Image forming device

Abstract

To provide an image forming apparatus that allows an optical scanner to be attached to an image forming apparatus body around a rotation axis in a rotation adjustable manner, the image forming apparatus capable of preventing transmission of vibration from the image forming apparatus body to the optical scanner, and thereby capable of effectively preventing occurrence of an image defect due to disturbance of an image written in an image carrier.SOLUTION: An image forming apparatus 100 allows an optical scanner 200 to be attached to an image forming apparatus body 110 in a rotation adjustable manner around a rotation axis λ parallel to an axis orthogonal to a main scanning direction X1 of a light beam L. The image forming apparatus body 110 is provided with an axis support part 121 that supports the optical scanner 200 rotatably around the rotation axis λ, and a holding part 130 that faces a housing 201 at a position different from the axis support part 121. The optical scanner 200 is held in the image forming apparatus body 110 with an elastic member 300 being in pressure contact and sandwiched between the housing 201 and the holding part 130.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a copying machine, a multifunction machine, a printer, or a facsimile machine. [Background technology]

[0002] Fig. 14 is a schematic cross-sectional view of an image forming apparatus 100X as viewed from the front, with necessary reference symbols added and unnecessary reference symbols removed from Fig. 1 of Patent Document 1. Figs. 15A and 15B are perspective views of the front and rear sides of an optical scanning device 200X as viewed from above, with necessary reference symbols added and unnecessary reference symbols removed from Figs. 2 and 3 of Patent Document 1. In the figures, the symbol X represents the depth direction, the symbol Y represents the left-right direction (width direction), the symbol Z represents the vertical direction (up-down direction), and the symbol X1 represents the main scanning direction.

[0003] 14 to 15B, in a conventional image forming apparatus 100X described in Patent Document 1, an optical scanning device 200X is attached to an image forming apparatus main body 110X so as to be rotatable about a rotation axis λ parallel to an axis perpendicular to the main scanning direction X1 of the light beam L in a deflection scanning plane of the light beam L (see FIG. 15A). A housing 201X of the optical scanning device 200X is provided with a rotation shaft 260X whose axis is the rotation axis λ. More specifically, a first rotation shaft 261X (see FIG. 15A) is provided on the side of the housing 201X of the optical scanning device 200X from which the light beam L is emitted, and a second rotation shaft 262X (see FIG. 15B) is provided on the opposite side to the emission side.

[0004] 16A to 16C are side views schematically showing a state in which the optical scanning device 200X is rotated and adjusted around the rotation axis λ.

[0005] An eccentric cam member 263 rotatable about a rotation axis β parallel to the rotation axis λ is in contact with a position corresponding to the bottom surface on one side of the housing 201X of the optical scanning device 200X in the depth direction X, and the rotation of the eccentric cam member 263 about the rotation axis β allows the optical scanning device 200X to rotate about the rotation axis λ. Here, Fig. 16A shows a state in which the optical scanning device 200X is parallel to the depth direction X. Fig. 16B shows a state in which one side (the operation side) of the optical scanning device 200X in the depth direction X is higher. Fig. 16C shows a state in which the other side (the opposite side to the operation side) of the optical scanning device 200X in the depth direction X is higher.

[0006] Then, some part of the housing 201X (for example, the side opposite to the emission side of the light beam L of the housing 201X) is fixed to the image forming apparatus main body 110X with a fixing member such as a screw so that the scanning locus α (see FIG. 15A) of the light beam L is parallel to the rotation axis δ of the photosensitive drum 3X (see FIG. 14) acting as an image carrier. That is, some part of the housing 201X (for example, the emission side of the light beam L of the housing 201X) may not be fixed to the image forming apparatus main body 110X with a fixing member. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-092661 Summary of the Invention [Problem to be solved by the invention]

[0008] In such an image forming device, vibrations from the image forming device main body, such as vibrations caused by driving the image forming section in the image forming device main body or driving the sheet conveying system, are transmitted to the optical scanning device, which could cause the image written on the image carrier (photosensitive body) to be distorted, resulting in image defects.

[0009] Therefore, the present invention aims to provide an image forming apparatus in which an optical scanning device is attached to the image forming apparatus main body so that it can be rotated and adjusted around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and which can suppress the transmission of vibrations from the image forming apparatus main body to the optical scanning device, thereby effectively preventing the occurrence of image defects due to distortion of the image written to the image carrier. [Means for solving the problem]

