.

The second conveying unit 32 includes a pickup roller and a conveying roller pair, feeds the object a2 from the second upstream end CP21 into the second conveying path CP2, and conveys the object a2 in the third direction D21 at a predetermined speed V2 in the second conveying path CP2 by the object a 2. The third direction D21 is a downstream side direction of the second transporting path CP2, and is a second example of a specific direction in the present invention.

The second sensor unit 33 is a second example of the sensor unit of the present invention, and is a transmission type ultrasonic sensor. The second sensor unit 33 includes a transmitting unit 331 and a receiving unit 332 facing each other with a predetermined detection position DP2 interposed therebetween. The detection position DP2 is a position on the second conveyance path CP2 immediately downstream of the second conveyance section 32. The second sensor portion 33 can emit a measurement wave having a predetermined amplitude level from the transmission portion 331 to the detection position DP 2. The second sensor unit 33 outputs a signal ES2 based on the measurement wave to the control unit 27 from the receiving unit 332. The level of the signal ES2 is related to the type and number of objects a2 passing through the detection position DP2 (see fig. 4A to 4D).

The second discharge portion 34 is a sheet discharge tray, and is disposed on the right side of the second downstream end CP 22. The second discharge portion 34 can carry the object a2 discharged from the second downstream end CP 22.

The contact portion 330 is a plate-like member having light permeability, such as a glass plate or a resin plate. The contact portion 330 is provided on the upper surface of the main body device 200 at a position closer to the left end. The contact portion 330 is attached to the upper surface of the main body device 200 along the lowermost portion in the second conveyance path CP 2. The contact portion 330 is preset with a reading region R1. The object a2 conveyed in the second conveyance path CP2 passes over the reading region R1.

The Image reading unit 340 is a cis (contact Image sensor). The image reading unit 340 is provided inside the main body device 200 at a position close to the upper surface. Further, the image reading unit 340 transmits light to the reading region R1 from a position below the contact portion 330. The image sensor 340 photoelectrically converts the reflected light from the object a2 passing through the reading region R1 to generate image data representing an image of the object a2, and outputs the image data to the controller 27.

The obtaining processing unit 27A may obtain the signal ES2 from the second sensor unit 33 instead of the first sensor unit 24. At this time, the determination processing unit 27B and the time measurement processing unit 27C execute the processing shown in fig. 6A to 6B based on the signal ES2 instead of the signal ES 1. The detection processing unit 27D detects whether or not the object a2 in the second conveyance path CP2 is overlapped with another object, based on the determination result of the determination processing unit 27B. The conveyance control unit 27E controls conveyance of the object a2 by the second conveyance unit 32 based on the detection result of the detection processing unit 27D.

The scope of the present invention is not limited to the above description, but is defined by the claims, and therefore, the embodiments described in the present specification are to be considered as illustrative and not restrictive. Therefore, all changes that do not depart from the scope and boundary of the claims and that are equivalent to the scope and boundary of the claims are intended to be embraced therein.

Claims (11)

1. A judging apparatus, comprising:

an acquisition processing unit that acquires a signal based on an ultrasonic wave emitted to an object conveyed in a specific direction; and

and a determination processing unit configured to determine whether or not a first time during which a level of the signal changes from a first level threshold that is set in advance to a second level threshold that is smaller than the first level threshold is equal to or greater than a first time threshold that is set in advance.

2. The judgment device according to claim 1,

the first time threshold is set based on a speed at which the object is conveyed in the specific direction and a distance from an end of the object on the specific direction side in a direction opposite to the specific direction.

3. The judgment device according to claim 1 or 2,

the first level threshold and the second level threshold are set according to a thickness of the object in a crossing direction crossing the specific direction.

4. The judgment device according to claim 1 or 2,

when the determination processing unit determines that the first time is not equal to or greater than the first time threshold, it further determines whether or not a second time during which the level of the signal is equal to or less than the first level threshold is equal to or greater than a second time threshold that is longer than the first time threshold.

5. The judgment device according to claim 4,

the second time threshold is preset in accordance with a speed at which the object is conveyed in the specific direction and a length of the object in the specific direction.

6. A conveyor apparatus, comprising:

a sensor unit that emits an ultrasonic wave to the object and outputs the signal whose level changes in accordance with an incident wave from the object; and

the judgment device according to claim 1 or 2.

7. The delivery device of claim 6,

the apparatus further includes a detection processing unit that detects whether or not the object is conveyed in an overlapping manner based on the determination result obtained by the determination device.

8. The delivery device of claim 7,

the detection processing unit detects that the overlapped feeding is not performed when the determination processing unit determines that the first time is equal to or longer than the first time threshold,

the transport device further includes a transport control unit that transports the object further downstream in the specific direction when the detection is made that the overlapped transport is not performed.

9. The delivery device of claim 8,

the detection processing unit detects the presence of the double feed when the determination processing unit determines that the first time is not equal to or greater than the first time threshold,

when the presence of the overlapped conveyance is detected, the conveyance control unit may stop the conveyance of the object in the specific direction.

10. An image reading apparatus is characterized in that,

comprising a determination device according to claim 1 or a delivery device according to claim 6.

11. An image forming apparatus is characterized in that,

comprising a determination device according to claim 1 or a delivery device according to claim 6.

Images