JP2020093880A - Paper feeder and image forming apparatus - Google Patents

Abstract

To provide a paper feeder capable of suitably setting a time period for detecting a rotational speed of a separation rotating body.SOLUTION: A paper feeder comprises an option pickup roller 203, an option feed roller 206, an option retard roller 205, an option encoder 204, a transport clutch 280, an option determining section 253 that determines whether or not the option retard roller 205 has reached a lifetime based on a detection result of the option encoder 204, and an option drive control unit 255. An option control unit 250 is comprised to determine a time t2 that is timing of starting a lifetime determination by the option determining section 253 based on timing (time Ta) in which the option drive control unit 255 outputted a drive signal and a detection result (time t1) of the option encoder 204.SELECTED DRAWING: Figure 5

Description

The present invention relates to a sheet feeding device and an image forming apparatus such as a copying machine or a printer including the sheet feeding device. In particular, the present invention relates to the detection of the life of a separation rotary member that is provided in a paper feeding device and separates and conveys a recording material.

2. Description of the Related Art Conventionally, image forming apparatuses such as copiers and printers are equipped with a paper feed mechanism that separates and feeds recording materials stacked in a paper feed unit one by one. Various types of paper feed mechanisms are adopted. One of them is a separation/conveyance system using a separation rotating body. The separation conveyance method using the separation rotator includes a retard separation method that drives a retard roller that is a kind of separation rotator and a separation roller method that does not drive the separation roller that is a kind of separation rotator. There is.

For a retard separation type sheet feeding mechanism using a feed roller and a retard roller, for example, a method as disclosed in Patent Document 1 has been proposed. That is, when the number of rotations of the retard roller is equal to or less than the predetermined number of rotations and the predetermined number of paper feeds continues, it is determined that the life of the rollers in the paper feed operation is approaching, and the display device displays that fact. .. Further, for a separation roller type paper feed mechanism, for example, a method as disclosed in Patent Document 2 has been proposed. That is, only the feed roller is driven without driving the separation roller, and the rotation state of the separation roller when the separation roller is rotated by the feed roller is monitored by an encoder that outputs a signal composed of a two-phase pulse signal. To do. Then, the phase difference between the monitored two-phase pulse signals of the encoder is detected, and the uneven wear of the separation roller is detected based on whether or not the phase difference is within the range of a preset reference value.

As the separating roller or other separating rotary member wears, the slip of the separating rotary member increases due to the adhesion of paper powder of the recording material, the shape of the separating rotary member being scraped off by abrasion, and the like. As a result, the rotational speed of the separated rotary body becomes an unstable state in which the high speed and the low speed are mixed. After that, when the abrasion further progresses and the transport performance of the separation rotary body deteriorates, the rotation speed continuously decreases. That is, the life of the separation rotating body can be determined by measuring the rotation speed of the separation rotating body.

JP-A-11-035183 Japanese Patent No. 4176551

However, in the conventional example, consideration is not given to an appropriate timing for detecting the rotation speed of the separated rotating body. That is, when measuring the rotation speed of the separation rotor, it is desirable to detect the rotation state during a period in which there are few disturbance factors and the rotation of the separation rotor is stable, in order to improve the detection accuracy of the rotation speed. On the contrary, if the rotation speed is detected during the period in which the rotation of the separating rotor is not stable, the life of the separating rotor may be erroneously detected. For example, if the detection is performed when the leading edge of the recording material enters the separating rotary member or when the trailing edge of the recording material passes through the feeding means such as the pickup roller, the leading edge of the recording material or the trailing edge of the recording material falls out. The reaction or the like at the time of impact affects the detection result of the separated rotating body.

Therefore, as an example of how to determine the period for detecting the rotation state of the separated rotating body (hereinafter referred to as the detection period), there is the following method. That is, there is a method of setting the detection period by estimating the period during which the separating rotary member is rotating based on the timing at which the front end of the recording material reaches the front end detecting means provided on the recording material conveyance path. However, when such a method is performed, depending on the size of the recording material and the stop position of the recording material, the detection timing overlaps the timing at which the separated rotating body stops, so that the rotation speed of the separated rotating body can be detected accurately. There are things you can't do. In addition, the electromagnetic clutch that transmits the driving force for conveying the recording material to each drive mechanism has a period of time until the electromagnetic clutch is engaged (hereinafter referred to as an engagement time) or a time required to release the engagement and stop (hereinafter referred to as an engagement time). , Called release time). If the connection time or the release time of the electromagnetic clutch fluctuates, the time to start or stop the conveyance of the recording material is affected. As a result, the detection period varies each time the recording material is conveyed, and it may not be possible to detect and obtain the rotation speed of the separated rotating body during the originally assumed detection period. Therefore, it is important to appropriately determine the detection period of the separated rotating body in consideration of the factors described above.

The present invention has been made under such a situation, and an object thereof is to appropriately set a period for detecting the rotation speed of the separation rotating body.

In order to solve the problems described above, the present invention has the following configurations.

(1) A feeding unit that feeds the recording material at an abutting position where it abuts the recording material loaded on the loading unit, and a paper feed rotating body that feeds the recording material fed by the feeding unit. , A separation nip portion is formed by abutting against the paper feed rotating body, and when a plurality of recording materials are fed from the stacking portion, one recording material is separated and conveyed downstream in the conveying direction. The separation rotary body, the first detection means for detecting the rotation state of the separation rotary body, and the drive force of the drive means are connected to each other at least when the drive force is transmitted to the paper feed rotary body, and the transmission of the drive force is interrupted. The transmission means is sometimes in a released state, the determination means determines whether or not the separated rotary body has reached the end of its life based on the detection result of the first detection means, and the drive means for controlling the transmission means. And a control unit configured to output a signal, wherein the determination unit determines the determination based on a timing when the control unit outputs the drive signal and a detection result of the first detection unit. A sheet feeding device, characterized in that the sheet feeding device is provided with a deciding unit for deciding a start timing.

(2) An image forming apparatus comprising: the paper feeding device according to (1) above; and an image forming unit that forms an image on a recording material fed from the paper feeding device.

According to the present invention, it is possible to appropriately set the period for detecting the rotation speed of the separated rotating body.

FIG. 1 is a diagram showing a configuration of an image forming apparatus and a sheet feeding option apparatus of Examples 1 to 3. FIG. 3 is a diagram showing a control block of the image forming apparatus of Examples 1 to 3. FIG. 3 is a diagram showing a control block of the paper feed option device according to the first to third embodiments. FIG. 6 is a diagram showing the operation of the paper feed control of Embodiments 1 to 3. Timing chart of paper feed control of Embodiment 1 FIG. 3 is a diagram showing a configuration of a paper feed option device according to a second embodiment. Timing chart of paper feed control of Embodiment 2 FIG. 6 is a diagram showing a configuration of a paper feed option device according to a third embodiment. Timing chart of paper feed control of Embodiment 3

Hereinafter, modes for carrying out the present invention will be described in detail with reference to the drawings by embodiments.