[0010] In order to solve the above problem, The present invention provides the following image forming apparatuses according to first to seventh aspects. (1) Image forming apparatus of the first aspect The present invention The first aspect The image forming apparatus has an optical scanning device attached to an image forming apparatus main body so as to be rotatable about a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in a deflection scanning plane of the light beam, and the image forming apparatus main body is provided with a shaft support part that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding part that faces a housing of the optical scanning device at a position different from the shaft support part, and the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and sandwiched between the housing and the holding part. The holding portions are provided on the image forming apparatus main body on the opposite side of the bottom of the housing so as to be positioned on both sides in the main scanning direction across the rotation axis when viewed from above. It is characterized by the fact that (2) Image forming apparatus according to the second aspect A second aspect of the image forming apparatus of the present invention is an image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so that it can be rotated around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and the image forming apparatus main body is provided with an axis support portion that supports the optical scanning device so that it can be rotated around the rotation axis, and a holding portion that faces the housing of the optical scanning device at a position different from the axis support portion, and the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and sandwiched between the housing and the holding portion, and the holding portion is provided on the image forming apparatus main body on the opposite side to the bottom of the housing so as to be located on a virtual vertical line passing through the rotation axis when viewed from above. (3) Image forming apparatus of the third aspect A third aspect of the image forming apparatus of the present invention is an image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so that it can be rotated around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and the image forming apparatus main body is provided with an axis support portion that supports the optical scanning device so that it can be rotated around the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the axis support portion, the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and clamped between the housing and the holding portion, the housing is provided with an opening through which the light beam passes, and the holding portion is provided in the image forming apparatus main body so as to be located on the opposite side of the opening from the bottom of the housing. (4) Image forming apparatus according to the fourth aspect A fourth aspect of the image forming apparatus of the present invention is an image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so that it can be rotated around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and the image forming apparatus main body is provided with an axis support portion that supports the optical scanning device so that it can be rotated around the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the axis support portion, the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and sandwiched between the housing and the holding portion, the housing is provided with a beam portion along the main scanning direction, and the holding portion is provided in the image forming apparatus main body so as to be located on the opposite side of the beam portion from the bottom of the housing. (5) Image forming apparatus of the fifth aspect An image forming apparatus according to a fifth aspect of the present invention is an image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so that it can be rotated around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and the image forming apparatus main body is provided with an axial support portion that supports the optical scanning device so that it can be rotated around the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the axial support portion, and the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and sandwiched between the housing and the holding portion, and the elastic member is provided between the upper surface of the housing of the optical scanning device and the lower surface of the holding portion of the image forming apparatus main body. (6) Image forming apparatus of the sixth aspect An image forming apparatus according to a sixth aspect of the present invention is an image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so that it can be rotated around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and the image forming apparatus main body is provided with an axis support portion that supports the optical scanning device so that it can be rotated around the rotation axis, and a holding portion that faces the housing of the optical scanning device at a position different from the axis support portion, and the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and sandwiched between the housing and the holding portion, and the holding portion has a base portion extending downward from the bottom surface of the top plate of the image forming apparatus main body, and an extension portion extending from the lower part of the base toward the housing of the optical scanning device. (7) Image forming apparatus of the seventh aspect An image forming apparatus according to a seventh aspect of the present invention is an image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so that it can be rotated around a rotation axis parallel to an axis perpendicular to the main scanning direction of the light beam in the deflection scanning plane of the light beam, and the image forming apparatus main body is provided with an axial support portion that supports the optical scanning device so that it can be rotated around the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the axial support portion, and the optical scanning device is held in the image forming apparatus main body with an elastic member pressed and sandwiched between the housing and the holding portion, and the elastic member is provided in a location on the housing that is not fixed to the image forming apparatus main body by a fixing member. [Effects of the Invention]

