This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2016-256775, filed on Dec. 28, 2016, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
This disclosure relates to a sheet conveying device, a sheet discharging device, and an image forming apparatus incorporating the sheet conveying device and the sheet discharging device.
Sheet discharging devices that discharge a sheet are known to employ a photointerrupter to detect that the height of stack of image printed sheets in a sheet ejection tray has reached a predetermined height or above, and a feeler that projects upward from the sheet ejection tray and swings in a vertical direction such that the photointerrupter detects the feeler when the amount of loaded sheets on the sheet ejection tray is equal to or above the predetermined amount.
In a known sheet discharging device, a part of a full detection feeler that functions as a feeler projecting upwardly from the sheet ejection tray to contact a sheet on the sheet ejection tray can retreat manually, in order to connect a post processing device immediately after the sheet discharging device. The full detection feeler vertically swings in a regular printing mode and is manually changed in a retreating direction that is perpendicular to the vertical direction when the feeler contacts the sheet discharging device.
However, the sheet discharging device has a problem that, when a sheet is picked up from the sheet ejection tray, the sheet to be picked up is caught by the full detection feeler, and therefore the operability is deteriorated and the full detection feeler is damaged or broken.
Further, in order to connect the post processing device immediately after the sheet discharging device, the full detection feeler is manually retreated to a position at which the full detection feeler does not contact the sheet to be picked up. However, when the sheet is picked up while the full detection feeler is retreated to the above-described position, there are many operation processes to take, which is troublesome.
Furthermore, when the machine is operated (when the printing operation is performed), the full detection feeler needs to be returned manually before the operation. Therefore, when the full detection feeler is not returned, the sheet full state is not detected. Accordingly, prevention of a sheet stacking failure and a paper jam is fairly costly.
At least one aspect of this disclosure provides a sheet conveying device including a contact body, a shaft, a sheet detector and a rotary body support. The contact body is configured to rotate while contacting a sheet in conveyance. The shaft is configured to rotate together with the contact body in a range of rotation of the contact body. The sheet detector is configured to detect presence of the sheet through detection of rotation of the shaft rotating with the contact body in contact with the sheet. The rotary body support is configured to rotatably support the contact body to the shaft that rotates together with the contact body in contact with the sheet, extending the range of rotation, in a same direction as the direction of rotation of the shaft.
Further, at least one aspect of this disclosure provides a sheet discharging device including a sheet discharging body, a sheet stacker and the above-described sheet conveying device. The sheet discharging body is configured to discharge the sheet. The sheet stacker is a stacker on which the sheet is discharged by the sheet discharging body. The sheet detector is a stack height detector configured to detect that the height of the sheet stacked on the sheet stacker is equal to or higher than a predetermined height.
Further, at least one aspect of this disclosure provides an image forming apparatus including one of the above-described sheet conveying device and the above-described sheet discharging device.
An exemplary embodiment of this disclosure will be described in detail based on the following figured, wherein:
It will be understood that if an element or layer is referred to as being “on”, “against”, “connected to” or “coupled to” another element or layer, then it can be directly on, against, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, if an element is referred to as being “directly on”, “directly connected to” or “directly coupled to” another element or layer, then there are no intervening elements or layers present. Like numbers referred to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements describes as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors herein interpreted accordingly.
Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layer and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.
The terminology used herein is for describing particular embodiments and examples and is not intended to be limiting of exemplary embodiments of this disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Descriptions are given, with reference to the accompanying drawings, of examples, exemplary embodiments, modification of exemplary embodiments, etc., of an image forming apparatus according to exemplary embodiments of this disclosure. Elements having the same functions and shapes are denoted by the same reference numerals throughout the specification and redundant descriptions are omitted. Elements that do not demand descriptions may be omitted from the drawings as a matter of convenience. Reference numerals of elements extracted from the patent publications are in parentheses so as to be distinguished from those of exemplary embodiments of this disclosure.
This disclosure is applicable to any image forming apparatus, and is implemented in the most effective manner in an electrophotographic image forming apparatus.
In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this disclosure is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes any and all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, preferred embodiments of this disclosure are described. Elements (for example, mechanical parts and components) having the same functions and shapes are denoted by the same reference numerals throughout the specification and redundant descriptions are omitted.
Here, it is to be noted in the following embodiments and variations that the term “swing” indicates a swing motion and a rotation in a forward direction and a backward direction at an angle of 360 degrees or smaller.
Now, a description is given of an electrophotographic image forming apparatus 100 for forming images by electrophotography.
First, a description is given of an exterior of an image forming apparatus 100 according to an embodiment of this disclosure, with reference to
It is to be noted that identical parts are given identical reference numerals and redundant descriptions are summarized or omitted accordingly.
The image forming apparatus 100 may be a copier, a facsimile machine, a printer, a multifunction peripheral or a multifunction printer (MFP) having at least one of copying, printing, scanning, facsimile, and plotter functions, or the like. According to the present example, the image forming apparatus 100 is an electrophotographic printer that prints toner images on recording media by electrophotography.
