Patent Grant
11852988
The present disclosure relates to an electrophotographic image forming apparatus.
An image forming apparatus adopting an electrophotographic image forming process forms a latent image by scanning a laser beam, which is emitted from a laser scanner, along an axis direction of a photosensitive drum on a surface of the photosensitive drum. While the laser beam is scanned in a main scanning direction, the photosensitive drum is rotated. Accordingly, the laser beam that is being scanned in the main scanning direction is sequentially scanned in a sub-scanning direction that is orthogonal to the main scanning direction, thereby forming the latent image. At this time, when the laser scanner vibrates in the sub-scanning direction, an irradiation position of the laser beam on the surface of the photosensitive drum is also shifted in the sub-scanning direction. As a result, the latent image is moved (shifted) in the sub-scanning direction from the originally intended position and is formed thereat. The shift in the sub-scanning direction appears on an image as a blur or as banding. Therefore, there has been a demand for a configuration of the scanner unit which is less liable to vibrate in the sub-scanning direction. In view of such demand, for example, there has been proposed a configuration in which a hollow elastic member and a plate spring are used for a coupling portion between a main body frame and a scanner unit so that vibration that occurs in the main body frame is less liable to propagate to the scanner unit (for example, Japanese Patent Application Laid-Open No. 2013-003329).
The related-art image forming apparatus needs a large number of components such as the elastic member and the plate spring. Therefore, the configuration thereof is complicated, thereby causing an increase in cost. Therefore, there has been a demand for improving the rigidity against vibration while achieving reduction in the number of components and cost.
The present disclosure has been made to address the vibration rigidity of a scanner unit with a simple configuration.
According to an aspect of the present disclosure, an image forming apparatus configured to form an image on a recording material, the image forming apparatus includes a photosensitive member, an exposure device configured to form a latent image on the photosensitive member, a tubular body defining a space in which at least a part of the exposure device is contained, a support portion which is provided along a rotation axis direction of the photosensitive member in the space of the tubular body, and is configured to support the exposure device, a first side plate fixed to one end portion of the tubular body in the rotation axis direction, and a second side plate fixed to another end portion of the tubular body in the rotation axis direction, wherein one end portion of the support portion in the rotation axis direction is fixed to the first side plate, and another end portion of the support portion in the rotation axis direction is fixed to the second side plate.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Now, modes for carrying out the present disclosure are described in detail with reference to the drawings based on the following embodiments.
[Overall Configuration of Image Forming Apparatus]
With reference to
The printer 1 includes a recording-material supplying portion 10, an image forming portion 20, an image fixing portion 30, and a recording-material delivery portion 40. The recording-material supplying portion 10 is configured to supply a recording material S. The image forming portion 20 is configured to perform image formation on the supplied recording material S. The image fixing portion 30 is configured to fix the formed image on the recording material S. The recording-material delivery portion 40 is configured to deliver the recording material S having the image fixed thereon to an outside of the printer 1. The recording-material supplying portion 10 is arranged on a lower side in the printer 1 and is configured to accommodate the recording material S. The recording-material supplying portion 10 mainly includes a feed roller 12, a conveyance roller 13, a separation roller 14, and a registration roller pair 15 and is configured to supply the accommodated recording material S to the image forming portion 20.
The image forming portion 20 includes a cartridge, a laser scanner 21, and a transfer roller 24 and is configured to perform image formation on the recording material S. The cartridge includes a photosensitive drum 22, which is a photosensitive member, and a developing sleeve 23. The laser scanner 21 is an exposure device. The laser scanner 21 includes a light source and is configured to irradiate a surface of the photosensitive drum 22 with a laser beam. The transfer roller 24 is opposed to the photosensitive drum 22 and is configured to transfer a toner image to the recording material S. The image fixing portion 30 is configured to heat and fix an unfixed toner image by allowing the recording material S to pass through a nip portion defined by a fixing-pressure roller 31 and a fixing-heating roller 34, which includes a fixing heater (not shown) provided therein. At the recording-material delivery portion 40, the recording material S having the toner image heated and fixed thereon is delivered to the outside of the printer 1 by a conveyance force of a delivery roller pair 41 and is then placed on a delivery tray 47 and a delivery extension tray 48. Here, the left side of
[Description of Operation of Image Forming Apparatus]
An image forming operation of the printer 1 having the above-mentioned configuration is described. First, based on an image signal from a controller (not shown) which is provided to the printer 1 and has received a print command, a laser beam is radiated from the laser scanner 21 to the photosensitive drum 22. The photosensitive drum 22 rotates counterclockwise, and is cleaned by a cleaning device (not shown) and irradiated with a laser beam on a uniformly charged surface thereof. An electrostatic latent image formed on the photosensitive drum 22 through irradiation with the laser beam is developed with toner on the developing sleeve 23, and therefore a toner image is formed on the surface of the photosensitive drum 22.
