JP2019131396A - Image formation device, error detection method, and error detection program - Google Patents

Abstract

To detect an error without adding sensors.SOLUTION: An MFP includes: a pickup roller 215 that is attachable to and detachable from a sub drive shaft 213; an upper limit sensor 303; a tray sensor 301; and a CPU that determines that the pickup roller 215 is not attached to the sub drive shaft 213 when there occurs a combination different from a combination of a first output value of the upper limit sensor 303 and a second output value of the tray sensor 301, which is generated in the condition where the pickup roller 215 is attached to the sub drive shaft 213.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus, an error detection method, and an error detection program, and more particularly to an image forming apparatus that forms an image on a recording medium such as paper, an error detection method and an error detection program executed by the image forming apparatus.

  In recent years, an image forming apparatus typified by a multi-function peripheral has a mechanism for taking out a sheet one by one from a paper feed tray in which a plurality of sheets are accumulated and transporting it in order to form an image on a recording medium such as a sheet. I have. Specifically, a cylindrical pickup roller is pressed onto the top of a plurality of sheets stored in a paper feed tray from above, and the pickup roller is rotated to take out the top sheet of the plurality of sheets. It has a mechanism. In this case, the frictional force between the pickup roller and the sheet is required to be larger than the frictional force between the uppermost sheet and the overlapping sheet. For this reason, when the pickup roller is worn out and the frictional force with the paper is reduced, it is necessary to replace the pickup roller. However, when replacing the pickup roller, the user may forget to attach a new pickup roller after removing the pickup roller.

  In order to solve this problem, Japanese Patent Laid-Open No. 2007-22762 discloses that a paper feed roller that feeds a recording paper placed on a paper feed unit from the paper feed unit is detachable from a paper feed rotation drive shaft. The mounted paper feeding device is provided with paper feed roller presence / absence detection means for detecting the presence / absence of the paper feed roller, and the paper feed roller presence / absence detection means is provided by an existing sensor means having a detection function for other members. An image forming apparatus having a combined configuration is described.

However, in the image forming apparatus described in Japanese Patent Application Laid-Open No. 2007-22762, since the existing sensor unit combines the detection of the presence / absence of a paper feed roller and the detection of the presence / absence of another member, There is a problem that it cannot be determined which of the other members does not exist.
JP 2007-22762 A

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide an image forming apparatus capable of detecting an error without adding a sensor.

  Another object of the present invention is to provide an error detection method capable of detecting an error without adding a sensor.

  Still another object of the present invention is to provide an error detection program capable of detecting an error without adding a sensor.

  In order to achieve the above-described object, according to one aspect of the present invention, an image forming apparatus includes a roller detachably attached to a rotating shaft, a first sensor, a second sensor, and a roller attached to the rotating shaft. When a combination different from the combination of the first output value of the first sensor and the second output value of the second sensor that occurs in the state is generated, it is determined that no roller is mounted on the rotating shaft. Error detection means.

  According to this aspect, since it is detected from the combination of the first output value of the first sensor and the second output value of the second sensor that the roller is not mounted on the rotating shaft, a plurality of events It is possible to detect an event different from the plurality of events by using a combination of outputs of the plurality of sensors for detecting each of the plurality of sensors. Accordingly, it is possible to provide an image forming apparatus capable of detecting a larger number of events than the number of sensors. As a result, it is possible to provide an image forming apparatus capable of detecting an error without adding a sensor.

  Preferably, the first sensor is turned on when a tangible object is present in a predetermined detection area, is turned off when a tangible object is not present in the detection area, and is fed to store paper conveyed by a roller. A tray and a moving member located at a second position different from the first position in the detection region at least in a detection period in which the second sensor is on with the roller mounted on the rotation shaft; And a fixing means for fixing the moving member to the first position when no roller is mounted on the rotating shaft, and the second sensor is turned on when the paper feed tray is at a predetermined position. And is turned off when the paper feed tray is not in a predetermined position.

  According to this aspect, during the detection period, the moving member is positioned at the second position when the roller is mounted on the rotating shaft, but is positioned at the first position when the roller is not mounted on the rotating shaft. Fixed. For this reason, in a state where no roller is mounted on the rotating shaft, a combination of the second sensor being on and the first sensor being on occurs during the detection period. In a state where the roller is mounted on the rotating shaft, a combination in which the second sensor is on and the first sensor is off occurs during the detection period. However, the second sensor is on and the first sensor is on. Does not occur. Therefore, it is possible to detect a state in which no roller is mounted on the rotation shaft during the detection period.

  According to another aspect of the present invention, the image forming apparatus is turned on when a tangible object is present in a predetermined detection area and a roller detachable from the rotation shaft, and when there is no tangible object in the detection area. A first sensor that is turned off, a moving member that is located at a second position different from the first position in the detection area, and is rotated during a predetermined detection period with the roller mounted on the rotation shaft When the roller is not mounted on the shaft and the first sensor is turned on during the detection period and the fixing means for fixing the moving member to the first position, it is determined that the roller is not mounted on the rotating shaft. Error detection means.

  According to this aspect, during the detection period, the moving member is positioned at the second position when the roller is mounted on the rotating shaft, but is positioned at the first position when the roller is not mounted on the rotating shaft. Fixed. For this reason, during the detection period, the first sensor can detect an event in which a roller is mounted on the rotating shaft and an event in which no roller is mounted on the rotating shaft. As a result, it is possible to provide an image forming apparatus capable of detecting an error without adding a sensor.

  Preferably, the fixing means includes a fixing member disposed so as to be movable along the rotation axis between the moving member and the roller, and an elastic member that urges the fixing member in a direction away from the moving member. The member pivotally supports the rotating shaft, and the fixed member is coupled to the main body case when the roller is not mounted on the rotating shaft, and is not coupled to the main body case when the roller is mounted on the rotating shaft.

  According to this aspect, in a state where the rotation shaft is not attached to the roller, the fixing member is urged by the elastic member to move away from the moving member, and is coupled to the main body case. Thereby, the fixing member fixes the rotating shaft to the main body case, and the moving member that supports the rotating shaft is fixed to the main body case. As a result, the moving member is fixed at the first position. Further, since the fixing member is not coupled to the main body case in a state where the rotating shaft is mounted on the roller, the moving member is not fixed at the first position. Therefore, the moving member can be fixed at the first position when no roller is mounted on the rotating shaft, and the moving member is prevented from being fixed at the first position when the roller is mounted on the rotating shaft. be able to.

  Preferably, the fixing means includes a fixing member that is movably disposed between the moving member and the roller along the rotation axis, and an elastic member that urges the fixing member in a direction away from the moving member. The member contacts the moving member in a state where the roller is not mounted on the rotating shaft and fixes the moving member in the first position, and does not contact the moving member in a state where the roller is mounted on the rotating shaft.

  According to this aspect, the fixing member is urged by the elastic member to move away from the moving member in a state where the roller is not attached to the rotating shaft, and contacts the moving member to move the moving member to the first position. Secure to. Further, since the fixed member is not in contact with the moving member in a state where the roller is mounted on the rotating shaft, the moving member is not fixed at the first position. Therefore, the moving member can be fixed at the first position in a state where the roller is not mounted on the rotating shaft, and the moving member is not fixed at the first position when the roller is mounted on the rotating shaft. can do.

