JP2019113702A - Image forming apparatus and sheet conveyance device - Google Patents

Abstract

To provide a printer which can prevent discomfort from being given to a user by an operation sound of a contact/separation mechanism for bringing into contact and separating a fixing roller and a pressure roller.SOLUTION: A printer 1 comprises: a pressure roller contact/separation mechanism for bringing into contact and separating a fixing roller 16a and a pressure roller 16b disposed opposite to the fixing roller 16a; and a controller 200 for controlling the pressure roller contact/separation mechanism. When a specific condition is established, the controller 200 operates the pressure roller contact/separation mechanism so as to separate the fixing roller 16a and the pressure roller 16b at a first speed. When a prescribed time elapses without a new image forming job being started after an image forming job is completed, it operates the pressure roller contact/separation mechanism so as to separate the fixing roller 16a and the pressure roller 16b at a second speed which is slower than the first speed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sheet conveying apparatus and an image forming apparatus.

  Generally, in an image forming apparatus such as a copying machine or a facsimile machine, a pressure roller is in pressure contact with a heating roller to form a nip, and an image is fixed on a sheet. Conventionally, in order to prevent deterioration due to leaving for a long time in a state in which the heating roller and the pressure roller are in pressure contact, separation of separating the pressure roller from the heating roller when transitioning to the sleep mode in which power consumption is smaller than normal An image forming apparatus provided with a mechanism has been proposed (see Patent Document 1). The image forming apparatus shifts to the sleep mode when a preset time elapses without a user operation on the image forming apparatus, and operates the separation mechanism to separate the pressure roller from the heating roller. It is configured to let you

Patent No. 5127311

  However, in the image forming apparatus described in Patent Document 1, the separation mechanism operates when a preset time elapses after the user finishes the operation, so that the operation noise is generated suddenly from the image forming apparatus. There is a possibility that the user is easily felt and the user feels uncomfortable.

  Therefore, the present invention provides a sheet conveying apparatus and an image forming apparatus capable of preventing the user from making the user uncomfortable by the operation noise of the contact / separation means for bringing the first and second rotary members into and out of contact with each other. The purpose is to

  According to the present invention, in an image forming apparatus for forming an image on a sheet conveyed along a conveyance path, a first rotation body and a second rotation body, which are rotated along with execution of an image forming job, the first rotation body, and A contact / separation means for bringing the second rotating body into and out of contact, and a control means for controlling the contact / separation means, wherein the control means performs the first rotation at a first speed when a specific condition is satisfied. The contact / separation unit is operated to separate the body and the second rotating body, and the first image forming job is ended after a predetermined time has elapsed without starting a new image forming job. The contact / separation means is operated to separate the first rotating body and the second rotating body at a second speed that is lower than the speed.

  A sheet conveying apparatus for conveying a sheet pinched by a rotating body and an abutting member capable of abutting on the rotating body, the contact / separation means for bringing the rotating body and the abutting member into contact with each other, and conveying the sheet And control means for controlling the contact / separation means while executing the transport job, and the control means separates the rotating body and the contact member at a first speed when a specific condition is satisfied. When the predetermined time has elapsed without starting a new conveyance job after the conveyance job is ended, the rotating body and the rotor are rotated at a second speed lower than the first speed. The contact / separation means is operated to be separated from the contact member.

  According to the present invention, it is possible to reduce the operation noise generated suddenly from the contact and separation means without increasing the waiting time of the user, and to prevent the user from feeling uncomfortable.

FIG. 1 is an overall schematic view showing a printer according to an embodiment of the present invention. FIG. 2 is a block diagram showing a control configuration of a printer. (A) is a diagram schematically showing the pressure roller contact / separation mechanism in a state where the pressure roller is positioned at the pressure contact position, (b) is a pressure roller contact / separation mechanism in a state where the pressure roller is positioned at the separation position The figure shown typically. (A) A diagram schematically showing the transfer roller contact / separation mechanism in a state in which the primary transfer roller is positioned at the pressing position, and (b) schematically illustrates the transfer roller contact / separation mechanism in a state in which the primary transfer roller is positioned at the separation position Figure showing. (A) Diagram schematically showing the developing roller contact / separation mechanism in a state where the holding member is located at the proximity position, (b) is a diagram schematically showing the developing roller contact / separation mechanism in the state where the holding member is located at the separation position . The flowchart which shows the process which a controller performs in a normal state. The flowchart which shows the process which a controller performs in a shutdown state. The flowchart which shows the process which a controller performs in a power-saving state and a partial power supply state.

〔overall structure〕
First, the present embodiment will be described. The printer 1 as an image forming apparatus according to the present embodiment is an electrophotographic laser beam printer. As shown in FIG. 1, the printer 1 is a so-called intermediate transfer tandem system including four image forming units 1Y, 1M, 1C, and 1Bk, an intermediate transfer unit 20, and a sheet conveyance unit 50 as a sheet conveyance device. Is a printer. The printer 1 executes an image forming job for forming and outputting an image on the conveyed sheet P based on image information read from a document and image information input from an external device. The sheet P includes, in addition to plain paper, special paper such as coated paper, special paper such as envelope and index paper, plastic film for overhead projector, cloth and the like.

  Image forming units 1Y, 1M, 1C and 1Bk are image forming units for forming toner images of yellow, magenta, cyan and black, respectively, and photosensitive drums 2a, 2b, 2c and 2d, which are image carriers for electrophotography, respectively. Have. The image forming units 1Y, 1M, 1C, and 1Bk have charging devices 10a, 10b, 10c and 10d, developing devices 4a, 4b, 4c and 4d, and drum cleaners 6a, 6b, 6c and 6d, respectively. The developing devices 4a to 4d respectively include holding members 903a, 903b, 903c, and 903d, developing rollers 904a, 904b, 904c, and 904d, and toner sensors 905a, 905b, 905c, and 905d. Further, an exposure device 7 is provided in the vicinity of the image forming units 1Y, 1M, 1C, and 1Bk. The configurations of the image forming units 1Y, 1M, 1C, and 1Bk are basically the same except that the color of toner used for development is different. Therefore, the configuration of the yellow image forming unit 1Y will be described as an example. Do.

  A photosensitive drum 2a as a photosensitive member is a negatively charged OPC photosensitive member, and is made of an aluminum drum substrate having a photoconductive layer formed on the surface. The photosensitive drum 2a is rotated at a predetermined process speed by a motor (not shown). The charging device 10a uniformly charges the surface of the photosensitive drum 2a to a predetermined negative potential by a charging bias applied from a charging bias power supply (not shown). The exposure device 7 includes a laser emission unit 71 that emits light based on image data input from an external device (hereinafter referred to as a PC) such as a personal computer (not shown), a polygon lens 72, a reflection mirror 73, and the like. The photosensitive drum 2a is exposed and scanned by the laser beam emitted from the laser emitting unit 71, and an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 2a charged by the charging device 10a. .

  The developing device 4a of the image forming unit 1Y stores toner of the corresponding color, that is, yellow toner. The developing device 4a has a holding member 903a supported by the apparatus main body 30, and an elastic layer made of synthetic rubber or the like having minute asperities formed on the surface, and supplies the toner to the photosensitive drum 2a. And have. The developing roller 904a is rotatably supported by the holding member 903a, and the holding member 903a slides relative to the apparatus main body 30, so that the developing roller 904a can contact and be separated from the photosensitive drum 2a. The developing device 4a is biased to a position where the developing roller 904a approaches the photosensitive drum 2a by a spring (not shown). The developing roller 904a is rotated by a motor (not shown) as the image forming job is executed by the printer 1, and supplies the yellow toner contained in the developing device 4a to the photosensitive drum 2a. The developing roller 904a supplies toner to the photosensitive drum 2a to develop the electrostatic latent image formed on the photosensitive drum 2a with toner, thereby forming a toner image on the surface of the photosensitive drum 2a.

  Further, the developing device 4a has a toner sensor 905a for detecting the amount of toner stored. The toner sensor 905a is formed of a photo interrupter, and outputs a toner small amount signal when the amount of toner stored in the developing device 4a is smaller than a predetermined amount.

  The drum cleaner 6a has a cleaning blade (not shown), and uses the cleaning blade to scrape off and collect the toner remaining on the surface of the photosensitive drum 2a after the primary transfer of the toner image described later.

  The intermediate transfer unit 20 includes an intermediate transfer belt 8 as an intermediate transfer member, which is an endless belt member, a secondary transfer inner roller 14 rotatably supported by the apparatus main body 30 and stretching the intermediate transfer belt 8; And a tension roller 11. The intermediate transfer belt 8 is formed in a film shape from a dielectric resin such as polycarbonate, polyethylene terephthalate, polyvinylidene fluoride or the like. It is wound around the secondary transfer inner roller 14 and the tension roller 11, and is disposed so as to face the surfaces of the photosensitive drums 2a to 2d of the image forming portions 1Y, 1M, 1C, and 1Bk on the outer peripheral surface.

  The intermediate transfer unit 20 is disposed on the inner peripheral side of the intermediate transfer belt 8 so as to face the intermediate transfer belt 8 at positions corresponding to the photosensitive drums 2a to 2d of the image forming units 1Y, 1M, 1C, and 1Bk. The primary transfer rollers 5a, 5b, 5c and 5d are provided. The primary transfer rollers 5a to 5d as transfer rollers have an elastic layer made of synthetic rubber or the like on the surface, and can be separated from the intermediate transfer belt 8 by a spring (not shown). It is urged to press against it. The primary transfer rollers 5 a to 5 d are rotatably supported by the apparatus main body 30. Thus, the photosensitive drums 2a to 2d, the intermediate transfer belt 8 and the primary transfer rollers 5a to 5d transfer primary toner images from the photosensitive drums 2a to 2d to the intermediate transfer belt 8 at the primary transfer portions T1a, T1b, T1c, It forms T1d.