[0011] According to the present invention, it is possible to suppress the transmission of vibrations from the image forming device main body to the optical scanning device, thereby effectively preventing the occurrence of image defects due to distortion of the image written on the image carrier. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention, as viewed from the front. [Figure 2A] 2 is a perspective view of the front side of the optical scanning device in the image forming apparatus shown in FIG. 1, viewed from above. [Figure 2B] 2 is a perspective view of the rear side of the optical scanning device in the image forming apparatus shown in FIG. 1, viewed from above. [Figure 3A] 2 is a perspective view of the front side of the optical scanning device and the photosensitive drum, with the top cover portion of the image forming apparatus shown in FIG. 1 cut away, viewed from the upper left. [Figure 3B] 3B is a perspective view of the front side of the optical scanning device shown in FIG. 3A as viewed from the lower right. [Figure 4] 3B is a cross-sectional view of the optical scanning device shown in FIG. 3A as viewed from above. [Figure 5A] 1 is an exploded perspective view of an image forming apparatus according to a first embodiment, viewed obliquely from above on the front side, showing a state before a photosensitive unit and an optical scanning device are mounted on a main body frame. FIG. [Figure 5B] 2 is an exploded perspective view of the image forming apparatus according to the first embodiment, in which a photosensitive unit and an optical scanning device are mounted on a main body frame, as viewed obliquely from above on the front side. FIG. [Figure 6] 5C is a perspective view of the state shown in FIG. 5B with the optical scanning device side of the main body frame removed, as viewed from the optical scanning device side. FIG. [Figure 7] 5C is a perspective view showing an opening from which a light beam is emitted, with the opposite side of the optical scanning device in the main body frame removed in the state shown in FIG. 5B. FIG. [Figure 8A] 5C is a perspective view of the main body frame from the optical scanning device side, showing the state in which the optical scanning device has been removed from the state shown in FIG. 5B. FIG. [Figure 8B]8B is an enlarged perspective view of the holding portion shown in FIG. 8A. FIG. [Figure 9] 8B is a perspective view showing a state in which the optical scanning device is held by the holding portion shown in FIG. 8A via an example of an elastic member. FIG. [Figure 10A] 10 is a perspective view showing a state in which an optical scanning device is held via an example of an elastic member in the holding portion shown in FIG. 9 in the image forming apparatus according to the second embodiment. FIG. [Figure 10B] 10 is a perspective view showing a state in which an optical scanning device is held by the holding portion shown in FIG. 9 via another example of an elastic member in the image forming apparatus according to the second embodiment. FIG. [Figure 11] FIG. 11 is a perspective view of an image forming apparatus according to a third embodiment, with the optical scanning device side of the main body frame removed, as viewed from the optical scanning device side. [Figure 12A] FIG. 11 is a perspective view of an image forming apparatus according to a third embodiment, from which an optical scanning device has been removed, as viewed from the optical scanning device side of the main body frame. [Figure 12B] 12B is an enlarged perspective view of the holding portion shown in FIG. 12A. FIG. [Figure 13] 12C is a perspective view showing a state in which an optical scanning device is held via an example of an elastic member in the holding portion shown in FIGS. 12A and 12B in an image forming apparatus according to a third embodiment. FIG. [Figure 14] FIG. 2 is a schematic cross-sectional view of an image forming apparatus as seen from the front, in which reference numerals unnecessary for explanation in FIG. 1 of Patent Document 1 have been deleted and necessary reference numerals have been added. [Figure 15A] FIG. 2 is a perspective view of the front side of the optical scanning device as seen from above, with reference numerals unnecessary for explanation removed and necessary reference numerals added in FIG. 2 of Patent Document 1. [Figure 15B] FIG. 4 is a perspective view of the rear side of the optical scanning device as seen from above, with reference numerals unnecessary for explanation in FIG. 3 of Patent Document 1 deleted and necessary reference numerals added. [Figure 16A] 10 is a side view schematically showing a state in which the optical scanning device is rotated and adjusted around a rotation axis; FIG. [Figure 16B] 10 is a side view schematically showing a state in which the optical scanning device is rotated and adjusted around a rotation axis; FIG. [Figure 16C] 10 is a side view schematically showing a state in which the optical scanning device is rotated and adjusted around a rotation axis; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of these components are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0014] [Image forming device] 1 is a schematic cross-sectional view of an image forming apparatus 100 according to the present embodiment as viewed from the front. In the figure, the symbol X represents the depth direction, the symbol Y represents the left-right direction (width direction), the symbol Z represents the vertical direction (up-down direction), and the symbol X1 represents the main scanning direction.

[0015] The image forming apparatus 100 according to this embodiment is a monochrome image forming apparatus. The image forming apparatus 100 performs image formation processing in accordance with image data read by the image reading device 1 or image data transmitted from an external device. Note that the image forming apparatus 100 may also be a color image forming apparatus that forms multicolor and monochrome images on paper P (sheets).

[0016] The image forming apparatus 100 includes an original feeder 108 and an image forming apparatus main body 110. The image forming apparatus main body 110 includes an image forming section 102 and a sheet transport system 103.

[0017] The image forming section 102 includes an optical scanning device 200 (optical scanning unit), a developing unit 2, a photosensitive drum 3 that functions as an image carrier, a cleaning section 4, a charging device 5, and a fixing unit 7. The sheet transport system 103 includes a paper feed tray 81, a manual paper feed tray 82, a discharge roller 31, and a discharge tray 14.

[0018] An image reading device 1 for reading an image of an original G is provided on top of the image forming apparatus main body 110. The image reading device 1 is equipped with an original placement table 107 on which the original G is placed. In addition, an original feeding device 108 is provided above the original placement table 107. In the image forming apparatus 100, the image of the original G read by the image reading device 1 is sent to the image forming apparatus main body 110 as image data, and the image is recorded on a paper P.

[0019] A paper transport path S1 is provided in the image forming apparatus main body 110. A paper feed tray 81 or a manual paper feed tray 82 supplies paper P to the paper transport path S1. The paper transport path S1 leads the paper P to an output tray 14 via a transfer roller 10 and a fixing unit 7. The fixing unit 7 heats and fixes the toner image formed on the paper P to the paper P. Near the paper transport path S1, pickup rollers 11a and 11b, a transport roller 12a, a registration roller 13, a transfer roller 10, a fixing roller 71 and a pressure roller 72 in the fixing unit 7, and an output roller 31 are arranged.

[0020] In the image forming apparatus 100, a sheet of paper P supplied from a paper feed tray 81 or a manual paper feed tray 82 is conveyed to registration rollers 13. Next, the sheet of paper P is conveyed to transfer rollers 10 by registration rollers 13 at a timing that aligns the sheet of paper P with the toner image on the photosensitive drum 3. The toner image on the photosensitive drum 3 is transferred onto the sheet of paper P by transfer rollers 10. The sheet of paper P then passes through fixing rollers 71 and pressure rollers 72 in the fixing unit 7, and is then conveyed via conveyance rollers 12a and discharge rollers 31 onto a discharge tray 14. When an image is to be formed on the back side of the sheet of paper P in addition to the front side, the sheet of paper P is conveyed in the opposite direction from discharge rollers 31 to a reverse sheet conveyance path S2. The sheet of paper P passes through reversal conveyance rollers 12b to 12b, and is then reversed and guided again to registration rollers 13. Then, a toner image is formed and fixed on the back side of the sheet of paper P in the same manner as on the front side, and the sheet of paper P is then discharged towards a discharge tray 14.