  Preferably, the first sensor is turned on when a tangible object is present in a predetermined detection area, is turned off when a tangible object is not present in the detection area, and is fed to store paper conveyed by a roller. In a state where the tray, the moving member located at the second position different from the first position in the detection area, and the roller are not attached to the rotation shaft at least in the detection period when the second sensor is on. And a counterfeiting means for controlling the first sensor to be turned on. The second sensor is turned on when the paper feed tray is in a predetermined position, and the paper feed tray is not in the predetermined position. Sometimes off.

  According to this aspect, since the moving member is located at the second position during the detection period, a combination in which the second sensor is on and the first sensor is off occurs, but a roller is mounted on the rotating shaft. In this state, the first sensor is assumed to be turned on, so that a combination of turning on the second sensor and turning on the first sensor occurs during the detection period. Therefore, it is possible to detect a state in which no roller is mounted on the rotation shaft.

  According to still another aspect of the present invention, the image forming apparatus is turned on when a tangible object is present in a predetermined detection area and a roller detachable from the rotation shaft, and there is no tangible object in the detection area. And a moving member located at a second position different from the first position in the detection area during a predetermined detection period with the roller mounted on the rotation shaft. If the first sensor is turned on during the detection period, and a fake means for controlling the first sensor to be turned on when no roller is attached to the rotating shaft, the roller is not attached to the rotating shaft. Error detection means for determining.

  According to this aspect, since the moving member is located at the second position in the detection period, the first sensor is turned off, but the first sensor is not mounted on the rotating shaft. Since it is assumed to be turned on, the first sensor is turned on during the detection period. Therefore, it is possible to detect a state in which no roller is mounted on the rotation shaft. As a result, it is possible to provide an image forming apparatus capable of detecting an error without adding a sensor.

  Preferably, the pseudo control means includes a pseudo control member, a part of which is disposed between the moving member and the roller, and the pseudo control member is in a restricted state in which the position of the rotary shaft is fixed with the roller mounted on the rotary shaft. Thus, when the roller is not attached to the rotation shaft, the position relative to the rotation shaft is not fixed, and the pseudo-control member is separated from the detection region of the first sensor in the restricted state, and at least a part of the pseudo control member is in the idle state. It is located within the detection area of the first sensor.

  According to this aspect, the pseudo control member is separated from the detection region in a state where the roller is attached to the rotation shaft, and a part thereof is located in the detection region in a state where the roller is not attached to the rotation shaft. The sensor is turned on. For this reason, the first sensor can be turned on even when the moving member is positioned at the second position in a state where the roller is mounted on the rotation shaft during the detection period.

  Preferably, the information processing apparatus further includes notification means for notifying a user when it is determined that no roller is attached to the rotation shaft.

  According to this aspect, the user can be notified that the roller is not attached to the rotating shaft.

  Preferably, the first sensor further includes monitoring means for detecting that the roller is mounted on the rotating shaft when the detection period is off and the detection value is on after the detection period elapses.

  According to this aspect, since it is detected that the roller is mounted on the rotating shaft, an image can be formed with the roller mounted on the rotating shaft.

  According to still another aspect of the present invention, the error detection method is an error detection method executed in the image forming apparatus, and the image forming apparatus includes a roller detachable from the rotation shaft, a first sensor, A combination different from the combination of the first output value of the first sensor and the second output value of the second sensor generated in a state where the roller is mounted on the rotation shaft. If it occurs, the image forming apparatus is caused to execute an error detection step for determining that the roller is not attached to the rotating shaft.

  If this aspect is followed, the error detection method which can detect an error, without adding a sensor can be provided.

  According to still another aspect of the present invention, the error detection program is an error detection program executed by a computer that controls the image forming apparatus. The image forming apparatus includes a roller detachably attached to the rotation shaft, A first output value of the first sensor and a second output value of the second sensor generated in a state where the roller is mounted on the rotation shaft. When a combination different from the above occurs, the computer is caused to execute an error detection step for determining that the roller is not mounted on the rotating shaft.

  According to this aspect, it is possible to provide an error detection program capable of detecting an error without adding a sensor.

1 is a front view of an MFP according to one embodiment of the present invention. 2 is a block diagram illustrating an outline of a hardware configuration of an MFP. FIG. It is a top view of the paper feed tray in the open state. It is a top view of the paper feed tray in the closed state. It is a perspective view which shows an example of a pick-up mechanism. FIG. 6 is a first front view of the pickup mechanism of FIG. 5 as viewed in the direction of arrow K. FIG. 6 is a second front view of the pickup mechanism of FIG. 5 as viewed in the direction of arrow K. FIG. 6 is a third front view of the pickup mechanism of FIG. 5 as viewed in the direction of arrow K. FIG. 6 is a fourth front view of the pickup mechanism of FIG. 5 as viewed along the direction of arrow K. It is a perspective view of the pickup mechanism in a state where the pickup roller is removed. It is a figure for demonstrating a paper detection mechanism. It is a flowchart which shows an example of the flow of an error detection process. It is a first perspective view showing an example of a pickup mechanism and a paper detection mechanism in a modified example. It is a 2nd perspective view which shows an example of the pick-up mechanism in a modification, and a paper detection mechanism. It is a flowchart which shows an example of the flow of the error detection process in a modification. It is a 1st perspective view which shows an example of the pick-up mechanism and paper detection mechanism in 2nd Embodiment. It is a 2nd perspective view which shows an example of the pick-up mechanism and paper detection mechanism in 2nd Embodiment. It is a right side view showing an example of a pickup mechanism and a paper detection mechanism in a second modification. FIG. 19 is a first front view of the pickup mechanism of FIG. 18 as viewed along the direction of arrow K. It is the 2nd front view which looked at the pickup mechanism of FIG. 18 along the direction of the arrow K. It is a 1st figure which shows the relationship between the fixing | fixed part of a pseudo control part and a link member. It is a 2nd figure which shows the relationship between the fixing | fixed part of a pseudo control part and a link member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a front view of an MFP according to one embodiment of the present invention. FIG. 2 is a block diagram showing an outline of the hardware configuration of the MFP. 1 and 2, MFP 100 includes a main circuit 110, a document reading unit 130 for reading a document, an automatic document conveying device 120 for conveying a document to document reading unit 130, and a document reading unit. An image is formed by an image forming unit 140 for forming an image on a sheet or the like based on image data output by the manuscript 130 reading and outputting a document, a paper feeding unit 150 for supplying the image to the image forming unit 140, and an image. A post-processing unit 155 that processes paper and an operation panel 160 as a user interface are included.

  The automatic document feeder 120 automatically conveys a plurality of documents set on the document tray one by one to a predetermined document reading position set on the platen glass of the document reading unit 130, and the document reading unit 130. Thus, the document on which the image formed on the document is read is discharged to the document discharge tray. The document reading unit 130 includes a light source that irradiates light to the document conveyed to the document reading position and a photoelectric conversion element that receives light reflected from the document, and scans a document image corresponding to the size of the document. The photoelectric conversion element converts the received light into image data, which is an electrical signal, and stores it in the HDD 115.