The feed roller 12 starts rotating counterclockwise at a predetermined timing After that, when a command for starting feeding is received from the controller, a feed arm 16 is lowered counterclockwise about the conveyance roller 13. The feed roller 12 is brought into abutment against the uppermost sheet of a bundle of recording materials S accommodated in the feed tray 11 and conveys the recording material S to the conveyance roller 13 with a friction force. After the conveyance to the conveyance roller 13 is terminated, the feed arm 16 is raised reversely, that is, clockwise so that the feed roller 12 separates away from the recording material S. When a plurality of recording materials S are simultaneously sent out to the conveyance roller 13, only the uppermost sheet is separated by an action of the separation roller 14 and is conveyed to the registration roller pair 15 arranged on downstream.
The recording material S that has been sent from the conveyance roller 13 to the registration roller pair 15 is conveyed to the image forming portion 20 including the photosensitive drum 22 and the transfer roller 24. At the image forming portion 20, the toner image formed on the surface of the photosensitive drum 22 in the above-mentioned manner is transferred to the surface of the recording material S. After that, the recording material S having the unfixed toner image transferred thereto is conveyed to the image fixing portion 30. At the image fixing portion 30, the recording material S passes through a fixing nip portion defined between the fixing-pressure roller 31, which rotates clockwise, and the fixing-heating roller 34, which is rotated counterclockwise by the fixing-pressure roller 31. The fixing-heating roller 34 includes the fixing heater provided therein, and is configured to fix the unfixed toner image on the recording material S by pressurizing the recording material S at the fixing nip portion and heating the recording material S with the fixing heater.
Finally, the recording material S is delivered to the outside of the printer 1 by the delivery roller pair 41. The delivery roller pair 41 is provided at the recording-material delivery portion 40 and defines a nip portion with a delivery driving roller 42, which is configured to rotate clockwise, and a delivery driven roller 43, which is configured to be rotated by the delivery driving roller 42. The recording material S having been delivered is placed on the delivery tray 47 and the delivery extension tray 48, for example, with an image transfer surface thereof facing downward. The delivery tray 47 is arranged below the nip portion of the delivery roller pair 41, and subsequent sheets are sequentially stacked on the recording material S having been delivered.
In a case of performing printing on both front and back faces of the recording material S, after a trailing end of the recording material S having an image formed on a first face thereof passes through the most downstream end of a fixing guide 33, which is provided between the fixing nip portion and the delivery roller pair 41, in the conveyance direction, the rotation direction of the delivery driving roller 42 is reversed and set to the counterclockwise direction. Then, the recording material S enters the duplex-printing conveyance passage formed of a duplex-printing upper guide 44 and a duplex-printing lower guide 45 to be conveyed to a duplex-printing roller pair 46. When the recording material S is no longer present at the nip portion of the delivery roller pair 41, the delivery driving roller 42 starts rotating clockwise again to prepare for delivery of the recording material S having an image formed on a second face. The recording material S is conveyed by the duplex roller pair 46 to the nip portion defined by the registration roller pair 15. After that, image formation for the second face is performed through the same processes as those for the first face of the recording material S.