[0021] [Optical scanning device] 2A and 2B are perspective views of the front and rear sides, respectively, of the optical scanning device 200 in the image forming apparatus 100 shown in FIG. 1, viewed from above. FIG. 3A is a perspective view of the front side of the optical scanning device 200 and the photosensitive drum 3, with the top cover 202 side portion of the image forming apparatus 100 shown in FIG. 1 cut away, viewed from the upper left. FIG. 3B is a perspective view of the front side of the optical scanning device 200 shown in FIG. 3A, viewed from the lower right. FIG. 4 is a cross-sectional view of the optical scanning device 200 shown in FIG. 3A, viewed from the top side.

[0022] In the optical scanning device 200, a light beam L (laser beam) from a light source 211 (laser diode element) passes through a collimator lens 212 to be converted into a substantially parallel beam, narrowed by an aperture member 213, passes through a cylindrical lens 214, is incident on a light source reflecting mirror 215, is reflected, and then is incident on a reflecting surface 223a of a deflection scanning member 223 (a rotating polygon mirror). The deflection scanning member 223 is rotated in a predetermined rotation direction R at a constant angular velocity by a deflection scanning motor 222, and successively reflects the light beam L at each reflecting surface 223a, repeatedly deflecting the light beam L in the main scanning direction X1 at a constant angular velocity. The fθ lens 231 condenses the light beam L to a predetermined beam diameter on the surface of the photosensitive drum 3 in both the main scanning direction X1 and the sub-scanning direction. Furthermore, the fθ lens 231 converts the light beam L deflected at a constant angular velocity in the main scanning direction X1 by the deflection scanning member 223 so that it moves at a constant linear velocity on the photosensitive drum 3. This allows the light beam L to repeatedly scan the surface of the photosensitive drum 3 in the main scanning direction X1.

[0023] In addition, a beam detection unit 234 [Beam Detect sensor (BD sensor)] (see FIG. 4) receives the light beam L reflected by the beam detection reflecting mirror 232 and passes through a beam detection lens 233 (condenser lens) just before the main scanning (writing) of the photosensitive drum 3 begins. The beam detection unit 234 receives the light beam L at the timing just before the main scanning of the surface of the photosensitive drum 3 begins and outputs a BD signal indicating the timing just before the start of the main scanning. The start timing of the main scanning of the photosensitive drum 3, at which a toner image is formed, is set in accordance with this BD signal, and writing of the light beam L according to image data begins. The two-dimensional surface (circumferential surface) of the photosensitive drum 3, which is rotated and charged, is then scanned by the light beam L, and electrostatic latent images are formed on the surface of the photosensitive drum 3.

[0024] The housing 201 has a rectangular bottom plate 201a and four side plates 201b to 201e surrounding the bottom plate 201a. The light beam L scanned by the deflection scanning member 223 and passed through the fθ lens 231 is emitted to the outside of the housing 201 through an opening 201f formed in the side plate 201e on the fθ lens 231 side of the side plates 201b to 201e. A second dustproof glass plate 236 (transparent body) is provided in the opening 201f. This makes it possible to effectively prevent dust and other unwanted substances from entering the housing 201.

[0025] (First embodiment) 5A and 5B are exploded perspective views of the image forming apparatus 100 according to the first embodiment, viewed obliquely from above the front side, showing the photosensitive unit 30 and the optical scanning device 200 before and after they are attached to the main body frame 110a. The photosensitive unit 30 includes a photosensitive drum 3. The optical scanning device 200 shown in FIG. 5A has its top cover 202 removed. FIG. 6 is a perspective view of the main body frame 110a in the state shown in FIG. 5B, with the optical scanning device 200 side removed, viewed from the optical scanning device 200 side. FIG. 7 is a perspective view of the main body frame 110a in the state shown in FIG. 5B, with the side opposite the optical scanning device 200 removed, to show the opening 201f through which the light beam L is emitted. FIG. 8A is a perspective view of the main body frame 110a in the state shown in FIG. 5B, with the optical scanning device 200 removed, viewed from the optical scanning device 200 side. FIG. 8B is an enlarged perspective view of the holding portion 130 (130a, 130b) shown in FIG. 8A.

[0026] 5A to 7, in the image forming apparatus 100 according to the present embodiment, the optical scanning device 200 is attached to the image forming apparatus main body 110 so as to be rotatable about a rotation axis λ (see FIGS. 3A, 3B, 4, 5B, and 6) that is parallel to an axis perpendicular to the main scanning direction X1 of the light beam L in the deflection scanning plane of the light beam L. A rotation shaft 260 having its axis center on the rotation axis λ is provided in a housing 201 of the optical scanning device 200. More specifically, a first rotation shaft 261 (see FIG. 7) is provided on the side of the housing 201 of the optical scanning device 200 from which the light beam L is emitted, and a second rotation shaft 262 (see FIGS. 5A to 6) is provided on the side opposite to the emission side of the optical scanning device 200.