It is to be noted in the following examples that: the term “image forming apparatus” indicates an apparatus in which an image is formed on a recording medium such as paper, OHP (overhead projector) transparencies, OHP film sheet, thread, fiber, fabric, leather, metal, plastic, glass, wood, and/or ceramic by attracting developer or ink thereto; the term “image formation” indicates an action for providing (i.e., printing) not only an image having meanings such as texts and figures on a recording medium but also an image having no meaning such as patterns on a recording medium; and the term “sheet” is not limited to indicate a paper material but also includes the above-described plastic material (e.g., a OHP sheet), a fabric sheet and so forth, and is used to which the developer or ink is attracted. In addition, the “sheet” is not limited to a flexible sheet but is applicable to a rigid plate-shaped sheet and a relatively thick sheet.
Further, size (dimension), material, shape, and relative positions used to describe each of the components and units are examples, and the scope of this disclosure is not limited thereto unless otherwise specified.
Further, it is to be noted in the following examples that: the term “sheet conveying direction” indicates a direction in which a recording medium travels from an upstream side of a sheet conveying path to a downstream side thereof; the term “width direction” indicates a direction basically perpendicular to the sheet conveying direction.
In
The image forming apparatus 100 in
A sheet feed tray 11 is disposed at the lower part of the color laser printer 200. The sheet feed tray 11 is detachably attachable to the color laser printer 200 of the image forming apparatus 100 in the front-and-back direction Y and contains a sheet P or sheets P as sheet-shaped conveyance target member(s).
A sheet stacker 15 is disposed at the lower part of the color laser printer 200. The sheet stacker 15 stacks a printed sheet P′ to be discharged after image formation performed in the color laser printer 200. The sheet stacker 15 receives the printed sheet P′ to stack or load the printed sheet P′ in a state in which the leading end of the printed sheet P′ is directed to a downstream side of the sheet discharging direction Ya.
Further, a control unit 800 is disposed at an upstream side of the sheet discharging direction Ya of the sheet stacker 15 disposed above the color laser printer 200. The control unit 800 is an interface that is used when instructions for operation are sent to the image forming apparatus 100.
The image forming apparatus 100 is designed for users to perform various operations from one side thereof. That is, a user can operate the sheet feed tray 11, the sheet stacker 15 and the control unit 800 of the image forming apparatus 100 from a front side in the front-and-back direction Y of the image forming apparatus 100 (i.e., the left side of
Due to the exterior configuration of the image forming apparatus 100 with the control unit 800 disposed on the front side, as illustrated in
Now, a description is given of the entire configuration and functions of the image forming apparatus 100 of
The color laser printer 200 includes an image forming device 50, a sheet feeding device 60, a fixing device 8 and a sheet discharging device 9. The image forming device 50 performs image formation by electrophotography. The sheet feeding device 60 feeds the sheet P from the sheet feed tray 11 to the image forming device 50. The fixing device 8 fixes an unfixed color or monochrome image transferred onto the sheet P in the image forming device 50 to the sheet P. The sheet P having a fixed toner image corresponds to the printed sheet P′. The sheet discharging device 9 functions as a recording medium discharging device to discharge the printed sheet P′ to the sheet stacker 15 after printing (fusing).
The image forming device 50 has a tandem-type intermediate transfer system in which a full color toner image, a two-color toner image, a three-color toner image or a monochrome toner image is formed with four process cartridges 51. The process cartridges 51 are aligned corresponding to respective colors of black toner image, yellow toner image, magenta toner image and cyan toner image.
The four process cartridges 51 basically have an identical configuration to each other, except that the colors of respective toners used to form a color toner image are different. Therefore, the following description is given with reference numeral “51” without any suffix, K, Y, M and C, but is applied to any one of the process cartridges 51Y, 51M, 51C, and 51K. In
The process cartridge 51 (i.e. the process cartridges 51K, 51Y, 51M and 51C) includes a photoconductor 1, a charging device 2, an exposure device 3, a developing device 4 and a cleaning device 5. The photoconductor 1 functions as a rotatable image bearer. The charging device 2 uniformly charges a surface of the photoconductor 1. The developing device 4 includes a developer cartridge 5A and supplies toner onto the electrostatic latent image formed on the surface of the photoconductor 1 so as to develop the electrostatic latent image into a visible toner image. The cleaning device 5 cleans the surface of the photoconductor 1 after the toner image is transferred onto an intermediate transfer belt 6. Since the photoconductor 1, the charging device 2, the exposure device 3, the developing device 4 and the cleaning device 5 are integrally assembled in the process cartridge 51 (i.e. the process cartridges 51K, 51Y, 51M and 51C), these image forming parts are detachably attached to the casing of the color laser printer 200.
The exposure device 3 is disposed between the charging device 2 and the developing device 4 in the color laser printer 200 as an apparatus body, for the photoconductor 1 of each process cartridge 51. The exposure device 3 includes an optical writing head. The optical writing head of the exposure device 3 includes a light emitting element that uses a light emitting diode (LED) array to emit a light beam onto the charged surface of the photoconductor 1 so as to form an electrostatic latent image on the photoconductor 1.
Through the operation instructed via the control unit 800, the instruction of a copying operation or a printing operation is sent to the image forming apparatus 100, the image formation starts in the image forming device 50. The instruction of a printing operation via the control unit 800 is sent when image data is stored in the image forming apparatus 100. The instruction of the printing operation is issued normally from a personal computer different from the image forming apparatus 100.
