Patent Grant
10429791
The present invention relates to an image forming apparatus where a light emission faces of lenses that an optical print head has can be easily cleaned.
Image forming apparatuses such as printers, copying machines, and so forth, have an optical print head that has multiple light-emitting elements for exposing a photosensitive drum. Some optical print heads use light-emitting diodes (LEDs) or organic electroluminescence (EL) devices or the like, which are examples of light-emitting elements. There are known arrangements where such light-emitting elements are arrayed in one row or two staggered rows, for example, in the rotational axis direction of the photosensitive drum. Optical print heads also have multiple lenses for condensing light emitted from the multiple light-emitting elements onto the photosensitive drum. The multiple lenses are disposed facing the surface of the photosensitive drum, having been arrayed in the direction of array of the light-emitting elements, between the multiple light-emitting elements and the photosensitive drum. Light emitted from the multiple light-emitting elements is condensed on the surface of the photosensitive drum through the lenses, and an electrostatic latent image is formed on the photosensitive drum.
The photosensitive drum is a consumable item, and accordingly is periodically replaced. A worker performing the work of replacing a photosensitive drum or the like can perform maintenance of the image forming apparatus by replacing the replacement unit containing the photosensitive drum. The replacement unit has a configuration where it is detachably mountable to a main body of the image forming apparatus, by being extracted from and inserted to the apparatus main body from the side face of the image forming apparatus by sliding movement. The clearance between the lenses and the surface of the photosensitive drum is extremely narrow at an exposure position of the optical print head for when exposing the photosensitive drum (a position near to and facing the surface of the drum). Accordingly, the optical print head needs to be retracted from the exposure position when replacing the replacement unit, test the optical print head and photosensitive drum or the like come into contact and the surface of the photosensitive drum and the lenses be damaged. Accordingly, a mechanism needs to be provided to the image forming apparatus where the optical print head is reciprocally moved between the exposure position and a retracted position where the optical print head is further distanced from the replacement unit than the exposure position, in order to mount/detach the replacement unit.
Now, an exposure unit such as an optical print head may be provided to the image forming apparatus between a charger and a developing unit. Maximally reducing the distances among the photosensitive drum, optical print head, charger, developing unit, and so forth, is an effective way to realize reduction in size of the apparatus. Accordingly, there has been a problem where the light emission faces of lenses that the optical print head has are contaminated by toner falling from the photosensitive drum and developing unit. Contamination of the light emission faces of lenses can partially shield light emitted from light-emitting elements, and is a factor leading to deterioration in image quality of output images. A cleaning unit has been proposed to prevent such contamination of light emission faces of the optical print head that would lead to deterioration in image quality. One example of a cleaning unit is that described in Japanese Patent Laid-Open No. 2014-213541.
An exposing module EM described in Japanese Patent Laid-Open No. 2014-213541 has a light-emitting diode (LED) print head (LPH) 14 and an advancing/retracting mechanism 17. A sliding member 67 used to clean a rod lens array 64 is attached to the LPH 14. The sliding member 67 has a supporting portion 67a provided to the rear side that supports a blade that comes into contact with a light emission face of the rod lens array 64 while sliding and cleans the light emission face, and a handle 67b that is provided to the front side and receives advancing/retracting operations when cleaning. In a case of sliding the sliding member 67 in the X direction using the handle 67b, dust and the like adhering to the upper face of the rod lens array 64 will be removed by the blade moving in contact over the upper face of the rod lens array 64.
The LPH 14 reciprocally moves between an exposure position that is a position assumed when forming images, and a retracted position where the LPH 14 is retracted away from a photosensitive member 12, from the exposure position, in order to clean the upper face of the rod lens array 64. A first front positioning pin 611F that positions the front side of the LPH 14 in the Z direction is provided to the front side of the LPH 14, and a first rear positioning pin 611R that positions the rear side of the LPH 14 in the Z direction is provided to the rear side of the LPH 14.
However, in the structure of the cleaning mechanism described in Japanese Patent Laid-Open No. 2014-213541, the sliding portion 67 has the supporting portion 67a so as to be capable of moving by sliding in the longitudinal direction of the LPH 14, which is a factor in the apparatus becoming complex and large in size. Now, a mechanism will be considered where a rod-shaped cleaning member is inserted into the main body of an image forming apparatus 1 from the outside, and the light emission face of the rod lens array is cleaned by rubbing with a rubbing portion provided to the cleaning member. However, in a case of applying this mechanism to Japanese Patent Laid-Open No. 2014-213541, it is difficult to insert a cleaning member into the main body of an image forming apparatus 1 from the outside toward the light emission face of the rod lens array 64, since the first front positioning pin 611F is on the path of movement of the cleaning member that has been inserted.
An image forming apparatus according to the present invention is an image forming apparatus configured to have a drum unit rotatably supporting a photosensitive drum. The image forming apparatus includes: an optical print head having a light emission face where light for exposing the photosensitive drum is emitted; a movement mechanism configured to reciprocally move the optical print head between an exposure position where the light emission face exposes the photosensitive drum, and a retracted position retracted further from the drum unit than the exposure position; a stopping mechanism configured to stop the optical print head, being moved by the movement mechanism from the exposure position toward the retracted position, at the retracted position; an abutting portion configured to abut the drum unit by protruding from one end side of the optical print head, in the longitudinal direction of the optical print head, farther to the drum unit side than the light emission face, to stop the optical print head, being moved by the movement mechanism from the retracted position toward the exposure position, at the exposure position; and an insertion portion where a rod-shaped cleaning member configured to rub and clean the light emission face is inserted from a side face of a main body of the image forming apparatus by an operator in the longitudinal direction. The movement mechanism moves the optical print head so a movement path of the abutting portion intersects a movement path of the cleaning member guided over the light emission face by the insertion portion. An end portion of the abutting portion at the drum unit side when the optical print head is situated at the retracted position is situated on an opposite side of the movement path of the cleaning member from an end portion of the abutting portion at the drum unit side when the optical print head is situated in the exposure position.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
FIGS. 7A1 through 7B2 are diagrams illustrating a state where an optical print head is in contact with a drum unit, and a retracted state.
FIGS. 15A1 through 15B are diagrams describing an X-type movement mechanism.
FIGS. 29A1 through 29B are diagrams for describing an abutted portion (stopper) according to a first modification and a second modification.
Image Forming Apparatus
First, a schematic configuration of an image forming apparatus 1 will be described.
The image forming apparatus 1 illustrated in
The image forming apparatus 1 is provided with an intermediate transfer belt 107 onto which toner images formed on the photosensitive drums 103 are transferred, and primary transfer roller 108 (Y, M, C, K) that sequentially transfer the toner images formed on the photosensitive drums 103 of the image forming units 102 onto the intermediate transfer belt 107. The image forming apparatus 1 further is provided with a secondary transfer roller 109 that transfers the toner image on the intermediate transfer belt 107 onto a recording sheet P conveyed from a sheet feed unit 101, and a fixing unit 100 that fixes the secondary-transferred image onto the recording sheet P.
Drum Unit
Next, drum units 518 (Y, M, C, K), and developing units 641 (Y, M, C, K), which are an example of replacement units detachably mounted to the image forming apparatus 1 according to the present embodiment, will be described.