[Image forming device]
An outline of the electrophotographic image forming apparatus and the printing operation of the image forming apparatus of the first embodiment will be described. FIG. 1 is a schematic diagram of the image forming apparatus 101 and a paper feed option apparatus 201 that is removable from the image forming apparatus 101. The cassette 102, which is an example of a sheet feeding unit, is a storage unit for the recording material S and is attachable to and detachable from the image forming apparatus 101. With the cassette 102 installed in the main body of the image forming apparatus 101, the pickup roller 103 as a feeding unit feeds the recording material S contained in the cassette 102. The recording material S fed by the pickup roller 103 is conveyed to a nip portion formed by a feed roller 106 that is a sheet feeding rotating body and a retard roller 105 that is an example of a separating rotating body. The feed roller 106 forms a nip portion with the retard roller 105, and prevents a plurality of (two or more) recording materials S from being fed to the downstream side of the nip portion in the transport direction. The recording material S conveyed by only one sheet reaches the top sensor 108 via a registration roller pair (hereinafter referred to as a registration roller pair) 107.

Next, the recording material S is conveyed to the image forming unit. The image forming unit includes a photosensitive drum 109, a transfer roller 110, a charging roller 111, a developing device 112, a laser scanner 113, and a fixing device 114. After the photosensitive drum 109 is charged by the charging roller 111, the laser beam L is emitted from the laser scanner 113, and an electrostatic latent image is formed on the surface. The electrostatic latent image formed on the photosensitive drum 109 is visualized as a toner image by supplying toner from the developing device 112. The photosensitive drum 109 and the transfer roller 110 form a transfer nip portion, and the recording material S is conveyed to the transfer nip portion in synchronization with the rotation of the photosensitive drum 109. The toner image formed on the photosensitive drum 109 is transferred to the recording material S by applying a voltage to the transfer roller 110 at the transfer nip portion. The recording material S to which the unfixed toner image is transferred is conveyed to the fixing device 114, and is heated and pressed. As a result, the unfixed toner image transferred onto the recording material S is fixed onto the recording material S. The recording material S on which the toner image is fixed is conveyed by the triple roller 116, the intermediate discharge roller 117, and the discharge roller 118, and is discharged to the discharge tray 121, and a series of printing operations is completed.

Further, when performing double-sided printing on the recording material S, the recording material S, which has been printed on one side, is not discharged to the discharge tray 121, but the trailing end of the recording material S passes through the triple roller 116 (falls out. ) After that, the triple roller 116, the intermediate discharge roller 117, and the discharge roller 118 are reversely rotated. As a result, the recording material S is transported to the double-sided transport path 125, and further transported to the image forming unit by the double-sided transport rollers 122. Further, in FIG. 1, the fixing discharge sensor 115 and the double-sided conveyance sensor 123 are provided to determine whether the recording material S is normally conveyed. The control unit 150 will be described later.

[Paper feeding optional device]
Next, an outline of the operation of the electrophotographic paper feed option device 201 of the first embodiment will be described. The option cassette 202 in FIG. 1 is a storage unit (loading unit) for the recording material S and is attachable to and detachable from the paper feed option device 201. While the option cassette 202 is mounted on the main body of the paper feeding option device 201, the option pickup roller 203 as a feeding unit feeds the recording material S accommodated in the option cassette 202. The recording material S fed by the option pickup roller 203 is fed downstream in the transport direction of the recording material S by the option feed roller 206 which is a paper feeding rotating body. The optional feed roller 206 forms a nip portion with the optional retard roller 205 which is a separating rotary member, and a plurality of (two or more) recording materials S are fed together to the downstream side of the nip portion in the transport direction. To prevent The recording material S conveyed by only one sheet reaches the optional conveyance sensor 208 via the pair of optional conveyance rollers 207. Further, the recording material S is conveyed by the optional conveying roller pair 207 and reaches the top sensor 108 via the registration roller pair 107 of the image forming apparatus 101. After that, the operation after the recording material S is conveyed to the image forming unit is the same as the printing operation of the image forming apparatus 101. The paper feed option device 201 can also be used by mounting a plurality of paper feed option devices on the image forming apparatus 101. The option controller 250 will be described later. The above is a schematic description of the configurations and printing operations of the image forming apparatus 101 and the paper feed option apparatus 201.

[Control part]
Next, the configuration and function of the control unit 150 included in the image forming apparatus 101 will be described. FIG. 2 is a block diagram of a control unit 150 included in the image forming apparatus 101 and a driving unit of the image forming apparatus 101. The control unit 150 includes a measurement unit 151, a storage unit 152, a determination unit 153, and a drive control unit 155, and controls each drive mechanism. A motor 160, which is a drive unit, is a drive source that drives the registration roller pair 107 and the electromagnetic clutch 170. Further, the electromagnetic clutch 170 transmits or interrupts the driving force of the motor 160 to the pickup roller 103, the feed roller 106, and the separation rotary body. In the first embodiment, as an example of the separating rotary member, the retard roller 105 whose drive is transmitted in the direction in which the feeding of the recording material S is disturbed will be described. However, it is also possible to use a roller to which drive is not transmitted, that is, a so-called separation roller, as the separation rotating body. Further, the top sensor 108 that detects the leading end position of the recording material S that has been conveyed through the registration roller pair 107 and notifies the control unit 150, and the encoder 104 that detects the rotational state of the retard roller 105 and notifies the measurement unit 151 are also driven. It is a mechanism related to. In the first embodiment, the encoder 104 uses, for example, a code wheel provided coaxially with the retard roller 105. However, the configuration of the encoder 104 is not limited to this, and an optical rotary encoder, a magnetic rotary encoder, a photo interrupter, or the like can be used in addition to the above, depending on the required accuracy and the place where the encoder 104 is arranged.

Next, the functions of the control unit 150 and the detection mechanism will be described. By controlling the motor 160 and the electromagnetic clutch 170, the drive control unit 155 can switch the drive of each mechanism between on and off. The measuring unit 151 starts a rotation of the retard roller 105 from the timing when the drive control unit 155 outputs a signal for driving the electromagnetic clutch 170 (hereinafter referred to as an ON signal), and a signal received from the encoder 104 rises. To measure the time to. Further, the measuring unit 151 measures the rotation state of the retard roller 105 detected by the encoder 104, and outputs the result to the storage unit 152 and the determining unit 153. An example of the information detected by the encoder 104 is the rotation speed of the retard roller 105. In the first embodiment, as the rotation speed of the retard roller 105 output to the determination unit 153, the average value V1 of the rotation speed of the retard roller 105 during the period in which the retard roller 105 stably rotates is used. A method of setting the period during which the retard roller 105 stably rotates will be described later.

