Image forming apparatus

Abstract

To provide an image forming apparatus capable of easily suppressing the transmission of unnecessary vibration from the outside to an exposure device as compared with the case where interposing a vibration-proof member or adopting a non-contact structure is not adopted.SOLUTION: The image forming device includes a rotating photoconductor (photoconductor drum 21), an exposure device 23 that emits light LB from light emitting elements 231 disposed along an axial direction J of the photoconductor to form latent images, spacing members 214215 that maintain a spacing between the photoconductor and the exposure device 23, and frame side 15F and frame side 15R to which at least the photoconductor and the exposure device 23 are attached, and vibration-proof members 60F and 60R are interposed between the spacing members 214215 and a portion in contact with the exposure device 23.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] The following Patent Document 1 describes an image forming apparatus that includes a photosensitive drum, a light emitter, a first biasing means, and a second biasing means. The light emitter is a detachable light emitter that extends along the axial direction of the photosensitive drum, has a plurality of light emitting elements arranged to irradiate the surface of the photosensitive drum with light, and has both ends supported by a frame member. The first biasing means is a means for biasing a first inner surface portion that is an inner surface constituting a hollow portion formed in the light emitter. The second biasing means is a means for biasing a second inner surface portion that is another inner surface facing the first inner surface portion.

[0003] The following Patent Document 2 describes an image forming apparatus that includes a rotating image carrier and an exposure device that exposes the image carrier. Furthermore, Patent Document 2 describes that the exposure device includes an exposure unit, a weight, and an elastic unit. The exposure unit includes a plurality of exposure elements aligned along the axial direction of the image carrier, positioned relative to the image carrier at both ends in the axial direction, and emitting light to the image carrier to expose it. The weight is disposed opposite the exposure unit, has a predetermined mass, and has an opening extending in the axial direction. The elastic unit is elastic, is disposed between the exposure unit and the weight, and supports the weight so that it can vibrate. Patent document 2 also describes that the elastic portion penetrates the opening of the weight in the axial direction, is continuously provided from one axial end side to the other axial end side of the weight, and is attached to the exposure portion via an attachment member.

[0004] The following Patent Document 3 describes an image forming apparatus that includes an image carrier and a printer head that irradiates the image carrier with a light beam. Furthermore, Patent Document 3 describes that the printer head includes a light source, an optical system, a housing, and one installation member. The light source has a plurality of light-emitting elements arranged along a first direction. The optical system condenses each of a plurality of light beams emitted from the light source in a second direction perpendicular to the first direction. The housing has a top plate that holds the optical system and two side plates that face each other across the light source in a third direction perpendicular to both the first and second directions and are fixed to the top plate near one end of each side in the second direction. The bridging member is a member that bridges a portion of the other end of each of the two side plates in the second direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5205830 (Claim 1, Figures 1-5) [Patent Document 2] Patent No. 7163597 (Claim 1, Figures 1-9) [Patent Document 3] JP 2012-254539 A (Claim 1, Figures 1 and 16) Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides an image forming device that can easily suppress the transmission of unnecessary vibrations from the outside to an exposure device, compared to when an anti-vibration member or a non-contact structure is not used. [Means for solving the problem]

[0007] The first aspect of the present invention is A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with In the image forming apparatus, a vibration isolating member is interposed between the distance maintaining member and the portion that comes into contact with the exposure device.

[0008] The second aspect of the present invention is A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with The image forming apparatus is configured such that the distance maintaining member and the exposure device are spaced apart.

[0009] The third aspect of the present invention is A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with The image forming apparatus has a vibration isolating member interposed between the exposure device and the portion where the support member comes into contact.

[0010] A fourth aspect of the present invention is the image forming apparatus of the first aspect, The image forming apparatus has a vibration isolating member interposed between the exposure device and the portion where the support member comes into contact.

[0011] A fifth aspect of the present invention is the image forming apparatus of the second aspect, The image forming apparatus has a vibration isolating member interposed between the exposure device and the portion where the support member comes into contact. [Effects of the Invention]

[0012] According to the image forming apparatus of the first aspect, it is possible to more easily prevent unnecessary vibrations from being transmitted from the outside to the exposure device than when no vibration-isolating member is used.

[0013] According to the image forming apparatus of the second means, it is possible to more easily prevent unnecessary vibrations from being transmitted to the exposure device from the outside, compared to a case where a non-contact structure is not adopted.

[0014] According to the image forming apparatus of the third aspect, it is possible to more easily prevent unnecessary vibrations from being transmitted from the outside to the exposure device than when no vibration-isolating member is used.

[0015] According to the image forming apparatus of the fourth and fifth means, the transmission of unnecessary vibrations from the outside to the exposure device can be more easily suppressed than in the case where neither the interposition of a vibration-damping member nor a non-contact structure is adopted. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram of an image forming unit in the image forming apparatus of FIG. [Figure 3] 2 is a schematic diagram showing a configuration for suppressing vibration propagation to an exposure device in the image forming apparatus of FIG. 1. FIG. [Figure 4] 10 is a schematic diagram showing a configuration for suppressing vibration propagation to an exposure device in an image forming apparatus according to a second embodiment. FIG. [Figure 5] FIG. 11 is a schematic diagram showing a configuration for suppressing vibration propagation to an exposure device in an image forming apparatus according to a third embodiment. [Figure 6] 10 is a schematic diagram showing a configuration for suppressing vibration propagation to an exposure device in an image forming apparatus according to a fourth embodiment. FIG. [Figure 7]FIG. 11 is a schematic diagram showing a configuration for suppressing vibration propagation to an exposure device in an image forming apparatus according to a fifth embodiment. [Figure 8] FIG. 10 is a graph showing an example of adjustment settings of meshing frequency. [Figure 9] 10A and 10B are schematic diagrams illustrating a configuration of a comparative example and an example of vibration propagation in that case. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described.