The image forming apparatus 1 has a front-side plate 642 and a rear-side plate 643 that are formed from sheet metal, as illustrated in
Openings are formed on the front-side plate 642, through which the drum units 518 and developing units 641 can be inserted and extracted from the front side of the image forming apparatus 1. The drum units 518 and developing units 641 are mounted through openings to predetermined positions in the main body of the image forming apparatus 1 (mounting positions). The image forming apparatus 1 also has covers 558 (Y, M, C, K) that cover the front side of the drum units 518 and developing units 641 mounted to the mounting positions. The covers 558 have one end thereof fixed integrally to the main body of the image forming apparatus 1 by a hinge, and are capable of pivoting as to the main body of the image forming apparatus 1 on the hinge. Unit replacement work is completed by a worker who performs maintenance opening a cover 558 and extracting a drum unit 518 or developing unit 641 within the main body, inserting a new drum unit 518 or developing unit 641, and closing the cover 558. The covers 558 will be described in detail later.
In the following description, the front-side plate 642 side of the image forming apparatus 1 is defined as the front side, and the rear-side plate 643 side as the rear side, as illustrated in
Drum units 518 are attached to the image forming apparatus 1 according to the present embodiment. The drum units 518 are cartridges that are replaced. The drum units 518 according to the present embodiment have photosensitive drums 103 rotatably supported as to the casing of the drum units 518. The drum units 518 each have a photosensitive drum 103, charger 104, and cleaning device that is omitted from illustration. When the lifespan of a photosensitive drum 103 is expended due to wear by cleaning by the cleaning device for example, a worker who performs maintenance extracts the drum unit 518 from the apparatus main body, and replaces the photosensitive drum 103, as illustrated in
The developing units 641, which are separate from the drum units 518, are attached to the image forming apparatus 1 according to the present embodiment. The developing units 641 include the developing units 106 illustrated in
Image Forming Process
Next, an image forming process will be described. A later-described optical print head 105Y exposes the surface of the photosensitive drum 103Y that has been charged by the charger 104Y. Accordingly, an electrostatic latent image is formed on the photosensitive drum 103Y. Next, the developing unit 106Y develops the electrostatic latent image formed on the photosensitive drum 103Y by yellow toner. The yellow toner image developed on the surface of the photosensitive drum 103Y is transferred onto the intermediate transfer belt 107 by the primary transfer roller 108Y at a primary transfer position Ty. Magenta, cyan, and black toner images are also transferred onto the intermediate transfer belt 107 by the same image forming process.
The toner images of each color transferred onto the intermediate transfer belt 107 are conveyed to a secondary transfer position T2 by the intermediate transfer belt 107. Transfer bias for transferring the toner images onto a recording sheet P is applied to the secondary transfer roller 109 disposed at the secondary transfer position T2. The toner images conveyed to the secondary transfer position T2 are transferred onto a recording sheet P conveyed from the sheet feed unit 101 by the transfer bias of the secondary transfer roller 109. The recording sheet P onto which the toner images have been transferred is conveyed to the fixing unit 100. The fixing unit 100 fixes the toner images onto the recording sheet P by heat and pressure. The recording sheet P subjected to fixing processing by the fixing unit 100 is discharged to a sheet discharge unit 111.
Exposing Unit
The exposing unit 500 including the optical print head 105 will be described next.
The optical print head 105 is provided with a holding member 505 that holds a lens array 506 (lenses) and circuit board 502, an abutting pin 514 (example of an abutting portion and a first abutting portion), and an abutting pin 515 (second abutting portion). The abutting pin 514 is provided protruding toward the drum unit 518 side at one end side (front side) of the holding member 505 in the rotational axis direction of the photosensitive drum 103, which will be described in detail later. The abutting pin 515 is provided protruding toward the drum unit 518 side at the other end side (rear side) of the holding member 505 in the rotational axis direction of the photosensitive drum 103. In other words, the abutting pin 514 is provided at one end side (front side) of the optical print head 105 in the longitudinal direction, and the abutting pin 515 is provided at the other end side (rear side) of the optical print head 105 in the longitudinal direction. The movement mechanism 640 has a first link mechanism 861, a second link mechanism 862, a sliding portion 525, a first support portion 527 (an example of a support member), a second support portion 528 (an example of a support member), and a third support portion 526 as an example of a slide supporting member. The first link mechanism 861 includes a link member 651 and link member 653, and the second link mechanism 862 includes a link member 652 and a link member 654. Although the abutting pin 514 and abutting pin 515 are described as being cylindrical pins in the present embodiment, the shape thereof is not restricted to being cylindrical, and may be polygonal posts, or conical shapes where the diameter is tapered toward the tip.
First, the holding member 505 will be described. The holding member 505 is a holder that holds the later-described circuit board 502, lens array 506, abutting pin 514, and abutting pin 515. As one example in the present embodiment, the length of the abutting pin 514 protruding from the upper face of the holding member 505 is 7 mm, the length of the abutting pin 515 protruding from the upper face of the holding member 505 is 11 mm, the length of the abutting pin 514 protruding from the lower face of the holding member 505 is 22 mm, and the length of the abutting pin 515 protruding from the lower face of the holding member 505 is 22 mm. That is to say, the total length of the abutting pin 514 is shorter than the total length of the abutting pin 515. The holding member 505 is provided with lens attaching portions 701 where the lens array 506 is attached, and circuit board attaching portions 702 where the circuit board 502 is attached, as illustrated in
The spring attaching portion 661 to which the link member 651 is attached is provided between the lens array 506 and the pin attaching portion 632 in the front-and-rear direction, as illustrated in
The lens attaching portion 701 has a first inner wall face 507 that extends in the longitudinal direction of the holding member 505, and a second inner wall face 508 that faces the first inner wall face 507 and also extends in the longitudinal direction of the holding member 505. The lens array 506 is inserted between the first inner wall face 507 and the second inner wall face 508 when assembling the optical print head 105. Adhesive agent is coated between the side face of the lens array 506 and the lens attaching portion 701, thereby fixing the lens array 506 to the holding member 505.
The circuit board attaching portion 702 has a cross-sectional open-box shape, and has a third inner wall face 900 extending in the longitudinal direction of the holding member 505, and a fourth inner wall face 901 that faces the third inner wall face 900 and extends in the longitudinal direction of the holding member 505, as illustrated in
Next, the circuit board 502 held by the holding member 505 will be described.
LED chips 639 are mounted on the circuit board 502. The LED chips 639 are mounted on one face of the circuit board 502, while a connector 504 is provided to the rear face side, as illustrated in
The LED chips 639 mounted on the circuit board 502 will be described in further detail. Multiple (29) LED chips 639-1 through 639-29, on which multiple LEDs 503 are arrayed, are arrayed on one face of the circuit board 502, as illustrated in FIGS. 5B1 and 5B2. Each of the LED chips 639-1 through 639-29 has 516 LEDs (light-emitting elements) arrayed in a single row in the longitudinal direction thereof. The center-to-center distance k2 between LEDs adjacent in the longitudinal direction in the LED chips 639 corresponds to the resolution of the image forming apparatus 1. The resolution of the image forming apparatus 1 according to the present embodiment is 1200 dpi, so the LEDs are arrayed in a single row so that the center-to-center distance k2 between adjacent LEDs in the longitudinal direction of the LED chips 639-1 through 639-29 is 21.16 μm. Accordingly, the range of exposure of the optical print head 105 according to the present embodiment is 316 mm. The photosensitive layer of the photosensitive drum 103 is formed 316 mm or wider. The long side of an A4-size recording sheet and the short side of an A3-size recording sheet are 297 mm, so the optical print head 105 according to the present embodiment has an exposing range capable of forming images on A4-size recording sheets and A3-size recording sheets.