The copying operation is performed based on a result of reading by the image reading device 301, of an image formed on an original document conveyed from the ADF 302 or a result of reading by the image reading device 301, of an image formed on an original document placed on top of an exposure glass of the image reading device 301.
In image formation, the charging device 2 uniformly charges the surface of the photoconductor 1. Then, based on an image data signal after color separation, the exposure device 3 emits a laser light beam form the light emitting element of the optical writing head of the exposure device 3 to the surface of the photoconductor 1. Consequently, an electrostatic latent image is formed on the photoconductor 1 that rotates in a clockwise direction as indicated by arrows in
Then, the developing device 4 includes the developer cartridge 5A that contains one-component developer (i.e., toner). As the developer cartridge 5A supplies toner, the developing device 4 develops the electrostatic latent image formed on the surface of the photoconductor 1 into a visible toner image with toner electrostatically attached thereto. It is to be noted that, when the developing device 4 uses two-component developer that includes toner and carrier, toner of the two-component developer is electrostatically attached to the electrostatic latent image on the photoconductor 1 to be developed into a visible toner image.
The above-described operations are performed in the four process cartridges 51 in parallel. The color laser printer 200 further includes primary transfer rollers 603 disposed opposing the respective photoconductors 1 with the intermediate transfer belt 6 therebetween. A primary transfer bias is applied to the intermediate transfer belt 6 and each primary transfer roller 603. The intermediate transfer belt 6 is in contact with the photoconductors 1. The respective toner images formed on the respective surfaces of the photoconductors 1 are sequentially transferred onto a surface of the intermediate transfer belt 6. It is to be noted that the intermediate transfer belt 6 functions as an intermediate transfer body and is wound around a drive roller 601 and a driven roller 602.
The transfer of the toner images from the photoconductors 1 onto the intermediate transfer belt 6 is performed at respect opposing positions of the photoconductors 1 facing the intermediate transfer belt 6. After the photoconductor 1 passes the opposing position to the intermediate transfer belt 6, residual toner remaining on the surface of the photoconductor 1 is removed by the cleaning device 5, so that the photoconductor 1 is cleaned.
Along with the above-described operations, a sheet feeding operation starts to feed the sheet P to the image forming device 50. The sheet P loaded in the sheet feed tray 11 is fed by rotation of a sheet feed roller 111. The sheet P is then passes a relay roller 112 disposed in a single-side conveyance passage 12, and brought to contact a nip region formed by a pair of registration rollers 14 that is temporarily stopped. Due to the contact of the sheet P to the nip region of the pair of registration rollers 14, the sheet is curved. Accordingly, after the sheet P is corrected on an angular displacement that is a displacement to an axial direction of the pair of registration rollers 14, the pair of registration rollers 14 starts the rotation thereof in synchronization with movement of the full-color toner image transferred onto the intermediate transfer belt 6. Then, the sheet P is conveyed to a secondary transfer nip region formed between the intermediate transfer belt 6 and a secondary transfer roller 7 via the driven roller 602. Then, the full-color toner image formed on the surface of the intermediate transfer belt 6 is applied with a secondary transfer bias having high electric potential by the secondary transfer roller 7. Due to generation of a potential difference between the intermediate transfer belt 6 and the secondary transfer roller 7, the full-color toner images formed on the intermediate transfer belt 6 is transferred onto the sheet P collectively.
The sheet P having the full-color toner image transferred thereon is fixed to the sheet P in the fixing device 8, by application of heat and pressure. Further, the printed sheet V to which the color toner image is fixed is conveyed by a sheet discharging roller 95 and a sheet discharging driven roller 96 of the sheet discharging device 9 and is then discharged form an outlet port 90 of the sheet discharging device 9 before being stacked sequentially in the sheet stacker 15. Accordingly, the printing operation is completed. The sheet discharging roller 95 and the sheet discharging driven roller 96 function as sheet discharging bodies by which the sheet P is discharged as the printed sheet P′.
By contrast, residual toner remaining on the surface of the intermediate transfer belt 6 without being transferred onto the sheet P at the secondary transfer nip region is removed by a belt cleaning device 604, so that the intermediate transfer belt 6 is cleaned.
The sheet stacker 15 is formed on top of the color laser printer 200, from the downstream side to the upstream side of the sheet discharging direction Ya (i.e., from the back side to the front side of the front-and-back direction Y) and being sloped toward the downward side in the vertical direction Z. The sheet stacker 15 has a sheet discharging rear end guide plate 93 that functions as a sheet discharging guide. The sheet discharging rear end guide plate 93 stands from the lowermost part of the sheet stacker 15, upwardly toward an outlet port 90. The sheet discharging guide is a member to regulate the position of the trailing end of the printed sheet P′ stacked in the sheet stacker 15 (i.e., the sheet discharging rear end guide plate 93) and to separate from the fixing device 8 provided to the color laser printer 200.