[0018] Embodiment 1 FIG. 1 is a schematic diagram of an image forming apparatus according to a first embodiment of the present invention.

[0019] In this specification and the drawings, substantially the same components are denoted by the same reference numerals, and redundant explanations of the same components will be omitted in this specification. The arrow +X in Figure 1 etc. indicates the right direction when viewed from the front side of the image forming apparatus 1 etc., and the arrow -X indicates the left direction at that time. The arrow +Y in Figure 1 etc. indicates the upward direction of the image forming apparatus 1 etc., and the arrow -Y indicates the downward direction. The symbol +Z in Figure 1 etc. indicates the depth direction when viewed from the front side of the image forming apparatus 1 etc., and the symbol -Z indicates the forward direction at that time. In addition, the symbol "x" inside a "circle" in Figure 1 etc. indicates the direction from the front to the back of the paper of the drawing. The symbol "·" inside a "circle" in Figure 1 etc. indicates the direction from the back to the front of the paper of the drawing.

[0020] (Image forming device) The image forming apparatus 1 according to the first embodiment has an image forming unit 2, a medium supply unit 40, a fixing unit 50, and the like arranged inside a housing 10.

[0021] Of these, the housing 10 is a structure formed in a predetermined shape and having an internal space. The housing 10 is divided into an upper section and a lower section, for example, by a partition plate 11. The image forming section 2, the fixing section 50, etc. are arranged in the upper section. The upper section has a discharge storage section 12 formed on its top surface, and a discharge outlet 13 formed in the wall surface of the discharge storage section 12. The lower section has a medium supply section 40, etc.

[0022] The image forming unit 2 is a unit that forms a toner image as an unfixed image on a recording medium 9. The image forming unit 2 includes an image creating unit 20, an intermediate transfer unit 30, and a medium supply unit 40.

[0023] The image forming unit 20 is a part that forms a toner image by developing a latent image corresponding to image information with a developer. As shown in FIG. 1, the imaging section 20 in the first embodiment is made up of four imaging units 20A, 20B, 20C, and 20D.

[0024] The imaging units 20A, 20B, 20C, and 20D are units that create toner images using an electrophotographic method. Each imaging unit 20A, 20B, 20C, and 20D has a photosensitive drum 21, which is an example of a rotating photosensitive body. Each imaging unit 20A, 20B, 20C, and 20D creates an undeveloped image on each photosensitive drum 21 by developing it with a developer of a predetermined color (A, B, C, or D). The predetermined colors (A, B, C, D) include, for example, yellow, magenta, cyan, black, etc. The photosensitive drum 21 is a photosensitive member in the form of a drum.

[0025] As shown in Figures 1 and 2, the imaging units 20A, 20B, 20C, and 20D each have a charging device 22, an exposure device 23, a developing device 24, a drum cleaning device 26, etc. arranged around each photosensitive drum 21. 1, the reference symbols for the charging device 22, the exposure device 23, and the drum cleaning device 26 are shown only for the imaging unit 20D. The developing devices 24 are shown as developing devices 24A, 24B, 24C, and 24D because they use different colors of developer (A, B, C, and D).

[0026] The photosensitive drum 21 rotates in the direction indicated by arrow A by power transmitted from a rotation drive device (not shown). The exposure device 23 is a device that forms an electrostatic latent image by irradiating light LB onto the charged outer peripheral surface of the photosensitive drum 21. Image information is input to the exposure device 23 from an externally connected device (not shown), such as an information terminal or storage medium, connected to the image forming apparatus 1. The developing devices 24A, 24B, 24C, and 24D each have a developing housing, a developing roll, a transport member, a layer thickness regulating member, etc. Among them, the developing roll, the transport member, etc. are rotated in a predetermined direction by power transmitted from a rotation drive device (not shown).

[0027] The intermediate transfer section 30 is a section that relays the toner images formed by the image forming units 20A, 20B, 20C, and 20D of the image forming section 20 and transfers them onto the recording medium 9. The intermediate transfer unit 30 in the first embodiment includes an intermediate transfer belt 31, a primary transfer device 33, a secondary transfer device 34, a belt cleaning device 36, and the like.

[0028] The intermediate transfer belt 31 is an endless belt that can transport a toner image while holding it on its outer circumferential surface mainly by electrostatic force. The intermediate transfer belt 31 rotates while passing through each of the photosensitive drums 21 of the imaging units 20A, 20B, 20C, and 20D. Specifically, the intermediate transfer belt 31 is wound around a predetermined number of support rolls 32a, 32b, 32c, and 32d and rotates in the direction indicated by arrow B. Of these, the support roll 32a is a drive roll, and the support roll 32b is a secondary transfer back roll. Power is transmitted to the support roll 32a of the drive roll from a rotation drive device (not shown).

