JP2019159002A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that has a function to irradiate two points of one photoreceptor with static eliminating light without providing a plurality of light sources for the photoreceptor.SOLUTION: An image forming apparatus comprises photoreceptors 41, a transfer device, light sources 461 and branched light guides 463, 465, and 467. The photoreceptors 41 each carry a toner image on an outer peripheral surface while rotating in a fixed rotation direction R0. The transfer device transfers the toner images on the photoreceptors 41 to a transfer target material at predetermined transfer positions. The branched light guides 463, 465, and 467 guide static eliminating light emitted from the light sources 461 to pre-transfer areas 41b and post-transfer areas 41a located respectively on the upstream side and downstream side in the fixed rotation direction R0 with respect to the respective transfer positions on the outer peripheral surfaces of the photoreceptors 41.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus having a function of irradiating neutralizing light to two places on a photoreceptor.

  An electrophotographic image forming apparatus includes a charge removal unit that removes charge by irradiating light on the surface of a photosensitive member that carries a toner image while rotating. In the following description, the light that neutralizes the surface of the photoconductor is referred to as neutralizing light.

  The charge removal unit may include a long light guide member along the axial direction of the photoconductor and a light source that emits the charge removal light at one end of the light guide member. The light guide member includes a reflection portion that reflects the charge removal light in a direction toward the surface of the photoreceptor. For example, the reflection part is composed of a plurality of recesses arranged in the axial direction.

  In the tandem image forming apparatus, the two reflection portions formed on the light guide member reflect the static elimination light toward the surfaces of the two adjacent photoconductors in the traveling direction of the lower surface of the intermediate transfer belt. (For example, refer to Patent Document 1).

  In the above case, three of the four photosensitive members other than the one located on the uppermost stream in the advancing direction on the lower surface of the intermediate transfer belt are the region before the toner image is transferred and the region after the toner image is transferred. The neutralization light is irradiated at two locations with the region.

JP2013-113901A

  By the way, in the tandem image forming apparatus, it is desirable that the neutralizing light is applied to two areas of the pre-transfer area and the post-transfer area on all four photoconductors.

  Also in the monochrome image forming apparatus, it is desirable that the neutralizing light is applied to two areas of the photoconductor before the transfer and after the transfer.

  On the other hand, it is not preferable to provide two light sources for each photoconductor in order to irradiate the neutralizing light at two places on the photoconductor.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of irradiating two portions of the photosensitive member with static elimination light without providing a plurality of light sources for one photosensitive member.

  An image forming apparatus according to one aspect of the present invention includes a photoconductor, a transfer device, a light source, and a branching light guide. The photosensitive member carries a toner image on the outer peripheral surface while rotating in a predetermined rotation direction. The transfer device transfers the toner image on the photoconductor to a transfer material at a predetermined transfer position. The branching light guide is a pre-transfer area and a post-transfer area, respectively, for removing the neutralizing light emitted from the light source on the upstream side and the downstream side in the predetermined rotation direction with respect to the transfer position on the outer peripheral surface of the photoreceptor. Lead to.

  According to the present invention, it is possible to provide an image forming apparatus capable of irradiating two places on the photoconductor with charge eliminating light without providing a plurality of light sources for one photoconductor.

FIG. 1 is a configuration diagram of an image forming apparatus according to an embodiment. FIG. 2 is a configuration diagram of an image forming unit in the image forming apparatus according to the embodiment. FIG. 3 is a configuration diagram of a static eliminator in the image forming apparatus according to the embodiment. FIG. 4 is a plan view of the downstream light guide member in the static eliminator of the image forming apparatus according to the embodiment. FIG. 5 is a cross-sectional view of a part of the reflection portion of the light guide member in the image forming apparatus according to the embodiment. FIG. 6 is a diagram of a connection portion between the base portion of the downstream light guide member and the relay light guide member in the static eliminator of the image forming apparatus according to the embodiment. FIG. 7 is a cross-sectional view of the facing portion of the downstream light guide member in the static eliminator of the image forming apparatus according to the embodiment. FIG. 8 is a cross-sectional view of the upstream light guide member in the static eliminator of the image forming apparatus according to the embodiment. FIG. 9 is a perspective view of a support mechanism for the downstream light guide member in the static eliminator of the image forming apparatus according to the embodiment. FIG. 10 is a configuration diagram of a static eliminator according to a first application example. FIG. 11 is a configuration diagram of a static eliminator according to a second application example. FIG. 12 is a cross-sectional view of the facing portion of the downstream light guide member in the static eliminator according to the third application example.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

[Configuration of Image Forming Apparatus 10]
The image forming apparatus 10 according to the embodiment is an apparatus that executes a printing process for forming an image on a sheet. The sheet is a sheet-like image forming medium such as paper or an envelope.

  As shown in FIG. 1, the image forming apparatus 10 includes a sheet supply mechanism 2, a sheet transport mechanism 3, an image forming unit 40, a control device 8, and the like in the main body 1.

  The image forming unit 40 is an apparatus that executes the printing process by electrophotography. Therefore, the image forming unit 40 includes the image forming device 4, an optical scanning device 47, a transfer device 44, and a fixing device 48.

  The image forming device 4 includes a photoconductor 41, a charging device 42, a developing device 43, a photoconductor cleaning device 45, a charge eliminating device 46, and the like.

  An image forming apparatus 10 shown in FIG. 1 is a color image forming apparatus having a tandem image forming unit 40. Therefore, the image forming apparatus 10 includes four image forming apparatuses 4 corresponding to toners of four colors of cyan, magenta, yellow, and black. That is, the four image forming devices 4 include a photoconductor 41 and a developing device 43 corresponding to different color toners.

  Further, the transfer device 44 includes an endless intermediate transfer belt 44a, four primary transfer devices 44b corresponding to the four image forming devices 4, a secondary transfer device 44c, and a belt cleaning device 44d.