The image forming apparatus 100 further includes a sheet reversing device 10. The sheet reversing device 10 reverses the sheet P having a toner image on a first face thereof and guide the reversed sheet P to a duplex sheet conveyance passage 13 for duplex printing. The sheet reversing device 10 includes the sheet discharging roller 95, a sheet reversing roller 97 and a passage switching member 98. The sheet discharging roller 95 and the sheet reversing roller 97 change and reverse the sheet conveying direction of the leading end and the trailing end of the sheet P. The passage switching member 98 switches the direction of the sheet P from the single-side conveyance passage 12 to the duplex sheet conveyance passage 13.
In addition, the image forming apparatus 100 further includes a bypass sheet tray 16 and a bypass sheet feed roller 161, both are used when the sheet P is inserted from the bypass sheet tray 16.
Further, the image forming apparatus 100 further includes a front cover 20 that opens and closed relative to the image forming apparatus 100. The front cover 20 opens to release and expose the locations of the pair of registration rollers 14 and the secondary transfer roller 7, disposed above the single-side conveyance passage 12. When the front cover 20 is open toward the front side in the front-and-back direction Y of the image forming apparatus 100 (i.e., on the right side of
Now, a description is given of a full detection feeler 91 provided to the sheet discharging device 9.
As illustrated in
When the stacking amount of the printed sheets P′ on the sheet stacker 15 is in an initial stacking state where the stacking amount is smaller than and equal to the predetermined stacking amount (
As illustrated in
Now, a description is given of a configuration of detection of a sheet full state of the printed sheets P′ on the sheet stacker 15, with reference to
As illustrated in
Further, the sheet discharging device 9 includes the full detection feeler 91 having the contact feeler portion 91d. Both left and right end portions of the full detection feeler 91 extend in the width direction X and are attached to and supported by the sheet discharging side guide plates 93d and 93e.
As illustrated in
On both ends in the width direction X of the full detection feeler 91, first swing target supports 91a and 91b that function as first rotation target supports are mounted integrally. The first swing target supports 91a and 91b are swing fulcrums as coaxial rotation fulcrums. The first swing target support 91a of the full detection feeler 91 is attached to and supported by the first swing support 93a of the sheet discharging side guide plate 93d. The first swing target support 91b of the full detection feeler 91 is attached to and supported by the first swing support 93b of the sheet discharging side guide plate 93e.
Further, a photointerrupter 92 is provided in the vicinity of the first swing support 93b of the sheet discharging side guide plate 93e.
As illustrated in
The blocking member 91c that functions as a light blocking portion mounted on the end portion of the full detection feeler 91 performs transmission and blockage of an optical path of the laser light beam emitted from the light emitting part 92a. By so doing, the light receiving part 92b generates a signal related to whether the sheet full state is detected or not.
Based on the signal related to whether the sheet full state is detected or not, sent from the light receiving part 92b of the photointerrupter 92, a controller included in the image forming apparatus 100 determines whether the sheet stacker 15 is full with the printed sheets P′ or not, and finally determines whether the print job is interrupted or continued. The controller then sends an instruction signal to devices and mechanisms related to the print job to control the devices and the mechanisms.
As illustrated in
As illustrated in
Now, a description is given of movement of the full detection feeler 91 during the print job, with reference to
Specifically,
As illustrated in
At this time, the full detection feeler 91 is at a location occupying an equilibrium position (hereinafter, referred to as a “standby position”) in the predetermined swinging range of the full detection feeler 91 by the own weight of the full detection feeler 91 including the contact feeler portion 91d (about the first swing target support 91a).
As the print job starts, the printed sheet P′ conveyed from the fixing device 8 is guided by the sheet discharging roller 95 and the sheet discharging driven roller 96 toward the sheet discharging device 9. Then, as illustrated in
Further, as the printed sheet P′ is conveyed, the printed sheet P′ is further conveyed to the sheet stacker 15 by further pushing and rotating the contact feeler portion 91d of the full detection feeler 91, as illustrated in
When the printed sheet P′ is completely discharged to the sheet stacker 15, as illustrated in
When the contact feeler portion 91d of the full detection feeler 91 is separated from the printed sheet P′ and the full detection feeler 91 returns to the initial standby state due to the weight of the contact feeler portion 91d (the state illustrated in
A duration of contact of the printed sheet P′ (A4 size, portrait orientation) and the contact feeler portion 91d is approximately 2 seconds and a duration of a transmission state of the photointerrupter 92 is a constant duration (approximately 2 seconds).
According to these conditions, in a case in which the transmission state of the photointerrupter 92 is less than a predetermined duration (approximately 3 seconds) longer that the constant duration (approximately 2 seconds), even when the transmission state of the photointerrupter 92 is detected, the controller does not determine that the sheet stacker 15 is full with the printed sheets P′ (sheet full) but determines that the sheet stacker 15 is not full (sheet not full). In a case in which the transmission state reaches and continues over the predetermined duration (approximately 3 seconds), the controller determines that the sheet stacker 15 is full with the printed sheets P′ and determines to interrupt the print job. Then, the controller sends an instruction signal of determinations to the devices and mechanisms related to the print job to control the devices and mechanisms.
When multiple sheets P are printed, the printed sheets P′ are sequentially stacked onto the sheet stacker 15. As described above, due to swing of the full detection feeler 91 in response to the sheet discharging operation of the multiple printed sheets P′ to the sheet stacker 15, the blocking member 91c of the full detection feeler 91 repeatedly performs blockage and transmission of light of the photointerrupter 92.