  The paper feed unit 150 includes an upper paper feed tray 151 and a lower paper feed tray 152. Each of the paper feed trays 151 and 152 can store a plurality of sheets. Each of the paper feed trays 151 and 152 can be pulled out from the front of the MFP 100 in order to supply paper by the user. Hereinafter, the state in which the paper feed trays 151 and 152 are pulled out is referred to as an open state, and the state before being pulled out is referred to as a closed state. Each of the paper feed trays 151 and 152 is a cube whose upper side is open, and in an open state, the user can supply a sheet bundle of a plurality of sheets from the upper side. The sheet feeding unit 150 conveys a plurality of sheets stored in one of the sheet feeding trays 151 and 152 to the image forming unit 140 one by one. The image forming unit 140 forms an image by a known electrophotographic method, forms an image on a sheet conveyed by the sheet feeding unit 150 based on the image data, and discharges the sheet on which the image is formed. Discharge to the tray.

  The post-processing unit 155 executes a sorting process for sorting and discharging one or more sheets on which images are formed by the image forming unit 140, a punching process for punch hole processing, and a staple process for driving staple needles.

  The main circuit 110 includes a central processing unit (CPU) 111, a communication interface (I / F) unit 112, a ROM (Read Only Memory) 113, and a RAM (Random Access Memory) 114 used as a work area of the CPU 111. , A hard disk drive (HDD) 115 as a mass storage device, a facsimile unit 116, and an external storage device 117 on which a CD-ROM (Compact Disk ROM) 118 is mounted. CPU 111 is connected to automatic document feeder 120, document reading unit 130, image forming unit 140, paper feeding unit 150, post-processing unit 155, and operation panel 160, and controls the entire MFP 100.

  The ROM 113 stores a program executed by the CPU 111 or data necessary for executing the program. The RAM 114 is used as a work area when the CPU 111 executes a program. Further, the RAM 114 temporarily stores read data (image data) continuously sent from the document reading unit 130.

  Communication I / F unit 112 is an interface for connecting MFP 100 to a network. The CPU 111 communicates with other computers connected to the network via the communication I / F unit 112 to transmit and receive data. The network is, for example but not limited to, a local area network. Further, when the network is connected to the Internet, the communication I / F unit 112 can communicate with a computer connected to the Internet via the network.

  The facsimile unit 116 is connected to the public switched telephone network (PSTN) and transmits facsimile data to the PSTN or receives facsimile data from the PSTN. The facsimile unit 116 stores the received facsimile data in the HDD 115 or outputs it to the image forming unit 140. The image forming unit 140 prints the facsimile data received by the facsimile unit 116 on a sheet. Further, the facsimile unit 116 converts the data stored in the HDD 115 into facsimile data, and transmits the facsimile data to a facsimile machine connected to the PSTN.

  The external storage device 117 is loaded with a CD-ROM 118. The CPU 111 can access the CD-ROM 118 via the external storage device 117. The CPU 111 loads the program recorded on the CD-ROM 118 attached to the external storage device 117 to the RAM 114 and executes it. The medium for storing the program executed by the CPU 111 is not limited to the CD-ROM 118, but an optical disc (MO (Magnetic Optical Disc) / MD (Mini Disc) / DVD (Digital Versatile Disc)), IC card, optical card, It may be a semiconductor memory such as a mask ROM or an EPROM (Erasable Programmable ROM).

  Further, the program executed by the CPU 111 is not limited to the program recorded on the CD-ROM 118, and the program stored in the HDD 115 may be loaded into the RAM 114 and executed. In this case, another computer connected to the network may rewrite the program stored in HDD 115 of MFP 100 or may add a new program and write it. Further, MFP 100 may download a program from another computer connected to the network and store the program in HDD 115. The program here includes not only a program directly executable by the CPU 111 but also a source program, a compressed program, an encrypted program, and the like.

  Operation panel 160 is provided on the upper surface of MFP 100 and includes a display unit 161 and an operation unit 163. The display unit 161 is, for example, a liquid crystal display (LCD) or an organic EL (electroluminescence) display, and displays an instruction menu for a user, information about acquired image data, and the like. The operation unit 163 includes a touch panel 165 and a hard key unit 167. The touch panel 165 is provided to overlap the display unit 161 on the upper surface or the lower surface of the display unit 161. Hard key portion 167 includes a plurality of hard keys. The hard key is, for example, a contact switch. The touch panel 165 detects a position designated by the user on the display surface of the display unit 161. When the user operates the MFP 100, the user often takes an upright posture, and thus the display surface of the display unit 161, the operation surface of the touch panel 165, and the hard key unit 167 are arranged facing upward. This is because the user can easily visually recognize the display surface of the display unit 161 and the user can easily instruct the operation unit 163 with a finger.

  Next, the paper feeding unit 150 will be described in detail. The paper feed unit 150 includes an upper paper feed tray 151 and a lower paper feed tray 152. Since the configuration of the paper feed trays 151 and 152 is the same, here, the paper feed tray 151 will be described as an example. Hereinafter, for the sake of explanation, the front side of MFP 100 is referred to as the front side, the back side as the rear side, the right side surface as the right side, and the left side surface as the left side.

  FIG. 3 is a plan view of the paper feed tray in the opened state. FIG. 4 is a plan view of the paper feed tray in the closed state. Referring to FIGS. 3 and 4, paper feed tray 151 is arranged on a pair of left and right rails 201 </ b> A and 201 </ b> B provided in the main body case of MFP 100 in parallel in the front-rear direction. Therefore, the paper feed tray 151 can be moved back and forth with respect to the main body case of the MFP 100 along the rails 201A and 201B.

  The paper feed tray 151 includes an elevating plate 207 on which a bundle of sheets on which a plurality of sheets are stacked is placed, a pair of pressing plates 205A and 205B on the front and back, and a pair of pressing plates 203A and 203B on the left and right. The pressing plate 203B also serves as the side wall of the paper feed tray 151. The pressing plates 205A and 205B and the pressing plates 203A and 203B are in contact with the four side surfaces of the sheet bundle, and align a plurality of sheets. Further, the interval between the press plates 205A and 205B and the interval between the press plates 203A and 203B can be changed. For this reason, the paper feed tray 151 is set to one of a plurality of sizes by setting the distance between the press plates 205A and 205B and the distance between the press plates 203A and 203B in accordance with the size of the stored paper. Can be stored.

  The paper feed tray 151 has a back protrusion 209 that protrudes from the back. A tray sensor 301 that functions as a second sensor is installed in the main body case of the MFP 100, and the rear protrusion 209 is positioned within the detection area of the tray sensor 301 when the paper feed tray 151 is closed. It is disposed on the back surface of the paper feed tray 151. The tray sensor 301 is arranged in the main body case so that the rear protrusion 209 is located outside the detection area when the paper feed tray 151 is open. The tray sensor 301 is, for example, a photoelectric sensor including a light projecting unit that emits light and a light receiving unit that receives light. The light receiving unit converts the received light into an electrical signal and outputs it to the CPU 111. Specifically, the tray sensor 301 outputs a signal indicating OFF to the CPU 111 while the light receiving unit receives the light emitted from the light projecting unit, and the light receiving unit receives the light emitted from the light emitting unit. While it is not, a signal indicating ON is output to the CPU 111.