The determination unit 153 determines whether or not the life of the retard roller 105 is near, based on the average value V1 calculated by the measurement unit 151. Note that the life of the separation rotor is, for example, the operating time of the separation rotor that is assumed in design. When the rotation performance of the retard roller 105 following the recording material S is deteriorated due to wear or the like, the rotation speed of the retard roller 105 per unit time becomes slow. Therefore, the average value V1 is used to determine the life of the retard roller 105. can do. When the average value V1 is lower than the preset rotation speed, the determination unit 153 determines that the retard roller 105 has reached the end of its life, and notifies the result. Further, the determination unit 153 notifies the panel (not shown) of the image forming apparatus 101 or the user of information regarding the life of the retard roller 105. The storage unit 152 has a function of storing the rotation speed of the retard roller 105 output from the measurement unit 151, the time from the driving of the electromagnetic clutch 170 to the rise of the signal output from the encoder 104, and the like. The information about the life of the separation rotor can be used for determining the life of the separation rotor, such as the usage time of the separation rotor, the total number of rotations, and the total number of recording materials S conveyed in the nip portion. Refers to information.

The control unit 150 included in the image forming apparatus 101 has been described above. These configurations and functions can be similarly applied to the case where the paper feed option device 201 includes a control unit. FIG. 3 is a block diagram showing an example of a configuration in which the paper feed option device 201 has the option control unit 250. In the example of FIG. 3, a motor 160 provided on the image forming apparatus 101 side is used as a drive source of the paper feed option apparatus 201. However, it is also possible to provide the paper feeding option device 201 with a motor as a drive source of the paper feeding option device 201.

[Option control part]
The option control unit 250 in FIG. 3 includes an option measurement unit 251, an option storage unit 252, an option determination unit 253, and an option drive control unit 255, and controls each drive mechanism of the paper feed option device 201. The motor 160 is a drive source that drives at least the paper feed clutch 270 and the transport clutch 280. The paper feed clutch 270 transmits or blocks the driving force of the motor 160 to the optional pickup roller 203. On the other hand, the conveyance clutch 280, which is a transmission means, transmits or blocks the driving force of the motor 160 to the option feed roller 206, the option conveyance roller pair 207, and the option retard roller 205 as an example of the separation rotating body. The optional retard roller 205 is connected to the transport clutch 280 via a torque limiter 209. As the separation rotating body, a separation roller to which the drive is not transmitted can be used, and the transport clutch 280 transmits the driving force of the motor 160 to at least the optional feed roller 206. The option conveyance sensor 208 detects the position of the leading edge of the recording material S conveyed through the option conveyance roller pair 207, and transmits it to the option controller 250. The option encoder 204, which is the first detection means, detects the rotation state of the option retard roller 205 and sends it to the option measurement unit 251.

Functions of the option controller 250 and the detection mechanism will be described. Upon receiving a command from the control unit 150, the option drive control unit 255, which is a control unit, controls the paper feed clutch 270 and the transport clutch 280, thereby turning on and off the drive of each mechanism. The option measuring unit 251 measures the next time. That is, the time from the timing when the option drive control unit 255 outputs an ON signal for driving the transport clutch 280 until the option retard roller 205 actually starts rotating and the signal received from the option encoder 204 rises is measured. Further, the option measuring unit 251 measures the rotation state of the option retard roller 205 detected by the option encoder 204, and outputs the result to the option storage unit 252 and the option determining unit 253. Then, the option determination unit 253, which is a determination unit, determines whether the life of the option retard roller 205 is near, based on the data calculated by the option measurement unit 251, that is, the detection result of the option encoder 204. Since the mechanism of the option encoder 204, the information to be detected, and the data calculated by the option measuring unit 251 are the same as those of the encoder 104 and the measuring unit 151 of the image forming apparatus 101, the description thereof will be omitted. Further, the method of determining the life of the option retard roller 205 by the option determination unit 253, the information stored in the option storage unit 252, and the like are the same as those of the determination unit 153 and the storage unit 152 of the image forming apparatus 101, and thus the description thereof will be omitted.

[Setting method of detection period T]
Next, details of a method of setting a period T (hereinafter, referred to as a detection period T) for detecting the rotation speed of the separation rotating body (optional retard roller 205) for performing paper feed control and determining the life of the separation rotating body will be described with reference to FIG. , FIG. 5 will be described. For the description, the paper feed configuration of the paper feed option device 201, which has the same configuration as the paper feed mechanism of the image forming apparatus 101, will be used. FIG. 4 shows a state in which the recording material S stored in the option cassette 202 is being fed and conveyed. The option cassette 202 contains a plurality of recording materials S. The recording material S on the uppermost surface of the plurality of recording materials S is the recording material S1, and the recording material S stored in contact with the recording material S1 is recorded. Material S2.

The horizontal axis of FIG. 5 indicates the elapsed time t. The vertical axis of FIG. 5A indicates ON (ON) and OFF (OFF) of the drive signal of the sheet feeding clutch 270. The vertical axis of FIG. 5B indicates ON (ON) and OFF (OFF) of the drive signal of the transport clutch 280. When these drive signals are on, the paper feed clutch 270 or the transport clutch 280 is in a connected state, and when the drive signals are off, the paper feed clutch 270 or the transport clutch 280 is in a released state. The vertical axis of FIG. 5C shows the state of the output signal of the optional transport sensor 208. The option control unit 250 detects “presence” of the recording material S when the output signal of the optional conveyance sensor 208 is on (ON), and detects “absence” of the recording material S when it is off (OFF). That is, the option control unit 250 determines that the leading edge of the recording material S has reached the option conveyance sensor 208 (or the option conveyance roller pair 207) when the output signal of the option conveyance sensor 208 rises from OFF to ON. When the output signal of the option conveyance sensor 208 falls from ON to OFF, the option controller 250 determines that the trailing edge of the recording material S has passed (lost) the option conveyance sensor 208 (or the option conveyance roller pair 207). to decide. The vertical axis of FIG. 5D shows the rotation speed V of the option retard roller 205, and shows a waveform obtained by converting the signal output from the option encoder 204 (option encoder signal) into the rotation speed. V1 indicates an average value of the rotation speed V of the optional retard roller 205 described later, and will be referred to as an average value V1 hereinafter.