  The secondary transfer inner roller 14 is rotated in the direction of arrow R8 by a motor (not shown) in accordance with the execution of the image forming job, and the intermediate transfer belt 8 is rotated by the photosensitive drums 2a of the image forming units 1Y, 1M, 1C, 1Bk. It rotates in the direction of arrow R7 that rotates with the rotation of 2d.

  When an image forming job is started by the printer 1, the photosensitive drums 2a to 2d, the inner secondary transfer roller 14, the intermediate transfer belt 8 and the developing rollers 904a to 904d start to rotate. Further, with the start of rotation, the surfaces of the photosensitive drums 2a to 2d are uniformly charged by the charging devices 10a to 10d, and then electrostatic latent images are formed on the surfaces of the photosensitive drums 2a to 2d by the exposure device 7. Be done. Toners are supplied from the rotating developing rollers 904a to 904d to the photosensitive drums 2a to 2d, and the electrostatic latent image formed on the photosensitive drum 2a is developed as a toner image of the corresponding color by the supplied toner. It is visualized. The toner images formed on the photosensitive drums 2a to 2d are primarily transferred onto the intermediate transfer belt 8 at the primary transfer portions T1a to T1d by electrostatic bias applied to the primary transfer rollers 5a to 5d. At this time, in the case of forming a color image, the toner images carried on the respective photosensitive drums 2a to 2d are subjected to multiple transfer so as to be in a state where they overlap each other.

  The sheet conveying unit 50 includes a feeding cassette 17 for storing and storing sheets P, a manual feed tray 33 capable of supplying the sheets P from the outside of the printer 1, a conveying path 23 and a reverse conveying path 24 in which the sheet P is conveyed. And. Further, the sheet conveyance unit 50 includes a conveyance unit main body 51 supported by the apparatus main body 30 and a conveyance door 52 supported openably and closably with respect to the conveyance unit main body 51. The conveyance door 52 is openable and closable about a rotation shaft 52a extending in parallel with the width direction orthogonal to the conveyance direction of the sheet P between the sheet conveyance position where the sheet P can be conveyed and the open position where the sheet can not be conveyed. Is pivotally supported by the apparatus main body 30. When the conveyance door 52 is located at the sheet conveyance position, the reverse conveyance path 24 is formed between the left end of the conveyance door 52 and the right end of the conveyance unit main body 51, and the conveyance door 52 rotates in the R9 direction. When it is positioned at the open position, the reverse conveyance path 24 is opened.

  The sheet conveyance unit 50 detects a sheet sensor 23 a for detecting the sheet P on the conveyance path 23, a sheet sensor 24 a for detecting the sheet P on the reverse conveyance path 24, and an opening of the conveyance door 52. And an open sensor 52b. The sheet sensors 23a and 24a are formed of photo interrupters, and output a sheet detection signal when light is blocked by the sheet P on the conveyance path 23 or the sheet P on the reverse conveyance path 24. Further, the opening sensor 52b outputs an opening signal when the conveyance door 52 is rotated and the reverse conveyance path 24 is opened.

  The feeding cassette 17 is provided slidably with respect to the apparatus body 30 between a sheet feeding position where the sheet P can be fed and a drawing position where the sheet P is pulled out and can not be fed. ing. The apparatus main body 30 has a feeding cassette sensor 15 for detecting the position of the feeding cassette 17. The feeding cassette sensor 15 is constituted by a photo interrupter, and outputs a feeding cassette pulling out signal when the feeding cassette 17 is located at the pulling out position.

  Further, the sheet conveying unit 50 is disposed at the downstream end of the sheet feeding cassette 17 and disposed so as to face the feeding roller 31 rotatably supported by the apparatus main body 30 and the feeding roller 31. And a feed separation pad 32. Further, the sheet conveying unit 50 is provided with a feed pad arm (not shown) which is swingably supported by the apparatus main body 30 and to which the feed separation pad 32 is attached. The feed roller 31 has an elastic layer made of synthetic rubber or the like on the surface, and is rotated by a motor (not shown) as the printer 1 executes an image forming job. The feed separation pad 32 is formed of an elastic material such as synthetic rubber, and can be brought into contact with and separated from the feed roller 31 by swinging the feed pad arm, and is pressed against the feed roller 31 by a spring not shown. It is urged to do. The feed roller 31 and the feed separation pad 32 separate and feed the sheets P stored in the feed cassette 17 one by one as the feed roller 31 rotates.

  The manual feed tray 33 is configured to be able to load and support the sheets P supplied by the user. The sheet conveying unit 50 includes a manual feed roller 35 rotatably supported on the apparatus main body 30 at the downstream end of the manual feed tray 33, and a manual feed separation pad 36 disposed opposite to the manual feed roller 35. ing. Further, the sheet conveying unit 50 is provided with a manual feed pad arm 37 which is supported by the apparatus main body 30 so as to be pivotable about the rotation shaft 38 and to which the manual feed separation pad 36 is attached. The manual feed roller 35 has an elastic layer made of synthetic rubber or the like on its surface, and rotates as the printer 1 executes an image forming job. The manual feed separation pad 36 is formed of an elastic material such as synthetic rubber, and can be brought into or out of contact with the manual feed roller 35 by swinging the manual feed pad arm 37 and be in pressure contact with the manual feed roller 35 by a spring not shown. It is energized. The manual feed roller 35 and the manual feed separation pad 36 separate and feed the sheets P supported by the manual feed tray 33 one by one as the manual feed roller 35 rotates.

  The sheet conveying unit 50 includes a registration roller pair (hereinafter, referred to as a registration roller pair) 19 downstream of the feed roller 31 and the manual feed roller 35. The feed roller 31 and the manual feed roller 35 convey the fed sheet P to the registration roller pair 19 along the conveyance path 23. The registration roller pair 19 includes a drive roller 19a rotatably supported on the apparatus main body 30, and a driven roller 19b disposed to face the drive roller 19a. The driving roller 19 a has an elastic layer made of synthetic rubber or the like on the surface, and rotates with the execution of the image forming job by the printer 1. The driven roller 19b has an elastic layer made of synthetic rubber or the like on the surface, and is capable of coming into contact with and separating from the drive roller 19a, and is urged to press against the drive roller 19a by a spring not shown. . Further, the driven roller 19 b is rotatably supported by the conveyance unit main body 51, and forms a nip with the drive roller 19 a. When the drive roller 19a rotates, the driven roller 19b is driven to rotate the driven roller 19a, and the registration roller pair 19 holds the sheet P by the nip of the registration roller pair 19 to correct the sheet P for skew feeding. The registration roller pair 19 conveys the sheet P along the conveyance path 23 in synchronization with the progress of the image forming job by the rotation of the drive roller 19 a.

  The sheet conveying unit 50 includes a secondary transfer outer roller 12 disposed so as to sandwich the secondary transfer inner roller 14 and the intermediate transfer belt 8 so as to face the intermediate transfer belt 8 downstream of the registration roller pair 19. There is. The secondary transfer outer roller 12 is rotatably supported by the transport unit main body 51, forms a nip with the intermediate transfer belt 8, and transfers the toner image to the sheet P while transporting the sheet P. The secondary transfer portion T2 is configured. Further, the secondary transfer outer roller 12 has an elastic layer made of synthetic rubber or the like on the surface, can contact with and separate from the intermediate transfer belt 8, and can move against the intermediate transfer belt 8 by a spring (not shown). It is biased to press fit.

  The secondary transfer portion T2 holds the sheet P by the nip, and is rotated by the rotating intermediate transfer belt 8 and the secondary transfer outer roller 12 which is rotated by the intermediate transfer belt 8 and to which an electrostatic bias is applied. The toner image carried on the intermediate transfer belt 8 is secondarily transferred to the sheet P. An extraneous substance such as transfer residual toner remaining on the intermediate transfer belt 8 after passing through the secondary transfer portion T2 is removed by the belt cleaning device 13 provided in the intermediate transfer unit 20.

  The sheet conveying unit 50 includes a fixing device 16 downstream of the secondary transfer unit T2. The secondary transfer portion T2 conveys the sheet P on which the unfixed toner image has been transferred to the fixing device 16 by the rotation of the intermediate transfer belt 8. The fixing device 16 includes a fixing roller 16 a rotatably supported by the apparatus main body 30 and a pressure roller 16 b disposed to face the fixing roller 16 a. The fixing roller 16a has an elastic layer made of synthetic rubber or the like on the surface, and is rotated as the image forming job is performed by the printer 1 and is heated by a heat source such as a halogen heater. The pressure roller 16b has an elastic layer made of synthetic rubber or the like on its surface, and is capable of coming into contact with and separating from the fixing roller 16a, and is urged to press the fixing roller 16a by a spring (not shown). There is. The pressure roller 16b is rotatably supported by the conveyance section main body 51, and a fixing nip 16c for fixing an image on the sheet P is formed between the pressure roller 16b and the fixing roller 16a. In the fixing device 16, when the fixing roller 16 a is rotated, the pressure roller 16 b is rotated by being driven by the fixing roller 16 a and applies heat and pressure to the toner image while conveying the sheet P by nipping the fixing nip 16 c. Do. Thereby, the toner particles are melted and fixed, and the image is fixed on the sheet P.