[Frame Configuration]
With reference to
[Support Configuration for Laser Scanner 21]
(Main Frame and Subframe)
A support configuration for the laser scanner 21 of the first embodiment is described with reference to
As illustrated in
(Scanner Stay)
(Installation of Laser Scanner)
The main frame 52 includes a first face 52A and a second face 52B (
Moreover, frame-side abutting portions 54 each being a first abutting portion are provided to the rim portion 52A1 of the first face 52A of the main frame 52. That is, the frame-side abutting portions 54 are provided on a trailing end side in the direction of inserting the laser scanner 21 into the opening 52C. Further, first abutment portions 21A each being a first abutted portion are provided to the laser scanner 21 on the front face side corresponding to one end portion in the front-and-rear direction. In the first embodiment, the frame-side abutting portions 54 of the first face 52A of the main frame 52 are configured to be brought into abutment against the first abutment portions 21A of the laser scanner 21. More in detail, upper parts of the frame-side abutting portions 54 and lower parts of the first abutment portions 21A are brought into abutment against each other. With this, the front end portion of the laser scanner 21 is positioned in the up-and-down direction.
In
(Fixing Laser Scanner)
As illustrated in
The second abutment portion 21B also fixes the laser scanner 21 by urging the laser scanner 21 downward with a restoring force for elastic deformation of a stay-side spring 57 being a fixing member. As illustrated in
The shapes of the frame-side springs 56 and the stay-side spring 57 are not limited to the modes illustrated in, for example,
[Scanner Frame 51]
Now, a configuration of the scanner frame 51 relating to a characteristic portion of the first embodiment is described with reference to, for example,
As described later, the main frame 52 and the subframe 53 are connected to each other through caulking at a plurality of positions. At the right and left end portions of the scanner frame 51, the right frame 70 and the left frame 71 are fastened to one end and another end of each of the main frame 52 and the subframe 53 with fastening screws 75 (
Moreover, as illustrated in
The sectional shape of the scanner stay 50 is also not limited to the shape given in the first embodiment and may be, for example, a quadrilateral shape, or an L-shape having an increased plate thickness. The scanner stay 50 of the first embodiment is not limited to the bent sheet metal, and may be formed of, for example, a resin having a rod shape as long as the rigidity can be secured so that the scanner stay 50 itself is less liable to be bent. Moreover, it is only required that the scanner stay 50 be capable of receiving the laser scanner 21 in a fixed manner and be fixed to the right frame 70 and the left frame 71, and the fixed portion 50A and the connection portion 50B may be omitted.
(Caulked Portion)
With reference to
The subframe 53 has a plurality of fastening holes 58A which are formed at predetermined intervals in the longitudinal direction (right-and-left direction) in one connection portion adjacently connected to the first face 52A of the main frame 52 and in another connection portion connected to the second face 52B of the main frame 52.
One connection portion of the main frame 52 includes caulking shafts 58B, which are provided at positions corresponding to the fastening holes 58A of the subframe 53 in the portion connected to one end of the subframe 53. Moreover, the connection portion of the second face 52B of the main frame 52 also includes caulking shafts 58B (
The caulked portions 58 are arranged such that the caulking shafts 58B of the main frame 52 pass through the fastening holes 58A of the subframe 53. In such a manner, the one end and the another end of the subframe 53 are arranged so as to be laid on the connection portion of the main frame 52 connected adjacent to the first face 52A and on the connection portion of the second face 52B, respectively. The caulking shafts 58B are caulked to be plastically deformed so that the subframe 53 is sandwiched between the deformed portions of the caulking shafts 58B and the connection portion of the main frame 52 connected adjacent to the first face 52A and between the deformed portions of the caulking shafts 58B and the connection portion of the second face 52B. In such a manner, the subframe 53 is fixed at the caulked portions 58 to each of the connection portion of the main frame 52 connected adjacent to the first face 52A and the connection portion of the second face 52B. That is, the caulked portions 58 are each formed of the fastening hole 58A and the caulking shaft 58B and are provided at the connection portion of the main frame 52 connected adjacent to the first face 52A and the connection portion of the second face 52B.