[0027] In detail, the central axes of the first rotating shaft portion 261 and the second rotating shaft portion 262 are on the same axis and are formed cylindrically along the perpendicular direction W (in this example, the left-right direction Y) that is perpendicular to the main scanning direction X1 of the light beam L toward the optical scanning device 200.

[0028] As shown in FIGS. 8A and 8B, in the image forming apparatus main body 110 (main body frame 110a), a shaft support portion 121 (a cylindrical portion in this example) is provided on the side from which the light beam L of the optical scanning device 200 is emitted. The shaft support portion 121 has a hole portion 121a along the orthogonal direction W. The first rotation shaft portion 261 is inserted into the hole portion 121a of the shaft support portion 121. The inner diameter of the hole portion 121a is set to be slightly larger (by a predetermined amount) than the outer diameter of the first rotation shaft portion 261, to such an extent that the first rotation shaft portion 261 can rotate around the rotation axis λ relative to the hole portion 121a.

[0029] Furthermore, a support member 122 having a U-shaped recess 122a is provided on the image forming apparatus main body 110 (main body frame 110a) on the side opposite to the side from which the light beam L of the optical scanning device 200 is emitted. The second rotation shaft portion 262 is supported by the support member 122. The width and lower inner diameter of the recess 122a are slightly larger (by a predetermined amount) than the outer diameter of the second rotation shaft portion 262, to an extent that the second rotation shaft portion 262 can rotate around the rotation axis λ relative to the recess 122a. The support member 122 is fixed to the main body frame 110a on the side opposite to the side from which the light beam L is emitted by a plurality of fixing members (screws) SC-SC (see FIG. 6).

[0030] The configuration for rotation adjustment of the optical scanning device 200 around the rotation axis λ is the same as the conventional configuration shown in FIGS. 16A to 16C, and therefore a description thereof will be omitted here.

[0031] Some part of the housing 201 (in this example, the side of the housing 201 opposite to the emission side of the light beam L) is fixed to the image forming apparatus main body 110 with fixing members SC to SC such as screws so that the scanning locus α of the light beam L is parallel to the rotation axis δ of the photosensitive drum 3 (see FIG. 3A) acting as an image carrier. In other words, some part of the housing 201 (in this example, the emission side of the light beam L of the housing 201) is not fixed to the image forming apparatus main body 110 with fixing members SC to SC.

[0032] In this case, vibrations from the image forming apparatus main body 110, such as vibrations caused by driving the image forming unit 102 in the image forming apparatus main body 110 or the sheet conveying system 103, are transmitted to the optical scanning device 200, which may cause the image written on the photosensitive drum 3 to be distorted, resulting in image defects.

[0033] In this regard, the image forming apparatus 100 according to the present embodiment has a configuration as shown in FIG.

[0034] FIG. 9 is a perspective view showing a state in which the optical scanning device 200 is held by the holding portion 130 (130a, 130b) shown in FIG. 8A via an example of the elastic member 300.

[0035] The image forming apparatus main body 110 (main body frame 110a) is provided with a shaft support portion 121 that supports the optical scanning device 200 so that it can rotate about a rotation axis λ, and a holding portion 130 that faces a housing 201 of the optical scanning device 200 at a position different from the shaft support portion 121. The optical scanning device 200 is held in the image forming apparatus main body 110 (main body frame 110a) with an elastic member 300 (a buffer member) being pressed and sandwiched between the housing 201 (in this example, the side plate 201e on the emission side of the light beam L) and the holding portion 130.

[0036] As described above, in the image forming apparatus 100 according to the present embodiment, the optical scanning device 200 is held in the image forming apparatus main body 110 with the elastic member 300 being pressed and sandwiched between the housing 201 and the holding portion 130. This allows the elastic member 300 to absorb vibrations from the image forming apparatus main body 110, such as vibrations caused by driving the image forming unit 102 and the sheet conveying system 103 in the image forming apparatus main body 110. This suppresses transmission of vibrations from the image forming apparatus main body 110 to the optical scanning device 200, thereby effectively preventing image defects due to distortion of the image written on the photosensitive drum 3. This is particularly effective when any part of the housing 201 (in this example, the emission side of the light beam L of the housing 201) is not fixed to the image forming apparatus main body 110 with fixing members SC-SC such as screws.

[0037] Incidentally, the portions of the housing 201 of the optical scanning device 200 that are not fixed to the image forming apparatus main body 110 by the fixing members SC to SC are likely to vibrate due to vibrations from the image forming apparatus main body 110.

[0038] In this regard, in the present embodiment, the elastic member 300 is provided in a location in the housing 201 that is not fixed to the image forming apparatus main body 110 by the fixing members SC to SC.