The LED chips 639-1 through 639-29 are alternately arrayed to form two rows in the rotational axis direction of the photosensitive drum 103. That is to say, odd-numbered LED chips 639-1, 639-3, and so on through 639-29, are arrayed on one line in the longitudinal direction of the circuit board 502 from the left, and even-numbered LED chips 639-2, 639-4, and so on through 639-28, are arrayed on one line in the longitudinal direction of the circuit board 502, as illustrated in FIG. 5B1. Arraying the LED chips 639 in this way enables the center-to-center distance k1 between the LEDs disposed on one end of one LED chip 639 and the other end of another LED chip 639 among different adjacent LED chips 639 to be equal to the center-to-center distance k2 of LEDs on the same LED chip 639, in the longitudinal direction of the LED chips 639, as illustrated in FIG. 5B2.
An example where the exposing light source is configured using LEDs is described in the present embodiment. However, organic electroluminescence (EL) devices may be used instead of the exposing light source.
Next, the lens array 506 will be described. FIG. 5C1 is a schematic diagram viewing the lens array 506 from the photosensitive drum 103 side. FIG. 5C2 is a schematic perspective view of the lens array 506. These multiple lenses are arrayed in two rows following the direction of array of the multiple LEDs 503, as illustrated in FIG. 5C1. The lenses are disposed in a staggered manner such that each lens in one row comes into contact with two lenses in the other row that are adjacent in the direction of array of the lenses. The lenses are cylindrical glass rod lenses. Note that the material of the lenses is not restricted to glass, and that plastic may be used. The shape of the lenses is not restricted to a cylindrical shape either, and may be polygonal posts such as hexagonal posts or the like, for example.
A dotted line Z in FIG. 5C2 indicates the optical axis of a lens. The optical print head 105 is moved by the above-described movement mechanism 640 in a direction generally following the optical axis of the lens indicated by the dotted line Z. The term optical axis of a lens here means a line that connects the center of the light emitting face of the lens and the focal point of this lens. The discharged light emitted from an LED enters a lens included in the lens array 506, as illustrated in
Now, the necessity of moving the optical print head 105 will be described. When replacing a drum unit 518 in the image forming apparatus 1 according to the present embodiment, the drum unit 518 is moved by sliding in the rotational axis direction of the photosensitive drum 103 to the front side of the apparatus main body, as illustrated in
FIG. 7A1 is a perspective view illustrating a bushing 671 provided to the rear side of the optical print head 105 situated in the exposure position and the rear side of the drum unit 518. FIG. 7A2 is a cross-sectional view illustrating the second support portion 528 and the bushing 671 provided to the rear side of the drum unit 518 when the optical print head 105 situated in the exposure position. FIG. 7B1 is a perspective view illustrating the bushing 671 provided to the rear side of the optical print head 105 situated in the retracted position and the rear side of the drum unit 518. FIG. 7B2 is a cross-sectional view illustrating the second support portion 528 and the bushing 671 provided to the rear side of the drum unit 518 when the optical print head 105 is in the retracted position.
The way in which the end portion of the abutting pin 515 provided to the drum unit 518 side abuts the bushing 671 will be described with reference to FIGS. 7A1 through 7B2. A part equivalent to the bushing 671 is provided on the front side of the drum unit 518, the structure and function thereof is the same as that of the bushing 671. The end portion of the abutting pin 514 at the drum unit 518 side abuts this part. The way in which the end portion of the abutting pin 515 at the drum unit 518 side comes into contact with the bushing 671 will be described here.
It can be seen from FIGS. 7A1 and 7B1 that the portion where the link member 652 is attached to the holding member 505 is closer to the photosensitive drum 103 side from the one of the ends of the abutting pin 515 that is opposite to the replacement unit side (the side where the drum unit 518 is disposed), in the vertical direction (the direction in which the optical print head 105 moves between the exposure position and the retracted position, i.e., in the direction of reciprocal movement). The spring attaching position 662 to which the link member 652 is attached is disposed so as to not intersect the abutting pin 515 in the vertical direction. The portion where the link member 651 is attached to the holding member 505 also is closer to the photosensitive drum 103 side from the one of the ends of the abutting pin 514 that is opposite to the replacement unit side (the side where the drum unit 518 is disposed), in the vertical direction (the direction in which the optical print head 105 moves between the exposure position and the retracted position, i.e., in the direction of reciprocal movement), although omitted from illustration here. The spring attaching portion 661 where the link member 651 is attached is disposed so as to not intersect the abutting pin 514 in the vertical direction. Accordingly, the size of the exposing unit 500 in the vertical direction can be suppressed.
The second support portion 528 has a second seating face 587, a restricting portion 128, a first wall face 588, and a second wall face 589, as illustrated in FIGS. 7A2 and 7B2. The second seating face 587 is provided to the lower side of the holding member 505. The lower side of the holding member 505 moving from the exposure position toward the retracted position abuts the second seating face 587 and the first seating face 586 of the later-described first support portion 527 from above in the vertical direction, and thus the optical print head 105 is at the retracted position. The restricting portion 128 is a recess formed in the second support portion 528 and having the shape of a box with one side open, being opened toward the front side. The restricting portion 128 is formed to the opposite side of the holding member 505 from the side where the drum unit 518 is situated, and is fit further from the rear side than the abutting pin 515, so that the abutting pin 515 is capable of vertical movement. The abutting pin 515 that has protruded from the lower side of the holding member 505 moves through the gap formed by the restricting portion 128, and vertically moves along with the holding member 505. The first support portion 527 also has a restricting portion 127, though omitted from illustration here. The restricting portion 127 is a recess formed in the first support portion 527 and having the shape of a box with one side open, being opened toward the front side. The restricting portion 127 is formed to the opposite side of the holding member 505 from the side where the drum unit 518 is situated, and is fit further from the front side than the abutting pin 514, so that the abutting pin 514 is capable of vertical movement. The abutting pin 514 that has protruded from the lower side of the holding member 505 moves through the gap formed by the restricting portion 127, and vertically moves along with the holding member 505. The restricting portion 127 is formed tapered, to maximally reduce friction occurring due to contact with the abutting pin 514. Thus, the abutting pin 514 can smoothly move vertically in the gap at the restricting portion 127. Accordingly, movement of the holding member 505 that is integral with the abutting pin 515 and abutting pin 514 is restricted in directions intersecting both the front-and-rear direction (rotational axis direction of the photosensitive drum 103) and the vertical direction (the direction in which the optical print head 105 moves between the exposure position and the retracted position, i.e., in the direction of reciprocal movement). The restricting portion 127 may restrict the abutting pin 514 from moving from the rear side to the front side, and the restricting portion 128 may restrict the abutting pin 515 from moving from the front side to the rear side.
The first wall face 588 and second wall face 589 are disposed at positions facing each other in the left-and-right direction, with a gap formed. When the optical print head 105 reciprocally moves between the exposure position and the retracted position, the holding member 505 moves vertically through the gap formed by the first wall face 588 and second wall face 589. During this time, movement of the holding member 505 is restricted in directions intersecting both the front-and-rear direction (rotational axis direction of the photosensitive drum 103) and the vertical direction (the direction in which the optical print head 105 moves between the exposure position and the retracted position, i.e., in the direction of reciprocal movement), by the first wall face 588 and second wall face 589.
According to the above configuration, the optical print head 105 moves between the exposure position and retracted position in a state where movement is restricted in directions intersecting both the front-and-rear direction (rotational axis direction of the photosensitive drum 103) and the vertical direction (the direction in which the optical print head 105 moves between the exposure position and the retracted position, i.e., in the direction of reciprocal movement). Note that it is sufficient for at least one of the restricting portion 127 and restricting portion 128 to be provided to the first support portion 527 or second support portion 528. That is to say, it is sufficient for the restricting portion 127 to be provided to the first support portion 527 that is an example of a support portion, or the restricting portion 128 to be provided to the second support portion 528.