(Time Ta)
FIG. 4A shows a cross-sectional view of the option cassette 202 at the timing of feeding the recording material S1 at the top of the recording materials S stored in the option cassette 202. The recording material S in the option cassette 202 is positioned by a regulation plate (not shown) or the like in the option cassette 202, and the leading end of the recording material S1 when feeding the recording material S1 is the position of Ps in FIG. 4A. (Hereinafter, referred to as position Ps). The timing of FIG. 4A is time Ta of FIG. When the paper feed control is started, the drive control unit 155 rotates the motor 160. The option drive control unit 255, which receives the instruction from the control unit 150 at time t0, outputs the drive signal (ON signal) of the sheet feeding clutch 270 to turn on the sheet feeding clutch 270, and the driving force of the motor 160 is changed to the optional pickup roller. It is transmitted to 203. Then, in response to the instruction from the control unit 150, the option drive control unit 255 outputs a drive signal (ON signal) for the transport clutch 280 to turn on the transport clutch 280 at time Ta. Then, the driving force of the motor 160 is transmitted to the option feed roller 206, the option retard roller 205, and the option transport roller pair 207. As a result, the option pickup roller 203, the option feed roller 206, the option retard roller 205, and the option transport roller pair 207 start rotating, and the recording material S1 is fed and transported in the paper feeding direction indicated by the arrow in FIG. To do. The position Pp in FIG. 4A is a position (contact position) where the option pickup roller 203 contacts the recording material S, that is, a position where the recording material S is fed into the paper feed nip. Hereinafter, the position Pp is also referred to as the paper feed nip portion Pp. The position Pfr is the position of the separation nip portion formed by the option feed roller 206 and the option retard roller 205. Hereinafter, the position Pfr is also referred to as the separation nip portion Pfr.

The optional retard roller 205 is provided with a torque limiter 209, and the drive is transmitted in a direction in which the recording material S is prevented from being fed. The torque limiter 209 is located between the transport clutch 280 and the optional retard roller 205 and has a constant rotational load. The option feed roller 206 starts rotating in the direction of feeding the recording material S (counterclockwise direction in FIG. 4). Here, when the recording material S is not present in the separation nip portion, the force that the option retard roller 205 receives by friction with the option feed roller 206 exceeds the rotational load of the torque limiter 209 provided on the option retard roller 205. Therefore, the optional retard roller 205 rotates in the direction of feeding the recording material S (clockwise direction in FIG. 4). Even when only one recording material S is conveyed to the separation nip portion Pfr, the force received by the friction between the optional retard roller 205 and one recording material S is set to exceed the rotational load of the torque limiter 209. .. Therefore, the optional retard roller 205 is driven to rotate in the direction of feeding the recording material S (clockwise direction in FIG. 4). On the other hand, when two or more recording materials are conveyed to the separation nip portion Pfr, the rotation of the torque limiter 209 is greater than the force received by the frictional force between the recording materials S conveyed by the optional retard roller 205 in an overlapping manner. The load is set to be superior. For this reason, the option retard roller 205 is stopped in the direction in which the force received by friction and the rotational load compete with each other, or the rotational load of the torque limiter 209 overcomes the force received by friction to prevent sheet feeding (counterclockwise rotation in FIG. 4). Direction). At time Ta, the drive signal for the transport clutch 280 rises from OFF to ON.

(Time Tb)
FIG. 4B is a cross-sectional view of the option cassette 202 at the timing when the leading edge of the recording material S1 reaches the option transport roller pair 207 and the option transport sensor 208 that is the second detection unit. The timing of FIG. 4B is time Tb of FIG. The conveyance speed of the recording material S1 may fluctuate due to the vibration of the recording material S1 coming into contact with the optional conveyance roller pair 207 and the conveyance force from the optional conveyance roller pair 207 transmitted to the recording material S1 (FIG. )). In addition, when there is the recording material S conveyed earlier than the recording material S1, the recording material S may be temporarily stopped when the front end of the recording material S1 reaches the option conveyance sensor 208 in order to match the timing of image formation. As a result, the rotation speed of the optional retard roller 205 that is rotated by the recording material S1 may vary. At time Tb, the output signal of the optional conveyance sensor 208 rises from OFF to ON.

(Time Tc)
FIG. 4C is a sectional view of the option cassette 202 at the timing when the trailing edge of the recording material S1 reaches the paper feed nip portion Pp of the option pickup roller 203. The timing in FIG. 4C is time Tc in FIG. In the paper feeding option device 201, in order to prevent the recording material S2, which is the succeeding recording material (hereinafter referred to as the succeeding paper) that is fed following the recording material S1, from being pushed into the separation nip portion and causing a paper jam, The following control is performed. That is, the paper feed clutch 270 is switched from on to off before the trailing edge of the recording material S1 passes through the paper feed nip portion Pp. As a result, the transmission of the driving force from the motor 160 to the option pickup roller 203 is interrupted and the rotation of the option pickup roller 203 is stopped. Also in the first embodiment, the drive signal of the sheet feeding clutch 270 falls from ON to OFF at time t3 before time Tc in FIG. Even if the rotation of the option pickup roller 203 is stopped, the recording material S1 is conveyed in the paper feeding direction by the pair of option conveyance rollers 207. Therefore, the option feed roller 206 and the option retard roller 205 are also driven to rotate following the recording material S1. At time Tc when the trailing edge of the recording material S1 passes through the paper feed nip portion Pp, the frictional force applied to the recording material S1 by the optional pickup roller 203 disappears. Therefore, the recording material S1 may vibrate, and the rotation speed of the optional retard roller 205 may fluctuate (FIG. 5D). Even after the trailing edge of the recording material S1 has passed through the paper feed nip portion Pp, the recording material S1 is conveyed by the optional conveyance roller pair 207 to the downstream side in the paper feeding direction.

(Time Td)
FIG. 4D shows a cross-sectional view of the option cassette 202 at the timing when the trailing edge of the recording material S1 has passed the separation nip portion Pfr. The timing of FIG. 4D is time Td of FIG. When the trailing edge of the recording material S1 passes through the separation nip portion Pfr, the recording material S1 is transported to the downstream side in the paper feeding direction by the option transport roller pair 207. When the recording material S1 passes through the optional conveyance sensor 208 as it is and the leading end of the recording material S1 reaches the registration roller pair 107 and the top sensor 108, the drive signal of the conveyance clutch 280 changes from ON to OFF at the time t4, and the motor 160 moves. Cut off the transmission of driving force. As a result, the rotation of the option feed roller 206, the option transport roller pair 207, and the option retard roller 205 is stopped. The recording material S1 is conveyed as it is on the conveyance path of the image forming apparatus 101 while being pulled by the registration roller pair 107. The time from the time t4 when the drive signal (OFF signal) of the transport clutch 280 is output to the time Td when the trailing edge of the recording material S1 passes through the separation nip portion Pfr is Tla.