[0039] In this way, by providing elastic member 300 in a location on housing 201 that is not fixed to image forming apparatus main body 110 by fixing members SC-SC, vibrations from image forming apparatus main body 110 can be absorbed by elastic member 300 in a location that is likely to vibrate due to vibrations from image forming apparatus main body 110. Therefore, transmission of vibrations from image forming apparatus main body 110 to optical scanning device 200 can be further suppressed, and thereby image defects due to distortion of the image written on photosensitive drum 3 can be more effectively prevented.

[0040] The material of the elastic member 300 can be a commonly used vibration-proof material, including, but not limited to, solid rubber materials such as chloroprene rubber and silicone rubber. The hardness of the elastic member 300 can be, but is not limited to, approximately 25±5 degrees. The hardness of the elastic member 300 can be determined in accordance with JIS K6253.

[0041] The thickness of the elastic member 300 when the elastic member 300 is not provided between the housing 201 (in this example, the upper surface 201k of the housing 201) and the holding portion 130 (in this example, the lower surface 130c of the holding portion 130) is not limited to this, but can be, for example, a thickness (3 mm in this example) that is approximately 1.5 to 2 times the distance d (d1) (2 mm in this example) between the housing 201 (the upper surface 201k) and the holding portion 130 (the lower surface 130c) (see Figure 9).

[0042] Incidentally, if the rotation shaft 260 having the rotation axis λ as its axis center is provided in a part of the housing 201 that has weak strength, the housing 201 is likely to bend when the optical scanning device 200 is rotated around the rotation axis λ, which may distort the optical members (e.g., the fθ lens 231) inside the housing 201, making it impossible to obtain a good image. Meanwhile, in the strength distribution in the housing 201, the bottom 201g (bottom plate 201a portion) has the greatest strength.

[0043] In this regard, in the present embodiment, the optical scanning device 20 is provided with a rotation shaft 260 having a rotation axis λ as its center (axial center) on the bottom 201g of the housing 201, and is rotatably supported by the shaft support 121. More specifically, a first rotation shaft 261 (see FIG. 2A) having an axis λ as its axis center is provided on the light beam L emission side of the bottom 201g of the housing 201, and a second rotation shaft 262 (see FIG. 2B) having an axis λ as its axis center is provided on the opposite side to the emission side of the light beam L. This makes it possible to make the housing 201 less likely to bend when the optical scanning device 200 is rotated around the rotation axis λ, thereby effectively preventing distortion of the optical members inside the housing 201 and therefore enabling a good image to be obtained.

[0044] In the present embodiment, one or more holding units 130 (130a, 130b) are provided on the image forming apparatus main body 110 (main body frame 110a) on the opposite side of the bottom 201g of the housing 201 so as to be located on both sides in the main scanning direction X1 across the rotation axis λ in a top view (at the same distance from the rotation axis λ on both sides in this example). This allows the optical scanning device 200 to be held at three locations: the rotation shaft 260 provided on the bottom 201g of the housing 201, and the holding units 130 (130a, 130b) on both sides in the main scanning direction X1 across the rotation axis λ with respect to the rotation shaft 260. This allows the housing 201 of the optical scanning device 200 to be stably held, and the optical properties of the optical members in the housing 201 to be maintained.

[0045] From the viewpoint of suppressing vibrations from the image forming apparatus main body 110, it is preferable to provide the holding parts 130 at both ends in the main scanning direction X1 of the optical scanning device 200. Vibrations from the image forming apparatus main body 110 can be further suppressed by the elastic member 300.

[0046] In the present embodiment, the holding portion 130 (130a, 130b) has a base portion 131 and an extension portion 132. The base portion 131 extends downward from a bottom surface 111a of a ceiling portion 111 (in this example, the ceiling portion 111 provided on the emission side of the light beam L of the optical scanning device 200) (see FIGS. 6, 8A, and 8B) in the image forming apparatus main body 110 (main body frame 110a). The extension portion 132 extends from the bottom of the base portion 131 toward a housing 201 of the optical scanning device 200.

[0047] By doing this, even if it is not possible to provide a holding portion near the center of the top surface of the optical scanning device 200, the optical scanning device 200 can be held in the image forming device main body 110 with the elastic member 300 pressed and clamped between the peripheral portion of the housing 201 of the optical scanning device 200 and the holding portion 130 in the image forming device main body 110.

[0048] In this embodiment, the housing 201 is provided with an opening 201f through which the light beam L passes. Incidentally, the opening 201f of the housing 201 is easily bent by an external force near the side opposite to the bottom 201g.

[0049] In this regard, in the present embodiment, the holding portion 130 (130a, 130b) is provided on the image forming apparatus main body 110 (main body frame 110a) so as to be located on the opposite side of the opening 201f (see Figures 2A, 3A, and 3B) from the bottom 201g of the housing 201.

[0050] In this way, by providing the holding portion 130 (130a, 130b) on the opposite side of the bottom 201g of the housing 201 at the opening 201f, it is possible to make it easier for the elastic member 300 to absorb vibrations from the image forming apparatus main body 110 near the opposite side of the bottom 201g of the opening 201f of the housing 201, which is easily bent by external forces.