The position at which the abutting pin 515 comes into contact with the bushing 671 provided to the rear side of the drum unit 518, and the abutting pin 514 (omitted from illustration) comes into contact with the part equivalent to the bushing 671 that is provided to the front side of the drum unit 518, is the exposure position of the optical print head 105, as illustrated in FIGS. 7A1 and 7A2. The distance between the lens array 506 and the surface of the photosensitive drum 103 becomes the designed nominal distance by the abutting pin 514 and the abutting pin 515 abutting the bushing 671 and the part equivalent to the bushing 671 (example of first recess and second recess).
On the other hand, the position where the abutting pin 515 is retracted from the bushing 671 provided to the rear side of the drum unit 518, as illustrated in FIGS. 7B1 and 7B2 is equivalent to the retracted position of the optical print head 105. The optical print head 105 is in a state where the drum unit 518 that moves by sliding for being replaced and the optical print head 105 do not come into contact, by the optical print head 105 being at the retracted position illustrated in FIGS. 7B1 and 7B2.
Now, the bushing 671 that the drum unit 518 has will be described.
The photosensitive drum 103 has a photosensitive layer formed on an outer wall face of a hollow cylindrical aluminum tube. Flanges 673 are press-fitted top both ends of the aluminum tube. The flange 673 at the other end side of the photosensitive drum 103 is rotatably inserted into the opening 916 formed in the bushing 671. The flange 673 rotates while rubbing against the inner wall face of the opening 916 formed in the bushing 671. That is to say, the bushing 671 rotatably bears the photosensitive drum 103. An opening the same as that of the bushing 671 is also formed at the middle portion of the part equivalent to the bushing 671 provided to the front side of the drum unit 518, with which the abutting pin 514 comes into contact. The flange 673 of the one end side (front side) of the photosensitive drum 103 is rotatably inserted into the opening formed in the part equivalent to the bushing 671. The flange 673 rotates while rubbing against the inner wall face of this opening. That is to say, the part equivalent to the bushing 671 rotatably bears the photosensitive drum 103 at the front side, the same as the rear side of the drum unit 518.
The bushing 671 has a fitting portion 685 (second recess) to which the abutting pin 515 fits. The fitting portion 685 is provided with an abutting face 551, a rear-side wall face 596, and a tapered portion 585. The fitting portion 685 (second recess) may be recessed as to the bushing 671, or may be erected. The abutting pin 515 that moves in the direction from the retracted position toward the exposure position abuts the abutting face 551. The lower edge of the fitting portion 685 has the tapered portion 585 formed, that is tapered. The tapered portion 585 guides movement of the abutting pin 515 heading from the retracted position toward the exposure position, so as to abut the abutting face 551. Contact of the rear-side wall face 596 and the abutting pin 515 will be described later.
The movement of the abutting pin 515 that has abutted the abutting face 551 of the fitting portion 685 is restricted in directions intersecting both the front-and-rear direction (rotational axis direction of the photosensitive drum 103) and the vertical direction (the direction in which the optical print head 105 moves between the exposure position and the retracted position, i.e., in the direction of reciprocal movement) by the fitting portion 685. That is to say, movement of the upper end of the abutting pin 515 is restricted in directions intersecting both the front-and-rear direction and the vertical direction by the fitting portion 685, and movement of the lower end of the abutting pin 515 is restricted in directions intersecting both the front-and-rear direction and the vertical direction by the restricting portion 128, with regard to the optical print head 105 situated in the exposure position (FIG. 7A2). Now, the difference between the diameter of the fitting portion 685 in the left-and-right direction and the diameter of the upper end of the abutting pin 515 in the left-and-right direction, and the difference between the diameter of the restricting portion 128 in the left-and-right direction and the diameter of the lower end of the abutting pin 515 in the left-and-right direction, are smaller than the difference between the gap in the left-and-right direction between the first wall face 588 and second wall face 589 and holding member 505 situated between the first wall face 588 and second wall face 589. Accordingly, when the optical print head 105 is in the exposure position, the first wall face 588 and second wall face 589 do not contribute to restriction of movement of the holding member 505 in directions intersecting either of the front-and-rear direction and the vertical direction.
Movement Mechanism
The movement mechanism 140 for moving the optical print head 105 will be described next. First, the first support portion 527 will be described.
The first seating face 586 is a portion where the lower side of the holding member 505 moving from the exposure position toward the retracted position abuts from above in the vertical direction, and is fixed to the main body of the image forming apparatus 1. The lower side of the holding member 505 abuts the first seating face 586, and the optical print head 105 is at the retracted position.
A cleaning member 572 for cleaning the light-emitting face of the lens array 506 contaminated by toner or the like is inserted through the opening 700 from the outer side of the main body of the image forming apparatus 1 by a worker such as the user or service staff. The cleaning member 572 is inserted to the opening 700 following the longitudinal direction of the optical print head 105. The cleaning member 572 is a slender rod-like member. Although a through hole through which the cleaning member 572 passes in the front-and-rear direction is illustrated as an example of the opening 700 in the present embodiment, this is not restricted to being a hole, and a slit may be formed above, for example. The abutting portion 529 is a rear-side face of the first support portion 527, as indicated by hatching in
The restricting portion 127 is a recess formed in the first support portion 527 and having the shape of a box with one side open, being opened toward the rear side, as illustrated in
The first support portion 527 is fixed to the front-side face of the front-side plate 642. Multiple holes (omitted from illustration), corresponding to the positioning boss 603, positioning boss 604, and fixing screws are formed in the front-side plate 642. The positioning boss 603 and positioning boss 604 are inserted into respective holes of the multiple holes provided to the front-side plate 642, and in this state, the first support portion 527 is fixed to the front-side plate 642 by screws passed through the screw holes of the first support portion 527.
The third support portion 526, which will be described later, is sheet metal folded into the shape of a box with one end opened.
Next, the second support portion 528 will be described.
The second support portion 528 is fixed to the front-side face of the rear-side plate 643, as illustrated in
Note that an arrangement may be made where the second support portion 528 is fixed to the third support portion 526 by screws or the like, and is not fastened to the rear-side plate 643 by screws. In this case, a structure is made, for example, where a recessed portion is formed in the second support portion 528, which fits with a protruding portion formed on the rear-side plate 643, thereby positioning the second support portion 528 as to the rear-side plate 643. The first wall face 588 and second wall face 589 of the second support portion 528 will be described later.
The restricting portion 128 is a recess formed in the second support portion 528 and having the shape of a box with one side open, being opened toward the front side, as illustrated in
Next, the third support portion 526 and sliding portion 525 will be described with reference to
A slide aiding member 539 having an accommodation space 562 from the left side to the lower side is attached to one end side of the sliding portion 525. The slide aiding member 539 is fixed to the sliding portion 525 by being fastened by a screw from the left side. The accommodation space 562 accommodates a later-described pressing member 561 that the cover 558 has. The relation between the accommodation space 562 and the pressing member 561, and structural features thereof, will be described later along with description of the cover 558.
The movement mechanism 640 will be described with reference to
The first link mechanism 861 will be described with reference to
The link member 651 has a bearing 610, a protrusion 655, and a connecting shaft portion 538. The bearing 610 is provided to one end side in the longitudinal direction of the link member 651. The protrusion 655 is a cylindrical protrusion erected in the pivoting axis direction of the link member 651 provided at the other end side in the longitudinal direction of the link member 651, for causing deformation of a spring provided to the holding member 505 side of the optical print head 105. The connecting shaft portion 538 is provided between the bearing 610 and protrusion 655 in the longitudinal direction of the link member 651. Although the protrusion 655 serves as a first moving portion, the first moving portion is not restricted to the protrusion 655, and may be a structure where one end side in the longitudinal direction of the link member 651 is bent in the pivoting axis direction.