(Setting of detection period T)
By the way, the life of the option retard roller 205 is determined based on the result of detecting the average value V1 of the rotation speed of the option retard roller 205 as described above. Therefore, the life judgment is detected by avoiding the timing at which the rotation speed is likely to change due to disturbance, such as the moment when the leading edge of the recording material S1 enters the nip portion of each roller or the trailing edge of the recording material S1 passes through each roller. It is desirable to provide the period T. For example, the time from time t2 to time t3 can be set as the detection period T while avoiding the times Tb and Tc in FIG. It is assumed that the detection period T is set in advance avoiding the times Tb and Tc and is stored in, for example, the option storage unit 252. The time when the preset detection period, particularly the preset detection period starts, is defined as time t2′. The preset detection period is set, for example, as a period from time t2′ to a predetermined time with reference to the timing (time Ta) when the drive signal of the transport clutch 280 rises from OFF to ON. And

However, the expected detection period (which is also the time t2′ described above) and the time that should actually be the detection period T (hereinafter, referred to as the actual detection period T) may deviate from each other. For example, after the option drive control unit 255 outputs a drive signal for the transport clutch 280 (time Ta), until the drive force of the motor 160 is transmitted and the rotation of the option retard roller 205 actually starts (time t1). There is a slight delay Tlb. Hereinafter, the delay Tlb is referred to as a time lag Tlb. The time lag Tlb, which is the first time, is influenced by the time from the reception of the drive signal (ON signal) by the transport clutch 280 to the completion of the coupling, and the time until the gear parts are engaged with each other. This time lag Tlb leads to a delay in the timing of starting the conveyance of the recording material S1 (hereinafter referred to as the conveyance start timing). In other words, if the time until the conveyance clutch 280 is engaged becomes long, the transmission of the driving force to the option feed roller 206 and the option retard roller 205 is delayed, and the conveyance of the recording material S1 is delayed (hereinafter referred to as conveyance delay). If the time lag Tlb is always a fixed time, it is possible to set the detection period T of the life judgment in consideration of it, but in reality, since there are individual variations of the transport clutch 280 and gears, the detection time T is not always fixed. I won't. In particular, this time lag Tlb has a greater variation as the rotation speed of the transport clutch 280 is slower, and affects the transport characteristics of the recording material S1.

In the first embodiment, the option control unit 250 calculates the time from time Ta to time t1, that is, the time lag Tlb. Here, the time Ta is the time when the optional drive control unit 255 outputs the drive signal (ON signal) for the transport clutch 280. Time t1 is the rotation speed of the option retard roller 205, that is, the time when the output signal of the option encoder 204 rises. As a result, the option control unit 250 determines the detection period T for determining the life. The option control unit 250 functions as a determination unit that determines the timing to start the detection period T. In this method, the detection period T is set after the rise of the output signal of the option encoder 204 (time t1) is detected, so that the rotation speed is detected when the option retard roller 205 is reliably rotating. be able to.

Further, the distance from the paper feed nip portion Pp to the separation nip portion Pfr and the distance from the separation nip portion Pfr to the nip portion of the optional transport roller pair 207 are known in advance. Therefore, avoid the timing (time Tb) when the leading edge of the recording material S1 enters the nip portion of the pair of optional transport rollers 207 (time Tb) and the timing (time Tc) when the trailing edge of the recording material S passes through the paper feeding nip portion Pp. You can That is, the time t2′ at which the detection period T is started is corrected by using the time lag Tlb, and the detection period T in which the rotation of the option retard roller 205 is stable and the conveyance variation of the recording material S is taken into consideration is provided. It becomes possible. In the first embodiment, the time “t2′+Tlb” obtained by adding the delay time lag Tlb to the time t2′ with respect to the time from the time Ta when the drive signal is output to the time t2′ at which the detection period T is started is calculated. At time t2, which is the start timing of the corrected detection period T. That is, in the first embodiment, the predetermined time t2′ at which the detection period T is started is corrected by the time lag Tlb to obtain the time t2=t2′+Tlb, and the predetermined time from the time t2 is set as the detection period T. ..

As described above, in the first embodiment, the detection period T for determining the life of the optional retard roller 205 is set in consideration of the stable rotation of the separation rotary member and the correction of the transport variation at the start of transport. In the first embodiment, the description has been given using the paper feed option device 201, but this can also be applied to the method of setting the detection period of the life judgment of the retard roller 105 of the image forming apparatus 101.

As described above, according to the first embodiment, it is possible to appropriately set the period for detecting the rotation speed of the separated rotating body.

[Paper feeding optional device]
In the second embodiment, a method of setting the detection period for determining the life of the separated rotary body will be described in consideration of the correction of the variation in the transport when the transport is started and when the transport is stopped. The paper feeding option device 201 can be used by stacking several stages. FIG. 6 shows an example of a cross-sectional view in the case where the paper feed option devices 201 are stacked, for example, in three stages. Here, regarding the three sheet feeding option devices 201, the uppermost stage is denoted by the reference numeral (i), the lowermost stage is denoted by the reference numeral (iii), and the middle stage is denoted by the reference numeral (ii). Further, in the second embodiment, with respect to the recording material S conveyed toward the image forming unit, the recording material S (hereinafter also referred to as preceding paper) that is previously conveyed to the image forming unit is the recording material S1 and the recording material S1. The succeeding recording material S (hereinafter referred to as the succeeding paper) that is conveyed to the image forming unit is referred to as a recording material S2. Although the image forming apparatus 101 is attached to the upper stage of the paper feed option apparatus 201, the image forming apparatus 101 is described in the first embodiment, and therefore the illustration thereof is omitted in the first embodiment. Further, in the second embodiment, the image forming apparatus 101 includes a motor 160 that serves as a drive source for all the sheet feeding mechanisms included in the sheet feeding option device 201. This is an example of the configuration, and the motors responsible for the drive sources of all the sheet feeding mechanisms provided in the sheet feeding option device 201 can be provided in the sheet feeding option device 201.

When the sheet feeding option devices 201 are stacked and used as in the second embodiment, the recording materials S can be fed and conveyed from different sheet feeding option devices 201 alternately. FIG. 6 shows an example thereof. In FIG. 6, the recording material S1 is the recording material S that is fed in advance from the uppermost sheet feeding option device 201(i). Further, the recording material S2 is the recording material S2 fed from the lowermost sheet feeding option device 201(iii). When the recording material S1 fed from the paper feeding option device 201(i) is conveyed to the image forming apparatus 101 in advance, the recording material S2 conveyed later should not collide with the recording material S1 in the conveying path (collision). It is necessary to secure a certain interval or more to carry it. Depending on the image forming conditions, it may be necessary to temporarily stop the recording material S2 in order to secure a gap with the recording material S1, and then start the transportation again (hereinafter referred to as re-transportation). When the recording material S2 is temporarily stopped, not only the variation when the recording material S2 is initially fed, but also the variation when the recording material S2 is stopped and re-conveyed affects the detection period T. Will need to be considered.