  When the back projection 209 does not exist in the detection region of the tray sensor 301, the light emitted from the light projecting unit is received by the light receiving unit, but when the back projection 209 exists in the detection region of the tray sensor 301. Since the light emitted from the light projecting unit is blocked by the rear projection 209, the light receiving unit does not receive light. Therefore, the tray sensor 301 is turned on when the rear protrusion 209 is present in the detection area, and is turned off when the rear protrusion 209 is not present in the detection area. For this reason, the CPU 111 detects that the paper feed tray 151 is closed while the signal indicating ON is input from the tray sensor 301, and while the signal indicating OFF is input from the tray sensor 301. It is detected that the paper feed tray 151 is open.

  FIG. 5 is a perspective view showing an example of a pickup mechanism. Referring to FIG. 5, the pickup mechanism 210 includes a main drive shaft 217 that is pivotally supported by the main body case, a bearing base 211 that is rotatably attached to the main drive shaft 217, and a supply that is attached to the main drive shaft 217. A paper roller 219, a sub drive shaft 213 pivotally supported by the bearing base 211, a pickup roller 215 attached to the sub drive shaft 213, an elastic member 231, a fixing member 233, and a support shaft 221 attached to the main body case. And a pick lever 223 that is rotatably attached to the support shaft 221.

  The main drive shaft 217 is supported by the body case and is rotated by a motor (not shown). The paper feed roller 219 can be attached to and detached from the main drive shaft 217. When the paper feed roller 219 is attached to the main drive shaft 217, the paper feed roller 219 is attached to the main drive shaft 217 while being fixed in its rotational direction. For this reason, when the paper feed roller 219 is mounted on the main drive shaft 217, it rotates with the main drive shaft 217 as the rotation axis as the main drive shaft 217 rotates. The bearing stand 211 functions as a moving member and is positioned and attached to a predetermined position in the axial direction of the main drive shaft 217 while being rotatable on the main drive shaft 217. The bearing stand 211 pivotally supports the sub drive shaft 213 at a position parallel to the main drive shaft 217. The amount of rotation by which the bearing stand 211 can rotate around the main drive shaft 217 is limited by a stopper attached to the main body case based on the height of the sub drive shaft 213. Therefore, the bearing stand 211 can rotate around the main drive shaft 217 between an upper limit position where the sub drive shaft 213 is highest and a lower limit position where the sub drive shaft 213 is lowest. FIG. 5 shows a case where the bearing stand 211 is located at the upper limit position.

  The main drive shaft 217 and the sub drive shaft 213 are coupled by a gear, and when the main drive shaft 217 is rotated by a motor, the sub drive shaft 213 is rotated. The gears are set so that the rotation direction and the rotation amount of the main drive shaft 217 and the sub drive shaft 213 are the same. The pickup roller 215 can be attached to and detached from the sub drive shaft 213. When the pickup roller 215 is attached to the sub drive shaft 213, the pickup roller 215 is attached to the sub drive shaft 213 while being fixed in the rotation direction. For this reason, when the pickup roller 215 is mounted on the sub drive shaft 213, the pickup roller 215 rotates around the sub drive shaft 213 as the rotation shaft as the sub drive shaft 213 rotates.

  FIG. 6 is a first front view of the pickup mechanism of FIG. 5 as viewed along the direction of arrow K. FIG. 5 shows the pickup mechanism when the bearing stand 211 is located at the upper limit position. FIG. 7 is a second front view of the pickup mechanism of FIG. 5 as viewed along the direction of arrow K. FIG. 7 shows the pickup mechanism when the bearing stand 211 is located at the lower limit position. When the bearing stand 211 is at the upper limit position, the sub drive shaft 213 is preferably at the same height as the main drive shaft 217. The bearing stand 211 is biased by a spring so as to rotate in the direction of moving from the upper limit position to the lower limit position. For this reason, the bearing stand 211 moves to the lower limit position in a state where no force is received from the outside. When the bearing stand 211 is at the upper limit position, a part of the bearing stand 211 is located within the detection region of the upper limit sensor 303, and when the bearing stand 211 is at the lower limit position, a part of the bearing stand 211 is detected by the upper limit sensor 303. Located outside the area. For this reason, the upper limit position is the first position, and the lower limit position is the second position.

  Returning to FIG. 5, the pick lever 223 is rotatably attached to the support shaft 221. The support shaft 221 is positioned so that the first end 223A of the pick lever 223 is positioned below the end 211A of the bearing base 211.

  The pick lever 223 is biased by a spring so that the first end 223A rotates in a direction in which the first end 223A moves upward. The second end 223B opposite to the first end 223A of the pick lever 223 comes into contact with the side wall on the back surface of the paper feed tray 151 in the process of the paper feed tray 151 transitioning from the open state to the closed state. The end 223B is pushed upward. As a result, the pick lever 223 rotates around the support shaft 221 and the first end 223A moves downward. When the paper feed tray 151 is in the released state, the second end 223B does not come into contact with the rear side wall of the paper feed tray 151, so the pick lever 223 is biased by a spring and the first end 223A moves upward. Rotate to.

  Therefore, when the paper feed tray 151 is open, the pick lever 223 rotates around the support shaft 221 in the direction in which the first end 223A of the pick lever 223 moves upward. The force that urges the pick lever 223 to rotate in the direction in which the first end 223A moves upward is set larger than the force that urges the bearing base 211 in the direction to move from the upper limit position to the lower limit position. Yes. Therefore, as the pick lever 223 rotates, the first end 223A comes into contact with the end 211A of the bearing base 211, pushes the end 211A upward, and the bearing base 211 moves from the lower limit position to the upper limit position. To reach the upper limit position.

  Since the second end 223B of the pick lever 223 is pushed up during the transition of the paper feed tray 151 from the open state to the closed state, the first end 223A moves downward. As a result, the bearing base 211 does not receive the force from the pick lever 223, so the bearing base 211 rotates in the direction of moving from the upper limit position to the lower limit position and reaches the lower limit position.

  The upper limit sensor 303 functions as a first sensor, and when the bearing stand 211 is located at the upper limit position, the upper limit sensor 303 is positioned and arranged in the main body case so that a part of the bearing stand 211 is located within the detection region. Yes. The upper limit sensor 303 is, for example, a photoelectric sensor.

  FIG. 8 is a third front view of the pickup mechanism of FIG. 5 as viewed in the direction of the arrow K. FIG. 8 also shows a cross-sectional view of the separating roller 243 and the paper feed tray 151 immediately after the paper feed tray 151 shifts from the open state to the closed state. Referring to FIG. 8, as described above, immediately after the paper feed tray 151 shifts from the open state to the closed state, the bearing stand 211 is in the lower limit position. The roller 243 is rotatably attached to a rotation shaft 241 that is supported by the main body case in parallel with the main drive shaft 217. The roller 243 can be attached to and detached from the rotating shaft 241. Immediately after the paper feed tray 151 shifts from the open state to the closed state, the paper feed roller 219 is in contact with the separating roller 243.

  Further, the lifting plate 207 of the paper feed tray 151 is at the lowest point. When detecting that the tray sensor 301 is turned on, the CPU 111 detects the closed state of the paper feed tray 151. The CPU 111 raises the elevating plate 207 in response to detecting the closed state of the paper feed tray 151. As a result, the sheet bundle 200 rises and the uppermost part of the sheet bundle 200 comes into contact with the pickup roller 215. The force by which the elevating plate 207 is raised is greater than the force urged by the bearing base 211. Therefore, when the elevating plate 207 is further raised, the sheet bundle 200 pushes the bearing base 211 upward. When the CPU 111 detects that the bearing base 211 has reached the upper limit position by turning on the upper limit sensor 303, the CPU 111 stops the lifting of the lifting plate 207.