All of the caulked portions 58 have substantially the same shape as the shape illustrated in
(Effect)
In the first embodiment, the scanner frame 51 has such a box shape that the right frame 70 and the left frame 71 arranged on the right and left of the main body of the printer 1 are connected to each other by the main frame 52 and the subframe 53. That is, the main frame 52 and the subframe 53 have such a configuration that the sectional shape taken along the direction orthogonal to the longitudinal direction is the triangle. With this, the rigidity against twisting around the axis extending in the longitudinal direction can be improved. Moreover, the right frame 70 and the left frame 71 are provided at end portions of the main frame 52 and the subframe 53 in the longitudinal direction. With this, the rigidity against twisting around the axis extending in the longitudinal direction can be improved, and deformation of the first face 52A of the main frame 52, the second face 52B of the main frame 52, and the subframe 53, which correspond to the sides of the triangle in the cross section taken along the direction orthogonal to the longitudinal direction, in such a manner as to be bent toward the inner side or the outer side of the space Sp can be suppressed. Here, in the first embodiment, the scanner stay 50 is fixed to each of the right frame 70 and the left frame 71 to connect the right frame 70 and the left frame 71 to each other. With this configuration, even when the second face 52B of the main frame 52 is bent, displacement of the scanner stay 50 as well as the laser scanner 21 can be suppressed. Further, the screws 78 are provided at portions of the right frame 70 and the left frame 71 which overlap regions of end faces of a triangular prism formed of the main frame 52 and the subframe 53 in the longitudinal direction. With this configuration, the scanner stay 50 can be provided at portions of the right frame 70 and the left frame 71 which are less liable to be deformed when an external force is applied, thereby being capable of more effectively suppressing displacement of the scanner stay 50. With such a configuration that twisting of the scanner frame 51 and bending of the members forming the scanner frame 51 are suppressed, vibration that causes displacement of the laser scanner 21 in the sub-scanning direction is suppressed, thereby being capable of improving the vibration rigidity of the scanner frame 51.
In particular, in the first embodiment, a cutout or a hole shape is not formed at least in the end portions of the main frame 52 and the subframe 53 in the longitudinal direction, and the cross section that is taken along the direction orthogonal to the longitudinal direction and surrounds the space Sp has a shape of an uninterrupted and continuous annulus. That is, the scanner frame 51 has such a configuration that the right frame 70 and the left frame 71 are fixed to the end faces of the tubular body having the shape of the triangular annulus and being formed of the main frame 52 and the subframe 53. Specifically, in a cross section taken at a center portion of the scanner frame 51 in the longitudinal direction, the first face 52A of the main frame 52 has the opening 52C, and the subframe 53 has the opening 53A. As a result, the sectional shape is not a triangular annulus, and the side of the triangle is interrupted. However, such openings are not formed at least in the one end portion and the another end portion of the scanner frame 51, and the sectional shape is a triangular annulus with continuous sides. With this, the right frame 70 and the left frame 71 can be rigidly fixed to the main frame 52 and the subframe 53, thereby improving the rigidity against application of a sudden external force and deformation in the twisting direction. The scanner stay 50 is fixed to the scanner frame 51 having high rigidity, and hence propagation of vibration to the laser scanner 21 is suppressed, thereby being capable of suppressing image defects such as a blur and banding. The material of the right frame 70 and the left frame 71 is not limited to the sheet metal material and may be a resin material. Further, the right frame 70 and the left frame 71 may be integrated with the right side plate 73 and the left side plate 74. Moreover, as long as the rigidity of the scanner frame 51 can be secured, for example, the plate thickness of the subframe 53 may be set smaller than that of the main frame 52, or the main frame 52 and the subframe 53 may be integrated with each other, thereby being capable of reducing cost for materials and the number of components. Moreover, the scanner frame 51 may be formed with use of the three frames having the caulked portions 58 at both end portions as described with reference to
In the first embodiment, the scanner stay 50 and the second face 52B of the main frame 52 are in contact with each other, specifically, are fixed to each other. However, it is only required that the scanner stay 50 be fixed to the right frame 70 and the left frame 71 at least at the stay fastening portions 72 (
As described above, according to the first embodiment, the vibration rigidity of the scanner unit can be improved with a simple configuration. In this case, the rigidity can be increased limitedly at parts that require high vibration rigidity. Therefore, an increase in unnecessary cost caused by excessive rigidity can be eliminated. Moreover, the twisting rigidity can be secured in a periphery of the scanner unit. Therefore, a configuration which is highly resistant against plastic deformation caused by a shock given during transport can be achieved.