A circular hollowed space that extends in the left-and-right direction in
The link member 653 has a connecting shaft portion 530. The connecting shaft portion 530 is provided to one end side in the longitudinal direction of the link member 653. The connecting shaft portion 530 is a cylindrical protrusion erected from the link member 653 to the left side in
A circular hole that extends in the left-and-right direction in
Note that the configuration of the second link mechanism 862 is the same as the configuration of the first link mechanism 861 described above. The link member 652 and link member 654 that the second link mechanism 862 has correspond to the link member 651 and link member 653, respectively. The one end side in the longitudinal direction of the link member 652 and the connecting portion of the sliding portion 525 make up a second connecting portion, corresponding to the first connecting portion. Note that one of the link member 653 and link member 654 may be omitted from the embodiment regarding the movement mechanism 640.
According to the above configuration, when the sliding portion 525 moves by sliding from the front side toward the rear side with regard to the third support portion 526, the bearing 610 to which the fitting shaft portion 534 has been fit moves by sliding from the front side toward the rear side as to the third support portion 526, along with the sliding portion 525. Accordingly, when viewing the first link mechanism 861 from the right side as illustrated in
On the other hand, when the sliding portion 525 moves by sliding from the rear side toward the front side as to the third support portion 526, the link member 651 and link member 653 move in the opposite directions as to the arrows in
Now,
(1) the distance between the pivoting center axis of the connecting shaft portion 538 and the pivoting center axis of the bearing 610 will be referred to as L1,
(2) the distance between the pivoting center axis of the connecting shaft portion 538 and the pivoting center axis of the connecting shaft portion 530 will be referred to as L2, and
(3) the distance between the pivoting center axis of the connecting shaft portion 538 and the pivoting center axis of the protrusion 655 will be referred to as L3. In the movement mechanism 640, the first link mechanism 861 forms a Scott Russel linkage where L1, L2, and L3 are equal (see
A configuration may be made where the front-and-rear directions of the first link mechanism 861 and second link mechanism 862 are opposite, so that when the sliding portion 525 is moved by sliding from the front side toward the rear side, the optical print head 105 moves from the retracted position toward the exposure position, and when the sliding portion 525 is moved by sliding from the rear side toward the front side, the optical print head 105 moves from the exposure position toward the retracted position. In this case, the later-described cover 558 presses the sliding portion 525 from the front side toward the rear side when moving from an opened state to a closed state, and pulls the sliding portion 525 from the rear side toward the front side when moving from a closed state to an opened state.
The mechanism for moving optical print head 105 is not restricted to the movement mechanism 640. A movement mechanism 140 illustrated in
The arrangement by which the movement mechanism 140 moves the holding member 505 will be described with reference to
The link member 151 has a bearing 110 and a protrusion 155, as illustrated in
A circular hollowed space that extends in the left-and-right direction is formed in the bearing 110, as a hole. A fitting shaft portion 534 is provided to the sliding portion 525, as illustrated in
Note that a shaft the same as the support shaft 531 is provided at the rear side of the third support portion 526, a slot the same as the slot 691 is formed at the rear side of the sliding portion 525, and the structure of the rear side of the movement mechanism 140 is the same as the front side. The structure of the link member 152 also is the same as the structure of the first moving member described above, with the link member 152 corresponding to the link member 151. The connecting portion of the one end side in the longitudinal direction of the link member 152 and the sliding portion 525 make up the second connecting portion, corresponding to the first connecting portion.
The abutting portion 529 of the first support portion 527 (omitted from illustration in
On the other hand, when the sliding portion 525 moves by sliding as to the third support portion 526 from the front side to the rear side, the bearing 110 fit to the fitting shaft portion 534 moves by sliding as to the third support portion 526 from the rear side to the front side, along with the sliding portion 525. Accordingly, the link member 151 pivots in a clockwise direction with the fitting shaft portion 534 as the center of pivoting, as viewed from the right side as illustrated in
When the optical print head 105 moves generally in the optical axis direction of the lens, the rear side of the holding member 505 moves through a gap formed by the first wall face 588 and the second wall face 589 of the second support portion 528, as described earlier. This prevents the holding member 505 from tilting in the left or right directions.
Note that the link member 151 and link member 152 may be arranged such that the other end side is situated further toward the front side than the one end side, with the abutting portion 529 situated further toward the rear side than the other end of the holding member 505. That is to say, when the sliding portion 525 moves by sliding as to the third support portion 526 from the front side to the rear side, the bearing 110 to which the fitting shaft portion 534 is fit also moves by sliding as to the third support portion 526 from the front side to the rear side, along with the sliding portion 525. The holding member 505 to which the protrusion 155 is attached also attempts to move to the rear side in conjunction with this, but the other end of the holding member 505 is abutting the abutting portion 529, and accordingly movement toward the rear side is restricted. Accordingly, the link member 151 and link member 152 pivot in the clockwise direction as to the sliding portion 525 when viewing the link member 151 from the right side, and the holding member 505 moves from the retracted position toward the exposure position with the other end of the holding member 505 abutting the abutting portion 529. In this case, the cover 558 presses the sliding portion 525 from the front side toward the rear side when moving from the opened state to the closed state, and pulls the sliding portion 525 from the rear side toward the front side when moving from the closed state to the opened state.
The mechanism for moving the optical print head 105 is not restricted to the movement mechanism 140 and movement mechanism 640. A movement mechanism 840 illustrated in FIGS. 15A1 through 15B may be used. The movement mechanism 840 will be described below with reference to FIGS. 15A1 through 15B. Note that members having substantially the same functions as members making up the movement mechanism 140 (640) are denoted by the same reference numerals, and redundant description may be omitted.
FIGS. 15A1 and 15A2 illustrate the movement mechanism 840. The movement mechanism 840 includes a first link mechanism 858, a second link mechanism 859, sliding portion 825, and the third support portion 526, as illustrated in FIGS. 15A1 and 15A2. The first link mechanism 858 includes a link member 843 and a link member 844, and the second link mechanism 859 includes a link member 845 and a link member 846. The link member 843 and link member 844, and the link member 845 and link member 846, each pivotably intersect each other, making up an X-shaped link mechanism as illustrated in FIGS. 15A1 through 15B. A protrusion 847 of the link member 843, a protrusion 848 of the link member 844, a protrusion 849 of the link member 845, and a protrusion 850 of the link member 846, are each pivotably attached to a holding member 805 that is omitted from illustration. When a sliding portion 825 is moved by sliding in the direction of the arrow A in FIG. 15A1, the link members 843 through 846 pivot with regard to the sliding portion 825, and the protrusions 847 through 850 move downwards (FIG. 15A2). On the other hand, when the sliding portion 825 is moved by sliding in the direction of the arrow B in FIG. 15A2, the link members 843 through 846 pivot with regard to the sliding portion 825, and the protrusions 847 through 850 move upwards (FIG. 15A1).
The movement mechanism 840 in
The link member 843 has a protrusion 810, the protrusion 847, and the connecting shaft portion 538. The protrusion 810 is provided to one end side in the longitudinal direction of the link member 843. The protrusion 847 is a cylindrical protrusion erected to the right side in the pivoting axial direction of the link member 843, provided to the other end side in the longitudinal direction of the link member 843. The connecting shaft portion 538 is provided between the protrusion 810 and protrusion 847 in the longitudinal direction of the link member 843. Although the protrusion 847 serves as a first moving portion, the first moving portion is not restricted to the protrusion 847, and may be a structure where one end side in the longitudinal direction of the link member 843 is bent in the pivoting axis direction.