  The sheet conveying unit 50 includes a discharge roller pair 21 downstream of the fixing device 16. The fixing device 16 conveys the sheet P on which the image is fixed to the discharge roller pair 21 along the conveyance path 23. The discharge roller pair 21 includes a discharge drive roller 21a rotatably supported on the apparatus main body 30, and a discharge driven roller 21b disposed to face the discharge drive roller 21a. The discharge drive roller 21 a has an elastic layer made of synthetic rubber or the like on the surface, and rotates with the execution of the image forming job by the printer 1. The discharge driven roller 21b has an elastic layer made of synthetic rubber or the like on the surface, is capable of coming into contact with and separating from the discharge drive roller 21a, and is in pressure contact with the discharge drive roller 21a by a spring not shown. It is energized. Further, the discharge driven roller 21b is rotatably supported by the transport unit main body 51, and forms a nip with the discharge drive roller 21a. When the discharge drive roller 21 a rotates, the discharge driven roller 21 b rotates following the discharge drive roller 21 a, and the discharge roller pair 21 nips and conveys the sheet P by the nip of the discharge roller pair 21. The discharge roller pair 21 conveys the sheet P and discharges the sheet P to a discharge tray 22 disposed in the upper part of the printer 1.

  When the printer 1 starts an image forming job for forming an image on the sheet P stored in the feeding cassette 17, the feeding roller 31 starts to rotate, and is pinched by the feeding roller 31 and the feeding separation pad 32. The sheets P are fed one by one. In addition, when the printer 1 starts an image forming job for forming an image on the sheet P supported by the manual feed tray 33, the manual feed roller 35 starts to rotate, and the sheet pinched by the manual feed roller 35 and the manual feed separation pad 36. P is fed one by one. Thereafter, the sheet P fed one by one is nipped by the drive roller 19 a and the driven roller 19 b of the registration roller pair 19, and is conveyed to the conveyance path 23 so as to match the progress of the image forming job while being subjected to skew correction. It is transported along.

  The toner image is secondarily transferred while the sheet P conveyed to the registration roller pair 19 is conveyed while being sandwiched between the intermediate transfer belt 8 and the secondary transfer outer roller 12 at the secondary transfer portion T2. The sheet P on which the toner image has been transferred at the secondary transfer portion T2 is fixed by the fixing device 16 while being nipped and conveyed by the fixing roller and the pressure roller, and the toner image is fixed, and the discharge driving roller 21a and the discharge driven roller 21b The sheet is pinched and conveyed, and discharged to the discharge tray 22. The sheet conveyance unit 50 feeds the sheet P from the feeding cassette 17 or the manual feed tray 33, conveys the sheet P along the conveyance path 23, and discharges the sheet P to the discharge tray 22. A series of processes is also referred to as a transfer job. The transport job includes an image forming job for forming an image on a sheet. When double-sided printing is performed, the sheet P is conveyed along the reverse conveyance path 24 by reversing the discharge driving roller 21 a. Thereafter, the sheet P in a state in which the first surface (front surface) and the second surface (back surface) are reversed is re-conveyed by the registration roller pair 19, passes through the secondary transfer portion T2 and the fixing device 16, and the image is printed on the back surface. And discharged to the discharge tray 22.

  The photosensitive drums 2a to 2d, the intermediate transfer belt 8 and the fixing roller 16a constitute a first rotating body in the present embodiment. The developing rollers 904a to 904d, the primary transfer rollers 5a to 5d, and the pressure roller 16b constitute a second rotating body in the present embodiment.

  Further, the fixing roller 16a constitutes a rotating body in the present embodiment. Further, the pressure roller 16 b is configured to be capable of being in pressure contact with the fixing roller 16 a as a rotating body. For this reason, it can be said that the pressure roller 16b is an abutting member that can abut on the rotating body.

  Although the developing rollers 904a to 904d are configured to be urged to positions approaching the photosensitive drums 2a to 2d, the present invention is not limited thereto. For example, the developing rollers 904a to 904d may be biased to a position in contact with or in pressure contact with the photosensitive drums 2a to 2d. In this case, it can be said that the developing rollers 904a to 904d are also contact members that can contact the rotating body.

  Further, hereinafter, the photosensitive drums 2a to 2d, the intermediate transfer belt 8, the feed roller 31, the manual feed roller 35, the drive roller 19a, the fixing roller 16a, and the discharge drive roller 21a are all referred to. Also stated. Further, hereinafter, any of the developing rollers 904a to 904d, the primary transfer rollers 5a to 5d, the feed separation pad 32, the manual feed separation pad 36, the driven roller 19b, the secondary transfer outer roller 12, the pressure roller 16b and the discharge driven roller 21b. The term "separation member 3b" is also used to indicate one or the other.

[Control configuration]
Next, the control configuration of the printer 1 in the present embodiment will be described with reference to FIG. As shown in FIG. 2, the control configuration of the printer 1 includes a controller 200, an input / output interface (hereinafter referred to as an input / output I / F) 205, a timer 206, an image processing unit 207, an operation unit 100, a printer engine 300 and It comprises the power supply unit 400 and the like. The controller 200 as control means includes a CPU 201, a ROM 202, a RAM 203, and an EEPROM 204.

  The CPU 201 controls the input / output I / F 205, the timer 206, the image processing unit 207, the operation unit 100, the power supply unit 400, and the printer engine 300 in accordance with control programs and information stored in the ROM 202 and the EEPROM 204. The RAM 203 provides a work area of the CPU 201. The input / output I / F 205 is an interface for inputting image data from the PC into the controller 200 and outputting information from the controller 200 to the PC. The timer 206 is a timer for measuring an elapsed time t after the end of the image forming job. The controller 200 uses the timer 206 to measure the elapsed time t. The image processing unit 207 converts image data input from the PC into image data of each color of yellow, magenta, cyan, and black interpretable by the printer engine 300, and transmits the converted image data to the exposure device 7. .

  The operation unit 100 has a plurality of hard keys (not shown) and a liquid crystal panel (not shown) for shifting the power supply state of the printer 1 including the normal state, the power saving state and the shutdown state. A plurality of hard keys include a power saving start key for instructing the start of the power saving state, a shutdown start key for instructing the start of the shutdown state, and a return key for instructing the termination of the power saving state or the shutdown state. , Is included. The power saving start key is configured to be able to transmit a power saving start signal by the user operation, the shutdown start key to the shutdown start signal by the user operation, and the return key to the controller 200 by transmitting the return signal by the user operation. There is. The controller 200 controls the transition of the power supply state of the printer 1 based on the reception of the power saving start signal, the shutdown start signal, and the return signal.

  The liquid crystal panel is a touch panel type liquid crystal display, and is configured to be able to operate the device when the user touches with a fingertip, and displays various states of the printer 1, various settings of the printer 1, and the like. The operation unit 100 transmits, to the controller 200, information input by operating the plurality of hard keys and the liquid crystal panel. The power supply unit 400 receives power supply from the outside, and supplies power to the operation unit 100 and the printer engine 300 via the controller 200 and the controller 200 based on the power supply state of the printer 1. Details of the power supply state will be described later.

  The printer engine 300 operates each unit of the printer 1 to form an image indicated by the image data received from the image processing unit 207 on the sheet P when the image forming job is executed by the printer 1. The printer engine 300 includes a CPU 301, a ROM 303, a RAM 304, an I / O circuit 305, an exposure device 7, a driver group 307, a sensor group 308, a high voltage driver 309, a pressure roller contact / separation mechanism 310, a transfer roller contact / separation mechanism 311, and a developing roller. A contact / separation mechanism 312 is included. The pressure roller contact / separation mechanism 310, the transfer roller contact / separation mechanism 311, and the developing roller contact / separation mechanism 312 respectively constitute contact / separation means in the present embodiment, and any one of these three contact / separation means It is also referred to as contact / separation mechanism 3.

  The CPU 301 controls an image forming job by controlling the driver group 307, the sensor group 308 and the high voltage driver 309 by reading out and executing a corresponding program from the ROM 303 based on an instruction of the CPU 201. The CPU 301 also controls the operation of each contact / separation mechanism 3. The CPU 301 of the printer engine 300 constitutes a control unit in the present embodiment.

  The RAM 304 provides a work area of the CPU 301 when an image forming job is executed by the printer 1. The I / O circuit 305 is an interface for controlling input and output between the CPU 301 and each component included in the printer engine 300. Specifically, the I / O circuit 305 controls input / output between the CPU 301, the driver group 307, the sensor group 308, the high voltage driver 309, and each contact / separation mechanism 3.

  The pressure roller contact / separation mechanism 310 applies pressure to the fixing roller 16a between a pressure contact position where the pressure roller 16b is in pressure contact with the fixing roller 16a and a separation position where the pressure roller 16b separates from the fixing roller 16a. The pressure roller 16b is brought into contact and separated. The transfer roller contact / separation mechanism 311 performs intermediate transfer between the pressing position where the primary transfer rollers 5 a to 5 d press against the intermediate transfer belt 8 and the separation position where the primary transfer rollers 5 a to 5 d separate from the intermediate transfer belt 8. The primary transfer rollers 5 a to 5 d are brought into contact with or separated from the belt 8. The developing roller contacting / separating mechanism 312 slides the holding members 903a to 903d, and brings the developing rollers 904a to 904d into contact with or separated from the photosensitive drums 2a to 2d between the close position and the separated position.