In the first embodiment, the right side plate 73 is mounted to the right frame 70, and the left side plate 74 is mounted to the left frame 71, thereby forming the frame of the main body of the printer 1. That is, members such as the photosensitive drum 22 are positioned and mounted on the right side plate 73 and the left side plate 74 with the laser scanner 21 as a reference point. Therefore, with the configuration in which the rigidity of the scanner frame 51 for the scanner unit is improved, the positioning accuracy of the members such as the photosensitive drum 22 with respect to the laser scanner 21 can be improved.
[Modification Example of First Embodiment]
The method of fixing the laser scanner 21 is not limited to the configuration described in the first embodiment. In view of this, in the following, a modification example of the support configuration for the laser scanner 21 is described. In this modification example, after description is made of a configuration of the laser scanner 21 which is not described in detail in the first embodiment, the support configuration for the laser scanner 21 is described.
[Configuration of Laser Scanner]
A light deflector 211 configured to deflect a laser beam and various optical members are arranged inside a housing 203 of the laser scanner 21. The light deflector 211 includes, for example, a rotary polygon mirror 213, a scanner motor 212, and a control IC. The rotary polygon mirror 213 is configured to deflect an optical path of an entering laser beam. The scanner motor 212 is configured to drive the rotary polygon mirror 213 to rotate. The control IC is configured to control the rotation of the scanner motor 212. A resonant optical scanning element such as so-called MEMS may be used as the light deflector 211 configured to deflect a laser beam L. Moreover, the housing 203 of this modification example is made of a resin. In the following description, a direction in which the laser beam L deflected and scanned by the light deflector 211 scans the surface of the photosensitive drum 22 (also the rotation axis direction of the photosensitive drum 22) is referred to as “main scanning direction”, and a direction perpendicular to the main scanning direction (also the rotation direction of the photosensitive drum 22) is referred to as “sub-scanning direction”.
The laser beam L emitted from a laser diode 201 being a light source in accordance with image information is formed into substantially parallel light or convergent light in the main scanning direction and into convergent light in the sub-scanning direction by a composite anamorphic collimator lens 202. Then, the laser beam L having passed through the composite anamorphic collimator lens 202 is formed into a laser beam having a predetermined beam diameter limited by an optical diaphragm 204 formed in the housing 203. The laser beam L having passed through the optical diaphragm 204 proceeds to the rotary polygon mirror 213 driven by the scanner motor 212 and is reflected on a reflection surface of the rotary polygon mirror 213 to be deflected. The laser beam L having been deflected proceeds to an fθ lens 205. After passing through the fθ lens 205, the laser beam L is condensed on the photosensitive drum 22 from an opening portion (emission slot), which is formed in the housing 203 and allows the laser beam L to pass therethrough. As a result, an electrostatic latent image is formed on the photosensitive drum 22. Moreover, in
Next, the two first abutment portions 21A and the second abutment portion 21B, which are mounting reference surfaces, are described.
Moreover, as described later, the two first abutment portions 21A and the second abutment portion 21B are parallel to one another when being brought into abutment against the scanner stay 50 and the main frame 52. That is, the housing 203 of the laser scanner 21 is inclined at a predetermined angle of elevation so that the laser beam L is directed to the photosensitive drum 22, and the two first abutment portions 21A and the second abutment portion 21B are formed as inclined surfaces having the same angle with respect to the bottom face of the housing 203. Further, on outer sides of an outer periphery of the housing 203 at positions corresponding to the two first abutment portions 21A and the second abutment portion 21B in the longitudinal direction of the housing 203 (also the main scanning direction), there are provided the two spring receiving portions 21A1 and the spring receiving portion 21B1 each having such a shape as to protrude from the housing 203. As described later, the two spring receiving portions 21A1 and the spring receiving portion 21B1 are provided to urge the laser scanner 21 against the scanner stay 50 and the main frame 52 with use of the stay-side spring 57 and the frame-side spring 56 (see
[Configuration for Supporting Laser Scanner]
Next, a method of supporting the laser scanner 21 with use of the scanner stay 50 and the main frame 52 in this modification example is described.