The protrusion 810 is pivotably loosely fit to the slot 863 of the sliding portion 825, thereby forming the first connecting portion. That is to say, the link member 843 is pivotable as to the sliding portion 825 with the first connecting portion as the center of pivoting. The protrusion 810 is capable of moving in the front-and-rear direction within the range of the slot 863 in the front-and-rear direction (within the opening). A coil spring 860 is disposed between the rear-side edge of the slot 863 and the protrusion 810.
The link member 844 has the connecting shaft portion 530 and the protrusion 848. The connecting shaft portion 530 is provided to one end side in the longitudinal direction of the link member 844. The connecting shaft portion 530 is a cylindrical protrusion erected from the link member 844 to the right side in
The protrusion 848 is a cylindrical protrusion provided to the other end side in the longitudinal direction of the link member 844, erected to the right side in the pivoting axis direction of the link member 844. A circular hole that extends in the left-and-right direction in
The holding member 805 has the lens array 506, a link attaching portion 851, a link attaching portion 852, and a pin attaching portion 855. The link attaching portion 851 and link attaching portion 852 both are provided between pins 514 attached to the lens array 506 and holding member 805. Although omitted from illustration, a link attaching portion 853 and link attaching portion 854 to which the link member 859 and link member 846 making up the second link mechanism are attached are both provided between pins 515 attached to the other end side of the lens array 506 and holding member 805. The link attaching portion 851 is a hole formed to the holding member 805 between the lens array 506 and pin attaching portion 855, passing through in the left-and-right direction. The link attaching portion 852 is a slot that is formed in the holding member 805 between the lens array 506 and the link attaching portion 851, and that passes through in the left-and-right direction and extends in the front-and-rear direction.
The protrusion 847 of the link member 843 is pivotably attached to the link attaching portion 851, and the protrusion 848 of the link member 844 is pivotably attached to the link attaching portion 852. The protrusion 848 is attached to the link attaching portion 851 so as to be capable of moving in the front-and-rear direction. Accordingly, the link member 844 is capable of moving by sliding in the front-and-rear direction within the range of the link attaching portion 852 in the front-and-rear direction, while pivoting with the protrusion 848 as a center of pivoting.
According to the above-described configuration, when the sliding portion 825 moves by sliding from the front side to the rear side as to the third support portion 526, the protrusion 810 moves by sliding from the front side to the rear slide as to the third support portion 526 along with the sliding portion 825. Accordingly, when viewing the first link mechanism 858 from the right side as illustrated in FIG. 15A1, the protrusion 848 moves from the front side to the rear side at the link attaching portion 852 with the link member 843 pivoting clockwise with the protrusion 810 as the center of pivoting and the link member 844 pivoting counter-clockwise with the connecting shaft portion 530 as the center of pivoting. Accordingly, the protrusion 847 and protrusion 848 move in the direction from the exposure position toward the retracted position.
On the other hand, when the sliding portion 825 moves by sliding from the rear side to the front side as to the third support portion 526, the protrusion 810 moves by sliding from the rear side to the front slide as to the third support portion 526 along with the sliding portion 825. Accordingly, when viewing the first link mechanism 858 from the right side as illustrated in FIG. 15A2, the protrusion 848 moves from the rear side to the front side at the link attaching portion 852 with the link member 843 pivoting counter-clockwise with the protrusion 810 as the center of pivoting and the link member 844 pivoting clockwise with the connecting shaft portion 530 as the center of pivoting. Accordingly, the protrusion 847 and protrusion 848 move from the retracted position toward the exposure position. When the sliding portion 825 further moves by sliding to the front side in a state where the abutting pin 514 is in contact with an abutting face 550, as illustrated in
A configuration may be made where the front-and-rear directions of the first link mechanism 858 and second link mechanism 859 are opposite, so that when the sliding portion 825 is moved by sliding from the front side toward the rear side, the optical print head 105 moves from the retracted position toward the exposure position, and when the sliding portion 825 is moved by sliding from the rear side toward the front side, the optical print head 105 moves from the exposure position toward the retracted position. In this case, the later-described cover 558 presses the sliding portion 825 from the front side toward the rear side when moving from an opened state to a closed state, and pulls the sliding portion 825 from the rear side toward the front side when moving from a closed state to an opened state.
The mechanism for moving the optical print head 105 is not restricted to the movement mechanism 140, movement mechanism 640, and movement mechanism 840. A movement mechanism 940 illustrated in
As illustrated in
Accordingly, the lower ends of the movement support portion 114 and movement support portion 115 provided to the holding member 905 abut the first cam portion 112 and second cam portion 113, and the movement support portion 114 and movement support portion 115 move along the first cam portion 112 and second cam portion 113 in a direction from the exposure position toward the retracted position.
Now an arrangement may be made where the direction of inclination of the inclined faces that the first cam portion 112 and second cam portion 113 have is inclined downwards from the front side toward the rear side, with sliding movement of the sliding portion 525 from the front side to the rear side moving the optical print head 105 from the retracted position toward the exposure position, and sliding movement of the sliding portion 525 from the rear side to the front side moving the optical print head 105 from the exposure position toward the retracted position. In this case, the later-described cover 558 presses the sliding portion 525 from the front side toward the rear side when moving from an opened state to a closed state, and pulls the sliding portion 525 from the rear side toward the front side when moving from a closed state to an opened state.
Next, the cover 558 will be described with reference to
Next, the configuration by which the sliding portion 525 moves by sliding in the pivoting axis direction of the photosensitive drum 103 in conjunction with opening/closing operations of the cover 558 will be described in detail with reference to
The cover 558 pivots as to the main body of the image forming apparatus 1 centered on the pivoting axis 563, as illustrated in
The operations of the pressing member 561 on the sliding portion 525 will be described with reference to
Further, when the cover 558 pivots even more in the clockwise direction, the pressing member 561 moves from the first pressed portion 566 to a second pressed portion 567 (
It can be seen from
In the closed state of the cover 558 illustrated in
When the cover 558 pivots in the counter-clockwise direction from the state in
The mechanism where the pressing member 561 presses the third pressed portion 568 is provided from the following reason. That is to say, a case can be conceived where the sliding portion 525 does not move to the rear side even if restriction on movement of the slide aiding member 539 by the pressing member 561 is released by the cover 558 being pivoted in the counter-clockwise direction from the state in
Next, a connection mechanism between the holding member 505 and the link member 151 will be described. Note that the connection mechanism of the holding member 505 and link member 151 described below is substantially the same mechanism as the connection mechanism of the holding member 505 and link member 651.
The holding member 505 is provided with the lens attaching portion 701 to which the lens array 506 is attached, the spring attaching portion 661 to which a coil spring 547 is attached, the spring attaching portion 662 to which a coil spring 548 is attached, the pin attaching portion 632 to which the abutting pin 514 is attached, and the pin attaching portion 633 to which the abutting pin 515 is attached, as illustrated in
First, description will be made regarding the spring attaching portion 661. The spring attaching portion 661 includes a first wall portion 751, a second wall portion 752, a first engaging portion 543, and a second engaging portion 544. The first wall portion 751 is disposed to the one end side of the holding member 505 in the left-and-right direction, and the second wall portion 752 is disposed to the other end side of the holding member 505 in the left-and-right direction. The first wall portion 751 and second wall portion 752 are disposed to both sides of the abutting pin 514 in the left-and-right direction, in the present embodiment. The first wall portion 751 and second wall portion 752 each have an inner wall face facing each other, as illustrated in
The first engaging portion 543 and second engaging portion 544 are disposed at positions that are different from each other in the vertical direction. The first engaging portion 543 is disposed closer to the photosensitive drum 103 side than the second engaging portion 544 in the present embodiment. Note that an arrangement may be made where the first engaging portion 543 and second engaging portion 544 are generally the same in the vertical direction, and the second engaging portion 544 may be disposed closer to the photosensitive drum 103 side than the first engaging portion 543.