[Feeding Conveyance Control of Embodiment 2]
FIG. 7 shows a time chart of each signal and sensor of the second embodiment. The horizontal axis of FIG. 7 indicates the elapsed time t. The vertical axis of FIG. 7A indicates the drive signal (ON signal or OFF signal) of the paper feed clutch 270 (iii) of the paper feed option device 201 (iii) at the bottom. The vertical axis of FIG. 7B shows the drive signal (ON signal or OFF signal) of the transport clutch 280(iii) of the paper feed option device 201(iii) at the bottom. The vertical axis of FIG. 7C shows the output signal (ON signal or OFF signal) of the option transport sensor 208 (iii) of the paper feed option device 201 (iii) at the bottom. The vertical axis of FIG. 7D shows the output signal (ON signal or OFF signal) of the optional transport sensor 208(i) of the uppermost sheet feeding option device 201(i). The ON signal of the optional transport sensor 208(i) indicates that the recording material S1 and the recording material S2 are detected, respectively. The vertical axis of FIG. 7E indicates the rotation speed (option encoder signal) of the option retard roller 205(iii) of the lowermost sheet feeding option device 201(iii). FIG. 7E also shows rotational speeds Vmin and Vmax described later. In addition, the time having the same meaning as in FIG. Note that the time t4′ in FIG. 7E corresponds to the time t4 in FIG. 5D, and the time t4 in the second embodiment will be described later.

In the second embodiment, the life determination of the option retard roller 205(iii) is performed using the minimum value Vmin and the maximum value Vmax of the rotation speed of the option retard roller 205(iii) in the detection period T of the life determination. When the rotation speed Vmin and the rotation speed Vmax are outside the predetermined speed range (outside the range), the optional retard roller 205 (iii) is used more and is unevenly worn, so that the rotation speed varies greatly and the life is increased. Is judged to have reached. When the rotation speed Vmin and the rotation speed Vmax are within a predetermined speed range, it is determined that the option retard roller 205(iii) is in a nearly circular shape and the rotation speed is stable and has not reached the end of its life. It In the configuration of the second embodiment, the life of the option retard roller 205(iii) may be determined based on the average value V1 of the rotation speed V. Further, the life judgment of the separated rotary body based on the rotation speeds Vmin and Vmax may be applied to other embodiments.

When the conveyance of the recording material S2 is started, the next time lag Tlb1 occurs. That is, from the time Ta at which the option drive control unit 255(iii) outputs the drive signal (ON signal) for the transport clutch 280(iii) to the time t1 at which the rotation of the option retard roller 205(iii) actually starts, it is slightly Then, a time lag Tlb1 occurs. The time lag Tlb1 influences the time from the reception of the drive signal (ON signal) by the transport clutch 280(iii) to the completion of the connection, and the time until the gear parts are engaged with each other. The time lag Tlb1 similarly exists when the conveyance of the recording material S2 is restarted. The time lag from the time ts' to the time t1' which occurs when the conveyance of the recording material S2 is restarted is Tlb2. Further, when the conveyance of the recording material S2 is temporarily stopped at a predetermined timing, the next time lag Tla occurs. That is, a time lag from time t4 when the option drive control unit 255 (iii) outputs the stop signal (OFF signal) of the transport clutch 280 (iii) to time ts when the rotation of the option retard roller 205 (iii) completely stops. Tla occurs. These two types of time lags Tlb1, Tlb2, and Tla affect the transport performance of the recording material S2. Therefore, the detection period T for determining the life of the optional retard roller 205(iii) must be set in consideration of the time lags Tlab1, Tlb2, and Tla. If these are not taken into consideration, the period during which the option retard roller 205(iii) is not rotating stably overlaps the detection period T for the life judgment, and there is a possibility that the correct life judgment cannot be performed.

[Setting of detection period T]
Therefore, a method for setting the detection period T for determining the life of the optional retard roller 205(iii) in consideration of the time lags Tlb1, Tlb2, and Tla at the time of starting and stopping the conveyance of the recording material S2 will be described in detail with reference to FIG. I do. After the conveyance of the recording material S1 is started, the option drive control unit 255(iii) outputs the drive signal of the conveyance clutch 280(iii) for starting the feeding of the recording material S2 at time Ta, and the optional pickup roller 203(iii). Drive. The optional drive control unit 255 (iii) outputs a drive signal for the transport clutch 280 (iii) that starts transporting the recording material S2 at time Ta. Then, the driving force of the motor 160 is transmitted to the option feed roller 206(iii), the option retard roller 205(iii) and the option transport roller pair 207(iii), and the rotation of the option retard roller 205(iii) is rotated at time t1. Begins. At this time, the option measuring unit 251(iii) measures the time lag Tlb1. Specifically, the option measuring unit 251(iii) measures the time from time Ta to time t1. Time Ta is the time when the optional drive control unit 255(iii) outputs the drive signal for the transport clutch 280(iii). Time t1 is a time at which the signal of the option encoder 204(iii) indicating that the rotation of the option retard roller 205(iii) actually starts.

After a lapse of a certain time (predetermined timing) after the leading edge of the recording material S1 reaches the option conveyance sensor 208(i) which is the second detection unit, the option drive control unit 255(iii) performs the next control. I do. That is, in order to prevent the recording material S2 from colliding with the recording material S1, the option drive control unit 255(iii) outputs a stop signal for the paper feed clutch 270(iii) and the transport clutch 280(iii) at time t4. At this time, the option measuring unit 251(iii) measures the time lag Tla. Specifically, the option measurement unit 251(iii) measures the time from time t4 to time ts. Time t4 is a time when the option drive control unit 255(iii) outputs a stop signal for the transport clutch 280(iii). Time ts is the time when the signal of the option encoder 204(iii) indicating that the rotation of the option retard roller 205(iii) has stopped falls.

The recording material S1 is conveyed, and at time ts', the trailing edge of the recording material S1 passes through the optional conveyance sensor 208(i) (FIG. 7(d)). At time ts′, the optional drive control unit 255 (iii) drives the recording material S2 to start (restart) the feed clutch 270 (iii) drive signal and the transport clutch 280 (iii) to start the transport of the recording material S2. ) Is output again. As a result, the conveyance of the recording material S2 is restarted. The option measuring unit 251(iii) measures the time lag Tlb2. Specifically, the option measurement unit 251(iii) measures the time from time ts' to time t1'. Time ts' is the time when the optional drive control unit 255(iii) outputs the drive signal for the transport clutch 280(iii). At time t1', the signal of the option encoder 204(iii) indicating that the rotation of the option retard roller 205(iii) has rotated rises.

Then, the option measuring unit 251(iii) uses the time lags Tlb1 and Tlb2 that are the first time and the time lag Tla that is the second time to determine the detection period T of the life determination of the option retard roller 205(iii). decide. For example, the option measuring unit 251 calculates the final detection period T of the life determination by including the difference value obtained by subtracting the value of the time lag Tla from the total value of the time lag Tlb1 and the time lag Tlb2 in the detection period that is assumed in advance. To do. In the detection period T, the time Ta at which the drive signal of the transport clutch 280(iii) that transports the recording material S2 is first output is used as a reference.

Here, the time lags Tlb1 and Tlb2 are delays in the start of the conveyance of the recording material S2, and when the recording material S2 is stopped, the recording material S2 is stopped on the upstream side in the conveying direction from the position designated by the option drive control unit 255(iii). Means to do. On the contrary, the time lag Tla delays the stop of the conveyance of the recording material S, and means that the recording material S2 stops at the downstream side in the conveyance direction from the position designated by the option drive control unit 255(iii).