In this modification example, a position of the stay-side abutting portion 55 of the scanner stay 50, against which the second abutment portion 21B of the laser scanner 21 is brought into abutment, from the bottom face inside the printer 1 is higher than positions of the frame-side abutting portions 54 of the main frame 52, against which the first abutment portions 21A are brought into abutment. Therefore, the laser scanner 21 is installed on the scanner stay 50 and the main frame 52 at an angle θ, which is an angle of elevation from the horizontal direction (X-axis direction of
Moreover, the stay-side spring 57 extends so as to pass the upper side in
[Configuration of Main Body Frame]
Here, configurations of the scanner stay 50 and the main frame 52 illustrated in
The subframe 53 includes a face 53b, as a center, and four faces 53c, 53d, 53e, and 53f which are adjacent to the face 53b. The face 53b has the opening 53A at a center portion thereof to allow the laser beam emitted from the laser scanner 21 to pass therethrough. The faces 53c and 53d provided on both sides of the face 53b in the right-and-left direction of
The scanner stay 50 is formed by bending one piece of sheet metal into an L-shape. The scanner stay 50 includes the fixed portion 50A (first face) and the connection portion 50B (second face) that is bent so as to be perpendicular to the fixed portion 50A or extend in the vertical direction. The fixed portion 50A has holes for connecting the scanner stay 50 to the main frame 52 with a screw 103 (see
The main frame 52 is formed by subjecting one piece of sheet metal to a bending process of bending the sheet metal into an L-shape and a process of forming the opening portion. The main frame 52 includes the first face 52A (third face), the second face 52B (fourth face) that is bent so as to be perpendicular to the first face 52A or extend in the vertical direction, and the face 52D that is bent so as to be perpendicular to the second face 52B. The face 52D is, as mentioned above, the face that is formed for connection to the face 53e of the subframe 53, and has the screw holes for screwing the face 52D to the face 53e of the subframe 53. Moreover, the first face 52A has, in addition to the screw holes for connection to the scanner stay 50, screw holes for fixing the main frame 52 to the bottom face of the housing of the printer 1. The second face 52B has an opening portion which serves as an inlet and an outlet for the laser scanner 21 at the time of mounting and removing the laser scanner 21. Moreover, the rim portion 52B1 of the opening portion is a flat surface (supporting seat surface) against which the two first abutment portions 21A of the housing 203 of the laser scanner 21 are brought into abutment.
Moreover, the three spring stopper portions 54E each having such a shape as to project from the second face 52B are provided in the vicinity of the rim portion 52B1 of the opening portion to urge the spring receiving portions 21A1 of the housing 203 with the frame-side spring 56. The three spring stopper portions 54E are formed by cutting out parts in the vicinity of the rim portion 52B1 of the second face 52B at such a position that each spring receiving portions 21A1 of the housing 203 is located at the center of the adjacent spring stopper portions 54E and bending the cut-out parts so as to be perpendicular to the second face 52B. The laser scanner 21 of
[Urging Scanning Optical Device with Wire Spring]
As described above, in this modification example, the laser scanner 21 is supported by the stay-side abutting portion 55 of the scanner stay 50 and the rim portion 52B1 of the main frame 52 through intermediation of the two first abutment portions 21A and the second abutment portion 21B. The vibration of the laser scanner 21 caused by the scanner motor 212 of the light deflector 211 is less liable to be transmitted in the direction perpendicular to the flat surfaces of the scanner stay 50 and the main frame 52. Therefore, bending of the connection portions 50B and 52B (see
Moreover, as illustrated in
Further, the two first abutment portions 21A and the second abutment portion 21B, which are provided to the housing 203 of the laser scanner 21, come into surface contact with the stay-side abutting portion 55 of the scanner stay 50 and the rim portion 52B1 of the main frame 52. Thus, the two first abutment portions 21A and the second abutment portion 21B are prevented from being brought into contact with corner portions of the stay-side abutting portion 55 of the scanner stay 50 and corner portions of the rim portion 52B1 of the main frame 52. Therefore, the two first abutment portions 21A and the second abutment portion 21B are prevented from being shaved through contact with the corner portions of the stay-side abutting portion 55 and the corner portions of the rim portion 52B1. With this, scattering of dust shaved off from the two first abutment portions 21A and the second abutment portion 21B into the printer 1 is suppressed, and hence degradation in support accuracy for the laser scanner 21 caused by the two first abutment portions 21A and the second abutment portion 21B shaved off can be suppressed.