As illustrated in
It is to be noted that, in
A description is given of how to remove the printed sheet P′, with reference to
As illustrated in
As illustrated in
When the sheet stacker 15 is full with the printed sheets P′ and the controller stops the print job, the printed sheets P′ stacked in the sheet stacker 15 cannot be removed from the sheet stacker 15 horizontally or in the horizontal direction to the upstream side of the sheet discharging direction Ya (i.e., to the front side F of the front-and-back direction Y), because the control unit 800 is disposed above the sheet discharging rear end guide plate 93 that rises from the bottom of the sheet stacker 15. Therefore, the printed sheet P′ is firstly lifted upwardly in the vertical direction Z and then is pulled out to the front side F of the front-and-back direction Y. Specifically, the printed sheet P′ is removed from the sheet stacker 15 in a movement path indicated by arrow A in
Further, a user or an operator normally uses the image forming apparatus 100 when standing at the front side of the image forming apparatus 100 as illustrated in
At this time, since the full detection feeler 91 is disposed above the movement path A of the printed sheet P′ to be removed from the sheet stacker 15, the full detection feeler 91 rotates to the state illustrated in
Generally, in the image forming apparatus 100 illustrated in
Further, when performing a full front operation, in which a jammed sheet is removed from the color laser printer 200 by opening the front cover 20 on the side on which the control unit 800 is disposed, the following inconvenience is likely to occur. In the full front operation, the trailing end of the sheet P after image formation is discharged in the sheet stacker 15 on a side close to the control unit 800. In this case, since the sheet discharging device 9 and the control unit 800 are disposed on the front side of the sheet stacker 15 (on the side of the control unit 800), it is difficult to visually recognize removal of the printed sheet P′ from the sheet stacker 15, resulting in the above-described inconvenience.
In order to eliminate the above-described inconvenience, the upper limit of swing (rotation) of the full detection feeler 91 is set to a higher level, the full detection feeler 91 is likely to stay at the higher upper limit position. Therefore, the return of the full detection feeler 91 to the standby position Sa becomes unstable or the return operation of the full detection feeler 91 takes long, and therefore it is likely that an incorrect detection of the sheet full state is performed. In order to address this inconvenience, the full detection feeler 91 is set to a position at which the full detection feeler 91 stably returns to the standby position in the initial standby state and the control operation is reliably performed.
Here, a description is given of the position of the full detection feeler 91 of the sheet discharging device 9 in
In the above-described examples, after the printed sheet P′ is removed, the full detection feeler 91 returns from the swing upper limit position Sb to the initial standby state, that is, the standby position Sa illustrated in
In the above description, an A4 size (portrait orientation) is used as an of a sheet size used for printing but any sheet size can be applied to this disclosure as long as the sheet is a cut sheet.
Further, the regulator 93c is disposed at one position illustrated in
As described above, the swing upper limit position Sb is set for the full detection feeler 91 in order to remove the printed sheet P′ smoothly. However, when the full detection feeler 91 is rotated beyond the swing upper limit position Sb, the trailing end of the printed sheet P′ is likely to be caught by the contact feeler portion 91d of the full detection feeler 91, and therefore the operability of removing the printed sheet P′ is degraded. In addition, the full detection feeler 91 can be damaged or broken and the printed sheet P′ can be damaged.
A description is given of a sheet discharging device according to Embodiment 1 of this disclosure, with reference to
Specifically,
The sheet discharging device 9A according to Embodiment 1 illustrated in
The full detection feeler 901 includes a sheet contact member 903 and a feeler body 902. The sheet contact member 903 functions as a contact member that is rotated or swung by contact with a sheet. The feeler body 902 is a shaft that is rotated or swung together with the sheet contact member 903 within a predetermined swinging range that is a predetermined rotating range of the sheet contact member 903. The sheet contact member 903 is attached to a substantially center in the width direction X of the feeler body 902 that is a separated part different from the sheet contact member 903.
On both left and right ends in the width direction X of the feeler body 902, first swing target supports 901a and 901b that function as first rotation target supports are mounted integrally. The first swing target supports 901a and 901b are swing fulcrums as coaxial rotation fulcrums. The first swing target support 901a of the full detection feeler 901 is attached and supported to the first swing support 93a of the sheet discharging side guide plate 93d. The first swing target support 901b of the full detection feeler 901 is attached and supported to the first swing support 93b of the sheet discharging side guide plate 93e.
Further, the photointerrupter 92 is provided in the vicinity of the first swing support 93b of the sheet discharging side guide plate 93e.
Further, a blocking member 91c is integrally provided at an end of the first swing target support 901b of the feeler body 902. The blocking member 91c blocks and transmits light along the light path between the light emitting part 92a and the light receiving part 92b of the photointerrupter 92 that is attached to the sheet discharging side guide plate 93e.