  The drum-shaped photoreceptor 41 in each of the intermediate transfer belt 44a and the image forming device 4 is rotationally driven by a drive mechanism (not shown). The four image forming devices 4 are arranged along a portion of the intermediate transfer belt 44a that moves in the predetermined movement direction. In the present embodiment, the four image forming devices 4 are arranged along the lower surface portion of the intermediate transfer belt 44a.

  Hereinafter, the predetermined moving direction of the portion along the four image forming devices 4 in the intermediate transfer belt 44a is referred to as a first direction D1. The axial direction of the photoconductor 41 is referred to as a second direction D2 (see FIG. 2). The second direction D2 is also the longitudinal direction of the photoconductor 41.

  The second direction D2 is a so-called main scanning direction, and the first direction D1 is a so-called sub-scanning direction. The second direction D2 is a direction orthogonal to the first direction D1.

  The sheet supply mechanism 2 sends out the sheet to the conveyance path 30. The sheet transport mechanism 3 transports the sheet along the transport path 30.

  The charging device 42 uniformly charges the surface of the photoreceptor 41 that rotates in a predetermined direction. The optical scanning device 47 writes an electrostatic latent image on the surface of the photoreceptor 41. In the following description, the predetermined rotation direction of the photoconductor 41 is referred to as a drum rotation direction R0 (see FIG. 2).

  The developing device 43 develops the electrostatic latent image on the surface of the photoreceptor 41 into a toner image. As a result, the photoconductor 41 carries the toner image on the outer peripheral surface while rotating in the drum rotation direction R0.

  As shown in FIG. 2, the primary transfer device 44b transfers the toner image on the photoconductor 41 to the intermediate transfer belt 44a at a predetermined transfer position P0. As a result, the four color toner images are formed on the intermediate transfer belt 44a as color images.

  The control device 8 causes the image forming unit 40 to perform color printing processing by operating all of the four image forming devices 4. On the other hand, the control device 8 causes the image forming unit 40 to execute the monochrome printing process by operating only one image forming device 4 located on the most downstream side in the first direction D1.

  That is, one image forming device 4 located on the most downstream side in the first direction D <b> 1 forms the black toner image on the photoreceptor 41.

  The photoconductor cleaning device 45 removes toner remaining on the surface of the photoconductor 41. In the tandem image forming unit 40, the intermediate transfer belt 44a is a transfer material onto which the toner image is transferred from the photoreceptor 41.

  The secondary transfer device 44 c transfers the toner image on the intermediate transfer belt 44 a to the sheet conveyed along the conveyance path 30. The fixing device 48 fixes the toner image on the sheet by heating the toner image transferred to the sheet. The belt cleaning device 44d removes the toner remaining on the intermediate transfer belt 44a.

  The control device 8 controls electrical equipment in the image forming apparatus 10. For example, the control device 8 includes a processor such as a CPU (Central Processing Unit) (not shown), a main storage device such as a RAM (Random Access Memory), and a secondary storage device such as a flash memory.

  The processor executes various kinds of data processing and control of the electric device by executing a program stored in advance in the secondary storage device. At that time, the processor temporarily stores the program being executed and the data being processed in the RAM.

  The processor inputs signals from various sensors and switches, and outputs control signals to devices to be controlled.

  The neutralization device 46 neutralizes the outer peripheral surface of the photoconductor 41 by irradiating the outer peripheral surface of the photoconductor 41 with static elimination light. As shown in FIG. 2, the static elimination device 46 irradiates the static elimination light at two locations on the outer peripheral surface of the photoreceptor 41, the pre-transfer area 41 b and the post-transfer area 41 a.

  As shown in FIG. 3, each static elimination device 46 includes one light source 461 that emits the static elimination light. Accordingly, the image forming apparatus 10 includes four light sources 461 corresponding to the four photoconductors 41. The light source 461 is, for example, an LED (Light Emitting Diode).

  The pre-transfer area 41b is an area located upstream of the transfer position P0 on the outer peripheral surface of the photoconductor 41 in the drum rotation direction R0. The pre-transfer area 41b is an area between the position facing the developing device 43 on the outer peripheral surface of the photoconductor 41 and the transfer position P0.

  The post-transfer area 41a is an area downstream of the transfer position P0 on the outer peripheral surface of the photoconductor 41 in the drum rotation direction R0. The post-transfer area 41 a is an area between the transfer position P 0 on the outer peripheral surface of the photoconductor 41 and a position facing the photoconductor cleaning device 45.

  By the way, in the tandem image forming apparatus 10, it is desirable that the neutralizing light is irradiated to two places, the pre-transfer area 41 b and the post-transfer area 41 a, on all four photoconductors 41.

  Also in the monochrome image forming apparatus, it is desirable that the neutralizing light is applied to two areas of the photoreceptor 41, the pre-transfer area 41b and the post-transfer area 41a.

  On the other hand, it is not preferable to provide two light sources 461 for each photosensitive member 41 in order to irradiate the two portions of the photosensitive member 41 with the charge eliminating light.

  In the image forming apparatus 10, the four static elimination devices 46 can irradiate the static elimination light to two places on the photosensitive member 41 without providing a plurality of light sources 461 for one photosensitive member 41.

[Staticizer 46]
In the present embodiment, the four static elimination devices 46 include one first static elimination device 46a and three second static elimination devices 46b. The first static elimination device 46a is different in configuration from the second static elimination device 46b.

  The first static elimination device 46a is included in one of the four image forming devices 4 that is located at the uppermost stream in the first direction D1. The second static elimination device 46b is included in each of the other three image forming devices 4.

[First neutralization device 46a]
As shown in FIG. 3, the first static elimination device 46a includes one light source 461, a downstream light guide member 463, a first mirror 462, a second mirror 464, a relay light guide member 465, and a third mirror. 466, an upstream light guide member 467, and a fourth mirror 468.

  The downstream light guide member 463, the relay light guide member 465, and the upstream light guide member 467 are supported by a housing 450 of a unit including the photoreceptor cleaning device 45 in the corresponding image forming device 4.