Moreover, in this modification example, the laser scanner 21 itself is inclined so that an angle is given to the laser beam L radiated to the photosensitive drum 22. With this, there is no need to install separate members such as a reflection mirror inside the laser scanner 21 to give an emission angle to the laser beam L emitted from the laser scanner 21. As a result, a space for arranging the reflection mirror and the like in the laser scanner 21 can be reduced, thereby being capable of achieving downsizing and cost reduction of the laser scanner 21.
Further, in this modification example, the laser scanner 21 is installed in an inclined state so that the laser beam L can be radiated obliquely from the lower side with respect to the photosensitive drum 22. Therefore, the installation position of the laser scanner 21 can be arranged at a position lower than the position given in the case of radiating the laser beam L to the photosensitive drum 22 in the horizontal direction. With this, the height of the printer 1 can be set lower, for example, as the installation position of the laser scanner 21 is set lower. Further, through the installation of the laser scanner 21 in the inclined state, the length of the printer 1 in the horizontal direction can also be suppressed, thereby being capable of further downsizing the printer 1.
Further, as described above, the two first abutment portions 21A and the second abutment portion 21B, which are provided to the housing 203 of the scanning optical device, are supported by the stay-side abutting portion 55 of the scanner stay 50 and the rim portion 52B1 of the main frame 52. In this modification example, both end portions of the scanner stay 50 and the main frame 52 in the longitudinal direction (main scanning direction) are in contact with the side plate frames (not shown) provided inside the printer 1. Therefore, even when the laser scanner 21 is downsized, and the length of the housing 203 in the longitudinal direction is reduced, the laser scanner 21 can be supported by the stay-side abutting portion 55 and the rim portion 52B1 of the scanner stay 50 and the main frame 52. Therefore, no additional supporting member is required, thereby being capable of suppressing an increase in cost of the printer 1. As a result, the degree of freedom in arrangement of the laser scanner 21 in the printer 1 is improved, thereby being capable of providing the printer 1 that is downsized and reduced in cost.
As described above, according to this modification example, the scanning optical device can be stably supported with the sheet metal frame.
In the second embodiment, the stay-side abutting portion 55 and the stay fastening portions 72 are formed on the second face 52B of the main frame 52. Moreover, the hole 55A and the spring stopper portion 55B are also provided to the second face 52B of the main frame 52. In the second embodiment, the number of components can be further reduced, thereby being capable of achieving a simpler configuration. The shape of the part corresponding to the scanner stay 50 is set such that a sectional shape orthogonal to the longitudinal direction is a substantially U-shape with an open lower side. Further, at both right and left end portions, which are both end portions in the longitudinal direction, of the part corresponding to the scanner stay 50, there are provided protruded portions 77 projecting outward. The right frame 70 and the left frame 71 have openings 76, respectively, at positions corresponding to the protruded portions 77.
Specifically, the scanner stay 50 includes a protruded portion 77R and a protruded portion 77L. The protruded portion 77R is a first protruded portion provided at one end portion in the longitudinal direction. The protruded portion 77L is a second protruded portion provided at another end portion in the longitudinal direction. Moreover, the right frame 70 has an opening 76R into which the protruded portion 77R is inserted, and the left frame 71 has an opening 76L into which the protruded portion 77L is inserted.
At the time of fixing the right frame 70 and the left frame 71 to the scanner frame 51, screws can be fastened under a state in which the right frame 70 and the left frame 71 are positioned through insertion of the protruded portions 77, which are provided on both right and left end portions, into the openings 76 formed in the right frame 70 and the left frame 71. Through such positioning, the rigidity of the scanner frame 51 is secured.
The configuration including the protruded portions 77 may be applied to the configuration of the first embodiment in which the scanner stay 50 which is separate from the second face 52B of the main frame 52 is provided. In this case, the right frame 70 and the left frame 71 of the first embodiment have the openings 76 into which the protruded portions 77 are inserted. With this, also in the first embodiment, the scanner stay 50 can be easily positioned with respect to the right frame 70 and the left frame 71, thereby being capable of improving the rigidity of the scanner frame 51. Moreover, in the case of the configuration in which the separate scanner stay 50 is not brought into contact with the second face 52B of the main frame 52, both end portions of the scanner stay 50 can be easily positioned with respect to the right frame 70 and the left frame 71.