It is to be noted that movement of swing of the blocking member 91c that is integrally formed on the feeler body 902 of the full detection feeler 901 and the configuration and operations of sheet full detection based on blocking of light of the photointerrupter 92 are identical to the above-described configuration and operations. In addition, after the printed sheet P′ is removed, the full detection feeler 901 returns from the swing upper limit position Sb to the initial standby state, that is, the standby position Sa due to the weight thereof. However, the movement of the full detection feeler 901 is not limited thereto. For example, the full detection feeler 901 may return to the initial standby state due to a biasing force applied by a weight or a spring, which is also same as the above-described configuration and operations.
Now, a description is given of a swing range of the sheet contact member 903 and the feeler body 902 of the full detection feeler 901, with reference to
Specifically,
The sheet contact member 903 and the feeler body 902 are separate parts and are mounted on the full detection feeler 901. The sheet contact member 903 and the feeler body 902 are integrally formed by resin.
As illustrated in
As illustrated in
According to the above-described configuration, the sheet contact member 903 and the feeler body 902 swing together to the swing upper limit position Sb and the sheet contact member 903 further rotates about the second swing support 904, exceeding the predetermined swinging range while the feeler body 902 is engaged at the swing upper limit position Sb. By so doing, the sheet contact member 903 retreats to the retracted position Sd.
The sheet contact member 903 is significantly different from the contact feeler portion 91d having a claw shape as illustrated in
In addition, the sheet contact member 903 may have a resin portion to contact the end of the printed sheet P′ and have an appropriate surface treatment.
As described above, the full detection feeler 901 includes the sheet contact member 903 and the feeler body 902. The feeler body 902 includes the first swing target support 901a that is swingably supported by the first swing supports 93a, the first swing target support 901b that is swingably supported by the first swing support 93b (see
A detailed description is given of the configuration of the sheet contact member 903 and the second swing support 904 of the full detection feeler 901, with reference to
As illustrated in
As illustrated in
Further, in a state in which the sheet contact member 903 is arranged as illustrated in
Then, a retaining ring 907 is attached to a groove 905a of the shaft 905 that is attached as described above. Accordingly, the shaft 905 is prevented from coming off in a thrust direction (i.e., an axial direction). As a result of this assembly, the sheet contact member 903 can swing to the feeler body 902 about the shaft 905 that functions as a fulcrum and is supported by the bearings 903a and 903b.
As illustrated in
Accordingly, as illustrated in
As illustrated in
Then, as illustrated in
Now, a description is given of the configuration and operations including a pressing operations of the sheet contact member 903 of the full detection feeler 901, with reference to
In a state illustrated in
After detection of the sheet full state, the full detection feeler 901 moves to the swing upper limit position Sb illustrated in
In a state illustrated in
Consequently, the biasing force applied against the second pressing force is set based on the biasing force applied by the biasing member of the torsion coil spring 906 (see
The biasing force applied against the second pressing force is greater than the pressing force by which the printed sheet P′ is conveyed and the sheet contact member 903 is pressed and smaller than the pressing force by which the sheet contact member 903 is pressed along with removal of the printed sheet P′. That is, the biasing force of the torsion coil spring 906 is set to meet the relation of “the first pressing force<the second pressing force” and the relation of “the biasing force<the second pressing force.”
During the print job, the load to the full detection feeler corresponds to the contact force by the printed sheet P′ during conveyance for discharging, and therefore the full detection feeler swings within a range in which the full detection feeler moves by the first swing support. Therefore, the first pressing force does not exceed the biasing force of the torsion coil spring 906 in the above-described state. Consequently, the sheet contact member 903 does not move (rotate) about the second swing support 904 and the sheet contact member 903 has a constant relative position to the feeler body 902. Accordingly, the full state detection can be performed by the photointerrupter 92.
Further, the torsion coil spring 906 that is used to apply the biasing force against the second pressing force is attached to the shaft 905 of the second swing support 904 (through the inner circumference of the shaft 905), and therefore an effect of space saving can be achieved.
As described above, the biasing force against the second pressing force is greater than the first pressing force and smaller than the second pressing force. However, the maximum biasing force is set so as not to cause any damage to the sheet by the second pressing force (for example, the printed sheet P′ is scratched or torn) when the printed sheet P′ stacked in the sheet stacker 15 is removed. In this setting, the type of the sheet P′ to be removed (for example, a thin paper and a film sheet are damaged more easily than a regular sheet) is taken into consideration. However, instead of considering the type of the sheet P′, an adjusting mechanism by which the biasing force can be adjusted may be provided.
It is to be noted that the biasing force against the second pressing force is not limited to be applied by the biasing member including the torsion coil spring 906. For example, a biasing force against the second pressing force may be applied according to a self-weight moment of the sheet contact member (a contact member) and the feeler body (a shaft) having the material, center of gravity, shape and so forth appropriately devised to generate the moment) or may be applied by a weight as a separate part attached to the sheet contact member (a contact member) and the feeler body (a shaft). However, the biasing force is set to cause the sheet contact member 903 to return to the standby position Sa.
As illustrated in
As illustrated in
It is to be noted that, since the leading end of the one end portion 906a of the torsion coil spring 906 and the leading end of the opposed end portion 906b of the torsion coil spring 906 are deformed (compress or extend) in the front-and-back direction Y along with swing of the sheet contact member 903, the recess 903d is formed by taking the deformation of the torsion coil spring 906.