  In the following description, the operation of moving the contact / separation mechanism 3 from the contact position or proximity position to the separation position from the contact / separation mechanism 3 is also referred to as separation operation, and the contact / separation mechanism 3 contacts the contact / separation body 3b from the separation position Alternatively, the operation of moving to the close position is also referred to as return operation. Details of each contact / separation mechanism 3 will be described later.

  The driver group 307 drives a motor for rotating the photosensitive drums 2a to 2d, the developing rollers 904a to 904d, the secondary transfer inner roller 14, the feeding roller 31, and the fixing roller 16a, and a motor for operating the contact / separation mechanism 3. Includes each driver. Each driver configuring the driver group 307 drives each device based on a control signal from the CPU 301. The high voltage driver 309 generates various high voltages such as charging biases of the charging devices 10a to 10d, developing biases of the respective developing devices 4a to 4d, and transfer voltages of the primary transfer rollers 5a to 5d based on control signals from the CPU 301. Let The sensor group 308 includes a toner sensor 905a, sheet sensors 23a and 24a, an open sensor 52b, a feeding cassette sensor 15, a position sensor for detecting a home position of each device, and the like. Each sensor constituting the sensor group 308 transmits a signal to the CPU 301 via the I / O circuit 305.

  The CPU 301 also monitors the state of the printer 1. For example, when the CPU 301 receives a toner small amount signal, the CPU 301 detects a toner small amount state in which the amount of toner stored in the developing devices 4 a to 4 d is equal to or less than a predetermined amount. The CPU 301 transmits a toner small amount detection signal to the controller 200 when detecting the toner small amount state. When the CPU 301 does not receive the toner small amount signal after detecting the toner small amount state, the CPU 301 determines that the toner is supplied to the developing devices 4a to 4d, and transmits an error release signal to the controller 200.

  Also, for example, after starting the image forming job, the CPU 301 monitors whether or not there is a reception of a sheet detection signal from the sheet sensor 23a within a predetermined time after the start of driving of the motor for rotating the feeding roller 31. Do. When the CPU 301 does not receive the sheet detection signal within a predetermined time, the sheet P stagnates, and detects a sheet stagnant state in which the conveyance of the sheet P and the image formation on the sheet can not be performed. Also, for example, the CPU 301 monitors the time during which the state in which the sheet detection signal from the sheet sensors 23 a and 24 a is received continues while the image forming job is being executed. When the state in which the sheet detection signal is received continues for a predetermined time or more, the CPU 301 retains the sheet P in the transport path 23 or the reverse transport path 24 and can not transport the sheet P or form an image on the sheet. Detect the condition. The CPU 301 transmits a retention detection signal to the controller 200 when detecting a sheet retention state.

  After the detection of the sheet retention state, the CPU 301 receives the release signal to detect that the transport door 52 is opened and closed, and determines that the stagnated sheet P has been removed when the sheet detection signal is not received. An error clear signal is sent to the controller 200. Further, for example, when the CPU 301 receives the release signal in the state where the sheet is not in the sheet retention state, the CPU 301 detects that the transport unit main body 51 is positioned at the release position. When detecting that the transport door 52 is at the open position, the CPU 301 transmits an open detection signal to the controller 200. After detecting that the transport door 52 is at the open position, the CPU 301 determines that the transport door 52 has moved from the open position to the sheet transport position when the open signal is not received, and the controller 200 clears the error. Send a signal. Also, for example, when the CPU 301 receives a feeding cassette withdrawal signal in a state where the sheet is not in a stagnant state, the CPU 301 detects that the feeding cassette 17 is at the withdrawal position. When the CPU 301 detects that the feeding cassette 17 is at the withdrawal position, the CPU 301 transmits a withdrawal detection signal to the controller 200.

  In the following description, any one of a toner small amount detection signal, a retention detection signal, an open detection signal, and a withdrawal detection signal is referred to as an error detection signal.

  After detecting that the feeding cassette 17 is in the withdrawal position, the CPU 301 determines that the feeding cassette 17 has moved from the withdrawal position to the sheet feeding position when the feeding cassette withdrawal signal is not received. , And sends an error release signal to the controller 200.

[Details of power supply status]
Next, the details of the power supply state of the printer 1 in the present embodiment will be described. The controller 200 controls the transition of the power supply state of the printer 1 including the normal state, the power saving state, the partial power supply state and the shutdown state. In the normal state, power is supplied to each of the controller 200, the operation unit 100, and the printer engine 300 so that an image forming job can be performed. In the power saving state, power is supplied only to the corresponding configuration, and power consumption is less than in the normal state. Specifically, when the printer 1 is in the power saving state, power is supplied only to the controller 200, the input / output I / F 205, and the timer 206.

  The partial power supply state is a power supply state in which at least the power necessary for performing the separation operation with respect to each contact / separation mechanism 3 is supplied, the power consumption is smaller than the normal state, and the power consumption is larger than the power saving state. Specifically, when the printer 1 is in the partial power supply state, power is supplied to the controller 200, the input / output I / F 205, the timer 206, the CPU 301, and each motor constituting the contact / separation mechanism 3. The shutdown state is a power supply state in which power is supplied only to the corresponding configuration and power consumption is lower than the power saving state or the partial power supply state. Specifically, when the printer 1 is in the shutdown state, power is supplied only to the controller 200 and the input / output I / F 205.

  The controller 200 monitors the operation of the power saving start key and the shutdown start key and the reception of the error detection signal from the CPU 301 when the printer 1 is in the normal state. Further, when the printer 1 is in the normal state, the controller 200 causes the timer 206 to count an elapsed time t after the end of the image forming job. When the controller 200 does not start a new image formation job until the elapsed time t exceeds the first set time t1 as the first time, or when the controller 200 receives a signal based on the operation of the power saving start key, the power of the printer 1 is Shift the supply state to the power saving state. The first set time t1 constitutes a first time in the present embodiment.

  When the printer 1 is in the normal state, the controller 200 causes the contact / separation mechanism to separate the contact / separation member 3b from the contact / separation member 3a at the first speed when receiving either the shutdown start signal or the error detection signal. The CPU 301 transmits a first separation signal to cause the CPU 301 to perform separation operation. When the first separation signal is received, the CPU 301 configures each contact / separation mechanism 3 via the I / O circuit 305 so that the contact / separation member 3b is separated from the contact / separation member 3a at the first speed. Drive.

  The controller 200 shifts the power supply state of the printer 1 to the shutdown state after each contact / separation mechanism 3 performs the separation operation by the operation of the shutdown start key. The specific condition in the present embodiment is that the printer 1 is in the normal state and that at least one of the shutdown start signal and the error detection signal is received. For this reason, it can be said that the CPU 301 operates the contact / separation means so as to separate the contact / separation member 3a and the contact / separation member 3b at the first speed when the user performs a transition operation to the shutdown state. In addition, when the sheet P stays in the conveyance path 23, the CPU 301 can be said to operate the contact / separation unit so as to separate the contact / separation member 3a and the contact / separation member 3b at the first speed. In addition, when the printer 1 is in the normal state, the controller 200 transmits, to the CPU 301, a return signal for returning each contact / separation mechanism 3 when receiving an error release signal. When receiving the return signal, the CPU 301 drives the motors constituting the contact / separation mechanism 3 via the I / O circuit 305 so as to cause the contact / separation mechanism 3 to return.

  Further, when the printer 1 is in the power saving state, the controller 200 does not start a new image forming job or conveyance job until the elapsed time t exceeds the second set time t2, which is longer than the first set time t1. The contact / separation mechanism 3 is shifted to the operable partial power supply state. Then, when the controller 200 shifts the power supply state of the printer 1 from the power saving state to the partial power supply state, the contact / separation member 3b is separated from the contact / separation member 3a at the second speed slower than the first speed. The CPU 301 transmits a second separation signal for causing the contact / separation mechanism 3 to perform a separation operation to the CPU 301. When the CPU 301 receives the second separation signal, the motors constituting the contact / separation mechanism 3 via the I / O circuit 305 so that the contact / separation member 3b is separated from the contact / separation member 3a at the second speed. Drive. Since the second set time t2 is longer than the first set time t1, the controller 200 shifts the power supply state to the power saving state and then performs the first rotation at the second speed after a predetermined time has elapsed. It can be said that the contacting / separating mechanism 3 is operated to separate the body and the second rotating body.

  The second set time t2 is the time taken for the contact / separation members 3a and the contact / separation members 3b to deteriorate due to proximity or pressure contact, the number of times the contact / separation mechanism 3 can operate, and the other configurations of the printer 1 An appropriate value is set in advance in consideration of the service life and the like. Specifically, assuming that the service life of printer 1 is 10 years and the service life of contact / separation mechanism 3 is 10,000 times, the contact / separation mechanism 3 is allowed to operate approximately 2.7 times per day. Be done. In such a case, the second set time t2 is set to a value such that the number of operations of the contact / separation mechanism 3 is 2.7 times or less per day based on the execution frequency of a standard image forming job. In addition, whether or not the deterioration when each contact / separation member 3a and each contact / separation member 3b are in proximity or in pressure contact with each other until the second set time t2 set in this way elapses is acceptable. It is verified. If there is an unacceptable deterioration, the service life of the printer 1 or the number of times of service of the contact / separation mechanism 3 is reviewed so that the second set time t2 becomes an appropriate value, and the second setting is performed. The value of time t2 is set. As a result, the printer 1 can properly set the service life of each contact / separation mechanism 3, each contact / separation member 3a, each contact / separation member 3b, and other components of the printer 1, for example, each motor. The frequency of occurrence can be reduced. Furthermore, more specifically, in the present embodiment, the first set time t1 is preset to 10 minutes, and the second set time t2 is preset to 120 minutes.