[0029] The primary transfer device 33 is a device that performs primary transfer of each toner image formed on each photosensitive drum 21 onto the outer circumferential surface of the intermediate transfer belt 31. In the intermediate transfer section 30, the position where the primary transfer device 33 faces each photosensitive drum 21 with the intermediate transfer belt 31 therebetween is the primary transfer position TP1. The primary transfer device 33 is a device that uses a primary transfer roll that rotates in contact with the outer circumferential surface of the intermediate transfer belt 31 at the primary transfer position TP1. A predetermined primary transfer bias is supplied to the primary transfer roll from a power supply device (not shown).

[0030] The secondary transfer device 34 is a device that performs secondarily transferring the toner image that has been primarily transferred onto the outer peripheral surface of the intermediate transfer belt 31 onto one side of the recording medium 9. In the intermediate transfer section 30, the position where the secondary transfer device 34 faces the support roll 32b across the intermediate transfer belt 31 becomes the secondary transfer position TP2.

[0031] The secondary transfer device 34 is a secondary transfer roll that rotates in contact with the outer circumferential surface of the intermediate transfer belt 31 at the secondary transfer position TP2. A predetermined secondary transfer bias is supplied to the secondary transfer roll from a power supply device (not shown). The medium supply unit 40 is a part that stores the recording medium 9 on which an image is to be formed and supplies it to a predetermined position in the image forming unit 2. The predetermined position in the first embodiment is the secondary transfer position TP2 of the intermediate transfer unit 30.

[0032] The medium supply unit 40 includes a storage body 41 for storing a plurality of recording media 9, a delivery device 43 for delivering the recording media 9 one by one from the storage body 41, etc. A loading plate for loading the recording media 9 is arranged in the storage body 41. The recording medium 9 is a medium onto which a toner image can be transferred and held when conveyed to the image forming unit 2. As the recording medium 9, a medium such as paper cut to a predetermined size is used. A plurality of sets of the container 41 and the delivery device 43 may be provided.

[0033] In addition, the housing 10 is provided with a medium transport path Rt, which is illustrated by a dashed line in FIG. The medium transport path Rt has a transport path that extends from at least the medium supply unit 40 to the discharge port 13 via the secondary transfer position TP2 and the fixing unit 50. The medium transport path Rt is also composed of a predetermined number of transport roll pairs 45a, 45b, 45c, and 45d, transport guide members (not shown), and the like.

[0034] The fixing unit 50 is a part that fixes the toner image formed on the recording medium 9 by the image forming unit 2 onto the recording medium 9. The fixing unit 50 is configured by arranging a heating rotor 52, a pressure rotor 53, and the like inside a fixing housing 51. The heating rotor 52 and the pressure rotor 53 are roller-shaped or belt-shaped rotors. The heating rotor 52 and the pressure rotor 53 are in contact with each other under pressure and rotate in the direction indicated by the dashed arrow. In the fixing unit 50, the contact area between the heating rotor 52 and the pressure rotor 53 becomes the fixing nip FN where the recording medium 9 passes and is fixed. In the fixing unit 50, one of the heating rotor 52 and the pressure rotor 53 is rotated by power transmitted from a rotation drive device (not shown).

[0035] (Image formation operation) The image forming apparatus 1 forms an image as follows. Here, a description will be given assuming that toner images are formed in all of the image forming units 20A, 20B, 20C, and 20D of the image forming section 2.

[0036] First, in the image forming units 20A, 20B, 20C, and 20D of the image forming section 20, when a command for an image forming operation is received, each photosensitive drum 21 starts to rotate in the direction indicated by arrow A. In the intermediate transfer unit 30, the intermediate transfer belt 31 starts to rotate in the direction indicated by the arrow B when the image forming operation starts.

[0037] Subsequently, in the imaging units 20A, 20B, 20C, and 20D, the charging devices 22 charge the outer circumferential surfaces of the respective photosensitive drums 21 to a predetermined surface potential. Thereafter, each exposure device 23 exposes the charged outer peripheral surface of each photosensitive drum 21 to light of each color component configured in accordance with the image information, thereby forming an electrostatic latent image divided into predetermined color components (A, B, C, D) on the outer peripheral surface of each photosensitive drum 21.

[0038] Next, each developing device 24A, 24B, 24C, and 24D develops the electrostatic latent image on the outer circumferential surface of each photosensitive drum 21 with a developer of the corresponding color. As a result, a toner image of a predetermined color (A, B, C, or D) is formed separately on the outer circumferential surface of each photosensitive drum 21. Subsequently, in the image forming units 20A, 20B, 20C, and 20D of the image forming section 20, the toner images on the photosensitive drums 21 are transferred to the intermediate transfer section 30.

[0039] In the imaging units 20A, 20B, 20C, and 20D, the drum cleaning device 26 cleans the outer circumferential surface of each photosensitive drum 21 after transfer. After the photosensitive drums 21 of the imaging units 20A, 20B, 20C, and 20D have been cleaned, the imaging units 20A, 20B, 20C, and 20D prepare for the next imaging process.

[0040] Meanwhile, in the intermediate transfer unit 30, the primary transfer device 33 sequentially performs primary transfer of the toner images on the photosensitive drums 21 onto the outer circumferential surface of the intermediate transfer belt 31 passing through the primary transfer position TP1. At this time, the intermediate transfer belt 31 carries the toner image that has been primarily transferred onto its outer circumferential surface to the secondary transfer position TP2.