Further, as illustrated in
As illustrated in
By disposing the first regulator 902e in the vicinity of the feeler body 902, the height of accumulation of the parts can be reduced, and therefore variation in the second pressing force can be reduced. Accordingly, the operability without variation can be achieved.
The feeler body 902 is elastically formed by resin and extends in the width direction X. Therefore, the material of the feeler body 902 is set to resin, even after the swing of the feeler body 902 is regulated by the first regulator 902e, by using twist and bend of the feeler body 902 due to elasticity of resin material, the sheet contact member 903 can be swung to the position illustrated in
When the feeler body 902 is elastically deformed to cause the sheet contact member 903 to swing to the flexibly retracted position Se as illustrated in
As described above, by providing the second regulator 810a to the cover 810 at the upper part of the sheet discharging device 9A when the feeler body 902 further moves due to elastic twist thereof, the further twist of the feeler body 902 can be prevented, and therefore breakage of the sheet contact member 903 can also be prevented. Accordingly, the operability of removal of the sheets stacked in the sheet stacker can be enhanced.
As described above, the sheet discharging device 9 according to Embodiment 1 of this disclosure includes a sheet discharging body such as the sheet discharging roller 95 and the sheet discharging driven roller 96, a sheet stacker such as the sheet stacker 15, a contact body such as the sheet contact member 903, a shaft such as the feeler body 902, and a stack height detector such as the full detection feeler 91 and the photointerrupter 92. The sheet discharging body is configured to discharge the sheet such as the sheet P′. The sheet stacker is a stacker on which the sheet discharged by the sheet discharging body. The contact body is configured to rotate while contacting the sheet. The shaft is configured to rotate together with the contact body in a range of rotation of the contact body. The stack height detector is configured to detect that the height of the sheet stacked on the sheet stacker is equal to or higher than the predetermined height through detection of rotation of the shaft rotating with the contact body in contact with the sheet. The sheet discharging device according to Embodiment 1 of this disclosure further includes a rotary body support configured to rotatably support the contact body to the shaft that rotates together with the contact body in contact with the sheet, extending the range of rotation, in a same direction as the direction of rotation of the shaft.
According to Embodiment 1, when the printed sheet P′ is removed from the sheet stacker 15, the printed sheet P′ and the sheet contact member 903 contact with each other, and the sheet contact member 903 swings and retracts in the substantially same direction as the sheet removing direction of the printed sheet P′ stacked on the sheet stacker 15. Accordingly, the preferable performance of sheet removal of the sheet stacked on the sheet stacker 15 can be maintained without retracting and returning the sheet contact member 903, and therefore the operability can be enhanced.
In addition, the full detection feeler 901 can be prevented from being damaged or broken and the printed sheet P′ can be prevented from being damaged. Further, the failure caused by forgetting of return of the sheet contact member 903 can be prevented before the occurrence.
Now, a description is given of the biasing force against the second pressing force, with reference to
The configuration of Variation illustrated in
It is to be noted that the first swing support according to Variation is identical to the first swing support illustrated in
As illustrated in
As illustrated in
As illustrated in
According to this configuration, the compression coil spring 916 that is used in the thrust direction can be directly attached to the shaft 912b of the feeler body 912 that functions as a second swing support. Therefore, the configuration according to Variation can achieve the same effect as the configuration according to Embodiment 1.
The configuration of Embodiment 1 and the configuration of Variation are applied to the sheet discharging device 9A that is included in the image forming apparatus 100 and functions as a sheet discharging device that conveys a sheet-like transfer target medium such as a sheet to be discharged from the image forming apparatus 100. These configurations can be applied to a sheet conveying device that feeds a sheet-like transfer target medium such as a sheet to be fed in the image forming apparatus 100, as described in Embodiment 2. In this case, if a known technique is employed to a sheet conveying device that feeds a sheet-like transfer target medium such as a sheet to be fed in an image forming apparatus, when a jammed sheet is removed from the sheet conveying device that includes a sheet detection feeler to detect the sheet by swinging a contact member that contacts the fed sheet, the same inconvenience as the sheet detection feeler of the above-described sheet discharging device may occur.
Specifically, instead of the above-described inconvenience that occurs when the sheet is removed from the sheet discharging tray in the sheet discharging device that includes the full detection feeler, the same inconvenience is generated when a paper jam occurs in the vicinity of the sheet detection feeler in a sheet conveyance passage of the sheet conveying device.
When a jammed sheet is removed from a jammed sheet remaining position in the vicinity of the sheet detection feeler, the jammed sheet is caught by the sheet detection feeler, and therefore the operability of removal of the jammed sheet becomes worse and the sheet detection feeler is damaged or broken. Further, when the sheet detecting feeler is employed instead of the full detection feeler and a manual retraction of the sheet detecting feeler is performed to remove the jammed sheet after retracting the sheet detection feeler manually to a position at which the jammed sheet does not contact, there are many operation processes to take, which is troublesome. Furthermore, when the machine is operated (when the printing operation is performed), the sheet needs to be returned manually before the operation. Therefore, when the sheet detection feeler is not returned, the sheet full state is not detected. Accordingly, prevention of a sheet stacking failure and a paper jam is fairly costly.