  In the present embodiment, for each image forming device 4, the photoconductor 41, the charging device 42, and the photoconductor cleaning device 45 constitute one drum unit. The downstream light guide member 463, the relay light guide member 465, and the upstream light guide member 467 are supported by a housing 450 that encloses the charging device 42 and the photoreceptor cleaning device 45 in the drum unit.

  In the example shown in FIG. 3, four light sources 461 in the four static elimination devices 46 are mounted on one electronic board 4610. However, it is also conceivable that the four light sources 461 are mounted on individual electronic boards 4610, respectively.

  It is also conceivable that the light source 461 of the first static elimination device 46a is mounted on one electronic substrate 4610, and the three light sources 461 in the three second static elimination devices 46b are mounted on the other electronic substrate 4610.

  The downstream light guide member 463, the relay light guide member 465, and the upstream light guide member 467 are transparent members. For example, the downstream light guide member 463, the relay light guide member 465, and the upstream light guide member 467 are transparent synthetic resin members.

  The downstream light guide member 463 is a rod-shaped member along the second direction D2. The downstream light guide member 463 is disposed on the downstream side in the drum rotation direction R <b> 0 with respect to the photoreceptor 41. In other words, the downstream light guide member 463 is disposed on the downstream side in the first direction D1 with respect to the photoreceptor 41.

  As shown in FIG. 4, the downstream light guide member 463 includes a base portion 463 x into which the charge removal light enters from the light source 461 and a downstream facing portion 463 y that faces the post-transfer area 41 a. In the present embodiment, the static elimination light emitted from the light source 461 is incident on the end surface of the base portion 463x.

  The second mirror 464 is disposed to face the end surface opposite to the light source 461 in the downstream light guide member 463. For example, the second mirror 464 can be a sheet-like mirror. In this case, the second mirror 464 is attached to the end surface of the downstream light guide member 463 opposite to the light source 461.

  The static elimination light incident on the base portion 463x passes through the base portion 463x along the second direction D2, and travels along the second direction D2 in the downstream facing portion 463y. The second mirror 464 prevents the static elimination light from leaking from the end surface opposite to the light source 461 in the downstream light guide member 463.

  Due to the action of the second mirror 464, the static elimination light travels in the downstream light guide member 463 along the second direction D2 in the direction from the first end on the light source 461 side to the second end on the opposite side, and further. Proceed in the opposite direction.

  The base portion 463x of the downstream light guide member 463 has a branch reflection portion 463a. The branch reflection part 463a reflects a part of the static elimination light traveling inside the base part 463x along the second direction D2 toward the base end 465a of the relay light guide member 465.

  The branch reflection portion 463a is formed on the side of the base portion 463x opposite to the photoreceptor 41.

  As shown in FIG. 5, the branch reflection part 463a is a part in which a plurality of concave portions 460 arranged at intervals in the second direction D2 are formed. Each of the recesses 460 is a groove along a direction intersecting the second direction D2.

  In the example shown in FIG. 5, each of the recesses 460 is a groove having a triangular cross section along a direction orthogonal to the second direction D2. The static elimination light traveling along the second direction D2 is reflected and transmitted at the interfaces of the plurality of recesses 460. Further, the static elimination light reflected at the interfaces of the plurality of recesses 460 travels to the opposite side of the outer peripheral surface of the base portion 463x where the branch reflection portion 463a is formed.

  Therefore, as shown in FIG. 6, the static elimination light reflected by the branch reflection portion 463a is radiated from a portion opposite to the portion where the branch reflection portion 463a is formed on the outer peripheral surface of the base portion 463x. Thereby, the static elimination light incident on the base portion 463x branches into light traveling toward the downstream facing portion 463y along the second direction D2 and light emitted from a portion of the base portion 463x opposite to the branch reflection portion 463a. .

  Note that another part of the static elimination light traveling along the second direction D2 passes through the interfaces of the plurality of recesses 460. Depending on the angle of the inner surface of the plurality of recesses 460 and the depth of the plurality of recesses 460, the ratio of the neutralizing light reflected at the interface of the plurality of concave portions 460 and the neutralizing light transmitted therethrough changes. The shape of the plurality of recesses 460 in the branch reflection part 463a is designed so that the proportion of the static elimination light that passes through the branch reflection part 463a becomes smaller.

  In this embodiment, the 1st mirror 462 is arrange | positioned in the outer side of the branch reflection part 463a in the base part 463x. The first mirror 462 reflects the static elimination light transmitted through the branch reflection part 463a into the base part 463x.

  For example, the first mirror 462 may be a sheet-like mirror. In this case, the 1st mirror 462 is affixed on the surface of the outer side of the branch reflection part 463a in the base part 463x.

  In the following description, the portion on the outer peripheral surface of the base portion 463x opposite to the portion where the branch reflecting portion 463a is formed is referred to as a branch surface 463c. The base portion 463x branches the static elimination light into light traveling in the second direction D2 and light emitted from the branch surface 463c of the base portion 463x.

  The branch surface 463c of the base portion 463x faces the base end 465a of the relay light guide member 465. Therefore, the static elimination light reflected by the branch reflection part 463 a is incident on the surface of the base end 465 a of the relay light guide member 465.

  The downstream facing portion 463y of the downstream light guide member 463 includes a light distribution portion 463b. The light distribution part 463b reflects a part of the charge removal light traveling in the downstream facing part 463y along the second direction D2 in the direction toward the post-transfer area 41a of the photoconductor 41 and the other light removal light. A part is permeated downstream in the first direction D1.

  The light distribution part 463b is also a part in which a plurality of recesses 460 arranged at intervals in the second direction D2 are formed in the same manner as the branch reflection part 463a (see FIG. 5). For example, it is conceivable that the ratio of the static elimination light that passes through the light distribution part 463b is larger than the percentage of the static elimination light that passes through the branch reflection part 463a. The shape of the plurality of recesses 460 in the light distribution unit 463b is designed so that the charge removal light passes through the light distribution unit 463b by a desired amount.