  In this way, the CPU 111 determines that the paper feed tray 151 has transitioned from the open state to the closed state in a state where the tray sensor 301 is turned on from the off state, raises the lifting plate 207, and then the upper limit sensor 303 When turned on, it is determined that the sheet can be conveyed. Therefore, the upper limit sensor 303 is not turned on immediately after the tray sensor 301 is turned on from off.

  FIG. 9 is a fourth front view of the pickup mechanism of FIG. 5 as viewed in the direction of the arrow K. FIG. 9 also shows a sectional view of the separating roller 243 and the paper feed tray 151 when the upper limit sensor 303 is turned on. When the sheet feeding roller 219 and the pickup roller 215 are rotated in a state where the bearing stand 211 has reached the upper limit position, the uppermost sheet of the sheet bundle 200 is moved by friction with the pickup roller 215 and directed toward the sheet feeding roller 219. Are transported. The whirling roller 243 rotates together with the paper feeding roller 219 by the frictional force with the paper feeding roller 219 while in contact with the paper feeding roller 219. The whirling roller 243 is rotatably attached to the rotating shaft 241, and is set so that a predetermined frictional force is generated between the whirling roller 243 and the rotating shaft 241. For this reason, the roller 243 rotates when a predetermined force is applied, but does not rotate with an external force smaller than the predetermined force.

  When the uppermost sheet of the sheet bundle is conveyed by the pickup roller 215, the sheet overlapping the uppermost sheet may be conveyed together with the uppermost sheet by a frictional force generated between the uppermost sheet and the uppermost sheet. When two or more sheets arrive between the sheet feeding roller 219 and the separating roller 243, the sheet overlapping the uppermost sheet has a frictional force generated between the uppermost sheet and the separating roller 243. Friction force generated between them is received. Here, the frictional force generated between the paper overlapping the uppermost paper and the roller 243 is larger than the frictional force generated between the paper overlapping the uppermost paper and the uppermost paper. A frictional force generated between the rolling roller 243 and the rotating shaft 241 is set. For this reason, since the separating roller 243 does not rotate, the sheet overlapping the uppermost sheet is stopped, and only the uppermost sheet is conveyed by the sheet feeding roller 219. As described above, when the pick-up roller 215 conveys two or more sheets overlapped with each other, the separation roller 243 prevents the sheet overlapping below the uppermost sheet from being conveyed.

  As the sheets are conveyed sequentially from the top of the sheet bundle 200, the height of the sheet bundle 200 decreases. Accordingly, since the bearing stand 211 moves toward the lower limit position, the upper limit sensor 303 is turned off, and the CPU 111 raises the lifting plate 207. As described above, when the upper limit sensor 303 is turned off, the CPU 111 raises the lifting plate 207 until the upper limit sensor 303 is turned on or until a predetermined time elapses after the upper limit sensor 303 is turned on. Thereby, the pickup roller 215 can be in a state in which the paper can be conveyed.

  Returning to FIG. 5, the pickup roller 215 can be attached to and detached from the sub drive shaft 213. An elastic member 231 and a fixing member 233 are disposed between the pickup roller 215 and the bearing base 211. Here, the elastic member 231 uses a spring. The fixing member 233 has a hole through which the sub drive shaft 213 passes, and is movable along the sub drive shaft 213. Further, the fixing member 233 has a restricting portion 233B that extends to above the bearing base 211 so as not to rotate around the sub drive shaft 213. The elastic member 231 is disposed between the bearing base 211 and the fixing member 233 and biases the fixing member 233 in a direction away from the bearing base 211. In a state where the pickup roller 215 is mounted on the sub drive shaft 213, the elastic member 231 is elastically deformed, and the fixing member 233 is positioned away from the bearing base 211 by a predetermined distance.

  FIG. 10 is a perspective view of the pickup mechanism with the pickup roller 215 removed. When the pickup roller 215 is removed from the sub drive shaft 213, the fixing member 233 moves away from the bearing base 211 by the elastic force of the elastic member 231, and the end 233A of the fixing member 233 is provided in the main body case. Coupled with the locking portion 235.

  For this reason, even if the first end portion 223A of the pick lever 223 moves downward after the paper feed tray 151 transitions from the open state to the closed state, the fixing member does not receive any force from the pick lever 223. Since 233 is coupled to the locking portion 235 of the main body case, the bearing stand 211 remains in the upper limit position without rotating in the direction of moving from the upper limit position to the lower limit position. For this reason, the upper limit sensor 303 is turned on immediately after the tray sensor 301 is turned on from off.

  FIG. 11 is a diagram for explaining the sheet detection mechanism. Referring to FIG. 11, paper detection mechanism 250 includes a rotation shaft 251 fixed to the main body case, a paper detection lever 253 rotatably attached to rotation shaft 251, and a paper sensor 305.

  The paper detection lever 253 hangs down from the rotating shaft 251 with its own weight, and the end 253A is positioned at the lowest point. When the lifting plate 207 is raised while the sheet is placed on the lifting plate 207, the end 253A comes into contact with the upper surface of the sheet, and the sheet detection lever 253 is pushed up and positioned at the uppermost point. When the paper detection lever 253 is positioned at the uppermost point, the protrusion 255 of the paper detection lever 253 enters the detection area of the paper sensor 305. The paper sensor 305 is arranged in the main body case so that the protrusion 255 of the paper detection lever 253 is located in the detection area when the paper detection lever 253 is located at the uppermost point. The paper sensor 305 is, for example, a photoelectric sensor.

  Further, the elevating plate 207 is formed with a hole portion 207A penetrating therethrough, and the paper detection lever 253 is disposed at a position above the hole portion 207A of the elevating plate 207. For this reason, when the lifting plate 207 is raised while no paper is placed on the lifting plate 207, the end portion 253A enters the hole portion 207A, so that the sheet detection lever 253 is not pushed upward and is moved to the bottom. Located at a point.

  For this reason, the CPU 111 detects the presence of a sheet when the sheet sensor 305 is on, and the sheet is not present when the sheet sensor 305 is off with the lifting plate 207 moved to the upper limit. Is detected. Therefore, the paper sensor 305 is not turned on before the lifting plate 207 is raised.

  FIG. 12 is a flowchart illustrating an example of the flow of error detection processing. The error detection process is a process executed by CPU 111 when CPU 111 provided in MFP 100 executes an error detection program stored in ROM 113, HDD 115, or CD-ROM 118. Referring to FIG. 12, CPU 111 provided in MFP 100 determines whether or not the output of tray sensor 301 is turned on from off (step S01). The process waits until the output of the tray sensor 301 changes from off to on (NO in step S01). If the output of the tray sensor 301 changes from off to on (YES in step S01), the process proceeds to step S02. . In step S02, it is determined whether upper limit sensor 303 is off. If upper limit sensor 303 is off, the process proceeds to step S03; otherwise, the process proceeds to step S13.

  The process proceeds to step S13 when the upper limit sensor 303 is on. In step S13, it is determined that the pickup roller 215 is not in an abnormal state, and the process proceeds to step S14. Here, the period from when the tray sensor 301 is turned on to before the lift plate 207 is raised is a detection period. In step S <b> 14, the CPU 111 notifies the user that the pickup roller 215 is not mounted and ends the process. For example, a message indicating that the pickup roller 215 is not attached is displayed on the display unit 161.