  The time obtained by subtracting the first set time t1 from the second set time t2 constitutes a second time in the present embodiment. Therefore, the CPU 201 shifts the state of the printer from the normal state to the power saving state when the first time elapses without the start of a new image forming job or conveyance job after the image forming job or conveyance job is ended. It can be said that The CPU 201 moves the printer state from the normal state to the power saving state and does not start a new image forming job or transport job until the second time elapses, and the separated object 3a and the separated object 3a at the second speed. It can be said that each contact and separation means is operated so as to separate the contact and separation body 3b. In addition, the velocity of the contact / separation body 3b means the average velocity from the start of the movement of the contact / separation body 3b by the separation operation of the contact / separation mechanism 3 to the end of the movement.

  When each contact / separation mechanism 3 ends the separation operation in the partial power supply state, the controller 200 shifts the power supply state of the printer 1 to the shutdown state. Further, when the printer 1 is in the power saving state or the shutdown state, the controller 200 monitors the input of data from the input / output I / F 205 and the reception of the signal based on the operation of the return key. When the controller 200 receives an input of data from the input / output I / F 205 or a signal based on the operation of the return key in the power saving state, the controller 200 shifts the power supply mode of the printer 1 from the power saving state to the normal state.

  Further, when the controller 200 receives input of data from the input / output I / F 205 or reception of a signal based on the operation of the return key in the shutdown state, the power supply mode of the printer 1 shifts from the shutdown state to the normal state. Let Further, the controller 200 transmits a return signal to the CPU 301 when shifting the power supply state of the printer 1 from the power saving state after the partial power supply state to the normal state or from the shutdown state to the normal state.

[Details of contact / separation mechanism]
Next, details of each contact / separation mechanism 3 in the present embodiment will be described with reference to FIGS. 3 to 5. FIG. 3A is a view schematically showing a configuration of the pressure roller contact / separation mechanism 310 in a state where the pressure roller 16b is positioned at the pressure contact position. As shown in FIG. 3A, the pressure roller contact / separation mechanism 310 includes a lift cam 606, a moving member 607, a motor 604, and a photo sensor 605. The lift cam 606 has a circumferential surface whose distance from the rotation center to the circumferential surface is not constant, and is rotated by driving of the motor 604.

  The moving member 607 slides on the circumferential surface of the lift cam 606, and the pressing roller 16b is pressed against the fixing roller 16a. The rotation center of the fixing roller 16a is between the pressing position and the separating position separating from the fixing roller 16a. Move in the direction orthogonal to The lift cam 606 has a light shielding portion 606a. The photosensor 605 is in a light blocking state where the light blocking portion 606a blocks light when the lift cam 606 is located at a rotational position corresponding to the pressure contact position of the pressure roller 16b, ie, a reference position, and transmits a light blocking signal to the CPU 301. The CPU 301 controls the motor 604 based on the light shielding signal received from the photo sensor 605. Specifically, when the CPU 301 receives a light shielding signal from the photo sensor 605, the lift cam 606 is positioned at the reference position, and determines that the pressure roller 16b is in pressure contact with the fixing roller 16a.

  FIG. 3B is a view schematically showing a configuration of the pressure roller contact / separation mechanism 310 in a state where the pressure roller 16b is located at the separation position. As shown in FIG. 3B, the CPU 301 rotates the lift cam 606 in the R10 direction when the first separation signal or the second separation signal is received when the pressure roller 16b is positioned at the pressure contact position. The motor 604 is driven at a high speed or a low speed by a predetermined amount. When the lift cam 606 rotates in the R10 direction, the photosensor 605 is in a non-light shielding state where the light shielding portion 606a does not shield light. As a result, the pressure roller 16b moves from the press-contacting position to the separated position at the first speed or the second speed. When the motor 604 is driven at a low speed for a predetermined amount and the pressure roller 16b moves at the second speed, the motor 604 is driven at a high speed for a predetermined amount, compared to when the pressure roller 16b moves at the first speed. The operation noise associated with the operation of the pressure roller contact / separation mechanism 310 is reduced.

  When the pressure roller 16b is at the separated position, the CPU 301 drives the motor 604 at a predetermined speed at a predetermined speed so that the lift cam 606 rotates in the direction opposite to the R10 direction when receiving a return signal. Thus, the pressure roller 16b moves from the separated position to the pressure contact position. When the lift cam 606 rotates and moves to the reference position, the photosensor 605 is in a light blocking state where the light blocking portion 606 a blocks light, and transmits a light blocking signal to the CPU 301. When the CPU 301 receives the light blocking signal from the photo sensor 605, the lift cam 606 is positioned at the reference position, and determines that the pressure roller 16b is in pressure contact with the fixing roller 16a, and stops the driving of the motor 604.

  FIG. 4A is a view schematically showing the configuration of the transfer roller contact / separation mechanism 311 in a state in which the primary transfer roller 5a is located at the pressing position. The respective configurations of the transfer roller contact / separation mechanism 311 for contacting / separating the primary transfer rollers 5a to 5d with respect to the intermediate transfer belt 8 are the same. The configuration of the transfer roller contact / separation mechanism 311 will be described as an example.

  As shown in FIG. 4A, the transfer roller contact / separation mechanism 311 has a lift cam 806, a moving member 807, a motor 804, and a photosensor 805. The lift cam 806 has a circumferential surface whose distance from the rotation center to the circumferential surface is not constant, and is rotated by driving of the motor 804. The moving member 807 slides on the circumferential surface of the lift cam 806, and presses the primary transfer rollers 5a to 5d against the intermediate transfer belt 8 between the press-contacting position and the separated position separating from the intermediate transfer belt 8. The transfer rollers 5a to 5d are moved in the direction orthogonal to the rotation center of the transfer rollers 5a to 5d. The lift cam 806 has a light shielding portion 806a.

  When the lift cam 806 is located at the rotational position corresponding to the pressure contact position of the primary transfer rollers 5a to 5d, that is, the reference position, the photosensor 805 is shielded by the light shielding portion 806a and transmits a light shielding signal to the CPU 301 . The CPU 301 controls the motor 804 based on the light shielding signal received from the photosensor 805. Specifically, when the CPU 301 receives a light blocking signal from the photosensor 805, it determines that the lift cam 806 is located at the reference position and the primary transfer rollers 5a to 5d are in pressure contact with the intermediate transfer belt 8.

  FIG. 4B is a view schematically showing the configuration of the transfer roller contact / separation mechanism 311 in a state where the primary transfer rollers 5a to 5d are located at the separation position. As shown in FIG. 4B, the CPU 301 rotates the lift cam 806 in the R11 direction when it receives the first separation signal or the second separation signal when the primary transfer rollers 5a to 5d are located at the pressure contact position. The motor 804 is driven a predetermined amount at high speed or low speed. When the lift cam 806 rotates in the R11 direction, the photosensor 805 is in the non-light shielding state where the light shielding portion 806a does not shield light. Thereby, the primary transfer rollers 5a to 5d move from the press-contacting position to the separating position at the first speed or the second speed. When the motor 804 is driven at a low speed for a predetermined amount and the primary transfer rollers 5a to 5d move at a second speed, the motor 804 is driven at a high speed for a predetermined amount to move the primary transfer rollers 5a to 5d at a first speed. Compared to the case, the noise associated with the operation of the transfer roller contact / separation mechanism 311 is reduced.

  When the primary transfer rollers 5a to 5d are at the separated position, the CPU 301 drives the motor 804 by a predetermined amount at a predetermined speed so that the lift cam 806 rotates in the direction opposite to the R11 direction when receiving a return signal. . Thus, the primary transfer rollers 5a to 5d move from the separated position to the pressure contact position. When the lift cam 806 rotates and moves to the reference position, the photo sensor 805 is in a light blocking state where the light blocking portion 806 a blocks the light, and transmits a light blocking signal to the CPU 301. When the CPU 301 receives the light blocking signal from the photo sensor 805, the lift cam 806 is located at the reference position, determines that the primary transfer rollers 5a to 5d are in pressure contact with the intermediate transfer belt 8, and stops driving the motor 804. .

  FIG. 5A is a view schematically showing a configuration of the developing roller contact / separation mechanism 312 in a state where the developing roller 904a is located at the close position. The respective configurations of the developing roller contact / separation mechanism 312 for contacting and separating the developing rollers 904a to 904d with respect to the photosensitive drums 2a to 2d are the same, and hence the developing rollers 904a to 904d The configuration of the developing roller contact / separation mechanism 312 which contacts and separates will be described as an example.

  As shown in FIG. 5A, the developing roller contact / separation mechanism 312 has a cam 905, a moving member 907, and a motor 906. The cam 905 has a circumferential surface whose distance from the rotation center to the circumferential surface is not constant, and is rotated by driving of the motor 906. The moving member 907 slides on the circumferential surface of the cam 905, and moves the developing rollers 904a to 904d between the approaching position approaching the photosensitive drums 2a to 2d and the separating position separating the developing rollers 904a to 904d from the photosensitive drums 2a to 2d. The photosensitive drums 2a to 2d are moved in the direction orthogonal to the rotation center.