  As shown in FIG. 7, the light distribution portion 463b is formed in a range on the downstream side in the first direction D1 on the outer peripheral surface of the downstream facing portion 463y.

  As shown in FIG. 7, the static elimination light reflected by the light distribution part 463b is radiated from the upstream curved surface 463g opposite to the light distribution part 463b on the outer peripheral surface of the downstream facing part 463y.

  The neutralizing light emitted from the upstream curved surface 463g is applied to the post-transfer area 41a of the corresponding photoconductor 41 as shown in FIGS. That is, the static elimination light reflected by the light distribution unit 463b to the upstream side in the first direction D1 is applied to the post-transfer area 41a of the corresponding photoconductor 41.

  On the other hand, the static elimination light transmitted through the light distribution unit 463b is applied to the pre-transfer area 41b of the adjacent photoconductor 41 on the downstream side in the first direction D1, as shown in FIGS. That is, the static elimination light transmitted by the light distribution unit 463b to the downstream side in the first direction D1 is applied to the pre-transfer area 41b of the adjacent photoconductor 41.

  That is, the light distribution unit 463b is configured to cause the static elimination light traveling in the downstream facing portion 463y along the second direction D2 to be directed toward the upstream side in the first direction D1 and the direction toward the downstream side in the first direction D1. Distribute to

  As described above, the downstream light guide member 463 guides the static elimination light emitted from the light source 461 along the second direction D2. Further, the downstream light guide member 463 is in the post-transfer area 41a over the entire second direction D2 in the photoconductor 41 located on the upstream side in the first direction D1, and in the photoconductor 41 located on the downstream side in the first direction D1. The static elimination light is irradiated to the pre-transfer area 41b over the entire second direction D2.

  The relay light guide member 465 is a member formed to extend from the base end 465a facing the side surface of the base portion 463x of the downstream light guide member 463 toward the upstream position in the drum rotation direction R0 of the photoreceptor 41.

  In the relay light guide member 465, the portion from the base end 465a to the intermediate corner portion 465c is formed along the first direction D1, and the portion from the corner portion 465c to the end 465b is along the second direction D2. Is formed.

  As shown in FIG. 6, the surface of the base end 465a of the relay light guide member 465 is in surface contact with the branch surface 463c of the base portion 463x. Thereby, the static elimination light reflected by the branch reflection part 463a of the base part 463x efficiently travels from the base part 463x to the relay light guide member 465.

  In the example shown in FIG. 6, the branch surface 463c is a convex curved surface, and the surface of the base end 465a of the relay light guide member 465 is a concave curved surface along the branch surface 463c. Note that the surfaces of the branch surface 463c and the base end 465a may be flat.

  The third mirror 466 is disposed to face the outer surface of the corner portion 465c in the relay light guide member 465. The third mirror 466 prevents the charge removal light from leaking out of the relay light guide member 465 from the corner portion 465c.

  For example, it is conceivable that the third mirror 466 is a sheet-like mirror. In this case, the third mirror 466 is attached to the outer surface of the corner portion 465c of the relay light guide member 465.

  The upstream light guide member 467 is a rod-shaped member along the second direction D2. The upstream light guide member 467 is disposed at a position on the extension line of the relay light guide member 465 on the upstream side in the drum rotation direction R0 with respect to the photoconductor 41.

  The end surface of the upstream light guide member 467 is in surface contact with the surface of the end 465 b of the relay light guide member 465. For example, the end surface of the upstream light guide member 467 and the surface of the end 465b of the relay light guide member 465 are flat.

  The fourth mirror 468 is disposed to face the end surface opposite to the relay light guide member 465 in the upstream light guide member 467. For example, it is conceivable that the fourth mirror 468 is a sheet-like mirror. In this case, the fourth mirror 468 is attached to the end surface of the upstream light guide member 467 opposite to the relay light guide member 465.

  The static elimination light that has entered the upstream light guide member 467 from the end 465b of the relay light guide member 465 travels in the upstream light guide member 467 along the second direction D2 along the second direction D2. The fourth mirror 468 prevents the static elimination light from leaking from the end surface opposite to the relay light guide member 465 in the upstream light guide member 467.

  As shown in FIGS. 3 and 8, the upstream light guide member 467 includes an upstream reflection portion 467a that reflects the static elimination light traveling inside along the second direction D2 toward the pre-transfer area 41b.

  Similarly to the branch reflection part 463a, the upstream reflection part 467a is also a part in which a plurality of recesses 460 arranged at intervals in the second direction D2 are formed (see FIG. 5). The shape of the plurality of recesses 460 in the upstream reflection portion 467a is designed so that the proportion of the static elimination light that passes through the upstream reflection portion 467a is smaller.

  As shown in FIG. 8, the static elimination light reflected by the upstream reflection portion 467a is radiated from the downstream curved surface 467b on the outer peripheral surface of the upstream light guide member 467 on the opposite side of the upstream reflection portion 467a.

  As shown in FIGS. 2 and 3, the static elimination light emitted from the downstream curved surface 467 b is applied to the corresponding pre-transfer area 41 b of the photoconductor 41. That is, the static elimination light reflected by the upstream reflection portion 467a toward the downstream side in the first direction D1 is irradiated to the corresponding pre-transfer area 41b of the photoconductor 41.

  The upstream light guide member 467 guides the static elimination light branched by the branch reflection portion 463a and then guided by the relay light guide member 465 along the second direction D2. Further, the upstream light guide member 467 irradiates the pre-transfer area 41b over the entire second direction D2 of the photoconductor 41 located next to the downstream side in the first direction D1 with the charge removal light.

  The downstream light guide member 463, the second mirror 464, the relay light guide member 465, the third mirror 466, the upstream light guide member 467, and the fourth mirror 468 in the first static elimination device 46a are examples of branch light guides.