Therefore, when the value of the above-described arithmetic expression “(Tlb1+Tlb2)−Tla” is a positive value, the delay in the start of conveyance is larger than the delay in the stop of conveyance ((Tlb1+Tlb2)>Tla). This means that the recording material S2 has to be additionally conveyed by the temporary stop of the conveyance and the restart of the conveyance, that is, the detection period T is shifted to the rear side with respect to the time previously assumed. On the other hand, when the value of the above-mentioned arithmetic expression “(Tlb1+Tlb2)−Tla” is a negative value, the delay of the conveyance stop is larger than the delay of the conveyance start ((Tlb1+Tlb2)<Tla). This means that the recording material S2 must be conveyed with a delay due to the temporary stop of the conveyance and the restart of the conveyance, that is, the detection period T is shifted to the front side in time earlier than previously assumed.

The option control unit 250(iii) corrects the time t2, which is the start time of the detection period T, using the time lags Tlb1, Tlb2, and Tla that have measured these deviations. Accordingly, the detection period T of the life determination of the option retard roller 205(iii) excluding the deviation of the transport start timing and the transport stop timing of the recording material S2 is set, and the life determination of the option retard roller 205(iii) is appropriately performed. It becomes possible to do it.

In the second embodiment, the following correction is performed for the time from the time Ta when the drive signal is output to the start time t2' of the detection period T that is assumed in advance. That is, the time obtained by adding "(Tlb1+Tlb2)-Tla" to the time t2' that is the detection start timing that is provided in advance becomes the time t2 that is the start timing of the corrected detection period T. Specifically, when the value of the arithmetic expression “(Tlb1+Tlb2)−Tla” described above is a positive value, a positive value is added to the time t2′, and the time t2 at which the detection period T is started is the time t2′. Set slower than. When the value of the above-described arithmetic expression “(Tlb1+Tlb2)−Tla” is a negative value, a negative value is added to the time t2′ (the value is subtracted), and the time t2 when the detection period T is started is the time t2. Set earlier than'.

As described above, in the second embodiment, the method of setting the detection period T for determining the life of the separated rotating body in consideration of the correction of the variation in the transport at the start and the stop of the transport has been described. Although the second embodiment has been described using the paper feed option device 201, this can be applied to the method of setting the detection period T for determining the life of the retard roller 105 of the image forming apparatus 101. Further, although the sheet feeding option devices 201(i) and 201(iii) attached to the uppermost stage and the lowermost stage are described as an example in the second embodiment, they are also applied to the sheet feeding option devices 201 in different stages. Is possible.

As described above, according to the second embodiment, it is possible to appropriately set the period for detecting the rotation speed of the separated rotating body.

[Paper feeding optional device]
In the third embodiment, a method of setting the detection period for determining the life of the separated rotating body in consideration of the correction of the transport variation when the transport of the recording material S is stopped will be described. FIG. 8 shows an example of a cross-sectional view in the case where the sheet feeding option devices 201 are stacked in three stages and the recording material S is continuously conveyed from the lowermost sheet feeding option device 201 (iii). The method of attaching the reference numerals is the same as in the second embodiment. In the third embodiment, the recording material S is a long paper whose length in the transport direction is longer than that of plain paper (recording material having a predetermined length), and the recording material S1 is the recording material S previously transported, The material S2 is the recording material S conveyed after the recording material S1. Although the image forming apparatus 101 is attached to the upper stage of the paper feed option apparatus 201, the image forming apparatus 101 is not shown in FIG. Further, in the third embodiment, the image forming apparatus 101 includes a motor 160 that serves as a drive source for all the sheet feeding mechanisms included in the sheet feeding option device 201. The image forming apparatus 101 and the paper feed option apparatus 201 are a body that can convey the recording material S at a higher speed than the conveyance speed of plain paper. This is an example of the configuration, and the motor serving as a drive source of the sheet feeding mechanism provided in the sheet feeding option device 201 can be provided in the sheet feeding option device 201.

[Sheet feeding control of Embodiment 3]
FIG. 9 is a time chart of each signal and sensor of the paper feed option device 201(iii) according to the third embodiment. The horizontal axis of FIG. 9 indicates the elapsed time t. The vertical axis of FIG. 9A indicates the drive signal (ON signal or OFF signal) of the paper feed clutch 270 (iii) of the paper feed option device 201 (iii) at the bottom. The vertical axis of FIG. 9B indicates the drive signal (ON signal or OFF signal) of the transport clutch 280(iii) of the paper feed option device 201(iii) at the bottom. The vertical axis of FIG. 9C shows the output signal (ON signal or OFF signal) of the option conveyance sensor 208 (iii) of the paper feed option device 201 (iii) at the bottom. The vertical axis of FIG. 9D indicates the rotation speed (option encoder signal) of the option retard roller 205(iii) of the paper feed option device 201(iii) at the bottom. FIG. 9D also shows the average value V1 of the rotation speed V. Further, the time having the same meaning as in FIG. 7E is given the same symbol at each time given on the horizontal axis.

After the recording material S1 is conveyed, at time Ta, the optional drive control unit 255(iii) outputs the drive signal of the paper feed clutch 270(iii) for feeding the recording material S2 and the drive signal of the conveyance clutch 280(iii). To do. Then, the driving force of the motor 160 is transmitted to the option pickup roller 203 (iii), the option feed roller 206 (iii), the option retard roller 205 (iii), and the option transport roller pair 207 (iii). As a result, the optional retard roller 205(iii) starts to rotate at time t1. At this time, a time lag Tlb1 occurs. The time lag Tlb1 is the time from time Ta to time t1. Time Ta is the time when the optional drive control unit 255(iii) outputs the drive signal for the transport clutch 280(iii). Time t1 is a time at which the signal of the option encoder 204(iii) indicating that the option retard roller 205(iii) has actually started rotating.

The time lag Tlb at the start of conveyance is generated also when the conveyance of the recording material S2 is temporarily stopped at the time ts' after the conveyance of the recording material S2 is temporarily stopped in order to maintain a distance from the recording material S1. .. The time lag that occurs at this time is Tlb2. The time lags Tlb1 and Tlb2 are the main factors of the time until the transport clutch 280(iii) is engaged and the time before the gears are engaged. The time lags Tlb1 and Tlb2 become shorter as the rotation speed of the transport clutch 280 and the rotation speed of the gear become faster. When the conveyance speed of the recording material S is high as in the third embodiment, the time lags Tlb1 and Tlb2 at the start of conveyance are shorter than those when the conveyance speed of the recording material S is low, and the conveyance characteristics of the recording material S are reduced. Can be ignored because it does not affect much.