  In step S03, the elevating plate 207 is raised, and the process proceeds to step S04. In step S03, it is determined whether upper limit sensor 303 is on. If upper limit sensor 303 is on, the process proceeds to step S05; otherwise, the process proceeds to step S07. In step S05, the lifting of the lifting plate 207 is stopped, and the process proceeds to step S06. In step S06, it is determined that the pickup roller 215 is in a normal state, and the process ends.

  In step S07, it is determined whether or not the lifting plate 207 has reached the highest point. If lift plate 207 has reached the highest point, the process proceeds to step S08. If not, the process returns to step S04. In step S08, it is determined whether paper sensor 305 is off. If paper sensor 305 is off, the process proceeds to step S09; otherwise, the process proceeds to step S11. In step S09, it is determined that there is no sheet, and the process proceeds to step S10. In step S10, the user is notified that there is no sheet, and the process ends. For example, a message indicating that there is no sheet is displayed on the display unit 161.

  In step S11, it is determined that another error has occurred, and the process proceeds to step S12. In step S12, the user is notified that another error has occurred, and the process ends.

<First Modification>
In the above-described embodiment, the bearing base 211 functions as a moving member, and the fixing member 233 fixes the bearing base 211 at the upper limit position that is the first position. However, in the first modification, The paper detection lever 253 is made to function as a moving member. When the paper detection lever 253 functions as a moving member, when the paper detection lever 253 is at the uppermost point, the protrusion 255 of the paper detection lever 253 is positioned within the detection area of the paper sensor 305, and the paper detection lever 253 is at the lowermost position. If it is at a point, a part of the paper detection lever 253 is located outside the detection area of the paper sensor 305. Therefore, the uppermost point of the paper detection lever 253 is the first position, and the lowermost point of the paper detection lever 253 is the second position. In the MFP 100 according to the modified example, the paper sensor 305 functions as a first sensor.

  FIG. 13 is a first perspective view illustrating an example of a pickup mechanism and a sheet detection mechanism in a modification. FIG. 13 shows an example in which the bearing stand 211 is in the upper limit position. The pickup mechanism 210A in the modification is different from the pickup mechanism 210 shown in FIG. 5 in that the fixing member 233 is changed to the fixing member 237, and the paper detection mechanism 250A is the paper detection mechanism 250 shown in FIG. The difference is that the paper detection lever 253 is changed to a paper detection lever 257.

  The fixing member 237 has a hole through which the sub drive shaft 213 passes, and is movable along the sub drive shaft 213. Further, the fixing member 237 has a restricting portion 237B that extends to above the bearing base 211 so as not to rotate around the sub drive shaft 213. The elastic member 231 is disposed between the bearing base 211 and the fixing member 237 and biases the fixing member 237 in a direction away from the bearing base 211. In a state where the pickup roller 215 is mounted on the sub drive shaft 213, the elastic member 231 is elastically deformed, and the fixing member 237 is positioned away from the bearing base 211 by a predetermined distance.

  Unlike the paper detection lever 253, the paper detection lever 257 has an extending portion 259 extending upward from the end portion 253A.

  FIG. 14 is a second perspective view illustrating an example of a pickup mechanism and a sheet detection mechanism in a modified example. In FIG. 14, the case where the bearing stand 211 is at the lower limit position with the pickup roller 215 removed is shown as an example. Referring to FIG. 14, in a state where pickup roller 215 is removed from sub drive shaft 213, fixing member 237 moves away from bearing base 211 by the elastic force of elastic member 231, and end portion 273 </ b> A of fixing member 237 is moved. Contacts the extending portion 259 of the paper detection lever 253.

  The paper detection lever 257 receives a horizontal force from the fixing member 237 when the extending portion 259 comes into contact with the fixing member 237. Since the extending portion 259 of the paper detection lever 257 has an acute angle with respect to the moving direction of the fixing member 237, the paper detection lever 257 is pushed upward by the fixing member 237. As a result, the paper detection lever 257 reaches the uppermost point, and the protrusion 255 of the paper detection lever 257 enters the detection area of the paper sensor 305.

  For this reason, after the paper feed tray 151 transitions from the open state to the closed state, the paper detection lever 257 reaches the highest point even if the lifting plate 207 does not reach the highest point. For this reason, the sheet sensor 305 is turned on immediately after the tray sensor 301 is turned on.

  The CPU 111 raises the elevating plate 207 when the paper sensor 305 is turned off immediately after the tray sensor 301 is turned on, and stops the elevating plate 207 when the upper limit sensor 303 is turned on, and the pickup roller 215 is attached. Judged to be in a normal state. When the lifting plate 207 reaches the uppermost point with the upper limit sensor 303 turned off without being turned on, when the paper sensor 305 is turned off without being turned on, the pickup roller 215 is in a normal state. However, it is determined that there is no sheet.

  The CPU 111 determines that the pickup roller 215 is not in an abnormal state when the sheet sensor 305 is turned on immediately after the tray sensor 301 is turned on from off.

  In the modification, the elastic member 231 and the fixing member 237 are provided only between the pickup roller 215 and the bearing base 211, but by providing between the paper feed roller 219 and the bearing base 211, An abnormal state in which the paper feed roller 219 is not attached can be determined.

  FIG. 15 is a flowchart illustrating an example of a flow of error detection processing in the modification. The difference between the error detection process in the modification and the error detection process shown in FIG. 12 is that step S02 is changed to step S02A. The other processing is the same as the error detection processing shown in FIG. 12, and therefore description thereof will not be repeated here. In step S02A, CPU 111 provided in MFP 100 determines whether or not the output value of sheet sensor 305 is off. If the output value of paper sensor 304 is off, the process proceeds to step S03. If the output value is on, the process proceeds to step S13.

<Second Embodiment>
In the first embodiment, the bearing base 211 or the paper detection levers 253 and 257 are fixed to the main body case. The MFP 100 according to the second embodiment causes the paper sensor 305 to function as the first sensor and simulates the paper sensor 305 to be in an on state when the paper sensor 305 is normally in an off state. It is intended to detect the absence of. Hereinafter, differences from MFP 100 in the first embodiment will be mainly described.

  FIG. 16 is a first perspective view illustrating an example of a pickup mechanism and a sheet detection mechanism according to the second embodiment. Referring to FIG. 16, the difference from pickup mechanism 210 shown in FIG. 5 is that elastic member 231 and fixing member 233 are deleted, and pseudo-control member 261 is added. The other members are the same as those shown in FIG. 5, and therefore description thereof will not be repeated here.

  The dummy member 261 has a U-shaped cross section. The fixing portion 261A at one end of the pseudo-control member 261 has a plate shape, and a hole having an inner diameter larger than the outer diameter of the main drive shaft 217 is formed in the fixing portion 261A. The pseudo control member 261 is disposed between the bearing base 211 and the paper feed roller 219 with the main drive shaft 217 passing through a hole formed in the fixed portion 261A.

  The light shielding portion 261B, which is the end portion of the pseudo control member 261 opposite to the fixed portion 261A, has a plate shape, and has a size and shape that can enter the detection region of the paper sensor 305.