  The branching light guide is configured to transfer the static elimination light emitted from the light source 461 to the pre-transfer area 41b and the transfer area 41b that are respectively located upstream and downstream in the drum rotation direction R0 with respect to the transfer position P0 on the outer peripheral surface of the photoreceptor 41. This is an optical component group leading to the rear region 41a.

[Second neutralization device 46b]
As shown in FIG. 3, each second static elimination device 46 b includes one light source 461, a downstream light guide member 463, a second mirror 464, and a fifth mirror 469.

  That is, the light source 461, the downstream light guide member 463, and the second mirror 464 of each of the second static elimination devices 46b are the same as the light source 461, the downstream light guide member 463, and the second mirror 464 of the first static elimination device 46a.

  The fifth mirror 469 is disposed to face the branch reflection portion 463a of the downstream light guide member 463 via the base portion 463x. For example, it is conceivable that the fifth mirror 469 is a sheet-like mirror. In this case, the fifth mirror 469 is attached to the branch surface 463 c of the downstream light guide member 463.

  The fifth mirror 469 prevents the static elimination light reflected by the branch reflection part 463a from leaking out of the downstream light guide member 463 from the branch surface 463c.

  In addition, it is also conceivable that the sixth mirror (not shown) is arranged to face the branch reflection portion 463a of the downstream light guide member 463 from the outside. The sixth mirror prevents the static elimination light reflected by the fifth mirror 469 from leaking out of the downstream light guide member 463 from the branch reflection portion 463a.

  In each of the second static elimination devices 46b, the downstream light guide member 463 guides the static elimination light emitted from the light source 461 along the second direction D2. Further, the downstream light guide member 463 is disposed on the entire post-transfer area 41a in the second direction D2 in the corresponding photoconductor 41 and in the entire second direction D2 in the photoconductor 41 located adjacent to the downstream side in the first direction D1. The neutralizing light is irradiated to the pre-transfer area 41b.

  However, in the second static elimination device 46b provided in the image forming device 4 located on the most downstream side in the first direction D1, there is a photoreceptor 41 located next to the downstream side of the first light guide member 463 in the first direction D1. do not do.

  In the image forming apparatus 10, the downstream light guide member 463 of the first static elimination device 46a and the downstream light guide members 463 of the three second static elimination devices 46b are common components. Similarly, the light source 461 of the first static elimination device 46a and the light sources 461 of the three second static elimination devices 46b are common parts.

  The control device 8 turns on all four light sources 461 when the color printing process is executed. On the other hand, when the monochrome printing process is executed, the control device 8 turns on only one light source 461 included in the second static elimination device 46b located on the most downstream side in the first direction D1 among the four light sources 461.

  Accordingly, the image forming apparatus 10 collectively collects the first power supply line for supplying power to one light source 461 provided in the second static elimination device 46b located on the most downstream side in the first direction D1, and the other three light sources 461. It is conceivable to include a second power supply line that supplies electric power.

  When three light sources 461 having the same specifications are electrically connected in series by the second power supply line, the amount of the neutralizing light emitted from the three light sources 461 is substantially the same.

  On the other hand, in the first static elimination device 46a, the static elimination light is branched into the downstream light guide member 463 and the upstream light guide member 467, but in the three second static elimination devices 46b, the static elimination light is transmitted to the fifth mirror 469. Is guided only into the downstream light guide member 463.

  Therefore, when the amount of the static elimination light emitted from the four light sources 461 is substantially the same, the amount of the static elimination light emitted from the downstream light guide member 463 of the first static elimination device 46a and the three second static elimination devices 46b. The amount of the neutralizing light emitted from the downstream light guide member 463 is different.

  Accordingly, it is conceivable that the downstream light guide member 463 is supported rotatably around the second direction D2 in the three second static elimination devices 46b.

  For example, as shown in FIG. 9, each of the three second static elimination devices 46 b includes a support member 4600 that directly supports the downstream light guide member 463 and is supported by the housing 450. The downstream light guide member 463 is fitted into a non-circular hole formed in the support member 4600.

  The support member 4600 is supported by the housing 450 so as to be rotatable around the second direction D2. The support member 4600 is fixed to the housing 450 with screws or the like at an arbitrary angle in the rotation direction.

  By fixing the support member 4600 in an arbitrary direction, the support member 4600 is held in an arbitrary direction in the rotation direction. Thereby, the radiation direction of the static elimination light from the downstream light guide member 463 can be arbitrarily adjusted.

  By adjusting the radiation direction of the charge removal light from the downstream light guide member 463, the amount of the charge removal light irradiated on the photoconductor 41 can be adjusted. As a result, all the photoconductors 41 can be adjusted so that the dose of the neutralizing light becomes equal.

  According to the present embodiment, it is possible to irradiate the two portions of the pre-transfer area 41b and the post-transfer area 41a of the photoconductor 41 with the static elimination light without providing a plurality of light sources 461 for one photoconductor 41.

[First application example]
Next, with reference to FIG. 10, a static elimination device 46P according to a first application example applicable to the image forming apparatus 10 will be described.

  In this application example, the four image forming devices 4 each include the same static elimination device 46P. In FIG. 10, the same components as those shown in FIGS. 1 to 9 are given the same reference numerals.

  The neutralization device 46P, like the first neutralization device 46a described above, includes one light source 461, a downstream light guide member 463P, a second mirror 464, a relay light guide member 465, a third mirror 466, and an upstream guide. An optical member 467 and a fourth mirror 468 are provided.

  That is, the static elimination apparatus 46P includes a configuration in which the downstream light guide member 463 is replaced with a similar downstream light guide member 463P in the first static elimination apparatus 46a. Similarly to the downstream light guide member 463P, the downstream light guide member 463P is also a transparent rod-shaped member.

  The downstream light guide member 463P of the charge removal device 46P includes a configuration in which the light distribution unit 463b in the downstream light guide member 463 of the first charge removal device 46a is replaced with a downstream reflection unit 463h.