Now, a description is given of a sheet conveying device 700 according to Embodiment 2 of this disclosure.
The front cover 20 includes the sheet conveying unit 70 (see
As illustrated in
The sheet detection feeler 901A is not used as a detector to detect the height of the sheets stacked in the sheet stacker 15, together with the full detection feeler 901 and the photointerrupter 92, but is used as a detector to detect passage of the sheet P one by one in the sheet conveying device 700, together with the photointerrupter 92.
Similar to the configuration according to Embodiment 1 described above, the sheet detection feeler 901A includes the sheet contact member 903, the feeler body 902 and the second swing support 904. The sheet contact member 903 functions as a contact body that swings together with the sheet while contacting the sheet. The feeler body 902 that functions as a shaft that swings together with the sheet contact member 903 in the range of rotation of the sheet contact member 903. The second swing support 904 is provided to the feeler body 902. The configuration and functions of the sheet detection feeler 901A are identical to the full detection feeler 901, except that the above-described features. Accordingly, the presence or absence of the sheet P is determined with a sheet detecting member such as the sheet detection feeler 901A and the photointerrupter 92 to interrupt or stop the print job.
As described above, the sheet conveying device such as the sheet conveying device 700 according to Embodiment 2 of this disclosure includes a contact body such as the sheet contact member 913, a shaft such as the feeler body 912, and a sheet detector such as the full detection feeler 91 and the photointerrupter 92. The contact body is configured to rotate while contacting the sheet. The shaft is configured to rotate together with the contact body in a range of rotation of the contact body. The sheet detector is configured to detect presence of the sheet through detection of rotation of the shaft rotating with the contact body in contact with the sheet. The sheet conveying device according to Embodiment 2 of this disclosure further includes a rotary body support configured to rotatably support the contact body to the shaft that rotates together with the contact body in contact with the sheet, extending the range of rotation, in a same direction as the direction of rotation of the shaft.
According to Embodiment 2, the performance of sheet conveyance can be enhanced without retracting and returning the sheet contact member 903, and therefore the sheet contact member 903 and the sheet can be prevented from being damaged or torn. Further, the failure caused by forgetting of return of the sheet contact member 903 can be prevented before the occurrence.
An image forming apparatus to which this disclosure is applied is explained with the image forming apparatus 100 that forms image by electrophotography. However, the configuration of an image forming apparatus to which this disclosure is applied is not limited to the image forming apparatus 100. For example, any image forming apparatus can be applied as long as the image forming apparatus includes a sheet discharging device to discharge a recording medium. For example, this disclosure can be applied to an inkjet image forming apparatus that forms an image using at least one liquid inkjet print head, a printing apparatus such as a stencil printing machine, a post processing device or finisher including at least one function of a sorting function, a punching function and a binding function, or a multifunction machine having the above-described functions.
Further, the sheet conveying device is not limited to a sheet conveying device disposed in the sheet conveyance passage in the vicinity of the pair of registration rollers as described above. For example, the sheet conveying device may be disposed in a sheet conveyance passage in the vicinity of a multiple step sheet feeder and a bank type sheet feeder.
In the above-described embodiments, the sheet P is used as a sheet-like transfer target medium that is conveyed or on which an image is formed. However, the sheet P is not limited thereto but also includes thick paper, postcard, envelope, plain paper, thin paper, coated paper, art paper, tracing paper, and the like. Further, as a transfer target medium other than a paper material, the sheet P further includes a non-paper material such as OHP sheet, OHP film, resin film, and any other sheet-shaped material to be conveyed or on which an image can be formed.
The above-described embodiments are illustrative and do not limit this disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements at least one of features of different illustrative and exemplary embodiments herein may be combined with each other at least one of substituted for each other within the scope of this disclosure and appended claims. Further, features of components of the embodiments, such as the number, the position, and the shape are not limited the embodiments and thus may be preferably set. It is therefore to be understood that within the scope of the appended claims, the disclosure of this disclosure may be practiced otherwise than as specifically described herein.
Number | Date | Country | Kind |
---|---|---|---|
2016-256775 | Dec 2016 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
7677557 | Ino | Mar 2010 | B2 |
8651479 | Onishi | Feb 2014 | B2 |
9302878 | Ono | Apr 2016 | B2 |
20050035535 | Ogata | Feb 2005 | A1 |
20050281598 | Hattori | Dec 2005 | A1 |
20070069454 | Ino | Mar 2007 | A1 |
20120112402 | Onishi | May 2012 | A1 |
20120248682 | Arikawa et al. | Oct 2012 | A1 |
20140239578 | Honda et al. | Aug 2014 | A1 |
20150102551 | Koga | Apr 2015 | A1 |
20150307311 | Ono | Oct 2015 | A1 |
Number | Date | Country |
---|---|---|
5-058545 | Mar 1993 | JP |
2000-211809 | Aug 2000 | JP |
2000-219397 | Aug 2000 | JP |
2002-062704 | Feb 2002 | JP |
2002-128389 | May 2002 | JP |
Entry |
---|
Extended European Search Report dated Jun. 5, 2018 issued in corresponding European Application No. 17211173.4. |
Number | Date | Country | |
---|---|---|---|
20180179010 A1 | Jun 2018 | US |