  FIG. 5B is a view schematically showing the configuration of the transfer roller contact / separation mechanism 311 in a state where the developing rollers 904 a to 904 d are located at the separation position. As shown in FIG. 5B, the CPU 301 rotates the cam 905 in the direction of R12 when the first separation signal or the second separation signal is received when the developing rollers 904a to 904d are located at the close position. Thus, the motor 906 is driven at a high speed or a low speed by a predetermined amount. Thus, the developing rollers 904a to 904d move from the close position to the separated position at the first speed or the second speed. When the motor 906 is driven at a low speed for a predetermined amount and the developing rollers 904a to 904d move at a second speed, the motor 906 is driven at a high speed for a predetermined amount and the developing rollers 904a to 904d move at a first speed. In comparison, noise associated with the operation of the transfer roller contact / separation mechanism 311 is reduced.

  The CPU 301 drives the motor 906 by a predetermined amount at a predetermined speed so that the cam 905 rotates in the direction opposite to the R12 direction when receiving the return signal when the developing rollers 904a to 904d are at the separated position. Thereby, the developing rollers 904a to 904d move from the separated position to the pressure contact position.

[Details of control in each power supply state]
Next, details of processing executed by the controller 200 when the power supply state of the printer 1 is the normal state, the power saving state, and the shutdown state will be described. FIG. 6 is a flowchart showing processing executed by the controller 200 when the power supply state of the printer 1 is normal.

  When the printer 1 is in the normal state, the controller 200 first determines whether an error detection signal has been received (step S701). In this process, the controller 200 determines, based on the reception of the error detection signal, whether or not the printer 1 can execute the image forming job and the conveyance job. When it is determined in the process of step S701 that an error detection signal has been received (YES in step S701), the controller 200 separates each contact / separation member 3b from each contact / separation member 3a at the first speed, that is, high speed. The first separation signal is transmitted to the CPU 301 (step S702). In this process, the controller 200 causes the printer engine 300 to separate the contact / separation mechanisms 3 so as to separate the contact / separation members 3b from the contact / separation members 3a at a high speed, and the contact / separation members 3b and the contact / separation members are separated. The body 3a is protected in a short time and the user's waiting time is reduced.

  After the process of step S702 is executed and the separation operation of each contact / separation mechanism 3 is completed, the controller 200 causes the liquid crystal panel of the operation unit 100 to display an error message notifying that an error detection signal has been received (step S 715). In this process, the controller 200 notifies the user that the printer 1 can not execute the image forming job and the conveyance job. When the process of step S 715 ends, the controller 200 determines whether an error release signal has been received (step S 703). In this process, the controller 200 determines whether the cause of the printer 1 being unable to execute the image forming job and the conveying job, that is, whether the sheet stagnation state or the toner small amount state has been eliminated.

  If it is determined in the process of step S703 that an error release signal has not been received (NO in step S703), the controller 200 interrupts the process until an error release signal is received. When it is determined in the process of step S703 that an error release signal has been received (YES in step S703), the controller 200 transmits a return signal for returning each contact / separation mechanism 3 to the CPU 301 (step S704). In this process, the controller 200 determines that the factor that the printer 1 can not execute the image formation job and the conveyance job is eliminated, and causes each contact / separation mechanism 3 to return, and the printer 1 performs the image formation job and the conveyance job Is ready to run.

  When the process of step S704 ends, the controller 200 executes the process of step S701 again. When it is determined in the process of step S701 that an error detection signal has not been received (NO in step S701), the controller 200 determines whether an image forming job or a conveyance job is being executed (step S705). ). In this process, the controller 200 determines whether or not to start timing by the timer 206 which causes the printer 1 to shift from the normal state to the power saving state. In the process of step S705, when it is determined that one or both of the image forming job and the conveyance job are being executed (YES in step S705), the controller 200 executes the process of step S701 again.

  When it is determined in the process of step S705 that neither the image forming job nor the conveyance job is being executed (NO in step S705), the controller 200 starts clocking by the timer 206 (step S706). In this process, the controller 200 uses the timer 206 to determine the trigger for shifting the power supply state of the printer 1 from the normal state to the power saving state, etc., the elapsed time since both the image forming job and the conveyance job end. Timekeeping of t has started. When the process of step S706 ends, the controller 200 determines whether there is an input of data from the PC via the input / output I / F 205 (step S707). In this process, the controller 200 monitors the input of data from the PC, which is one of the triggers for ending the counting of the elapsed time t by the timer 206, and determines whether the printer 1 is maintained in the normal state. ing. In this process, when it is determined that there is data input from the PC (YES in step S 707), the controller 200 initializes the value of the elapsed time t, and ends the clocking by the timer 206 (step S 708), The process of step S701 is performed again.

  When it is determined in the process of step S707 that there is no input of data from the PC (NO in step S707), the controller 200 determines whether a shutdown start signal is received from the shutdown start key (step S709). . In this process, the controller 200 monitors the operation of the shutdown start key by the user, which is one of the triggers for ending the counting of the elapsed time t by the timer 206, and shifts the power supply state of the printer 1 to the shutdown state. It is judged whether or not. When it is determined that the shutdown start signal is received in the process of step S709 (YES in step S709), the controller 200 separates the contact / separation members 3b from the contact / separation members 3a at the first speed, that is, high speed. A signal is sent to the CPU 301 (step S710). In this process, the controller 200 causes the printer engine 300 to separate the contact / separation mechanisms 3 so as to separate the contact / separation members 3b from the contact / separation members 3a at a high speed, whereby the contact / separation members 3b and the contacts are separated. The separation body 3a is protected in a short time. Further, in this process, the controller 200 initializes the value of the elapsed time t, and ends the time counting by the timer 206.

  When the process of step S710 ends, the controller 200 shifts the power supply state of the printer 1 from the normal state to the shutdown state (step S711), and ends the process in the normal state. In this process, the controller 200 shifts the power supply state of the printer 1 to the shutdown state with the least power consumption based on the user's operation of the shutdown start key, thereby reducing the power consumption.

  When it is determined in the process of step S709 that the shutdown start signal is not received (NO in step S709), the controller 200 determines whether the power saving start signal is received from the power saving start key (step S712). . In this process, the controller 200 monitors the user's operation of the power saving start key, which is an opportunity to shift the power supply state of the printer 1 to the power saving state. When it is determined in the process of step S712 that the power saving start signal is not received (NO in step S712), the controller 200 determines whether the elapsed time t exceeds the first set time t1 (step S712). Step S713). In this process, the controller 200 refers to the value of the elapsed time t and determines whether the elapsed time t exceeds a first set time t1 that triggers the transition of the power supply state of the printer 1 to the power saving state. It is judged. When it is determined in the process of step S713 that the elapsed time t is equal to or less than the first set time t1 (NO in step S713), the controller 200 executes the process of step S707 again. As described above, when the printer 1 is in the normal state and does not receive an error detection signal, the controller 200 inputs data from the PC and starts shutdown until the elapsed time t exceeds the first set time t1. Continue to monitor the reception of the signal and the reception of the power saving start signal.

  If it is determined that the power saving start signal is received in the process of step S712 (YES in step S712), the controller 200 shifts the power supply state of the printer 1 to the power saving state (step S714). If it is determined in step S713 that the elapsed time t exceeds the first set time t1 (YES in step S713), the controller 200 shifts the power supply state of the printer 1 to the power saving state (step S714). ). In the process of step S714, the controller 200 determines that the condition for shifting the power supply state of the printer 1 to the power saving state where power consumption is smaller than the normal state is satisfied, and shifts the power supply state of the printer 1 to the power saving state. There is. When the process of step S714 ends, the controller 200 ends the process in the normal state. The controller 200 continues measuring the elapsed time t by the timer 206 even after shifting the power supply state of the printer 1 to the power saving state.

  FIG. 7 is a flowchart showing processing executed by the controller 200 when the power supply state of the printer 1 is the shutdown state. If the power supply state of the printer 1 is in the shutdown state, the controller 200 first determines whether there is an input of data from the PC via the input / output I / F 205 (step S901). In this process, the controller 200 monitors the input of data from the PC, which is one of the triggers for shifting the power supply state of the printer 1 from the shutdown state to the normal state.

  When it is determined in the process of step S901 that there is no data input from the PC (NO in step S901), the controller 200 determines whether a return signal from the return key has been received (step S902). In this process, the controller 200 monitors the operation of the recovery key by the user, which is one of the triggers for shifting the power supply state of the printer 1 from the shutdown state to the normal state. In the process of step S902, when it is determined that the return signal is not received (NO in step S902), the controller 200 executes the process of step S901 again. Thus, the controller 200 keeps monitoring the data input from the PC and the reception of the return signal when the printer 1 is in the shutdown state.

  If it is determined in the process of step S901 that data has been input from the PC (YES in step S901), the controller 200 shifts the power supply state of the printer 1 from the shutdown state to the normal state (step S903). If it is determined in the process of step S902 that a return signal has been received (YES in step S902), the controller 200 shifts the power supply state of the printer 1 from the shutdown state to the normal state (step S903). In the process of step S903, the controller 200 determines that the condition for shifting the power supply state of the printer 1 to the normal state is established, shifts the power supply state of the printer 1 to the normal state, and performs the image forming job and the conveyance job. Prepare for the execution of When the process of step S903 is completed, the controller 200 transmits a return signal for returning each contact / separation mechanism 3 to the SPU 301 (step S904), and ends the process in the shutdown state. In this process, the controller 200 moves the contact / separation members 3b to the pressure contact position or the proximity position, and the printer 1 is in a state capable of executing the image forming job and the conveyance job.