[0041] Furthermore, in the medium supply unit 40, in accordance with the secondary transfer timing, the delivery device 43 delivers a predetermined recording medium 9 from the container 41 toward the secondary transfer position TP2 of the intermediate transfer unit 30. At this time, the recording medium 9 is transported to the secondary transfer position TP2 via the medium transport path Rt.

[0042] Subsequently, in the intermediate transfer unit 30, the secondary transfer device 34 performs secondary transfer of the toner image onto the recording medium 9 from the outer circumferential surface of the intermediate transfer unit 30 which passes through the secondary transfer position TP2. In the intermediate transfer unit 30, a belt cleaning device 36 cleans the outer peripheral surface of the intermediate transfer belt 31 after the secondary transfer. After the intermediate transfer belt 31 is cleaned, the intermediate transfer unit 30 prepares for the next transfer step.

[0043] The recording medium 9 onto which the toner image has been secondarily transferred in the intermediate transfer unit 30 is transported to be introduced into the fixing unit 50 via the medium transport path Rt. In the fixing unit 50, the recording medium 9 onto which the toner image has been secondarily transferred is heated under pressure as it passes through the fixing nip FN, whereby the toner image is melted and fixed onto the recording medium 9.

[0044] Finally, the recording medium 9 after fixing is conveyed to be discharged from the discharge port 13 via the medium conveyance path Rt, and then accommodated in the discharge accommodation unit 12. With the above, the image forming operation on one side of one recording medium 9 is completed.

[0045] (Configuration of exposure device and photosensitive drum, etc.) Next, the configuration of the exposure device 23, the photosensitive drum 21, and the like in the imaging units 20A, 20B, 20C, and 20D will be described.

[0046] As shown in FIG. 3, the exposure device 23 in the first embodiment is made up of a light emitting unit 230 and a holding unit 237. The light emitting unit 230 emits light to form an electrostatic latent image. The holding unit 237 holds the light emitting unit 230.

[0047] As shown in FIGS. 2 and 3, the light emitting section 230 includes a light emitting element 231, a circuit board 232, an imaging lens 233, a support member 234, and the like.

[0048] The light emitting element 231 is an element (light source) that is arranged along the axial direction J of the photosensitive drum 21 and emits light. A large number of LEDs (Light Emitting Diodes) are used as the light emitting element 231. The light emitting element 231 is configured as an LED array in which LED chips are arranged in a line along the axial direction J.

[0049] The circuit board 232 is a board on which circuits are mounted that supply various signals for controlling the driving of the LED array. The imaging lens 233 is a lens that forms an image of the light LB emitted from the LEDs of the LED array on the surface of the photosensitive drum 21. As the imaging lens 233, a lens array in which a number of rod lenses are arranged along the axial direction J of the photosensitive drum 21 is used.

[0050] The support member 234 is a member that supports the light emitting element 231, the circuit board 232, and the imaging lens 233. The light emitting element 231 and the circuit board 232 are arranged inside the support member 234. The imaging lens 233 is arranged on the upper surface of the support member 234 that faces the photosensitive drum 21. The support member 234 is a structure having a shape extending along the axial direction J of the photosensitive drum 21, and is made of a resin material or the like.

[0051] Furthermore, the support member 234 is provided with positioning portions 235 and 236 at both ends in the axial direction J. The positioning portions 235, 236 have upper end portions 235a, 236a that are set at a predetermined height on the support member 234. The positioning portions 235, 236 are also configured so that the upper end portions 235a, 236a can come into contact with lower end portions 214b, 215b of the spacing maintaining members 214, 215, which will be described later.

[0052] The exposure device 23 configured with the light emitting elements 231 made of the LEDs is sometimes called an LED print head, or LPH for short.

[0053] As shown in FIG. 3, the holding portion 237 includes a holding frame 238, an elastic member 239, and the like.

[0054] The holding frame 238 is a frame that holds the light emitting unit 230. The holding frame 238 has a main body portion 238a and side wall portions 238b and 238c. The main body portion 238a is a plate-shaped portion extending with a predetermined width along the axial direction J of the photosensitive drum 21. The side wall portions 238b and 238c are portions that are bent upward almost vertically at both longitudinal end portions of the main body portion 238a to form side walls.

[0055] The holding frame 238 is fixed to frames 15F, 15R, which are an example of a support member to which at least the photosensitive drum 21 and the exposure device 23 are attached. The holding frame 238 is fixed by contacting its side wall portions 238b, 238c with the frames 15F, 15R and using fixing means such as screws or welding.

[0056] The elastic member 239 is a member that attaches the light emitting unit 230 to the holding frame 238 in a state where the light emitting unit 230 is elastically biased. The elastic member 239 functions to suppress transmission of unnecessary vibrations from the holding frame 238 to the light emitting unit 230. The elastic member 239 also functions to elastically press the positioning portions 235, 236 of the support member 234 of the light emitting unit 230 against the distance maintaining members 214, 215.

[0057] Two elastic members 239 are arranged between the lower ends of the positioning portions 235 and 236 of the support member 234 of the light emitting portion 230 and the upper surface of the main body portion 238a of the holding frame 238. For example, a coil spring is used as the elastic member 239. Any elastic member can be used as the elastic member 239 as long as it can perform the above-mentioned functions, and other elastic members such as a leaf spring may also be used.