[0051] In this embodiment, beam portions 201h (see FIGS. 2A, 3A, 7, and 9) extending along the main scanning direction X1 are provided on the housing 201. Incidentally, the beam portions 201h of the housing 201 extending along the main scanning direction X1 are easily bent by an external force.

[0052] In this regard, in this embodiment, the holding portion 130 is provided on the image forming apparatus main body 110 (main body frame 110a) so as to be located on the opposite side of the beam portion 201h from the bottom portion 201g of the housing 201.

[0053] In this way, by providing the holding portion 130 (130a, 130b) on the opposite side of the beam portion 201h from the bottom portion 201g of the housing 201, it becomes possible to make it easier for the elastic member 300 to absorb vibrations from the image forming apparatus main body 110 on the opposite side of the bottom portion 201g of the beam portion 201h along the main scanning direction X1 of the housing 201, which is easily bent by external forces.

[0054] In this example, the housing 201 is provided with an opening 201f through which the light beam L passes so as to form a beam portion 201h along the main scanning direction X1 on the part (upper part) opposite to the bottom portion 201g of the housing 201.

[0055] In this embodiment, a slit 201i (see FIGS. 2A and 7) is provided along the main scanning direction X1 at a position of the beam portion 201h corresponding to the holding portion 130 (130a, 130b). In this example, the area around the slit 201i is reinforced by a reinforcing portion 201j (see FIGS. 2A, 2B, 7, and 9).

[0056] In this way, by providing the slit 201i along the main scanning direction X1 at a position corresponding to the holding portion 130 (130a, 130b) of the beam portion 201h, it is possible to make it easier for the elastic member 300 to absorb vibrations from the image forming apparatus main body 110 in the slit 201i along the main scanning direction X1, which is prone to elastic deformation due to external forces (although in this embodiment it is reinforced by the reinforcing portion 201j).

[0057] In this embodiment, the holding portions 130 (130a, 130b) of the image forming apparatus main body 110 (main body frame 110a) have a lower surface 130c (see FIG. 9) facing an upper surface 201k (see FIG. 9) of the housing 201. The elastic member 300 is provided between the upper surface 201k of the housing 201 of the optical scanning device 200 and the lower surface 130c of the holding portions 130 (130a, 130b) of the image forming apparatus main body 110 (main body frame 110a). This makes it possible for the elastic member 300 to easily absorb vibrations from the image forming apparatus main body 110 in a direction intersecting the lower surface 130c. Therefore, transmission of vibrations from the image forming apparatus main body 110 in a direction intersecting the lower surface 130c to the optical scanning device 200 can be suppressed.

[0058] (Second embodiment) 10A and 10B are perspective views showing a state in which the optical scanning device 200 is held by the holding portion 130 (130a, 130b) shown in FIG. 9 in the image forming apparatus 100 according to the second embodiment via one example and another example of the elastic member 300. Note that FIG. 10B shows an example in which the example shown in FIG. 9 and the example shown in FIG. 10A are combined. Here, the elastic member 300 in which the example shown in FIG. 9 and the example shown in FIG. 10A are combined is integrally formed.

[0059] In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0060] In this embodiment, the holding portion 130 (130a, 130b) of the image forming apparatus main body 110 (main body frame 110a) has a side surface 130d that faces the side surface 201m of the housing 201. The elastic member 300 is provided between the side surface 201m of the housing 201 of the optical scanning device 200 and the side surface 130d of the holding portion 130 of the image forming apparatus main body 110 (main body frame 110a). This makes it possible to easily absorb vibrations from the image forming apparatus main body 110 in a direction intersecting the side surface 130d by the elastic member 300. Therefore, it is possible to suppress transmission of vibrations from the image forming apparatus main body 110 in a direction intersecting the side surface 130d to the optical scanning device 200.

[0061] The thickness of the elastic member 300 when the elastic member 300 is not provided between the housing 201 (in this example, side surface 201m) and the holding portion 130 (in this example, side surface 130d) is not limited to this, but can be, for example, a thickness (3 mm in this example) that is approximately 1.5 to 2 times the distance d (d2) (2 mm in this example) between the housing 201 (side surface 201m) and the holding portion 130 (side surface 130d) (see Figure 10A).

[0062] (Third embodiment) In the first and second embodiments, the holding portion 130 is a plurality of holding portions, but it may be a single holding portion.

[0063] FIG. 11 is a perspective view of the image forming apparatus 100 according to the third embodiment, with the optical scanning device 200 side of the main body frame 110a removed, as viewed from the optical scanning device 200 side. FIG. 12A is a perspective view of the image forming apparatus 100 according to the third embodiment, with the optical scanning device 200 removed, as viewed from the optical scanning device 200 side of the main body frame 110a. FIG. 12B is an enlarged perspective view of the holding unit 130 shown in FIG. 12A. FIG. 13 is a perspective view of the image forming apparatus 100 according to the third embodiment, with the optical scanning device 200 held by the holding unit 130 shown in FIGS. 12A and 12B via an example of an elastic member 300. Note that FIG. 13 illustrates an example that combines the example shown in FIG. 9 and the example shown in FIG. 10A.