  That is, the downstream light guide member 463P has a base portion 463x and a downstream facing portion 463y. The base portion 463x has a branch reflection portion 463a, and the downstream facing portion 463y has a downstream reflection portion 463h.

  The downstream reflecting portion 463h reflects the static elimination light traveling in the downstream facing portion 463y along the second direction D2 in a direction toward the post-transfer area 41a of the photoconductor 41.

  The downstream reflection portion 463h is also a portion in which a plurality of recesses 460 arranged at intervals in the second direction D2 are formed in the same manner as the branch reflection portion 463a (see FIG. 5). The shape of the plurality of recesses 460 in the downstream reflection portion 463h is designed so that the ratio of the static elimination light that passes through the downstream reflection portion 463h is smaller.

  In this application example, the downstream light guide member 463P, the second mirror 464, the relay light guide member 465, the third mirror 466, the upstream light guide member 467, and the fourth mirror 468 are examples of the branch light guide. Even when the static eliminator 46P is adopted, the same effect as that obtained when the static eliminator 46 is adopted can be obtained.

[Second application example]
Next, with reference to FIG. 11, a static elimination device 46Q according to a second application example applicable to the image forming apparatus 10 will be described. The static eliminator 46Q is an application example of the static eliminator 46P.

  In this application example, each of the four image forming devices 4 includes the same static elimination device 46Q. In FIG. 11, the same components as those shown in FIGS. 1 to 10 are given the same reference numerals.

  The static eliminator 46Q includes a light source 461, a downstream light guide member 463Q, a second mirror 464, a light branching member 465Q, two third mirrors 466, an upstream light guide member 467, a fourth mirror 468, 6 mirrors 466a.

  The light branching member 465Q is a transparent member that guides the static elimination light emitted from the light source 461. The light branching member 465Q has a trunk portion 465d, a downstream branch portion 465e, and an upstream branch portion 465f.

  The trunk portion 465d is a portion where the static elimination light emitted from the light source 461 is incident. The downstream branch portion 465e is a portion branched from the trunk portion 465d to the downstream side in the drum rotation direction R0 of the photosensitive member 41. The upstream branch portion 465f is a portion branched from the trunk portion 465d to the upstream side of the photosensitive drum 41 in the drum rotation direction R0.

  The surface of the end 465g of the downstream branch portion 465e faces the position on the downstream side in the drum rotation direction R0 with respect to the photoreceptor 41. Similarly, the surface of the end 465i of the upstream branch portion 465f faces the position on the upstream side in the drum rotation direction R0 with respect to the photoreceptor 41.

  Part of the static elimination light incident on the trunk 465d propagates to the downstream branch 465e, and the other part propagates to the upstream branch 465f. That is, the static elimination light incident on the trunk portion 465d is branched into two branches, a downstream branch portion 465e and an upstream branch portion 465f.

  One of the bifurcated static elimination light enters the downstream light guide member 463Q from the downstream branch portion 465e, and the other enters the upstream light guide member 467 from the upstream branch portion 465f.

  For example, a recessed portion 465k having a triangular cross section is formed on the surface of the trunk portion 465d opposite to the incident surface of the charge removal light. Further, the sixth mirror 466a is disposed along two planes forming the inner surface of the recess 465k.

  In addition, it is conceivable that the sixth mirror 466a is a sheet-like mirror that is attached to two planes that form the inner surface of the recess 465k.

  One of the two inclined interfaces formed by the recess 465k reflects the static elimination light to the downstream branch 465e, and the other reflects the static elimination light to the upstream branch 465f.

  In the example shown in FIG. 11, the concave portion 465k is formed at a position shifted to the upstream side in the drum rotation direction R0 with respect to the optical axis of the static elimination light incident on the trunk portion 465d. In this case, the amount of the charge removal light branched to the downstream branch portion 465e is larger than the amount of the charge removal light branched to the upstream branch portion 465f.

  The downstream branch portion 465e is formed along the first direction D1 from the portion connected to the trunk portion 465d to the intermediate downstream corner portion 465h, and the portion from the downstream corner portion 465h to the end 465g is formed in the second direction D2. Are formed along.

  Similarly, the upstream branch portion 465f is formed along the first direction D1 from the portion connected to the trunk portion 465d to the intermediate upstream corner portion 465j, and the portion from the upstream corner portion 465j to the end 465i is the second portion. It is formed along the direction D2.

  The two third mirrors 466 are disposed to face the outer surfaces of the downstream corner portion 465h and the upstream corner portion 465j of the light branching member 465Q. The two third mirrors 466 prevent the charge removal light from leaking out of the light branching member 465Q from the downstream corner portion 465h and the upstream corner portion 465j.

  For example, it is conceivable that the two third mirrors 466 are sheet-like mirrors. In this case, the two third mirrors 466 are attached to the outer surfaces of the downstream corner portion 465h and the upstream corner portion 465j.

  The downstream light guide member 463Q is a bar-shaped transparent member along the second direction D2. The downstream light guide member 463Q is disposed on the extended line of the downstream branch portion 465e on the downstream side in the drum rotation direction R0 with respect to the photoreceptor 41.

  One end surface of the downstream light guide member 463Q is in surface contact with the end 465g of the downstream branch portion 465e.

  The second mirror 464 is disposed to face the end surface opposite to the downstream branch portion 465e in the downstream light guide member 463Q. For example, the second mirror 464 is a sheet-like mirror affixed to the end surface opposite to the downstream branch portion 465e in the downstream light guide member 463.

  The static elimination light that has passed through the downstream branch portion 465e travels in the downstream light guide member 463Q along the second direction D2. The second mirror 464 prevents the static elimination light from leaking from the end surface of the downstream light guide member 463Q.

  The downstream light guide member 463Q includes a downstream reflection portion 463h that reflects the static elimination light traveling inside along the second direction D2 toward the post-transfer area 41a. The downstream reflection portion 463h has the same structure as the upstream reflection portion 467a shown in FIGS.