[0058] The two elastic members 239 made of coil springs have their lower ends fixed to the upper surface of the main body 238a of the holding frame 238. In addition, the two elastic members 239 have their upper ends fixed to the lower ends of the positioning portions 235 and 236 of the support member 234. The upper ends of the two elastic members 239 do not have to be fixed to the lower ends of the positioning portions 235, 236 of the support member 234 in the following case: for example, when the support structure is such that the light emitting portion 230 is guided so as to be movable in the up and down direction.

[0059] On the other hand, as shown in FIG. 3, the photosensitive drum 21 has a main body portion 211, a flange end portion 212, shaft portions 213F and 213R, and the like.

[0060] The main body 211 is a cylindrical or columnar part provided with a photosensitive functional layer on which an electrostatic latent image is formed. The flange end portions 212 are rigid portions provided at both ends of the main body portion 211 in the axial direction J. Shafts 213F and 213R are portions that protrude a predetermined length outward from the center position of flange end 212. Shaft 213F is a shaft portion that is disposed on the front side (front side) of image forming apparatus 1. Shaft 213R is a shaft portion that is disposed on the back side (rear side) of image forming apparatus 1. The shafts 213F and 213R serve as rotation shafts that support the rotation of the photosensitive drum 21.

[0061] As shown in FIG. 3, the photosensitive drum 21 is provided with gap maintaining members 214 and 215 on the shaft portions 213F and 213R.

[0062] The gap maintaining members 214 and 215 are members for maintaining the gap between the photosensitive drum 21 and the light emitting unit 230 of the exposure device 23 within a predetermined range. Strictly speaking, the gap maintaining members 214 and 215 function to prevent the gap from becoming smaller (narrower) than a predetermined value. Furthermore, the gap maintaining members 214 and 215 have bearing portions for the shaft portions 213F and 213R and support portions that support the bearing portions. The support portions of the distance maintaining members 214 and 215 are shaped so that the lower end portions 214b and 215b thereof face the upper end portions 235a and 236a of the positioning portions 235 and 236.

[0063] Furthermore, one of the gap maintaining members 214 has a positioning protrusion 214p that protrudes outward (actually, toward the front side). The positioning protrusion 214p is a protrusion that is fitted into a positioning hole (not shown) provided in the frame 15F. The gap maintaining member 214 is fixed at a predetermined mounting position by fitting the positioning protrusion 214p into the positioning hole of the frame 15F.

[0064] Furthermore, the shaft portion 213R of the photosensitive drum 21 is connected to a power transmission shaft 216 that rotates by receiving power from a rotation drive device (not shown).

[0065] The shaft portion 213R and the power transmission shaft 216 are connected via a pair of detachable shaft couplings 217 and 218. The shaft coupling 217 is fixed to the shaft portion 213R. The shaft coupling 218 is fixed to the power transmission shaft 216. The power transmission shaft 216 is supported by the frame 15R via a bearing (not shown). The photosensitive drum 21 rotates in the direction indicated by the arrow A by power transmitted from the power transmission shaft 216 via the shaft portion 213R.

[0066] The frames 15F and 15R are frames on which at least the photosensitive drum 21 and the exposure device 23 are attached. The frame 15F is a frame disposed on the front side of the image forming apparatus 1. The frame 15R is a frame disposed on the rear side of the image forming apparatus 1. The frame 15R also constitutes a part of the housing 10.

[0067] (Problems caused by vibrations propagating to the exposure equipment) Incidentally, in the image forming apparatus 1, as exemplified in FIG. 8, the meshing frequencies of the devices that rotate or otherwise operate and are disposed around the exposure device 23 are adjusted and set (designed) in advance.

[0068] In other words, the meshing frequencies of the gears that transmit power to the devices that perform the above-mentioned rotations and other operations are individually set to values ​​that do not cause resonance outside the range of the natural frequency of the exposure device 23. The peripheral devices that perform rotations and other operations include the photosensitive drum 21, the developing device 24, the primary transfer device 33, the drum cleaning device 26, etc. This makes it difficult for the exposure device 23 to resonate even when vibrations generated during operation, such as rotation, of devices arranged around it are transmitted. For reference, in the setting example shown in FIG. 8, the meshing frequency of the photosensitive drum 21 is set to a value slightly outside the upper limit of the natural frequency of the exposure device 23.

[0069] However, in reality, the following problem may occur in the image forming apparatus 1 employing the configuration illustrated in FIG. The configuration illustrated in FIG. 9 is a configuration in which the lower ends 214b, 215b of the distance maintaining members 214X, 215X are in contact with the upper ends 235a, 236a of the positioning portions 235, 236 in the exposure device 23, respectively.

[0070] In the image forming apparatus 1 employing this configuration, image quality defects (banding) may occur due to vibrations caused by the rotation of the photosensitive drum 21 being transmitted to the exposure device 23. Banding is, for example, streaky or striped image unevenness. The cause of the poor image quality at this time is thought to be, for example, that some of the vibrations S1, S2 (see Figure 9) generated by the rotation of the photosensitive drum 21 are transmitted directly to the exposure device 23 via the spacing maintaining members 214X, 215X, causing the exposure device 23 to resonate.