[0064] In this embodiment, the holding portion 130 is provided on the image forming apparatus main body 110 (main body frame 110a) on the side opposite the bottom portion 201g of the housing 201 so as to be located on a virtual vertical line γ passing through the rotation axis λ in a top view. This makes it possible to make the housing 201 less likely to twist when the optical scanning device 200 is rotated about the rotation axis λ and fixed to the image forming apparatus main body 110, thereby effectively preventing distortion of the optical members inside the housing 201 and therefore enabling the acquisition of a good image. Moreover, the elastic member 300 can stably absorb vibrations from the image forming apparatus main body 110.

[0065] (Other embodiments) In the first and second embodiments, the holding portions 130 are provided on both sides of the rotation axis λ in the main scanning direction X1, and in the third embodiment, the holding portions 130 are provided on the virtual vertical line γ passing through the rotation axis λ. However, a configuration combining these two may also be used, i.e., a configuration in which the holding portions 130 are provided on both sides of the rotation axis λ in the main scanning direction X1 and on the virtual vertical line γ passing through the rotation axis λ.

[0066] The present invention is not limited to the above-described embodiments, but can be embodied in various other forms. Therefore, the embodiments are merely illustrative in all respects and should not be interpreted as limiting. The scope of the present invention is defined by the claims and is not limited in any way by the text of the specification. Furthermore, all modifications and variations that fall within the equivalent scope of the claims are within the scope of the present invention. [Explanation of symbols]

[0067] 100 Image forming device 102 Image forming unit 103 Sheet transport system 110 Image forming device main body 110a main frame 111 Ceiling 111a Bottom 121 Shaft support part 121a Hole 122 Support member 122a Recess 130 Holding part 130c bottom surface 130d side 131 Base 132 Extension section 200 Optical scanning device 201 Case 201a bottom plate 201b side plate 201c side plate 201d Side panel 201e side plate 201f opening 201g bottom 201h Beam section 201i Slit 201j Reinforcement 201k top 201m side 202 Top lid 260 Rotating shaft 261 First rotating shaft 262 Second rotating shaft 263 Eccentric cam member 3 Photosensitive drum 30 Photoconductor unit 300 Elastic member L Light beam R Rotation direction W perpendicular direction X depth direction X1 Main scanning direction Y left / right direction Z vertical direction d distance α scanning trajectory β rotation axis γ Virtual vertical line δ rotation axis λ Rotation axis

Claims

1. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam on a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, An image forming apparatus characterized in that the holding portion is provided on the image forming apparatus main body on the opposite side of the bottom of the housing, so as to be located on both sides in the main scanning direction across the rotation axis when viewed from above.

2. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam in a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, An image forming apparatus characterized in that the holding portion is provided on the image forming apparatus main body on the opposite side to the bottom of the housing so as to be located on a virtual vertical line passing through the rotation axis when viewed from above.

3. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam in a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, the housing is provided with an opening through which the light beam passes; The image forming apparatus according to claim 1, wherein the holding portion is provided on the image forming apparatus body so as to be located on the opposite side of the opening from the bottom portion of the housing.

4. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam in a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, The housing is provided with a beam portion extending along the main scanning direction, The image forming apparatus according to claim 1, wherein the holding portion is provided on the image forming apparatus body so as to be located on the opposite side of the beam portion from the bottom portion of the housing.

5. 5. The image forming apparatus according to claim 4, an image forming apparatus, characterized in that a slit is provided along the main scanning direction at a position of the beam portion corresponding to the holding portion;

6. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam in a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, The image forming apparatus according to claim 1, wherein the elastic member is provided between an upper surface of the housing of the optical scanning device and a lower surface of the holding portion of the image forming apparatus main body.

7. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus main body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam in a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, An image forming apparatus characterized in that the holding portion has a base portion extending downward from the bottom surface of the top plate in the image forming apparatus main body, and an extension portion extending from the bottom of the base toward the housing of the optical scanning device.

8. An image forming apparatus in which an optical scanning device is attached to an image forming apparatus body so as to be rotatable about a rotation axis parallel to an axis perpendicular to a main scanning direction of the light beam in a deflection scanning plane of the light beam, the image forming apparatus main body is provided with a shaft support portion that supports the optical scanning device so as to be rotatable about the rotation axis, and a holding portion that faces a housing of the optical scanning device at a position different from the shaft support portion, the optical scanning device is held in the image forming apparatus main body in a state in which an elastic member is pressed and sandwiched between the housing and the holding portion, The image forming apparatus according to claim 1, wherein the elastic member is provided at a location on the housing that is not fixed to the image forming apparatus main body by a fixing member.

9. 9. The image forming apparatus according to claim 1, The image forming apparatus is characterized in that the optical scanning device has a rotation shaft portion that is provided on the bottom of the housing and that is centered on the rotation axis line, and is rotatably supported by the shaft support portion.

10. 10. The image forming apparatus according to claim 1, The image forming apparatus according to claim 1, wherein the elastic member is provided between a side surface of the housing of the optical scanning device and a side surface of the holding portion of the image forming apparatus main body.

Images