As described above, according to the second embodiment, the vibration rigidity of the scanner unit can be improved with a simple configuration.
The embodiments described above are each one embodiment of the image forming apparatus according to the present disclosure, and are not limited to the above-mentioned modes.
For example, in the above-mentioned embodiments, it is supposed that the scanner stay 50 is the sheet metal material. However, as long as the required rigidity is satisfied, a resin material may be used. For example, in the above-mentioned embodiments, the laser scanner 21 is fixed through urging with the springs. However, the laser scanner 21 may be fixed through use of other fixing members such as screws. For example, in the above-mentioned embodiments, the scanner frame 51 has a sectional shape of a substantially triangle. However, as long as a shape that does not impair the second moment of area, the sectional shape may be a circle, an oval, or any other polygonal shape.
For example, in the above-mentioned embodiments, the monochrome printer 1 including one photosensitive drum 22 is described. However, the present disclosure is not limited to this mode, and may also be applied to a color image forming apparatus of, for example, a tandem type including a plurality of photosensitive drums 22. Moreover, the present disclosure is applicable also to an image forming apparatus that uses a transfer material carrying belt configured to carry and convey a transfer material.
As described above, also in other embodiments, the vibration rigidity of the scanner unit can be improved with a simple configuration.
Further, there may be provided a configuration in which the movement of the laser scanner 21 can be restricted with an exterior cover of the printer 1. For example, there may be provided a configuration of this modification example in which a pressing portion is provided to the exterior cover of the image forming apparatus.
As illustrated in
With the configuration described above, when the printer 1 vibrates along with the operation of the printer 1, the laser scanner 21 is prevented from significantly separating away from the main frame 52. For example, when a strong impact due to, for example, falling during distribution, the laser scanner 21 may separate in a direction of being removed from the main frame 52 with respect to the direction of being urged by the stay-side spring 57. However, through the arrangement of the pressing portion 102 through a space defined between the pressing portion 102 and the laser scanner 21 as illustrated in
With the pressing portion 102 provided to the exterior cover 101, even when the opening portion of the main frame 52 cannot be narrowed, removal of the laser scanner 21 from the main frame 52 can be prevented. For example, it is also effective for the case in which the gap between the laser scanner 21 and the opening portion of the main frame 52 is large, such as a configuration in which the protruded portions are provided on the upper face of the laser scanner 21.
Further, widening the opening portion of the main frame 52 may lead to improvement in ease of assembly. Therefore, when there arises need for maintenance of the laser scanner 21, the laser scanner 21 can be easily removed by only removing one exterior cover 101, thereby being capable of also improving the service operability.
In this modification example, the exterior cover 101 is always fixed to the main frame 52. However, there may be given a configuration in which the pressing portion 102 is provided to the exterior cover 101 that is openable and closable about a rotation fulcrum 106 as illustrated in
Embodiment(s) of the present disclosure can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may include one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random access memory (RAM), a read-only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-197460 | Oct 2019 | JP | national |
| 2019-234670 | Dec 2019 | JP | national |
| 2020-146177 | Aug 2020 | JP | national |
The present application is a continuation of U.S. patent application Ser. No. 17/246,958, filed on May 3, 2021, which is a continuation of U.S. patent application Ser. No. 17/080,590, filed on Oct. 26, 2020 and issued as U.S. Pat. No. 11,022,908 on Jun. 1, 2021, which claims priority from Japanese Patent Application No. 2019-197460, filed Oct. 30, 2019, Japanese Patent Application No. 2019-234670, filed Dec. 25, 2019, and Japanese Patent Application No. 2020-146177, filed Aug. 31, 2020, which are hereby incorporated by reference herein in their entireties.
| Number | Name | Date | Kind |
|---|---|---|---|
| 11022908 | Yamamoto | Jun 2021 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20220260938 A1 | Aug 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17246958 | May 2021 | US |
| Child | 17737751 | US | |
| Parent | 17080590 | Oct 2020 | US |
| Child | 17246958 | US |