[0071] (Configuration for suppressing vibration propagation to exposure device) In contrast to this, in the image forming apparatus 1 according to the first embodiment, as shown in FIG. 3, vibration isolators 60F and 60R are interposed between the gap maintaining members 214 and 215 and the portions where the exposure device 23 comes into contact. In the first embodiment, the vibration isolators 60F and 60R are interposed between the lower ends 214b and 215b of the distance maintaining members 214 and 215 and the upper ends 235a and 236a of the positioning portions 235 and 236 of the support member 234 of the exposure device .

[0072] The vibration-proof members 60F and 60R are members that can suppress and prevent the transmission of vibrations. The vibration-proof members 60F, 60R are made of a material such as rubber that can reduce or eliminate the propagation of vibrations.

[0073] Furthermore, the vibration-damping members 60F, 60R are installed with a predetermined thickness to obtain vibration-damping effects. The predetermined thickness is set to, for example, a value of 1 mm or more. If this thickness is thinner than 1 mm, there is a problem that the propagation of vibration cannot be sufficiently reduced or eliminated. Incidentally, the height of at least one of the lower end portions 214b, 215b of the distance maintaining members 214, 215 and the upper end portions 235a, 236a of the positioning portions 235, 236 is adjusted taking into consideration the presence of the vibration-isolating members 60F, 60R.

[0074] Furthermore, the vibration-isolating members 60F, 60R are attached to the upper end portions 235a, 236a of the positioning portions 235, 236. The vibration-isolating members 60F, 60R may also be attached to the lower end portions 214b, 215b of the distance maintaining members 214, 215.

[0075] In the image forming apparatus 1 according to the first embodiment, the photosensitive drum 21 rotates during the image forming operation, and vibrations may occur. In addition, some of the generated vibrations, S1 and S2 (see FIG. 9), may be transmitted to the gap maintaining members 214 and 215. However, in the image forming apparatus 1, some of the vibrations S1 and S2 are reduced or eliminated by the vibration-isolating members 60F and 60R.

[0076] Therefore, according to the image forming apparatus 1, the transmission of the parts S1 and S2 of the vibrations from the gap maintaining members 214 and 215 to the exposure device 23 is more easily suppressed than in the case where the vibration isolating members 60F and 60R are not interposed. That is, in this image forming apparatus 1, it is possible to suppress the propagation of vibration to the exposure device 23 without adding new parts such as dampers (vibration-damping parts) or vibration-damping reinforcing members. This also applies to the following embodiments 2 and 3.

[0077] In addition, in the image forming apparatus 1, the occurrence of banding caused by vibrations from the photosensitive drum 21 propagating to the exposure device 23 and resonating therewith is also suppressed or prevented. Furthermore, in this image forming apparatus 1, some of the vibrations S3 and S4 generated by the rotation of the photosensitive drum 21 may be transmitted to the exposure device 23 via the frames 15F and 15R. Even in this case, if the vibrations S3 and S4 are small and within the expected range, they are absorbed by the elastic member 239 of the holding portion 237 of the exposure device 23 and are not easily transmitted.

[0078] Embodiment 2 FIG. 4 is a schematic diagram showing a configuration for suppressing vibration propagation to exposure device 23 in an image forming apparatus according to the second embodiment of the present invention. Image forming apparatus 1 according to the second embodiment has the same configuration as image forming apparatus 1 according to the first embodiment, except that the configuration relating to vibration propagation suppression is changed.

[0079] In the second embodiment, as shown in FIG. 4, the contacting portions of the distance maintaining members 214 and 215 and the exposure device 23 are spaced apart. Specifically, the lower ends 214b, 215b of the distance maintaining members 214, 215 and the upper ends 235a, 236a of the positioning portions 235, 236 of the support member 234 of the exposure device 23 are spaced apart from each other.

[0080] The distance maintaining member 214 and the exposure device 23 are spaced apart so as to provide a predetermined gap E1. The distance maintaining member 215 and the exposure device 23 are spaced apart so as to provide a predetermined gap E2. In other words, the distance maintaining members 214, 215 and the exposure device 23 have a non-contact structure in which they do not come into contact with each other. The gaps E1 and E2 are usually set to the same value. The gaps E1 and E2 are set to a value within a range of 0.95 mm to 1.05 mm, for example. If this gap is narrower than the lower limit, there is a problem that the exposure device 23 may lose focus during exposure. Conversely, if this gap is wider than the upper limit, there is a similar problem.

[0081] The elastic member 239 of the holding portion 237 in the exposure device 23 elastically biases the upper ends 235a and 236a of the positioning portions 235 and 236 of the support member 234 upward. However, the elastic member 239 is set under conditions that keep the upper ends 235a, 236a of the positioning portions 235, 236 out of contact with the lower ends 214b, 215b of the distance maintaining members 214, 215.

[0082] Also in the image forming apparatus 1 according to the second embodiment, the photosensitive drum 21 rotates during the image forming operation, generating vibrations, and some of the vibrations S1 and S2 (see FIG. 9) may be transmitted to the gap maintaining members 214 and 215. However, in this image forming apparatus 1, some of the vibrations S1 and S2 are blocked by the gaps E1 and E2 due to the separation, and are not transmitted to the upper ends 235a and 236a of the positioning portions 235 and 236 in the exposure device .

[0083] Therefore, in the image forming apparatus 1 according to the second embodiment, the transmission of some of the vibrations S1 and S2 from the spacing maintaining members 214 and 215 to the exposure device 23 is easily suppressed compared to when the non-contact structure achieved by the separation is not used.