On the other hand, in order to temporarily stop the recording material S2, at time t4, the option drive control unit 255(iii) outputs a stop signal for the paper feed clutch 270(iii) and a stop signal for the transport clutch 280(iii). Then, the driving force of the motor 160 to the option pickup roller 203 (iii), the option feed roller 206 (iii), the option transport roller pair 207 (iii), and the option retard roller 205 (iii) is cut off. As a result, the rotation of the optional retard roller 205(iii) is stopped at the time ts. However, even if the stop signal of the transport clutch 280(iii) is output, the transport clutch 280(iii) and the optional retard roller 205(iii) do not stop immediately, but stop after rotating for a while due to inertia. This becomes the time lag Tla1. The time lag Tla1 that is the second time delays the conveyance stop of the recording material S2, and the recording material S2 stops downstream of the position instructed by the option drive control unit 255(iii) in the conveyance direction. Further, the time lag Tla1 becomes longer as the rotation speed of the optional retard roller 205(iii) becomes faster.

Therefore, in the third embodiment, the option measuring unit 251(iii) takes time from the time t4 when the stop signal of the transport clutch 280(iii) is output to the time ts when the rotation of the option retard roller 205(iii) is completely stopped. To measure. That is, the option measuring unit 251(iii) measures the time lag Tla1 which is the time until the signal of the option encoder 204(iii) falls. The option control unit 250(iii) determines the time t2 which is the start timing of the detection period T based on the time lag Tla1. This makes it possible to set the detection period T for determining the life of the optional retard roller 205(iii) that is not affected by the transport characteristics of the recording material S2.

By the way, in FIG. 7 of the second embodiment, the paper feed clutch 270(iii) is turned off at time t3 before turning off the transport clutch 280(iii) at time t4'. On the other hand, in the third embodiment, at the time t4', the feed clutch 270(iii) is turned off together with the conveyance clutch 280(iii). This is because the recording material S of Example 3 is a long paper. While the recording material S2 is being conveyed, the paper feed clutch 270 is turned on as much as possible to reduce the back tension on the recording material S2 by the optional pickup roller 203 so that the conveyance characteristics are not affected. Further, when the recording material S next to the recording material S2 is continuously conveyed, the time lag Tla2 measured by the option measuring unit 251(iii) is used so that the distance between the recording material S and the recording material S conveyed later is appropriate. It becomes possible to secure it. The time lag Tla2 is the time from time t4' to time Td.

In the third embodiment, the option control unit 250(iii) subtracts the time lag Tla1 from the time t2′ that is the start timing of the detection period T that is provided in advance from the time Ta when the drive signal is output (t2=t2′− Tla1). As described above, in the third embodiment, the time lags Tlb1 and Tlb2 can be ignored. This value becomes the time t2 which is the corrected start timing of the detection period T.

In the third embodiment, the method of setting the detection period for determining the life of the separated rotating body in consideration of the transport variation when the transport of the recording material is stopped has been described. Although the third embodiment has been described using the paper feed option device 201, this can also be applied to the method of setting the detection period for determining the life of the retard roller 105 of the image forming apparatus 101. Further, in the third embodiment, the sheet feeding option device 201(iii) attached to the lowermost stage has been described as an example, but the present invention can be applied to the sheet feeding option device 201 in another stage.

As described above, according to the third embodiment, it is possible to appropriately set the period for detecting the rotation speed of the separated rotating body.

203 Option pickup roller 204 Option encoder 205 Option retard roller 206 Option feed roller 250 Option control unit 253 Option determination unit 255 Option drive control unit 280 Transport clutch

Claims (13)

A feeding unit that feeds the recording material at the contact position where the recording material is stacked on the stacking unit,
A paper feed rotator for feeding the recording material fed by the feeding means,
A separation nip portion is formed by abutting against the sheet feeding rotating body, and when a plurality of recording materials are fed from the stacking portion, one recording material is separated and is conveyed downstream in the conveying direction. A rotating body,
A first detection means for detecting a rotation state of the separated rotating body;
Transmission means that is in a connected state when transmitting the driving force of the driving means to at least the sheet feeding rotating body and is in a released state when the transmission of the driving force is cut off;
Determination means for determining whether or not the separation rotor has reached the end of its life, based on the detection result of the first detection means,
Control means for outputting a drive signal to control the transmission means,
A paper feeding device comprising:
A sheet feeding device, comprising: a determining unit that determines a timing at which the determination unit starts the determination based on a timing at which the control unit outputs the drive signal and a detection result of the first detection unit. apparatus. The deciding means has a first time from the timing of outputting the drive signal for bringing the transmitting means into the connected state to the timing of detecting the start of rotation of the separated rotating body by the first detecting means. The sheet feeding device according to claim 1, wherein the timing for starting the determination is determined based on the above. 3. The salary according to claim 2, wherein the determining unit determines the timing to start the determination by adding the first time to a predetermined timing to start the determination. Paper equipment. The deciding means has a first time from the timing of outputting the drive signal for bringing the transmitting means into the connected state to the timing of detecting the start of rotation of the separated rotating body by the first detecting means. And a second time from the timing of outputting the drive signal for setting the transmission means to the release state to the timing of detecting that the separation rotary body stops rotating by the first detection means. The sheet feeding device according to claim 1, wherein the timing for starting the determination is determined based on the determination. The determination means determines the timing to start the determination by adding a value obtained by subtracting the second time from the first time to a predetermined timing for starting the determination. The paper feeding device according to claim 4, wherein The sheet feeding device according to any one of claims 2 to 5, wherein the first time period increases as the rotation speed of the transmission unit decreases. The deciding means has a second time from the timing of outputting the drive signal for bringing the transmitting means to the release state to the timing of detecting the stop of the rotation of the separated rotary body by the first detecting means. The sheet feeding device according to claim 1, wherein the timing for starting the determination is determined based on the above. 8. The salary according to claim 7, wherein the determining unit determines the timing to start the determination by subtracting the second time from a predetermined timing to start the determination. Paper equipment. 9. The paper feeding device according to claim 7, wherein the second time is longer as the rotation speed of the separating rotary body is higher. A second detection unit provided on the downstream side of the separation nip portion in the transport direction,
The predetermined timing is a timing after the leading edge of the preceding paper conveyed prior to the recording material conveyed in the separation nip portion is after the timing detected by the second detecting means. And the trailing edge of the preceding paper is set in advance so as to come before the timing when the trailing edge of the preceding paper leaves the abutting position. The sheet feeding device according to item 1. 2. The determining means determines that the separating rotary body has reached the end of its life, based on the average value of the rotation speeds of the separating rotary body detected by the first detecting means. 11. The sheet feeding device according to claim 10. The determining means may determine that the separating rotary body has reached the end of its life, based on the maximum value and the minimum value of the rotation speed of the separating rotary body detected by the first detecting means. The sheet feeding device according to claim 1. A sheet feeding device according to any one of claims 1 to 12,
An image forming unit for forming an image on the recording material fed from the paper feeding device;
An image forming apparatus comprising:

Images