  When the paper feed roller 219 is attached to the main drive shaft 217, the fixing portion 261 </ b> A of the pseudo control member 261 is sandwiched between the bearing base 211 and the paper feed roller 219. The interval between the bearing stand 211 and the paper feed roller 219 is set to be the same as or slightly larger than the thickness of the fixing portion 261A of the pseudo-control member 261. For this reason, the posture of the pseudo member 261 is fixed in a state where the fixing portion 261A of the pseudo member 261 is substantially perpendicular to the main drive shaft 217. In this case, the light shielding part 261B of the pseudo control member 261 is located outside the detection area of the paper sensor 305.

  FIG. 17 is a second perspective view illustrating an example of a pickup mechanism and a sheet detection mechanism according to the second embodiment. Referring to FIG. 17, the difference from pickup mechanism 210 shown in FIG. 16 is that paper feed roller 219 does not exist. In a state where the paper feed roller 219 is detached from the main drive shaft 217, the movement of the fixing portion 261A of the pseudo-control member 261 is restricted by the bearing base 211, but the movement is not restricted from the side opposite to the bearing base 211. For this reason, the pseudo member 261 changes its posture due to gravity, and the light shielding portion 261B is located within the detection area of the paper sensor 305.

  CPU 111 provided in MFP 100 in the second embodiment executes the error detection process shown in FIG. That is, immediately after the tray sensor 301 is turned off, the CPU 111 raises the lifting plate 207 when the paper sensor 305 is turned off. When the upper limit sensor 303 is turned on, the CPU 111 stops the lifting plate 207 and feeds the paper. It is determined that the roller 219 is attached in a normal state. Further, when the lifting plate 207 reaches the uppermost point with the upper limit sensor 303 being turned off without being turned on, when the paper sensor 305 is turned off without being turned on, the paper feed roller 219 is normally attached. In this state, it is determined that there is no sheet. Further, the CPU 111 determines that the sheet feeding roller 219 is not attached when the sheet sensor 305 is turned on immediately after the tray sensor 301 is turned on.

  In the second embodiment, the pseudo member 261 is positioned within the detection area of the paper sensor 305, but may be positioned within the detection area of the upper limit sensor 303. In this case, the upper limit sensor 303 functions as the first sensor. In addition, the CPU 111 provided in the MFP 100 executes the error detection process illustrated in FIG.

<Second Modification>
FIG. 18 is a right side view illustrating an example of a pickup mechanism and a sheet detection mechanism in the second modification. Referring to FIG. 18, a difference from pickup mechanism 210 shown in FIG. 16 is that pseudo member 261 is changed to pseudo member 263. Since the other members are the same as those shown in FIG. 16, description thereof will not be repeated here.

  The pseudo control member 263 has a U-shaped cross section and is rotatably attached to a rotation shaft 265 fixed to the main body case. The fixing portion 263A at one end of the pseudo-control member 263 is formed in a plate shape, and a cut having a width larger than the outer diameter of the main drive shaft 217 is formed. The dummy control member 263 is disposed between the bearing base 211 and the paper feed roller 219 in a state where the main drive shaft 217 passes through the cut formed in the fixed portion 263A.

  The light-shielding portion 263B at the other end opposite to the fixing portion 263A of the pseudo-control member 263 has a plate shape, and has a size and shape that can enter the detection region of the paper sensor 305.

  In this case, in the pseudo member 263, the weight of the part on the light shielding part 263B side from the part attached to the rotating shaft 265 is heavier than the weight of the part on the fixing part 263A side. Since the fixing portion 263A of the pseudo control member 263 has a cut, when the paper feed roller 219 is not mounted on the main drive shaft 217, the pseudo control member 263 changes its posture by rotating around the rotation shaft 265 by gravity. 263B enters the detection area of the paper sensor 305.

  When the paper feed roller 219 is attached to the main drive shaft 217, the fixing portion 263 </ b> A of the pseudo control member 263 is sandwiched between the bearing base 211 and the paper feed roller 219. The interval between the bearing stand 211 and the paper feed roller 219 is set to be the same as or slightly larger than the thickness of the fixing portion 263A of the pseudo-control member 263. For this reason, the pseudo member 263 changes its posture against gravity, and the posture of the pseudo member 263 is fixed in a state where the fixing portion 263A of the pseudo member 263 is substantially perpendicular to the main drive shaft 217. In this case, the light shielding portion 263B is located outside the detection area of the paper sensor 305.

  In a state where the paper feed roller 219 is detached from the main drive shaft 217, the movement of the fixing portion 263A of the pseudo-control member 263 is restricted by the bearing base 211, but the movement is not restricted from the side opposite to the bearing base 211. For this reason, the pseudo member 263 changes its posture due to gravity, and the light shielding portion 263 </ b> B is positioned within the detection region of the paper sensor 305.

  FIG. 19 is a first front view of the pickup mechanism of FIG. 18 as viewed in the direction of the arrow K. Here, the state where the roller 243 is mounted on the rotary shaft 241 is also shown. The separation roller 243 is positioned at a predetermined interval without coming into contact with the paper feed roller 219 when the paper feed tray 151 is open. The rotary shaft 241 has a mechanism for moving in parallel according to the opening and closing of the paper feed tray 151, and the position of the rotary shaft 241 when the paper feed tray 151 is in an open state is determined. When the paper feed tray 151 is converted from the open state to the closed state, as shown in FIG. 19, the rotating shaft 241 is biased toward the main drive shaft 217 by an elastic material such as a spring. For this reason, the separating roller 243 comes into contact with the paper feed roller 219 while being pressed with a predetermined force in a direction toward the paper feed roller 219.

  The distance between the main drive shaft 217 and the rotation shaft 241 is a distance L1. The distance L1 is determined by the diameter and the amount of elastic deformation of the paper feed roller 219 and the roller 243, respectively.

FIG. 20 is a second front view of the pickup mechanism of FIG. 18 as viewed along the direction of arrow K. Here, the state where the roller 243 is removed from the rotating shaft 241 is also shown. A link member 269 is attached to the rotary shaft 241 to which the separating roller 243 is attached. The link member 269 has a plate shape, is formed with a hole through which the rotation shaft 241 passes, and is fixed to the main body case so as not to rotate together with the roller 243.
Since the roller 243 is not present, the distance between the main drive shaft 217 and the rotation shaft 241 is a distance L2 shorter than the distance L1.

  FIG. 21 is a first diagram illustrating a relationship between the fixing portion of the pseudo control portion and the link member. FIG. 21 shows a state where the roller 243 is attached. In this case, since the paper feed roller 219 and the roller 243 are in contact with each other, the distance between the main drive shaft 217 and the rotary shaft 241 is L1. The fixing portion 263A of the dummy member 263 and the link member 269 are positioned at a predetermined interval.

  FIG. 22 is a second diagram illustrating the relationship between the fixing portion of the pseudo control portion and the link member. FIG. 22 shows a state where the roller 243 is removed. In this case, since the feed roller 219 and the rotating shaft 241 are in contact with each other, the distance between the main drive shaft 217 and the rotating shaft 241 is L2, and the link member 269 is in contact with the fixing portion 263A of the pseudo-control member 263. The link member 269 pushes up the pseudo member 263 upward. As a result, the pseudo control member 263 changes its posture by rotating around the rotation shaft 265 by the force by which the fixing portion 263A is pushed upward, and the light shielding portion 263B enters the detection area of the paper sensor 305.