[0084] Embodiment 3 FIG. 5 is a schematic diagram showing a configuration for suppressing vibration propagation to exposure device 23 in an image forming apparatus according to the third embodiment of the present invention. The image forming apparatus 1 according to the third embodiment has the same configuration as the image forming apparatus 1 according to the first embodiment, except that the configuration relating to vibration propagation suppression is changed.

[0085] In the third embodiment, as shown in FIG. 5, vibration isolating members 62F and 62R are interposed between the exposure device 23 and the contacting portions of the frames 15F and 15R. More specifically, vibration-isolating members 62F and 62R are interposed between the side wall portions 238b and 238c of the holding frame 238 in the holding portion 237 of the exposure device 23 and the frames 15F and 15R.

[0086] The vibration-isolating members 62F and 62R are substantially the same as the vibration-isolating members 60F and 60R in the first embodiment. The vibration-isolating members 62F and 62R are attached to the side wall portions 238b and 238c of the holding frame 238. The vibration-isolating members 62F and 62R may also be attached to the frames 15F and 15R.

[0087] In the image forming apparatus 1 according to the third embodiment, the photosensitive drum 21 rotates during the image forming operation, and vibrations may occur. In addition, some of the generated vibrations, S3 and S4 (see FIG. 9), may be transmitted to the frames 15F and 15R. However, in this image forming apparatus 1, the propagation of parts S3 and S4 of the vibrations is reduced or eliminated by the vibration-isolating members 62F and 62R.

[0088] Therefore, according to this image forming apparatus 1, the transmission of the parts of vibration S3 and S4 from the frames 15F and 15R to the exposure device 23 is more easily suppressed than in the case where the vibration-isolating members 62F and 62R are not interposed.

[0089] Furthermore, in this image forming apparatus 1, the vibration of the power transmission shaft 216 connected to the shaft portion 213R of the photosensitive drum 21 is easily prevented from being transmitted to the exposure device 23 via the frame 15R. Furthermore, this image forming apparatus 1 is effective when other operating devices such as the developing device 24 and the drum cleaning device 26 are attached to the frames 15F and 15R. In other words, in this case, vibrations generated by the other operating devices are easily prevented from being transmitted to the exposure device 23 via the frames 15F and 15R.

[0090] Incidentally, in this image forming apparatus 1, as shown in FIG. 5, the contacting portions of the distance maintaining members 214 and 215 and the exposure device 23 are brought into contact with each other. However, even in this case, it is effective when the meshing frequency of the photosensitive drum 21 is as set, but the meshing frequency of other devices such as the developing device 24 is not as set. It is also effective when the magnitude of the vibrations S1 and S2 transmitted to the exposure device 23 via the gap maintaining members 214 and 215 is at an allowable level.

[0091] Embodiment 4 FIG. 6 is a schematic diagram showing a configuration for suppressing vibration propagation to exposure device 23 in an image forming apparatus according to a fourth embodiment of the present invention. The image forming apparatus 1 according to the fourth embodiment has the same configuration as the image forming apparatus 1 according to the first embodiment, except that the configuration relating to vibration propagation suppression is partially changed.

[0092] In the fourth embodiment, the configuration relating to vibration propagation suppression in the third embodiment is added to the configuration relating to vibration propagation suppression in the first embodiment. In other words, in embodiment 4, in addition to interposing vibration-isolating members 60F, 60R at the contact points between the spacing maintaining members 214, 215 and the exposure device 23, vibration-isolating members 62F, 62R are interposed at the contact points between the exposure device 23 and the frames 15F, 15R.

[0093] In the image forming apparatus 1 according to this embodiment 4, some of the vibrations S1, S2 (see Figure 9) generated by the rotation of the photosensitive drum 21 during image formation operation are transmitted to the exposure device 23 via the spacing maintaining members 214, 215, but are reduced or eliminated by the vibration-damping members 60F, 60R. Furthermore, in this image forming device 1, some of the vibrations S3, S4 (see Figure 9) generated by the rotation of the photosensitive drum 21 during image formation operation are transmitted to the exposure device 23 via the frames 15F, 15R, and are reduced or eliminated by the vibration-damping members 62F, 62R.

[0094] Therefore, according to this image forming device 1, the transmission of some of the vibrations generated by the rotational movement of the photosensitive drum 21, etc. to the exposure device 23 is further suppressed compared to the case where only the vibration propagation suppression configuration in embodiment 1 is adopted.

[0095] Embodiment 5. FIG. 7 is a schematic diagram showing a configuration for suppressing vibration propagation to exposure device 23 in an image forming apparatus according to a fifth embodiment of the present invention. The image forming apparatus 1 according to the fifth embodiment has the same configuration as the image forming apparatus 1 according to the second embodiment, except that the configuration relating to vibration propagation suppression is partially changed.

[0096] In the fifth embodiment, the configuration relating to vibration propagation suppression in the third embodiment is added to the configuration relating to vibration propagation suppression in the second embodiment. In other words, in embodiment 5, in addition to separating the contacting parts of the distance maintaining members 214, 215 and the exposure device 23, vibration-damping members 62F, 62R are interposed between the contacting parts of the exposure device 23 and the frames 15F, 15R.