  However, the downstream reflecting portion 463h is formed on the downstream surface of the downstream light guide member 463Q in the drum rotation direction R0, that is, the downstream surface of the downstream light guide member 463Q in the first direction D1.

  The downstream light guide member 463 </ b> Q is the same member as the upstream light guide member 467 shown in FIG. 8, and is arranged in a different direction from the upstream light guide member 467. That is, the downstream light guide member 463Q and the upstream light guide member 467 are common parts.

  The upstream light guide member 467 of the static elimination device 46Q is the same member as the upstream light guide member 467 of the first static elimination device 46a (see FIGS. 3 and 8). That is, the upstream light guide member 467 has an upstream reflection portion 467a as shown in FIG.

  The upstream light guide member 467 of the static eliminator 46Q is disposed on the extended line of the upstream branch portion 465f on the upstream side in the drum rotation direction R0 with respect to the photoreceptor 41. One end surface of the upstream light guide member 467 is in surface contact with the end 465i of the upstream branch portion 465f.

  The fourth mirror 468 is disposed to face the end surface opposite to the upstream branch portion 465f of the upstream light guide member 467. For example, the fourth mirror 468 is a sheet-like mirror attached to the end surface opposite to the upstream branch portion 465f of the upstream light guide member 467.

  The static elimination light that has passed through the upstream branch portion 465f travels in the upstream light guide member 467 along the second direction D2. The fourth mirror 468 prevents the static elimination light from leaking from the end surface of the upstream light guide member 467.

  In this application example, the downstream light guide member 463Q, the second mirror 464, the light branching member 465Q, the two third mirrors 466, the upstream light guide member 467, the fourth mirror 468, and the sixth mirror 466a are the branching light guide. It is an example. When the static eliminator 46Q is employed, the same effect as that obtained when the static eliminator 46 is employed can be obtained.

[Third application example]
Next, a static eliminating device 46R according to a third application example applicable to the image forming apparatus 10 will be described with reference to FIG. The static eliminator 46R is an application example of the static eliminator 46 shown in FIGS.

  The static eliminator 46R has a configuration in which the light distribution unit 463b of the downstream light guide member 463 in the first static eliminator 46a of the static eliminator 46 is replaced with a first downstream reflector 463d and a second downstream reflector 463e.

  In the static eliminator 46R, the downstream facing portion 463y of the downstream light guide member 463 includes a first downstream reflection portion 463d and a second downstream reflection portion 463e. The first downstream reflection portion 463d and the second downstream reflection portion 463e have a first direction and a direction toward the post-transfer area 41a of the photoconductor 41 with the neutralizing light traveling in the downstream facing portion 463y along the second direction D2. Reflects downstream of D1.

  Specifically, the first downstream reflecting portion 463d reflects the neutralizing light traveling inside the downstream facing portion 463y along the second direction D2 in a direction toward the post-transfer area 41a of the photoconductor 41.

  The second downstream reflecting portion 463e reflects the static elimination light traveling in the downstream facing portion 463y along the second direction D2 to the downstream side in the first direction D1.

  Similarly to the branch reflection part 463a, the first downstream reflection part 463d and the second downstream reflection part 463e are also portions where a plurality of recesses 460 arranged at intervals in the second direction D2 are formed (see FIG. 5).

  The shapes of the plurality of recesses 460 in the first downstream reflection portion 463d and the second downstream reflection portion 463e are designed so that the ratio of the static elimination light that passes through the first downstream reflection portion 463d and the second downstream reflection portion 463e becomes smaller. Is done.

  As shown in FIG. 12, the first downstream reflecting portion 463d is formed in a range on the downstream side in the first direction D1 on the outer peripheral surface of the downstream facing portion 463y. On the other hand, the second downstream reflecting portion 463e is formed in the upstream side range in the first direction D1 on the outer peripheral surface of the downstream facing portion 463y.

  As shown in FIG. 12, the static elimination light reflected by the first downstream reflection portion 463d is radiated from the upstream curved surface 463g opposite to the first downstream reflection portion 463d on the outer peripheral surface of the downstream facing portion 463y.

  The static elimination light emitted from the upstream curved surface 463g is applied to the post-transfer area 41a of the corresponding photoconductor 41 (see FIGS. 2 and 3). That is, the static elimination light reflected by the first downstream reflecting portion 463d on the upstream side in the first direction D1 is applied to the post-transfer area 41a of the corresponding photoconductor 41.

  On the other hand, as shown in FIG. 12, the static elimination light reflected by the second downstream reflecting portion 463e is radiated from the downstream curved surface 463f opposite to the second downstream reflecting portion 463e on the outer peripheral surface of the downstream facing portion 463y. The

  The static elimination light emitted from the downstream curved surface 463f is applied to the pre-transfer area 41b of the adjacent photoconductor 41 on the downstream side in the first direction D1 (see FIGS. 2 and 3). That is, the static elimination light reflected by the second downstream reflection portion 463e toward the downstream side in the first direction D1 is applied to the pre-transfer area 41b of the adjacent photoconductor 41.

  When the static eliminator 46R is employed, the same effect as that obtained when the static eliminator 46 is employed can be obtained.

[Other application examples]
In the first static elimination device 46a shown in FIG. 3 and the static elimination device 46P shown in FIG. 10, the relay light guide member 465 and the upstream light guide member 467 may be formed of one member.

  Further, the charge removal device 46P or the charge removal device 46Q may be applied to a monochrome image forming apparatus including one image forming device 4 for black toner. In this case, the primary transfer device 44b transfers the toner image on the photoreceptor 41 to a sheet which is an example of a transfer material.