  FIG. 8 is a flowchart showing processing executed by the controller 200 when the power supply state of the printer 1 is the power saving state and the partial power supply state. When the power supply state of the printer 1 is the power saving state, the controller 200 first determines whether there is an input of data from the PC via the input / output I / F 205 (step S801). In this process, the controller 200 monitors the input of data from the PC, which is one of the triggers for shifting the power supply state of the printer 1 from the power saving state to the normal state. If it is determined in the process of step S801 that there is no data input from the PC (NO in step S801), the controller 200 determines whether a return signal from the return key has been received (step S802). In this process, the controller 200 monitors the operation of the recovery key by the user, which is one of the triggers for shifting the power supply state of the printer 1 from the power saving state to the normal state.

  If it is determined in the process of step S801 that data has been input from the PC (YES in step S801), the controller 200 shifts the power supply state of the printer 1 from the power saving state to the normal state (step S807). When it is determined in the process of step S802 that the return signal is received (YES in step S802), the controller 200 shifts the power supply state of the printer 1 from the power saving state to the normal state (step S807). In the process of step S 807, the controller 200 determines that the condition for shifting the power supply state of the printer 1 to the normal state is satisfied, shifts the power supply state of the printer 1 to the normal state, and performs the image forming job and the conveyance job Prepare for the execution of When the process of step S 807 ends, the controller 200 initializes the value of the elapsed time t, ends the counting of the elapsed time t by the timer 206 (step S 808), and ends the process in the power saving state and the partial power supply state.

  If it is determined in the process of step S802 that the return signal is not received (NO in step S802), the controller 200 determines whether the elapsed time t exceeds the second set time t2 (step S802). S803). In this process, the controller 200 refers to the value of the elapsed time t and determines whether the elapsed time t exceeds a second set time t2 that triggers the separation mechanism 3 to move apart. ing. When it is determined in the process of step S803 that the elapsed time t is equal to or less than the second set time t2 (NO in step S803), the controller 200 executes the process of step S801 again. As described above, when the printer 1 is in the power saving state, the controller 200 keeps monitoring the data input from the PC and the reception of the return signal until the elapsed time t exceeds the second set time t2.

  In the process of step S803, when it is determined that the elapsed time t exceeds the second set time t2 (YES in step S803), the controller 200 shifts the power supply state of the printer 1 to the partial power supply state. (Step S804). In this process, the controller 200 changes the power supply state of the printer 1 to the partial power supply state in which power is supplied to the contact / separation mechanisms 3 based on the satisfaction of the conditions for causing the contact / separation mechanisms 3 to move apart. I am migrating. When the process of step S804 is completed, the controller 200 causes the contact / separation mechanism 3 to move away from the contact / separation member 3b at the second speed, that is, the low speed at a low speed. (Step S805). In this process, the controller 200 operates the contact / separation mechanism 3 by operating the contact / separation mechanism 3 so as to separate the contact / separation member 3b from the contact / separation member 3a at the second speed, that is, low speed. The accompanying operation noise is reduced. When the process of step S805 ends, the controller 200 shifts the power supply state of the printer 1 from the partial power supply state to the shutdown state (step S806), and ends the processing in the power saving state and the partial power supply state.

  In the present embodiment, each contact / separation mechanism 3 is operated at the first speed when a specific condition is satisfied, and a predetermined time has elapsed without a new image formation job being started after the image formation job is completed. In the case, each contact / separation mechanism 3 is operated at a second speed that is lower than the first speed. As a result, it is possible to reduce the operation noise generated suddenly from each contact / separation mechanism 3 without increasing the waiting time of the user and to prevent the user from feeling uncomfortable.

  Further, in the present embodiment, each contact / separation mechanism 3 is operated at the first speed when a specific condition is satisfied, and a predetermined time has elapsed without a new conveyance job being started after the conveyance job is completed. In the case, each contact / separation mechanism 3 is operated at a second speed that is lower than the first speed. As a result, it is possible to reduce the operation noise generated suddenly from the contact / separation mechanism 3 without increasing the waiting time of the user, and to prevent the user from feeling uncomfortable.

  In the embodiment described above, when the controller 200 transmits the first separation signal to the CPU 301, each contacting / separating mechanism 3 causes the contacting / separating member 3b to separate from the contacting / separating member 3a at the first speed. Is configured to move apart. Further, the printer 1 performs a separation operation so that each contacting / separating mechanism 3 separates the contacting / separating member 3b from the contacting / separating member 3a at the second speed when the controller 200 transmits the second separating signal to the CPU 301. Although it is comprised, it is not limited to this. When the controller 200 transmits the second separation signal to the CPU 301, the printer 1 contacts or separates the contact / separation mechanism 3 from the contact / separation member 3a at a speed slower than the reference speed when the first separation signal is transmitted. It should just be comprised so that separation | spacing operation | movement may be carried out so that the body 3b may be spaced apart. For example, the printer 1 sets the first speed and the first speed within the range in which the second speed does not exceed the first speed based on the input information by the operation of the other hard keys and the liquid crystal panel (not shown) of the operation unit 100 by the user. Each of the two speed values may be adjustable. Specifically, the first speed and the second speed are “fast” within the range in which the second speed does not exceed the first speed based on the operation of the other hard key or liquid crystal panel (not shown) of the operation unit 100. The user may be configured to be arbitrarily selectable from a plurality of “slow” speeds. Further, for example, the pressure roller 16b, the primary transfer rollers 5a to 5d, and the developing rollers 904a to 904d are configured to be separated at different speeds, for example, the portions having large operation noises due to the separation operation are separated at a slower speed. It may be done. Further, the printer 1 is not limited to one in which the speed at which the contact / separation body 3b is separated from the contact / separation body 3a is constant. The printer 1 is controlled so that, for example, when the contact / separation body 3b moves from the proximity position to the separation position, the movement starts moving at a large speed and decreases the speed just before reaching the separation position. It may be configured.

  Further, in the embodiment described above, the printer 1 is configured to include the pressure roller contact / separation mechanism 310, the transfer roller contact / separation mechanism 311, and the developing roller contact / separation mechanism 312 as the contact / separation mechanism 3. However, it is not limited to this. The printer 1 may be configured to include contact / separation means for bringing the contact / separation member 3b into / from / from the contact / separation member 3a, and the contact / separation member 3a and the contact / separation member 3b face each other. It may be a first opposing member and a second opposing member which are disposed and one or both do not rotate. Specifically, it may be configured to be provided with a feeding separation pad contacting / separating mechanism that brings the feeding / separating pad 32 into contact with or away from the feeding roller 31. The printer 1 also includes a manual feed separation pad contacting / separating mechanism 3 for contacting / separating the manual feeding separation pad 36 with respect to the manual feed roller 35, and a driven roller contacting / separating mechanism for contacting / separating the driven roller 19b with respect to the driving roller 19a. It may be configured as follows. The printer 1 further includes a secondary transfer outer roller contacting / separating mechanism for contacting / separating the secondary transfer outer roller 12 with respect to the intermediate transfer belt 8, and a discharge driven roller for contacting / separating the discharge driven roller 21b with the discharge driving roller 21a. You may be comprised so that the contact / separation mechanism may be provided. Further, the printer 1 is not limited to the one provided with all the contact / separation mechanisms 3 as long as at least one contact / separation mechanism is provided.

  Moreover, in the embodiment mentioned above, although each contact / separation mechanism 3 is comprised so that the contact / separation body 3b may be contacted / separated with respect to the to-be-contacted body 3a, it is not limited to this. The contacting / separating mechanism 3 may be configured to contact / separate the contact / separation body 3 a and the contacting / separating body 3 b. For example, in the present embodiment, the separated body 3a may be configured to be able to contact or separate from the separated body 3b, or both the separated body 3b and the separated body 3a move and contact each other. It may be configured to release.

  Further, in the embodiment described above, each contacting / separating mechanism 3 is configured to move the contacting / separating member 3b in the direction orthogonal to the rotation center of the contact / separating member 3a or the contacting / separating member 3b. It is not limited to. The contacting / separating mechanism 3 may be configured to be capable of contacting / separating the contact / separation body 3 a and the contacting / separating body. For example, the contact / separation member 3b may be moved in a direction parallel to the rotation center of the contact / separation member 3a or the contact / separation member 3b, or the contact / separation member 3b may be moved in a direction different from any of the above directions. It may be configured to move. Moreover, the contacting / separating mechanism 3 is not limited to what linearly contacts / separates the to-be-contacted body 3a and the contacting / separating body 3b. The contact / separation mechanism 3 may be configured, for example, to move the contact / separation member 3b along the arc trajectory with respect to the contact / separation member 3a, or a plurality of intersecting linear trajectories, L-shaped trajectories It may be configured to move along.

  In the embodiment described above, the printer 1 is configured such that each contact / separation member 3a includes a unique motor, and each contact / separation mechanism 3 includes a unique motor, but is not limited thereto. I will not. For example, the printer 1 may be configured to rotate the plurality of contact / separation members 3a by one motor, or may be configured to operate the plurality of contact / separation mechanisms 3 by one motor. Good. Further, the printer 1 may be configured to operate the contact and separation mechanism 3 by a driving device other than a motor such as a solenoid.