The protrusion 155 is inserted to the opening 756 of the second wall portion 752 from the outer wall face side thereof, passes beneath the coil spring 547 strung between the first engaging portion 543 and second engaging portion 544, and is inserted into the opening 755 of the first wall portion 751, as illustrated in
Next, description will be made regarding the spring attaching portion 662. The spring attaching portion 662 includes a third wall portion 753, a fourth wall portion 754, a third engaging portion 545, and a fourth engaging portion 546, as illustrated in
The third wall portion 753 and fourth wall portion 754 each have an inner wall face facing each other, as illustrated in
The third engaging portion 545 and fourth engaging portion 546 are disposed at positions that are different from each other in the vertical direction. The third engaging portion 545 is disposed closer to the photosensitive drum 103 side than the fourth engaging portion 546 in the present embodiment. Note that an arrangement may be made where the third engaging portion 545 and fourth engaging portion 546 are generally the same in the vertical direction, and the fourth engaging portion 546 may be disposed closer to the photosensitive drum 103 side than the third engaging portion 545.
The protrusion 156 is inserted to the opening 758 of the fourth wall portion 754 from the outer wall face side thereof, passes beneath the coil spring 548 strung between the third engaging portion 545 and fourth engaging portion 546, and is inserted into the opening 757 of the third wall portion 753, as illustrated in
Next, the operations of the protrusion 155 provided to the link member 151 on the coil spring 547, and the operations of the protrusion 156 provided to the link member 152 on the coil spring 548, will be described with reference to
Upon the sliding portion 525 moving by sliding in the state in
When the holding member 505 moves upwards, the abutting pin 515 abuts the abutting face 551 of the drum unit 518 as illustrated in
Further pivoting the link member 152 in the counter-clockwise direction from the state in
The state in
As described above, the third engaging portion 545 is disposed closer to the photosensitive drum 103 side than the fourth engaging portion 546, so normal force in the direction of the arrow N acts on the coil spring 548 from the protrusion 156. The force component in the direction of the arrow N acts on the holding member 505. Accordingly, force toward the rear side in the front-and-rear direction acts on the abutting pin 515, and the abutting pin 515 abutting the abutting face 551 is biased against and abuts the rear-side wall face 596 at the deepest part of the fitting portion 685. The reason why the first engaging portion 543 is disposed closer to the photosensitive drum 103 side than the second engaging portion 544 is also the same.
Cleaning Mechanism
An exposing unit such as the optical print head 105, for example, is disposed between the charger 104 and developing unit 106 in the image forming apparatus 1. Accordingly, there are cases where the light emission faces of the lens array 506 that the optical print head 105 has are contaminated by toner falling from the photosensitive drum 103 or developing unit 106. Contamination of the light emission faces of the lens array 506 can partially shield light emitted from the light-emitting elements, and is a factor leading to deterioration in image quality of output images. Accordingly, the light emission faces of the optical print head 105 are preferably periodically cleaned.
The rubbing portion 574 is provided to the tip side of the cleaning member 572 (other end side in the rotational axis direction of the photosensitive drum 103) at the lower side thereof. The rubbing portion 574 is an unwoven fabric formed of fibers of cotton, nylon, polyester, or the like, for example, and wipes off and cleans contamination of toner and so forth that has fallen onto the light emission faces of the lens array 506. The rubbing portion 574 is not restricted to unwoven fabric, and may be a rubber elastically deformable member such as a sponge or elastomer for example, which cleans by scraping off contamination of toner and so forth that has fallen onto the light emission faces of the lens array 506.
The engaging portions 576 of the cleaning member 572 that has been inserted to the opening 700 protrude toward a position facing the lower side of the protruding portions 580 from the outer side of the protruding portions 580 in the widthwise direction, i.e., toward inside of the gaps 579, and engage the protruding portions 580. Tapered portions 581 are formed at the front end (the end portion at front side) of the protruding portions 580, and are inclined further downwards the closer to the gaps 579. These tapered portions 581 serve to guide the engaging portions 576 of the cleaning member 572, inserted into the opening 700 and moving downstream in the insertion direction, into the gaps 579.
The lower-side protruding portions 577 that are an example of an abutting portion that the cleaning member 572 has is formed along the longitudinal direction, so as to face the upper side of the holding member 505 at the lower side of the cleaning member 572.
Movement of the cleaning member 572 in directions orthogonal to the longitudinal direction is restricted by the cleaning member 572 being loosely fit to the inner side of the opening 700 with a gap of around 0.5 mm therebetween, as illustrated in
The position of the cleaning member 572 engaged with the optical print head 105 is a position where the rubbing portion 574 comes into contact with the light emission faces of the lens array 506. The optical print head 105 is situated at the retracted position at this time. The retracted position of the optical print head 105 is the position of the optical print head 105 in a state where the lower face of the holding member 505 (optical print head 105), moving toward the lower side from the exposure position, abuts from above in the vertical direction the first seating face 586 (serving as an example of a first abutted portion) and a second seating face 587 (serving as an example of a second abutted portion) that together serve as an example of an abutted portion (stopping mechanism), as described earlier. That is to say, the light emission faces of the lens array 506 that the optical print head 105 abutting the first seating face 586 and second seating face 587 has are positioned so as to be overlaid on the movement path of the rubbing portion 574 provided to the cleaning member 572 that is inserted to and extracted from the opening 700. Note that the first seating face 586 (and second seating face 587) preferably is integrally formed with the first support portion 527 (and second support portion 528), but may be formed as separate members. Note that for the abutted portion (stopping mechanism) serving to bring the optical print head 105 to the retracted position, it is sufficient for the first support portion 527 to have the first seating face 586, at the least. That is to say, a configuration may be made where the first support portion 527 has the first seating face 586 and the second support portion 528 does not have the second seating face 587. The reason is that if the first support portion 527 does not have the first seating face 586, one end side of the holding member 505 may flex downward under its own weight, and the light emission face of the lens array 506 in close proximity with the opening 700 may not come into contact with the rubbing portion 574 of the cleaning member 572.
Another feature of the opening 700 and cleaning member 572 is that the opening 700 and the cleaning member 572 will not fit to each other if inserting the cleaning member 572 to the opening 700 is attempted in a state where the cleaning member 572 is vertically inverted. That is to say, the opening 700 prevents the worker such as the user, service staff, or the like, from erroneously inserting the cleaning member 572 into the opening 700 in a vertically inverted state.
It can be seen from
One reason why the holding member 505 has the abutting pin 514 and abutting pin 515 is to form a gap between the light emission faces of the lens array 506 and the photosensitive drum 103, as described earlier. As for the structure of the abutting pin 514 and abutting pin 515 to achieve this, a structure may be made where the length of the abutting pin 514 protruding from the upper side of the holding member 505 is around the same as that of the abutting pin 515, i.e., the position of the upper end of the abutting pin 514 is above the light emission faces of the lens array 506. However, in a case of making this configuration, the abutting pin 514 exists on the movement path of the cleaning member 572 inserted into the opening 700 from the outer side of the main body of the image forming apparatus 1, and the cleaning member 572 and abutting pin 514 will come into contact when the cleaning member 572 is inserted into the opening 700 and moves to the downstream side in the direction of insertion. Accordingly, sufficiently cleaning the light emission faces of the lens array 506 will be difficult.