[0097] In the image forming apparatus 1 according to this embodiment 5, the presence of gaps E1 and E2 due to the separation prevents some of the vibrations S1 and S2 (see Figure 9) generated by the rotation of the photosensitive drum 21 during image formation operation from being transmitted to the exposure device 23 via the spacing maintaining members 214 and 215. Furthermore, in this image forming device 1, some of the vibrations S3, S4 (see Figure 9) generated by the rotation of the photosensitive drum 21 during image formation operation are transmitted to the exposure device 23 via the frames 15F, 15R, and are reduced or eliminated by the vibration-damping members 62F, 62R.

[0098] Therefore, according to this image forming device 1, the transmission of some of the vibrations generated by the rotational operation of the photosensitive drum 21, etc. to the exposure device 23 is further suppressed compared to the case where only the vibration propagation suppression configuration in embodiment 2 is adopted.

[0099] Variant. The present invention is not limited to the configurations exemplified as the above-mentioned Embodiments 1 to 5. In other words, the present invention can be modified and combined in various ways within the scope of the claims without departing from the spirit of the inventions. The present invention also includes, for example, the following modifications.

[0100] The photosensitive drum 21 and the exposure device 23 are not limited to a configuration in which the exposure device 23 is disposed at a position substantially directly below the photosensitive drum 21. In other words, the photosensitive drum 21 and the exposure device 23 may be configured such that the exposure device 23 is disposed at another position, such as a position substantially directly above the photosensitive drum 21 or a position substantially directly to the side of the photosensitive drum 21.

[0101] The photosensitive drum 21, the exposure device 23, etc. may be configured to be detachably mounted to a mounting portion of the housing 10 of the image forming apparatus 1. However, when this structure is adopted, a structure in which the photosensitive drum 21 and the exposure device 23 are temporarily separated from each other during the attachment and detachment work is also used. In this case, the frame 15F is divided into a portion where the photosensitive drum 21 is attached and a portion where the exposure device 23 is attached, and the divided frame portions are configured to be connected when attached. In the present invention, a photosensitive belt having a belt shape may be used as the photosensitive member in place of the photosensitive drum 21.

[0102] The image forming apparatus 1 of the present invention may be any apparatus that uses a photosensitive member and an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction J of the photosensitive member. Therefore, the image forming apparatus 1 is not limited to one that forms a color (multi-color) image, but may also be one that forms a monochromatic image (such as a black and white image). Furthermore, the image forming unit 2 in the image forming apparatus 1 may be an image forming unit that does not employ the intermediate transfer unit 30. Furthermore, the image forming section 20 in the image forming unit 2 is not limited to being composed of four image forming units 20A, 20B, 20C, and 20D. The number of image forming units may be any number other than four, or may be one.

[0103] (Addendum) (((1))) A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with An image forming apparatus in which a vibration isolating member is interposed between the distance maintaining member and a portion that comes into contact with the exposure device. (((2))) A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with an image forming apparatus in which the distance maintaining member and the exposure device are spaced apart; (((3))) A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with An image forming apparatus, wherein a vibration isolating member is interposed between the exposure device and a portion where the support member comes into contact. (((4))) The image forming apparatus according to (((1))), wherein a vibration-isolating member is interposed between the exposure device and the contact portion of the support member. (((5))) The image forming apparatus according to (((2))), wherein a vibration-isolating member is interposed between the exposure device and the contact portion of the support member.

[0104] According to the image forming apparatus of (((1))), the transmission of unnecessary vibrations from the outside to the exposure device can be more easily suppressed than in the case where the vibration-damping member is not interposed. According to the image forming apparatus of (((2))), it is possible to more easily prevent unnecessary vibrations from being transmitted from the outside to the exposure device than in a case where a non-contact structure is not adopted. According to the image forming apparatus of (((3))), the transmission of unnecessary vibrations from the outside to the exposure device can be more easily suppressed than in the case where the vibration-damping member is not interposed. According to the image forming apparatuses of (((4))) and (((5))), the transmission of unnecessary vibrations from the outside to the exposure device can be more easily suppressed than in the case where neither the interposition of a vibration-damping member nor a non-contact structure is adopted. [Explanation of symbols]

[0105] 1...Image forming device 15F, 15R...frame (an example of a support member) 21...Photosensitive drum (an example of a photosensitive body) 23...Exposure equipment 60F, 60R, 62F, 62R... Vibration-proof material 214, 215... Spacing maintaining members 231...light-emitting element J…Axis direction LB…light

Claims

1. A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with An image forming apparatus in which a vibration isolating member is interposed between the distance maintaining member and a portion that comes into contact with the exposure device.

2. A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with an image forming apparatus in which the distance maintaining member and the exposure device are spaced apart;

3. A rotating photoreceptor; an exposure device that forms a latent image by irradiating light from light-emitting elements arranged along the axial direction of the photosensitive member; a gap maintaining member for maintaining a gap between the photosensitive member and the exposure device; a support member to which at least the photosensitive member and the exposure device are attached; Equipped with An image forming apparatus, wherein a vibration isolating member is interposed between the exposure device and a portion where the support member comes into contact.

4. 2. The image forming apparatus according to claim 1, wherein a vibration isolating member is interposed between the exposure device and the contact portion of the support member.

5. 3. The image forming apparatus according to claim 2, wherein a vibration isolating member is interposed between the exposure device and the contact portion of the support member.

Images