  Further, in the embodiment described above, the printer 1 is configured such that the contact / separation member 3b is separated from the contact / separation member 3a at the first speed based on the shutdown start signal or the error detection signal in the normal state. Although it is comprised so that separation operation | movement of 3 may be carried out, it is not limited to this. The printer 1 may be configured to cause the contacting / separating mechanism 3 to perform the separating operation so that the contacting / separating member 3b is separated from the contacting / separating member 3a at the first speed when the image forming job becomes impossible to execute. . For example, the printer 1 operates the separating mechanism 3 so that the separating member 3b separates from the separated member 3a at the first speed when the external power supply to the power supply unit 400 is cut off. May be configured. In addition, an error signal that triggers separation operation of the contact / separation mechanism 3 is an open detection signal that the CPU 301 transmits to the controller 200 when the openable / closable open / close units other than the transport door 52 are located at the open position. May be Thus, the printer 1 separates the contact / separation member 3b from the contact / separation member 3a at the first speed on the basis of various triggers when the image forming job or the conveyance job can not be executed other than the above. The contact / separation mechanism 3 may be configured to be separated.

  In the embodiment described above, the printer 1 is configured to include the sheet sensors 23a and 24a and the opening sensor 52b as different sensors, but the present invention is not limited to this. In the printer 1, for example, the sheet sensor 23 a may be configured to also have the function of an opening sensor for detecting the opening of the conveyance door 52.

  Further, in the embodiment described above, when the first separation signal is transmitted from the controller 200 to the CPU 301, the printer 1 makes each contact so that the separated body 3b separates from the separated body 3a at the first speed. The separating mechanism 3 is configured to be separated. In addition, when the second separation signal is transmitted from the controller 200 to the CPU 301, the printer 1 causes the separation mechanism 3 to separate so that the separation member 3b separates from the separation member 3a at the second speed. Although it is comprised, it is not limited to this. For example, the printer 1 determines at which speed the CPU 301 operates the contact / separation mechanism 3 based on the power supply state of the printer 1 when the CPU 301 receives the separation signal from the controller 200. It may be configured.

  In the embodiment described above, the printer 1 shifts to the power saving state when the elapsed time t exceeds the first set time t1, and each contact / separation mechanism 3 when the second set time t2 is exceeded. Is configured to operate. Here, the printer 1 is not limited to the one in which the first set time t1 and the second set time t2 are not changeable at predetermined times. In the printer 1, for example, the controller 200 determines the values of the first set time t1 and the second set time t2 based on information input by the user using the other hard keys (not shown) of the operation unit 100 and the liquid crystal panel. May be configured to set Specifically, the printer 1 selects a plurality of setting times t1 and t2 stored in advance based on the user's selection from a plurality of items such as “long” and “short” displayed on the liquid crystal panel. The controller 200 may be configured to select one of the values. Further, specifically, the printer 1 operates the operation unit 100 to allow the user to select one of the plurality of set times t1 and set times t2 which are predetermined and stored in the controller 200. It may be configured to be arbitrarily selectable.

  The printer 1 may be configured to be able to change one of the setting time t1 and the setting time t2, or calculates and sets the other value based on one of the values. It may be configured as follows. Further, the printer 1 may be configured such that the changeable range of the other value decreases when one of the setting time t1 and the setting time t2 is changed. Specifically, in the printer 1, the user selects one of the setting time t1 for 10 minutes, 30 minutes and 60 minutes, and the setting time t2 for 40 minutes, 80 minutes and 120 minutes. It may be configured to be able to In this case, when the user selects 60 minutes as the set time t1, 40 minutes can not be selected as the set time t2, and either 80 minutes or 120 minutes may be selected.

  The first set time t1 and the second set time t2 store, for example, the frequency of the image forming job executed by the controller 200 in the past, the number of times the image forming job has been executed in the past, and the like. It may be time set by the controller 200 based on these memories. With such a configuration, the first set time t1 and the second set time t2 are set to appropriate times for the lifetimes of the respective components of the printer 1 in consideration of the use situation of the printer 1 by the user. can do. The printer 1 may be configured to allow the user to directly input the set time t1 and the set time t2 by operating the operation unit 100.

  In the embodiment described above, the printer 1 is configured to have the power saving start key, the shutdown start key, and the return key as the plurality of hard keys, but the present invention is not limited to this. For example, when the power supply state is the power saving state, the printer 1 may be configured to shift from the power saving state to the normal state by operating the power saving start key. Further, the printer 1 may be configured not to have, for example, a power saving start key or a return key, and to realize all the functions of these hard keys with a liquid crystal panel that is a touch panel liquid crystal display.

  Further, in the embodiment described above, the printer 1 is configured to shift to the shutdown state after each contact / separation mechanism 3 performs the separation operation in the partial power supply state, but is not limited to this. The printer 1 shifts to the power saving state again after each contact / separation mechanism 3 performs the separation operation in the partial power supply state, for example, and the elapsed time t exceeds the third set time longer than the second set time. May be configured to transition to the shutdown state.

  In the embodiment described above, the printer 1 is configured not to monitor the presence or absence of the error detection signal in the power saving state, but the present invention is not limited to this. The printer 1 may be configured to shift to the normal state and initialize the value of the elapsed time t, for example, when the transport door 52 or the feeding cassette 17 is opened and closed in the power saving state.

  In the embodiment described above, the printer 1 for forming an image on the sheet P conveyed along the conveyance paths 23 and 24 has been described, but the present invention is not limited to this. The present invention is also applicable to a sheet conveying device provided independently of the printer 1, for example, a finisher for conveying a sheet on which an image is formed, a paper deck for stacking and storing sheets, and feeding the sheet to the printer 1. It is possible to apply.

  Also, in any of the embodiments described above, the description has been made using the electrophotographic printer 1, but the present invention is not limited to this. For example, the present invention can be applied to an inkjet type image forming apparatus that forms an image on a sheet by discharging ink liquid from a nozzle.

  1: Printer (image forming apparatus) / 2a, 2b, 2c, 2d: Photosensitive drum (first rotating body, photosensitive body) / 3: Contact / separation mechanism (contact / separation unit) / 5a, 5b, 5c, 5d: Primary transfer Roller (second rotary member, transfer roller) / 8: Intermediate transfer belt (first rotary member, intermediate transfer member) / 16a: Fixing roller (first rotary member, rotary member) / 16b: Pressure roller (second rotation) Body, contact member) / 16c: fixing nip / 23: conveyance path / 24: reverse conveyance path (conveyance path) / 50: sheet conveyance unit (sheet conveyance device) / 310: pressure roller contact and separation mechanism (contact and separation means) / 200: controller (control means) / 301: CPU (control means) / 311: transfer roller contact / separation mechanism (contact / separation means) / 312: developing roller contact / separation mechanism (contact / separation means) / 904a, 904b, 904c, 904d: developing roller (second rotating body) / P: Door

Claims (9)

In an image forming apparatus for forming an image on a sheet conveyed along a conveyance path,
A first rotating body and a second rotating body that rotate with execution of the image forming job;
Contact / separation means for bringing the first rotating body and the second rotating body into and out of contact with each other;
And control means for controlling the contact / separation means.
The control means
Operating the contact / separation unit so as to separate the first rotating body and the second rotating body at a first speed when a specific condition is satisfied;
When a predetermined time passes without a new image forming job being started after the image forming job is completed, the first rotating body and the second rotating body are separated at a second speed that is slower than the first speed. Activate the contact / separation means to
An image forming apparatus characterized by The control means
Controlling transition of the state of the image forming apparatus between a normal state and a power saving state in which the power consumption of the image forming apparatus is smaller than that of the normal state;
The contact / separation is performed such that the first rotating body and the second rotating body are separated at the second speed after a predetermined time has elapsed since the state of the image forming apparatus is shifted from the normal state to the power saving state. Activate the means,
The image forming apparatus according to claim 1, The control means
When the new image forming job is not started until the first time elapses from the end of the image forming job, the state of the image forming apparatus is shifted from the normal state to the power saving state,
When a new image forming job is not started until a second time has elapsed since the state of the image forming apparatus has been shifted from the normal state to the power saving state, the first rotating body and the first rotating body can be operated at the second speed. Operate the contact / separation means to separate the two rotating bodies from each other;
The image forming apparatus according to claim 2, The specific conditions include that the sheet stagnates in the transport path.
The image forming apparatus according to any one of claims 1 to 3, wherein The particular condition includes that the image forming apparatus is operated to shift to a shutdown state in which the power consumption of the image forming apparatus is smaller than that in the power saving state.
The image forming apparatus according to any one of claims 2 to 4, characterized in that: The second rotating body is in contact with the first rotating body to form a fixing nip for fixing an image on a sheet.
The image forming apparatus according to any one of claims 1 to 5, wherein The first rotating body is a photosensitive body on which an electrostatic latent image is formed,
The second rotating body is a developing roller that develops an electrostatic latent image formed on the photosensitive body.
The image forming apparatus according to any one of claims 1 to 6, wherein Equipped with a rotating intermediate transfer body,
The first rotating body is a photosensitive body on which an electrostatic latent image is formed,
The second rotating body is a transfer roller for transferring the image formed on the photosensitive body to the intermediate transfer body.
The image forming apparatus according to any one of claims 1 to 7, wherein In a sheet conveying apparatus for conveying a sheet sandwiched by a rotating body and an abutting member capable of abutting on the rotating body,
Contacting / separating means for contacting / separating the rotating body and the contacting member;
And control means for executing a conveyance job for conveying a sheet and controlling the contact / separation means.
The control means
Operating the contact / separation unit so as to separate the rotating body and the contact member at a first speed when a specific condition is satisfied;
When the predetermined time passes without a new conveyance job being started after the conveyance job is completed, the contact between the rotating body and the contact member is performed at a second speed that is lower than the first speed. Activate the release means,
Sheet conveying apparatus characterized in that.

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