It is from this reason that the length of the abutting pin 514 protruding from the upper side of the holding member 505 is shorter than that of the abutting pin 515 protruding from the upper side of the holding member 505, and that the upper end of the abutting pin 514 is situated lower than the position of the light emission faces of the lens array 506 as illustrated in
The mechanism bringing the optical print head 105 to the retracted position (cleaning position) is not restricted to the above-described mechanism where the holding member 505 comes into contact with the first seating face 586 and second seating face 587 described earlier, thereby restricting downward movement of the holding member 505. A mechanism such as described next may be made.
FIG. 29A1 illustrates a structure using the slot 691, which is an elongated opening provided to the sliding portion 525, as an example of an abutted portion (stopping mechanism). The mechanism illustrated in FIG. 29A1 is a mechanism that stops sliding movement of the sliding portion 525 that moves by sliding along with movement of the optical print head 105 from the exposure position toward the retracted position, thereby bringing the optical print head 105 to the retracted position. The sliding portion 525 in FIG. 29A1 has the slot 691. The slot 691 has an abutting portion 591. Out of the edges that the slot 691 has, the abutting portion 591 is formed to the edge at the front side.
The slot 691 is formed in the sliding portion 525, and accordingly moves along with the sliding movement of the sliding portion 525. The support shaft 531 and abutting portion 591 are disposed facing each other on the rotational axis of the photosensitive drum 103. The support shaft 531 is fixed to the third support portion 526 by the E-type snap ring 533, and is loosely fit to the slot 691 with a gap around 0.1 to 0.5 mm in the vertical direction. That is to say, sliding movement of the sliding portion 525 is restricted by the support shaft 531, and movement by sliding can be performed within the range of the slot 691 (within the opening) in the front-and-rear direction. Note that support shaft 531 is disposed toward the rear side from the abutting portion 591 of the slot 691 when the cover 558 is in a closed state. Accordingly, the abutting portion 591 of the slot 691 and the support shaft 531 do not come into contact until the cover 558 is in an open state.
The range over which the sliding portion 525 can move by sliding can be changed by changing the range of the slot 691 in the rotational axis direction of the photosensitive drum 103 in the direction of the arrow X as illustrated in FIG. 29A2. For example, the range of the slot 691 in the front-and-rear direction is narrowed as illustrated in FIG. 29A2, so that the edge of the slot 691 toward the front side is closer to the support shaft 531 as compared with FIG. 29A1. Accordingly, the distance in the vertical direction from the third support portion 526 to the holding member 505 when the optical print head 105 is in the retracted position is greater than the distance in the vertical direction from the third support portion 526 to the holding member 505 when the optical print head 105 is in the retracted position before narrowing the range of the slot 691.
According to the above configuration, when the sliding portion 525 moves by sliding from the front side toward the rear side, the support shaft 531 abuts the end portion at the front side of the slot 691 in the opposite direction as to the direction of sliding movement (direction from rear side toward front side), sliding movement of the sliding portion 525 and pivoting of the link member 651 stop, and the holding member 505 is at the retracted position. Accordingly, the light emission faces of the lens array 506 that the holding member 505 has are situated on the movement path of the rubbing portion 574 of the rod-shaped cleaning member 572 inserted through the opening 700 and inserted and extracted. Also, the tip portion (upper end) of the abutting pin 514 of the optical print head 105 situated at the retracted position is situated on the opposite side of the movement path of the rod-shaped cleaning member 572 from the tip end (upper end) the abutting pin 514 of the optical print head 105 situated in the exposure position. Accordingly, interference between the abutting pin 514 and the cleaning member 572 inserted from the opening 700 is suppressed, and the light emission faces of the lens array 506 can be sufficiently cleaned.
The mechanism bringing the optical print head 105 to the retracted position may be a mechanism where pivoting of the link member 651 serving as an example of a link portion is stopped using an abutting member 982 as an example of the abutted portion (stopping mechanism), as illustrated in
The abutting member 982 serving as an example of the abutted portion (stopping mechanism) is fixed to the third support portion 526 as illustrated in
Note that the farther to the front side the abutting member 982 is positioned on the third support portion 526, the greater the distance is in the vertical direction from the third support portion 526 to the holding member 505 when the optical print head 105 is at the retracted position. Also note that while the abutting member 982 has been described as being fixed to the third support portion 526 here, the member to which the abutting member 982 is fixed is not restricted to the third support portion 526, and may be fixed to any member that does not move relative to the third support portion 526.
As described above, the image forming apparatus 1 according to the second modification has the abutting member 982 as an example of the abutted portion (stopper). The abutting member 982 stops pivoting of the link member 651 that moves the holding member 505 from the exposure position to the retracted position while pivoting, and brings the holding member 505 to the retracted position. Accordingly, the light emission faces of the lens array 506 of the holding member 505 are situated being overlaid on the moving path of the rubbing portion 574 provided to the rod-shaped cleaning member 572 inserted from the opening 700 and inserted and extracted. Also, the tip portion (upper end) of the abutting pin 514 of the optical print head 105 situated at the retracted position is situated on the opposite side of the movement path of the rod-shaped cleaning member 572 from the tip end (upper end) of the abutting pin 514 of the optical print head 105 situated in the exposure position. Accordingly, interference between the abutting pin 514 and the cleaning member 572 inserted from the abutting pin 514 is suppressed, and the light emission faces of the lens array 506 can be sufficiently cleaned.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2017-119006, filed Jun. 16, 2017, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-119006 | Jun 2017 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 8112012 | Wong et al. | Feb 2012 | B2 |
| 8269812 | Morimoto | Sep 2012 | B2 |
| 8305419 | Morita | Nov 2012 | B2 |
| 8725028 | Imai | May 2014 | B2 |
| 20070024943 | Mamba Masanori | Feb 2007 | A1 |
| 20070126852 | Fukutome | Jun 2007 | A1 |
| 20100245525 | Morimoto et al. | Sep 2010 | A1 |
| 20100271639 | Iijima | Oct 2010 | A1 |
| 20110050834 | Umezawa | Mar 2011 | A1 |
| 20120177418 | Hashiyada et al. | Jul 2012 | A1 |
| 20120207511 | Sato et al. | Aug 2012 | A1 |
| 20130164027 | Sato et al. | Jun 2013 | A1 |
| 20130170855 | Mori et al. | Jul 2013 | A1 |
| 20130194369 | Shimamoto | Aug 2013 | A1 |
| 20140212170 | Kato et al. | Jul 2014 | A1 |
| 20150050043 | Sato et al. | Feb 2015 | A1 |
| 20150109398 | Park et al. | Apr 2015 | A1 |
| 20180095405 | Iwai et al. | Apr 2018 | A1 |
| Number | Date | Country |
|---|---|---|
| 2006258909 | Sep 2006 | JP |
| 2007072321 | Mar 2007 | JP |
| 2009244542 | Oct 2009 | JP |
| 2010230954 | Oct 2010 | JP |
| 2011020414 | Feb 2011 | JP |
| 2012234200 | Nov 2012 | JP |
| 2013134370 | Jul 2013 | JP |
| 2014213541 | Nov 2014 | JP |
| 2015018132 | Jan 2015 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20180364636 A1 | Dec 2018 | US |