  In MFP 100 according to the second modification, CPU 111 raises lift plate 207 when sheet sensor 305 is turned off immediately after tray sensor 301 is turned on, and lift plate 207 when upper limit sensor 303 is turned on. Is determined to be in a normal state in which the paper feed roller 219 and the separating roller 243 are mounted. Further, when the lifting plate 207 reaches the uppermost point without turning on the upper limit sensor 303 and the paper sensor 305 is turned off without being turned on, the paper feed roller 219 and the separation roller 243 are mounted. In the normal state, it is determined that there is no sheet.

  When the paper sensor 305 is turned on immediately after the tray sensor 301 is turned on from the off state, the CPU 111 determines that the paper feeding roller 219 and / or the separating roller 243 is not in an abnormal state.

  In the second modification, the pseudo member 263 is positioned within the detection area of the paper sensor 305, but may be positioned within the detection area of the upper limit sensor 303. In this case, the upper limit sensor 303 functions as the first sensor.

  In the above-described embodiment, the MFP 100 has been described as an example of the image processing apparatus. However, an apparatus having a function of forming an image of data, for example, a printer or a facsimile apparatus may be used.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 MFP, 110 Main circuit, 111 CPU, 112 Communication I / F unit, 113 ROM, 114 RAM, 115 HDD, 116 Facsimile unit, 117 External storage device, 120 Automatic document feeder, 130 Document reading unit, 140 Image forming unit , 150 paper feed unit, 151,152 paper feed tray, 155 post-processing unit, 160 operation panel, 161 display unit, 163 operation unit, 165 touch panel, 167 hard key unit, 200 paper bundle, 201A, 201B rail, 203A, 203B 205A, 205B Presser plate, 207 Lift plate, 207A Hole, 209 Back projection, 210, 210A Pickup mechanism, 211 Bearing stand, 211A End, 213 Sub drive shaft, 215 Pickup roller, 217 Main drive shaft, 219 Supply Paper 221 Support shaft, 223 Pick lever, 223A First end, 223B Second end, 231 Elastic member, 233, 233A Fixing member, 235 Locking portion, 236 Pseudo member, 241, 251, 265 Rotating shaft, 243 Rolling roller, 250, 250A, paper detection mechanism, 253, 253A, paper detection lever, 253A end, 255 protrusion, 259 extension, 261, 263 pseudo-control member, 261A, 263A fixing part, 261B, 263B, light shielding part, 269 link member , 301 tray sensor, 303 upper limit sensor, 305 paper sensor.

Claims (12)

A roller detachable from the rotation shaft;
A first sensor;
A second sensor;
When a combination different from the combination of the first output value of the first sensor and the second output value of the second sensor generated in a state where the roller is mounted on the rotation shaft, And an error detection unit that determines that the roller is not mounted on the rotation shaft. The first sensor is turned on when a tangible object is present in a predetermined detection area, and is turned off when a tangible object is not present in the detection area,
A paper feed tray for storing paper conveyed by the roller;
A moving member located at a second position different from the first position in the detection region in at least a detection period when the second sensor is in an on state with the roller mounted on the rotation shaft. When,
Fixing means for fixing the moving member to the first position in a state where the roller is not mounted on the rotating shaft;
The image forming apparatus according to claim 1, wherein the second sensor is turned on when the paper feed tray is in a predetermined position, and is turned off when the paper feed tray is not in the predetermined position. A roller detachable from the rotation shaft;
A first sensor that is turned on when a tangible object is present in a predetermined detection area and is turned off when a tangible object is not present in the detection area;
A moving member located at a second position different from the first position in the detection region in a predetermined detection period in a state where the roller is mounted on the rotation shaft;
Fixing means for fixing the moving member to the first position in a state where the roller is not mounted on the rotating shaft;
And an error detection unit that determines that the roller is not attached to the rotating shaft when the first sensor is turned on during the detection period. The fixing means is disposed between the moving member and the roller so as to be movable along the rotation axis; and
An elastic member that urges the fixing member in a direction away from the moving member,
The moving member pivotally supports the rotating shaft,
4. The fixing member according to claim 2, wherein the fixing member is coupled to the main body case in a state where the roller is not mounted on the rotating shaft, and is not coupled to the main body case in a state where the roller is mounted on the rotating shaft. The image forming apparatus described. The fixing means is disposed between the moving member and the roller so as to be movable along the rotation axis; and
An elastic member that urges the fixing member in a direction away from the moving member,
The fixing member contacts the moving member to fix the moving member at the first position in a state where the roller is not mounted on the rotating shaft, and the roller is mounted on the rotating shaft. The image forming apparatus according to claim 2, wherein the image forming apparatus does not contact the moving member in a state. The first sensor is turned on when a tangible object is present in a predetermined detection area, and is turned off when a tangible object is not present in the detection area,
A paper feed tray for storing paper conveyed by the roller;
A moving member located at a second position different from the first position in the detection region at least in a detection period in which the second sensor is on;
Fake means for faking so that the first sensor is turned on when the roller is not mounted on the rotating shaft,
The image forming apparatus according to claim 1, wherein the second sensor is turned on when the paper feed tray is in a predetermined position, and is turned off when the paper feed tray is not in the predetermined position. A roller detachable from the rotation shaft;
A first sensor that is turned on when a tangible object is present in a predetermined detection area and is turned off when a tangible object is not present in the detection area;
A moving member located at a second position different from the first position in the detection region in a predetermined detection period in a state where the roller is mounted on the rotation shaft;
Fake means for faking so that the first sensor is turned on when the roller is not mounted on the rotating shaft;
An image forming apparatus comprising: an error detection unit that determines that the roller is not attached to the rotating shaft when the first sensor is turned on during the detection period. The imitation means includes an imitation member, a part of which is disposed between the moving member and the roller,
The pseudo-control member is in a restricted state in which the position with respect to the rotation shaft is fixed when the roller is mounted on the rotation shaft, and the position with respect to the rotation shaft is fixed when the roller is not mounted on the rotation shaft. In an idle state,
The said pseudo control member is separated from the detection area | region of the said 1st sensor in the said control state, At least one part is located in the detection area | region of the said 1st sensor in the said idle state. Image forming apparatus.   The image forming apparatus according to claim 1, further comprising notification means for notifying a user when it is determined that the roller is not attached to the rotation shaft.   Monitoring means for detecting that the roller is mounted on the rotating shaft when the output value of the first sensor is turned on after the detection period has elapsed and the detection period has elapsed; An image forming apparatus according to any one of claims 1 to 9. An error detection method executed in an image forming apparatus,
The image forming apparatus includes a roller detachably attached to a rotation shaft,
A first sensor;
A second sensor,
When a combination different from the combination of the first output value of the first sensor and the second output value of the second sensor generated in a state where the roller is mounted on the rotation shaft, An error detection method for causing the image forming apparatus to execute an error detection step of determining that the roller is not mounted on a rotation shaft. An error detection program executed by a computer that controls the image forming apparatus,
The image forming apparatus includes a roller detachably attached to a rotation shaft,
A first sensor;
A second sensor,
When a combination different from the combination of the first output value of the first sensor and the second output value of the second sensor generated in a state where the roller is mounted on the rotation shaft, An error detection program for causing the computer to execute an error detection step for determining that the roller is not mounted on a rotating shaft.

Images