1: Main body 2: Sheet feeding mechanism 3: Sheet conveying mechanism 4: Image forming device 8: Control device 10: Image forming device 30: Conveying path 40: Image forming unit 41: Photoconductor 41a: Post-transfer area 41b: Pre-transfer area 42: Charging device 43: Developing device 44: Transfer device 44a: Intermediate transfer belt 44b: Primary transfer device 44c: Secondary transfer device 44d: Belt cleaning device 45: Photoconductor cleaning device 46: Charge removal device 46P: Charge removal device 46Q: Charge removal device Device 46a: First neutralization device 46b: Second neutralization device 47: Optical scanning device 48: Fixing device 450: Housing 460: Concave portion 461: Light source 462: First mirror 463: Downstream light guide member 463P: Downstream light guide member 463Q: Downstream light guide member 463a: branch reflection part 463b: light distribution part 463c: branch surface 463d: first downstream reflection part 463e: second downstream reflecting portion 463f: downstream curved surface 463g: upstream curved surface 463h: downstream reflective portion 463x: base portion 463y: downstream facing portion 464: second mirror 465: relay light guide member 465Q: light branching member 465a: Relay light guide member base end 465b: Relay light guide member end 465c: Relay light guide member corner 465d: Trunk 465e: Downstream branch 465f: Upstream branch 465g: Downstream branch end 465h: Downstream corner 465i: upstream branch end 465j: upstream corner portion 465k: recess 466: third mirror 466a: sixth mirror 467: upstream light guide member 467a: upstream reflecting portion 467b: downstream curved surface 468: fourth mirror 469: Fifth mirror 4600: support member 4610: electronic substrate D1: first direction (predetermined movement direction)
D2: Second direction (axial direction)
P0: Transfer position R0: Drum rotation direction (default rotation direction)

Claims (6)

A photoconductor carrying a toner image on the outer peripheral surface while rotating in a predetermined rotation direction;
A transfer device for transferring the toner image on the photoconductor to a transfer material at a predetermined transfer position;
A light source;
A branching light guide that guides the neutralizing light emitted from the light source to a pre-transfer area and a post-transfer area that are respectively located upstream and downstream in the predetermined rotation direction with respect to the transfer position on the outer peripheral surface of the photoconductor; And an image forming apparatus. An intermediate transfer belt that is the endless rotating material to be transferred;
And four image forming devices arranged along a portion of the intermediate transfer belt that moves in a predetermined moving direction, the photosensitive members corresponding to different color toners,
One of the four imaging devices located in the uppermost stream in the predetermined movement direction includes the light source and the branch light guide,
The branch light guide is
A transparent rod disposed downstream of the photoconductor in the predetermined rotation direction and having a rod shape along the axial direction of the photoconductor, and having a base on which the charge removal light is incident and a downstream facing portion facing the post-transfer area. A downstream light guide member;
A transparent relay light-guiding member formed extending from the base end facing the side surface of the base portion toward the upstream position in the predetermined rotation direction of the photoreceptor;
A rod-shaped transparent upstream light guide member that is disposed at a position on an extension line of the relay light guide member on the upstream side in the predetermined rotation direction with respect to the photoconductor, and includes a rod-shaped transparent upstream light guide member along the axial direction;
The base portion of the downstream light guide member has a branch reflection portion that reflects a part of the static elimination light traveling inside along the axial direction toward the base end of the relay light guide member,
The downstream facing portion of the downstream light guide member reflects a part of the charge removal light traveling inside along the axial direction in a direction toward the post-transfer area and another part of the charge removal light. It has a light distribution part that transmits to the downstream side in the default moving direction,
The upstream light guide member has an upstream reflection portion that reflects the static elimination light traveling inside along the axial direction toward the pre-transfer region,
2. The image according to claim 1, wherein each of the other three of the four image forming devices includes the light source, the downstream light guide member, and a mirror that faces the branch reflection portion via the base portion. Forming equipment.   The downstream light guide member is rotatably supported around the axial direction in three of the four image forming devices that are not positioned at the most upstream in the predetermined movement direction. Image forming apparatus. The branch light guide is
A transparent rod disposed downstream of the photoconductor in the predetermined rotation direction and having a rod shape along the axial direction of the photoconductor, and having a base on which the charge removal light is incident and a downstream facing portion facing the post-transfer area. A downstream light guide member;
A transparent relay light-guiding member formed extending from the base end facing the side surface of the base portion toward the upstream position in the predetermined rotation direction of the photoreceptor;
A rod-shaped transparent upstream light guide member that is disposed at a position on an extension line of the relay light guide member on the upstream side in the predetermined rotation direction with respect to the photoconductor, and includes a rod-shaped transparent upstream light guide member along the axial direction;
The base portion of the downstream light guide member has a branch reflection portion that reflects a part of the static elimination light traveling inside along the axial direction toward the base end of the relay light guide member,
The downstream facing portion of the downstream light guide member has a downstream reflecting portion that reflects the static elimination light traveling inside along the axial direction toward the post-transfer region,
2. The image forming apparatus according to claim 1, wherein the upstream light guide member includes an upstream reflection portion that reflects the static elimination light traveling inside along the axial direction toward the pre-transfer area.   The image forming apparatus according to claim 2, wherein the relay light guide member and the upstream light guide member are formed of a single member. The branch light guide is
The trunk portion into which the charge removal light is incident, the downstream branch portion from which the stem portion is branched to the downstream side in the predetermined rotation direction of the photosensitive member, and the portion of the charge removal light propagates in the predetermined rotation direction from the trunk portion to the photosensitive member. A transparent light branching member having an upstream branching portion that branches to the upstream side and another part of the static elimination light propagates;
A rod-shaped transparent downstream light guide member disposed at a position on an extension line of the downstream branch on the downstream side in the predetermined rotation direction with respect to the photoconductor, and along the axial direction of the photoconductor;
A rod-shaped transparent upstream light guide member that is disposed at a position on an extension line of the upstream branch on the upstream side in the predetermined rotation direction with respect to the photosensitive member,
The downstream light guide member has a downstream reflection portion that reflects the static elimination light traveling inside along the axial direction toward the post-transfer area,
2. The image forming apparatus according to claim 1, wherein the upstream light guide member includes an upstream reflection portion that reflects the static elimination light traveling inside along the axial direction toward the pre-transfer area.

Images